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Sample records for chemical plugs based

  1. Preparation and Characterization of Chemical Plugs Based on Selected Hanford Waste Simulants

    SciTech Connect

    Mattigod, Shas V.; Wellman, Dawn M.; Parker, Kent E.; Cordova, Elsa A.; Gunderson, Katie M.; Baum, Steven R.; Crum, Jarrod V.; Poloski, Adam P.

    2008-09-15

    This report presents the results of preparation and characterization of chemical plugs based on selected Hanford Site waste simulants. Included are the results of chemical plug bench testing conducted in support of the M1/M6 Flow Loop Chemical Plugging/Unplugging Test (TP-RPP-WTP-495 Rev A). These results support the proposed plug simulants for the chemical plugging/ unplugging tests. Based on the available simulant data, a set of simulants was identified that would likely result in chemical plugs. The three types of chemical plugs that were generated and tested in this task consisted of: 1. Aluminum hydroxide (NAH), 2. Sodium aluminosilicate (NAS), and 3. Sodium aluminum phosphate (NAP). While both solvents, namely 2 molar (2 M) nitric acid (HNO3) and 2 M sodium hydroxide (NaOH) at 60°C, used in these tests were effective in dissolving the chemical plugs, the 2 M nitric acid was significantly more effective in dissolving the NAH and NAS plugs. The caustic was only slightly more effecting at dissolving the NAP plug. In the bench-scale dissolution tests, hot (60°C) 2 M nitric acid was the most effective solvent in that it completely dissolved both NAH and NAS chemical plugs much faster (1.5 – 2 x) than 2 M sodium hydroxide. So unless there are operational benefits for the use of caustic verses nitric acid, 2 M nitric acid heated to 60°C C should be the solvent of choice for dissolving these chemical plugs. Flow-loop testing was planned to identify a combination of parameters such as pressure, flush solution, composition, and temperature that would effectively dissolve and flush each type of chemical plug from preformed chemical plugs in 3-inch-diameter and 4-feet-long pipe sections. However, based on a review of the results of the bench-top tests and technical discussions, the Waste Treatment Plant (WTP) Research and Technology (R&T), Engineering and Mechanical Systems (EMS), and Operations concluded that flow-loop testing of the chemically plugged pipe

  2. Production of arrays of chemically distinct nanolitre plugs via repeated splitting in microfluidic devices†

    PubMed Central

    Adamson, David N.; Mustafi, Debarshi; Zhang, John X. J.; Zheng, Bo; Ismagilov, Rustem F.

    2006-01-01

    This paper reports a method for the production of arrays of nanolitre plugs with distinct chemical compositions. One of the primary constraints on the use of plug-based microfluidics for large scale biological screening is the difficulty of fabricating arrays of chemically distinct plugs on the nanolitre scale. Here, using microfluidic devices with several T-junctions linked in series, a single input array of large (~320 nL) plugs was split to produce 16 output arrays of smaller (~20 nL) plugs; the composition and configuration of these arrays were identical to that of the input. This paper shows how the passive break-up of plugs in T-junction microchannel geometries can be used to produce a set of smaller-volume output arrays useful for chemical screening from a single large-volume array. A simple theoretical description is presented to describe splitting as a function of the Capillary number, the capillary pressure, the total pressure difference across the channel, and the geometric fluidic resistance. By accounting for these considerations, plug coalescence and plug–plug contamination can be eliminated from the splitting process and the symmetry of splitting can be preserved. Furthermore, single-outlet splitting devices were implemented with both valve- and volume-based methods for coordinating the release of output arrays. Arrays of plugs containing commercial sparse matrix screens were obtained from the presented splitting method and these arrays were used in protein crystallization trials. The techniques presented in this paper may facilitate the implementation of high-throughput chemical and biological screening. PMID:16929397

  3. The plug-based nanovolume Microcapillary Protein Crystallization System (MPCS)

    SciTech Connect

    Gerdts, Cory J.; Elliott, Mark; Lovell, Scott; Mixon, Mark B.; Napuli, Alberto J.; Staker, Bart L.; Nollert, Peter; Stewart, Lance

    2012-02-08

    The Microcapillary Protein Crystallization System (MPCS) embodies a new semi-automated plug-based crystallization technology which enables nanolitre-volume screening of crystallization conditions in a plasticware format that allows crystals to be easily removed for traditional cryoprotection and X-ray diffraction data collection. Protein crystals grown in these plastic devices can be directly subjected to in situ X-ray diffraction studies. The MPCS integrates the formulation of crystallization cocktails with the preparation of the crystallization experiments. Within microfluidic Teflon tubing or the microfluidic circuitry of a plastic CrystalCard, {approx}10-20 nl volume droplets are generated, each representing a microbatch-style crystallization experiment with a different chemical composition. The entire protein sample is utilized in crystallization experiments. Sparse-matrix screening and chemical gradient screening can be combined in one comprehensive 'hybrid' crystallization trial. The technology lends itself well to optimization by high-granularity gradient screening using optimization reagents such as precipitation agents, ligands or cryoprotectants.

  4. The plug-based nanovolume Microcapillary Protein Crystallization System (MPCS)

    SciTech Connect

    Gerdts, Cory J.; Elliott, Mark; Lovell, Scott; Mixon, Mark B.; Napuli, Alberto J.; Staker, Bart L.; Nollert, Peter; Stewart, Lance

    2008-11-01

    The Microcapillary Protein Crystallization System (MPCS) is a new protein-crystallization technology used to generate nanolitre-sized crystallization experiments for crystal screening and optimization. Using the MPCS, diffraction-ready crystals were grown in the plastic MPCS CrystalCard and were used to solve the structure of methionine-R-sulfoxide reductase. The Microcapillary Protein Crystallization System (MPCS) embodies a new semi-automated plug-based crystallization technology which enables nanolitre-volume screening of crystallization conditions in a plasticware format that allows crystals to be easily removed for traditional cryoprotection and X-ray diffraction data collection. Protein crystals grown in these plastic devices can be directly subjected to in situ X-ray diffraction studies. The MPCS integrates the formulation of crystallization cocktails with the preparation of the crystallization experiments. Within microfluidic Teflon tubing or the microfluidic circuitry of a plastic CrystalCard, ∼10–20 nl volume droplets are generated, each representing a microbatch-style crystallization experiment with a different chemical composition. The entire protein sample is utilized in crystallization experiments. Sparse-matrix screening and chemical gradient screening can be combined in one comprehensive ‘hybrid’ crystallization trial. The technology lends itself well to optimization by high-granularity gradient screening using optimization reagents such as precipitation agents, ligands or cryoprotectants.

  5. The comparison of removing plug by ultrasonic wave, chemical deplugging agent and ultrasound-chemical combination deplugging for near-well ultrasonic processing technology.

    PubMed

    Wang, Zhenjun; Xu, Yuanming; Bajracharya, Suman

    2015-11-01

    Near-well ultrasonic processing technology is characterized by high adaptability, simple operation, low cost and zero pollution. The main plugs of oil production include paraffin deposition plug, polymer plug, and drilling fluid plug etc. Although some good results have been obtained through laboratory experiments and field tests, systematic and intensive studies are absent for certain major aspects, such as: effects of ultrasonic treatment for different kinds of plugs and whether effect of ultrasound-chemicals combination deplugging is better than that of ultrasonic deplugging. In this paper, the experiments of removing drilling fluid plug, paraffin deposition plug and polymer plug by ultrasonic wave, chemical deplugging agent and ultrasound-chemical combination deplugging respectively are carried out. Results show that the effect of ultrasound-chemical combination deplugging is clearly better than that of using ultrasonic wave and chemical deplugging agent separately, which indicates that ultrasonic deplugging and chemical deplugging can produce synergetic effects. On the one hand, ultrasonic treatment can boost the activity of chemical deplugging agent and turn chemical deplugging into dynamic chemical process, promoting chemical agent reaction speed and enhancing deplugging effect; on the other hand, chemical agent can reduce the adhesion strength of plugs so that ultrasonic deplugging effect can be improved significantly. Experimental results provide important reference for near-well ultrasonic processing technology.

  6. Decentralized scenario-based plug and play MPC for linear systems with multiplicative uncertainties

    NASA Astrophysics Data System (ADS)

    Nehring, Anna; Zhang, Ping

    2017-01-01

    This paper proposes a novel approach to decentralized control with Plug and Play capabilities. Plug and Play allows a flexible addition and removal of subsystems to an existing plant. The proposed approach guarantees stability and robustness to a certain degree for systems with additive disturbances and multiplicative uncertainties. For the controller design, the plant is decomposed into subsystems. The algorithms for adding and removing subsystems are given. By applying the basic idea of scenario-based methods, the proposed approach is less conservative and can handle complex multiplicative uncertainties.

  7. Chemical aspects of iron colloid plugging in quartz sands and implications for formation damage

    SciTech Connect

    Potter, J.M.; Dibble, W.E.

    1985-09-01

    A research direction having great potential for better understanding of formation damage is the influence of colloid plugging on fluid flow behavior in porous media. Using flow through experimental equipment, we have explored the dependence of the degree of ferric oxyhydroxide colloid plugging of quartz sand packs on the solution pH and anion type at a constant temperature of 208/sup 0/F (97.7/sup 0/C). At a pH of 5, permeability reductions were greatest in the order PO/sup 3//sub 4/-, SO/sup 2//sub 4/-, and Cl-. This order was reversed at a pH of 9. The results suggest that plugging occurs by two fundamentally different mechanisms. First, flocculation/coagulation of the ferric hydroxide leads to formation of filter cake in the low-pH case. Second, colloid/quartz surface interaction produces a more uniform accumulation of colloid throughout the core at higher pH's.

  8. Plugging meter

    DOEpatents

    Nagai, Akinori

    1979-01-01

    A plugging meter for automatically measuring the impurity concentration in a liquid metal is designed to have parallel passages including a cooling passage provided with a plugging orifice and with a flow meter, and a by-pass passage connected in series to a main passage having another flow meter, so that the plugging points may be obtained from the outputs of both flow meters. The plugging meter has a program signal generator, a flow-rate ratio setter and a comparator, and is adapted to change the temperature of the plugging orifice in accordance with a predetermined pattern or gradient, by means of a signal representative of the temperature of plugging orifice and a flow-rate ratio signal obtained from the outputs of both flow meters. This plugging meter affords an automatic and accurate measurement of a multi-plugging phenomenon taking place at the plugging orifice.

  9. Plug valve

    DOEpatents

    Wordin, John J.

    1989-01-01

    An improved plug valve wherein a novel shape for the valve plug and valve chamber provide mating surfaces for improved wear characteristics. The novel shape of the valve plug is a frustum of a body of revolution of a curved known as a tractrix, a solid shape otherwise known as a peudosphere.

  10. Plug-in module acceleration feedback control for fast steering mirror-based beam stabilization systems

    NASA Astrophysics Data System (ADS)

    Deng, Chao; Ren, Wei; Mao, Yao; Ren, Ge

    2017-08-01

    A plug-in module acceleration feedback control (Plug-In AFC) strategy based on the disturbance observer (DOB) principle is proposed for charge-coupled device (CCD)-based fast steering mirror (FSM) stabilization systems. In classical FSM tracking systems, dual-loop control (DLC), including velocity feedback and position feedback, is usually utilized to enhance the closed-loop performance. Due to the mechanical resonance of the system and CCD time delay, the closed-loop bandwidth is severely restricted. To solve this problem, cascade acceleration feedback control (AFC), which is a kind of high-precision robust control method, is introduced to strengthen the disturbance rejection property. However, in practical applications, it is difficult to realize an integral algorithm in an acceleration controller to compensate for the quadratic differential contained in the FSM acceleration model, resulting in a challenging controller design and a limited improvement. To optimize the acceleration feedback framework in the FSM system, different from the cascade AFC, the accelerometers are used to construct DOB to compensate for the platform vibrations directly. The acceleration nested loop can be plugged into the velocity loop without changing the system stability, and the controller design is quite simple. A series of comparative experimental results demonstrate that the disturbance rejection property of the CCD-based FSM can be effectively improved by the proposed approach.

  11. A Laser-Based Calibration System, for the CDF Plug Upgrade Calorimeters

    NASA Astrophysics Data System (ADS)

    Cauz, Diego

    A laser-based calibration and monitoring system for the plug upgrade calorimeter is described. A pulsed nitrogen ultraviolet laser excites all of the about 1000 photomultiplier tubes (PMTs) in each plug calorimeter. The light is focused into a quartz fiber and routed first to a primary distributor (PD) and from there to 12 secondary distributors (COWs), which feed the individual PMTs. The system will be used as a debugging tool during calorimeter rigging and will help the wire source calibration system in initially equalizing the PMT gains. In addition, an LED imbedded in each COW can set a continuous DC level on each PMT, allowing for PMT burn-in and gain conditioning.

  12. "Plug and play" logic gates based on fluorescence switching regulated by self-assembly of nucleotide and lanthanide ions.

    PubMed

    Pu, Fang; Ren, Jinsong; Qu, Xiaogang

    2014-06-25

    Molecular logic gates in response to chemical, biological, or optical input signals at a molecular level have received much interest over the past decade. Herein, we construct "plug and play" logic systems based on the fluorescence switching of guest molecules confined in coordination polymer nanoparticles generated from nucleotide and lanthanide ions. In the system, the addition of new modules directly enables new logic functions. PASS 0, YES, PASS 1, NOT, IMP, OR, and AND gates are successfully constructed in sequence. Moreover, different logic gates (AND, INH, and IMP) can be constructed using different guest molecules and the same input combinations. The work will be beneficial to the future logic design and expand the applications of coordination polymers.

  13. Spectroscopic Characterization and Simulation of Chemical Sputtering Using the DiMES Porous Plug Injector in DIII-D

    SciTech Connect

    McLean, A G; Davis, J W; Stangeby, P C; Brooks, N H; Whyte, D G; Allen, S L; Bray, B D; Brezinsek, S; Elder, J D; Fenstermacher, M E; Groth, M; Haasz, A A; Hollmann, E M; Isler, R; Lasnier, C J; Rudakov, D L; Watkins, J G; West, W P; Wong, C C

    2006-05-15

    A self-contained gas injection system for the Divertor Material Evaluation System (DiMES) on DIII-D has been employed for in-situ study of chemical erosion in the tokamak divertor environment. The Porous Plug Injector (PPI) releases methane, a major component of molecular influx due to chemical sputtering of graphite, from the tile surface into the plasma at a controlled rate through a porous graphite surface. Perturbation to local plasma is minimized, while also simulating the immediate environment of methane molecules released from a solid graphite surface. The release rate was chosen to be of the same order of magnitude as natural sputtering. Photon efficiencies of CH{sub 4} for measured local plasma conditions are reported. The contribution of chemical versus physical sputtering to the source of C{sup +} at the target is assessed through measurement of CII and CD/CH band emissions during release of CH{sub 4} from the PPI, and due to intrinsic emission.

  14. Research on ultrasonic excitation for the removal of drilling fluid plug, paraffin deposition plug, polymer plug and inorganic scale plug for near-well ultrasonic processing technology.

    PubMed

    Wang, Zhenjun; Zeng, Jing; Song, Hao; Li, Feng

    2017-05-01

    Near-well ultrasonic processing technology attracts more attention due to its simple operation, high adaptability, low cost and no pollution to the formation. Although this technology has been investigated in detail through laboratory experiments and field tests, systematic and intensive researches are absent for certain major aspects, such as whether ultrasonic excitation is better than chemical agent for any plugs removal; whether ultrasound-chemical combination plug removal technology has the best plugs removal effect. In this paper, the comparison of removing drilling fluid plug, paraffin deposition plug, polymer plug and inorganic scale plug using ultrasonic excitation, chemical agent and ultrasound-chemical combination plug removal technology is investigated. Results show that the initial core permeability and ultrasonic frequency play a significant role in plug removal. Ultrasonic excitation and chemical agent have different impact on different plugs. The comparison results show that the effect of removing any plugs using ultrasound-chemicals composite plug removal technology is obviously better than that using ultrasonic excitation or chemical agent alone. Such conclusion proves that ultrasonic excitation and chemical agent can cause synergetic effects.

  15. An Approach of Web-based Point Cloud Visualization without Plug-in

    NASA Astrophysics Data System (ADS)

    Ye, Mengxuan; Wei, Shuangfeng; Zhang, Dongmei

    2016-11-01

    With the advances in three-dimensional laser scanning technology, the demand for visualization of massive point cloud is increasingly urgent, but a few years ago point cloud visualization was limited to desktop-based solutions until the introduction of WebGL, several web renderers are available. This paper addressed the current issues in web-based point cloud visualization, and proposed a method of web-based point cloud visualization without plug-in. The method combines ASP.NET and WebGL technologies, using the spatial database PostgreSQL to store data and the open web technologies HTML5 and CSS3 to implement the user interface, a visualization system online for 3D point cloud is developed by Javascript with the web interactions. Finally, the method is applied to the real case. Experiment proves that the new model is of great practical value which avoids the shortcoming of the existing WebGIS solutions.

  16. Principles of Chemical Biology: From MAGIC to Gut Fungi, via "Plug-And-Play" Biosensors.

    PubMed

    2017-04-20

    This month: New MAGIC linking mitochondrial biology and proteostasis, split RNA polymerase based biosensors, and a role that fungi play in human gut microbiome. Copyright © 2017. Published by Elsevier Ltd.

  17. Plug-n-play microfluidic systems from flexible assembly of glass-based flow-control modules.

    PubMed

    Meng, Zhi-Jun; Wang, Wei; Liang, Xuan; Zheng, Wei-Chao; Deng, Nan-Nan; Xie, Rui; Ju, Xiao-Jie; Liu, Zhuang; Chu, Liang-Yin

    2015-04-21

    In this study, we report on a simple and versatile plug-n-play microfluidic system that is fabricated from flexible assembly of glass-based flow-control modules for flexibly manipulating flows for versatile emulsion generation. The microfluidic system consists of three basic functional units: a flow-control module, a positioning groove, and a connection fastener. The flow-control module that is based on simple assembly of low-cost glass slides, coverslips, and glass capillaries provides excellent chemical resistance and optical properties, and easy wettability modification for flow manipulation. The flexible combination of the flow-control modules with 3D-printed positioning grooves and connection fasteners enables creation of versatile microfluidic systems for generating various higher-order multiple emulsions. The simple and reversible connection of the flow-control modules also allows easy disassembly of the microfluidic systems for further scale-up and functionalization. We demonstrate the scalability and controllability of flow manipulation by creating microfluidic systems from flexible assembly of flow-control modules for controllable generation of multiple emulsions from double emulsions to quadruple emulsions. Meanwhile, the flexible flow manipulation in the flow-control module provides advanced functions for improved control of the drop size, and for controllable generation of drops containing distinct components within multiple emulsions to extend the emulsion structure. Such modular microfluidic systems provide flexibility and versatility to flexibly manipulate micro-flows for enhanced and extended applications.

  18. Insights into head-column field-amplified sample stacking: Part I. Detailed study of electrokinetic injection of a weak base across a short water plug.

    PubMed

    Šesták, Jozef; Thormann, Wolfgang

    2017-06-16

    The fundamentals of electrokinetic injection of the weak base methadone across a short water plug into a phosphate buffer at low pH were studied experimentally and with computer simulation. The current during electrokinetic injection, the formation of the analyte zone, changes occurring within and around the water plug and mass transport of all compounds in the electric field were investigated. The impact of water plug length, plug injection velocity, and composition of sample, plug and background electrolyte are discussed. Experimental data revealed that properties of sample, water plug and stacking boundary are significantly and rapidly altered during electrokinetic injection. Simulation provided insight into these changes, including the nature of the migrating boundaries and the stacking of methadone at the interface to a newly formed phosphoric acid zone. The data confirm the role of the water plug to prevent contamination of the sample by components of the background electrolyte and suggest that mixing caused by electrohydrodynamic instabilities increases the water plug conductivity. The sample conductivity must be controlled by addition of an acid to prevent generation of reversed flow which removes the water plug and to create a buffering environment. Results revealed that a large increase in background electrolyte concentration is not accompanied with a significant increase in stacking. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. On-Chip Titration of an Anticoagulant Argatroban and Determination of the Clotting Time within Whole Blood or Plasma Using a Plug-Based Microfluidic System

    PubMed Central

    Song, Helen; Li, Hung-Wing; Munson, Matthew S.; Van Ha, Thuong G.; Ismagilov, Rustem F.

    2006-01-01

    This paper describes extending plug-based microfluidics to handling complex biological fluids such as blood, solving the problem of injecting additional reagents into plugs, and applying this system to measuring of clotting time in small volumes of whole blood and plasma. Plugs are droplets transported through microchannels by fluorocarbon fluids. A plug-based microfluidic system was developed to titrate an anticoagulant (argatroban) into blood samples and to measure the clotting time using the activated partial thromboplastin time (APTT) test. To carry out these experiments, the following techniques were developed for a plug-based system: (i) using Teflon AF coating on the microchannel wall to enable formation of plugs containing blood and transport of the solid fibrin clots within plugs, (ii) using a hydrophilic glass capillary to enable reliable merging of a reagent from an aqueous stream into plugs, (iii) using bright-field microscopy to detect the formation of a fibrin clot within plugs and using fluorescent microscopy to detect the production of thrombin using a fluorogenic substrate, and (iv) titration of argatroban (0–1.5 μg/mL) into plugs and measurement of the resulting APTTs at room temperature (23 °C) and physiological temperature (37 °C). APTT measurements were conducted with normal pooled plasma (platelet-poor plasma) and with donor’s blood samples (both whole blood and platelet-rich plasma). APTT values and APTT ratios measured by the plug-based microfluidic device were compared to the results from a clinical laboratory at 37 °C. APTT obtained from the on-chip assay were about double those from the clinical laboratory but the APTT ratios from these two methods agreed well with each other. PMID:16841902

  20. On-chip titration of an anticoagulant argatroban and determination of the clotting time within whole blood or plasma using a plug-based microfluidic system.

    PubMed

    Song, Helen; Li, Hung-Wing; Munson, Matthew S; Van Ha, Thuong G; Ismagilov, Rustem F

    2006-07-15

    This paper describes extending plug-based microfluidics to handling complex biological fluids such as blood, solving the problem of injecting additional reagents into plugs, and applying this system to measuring of clotting time in small volumes of whole blood and plasma. Plugs are droplets transported through microchannels by fluorocarbon fluids. A plug-based microfluidic system was developed to titrate an anticoagulant (argatroban) into blood samples and to measure the clotting time using the activated partial thromboplastin time (APTT) test. To carry out these experiments, the following techniques were developed for a plug-based system: (i) using Teflon AF coating on the microchannel wall to enable formation of plugs containing blood and transport of the solid fibrin clots within plugs, (ii) using a hydrophilic glass capillary to enable reliable merging of a reagent from an aqueous stream into plugs, (iii) using bright-field microscopy to detect the formation of a fibrin clot within plugs and using fluorescent microscopy to detect the production of thrombin using a fluorogenic substrate, and (iv) titration of argatroban (0-1.5 microg/mL) into plugs and measurement of the resulting APTTs at room temperature (23 degrees C) and physiological temperature (37 degrees C). APTT measurements were conducted with normal pooled plasma (platelet-poor plasma) and with donor's blood samples (both whole blood and platelet-rich plasma). APTT values and APTT ratios measured by the plug-based microfluidic device were compared to the results from a clinical laboratory at 37 degrees C. APTT obtained from the on-chip assay were about double those from the clinical laboratory but the APTT ratios from these two methods agreed well with each other.

  1. Cost Analysis of Plug-In Hybred Electric Vehicles Using GPS-Based Longitudinal Travel Data

    SciTech Connect

    Wu, Xing; Dong, Jing; Lin, Zhenhong

    2014-01-01

    Using spatial, longitudinal travel data of 415 vehicles over 3 18 months in the Seattle metropolitan area, this paper estimates the operating costs of plug-in hybrid electric vehicles (PHEVs) of various electric ranges (10, 20, 30, and 40 miles) for 3, 5, and 10 years of payback period, considering different charging infrastructure deployment levels and gasoline prices. Some key findings were made. (1) PHEVs could help save around 60% or 40% in energy costs, compared with conventional gasoline vehicles (CGVs) or hybrid electric vehicles (HEVs), respectively. However, for motorists whose daily vehicle miles traveled (DVMT) is significant, HEVs may be even a better choice than PHEV40s, particularly in areas that lack a public charging infrastructure. (2) The incremental battery cost of large-battery PHEVs is difficult to justify based on the incremental savings of PHEVs operating costs unless a subsidy is offered for largebattery PHEVs. (3) When the price of gasoline increases from $4/gallon to $5/gallon, the number of drivers who benefit from a larger battery increases significantly. (4) Although quick chargers can reduce charging time, they contribute little to energy cost savings for PHEVs, as opposed to Level-II chargers.

  2. The effect of removing plugs and adding arch support to foam based insoles on plantar pressures in people with diabetic peripheral neuropathy

    PubMed Central

    2013-01-01

    Background Removable plug insoles appear to be beneficial for patients with diabetic neuropathic feet to offload local plantar pressure. However, quantitative evidence of pressure reduction by means of plug removal is limited. The value of additional insole accessories, such as arch additions, has not been tested. The purpose of this study was to evaluate the effect of removing plugs from foam based insoles, and subsequently adding extra arch support, on plantar pressures. Methods In-shoe plantar pressure measurements were performed on 26 patients with diabetic neuropathic feet at a baseline condition, in order to identify the forefoot region with the highest mean peak pressure (MPP). This was defined as the region of interest (ROI) for plug removal.The primary outcome was measurement of MPP using the pedar® system in the baseline and another three insole conditions (pre-plug removal, post-plug removal, and post-plug removal plus arch support). Results Among the 26 ROIs, a significant reduction in MPP (32.3%, P<0.001) was found after removing the insole plugs. With an arch support added, the pressure was further reduced (9.5%, P<0.001). There were no significant differences in MPP at non-ROIs between pre- and post-plug removal conditions. Conclusions These findings suggest that forefoot plantar pressure can be reduced by removing plugs and adding arch support to foam-based insoles. This style of insole may therefore be clinically useful in managing patients with diabetic peripheral neuropathy. PMID:23895323

  3. Transmission network-based energy and environmental assessment of plug-in hybrid electric vehicles

    NASA Astrophysics Data System (ADS)

    Valentine, Keenan; Acquaviva, Jonathan; Foster, E. J.; Zhang, K. Max

    2011-03-01

    The introduction of plug-in hybrid electric vehicles (PHEVs) is expected to have a significant impact on regional power systems and pollutant emissions. This paper analyzes the effects of various penetrations of PHEVs on the marginal fuel dispatch of coal, natural gas and oil, and on pollutant emissions of CO2, NOx, SO2 in the New York Metropolitan Area for two battery charging scenarios in a typical summer and winter day. A model of the AC transmission network of the Northeast Power Coordinating Council (NPCC) region with 693 generators is used to realistically incorporate network constraints into an economic dispatch model. A data-based transportation model of approximately 1 million commuters in NYMA is used to determine battery charging pattern. Results show that for all penetrations of PHEVs network-constrained economic dispatch of generation is significantly more realistic than unconstrained cases. Coal, natural gas and oil units are on the margin in the winter, and only natural gas and oil units are on the margin in the summer. Hourly changes in emissions from transportation and power production are dominated by vehicular activity with significant overall emissions reductions for CO2 and NOx, and a slight increase for SO2. Nighttime regulated charging produces less overall emissions than unregulated charging from when vehicles arrive home for the summer and vice versa for the winter. As PHEVs are poised to link the power and transportation sectors, data-based models combining network constraints and economic dispatch have been shown to improve understanding and facilitate control of this link.

  4. Laterally Mobile, Functionalized Self-Assembled Monolayers at the Fluorous−Aqueous Interface in a Plug-Based Microfluidic System: Characterization and Testing with Membrane Protein Crystallization

    SciTech Connect

    Kreutz, Jason E.; Li, Liang; Roach, L. Spencer; Hatakeyama, Takuji; Ismagilov, Rustem F.

    2009-11-04

    This paper describes a method to generate functionalizable, mobile self-assembled monolayers (SAMs) in plug-based microfluidics. Control of interfaces is advancing studies of biological interfaces, heterogeneous reactions, and nanotechnology. SAMs have been useful for such studies, but they are not laterally mobile. Lipid-based methods, though mobile, are not easily amenable to setting up the hundreds of experiments necessary for crystallization screening. Here we demonstrate a method, complementary to current SAM and lipid methods, for rapidly generating mobile, functionalized SAMs. This method relies on plugs, droplets surrounded by a fluorous carrier fluid, to rapidly explore chemical space. Specifically, we implemented his-tag binding chemistry to design a new fluorinated amphiphile, RfNTA, using an improved one-step synthesis of RfOEG under Mitsunobu conditions. RfNTA introduces specific binding of protein at the fluorous-aqueous interface, which concentrates and orients proteins at the interface, even in the presence of other surfactants. We then applied this approach to the crystallization of a his-tagged membrane protein, Reaction Center from Rhodobacter sphaeroides, performed 2400 crystallization trials, and showed that this approach can increase the range of crystal-producing conditions, the success rate at a given condition, the rate of nucleation, and the quality of the crystal formed.

  5. Detecting bacteria and Determining Their Susceptibility to Antibiotics by Stochastic Confinement in Nanoliter Droplets using Plug-Based Microfluidics

    SciTech Connect

    Boedicker, J.; Li, L; Kline, T; Ismagilov, R

    2008-01-01

    This article describes plug-based microfluidic technology that enables rapid detection and drug susceptibility screening of bacteria in samples, including complex biological matrices, without pre-incubation. Unlike conventional bacterial culture and detection methods, which rely on incubation of a sample to increase the concentration of bacteria to detectable levels, this method confines individual bacteria into droplets nanoliters in volume. When single cells are confined into plugs of small volume such that the loading is less than one bacterium per plug, the detection time is proportional to plug volume. Confinement increases cell density and allows released molecules to accumulate around the cell, eliminating the pre-incubation step and reducing the time required to detect the bacteria. We refer to this approach as stochastic confinement. Using the microfluidic hybrid method, this technology was used to determine the antibiogram - or chart of antibiotic sensitivity - of methicillin-resistant Staphylococcus aureus (MRSA) to many antibiotics in a single experiment and to measure the minimal inhibitory concentration (MIC) of the drug cefoxitin (CFX) against this strain. In addition, this technology was used to distinguish between sensitive and resistant strains of S. aureus in samples of human blood plasma. High-throughput microfluidic techniques combined with single-cell measurements also enable multiple tests to be performed simultaneously on a single sample containing bacteria. This technology may provide a method of rapid and effective patient-specific treatment of bacterial infections and could be extended to a variety of applications that require multiple functional tests of bacterial samples on reduced timescales.

  6. Detecting bacteria and determining their susceptibility to antibiotics by stochastic confinement in nanoliter droplets using plug-based microfluidics.

    PubMed

    Boedicker, James Q; Li, Liang; Kline, Timothy R; Ismagilov, Rustem F

    2008-08-01

    This article describes plug-based microfluidic technology that enables rapid detection and drug susceptibility screening of bacteria in samples, including complex biological matrices, without pre-incubation. Unlike conventional bacterial culture and detection methods, which rely on incubation of a sample to increase the concentration of bacteria to detectable levels, this method confines individual bacteria into droplets nanoliters in volume. When single cells are confined into plugs of small volume such that the loading is less than one bacterium per plug, the detection time is proportional to plug volume. Confinement increases cell density and allows released molecules to accumulate around the cell, eliminating the pre-incubation step and reducing the time required to detect the bacteria. We refer to this approach as 'stochastic confinement'. Using the microfluidic hybrid method, this technology was used to determine the antibiogram - or chart of antibiotic sensitivity - of methicillin-resistant Staphylococcus aureus (MRSA) to many antibiotics in a single experiment and to measure the minimal inhibitory concentration (MIC) of the drug cefoxitin (CFX) against this strain. In addition, this technology was used to distinguish between sensitive and resistant strains of S. aureus in samples of human blood plasma. High-throughput microfluidic techniques combined with single-cell measurements also enable multiple tests to be performed simultaneously on a single sample containing bacteria. This technology may provide a method of rapid and effective patient-specific treatment of bacterial infections and could be extended to a variety of applications that require multiple functional tests of bacterial samples on reduced timescales.

  7. A stochastic model of turbulent mixing with chemical reaction: Nitric oxide formulation in a plug-flow burner

    NASA Technical Reports Server (NTRS)

    Flagan, R. C.; Appleton, J. P.

    1973-01-01

    A stochastic model of turbulent mixing was developed for a reactor in which mixing is represented by n-body fluid particle interactions. The model was used to justify the assumption (made in previous investigations of the role of turbulent mixing on burner generated thermal nitric oxide and carbon monoxide emissions) that for a simple plug flow reactor, composition nonuniformities can be described by a Gaussian distribution function in the local fuel:air equivalence ratio. Recent extensions of this stochastic model to include the combined effects of turbulent mixing and secondary air entrainment on thermal generation of nitric oxide in gas turbine combustors are discussed. Finally, rate limited upper and lower bounds of the nitric oxide produced by thermal fixation of molecular nitrogen and oxidation of organically bound fuel nitrogen are estimated on the basis of the stochastic model for a plug flow burner; these are compared with experimental measurements obtained using a laboratory burner operated over a wide range of test conditions; good agreement is obtained.

  8. Fast hydrothermal liquefaction for production of chemicals and biofuels from wet biomass - The need to develop a plug-flow reactor.

    PubMed

    Tran, Khanh-Quang

    2016-08-01

    Hydrothermal liquefaction (HTL) is a promising technology for converting wet plant biomass directly to liquid fuels and chemicals. However, some aspects of the technology are not fully understood and still disputed. The reactor material constraints and difficulties coupled with the formation of unwanted products are the main challenges limiting the applications of the technology. In addition, heat and mass transfer limitations in the reaction system result in a lower conversion efficiency and selectivity, of which the later would make it difficult and expensive for products separation, purification, and/or modification of the products. This paper discusses the challenges and current status of possible solutions to the challenges, focusing on the need of developing a special plug-flow reactor for scaling up of the HTL process. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. An asymptotic observer-based monitoring scheme for a class of plug flow reactors.

    PubMed

    Aguilar-Garnica, Efrén; García-Sandoval, Juan Paulo; Aceves-Lara, César Arturo; Escalante, Froylán Mario E

    2012-01-01

    In this paper a monitoring tool is designed for a class of plug flow reactors whose mathematical model is described by a set of first-order partial differential equations with different coefficients in the convective terms. The infinite dimensional structure of such a tool is derived according to the methodology established in the design of the well-known asymptotic observer. As a consequence, it preserves the robustness of the aforementioned observer against the lack of information of the nonlinear terms involved in the model. The original structure of the estimator is then represented as a couple of integral equations by means of the method of characteristics and its behaviour is analyzed through simulation experiments. These simulations show that the mean square observation error is 0.58 when the proposed observer is implemented in a solid-waste anaerobic digestion process to estimate the evolution of biomass concentration.

  10. Evaluation of plug-in electric vehicles impact on cost-based unit commitment

    NASA Astrophysics Data System (ADS)

    Talebizadeh, Ehsan; Rashidinejad, Masoud; Abdollahi, Amir

    2014-02-01

    Incorporating plug in electric vehicles (PEVs) to power systems may address both additional demand as well as mobile storage to support electric grid spatially. Better utilization of such potential depends on the optimal scheduling of charging and discharging PEVs. Charging management malfunction of PEVs may increase the peak load which leads to additional generation. Therefore, charging and discharging of PEVs must be scheduled intelligently to prevent overloading of the network at peak hours, take advantages of off peak charging benefits and delaying any load shedding. A charging and discharging schedule of PEVs with respect to load curve variations is proposed in this paper. The proposed methodology incorporates integrated PEVs; the so-called parking lots; into the unit commitment problem. An IEEE 10-unit test system is employed to investigate the impacts of PEVs on generation scheduling. The results obtained from simulation analysis show a significant techno-economic saving.

  11. Percutaneous Vascular Closure System Based on an Extravascular, Bioabsorbable Polyglycolic Plug (ExoSeal): Results from 1000 Patients

    PubMed Central

    Kamusella, P; Wissgott, C; Jahnke, T; Brossmann, J; Scheer, F; Lüdtke, CW; Andresen, R

    2014-01-01

    PURPOSE The objective of this prospective study was to evaluate the effectiveness and safety of a percutaneous closure system based on a polyglycolic acid plug for achieving hemostasis. MATERIAL AND METHODS In this study from 2011 to 2014, a percutaneous vascular closure system (ExoSeal) was used in 1000 patients (mean age 70.6 ± 10.2 years), using antegrade and retrograde techniques within the context of an angiographic intervention. The system was used in conjunction with transfemoral approaches with a sheath size of 6F. Post the intervention (on the following day and after 6 weeks), follow-up was conducted clinically and using color-coded duplex ultrasound. RESULTS Immediate hemostasis was achieved in 939/1000 patients (93.9%). In the remaining 61 cases, a correct positioning of the polyglycolic acid plug was not possible because of malfunctioning of the device, massive vascular wall calcifications, postoperative scar tissue, or too steep a puncture angle. In these cases, manual compression was successful. There was one retroperitoneal bleeding requiring transfusion. Minor complications were observed (7.4% in total) with 10 pseudoaneurysm (1%), 63 inguinal hematomas (up to 3 cm; 6.3%), and 1 stenosis (0.1%). CONCLUSION Safe and effective hemostasis is possible with the percutaneous ExoSeal closure system at puncture sizes of 6F. PMID:26085789

  12. Energy management of a power-split plug-in hybrid electric vehicle based on genetic algorithm and quadratic programming

    NASA Astrophysics Data System (ADS)

    Chen, Zheng; Mi, Chris Chunting; Xiong, Rui; Xu, Jun; You, Chenwen

    2014-02-01

    This paper introduces an online and intelligent energy management controller to improve the fuel economy of a power-split plug-in hybrid electric vehicle (PHEV). Based on analytic analysis between fuel-rate and battery current at different driveline power and vehicle speed, quadratic equations are applied to simulate the relationship between battery current and vehicle fuel-rate. The power threshold at which engine is turned on is optimized by genetic algorithm (GA) based on vehicle fuel-rate, battery state of charge (SOC) and driveline power demand. The optimal battery current when the engine is on is calculated using quadratic programming (QP) method. The proposed algorithm can control the battery current effectively, which makes the engine work more efficiently and thus reduce the fuel-consumption. Moreover, the controller is still applicable when the battery is unhealthy. Numerical simulations validated the feasibility of the proposed controller.

  13. Rotating arc spark plug

    DOEpatents

    Whealton, John H.; Tsai, Chin-Chi

    2003-05-27

    A spark plug device includes a structure for modification of an arc, the modification including arc rotation. The spark plug can be used in a combustion engine to reduce emissions and/or improve fuel economy. A method for operating a spark plug and a combustion engine having the spark plug device includes the step of modifying an arc, the modifying including rotating the arc.

  14. Selective plugging strategy-based microbial-enhanced oil recovery using Bacillus licheniformis TT33.

    PubMed

    Suthar, Harish; Hingurao, Krushi; Desai, Anjana; Nerurkar, Anuradha

    2009-10-01

    The selective plugging strategy of microbial enhanced oil recovery involves the use of microbes that grow and produce exopolymeric substances, which block the high permeability zones of an oil reservoir, thus allowing the water to flow through the low permeability zones leading to increase in oil recovery. Bacillus licheniformis TT33, a hot water spring isolate, is facultatively anaerobic, halotolerant, and thermotolerant. It produces EPS as well as biosurfactant and has a biofilm-forming ability. The viscosity of its cell-free supernatant is 120 mPas at 28 degrees C. Its purified EPS contained 26% carbohydrate and 3% protein. Its biosurfactant reduced the surface tension of water from 72 to 34 mN/m. This strain gave 27.7+/-3.5% oil recovery in a sand pack column. Environmental scanning electron microscopy analysis showed bacterial growth and biofilm formation in the sand pack. Biochemical tests and amplified ribosomal DNA restriction analysis confirmed that the oil recovery obtained in the sand pack column was due to Bacillus licheniformis TT33.

  15. Implementation Approach for Plug-in Electric Vehicles at Joint Base Lewis McChord. Task 4

    SciTech Connect

    Schey, Stephen; Francfort, Jim

    2014-12-01

    This study focused on Joint Base Lewis McChord (JBLM), which is located in Washington State. Task 1 consisted of a survey of the non-tactical fleet of vehicles at JBLM to begin the review of vehicle mission assignments and the types of vehicles in service. In Task 2, daily operational characteristics of select vehicles were identified and vehicle movements were recorded in data loggers in order to characterize the vehicles’ missions. In Task 3, the results of the data analysis and observations were provided. Individual observations of the selected vehicles provided the basis for recommendations related to PEV adoption (i.e., whether a battery electric vehicle or plug-in hybrid electric vehicle [collectively referred to as PEVs] can fulfill the mission requirements0, as well as the basis for recommendations related to placement of PEV charging infrastructure. This report focuses on an implementation plan for the near-term adoption of PEVs into the JBLM fleet.

  16. Fabrication and evaluation of a biodegradable cohesive plug based on reconstituted collagen/γ-polyglutamic acid.

    PubMed

    Hsu, Fu-Yin; Cheng, Ya-Yun; Tsai, Shiao-Wen; Tsai, Wei-Bor

    2010-10-01

    In the past decade, numerous studies have been devoted to developing natural bioadhesives that have the notable capacity to adhere to wet surfaces. Collagen and γ-polyglutamic acid (γ-PGA) are well-known natural hydrophilic polymers that have both been utilized for their versatility in a wide range of biomedical applications. The aim of this study was the construction and characterization of a cohesive plug composed of γ-PGA and reconstituted collagen fibrils crosslinked with water-soluble carbodiimide. Transmission electron microscopy examinations confirmed that the collagen fibrils in the reconstituted collagen/γ-PGA gel retained their native specific D-period structure. This unique D-pattern structure of collagen plays a major role in hemostasis and is also related to several cellular behaviors. The bonding strength of the reconstituted collagen/γ-PGA adhesive was approximately 42.9 ± 4.0 KPa after 5 min of application and increased to 76.5 ± 15.1 KPa after 24 h. This was much stronger than the fibrin adhesive, whose bonding strength was 30.9 ± 0.2 KPa. Furthermore, the reconstituted collagen/γ-PGA gel degraded gradually after subcutaneous implantation in the backs of rats over a period of 8 weeks, without any severe inflammatory response. On the basis of the histological analysis, fibroblasts migrated into the gel while it degraded, which indicates that the gel is not harmful to cellular activity. Together, these findings demonstrate that using reconstituted collagen with retained D-periodicity as a component of the bioadhesive is a possibly better option to formulate effective adhesiveness and is promising as a scaffold for tissue repair.

  17. TelluSim: A Python Plug-in Based Computational Framework for Spatially Distributed Environmental and Earth Sciences Modelling

    NASA Astrophysics Data System (ADS)

    Willgoose, G. R.

    2008-12-01

    TelluSim is a python-based computational framework for integrating and manipulating modules written in a variety of computer languages. TelluSim consists of a main program that dynamically, at run time, assembles a series of modules. These modules can be written in any language that can be accessed by Python. Currently we have modules in Fortran and Python, with C to be supported soon. New modules are incorporated as plug-ins like done for a browser or Photoshop, simply by copying the module binary into a plug-in directory. TelluSim automatically generates a GUI for parameter and state I/O, and automatically creates the intermodule communication mechanisms needed for the computations. A decision to use Python was arrived at after detailed trials using other languages including C, Tcl/Tk and Fortran. An important aspect of the design of TelluSim was to minimise the overhead in interfacing the modules with TelluSim, and minimise any requirement for recoding of existing software, so eliminating a major disadvantage of more complex frameworks (e.g. JAMS, openMI). Several significant Fortran codes developed by the author have been incorporated as part of the design process and as proof of concept. In particular the SIBERIA landform evolution code (a high performance F90 code, including parallel capability) has been broken up into a series of TelluSim modules, so that the SIBERIA now consists of a Python script of 20 lines. These 20 lines assemble and run the underlying modules (about 50,000 lines of Fortran code). The presentation will discuss in more detail the design of TelluSim, and our experiences of the advantages and disadvantages of using Python relative to other approaches.

  18. Compact 4.7 W, 18.3% wall-plug efficiency green laser based on an electrically pumped VECSEL using intracavity frequency doubling.

    PubMed

    Zhao, Pu; Xu, Bing; van Leeuwen, Robert; Chen, Tong; Watkins, Laurence; Zhou, Delai; Gao, Peng; Xu, Guoyang; Wang, Qing; Ghosh, Chuni

    2014-08-15

    We have demonstrated a compact, 4.7 W green laser based on an electrically pumped vertical external-cavity surface emitting laser through intracavity frequency doubling. The overall wall-plug efficiency (electrical to green) was 18.3%. The power fluctuations were measured to be ±1.4% over a 2 h time period.

  19. Initial Study of Friction Pull Plug Welding

    NASA Technical Reports Server (NTRS)

    Rich, Brian S.

    1999-01-01

    Pull plug friction welding is a new process being developed to conveniently eliminate defects from welded plate tank structures. The general idea is to drill a hole of precise, optimized dimensions and weld a plug into it, filling the hole perfectly. A conically-shaped plug is rotated at high angular velocity as it is brought into contact with the plate material in the hole. As the plug is pulled into the hole, friction rapidly raises the temperature to the point at which the plate material flows plastically. After a brief heating phase, the plug rotation is terminated. The plug is then pulled upon with a forging force, solidly welding the plug into the hole in the plate. Three aspects of this process were addressed in this study. The transient temperature distribution was analyzed based on slightly idealized boundary conditions for different plug geometries. Variations in hole geometry and ram speed were considered, and a program was created to calculate volumes of displaced material and empty space, as well as many other relevant dimensions. The relation between the axially applied forging force and the actual forging pressure between the plate and plug surfaces was determined for various configurations.

  20. Study of a Liquid Plug-Flow Thermal Cycling Technique Using a Temperature Gradient-Based Actuator

    PubMed Central

    Fuchiwaki, Yusuke; Nagai, Hidenori

    2014-01-01

    Easy-to-use thermal cycling for performing rapid and small-volume DNA amplification on a single chip has attracted great interest in the area of rapid field detection of biological agents. For this purpose, as a more practical alternative to conventional continuous flow thermal cycling, liquid plug-flow thermal cycling utilizes a thermal gradient generated in a serpentine rectangular flow microchannel as an actuator. The transit time and flow speed of the plug flow varied drastically in each temperature zone due to the difference in the tension at the interface between temperature gradients. According to thermal distribution analyses in microfluidics, the plug flow allowed for a slow heating process, but a fast cooling process. The thermal cycle of the microfluid was consistent with the recommended temperature gradient for PCR. Indeed, amplification efficiency of the plug flow was superior to continuous flow PCR, and provided an impressive improvement over previously-reported flow microchannel thermal cycling techniques. PMID:25350508

  1. Study of a liquid plug-flow thermal cycling technique using a temperature gradient-based actuator.

    PubMed

    Fuchiwaki, Yusuke; Nagai, Hidenori

    2014-10-27

    Easy-to-use thermal cycling for performing rapid and small-volume DNA amplification on a single chip has attracted great interest in the area of rapid field detection of biological agents. For this purpose, as a more practical alternative to conventional continuous flow thermal cycling, liquid plug-flow thermal cycling utilizes a thermal gradient generated in a serpentine rectangular flow microchannel as an actuator. The transit time and flow speed of the plug flow varied drastically in each temperature zone due to the difference in the tension at the interface between temperature gradients. According to thermal distribution analyses in microfluidics, the plug flow allowed for a slow heating process, but a fast cooling process. The thermal cycle of the microfluid was consistent with the recommended temperature gradient for PCR. Indeed, amplification efficiency of the plug flow was superior to continuous flow PCR, and provided an impressive improvement over previously-reported flow microchannel thermal cycling techniques.

  2. Analysis of Plug-In hybrid Electric Vehicles' utility factors using GPS-based longitudinal travel data

    NASA Astrophysics Data System (ADS)

    Aviquzzaman, Md

    The benefit of using a Plug-in Hybrid Electric Vehicle (PHEV) comes from its ability of substituting gasoline with electricity in operation. Defined as the share of distance traveled in the electric mode, the utility factor (UF) depends mostly on the battery capacity but also on many other factors, such as travel pattern and recharging pattern. Conventionally, the UFs are calculated from the daily vehicle miles traveled (DVMT) of vehicles by assuming motorists leaving home in the morning with full battery and return home in the evening. Such assumption, however, ignores the impact of the heterogeneity in both travel and charging behavior. The main objective of the thesis is to compare the UF by using multiday GPS-based travel data in regards to the charging decision. This thesis employs the global positioning system (GPS) based longitudinal travel data (covering 3-18 months) collected from 403 vehicles in the Seattle metropolitan area to investigate the impacts of such travel and charging behavior on UFs by analyzing the DVMT and home and work related tours. The UFs based on the DVMT are found close to those based on home-to-home tours. On the other hand, it is seen that the workplace charge opportunities largely improve UFs if the battery capacity is no more than 50 miles. It is also found that the gasoline price does not have significant impact on the UFs.

  3. Assessment of Charging Infrastructure for Plug-in Electric Vehicles at Marine Corps Base Camp Lejeune. Task 3

    SciTech Connect

    Schey, Stephen; Francfort, Jim

    2015-11-01

    Battelle Energy Alliance, LLC, managing and operating contractor for the U.S. Department of Energy’s Idaho National Laboratory, is the lead laboratory for the U.S. Department of Energy’s advanced vehicle testing. Battelle Energy Alliance, LLC contracted with Intertek Testing Services, North America (Intertek) to conduct several U.S. Department of Defense-based studies to identify potential U.S. Department of Defense transportation systems that are strong candidates for introduction or expansion of plug-in electric vehicles (PEVs). Task 1 consisted of a survey of the non-tactical fleet of vehicles at Marine Corps Base Camp Lejeune to begin the review of vehicle mission assignments and types of vehicles in service. Task 2 selected vehicles for further monitoring and involved identifying daily operational characteristics of these select vehicles. Data logging of vehicle movements was initiated in order to characterize the vehicle’s mission. The Task 3 vehicle utilization report provided results of the data analysis and observations related to the replacement of current vehicles with PEVs. Finally, this report provides an assessment of charging infrastructure required to support the suggested PEV replacements. Intertek acknowledges the support of Idaho National Laboratory, Marine Corps headquarters, and Marine Corps Base Camp Lejeune Fleet management and personnel for participation in this study. Intertek is pleased to provide this report and is encouraged by enthusiasm and support from Marine Corps Base Camp Lejeune personnel.

  4. Data-driven reinforcement learning–based real-time energy management system for plug-in hybrid electric vehicles

    SciTech Connect

    Qi, Xuewei; Wu, Guoyuan; Boriboonsomsin, Kanok; Barth, Matthew J.; Gonder, Jeffrey

    2016-01-01

    Plug-in hybrid electric vehicles (PHEVs) show great promise in reducing transportation-related fossil fuel consumption and greenhouse gas emissions. Designing an efficient energy management system (EMS) for PHEVs to achieve better fuel economy has been an active research topic for decades. Most of the advanced systems rely either on a priori knowledge of future driving conditions to achieve the optimal but not real-time solution (e.g., using a dynamic programming strategy) or on only current driving situations to achieve a real-time but nonoptimal solution (e.g., rule-based strategy). This paper proposes a reinforcement learning–based real-time EMS for PHEVs to address the trade-off between real-time performance and optimal energy savings. The proposed model can optimize the power-split control in real time while learning the optimal decisions from historical driving cycles. Here, a case study on a real-world commute trip shows that about a 12% fuel saving can be achieved without considering charging opportunities; further, an 8% fuel saving can be achieved when charging opportunities are considered, compared with the standard binary mode control strategy.

  5. Prediction-based optimal power management in a fuel cell/battery plug-in hybrid vehicle

    NASA Astrophysics Data System (ADS)

    Bubna, Piyush; Brunner, Doug; Advani, Suresh G.; Prasad, Ajay K.

    A prediction-based power management strategy is proposed for fuel cell/battery plug-in hybrid vehicles with the goal of improving overall system operating efficiency. The main feature of the proposed strategy is that, if the total amount of energy required to complete a particular drive cycle can be reliably predicted, then the energy stored in the onboard electrical storage system can be depleted in an optimal manner that permits the fuel cell to operate in its most efficient regime. The strategy has been implemented in a vehicle power-train simulator called LFM which was developed in MATLAB/SIMULINK software and its effectiveness was evaluated by comparing it with a conventional control strategy. The proposed strategy is shown to provide significant improvement in average fuel cell system efficiency while reducing hydrogen consumption. It has been demonstrated with the LFM simulation that the prediction-based power management strategy can maintain a stable power request to the fuel cell thereby improving fuel cell durability, and that the battery is depleted to the desired state-of-charge at the end of the drive cycle. A sensitivity analysis has also been conducted to study the effects of inaccurate predictions of the remaining portion of the drive cycle on hydrogen consumption and the final battery state-of-charge. Finally, the advantages of the proposed control strategy over the conventional strategy have been validated through implementation in the University of Delaware's fuel cell hybrid bus with operational data acquired from onboard sensors.

  6. Data-driven reinforcement learning–based real-time energy management system for plug-in hybrid electric vehicles

    DOE PAGES

    Qi, Xuewei; Wu, Guoyuan; Boriboonsomsin, Kanok; ...

    2016-01-01

    Plug-in hybrid electric vehicles (PHEVs) show great promise in reducing transportation-related fossil fuel consumption and greenhouse gas emissions. Designing an efficient energy management system (EMS) for PHEVs to achieve better fuel economy has been an active research topic for decades. Most of the advanced systems rely either on a priori knowledge of future driving conditions to achieve the optimal but not real-time solution (e.g., using a dynamic programming strategy) or on only current driving situations to achieve a real-time but nonoptimal solution (e.g., rule-based strategy). This paper proposes a reinforcement learning–based real-time EMS for PHEVs to address the trade-off betweenmore » real-time performance and optimal energy savings. The proposed model can optimize the power-split control in real time while learning the optimal decisions from historical driving cycles. Here, a case study on a real-world commute trip shows that about a 12% fuel saving can be achieved without considering charging opportunities; further, an 8% fuel saving can be achieved when charging opportunities are considered, compared with the standard binary mode control strategy.« less

  7. Optimal economy-based battery degradation management dynamics for fuel-cell plug-in hybrid electric vehicles

    NASA Astrophysics Data System (ADS)

    Martel, François; Kelouwani, Sousso; Dubé, Yves; Agbossou, Kodjo

    2015-01-01

    This work analyses the economical dynamics of an optimized battery degradation management strategy intended for plug-in hybrid electric vehicles (PHEVs) with consideration given to low-cost technologies, such as lead-acid batteries. The optimal management algorithm described herein is based on discrete dynamic programming theory (DDP) and was designed for the purpose of PHEV battery degradation management; its operation relies on simulation models using data obtained experimentally on a physical PHEV platform. These tools are first used to define an optimal management strategy according to the economical weights of PHEV battery degradation and the secondary energy carriers spent to manage its deleterious effects. We then conduct a sensitivity study of the proposed optimization process to the fluctuating economic parameters associated with the fuel and energy costs involved in the degradation management process. Results demonstrate the influence of each parameter on the process's response, including daily total operating costs and expected battery lifetime, as well as establish boundaries for useful application of the method; in addition, they provide a case for the relevance of inexpensive battery technologies, such as lead-acid batteries, for economy-centric PHEV applications where battery degradation is a major concern.

  8. Deterministic bead-in-droplet ejection utilizing an integrated plug-in bead dispenser for single bead–based applications

    PubMed Central

    Kim, Hojin; Choi, In Ho; Lee, Sanghyun; Won, Dong-Joon; Oh, Yong Suk; Kwon, Donghoon; Sung, Hyung Jin; Jeon, Sangmin; Kim, Joonwon

    2017-01-01

    This paper presents a deterministic bead-in-droplet ejection (BIDE) technique that regulates the precise distribution of microbeads in an ejected droplet. The deterministic BIDE was realized through the effective integration of a microfluidic single-particle handling technique with a liquid dispensing system. The integrated bead dispenser facilitates the transfer of the desired number of beads into a dispensing volume and the on-demand ejection of bead-encapsulated droplets. Single bead–encapsulated droplets were ejected every 3 s without any failure. Multiple-bead dispensing with deterministic control of the number of beads was demonstrated to emphasize the originality and quality of the proposed dispensing technique. The dispenser was mounted using a plug-socket type connection, and the dispensing process was completely automated using a programmed sequence without any microscopic observation. To demonstrate a potential application of the technique, bead-based streptavidin–biotin binding assay in an evaporating droplet was conducted using ultralow numbers of beads. The results evidenced the number of beads in the droplet crucially influences the reliability of the assay. Therefore, the proposed deterministic bead-in-droplet technology can be utilized to deliver desired beads onto a reaction site, particularly to reliably and efficiently enrich and detect target biomolecules. PMID:28393911

  9. Deterministic bead-in-droplet ejection utilizing an integrated plug-in bead dispenser for single bead-based applications

    NASA Astrophysics Data System (ADS)

    Kim, Hojin; Choi, In Ho; Lee, Sanghyun; Won, Dong-Joon; Oh, Yong Suk; Kwon, Donghoon; Sung, Hyung Jin; Jeon, Sangmin; Kim, Joonwon

    2017-04-01

    This paper presents a deterministic bead-in-droplet ejection (BIDE) technique that regulates the precise distribution of microbeads in an ejected droplet. The deterministic BIDE was realized through the effective integration of a microfluidic single-particle handling technique with a liquid dispensing system. The integrated bead dispenser facilitates the transfer of the desired number of beads into a dispensing volume and the on-demand ejection of bead-encapsulated droplets. Single bead-encapsulated droplets were ejected every 3 s without any failure. Multiple-bead dispensing with deterministic control of the number of beads was demonstrated to emphasize the originality and quality of the proposed dispensing technique. The dispenser was mounted using a plug-socket type connection, and the dispensing process was completely automated using a programmed sequence without any microscopic observation. To demonstrate a potential application of the technique, bead-based streptavidin-biotin binding assay in an evaporating droplet was conducted using ultralow numbers of beads. The results evidenced the number of beads in the droplet crucially influences the reliability of the assay. Therefore, the proposed deterministic bead-in-droplet technology can be utilized to deliver desired beads onto a reaction site, particularly to reliably and efficiently enrich and detect target biomolecules.

  10. MANTA, a novel plug-based vascular closure device for large bore arteriotomies: technical report.

    PubMed

    van Gils, Lennart; Daemen, Joost; Walters, Greg; Sorzano, Todd; Grintz, Todd; Nardone, Sam; Lenzen, Mattie; De Jaegere, Peter P T; Roubin, Gary; Van Mieghem, Nicolas M

    2016-09-18

    Catheter-based interventions have become a less invasive alternative to conventional surgical techniques for a wide array of cardiovascular diseases but often create large arteriotomies. A completely percutaneous technique is attractive as it may reduce the overall complication rate and procedure time. Currently, large bore arteriotomy closure relies on suture-based techniques. Access-site complications are not uncommon and often seem related to closure device failure. The MANTA VCD is a novel collagen-based closure device that specifically targets arteriotomies between 10 and 22 Fr. This technical report discusses the MANTA design concept, practical instructions for use and preliminary clinical experience.

  11. Plug-to-plug gas transfer system

    DOEpatents

    Poindexter, Allan M.

    1978-01-01

    A system for conducting a fluid from one component to another component of a nuclear reactor wherein at least one such component is a rotatable closure head plug capable of movement relative to the other component. The conducting system utilizes the annulus located between the components as a connecting passageway for the fluid.

  12. Plug and Play web-based visualization of mobile air monitoring data (Abstract)

    EPA Science Inventory

    EPA’s Real-Time Geospatial (RETIGO) Data Viewer web-based tool is a new program reducing the technical barrier to visualize and understand geospatial air data time series collected using wearable, bicycle-mounted, or vehicle-mounted air sensors. The RETIGO tool, with anticipated...

  13. Plug and Play web-based visualization of mobile air monitoring data (Abstract)

    EPA Science Inventory

    EPA’s Real-Time Geospatial (RETIGO) Data Viewer web-based tool is a new program reducing the technical barrier to visualize and understand geospatial air data time series collected using wearable, bicycle-mounted, or vehicle-mounted air sensors. The RETIGO tool, with anticipated...

  14. Modeling the Dilution of Static Droplet Arrays with Moving Plugs

    NASA Astrophysics Data System (ADS)

    Wang, William; Vanapalli, Siva

    2014-11-01

    Generation of arrays of immobilized microfluidic droplets with variation in reagent concentration from drop-to-drop is important for a variety of biochemical and screening assays. Recently our laboratory (Sun et al., Lab Chip, 2011) showed that such gradients in chemical concentration can be achieved by coalescing diluting plugs with drops immobilized in a microfluidic parking network. In this study, we investigate the key hydrodynamic mechanisms responsible for generation of concentration gradients in static droplet arrays, with the goal of predicting the dilution profiles observed in experiments. We conduct simulations based on a phenomenological model that includes diffusion, advection due to circulating flow within moving plugs, enhanced material transfer due to coalescence and break-up events, and geometry. Consistent with experiments, we find that the concentration profiles can exhibit segmentation between rows of parked droplets due to coalescence events occurring on alternating sides of the diluting plug. Tail-sweeping of wall material can increase concentrations in the plug tail. Also, coalescence and break-up events can significantly enhance dilution rates and ranges. Our results impact the design of SDAs for creating broad and predictable concentration gradients. NSF CAREER.

  15. Instructions for Installing digiBASE Plug-in on a Terra Harvest Controller

    DTIC Science & Technology

    2015-03-01

    be posted in an observation. Figure 4 shows a graph of the background radiation. The appendix contains a sample Extensible Markup Language (XML...A sample of the Extensible Markup Language (XML) document containing the graph of a spectrum is shown below. The image of the graph is base 64...Open Standards for Unattended Sensors PMT photomultiplier tube USB Universal Serial Bus XML Extensible Markup Language 14 1 DEFENSE

  16. Aquarius' Object-Oriented, Plug and Play Component-Based Flight Software

    NASA Technical Reports Server (NTRS)

    Murray, Alexander; Shahabuddin, Mohammad

    2013-01-01

    The Aquarius mission involves a combined radiometer and radar instrument in low-Earth orbit, providing monthly global maps of Sea Surface Salinity. Operating successfully in orbit since June, 2011, the spacecraft bus was furnished by the Argentine space agency, Comision Nacional de Actividades Espaciales (CONAE). The instrument, built jointly by NASA's Caltech/JPL and Goddard Space Flight Center, has been successfully producing expectation-exceeding data since it was powered on in August of 2011. In addition to the radiometer and scatterometer, the instrument contains an command & data-handling subsystem with a computer and flight software (FSW) that is responsible for managing the instrument, its operation, and its data. Aquarius' FSW is conceived and architected as a Component-based system, in which the running software consists of a set of Components, each playing a distinctive role in the subsystem, instantiated and connected together at runtime. Component architectures feature a well-defined set of interfaces between the Components, visible and analyzable at the architectural level (see [1]). As we will describe, this kind of an architecture offers significant advantages over more traditional FSW architectures, which often feature a monolithic runtime structure. Component-based software is enabled by Object-Oriented (OO) techniques and languages, the use of which again is not typical in space mission FSW. We will argue in this paper that the use of OO design methods and tools (especially the Unified Modeling Language), as well as the judicious usage of C++, are very well suited to FSW applications, and we will present Aquarius FSW, describing our methods, processes, and design, as a successful case in point.

  17. Aquarius' Object-Oriented, plug and play component-based flight software

    NASA Astrophysics Data System (ADS)

    Murray, A.; Shahabuddin, M.

    The Aquarius mission involves a combined radiometer and radar instrument in low-Earth orbit, providing monthly global maps of Sea Surface Salinity. Operating successfully in orbit since June, 2011, the spacecraft bus was furnished by the Argentine space agency, Comision Nacional de Actividades Espaciales (CONAE). The instrument, built jointly by NASA's Caltech/JPL and Goddard Space Flight Center, has been successfully producing expectation-exceeding data since it was powered on in August of 2011. In addition to the radiometer and scatterometer, the instrument contains an command & data-handling subsystem with a computer and flight software (FSW) that is responsible for managing the instrument, its operation, and its data. Aquarius' FSW is conceived and architected as a Component based system, in which the running software consists of a set of Components, each playing a distinctive role in the subsystem, instantiated and connected together at runtime. Component architectures feature a well-defined set of interfaces between the Components, visible and analyzable at the architectural level. As we will describe, this kind of an architecture offers significant advantages over more traditional FSW architectures, which often feature a monolithic runtime structure. Component-based software is enabled by Object-Oriented (OO) techniques and languages, the use of which again is not typical in space mission FSW. We will argue in this paper that the use of OO design methods and tools (especially the Unified Modeling Language), as well as the judicious usage of C++, are very well suited to FSW applications, and we will present Aquarius FSW, describing our methods, processes, and design, as a successful case in point.

  18. Multi-objective component sizing of a power-split plug-in hybrid electric vehicle powertrain using Pareto-based natural optimization machines

    NASA Astrophysics Data System (ADS)

    Mozaffari, Ahmad; Vajedi, Mahyar; Chehresaz, Maryyeh; Azad, Nasser L.

    2016-03-01

    The urgent need to meet increasingly tight environmental regulations and new fuel economy requirements has motivated system science researchers and automotive engineers to take advantage of emerging computational techniques to further advance hybrid electric vehicle and plug-in hybrid electric vehicle (PHEV) designs. In particular, research has focused on vehicle powertrain system design optimization, to reduce the fuel consumption and total energy cost while improving the vehicle's driving performance. In this work, two different natural optimization machines, namely the synchronous self-learning Pareto strategy and the elitism non-dominated sorting genetic algorithm, are implemented for component sizing of a specific power-split PHEV platform with a Toyota plug-in Prius as the baseline vehicle. To do this, a high-fidelity model of the Toyota plug-in Prius is employed for the numerical experiments using the Autonomie simulation software. Based on the simulation results, it is demonstrated that Pareto-based algorithms can successfully optimize the design parameters of the vehicle powertrain.

  19. Friction pull plug welding: chamfered heat sink pull plug design

    NASA Technical Reports Server (NTRS)

    Coletta, Edmond R. (Inventor); Cantrell, Mark A. (Inventor)

    2005-01-01

    The average strength of a pull plug weld is increased and weak bonding eliminated by providing a dual included angle at the top one third of the pull plug. Plugs using the included angle of the present invention had consistent high strength, no weak bonds and were substantially defect free. The dual angle of the pull plug body increases the heat and pressure of the weld in the region of the top one third of the plug. This allows the plug to form a tight high quality solid state bond. The dual angle was found to be successful in elimination of defects on both small and large plugs.

  20. Friction plug welding

    NASA Technical Reports Server (NTRS)

    Takeshita, Riki (Inventor); Hibbard, Terry L. (Inventor)

    2001-01-01

    Friction plug welding (FPW) usage is advantageous for friction stir welding (FSW) hole close-outs and weld repairs in 2195 Al--Cu--Li fusion or friction stir welds. Current fusion welding methods of Al--Cu--Li have produced welds containing varied defects. These areas are found by non-destructive examination both after welding and after proof testing. Current techniques for repairing typically small (<0.25) defects weaken the weldment, rely heavily on welders' skill, and are costly. Friction plug welding repairs increase strength, ductility and resistance to cracking over initial weld quality, without requiring much time or operator skill. Friction plug welding while pulling the plug is advantageous because all hardware for performing the weld can be placed on one side of the workpiece.

  1. Bellows sealed plug valve

    DOEpatents

    Dukas, Jr., Stephen J.

    1990-01-01

    A bellows sealed plug valve includes a valve body having an inlet passage and an outlet passage, a valve chamber between the inlet and outlet passages. A valve plug has substantially the same shape as the valve chamber and is rotatably disposed therein. A shaft is movable linearly in response to a signal from a valve actuator. A bellows is sealingly disposed between the valve chamber and the valve actuator and means are located between the bellows and the valve plug for converting linear movement of the shaft connected to the valve actuator to rotational movement of the plug. Various means are disclosed including helical thread mechanism, clevis mechanism and rack and pinion mechanism, all for converting linear motion to rotational motion.

  2. Clearance of a Mucus Plug

    NASA Astrophysics Data System (ADS)

    Bian, Shiyao; Zheng, Ying; Grotberg, James B.

    2008-11-01

    Mucus plugging may occur in pulmonary airways in asthma, chronic obstructive pulmonary disease (COPD) and cystic fibrosis. How to clear the mucus plug is essential and of fundamental importance. Mucus is known to have a yield stress and a mucus plug behaves like a solid plug when the applied stresses are below its yield stress τy. When the local stresses reaches τy, the plug starts to move and can be cleared out of the lung. It is then of great importance to examine how the mucus plug deforms and what is the minimum pressure required to initiate its movement. The present study used the finite element method (FEM) to study the stress distribution and deformation of a solid mucus plug under different pressure loads using ANSYS software. The maximum shear stress is found to occur near the rear transition region of the plug, which can lead to local yielding and flow. The critical pressure increases linearly with the plug length and asymptotes when the plug length is larger than the half channel width. Experimentally a mucus simulant is used to study the process of plug deformation and critical pressure difference required for the plug to propagate. Consistently, the fracture is observed to start at the rear transition region where the plug core connects the films. However, the critical pressure is observed to be dependent on not only the plug length but also the interfacial shape.

  3. Friction pull plug welding: chamfered heat sink pull plug design

    NASA Technical Reports Server (NTRS)

    Coletta, Edmond R. (Inventor); Cantrell, Mark A. (Inventor)

    2002-01-01

    Friction Pull Plug Welding (FPPW) is a solid state repair process for defects up to one inch in length, only requiring single sided tooling (OSL) for usage on flight hardware. Experimental data has shown that the mass of plug heat sink remaining above the top of the plate surface after a weld is completed (the plug heat sink) affects the bonding at the plug top. A minimized heat sink ensures complete bonding of the plug to the plate at the plug top. However, with a minimal heat sink three major problems can arise, the entire plug could be pulled through the plate hole, the central portion of the plug could be separated along grain boundaries, or the plug top hat can be separated from the body. The Chamfered Heat Sink Pull Plug Design allows for complete bonding along the ISL interface through an outside diameter minimal mass heat sink, while maintaining enough central mass in the plug to prevent plug pull through, central separation, and plug top hat separation.

  4. Plug nozzle propulsion system

    NASA Astrophysics Data System (ADS)

    Heald, Dan A.

    1992-02-01

    General Dynamics studied a vertical takeoff/vertical landing fully reusable single-stage-to-orbit (SSTO) concept for medium payload missions. A hydrogen oxygen plug nozzle main engine integrates well in the wide aft end. The principal driver for its selection was the promise of very high I(sub SP), 480 seconds vacuum. Further, preliminary design and analysis with Rocketdyne showed uncertainties and performance losses degrading this number to 467.4 seconds. Nevertheless, this SSTO configuration appears to be optimum for a plug nozzle main engine system. The merits and risks of this propulsion system are discussed. Continued development is recommended.

  5. The effects of select factors on the pour point, cloud point, and cold filter plugging point of soybean-, choice white grease-, and corn-based biodiesel blends

    NASA Astrophysics Data System (ADS)

    Jezierski, Kelly

    Soybean-, choice white grease-, and corn-based biodiesel from different sources blended with cold flow modifiers from 0.0% to 4.0% by weight were tested for cloud point (CP), cold filter plugging point (CFPP), and pour point (PP). The soybean-based blend that showed the best result was four weight percent of TechnolRTM B100 Biodiesel Cold Flow Improver used on B99 obtained from Wacker Oil, which resulted in a CP of -3°C, a PP of -18 °C, and a CFPP of -7°C. The TechnolRTM product slightly improved the CFPP of corn-based biodiesel when used at 2.0 weight percent, reducing it from -1°C to -4°C. No significant improvements were observed on choice white grease-based biodiesel blends. It was shown that, CFPP is not a linear function of the CP; the order of cold flow properties here occasionally follows the trend of the Cloud Point being greater than or equal to the Pour Point which is greater than or equal to the Cold Filter Plugging Point; and the source of the biodiesel also has a significant effect on the cold flow properties.

  6. PLUGGING AND UNPLUGGING OF WASTE TRANSFER PIPELINES

    SciTech Connect

    M.A. Ebadian, Ph.D.

    1999-01-01

    This project, which began in FY97, involves both the flow loop research on plugging and unplugging of waste transfer pipelines, and the large-scale industrial equipment test of plugging locating and unplugging technologies. In FY98, the related work was performed under the project name ''Mixing, Settling, and Pipe Unplugging of Waste Transfer Lines.'' The mixing, settling, and pipeline plugging and unplugging are critical to the design and maintenance of a waste transfer pipeline system, especially for the High-Level Waste (HLW) pipeline transfer. The major objective of this work is to recreate pipeline plugging conditions for equipment testing of plug locating and removal and to provide systematic operating data for modification of equipment design and enhancement of performance of waste transfer lines used at DOE sites. As the waste tank clean-out and decommissioning program becomes active at the DOE sites, there is an increasing potential that the waste slurry transfer lines will become plugged and unable to transport waste slurry from one tank to another or from the mixing tank to processing facilities. Transfer systems may potentially become plugged if the solids concentration of the material being transferred increases beyond the capability of the prime mover or if upstream mixing is inadequately performed. Plugging can occur due to the solids' settling in either the mixing tank, the pumping system, or the transfer lines. In order to enhance and optimize the slurry's removal and transfer, refined and reliable data on the mixing, sampling, and pipe unplugging systems must be obtained based on both laboratory-scale and simulated in-situ operating conditions.

  7. Playing with Plug-ins

    ERIC Educational Resources Information Center

    Thompson, Douglas E.

    2013-01-01

    In today's complex music software packages, many features can remain unexplored and unused. Software plug-ins--available in most every music software package, yet easily overlooked in the software's basic operations--are one such feature. In this article, I introduce readers to plug-ins and offer tips for purchasing plug-ins I have…

  8. Playing with Plug-ins

    ERIC Educational Resources Information Center

    Thompson, Douglas E.

    2013-01-01

    In today's complex music software packages, many features can remain unexplored and unused. Software plug-ins--available in most every music software package, yet easily overlooked in the software's basic operations--are one such feature. In this article, I introduce readers to plug-ins and offer tips for purchasing plug-ins I have…

  9. Vascular plugs - A key companion to Interventionists - 'Just Plug it'.

    PubMed

    Ramakrishnan, Sivasubramanian

    2015-01-01

    Vascular plugs are ideally suited to close extra-cardiac, high flowing vascular communications. The family of vascular plugs has expanded. Vascular plugs in general have a lower profile and the newer variants can be delivered even through a diagnostic catheter. These features make them versatile and easy to use. The Amplatzer vascular plugs are also used for closing intracardiac defects including coronary arterio-venous fistula and paravalvular leakage in an off-label fashion. In this review, the features of currently available vascular plugs are reviewed along with tips and tricks of using them in the cardiac catheterization laboratory. Copyright © 2015. Published by Elsevier B.V.

  10. Energy management of power-split plug-in hybrid electric vehicles based on simulated annealing and Pontryagin's minimum principle

    NASA Astrophysics Data System (ADS)

    Chen, Zheng; Mi, Chunting Chris; Xia, Bing; You, Chenwen

    2014-12-01

    In this paper, an energy management method is proposed for a power-split plug-in hybrid electric vehicle (PHEV). Through analyzing the PHEV powertrain, a series of quadratic equations are employed to approximate the vehicle's fuel-rate, using battery current as the input. Pontryagin's Minimum Principle (PMP) is introduced to find the battery current commands by solving the Hamiltonian function. Simulated Annealing (SA) algorithm is applied to calculate the engine-on power and the maximum current coefficient. Moreover, the battery state of health (SOH) is introduced to extend the application of the proposed algorithm. Simulation results verified that the proposed algorithm can reduce fuel-consumption compared to charge-depleting (CD) and charge-sustaining (CS) mode.

  11. Friction pull plug welding: top hat plug design

    NASA Technical Reports Server (NTRS)

    Coletta, Edmond R. (Inventor); Cantrell, Mark A. (Inventor)

    2001-01-01

    Friction Pull Plug Welding is a solid state repair process for defects up to one inch in length, only requiring single sided tooling, or outside skin line (OSL), for preferred usage on flight hardware. The most prevalent defect associated with Friction Pull Plug Welding (FPPW) was a top side or inside skin line (ISL) lack of bonding. Bonding was not achieved at this location due to the reduction in both frictional heat and welding pressure between the plug and plate at the end of the weld. Thus, in order to eliminate the weld defects and increase the plug strength at the plug `top` a small `hat` section is added to the pull plug for added frictional heating and pressure.

  12. Friction pull plug welding: top hat plug design

    NASA Technical Reports Server (NTRS)

    Coletta, Edmond R. (Inventor); Cantrell, Mark A. (Inventor)

    2002-01-01

    Friction Pull Plug Welding is a solid state repair process for defects up to one inch in length, only requiring single sided tooling, or outside skin line (OSL), for preferred usage on flight hardware. The most prevalent defect associated with Friction Pull Plug Welding (FPPW) was a top side or inside skin line (ISL) lack of bonding. Bonding was not achieved at this location due to the reduction in both frictional heat and welding pressure between the plug and plate at the end of the weld. Thus, in order to eliminate the weld defects and increase the plug strength at the plug `top` a small `hat` section is added to the pull plug for added frictional heating and pressure.

  13. Enhanced wall-plug efficiency in AlGaN-based deep-ultraviolet light-emitting diodes with uniform current spreading p-electrode structures

    NASA Astrophysics Data System (ADS)

    Hao, Guo-Dong; Taniguchi, Manabu; Tamari, Naoki; Inoue, Shin-ichiro

    2016-06-01

    The current crowding is an especially severe issue in AlGaN-based deep-ultraviolet (DUV) light-emitting diodes (LEDs) because of the low conductivity of the n-AlGaN cladding layer that has a high Al fraction. We theoretically investigated the improvement in internal quantum efficiency and total resistances in DUV-LEDs with an emission wavelength of 265 nm by a well-designed p-electrode geometry to produce uniform current spreading. As a result, the wall-plug efficiency was enhanced by a factor of 60% at an injection current of 350 mA in the designed uniform-current-spreading p-electrode LED when compared with an LED with a conventional cross-bar p-electrode pattern.

  14. AlGaAs ridge laser with 33% wall-plug efficiency at 100 °C based on a design of experiments approach

    NASA Astrophysics Data System (ADS)

    Fecioru, Alin; Boohan, Niall; Justice, John; Gocalinska, Agnieszka; Pelucchi, Emanuele; Gubbins, Mark A.; Mooney, Marcus B.; Corbett, Brian

    2016-04-01

    Upcoming applications for semiconductor lasers present limited thermal dissipation routes demanding the highest efficiency devices at high operating temperatures. This paper reports on a comprehensive design of experiment optimisation for the epitaxial layer structure of AlGaAs based 840 nm lasers for operation at high temperature (100 °C) using Technology Computer-Aided Design software. The waveguide thickness, Al content, doping level, and quantum well thickness were optimised. The resultant design was grown and the fabricated ridge waveguides were optimised for carrier injection and, at 100 °C, the lasers achieve a total power output of 28 mW at a current of 50 mA, a total slope efficiency 0.82 W A-1 with a corresponding wall-plug efficiency of 33%.

  15. Spark Plug Defects and Tests

    NASA Technical Reports Server (NTRS)

    Silsbee, F B; Loeb, L B; Sawyer, L G; Fonseca, E L; Dickinson, H C; Agnew, P G

    1920-01-01

    The successful operation of the spark plug depends to a large extent on the gas tightness of the plug. Part 1 of this report describes the method used for measuring the gas tightness of aviation spark plugs. Part 2 describes the methods used in testing the electrical conductivity of the insulation material when hot. Part 3 describes the testing of the cold dielectric strength of the insulation material, the resistance to mechanical shock, and the final engine test.

  16. Plug Loads Conservation Measures

    SciTech Connect

    Ian Metzger, Jesse Dean

    2010-12-31

    This software requires inputs of simple plug loads inventory information and calculates the energy and cost benefits of various retrofit opportunities. This tool includes energy conservation measures for: Vending Machine Misers, Delamp Vending Machine, Desktop to Laptop retrofit, CRT to LCD monitors retrofit, Computer Power Management Settings, and Energy Star Refrigerator retrofit. This tool calculates energy savings, demand reduction, cost savings, building life cycle costs including: simple payback, discounted payback, net-present value, and savings to investment ratio. In addition this tool also displays the environmental benefits of a project.

  17. Unbalanced-flow, fluid-mixing plug with metering capabilities

    NASA Technical Reports Server (NTRS)

    England, John Dwight (Inventor); Kelley, Anthony R. (Inventor); Van Buskirk, Paul D. (Inventor)

    2009-01-01

    A fluid mixer plug has holes formed therethrough such that a remaining portion is closed to fluid flow. The plug's inlet face defines a central circuit region and a ring-shaped region with the ring-shaped region including at least some of the plug's remaining portion so-closed to fluid flow. This remaining portion or closed region at each radius R of the ring shaped region satisfies a radius independent, flow-based relationship. Entry openings are defined in the plug's inlet face in correspondence with the holes. The entry openings define an open flow area at each radius of the ring-shaped region. The open flow area at each such radius satisfies the inverse of the flow-based relationship defining the closed regions of the plug.

  18. Polysaccharides and bacterial plugging

    SciTech Connect

    Fogler, H.S.

    1991-11-01

    Before any successful application of Microbial Enhanced Oil Recovery process can be realized, an understanding of the cells' transport and retentive mechanisms in porous media is needed. Cell transport differs from particle transport in their ability to produce polysaccharides, which are used by cells to adhere to surfaces. Cell injection experiments have been conducted using Leuconostoc cells to illustrate the importance of cellular polysaccharide production as a transport mechanism that hinders cell movement and plugs porous media. Kinetic studies of the Leuconostoc cells, carried out to further understand the plugging rates of porous media, have shown that the cells' growth rates are approximately equal when provided with monosaccharide (glucose and fructose) or sucrose. The only difference in cell metabolism is the production of dextran when sucrose is supplied as a carbon source. Experimentally it has also been shown that the cells' growth rate is weakly dependent upon the sucrose concentration in the media, and strongly dependent upon the concentration of yeast extract. The synthesis of cellular dextran has been found to lag behind cell generation, thus indicating that the cells need to reach maturity before they are capable of expressing the detransucrase enzyme and synthesizing insoluble dextran. Dextran yields were found to be dependent upon the sucrose concentration in the media. 10 refs., 9 figs., 9 tabs.

  19. Evolution of catalysts directed by genetic algorithms in a plug-based microfluidic device tested with oxidation of methane by oxygen.

    PubMed

    Kreutz, Jason E; Shukhaev, Anton; Du, Wenbin; Druskin, Sasha; Daugulis, Olafs; Ismagilov, Rustem F

    2010-03-10

    This paper uses microfluidics to implement genetic algorithms (GA) to discover new homogeneous catalysts using the oxidation of methane by molecular oxygen as a model system. The parameters of the GA were the catalyst, a cocatalyst capable of using molecular oxygen as the terminal oxidant, and ligands that could tune the catalytic system. The GA required running hundreds of reactions to discover and optimize catalyst systems of high fitness, and microfluidics enabled these numerous reactions to be run in parallel. The small scale and volumes of microfluidics offer significant safety benefits. The microfluidic system included methods to form diverse arrays of plugs containing catalysts, introduce gaseous reagents at high pressure, run reactions in parallel, and detect catalyst activity using an in situ indicator system. Platinum(II) was identified as an active catalyst, and iron(II) and the polyoxometalate H(5)PMo(10)V(2)O(40) (POM-V2) were identified as active cocatalysts. The Pt/Fe system was further optimized and characterized using NMR experiments. After optimization, turnover numbers of approximately 50 were achieved with approximately equal production of methanol and formic acid. The Pt/Fe system demonstrated the compatibility of iron with the entire catalytic cycle. This approach of GA-guided evolution has the potential to accelerate discovery in catalysis and other areas where exploration of chemical space is essential, including optimization of materials for hydrogen storage and CO(2) capture and modifications.

  20. Pulse-actuated fuel-injection spark plug

    DOEpatents

    Murray, Ian; Tatro, Clement A.

    1978-01-01

    A replacement spark plug for reciprocating internal combustion engines that functions as a fuel injector and as a spark plug to provide a "stratified-charge" effect. The conventional carburetor is retained to supply the main fuel-air mixture which may be very lean because of the stratified charge. The replacement plug includes a cylindrical piezoelectric ceramic which contracts to act as a pump whenever an ignition pulse is applied to a central rod through the ceramic. The rod is hollow at its upper end for receiving fuel, it is tapered along its lower length to act as a pump, and it is flattened at its lower end to act as a valve for fuel injection from the pump into the cylinder. The rod also acts as the center electrode of the plug, with the spark jumping from the plug base to the lower end of the rod to thereby provide spark ignition that has inherent proper timing with the fuel injection.

  1. Glovebox plug for glove changing

    DOEpatents

    Carlson, David O.; Shalkowski, Jr., Edward

    1992-01-01

    A plug for use in plugging a glove opening of a glovebox when the glove is eplaced. An inflated inner tube which is retained between flat plates mounted on a threaded rod is compressed in order to expand its diameter to equal that of the inside of the glove opening.

  2. Mechanics Model of Plug Welding

    NASA Technical Reports Server (NTRS)

    Zuo, Q. K.; Nunes, A. C., Jr.

    2015-01-01

    An analytical model has been developed for the mechanics of friction plug welding. The model accounts for coupling of plastic deformation (material flow) and thermal response (plastic heating). The model predictions of the torque, energy, and pull force on the plug were compared to the data of a recent experiment, and the agreements between predictions and data are encouraging.

  3. Rotating plug bearing and seal

    DOEpatents

    Wade, Elman E.

    1977-01-01

    A bearing and seal structure for nuclear reactors utilizing rotating plugs above the nuclear reactor vessel. The structure permits lubrication of bearings and seals of the rotating plugs without risk of the lubricant draining into the reactor vessel below. The structure permits lubrication by utilizing a rotating outer race bearing.

  4. 49 CFR 230.58 - Flue plugs.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... TRANSPORTATION STEAM LOCOMOTIVE INSPECTION AND MAINTENANCE STANDARDS Boilers and Appurtenances Injectors, Feedwater Pumps, and Flue Plugs § 230.58 Flue plugs. (a) When plugging is permitted. Flues greater than...

  5. 49 CFR 230.58 - Flue plugs.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... TRANSPORTATION STEAM LOCOMOTIVE INSPECTION AND MAINTENANCE STANDARDS Boilers and Appurtenances Injectors, Feedwater Pumps, and Flue Plugs § 230.58 Flue plugs. (a) When plugging is permitted. Flues greater than...

  6. 49 CFR 230.58 - Flue plugs.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... TRANSPORTATION STEAM LOCOMOTIVE INSPECTION AND MAINTENANCE STANDARDS Boilers and Appurtenances Injectors, Feedwater Pumps, and Flue Plugs § 230.58 Flue plugs. (a) When plugging is permitted. Flues greater than...

  7. 49 CFR 230.58 - Flue plugs.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... TRANSPORTATION STEAM LOCOMOTIVE INSPECTION AND MAINTENANCE STANDARDS Boilers and Appurtenances Injectors, Feedwater Pumps, and Flue Plugs § 230.58 Flue plugs. (a) When plugging is permitted. Flues greater than...

  8. 49 CFR 230.58 - Flue plugs.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... TRANSPORTATION STEAM LOCOMOTIVE INSPECTION AND MAINTENANCE STANDARDS Boilers and Appurtenances Injectors, Feedwater Pumps, and Flue Plugs § 230.58 Flue plugs. (a) When plugging is permitted. Flues greater than...

  9. Static Gas-Charging Plug

    NASA Technical Reports Server (NTRS)

    Indoe, William

    2012-01-01

    A gas-charging plug can be easily analyzed for random vibration. The design features two steeped O-rings in a radial configuration at two different diameters, with a 0.050-in. (.1.3-mm) diameter through-hole between the two O-rings. In the charging state, the top O-ring is engaged and sealing. The bottom O-ring outer diameter is not squeezed, and allows air to flow by it into the tank. The inner diameter is stretched to plug the gland diameter, and is restrained by the O-ring groove. The charging port bushing provides mechanical stop to restrain the plug during gas charge removal. It also prevents the plug from becoming a projectile when removing gas charge from the accumulator. The plug can easily be verified after installation to ensure leakage requirements are met.

  10. Borehole plugging materials development program, report 2

    SciTech Connect

    Gulick, C.W. Jr.; Boa, J.A. Jr.; Walley, D.M.; Buck, A.D.

    1980-02-01

    The data for 2 yr of grout mixtures durability studies developed for the borehole plugging program of the Nuclear Waste Isolation Pilot Plant (WIPP) are reported. In addition, data for 1 yr of durability studies of grout mixture field samples used to plug the ERDA No. 10 exploratory drill hole near the WIPP site are included. The grout samples and the data do not show any evidence of deterioration during the durability studies that include exposure to brine at both ambient and elevated temperatures. The data include strength, compressional wave velocity, dynamic modulus, expansion, weight change, porosity, permeability, bond strength, chemical analysis of cements, and petrographic examinations. The work was performed at the Concrete Division of the Structures Laboratory of the US Army Engineer Waterways Experiments Station (WES), Vicksburg, Mississippi. The work is continuing at WES.

  11. FY-1979 progress report. Hydrotransport plugging study.

    SciTech Connect

    Eyler, L.L.; Lombardo, N.J.

    1980-01-01

    The objective of the Hydrotransport Plugging Study is to investigate phenomena associated with predicting the onset and occurrence of plugging in pipeline transport of coal. This study addresses large particle transport plugging phenomena that may be encountered in run-of-mine operations. The project is being conducted in four tasks: review and analysis of current capabilities and available data, analytical modeling, experimental investigations, and unplugging and static start-up. This report documents work completed in FY-1979 as well as work currently in progress. A review of currently available prediction methods was completed. Applicability of the methods to large particle hydrotransport and the prediction of plugging was evaluated. It was determined that available models were inadequate, either because they are empirical and tuned to a given solid or because they are simplified analytical models incapable of accounting for a wide range of parameters. Complicated regression curve fit models lacking a physical basis cannot be extrapolated with confidence. Several specific conclusions were reached: Recent developments in mechanistic modeling, describing flow conditions at the limit of stationary deposition, provide the best basis for prediction and extrapolation of large particle flow. Certain modeled phenomena require further analytical and experimental investigation to improve confidence levels. Experimental work needs to be performed to support modeling and to provide an adequate data base for comparison purposes. No available model permits treatment of solids mixtures such as coal and rock.

  12. Chemical Transformation System: Cloud Based ...

    EPA Pesticide Factsheets

    Integrated Environmental Modeling (IEM) systems that account for the fate/transport of organics frequently require physicochemical properties as well as transformation products. A myriad of chemical property databases exist but these can be difficult to access and often do not contain the proprietary chemicals that environmental regulators must consider. We are building the Chemical Transformation System (CTS) to facilitate model parameterization and analysis. CTS integrates a number of physicochemical property calculators into the system including EPI Suite, SPARC, TEST and ChemAxon. The calculators are heterogeneous in their scientific methodologies, technology implementations and deployment stacks. CTS also includes a chemical transformation processing engine that has been loaded with reaction libraries for human biotransformation, abiotic reduction and abiotic hydrolysis. CTS implements a common interface for the disparate calculators accepting molecular identifiers (SMILES, IUPAC, CAS#, user-drawn molecule) before submission for processing. To make the system as accessible as possible and provide a consistent programmatic interface, we wrapped the calculators in a standardized RESTful Application Programming Interface (API) which makes it capable of servicing a much broader spectrum of clients without constraints to interoperability such as operating system or programming language. CTS is hosted in a shared cloud environment, the Quantitative Environmental

  13. Towards a Multifunctional Electrochemical Sensing and Niosome Generation Lab-on-Chip Platform Based on a Plug-and-Play Concept

    PubMed Central

    Kara, Adnane; Rouillard, Camille; Mathault, Jessy; Boisvert, Martin; Tessier, Frédéric; Landari, Hamza; Melki, Imene; Laprise-Pelletier, Myriam; Boisselier, Elodie; Fortin, Marc-André; Boilard, Eric; Greener, Jesse; Miled, Amine

    2016-01-01

    In this paper, we present a new modular lab on a chip design for multimodal neurotransmitter (NT) sensing and niosome generation based on a plug-and-play concept. This architecture is a first step toward an automated platform for an automated modulation of neurotransmitter concentration to understand and/or treat neurodegenerative diseases. A modular approach has been adopted in order to handle measurement or drug delivery or both measurement and drug delivery simultaneously. The system is composed of three fully independent modules: three-channel peristaltic micropumping system, a three-channel potentiostat and a multi-unit microfluidic system composed of pseudo-Y and cross-shape channels containing a miniature electrode array. The system was wirelessly controlled by a computer interface. The system is compact, with all the microfluidic and sensing components packaged in a 5 cm × 4 cm × 4 cm box. Applied to serotonin, a linear calibration curve down to 0.125 mM, with a limit of detection of 31 μM was collected at unfunctionalized electrodes. Added sensitivity and selectivity was achieved by incorporating functionalized electrodes for dopamine sensing. Electrode functionalization was achieved with gold nanoparticles and using DNA and o-phenylene diamine polymer. The as-configured platform is demonstrated as a central component toward an “intelligent” drug delivery system based on a feedback loop to monitor drug delivery. PMID:27240377

  14. Towards a Multifunctional Electrochemical Sensing and Niosome Generation Lab-on-Chip Platform Based on a Plug-and-Play Concept.

    PubMed

    Kara, Adnane; Rouillard, Camille; Mathault, Jessy; Boisvert, Martin; Tessier, Frédéric; Landari, Hamza; Melki, Imene; Laprise-Pelletier, Myriam; Boisselier, Elodie; Fortin, Marc-André; Boilard, Eric; Greener, Jesse; Miled, Amine

    2016-05-28

    In this paper, we present a new modular lab on a chip design for multimodal neurotransmitter (NT) sensing and niosome generation based on a plug-and-play concept. This architecture is a first step toward an automated platform for an automated modulation of neurotransmitter concentration to understand and/or treat neurodegenerative diseases. A modular approach has been adopted in order to handle measurement or drug delivery or both measurement and drug delivery simultaneously. The system is composed of three fully independent modules: three-channel peristaltic micropumping system, a three-channel potentiostat and a multi-unit microfluidic system composed of pseudo-Y and cross-shape channels containing a miniature electrode array. The system was wirelessly controlled by a computer interface. The system is compact, with all the microfluidic and sensing components packaged in a 5 cm × 4 cm × 4 cm box. Applied to serotonin, a linear calibration curve down to 0.125 mM, with a limit of detection of 31 μ M was collected at unfunctionalized electrodes. Added sensitivity and selectivity was achieved by incorporating functionalized electrodes for dopamine sensing. Electrode functionalization was achieved with gold nanoparticles and using DNA and o-phenylene diamine polymer. The as-configured platform is demonstrated as a central component toward an "intelligent" drug delivery system based on a feedback loop to monitor drug delivery.

  15. Guidable pipe plug

    DOEpatents

    Glassell, Richard L.; Babcock, Scott M.; Lewis, Benjamin E.

    2001-01-01

    A plugging device for closing an opening defined by an end of a pipe with sealant comprises a cap, an extension, an inner seal, a guide, and at least one stop. The cap has an inner surface which defines a chamber adapted for retaining the sealant. The chamber is dimensioned slightly larger than the end so as to receive the end. The chamber and end define a gap therebetween. The extension has a distal end and is attached to the inner surface opposite the distal end. The inner seal is attached to the extension and sized larger than the opening. The guide is positioned forward of the inner seal and attached to the distal end. The guide is also dimensioned to be inserted into the opening. The stop is attached to the extender, and when the stop is disposed in the pipe, the stop is movable with respect to the conduit in one direction and also prevents misalignment of the cap with the pipe. A handle can also be included to allow the cap to be positioned robotically.

  16. Plug cluster module demonstration

    NASA Technical Reports Server (NTRS)

    Rousar, D. C.

    1978-01-01

    The low pressure, film cooled rocket engine design concept developed during two previous ALRC programs was re-evaluated for application as a module for a plug cluster engine capable of performing space shuttle OTV missions. The nominal engine mixture ratio was 5.5 and the engine life requirements were 1200 thermal cycles and 10 hours total operating life. The program consisted of pretest analysis; engine tests, performed using residual components; and posttest analysis. The pretest analysis indicated that operation of the operation of the film cooled engine at O/F = 5.5 was feasible. During the engine tests, steady state wall temperature and performance measurement were obtained over a range of film cooling flow rates, and the durability of the engine was demonstrated by firing the test engine 1220 times at a nominal performance ranging from 430 - 432 seconds. The performance of the test engine was limited by film coolant sleeve damage which had occurred during previous testing. The post-test analyses indicated that the nominal performance level can be increased to 436 seconds.

  17. Friction Plug Weld Repair Geometric Innovations

    NASA Technical Reports Server (NTRS)

    Coletta, Edmond R.; Cantrell, Mark A.; McCool, A. (Technical Monitor)

    2000-01-01

    A viewgraph presentation outlines the fundamentals of friction plug welding. A process overview is given for friction push plug welding, including different uses and strengths of push plug welding. Details are given for friction pull plug welding, including welding parameters, details on observed defects, expected benefits, and test results.

  18. 49 CFR 230.59 - Fusible plugs.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ..., DEPARTMENT OF TRANSPORTATION STEAM LOCOMOTIVE INSPECTION AND MAINTENANCE STANDARDS Boilers and Appurtenances Fusible Plugs § 230.59 Fusible plugs. If boilers are equipped with fusible plugs, the plugs shall be removed and cleaned of scale each time the boiler is washed but not less frequently than during every...

  19. Chemical Sensors Based on Cyclodextrin Derivatives.

    PubMed

    Ogoshi, Tomoki; Harada, Akira

    2008-08-25

    This review focuses on chemical sensors based on cyclodextrin (CD) derivatives. This has been a field of classical interest, and is now of current interest for numerous scientists. First, typical chemical sensors using chromophore appended CDs are mentioned. Various "turn-off" and "turn-on" fluorescent chemical sensors, in which fluorescence intensity was decreased or increased by complexation with guest molecules, respectively, were synthesized. Dye modified CDs and photoactive metal ion-ligand complex appended CDs, metallocyclodextrins, were also applied for chemical sensors. Furthermore, recent novel approaches to chemical sensing systems using supramolecular structures such as CD dimers, trimers and cooperative binding systems of CDs with the other macrocycle [2]rotaxane and supramolecular polymers consisting of CD units are mentioned. New chemical sensors using hybrids of CDs with p-conjugated polymers, peptides, DNA, nanocarbons and nanoparticles are also described in this review.

  20. Chemical Sensors Based on Cyclodextrin Derivatives

    PubMed Central

    Ogoshi, Tomoki; Harada, Akira

    2008-01-01

    This review focuses on chemical sensors based on cyclodextrin (CD) derivatives. This has been a field of classical interest, and is now of current interest for numerous scientists. First, typical chemical sensors using chromophore appended CDs are mentioned. Various “turn-off” and “turn-on” fluorescent chemical sensors, in which fluorescence intensity was decreased or increased by complexation with guest molecules, respectively, were synthesized. Dye modified CDs and photoactive metal ion-ligand complex appended CDs, metallocyclodextrins, were also applied for chemical sensors. Furthermore, recent novel approaches to chemical sensing systems using supramolecular structures such as CD dimers, trimers and cooperative binding systems of CDs with the other macrocycle [2]rotaxane and supramolecular polymers consisting of CD units are mentioned. New chemical sensors using hybrids of CDs with π-conjugated polymers, peptides, DNA, nanocarbons and nanoparticles are also described in this review. PMID:27873795

  1. Analysis of plug-in hybrid electric vehicles' utility factors using GPS-based longitudinal travel data

    DOE PAGES

    Wu, Xing; Aviquzzaman, Md.; Lin, Zhenhong

    2015-05-29

    The benefit of using a PHEV comes from its ability to substitute gasoline with electricity in operation. Defined as the proportion of distance traveled in the electric mode, the utility factor (UF) depends mostly on the battery capacity, but also on many other factors, such as travel pattern and recharging pattern. Conventionally, the UFs are calculated based on the daily vehicle miles traveled (DVMT) by assuming motorists leave home in the morning with a full battery, and no charge occurs before returning home in the evening. Such an assumption, however, ignores the impact of the heterogeneity in both travel andmore » charging behavior, such as going back home more than once in a day, the impact of available charging time, and the price of gasoline. In addition, the conventional UFs are based on the National Household Travel Survey (NHTS) data, which are one-day travel data of each sample vehicle. A motorist's daily distance variation is ignored. This paper employs the GPS-based longitudinal travel data (covering 3-18 months) collected from 403 vehicles in the Seattle metropolitan area to investigate how such travel and charging behavior affects UFs. To do this, for each vehicle, we organized trips to a series of home and work related tours. The UFs based on the DVMT are found close to those based on home-to-home tours. However, it is seen that the workplace charge opportunities significantly increase UFs if the CD range is no more than 40 miles.« less

  2. Analysis of plug-in hybrid electric vehicles' utility factors using GPS-based longitudinal travel data

    SciTech Connect

    Wu, Xing; Aviquzzaman, Md.; Lin, Zhenhong

    2015-05-29

    The benefit of using a PHEV comes from its ability to substitute gasoline with electricity in operation. Defined as the proportion of distance traveled in the electric mode, the utility factor (UF) depends mostly on the battery capacity, but also on many other factors, such as travel pattern and recharging pattern. Conventionally, the UFs are calculated based on the daily vehicle miles traveled (DVMT) by assuming motorists leave home in the morning with a full battery, and no charge occurs before returning home in the evening. Such an assumption, however, ignores the impact of the heterogeneity in both travel and charging behavior, such as going back home more than once in a day, the impact of available charging time, and the price of gasoline. In addition, the conventional UFs are based on the National Household Travel Survey (NHTS) data, which are one-day travel data of each sample vehicle. A motorist's daily distance variation is ignored. This paper employs the GPS-based longitudinal travel data (covering 3-18 months) collected from 403 vehicles in the Seattle metropolitan area to investigate how such travel and charging behavior affects UFs. To do this, for each vehicle, we organized trips to a series of home and work related tours. The UFs based on the DVMT are found close to those based on home-to-home tours. However, it is seen that the workplace charge opportunities significantly increase UFs if the CD range is no more than 40 miles.

  3. Ranking chemicals based on chronic toxicity data.

    PubMed

    De Rosa, C T; Stara, J F; Durkin, P R

    1985-12-01

    During the past 3 years, EPA's ECAO/Cincinnati has developed a method to rank chemicals based on chronic toxicity data. This ranking system reflects two primary attributes of every chemical: the minimum effective dose and the type of effect elicited at that dose. The purpose for developing this chronic toxicity ranking system was to provide the EPA with the technical background required to adjust the RQs of hazardous substances designated in Section 101(14) of CERCLA or "Superfund." This approach may have applications to other areas of interest to the EPA and other regulatory agencies where ranking of chemicals based on chronic toxicity is desired.

  4. Plug-and-play Integration of dual-model based Knowledge Artefacts into an Open Source Ehr System.

    PubMed

    Krexner, Rabea; Duftschmid, Georg

    2014-01-01

    In this paper we present our experiences with extending an existing approach for an archetype-compliant collection and export of data according to the openEHR specifications within the open source EHR system OpenMRS. It allows an automatic generation of forms from templates, which were introduced by openEHR as an extension of the dual-model approach. Data entered in these forms can be exported in form of standardized EHR extracts. The use of templates allowed us to solve problems reported for the original archetype-based version of the approach, which were caused by the high optionality within archetypes.

  5. Modeling of plug-in electric vehicle travel patterns and charging load based on trip chain generation

    NASA Astrophysics Data System (ADS)

    Wang, Dai; Gao, Junyu; Li, Pan; Wang, Bin; Zhang, Cong; Saxena, Samveg

    2017-08-01

    Modeling PEV travel and charging behavior is the key to estimate the charging demand and further explore the potential of providing grid services. This paper presents a stochastic simulation methodology to generate itineraries and charging load profiles for a population of PEVs based on real-world vehicle driving data. In order to describe the sequence of daily travel activities, we use the trip chain model which contains the detailed information of each trip, namely start time, end time, trip distance, start location and end location. A trip chain generation method is developed based on the Naive Bayes model to generate a large number of trips which are temporally and spatially coupled. We apply the proposed methodology to investigate the multi-location charging loads in three different scenarios. Simulation results show that home charging can meet the energy demand of the majority of PEVs in an average condition. In addition, we calculate the lower bound of charging load peak on the premise of lowest charging cost. The results are instructive for the design and construction of charging facilities to avoid excessive infrastructure.

  6. CDF End Plug calorimeter Upgrade Project

    SciTech Connect

    Apollinari, G.; de Barbaro, P.; Mishina, M.

    1994-01-01

    We report on the status of the CDF End Plug Upgrade Project. In this project, the CDF calorimeters in the end plug and the forward regions will be replaced by a single scintillator based calorimeter. After an extensive R&D effort on the tile/fiber calorimetry, we have now advanced to a construction phase. We review the results of the R&D leading to the final design of the calorimeters and the development of tooling devised for this project. The quality control program of the production of the electromagnetic and hadronic calorimeters is described. A shower maximum detector for the measurement of the shower centroid and the shower profile of electrons, {gamma} and {pi}{sup 0} has been designed. Its performance requirements, R&D results and mechanical design are discussed.

  7. A plug-and-play approach to antibody-based therapeutics via a chemoselective dual click strategy

    PubMed Central

    Maruani, Antoine; Smith, Mark E.B.; Miranda, Enrique; Chester, Kerry A.; Chudasama, Vijay; Caddick, Stephen

    2015-01-01

    Although recent methods for the engineering of antibody–drug conjugates (ADCs) have gone some way to addressing the challenging issues of ADC construction, significant hurdles still remain. There is clear demand for the construction of novel ADC platforms that offer greater stability, homogeneity and flexibility. Here we describe a significant step towards a platform for next-generation antibody-based therapeutics by providing constructs that combine site-specific modification, exceptional versatility and high stability, with retention of antibody binding and structure post-modification. The relevance of the work in a biological context is also demonstrated in a cytotoxicity assay and a cell internalization study with HER2-positive and -negative breast cancer cell lines. PMID:25824906

  8. Laser-based detection of chemical contraband

    NASA Astrophysics Data System (ADS)

    Clemmer, Robert G.; Kelly, James F.; Martin, Steven W.; Mong, Gary M.; Sharpe, Steven W.

    1997-02-01

    The goal of our work is tow fold; 1) develop a portable and rapid laser based air sampler for detection of specific chemical contraband and 2) compile a spectral data base in both the near- and mid-IR of sufficiently high quality to be useful for gas phase spectroscopic identification of chemical contraband. During the synthesis or 'cooking' of many illicit chemical substances, relatively high concentrations of volatile solvents, chemical precursors and byproducts are unavoidably released to the atmosphere. In some instances, the final product may have sufficient vapor pressure to be detectable in the surrounding air. The detection of a single high-value effluent or the simultaneous detection of two or more low-value effluents can be used as reliable indicators of a nearby clandestine cooking operation. The designation of high- versus low-value effluent reflects both the commercial availability and legitimate usage of a specific chemical. This paper will describe PNNL's progress and efforts towards the development of a portable laser based air sampling system for the detection of clandestine manufacturing of methamphetamine. Although our current efforts ar focused on methamphetamine, we see no fundamental limitations on detection of other forms of chemical contraband manufacturing. This also includes the synthesis of certain classes of chemical weapons that have recently been deployed by terrorist groups.

  9. Plug engine systems for future launch vehicle applications

    NASA Astrophysics Data System (ADS)

    Immich, H.; Parsley, R. C.

    1993-06-01

    Based on improved viability resulting from modern analysis techniques, plug nozzle rocket engines are once again being investigated with respect to advanced launch vehicle concepts. The advantage of these engines is the external expansion, which self-adapts to external pressure variation, as well as the short compact design for high expansion ratios. This paper describes feasible design options ranging from a plug nozzle engine with an annular combustion chamber to a segmented modular design, to the integration of a number of conventional engines around a common plug. The advantages and disadvantages of these options are discussed for a range of potential applications including single-stage-to-orbit (SSTO) vehicles, as well as upper stage vehicles such as the second stage of the SAeNGER HTOL launch vehicle concept. Also included is a discussion of how maturing computational fluid dynamic (CFD) modeling techniques could significantly reduce installed performance uncertainties, reducing plug engine development risk.

  10. Bentonite borehole plug flow testing with five water types

    SciTech Connect

    Gaudette, M.V.; Daemen, J.J.K.

    1988-04-01

    The hydraulic conductivity has been determined of plugs constructed with commercial precompressed bentonite pellets. Bentonite has been hydrated and tested with waters of five different chemical compositions, including one groundwater (Ogallala aquifer, Texas). The groundwater contained a significant amount of solids: waters prepared in the laboratory did not. Prepared waters used for testing included distilled water, a high (1000 ppM) and a low (45 ppM) calcium solution, and a 39 ppM sodium water. Uncompacted plugs were constructed by dropping bentonite tablets into waterfilled cylinders, or by mixing powdered bentonite with preselected water volumes in order to obtain controlled initial water contents. The hydraulic conductivity of all plugs tested with all waters would result in a classification of practically impervious, by conventional soil mechanics standards. Variations of several orders of magnitude of the hydraulic conductivity are observed.

  11. Classification of Chemicals Based On Structured Toxicity ...

    EPA Pesticide Factsheets

    Thirty years and millions of dollars worth of pesticide registration toxicity studies, historically stored as hardcopy and scanned documents, have been digitized into highly standardized and structured toxicity data within the Toxicity Reference Database (ToxRefDB). Toxicity-based classifications of chemicals were performed as a model application of ToxRefDB. These endpoints will ultimately provide the anchoring toxicity information for the development of predictive models and biological signatures utilizing in vitro assay data. Utilizing query and structured data mining approaches, toxicity profiles were uniformly generated for greater than 300 chemicals. Based on observation rate, species concordance and regulatory relevance, individual and aggregated effects have been selected to classify the chemicals providing a set of predictable endpoints. ToxRefDB exhibits the utility of transforming unstructured toxicity data into structured data and, furthermore, into computable outputs, and serves as a model for applying such data to address modern toxicological problems.

  12. Susceptibility based upon Chemical Interaction with Disease ...

    EPA Pesticide Factsheets

    One of the challenges facing toxicology and risk assessment is that numerous host and environmental factors may modulate vulnerability and risk. An area of increasing interest is the potential for chemicals to interact with background aging and disease processes, an interaction that may yield cumulative damage, altered chemical potency, and increased disease incidence. This review outlines the interactions possible between chemicals and background disease and identifies the type of information needed to evaluate such interactions. Key among these is the existence of a clinically relevant and easy to measure biomarker of disease risk which allows the identification of vulnerable individuals based upon the level of risk biomarker. The impact of toxic chemicals on this biomarker can then be used to predict how the chemical modifies disease risk as long as related mechanistic and toxicological data are consistent with toxicant effect on the disease process. Several case studies are briefly presented which describe the toxic chemical, the clinical biomarker and the impacted disease including: fine particulate matter/decreased heart rate variability/increased cardiopulmonary events; cadmium/decreased glomerular filtration rate/increased chronic kidney disease; methyl mercury/decreased paraoxonase-1/increased cardiovascular risk; trichloroethylene/increased anti-nuclear antibody/autoimmunity; dioxin/increased CYP1A1/hypertension. These case studies point o

  13. Susceptibility based upon Chemical Interaction with Disease ...

    EPA Pesticide Factsheets

    One of the challenges facing toxicology and risk assessment is that numerous host and environmental factors may modulate vulnerability and risk. An area of increasing interest is the potential for chemicals to interact with background aging and disease processes, an interaction that may yield cumulative damage, altered chemical potency, and increased disease incidence. This review outlines the interactions possible between chemicals and background disease and identifies the type of information needed to evaluate such interactions. Key among these is the existence of a clinically relevant and easy to measure biomarker of disease risk which allows the identification of vulnerable individuals based upon the level of risk biomarker. The impact of toxic chemicals on this biomarker can then be used to predict how the chemical modifies disease risk as long as related mechanistic and toxicological data are consistent with toxicant effect on the disease process. Several case studies are briefly presented which describe the toxic chemical, the clinical biomarker and the impacted disease including: fine particulate matter/decreased heart rate variability/increased cardiopulmonary events; cadmium/decreased glomerular filtration rate/increased chronic kidney disease; methyl mercury/decreased paraoxonase-1/increased cardiovascular risk; trichloroethylene/increased anti-nuclear antibody/autoimmunity; dioxin/increased CYP1A1/hypertension. These case studies point o

  14. Hot cell shield plug extraction apparatus

    DOEpatents

    Knapp, Philip A.; Manhart, Larry K.

    1995-01-01

    An apparatus is provided for moving shielding plugs into and out of holes in concrete shielding walls in hot cells for handling radioactive materials without the use of external moving equipment. The apparatus provides a means whereby a shield plug is extracted from its hole and then swung approximately 90 degrees out of the way so that the hole may be accessed. The apparatus uses hinges to slide the plug in and out and to rotate it out of the way, the hinge apparatus also supporting the weight of the plug in all positions, with the load of the plug being transferred to a vertical wall by means of a bolting arrangement.

  15. Chemical Sensors Based on Optical Ring Resonators

    NASA Technical Reports Server (NTRS)

    Homer, Margie; Manfreda, Allison; Mansour, Kamjou; Lin, Ying; Ksendzov, Alexander

    2005-01-01

    Chemical sensors based on optical ring resonators are undergoing development. A ring resonator according to this concept is a closed-circuit dielectric optical waveguide. The outermost layer of this waveguide, analogous to the optical cladding layer on an optical fiber, is a made of a polymer that (1) has an index of refraction lower than that of the waveguide core and (2) absorbs chemicals from the surrounding air. The index of refraction of the polymer changes with the concentration of absorbed chemical( s). The resonator is designed to operate with relatively strong evanescent-wave coupling between the outer polymer layer and the electromagnetic field propagating along the waveguide core. By virtue of this coupling, the chemically induced change in index of refraction of the polymer causes a measurable shift in the resonance peaks of the ring. In a prototype that has been used to demonstrate the feasibility of this sensor concept, the ring resonator is a dielectric optical waveguide laid out along a closed path resembling a racetrack (see Figure 1). The prototype was fabricated on a silicon substrate by use of standard techniques of thermal oxidation, chemical vapor deposition, photolithography, etching, and spin coating. The prototype resonator waveguide features an inner cladding of SiO2, a core of SixNy, and a chemical-sensing outer cladding of ethyl cellulose. In addition to the ring Chemical sensors based on optical ring resonators are undergoing development. A ring resonator according to this concept is a closed-circuit dielectric optical waveguide. The outermost layer of this waveguide, analogous to the optical cladding layer on an optical fiber, is a made of a polymer that (1) has an index of refraction lower than that of the waveguide core and (2) absorbs chemicals from the surrounding air. The index of refraction of the polymer changes with the concentration of absorbed chemical( s). The resonator is designed to operate with relatively strong

  16. A rule-based expert system for chemical prioritization using effects-based chemical categories.

    PubMed

    Schmieder, P K; Kolanczyk, R C; Hornung, M W; Tapper, M A; Denny, J S; Sheedy, B R; Aladjov, H

    2014-01-01

    A rule-based expert system (ES) was developed to predict chemical binding to the estrogen receptor (ER) patterned on the research approaches championed by Gilman Veith to whom this article and journal issue are dedicated. The ERES was built to be mechanistically transparent and meet the needs of a specific application, i.e. predict for all chemicals within two well-defined inventories (industrial chemicals used as pesticide inerts and antimicrobial pesticides). These chemicals all lack structural features associated with high affinity binders and thus any binding should be low affinity. Similar to the high-quality fathead minnow database upon which Veith QSARs were built, the ERES was derived from what has been termed gold standard data, systematically collected in assays optimized to detect even low affinity binding and maximizing confidence in the negatives determinations. The resultant logic-based decision tree ERES, determined to be a robust model, contains seven major nodes with multiple effects-based chemicals categories within each. Predicted results are presented in the context of empirical data within local chemical structural groups facilitating informed decision-making. Even using optimized detection assays, the ERES applied to two inventories of >600 chemicals resulted in only ~5% of the chemicals predicted to bind ER.

  17. Plug-Volume-Modulated Dilution Generator for Flask-Free Chemistry.

    PubMed

    Liu, Pei-Han; Urban, Pawel L

    2016-12-06

    Dilution is one of the common chemical procedures which are carried out in all chemistry laboratories-to prepare standard solutions with different concentrations for assay calibration, and to reduce matrix effects while handling complex samples. Yet dilution is mostly performed manually using large-volume manual liquid-handling tools (volumetric flasks, graduated cylinders, and pipettes). Here we describe a simple continuous and automated method of diluting complex samples and stock solutions using an Arduino-based control unit. The proposed plug-volume-modulation approach relies on continuous introduction of short plugs of samples separated with short plugs of solvent. The train of sample pulses is generated by opening and closing two pinch valves interchangeably, so that either sample or solvent can enter the mixing zone (T-junction). The plugs of sample and solvent are pulled along a transfer flow line by a peristaltic pump. They mix due to advection, turbulence, and diffusion. The effluent of the flow line supplies diluted samples with well-defined dilution factors. The desired dilution factor is programmed by setting the duration of sample and solvent pulses injected in every cycle. The sample duty cycle effectively determines the dilution factor. Initially, we verified the quality of the generated diluted samples by off-line and online optical detection. We further demonstrated the usefulness of this dilution generator when selecting the optimum dilution factors for complex samples analyzed by direct infusion electrospray ionization mass spectrometry. The proposed method eliminates conventional glassware from dilution steps. Hence, it can readily be incorporated into automated analytical systems.

  18. Reduced-dimension model of liquid plug propagation in tubes

    NASA Astrophysics Data System (ADS)

    Fujioka, Hideki; Halpern, David; Ryans, Jason; Gaver, Donald P.

    2016-09-01

    We investigate the flow resistance caused by the propagation of a liquid plug in a liquid-lined tube and propose a simple semiempirical formula for the flow resistance as a function of the plug length, the capillary number, and the precursor film thickness. These formulas are based on computational investigations of three key contributors to the plug resistance: the front meniscus, the plug core, and the rear meniscus. We show that the nondimensional flow resistance in the front meniscus varies as a function of the capillary number and the precursor film thickness. For a fixed capillary number, the flow resistance increases with decreasing precursor film thickness. The flow in the core region is modeled as Poiseuille flow and the flow resistance is a linear function of the plug length. For the rear meniscus, the flow resistance increases monotonically with decreasing capillary number. We investigate the maximum mechanical stress behavior at the wall, such as the wall pressure gradient, the wall shear stress, and the wall shear stress gradient, and propose empirical formulas for the maximum stresses in each region. These wall mechanical stresses vary as a function of the capillary number: For semi-infinite fingers of air propagating through pulmonary airways, the epithelial cell damage correlates with the pressure gradient. However, for shorter plugs the front meniscus may provide substantial mechanical stresses that could modulate this behavior and provide a major cause of cell injury when liquid plugs propagate in pulmonary airways. Finally, we propose that the reduced-dimension models developed herein may be of importance for the creation of large-scale models of interfacial flows in pulmonary networks, where full computational fluid dynamics calculations are untenable.

  19. Damage Tolerance Assessment of Friction Pull Plug Welds

    NASA Technical Reports Server (NTRS)

    McGill, Preston; Burkholder, Jonathan

    2012-01-01

    Friction stir welding is a solid state welding process developed and patented by The Welding Institute in Cambridge, England. Friction stir welding has been implemented in the aerospace industry in the fabrication of longitudinal welds in pressurized cryogenic propellant tanks. As the industry looks to implement friction stir welding in circumferential welds in pressurized cryogenic propellant tanks, techniques to close out the termination hole associated with retracting the pin tool are being evaluated. Friction pull plug welding is under development as a one means of closing out the termination hole. A friction pull plug weld placed in a friction stir weld results in a non-homogenous weld joint where the initial weld, plug weld, their respective heat affected zones and the base metal all interact. The welded joint is a composite, plastically deformed material system with a complex residual stress field. In order to address damage tolerance concerns associated with friction plug welds in safety critical structures, such as propellant tanks, nondestructive inspection and proof testing may be required to screen hardware for mission critical defects. The efficacy of the nondestructive evaluation or the proof test is based on an assessment of the critical flaw size in the test or service environments. Test data relating residual strength capability to flaw size in two aluminum alloy friction plug weld configurations is presented.

  20. Comparison of Experimental Data and Computations Fluid Dynamics Analysis for a Three Dimensional Linear Plug Nozzle

    NASA Technical Reports Server (NTRS)

    Ruf, J. H.; Hagemann, G.; Immich, H.

    2003-01-01

    A three dimensional linear plug nozzle of area ratio 12.79 was designed by EADS Space Transportation (former Astrium Space Infrastructure). The nozzle was tested within the German National Technology Program 'LION' in a cold air wind tunnel by TU Dresden. The experimental hardware and test conditions are described. Experimental data was obtained for the nozzle without plug side wall fences at a nozzle pressure ratio of 116 and then with plug side wall fences at NPR 110. Schlieren images were recorded and axial profiles of plug wall static pressures were measured at several spanwise locations and on the plug base. Detailed CFD analysis was performed for these nozzle configurations at NPR 116 by NASA MSFC. The CFD exhibits good agreement with the experimental data. A detailed comparison of the CFD results and the experimental plug wall pressure data are given. Comparisons are made for both the without and with plug side wall fence configurations. Numerical results for density gradient are compared to experimental Schlieren images. Experimental nozzle thrust efficiencies are calculated based on the CFD results. The CFD results are used to illustrate the plug nozzle fluid dynamics. The effect of the plug side wall is emphasized.

  1. Halliburton Composite Bridge Plug Assembly

    SciTech Connect

    Starbuck, J.M.; Luttrell, C.R.; Aramayo, G.

    2005-01-15

    The overall objectives of this CRADA were to assist Halliburton in analyzing a composite bridge plug and to determine why their original design was failing in the field. In Phase 1, finite element analyses were done on the original composite slip design and several alternative designs. The composite slip was the component in the bridge plug that was failing. The finite element code ABAQUS was used for these calculations and I-DEAS was used as the pre- and post-processor in the analyses. Several different designs and materials were analyzed and recommendations were made towards improving the design. In Phase 2, the objective was to develop finite element models that would accurately represent the deformations in the entire all-composite 4-1/2' diameter bridge plug assembly. The finite element code LS-DYNA was used and the results from this effort were intended to expand Halliburton's composite design and analysis capabilities with regard to developing future composite components for downhole tools. In addition to the finite element modeling, this effort involved the utilization of micromechanics to determine the necessary composite material properties that were needed as input for finite element codes.

  2. Amineborane Based Chemical Hydrogen Storage - Final Report

    SciTech Connect

    Sneddon, Larry G.

    2011-04-21

    The development of efficient and safe methods for hydrogen storage is a major hurdle that must be overcome to enable the use of hydrogen as an alternative energy carrier. The objectives of this project in the DOE Center of Excellence in Chemical Hydride Storage were both to develop new methods for on-demand, low temperature hydrogen release from chemical hydrides and to design high-conversion off-board methods for chemical hydride regeneration. Because of their reactive protic (N-H) and hydridic (B-H) hydrogens and high hydrogen contents, amineboranes such as ammonia borane, NH3BH3 (AB), 19.6-wt% H2, and ammonia triborane NH3B3H7 (AT), 17.7-wt% H2, were initially identified by the Center as promising, high-capacity chemical hydrogen storage materials with the potential to store and deliver molecular hydrogen through dehydrogenation and hydrolysis reactions. In collaboration with other Center partners, the Penn project focused both on new methods to induce amineborane H2-release and on new strategies for the regeneration the amineborane spent-fuel materials. The Penn approach to improving amineborane H2-release focused on the use of ionic liquids, base additives and metal catalysts to activate AB dehydrogenation and these studies successfully demonstrated that in ionic liquids the AB induction period that had been observed in the solid-state was eliminated and both the rate and extent of AB H2-release were significantly increased. These results have clearly shown that, while improvements are still necessary, many of these systems have the potential to achieve DOE hydrogen-storage goals. The high extent of their H2­-release, the tunability of both their H2 materials weight-percents and release rates, and their product control that is attained by either trapping or suppressing unwanted volatile side products, such as borazine, continue to make AB/ionic­-liquid based systems attractive candidates for chemical hydrogen storage applications. These studies also

  3. Comparison of Experimental Data and Computations Fluid Dynamics Analysis for a Three Dimensional Linear Plug Nozzle

    NASA Technical Reports Server (NTRS)

    Ruf, J. H.; Hagemann, G.; Immich, H.

    2003-01-01

    A three dimensional linear plug nozzle of area ratio 12.79 was designed by Astrium. The nozzle was tested within the German National Technology Program LION in a cold air wind tunnel by TU Dresden. The experimental hardware and test conditions are described. Experimental data was obtained for the nozzle without plug side wall fences and then with plug side wall fences. Experimental data for two nozzle pressure ratios (NPR), 116 and 45, are presented for the without fence and with fence configurations. Schlieren images of both NPR were recorded. Axial profiles of plug wall static pressures were measured at several spanwise locations and on the plug base. Detailed computational fluid dynamics (CFD) analysis was performed for these nozzle configurations by NASA MSFC. The CFD exhibits good agreement with the experimental data. A detailed comparison of the CFD results and the experimental plug wall pressure data is given for four test conditions; at both NPRs, without and with plug side wall fences. Numerical schlieren images are compared to experimental schlieren images. Nozzle thrust efficiencies are calculated from the CFD results. The CFD results are used to illustrate the plug nozzle fluid dynamics for all four test conditions. The effect of the plug side wall fences at both NPRs is emphasized.

  4. SpaceWire Plug and Play

    NASA Technical Reports Server (NTRS)

    Rakow, Glenn; McGuirk, Patrick; Kimmery, Clifford; Jaffe, Paul

    2006-01-01

    The ability to rapidly deploy inexpensive satellites to meet tactical goals has become an important goal for military space systems. In fact, Operationally Responsive Space (ORS) has been in the spotlight at the highest levels. The Office of the Secretary of Defense (OSD) has identified that the critical next step is developing the bus standards and modular interfaces. Historically, satellite components have been constructed based on bus standards and standardized interfaces. However, this has not been done to a degree, which would allow the rapid deployment of a satellite. Advancements in plug-and-play (PnP) technologies for terrestrial applications can serve as a baseline model for a PnP approach for satellite applications. Since SpaceWire (SpW) has become a de facto standard for satellite high-speed (greater than 200Mbp) on-board communications, it has become important for SpW to adapt to this Plug and Play (PnP) environment. Because SpW is simply a bulk transport protocol and lacks built-in PnP features, several changes are required to facilitate PnP with SpW. The first is for Host(s) to figure out what the network looks like, i.e., how pieces of the network, routers and nodes, are connected together; network mapping, and to receive notice of changes to the network. The second is for the components connected to the network to be understood so that they can communicate. The first element, network topology mapping & change of status indication, is being defined (topic of this paper). The second element describing how components are to communicate has been defined by ARFL with the electronic data sheets known as XTEDS. The first element, network mapping, is recent activities performed by Air Force Research Lab (ARFL), Naval Research Lab (NRL), NASA and US industry (Honeywell, Clearwater, FL, and others). This work has resulted in the development of a protocol that will perform the lower level functions of network mapping and Change Of Status (COS) indication

  5. SpaceWire Plug and Play

    NASA Technical Reports Server (NTRS)

    Rakow, Glenn; McGuirk, Patrick; Kimmery, Clifford; Jaffe, Paul

    2006-01-01

    The ability to rapidly deploy inexpensive satellites to meet tactical goals has become an important goal for military space systems. In fact, Operationally Responsive Space (ORS) has been in the spotlight at the highest levels. The Office of the Secretary of Defense (OSD) has identified that the critical next step is developing the bus standards and modular interfaces. Historically, satellite components have been constructed based on bus standards and standardized interfaces. However, this has not been done to a degree, which would allow the rapid deployment of a satellite. Advancements in plug-and-play (PnP) technologies for terrestrial applications can serve as a baseline model for a PnP approach for satellite applications. Since SpaceWire (SpW) has become a de facto standard for satellite high-speed (greater than 200Mbp) on-board communications, it has become important for SpW to adapt to this Plug and Play (PnP) environment. Because SpW is simply a bulk transport protocol and lacks built-in PnP features, several changes are required to facilitate PnP with SpW. The first is for Host(s) to figure out what the network looks like, i.e., how pieces of the network, routers and nodes, are connected together; network mapping, and to receive notice of changes to the network. The second is for the components connected to the network to be understood so that they can communicate. The first element, network topology mapping & change of status indication, is being defined (topic of this paper). The second element describing how components are to communicate has been defined by ARFL with the electronic data sheets known as XTEDS. The first element, network mapping, is recent activities performed by Air Force Research Lab (ARFL), Naval Research Lab (NRL), NASA and US industry (Honeywell, Clearwater, FL, and others). This work has resulted in the development of a protocol that will perform the lower level functions of network mapping and Change Of Status (COS) indication

  6. Carbon-Nanotube-Based Chemical Gas Sensor

    NASA Technical Reports Server (NTRS)

    Kaul, Arunpama B.

    2010-01-01

    Conventional thermal conductivity gauges (e.g. Pirani gauges) lend themselves to applications such as leak detectors, or in gas chromatographs for identifying various gas species. However, these conventional gauges are physically large, operate at high power, and have a slow response time. A single-walled carbon-nanotube (SWNT)-based chemical sensing gauge relies on differences in thermal conductance of the respective gases surrounding the CNT as it is voltage-biased, as a means for chemical identification. Such a sensor provides benefits of significantly reduced size and compactness, fast response time, low-power operation, and inexpensive manufacturing since it can be batch-fabricated using Si integrated-circuit (IC) process technology.

  7. Susceptibility-matched plugs for microcoil NMR probes

    NASA Astrophysics Data System (ADS)

    Kc, Ravi; Gowda, Yashas N.; Djukovic, Danijel; Henry, Ian D.; Park, Gregory H. J.; Raftery, Daniel

    2010-07-01

    For mass-limited samples, the residual sample volume outside the detection coil is an important concern, as is good base line resolution. Here, we present the construction and evaluation of magnetic susceptibility-matched plugs for microcoil NMR sample cells which address these issues. Mixed-epoxy glue and ultem tube plugs that have susceptibility values close to those of perfluorocarbon FC-43 (fluorinert) and copper were used in small volume (0.5-2 μL) and larger volume (15-20 μL) thin glass capillary sample cells. Using these plugs, the sample volume efficiency (i.e. ratio of active volume to total sample volume in the microcoil NMR cell) was improved by 6-12-fold without sensitivity and resolution trade-offs. Comparison with laser etched or heat etched microcoil sample cells is provided. The approaches described are potentially useful in metabolomics for biomarkers detection in mass limited biological samples.

  8. Susceptibility-matched plugs for microcoil NMR probes.

    PubMed

    Kc, Ravi; Gowda, Yashas N; Djukovic, Danijel; Henry, Ian D; Park, Gregory H J; Raftery, Daniel

    2010-07-01

    For mass-limited samples, the residual sample volume outside the detection coil is an important concern, as is good base line resolution. Here, we present the construction and evaluation of magnetic susceptibility-matched plugs for microcoil NMR sample cells which address these issues. Mixed-epoxy glue and ultem tube plugs that have susceptibility values close to those of perfluorocarbon FC-43 (fluorinert) and copper were used in small volume (0.5-2 microL) and larger volume (15-20 microL) thin glass capillary sample cells. Using these plugs, the sample volume efficiency (i.e. ratio of active volume to total sample volume in the microcoil NMR cell) was improved by 6-12-fold without sensitivity and resolution trade-offs. Comparison with laser etched or heat etched microcoil sample cells is provided. The approaches described are potentially useful in metabolomics for biomarkers detection in mass limited biological samples.

  9. 40 CFR 147.3108 - Plugging Class I, II, and III wells.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... injection zone. (2) A cement plug shall also be set from a point at least fifty (50) feet below the shoe of... 50 feet below the base of the USDW), a plug shall be set at least 50 feet below the shoe of the casing and extending at least 50 feet above the shoe of the casing; or (3) If the surface casing...

  10. 40 CFR 147.3108 - Plugging Class I, II, and III wells.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... injection zone. (2) A cement plug shall also be set from a point at least fifty (50) feet below the shoe of... 50 feet below the base of the USDW), a plug shall be set at least 50 feet below the shoe of the casing and extending at least 50 feet above the shoe of the casing; or (3) If the surface casing...

  11. 40 CFR 147.3108 - Plugging Class I, II, and III wells.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... injection zone. (2) A cement plug shall also be set from a point at least fifty (50) feet below the shoe of... 50 feet below the base of the USDW), a plug shall be set at least 50 feet below the shoe of the casing and extending at least 50 feet above the shoe of the casing; or (3) If the surface casing...

  12. Thermal energy harvesting plasmonic based chemical sensors.

    PubMed

    Karker, Nicholas; Dharmalingam, Gnanaprakash; Carpenter, Michael A

    2014-10-28

    Detection of gases such as H2, CO, and NO2 at 500 °C or greater requires materials with thermal stability and reliability. One of the major barriers toward integration of plasmonic-based chemical sensors is the requirement of multiple components such as light sources and spectrometers. In this work, plasmonic sensing results are presented where thermal energy is harvested using lithographically patterned Au nanorods, replacing the need for an external incident light source. Gas sensing results using the harvested thermal energy are in good agreement with sensing experiments, which used an external incident light source. Principal Component Analysis (PCA) was used to reduce the wavelength parameter space from 665 variables down to 4 variables with similar levels of demonstrated selectivity. The combination of a plasmonic-based energy harvesting sensing paradigm with PCA analysis offers a novel path toward simplification and integration of plasmonic-based sensing methods.

  13. Fact Sheet: Benzidine-Based Chemical Substances

    EPA Pesticide Factsheets

    EPA's existing chemicals programs address pollution prevention, risk assessment, hazard and exposure assessment and/or characterization, and risk management for chemicals substances in commercial use.

  14. Waveguide-based optical chemical sensor

    SciTech Connect

    Grace, Karen M.; Swanson, Basil I.; Honkanen, Seppo

    2007-03-13

    The invention provides an apparatus and method for highly selective and sensitive chemical sensing. Two modes of laser light are transmitted through a waveguide, refracted by a thin film host reagent coating on the waveguide, and analyzed in a phase sensitive detector for changes in effective refractive index. Sensor specificity is based on the particular species selective thin films of host reagents which are attached to the surface of the planar optical waveguide. The thin film of host reagents refracts laser light at different refractive indices according to what species are forming inclusion complexes with the host reagents.

  15. High temperature penetrator assembly with bayonet plug and ramp-activated lock

    NASA Technical Reports Server (NTRS)

    Wood, K. E. (Inventor)

    1982-01-01

    A penetration apparatus, for very high temperature applications in which a base plug is inserted into an opening through a bulkhead is described. The base plug has a head shape and is seated against the highest temperature surface of the bulkhead, which may be the skin of the nose cone or other part of a space vehicle intended for nondestructive atmospheric reentry. From the second side of the bulkhead at which the less severe environment is extant, a bayonet plug is inserted into the base plug and engages an internal shoulder at about 90 deg rotation. The bayonet plug has an integral flanged portion and a pair of ramping washers which are located between the flange and the second bulkhead surface with a spacing washer as necessary.

  16. Plug Load Behavioral Change Demonstration Project

    SciTech Connect

    Metzger, I.; Kandt, A.; VanGeet, O.

    2011-08-01

    This report documents the methods and results of a plug load study of the Environmental Protection Agency's Region 8 Headquarters in Denver, Colorado, conducted by the National Renewable Energy Laboratory. The study quantified the effect of mechanical and behavioral change approaches on plug load energy reduction and identified effective ways to reduce plug load energy. Load reduction approaches included automated energy management systems and behavioral change strategies.

  17. Non-plugging injection valve

    DOEpatents

    Carey, Jr., Henry S.

    1985-01-01

    A valve for injecting fluid into a conduit carrying a slurry subject to separation to form deposits capable of plugging openings into the conduit. The valve comprises a valve body that is sealed to the conduit about an aperture formed through the wall of the conduit to receive the fluid to be injected and the valve member of the valve includes a punch portion that extends through the injection aperture to the flow passage, when the valve is closed, to provide a clear channel into the conduit, when the valve is opened, through deposits which might have formed on portions of the valve adjacent the conduit.

  18. Chemical Sensors Based on Metal Oxide Nanostructures

    NASA Technical Reports Server (NTRS)

    Hunter, Gary W.; Xu, Jennifer C.; Evans, Laura J.; VanderWal, Randy L.; Berger, Gordon M.; Kulis, Mike J.; Liu, Chung-Chiun

    2006-01-01

    This paper is an overview of sensor development based on metal oxide nanostructures. While nanostructures such as nanorods show significan t potential as enabling materials for chemical sensors, a number of s ignificant technical challenges remain. The major issues addressed in this work revolve around the ability to make workable sensors. This paper discusses efforts to address three technical barriers related t o the application of nanostructures into sensor systems: 1) Improving contact of the nanostructured materials with electrodes in a microse nsor structure; 2) Controling nanostructure crystallinity to allow co ntrol of the detection mechanism; and 3) Widening the range of gases that can be detected by using different nanostructured materials. It is concluded that while this work demonstrates useful tools for furt her development, these are just the beginning steps towards realizati on of repeatable, controlled sensor systems using oxide based nanostr uctures.

  19. Friction Pull Plug and Material Configuration for Anti-Chatter Friction Pull Plug Weld

    NASA Technical Reports Server (NTRS)

    Littell, Justin Anderson (Inventor)

    2016-01-01

    A friction pull plug is provided for use in forming a plug weld in a hole in a material. The friction pull plug includes a shank and a series of three frustoconical sections. The relative sizes of the sections assure that a central one of the sections defines the initial contact point between the hole's sides. The angle defined by the central one of the sections reduces or eliminates chatter as the plug is pulled into the hole.

  20. A Rotating Plug Model of Friction Stir Welding Heat Transfer

    NASA Technical Reports Server (NTRS)

    Raghulapadu J. K.; Peddieson, J.; Buchanan, G. R.; Nunes, A. C.

    2006-01-01

    A simplified rotating plug model is employed to study the heat transfer phenomena associated with the fiction stir welding process. An approximate analytical solution is obtained based on this idealized model and used both to demonstrate the qualitative influence of process parameters on predictions and to estimate temperatures produced in typical fiction stir welding situations.

  1. Experimental plug and play quantum coin flipping.

    PubMed

    Pappa, Anna; Jouguet, Paul; Lawson, Thomas; Chailloux, André; Legré, Matthieu; Trinkler, Patrick; Kerenidis, Iordanis; Diamanti, Eleni

    2014-04-24

    Performing complex cryptographic tasks will be an essential element in future quantum communication networks. These tasks are based on a handful of fundamental primitives, such as coin flipping, where two distrustful parties wish to agree on a randomly generated bit. Although it is known that quantum versions of these primitives can offer information-theoretic security advantages with respect to classical protocols, a demonstration of such an advantage in a practical communication scenario has remained elusive. Here we experimentally implement a quantum coin flipping protocol that performs strictly better than classically possible over a distance suitable for communication over metropolitan area optical networks. The implementation is based on a practical plug and play system, developed by significantly enhancing a commercial quantum key distribution device. Moreover, we provide combined quantum coin flipping protocols that are almost perfectly secure against bounded adversaries. Our results offer a useful toolbox for future secure quantum communications.

  2. Vulnerability assessment of chemical industry facilities in South Korea based on the chemical accident history

    NASA Astrophysics Data System (ADS)

    Heo, S.; Lee, W. K.; Jong-Ryeul, S.; Kim, M. I.

    2016-12-01

    The use of chemical compounds are keep increasing because of their use in manufacturing industry. Chemical accident is growing as the consequence of the chemical use increment. Devastating damages from chemical accidents are far enough to aware people's cautious about the risk of the chemical accident. In South Korea, Gumi Hydrofluoric acid leaking accident triggered the importance of risk management and emphasized the preventing the accident over the damage reducing process after the accident occurs. Gumi accident encouraged the government data base construction relate to the chemical accident. As the result of this effort Chemical Safety-Clearing-house (CSC) have started to record the chemical accident information and damages according to the Harmful Chemical Substance Control Act (HCSC). CSC provide details information about the chemical accidents from 2002 to present. The detail informations are including title of company, address, business type, accident dates, accident types, accident chemical compounds, human damages inside of the chemical industry facilities, human damage outside of the chemical industry facilities, financial damages inside of the chemical industry facilities, and financial damages outside of the chemical industry facilities, environmental damages and response to the chemical accident. Collected the chemical accident history of South Korea from 2002 to 2015 and provide the spatial information to the each accident records based on their address. With the spatial information, compute the data on ArcGIS for the spatial-temporal analysis. The spatial-temporal information of chemical accident is organized by the chemical accident types, damages, and damages on environment and conduct the spatial proximity with local community and environmental receptors. Find the chemical accident vulnerable area of South Korea from 2002 to 2015 and add the vulnerable area of total period to examine the historically vulnerable area from the chemical accident in

  3. A rule-based expert system for chemical prioritization using effects-based chemical categories

    EPA Science Inventory

    A rule-based expert system (ES) was developed to predict chemical binding to the estrogen receptor (ER) patterned on the research approaches championed by Gilman Veith to whom this article and journal issue are dedicated. The ERES was built to be mechanistically-transparent and m...

  4. A rule-based expert system for chemical prioritization using effects-based chemical categories

    EPA Science Inventory

    A rule-based expert system (ES) was developed to predict chemical binding to the estrogen receptor (ER) patterned on the research approaches championed by Gilman Veith to whom this article and journal issue are dedicated. The ERES was built to be mechanistically-transparent and m...

  5. Image-Based Chemical Structure Determination.

    PubMed

    Ofner, Johannes; Brenner, Florian; Wieland, Karin; Eitenberger, Elisabeth; Kirschner, Johannes; Eisenmenger-Sittner, Christoph; Török, Szilvia; Döme, Balazs; Konegger, Thomas; Kasper-Giebl, Anne; Hutter, Herbert; Friedbacher, Gernot; Lendl, Bernhard; Lohninger, Hans

    2017-07-28

    Chemical imaging is a powerful tool for understanding the chemical composition and nature of heterogeneous samples. Recent developments in elemental, vibrational, and mass-spectrometric chemical imaging with high spatial resolution (50-200 nm) and reasonable timescale (a few hours) are capable of providing complementary chemical information about various samples. However, a single technique is insufficient to provide a comprehensive understanding of chemically complex materials. For bulk samples, the combination of different analytical methods and the application of statistical methods for extracting correlated information across different techniques is a well-established and powerful concept. However, combined multivariate analytics of chemical images obtained via different imaging techniques is still in its infancy, hampered by a lack of analytical methodologies for data fusion and analysis. This study demonstrates the application of multivariate statistics to chemical images taken from the same sample via various methods to assist in chemical structure determination.

  6. Continuous-variable quantum key distribution based on a plug-and-play dual-phase-modulated coherent-states protocol

    NASA Astrophysics Data System (ADS)

    Huang, Duan; Huang, Peng; Wang, Tao; Li, Huasheng; Zhou, Yingming; Zeng, Guihua

    2016-09-01

    We propose and experimentally demonstrate a continuous-variable quantum key distribution (CV-QKD) protocol using dual-phase-modulated coherent states. We show that the modulation scheme of our protocol works equivalently to that of the Gaussian-modulated coherent-states (GMCS) protocol, but shows better experimental feasibility in the plug-and-play configuration. Besides, it waives the necessity of propagation of a local oscillator (LO) between legitimate users and generates a real local LO for quantum measurement. Our protocol is proposed independent of the one-way GMCS QKD without sending a LO [Opt. Lett. 40, 3695 (2015), 10.1364/OL.40.003695; Phys. Rev. X 5, 041009 (2015), 10.1103/PhysRevX.5.041009; Phys. Rev. X 5, 041010 (2015), 10.1103/PhysRevX.5.041010]. In those recent works, the system stability will suffer the impact of polarization drifts induced by environmental perturbations, and two independent frequency-locked laser sources are necessary to achieve reliable coherent detection. In the proposed protocol, these previous problems can be resolved. We derive the security bounds for our protocol against collective attacks, and we also perform a proof-of-principle experiment to confirm the utility of our proposal in real-life applications. Such an efficient scheme provides a way of removing the security loopholes associated with the transmitting LO, which have been a notoriously hard problem in continuous-variable quantum communication.

  7. Vascular plugs – A key companion to Interventionists – ‘Just Plug it’

    PubMed Central

    Ramakrishnan, Sivasubramanian

    2015-01-01

    Vascular plugs are ideally suited to close extra-cardiac, high flowing vascular communications. The family of vascular plugs has expanded. Vascular plugs in general have a lower profile and the newer variants can be delivered even through a diagnostic catheter. These features make them versatile and easy to use. The Amplatzer vascular plugs are also used for closing intracardiac defects including coronary arterio-venous fistula and paravalvular leakage in an off-label fashion. In this review, the features of currently available vascular plugs are reviewed along with tips and tricks of using them in the cardiac catheterization laboratory. PMID:26304581

  8. Plug-In Tutor Agents: Still Pluggin'

    ERIC Educational Resources Information Center

    Ritter, Steven

    2016-01-01

    "An Architecture for Plug-in Tutor Agents" (Ritter and Koedinger 1996) proposed a software architecture designed around the idea that tutors could be built as plug-ins for existing software applications. Looking back on the paper now, we can see that certain assumptions about the future of software architecture did not come to be, making…

  9. Plug-In Tutor Agents: Still Pluggin'

    ERIC Educational Resources Information Center

    Ritter, Steven

    2016-01-01

    "An Architecture for Plug-in Tutor Agents" (Ritter and Koedinger 1996) proposed a software architecture designed around the idea that tutors could be built as plug-ins for existing software applications. Looking back on the paper now, we can see that certain assumptions about the future of software architecture did not come to be, making…

  10. 21 CFR 886.4155 - Scleral plug.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... stainless steel with or without a gold, silver, or titanium coating. The special controls for the surgical grade stainless steel scleral plug (with or without a gold, silver, or titanium coating) are: (i) The... titanium coating). The special controls for scleral plugs made of other materials are: (i) The device...

  11. Modeling of Biomass Plug Development and Propagation in Porous Media

    SciTech Connect

    Stewart, Terri L.; Kim, Dong-Shik

    2004-02-01

    Biomass accumulation and evolution in porous media were simulated using a combination of biofilm evolution model and a biofilm removal model. Theses models describe biomass plug development, removal, and propagation in biological applications such as microbial enhanced oil recovery, in situ bioremediation, and bio-barrier techniques. The biofilm evolution model includes the cell growth rate and exopolymer production kinetics. The biofilm removal model was used for describing the biomass plug propagation and channel breakthrough using Bingham yield stress of biofilm, which represents the stability of biofilm against shear stress. Network model was used to describe a porous medium. The network model consists of pore body and pore bond of which the sizes were determined based on the pore size distribution of ceramic cores. The pressure drop across the network is assumed to be generated from pore bonds only, and the cell growth and biomass accumulation took place in pore bonds. The simulation results showed that the biofilm models based on Bingham yield stress predicted the biomass accumulation and channel breakthrough well. The pressure oscillation (or, permeability oscillation) was also demonstrated well indicating the process of biomass accumulation and breakthrough channel formation. In addition, the effects of cell and biofilm sucrose concentration were significant on the biomass plug development and permeability reduction rates. The modeling elucidated some deficiencies in our knowledge of the biomass yield stress that enables us to predict the stability of biomass plug against shear stress.

  12. Plug-in Hybrid Initiative

    SciTech Connect

    Goodman, Angie; Moore, Ray; Rowden, Tim

    2013-09-27

    Our main project objective was to implement Plug-in Electric Vehicles (PEV) and charging infrastructure into our electric distribution service territory and help reduce barriers in the process. Our research demonstrated the desire for some to be early adopters of electric vehicles and the effects lack of education plays on others. The response of early adopters was tremendous: with the initial launch of our program we had nearly 60 residential customers interested in taking part in our program. However, our program only allowed for 15 residential participants. Our program provided assistance towards purchasing a PEV and installation of Electric Vehicle Supply Equipment (EVSE). The residential participants have all come to love their PEVs and are more than enthusiastic about promoting the many benefits of driving electric.

  13. Polymer grouts for plugging lost circulation in geothermal wells.

    SciTech Connect

    Galbreath, D. (Green Mountain International, Waynesvile, NC); Mansure, Arthur James; Bauer, Stephen J.

    2004-12-01

    We have concluded a laboratory study to evaluate the survival potential of polymeric materials used for lost circulation plugs in geothermal wells. We learned early in the study that these materials were susceptible to hydrolysis. Through a systematic program in which many potential chemical combinations were evaluated, polymers were developed which tolerated hydrolysis for eight weeks at 500 F. The polymers also met material, handling, cost, and emplacement criteria. This screening process identified the most promising materials. A benefit of this work is that the components of the polymers developed can be mixed at the surface and pumped downhole through a single hose. Further strength testing is required to determine precisely the maximum temperature at which extrusion through fractures or voids causes failure of the lost circulation plug.

  14. Data base of chemical explosions in Kazakhstan

    SciTech Connect

    Demin, V.N.; Malahova, M.N.; Martysevich, P.N.; Mihaylova, N.N.; Nurmagambetov, A.; Kopnichev, Yu.F. D.; Edomin, V.I.

    1996-12-01

    Within the bounds of this report, the following works were done: (1) Information about explosion quarries, located in Southern, Eastern and Northern Kasakstan was summarized. (2) The general information about seismicity of areas of location of explosion quarries was adduced. (3) The system of observation and seismic apparatus, recording the local earthquakes and quarry explosions at the territory of Kazakstan were described. (4) Data base of quarry explosions, that were carried out in Southern, Eastern and Northern Kazakstan during 1995 and first half of 1996 year was adduced. (5) Upon the data of registration of explosions in Southern Kazakstan the correlative dependences between power class of explosions and summary weight of charge were constructed. (6) Seismic records of quarry explosions were adduced. It is necessary to note, that the collection of data about quarry explosions in Kazakstan in present time is very difficult task. Organizations, that makes these explosions, are always suffering reorganizations and sometimes it is actually impossible to receive all the necessary information. Some quarries are situated in remote, almost inaccessible regions, and within the bounds of supplier financing not the every quarry was in success to visit. So the present data base upon the chemical explosions for 1995 is not full and in further it`s expansion is possible.

  15. A novel planarization method based on photoinduced confined chemical etching.

    PubMed

    Fang, Qiuyan; Zhou, Jian-Zhang; Zhan, Dongping; Shi, Kang; Tian, Zhao-Wu; Tian, Zhong-Qun

    2013-07-21

    A photoinduced confined chemical etching system based on TiO2 nanotube arrays is developed for the planarization of the copper surface, which is proved to be a prospective stress-free chemical planarization method for metals and semiconductors.

  16. Evaluation of commercial lithium-ion cells based on composite positive electrode for plug-in hybrid electric vehicle applications. Part I: Initial characterizations

    NASA Astrophysics Data System (ADS)

    Dubarry, Matthieu; Truchot, Cyril; Cugnet, Mikaël; Liaw, Bor Yann; Gering, Kevin; Sazhin, Sergiy; Jamison, David; Michelbacher, Christopher

    Evaluating commercial Li-ion batteries presents some unique benefits. One of them is to use cells made from established fabrication process and form factor, such as those offered by the 18650 cylindrical configuration, to provide a common platform to investigate and understand performance deficiency and aging mechanism of target chemistry. Such an approach shall afford us to derive relevant information without influence from processing or form factor variability that may skew our understanding on cell-level issues. A series of 1.9 Ah 18650 lithium ion cells developed by a commercial source using a composite positive electrode comprising {LiMn 1/3Ni 1/3Co 1/3O 2 + LiMn 2O 4} is being used as a platform for the investigation of certain key issues, particularly path-dependent aging and degradation in future plug-in hybrid electric vehicle (PHEV) applications, under the US Department of Energy's Applied Battery Research (ABR) program. Here we report in Part I the initial characterizations of the cell performance and Part II some aspects of cell degradation in 2C cycle aging. The initial characterizations, including cell-to-cell variability, are essential for life cycle performance characterization in the second part of the report when cell-aging phenomena are discussed. Due to the composite nature of the positive electrode, the features (or signature) derived from the incremental capacity (IC) of the cell appear rather complex. In this work, the method to index the observed IC peaks is discussed. Being able to index the IC signature in details is critical for analyzing and identifying degradation mechanism later in the cycle aging study.

  17. Evaluation of commercial lithium-ion cells based on composite positive electrode for plug-in hybrid electric vehicle applications. Part I: Initial characterizations

    SciTech Connect

    Matthieu Dubarry; Cyril Truchot; Mikael Cugnet; Bor Yann Liaw; Kevin Gering; Sergiy Sazhin; David Jamison; Christopher Michelbacher

    2011-12-01

    Evaluating commercial Li-ion batteries presents some unique benefits. One of them is to use cells made from established fabrication process and form factor, such as those offered by the 18650 cylindrical configuration, to provide a common platform to investigate and understand performance deficiency and aging mechanism of target chemistry. Such an approach shall afford us to derive relevant information without influence from processing or form factor variability that may skew our understanding on cell-level issues. A series of 1.9 Ah 18650 lithium ion cells developed by a commercial source using a composite positive electrode comprising (LiMn1/3Ni1/3Co1/3O2 + LiMn2O4) is being used as a platform for the investigation of certain key issues, particularly path-dependent aging and degradation in future plug-in hybrid electric vehicle (PHEV) applications, under the US Department of Energy's Applied Battery Research (ABR) program. Here we report in Part I the initial characterizations of the cell performance and Part II some aspects of cell degradation in 2C cycle aging. The initial characterizations, including cell-to-cell variability, are essential for life cycle performance characterization in the second part of the report when cell-aging phenomena are discussed. Due to the composite nature of the positive electrode, the features (or signature) derived from the incremental capacity (IC) of the cell appear rather complex. In this work, the method to index the observed IC peaks is discussed. Being able to index the IC signature in details is critical for analyzing and identifying degradation mechanism later in the cycle aging study.

  18. Friction pull plug welding: dual chamfered plate hole

    NASA Technical Reports Server (NTRS)

    Coletta, Edmond R. (Inventor); Cantrell, Mark A. (Inventor)

    2001-01-01

    Friction Pull Plug Welding (FPPW) is a solid state repair process for defects up to one inch in length, only requiring single sided tooling (OSL) for usage on flight hardware. Early attempts with FPPW followed the matching plug/plate geometry precedence of the successful Friction Push Plug Welding program, however no defect free welds were achieved due to substantial plug necking and plug rotational stalling. The dual chamfered hole has eliminated plug rotational stalling, both upon initial plug/plate contact and during welding. Also, the necking of the heated plug metal under a tensile heating/forging load has been eliminated through the usage of the dual chamfered plate hole.

  19. Chemical space visualization: transforming multidimensional chemical spaces into similarity-based molecular networks.

    PubMed

    de la Vega de León, Antonio; Bajorath, Jürgen

    2016-09-01

    The concept of chemical space is of fundamental relevance for medicinal chemistry and chemical informatics. Multidimensional chemical space representations are coordinate-based. Chemical space networks (CSNs) have been introduced as a coordinate-free representation. A computational approach is presented for the transformation of multidimensional chemical space into CSNs. The design of transformation CSNs (TRANS-CSNs) is based upon a similarity function that directly reflects distance relationships in original multidimensional space. TRANS-CSNs provide an immediate visualization of coordinate-based chemical space and do not require the use of dimensionality reduction techniques. At low network density, TRANS-CSNs are readily interpretable and make it possible to evaluate structure-activity relationship information originating from multidimensional chemical space.

  20. Simulating the Household Plug-in Hybrid Electric Vehicle Distribution and its Electric Distribution Network Impacts

    SciTech Connect

    Cui, Xiaohui; Kim, Hoe Kyoung; Liu, Cheng; Kao, Shih-Chieh; Bhaduri, Budhendra L

    2012-01-01

    This paper presents a multi agent-based simulation framework for modeling spatial distribution of plug-in hybrid electric vehicle ownership at local residential level, discovering plug-in hybrid electric vehicle hot zones where ownership may quickly increase in the near future, and estimating the impacts of the increasing plug-in hybrid electric vehicle ownership on the local electric distribution network with different charging strategies. We use Knox County, Tennessee as a case study to highlight the simulation results of the agent-based simulation framework.

  1. Vas deferens occlusion by percutaneous injection of polyurethane elastomer plugs: clinical experience and reversibility.

    PubMed

    Zhao, S C

    1990-05-01

    A non-incision method of vas occlusion based on the percutaneous injection of polyurethane elastomer solution to form plugs is described. The results are based on clinical experience in 12,000 men in which only 56 cases of minor complications were recorded. Follow-up of 500 men for up to 3 years demonstrated an azoospermia rate of 98%. Plugs have been removed from 86 men and, to date, 51 have made their wives pregnant. In those from which the plugs have been removed for more than 1 year (n = 31), the pregnancy rate is 100%.

  2. Mitigation of Syngas Cooler Plugging and Fouling

    SciTech Connect

    Bockelie, Michael J.

    2015-06-29

    understanding of deposit formation mechanisms; • performing Techno-Economic-Analysis for a representative IGCC plant to investigate the impact on plant economics, in particular the impacts on the Cost of Electricity (COE), due to plant shutdowns caused by syngas cooler plugging and fouling and potential benefits to plant economics of developing strategies to mitigate syngas cooler fouling; and • performing modeling and pilot scale tests to investigate the potential benefits of using a sorbent (fuel additive) to capture the vaporized metals that result in syngas cooler fouling. All project milestones for BP 1 and BP 2 were achieved. DOE was provided a briefing on our accomplishments in BP1 and BP2 and our proposed plans for Budget Period 3 (BP 3). Based on our research the mitigation technology selected to investigate in BP 3 was the use of a sorbent that can be injected into the gasifier with the fuel slurry to capture vaporized metals that lead to the deposit formation in the syngas cooler. The work effort proposed for BP 3 would have focused on addressing concerns raised by gasification industry personnel for the impacts on gasifier performance of sorbent injection, so that at the end of BP 3 the use of sorbent injection would be at “pre-commercial” stage and ready for use in a Field Demonstration that could be funded by industry or DOE. A Budget Continuation Application (BCA) was submitted to obtain funding for BP3 DOE but DOE chose to not fund the proposed BP3 effort.

  3. Friction Pull Plug Welding in Aluminum Alloys

    NASA Technical Reports Server (NTRS)

    Brooke, Shane A.; Bradford, Vann

    2012-01-01

    NASA's Marshall Space Flight Center (MSFC) has recently invested much time and effort into the process development of Friction Pull Plug Welding (FPPW). FPPW, is a welding process similar to Friction Push Plug Welding in that, there is a small rotating part (plug) being spun and simultaneously pulled (forged) into a larger part. These two processes differ, in that push plug welding requires an internal reaction support, while pull plug welding reacts to the load externally. FPPW was originally conceived as a post proof repair technique for the Space Shuttle fs External Tank. FPPW was easily selected as the primary weld process used to close out the termination hole on the Constellation Program's ARES I Upper Stage circumferential Self-Reacting Friction Stir Welds (SR-FSW). The versatility of FPPW allows it to also be used as a repair technique for both SR-FSW and Conventional Friction Stir Welds. To date, all MSFC led development has been concentrated on aluminum alloys (2195, 2219, and 2014). Much work has been done to fully understand and characterize the process's limitations. A heavy emphasis has been spent on plug design, to match the various weldland thicknesses and alloy combinations. This presentation will summarize these development efforts including weld parameter development, process control, parameter sensitivity studies, plug repair techniques, material properties including tensile, fracture and failure analysis.

  4. Friction Pull Plug Welding in Aluminum Alloys

    NASA Technical Reports Server (NTRS)

    Brooke, Shane A.; Bradford, Vann; Burkholder, Jonathon

    2011-01-01

    NASA fs Marshall Space Flight Center (MSFC) has recently invested much time and effort into the process development of Friction Pull Plug Welding (FPPW). FPPW, is a welding process similar to Friction Push Plug Welding in that, there is a small rotating part (plug) being spun and simultaneously pulled (forged) into a larger part. These two processes differ, in that push plug welding requires an internal reaction support, while pull plug welding reacts to the load externally. FPPW was originally conceived as a post proof repair technique for External Tank. FPPW was easily selected as the primary process used to close out the termination hole on the Constellation Program fs ARES I Upper Stage circumferential Self ] Reacting Friction Stir Welds (SR ]FSW). The versatility of FPPW allows it to also be used as a repair technique for both SR ]FSW and Conventional Friction Stir Welds. To date, all MSFC led development has been concentrated on aluminum alloys (2195, 2219, and 2014). Much work has been done to fully understand and characterize the process fs limitations. A heavy emphasis has been spent on plug design, to match the various weldland thicknesses and alloy combinations. This presentation will summarize these development efforts including weld parameter development, process control, parameter sensitivity studies, plug repair techniques, material properties including tensile, fracture and failure analysis.

  5. Pulsed plasma thruster ignitor plug ignition characteristics

    NASA Technical Reports Server (NTRS)

    Brady, M. E.; Aston, G.

    1982-01-01

    The operating characteristics of the semiconductor spark gap ignitor plug used to initiate the discharge in a pulsed plasma thruster are investigated. Current and voltage waveform measurements for the ignitor plug alone, and for the plug mounted in the thruster cathode indicate an average dynamic impedance of 0.2 ohms for a wide range of operating conditions, and a trigger circuit energy transfer efficiency to the plug on the order of 25%. Two modes of trigger ignition are found which are related to the rise time of the applied voltage pulse. Analysis of plasma characteristics reveals plug erosion to occur primarily in the semiconductor and anode regions, by mechanisms including plug metal embrittlement, plasma sputtering and vaporization caused by the discharge current pulse. Measurements also indicate a plume velocity on the order of 1580,000 cm/sec which increases with trigger circuit stored energy. The results establish levels of performance for future applications of semiconductor spark gap ignitor plugs in plasma devices.

  6. Sol-gel based optical chemical sensors

    NASA Astrophysics Data System (ADS)

    Lobnik, Aleksandra; Korent Urek, Špela; Turel, Matejka; Frančič, Nina

    2011-05-01

    The growing activity in the field of optical chemical sensors has resulted in numerous sensing schemes, new indicator dyes, various polymeric matrix, size and shapes and highly diversified methods of immobilization. The sensor characteristics are dependent upon the choice of indicator, polymer, immobilization technique, and also size. Sol-gel technology provides a low-temperature method for obtaining porous silicate glass matrices. It enables to obtain material in the form of films, powders, monoliths, fibres or nanoparticles. Organic reagents and molecular receptors can be easily immobilized in the matrices. Moreover, one of the unique features of the sol-gel process is that the properties of the final network structure, such as hydrophobicity, thickness, porosity, flexibility, reactivity and stability can be easily tailored by controlling the process conditions, the type and the size of the precursors and catalysis. Here we will report about several sensor designed over the years based on sol-gel materials for monitoring and controlling different parameters, such as heavy metals, amines, phosphates, organophosphates.

  7. Synthetic bioabsorbable hernia plug for plug and patch inguinal herniorrhaphy implantation technique.

    PubMed

    Doerhoff, Carl

    2012-12-01

    New products have led the way in advancements of inguinal hernia repair. None is more impressive than the evolution of the plug patch. In 1968 Irving Lichtenstein introduced the first Marlex mesh plug repair when he rolled a piece of flat polypropylene into the shape of a cigarette to fill a femoral defect. He later expanded his use of the "cigarette plug" to repair recurrent hernias. Today, a wide array of mesh plugs, ranging from nonabsorbable to partially and fully absorbable biomaterials, are available from manufacturers. While some surgeons have used the plug alone for repair, most believe the overlay patch is of greater importance for the durability of the repair. With larger overlays, it is questionable whether a plug should be a permanent, nonabsorbable material. Heavyweight plugs have been reported to erode, migrate, or cause vocational-limiting inguinodynia. Using a fully absorbable plug in inguinal hernia repair minimizes the risk of these complications. This article focuses on the technical refinements associated with using the completely absorbable GORE BIO-A Hernia Plug (W.L. Gore & Associates, Inc, Elkton, MD) in combination with macroporous polypropylene or polyester. Additionally, this paper describes the use of GORE BIO-A Tissue Reinforcement as an alternative for repair following removal of prior polypropylene plug-patch herniorrhaphy that cause inguinodynia.

  8. Small-Scale Spray Releases: Orifice Plugging Test Results

    SciTech Connect

    Mahoney, Lenna A.; Gauglitz, Phillip A.; Blanchard, Jeremy; Kimura, Marcia L.; Kurath, Dean E.

    2012-09-01

    One of the events postulated in the hazard analysis at the Waste Treatment and Immobilization Plant (WTP) and other U.S. Department of Energy (DOE) nuclear facilities, is a breach in process piping that produces aerosols with droplet sizes in the respirable range. The current approach for predicting the size and concentration of aerosols produced in a spray leak involves extrapolating from correlations published in the literature. These correlations are based on results obtained from small engineered spray nozzles using pure liquids with Newtonian fluid behavior. The narrow ranges of physical properties on which the correlations are based do not cover the wide range of slurries and viscous materials present in the WTP and across processing facilities in the DOE complex. Two key technical areas were identified where testing results were needed to improve the technical basis by reducing the uncertainty introduced by extrapolating existing literature results. The first technical need was to quantify the role of slurry particles in small breaches in which the slurry particles may plug and result in substantially reduced, or even negligible, respirable fraction formed by high pressure sprays. The second technical need was to determine the aerosol droplet size distribution and volume from prototypic breaches and fluids, specifically including sprays from larger breaches with slurries where data from the literature are largely absent. To address these technical areas, small- and large-scale test stands were constructed and operated with simulants to determine the aerosol release fractions and aerosol generation rates from a range of breach sizes and geometries. The properties of the simulants represented the range of properties expected in the WTP process streams and included water, sodium salt solutions, slurries containing boehmite or gibbsite, and a hazardous chemical simulant. The effect of anti-foam agents (AFA) was assessed with most of the simulants. Orifices

  9. Polysaccharides and bacterial plugging. Final report, 1992--1993

    SciTech Connect

    Fogler, H.S.

    1995-02-01

    In situ core plugging experiments and transport experiments, using the model bacteria Leuconostoc m., have been conducted. Results demonstrated that cellular polysaccharide production increases cell distribution in porous media and caused an overall decrease in media permeability. Further, a parallel core plugging experiment was conducted and showed the feasibility of this system to divert injection fluid from high permeability zones into low permeability zones within porous media as is needed for profile modification. To implement this type of application, however, controlled placement of cells and rates of polymer production are needed. Therefore, kinetic studies were performed. A kinetic model was subsequently developed for Leuconostoc m. bacteria. This model is based on data generated from batch growth experiments and allows for the prediction of saccharide utilization, cell generation, and dextran production. These predictions can be used to develop injection strategies for field implementation. Transport and in situ growth micromodel experiments have shown how dextran allow cells to remain as clusters after cell division which enhanced cell capture and retention in porous media. Additional Damkohler experiments have been performed to determine the effects of the nutrient injection rate and nutrient concentration on the rate of porous media plugging. As shown experimentally and as predicted by a model for in situ growth, an increase in nutrient concentration and/or its injection rate will result in a faster rate of porous media plugging. Through continuum model simulations, it has been shown that the initial cell profiles play a key role on the core plugging rate. Controlling the location of the inoculating cells is thus another key factor in using bacteria for profile modification.

  10. Effects-based chemical category approach for prioritization of low affinity estrogenic chemicals.

    PubMed

    Hornung, M W; Tapper, M A; Denny, J S; Kolanczyk, R C; Sheedy, B R; Hartig, P C; Aladjov, H; Henry, T R; Schmieder, P K

    2014-01-01

    Regulatory agencies are charged with addressing the endocrine disrupting potential of large numbers of chemicals for which there is often little or no data on which to make decisions. Prioritizing the chemicals of greatest concern for further screening for potential hazard to humans and wildlife is an initial step in the process. This paper presents the collection of in vitro data using assays optimized to detect low affinity estrogen receptor (ER) binding chemicals and the use of that data to build effects-based chemical categories following QSAR approaches and principles pioneered by Gilman Veith and colleagues for application to environmental regulatory challenges. Effects-based chemical categories were built using these QSAR principles focused on the types of chemicals in the specific regulatory domain of concern, i.e. non-steroidal industrial chemicals, and based upon a mechanistic hypothesis of how these non-steroidal chemicals of seemingly dissimilar structure to 17ß-estradiol (E2) could interact with the ER via two distinct binding types. Chemicals were also tested to solubility thereby minimizing false negatives and providing confidence in determination of chemicals as inactive. The high-quality data collected in this manner were used to build an ER expert system for chemical prioritization described in a companion article in this journal.

  11. What makes a good spark plug?

    NASA Astrophysics Data System (ADS)

    Yu, Andrew

    2006-05-01

    The quality and condition of spark plugs play a key role in achieving peak efficiency of a gasoline internal combustion engine. Since the first mass-produced spark plug, the design has remained constant, but the materials used in making them have changed. The original copper and nickel center and ground electrodes have been replaced with materials such as platinum and iridium. I will study the thermal and electrical conductivity and resistance to corrosion of a variety of spark plugs, and compare their performance to manufacturer's claims.

  12. Avioptic plug-in interconnection

    NASA Astrophysics Data System (ADS)

    Caserta, Anthony L.; Lijoi, Bruno

    1989-05-01

    A secure interconnection is claimed for optical and avioptic cables located in exposed positions, which often occur on aircraft communications circuits, for connecting those cables into equipment such as circuit boards. In this invention the interconnection for optical fiber cables comprises a connector which is engaged in a receptacle in a mother board provided with optical circuitry. The connector comprises a cuplike body or plug containing a metal sleeve which encases the optical fiber cable such that the cable end is exposed. The mating receptacle comprises a cylindrical shell having its lower end embedded in the mother board. A hole in the receptacle shell wall receives the end of an optical fiber on the optical circuitry of the mother board. The end of the sleeve of the connector fits over the end of the receptacle shell protruding from the mother board. Beam deflection means in the receptacle or on the connector directs light between the fiber optic cable and the optical circuit element of the mother board. Electrical coupling can be incorporated into the interconnection such that the termination can accommodate electrical as well as optical functions.

  13. Simulation on friction taper plug welding of AA6063-20Gr metal matrix composite

    NASA Astrophysics Data System (ADS)

    Hynes, N. Rajesh Jesudoss; Nithin, Abeyram M.

    2016-05-01

    Friction taper plug welding a variant of friction welding is useful in welding of similar and dissimilar materials. It could be used for joining of composites to metals in sophisticated aerospace applications. In the present work numerical simulation of friction taper plug welding process is carried out using finite element based software. Graphite reinforced AA6063 is modelled using the software ANSYS 15.0 and temperature distribution is predicted. Effect of friction time on temperature distribution is numerically investigated. When the friction time is increased to 30 seconds, the tapered part of plug gets detached and fills the hole in the AA6063 plate perfectly.

  14. Effect of flow rate and initial aperture on fractured cement plug subjected to CO2

    NASA Astrophysics Data System (ADS)

    Abdoulghafour, H.; Luquot, L.; Gouze, P.

    2012-04-01

    Effect of flow rate and initial aperture on fractured cement plugs subjected to CO2 rich brine under geo-sequestration conditions Abdoulghafour Halidi, Linda Luquot and Philippe Gouze Laboratoire Géosciences Montpellier, UMR 5243, Montpellier, France (1,3), CSIC Barcelona, Spain(2) Laboratory studies conducted on cement materials under CO2 sequestration conditions, showed evidence of alteration due to CO2 attack.Therefore cement alteration is controlled by hydrodynamic parameters and chemical processes. In this study we present three percolation experiments conducted on fractured cement plugs using the same thermodynamic conditions (T = 60°C, P = 10MPa).Such experiment allow to simulate leakage limestone reservoirs. Hydro-chemical processes were determined based on fluid flow velocity and initial fracture aperture. During experiment conducted on most opened fracture (a0 = 43µm), with high flow rate of 2ml/min and lasted 25h, in situ permeability remains constant for 18h exposure, then decreases to the end of experiment. Similar observation has been seen for experiment conducted on more or less closed fracture (a0~7µm), with very slow flow (0.05) where slow increase of permeability was recorded followed by progressive decrease from 13h to the end of experiment (28h). On the other hand, we performed short-term experiment lasted 6h on intermediate opened fracture (a0 = 27µm), using high flow rate of 2ml/min. Permeability change was recorded during the first hour experiment, then remains constant still the end of CO2 exposure. Chemical analysis performed on outlet fluid match with permeability evolution as they showed the effect of flow rate on dissolution as well as precipitation. From this data set we could evidence the determining role of local velocity of fluid renewal on reaction processes, leading to structures and hydrodynamic changes. Presented results were reproduced using coupled reactive-transport model highlighting the important role of transport

  15. Hybrid and Plug-in Electric Vehicles

    SciTech Connect

    2014-05-20

    Hybrid and plug-in electric vehicles use electricity either as their primary fuel or to improve the efficiency of conventional vehicle designs. This new generation of vehicles, often called electric drive vehicles, can be divided into three categories: hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles(PHEVs), and all-electric vehicles (EVs). Together, they have great potential to reduce U.S. petroleum use.

  16. Controlled evaporation of superfluid helium in a porous plug phase separator

    NASA Astrophysics Data System (ADS)

    Lages, Christopher R.

    1998-12-01

    New cryogenic propulsion system technology to be used on the Relativity Mission (GP-B) and MiniSTEP satellites requires the porous plug to operate in a dynamic environment with variable vent line impedance due to the use of the evaporated vapor as the propellant for the attitude and translational control system (ATCS). Ranges of ATCS thrust requirements for the satellite missions translate into a range of evaporative mass flow which must be provided by the porous plug. The mass flow profile of a porous plug defines its evaporative mass flow behavior during operation. As a porous plug can exhibit an evaporative mass flow profile reducing the overall performance of a cryogenic propulsion system, selection of a flight plug with the correct mass flow profile is of critical importance in system design. Currently, approximate but still incomplete theory in conjunction with experimental iteration provides a means for selecting a porous plug with repeatable flow behavior adequate for flight. An alternate technique of porous plug operation based on the ideal behavior and thermomechanical effect of superfluid helium provides the required mass flow rates, maintains the performance of the cryogenic propulsion system, and reduces iterative testing for flight porous plugs. Heating of the downstream surface of a porous plug while controlling the vent line impedance augments the mass flow through the plug. This technique greatly increases the operational range of the plug while providing the ability to maintain thermodynamic conditions at its downstream surface. Thus, a porous plug can meet extended ranges of mass flow and simultaneously maintain the highest performance of the propulsion system. In this thesis, we have extended this technique by performing experiments with controlled heating of the downstream surface of a porous plug while operating it in its repeatable flow regime. Our results demonstrate the evaporative mass flow rate can be increased in the repeatable flow

  17. Development of GaN-based micro chemical sensor nodes

    NASA Technical Reports Server (NTRS)

    Son, Kyung-ah; Prokopuk, Nicholas; George, Thomas; Moon, Jeong S.

    2005-01-01

    Sensors based on III-N technology are gaining significant interest due to their potential for monolithic integration of RF transceivers and light sources and the capability of high temperature operations. We are developing a GaN-based micro chemical sensor node for remote detection of chemical toxins, and present electrical responses of AlGaN/GaN HEMT (High Electron Mobility Transistor) sensors to chemical toxins as well as other common gases.

  18. Chemical-potential-based lattice Boltzmann method for nonideal fluids

    NASA Astrophysics Data System (ADS)

    Wen, Binghai; Zhou, Xuan; He, Bing; Zhang, Chaoying; Fang, Haiping

    2017-06-01

    Chemical potential, as an important thermodynamic quantity, has been popularly used in thermodynamic modeling for complex systems, especially for those involving the phase transitions and chemical reactions. Here we present a chemical-potential-based multiphase lattice Boltzmann model, in which the nonideal force is directly evaluated by a chemical potential. The numerical computation is more efficient than the pressure-tensor-based model [Wen et al. Europhys. Lett. 112, 44002 (2015), 10.1209/0295-5075/112/44002] because the calculations of the pressure tensor and its divergence are avoided. We have derived several chemical potentials of the popular equations of state from the free-energy density function. The theoretical analyses and numerical results support that the present model satisfies thermodynamics and Galilean invariance. An effective chemical-potential boundary condition is also implemented to investigate the wettability of a solid surface, and the contact angle can be linearly tuned by the surface chemical potential.

  19. Plug Nozzles: Summary of Flow Features and Engine Performance

    DTIC Science & Technology

    2006-01-01

    LV, Les Mureaux, France G.. Hagemann, H.Immich and P. Sacher, Astrium GmbH, Munich, Germany M. Onofri and F. Nasuti, University of Rome "La Sapienza...Base Chamber Design Nozzle exit Ideal Internal Plug Shroud Open/Closed wake transition SURVEY ON PAST AGARD ACTIVITIES prepared by P. Sacher Astrium ...REGARD TO PERFORMANCE Prepared by Gerald Hagemann, and Hans Immich, Astrium GmbH, Space Infrastructure Propulsion, Munich, Germany The aerodynamic

  20. Controlling droplet incubation using close-packed plug flow

    PubMed Central

    Mary, Pascaline; Abate, Adam R.; Agresti, Jeremy J.; Weitz, David A.

    2011-01-01

    Controlling droplet incubation is critical for droplet-based microfluidic applications; however, current techniques are either of limited precision or place strict limits on the incubation times that can be achieved. Here, we present a simple technique to control incubation time by exploiting close-packed plug flow. In contrast to other techniques, this technique is applicable to very short and very long incubation times. PMID:21544238

  1. Roots and promises of chemical-based computing.

    PubMed

    Rambidi, N

    2002-01-01

    General principles of information processing by chemical-based biomolecular systems (pseudobiological information processing paradigm) are discussed. These principles include very large scale parallelism of information processing, high behavioral complexity, complementarity of information features, self-organization, and multilevel architecture. Chemical-based information processing devices using these principles seem to be able to solve effectively problems of high computational complexity.

  2. Cystine plug and other novel mechanisms of large mechanical stability in dimeric proteins.

    PubMed

    Sikora, Mateusz; Cieplak, Marek

    2012-11-16

    We identify three dimeric proteins whose mechanostability is anisotropic and should exceed 1 nN along some directions. They come with distinct mechanical clamps: either shear-based, or involving a cystine slipknot, or due to dragging of a cystine plug through a cystine ring. The latter two mechanisms are topological in nature; the cystine plug mechanism has not yet been discussed but it turns out to provide the largest resistance to stretching. Its possible applications in elastomers are discussed.

  3. Cystine Plug and Other Novel Mechanisms of Large Mechanical Stability in Dimeric Proteins

    NASA Astrophysics Data System (ADS)

    Sikora, Mateusz; Cieplak, Marek

    2012-11-01

    We identify three dimeric proteins whose mechanostability is anisotropic and should exceed 1 nN along some directions. They come with distinct mechanical clamps: either shear-based, or involving a cystine slipknot, or due to dragging of a cystine plug through a cystine ring. The latter two mechanisms are topological in nature; the cystine plug mechanism has not yet been discussed but it turns out to provide the largest resistance to stretching. Its possible applications in elastomers are discussed.

  4. Laser-based Sensors for Chemical Detection

    SciTech Connect

    Myers, Tanya L.; Phillips, Mark C.; Taubman, Matthew S.; Bernacki, Bruce E.; Schiffern, John T.; Cannon, Bret D.

    2010-05-10

    Stand-off detection of hazardous materials ensures that the responder is located at a safe distance from the suspected source. Remote detection and identification of hazardous materials can be accomplished using a highly sensitive and portable device, at significant distances downwind from the source or the threat. Optical sensing methods, in particular infrared absorption spectroscopy combined with quantum cascade lasers (QCLs), are highly suited for the detection of chemical substances since they enable rapid detection and are amenable for autonomous operation in a compact and rugged package. This talk will discuss the sensor systems developed at Pacific Northwest National Laboratory and will discuss the progress to reduce the size and power while maintaining sensitivity to enable stand-off detection of multiple chemicals.

  5. Virus-Based Chemical and Biological Sensing

    PubMed Central

    Mao, Chuanbin; Liu, Aihua; Cao, Binrui

    2009-01-01

    Viruses have recently proven useful for the detection of target analytes such as explosives, proteins, bacteria, viruses, spores, and toxins with high selectivity and sensitivity. Bacteriophages (often shortened to phages), viruses that specifically infect bacteria, are currently the most studied viruses, mainly because target-specific nonlytic phages (and the peptides and proteins carried by them) can be identified by using the well-established phage display technique, and lytic phages can specifically break bacteria to release cell-specific marker molecules such as enzymes that can be assayed. In addition, phages have good chemical and thermal stability, and can be conjugated with nanomaterials and immobilized on a transducer surface in an analytical device. This Review focuses on progress made in the use of phages in chemical and biological sensors in combination with traditional analytical techniques. Recent progress in the use of virus—nanomaterial composites and other viruses in sensing applications is also high-lighted. PMID:19662666

  6. Bioprocessing of bio-based chemicals produced from lignocellulosic feedstocks.

    PubMed

    Kawaguchi, Hideo; Hasunuma, Tomohisa; Ogino, Chiaki; Kondo, Akihiko

    2016-12-01

    The feedstocks used for the production of bio-based chemicals have recently expanded from edible sugars to inedible and more recalcitrant forms of lignocellulosic biomass. To produce bio-based chemicals from renewable polysaccharides, several bioprocessing approaches have been developed and include separate hydrolysis and fermentation (SHF), simultaneous saccharification and fermentation (SSF), and consolidated bioprocessing (CBP). In the last decade, SHF, SSF, and CBP have been used to generate macromolecules and aliphatic and aromatic compounds that are capable of serving as sustainable, drop-in substitutes for petroleum-based chemicals. The present review focuses on recent progress in the bioprocessing of microbially produced chemicals from renewable feedstocks, including starch and lignocellulosic biomass. In particular, the technological feasibility of bio-based chemical production is discussed in terms of the feedstocks and different bioprocessing approaches, including the consolidation of enzyme production, enzymatic hydrolysis of biomass, and fermentation.

  7. Preliminary geochemical and physical testing of materials for plugging of man-made accesses to a repository in basalt

    SciTech Connect

    Taylor, C.L.; Anttonen, G.J.; O'Rourke, J.E.; Allirot, D.

    1980-04-01

    The available data on environmental conditions (both natural and man-made) at the Hanford Site are sufficient for preconceptual plug system design. Results of the geochemical testing program indicate that preferred candidate plug materials are chemically nonreactive during laboratory tests that simulated some of the expected environmental conditions. Agitated, crushed-basalt samples and mixtures containing basalt were found to be self-cementing under the hydrothermal conditions. Materials considered most suitable for consideration in future test programs and preconceptual plug design are mixtures of natural materials (basalt, clay, glaciofluvial sand, gravel, and zeolite) and processed natural materials (portland cement Type V and grouts plus additives).

  8. System and method for charging a plug-in electric vehicle

    DOEpatents

    Bassham, Marjorie A.; Spigno, Jr., Ciro A.; Muller, Brett T.; Newhouse, Vernon L.

    2017-05-02

    A charging system and method that may be used to automatically apply customized charging settings to a plug-in electric vehicle, where application of the settings is based on the vehicle's location. According to an exemplary embodiment, a user may establish and save a separate charging profile with certain customized charging settings for each geographic location where they plan to charge their plug-in electric vehicle. Whenever the plug-in electric vehicle enters a new geographic area, the charging method may automatically apply the charging profile that corresponds to that area. Thus, the user does not have to manually change or manipulate the charging settings every time they charge the plug-in electric vehicle in a new location.

  9. Microfluidic cartridges preloaded with nanoliter plugs of reagents: an alternative to 96-well plates for screening

    PubMed Central

    Chen, Delai L; Ismagilov, Rustem F

    2006-01-01

    In traditional screening with 96-well plates, microliters of substrates are consumed for each reaction. Further miniaturization is limited by the special equipment and techniques required to dispense nanoliter volumes of fluid. Plug-based microfluidics confines reagents in nanoliter plugs (droplets surrounded by fluorinated carrier fluid), and uses simple pumps to control the flow of plugs. By using cartridges pre-loaded with nanoliter plugs of reagents, only two pumps and a merging junction are needed to set up a screen. Screening with preloaded cartridges uses only nanoliters of substrate per reaction, and requires no microfabrication. The low cost and simplicity of this method has the potential of replacing 96-well and other multi-well plates, and has been applied to enzymatic assays, protein crystallization and optimization of organic reactions. PMID:16677848

  10. Simultaneous bioassays in a microfluidic channel on plugs of different magnetic particles.

    PubMed

    Bronzeau, Sandrine; Pamme, Nicole

    2008-02-18

    Magnetic particles coated with specific biomolecules are often used as solid supports for bioassays but conventional test tube based techniques are time consuming and labour intensive. An alternative is to work on magnetic particle plugs immobilised inside microfluidic channels. Most research so far has focussed on immobilising one type of particle to perform one type of assay. Here we demonstrate how several assays can be performed simultaneously by flushing a sample solution over several plugs of magnetic particles with different surface coatings. Within a microchannel, three plugs of magnetic particles were immobilised with external magnets. The particles featured surface coatings of glycine, streptavidin and protein A, respectively. Reagents were then flushed through the three plugs. Molecular binding occurred between matching antigens and antibodies in continuous flow and was detected by fluorescence. This first demonstration opens the door to a quicker and easier technique for simultaneous bioassays using magnetic particles.

  11. Nozzle dam having a unitary plug

    DOEpatents

    Veronesi, Luciano; Wepfer, Robert M.

    1992-01-01

    Apparatus for sealing the primary-side coolant flow nozzles of a nuclear steam generator. The steam generator has relatively small diameter manway openings for providing access to the interior of the steam generator including the inside surface of each nozzle, the manway openings having a diameter substantially less than the inside diameter of each nozzle. The apparatus includes a bracket having an outside surface for matingly sealingly engaging the inside surface of the nozzle. The bracket also has a plurality of openings longitudinally therethrough and a plurality of slots transversely therein in communication with each opening. A plurality of unitary plugs sized to pass through the manway opening are matingly sealingly disposed in each opening of the bracket for sealingly plugging each opening. Each plug includes a plurality of arms operable to engage the slots of the bracket for connecting each plug to the bracket, so that the nozzle is sealed as the plugs seal the openings and are connected to the bracket.

  12. Underwater connect and disconnect plug and receptacle

    NASA Astrophysics Data System (ADS)

    Dodier, Paul J.

    1989-06-01

    A plug and receptacle combination is transformer coupled. There are no exposed contacts to the environment at any time, whether the plug and receptacle combination are mated or separated from each other. By encapsulating the primary winding and secondary winding separately in a respective plug and receptacle, mating and unmating can be accomplished while submerged in water. The inventive device is useful in any underwater activity in which a diver must attach a power cable to a power driven tool, light, pump, etc., while submerged. In addition submarines could have the receptacles installed outboard of the pressure hull to be used in the event it became disabled at a depth attainable by a diver. A diver could descend with cables and plug them into the receptacles providing power and communications to the stranded crew awaiting rescue. The inventions could also be used in the home as a safety device where no voltage would be exposed. Either the plug or the receptacle shown could be built into the wall. Whichever items is built into the wall would receive the power source and have the primary winding.

  13. Nozzle dam having a unitary plug

    DOEpatents

    Veronesi, L.; Wepfer, R.M.

    1992-12-15

    Apparatus for sealing the primary-side coolant flow nozzles of a nuclear steam generator is disclosed. The steam generator has relatively small diameter manway openings for providing access to the interior of the steam generator including the inside surface of each nozzle, the manway openings having a diameter substantially less than the inside diameter of each nozzle. The apparatus includes a bracket having an outside surface for matingly sealingly engaging the inside surface of the nozzle. The bracket also has a plurality of openings longitudinally therethrough and a plurality of slots transversely therein in communication with each opening. A plurality of unitary plugs sized to pass through the manway opening are matingly sealingly disposed in each opening of the bracket for sealingly plugging each opening. Each plug includes a plurality of arms operable to engage the slots of the bracket for connecting each plug to the bracket, so that the nozzle is sealed as the plugs seal the openings and are connected to the bracket. 16 figs.

  14. Aeroacoustics of a porous plug jet noise suppressor

    NASA Technical Reports Server (NTRS)

    Dosanjh, D. S.

    1981-01-01

    The aeroacoustics of a porous plug jet noise suppressor was investigated. The predicted flow features of isentropic plug nozzles for different pressure ratios or exit flow Mach numbers, throat areas, ratios of the plug to annular nozzle radii, mass flow rates and the available run times possible with the existing compressed air supply system, are compiled. The dimensions and the coordinates of the contour of typical isentropic external expansion plugs with different exit flow Mach numbers are listed. Design details of the experimental facility and the plug nozzle selected for experimental aeroacoustic studies are reported. The analytical flow prediction by method of characteristics of a conical porous plug nozzles is initiated. The role of the shape, size, and porosity of the plug surface in achieving over a perforated conical plug a nearly isentropic shockfree supersonic flow field which is closely similar to the flow field of a contoured isentropic plug nozzle is examined.

  15. Finding candidate drugs for hepatitis C based on chemical-chemical and chemical-protein interactions.

    PubMed

    Chen, Lei; Lu, Jing; Huang, Tao; Yin, Jun; Wei, Lai; Cai, Yu-Dong

    2014-01-01

    Hepatitis C virus (HCV) is an infectious virus that can cause serious illnesses. Only a few drugs have been reported to effectively treat hepatitis C. To have greater diversity in drug choice and better treatment options, it is necessary to develop more drugs to treat the infection. However, it is time-consuming and expensive to discover candidate drugs using experimental methods, and computational methods may complement experimental approaches as a preliminary filtering process. This type of approach was proposed by using known chemical-chemical interactions to extract interactive compounds with three known drug compounds of HCV, and the probabilities of these drug compounds being able to treat hepatitis C were calculated using chemical-protein interactions between the interactive compounds and HCV target genes. Moreover, the randomization test and expectation-maximization (EM) algorithm were both employed to exclude false discoveries. Analysis of the selected compounds, including acyclovir and ganciclovir, indicated that some of these compounds had potential to treat the HCV. Hopefully, this proposed method could provide new insights into the discovery of candidate drugs for the treatment of HCV and other diseases.

  16. Predicting drugs side effects based on chemical-chemical interactions and protein-chemical interactions.

    PubMed

    Chen, Lei; Huang, Tao; Zhang, Jian; Zheng, Ming-Yue; Feng, Kai-Yan; Cai, Yu-Dong; Chou, Kuo-Chen

    2013-01-01

    A drug side effect is an undesirable effect which occurs in addition to the intended therapeutic effect of the drug. The unexpected side effects that many patients suffer from are the major causes of large-scale drug withdrawal. To address the problem, it is highly demanded by pharmaceutical industries to develop computational methods for predicting the side effects of drugs. In this study, a novel computational method was developed to predict the side effects of drug compounds by hybridizing the chemical-chemical and protein-chemical interactions. Compared to most of the previous works, our method can rank the potential side effects for any query drug according to their predicted level of risk. A training dataset and test datasets were constructed from the benchmark dataset that contains 835 drug compounds to evaluate the method. By a jackknife test on the training dataset, the 1st order prediction accuracy was 86.30%, while it was 89.16% on the test dataset. It is expected that the new method may become a useful tool for drug design, and that the findings obtained by hybridizing various interactions in a network system may provide useful insights for conducting in-depth pharmacological research as well, particularly at the level of systems biomedicine.

  17. Predicting Drugs Side Effects Based on Chemical-Chemical Interactions and Protein-Chemical Interactions

    PubMed Central

    Chen, Lei; Huang, Tao; Zhang, Jian; Zheng, Ming-Yue; Feng, Kai-Yan; Cai, Yu-Dong; Chou, Kuo-Chen

    2013-01-01

    A drug side effect is an undesirable effect which occurs in addition to the intended therapeutic effect of the drug. The unexpected side effects that many patients suffer from are the major causes of large-scale drug withdrawal. To address the problem, it is highly demanded by pharmaceutical industries to develop computational methods for predicting the side effects of drugs. In this study, a novel computational method was developed to predict the side effects of drug compounds by hybridizing the chemical-chemical and protein-chemical interactions. Compared to most of the previous works, our method can rank the potential side effects for any query drug according to their predicted level of risk. A training dataset and test datasets were constructed from the benchmark dataset that contains 835 drug compounds to evaluate the method. By a jackknife test on the training dataset, the 1st order prediction accuracy was 86.30%, while it was 89.16% on the test dataset. It is expected that the new method may become a useful tool for drug design, and that the findings obtained by hybridizing various interactions in a network system may provide useful insights for conducting in-depth pharmacological research as well, particularly at the level of systems biomedicine. PMID:24078917

  18. Burst Test Qualification Analysis of DWPF Canister-Plug Weld

    SciTech Connect

    Gupta, N.K.; Gong, Chung

    1995-02-01

    The DWPF canister closure system uses resistance welding for sealing the canister nozzle and plug to ensure leak tightness. The welding group at SRTC is using the burst test to qualify this seal weld in lieu of the shear test in ASME B&PV Code, Section IX, paragraph QW-196. The burst test is considered simpler and more appropriate than the shear test for this application. Although the geometry, loading and boundary conditions are quite different in the two tests, structural analyses show similarity in the failure mode of the shear test in paragraph QW-196 and the burst test on the DWPF canister nozzle Non-linear structural analyses are performed using finite element techniques to study the failure mode of the two tests. Actual test geometry and realistic stress strain data for the 304L stainless steel and the weld material are used in the analyses. The finite element models are loaded until failure strains are reached. The failure modes in both tests are shear at the failure points. Based on these observations, it is concluded that the use of a burst test in lieu of the shear test for qualifying the canister-plug weld is acceptable. The burst test analysis for the canister-plug also yields the burst pressures which compare favorably with the actual pressure found during burst tests. Thus, the analysis also provides an estimate of the safety margins in the design of these vessels.

  19. Construction of a Linux based chemical and biological information system.

    PubMed

    Molnár, László; Vágó, István; Fehér, András

    2003-01-01

    A chemical and biological information system with a Web-based easy-to-use interface and corresponding databases has been developed. The constructed system incorporates all chemical, numerical and textual data related to the chemical compounds, including numerical biological screen results. Users can search the database by traditional textual/numerical and/or substructure or similarity queries through the web interface. To build our chemical database management system, we utilized existing IT components such as ORACLE or Tripos SYBYL for database management and Zope application server for the web interface. We chose Linux as the main platform, however, almost every component can be used under various operating systems.

  20. Chemical compound navigator: a web-based chem-BLAST, chemical taxonomy-based search engine for browsing compounds.

    PubMed

    Prasanna, M D; Vondrasek, Jiri; Wlodawer, Alexander; Rodriguez, H; Bhat, T N

    2006-06-01

    A novel technique to annotate, query, and analyze chemical compounds has been developed and is illustrated by using the inhibitor data on HIV protease-inhibitor complexes. In this method, all chemical compounds are annotated in terms of standard chemical structural fragments. These standard fragments are defined by using criteria, such as chemical classification; structural, chemical, or functional groups; and commercial, scientific or common names or synonyms. These fragments are then organized into a data tree based on their chemical substructures. Search engines have been developed to use this data tree to enable query on inhibitors of HIV protease (http://xpdb.nist.gov/hivsdb/hivsdb.html). These search engines use a new novel technique, Chemical Block Layered Alignment of Substructure Technique (Chem-BLAST) to search on the fragments of an inhibitor to look for its chemical structural neighbors. This novel technique to annotate and query compounds lays the foundation for the use of the Semantic Web concept on chemical compounds to allow end users to group, sort, and search structural neighbors accurately and efficiently. During annotation, it enables the attachment of "meaning" (i.e., semantics) to data in a manner that far exceeds the current practice of associating "metadata" with data by creating a knowledge base (or ontology) associated with compounds. Intended users of the technique are the research community and pharmaceutical industry, for which it will provide a new tool to better identify novel chemical structural neighbors to aid drug discovery.

  1. Chemical Mixture Risk Assessment Additivity-Based Approaches

    EPA Science Inventory

    Powerpoint presentation includes additivity-based chemical mixture risk assessment methods. Basic concepts, theory and example calculations are included. Several slides discuss the use of "common adverse outcomes" in analyzing phthalate mixtures.

  2. Chemical Mixture Risk Assessment Additivity-Based Approaches

    EPA Science Inventory

    Powerpoint presentation includes additivity-based chemical mixture risk assessment methods. Basic concepts, theory and example calculations are included. Several slides discuss the use of "common adverse outcomes" in analyzing phthalate mixtures.

  3. Comprehensive Review of the Literature on Existing Punctal Plugs for the Management of Dry Eye Disease.

    PubMed

    Jehangir, Naz; Bever, Greg; Mahmood, S M Jafar; Moshirfar, Majid

    2016-01-01

    Numerous designs of punctal and canalicular plugs are available on the market. This variety presents challenges to ophthalmologists when choosing punctal plugs for the management of various ocular conditions. The aim of this literature review is to provide a classification system for lacrimal occlusive devices based on their location and duration of action as well as to identify different characteristics of each one of them. We want to give a comprehensive overview on punctal and canalicular plugs including their manufacturing companies, indications, and complications that have been reported in various articles. PubMed and Google Scholar were used to identify articles written in English as well as few articles written in Japanese, Chinese, Slovak, and Spanish that had abstracts in English. Nine different companies that manufacture punctal and canalicular plugs were identified and their plugs were included in this review. Punctal and canalicular plugs are used in the management of various ocular conditions including dry eye disease and punctal stenosis as well as in ocular drug delivery. Although they are a relatively safe option, associated complications have been reported in the literature such as infection, allergic reaction, extrusion, and migration.

  4. Comprehensive Review of the Literature on Existing Punctal Plugs for the Management of Dry Eye Disease

    PubMed Central

    Jehangir, Naz; Bever, Greg; Mahmood, S. M. Jafar; Moshirfar, Majid

    2016-01-01

    Numerous designs of punctal and canalicular plugs are available on the market. This variety presents challenges to ophthalmologists when choosing punctal plugs for the management of various ocular conditions. The aim of this literature review is to provide a classification system for lacrimal occlusive devices based on their location and duration of action as well as to identify different characteristics of each one of them. We want to give a comprehensive overview on punctal and canalicular plugs including their manufacturing companies, indications, and complications that have been reported in various articles. PubMed and Google Scholar were used to identify articles written in English as well as few articles written in Japanese, Chinese, Slovak, and Spanish that had abstracts in English. Nine different companies that manufacture punctal and canalicular plugs were identified and their plugs were included in this review. Punctal and canalicular plugs are used in the management of various ocular conditions including dry eye disease and punctal stenosis as well as in ocular drug delivery. Although they are a relatively safe option, associated complications have been reported in the literature such as infection, allergic reaction, extrusion, and migration. PMID:27088009

  5. A Decision Analytic Approach to Exposure-Based Chemical ...

    EPA Pesticide Factsheets

    The manufacture of novel synthetic chemicals has increased in volume and variety, but often the environmental and health risks are not fully understood in terms of toxicity and, in particular, exposure. While efforts to assess risks have generally been effective when sufficient data are available, the hazard and exposure data necessary to assess risks adequately are unavailable for the vast majority of chemicals in commerce. The US Environmental Protection Agency has initiated the ExpoCast Program to develop tools for rapid chemical evaluation based on potential for exposure. In this context, a model is presented in which chemicals are evaluated based on inherent chemical properties and behaviorally-based usage characteristics over the chemical’s life cycle. These criteria are assessed and integrated within a decision analytic framework, facilitating rapid assessment and prioritization for future targeted testing and systems modeling. A case study outlines the prioritization process using 51 chemicals. The results show a preliminary relative ranking of chemicals based on exposure potential. The strength of this approach is the ability to integrate relevant statistical and mechanistic data with expert judgment, allowing for an initial tier assessment that can further inform targeted testing and risk management strategies. The National Exposure Research Laboratory′s (NERL′s) Human Exposure and Atmospheric Sciences Division (HEASD) conducts research in suppor

  6. A Decision Analytic Approach to Exposure-Based Chemical Prioritization

    PubMed Central

    Mitchell, Jade; Pabon, Nicolas; Collier, Zachary A.; Egeghy, Peter P.; Cohen-Hubal, Elaine; Linkov, Igor; Vallero, Daniel A.

    2013-01-01

    The manufacture of novel synthetic chemicals has increased in volume and variety, but often the environmental and health risks are not fully understood in terms of toxicity and, in particular, exposure. While efforts to assess risks have generally been effective when sufficient data are available, the hazard and exposure data necessary to assess risks adequately are unavailable for the vast majority of chemicals in commerce. The US Environmental Protection Agency has initiated the ExpoCast Program to develop tools for rapid chemical evaluation based on potential for exposure. In this context, a model is presented in which chemicals are evaluated based on inherent chemical properties and behaviorally-based usage characteristics over the chemical’s life cycle. These criteria are assessed and integrated within a decision analytic framework, facilitating rapid assessment and prioritization for future targeted testing and systems modeling. A case study outlines the prioritization process using 51 chemicals. The results show a preliminary relative ranking of chemicals based on exposure potential. The strength of this approach is the ability to integrate relevant statistical and mechanistic data with expert judgment, allowing for an initial tier assessment that can further inform targeted testing and risk management strategies. PMID:23940664

  7. Automation of static and dynamic non-dispersive liquid phase microextraction. Part 1: Approaches based on extractant drop-, plug-, film- and microflow-formation.

    PubMed

    Alexovič, Michal; Horstkotte, Burkhard; Solich, Petr; Sabo, Ján

    2016-02-04

    Simplicity, effectiveness, swiftness, and environmental friendliness - these are the typical requirements for the state of the art development of green analytical techniques. Liquid phase microextraction (LPME) stands for a family of elegant sample pretreatment and analyte preconcentration techniques preserving these principles in numerous applications. By using only fractions of solvent and sample compared to classical liquid-liquid extraction, the extraction kinetics, the preconcentration factor, and the cost efficiency can be increased. Moreover, significant improvements can be made by automation, which is still a hot topic in analytical chemistry. This review surveys comprehensively and in two parts the developments of automation of non-dispersive LPME methodologies performed in static and dynamic modes. Their advantages and limitations and the reported analytical performances are discussed and put into perspective with the corresponding manual procedures. The automation strategies, techniques, and their operation advantages as well as their potentials are further described and discussed. In this first part, an introduction to LPME and their static and dynamic operation modes as well as their automation methodologies is given. The LPME techniques are classified according to the different approaches of protection of the extraction solvent using either a tip-like (needle/tube/rod) support (drop-based approaches), a wall support (film-based approaches), or microfluidic devices. In the second part, the LPME techniques based on porous supports for the extraction solvent such as membranes and porous media are overviewed. An outlook on future demands and perspectives in this promising area of analytical chemistry is finally given.

  8. Thin-film chemical sensors based on electron tunneling

    NASA Technical Reports Server (NTRS)

    Khanna, S. K.; Lambe, J.; Leduc, H. G.; Thakoor, A. P.

    1985-01-01

    The physical mechanisms underlying a novel chemical sensor based on electron tunneling in metal-insulator-metal (MIM) tunnel junctions were studied. Chemical sensors based on electron tunneling were shown to be sensitive to a variety of substances that include iodine, mercury, bismuth, ethylenedibromide, and ethylenedichloride. A sensitivity of 13 parts per billion of iodine dissolved in hexane was demonstrated. The physical mechanisms involved in the chemical sensitivity of these devices were determined to be the chemical alteration of the surface electronic structure of the top metal electrode in the MIM structure. In addition, electroreflectance spectroscopy (ERS) was studied as a complementary surface-sensitive technique. ERS was shown to be sensitive to both iodine and mercury. Electrolyte electroreflectance and solid-state MIM electroreflectance revealed qualitatively the same chemical response. A modified thin-film structure was also studied in which a chemically active layer was introduced at the top Metal-Insulator interface of the MIM devices. Cobalt phthalocyanine was used for the chemically active layer in this study. Devices modified in this way were shown to be sensitive to iodine and nitrogen dioxide. The chemical sensitivity of the modified structure was due to conductance changes in the active layer.

  9. Chemical characterization of carbohydrate-based biosurfactants

    USDA-ARS?s Scientific Manuscript database

    High-yield, glycolipid-based biosurfactants are of increasing interest for use in environmentally benign cleaning or emulsifying agents. We have developed a MALDI-TOF/MS screen for the rapid analysis of several types of biosurfactants, including various acylated rhamnolipids in Pseudomonas extracts...

  10. Weighted voting-based consensus clustering for chemical structure databases

    NASA Astrophysics Data System (ADS)

    Saeed, Faisal; Ahmed, Ali; Shamsir, Mohd Shahir; Salim, Naomie

    2014-06-01

    The cluster-based compound selection is used in the lead identification process of drug discovery and design. Many clustering methods have been used for chemical databases, but there is no clustering method that can obtain the best results under all circumstances. However, little attention has been focused on the use of combination methods for chemical structure clustering, which is known as consensus clustering. Recently, consensus clustering has been used in many areas including bioinformatics, machine learning and information theory. This process can improve the robustness, stability, consistency and novelty of clustering. For chemical databases, different consensus clustering methods have been used including the co-association matrix-based, graph-based, hypergraph-based and voting-based methods. In this paper, a weighted cumulative voting-based aggregation algorithm (W-CVAA) was developed. The MDL Drug Data Report (MDDR) benchmark chemical dataset was used in the experiments and represented by the AlogP and ECPF_4 descriptors. The results from the clustering methods were evaluated by the ability of the clustering to separate biologically active molecules in each cluster from inactive ones using different criteria, and the effectiveness of the consensus clustering was compared to that of Ward's method, which is the current standard clustering method in chemoinformatics. This study indicated that weighted voting-based consensus clustering can overcome the limitations of the existing voting-based methods and improve the effectiveness of combining multiple clusterings of chemical structures.

  11. Plug-in hybrid electric vehicle R&D plan

    SciTech Connect

    None, None

    2007-06-01

    FCVT, in consultation with industry and other appropriate DOE offices, developed the Draft Plug-In Hybrid Electric Vehicle R&D Plan to accelerate the development and deployment of technologies critical for plug-in hybrid vehicles.

  12. Jet noise suppression by porous plug nozzles

    NASA Technical Reports Server (NTRS)

    Bauer, A. B.; Kibens, V.; Wlezien, R. W.

    1982-01-01

    Jet noise suppression data presented earlier by Maestrello for porous plug nozzles were supplemented by the testing of a family of nozzles having an equivalent throat diameter of 11.77 cm. Two circular reference nozzles and eight plug nozzles having radius ratios of either 0.53 or 0.80 were tested at total pressure ratios of 1.60 to 4.00. Data were taken both with and without a forward motion or coannular flow jet, and some tests were made with a heated jet. Jet thrust was measured. The data were analyzed to show the effects of suppressor geometry on nozzle propulsive efficiency and jet noise. Aerodynamic testing of the nozzles was carried out in order to study the physical features that lead to the noise suppression. The aerodynamic flow phenomena were examined by the use of high speed shadowgraph cinematography, still shadowgraphs, extensive static pressure probe measurements, and two component laser Doppler velocimeter studies. The different measurement techniques correlated well with each other and demonstrated that the porous plug changes the shock cell structure of a standard nozzle into a series of smaller, periodic cell structures without strong shock waves. These structures become smaller in dimension and have reduced pressure variations as either the plug diameter or the porosity is increased, changes that also reduce the jet noise and decrease thrust efficiency.

  13. Bond strength of cementitious borehole plugs in welded tuff

    SciTech Connect

    Akgun, H.; Daemen, J.J.K.

    1991-02-01

    Axial loads on plugs or seals in an underground repository due to gas, water pressures and temperature changes induced subsequent to waste and plug emplacement lead to shear stresses at the plug/rock contact. Therefore, the bond between the plug and rock is a critical element for the design and effectiveness of plugs in boreholes, shafts or tunnels. This study includes a systematic investigation of the bond strength of cementitious borehole plugs in welded tuff. Analytical and numerical analysis of borehole plug-rock stress transfer mechanics is performed. The interface strength and deformation are studied as a function of Young`s modulus ratio of plug and rock, plug length and rock cylinder outside-to-inside radius ratio. The tensile stresses in and near an axially loaded plug are analyzed. The frictional interface strength of an axially loaded borehole plug, the effect of axial stress and lateral external stress, and thermal effects are also analyzed. Implications for plug design are discussed. The main conclusion is a strong recommendation to design friction plugs in shafts, drifts, tunnels or boreholes with a minimum length to diameter ratio of four. Such a geometrical design will reduce tensile stresses in the plug and in the host rock to a level which should minimize the risk of long-term deterioration caused by excessive tensile stresses. Push-out tests have been used to determine the bond strength by applying an axial load to cement plugs emplaced in boreholes in welded tuff cylinders. A total of 130 push-out tests have been performed as a function of borehole size, plug length, temperature, and degree of saturation of the host tuff. The use of four different borehole radii enables evaluation of size effects. 119 refs., 42 figs., 20 tabs.

  14. Safety upgrades plug car leaks

    SciTech Connect

    Not Available

    1993-08-01

    To lessen the chance of a chemical leak occurring during rail transport, some companies are improving tank car sturdiness and safety by adding such features as top-loading valves, on-board monitoring devices, and thicker, more impact-resistant hulls. Results include a dramatic drop in the number of rail incidents and leak tank cars. Chemicals Division of Olin Corporation (Stamford, Connecticut) has assigned its name to a new fleet of chlorine, caustic soda and toluene diisocyanate (TDI) tank cars. Each car carries the company's Care[trademark]Car registered trademark. The upgrade is part of a company-wide quality improvement process started in 1986. The company requires acoustic emissions (AE) testing on all hazardous materials tank cars. If an area has a defect, it expands and makes a slight sound when subjected to stress. In an AE test, cars are subject to simulated bumps and jolts as in rail shipment. Electronic sensors transfer any stress noises onto a computer screen, where an operator can pinpoint the trouble source.

  15. Carbon Nanotube-Based Chemical Sensors.

    PubMed

    Meyyappan, M

    2016-04-27

    The need to sense gases and vapors arises in numerous scenarios in industrial, environmental, security and medical applications. Traditionally, this activity has utilized bulky instruments to obtain both qualitative and quantitative information on the constituents of the gas mixture. It is ideal to use sensors for this purpose since they are smaller in size and less expensive; however, their performance in the field must match that of established analytical instruments in order to gain acceptance. In this regard, nanomaterials as sensing media offer advantages in sensitivity, preparation of chip-based sensors and construction of electronic nose for selective detection of analytes of interest. This article provides a review of the use of carbon nanotubes in gas and vapor sensing. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Proposal for dark exciton based chemical sensors

    PubMed Central

    Feierabend, Maja; Berghäuser, Gunnar; Knorr, Andreas; Malic, Ermin

    2017-01-01

    The rapidly increasing use of sensors throughout different research disciplines and the demand for more efficient devices with less power consumption depends critically on the emergence of new sensor materials and novel sensor concepts. Atomically thin transition metal dichalcogenides have a huge potential for sensor development within a wide range of applications. Their optimal surface-to-volume ratio combined with strong light–matter interaction results in a high sensitivity to changes in their surroundings. Here, we present a highly efficient sensing mechanism to detect molecules based on dark excitons in these materials. We show that the presence of molecules with a dipole moment transforms dark states into bright excitons, resulting in an additional pronounced peak in easy accessible optical spectra. This effect exhibits a huge potential for sensor applications, since it offers an unambiguous optical fingerprint for the detection of molecules—in contrast to common sensing schemes relying on small peak shifts and intensity changes. PMID:28294110

  17. Proposal for dark exciton based chemical sensors.

    PubMed

    Feierabend, Maja; Berghäuser, Gunnar; Knorr, Andreas; Malic, Ermin

    2017-03-15

    The rapidly increasing use of sensors throughout different research disciplines and the demand for more efficient devices with less power consumption depends critically on the emergence of new sensor materials and novel sensor concepts. Atomically thin transition metal dichalcogenides have a huge potential for sensor development within a wide range of applications. Their optimal surface-to-volume ratio combined with strong light-matter interaction results in a high sensitivity to changes in their surroundings. Here, we present a highly efficient sensing mechanism to detect molecules based on dark excitons in these materials. We show that the presence of molecules with a dipole moment transforms dark states into bright excitons, resulting in an additional pronounced peak in easy accessible optical spectra. This effect exhibits a huge potential for sensor applications, since it offers an unambiguous optical fingerprint for the detection of molecules-in contrast to common sensing schemes relying on small peak shifts and intensity changes.

  18. Proposal for dark exciton based chemical sensors

    NASA Astrophysics Data System (ADS)

    Feierabend, Maja; Berghäuser, Gunnar; Knorr, Andreas; Malic, Ermin

    2017-03-01

    The rapidly increasing use of sensors throughout different research disciplines and the demand for more efficient devices with less power consumption depends critically on the emergence of new sensor materials and novel sensor concepts. Atomically thin transition metal dichalcogenides have a huge potential for sensor development within a wide range of applications. Their optimal surface-to-volume ratio combined with strong light-matter interaction results in a high sensitivity to changes in their surroundings. Here, we present a highly efficient sensing mechanism to detect molecules based on dark excitons in these materials. We show that the presence of molecules with a dipole moment transforms dark states into bright excitons, resulting in an additional pronounced peak in easy accessible optical spectra. This effect exhibits a huge potential for sensor applications, since it offers an unambiguous optical fingerprint for the detection of molecules--in contrast to common sensing schemes relying on small peak shifts and intensity changes.

  19. Genetic and phenotypic influences on copulatory plug survival in mice

    PubMed Central

    Mangels, R; Young, B; Keeble, S; Ardekani, R; Meslin, C; Ferreira, Z; Clark, N L; Good, J M; Dean, M D

    2015-01-01

    Across a diversity of animals, male seminal fluid coagulates upon ejaculation to form a hardened structure known as a copulatory plug. Previous studies suggest that copulatory plugs evolved as a mechanism for males to impede remating by females, but detailed investigations into the time course over which plugs survive in the female's reproductive tract are lacking. Here, we cross males from eight inbred strains to females from two inbred strains of house mice (Mus musculus domesticus). Plug survival was significantly affected by male genotype. Against intuition, plug survival time was negatively correlated with plug size: long-lasting plugs were small and relatively more susceptible to proteolysis. Plug size was associated with divergence in major protein composition of seminal vesicle fluid, suggesting that changes in gene expression may play an important role in plug dynamics. In contrast, we found no correlation to genetic variation in the protein-coding regions of five genes thought to be important in copulatory plug formation (Tgm4, Svs1, Svs2, Svs4 and Svs5). Our study demonstrates a complex relationship between copulatory plug characteristics and survival. We discuss several models to explain unexpected variation in plug phenotypes. PMID:26103947

  20. 40 CFR 146.92 - Injection well plugging.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 24 2012-07-01 2012-07-01 false Injection well plugging. 146.92... to Class VI Wells § 146.92 Injection well plugging. (a) Prior to the well plugging, the owner or operator must flush each Class VI injection well with a buffer fluid, determine bottomhole reservoir...

  1. 40 CFR 146.92 - Injection well plugging.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 23 2014-07-01 2014-07-01 false Injection well plugging. 146.92... to Class VI Wells § 146.92 Injection well plugging. (a) Prior to the well plugging, the owner or operator must flush each Class VI injection well with a buffer fluid, determine bottomhole reservoir...

  2. 40 CFR 146.92 - Injection well plugging.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 24 2013-07-01 2013-07-01 false Injection well plugging. 146.92... to Class VI Wells § 146.92 Injection well plugging. (a) Prior to the well plugging, the owner or operator must flush each Class VI injection well with a buffer fluid, determine bottomhole reservoir...

  3. 21 CFR 878.4755 - Absorbable lung biopsy plug.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Absorbable lung biopsy plug. 878.4755 Section 878...) MEDICAL DEVICES GENERAL AND PLASTIC SURGERY DEVICES Surgical Devices § 878.4755 Absorbable lung biopsy plug. (a) Identification. A preformed (polymerized) absorbable lung biopsy plug is intended to...

  4. 40 CFR 146.92 - Injection well plugging.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 23 2011-07-01 2011-07-01 false Injection well plugging. 146.92 Section 146.92 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS... to Class VI Wells § 146.92 Injection well plugging. (a) Prior to the well plugging, the owner...

  5. Chemically modified graphene based supercapacitors for flexible and miniature devices

    NASA Astrophysics Data System (ADS)

    Ghosh, Debasis; Kim, Sang Ouk

    2015-09-01

    Rapid progress in the portable and flexible electronic devises has stimulated supercapacitor research towards the design and fabrication of high performance flexible devices. Recent research efforts for flexible supercapacitor electrode materials are highly focusing on graphene and chemically modified graphene owing to the unique properties, including large surface area, high electrical and thermal conductivity, excellent mechanical flexibility, and outstanding chemical stability. This invited review article highlights current status of the flexible electrode material research based on chemically modified graphene for supercapacitor application. A variety of electrode architectures prepared from chemically modified graphene are summarized in terms of their structural dimensions. Novel prototypes for the supercapacitor aiming at flexible miniature devices, i.e. microsupercapacitor with high energy and power density are highlighted. Future challenges relevant to graphene-based flexible supercapacitors are also suggested. [Figure not available: see fulltext.

  6. Efficient exploration of chemical space by fragment-based screening.

    PubMed

    Hall, Richard J; Mortenson, Paul N; Murray, Christopher W

    2014-01-01

    Screening methods seek to sample a vast chemical space in order to identify starting points for further chemical optimisation. Fragment based drug discovery exploits the superior sampling of chemical space that can be achieved when the molecular weight is restricted. Here we show that commercially available fragment space is still relatively poorly sampled and argue for highly sensitive screening methods to allow the detection of smaller fragments. We analyse the properties of our fragment library versus the properties of X-ray hits derived from the library. We particularly consider properties related to the degree of planarity of the fragments.

  7. Compact Fluorescent Plug-In Ballast-in-a-Socket

    SciTech Connect

    Rebecca Voelker

    2001-12-21

    The primary goal of this program was to develop a ballast system for plug-in CFLs (compact fluorescent lamps) that will directly replace standard metal shell, medium base incandescent lampholders (such as Levition No. 6098) for use with portable lamp fixtures, such as floor, table and desk lamps. A secondary goal was to identify a plug-in CFL that is optimized for use with this ballast. This Plug-in CFL Ballastin-a-Socket system will allow fixture manufacturers to easily manufacture CFL-based high-efficacy portable fixtures that provide residential and commercial consumers with attractive, cost-effective, and energy-efficient fixtures for use wherever portable incandescent fixtures are used today. The advantages of this proposed system over existing CFL solutions are that the fixtures can only be used with high-efficacy CFLs, and they will be more attractive and will have lower life-cycle costs than screw-in or adapter-based CFL retrofit solutions. These features should greatly increase the penetration of CFL's into the North American market. Our work has shown that using integrated circuits it is quite feasible to produce a lamp-fixture ballast of a size comparable to the current Edison-screw 3-way incandescent fixtures. As for price points for BIAS-based fixtures, end-users polled by the Lighting Research Institute at RPI indicated that they would pay as much as an additional $10 for a lamp containing such a ballast. The ballast has been optimized to run with a 26 W amalgam triple biax lamp in the base-down position, yet can accept non-amalgam versions of the lamp. With a few part alterations, the ballast can be produced to support 32 W lamps as well. The ballast uses GE's existing L-Comp[1] power topology in the circuit so that the integrated circuit design would be a design that could possibly be used by other CFL and EFL products with minor modifications. This gives added value by reducing cost and size of not only the BIAS, but also possibly other integral

  8. Learning of Chemical Equilibrium through Modelling-Based Teaching

    ERIC Educational Resources Information Center

    Maia, Poliana Flavia; Justi, Rosaria

    2009-01-01

    This paper presents and discusses students' learning process of chemical equilibrium from a modelling-based approach developed from the use of the "Model of Modelling" diagram. The investigation was conducted in a regular classroom (students 14-15 years old) and aimed at discussing how modelling-based teaching can contribute to students…

  9. Learning of Chemical Equilibrium through Modelling-Based Teaching

    ERIC Educational Resources Information Center

    Maia, Poliana Flavia; Justi, Rosaria

    2009-01-01

    This paper presents and discusses students' learning process of chemical equilibrium from a modelling-based approach developed from the use of the "Model of Modelling" diagram. The investigation was conducted in a regular classroom (students 14-15 years old) and aimed at discussing how modelling-based teaching can contribute to students…

  10. Plasmonics Based Harsh Environment Compatible Chemical Sensors

    SciTech Connect

    Michael Carpenter

    2012-01-15

    Au-YSZ, Au-TiO{sub 2} and Au-CeO{sub 2} nanocomposite films have been investigated as a potential sensing element for high-temperature plasmonic sensing of H{sub 2}, CO, and NO{sub 2} in an oxygen containing environment. The Au-YSZ and Au-TiO{sub 2} films were deposited using PVD methods, while the CeO{sub 2} thin film was deposited by molecular beam epitaxy (MBE) and Au was implanted into the as-grown film at an elevated temperature followed by high temperature annealing to form well-defined Au nanoclusters. Each of the films were characterized by x-ray diffraction (XRD) and Rutherford backscattering spectrometry (RBS). For the gas sensing experiments, separate exposures to varying concentrations of H{sub 2}, CO, and NO{sub 2} were performed at a temperature of 500°C in oxygen backgrounds of 5.0, 10, and ~21% O{sub 2}. Changes in the localized surface plasmon resonance (LSPR) absorption peak were monitored during gas exposures and are believed to be the result of oxidation-reduction processes that fill or create oxygen vacancies in the respective metal oxides. This process affects the LSPR peak position either by charge exchange with the Au nanoparticles or by changes in the dielectric constant surrounding the particles. Hyperspectral multivariate analysis was used to gauge the inherent selectivity of the film between the separate analytes. From principal component analysis (PCA), unique and identifiable responses were seen for each of the analytes. Linear discriminant analysis (LDA) was also used on the Au-CeO{sub 2} results and showed separation between analytes as well as trends in gas concentration. Results indicate that each of the films are is selective towards O{sub 2}, H{sub 2}, CO, and NO{sub 2} in separate exposures. However, when the films were analyzed in a sensor array based experiment, ie simultaneous exposures to the target gases, PCA analysis of the combined response showed an even greater selective character towards the target gases. Combined

  11. Plug-In Hybrid Electric Vehicle Penetration Scenarios

    SciTech Connect

    Balducci, Patrick J.

    2008-04-03

    This report examines the economic drivers, technology constraints, and market potential for plug-in hybrid electric vehicles (PHEVs) in the U.S. A PHEV is a hybrid vehicle with batteries that can be recharged by connecting to the grid and an internal combustion engine that can be activated when batteries need recharging. The report presents and examines a series of PHEV market penetration scenarios. Based on input received from technical experts and industry representative contacted for this report and data obtained through a literature review, annual market penetration rates for PHEVs are presented from 2013 through 2045 for three scenarios. Each scenario is examined and implications for PHEV development are explored.

  12. High-Throughput Models for Exposure-Based Chemical ...

    EPA Pesticide Factsheets

    The United States Environmental Protection Agency (U.S. EPA) must characterize potential risks to human health and the environment associated with manufacture and use of thousands of chemicals. High-throughput screening (HTS) for biological activity allows the ToxCast research program to prioritize chemical inventories for potential hazard. Similar capabilities for estimating exposure potential would support rapid risk-based prioritization for chemicals with limited information; here, we propose a framework for high-throughput exposure assessment. To demonstrate application, an analysis was conducted that predicts human exposure potential for chemicals and estimates uncertainty in these predictions by comparison to biomonitoring data. We evaluated 1936 chemicals using far-field mass balance human exposure models (USEtox and RAIDAR) and an indicator for indoor and/or consumer use. These predictions were compared to exposures inferred by Bayesian analysis from urine concentrations for 82 chemicals reported in the National Health and Nutrition Examination Survey (NHANES). Joint regression on all factors provided a calibrated consensus prediction, the variance of which serves as an empirical determination of uncertainty for prioritization on absolute exposure potential. Information on use was found to be most predictive; generally, chemicals above the limit of detection in NHANES had consumer/indoor use. Coupled with hazard HTS, exposure HTS can place risk earlie

  13. Lubricant base stock potential of chemically modified vegetable oils.

    PubMed

    Erhan, Sevim Z; Sharma, Brajendra K; Liu, Zengshe; Adhvaryu, Atanu

    2008-10-08

    The environment must be protected against pollution caused by lubricants based on petroleum oils. The pollution problem is so severe that approximately 50% of all lubricants sold worldwide end up in the environment via volatility, spills, or total loss applications. This threat to the environment can be avoided by either preventing undesirable losses, reclaiming and recycling mineral oil lubricants, or using environmentally friendly lubricants. Vegetable oils are recognized as rapidly biodegradable and are thus promising candidates as base fluids in environment friendly lubricants. Lubricants based on vegetable oils display excellent tribological properties, high viscosity indices, and flash points. To compete with mineral-oil-based lubricants, some of their inherent disadvantages, such as poor oxidation and low-temperature stability, must be corrected. One way to address these problems is chemical modification of vegetable oils at the sites of unsaturation. After a one-step chemical modification, the chemically modified soybean oil derivatives were studied for thermo-oxidative stability using pressurized differential scanning calorimetry and a thin-film micro-oxidation test, low-temperature fluid properties using pour-point measurements, and friction-wear properties using four-ball and ball-on-disk configurations. The lubricants formulated with chemically modified soybean oil derivatives exhibit superior low-temperature flow properties, improved thermo-oxidative stability, and better friction and wear properties. The chemically modified soybean oil derivatives having diester substitution at the sites of unsaturation have potential in the formulation of industrial lubricants.

  14. Analytical and experimental study of axisymmetric truncated plug nozzle flow fields

    NASA Technical Reports Server (NTRS)

    Muller, T. J.; Sule, W. P.; Fanning, A. E.; Giel, T. V.; Galanga, F. L.

    1972-01-01

    Experimental and analytical investigation of the flow field and base pressure of internal-external-expansion truncated plug nozzles are discussed. Experimental results for two axisymmetric, conical plug-cylindrical shroud, truncated plug nozzles are presented for both open and closed wake operations. These results include extensive optical and pressure data covering nozzle flow field and base pressure characteristics, diffuser effects, lip shock strength, Mach disc behaviour, and the recompression and reverse flow regions. Transonic experiments for a special planar transonic section are presented. An extension of the analytical method of Hall and Mueller to include the internal shock wave from the shroud exit is presented for closed wake operation. Results of this analysis include effects on the flow field and base pressure of ambient pressure ratio, nozzle geometry, and the ratio of specific heats. Static thrust is presented as a function of ambient pressure ratio and nozzle geometry. A new transonic solution method is also presented.

  15. Laser-based instrumentation for the detection of chemical agents

    SciTech Connect

    Hartford, A. Jr.; Sander, R.K.; Quigley, G.P.; Radziemski, L.J.; Cremers, D.A.

    1982-01-01

    Several laser-based techniques are being evaluated for the remote, point, and surface detection of chemical agents. Among the methods under investigation are optoacoustic spectroscopy, laser-induced breakdown spectroscopy (LIBS), and synchronous detection of laser-induced fluorescence (SDLIF). Optoacoustic detection has already been shown to be capable of extremely sensitive point detection. Its application to remote sensing of chemical agents is currently being evaluated. Atomic emission from the region of a laser-generated plasma has been used to identify the characteristic elements contained in nerve (P and F) and blister (S and Cl) agents. Employing this LIBS approach, detection of chemical agent simulants dispersed in air and adsorbed on a variety of surfaces has been achieved. Synchronous detection of laser-induced fluorescence provides an attractive alternative to conventional LIF, in that an artificial narrowing of the fluorescence emission is obtained. The application of this technique to chemical agent simulants has been successfully demonstrated. 19 figures.

  16. Chemical and structural effects of base modifications in messenger RNA

    NASA Astrophysics Data System (ADS)

    Harcourt, Emily M.; Kietrys, Anna M.; Kool, Eric T.

    2017-01-01

    A growing number of nucleobase modifications in messenger RNA have been revealed through advances in detection and RNA sequencing. Although some of the biochemical pathways that involve modified bases have been identified, research into the world of RNA modification -- the epitranscriptome -- is still in an early phase. A variety of chemical tools are being used to characterize base modifications, and the structural effects of known base modifications on RNA pairing, thermodynamics and folding are being determined in relation to their putative biological roles.

  17. Simulating Chemical Kinetics Without Differential Equations: A Quantitative Theory Based on Chemical Pathways.

    PubMed

    Bai, Shirong; Skodje, Rex T

    2017-08-17

    A new approach is presented for simulating the time-evolution of chemically reactive systems. This method provides an alternative to conventional modeling of mass-action kinetics that involves solving differential equations for the species concentrations. The method presented here avoids the need to solve the rate equations by switching to a representation based on chemical pathways. In the Sum Over Histories Representation (or SOHR) method, any time-dependent kinetic observable, such as concentration, is written as a linear combination of probabilities for chemical pathways leading to a desired outcome. In this work, an iterative method is introduced that allows the time-dependent pathway probabilities to be generated from a knowledge of the elementary rate coefficients, thus avoiding the pitfalls involved in solving the differential equations of kinetics. The method is successfully applied to the model Lotka-Volterra system and to a realistic H2 combustion model.

  18. Industry perspectives on Plug-& -Play Spacecraft Avionics

    NASA Astrophysics Data System (ADS)

    Franck, R.; Graven, P.; Liptak, L.

    This paper describes the methodologies and findings from an industry survey of awareness and utility of Spacecraft Plug-& -Play Avionics (SPA). The survey was conducted via interviews, in-person and teleconference, with spacecraft prime contractors and suppliers. It focuses primarily on AFRL's SPA technology development activities but also explores the broader applicability and utility of Plug-& -Play (PnP) architectures for spacecraft. Interviews include large and small suppliers as well as large and small spacecraft prime contractors. Through these “ product marketing” interviews, awareness and attitudes can be assessed, key technical and market barriers can be identified, and opportunities for improvement can be uncovered. Although this effort focuses on a high-level assessment, similar processes can be used to develop business cases and economic models which may be necessary to support investment decisions.

  19. Damage Tolerance Assessment of Friction Pull Plug Welds in an Aluminum Alloy

    NASA Technical Reports Server (NTRS)

    McGill, Preston; Burkholder, Jonathan

    2012-01-01

    Friction stir welding is a solid state welding process used in the fabrication of cryogenic propellant tanks. Self-reacting friction stir welding is one variation of the friction stir weld process being developed for manufacturing tanks. Friction pull plug welding is used to seal the exit hole that remains in a circumferential self-reacting friction stir weld. A friction plug weld placed in a self-reacting friction stir weld results in a non-homogenous weld joint where the initial weld, plug weld, their respective heat affected zones and the base metal all interact. The welded joint is a composite plastically deformed material system with a complex residual stress field. In order to address damage tolerance concerns associated with friction plug welds in safety critical structures, such as propellant tanks, nondestructive inspection and proof testing may be required to screen hardware for mission critical defects. The efficacy of the nondestructive evaluation or the proof test is based on an assessment of the critical flaw size. Test data relating residual strength capability to flaw size in an aluminum alloy friction plug weld will be presented.

  20. Frequency Response of Multipoint Chemical Shift Based Spectral Decomposition

    PubMed Central

    Brodsky, Ethan K.; Chebrolu, Venkata V.; Block, Walter F.; Reeder, Scott B.

    2010-01-01

    PURPOSE To provide a framework for characterizing the frequency response of multi-point chemical shift based species separation techniques. MATERIALS AND METHODS Multi-point chemical shift based species separation techniques acquire complex images at multiple echo times and perform maximum likelihood estimation to decompose signal from different species into separate images. In general, after a non-linear process of estimating and demodulating the field map, these decomposition methods are linear transforms from the echo-time domain to the chemical-shift-frequency domain, analogous to the Discrete Fourier Transform (DFT). In this work, we describe a technique for finding the magnitude and phase of chemical shift decomposition for input signals over a range of frequencies using numerical and experimental modeling and examine several important cases of species separation. RESULTS Simple expressions can be derived to describe the response to a wide variety of input signals. Agreement between numerical modeling and experimental results is very good. CONCLUSION Chemical shift based species separation is linear, and therefore can be fully described by the magnitude and phase curves of the frequency response. The periodic nature of the frequency response has important implications for the robustness of various techniques for resolving ambiguities in field inhomogeneity. PMID:20882625

  1. Plug into a Great Outlet for Creativity

    ERIC Educational Resources Information Center

    Skophammer, Karen

    2009-01-01

    Is there beauty in the wall socket that people plug their appliances into daily? Can one find beauty in the grate covering the heat vent in his classroom? The author posed these very questions to her third-grade students. She had the students take a good look at the outlet cover (or plate) on the wall. After thinking and discussing the outlets,…

  2. Plug into a Great Outlet for Creativity

    ERIC Educational Resources Information Center

    Skophammer, Karen

    2009-01-01

    Is there beauty in the wall socket that people plug their appliances into daily? Can one find beauty in the grate covering the heat vent in his classroom? The author posed these very questions to her third-grade students. She had the students take a good look at the outlet cover (or plate) on the wall. After thinking and discussing the outlets,…

  3. Detecting Chemically Modified DNA Bases Using Surface Enhanced Raman Spectroscopy.

    PubMed

    Barhoumi, Aoune; Halas, Naomi J

    2011-12-15

    Post-translational modifications of DNA- changes in the chemical structure of individual bases that occur without changes in the DNA sequence- are known to alter gene expression. They are believed to result in frequently deleterious phenotypic changes, such as cancer. Methylation of adenine, methylation and hydroxymethylation of cytosine, and guanine oxidation are the primary DNA base modifications identified to date. Here we show it is possible to use surface enhanced Raman spectroscopy (SERS) to detect these primary DNA base modifications. SERS detection of modified DNA bases is label-free and requires minimal additional sample preparation, reducing the possibility of additional chemical modifications induced prior to measurement. This approach shows the feasibility of DNA base modification assessment as a potentially routine analysis that may be further developed for clinical diagnostics.

  4. Regulation of platelet plug formation by phosphoinositide metabolism

    PubMed Central

    Min, Sang H.

    2013-01-01

    Phosphatidylinositol and its phosphorylated derivatives, phosphoinositides, are minor constituents of phospholipids at the cellular membrane level. Nevertheless, phosphatidylinositol and phosphoinositides represent essential components of intracellular signaling that regulate diverse cellular processes, including platelet plug formation. Accumulating evidence indicates that the metabolism of phosphoinositides is temporally and spatially modulated by the opposing effects of specific phosphoinositide-metabolizing enzymes, including lipid kinases, lipid phosphatases, and phospholipases. Each of these enzymes generates a selective phosphoinositide or second messenger within precise cellular compartments. Intriguingly, phosphoinositide-metabolizing enzymes exist in different isoforms, which all produce the same phosphoinositide products. Recent studies using isoform-specific mouse models and chemical inhibitors have elucidated that the different isoforms of phosphoinositide-metabolizing enzymes have nonredundant functions and provide an additional layer of complexity to the temporo-spatial organization of intracellular signaling events. In this review, we will discuss recent advances in our understanding of phosphoinositide organization during platelet activation. PMID:23757731

  5. A novel hydrogel plug of Sterculia urens for pulsatile delivery: in vitro and in vivo evaluation.

    PubMed

    Amrutkar, Jitendra R; Gattani, Surendra G

    2012-01-01

    The objective of this study was to investigate a novel hydrogel plug using isolated root mucilage of Sterculia urens to obtain a desired lag time for an oral chronotherapeutic colon-specific pulsatile drug delivery of indomethacin. Pulsatile drug delivery was developed using chemically treated hard gelatin capsule bodies filled with eudragit multiparticulates of indomethacin, and sealed with different hydrogel plugs (root mucilage of S. urens, xanthan gum, guar gum, HPMC K4M and combination of maltodextrin with guar gum). Indomethacin multiparticulates were prepared using extrusion spheronization, spray drying and solvent evaporation techniques with Eudragit® L-100 and S-100 (1:2) by varying drug-to-polymer ratio. After oral administration, the water-soluble cap of capsule dissolved in the intestinal fluid and the hydrogel plug swells. After a controlled time, the swollen plug subsequently ejected from the dosage form, releases the contents of the capsule. The formulation factors affecting the drug release were concentration and types of hydrogel plug used. In vivo gamma scintigraphy study in healthy rabbits proved the capability of the system to release drug in lower parts of the gastrointestinal tract after a programmed lag time. This study demonstrates that the indomethacin multiparticulates could be successfully colon-targeted by the design of time and pH-dependent modified chronopharmaceutical formulation. In conclusion, the investigated novel hydrogel plug could be a valuable tool for achieving desired lag time.

  6. Problem-Based Learning for Large Classes in Chemical Engineering.

    ERIC Educational Resources Information Center

    Woods, Donald R.

    1996-01-01

    Two McMaster University (Canada) chemical engineering courses enrolling 30-50 students incorporate problem-based learning (PBL). Issues addressed in implementation included overcoming faculty and student resistance, integrating PBL methods within a predominantly conventional curriculum, developing PBL problems and objectives, and using tutorless…

  7. Chemical Information in Scirus and BASE (Bielefeld Academic Search Engine)

    ERIC Educational Resources Information Center

    Bendig, Regina B.

    2009-01-01

    The author sought to determine to what extent the two search engines, Scirus and BASE (Bielefeld Academic Search Engines), would be useful to first-year university students as the first point of searching for chemical information. Five topics were searched and the first ten records of each search result were evaluated with regard to the type of…

  8. Chemical Information in Scirus and BASE (Bielefeld Academic Search Engine)

    ERIC Educational Resources Information Center

    Bendig, Regina B.

    2009-01-01

    The author sought to determine to what extent the two search engines, Scirus and BASE (Bielefeld Academic Search Engines), would be useful to first-year university students as the first point of searching for chemical information. Five topics were searched and the first ten records of each search result were evaluated with regard to the type of…

  9. A Reduced-dimension Model of Liquid Plug Propagation in Tubes

    NASA Astrophysics Data System (ADS)

    Halpern, David; Fujioka, Hideki; Ryans, Jason; Gaver, Donald

    2016-11-01

    We developed a reduced dimensional model of the flow resistance by the motion of a viscous plug through a liquid lined tube. This is motivated by our interest in developing large-scale models of interfacial flows in pulmonary networks. Unfortunately, full CFD calculations are not viable, so we propose a semi-empirical formula for the resistance as a function of plug length, capillary number (Ca) and precursor film thickness. We developed CFD-based empirical relationships for the resistance contributors (front and rear meniscus and the plug core). The front meniscus resistance varies with Ca and the precursor film thickness. The rear meniscus resistance increases monotonically with decreasing Ca. We use a Poiseuille model in the core region, so the resistance linearly increases with plug length. With this we estimate the max wall shear and normal stress and gradients. The results show that for fingers of air propagating through airways, the epithelial cell damage correlates with the pressure gradient. However, for shorter plugs the front meniscus may provide substantial stresses that could modulate this behavior and may influence cell injury.

  10. Effect of clustering on linear plug nozzle flow field for overexpanded internal jet

    NASA Astrophysics Data System (ADS)

    Chutkey, K.; Viji, M.; Verma, S. B.

    2017-07-01

    Experiments were carried out to analyze the flow field development of a linear plug nozzle wherein the internal nozzle was operating in the overexpanded regime. Steady and unsteady pressure measurements were taken along with the schlieren and oil flow visualization techniques to describe the flow field. Over the range of pressure ratios considered, the overexpanded shock pattern from the internal nozzle has been explained with regard to differential end conditions on either side of the core jet. The unsteady characteristics of the pressure fluctuations have been discussed with respect to the foot of the overexpansion shock on the plug surface. The effect of internal nozzle clustering on the plug nozzle flow field has been studied for two different cluster nozzles. The cluster module jet wave interactions along the spanwise direction have been explained with respect to the limiting streamline pattern on the plug surface. In addition to these, the base flow characteristics for these overexpanded internal nozzle pressure ratios have been discussed for two different truncated plug lengths.

  11. Magnetic and gravity modeling of a Paleogene diabase plug in Northeast Brazil

    NASA Astrophysics Data System (ADS)

    Damaceno, Juliana G.; de Castro, David Lopes; Valcácio, Samir N.; Souza, Zorano S.

    2017-01-01

    A joint magnetic and gravity survey was carried out in a Cenozoic magmatic plug in the northernmost of the Brazilian equatorial margin. The São João plug (0.5 km2) is located in the southern border of the Potiguar Basin, belonging to the N-S oriented Macau-Queimadas Alignment formed by Macau magmatism, the youngest magmatism of the Borborema Province. This plug is hosted in Açu and Jandaíra formations, composed of sandstones and limestones that suffered significant thermal changes. The study area is located in a region characterized by a sequence of magnetic highs and lows. Based on the MaxMin technique, no significant remnant magnetization could be detected in the magmatic body. We measured magnetic susceptibility and density of the igneous rocks and their metamorphic and sedimentary bedrocks. The thermal metamorphism promoted an overall increase of bulk density. Joint magnetic and gravity modeling revealed the complex internal geometry of the São João plug, formed by a 400-m deep, probably a lopolith like body with a magmatic conduit as deep as 970 m. In addition, 3D modeling allowed mapping other igneous bodies, with no superficial expression, near to the studied plug.

  12. Effect of clustering on linear plug nozzle flow field for overexpanded internal jet

    NASA Astrophysics Data System (ADS)

    Chutkey, K.; Viji, M.; Verma, S. B.

    2017-01-01

    Experiments were carried out to analyze the flow field development of a linear plug nozzle wherein the internal nozzle was operating in the overexpanded regime. Steady and unsteady pressure measurements were taken along with the schlieren and oil flow visualization techniques to describe the flow field. Over the range of pressure ratios considered, the overexpanded shock pattern from the internal nozzle has been explained with regard to differential end conditions on either side of the core jet. The unsteady characteristics of the pressure fluctuations have been discussed with respect to the foot of the overexpansion shock on the plug surface. The effect of internal nozzle clustering on the plug nozzle flow field has been studied for two different cluster nozzles. The cluster module jet wave interactions along the spanwise direction have been explained with respect to the limiting streamline pattern on the plug surface. In addition to these, the base flow characteristics for these overexpanded internal nozzle pressure ratios have been discussed for two different truncated plug lengths.

  13. Magnetic-resonance-based system for chemical agent screening

    NASA Astrophysics Data System (ADS)

    Kumar, Sankaran; Magnuson, Erik E.; Newman, David E.; Prado, Pablo J.; Lawton, Jess

    2003-09-01

    Quantum Magnetics is developing a system based on magnetic resonance (MR), combined with a proprietary technology, to screen for chemical agents in nonmetallic containers, without the need to open the container. It derives from the successful design and testing of a similar system for detecting liquid explosives. Preliminary measurements indicate that the system promises to quickly screen for many chemical agents and to offer an unambiguous hazard/safe result. The system will be designed to be portable and easy to operate, to need minimal human interpretation, and to be ideal for operation at checkpoints, government building, airports, and the like.

  14. Effects of inertia and gravity on liquid plug splitting at a bifurcation.

    PubMed

    Zheng, Y; Fujioka, H; Grotberg, J C; Grotberg, J B

    2006-10-01

    Liquid plugs may form in pulmonary airways during the process of liquid instillation or removal in many clinical treatments. During inspiration the plug may split at airway bifurcations and lead to a nonuniform final liquid distribution, which can adversely affect treatment outcomes. In this paper, a combination of bench top experimental and theoretical studies is presented to study the effects of inertia and gravity on plug splitting in an airway bifurcation model to simulate the liquid distributions in large airways. The splitting ratio, Rs, is defined as the ratio of the plug volume entering the upper (gravitationally opposed) daughter tube to the lower (gravitationally favored) one. Rs is measured as a function of parent tube Reynolds number, Rep; gravitational orientations for roll angle, phi, and pitch angle, gamma; parent plug length LP; and the presence of pre-existing plug blockages in downstream daughter tubes. Results show that increasing Rep causes more homogeneous splitting. A critical Reynolds number Rec is found to exist so that when Rep < or = Rec, Rs = 0, i.e., no liquid enters the upper daughter tube. Rec increases while Rs decreases with increasing the gravitational effect, i.e., increasing phi and gamma. When a blockage exists in the lower daughter, Rec is only found at phi = 60 deg in the range of Rep studied, and the resulting total mass ratio can be as high as 6, which also asymptotes to a finite value for different phi as Rep increases. Inertia is further demonstrated to cause more homogeneous plug splitting from a comparison study of Rs versus Cap (another characteristic speed) for three liquids: water, glycerin, and LB-400X. A theoretical model based on entrance flow for the plug in the daughters is developed and predicts Rs versus Rep. The frictional pressure drop, as a part of the total pressure drop, is estimated by two fitting parameters and shows a linear relationship with Rep. The theory provides a good prediction on liquid plug

  15. Plug flow cytometry extends analytical capabilities in cell adhesion and receptor pharmacology.

    PubMed

    Edwards, B S; Kuckuck, F W; Prossnitz, E R; Okun, A; Ransom, J T; Sklar, L A

    2001-03-01

    Plug flow cytometry is a recently developed system for the automated delivery of multiple small boluses or "plugs" of cells or particles to the flow cytometer for analysis. Important system features are that sample plugs are of precisely defined volume and that the sample vessel need not be pressurized. We describe how these features enable direct cell concentration determinations and novel ways to integrate flow cytometers with other analytical instruments. Adhesion assays employed human polymorphonuclear neutrophils (PMNs) loaded with Fura Red and Chinese hamster ovary (CHO) cells cotransfected with genes for green fluorescent protein (GFP) and human P-selectin. U937 cells expressing the human 7-transmembrane formyl peptide receptor were loaded with the fluorescent probe indo-1 for intracellular ionized calcium determinations. A computer-controlled syringe or peristaltic pump loaded the sample into a sample loop of the plug flow coupler, a reciprocating eight-port valve. When the valve position was switched, the plug of sample in the sample loop was transported to the flow cytometer by a pressure-driven fluid line. In stirred mixtures of PMNs and CHO cells, we used plug flow cytometry to directly quantify changes in concentrations of nonadherent singlet PMNs. This approach enabled accurate quantification of adherent PMNs in multicell aggregates. We constructed a novel plug flow interface between the flow cytometer and a cone-plate viscometer to enable real-time flow cytometric analysis of cell-cell adhesion under conditions of uniform shear. The High Throughput Pharmacology System (HTPS) is an instrument used for automated programming of complex pharmacological cell treatment protocols. It was interfaced via the plug flow coupling device to enable rapid (< 5 min) flow cytometric characterization of the intracellular calcium dose-response profile of U937 cells to formyl peptide. By facilitating the coupling of flow cytometers to other fluidics-based analytical

  16. Progress in chemical luminescence-based biosensors: A critical review.

    PubMed

    Roda, Aldo; Mirasoli, Mara; Michelini, Elisa; Di Fusco, Massimo; Zangheri, Martina; Cevenini, Luca; Roda, Barbara; Simoni, Patrizia

    2016-02-15

    Biosensors are a very active research field. They have the potential to lead to low-cost, rapid, sensitive, reproducible, and miniaturized bioanalytical devices, which exploit the high binding avidity and selectivity of biospecific binding molecules together with highly sensitive detection principles. Of the optical biosensors, those based on chemical luminescence detection (including chemiluminescence, bioluminescence, electrogenerated chemiluminescence, and thermochemiluminescence) are particularly attractive, due to their high-to-signal ratio and the simplicity of the required measurement equipment. Several biosensors based on chemical luminescence have been described for quantitative, and in some cases multiplex, analysis of organic molecules (such as hormones, drugs, pollutants), proteins, and nucleic acids. These exploit a variety of miniaturized analytical formats, such as microfluidics, microarrays, paper-based analytical devices, and whole-cell biosensors. Nevertheless, despite the high analytical performances described in the literature, the field of chemical luminescence biosensors has yet to demonstrate commercial success. This review presents the main recent advances in the field and discusses the approaches, challenges, and open issues, with the aim of stimulating a broader interest in developing chemical luminescence biosensors and improving their commercial exploitation. Copyright © 2015 Elsevier B.V. All rights reserved.

  17. Cascaded classifiers for confidence-based chemical named entity recognition.

    PubMed

    Corbett, Peter; Copestake, Ann

    2008-11-19

    Chemical named entities represent an important facet of biomedical text. We have developed a system to use character-based n-grams, Maximum Entropy Markov Models and rescoring to recognise chemical names and other such entities, and to make confidence estimates for the extracted entities. An adjustable threshold allows the system to be tuned to high precision or high recall. At a threshold set for balanced precision and recall, we were able to extract named entities at an F score of 80.7% from chemistry papers and 83.2% from PubMed abstracts. Furthermore, we were able to achieve 57.6% and 60.3% recall at 95% precision, and 58.9% and 49.1% precision at 90% recall. These results show that chemical named entities can be extracted with good performance, and that the properties of the extraction can be tuned to suit the demands of the task.

  18. Cascaded classifiers for confidence-based chemical named entity recognition

    PubMed Central

    Corbett, Peter; Copestake, Ann

    2008-01-01

    Background Chemical named entities represent an important facet of biomedical text. Results We have developed a system to use character-based n-grams, Maximum Entropy Markov Models and rescoring to recognise chemical names and other such entities, and to make confidence estimates for the extracted entities. An adjustable threshold allows the system to be tuned to high precision or high recall. At a threshold set for balanced precision and recall, we were able to extract named entities at an F score of 80.7% from chemistry papers and 83.2% from PubMed abstracts. Furthermore, we were able to achieve 57.6% and 60.3% recall at 95% precision, and 58.9% and 49.1% precision at 90% recall. Conclusion These results show that chemical named entities can be extracted with good performance, and that the properties of the extraction can be tuned to suit the demands of the task. PMID:19025690

  19. A constrained tracking algorithm to optimize plug patterns in multiple isocenter Gamma Knife radiosurgery planning

    SciTech Connect

    Li Kaile; Ma Lijun

    2005-10-15

    We developed a source blocking optimization algorithm for Gamma Knife radiosurgery, which is based on tracking individual source contributions to arbitrarily shaped target and critical structure volumes. A scalar objective function and a direct search algorithm were used to produce near real-time calculation results. The algorithm allows the user to set and vary the total number of plugs for each shot to limit the total beam-on time. We implemented and tested the algorithm for several multiple-isocenter Gamma Knife cases. It was found that the use of limited number of plugs significantly lowered the integral dose to the critical structures such as an optical chiasm in pituitary adenoma cases. The main effect of the source blocking is the faster dose falloff in the junction area between the target and the critical structure. In summary, we demonstrated a useful source-plugging algorithm for improving complex multi-isocenter Gamma Knife treatment planning cases.

  20. A DNA-based assay for toxic chemicals in wastewater.

    PubMed

    Foreman, Amy L; Phillips, Leo; Kanellis, Vangelis G; Hammoudeh, Daoud; Naumann, Christoph; Wong, Henri; Chisari, Robert; Hibbert, D Brynn; Lee, Garry S H; Patra, Ronald; Julli, Moreno; Chapman, John; Cooke, A Roger; dos Remedios, Cristobal G

    2011-08-01

    Chemical toxicants, particularly metal ions, are a major contaminant in global waterways. Live-organism bioassays used to monitor chemical toxicants commonly involve measurements of activity or survival of a freshwater cladoceran (Ceriodaphnia dubia) or light emitted by the marine bacterium Vibrio fischeri, used in the commercial Microtox® bioassay. Here we describe a novel molecule-based assay system employing DNA as the chemical biosensor. Metals bind to DNA, causing structural changes that expel a bound (intercalated) fluorescent reporter dye. Analyses of test data using 48 wastewater samples potentially contaminated by metal ions show that the DNA-dye assay results correlate with those from C. dubia and Microtox bioassays. All three assays exhibit additive, antagonistic, and synergistic responses that cannot be predicted by knowing individual metal concentrations. Analyses of metals in these samples imply the presence of chemical toxicants other than metal ions. The DNA-dye assay is robust, has a 12-month shelf life, and is only slightly affected by sample pH in the range 4 to 9. The assay is completed in a matter of minutes, and its portability makes it well suited as a screening assay for use in the field. We conclude that the DNA-dye test is a surrogate bioassay suitable for screening chemical toxicity.

  1. Microstructural and Chemical Rejuvenation of a Ni-Based Superalloy

    NASA Astrophysics Data System (ADS)

    Yao, Zhiqi; Degnan, Craig C.; Jepson, Mark A. E.; Thomson, Rachel C.

    2016-12-01

    The microstructural evolution of the Ni-based superalloy CMSX-4 including the change in gamma prime morphology, size, and distribution after high-temperature degradation and subsequent rejuvenation heat treatments has been examined using field emission gun scanning electron microscopy and transmission electron microscopy. In this paper, it is shown that there are significant differences in the size of the `channels' between gamma prime particles, the degree of rafting, and the size of tertiary gamma prime particles in each of the different microstructural conditions studied. Chemical analysis has been carried out to compare rejuvenated and pre-service samples after the same subsequent degradation procedure. The results indicate that although the microstructures of pre-service and rejuvenated samples are similar, chemical differences are more pronounced in the rejuvenated samples, suggesting that chemical segregation from partitioning of the elements was not completely eliminated through the applied rejuvenation heat treatment. A number of modified rejuvenation heat treatment trials were carried out to reduce the chemical segregation prior to creep testing. The creep test results suggest that chemical segregation has an immeasurable influence on the short-term mechanical properties under the test conditions used here, indicating that further work is required to fully understand the suitability of specific rejuvenation heat treatments and their role in the extension of component life in power plant applications.

  2. Plug-in to Eclipse environment for VHDL source code editor with advanced formatting of text

    NASA Astrophysics Data System (ADS)

    Niton, B.; Pozniak, K. T.; Romaniuk, R. S.

    2011-10-01

    The paper describes an idea and realization of a smart plug-in to the Eclipse software environment. The plug-in is predicted for editing of the VHDL source code. It extends considerably the capabilities of the VEditor program, which bases on the open license. There are presented the results of the formatting procedures performed on chosen examples of the VHDL source codes. The work is a part of a bigger project of building smart programming environment for design of advanced photonic and electronic systems. The examples of such systems are quoted in references.

  3. Chemical preparation of graphene-based nanomaterials and their applications in chemical and biological sensors.

    PubMed

    Jiang, Hongji

    2011-09-05

    Graphene is a flat monolayer of carbon atoms packed tightly into a 2D honeycomb lattice that shows many intriguing properties meeting the key requirements for the implementation of highly excellent sensors, and all kinds of proof-of-concept sensors have been devised. To realize the potential sensor applications, the key is to synthesize graphene in a controlled way to achieve enhanced solution-processing capabilities, and at the same time to maintain or even improve the intrinsic properties of graphene. Several production techniques for graphene-based nanomaterials have been developed, ranging from the mechanical cleavage and chemical exfoliation of high-quality graphene to direct growth onto different substrates and the chemical routes using graphite oxide as a precusor to the newly developed bottom-up approach at the molecular level. The current review critically explores the recent progress on the chemical preparation of graphene-based nanomaterials and their applications in sensors. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. A Plug and Play GNC Architecture Using FPGA Components

    NASA Technical Reports Server (NTRS)

    KrishnaKumar, K.; Kaneshige, J.; Waterman, R.; Pires, C.; Ippoloito, C.

    2005-01-01

    The goal of Plug and Play, or PnP, is to allow hardware and software components to work together automatically, without requiring manual setup procedures. As a result, new or replacement hardware can be plugged into a system and automatically configured with the appropriate resource assignments. However, in many cases it may not be practical or even feasible to physically replace hardware components. One method for handling these types of situations is through the incorporation of reconfigurable hardware such as Field Programmable Gate Arrays, or FPGAs. This paper describes a phased approach to developing a Guidance, Navigation, and Control (GNC) architecture that expands on the traditional concepts of PnP, in order to accommodate hardware reconfiguration without requiring detailed knowledge of the hardware. This is achieved by establishing a functional based interface that defines how the hardware will operate, and allow the hardware to reconfigure itself. The resulting system combines the flexibility of manipulating software components with the speed and efficiency of hardware.

  5. Effects of Distortion on Mass Flow Plug Calibration

    NASA Technical Reports Server (NTRS)

    Sasson, Jonathan; Davis, David O.; Barnhart, Paul J.

    2015-01-01

    A numerical, and experimental investigation to study the effects of flow distortion on a Mass Flow Plug (MFP) used to control and measure mass-flow during an inlet test has been conducted. The MFP was first calibrated using the WIND-US flow solver for uniform (undistorted) inflow conditions. These results are shown to compare favorably with an experimental calibration under similar conditions. The effects of distortion were investigated by imposing distorted flow conditions taken from an actual inlet test to the inflow plane of the numerical simulation. The computational fluid dynamic (CFD) based distortion study only showed the general trend in mass flow rate. The study used only total pressure as the upstream boundary condition, which was not enough to define the flow. A better simulation requires knowledge of the turbulence structure and a specific distortion pattern over a range of plug positions. It is recommended that future distortion studies utilize a rake with at least the same amount of pitot tubes as the AIP rake.

  6. Results from the Bell Canyon borehole plugging test

    SciTech Connect

    Christensen, C. L.

    1980-01-01

    The BHP is an integrated program involving consequence assessment and plug performance calculations, materials evaluation, instrumentation development and field testing, and interfaces directly with other WIPP-related activities. This paper describes an in situ test conducted under the BHP Field Test Task. The Bell Canyon Test was conducted to evaluate candidate grout plugging mixes and plug emplacement techniques, and to assess plug performance under in-situ cure conditions. Laboratory testing of the brine-grout/rock combination revealed an adverse reaction between the brine-grout and the anhydrite. This discovery permitted a timely change to an additional laboratory compatibility testing program with an alternate fresh-water mix to permit maintenance of the test schedule with little delay. While cement emplacement technology is generally adequate to satisfy repository plugging requirements, plug compatibility with the host rock must be carefully assessed for each repository site. Generally accepted laboratory cement-testing techniques need to include flow characteristics and geochemical stability.

  7. Chemical and structural effects of base modifications in messenger RNA

    PubMed Central

    Harcourt, Emily M.; Kietrys, Anna M.; Kool, Eric T.

    2017-01-01

    A growing number of nucleobase modifications in messenger RNA have been revealed through advances in detection and RNA sequencing. Although some of the biochemical pathways that involve modified bases have been identified, research into the world of RNA modification — the epitranscriptome — is still in an early phase. A variety of chemical tools are being used to characterize base modifications, and the structural effects of known base modifications on RNA pairing, thermodynamics and folding are being determined in relation to their putative biological roles. PMID:28102265

  8. Problem-based learning biotechnology courses in chemical engineering.

    PubMed

    Glatz, Charles E; Gonzalez, Ramon; Huba, Mary E; Mallapragada, Surya K; Narasimhan, Balaji; Reilly, Peter J; Saunders, Kevin P; Shanks, Jacqueline V

    2006-01-01

    We have developed a series of upper undergraduate/graduate lecture and laboratory courses on biotechnological topics to supplement existing biochemical engineering, bioseparations, and biomedical engineering lecture courses. The laboratory courses are based on problem-based learning techniques, featuring two- and three-person teams, journaling, and performance rubrics for guidance and assessment. Participants initially have found them to be difficult, since they had little experience with problem-based learning. To increase enrollment, we are combining the laboratory courses into 2-credit groupings and allowing students to substitute one of them for the second of our 2-credit chemical engineering unit operations laboratory courses.

  9. Flexible Graphene-Based Wearable Gas and Chemical Sensors.

    PubMed

    Singh, Eric; Meyyappan, M; Nalwa, Hari Singh

    2017-10-11

    Wearable electronics is expected to be one of the most active research areas in the next decade; therefore, nanomaterials possessing high carrier mobility, optical transparency, mechanical robustness and flexibility, lightweight, and environmental stability will be in immense demand. Graphene is one of the nanomaterials that fulfill all these requirements, along with other inherently unique properties and convenience to fabricate into different morphological nanostructures, from atomically thin single layers to nanoribbons. Graphene-based materials have also been investigated in sensor technologies, from chemical sensing to detection of cancer biomarkers. The progress of graphene-based flexible gas and chemical sensors in terms of material preparation, sensor fabrication, and their performance are reviewed here. The article provides a brief introduction to graphene-based materials and their potential applications in flexible and stretchable wearable electronic devices. The role of graphene in fabricating flexible gas sensors for the detection of various hazardous gases, including nitrogen dioxide (NO2), ammonia (NH3), hydrogen (H2), hydrogen sulfide (H2S), carbon dioxide (CO2), sulfur dioxide (SO2), and humidity in wearable technology, is discussed. In addition, applications of graphene-based materials are also summarized in detecting toxic heavy metal ions (Cd, Hg, Pb, Cr, Fe, Ni, Co, Cu, Ag), and volatile organic compounds (VOCs) including nitrobenzene, toluene, acetone, formaldehyde, amines, phenols, bisphenol A (BPA), explosives, chemical warfare agents, and environmental pollutants. The sensitivity, selectivity and strategies for excluding interferents are also discussed for graphene-based gas and chemical sensors. The challenges for developing future generation of flexible and stretchable sensors for wearable technology that would be usable for the Internet of Things (IoT) are also highlighted.

  10. The brass plug monument system for Doubler alignment

    SciTech Connect

    Murphy, C.T.

    1981-09-04

    The system of brass plugs set in the Main Ring tunnel floor for use in radial alignment of Doubler elements is described. Considerations leading to the choice of plug positions and properties are discussed. The quantitative relationship between the plugs and the Doubler orbit is presented in sufficient detail so that they can be used by anybody to align Doubler elements both radially and along the beam. Neither the origin or the accuracy of the system is discussed in detail.

  11. Plug engine systems for future launch vehicle applications

    NASA Astrophysics Data System (ADS)

    Immich, H.; Koelle, D. E.; Parsley, R. C.

    1992-08-01

    Several feasible design options are presented for plug engine systems designed for future launch vehicle applications, including a plug nozzle engine with an annular combustion chamber, a segmented modular design, and an integration of a number of conventional engines around a common plug. The advantages and disadvantages of these options are discussed for a range of potential applications, which include single-stage-to-orbit vehicles and upper stage vehicles such as the second stage of the Saenger HTOL launch vehicle concept.

  12. Plugging of cooling holes in film-cooled turbine vanes

    NASA Technical Reports Server (NTRS)

    Deadmore, D. L.; Lowell, C. E.

    1977-01-01

    The plugging of vane cooling holes by impurities in a marine gas turbine was closely simulated in burner rig tests where dopants were added to the combustion products of a clean fuel (Jet-A). Hole plugging occurred when liquid phases, resulting from the dopants, were present in the combustion products. Increasing flame temperature and dopant concentration resulted in an increased rate of deposition and hole plugging.

  13. The sparking voltage of spark plugs

    NASA Technical Reports Server (NTRS)

    Silsbee, F B

    1925-01-01

    This report has been prepared in order to collect and correlate into convenient and useful form the available data on this subject. The importance of the subject lies in the fact that it forms the common meeting ground for studies of the performance of spark generators and spark plugs on the one hand and of the internal combustion engines on the other hand. While much of the data presented was obtained from various earlier publications, numerous places were found where necessary data were lacking, and these have been provided by experiments in gasoline engines at the Bureau of Standards.

  14. Plug-type heat flux gauge

    NASA Technical Reports Server (NTRS)

    Liebert, Curt H. (Inventor); Koch, John, Jr. (Inventor)

    1991-01-01

    A plug-type heat flux gauge formed in a material specimen and having a thermoplug integrally formed in the material specimen, and a method for making the same are disclosed. The thermoplug is surrounded by a concentric annulus, through which thermocouple wires are routed. The end of each thermocouple wire is welded to the thermoplug, with each thermocouple wire welded at a different location along the length of the thermoplug. The thermoplug and concentric annulus may be formed in the material specimen by electrical discharge machining and trepanning procedures.

  15. Testing and plugging power plant heat exchangers

    SciTech Connect

    Sutor, F.

    1994-12-31

    Heat Exchanger tubes fail for any number of reasons including but certainly not limited to the cumulative effects of corrosion, erosion, thermal stress and fatigue. This presentation will attempt to identify the most common techniques for determining which tubes are leaking and then introduce the products in use to plug the leaking tubes. For the sake of time I will limit the scope of this presentation to include feedwater heaters and secondary system heat exchangers such as Hydrogen Coolers, Lube Oil Coolers, and nuclear Component Cooling Water, Emergency Cooling Water, Regenerative Heat Recovery heat exchangers.

  16. Agent-Based Chemical Plume Tracing Using Fluid Dynamics

    NASA Technical Reports Server (NTRS)

    Zarzhitsky, Dimitri; Spears, Diana; Thayer, David; Spears, William

    2004-01-01

    This paper presents a rigorous evaluation of a novel, distributed chemical plume tracing algorithm. The algorithm is a combination of the best aspects of the two most popular predecessors for this task. Furthermore, it is based on solid, formal principles from the field of fluid mechanics. The algorithm is applied by a network of mobile sensing agents (e.g., robots or micro-air vehicles) that sense the ambient fluid velocity and chemical concentration, and calculate derivatives. The algorithm drives the robotic network to the source of the toxic plume, where measures can be taken to disable the source emitter. This work is part of a much larger effort in research and development of a physics-based approach to developing networks of mobile sensing agents for monitoring, tracking, reporting and responding to hazardous conditions.

  17. Silicon-based sleeve devices for chemical reactions

    DOEpatents

    Northrup, M.A.; Mariella, R.P. Jr.; Carrano, A.V.; Balch, J.W.

    1996-12-31

    A silicon-based sleeve type chemical reaction chamber is described that combines heaters, such as doped polysilicon for heating, and bulk silicon for convection cooling. The reaction chamber combines a critical ratio of silicon and silicon nitride to the volume of material to be heated (e.g., a liquid) in order to provide uniform heating, yet low power requirements. The reaction chamber will also allow the introduction of a secondary tube (e.g., plastic) into the reaction sleeve that contains the reaction mixture thereby alleviating any potential materials incompatibility issues. The reaction chamber may be utilized in any chemical reaction system for synthesis or processing of organic, inorganic, or biochemical reactions, such as the polymerase chain reaction (PCR) and/or other DNA reactions, such as the ligase chain reaction, which are examples of a synthetic, thermal-cycling-based reaction. The reaction chamber may also be used in synthesis instruments, particularly those for DNA amplification and synthesis. 32 figs.

  18. Silicon-based sleeve devices for chemical reactions

    DOEpatents

    Northrup, M. Allen; Mariella, Jr., Raymond P.; Carrano, Anthony V.; Balch, Joseph W.

    1996-01-01

    A silicon-based sleeve type chemical reaction chamber that combines heaters, such as doped polysilicon for heating, and bulk silicon for convection cooling. The reaction chamber combines a critical ratio of silicon and silicon nitride to the volume of material to be heated (e.g., a liquid) in order to provide uniform heating, yet low power requirements. The reaction chamber will also allow the introduction of a secondary tube (e.g., plastic) into the reaction sleeve that contains the reaction mixture thereby alleviating any potential materials incompatibility issues. The reaction chamber may be utilized in any chemical reaction system for synthesis or processing of organic, inorganic, or biochemical reactions, such as the polymerase chain reaction (PCR) and/or other DNA reactions, such as the ligase chain reaction, which are examples of a synthetic, thermal-cycling-based reaction. The reaction chamber may also be used in synthesis instruments, particularly those for DNA amplification and synthesis.

  19. A model neural interface based on functional chemical stimulation.

    PubMed

    Mehenti, Neville Z; Fishman, Harvey A; Bent, Stacey F

    2007-08-01

    While functional electrical stimulation has been applied to treat a variety of neurological disorders, it cannot mimic function that is primarily achieved using neurochemical means. In this work, we present a neurotransmitter-based prosthetic interface in the form of a flexible microdevice that selectively releases chemical pulses through an aperture in a polymer membrane. The release profiles through the aperture are controlled by microfluidic switching in an underlying channel network. The profiles have been characterized using fluorescence microscopy as a function of pulse duration and frequency. Hippocampal neurons were cultured on the microdevices and cell stimulation via glutamate delivery was detected using calcium imaging. The release properties could be tuned to repeatedly elicit discrete action potentials in cells seeded proximate to the aperture, including single cell stimulation at 2 Hz. This model neural interface based on functional chemical stimulation may provide the biomimetic platform necessary to restore physiological pathways and function that electrical stimulation cannot fundamentally address.

  20. Plug Your Users into Library Resources with OpenSearch Plug-Ins

    ERIC Educational Resources Information Center

    Baker, Nicholas C.

    2007-01-01

    To bring the library catalog and other online resources right into users' workspace quickly and easily without needing much more than a short XML file, the author, a reference and Web services librarian at Williams College, learned to build and use OpenSearch plug-ins. OpenSearch is a set of simple technologies and standards that allows the…

  1. Wearable Ring-Based Sensing Platform for Detecting Chemical Threats.

    PubMed

    Sempionatto, Juliane R; Mishra, Rupesh K; Martín, Aida; Tang, Guangda; Nakagawa, Tatsuo; Lu, Xiaolong; Campbell, Alan S; Lyu, Kay Mengjia; Wang, Joseph

    2017-10-11

    This work describes a wireless wearable ring-based multiplexed chemical sensor platform for rapid electrochemical monitoring of explosive and nerve-agent threats in vapor and liquid phases. The ring-based sensor system consists of two parts: a set of printed electrochemical sensors and a miniaturized electronic interface, based on a battery-powered stamp-size potentiostat, for signal processing and wireless transmission of data. A wide range of electrochemical capabilities have thus been fully integrated into a 3D printed compact ring structure, toward performing fast square-wave voltammetry and chronoamperometric analyses, along with interchangeable screen-printed sensing electrodes for the rapid detection of different chemical threats. High analytical performance is demonstrated despite the remarkable miniaturization and integration of the ring system. The attractive capabilities of the wearable sensor ring system have been demonstrated for sensitive and rapid voltammetric and amperometric monitoring of nitroaromatic and peroxide explosives, respectively, along with amperometric biosensing of organophosphate (OP) nerve agents. Such ability of the miniaturized wearable sensor ring platform to simultaneously detect multiple chemical threats in both liquid and vapor phases and alert the wearer of such hazards offers considerable promise for meeting the demands of diverse defense and security scenarios.

  2. CytoKavosh: A Cytoscape Plug-In for Finding Network Motifs in Large Biological Networks

    PubMed Central

    Razaghi Moghadam Kashani, Zahra; Salehzadeh-Yazdi, Ali; Khakabimamaghani, Sahand

    2012-01-01

    Network motifs are small connected sub-graphs that have recently gathered much attention to discover structural behaviors of large and complex networks. Finding motifs with any size is one of the most important problems in complex and large networks. It needs fast and reliable algorithms and tools for achieving this purpose. CytoKavosh is one of the best choices for finding motifs with any given size in any complex network. It relies on a fast algorithm, Kavosh, which makes it faster than other existing tools. Kavosh algorithm applies some well known algorithmic features and includes tricky aspects, which make it an efficient algorithm in this field. CytoKavosh is a Cytoscape plug-in which supports us in finding motifs of given size in a network that is formerly loaded into the Cytoscape work-space (directed or undirected). High performance of CytoKavosh is achieved by dynamically linking highly optimized functions of Kavosh's C++ to the Cytoscape Java program, which makes this plug-in suitable for analyzing large biological networks. Some significant attributes of CytoKavosh is efficiency in time usage and memory and having no limitation related to the implementation in motif size. CytoKavosh is implemented in a visual environment Cytoscape that is convenient for the users to interact and create visual options to analyze the structural behavior of a network. This plug-in can work on any given network and is very simple to use and generates graphical results of discovered motifs with any required details. There is no specific Cytoscape plug-in, specific for finding the network motifs, based on original concept. So, we have introduced for the first time, CytoKavosh as the first plug-in, and we hope that this plug-in can be improved to cover other options to make it the best motif-analyzing tool. PMID:22952659

  3. Rule-Based Classification of Chemical Structures by Scaffold.

    PubMed

    Schuffenhauer, Ansgar; Varin, Thibault

    2011-08-01

    Databases for small organic chemical molecules usually contain millions of structures. The screening decks of pharmaceutical companies contain more than a million of structures. Nevertheless chemical substructure searching in these databases can be performed interactively in seconds. Because of this nobody has really missed structural classification of these databases for the purpose of finding data for individual chemical substructures. However, a full deck high-throughput screen produces also activity data for more than a million of substances. How can this amount of data be analyzed? Which are the active scaffolds identified by an assays? To answer such questions systematic classifications of molecules by scaffolds are needed. In this review it is described how molecules can be hierarchically classified by their scaffolds. It is explained how such classifications can be used to identify active scaffolds in an HTS data set. Once active classes are identified, they need to be visualized in the context of related scaffolds in order to understand SAR. Consequently such visualizations are another topic of this review. In addition scaffold based diversity measures are discussed and an outlook is given about the potential impact of structural classifications on a chemically aware semantic web.

  4. Deep Space Habitat Wireless Smart Plug

    NASA Technical Reports Server (NTRS)

    Morgan, Joseph A.; Porter, Jay; Rojdev, Kristina; Carrejo, Daniel B.; Colozza, Anthony J.

    2014-01-01

    NASA has been interested in technology development for deep space exploration, and one avenue of developing these technologies is via the eXploration Habitat (X-Hab) Academic Innovation Challenge. In 2013, NASA's Deep Space Habitat (DSH) project was in need of sensors that could monitor the power consumption of various devices in the habitat with added capability to control the power to these devices for load shedding in emergency situations. Texas A&M University's Electronic Systems Engineering Technology Program (ESET) in conjunction with their Mobile Integrated Solutions Laboratory (MISL) accepted this challenge, and over the course of 2013, several undergraduate students in a Capstone design course developed five wireless DC Smart Plugs for NASA. The wireless DC Smart Plugs developed by Texas A&M in conjunction with NASA's Deep Space Habitat team is a first step in developing wireless instrumentation for future flight hardware. This paper will further discuss the X-Hab challenge and requirements set out by NASA, the detailed design and testing performed by Texas A&M, challenges faced by the team and lessons learned, and potential future work on this design.

  5. The AMPLATZER Vascular Plug 4: Preliminary Experience

    SciTech Connect

    Ferro, Carlo; Rossi, Umberto G. Bovio, Giulio; Petrocelli, Francesco; Seitun, Sara

    2010-08-15

    The purpose of this communication is to describe our preliminary experience with the AMPLATZER Vascular Plug 4 (AVP 4) in peripheral vascular embolization. The AVP 4 was used for peripheral vascular embolization in five patients with renal pseudoaneurysm (n = 2), postsurgical peritoneal bleeding (n = 1), posttraumatic gluteal hemorrhage (n = 1), and intercostal pseudoaneurysm (n = 1). Occlusion time was recorded. Patients were followed up clinically and by imaging for 1 month after the procedure. All treated vessels or vascular abnormalities were successfully occluded within 3 min for low-flow circulation and over 8 min for high-flow circulation. At 1-month follow-up, all patients were symptom-free. All deployed devices remained in the original locations and desirable configurations. In conclusion, the AVP 4 seems to be safe and effective for occluding peripheral vessels and vascular abnormalities. Because of its compatibility with 0.038-in. catheters, it can be deployed through a diagnostic catheter following angiography without exchanging a sheath or guiding catheter. Compared with the previous generation of vascular plugs, the AVP 4 allows for faster procedure times and decreased exposure to radiation.

  6. Adaptation of complete denture bases submitted to chemical polishing.

    PubMed

    Gomes, Márcia; Broilo, Josué Ricardo; Walber, Luiz Fernando; Maccari, Paulo César Armani; Shinkai, Rosemary Sadami Arai

    2004-12-01

    This study evaluated the effect of chemical polishing on the internal adaptation of complete denture bases fabricated with Veracril® resin and polymerized by either the conventional (C) or microwave (M) techniques. Six groups (n=6/group) were tested: 1) C + no polishing (CO); 2) C + chemical polishing (CQ); 3) C + immersion in hot water at 75ºC (CW); 4) M + no polishing (MO); 5) M + chemical polishing (MQ); and 6) M + immersion in hot water at 75ºC (MW). Internal adaptation immediately after the polishing treatment and after 30 days of storage in water at 37ºC was evaluated by weighing a vinyl polysiloxane film reproducing the gap between resin base and metallic master model, using a precision scale. Data were analyzed by ANOVA and Tukey test and paired Student's t test, at a significance level of 0.05. No significant difference in immediate adaptation was found as a function of technique, polishing treatment, or interaction of technique/polishing. After 30 days, adaptation means (g) were: CO=2.46±0.32 a; CQ=3.40±0.23 d; CW=3.14±0.22 c; MO=3.23±0.37 c, d; MQ=3.41±0.47 d; MW=2.81±0.33 b (means followed by different letters are statistically different at alpha=0.05). All groups but group CO had significant increase of misfit over the tested period. The present results suggest that Veracril® resin denture bases submitted to chemical polishing had decrease of internal adaptation in 30 days, although immediate adaptation was not affected.

  7. Spatial chemical distance based on atomic property fields

    PubMed Central

    Grigoryan, A. V.; Kufareva, I.; Totrov, M.

    2010-01-01

    Similarity of compound chemical structures often leads to close pharmacological profiles, including binding to the same protein targets. The opposite, however, is not always true, as distinct chemical scaffolds can exhibit similar pharmacology as well. Therefore, relying on chemical similarity to known binders in search for novel chemicals targeting the same protein artificially narrows down the results and makes lead hopping impossible. In this study we attempt to design a compound similarity/distance measure that better captures structural aspects of their pharmacology and molecular interactions. The measure is based on our recently published method for compound spatial alignment with atomic property fields as a generalized 3D pharmacophoric potential. We optimized contributions of different atomic properties for better discrimination of compound pairs with the same pharmacology from those with different pharmacology using Partial Least Squares regression. Our proposed similarity measure was then tested for its ability to discriminate pharmacologically similar pairs from decoys on a large diverse dataset of 115 protein–ligand complexes. Compared to 2D Tanimoto and Shape Tanimoto approaches, our new approach led to improvement in the area under the receiver operating characteristic curve values in 66 and 58% of domains respectively. The improvement was particularly high for the previously problematic cases (weak performance of the 2D Tanimoto and Shape Tanimoto measures) with original AUC values below 0.8. In fact for these cases we obtained improvement in 86% of domains compare to 2D Tanimoto measure and 85% compare to Shape Tanimoto measure. The proposed spatial chemical distance measure can be used in virtual ligand screening. Electronic supplementary material The online version of this article (doi:10.1007/s10822-009-9316-x) contains supplementary material, which is available to authorized users. PMID:20229197

  8. Spatial chemical distance based on atomic property fields.

    PubMed

    Grigoryan, A V; Kufareva, I; Totrov, M; Abagyan, R A

    2010-03-01

    Similarity of compound chemical structures often leads to close pharmacological profiles, including binding to the same protein targets. The opposite, however, is not always true, as distinct chemical scaffolds can exhibit similar pharmacology as well. Therefore, relying on chemical similarity to known binders in search for novel chemicals targeting the same protein artificially narrows down the results and makes lead hopping impossible. In this study we attempt to design a compound similarity/distance measure that better captures structural aspects of their pharmacology and molecular interactions. The measure is based on our recently published method for compound spatial alignment with atomic property fields as a generalized 3D pharmacophoric potential. We optimized contributions of different atomic properties for better discrimination of compound pairs with the same pharmacology from those with different pharmacology using Partial Least Squares regression. Our proposed similarity measure was then tested for its ability to discriminate pharmacologically similar pairs from decoys on a large diverse dataset of 115 protein-ligand complexes. Compared to 2D Tanimoto and Shape Tanimoto approaches, our new approach led to improvement in the area under the receiver operating characteristic curve values in 66 and 58% of domains respectively. The improvement was particularly high for the previously problematic cases (weak performance of the 2D Tanimoto and Shape Tanimoto measures) with original AUC values below 0.8. In fact for these cases we obtained improvement in 86% of domains compare to 2D Tanimoto measure and 85% compare to Shape Tanimoto measure. The proposed spatial chemical distance measure can be used in virtual ligand screening.

  9. Biomass plug development and propagation in porous media.

    PubMed

    Stewart, T L; Fogler, H S

    2001-02-05

    Exopolymer-producing bacteria can be used to modify soil profiles for enhanced oil recovery or bioremediation. Understanding the mechanisms associated with biomass plug development and propagation is needed for successful application of this technology. These mechanisms were determined from packed-bed and micromodel experiments that simulate plugging in porous media. Leuconostoc mesenteroides was used, because production of dextran, a water-insoluble exopolymer, can be controlled by using different carbon sources. As dextran was produced, the pressure drop across the porous media increased and began to oscillate. Three pressure phases were identified under exopolymer-producing conditions: the exopolymer-induction phase, the plugging phase, and the plug-propagation phase. The exopolymer-induction phase extended from the time that exopolymer-producing conditions were induced until there was a measurable increase in pressure drop across the porous media. The plugging phase extended from the first increase in pressure drop until a maximum pressure drop was reached. Changes in pressure drop in these two phases were directly related to biomass distribution. Specifically, flow channels within the porous media filled with biomass creating a plugged region where convective flow occurred only in water channels within the biofilm. These water channels were more restrictive to flow causing the pressure drop to increase. At a maximum pressure drop across the porous media, the biomass yielded much like a Bingham plastic, and a flow channel was formed. This behavior marked the onset of the plug-propagation phase which was characterized by sequential development and breakthrough of biomass plugs. This development and breakthrough propagated the biomass plug in the direction of nutrient flow. The dominant mechanism associated with all three phases of plugging in porous media was exopolymer production; yield stress is an additional mechanism in the plug-propagation phase.

  10. Nanotechnology-Based Electrochemical Sensors for Biomonitoring Chemical Exposures

    PubMed Central

    Barry, Richard C.; Lin, Yuehe; Wang, Jun; Liu, Guodong; Timchalk, Charles A.

    2009-01-01

    The coupling of dosimetry measurements and modeling represents a promising strategy for deciphering the relationship between chemical exposure and disease outcome. To support the development and implementation of biological monitoring programs, quantitative technologies for measuring xenobiotic exposure are needed. The development of portable nanotechnology-based electrochemical sensors has the potential to meet the needs for low cost, rapid, high-throughput and ultrasensitive detectors for biomonitoring an array of chemical markers. Highly selective electrochemical (EC) sensors capable of pM sensitivity, high-throughput and low sample requirements (<50uL) are discussed. These portable analytical systems have many advantages over currently available technologies, thus potentially representing the next-generation of biomonitoring analyzers. This manuscript highlights research focused on the development of field-deployable analytical instruments based on EC detection. Background information and a general overview of EC detection methods and integrated use of nanomaterials in the development of these sensors are provided. New developments in EC sensors using various types of screen-printed electrodes, integrated nanomaterials, and immunoassays are presented. Recent applications of EC sensors for assessing exposure to pesticides or detecting biomarkers of disease are highlighted to demonstrate the ability to monitor chemical metabolites, enzyme activity, or protein biomarkers of disease. In addition, future considerations and opportunities for advancing the use of EC platforms for dosimetric studies are discussed. PMID:19018275

  11. Tissue-based standoff biosensors for detecting chemical warfare agents

    DOEpatents

    Greenbaum, Elias; Sanders, Charlene A.

    2003-11-18

    A tissue-based, deployable, standoff air quality sensor for detecting the presence of at least one chemical or biological warfare agent, includes: a cell containing entrapped photosynthetic tissue, the cell adapted for analyzing photosynthetic activity of the entrapped photosynthetic tissue; means for introducing an air sample into the cell and contacting the air sample with the entrapped photosynthetic tissue; a fluorometer in operable relationship with the cell for measuring photosynthetic activity of the entrapped photosynthetic tissue; and transmitting means for transmitting analytical data generated by the fluorometer relating to the presence of at least one chemical or biological warfare agent in the air sample, the sensor adapted for deployment into a selected area.

  12. Gravity and magnetic signatures of volcanic plugs related to Deccan volcanism in Saurashtra, India and their physical and geochemical properties

    NASA Astrophysics Data System (ADS)

    Chandrasekhar, D. V.; Mishra, D. C.; Poornachandra Rao, G. V. S.; Mallikharjuna Rao, J.

    2002-07-01

    plugs and Deccan basalt of Saurashtra is 30°N and 74°W, which is close to the VGP position corresponding to the early phases of Deccan eruption. Modeling of gravity and magnetic anomalies along two representative profiles across Junagadh and Barda volcanic plugs suggest a bulk density of 2900 and 2880 kg/m 3, respectively and susceptibility of 3.14×10 -2 SI units with a Qn ratio of 0.56 which are within the range of their values obtained from laboratory measurements on exposed rock samples. The same order of gravity and magnetic anomalies observed over the volcanic plugs of Saurashtra indicates almost similar bulk physical properties for them. The inferred directions of magnetization from magnetic anomalies, however, are D=337° and 340° and I=-38° and -50° which represent the bulk direction of magnetization and also indicate a reversal of the magnetic field during the eruption of these plugs. Some of these plugs are associated with seismic activities of magnitude ≤4 at their contacts. Based on this analysis, other circular/semi-circular gravity highs of NW India can be qualitatively attributed to similar subsurface volcanic plugs.

  13. Electrically heated particulate matter filter with recessed inlet end plugs

    DOEpatents

    Gonze, Eugene V [Pinckney, MI; Ament, Frank [Troy, MI

    2012-02-21

    A particulate matter (PM) filter includes filter walls having inlet ends and outlet ends. First adjacent pairs of the filter walls define inlet channels. Second adjacent pairs of the filter walls define outlet channels. Outlet end plugs are arranged in the inlet channels adjacent to the output ends. Inlet end plugs arranged in the outlet channels spaced from the inlet ends.

  14. 33 CFR 183.556 - Plugs and fittings.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Plugs and fittings. 183.556 Section 183.556 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED... fittings. (a) A fuel system must not have a fitting for draining fuel. (b) A plug used to service the...

  15. Dual Spark Plugs For Stratified-Charge Rotary Engine

    NASA Technical Reports Server (NTRS)

    Abraham, John; Bracco, Frediano V.

    1996-01-01

    Fuel efficiency of stratified-charge, rotary, internal-combustion engine increased by improved design featuring dual spark plugs. Second spark plug ignites fuel on upstream side of main fuel injector; enabling faster burning and more nearly complete utilization of fuel.

  16. 40 CFR 147.3102 - Plugging and abandonment plans.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 22 2010-07-01 2010-07-01 false Plugging and abandonment plans. 147... PROGRAMS (CONTINUED) STATE, TRIBAL, AND EPA-ADMINISTERED UNDERGROUND INJECTION CONTROL PROGRAMS Lands of Certain Oklahoma Indian Tribes § 147.3102 Plugging and abandonment plans. In lieu of the requirements...

  17. 40 CFR 147.3105 - Plugging and abandonment report.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 22 2010-07-01 2010-07-01 false Plugging and abandonment report. 147... PROGRAMS (CONTINUED) STATE, TRIBAL, AND EPA-ADMINISTERED UNDERGROUND INJECTION CONTROL PROGRAMS Lands of Certain Oklahoma Indian Tribes § 147.3105 Plugging and abandonment report. (a) In lieu of the time...

  18. Expandable rubber plug seals openings for pressure testing

    NASA Technical Reports Server (NTRS)

    1966-01-01

    Plug assembly seals openings in piping systems, vessels, and chambers for low pressure leak testing. The assembly, which consists of a rubber sealing plug and the mechanism for expanding it into a pressure-tight configuration, adequately seals irregular diameters without damage to mating surfaces.

  19. The Losing Battle against Plug-and-Chug

    ERIC Educational Resources Information Center

    Kortemeyer, Gerd

    2016-01-01

    I think most physics teachers would agree that two important components of a proper solution to a numerical physics problem are to first figure out a final symbolic solution and to only plug in numbers in the end. However, in spite of our best efforts, this is not what the majority of students is actually doing. Instead, they tend to plug numbers…

  20. Hybrid and Plug-In Electric Vehicles (Brochure)

    SciTech Connect

    Not Available

    2014-05-01

    Hybrid and plug-in electric vehicles use electricity as their primary fuel or to improve the efficiency of conventional vehicle designs. These vehicles can be divided into three categories: hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), all-electric vehicles (EVs). Together, they have great potential to cut U.S. petroleum use and vehicle emissions.

  1. Termination of flat conductor cable to NASA/MSFC plugs

    NASA Technical Reports Server (NTRS)

    Angele, W.

    1972-01-01

    Data, supplemented with artwork, are presented on the major steps involved with terminating flat conductor cable (FCC) to MSFC's FCC plugs. Cable and shield preparation steps include material cutting, insulation stripping, and plating of exposed conductors. Methods and equipment required to terminate FCC to each of four MSFC plugs are described.

  2. California Statewide Plug-In Electric Vehicle Infrastructure Assessment

    SciTech Connect

    Melaina, Marc; Helwig, Michael

    2014-05-01

    The California Statewide Plug-In Electric Vehicle Infrastructure Assessment conveys to interested parties the Energy Commission’s conclusions, recommendations, and intentions with respect to plug-in electric vehicle (PEV) infrastructure development. There are several relatively low-risk and high-priority electric vehicle supply equipment (EVSE) deployment options that will encourage PEV sales and

  3. Properties and preparation of ceramic insulators for spark plugs

    NASA Technical Reports Server (NTRS)

    Silsbee, F B; Honaman, R K; Fonseca, E L; Bleininger, A V; Staley, H F

    1920-01-01

    Report describes in detail the preliminary experiments which were made on the conductivity of spark-plug insulators in order to develop a satisfactory comparative method for testing various spark-plug materials. Materials tested were cements, porcelain, feldspar, and quartz.

  4. 40 CFR 147.2905 - Plugging and abandonment.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 23 2011-07-01 2011-07-01 false Plugging and abandonment. 147.2905 Section 147.2905 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS...-Class II Wells § 147.2905 Plugging and abandonment. The owner/operator shall notify the Osage UIC...

  5. 40 CFR 147.2905 - Plugging and abandonment.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 22 2010-07-01 2010-07-01 false Plugging and abandonment. 147.2905 Section 147.2905 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS...-Class II Wells § 147.2905 Plugging and abandonment. The owner/operator shall notify the Osage UIC...

  6. Hafnia-plugged microcavities for thermal stability of selective emitters

    NASA Astrophysics Data System (ADS)

    Lee, Heon-Ju; Smyth, Katherine; Bathurst, Stephen; Chou, Jeffrey; Ghebrebrhan, Michael; Joannopoulos, John; Saka, Nannaji; Kim, Sang-Gook

    2013-06-01

    Two-dimensional arrays of micro-cavities effectively control photon motion and selectively emit radiation tailored to the preferred bandgap of photovoltaic (PV) cells, thus enhancing the efficiency of thermophotovoltaic energy conversion. At the high operating temperatures, however, the micro- and nano-patterned structures of the selective emitters quickly lose their integrity--obliterating the tight tolerances required for precise spectral control. Even if oxidation, recrystallization, and grain growth could be avoided with single-crystal tungsten (W) selective emitters with vacuum packaging, surface diffusion, evaporation, and re-condensation are not avoidable in long-term operation at high temperatures. The concept of a planar array of plugged micro-cavities to suppress the curvature-dependent thermal degradation modes is proposed and tested. Based on scale-accelerated failure tests of silicon devices, the lifetime of W selective emitters operating at 1100 K is estimated to be at least 30 yr.

  7. Battery Test Manual For Plug-In Hybrid Electric Vehicles

    SciTech Connect

    Jeffrey R. Belt

    2010-09-01

    This battery test procedure manual was prepared for the United States Department of Energy (DOE), Office of Energy Efficiency and Renewable Energy (EERE), Vehicle Technologies Program. It is based on technical targets established for energy storage development projects aimed at meeting system level DOE goals for Plug-in Hybrid Electric Vehicles (PHEV). The specific procedures defined in this manual support the performance and life characterization of advanced battery devices under development for PHEV’s. However, it does share some methods described in the previously published battery test manual for power-assist hybrid electric vehicles. Due to the complexity of some of the procedures and supporting analysis, a revision including some modifications and clarifications of these procedures is expected. As in previous battery and capacitor test manuals, this version of the manual defines testing methods for full-size battery systems, along with provisions for scaling these tests for modules, cells or other subscale level devices.

  8. Battery Test Manual For Plug-In Hybrid Electric Vehicles

    SciTech Connect

    Jeffrey R. Belt

    2010-12-01

    This battery test procedure manual was prepared for the United States Department of Energy (DOE), Office of Energy Efficiency and Renewable Energy (EERE), Vehicle Technologies Program. It is based on technical targets established for energy storage development projects aimed at meeting system level DOE goals for Plug-in Hybrid Electric Vehicles (PHEV). The specific procedures defined in this manual support the performance and life characterization of advanced battery devices under development for PHEV’s. However, it does share some methods described in the previously published battery test manual for power-assist hybrid electric vehicles. Due to the complexity of some of the procedures and supporting analysis, a revision including some modifications and clarifications of these procedures is expected. As in previous battery and capacitor test manuals, this version of the manual defines testing methods for full-size battery systems, along with provisions for scaling these tests for modules, cells or other subscale level devices.

  9. Control of resistance plug welding using quantitative feedback theory

    SciTech Connect

    Bentley, A.E.; Horowitz, I. ||; Chait, Y.; Rodrigues, J.

    1996-12-01

    Resistance welding is used extensively throughout the manufacturing industry. Variations in weld quality often result in costly post-weld inspections. Applications of feed-back control to such processes have been limited by the lack of accurate models describing the nonlinear dynamics of this process. A new system based on electrode displacement feedback is developed that greatly improves quality control of the resistance plug welding process. The system is capable of producing repeatable welds of consistent displacement (and thus consistent quality), with wide variations in weld parameters. This paper describes the feedback design of a robust controller using Quantitative Feedback Theory for this highly complex process, and the experimental results of the applied system.

  10. Predictive spectroscopy and chemical imaging based on novel optical systems

    NASA Astrophysics Data System (ADS)

    Nelson, Matthew Paul

    1998-10-01

    This thesis describes two futuristic optical systems designed to surpass contemporary spectroscopic methods for predictive spectroscopy and chemical imaging. These systems are advantageous to current techniques in a number of ways including lower cost, enhanced portability, shorter analysis time, and improved S/N. First, a novel optical approach to predicting chemical and physical properties based on principal component analysis (PCA) is proposed and evaluated. A regression vector produced by PCA is designed into the structure of a set of paired optical filters. Light passing through the paired filters produces an analog detector signal directly proportional to the chemical/physical property for which the regression vector was designed. Second, a novel optical system is described which takes a single-shot approach to chemical imaging with high spectroscopic resolution using a dimension-reduction fiber-optic array. Images are focused onto a two- dimensional matrix of optical fibers which are drawn into a linear distal array with specific ordering. The distal end is imaged with a spectrograph equipped with an ICCD camera for spectral analysis. Software is used to extract the spatial/spectral information contained in the ICCD images and deconvolute them into wave length-specific reconstructed images or position-specific spectra which span a multi-wavelength space. This thesis includes a description of the fabrication of two dimension-reduction arrays as well as an evaluation of the system for spatial and spectral resolution, throughput, image brightness, resolving power, depth of focus, and channel cross-talk. PCA is performed on the images by treating rows of the ICCD images as spectra and plotting the scores of each PC as a function of reconstruction position. In addition, iterative target transformation factor analysis (ITTFA) is performed on the spectroscopic images to generate ``true'' chemical maps of samples. Univariate zero-order images, univariate first

  11. [Rationality of commercial specification of rhubarb based on chemical analysis].

    PubMed

    Wang, Jiabo; Zhang, Xueru; Xiao, Xiaohe; Chu, Xiaohui; Zhou, Canping; Jin, Cheng; Yan, Dan

    2010-02-01

    The differences of 34 rhubarb samples collected on the market and at producing area were investigated by chemical analysis on the contents of anthraquinones and chromatographic fingerprints, in order to assess the rationality of the commercial specification of rhubarb. The results indicated that the commercial specification of rhubarb was not correlated to the contents of anthraquinones as well as the price. The chromatographic fingerprints of rhubarb samples from different producing area were dissimilar, while the commercial specifications were difficult to be separated. Generally, the rhubarb samples produced in famous-region contained more anthraquinones. This demonstrated rationality on the traditional records of the famous-region of rhubarb from a chemical view. In this study, it was firstly reported that rhubarb could be categorized into two types, chrysophanol-type and rhein-type, based on the proportion of the two constituents in the total anthraquinones after acid hydrohysis. It was found that the rhubarb samples of rhein-type were mostly produced in famous-regions, such as Qinghai, Xizang, West Sichuan and Gansu. The literatures reported that rhein was superior to chrysophanol at many pharmacological effects and pharmacokinetic properties. Hence, we primarily considered that rhein-type rhubarb might be high-quality. These results were helpful to improve the commercial specification of rhubarb from a view of chemical information.

  12. Mechanism-based bioanalysis and biomarkers for hepatic chemical stress.

    PubMed

    Antoine, D J; Mercer, A E; Williams, D P; Park, B K

    2009-08-01

    Adverse drug reactions, in particular drug-induced hepatotoxicity, represent a major challenge for clinicians and an impediment to safe drug development. Novel blood or urinary biomarkers of chemically-induced hepatic stress also hold great potential to provide information about pathways leading to cell death within tissues. The earlier pre-clinical identification of potential hepatotoxins and non-invasive diagnosis of susceptible patients, prior to overt liver disease is an important goal. Moreover, the identification, validation and qualification of biomarkers that have in vitro, in vivo and clinical transferability can assist bridging studies and accelerate the pace of drug development. Drug-induced chemical stress is a multi-factorial process, the kinetics of the interaction between the hepatotoxin and the cellular macromolecules are crucially important as different biomarkers will appear over time. The sensitivity of the bioanalytical techniques used to detect biological and chemical biomarkers underpins the usefulness of the marker in question. An integrated analysis of the biochemical, molecular and cellular events provides an understanding of biological (host) factors which ultimately determine the balance between xenobiotic detoxification, adaptation and liver injury. The aim of this review is to summarise the potential of novel mechanism-based biomarkers of hepatic stress which provide information to connect the intracellular events (drug metabolism, organelle, cell and whole organ) ultimately leading to tissue damage (apoptosis, necrosis and inflammation). These biomarkers can provide both the means to inform the pharmacologist and chemist with respect to safe drug design, and provide clinicians with valuable tools for patient monitoring.

  13. Exploration of chemical space based on 4-anilinoquinazoline.

    PubMed

    Li, D-D; Hou, Y-P; Wang, W; Zhu, H-L

    2012-01-01

    Chemical space is defined as all possible small organic molecules, including those present in biological systems, which is so vast that so far only a tiny fraction of it has been explored. Indeed, a thorough examination of all "chemical space" is practically impossible. The success of three EGFR inhibitors (Gefitnib, Erlotinib, Lapatinib) suggests that 4-anilinoquinazoline scaffold is still worth developing in the future. To date hundreds of this sort of derivatives have been synthesized and show potent anticancer activities. Most of the compounds have been proved to be EGFR/HER2 kinase inhibitors, binding at the hinge region of the ATP site and some lead compounds have been optimized against a number of different kinases, including VEGFR-2, Src, Aurora A/B, Tpl, Clk and PDE10A. Now there is now a rich pipeline of novel anticancer agents based on 4-anilinoquinazoline in early phase clinical trials. This review will highlight the exploration of chemical space of 4-anilinoquinazoline in the past ten years and we hope that increasing knowledge of the SAR and cellular processes underlying the antitumor-activity of anilinoquinazoline derivatives will be beneficial to the rational design of new generation of small molecule anticancer drugs.

  14. QCL-based standoff and proximal chemical detectors

    NASA Astrophysics Data System (ADS)

    Dupuis, Julia R.; Hensley, Joel; Cosofret, Bogdan R.; Konno, Daisei; Mulhall, Phillip; Schmit, Thomas; Chang, Shing; Allen, Mark; Marinelli, William J.

    2016-05-01

    The development of two longwave infrared quantum cascade laser (QCL) based surface contaminant detection platforms supporting government programs will be discussed. The detection platforms utilize reflectance spectroscopy with application to optically thick and thin materials including solid and liquid phase chemical warfare agents, toxic industrial chemicals and materials, and explosives. Operation at standoff (10s of m) and proximal (1 m) ranges will be reviewed with consideration given to the spectral signatures contained in the specular and diffusely reflected components of the signal. The platforms comprise two variants: Variant 1 employs a spectrally tunable QCL source with a broadband imaging detector, and Variant 2 employs an ensemble of broadband QCLs with a spectrally selective detector. Each variant employs a version of the Adaptive Cosine Estimator for detection and discrimination in high clutter environments. Detection limits of 5 μg/cm2 have been achieved through speckle reduction methods enabling detector noise limited performance. Design considerations for QCL-based standoff and proximal surface contaminant detectors are discussed with specific emphasis on speckle-mitigated and detector noise limited performance sufficient for accurate detection and discrimination regardless of the surface coverage morphology or underlying surface reflectivity. Prototype sensors and developmental test results will be reviewed for a range of application scenarios. Future development and transition plans for the QCL-based surface detector platforms are discussed.

  15. Small Scale Mass Flow Plug Calibration

    NASA Technical Reports Server (NTRS)

    Sasson, Jonathan

    2015-01-01

    A simple control volume model has been developed to calculate the discharge coefficient through a mass flow plug (MFP) and validated with a calibration experiment. The maximum error of the model in the operating region of the MFP is 0.54%. The model uses the MFP geometry and operating pressure and temperature to couple continuity, momentum, energy, an equation of state, and wall shear. Effects of boundary layer growth and the reduction in cross-sectional flow area are calculated using an in- integral method. A CFD calibration is shown to be of lower accuracy with a maximum error of 1.35%, and slower by a factor of 100. Effects of total pressure distortion are taken into account in the experiment. Distortion creates a loss in flow rate and can be characterized by two different distortion descriptors.

  16. Unplugging the callose plug from sieve pores.

    PubMed

    Xie, Bo; Hong, Zonglie

    2011-04-01

    The presence of callose in sieve plates has been known for a long time, but how this polysaccharide plug is synthesized has remained unsolved. Two independent laboratories have recently reported the identification of callose synthase 7 (CalS7), also known as glucan synthase-like 7 (GSL7), as the enzyme responsible for callose deposition in sieve plates. Mutant plants defective in this enzyme failed to synthesize callose in developing sieve plates during phloem formation and were unable to accumulate callose in sieve pores in response to stress treatments. The mutant plants developed less open pores per sieve plate and the pores were smaller in diameter. As a result, phloem conductivity was reduced significantly and the mutant plants were shorter and set fewer seeds.

  17. Unplugging the callose plug from sieve pores

    PubMed Central

    Xie, Bo

    2011-01-01

    The presence of callose in sieve plates has been known for a long time, but how this polysaccharide plug is synthesized has remained unsolved. Two independent laboratories have recently reported the identification of callose synthase 7 (CalS7), also known as glucan synthase-like 7 (GSL7), as the enzyme responsible for callose deposition in sieve plates. Mutant plants defective in this enzyme failed to synthesize callose in developing sieve plates during phloem formation and were unable to accumulate callose in sieve pores in response to stress treatments. The mutant plants developed less open pores per sieve plate and the pores were smaller in diameter. As a result, phloem conductivity was reduced significantly and the mutant plants were shorter and set fewer seeds. PMID:21386663

  18. Nanotechnology-Based Electrochemical Sensors for Biomonitoring Chemical Exposures

    SciTech Connect

    Barry, Richard C.; Lin, Yuehe; Wang, Jun; Liu, Guodong; Timchalk, Charles

    2009-01-01

    This manuscript highlights research focused on the development of field-deployable analytical instruments based on EC detection. Background information and a general overview of EC detection methods and integrated use of nanomaterials in the development of these sensors are provided. New developments in EC sensors using various types of screen-printed electrodes, integrated nanomaterials, and immunoassays are discussed. Recent applications of EC sensors for assessing exposure to pesticides or detecting biomarkers of disease are highlighted to demonstrate the ability to monitor chemical metabolites, enzyme activity, or protein biomarkers of disease. In addition, future considerations and opportunities for advancing the use of EC platforms for dosimetric studies are covered.

  19. Toxic neuropathies: Mechanistic insights based on a chemical perspective.

    PubMed

    LoPachin, Richard M; Gavin, Terrence

    2015-06-02

    2,5-Hexanedione (HD) and acrylamide (ACR) are considered to be prototypical among chemical toxicants that cause central-peripheral axonopathies characterized by distal axon swelling and degeneration. Because the demise of distal regions was assumed to be causally related to the onset of neurotoxicity, substantial effort was devoted to deciphering the respective mechanisms. Continued research, however, revealed that expression of the presumed hallmark morphological features was dependent upon the daily rate of toxicant exposure. Indeed, many studies reported that the corresponding axonopathic changes were late developing effects that occurred independent of behavioral and/or functional neurotoxicity. This suggested that the toxic axonopathy classification might be based on epiphenomena related to dose-rate. Therefore, the goal of this mini-review is to discuss how quantitative morphometric analyses and the establishment of dose-dependent relationships helped distinguish primary, mechanistically relevant toxicant effects from non-specific consequences. Perhaps more importantly, we will discuss how knowledge of neurotoxicant chemical nature can guide molecular-level research toward a better, more rational understanding of mechanism. Our discussion will focus on HD, the neurotoxic γ-diketone metabolite of the industrial solvents n-hexane and methyl-n-butyl ketone. Early investigations suggested that HD caused giant neurofilamentous axonal swellings and eventual degeneration in CNS and PNS. However, as our review will point out, this interpretation underwent several iterations as the understanding of γ-diketone chemistry improved and more quantitative experimental approaches were implemented. The chemical concepts and design strategies discussed in this mini-review are broadly applicable to the mechanistic studies of other chemicals (e.g., n-propyl bromine, methyl methacrylate) that cause toxic neuropathies. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  20. Toxic Neuropathies: Mechanistic Insights Based On A Chemical Perspective

    PubMed Central

    LoPachin, Richard M.; Gavin, Terrence

    2014-01-01

    2,5-Hexanedione (HD) and acrylamide (ACR) are considered to be prototypical among chemical toxicants that cause central-peripheral axonopathies characterized by distal axon swelling and degeneration. Because the demise of distal regions was assumed to be causally related to the onset of neurotoxicity, substantial effort was devoted to deciphering the respective mechanisms. Continued research, however, revealed that expression of the presumed hallmark morphological features was dependent upon the daily rate of toxicant exposure. Indeed, many studies reported that the corresponding axonopathic changes were late developing effects that occurred independent of behavioral and/or functional neurotoxicity. This suggested that the toxic axonopathy classification might be based on epiphenomena related to dose-rate. Therefore, the goal of this mini-review is to discuss how quantitative morphometric analyses and the establishment of dose-dependent relationships helped distinguish primary, mechanistically relevant toxicant effects from non-specific consequences. Perhaps more importantly, we will discuss how knowledge of neurotoxicant chemical nature can guide molecular-level research toward a better, more rational understanding of mechanism. Our discussion will focus on HD, the neurotoxic γ-diketone metabolite of the industrial solvents n-hexane and methyl-n-butyl ketone. Early investigations suggested that HD caused giant neurofilamentous axonal swellings and eventual degeneration in CNS and PNS. However, as our review will point out, this interpretation underwent several iterations as the understanding of γ-diketone chemistry improved and more quantitative experimental approaches were implemented. The chemical concepts and design strategies discussed in this mini-review are broadly applicable to the mechanistic studies of other chemicals (e.g., n-propyl bromine, methyl methacrylate) that cause toxic neuropathies. PMID:25218479

  1. SmartBuild-a truly plug-n-play modular microfluidic system.

    PubMed

    Yuen, Po Ki

    2008-08-01

    In this Technical Note, for the first time, a truly "plug-n-play" modular microfluidic system (SmartBuild Plug-n-Play Modular Microfluidic System) is presented for designing and building integrated modular microfluidic systems for biological and chemical applications. The modular microfluidic system can be built by connecting multiple microfluidic components together to form a larger integrated system. The SmartBuild System comprises of a motherboard with interconnect channels/grooves, fitting components, microchannel inserts with different configurations and microchips/modules with different functionalities. Also, heaters, micropumps and valving systems can be designed and used in the system. Examples of an integrated mixing system and reaction systems are presented here to demonstrate the versatility of the SmartBuild System.

  2. Analysis of feline urinary calculi and urethral plugs by infrared spectroscopy and scanning electron microscopy.

    PubMed

    Escolar, E; Bellanato, J

    2003-05-17

    The chemical constituents of 34 feline urinary calculi and five urethral plugs were analysed by infrared spectroscopy. The analysis revealed that 18 (52.9 per cent) of the calculi contained magnesium ammonium phosphate hexahydrate (struvite) as the major component; 10 (29.4 per cent) contained complex ammonium urates (three of them also containing calcium phosphate, mainly on the surface); three were composed of calcium phosphates and three were composed mainly of calcium oxalate mono and dihydrates. The urethral plugs were composed primarily of struvite, but also contained large amounts of organic matter. The examination of 16 selected samples by scanning electron microscopy and electron dispersive x-ray analysis revealed that their crystalline structures were similar to those of canine stones.

  3. Arthroscopic meniscal allograft transplantation without bone plugs.

    PubMed

    Alentorn-Geli, Eduard; Seijas Vázquez, Roberto; García Balletbó, Montserrat; Álvarez Díaz, Pedro; Steinbacher, Gilbert; Cuscó Segarra, Xavier; Rius Vilarrubia, Marta; Cugat Bertomeu, Ramón

    2011-02-01

    Partial or total meniscectomy are common procedures performed at Orthopedic Surgery departments. Despite providing a great relief of pain, it has been related to early onset knee osteoarthritis. Meniscal allograft transplantation has been proposed as an alternative to meniscectomy. The purposes of this study were to describe an arthroscopic meniscal allograft transplantation without bone plugs technique and to report the preliminary results. All meniscal allograft transplantations performed between 2001 and 2006 were approached for eligibility, and a total of 35 patients (involving 37 menisci) were finally engaged in the study. Patients were excluded if they had ipsilateral knee ligament reconstruction or cartilage repair surgery before meniscal transplantation or other knee surgeries after the meniscal transplantation. Scores on Lysholm, Subjective IKDC Form, and Visual Analogue Scale (VAS) scale for pain were obtained at a mean follow-up of 38.6 months and compared to pre-operative data. Data on chondral lesions were obtained during the arthroscopic procedure and through imaging (radiographs and MRI) studies pre-operatively. Two graft failures out of 59 transplants (3.4%) were found. Daily life accidents were responsible for all graft failures. Significant improvements for Lysholm, Subjective IKDC Form, and VAS for pain scores following the meniscal allograft transplantation were found (P < 0.0001). Controlling for chondral lesion, there was no significant interactions for Lysholm (n.s.), Subjective IKDC Form (n.s.), and VAS for pain scores (n.s.). This study demonstrated that an arthroscopic meniscal allograft transplantation without bone plugs improved knee function and symptoms after a total meniscectomy. Improvements were observed independently of the degree of chondral lesion.

  4. Liquid plug propagation in flexible microchannels: A small airway model

    NASA Astrophysics Data System (ADS)

    Zheng, Y.; Fujioka, H.; Bian, S.; Torisawa, Y.; Huh, D.; Takayama, S.; Grotberg, J. B.

    2009-07-01

    In the present study, we investigate the effect of wall flexibility on the plug propagation and the resulting wall stresses in small airway models with experimental measurements and numerical simulations. Experimentally, a flexible microchannel was fabricated to mimic the flexible small airways using soft lithography. Liquid plugs were generated and propagated through the microchannels. The local wall deformation is observed instantaneously during plug propagation with the maximum increasing with plug speed. The pressure drop across the plug is measured and observed to increase with plug speed, and is slightly smaller in a flexible channel compared to that in a rigid channel. A computational model is then presented to model the steady plug propagation through a flexible channel corresponding to the middle plane in the experimental device. The results show qualitative agreements with experiments on wall shapes and pressure drops and the discrepancies bring up interesting questions on current field of modeling. The flexible wall deforms inward near the plug core region, the deformation and pressure drop across the plug increase with the plug speed. The wall deformation and resulting stresses vary with different longitudinal tensions, i.e., for large wall longitudinal tension, the wall deforms slightly, which causes decreased fluid stress and stress gradients on the flexible wall comparing to that on rigid walls; however, the wall stress gradients are found to be much larger on highly deformable walls with small longitudinal tensions. Therefore, in diseases such as emphysema, with more deformable airways, there is a high possibility of induced injuries on lining cells along the airways because of larger wall stresses and stress gradients.

  5. Portal vein embolization with plug/coils improves hepatectomy outcome.

    PubMed

    Malinowski, Maciej; Geisel, Dominik; Stary, Victoria; Denecke, Timm; Seehofer, Daniel; Jara, Maximillian; Baron, Annekathrin; Pratschke, Johann; Gebauer, Bernhard; Stockmann, Martin

    2015-03-01

    Portal vein embolization (PVE) has become the standard of care before extended hepatectomy. Various PVE methods using different embolization materials have been described. In this study, we compared PVE with polyvinyl alcohol particles alone (PVA only) versus PVA with plug or coils (PVA + plug/coils). Patients undergoing PVE before hepatectomy were included. PVA alone was used until December 2013, thereafter plug or coils were placed in addition. The volume of left lateral liver lobe (LLL), clinical parameters, and liver function tests were measured before PVE and resection. A total of 43 patients were recruited into the PVA only group and 42 were recruited into the PVA + plug/coils group. There were no major differences between groups except significantly higher total bilirubin level before PVE in the PVA only group, which improved before hepatectomy. Mean LLL volume increased by 25.7% after PVE in the PVA only group and by 44% in the PVA + plug/coils group (P < 0.001). Recanalization was significantly less common in the PVA + plug/coils group. In multivariate regression, initial LLL volume and use of plug or coils were the only parameters influencing LLL volume increase. The postoperative liver failure rate was significantly reduced in PVA + plug/coils group (P = <0.001). PVE using PVA particles together with plug or coils is a safe and efficient method to increase future liver remnant volume. The additional central embolization with plug or coils led to an increased hypertrophy, due to lower recanalization rates, and subsequently decreased incidence of postoperative liver failure. No additional procedure-specific complications were observed in this series. Copyright © 2015 Elsevier Inc. All rights reserved.

  6. Development of a software platform for a plug-in hybrid electric vehicle simulator

    NASA Astrophysics Data System (ADS)

    Karlis, Athanasios D.; Bibeau, Eric; Zanetel, Paul; Lye, Zelon

    2012-03-01

    Electricity use for transportation has had limited applications because of battery storage range issues, although many recent successful demonstrations of electric vehicles have been achieved. Renewable biofuels such as biodiesel and bioethanol also contribute only a small percentage of the overall energy mix for mobility. Recent advances in hybrid technologies have significantly increased vehicle efficiencies. More importantly, hybridization now allows a significant reduction in battery capacity requirements compared to pure electric vehicles, allowing electricity to be used in the overall energy mix in the transportation sector. This paper presents an effort made to develop a Plug-in Hybrid Electric Vehicle (PHEV) platform that can act as a comprehensive alternative energy vehicle simulator. Its goal is to help in solving the pressing needs of the transportation sector, both in terms of contributing data to aid policy decisions for reducing fossil fuel use, and to support research in this important area. The Simulator will allow analysing different vehicle configurations, and control strategies with regards to renewable and non-renewable fuel and electricity sources. The simulation platform models the fundamental aspects of PHEV components, that is, process control, heat transfer, chemical reactions, thermodynamics and fluid properties. The outcomes of the Simulator are: (i) determining the optimal combination of fuels and grid electricity use, (ii) performing greenhouse gas calculations based on emerging protocols being developed, and (iii) optimizing the efficient and proper use of renewable energy sources in a carbon constrained world.

  7. Strategies for Controlling Plug Loads. A Tool for Reducing Plug Loads in Commercial Buildings

    SciTech Connect

    Torcellini, Paul; Bonnema, Eric; Sheppy, Michael; Pless, Shanti

    2015-09-01

    Plug loads are often not considered as part of the energy savings measures in Commercial Buildings; however, they can account for up to 50% of the energy used in the building. These loads are numerous and often scattered throughout a building. Some of these loads are purchased by the owner and some designed into the building or the tenant finishes for a space. This document provides a strategy and a tool for minimizing these loads.

  8. CySBGN: a Cytoscape plug-in to integrate SBGN maps.

    PubMed

    Gonçalves, Emanuel; van Iersel, Martijn; Saez-Rodriguez, Julio

    2013-01-16

    A standard graphical notation is essential to facilitate exchange of network representations of biological processes. Towards this end, the Systems Biology Graphical Notation (SBGN) has been proposed, and it is already supported by a number of tools. However, support for SBGN in Cytoscape, one of the most widely used platforms in biology to visualise and analyse networks, is limited, and in particular it is not possible to import SBGN diagrams. We have developed CySBGN, a Cytoscape plug-in that extends the use of Cytoscape visualisation and analysis features to SBGN maps. CySBGN adds support for Cytoscape users to visualize any of the three complementary SBGN languages: Process Description, Entity Relationship, and Activity Flow. The interoperability with other tools (CySBML plug-in and Systems Biology Format Converter) was also established allowing an automated generation of SBGN diagrams based on previously imported SBML models. The plug-in was tested using a suite of 53 different test cases that covers almost all possible entities, shapes, and connections. A rendering comparison with other tools that support SBGN was performed. To illustrate the interoperability with other Cytoscape functionalities, we present two analysis examples, shortest path calculation, and motif identification in a metabolic network. CySBGN imports, modifies and analyzes SBGN diagrams in Cytoscape, and thus allows the application of the large palette of tools and plug-ins in this platform to networks and pathways in SBGN format.

  9. Carbon Nanotube Based Chemical Sensors for Space and Terrestrial Applications

    NASA Technical Reports Server (NTRS)

    Li, Jing; Lu, Yijiang

    2009-01-01

    A nanosensor technology has been developed using nanostructures, such as single walled carbon nanotubes (SWNTs), on a pair of interdigitated electrodes (IDE) processed with a silicon-based microfabrication and micromachining technique. The IDE fingers were fabricated using photolithography and thin film metallization techniques. Both in-situ growth of nanostructure materials and casting of the nanostructure dispersions were used to make chemical sensing devices. These sensors have been exposed to nitrogen dioxide, acetone, benzene, nitrotoluene, chlorine, and ammonia in the concentration range of ppm to ppb at room temperature. The electronic molecular sensing of carbon nanotubes in our sensor platform can be understood by intra- and inter-tube electron modulation in terms of charge transfer mechanisms. As a result of the charge transfer, the conductance of p-type or hole-richer SWNTs in air will change. Due to the large surface area, low surface energy barrier and high thermal and mechanical stability, nanostructured chemical sensors potentially can offer higher sensitivity, lower power consumption and better robustness than the state-of-the-art systems, which make them more attractive for defense and space applications. Combined with MEMS technology, light weight and compact size sensors can be made in wafer scale with low cost. Additionally, a wireless capability of such a sensor chip can be used for networked mobile and fixed-site detection and warning systems for military bases, facilities and battlefield areas.

  10. Photonic crystal fiber based chloride chemical sensors for corrosion monitoring

    NASA Astrophysics Data System (ADS)

    Wei, Heming; Tao, Chuanyi; Krishnaswamy, Sridhar

    2016-04-01

    Corrosion of steel is one of the most important durability issues in reinforced concrete (RC) structures because aggressive ions such as chloride ions permeate concrete and corrode steel, consequently accelerating the destruction of structures, especially in marine environments. There are many practical methods for corrosion monitoring in RC structures, mostly focusing on electrochemical-based sensors for monitoring the chloride ion which is thought as one of the most important factors resulting in steel corrosion. In this work, we report a fiber-optic chloride chemical sensor based on long period gratings inscribed in a photonic crystal fiber (PCF) with a chloride sensitive thin film. Numerical simulation is performed to determine the characteristics and resonance spectral response versus the refractive indices of the analyte solution flowing through into the holes in the PCF. The effective refractive index of the cladding mode of the LPGs changes with variations of the analyte solution concentration, resulting in a shift of the resonance wavelength, hence providing the sensor signal. This fiber-optic chemical sensor has a fast response, is easy to prepare and is not susceptible to electromagnetic environment, and can therefore be of use for structural health monitoring of RC structures subjected to such aggressive environments.

  11. Prediction of odor from pig production based on chemical odorants.

    PubMed

    Hansen, Michael J; Adamsen, Anders Peter S; Pedersen, Poul; Feilberg, Anders

    2012-01-01

    The present work was performed to investigate the use of odorant measurements for prediction of odor concentration in facilities with growing-finishing pigs and to analyze the odorant composition in facilities with different floor and ventilation systems. Air was sampled in Nalophan bags, odor concentrations were measured by dilution-to-threshold olfactometry, and concentrations of odorants were measured by proton-transfer-reaction mass spectrometry (PTR-MS). Olfactometry and chemical analyses were synchronized to take place at identical time intervals after sampling. A principal component analysis revealed that different facilities for growing-finishing pigs can be distinguished based on the odorants. Pit ventilation comprising a small amount of the total ventilation air (10-20%) in facilities with both room and pit ventilation can be used to concentrate odorants, whereas the room ventilation contains lower concentrations of most odorants. A partial least squares regression model demonstrated that prediction of the odor concentration based on odorants measured by PTR-MS is feasible. Hydrogen sulfide, methanethiol, trimethylamine, and 4-methylphenol were identified as the compounds having the largest influence on the prediction of odor concentration, whereas carboxylic acids had no significant influence. In conclusion, chemical measurement of odorants by PTR-MS is an alternative for expressing the odor concentration in facilities with growing-finishing pigs that can be used to increase the understanding of odor from different types of facilities and improve the development of odor reduction technologies.

  12. Dataset on photonic crystal fiber based chemical sensor.

    PubMed

    Ahmed, Kawsar; Paul, Bikash Kumar; Chowdhury, Sawrab; Islam, Md Shadidul; Sen, Shuvo; Islam, Md Ibadul; Asaduzzaman, Sayed; Bahar, Ali Newaz; Miah, Mohammad Badrul Alam

    2017-06-01

    This article represents the data set of micro porous core photonic crystal fiber based chemical sensor. The suggested structure is folded cladding porous shaped with circular air hole. Here is investigated four distinctive parameters including relative sensitivity, confinement loss, numerical aperture (NA), and effective area (Aeff). The numerical outcomes are computed over the E+S+C+L+U communication band. The useable sensed chemicals are methanol, ethanol, propanol, butanol, and pentanol whose are lies in the alcohol series (Paul et al., 2017) [1]. Furthermore, V-parameter (V), Marcuse spot size (MSS), and beam divergence (BD) are also investigated rigorously. All examined results have been obtained using finite element method based simulation software COMSOL Multiphysics 4.2 versions with anisotropic circular perfectly matched layer (A-CPML). The proposed PCF shows the high NA from 0.35 to 0.36; the low CL from ~10(-11) to ~10(-7) dB/m; the high Aeff from 5.50 to 5.66 µm(2); the MSS from 1.0 to 1.08 µm; the BD from 0.43 to 0.46 rad at the controlling wavelength λ = 1.55 µm for employing alcohol series respectively.

  13. Mechanistic Understanding of Microbial Plugging for Improved Sweep Efficiency

    SciTech Connect

    Steven Bryant; Larry Britton

    2008-09-30

    Microbial plugging has been proposed as an effective low cost method of permeability reduction. Yet there is a dearth of information on the fundamental processes of microbial growth in porous media, and there are no suitable data to model the process of microbial plugging as it relates to sweep efficiency. To optimize the field implementation, better mechanistic and volumetric understanding of biofilm growth within a porous medium is needed. In particular, the engineering design hinges upon a quantitative relationship between amount of nutrient consumption, amount of growth, and degree of permeability reduction. In this project experiments were conducted to obtain new data to elucidate this relationship. Experiments in heterogeneous (layered) beadpacks showed that microbes could grow preferentially in the high permeability layer. Ultimately this caused flow to be equally divided between high and low permeability layers, precisely the behavior needed for MEOR. Remarkably, classical models of microbial nutrient uptake in batch experiments do not explain the nutrient consumption by the same microbes in flow experiments. We propose a simple extension of classical kinetics to account for the self-limiting consumption of nutrient observed in our experiments, and we outline a modeling approach based on architecture and behavior of biofilms. Such a model would account for the changing trend of nutrient consumption by bacteria with the increasing biomass and the onset of biofilm formation. However no existing model can explain the microbial preference for growth in high permeability regions, nor is there any obvious extension of the model for this observation. An attractive conjecture is that quorum sensing is involved in the heterogeneous bead packs.

  14. An illustrative 'plug & play' catastrophe model for groundwater flooding

    NASA Astrophysics Data System (ADS)

    Wang, Lei; Hillier, John; Royse, Kate; Lee, Tzu-Fung; O'Niel, Jullian; Kingdon, Andrew; Hughes, Andrew

    2013-04-01

    Economic losses from natural catastrophes are substantial; e.g., US130 billion in 2010. 'Catastrophe models' are stochastic event-set based models that simulate these risks and underpin their assessment in the insurance industry. Most catastrophe models are proprietary 'black boxes', which limit the level of user interaction, but new regulations (Solvency II) require firms to understand better the assumptions upon which the calculations ultimately rest. Part of this greater transparency requires constraining where uncertainty originates, perhaps by interchanging components provided by rival model vendors in 'plug and play' catastrophe models. The objective of this paper is to demonstrate a practical, accessible way in which this may be made possible. Specifically to do this the first, illustrative 'plug and play' model was created efficiently and effectively using OpenMI, a free 'open-source' model linking standard. In about 100 man-hours climate, groundwater flow, vulnerability, exposure and loss components were linked to output financial losses, i.e., occurrence exceedance probability (OEP) curves. Groundwater flooding near Marlborough (UK) is used for this proof of concept. Losses from this example dataset are small, about £3.8 million for a 33 yr OEP, but groundwater is an important compounding factor in UK flooding and this is the first, albeit rudimentary, attempt to probabilistically model loss for this hazard. Selected components are swopped, and losses calculated to show how insights into the origin of uncertainty can be gained. Crucially, OpenMI has the future potential to operate online and shield valuable data within components whilst allowing them to be swopped. So, it has the potential to underpin a secure, open-source, practical framework of use to the insurance industry.

  15. Physics-based model for electro-chemical process

    SciTech Connect

    Zhang, Jinsuo

    2013-07-01

    Considering the kinetics of electrochemical reactions and mass transfer at the surface and near-surface of the electrode, a physics-based separation model for separating actinides from fission products in an electro-refiner is developed. The model, taking into account the physical, chemical and electrochemical processes at the electrode surface, can be applied to study electrorefining kinetics. One of the methods used for validation has been to apply the developed model to the computation of the cyclic voltammetry process of PuCl{sub 3} and UCl{sub 3} at a solid electrode in molten KCl-LiCl. The computed results appear to be similar to experimental measures. The separation model can be applied to predict materials flows under normal and abnormal operation conditions. Parametric studies can be conducted based on the model to identify the most important factors that affect the electrorefining processes.

  16. Chemical and Biological Dynamics Using Droplet-Based Microfluidics.

    PubMed

    Dressler, Oliver J; Casadevall I Solvas, Xavier; deMello, Andrew J

    2017-06-12

    Recent years have witnessed an increased use of droplet-based microfluidic techniques in a wide variety of chemical and biological assays. Nevertheless, obtaining dynamic data from these platforms has remained challenging, as this often requires reading the same droplets (possibly thousands of them) multiple times over a wide range of intervals (from milliseconds to hours). In this review, we introduce the elemental techniques for the formation and manipulation of microfluidic droplets, together with the most recent developments in these areas. We then discuss a wide range of analytical methods that have been successfully adapted for analyte detection in droplets. Finally, we highlight a diversity of studies where droplet-based microfluidic strategies have enabled the characterization of dynamic systems that would otherwise have remained unexplorable.

  17. Chemical Abstracts Service approach to management of large data bases.

    PubMed

    Huffenberger, M A; Wigington, R L

    1975-02-01

    When information handling is "the business," as it is at Chemical Abstract Service (CAS), the total organization must be involved in information management. Since 1967, when, as a result of long-range planning efforts, CAS adopted a "data-base approach" to management of both the processing system and the distribution of information files, CAS has been grappling with the problems of managing large collections of information in computer-based systems. This paper describes what has been done at CAS in the management of large files and what we see as necessary, as a result of our experience, to improve and complete the information management system that is the foundation of our production processes.

  18. Automated detection of mucus plugs within bronchial tree in MSCT images

    NASA Astrophysics Data System (ADS)

    Odry, Benjamin L.; Guiliguian, Diran; Kiraly, Atilla P.; Novak, Carol L.; Naidich, David P.; Lerallut, Jean-Francois

    2007-03-01

    Pulmonary diseases characterized by chronic airway inflammation, such as Chronic Obstructive Pulmonary (COPD), result in abnormal bronchial wall thickening, lumen dilatation and mucus plugs. Multi-Slice Computed Tomography (MSCT) allows for assessment of these abnormalities, even in airways that are obliquely oriented to the scan plane. Chronic airway inflammation typically results in limitations of airflow, allowing for the accumulation of mucus, especially in the distal airways. In addition to obstructing airways, retained secretions make the airways prone to infection. Patients with chronic airway disease are clinically followed over time to assess disease progression and response to treatment. In this regard, the ability to obtain an automatic standardized method to rapidly and objectively assess the entire airway tree morphologically, including the extent of mucus plugging, would be of particular clinical value. We have developed a method to automatically detect the presence and location of mucus plugs within the peripheral airways. We first start with segmentation of the bronchial tree using a previously developed method. The skeleton-based tree structure is then computed and each terminal branch is individually extended using an adaptive threshold algorithm. We compute a local 2-dimensional model, based on airway luminal diameter and wall thickness. We then select a few points along the principal axis beyond the terminal branches, to extract 2D cross sections for correlation with a model of mucus plugging. Airway shape is validated with a correlation value, and the lumen distribution is analyzed and compared to the model. A high correlation indicates the presence of a mucus plug. We tested our method on 5 datasets containing a total of 40 foci of mucoid impaction. Preliminary results show sensitivity of 77.5% with a specificity of 98.2% and positive predictive value of 66%.

  19. ChemDIS: a chemical-disease inference system based on chemical-protein interactions.

    PubMed

    Tung, Chun-Wei

    2015-01-01

    The characterization of toxicities associated with environmental and industrial chemicals is required for risk assessment. However, we lack the toxicological data for a large portion of chemicals due to the high cost of experiments for a huge number of chemicals. The development of computational methods for identifying potential risks associated with chemicals is desirable for generating testable hypothesis to accelerate the hazard identification process. A chemical-disease inference system named ChemDIS was developed to facilitate hazard identification for chemicals. The chemical-protein interactions from a large database STITCH and protein-disease relationship from disease ontology and disease ontology lite were utilized for chemical-protein-disease inferences. Tools with user-friendly interfaces for enrichment analysis of functions, pathways and diseases were implemented and integrated into ChemDIS. An analysis on maleic acid and sibutramine showed that ChemDIS could be a useful tool for the identification of potential functions, pathways and diseases affected by poorly characterized chemicals. ChemDIS is an integrated chemical-disease inference system for poorly characterized chemicals with potentially affected functions and pathways for experimental validation. ChemDIS server is freely accessible at http://cwtung.kmu.edu.tw/chemdis.

  20. Graphene-Based Chemical Vapor Sensors for Electronic Nose Applications

    NASA Astrophysics Data System (ADS)

    Nallon, Eric C.

    chemiresistor device and used as a chemical sensor, where its resistance is temporarily modified while exposed to chemical compounds. The inherent, broad selective nature of graphene is demonstrated by testing a sensor against a diverse set of volatile organic compounds and also against a set of chemically similar compounds. The sensor exhibits excellent selectivity and is capable of achieving high classification accuracies. The kinetics of the sensor's response are further investigated revealing a relationship between the transient behavior of the response curve and physiochemical properties of the compounds, such as the molar mass and vapor pressure. This kinetic information is also shown to provide important information for further pattern recognition and classification, which is demonstrated by increased classification accuracy of very similar compounds. Covalent modification of the graphene surface is demonstrated by means of plasma treatment and free radical exchange, and sensing performance compared to an unmodified graphene sensor. Finally, the first example of a graphene-based, cross-reactive chemical sensor array is demonstrated by applying various polymers as coatings over an array of graphene sensors. The sensor array is tested against a variety of compounds, including the complex odor of Scotch whiskies, where it is capable of perfect classification of 10 Scotch whiskey variations.

  1. NASA SLS Booster Nozzle Plug Pieces Fly During Test

    NASA Image and Video Library

    2016-06-28

    On June 28, a test version of the booster that will help power NASA's new rocket, the Space Launch System, fired up at nearly 6,000 degrees Fahrenheit for a successful, two-minute qualification test at Orbital ATK's test facilities in Promontory, Utah. This video shows the booster's nozzle plug intentionally breaking apart. The smoky ring coming off the booster is condensed water vapor created by a pressure difference between the motor gas and normal air. The nozzle plug is an environmental barrier to prevent heat, dust and moisture from getting inside the booster before it ignites. The plug isn't always part of a static test but was included on this one due to changes made to the hardware. The foam on the plug is denser than previous NASA launch vehicles, as the engines are now in the same plane as the boosters. A numbered grid was placed on the exterior of the plug before the test so the pieces retrieved could support plug breakup assessment and reconstruction. Along with video, collecting the pieces helps determine the size and speed of them when they break apart. Nozzle plug pieces were found as far as 1,500 to 2,000 feet away from the booster. This is the last full-scale qualification test for the booster before the first, uncrewed flight of SLS with the Orion spacecraft in 2018.

  2. Steady propagation of Bingham plugs in 2D channels

    NASA Astrophysics Data System (ADS)

    Zamankhan, Parsa; Takayama, Shuichi; Grotberg, James

    2009-11-01

    The displacement of the yield-stress liquid plugs in channels and tubes occur in many biological systems and industrial processes. Among them is the propagation of mucus plugs in the respiratory tracts as may occur in asthma, cystic fibrosis, or emphysema. In this work the steady propagation of mucus plugs in a 2D channel is studied numerically, assuming that the mucus is a pure Bingham fluid. The governing equations are solved by a mixed-discontinuous finite element formulation and the free surface is resolved with the method of spines. The constitutive equation for a pure Bingham fluid is modeled by a regularization method. Fluid inertia is neglected, so the controlling parameters in a steady displacement are; the capillary number, Ca, Bingham number ,Bn, and the plug length. According to the numerical results, the yield stress behavior of the plug modifies the plug shape, the pattern of the streamlines and the distribution of stresses in the plug domain and along the walls in a significant way. The distribution along the walls is a major factor in studying cell injuries. This work is supported through the grant NIH HL84370.

  3. Dynamics of Surfactant Liquid Plugs at Bifurcating Lung Airway Models

    NASA Astrophysics Data System (ADS)

    Tavana, Hossein

    2013-11-01

    A surfactant liquid plug forms in the trachea during surfactant replacement therapy (SRT) of premature babies. Under air pressure, the plug propagates downstream and continuously divides into smaller daughter plugs at continuously branching lung airways. Propagating plugs deposit a thin film on airway walls to reduce surface tension and facilitate breathing. The effectiveness of SRT greatly depends on the final distribution of instilled surfactant within airways. To understand this process, we investigate dynamics of splitting of surfactant plugs in engineered bifurcating airway models. A liquid plug is instilled in the parent tube to propagate and split at the bifurcation. A split ratio, R, is defined as the ratio of daughter plug lengths in the top and bottom daughter airway tubes and studied as a function of the 3D orientation of airways and different flow conditions. For a given Capillary number (Ca), orienting airways farther away from a horizontal position reduced R due to the flow of a larger volume into the gravitationally favored daughter airway. At each orientation, R increased with 0.0005 < Ca < 0.05. This effect diminished by decrease in airways diameter. This approach will help elucidate surfactant distribution in airways and develop effective SRT strategies.

  4. CHEMICAL SENSING BASED ON CATALYTIC NANOMOTORS: MOTION-BASED DETECTION OF TRACE SILVER

    PubMed Central

    Kagan, Daniel; Calvo-Marzal, Percy; Balasubramanian, Shankar; Sattayasamitsathit, Sirilak; Manesh, Kalayil Manian; Flechsig, Gerd-Uwe; Wang, Joseph

    2009-01-01

    A motion-based chemical sensing involving fuel-driven nanomotors is demonstrated. The new protocol relies on the use of an optical microscope for tracking changes in the speed of nanowire motors in the presence of the target analyte. Selective and sensitive measurements of trace silver ions are illustrated based on the dramatic and specific acceleration of bimetal nanowire motors in the presence of silver. Such nanomotor-based measurements would lead to a wide range of novel and powerful chemical and biological sensing protocols. PMID:19670862

  5. In-use measurement of activity, energy use, and emissions of a plug-in hybrid electric vehicle.

    PubMed

    Graver, Brandon M; Frey, H Christopher; Choi, Hyung-Wook

    2011-10-15

    Plug-in hybrid electric vehicles (PHEVs) could reduce transportation air emissions and energy use. However, a method is needed for estimating on-road emissions of PHEVs. To develop a framework for quantifying microscale energy use and emissions (EU&E), measurements were conducted on a Toyota Prius retrofitted with a plug-in battery system on eight routes. Measurements were made using the following: (1) a data logger for the hybrid control system; (2) a portable emissions measurement system; and (3) a global positioning system with barometric altimeter. Trends in EU&E are estimated based on vehicle specific power. Energy economy is quantified based on gasoline consumed by the engine and grid energy consumed by the plug-in battery. Emissions from electricity consumption are estimated based on the power generation mix. Fuel use is approximately 30% lower during plug-in battery use. Grid emissions were higher for CO₂, NO(x), SO₂, and PM compared to tailpipe emissions but lower for CO and hydrocarbons. EU&E depends on engine and plug-in battery operation. The use of two energy sources must be addressed in characterizing fuel economy; overall energy economy is 11% lower if including grid energy use than accounting only for fuel consumption.

  6. Impedimetric thrombin aptasensor based on chemically modified graphenes

    NASA Astrophysics Data System (ADS)

    Loo, Adeline Huiling; Bonanni, Alessandra; Pumera, Martin

    2011-12-01

    Highly sensitive biosensors are of high importance to the biomedical field. Graphene represents a promising transducing platform for construction of biosensors. Here for the first time we compare the biosensing performance of a wide set of graphenes prepared by different methods. In this work, we present a simple and label-free electrochemical impedimetric aptasensor for thrombin based on chemically modified graphene (CMG) platforms such as graphite oxide (GPO), graphene oxide (GO), thermally reduced graphene oxide (TR-GO) and electrochemically reduced graphene oxide (ER-GO). Disposable screen-printed electrodes were first modified with chemically modified graphene (CMG) materials and used to immobilize a DNA aptamer which is specific to thrombin. The basis of detection relies on the changes in impedance spectra of redox probe after the binding of thrombin to the aptamer. It was discovered that graphene oxide (GO) is the most suitable material to be used as compared to the other three CMG materials. Furthermore, the optimum concentration of aptamer to be immobilized onto the modified electrode surface was determined to be 10 μM and the linear detection range of thrombin was 10-50 nM. Lastly, the aptasensor was found to demonstrate selectivity for thrombin. Such simply fabricated graphene oxide aptasensor shows high promise for clinical diagnosis of biomarkers and point-of-care analysis.

  7. Chemical Signaling and Functional Activation in Colloidosome-Based Protocells.

    PubMed

    Sun, Shiyong; Li, Mei; Dong, Faqin; Wang, Shengjie; Tian, Liangfei; Mann, Stephen

    2016-04-13

    An aqueous-based microcompartmentalized model involving the integration of partially hydrophobic Fe(III)-rich montmorillonite (FeM) clay particles as structural and catalytic building blocks for colloidosome membrane assembly, self-directed membrane remodeling, and signal-induced protocell communication is described. The clay colloidosomes exhibit size- and charge-selective permeability, and show dual catalytic functions involving spatially confined enzyme-mediated dephosphorylation and peroxidase-like membrane activity. The latter is used for the colloidosome-mediated synthesis and assembly of a temperature-responsive poly(N-isopropylacrylamide)(PNIPAM)/clay-integrated hybrid membrane. In situ PNIPAM elaboration of the membrane is coupled to a glucose oxidase (GOx)-mediated signaling pathway to establish a primitive model of chemical communication and functional activation within a synthetic "protocell community" comprising a mixed population of GOx-containing silica colloidosomes and alkaline phosphatase (ALP)-containing FeM-clay colloidosomes. Triggering the enzyme reaction in the silica colloidosomes gives a hydrogen peroxide signal that induces polymer wall formation in a coexistent population of the FeM-clay colloidosomes, which in turn generates self-regulated membrane-gated ALP-activity within the clay microcompartments. The emergence of new functionalities in inorganic colloidosomes via chemical communication between different protocell populations provides a first step toward the realization of interacting communities of synthetic functional microcompartments.

  8. Application of physiologically based pharmacokinetic models in chemical risk assessment.

    PubMed

    Mumtaz, Moiz; Fisher, Jeffrey; Blount, Benjamin; Ruiz, Patricia

    2012-01-01

    Post-exposure risk assessment of chemical and environmental stressors is a public health challenge. Linking exposure to health outcomes is a 4-step process: exposure assessment, hazard identification, dose response assessment, and risk characterization. This process is increasingly adopting "in silico" tools such as physiologically based pharmacokinetic (PBPK) models to fine-tune exposure assessments and determine internal doses in target organs/tissues. Many excellent PBPK models have been developed. But most, because of their scientific sophistication, have found limited field application-health assessors rarely use them. Over the years, government agencies, stakeholders/partners, and the scientific community have attempted to use these models or their underlying principles in combination with other practical procedures. During the past two decades, through cooperative agreements and contracts at several research and higher education institutions, ATSDR funded translational research has encouraged the use of various types of models. Such collaborative efforts have led to the development and use of transparent and user-friendly models. The "human PBPK model toolkit" is one such project. While not necessarily state of the art, this toolkit is sufficiently accurate for screening purposes. Highlighted in this paper are some selected examples of environmental and occupational exposure assessments of chemicals and their mixtures.

  9. Application of Physiologically Based Pharmacokinetic Models in Chemical Risk Assessment

    PubMed Central

    Mumtaz, Moiz; Fisher, Jeffrey; Blount, Benjamin; Ruiz, Patricia

    2012-01-01

    Post-exposure risk assessment of chemical and environmental stressors is a public health challenge. Linking exposure to health outcomes is a 4-step process: exposure assessment, hazard identification, dose response assessment, and risk characterization. This process is increasingly adopting “in silico” tools such as physiologically based pharmacokinetic (PBPK) models to fine-tune exposure assessments and determine internal doses in target organs/tissues. Many excellent PBPK models have been developed. But most, because of their scientific sophistication, have found limited field application—health assessors rarely use them. Over the years, government agencies, stakeholders/partners, and the scientific community have attempted to use these models or their underlying principles in combination with other practical procedures. During the past two decades, through cooperative agreements and contracts at several research and higher education institutions, ATSDR funded translational research has encouraged the use of various types of models. Such collaborative efforts have led to the development and use of transparent and user-friendly models. The “human PBPK model toolkit” is one such project. While not necessarily state of the art, this toolkit is sufficiently accurate for screening purposes. Highlighted in this paper are some selected examples of environmental and occupational exposure assessments of chemicals and their mixtures. PMID:22523493

  10. Chemical Imaging of Platinum-Based Drugs and their Metabolites

    PubMed Central

    Liu, Xin; Hummon, Amanda B.

    2016-01-01

    Platinum-based drugs (cisplatin, carboplatin, and oxaliplatin) are widely used therapeutic agents for cancer treatment. Even though the platinum (Pt)-drugs are routinely used clinically, a clear picture of their distribution within tumor tissues is lacking. The current methods to image the distribution of Pt drugs are limited and do not enable the discrimination of the drug from its metabolites. In this manuscript, we demonstrate a methodology that enables chemical imaging of a Pt drug and its metabolites simultaneously and specifically. Matrix-Assisted Laser Desorption/Ionization (MALDI) Mass Spectrometry Imaging (MSI) is combined with an on-tissue chemical derivatization using diethyldithiocarbamate (DDTC). DDTC abstracts the Pt atom to generate ionizable complexes that can be imaged by MALDI MSI. We demonstrate that Pt drugs and their metabolites can be specifically imaged. This approach was successfully applied to map the penetration and metabolism of oxaliplatin in hyperthermic intraperitoneal chemotherapy (HIPEC)-like treated 3D colorectal tumor mimics. The distribution of cisplatin and carboplatin was mapped in additional 3D tumor mimics. We demonstrate that the approach can also be used to image the distribution of copper ions in cells. This method has the potential to be used to evaluate the penetration and distribution of a wide range of compounds. PMID:27917942

  11. Chemical Imaging of Platinum-Based Drugs and their Metabolites.

    PubMed

    Liu, Xin; Hummon, Amanda B

    2016-12-05

    Platinum-based drugs (cisplatin, carboplatin, and oxaliplatin) are widely used therapeutic agents for cancer treatment. Even though the platinum (Pt)-drugs are routinely used clinically, a clear picture of their distribution within tumor tissues is lacking. The current methods to image the distribution of Pt drugs are limited and do not enable the discrimination of the drug from its metabolites. In this manuscript, we demonstrate a methodology that enables chemical imaging of a Pt drug and its metabolites simultaneously and specifically. Matrix-Assisted Laser Desorption/Ionization (MALDI) Mass Spectrometry Imaging (MSI) is combined with an on-tissue chemical derivatization using diethyldithiocarbamate (DDTC). DDTC abstracts the Pt atom to generate ionizable complexes that can be imaged by MALDI MSI. We demonstrate that Pt drugs and their metabolites can be specifically imaged. This approach was successfully applied to map the penetration and metabolism of oxaliplatin in hyperthermic intraperitoneal chemotherapy (HIPEC)-like treated 3D colorectal tumor mimics. The distribution of cisplatin and carboplatin was mapped in additional 3D tumor mimics. We demonstrate that the approach can also be used to image the distribution of copper ions in cells. This method has the potential to be used to evaluate the penetration and distribution of a wide range of compounds.

  12. Drum plug piercing and sampling device and method

    DOEpatents

    Counts, Kevin T [Aiken, SC

    2011-04-26

    An apparatus and method for piercing a drum plug of a drum in order to sample and/or vent gases that may accumulate in a space of the drum is provided. The drum is not damaged and can be reused since the pierced drum plug can be subsequently replaced. The apparatus includes a frame that is configured for engagement with the drum. A cylinder actuated by a fluid is mounted to the frame. A piercer is placed into communication with the cylinder so that actuation of the cylinder causes the piercer to move in a linear direction so that the piercer may puncture the drum plug of the drum.

  13. Methodology for Mechanical Property Testing on Fuel Cladding Using an Expanded Plug Wedge Test

    SciTech Connect

    Wang, Jy-An John; Jiang, Hao

    2013-08-01

    compressive stresses were induced by clad bending deformation due to a clad bulging effect (or the barreling effect). The barreling effect caused very large localized shear stress in the clad and left testing material at a high risk of shear failure. The above combined effects will result in highly non-conservative predictions both in strength and ductility of the tested clad, and the associated mechanical properties as well. To overcome/mitigate the mentioned deficiencies associated with the current expansion plug test, systematic studies have been conducted. Through detailed parameter investigation on specific geometry designs, careful filtering of material for the expansion plug, as well as adding newly designed parts to the testing system, a method to reconcile the potential non-conservatism embedded in the expansion plug test system has been discovered. A modified expansion plug testing protocol has been developed based on the method. In order to closely resemble thin-wall theory, a general procedure was also developed to determine the hoop stress in the tested ring specimen. A scaling factor called -factor is defined to correlate the ring load P into hoop stress . , = . The generated stress-strain curve agrees very well with tensile test data in both the elastic and plastic regions.

  14. Instantaneous physico-chemical analysis of suspension-based nanomaterials

    PubMed Central

    Meng, Fanxu; Ugaz, Victor M.

    2015-01-01

    High-throughput manufacturing of nanomaterial-based products demands robust online characterization and quality control tools capable of continuously probing the in-suspension state. But existing analytical techniques are challenging to deploy in production settings because they are primarily geared toward small-batch ex-situ operation in research laboratory environments. Here we introduce an approach that overcomes these limitations by exploiting surface complexation interactions that emerge when a micron-scale chemical discontinuity is established between suspended nanoparticles and a molecular tracer. The resulting fluorescence signature is easily detectable and embeds surprisingly rich information about composition, quantity, size, and morphology of nanoparticles in suspension independent of their agglomeration state. We show how this method can be straightforwardly applied to enable continuous sizing of commercial ZnO nanoparticles, and to instantaneously quantify the anatase and rutile composition of multicomponent TiO2 nanoparticle mixtures pertinent to photocatalysis and solar energy conversion. PMID:25923196

  15. Limiting factors for carbon based chemical double layer capacitors

    NASA Technical Reports Server (NTRS)

    Rose, M. Frank; Johnson, C.; Owens, T.; Stevens, B.

    1993-01-01

    The Chemical Double Layer (CDL) capacitor improves energy storage density dramatically when compared with conventional electrolytic capacitors. When compared to batteries, the CDL Capacitor is much less energy dense; however, the power density is orders of magnitude better. As a result, CDL-battery combinations present an interesting pulse power system with many potential applications. Due to the nature of the CDL it is inherently a low voltage device. The applications of the CDL can be tailored to auxiliary energy and burst mode storages which require fast charge/discharge cycles. Typical of the applications envisioned are power system backup, directed energy weapons concepts, electric automobiles, and electric actuators. In this paper, we will discuss some of the general characteristics of carbon-based CDL technology describing the structure, performance parameters, and methods of construction. Further, analytical and experimental results which define the state of the art are presented and described in terms of impact on applications.

  16. Prodrugs design based on inter- and intramolecular chemical processes.

    PubMed

    Karaman, Rafik

    2013-12-01

    This review provides the reader a concise overview of the majority of prodrug approaches with the emphasis on the modern approaches to prodrug design. The chemical approach catalyzed by metabolic enzymes which is considered as widely used among all other approaches to minimize the undesirable drug physicochemical properties is discussed. Part of this review will shed light on the use of molecular orbital methods such as DFT, semiempirical and ab initio for the design of novel prodrugs. This novel prodrug approach implies prodrug design based on enzyme models that were utilized for mimicking enzyme catalysis. The computational approach exploited for the prodrug design involves molecular orbital and molecular mechanics (DFT, ab initio, and MM2) calculations and correlations between experimental and calculated values of intramolecular processes that were experimentally studied to assign the factors determining the reaction rates in certain processes for better understanding on how enzymes might exert their extraordinary catalysis.

  17. Evaluation of artificial intelligence based models for chemical biodegradability prediction.

    PubMed

    Baker, James R; Gamberger, Dragan; Mihelcic, James R; Sabljić, Aleksandar

    2004-12-31

    This study presents a review of biodegradability modeling efforts including a detailed assessment of two models developed using an artificial intelligence based methodology. Validation results for these models using an independent, quality reviewed database, demonstrate that the models perform well when compared to another commonly used biodegradability model, against the same data. The ability of models induced by an artificial intelligence methodology to accommodate complex interactions in detailed systems, and the demonstrated reliability of the approach evaluated by this study, indicate that the methodology may have application in broadening the scope of biodegradability models. Given adequate data for biodegradability of chemicals under environmental conditions, this may allow for the development of future models that include such things as surface interface impacts on biodegradability for example.

  18. Trends in information theory-based chemical structure codification.

    PubMed

    Barigye, Stephen J; Marrero-Ponce, Yovani; Pérez-Giménez, Facundo; Bonchev, Danail

    2014-08-01

    This report offers a chronological review of the most relevant applications of information theory in the codification of chemical structure information, through the so-called information indices. Basically, these are derived from the analysis of the statistical patterns of molecular structure representations, which include primitive global chemical formulae, chemical graphs, or matrix representations. Finally, new approaches that attempt to go "back to the roots" of information theory, in order to integrate other information-theoretic measures in chemical structure coding are discussed.

  19. Large-Scale Chemical Similarity Networks for Target Profiling of Compounds Identified in Cell-Based Chemical Screens

    PubMed Central

    Lo, Yu-Chen; Senese, Silvia; Li, Chien-Ming; Hu, Qiyang; Huang, Yong; Damoiseaux, Robert; Torres, Jorge Z.

    2015-01-01

    Target identification is one of the most critical steps following cell-based phenotypic chemical screens aimed at identifying compounds with potential uses in cell biology and for developing novel disease therapies. Current in silico target identification methods, including chemical similarity database searches, are limited to single or sequential ligand analysis that have limited capabilities for accurate deconvolution of a large number of compounds with diverse chemical structures. Here, we present CSNAP (Chemical Similarity Network Analysis Pulldown), a new computational target identification method that utilizes chemical similarity networks for large-scale chemotype (consensus chemical pattern) recognition and drug target profiling. Our benchmark study showed that CSNAP can achieve an overall higher accuracy (>80%) of target prediction with respect to representative chemotypes in large (>200) compound sets, in comparison to the SEA approach (60–70%). Additionally, CSNAP is capable of integrating with biological knowledge-based databases (Uniprot, GO) and high-throughput biology platforms (proteomic, genetic, etc) for system-wise drug target validation. To demonstrate the utility of the CSNAP approach, we combined CSNAP's target prediction with experimental ligand evaluation to identify the major mitotic targets of hit compounds from a cell-based chemical screen and we highlight novel compounds targeting microtubules, an important cancer therapeutic target. The CSNAP method is freely available and can be accessed from the CSNAP web server (http://services.mbi.ucla.edu/CSNAP/). PMID:25826798

  20. Large-scale chemical similarity networks for target profiling of compounds identified in cell-based chemical screens.

    PubMed

    Lo, Yu-Chen; Senese, Silvia; Li, Chien-Ming; Hu, Qiyang; Huang, Yong; Damoiseaux, Robert; Torres, Jorge Z

    2015-03-01

    Target identification is one of the most critical steps following cell-based phenotypic chemical screens aimed at identifying compounds with potential uses in cell biology and for developing novel disease therapies. Current in silico target identification methods, including chemical similarity database searches, are limited to single or sequential ligand analysis that have limited capabilities for accurate deconvolution of a large number of compounds with diverse chemical structures. Here, we present CSNAP (Chemical Similarity Network Analysis Pulldown), a new computational target identification method that utilizes chemical similarity networks for large-scale chemotype (consensus chemical pattern) recognition and drug target profiling. Our benchmark study showed that CSNAP can achieve an overall higher accuracy (>80%) of target prediction with respect to representative chemotypes in large (>200) compound sets, in comparison to the SEA approach (60-70%). Additionally, CSNAP is capable of integrating with biological knowledge-based databases (Uniprot, GO) and high-throughput biology platforms (proteomic, genetic, etc) for system-wise drug target validation. To demonstrate the utility of the CSNAP approach, we combined CSNAP's target prediction with experimental ligand evaluation to identify the major mitotic targets of hit compounds from a cell-based chemical screen and we highlight novel compounds targeting microtubules, an important cancer therapeutic target. The CSNAP method is freely available and can be accessed from the CSNAP web server (http://services.mbi.ucla.edu/CSNAP/).

  1. Evidence-Based Approaches to Improving Chemical Equilibrium Instruction

    ERIC Educational Resources Information Center

    Davenport, Jodi L.; Leinhardt, Gaea; Greeno, James; Koedinger, Kenneth; Klahr, David; Karabinos, Michael; Yaron, David J.

    2014-01-01

    Two suggestions for instruction in chemical equilibrium are presented, along with the evidence that supports these suggestions. The first is to use diagrams to connect chemical reactions to the effects of reactions on concentrations. The second is the use of the majority and minority species (M&M) strategy to analyze chemical equilibrium…

  2. Evidence-Based Approaches to Improving Chemical Equilibrium Instruction

    ERIC Educational Resources Information Center

    Davenport, Jodi L.; Leinhardt, Gaea; Greeno, James; Koedinger, Kenneth; Klahr, David; Karabinos, Michael; Yaron, David J.

    2014-01-01

    Two suggestions for instruction in chemical equilibrium are presented, along with the evidence that supports these suggestions. The first is to use diagrams to connect chemical reactions to the effects of reactions on concentrations. The second is the use of the majority and minority species (M&M) strategy to analyze chemical equilibrium…

  3. Effects-based chemical category approach for prioritization of low affinity estrogenic chemicals

    EPA Science Inventory

    Regulatory agencies are charged with addressing the endocrine disrupting potential of a large number of chemicals for which there is often little or no data on which to make decisions. Prioritizing the chemicals of greatest concern for potential hazard to humans and wildlife is a...

  4. Effects-based chemical category approach for prioritization of low affinity estrogenic chemicals

    EPA Science Inventory

    Regulatory agencies are charged with addressing the endocrine disrupting potential of a large number of chemicals for which there is often little or no data on which to make decisions. Prioritizing the chemicals of greatest concern for potential hazard to humans and wildlife is a...

  5. Study of Aerosol Chemical Composition Based on Aerosol Optical Properties

    NASA Astrophysics Data System (ADS)

    Berry, Austin; Aryal, Rudra

    2015-03-01

    We investigated the variation of aerosol absorption optical properties obtained from the CIMEL Sun-Photometer measurements over three years (2012-2014) at three AERONET sites GSFC; MD Science_Center and Tudor Hill, Bermuda. These sites were chosen based on the availability of data and locations that can receive different types of aerosols from land and ocean. These absorption properties, mainly the aerosol absorption angstrom exponent, were analyzed to examine the corresponding aerosol chemical composition. We observed that the retrieved absorption angstrom exponents over the two sites, GSFC and MD Science Center, are near 1 (the theoretical value for black carbon) and with low single scattering albedo values during summer seasons indicating presence of black carbon. Strong variability of aerosol absorption properties were observed over Tudor Hill and will be analyzed based on the air mass embedded from ocean side and land side. We will also present the seasonal variability of these properties based on long-range air mass sources at these three sites. Brent Holben, NASA GSFC, AERONET, Jon Rodriguez.

  6. Chemical fingerprinting of silicone-based breast implants.

    PubMed

    Keizers, Peter H J; Vredenbregt, Marjo J; Bakker, Frank; de Kaste, Dries; Venhuis, Bastiaan J

    2015-01-01

    With millions of women worldwide carrying them, silicone-based breast implants represent a large market. Even though silicone breast implants already have a history of use of more than 50 years, the discussion on their safety has not yet come to an end. To improve safety assessment, regulatory authorities should have the availability of a set of tests to be able to determine parameters of implant identity and quality. Therefore, the gels and envelopes of various brands and types of silicone-based breast implants have been subjected to infrared, Raman and NMR spectroscopy. We show that by using a combination of complementary spectroscopic techniques breast implants of various origins can be distinguished on typical chemical hallmarks. It was found that typical silicone-based implants display a surplus of vinyl signals in the gel, cyclosiloxane impurities are tolerable at low levels only and a barrier layer is present in the implant envelope. The techniques presented here and the results obtained offer a good starting point for market surveillance studies.

  7. SI Engine with repetitive NS spark plug

    NASA Astrophysics Data System (ADS)

    Pancheshniy, Sergey; Nikipelov, Andrey; Anokhin, Eugeny; Starikovskiy, Andrey; Laplase Team; Mipt Team; Pu Team

    2013-09-01

    Now de-facto the only technology for fuel-air mixtures ignition in IC engines exists. It is a spark discharge of millisecond duration in a short discharge gap. The reason for such a small variety of methods of ignition initiation is very specific conditions of the engine operation. First, it is very high-pressure of fuel-air mixture - from 5-7 atmospheres in old-type engines and up to 40-50 atmospheres on the operating mode of HCCI. Second, it is a very wide range of variation of the oxidizer/fuel ratio in the mixture - from almost stoichiometric (0.8-0.9) at full load to very lean (φ = 0.3-0.5) mixtures at idle and/or economical cruising mode. Third, the high velocity of the gas in the combustion chamber (up to 30-50 m/s) resulting in a rapid compression of swirling inlet flow. The paper presents the results of tests of distributed spark ignition system powered by repetitive pulse nanosecond discharge. Dynamic pressure measurements show the increased pressure and frequency stability for nanosecond excitation in comparison with the standard spark plug. Excitation by single nanosecond high-voltage pulse and short train of pulses was examined. In all regimes the nanosecond pulsed excitation demonstrate a better performance.

  8. Unique Signal Override Plug electromagnetic test report

    SciTech Connect

    Bonn, R.H.

    1990-10-01

    The MC4039 Unique Signal Override Plug (USOP) provides the unique signal for the B90 when fielded on aircraft that are not equipped with unique signal capability. Since the USOP is field installed, the concern is that it might be susceptible to electromagnetic radiation prior to installation on the weapon. This report documents a characterization of the USOP, evaluates various techniques for attaching electromagnetic shields, and evaluates the susceptibility of a fully assembled passive-USOP. Tests conducted evaluated the electromagnetic susceptibility of the passive, unconnected USOP. During normal operation the USOP is powered directly from the weapon. During the course of this test program two prototypes were developed. The prototype 1 USOP internal circuitry contains one SA3727 chip, five diodes, three resistors, and two capacitors; these are mounted on a circular circuit board and contained inside a metal back shell cover, which serves as an electromagnetic shield. The prototype 2 design incorporated four changes. The manufacturer of the SA3727 chip was changed from Lasarray to LSI Logic, the circuit board ground was tied to the case ground through a straight wire, Cl was changed from 1 microfarad to 0.1 microfarads. and the circuit board was changed, as required. 2 refs., 17 figs., 3 tabs. (JF)

  9. 2195 Aluminum-Copper-Lithium Friction Plug Welding Development

    NASA Technical Reports Server (NTRS)

    Takeshita, Rike P.; Hartley, Paula J.; Baker, Kent S.

    1997-01-01

    Technology developments and applications of friction plug welding is presented. This friction repair welding technology is being studied for implementation on the Space Transportation System's Super Light Weight External Tank. Single plug repairs will be used on a vast majority of weld defects, however, linear defects of up to several inches can be repaired by overlapping plug welds. Methods and results of tensile, bend, simulated service, surface crack tension and other tests at room and cryogenic temperatures is discussed. Attempts to implement Friction Plug Welding has led to both tool and process changes in an attempt to minimize expansive tooling and lengthy implementation times. Process control equipment and data storage methods intended for large scale production will also be addressed. Benefits include increased strength and toughness, decreased weld repair time, automated and highly reliable process, and a lower probability of having to re-repair defect locations.

  10. The Losing Battle Against Plug-and-Chug

    NASA Astrophysics Data System (ADS)

    Kortemeyer, Gerd

    2016-01-01

    I think most physics teachers would agree that two important components of a proper solution to a numerical physics problem are to first figure out a final symbolic solution and to only plug in numbers in the end. However, in spite of our best efforts, this is not what the majority of students is actually doing. Instead, they tend to plug numbers into formulas without considering the physical meaning of the equations, then frequently take the result and plug it into the next formula—a strategy known as "plug-and-chug." In this chain of calculations, frequently physical insights are lost. If teaching problem solving is proving ineffective, maybe it is possible to steer students onto the right path by posing the problems in different ways?

  11. Porous plug for reducing orifice induced pressure error in airfoils

    NASA Technical Reports Server (NTRS)

    Plentovich, Elizabeth B. (Inventor); Gloss, Blair B. (Inventor); Eves, John W. (Inventor); Stack, John P. (Inventor)

    1988-01-01

    A porous plug is provided for the reduction or elimination of positive error caused by the orifice during static pressure measurements of airfoils. The porous plug is press fitted into the orifice, thereby preventing the error caused either by fluid flow turning into the exposed orifice or by the fluid flow stagnating at the downstream edge of the orifice. In addition, the porous plug is made flush with the outer surface of the airfoil, by filing and polishing, to provide a smooth surface which alleviates the error caused by imperfections in the orifice. The porous plug is preferably made of sintered metal, which allows air to pass through the pores, so that the static pressure measurements can be made by remote transducers.

  12. Large discharge-volume, silent discharge spark plug

    DOEpatents

    Kang, Michael

    1995-01-01

    A large discharge-volume spark plug for providing self-limiting microdischarges. The apparatus includes a generally spark plug-shaped arrangement of a pair of electrodes, where either of the two coaxial electrodes is substantially shielded by a dielectric barrier from a direct discharge from the other electrode, the unshielded electrode and the dielectric barrier forming an annular volume in which self-terminating microdischarges occur when alternating high voltage is applied to the center electrode. The large area over which the discharges occur, and the large number of possible discharges within the period of an engine cycle, make the present silent discharge plasma spark plug suitable for use as an ignition source for engines. In the situation, where a single discharge is effective in causing ignition of the combustible gases, a conventional single-polarity, single-pulse, spark plug voltage supply may be used.

  13. Frictional Fluid Dynamics and Plug Formation in Multiphase Millifluidic Flow

    NASA Astrophysics Data System (ADS)

    Dumazer, Guillaume; Sandnes, Bjørnar; Ayaz, Monem; Mâløy, Knut Jørgen; Flekkøy, Eirik Grude

    2016-07-01

    We study experimentally the flow and patterning of a granular suspension displaced by air inside a narrow tube. The invading air-liquid interface accumulates a plug of granular material that clogs the tube due to friction with the confining walls. The gas percolates through the static plug once the gas pressure exceeds the pore capillary entry pressure of the packed grains, and a moving accumulation front is reestablished at the far side of the plug. The process repeats, such that the advancing interface leaves a trail of plugs in its wake. Further, we show that the system undergoes a fluidization transition—and complete evacuation of the granular suspension—when the liquid withdrawal rate increases beyond a critical value. An analytical model of the stability condition for the granular accumulation predicts the flow regime.

  14. Porous plug for reducing orifice induced pressure error in airfoils

    NASA Technical Reports Server (NTRS)

    Plentovich, Elizabeth B. (Inventor); Gloss, Blair B. (Inventor); Eves, John W. (Inventor); Stack, John P. (Inventor)

    1988-01-01

    A porous plug is provided for the reduction or elimination of positive error caused by the orifice during static pressure measurements of airfoils. The porous plug is press fitted into the orifice, thereby preventing the error caused either by fluid flow turning into the exposed orifice or by the fluid flow stagnating at the downstream edge of the orifice. In addition, the porous plug is made flush with the outer surface of the airfoil, by filing and polishing, to provide a smooth surface which alleviates the error caused by imperfections in the orifice. The porous plug is preferably made of sintered metal, which allows air to pass through the pores, so that the static pressure measurements can be made by remote transducers.

  15. A Plug Instead of A Snip for Male Birth Control?

    MedlinePlus

    ... A Plug Instead of a Snip for Male Birth Control? Monkey study shows injected gel may one day ... say Vasalgel will become a viable form of birth control. The procedure involving the gel starts off much ...

  16. Vas deferens obstruction due to fibrosis after plug hernioplasty.

    PubMed

    Valenti, Gabriele; Baldassarre, Emanuele; Torino, Giovanni

    2006-02-01

    The positioning of mesh and plug is routinely performed in hernioplasty, but knowledge about the long-term side effects of plug-induced fibrosis on the vas is incomplete. This is the first case of a documented fibrotic vas deferens obstruction resulting from compression of the plug that was in direct contact with the vas. During subsequent repair for a recurrent hernia, the cord and the plug appeared enveloped in dense fibrous tissue. Microscopy confirmed gross surgical findings. To reduce this morbidity, we suggest a cremaster sparing surgery, avoiding the positioning of bioprosthesis in direct contact with the vas deferens. We also found that positioning of a flat mesh over the transversalis fascia will avoid the unnecessary contact between mesh and bare vas below the transversalis fascia.

  17. 2195 Aluminum-Copper-Lithium Friction Plug Welding Development

    NASA Technical Reports Server (NTRS)

    Takeshita, Rike P.; Hartley, Paula J.; Baker, Kent S.

    1997-01-01

    Technology developments and applications of friction plug welding is presented. This friction repair welding technology is being studied for implementation on the Space Transportation System's Super Light Weight External Tank. Single plug repairs will be used on a vast majority of weld defects, however, linear defects of up to several inches can be repaired by overlapping plug welds. Methods and results of tensile, bend, simulated service, surface crack tension and other tests at room and cryogenic temperatures is discussed. Attempts to implement Friction Plug Welding has led to both tool and process changes in an attempt to minimize expansive tooling and lengthy implementation times. Process control equipment and data storage methods intended for large scale production will also be addressed. Benefits include increased strength and toughness, decreased weld repair time, automated and highly reliable process, and a lower probability of having to re-repair defect locations.

  18. Astronaut Hoffman replaces fuse plugs on Hubble Space Telescope

    NASA Technical Reports Server (NTRS)

    1993-01-01

    Astronaut Jeffrey A. Hoffman sees to the replacement of fuse plugs on the Hubble Space Telescope (HST) during the first of five space walks. Thunderclouds are all that is visible on the dark earth in the background.

  19. Engaging Tenants in Reducing Plug Load Energy Use

    SciTech Connect

    Schantz, Marta; Langner, Rois

    2016-08-26

    Plug and Process Loads (PPLs) account for an increasingly large percentage of commercial building energy use in the U.S. due to the rising number of energy intensive plug-in devices. In addition, buildings are becoming more and more efficient and plug load energy use has become an increasingly pertinent component to achieving aggressive energy targets and netzero energy status. For multi-tenant buildings, controlling plug loads in tenant spaces can be a significant challenge. Luckily, there are a number of PPL reduction strategies, best practices, and lessons learned from numerous commercial real estate and higher education leaders who have successfully engaged building occupants and tenants in reducing PPL energy use. This paper provides actionable PPL reduction strategies and best practices that building owners and managers can immediately apply to their own buildings.

  20. Description of a novel mating plug mechanism in spiders and the description of the new species Maeotasetastrobilaris (Araneae, Salticidae).

    PubMed

    Garcilazo-Cruz, Uriel; Alvarez-Padilla, Fernando

    2015-01-01

    Reproduction in arthropods is an interesting area of research where intrasexual and intersexual mechanisms have evolved structures with several functions. The mating plugs usually produced by males are good examples of these structures where the main function is to obstruct the female genitalia against new sperm depositions. In spiders several types of mating plugs have been documented, the most common ones include solidified secretions, parts of the bulb or in some extraordinary cases the mutilation of the entire palpal bulb. Here, we describe the first case of modified setae, which are located on the cymbial dorsal base, used directly as a mating plug for the Order Araneae in the species Maeotasetastrobilaris sp. n. In addition the taxonomic description of Maeotasetastrobilaris sp. n. is provided and based on our findings the geographic distribution of this genus is extended to the Northern hemisphere.

  1. Description of a novel mating plug mechanism in spiders and the description of the new species Maeota setastrobilaris (Araneae, Salticidae)

    PubMed Central

    Garcilazo-Cruz, Uriel; Alvarez-Padilla, Fernando

    2015-01-01

    Abstract Reproduction in arthropods is an interesting area of research where intrasexual and intersexual mechanisms have evolved structures with several functions. The mating plugs usually produced by males are good examples of these structures where the main function is to obstruct the female genitalia against new sperm depositions. In spiders several types of mating plugs have been documented, the most common ones include solidified secretions, parts of the bulb or in some extraordinary cases the mutilation of the entire palpal bulb. Here, we describe the first case of modified setae, which are located on the cymbial dorsal base, used directly as a mating plug for the Order Araneae in the species Maeota setastrobilaris sp. n. In addition the taxonomic description of Maeota setastrobilaris sp. n. is provided and based on our findings the geographic distribution of this genus is extended to the Northern hemisphere. PMID:26175601

  2. Dual spark plug ignition system for motorcycle internal combustion engine

    SciTech Connect

    Hoeptner, H.W.

    1991-04-02

    This patent describes an ignition system for a motorcycle two cylinder internal combustion engine, the system including magnetically coupled primary and secondary coil means, two spark plugs at each of the cylinders, a source of electrical current, and a single set of contacts controlling electrical current flow to the primary coil means for producing high voltage outputs from the secondary coil means to be delivered to all four of the spark plugs, the secondary coil means including certain secondary coil means operatively connected via the primary coil means with both the of spark plugs at one cylinder, a single cam controlling only the contacts, and a single magnetic core between the primary coil means and both the secondary coil means, and wherein the spark plugs include: two plugs at one cylinder and connected with the certain secondary coil means, two plugs at the second cylinder and connected with the other secondary coil means, the primary coil means including certain primary coil means magnetically coupled to the certain secondary coil means, and other primary coil means magnetically coupled to the other secondary coil means, the certain and other primary coil means being connected in series, electrically, the two spark plugs at one cylinder being electrically connected to opposite ends of the certain secondary coil means, and the two spark plugs at the other cylinder are electrically connected to opposite ends of the other secondary coil means. It comprises the cam driven by the engine for controlling opening of the contacts, the cam rotatable about a first axis, carrier means carrying the contacts, and adjustably rotatable about the axis.

  3. MTR MAIN FLOOR. MEN DEMONSTRATE INSERTION OF DUMMY PLUG INTO ...

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

    MTR MAIN FLOOR. MEN DEMONSTRATE INSERTION OF DUMMY PLUG INTO AN MTR BEAM HOLE. ONE MAN CHECKS RADIATION LEVEL AT THE END OF THE UNIVERSAL COFFIN, WHILE ANOTHER USES TOOL TO INSERT PLUG INTO HOLE THROUGH COFFIN. MEN WEAR "ANTI-C" (ANTI-CONTAMINATION) CLOTHING. INL NEGATIVE NO. 6198. R.G. Larsen, Photographer, 6/27/1952 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  4. Maturity Assessment of Space Plug-and-Play Architecture

    DTIC Science & Technology

    2013-03-01

    Architecture NATO North Atlantic Treaty Organization ORS Office of Responsive Space PnP Plug-and-Play PnPSat Plug-and-Play Satellite RWA Reaction Wheel Assembly... reaction wheel assembly and other parts. In a traditional spacecraft development, the bus and the payload are built separately and then mated together...Management c. Buffer Management d. Orbit Estimator e. Attitude Estimator f. Momentum Management g. Reaction Wheel Torque Distribution h. Sun

  5. Double-O-Ring Plug For Leak Tests

    NASA Technical Reports Server (NTRS)

    Greene, James H.

    1989-01-01

    Pressure plug features redundant O-ring bore seals and axial port opening laterally into space between O-rings to enable testing of seals. Axial passage in plug connected through radial passage to space between O-rings. Opening used to test O-rings, then sealed with smaller O-ring compressed by machine screw. Useful to seal test or cleanout holes normally kept closed in hydraulic actuators, pumps, and other pressurized systems.

  6. An open framework for automated chemical hazard assessment based on GreenScreen for Safer Chemicals: A proof of concept.

    PubMed

    Wehage, Kristopher; Chenhansa, Panan; Schoenung, Julie M

    2017-01-01

    GreenScreen® for Safer Chemicals is a framework for comparative chemical hazard assessment. It is the first transparent, open and publicly accessible framework of its kind, allowing manufacturers and governmental agencies to make informed decisions about the chemicals and substances used in consumer products and buildings. In the GreenScreen® benchmarking process, chemical hazards are assessed and classified based on 18 hazard endpoints from up to 30 different sources. The result is a simple numerical benchmark score and accompanying assessment report that allows users to flag chemicals of concern and identify safer alternatives. Although the screening process is straightforward, aggregating and sorting hazard data is tedious, time-consuming, and prone to human error. In light of these challenges, the present work demonstrates the usage of automation to cull chemical hazard data from publicly available internet resources, assign metadata, and perform a GreenScreen® hazard assessment using the GreenScreen® "List Translator." The automated technique, written as a module in the Python programming language, generates GreenScreen® List Translation data for over 3000 chemicals in approximately 30 s. Discussion of the potential benefits and limitations of automated techniques is provided. By embedding the library into a web-based graphical user interface, the extensibility of the library is demonstrated. The accompanying source code is made available to the hazard assessment community. Integr Environ Assess Manag 2017;13:167-176. © 2016 SETAC. © 2016 SETAC.

  7. 30 CFR 250.1715 - How must I permanently plug a well?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    .... Permanent Well Plugging Requirements If you have— Then you must use— (1) Zones in open hole Cement plug(s... zones to isolate fluids in the strata. (2) Open hole below casing (i) A cement plug, set by the displacement method, at least 100 feet above and below deepest casing shoe;(ii) A cement retainer...

  8. Reconstitutable control assembly having removable control rods with detachable split upper end plugs

    SciTech Connect

    Gjertsen, R.K.; Knott, R.P.; Sparrow, J.A.

    1991-02-19

    This patent describes, for use in facilitating replacement of a neutron absorber control rod on a control assembly spider structure, an end plug. It comprises a pair of separate upper and lower plug portions; the upper section of the upper plug portion being configured for rigid attachment; the middle section of the upper plug portion having angularly displaced flat surfaces formed on the exterior.

  9. Space-Based Chemical Lasers in strategic defense

    SciTech Connect

    Wildt, D. )

    1992-07-01

    The Strategic Defense Initiative Organization (SDIO) has made significant progress in developing Space-Based chemical Laser (SBL) technologies and in studying the SBLs global defense capability. In this mission, a constellation of several orbiting laser platforms provides continuous global defense by intercepting threatening missiles in their boost phase, including short range ballistic missiles (SRBMs). An optional smaller constellation provides defense against launches from the low and midlatitude regions. In addition, SBLs have utility in other important related missions such as surveillance, air defense and discrimination. The hardware necessary to build such a system has been developed to the point where it is mature and ready for demonstration in space. Advances have been made in each of the following major areas of the SBL: laser device; optics/beam control; beam pointing; ATP (acquisition, tracking and pointing); uncooled optics; and laser lethality. Integration of the key laser and beam control technologies is now occurring in the ground-based ALI experiment, and a space demonstration experiment, Star LITE, is in the planning and concept development phase.

  10. Calculations aid breaking of wax-plugged lines

    SciTech Connect

    Gilchrist, R.T. Jr.

    1986-08-01

    Manipulation of pressure/volume data helps locate a wax plug in a pipeline, and it may then be possible to clear the line by interception of the plug with a hot tap. Or, in an extreme case, information obtained from the pressure/volume data will allow better assessment of where to replace the pipe. The possibility of a pipeline becoming plugged by paraffin buildup is greatest in winter when cooler temperatures may cause wax to precipitate and plate out on the pipe walls or completely gel in the line. The risk of plugging is also greatest during pigging. This is because passage of the pig may cause a large mass of wax to accumulate by scraping a thin layer of wax from a long length of pipe. This type of plug does not enlarge once the pipeline is stopped up. It has been successfully cleared by tapping the pipeline at a point within the wax blockage and then pumping the plug out in sections.

  11. A plug-in to Eclipse for VHDL source codes: functionalities

    NASA Astrophysics Data System (ADS)

    Niton, B.; Poźniak, K. T.; Romaniuk, R. S.

    The paper presents an original application, written by authors, which supports writing and edition of source codes in VHDL language. It is a step towards fully automatic, augmented code writing for photonic and electronic systems, also systems based on FPGA and/or DSP processors. An implementation is described, based on VEditor. VEditor is a free license program. Thus, the work presented in this paper supplements and extends this free license. The introduction characterizes shortly available tools on the market which serve for aiding the design processes of electronic systems in VHDL. Particular attention was put on plug-ins to the Eclipse environment and Emacs program. There are presented detailed properties of the written plug-in such as: programming extension conception, and the results of the activities of formatter, re-factorizer, code hider, and other new additions to the VEditor program.

  12. Using a Multijunction Microfluidic Device To Inject Substrate into an Array of Preformed Plugs without Cross-Contamination

    PubMed Central

    Li, Liang; Boedicker, James Q.; Ismagilov, Rustem F.

    2007-01-01

    In this paper we describe a multijunction microfluidic device for the injection of a substrate into an array of preformed plugs carried by an immiscible fluid in a microchannel. The device uses multiple junctions to inject substrate into preformed plugs without synchronization of the flow of substrate and the array of preformed plugs of reagent, which reduces cross-contamination of the plugs, eliminates formation of small droplets of substrate, and allows a greater range of injection ratios compared to that of a single T-junction. The device was based on a previously developed physical model for transport that was here adapted to describe injection and experimentally verified. After characterization, the device was applied to two biochemical assays, including evaluation of the enzymatic activity of thrombin and determination of the coagulation time of human blood plasma, which both provided reliable results. The reduction of cross-contamination and greater range of injection ratios achieved by this device may improve the processes that involve addition and titration of reagents into plugs, such as high-throughput screening of protein crystallization conditions. PMID:17338503

  13. Graphene Electronic Device Based Biosensors and Chemical Sensors

    NASA Astrophysics Data System (ADS)

    Jiang, Shan

    Two-dimensional layered materials, such as graphene and MoS2, are emerging as an exciting material system for a new generation of atomically thin electronic devices. With their ultrahigh surface to volume ratio and excellent electrical properties, 2D-layered materials hold the promise for the construction of a generation of chemical and biological sensors with unprecedented sensitivity. In my PhD thesis, I mainly focus on graphene based electronic biosensors and chemical sensors. In the first part of my thesis, I demonstrated the fabrication of graphene nanomesh (GNM), which is a graphene thin film with a periodic array of holes punctuated in it. The periodic holes introduce long periphery active edges that provide a high density of functional groups (e.g. carboxylic groups) to allow for covalent grafting of specific receptor molecules for chemical and biosensor applications. After covalently functionalizing the GNM with glucose oxidase, I managed to make a novel electronic sensor which can detect glucose as well as pH change. In the following part of my thesis I demonstrate the fabrication of graphene-hemin conjugate for nitric oxide detection. The non-covalent functionalization through pi-pi stacking interaction allows reliable immobilization of hemin molecules on graphene without damaging the graphene lattice to ensure the highly sensitive and specific detection of nitric oxide. The graphene-hemin nitric oxide sensor is capable of real-time monitoring of nitric oxide concentrations, which is of central importance for probing the diverse roles of nitric oxide in neurotransmission, cardiovascular systems, and immune responses. Our studies demonstrate that the graphene-hemin sensors can respond rapidly to nitric oxide in physiological environments with sub-nanomolar sensitivity. Furthermore, in vitro studies show that the graphene-hemin sensors can be used for the detection of nitric oxide released from macrophage cells and endothelial cells, demonstrating their

  14. Accelerator-based chemical and elemental analysis of atmospheric aerosols

    NASA Astrophysics Data System (ADS)

    Mentes, Besim

    Aerosol particles have always been present in the atmosphere, arising from natural sources. But it was not until recently when emissions from anthropogenic (man made) sources began to dominate, that atmospheric aerosols came into focus and the aerosol science in the environmental perspective started to grow. These sources emit or produce particles with different elemental and chemical compositions, as well as different sizes of the individual aerosols. The effects of increased pollution of the atmosphere are many, and have different time scales. One of the effects known today is acid rain, which causes problems for vegetation. Pollution is also a direct human health risk, in many cities where traffic driven by combustion engines is forbidden at certain times when the meteorological conditions are unfavourable. Aerosols play an important role in the climate, and may have both direct and indirect effect which cause cooling of the planet surface, in contrast to the so-called greenhouse gases. During this work a technique for chemical and elemental analysis of atmospheric aerosols and an elemental analysis methodology for upper tropospheric aerosols have been developed. The elemental analysis is performed by the ion beam analysis (IBA) techniques, PIXE (elements heavier than Al). PESA (C, N and O), cPESA (H) and pNRA (Mg and Na). The chemical speciation of atmospheric aerosols is obtained by ion beam thermography (IBT). During thermography the sample temperature is stepwise increased and the IBA techniques are used to continuously monitor the elemental concentration. A thermogram is obtained for each element. The vaporisation of the compounds in the sample appears as a concentration decrease in the thermograms at characteristic vaporisation temperatures (CVTs). Different aspects of IBT have been examined in Paper I to IV. The features of IBT are: almost total elemental speciation of the aerosol mass, chemical speciation of the inorganic compounds, carbon content

  15. Amplatzer vascular plugs in congenital cardiovascular malformations

    PubMed Central

    Barwad, Parag; Ramakrishnan, Sivasubramanian; Kothari, Shyam S; Saxena, Anita; Gupta, Saurabh K; Juneja, Rajnish; Gulati, Gurpreet Singh; Jagia, Priya; Sharma, Sanjiv

    2013-01-01

    Background: Amplatzer vascular plugs (AVPs) are devices ideally suited to close medium-to-large vascular communications. There is limited published literature regarding the utility of AVPs in congenital cardiovascular malformations (CCVMs). Aims: To describe the use of AVPs in different CCVMs and to evaluate their safety and efficacy. Materials and Methods: All patients who required an AVP for the closure of CCVM were included in this retrospective review of our catheterization laboratory data. The efficacy and safety of AVPs are reported. Results: A total of 39 AVPs were implanted in 31 patients. Thirteen (33%) were AVP type I and 23 (59%) were AVP type II. AVP type III were implanted in two patients and type IV in one patient. The major indications for their use included closure of pulmonary arteriovenous malformation (AVM) (n = 7), aortopulmonary collaterals (n = 7), closure of a patent Blalock-Taussig shunt (n = 5), systemic AVM (n = 5), coronary AVM (n = 4), patent ductus arteriosus (PDA) (n = 3), pulmonary artery aneurysms (n = 3), and venovenous collaterals (n = 2). Deployment of the AVP was done predominantly via the 5 – 7F Judkin's right coronary guide catheter. Overall 92% of the AVPs could be successfully deployed and resulted in occlusion of the target vessel in all cases, within 10 minutes. No procedure-related or access site complication occurred. Conclusions: AVPs are versatile, easy to use, and effective devices to occlude the vascular communications in a variety of settings. AVP II is especially useful in the closure of tubular structures with a high flow. PMID:24688229

  16. Recognition of chemical entities: combining dictionary-based and grammar-based approaches

    PubMed Central

    2015-01-01

    Background The past decade has seen an upsurge in the number of publications in chemistry. The ever-swelling volume of available documents makes it increasingly hard to extract relevant new information from such unstructured texts. The BioCreative CHEMDNER challenge invites the development of systems for the automatic recognition of chemicals in text (CEM task) and for ranking the recognized compounds at the document level (CDI task). We investigated an ensemble approach where dictionary-based named entity recognition is used along with grammar-based recognizers to extract compounds from text. We assessed the performance of ten different commercial and publicly available lexical resources using an open source indexing system (Peregrine), in combination with three different chemical compound recognizers and a set of regular expressions to recognize chemical database identifiers. The effect of different stop-word lists, case-sensitivity matching, and use of chunking information was also investigated. We focused on lexical resources that provide chemical structure information. To rank the different compounds found in a text, we used a term confidence score based on the normalized ratio of the term frequencies in chemical and non-chemical journals. Results The use of stop-word lists greatly improved the performance of the dictionary-based recognition, but there was no additional benefit from using chunking information. A combination of ChEBI and HMDB as lexical resources, the LeadMine tool for grammar-based recognition, and the regular expressions, outperformed any of the individual systems. On the test set, the F-scores were 77.8% (recall 71.2%, precision 85.8%) for the CEM task and 77.6% (recall 71.7%, precision 84.6%) for the CDI task. Missed terms were mainly due to tokenization issues, poor recognition of formulas, and term conjunctions. Conclusions We developed an ensemble system that combines dictionary-based and grammar-based approaches for chemical named

  17. Recognition of chemical entities: combining dictionary-based and grammar-based approaches.

    PubMed

    Akhondi, Saber A; Hettne, Kristina M; van der Horst, Eelke; van Mulligen, Erik M; Kors, Jan A

    2015-01-01

    The past decade has seen an upsurge in the number of publications in chemistry. The ever-swelling volume of available documents makes it increasingly hard to extract relevant new information from such unstructured texts. The BioCreative CHEMDNER challenge invites the development of systems for the automatic recognition of chemicals in text (CEM task) and for ranking the recognized compounds at the document level (CDI task). We investigated an ensemble approach where dictionary-based named entity recognition is used along with grammar-based recognizers to extract compounds from text. We assessed the performance of ten different commercial and publicly available lexical resources using an open source indexing system (Peregrine), in combination with three different chemical compound recognizers and a set of regular expressions to recognize chemical database identifiers. The effect of different stop-word lists, case-sensitivity matching, and use of chunking information was also investigated. We focused on lexical resources that provide chemical structure information. To rank the different compounds found in a text, we used a term confidence score based on the normalized ratio of the term frequencies in chemical and non-chemical journals. The use of stop-word lists greatly improved the performance of the dictionary-based recognition, but there was no additional benefit from using chunking information. A combination of ChEBI and HMDB as lexical resources, the LeadMine tool for grammar-based recognition, and the regular expressions, outperformed any of the individual systems. On the test set, the F-scores were 77.8% (recall 71.2%, precision 85.8%) for the CEM task and 77.6% (recall 71.7%, precision 84.6%) for the CDI task. Missed terms were mainly due to tokenization issues, poor recognition of formulas, and term conjunctions. We developed an ensemble system that combines dictionary-based and grammar-based approaches for chemical named entity recognition, outperforming

  18. Exposure-Based Prioritization of Chemicals for Risk Assessment

    EPA Science Inventory

    Manufactured chemicals are used extensively to produce a wide variety of consumer goods and are required by important industrial sectors. Presently, information is insufficient to estimate risks posed to human health and the environment from the over ten thousand chemical substan...

  19. Raman-spectroscopy-based chemical contaminant detection in milk powder

    USDA-ARS?s Scientific Manuscript database

    Addition of edible and inedible chemical contaminants in food powders for purposes of economic benefit has become a recurring trend. In recent years, severe health issues have been reported due to consumption of food powders contaminated with chemical substances. This study examines the effect of sp...

  20. The Plug model: A potential new framework for modeling cyclic activity in Strombolian-type volcanoes

    NASA Astrophysics Data System (ADS)

    Suckale, J.; Hager, B. H.; Cashman, K. V.; Belien, I. L.; Persson, P. O.

    2011-12-01

    Normal Strombolian activity is possibly one of the most famous examples of cyclic activity in volcanology. The leading paradigm for this type of activity posits that each eruption represents the burst of a large gas slug ascending through liquid magma in the volcanic conduit. When this slug model was first devised, the petrological characteristics of the Strombolian plumbing system were poorly constrained. Since then, numerous petrological studies have established the existence of highly crystalline magma in the upper few hundred meters of the Strombolian conduit. The goal of this paper is to incorporate the recent petrological evidence into a more general framework of normal activity at Stromboli and potentially other basaltic volcanoes exhibiting comparable eruptive patterns. We model the gas- and crystal-rich magma in the upper part of the conduit as a porous material with finite yield strength. Since the ascent velocities of gas bubbles decreases upon reaching this zone, gas accumulates below the plug-like crystalline layer and exerts a buoyancy pressure in the vertical direction. In order to evaluate the resulting stress and strain inside the plug, we have developed a numerical model that captures the variable material properties of the plug and the surrounding host rock based on a finite-element discretization in 3D. Our simulations indicate that the accumulating gas pressure could cause yielding and failure in the plug. We hypothesize that failure of the plug in conjunction with drainage of gas-rich magma represents a normal eruption. Our alternative view of the mechanism behind normal eruptions also offers an explanation for the origin of the VLP signal as the seismic signal associated with the onset of failure, and sheds new light on the crater morphology at Stromboli. While our model is currently adjusted to reflect the geometry and magmatic properties of Stromboli volcano, it could be generalized to other volcanoes and could provide a framework for

  1. Recent developments in OLED-based chemical and biological sensors

    NASA Astrophysics Data System (ADS)

    Shinar, Joseph; Zhou, Zhaoqun; Cai, Yuankun; Shinar, Ruth

    2007-09-01

    Recent developments in the structurally integrated OLED-based platform of luminescent chemical and biological sensors are reviewed. In this platform, an array of OLED pixels, which is structurally integrated with the sensing elements, is used as the photoluminescence (PL) excitation source. The structural integration is achieved by fabricating the OLED array and the sensing element on opposite sides of a common glass substrate or on two glass substrates that are attached back-to-back. As it does not require optical fibers, lens, or mirrors, it results in a uniquely simple, low-cost, and potentially rugged geometry. The recent developments on this platform include the following: (1) Enhancing the performance of gas-phase and dissolved oxygen sensors. This is achieved by (a) incorporating high-dielectric TiO II nanoparticles in the oxygen-sensitive Pt and Pd octaethylporphyrin (PtOEP and PdOEP, respectively)- doped polystyrene (PS) sensor films, and (b) embedding the oxygen-sensitive dyes in a matrix of polymer blends such as PS:polydimethylsiloxane (PDMS). (2) Developing sensor arrays for simultaneous detection of multiple serum analytes, including oxygen, glucose, lactate, and alcohol. The sensing element for each analyte consists of a PtOEP-doped PS oxygen sensor, and a solution containing the oxidase enzyme specific to the analyte. Each sensing element is coupled to two individually addressable OLED pixels and a Si photodiode photodetector (PD). (3) Enhancing the integration of the platform, whereby a PD array is also structurally integrated with the OLED array and sensing elements. This enhanced integration is achieved by fabricating an array of amorphous or nanocrystalline Si-based PDs, followed by fabrication of the OLED pixels in the gaps between these Si PDs.

  2. A chemical-biological similarity-based grouping of complex substances as a prototype approach for evaluating chemical alternatives.

    PubMed

    Grimm, Fabian A; Iwata, Yasuhiro; Sirenko, Oksana; Chappell, Grace A; Wright, Fred A; Reif, David M; Braisted, John; Gerhold, David L; Yeakley, Joanne M; Shepard, Peter; Seligmann, Bruce; Roy, Tim; Boogaard, Peter J; Ketelslegers, Hans B; Rohde, Arlean M; Rusyn, Ivan

    2016-08-21

    Comparative assessment of potential human health impacts is a critical step in evaluating both chemical alternatives and existing products on the market. Most alternatives assessments are conducted on a chemical-by-chemical basis and it is seldom acknowledged that humans are exposed to complex products, not individual substances. Indeed, substances of Unknown or Variable composition, Complex reaction products, and Biological materials (UVCBs) are ubiquitous in commerce yet they present a major challenge for registration and health assessments. Here, we present a comprehensive experimental and computational approach to categorize UVCBs according to global similarities in their bioactivity using a suite of in vitro models. We used petroleum substances, an important group of UVCBs which are grouped for regulatory approval and read-across primarily on physico-chemical properties and the manufacturing process, and only partially based on toxicity data, as a case study. We exposed induced pluripotent stem cell-derived cardiomyocytes and hepatocytes to DMSO-soluble extracts of 21 petroleum substances from five product groups. Concentration-response data from high-content imaging in cardiomyocytes and hepatocytes, as well as targeted high-throughput transcriptomic analysis of the hepatocytes, revealed distinct groups of petroleum substances. Data integration showed that bioactivity profiling affords clustering of petroleum substances in a manner similar to the manufacturing process-based categories. Moreover, we observed a high degree of correlation between bioactivity profiles and physico-chemical properties, as well as improved groupings when chemical and biological data were combined. Altogether, we demonstrate how novel in vitro screening approaches can be effectively utilized in combination with physico-chemical characteristics to group complex substances and enable read-across. This approach allows for rapid and scientifically-informed evaluation of health impacts of

  3. Chemical and Biological Sensors Based on Organic Electrochemical Transistors

    NASA Astrophysics Data System (ADS)

    Lin, Peng

    Organic thin film transistors (OTFTs) have been explored for sensing applications for several decades due to their many advantages like easy fabrication, low cost, flexibility, and biocompatibility. Among these OTFTs, organic electrochemical transistors (OECTs) have attracted a great deal of interest in recent years since the devices can operate stably in aqueous environment with relatively low working voltages and are suitable for applications in chemical and biological sensing. In this thesis, ion-sensitive properties of OECTs based on poly(3,4- ethylenedioxythiophene):poly(styrene sulfonic acid) (PEDOT:PSS) have been systematically studied. It was found that the gate electrode played an important role on the ion-sensitive properties of OECTs. For the devices with Ag/AgCl gate electrode, Nernstian relationships between the shift of gate voltage and the concentrations of cations were obtained. For the devices with Pt and Au gate electrodes, the ion sensitivities were higher than that given by Nernst equation, which could be attributed to the interface between the metal gate electrode and the electrolyte. Moreover, OECTs based on PEDOT:PSS were integrated into flexible microfluidic systems. Then a novel label-free DNA sensor was developed, in which single-stranded DNA probes were immobilized on the surface of Au gate electrode. These devices successfully detected complementary DNA targets at concentrations as low as 1 nM. The detection limit was also extended to 10 pM by pulse-enhanced hybridization process of DNA. OECTs based on PEDOT:PSS were also exploited as cell-based biosensors. Human esophageal squamous epithelial cancer cell lines (KYSE30) and fibroblast cell lines (HFFI) were successfully grown on the surface of PEDOT:PSS film. Then the devices were used for in-vitro monitoring cell activities when the living cells were treated by trypsin and an anti-cancer drug, retinoic acid. It was found that the devices were sensitive to the change of surface charge

  4. Rigid-plug elastic-water model for transient pipe flow with entrapped air pocket

    SciTech Connect

    Zhou, Ling; Liu, Prof. Deyou; Karney, Professor Byran W.; Zhang, Qin Fen; OU, CHANGQI

    2011-01-01

    Pressure transients in a rapidly filling pipe with an entrapped air pocket are investigated analytically. A rigid-plug elastic water model is developed by applying elastic water hammer to the majority of the water column while applying rigid water analysis to a small portion near the air-water interface, which avoids effectively the interpolation error of previous approaches. Moreover, another two simplified models are introduced respectively based on constant water length and by neglecting water elasticity. Verification of the three models is confirmed by experimental results. Calculations show that the simplification of constant water length is feasible for small air pockets. The complete rigid water model is appropriate for cases with large initial air volume. The rigid-plug elastic model can predict all the essential features for the entire range of initial air fraction considered in this study, and it is the effective model for analysis of pressure transients of entrapped air.

  5. In vivo two-photon microscopy of the hippocampus using glass plugs

    PubMed Central

    Velasco, Mary Grace M.; Levene, Michael J.

    2014-01-01

    Two-photon microscopy has been used in conjunction with micro-optics, such as GRIN lenses, to access subcortical structures in the intact mouse brain. In this study, we demonstrate the use of thick glass windows, or plugs, for high-resolution, large field-of-view two-photon imaging of the hippocampus in a live mouse. These plugs are less expensive, yield larger fields-of-view and are simpler to use than GRIN lenses while requiring less tissue removal compared to previous methods based on cortical ablation. To demonstrate the capabilities of our system, we show fluorescence images of dendritic spines in the CA1 region of the hippocampus in THY1-YFP transgenic mice. PMID:24940533

  6. Plugoma: CT findings after prosthetic plug inguinal hernia repairs.

    PubMed

    Aganovic, Lejla; Ishioka, Kevin M; Hughes Cassidy, Fiona; Chu, Pauline K; Cosman, Bard C

    2010-10-01

    Unrecognized CT findings of a prosthetic plug used in inguinal hernia repair can lead to incorrect diagnosis or unnecessary workup of a patient. The objective of this study is to review the expected CT findings present in patients with a history of plug repair. Retrospective cohort study retrieving clinical and image data from a single-institution database. Patients who underwent prosthetic plug hernia repair during a 5-year period at our institution had their records queried for subsequent abdominal CT scans. These CT scans were reviewed by 2 radiologists for findings referable to the hernia repair. Five-hundred and sixty-four consecutive patients underwent prosthetic plug hernia repair during a 5-year period. Fifty-one patients who had had 55 surgical procedures had subsequent CT scans, none in the early postoperative period. Readers identified 100% of the plugs, 68% of which were described as round or oval in shape. All the plugs were in close proximity to the inferior epigastric artery and were of low density on CT images. Surgical scar was identifiable in 87% of patients. Thirty-two patients (63%) had a second CT scan, demonstrating no change in size and location of the plugoma. A prosthetic mesh plug is easily seen on CT images, typically appearing as a smooth round or oval hypodense mass close to the inferior epigastric artery, deep to a surgical scar, and stable over time. It can usually be distinguished from pathologic findings. It is important that the radiologist be familiar with the patient's surgical history when interpreting these images. Copyright © 2010. Published by Elsevier Inc.

  7. Methodology for physical modeling of melter electrode power plug

    SciTech Connect

    Heath, W.O.

    1984-09-01

    A method is presented for building and testing a one-third scale model of an electrode power plug used to supply up to 3000 amperes to a liquid fed ceramic melter. The method describes how a one-third scale model can be used to verify the ampacity of the power plug, the effectiveness of the power plug cooling system and the effect of the high amperage current on eddy current heating of rebar in the cell wall. Scale-up of the test data, including cooling air flow rate and pressure drop, temperature profiles, melter water jacket heat duty and electrical resistance is covered. The materials required to build the scale model are specified as well as scale surface finish and dimensions. The method for designing and testing a model power plug involves developing a way to recreate the thermal conditions including heat sources, sinks and boundary temperatures on a scale basis. The major heat sources are the molten glass in contact with the electrode, joule heat generation within the power plug, and eddy current heating of the wall rebar. The melting cavity heat source is modelled using a plate heater to provide radiant heat transfer to a geometrically similar, one-third scale electrode housed in a scale model of a melting cavity having a thermally and geometrically similar wall and floor. The joule heat generation within the power plug is simulated by passing electricity through the model power plug with geometrically similar rebar positioned to simulate the eddy heating phenomenon. The proposed model also features two forced air cooling circuits similar to those on the full design. The interaction of convective, natural and radiant heat transfer in the wall cooling circuit are considered. The cell environment and a melter water jacket, along with the air cooling circuits, constitute the heat sinks and are also simulated.

  8. Plug-in Electric Vehicle Policy Effectiveness: Literature Review

    SciTech Connect

    Zhou, Yan; Levin, Todd; Plotkin, Steven E.

    2016-05-01

    The U.S. federal government first introduced incentives for plug-in electric vehicles (PEVs) through the American Clean Energy and Security Act of 2009, which provided a tax credit of up to $7,500 for a new PEV purchase. Soon after, in December 2010, two mass-market PEVs were introduced, the plug-in hybrid electric vehicle (PHEV) Chevrolet Volt and the battery electric vehicle (BEV) Nissan LEAF. Since that time, numerous additional types of PEV incentives have been provided by federal and regional (state or city) government agencies and utility companies. These incentives cover vehicle purchases as well as the purchase and installation of electric vehicle supply equipment (EVSE) through purchase rebates, tax credits, or discounted purchase taxes or registration fees. Additional incentives, such as free high-occupancy vehicle (HOV) lane access and parking benefits, may also be offered to PEV owners. Details about these incentives, such as the extent to which each type is offered by region, can be obtained from the U.S. Department of Energy (DOE) Alternative Fuel Data Center (http://www.afdc.energy.gov/). In addition to these incentives, other policies, such as zero-emission vehicle (ZEV) mandates,1 have also been implemented, and community-scale federal incentives, such as the DOE PEV Readiness Grants, have been awarded throughout the country to improve PEV market penetration. This report reviews 18 studies that analyze the impacts of past or current incentives and policies that were designed to support PEV adoption in the U.S. These studies were selected for review after a comprehensive survey of the literature and discussion with a number of experts in the field. The report summarizes the lessons learned and best practices from the experiences of these incentive programs to date, as well as the challenges they face and barriers that inhibit further market adoption of PEVs. Studies that make projections based on future policy scenarios and those that focus solely

  9. CKB - the compound knowledge base: a text based chemical search system.

    PubMed

    Walker, Matthew J; Hull, Richard D; Singh, Suresh B

    2002-01-01

    The Compound Knowledge Base (CKB) was developed as a means of locating structures and additional relevant information from a given known structural identifier. Any of Chemical Abstracts Service Registry Number, company code (code number the producing company refers to the chemical entity internally), generic name (trivial or class name), or trade name (name under which the compound is marketed) can be provided as a query. CKB will provide the remaining available information as well as the corresponding structure for any matching compound in the database. The interface to the Compound Knowledge Base is Internet/World Wide Web-based, using Netscape Navigator and the ChemDraw Pro Plugin, which allows Merck scientists quick and easy access to the database from their desktop. The design and implementation of the database and the search interface are herein detailed.

  10. Digital Rock Physics: Mechanical Properties of Carbonate Core Plug at Different Resolutions

    NASA Astrophysics Data System (ADS)

    Faisal, T. F.; Jouini, M. S.; Islam, A.; Chevalier, S.; Jouiad, M.; Sassi, M.

    2014-12-01

    Digital Rock Physics (DRP) is a novel technology that could be used to generate accurate, fast and cost effective special core analysis (SCAL) properties to support reservoir characterization and simulation tools. For this work, Micro-CT images at different resolutions have been used to run simulations to determine elastic properties like bulk, shear, Young's Modulus and Poisson's ratio of a dry carbonate core plug from Abu Dhabi reservoirs. Pre processing and segmentation of raw images is performed in FEI 3D visualization and analysis tool Avizo. Carbonates are characterized by a very complex pore-space structure and so a high degree of heterogeneity. Abaqus that is based on Finite Element Method is used to run 2D and 3D elastic simulations. Results will be compared by simulating the same core-plug in an alternative segmentation and FEM modeling environment used previously by Jouini & Vega et al. 2012 [1]. Acoustic wave propagation experiments at different confining pressures are performed in the laboratory Triaxial machine to determine the dynamic Young's modulus and Poisson's ratio for the same core plug. Expeirmental results are compared with numerical results. [1] Jouini, M.S. and Vega, S. 2012. Simulation of carbonate rocks elastic properties using 3D X-Ray computed tomography images based on Discrete Element Method and Finite Element Method. 46th US Rock Mechanics / Geomechanics Symposium, Chicago, Il, USA, 24-27 June 2012.

  11. MODELLING THE UPTAKE AND DISPOSITION OF HYDROPHOBIC ORGANIC CHEMICALS IN FISH USING A PHYSIOLOGICALLY BASED APPROACH

    EPA Science Inventory

    The development of physiologically based toxicokinetic (PBTK) models for hydrophobic chemicals in fish requires: 1) an understanding of chemical efflux at fish gills; 2) knowledge of the factors that limit chemical exchange between blood and tissues; and, 3) a mechanistic descrip...

  12. Assessing the Robustness of Chemical Prioritizations Based on ToxCast Chemical Profiling

    EPA Science Inventory

    A central goal of the U.S. EPA’s ToxCast™ program is to provide empirical, scientific evidence to aid in prioritizing the toxicity testing of thousands of chemicals. The agency has developed a prioritization approach, the Toxicological Prioritization Index (ToxPi™), that calculat...

  13. Evaluation of a chemical munition dumpsite in the Baltic Sea based on geophysical and chemical investigations.

    PubMed

    Missiaen, Tine; Söderström, Martin; Popescu, Irina; Vanninen, Paula

    2010-08-01

    This paper discusses the results of geophysical and chemical investigations carried out in a chemical munition dumpsite in the southern Baltic Sea, east of the island of Bornholm. After WW2 over 32,000 tons of chemical war material was dumped here including shells and bombs as well as small drums and containers. The geophysical investigations combined very-high-resolution seismics and gradiometric measurements. The results indicate the presence of a large number of objects buried just below the seafloor. The size of the objects and their distribution, with a marked increase in density towards the center of the dumpsite, suggests that we are dealing with dumped war material. Sediment and near-bottom water samples, taken within the dumpsite and in the surrounding area, were analysed for the presence of various chemical warfare agents (CWA) including Adamsite, Clark, sulphur mustard, tabun, chlorobenzene and arsine oil. The results indicate a widespread contamination that reaches far beyond the dumpsite boundary. CWA degradation products were found in most of the sediment samples. The contamination was mostly related to arsenic containing compounds; only one sample indicated the presence of sulfur mustard. Although the correlation between detected objects and CWA concentrations is not always straightforward, the overall results suggest that a lot of the dumped war material is leaking and that over the years the contamination has reached the seafloor sediments.

  14. Photoassisted Chemically Deposited Tin Sulfide Thin Films Based on Two Different Chemical Formulations

    NASA Astrophysics Data System (ADS)

    Remadevi, T. L.; Dhanya, A. C.; Deepa, K.

    2014-11-01

    Photoassisted chemical deposition is a customized form of chemical bath deposition where the reaction is carried out in the presence of ultraviolet light. Deposition of tin sulfide films was carried out by this method using two different chemical baths. The as-prepared samples from the acetone bath were crystalline, exhibiting the orthorhombic structure of the Sn2S3 phase, but those from the glacial acetic acid bath were amorphous. The crystallinity of the films was improved on annealing. The deposition rate was found to depend on the pH of the bath and the chemical formulation. Distinct morphology was obtained for as-grown films. The films from the acetone bath were compact with uniform morphology of needle-shaped grains having equal diameters and lengths. The films from the glacial acetic acid bath were similar, with smaller needles. The high absorption coefficients of as-grown and annealed films show their potential application as absorber layers in photovoltaic devices. The refractive index was estimated from the reflectance of the films. The estimated activation energies of the as-prepared films from the acetone and glacial acetic acid baths were 0.4 eV and 0.46 eV, whereas those of the annealed samples were 0.2 eV and 0.44 eV, respectively. The activation energy was found to decrease for annealed films due to a decrease in trap sites.

  15. Assessing the Robustness of Chemical Prioritizations Based on ToxCast Chemical Profiling

    EPA Science Inventory

    A central goal of the U.S. EPA’s ToxCast™ program is to provide empirical, scientific evidence to aid in prioritizing the toxicity testing of thousands of chemicals. The agency has developed a prioritization approach, the Toxicological Prioritization Index (ToxPi™), that calculat...

  16. Evaluation of a biomimetic optical-filter based chemical sensor for detection of hazardous chemical vapors in the infrared

    NASA Astrophysics Data System (ADS)

    Major, Kevin J.; Poutous, Menelaos K.; Dunnill, Kevin F.; Ewing, Kenneth J.; Sanghera, Jasbinder S.; Deguzman, P. C.; Aggarwal, Ishwar D.

    2016-05-01

    Detection of concealed hazardous materials is a pressing need for the global defense community. To address this need, the development of reliable and readily-deployable sensing devices is a key area of research. A multitude of infrared sensing techniques are being studied which allow for reliable sensing of concealed threats. Continued development in this field is working to increase the selectivity of such infrared sensors, while at the same time reducing their complexity, size and cost. We have recently developed a biomimetic optical filter based approach, based on human color vision, that utilizes multiple, broadband, overlapping infrared (IR) filters to clearly discriminate between hazardous target chemicals and interferents with very similar mid-IR spectral signatures. This technique was extensively studied in order to select filters which provide optimum selectivity for specific chemical sets. Using this knowledge, we designed and assembled a gas-phase sensor which uses three broadband mid-IR filters to detect and discriminate between a target chemical, fuel oil, and various interferents with strongly overlapping IR absorption bands in the carbon - hydrogen stretch region of the IR absorption spectrum 2700 cm-1 - 3300 cm-1 (3.0 μm - 3.7 μm). We present an overview of the design and performance of this filter-based system and explore the ability of this system to detect and discriminate between strongly overlapping target and interferent chemicals. The detection results using the filter-based system are compared to numerical methods to demonstrate the operation of this methodology. We present the results of experiments with both target and interferent chemicals present with chemicals both in and out of the detection set, and discuss future field development and application of this approach.

  17. The water intensity of the plugged-in automotive economy.

    PubMed

    King, Carey W; Webber, Michael E

    2008-06-15

    Converting light-duty vehicles from full gasoline power to electric power, by using either hybrid electric vehicles or fully electric power vehicles, is likely to increase demand for water resources. In the United States in 2005, drivers of 234 million cars, lighttrucks, and SUVs drove approximately 2.7 trillion miles and consumed over 380 million gallons of gasoline per day. We compare figures from literature and government surveys to calculate the water usage, consumption, and withdrawal, in the United States during petroleum refining and electricity generation. In displacing gasoline miles with electric miles, approximately 2-3 [corrected] times more water is consumed (0.24 [corrected] versus 0.07--0.14 gallons/mile) and over 12 [corrected] times more water is withdrawn (7.8 [corrected] versus 0.6 gallons/mile) primarily due to increased water cooling of thermoelectric power plants to accommodate increased electricity generation. Overall, we conclude that the impact on water resources from a widespread shift to grid-based transportation would be substantial enough to warrant consideration for relevant public policy decision-making. That is not to say that the negative impacts on water resources make such a shift undesirable, but rather this increase in water usage presents a significant potential impact on regional water resources and should be considered when planning for a plugged-in automotive economy.

  18. Impedimetric immunoglobulin G immunosensor based on chemically modified graphenes

    NASA Astrophysics Data System (ADS)

    Loo, Adeline Huiling; Bonanni, Alessandra; Ambrosi, Adriano; Poh, Hwee Ling; Pumera, Martin

    2012-01-01

    Immunosensors which display high sensitivity and selectivity are of utmost importance to the biomedical field. Graphene is a material which has immense potential for the fabrication of immunosensors. For the first time, we evaluate the immunosensing capabilities of various graphene surfaces in this work. We propose a simple and label-free electrochemical impedimetric immunosensor for immunoglobulin G (IgG) based on chemically modified graphene (CMG) surfaces such as graphite oxide, graphene oxide, thermally reduced graphene oxide and electrochemically reduced graphene oxide. Disposable electrochemical printed electrodes were first modified with CMG materials before anti-immunoglobulin G (anti-IgG), which is specific to IgG, was immobilized. The principle of detection lies in the changes in impedance spectra of the redox probe after the attachment of IgG to the immobilized anti-IgG. It was found that thermally reduced graphene oxide has the best performance when compared to the other CMG materials. In addition, the optimal concentration of anti-IgG to be deposited onto the modified electrode surface is 10 μg ml-1 and the linear range of detection of the immunosensor is from 0.3 μg ml-1 to 7 μg ml-1. Finally, the fabricated immunosensor also displays selectivity for IgG.Immunosensors which display high sensitivity and selectivity are of utmost importance to the biomedical field. Graphene is a material which has immense potential for the fabrication of immunosensors. For the first time, we evaluate the immunosensing capabilities of various graphene surfaces in this work. We propose a simple and label-free electrochemical impedimetric immunosensor for immunoglobulin G (IgG) based on chemically modified graphene (CMG) surfaces such as graphite oxide, graphene oxide, thermally reduced graphene oxide and electrochemically reduced graphene oxide. Disposable electrochemical printed electrodes were first modified with CMG materials before anti-immunoglobulin G (anti

  19. "Pulling the plug"--management of meconium plug syndrome in neonates.

    PubMed

    Cuenca, Alex G; Ali, Anam S; Kays, David W; Islam, Saleem

    2012-06-15

    The significance of meconium plug syndrome (MPS) is unclear but has been associated with Hirschsprung's disease and magnesium tocolysis. We reviewed our experience to attempt to identify any potential association with these conditions and to review our outcomes. Using the International Classification of Diseases, Ninth revision, code for meconium obstruction, patient charts were identified during the 1998-2008 period. A total of 61 cases of MPS were found, after excluding 7 of meconium ileus. Data regarding the hospital course and outcomes were collected and analyzed. Approximately 30% of patients had spontaneous resolution of the meconium plug without any treatment. Of those patients requiring treatment, contrast barium enema was used, with 97% success. Only 2 patients required surgical intervention owing to worsening distension and subsequent peritonitis. When we stratified the patients according to gestational age of >36 and <36 wk, contrast barium enemas were performed 2.2 ± 1.8 versus 8.6 ± 7.8 d after birth (P = 0.003), respectively, and the lower gestational age patients had a longer length of stay. Contrast barium enema was still successful in 94% of patients with a gestational age of <36 wk. Magnesium tocolysis was noted in 16% of the cases, and Hirschsprung's disease was only found in 3.2% of patients. Patients with MPS have excellent outcomes, independent of gestational age. Contrast barium enema remains the initial diagnostic and treatment of choice for patients with MPS. Also, although previous reports have shown a link between magnesium tocolysis and Hirschsprung's disease with MPS, our experience suggests otherwise. Copyright © 2012 Elsevier Inc. All rights reserved.

  20. Chemical Sensors Based On Oxygen Detection By Optical Methods

    NASA Astrophysics Data System (ADS)

    Parker, Jennifer W.; Cox, M. E.; Dunn, Bruce S.

    1986-08-01

    Fluorescence quenching is shown to be a viable method of measuring oxygen concentration. Two oxygen/optical transducers based on fluorescence quenching have been developed and characterized: one is hydrophobic and the other is hydrophilic. The development of both transducers provides great flexibility in the application of fluorescence to oxygen measurement. One transducer is produced by entrapping a fluorophor, 9,10-diphenyl anthracene, in poly(dimethyl siloxane) to yield a homogeneous composite polymer matrix. The resulting matrix is hydrophobic. This transducer is extremely sensitive to PO2 as a result of oxygen quenching the fluorescence of 9,10-diphenyl anthracene. This quenching is utilized in the novel method employed to measure the transport properties of oxygen within Ulf 2matrix. Results show large values for the diffusion coefficient at 25°C, D = 3.5 x 10-5 cm /s. The fluorescence intensity varies inversely with P02. The second oxygen transducer is fabricated by entrapping 9,10-diphenyl anthracene in poly(hydroxy ethyl methacrylate). Free radical, room temperature polymerization is employed. This transducer is hydrophilic, and contains 37% water. The transport properties of oxygen within this transducer are compared with those of the hydrophobic transducer. The feasibility of generalizing the oxygen transducers to a wider class of chemical sensors through coupling to other chemistries is proposed. An example of such coupling is given in a glucose/oxygen transducer. The glucose transducer is produced by entrapping an enzyme, glucose oxidase, in the composite matrix of the hydrophilic oxygen transducer. Glucose oxidase catalyzes a reaction between glucose and oxygen, thereby lowering the local oxygen concentration. This transducer yields a glucose modified optical oxygen signal. The operation of this transducer and preliminary results of its characterization are presented.

  1. Preliminary Study of a Pull Plug Friction Weld

    NASA Technical Reports Server (NTRS)

    Buchanan, George R.

    1999-01-01

    A pull plug friction weld, simply defined, comprises inserting a rotating cone-shaped cylinder into a somewhat cone-shaped hole in a plate. The rotating plug makes contact with the edge of the plate and the resulting friction generates heat. The temperature of the plate material eventually reaches a magnitude that will cause the plate material at the edge of the hole to flow. This can be termed a temperature dependent plastic flow. The rotation of the plug is terminated, additional pressure is applied and the metal at the interface of the two materials cools and welding occurs. This preliminary study addresses only three aspects of a complete analysis that is multi-faceted. The transient temperature distribution for different pull plug configurations has been studied in some detail even though the initial conditions and boundary conditions may still be deemed tentative. The stress distribution within the pull plug caused by the heating pressure was studied along with a preliminary analysis of the thermoelastic stress distribution caused by friction heating. There are no definitive results for the stress analysis. Additional study will be required.

  2. RCC Plug Repair Thermal Tools for Shuttle Mission Support

    NASA Technical Reports Server (NTRS)

    Rodriguez, Alvaro C.; Anderson, Brian P.

    2010-01-01

    A thermal math model for the Space Shuttle Reinforced Carbon-Carbon (RCC) Plug Repair was developed to increase the confidence in the repair entry performance and provide a real-time mission support tool. The thermal response of the plug cover plate, local RCC, and metallic attach hardware can be assessed with this model for any location on the wing leading edge. The geometry and spatial location of the thermal mesh also matches the structural mesh which allows for the direct mapping of temperature loads and computation of the thermoelastic stresses. The thermal model was correlated to a full scale plug repair radiant test. To utilize the thermal model for flight analyses, accurate predictions of protuberance heating were required. Wind tunnel testing was performed at CUBRC to characterize the heat flux in both the radial and angular directions. Due to the complexity of the implementation of the protuberance heating, an intermediate program was developed to output the heating per nodal location for all OML surfaces in SINDA format. Three Design Reference Cases (DRC) were evaluated with the correlated plug thermal math model to bound the environments which the plug repair would potentially be used.

  3. Early experience on peripheral vascular application of the vascular plugs

    PubMed Central

    Rohit, Manoj Kumar; Sinha, Alok Kumar; Kamana, Naveen Krishna

    2013-01-01

    Background Transcatheter closure of various congenital and acquired vascular malformations with Amplatzer Vascular plugs I and II has been established. Here we present our experience with device closure. Materials and methods Between October 2006 and August 2012, nine (three males and six females) patients aged between 11 months and 62 years (mean age 19 years) underwent percutaneous device closure with AVP I and II vascular plugs for congenital and acquired arteriovenous malformation and cardiac diverticulum are presented here. Results One case of coronary cameral fistula, four cases of pulmonary arteriovenous fistula, one case of large major aortopulmonary collaterals (in tetralogy of Fallot closed before intracardiac repair), one case of congenital cardiac diverticulum, one case of fistula between external carotid artery and internal jugular vein and one case of iatrogenic carotid jugular fistula were successfully closed with AVP I and II plugs. Overall in nine cases, 16 AVP I and II plugs were deployed to occlude feeding vessels and one cardiac diverticulum. The technical success rate was 100%. No major complications were observed. Conclusion Amplatzer vascular plugs can be used successfully for closure of various congenital and acquired vascular malformations with good result. PMID:24206877

  4. Preliminary Study of a Pull Plug Friction Weld

    NASA Technical Reports Server (NTRS)

    Buchanan, George R.

    1999-01-01

    A pull plug friction weld, simply defined, comprises inserting a rotating cone-shaped cylinder into a somewhat cone-shaped hole in a plate. The rotating plug makes contact with the edge of the plate and the resulting friction generates heat. The temperature of the plate material eventually reaches a magnitude that will cause the plate material at the edge of the hole to flow. This can be termed a temperature dependent plastic flow. The rotation of the plug is terminated, additional pressure is applied and the metal at the interface of the two materials cools and welding occurs. This preliminary study addresses only three aspects of a complete analysis that is multi-faceted. The transient temperature distribution for different pull plug configurations has been studied in some detail even though the initial conditions and boundary conditions may still be deemed tentative. The stress distribution within the pull plug caused by the heating pressure was studied along with a preliminary analysis of the thermoelastic stress distribution caused by friction heating. There are no definitive results for the stress analysis. Additional study will be required.

  5. Experimental investigation of gas hydrate formation, plugging and transportability in partially dispersed and water continuous systems

    NASA Astrophysics Data System (ADS)

    Vijayamohan, Prithvi

    in water. These experiments indicate that the partially dispersed systems tend to be problematic and are more severe cases with respect to flow assurance when compared to systems where the water is completely dispersed in oil. We have found that the partially dispersed systems are distinct, and are not an intermediate case between water dominated, and water-in-oil emulsified systems. Instead the experiments indicate that the hydrate formation and plugging mechanism for these systems are very complex. Hydrate growth is very rapid for such systems when compared to 100% water cut systems. The plugging mechanism for these systems is a combination of various phenomena (wall growth, agglomeration, bedding/settling, etc). Three different oils with different viscosities have been used to investigate the transportability of hydrates with respect to oil properties. The experiments indicate that the transportability of hydrates increases with increase in oil viscosity. The data from the tests performed provide the basis for a mechanistic model for hydrate formation and plugging in partially dispersed systems. It is found that in systems that were in stratified flow regime before hydrate onset, the hydrates eventually settled on the pipe walls thereby decreasing the flow area for the flow of fluids. In systems that were in the slug flow regime before hydrate formation, moving beds of hydrates were the main cause for plugging. In both the flow regimes, the systems studied entered a plugging regime beyond a certain hydrate concentration. This is termed as φplugging onset and can be used as an indicator to calculate the amount of hydrates that can be transported safely without requiring any additional treatment for a given set of flow characteristics. A correlation to calculate this hydrate concentration based on easily accessible parameters is developed in terms of flow characteristics and oil properties. The work performed in this thesis has enhanced the understanding of the

  6. Modeling sulfur plugging of fractured wells under non-Darcy and non-equilibrium sulfur deposition

    NASA Astrophysics Data System (ADS)

    Qin, Peixin; Liu, Jingyan

    2017-06-01

    The issue of sulfur plugging has been a concern for engineers for a long time. Some conventional models for vertical wells have been presented by authors; however, analytical models of sulfur plugging for fractured wells have not been reported. Based on non-Darcy and non-equilibrium theory, this article presents a new sulfur deposition prediction model for fractured wells, and a new concept, named sulfur deposition equivalent wellbore radius (SDER), was induced into new equations to describe fractured well characteristics. In a conventional gas reservoir, the fracture conductivity is constant, but here it is changeable due to the presence of sulfur deposition. The SDER value will increase with the increasing fracture conductivity but will reach a stable point at a certain fracture conductivity value. The value of that stable point is equal to 0.5, which is just the value of the equivalent wellbore radius with infinite conductivity fractures. The influence of some important parameters on sulfur deposition was investigated, including gas production, relaxation time, water saturation, gas temperature, fracture conductivity, initial permeability, flow pressure, and radial distance. The results show that the plugging of the formation by deposited sulfur occurs later during the non-equilibrium process, occurs earlier when the flow rate is as high as expected, occurs earlier as the water saturation increases, occurs earlier under high temperature conditions, occurs earlier as the non-Darcy flow becomes stronger, and occurs earlier as the fracture conductivity becomes smaller.

  7. Computational Noise Study of a Supersonic Short Conical Plug-Nozzle Jet

    NASA Technical Reports Server (NTRS)

    Das, Indu S.; Khavaran, Abbas; Das, A. P.

    1996-01-01

    A computational jet noise study of a short conical plug-nozzle (CPN) is presented. The CPN has an exit diameter of 45 mm and the geometrical configuration closely approximates that of an ideal contoured plug-nozzle having shockless flow at pressure ratio xi(sub d) = 3.62. The gasdynamics of the jet flows have been predicted using the CFD code, NPARC with k-epsilon turbulence model; these data are then used for noise computations based on the modified GE/MGB code. The study covers a range of pressure ratio, 2.0 less than or equal to xi less than or equal to 5.0. The agreement of the computational results with the available experimental data is favorable. The results indicate consistent noise reduction effectiveness of the CPN as compared to equivalent convergent, convergent-divergent and ideal contoured plug nozzles at all pressure ratios. At design pressure ratio, codes predict noise levels within 4.0 dB of the measurements; and at off-design pressure ratios, in general, within 5.0 dB except at very high frequencies when deviations up to 10 dB are noted. The shock formation mechanism in the CPN jet is noted to be basically different from those in the convergent and CD nozzle jets.

  8. Spark anemometry of bulk gas velocity at the plug gap of a firing engine

    SciTech Connect

    Kim, J.; Anderson, R.W.

    1995-12-31

    The objective of the present work was to investigate a rapid method of obtaining the convection velocity of the bulk gas near the spark plug gap of a firing engine at the time of ignition. To accomplish this, a simple model was developed which utilized both the secondary current and voltage signals, from a conventional spark discharge. The model assumed the spark path was elongated in a rectangular U-shape by the flow. Based on experimentally measured electrical signals, the mean convection velocity was computed. The convection velocity calculated by the model first needed calibration which was accomplished with a bench test that used a hot wire anemometer. The technique has a weak correlation at low velocities of 1--2 m/s, but correlates well as higher velocities up to 15 m/s. Although the accuracy of prediction by the technique is moderate, it is shown to be suitable for rapidly studying the bulk flow velocity ear the plug gap in an operating engine without modification of the combustion system. It is also shown to favorably compare with data taken with a fiber optic equipped spark plug.

  9. Field Trial of a Low-Cost, Distributed Plug Load Monitoring System

    SciTech Connect

    Auchter, B.; Cautley, D.; Ahl, D.; Earle, L.; Jin, X.

    2014-03-01

    Researchers have struggled to inventory and characterize the energy use profiles of the ever-growing category of so-called miscellaneous electric loads (MELs) because plug-load monitoring is cost-prohibitive to the researcher and intrusive to the homeowner. However, these data represent a crucial missing link to understanding how homes use energy. Detailed energy use profiles would enable the nascent automated home energy management (AHEM) industry to develop effective control algorithms that target consumer electronics and other plug loads. If utility and other efficiency programs are to incent AHEM devices, they need large-scale datasets that provide statistically meaningful justification of their investments by quantifying the aggregate energy savings achievable. To address this need, NREL researchers investigated a variety of plug-load measuring devices available commercially and tested them in the laboratory to identify the most promising candidates for field applications. This report centers around the lessons learned from a field validation of one proof-of-concept system, called Smartenit (formerly SimpleHomeNet). The system was evaluated based on the rate of successful data queries, reliability over a period of days to weeks, and accuracy. This system offers good overall performance when deployed with up to 10 end nodes in a residential environment, although deployment with more nodes and in a commercial environment is much less robust. NREL concludes that the current system is useful in selected field research projects, with the recommendation that system behavior is observed over time.

  10. Modeling and characteristic of the SMT Board Plug connector in high speed optical communication system

    NASA Astrophysics Data System (ADS)

    Wu, Haoran; Dong, Zhenzhen; Wang, Tanglin; Zhao, Heng; Feng, Junbo; Cui, Naidi; Teng, Jie; Guo, Jin

    2015-04-01

    Modeling and characteristic of the SMT Board Plug connector, which is used to connect micro optical transceiver to the main board, are proposed and analyzed in this paper. When the high speed signal transfers from the PCB of transceiver to main board through SMT Board Plug connector, the structure and material discontinuity of the connector causes insertion losses and impedance mismatches. This makes the performance of high speed digital system exacerbated. So it is essential to analyze the signal transfer characteristics of the connector and find out what factors affected the signal quality at the design stage of the digital system. To solve this problem, Ansoft's High Frequency Structure Simulator (HFSS), based on the finite element method, was employed to build accurate 3D models, analyze the effects of various structure parameters, and obtain the full-wave characteristics of the SMT Board Plug connectors in this paper. Then an equivalent circuit model was developed. The circuit parameters were extracted precisely in the frequency range of interests by using the curve fitting method in ADS software, and the result was in good agreement with HFSS simulations up to 8GHz with different structure parameters. At last, the measurement results of S-parameter and eye diagram were given and the S-parameters showed good coincidence between the measurement and HFSS simulation up to 4GHz.

  11. Pit bearing capacity effect on status of soil plug during pile driving in ocean engineering

    NASA Astrophysics Data System (ADS)

    Yan, Shu-Wang; Zhou, Qun-Hua; Liu, Run; Dong, Wei

    2011-06-01

    Foundation piles of the offshore oil platforms in the Bohai Bay are usually longer than 100 m with a diameter larger than 2 m. Driving such long and large-sized piles into the ground is a difficult task. It needs a comprehensive consider ation of the pile dimensions, soil properties and the hammer energy. Thoughtful drivability analysis has to be performed in the design stage. It has been shown that judging whether the soil column inside the pile is fully plugged, which makes the pile behave as close-ended, strongly influences the accuracy of drivability analysis. Engineering practice repeatedly indicates that the current methods widely used for soil plug judgment often give incorrect results, leading the designers to make a wrong decision. It has been found that this problem is caused by the ignorance of the bearing capacity provided by the soil surrounding the pile. Based on the Terzaghi's bearing capacity calculation method for deep foundation, a new approach for judging soil plug status is put forward, in which the surcharge effect has been considered and the dynamic effect coefficient is included. This approach has been applied to some practical engineering projects successfully, which may give more reasonable results than the currently used method does.

  12. Acute Delamination of Commercially Available Decellularized Osteochondral Allograft Plugs

    PubMed Central

    Degen, Ryan M.; Tetreault, Danielle; Mahony, Greg T.; Williams, Riley J.

    2016-01-01

    Articular cartilage injuries, and corresponding surgical procedures, are occurring with increasing frequency as identified by a review of recent surgical trends. Concerns have grown in recent years regarding the longevity of results following microfracture, with a shift toward cartilage restoration procedures in recent years. This case report describes 2 cases of acute failure following the use of commercially available osteochondral allograft plugs used for the treatment of osteochondral defects of the distal femur. In both cases the chondral surface of the plug delaminated from the underlying cancellous bone, resulting in persistent pain and swelling requiring reoperation and removal of the loose fragments. Caution should be employed when considering use of these plugs for the treatment of osteochondral lesions, as similar outcomes have not been noted with other cartilage restoration techniques. PMID:27688840

  13. Plug nozzles: The ultimate customer driven propulsion system

    NASA Technical Reports Server (NTRS)

    Aukerman, Carl A.

    1991-01-01

    This paper presents the results of a study applying the plug cluster nozzle concept to the propulsion system for a typical lunar excursion vehicle. Primary attention for the design criteria is given to user defined factors such as reliability, low volume, and ease of propulsion system development. Total thrust and specific impulse are held constant in the study while other parameters are explored to minimize the design chamber pressure. A brief history of the plug nozzle concept is included to point out the advanced level of technology of the concept and the feasibility of exploiting the variables considered in this study. The plug cluster concept looks very promising as a candidate for consideration for the ultimate customer driven propulsion system.

  14. Flexible Plug Repair for Shuttle Wing Leading Edge

    NASA Technical Reports Server (NTRS)

    Camarda, Charles J.; Sikora, Joseph; Smith, Russel; Rivers, H.; Scotti, Stephen J.; Fuller, Alan M.; Klacka, Robert; Reinders, Martin; Schwind, Francis; Sullivan, Brian; hide

    2012-01-01

    In response to the Columbia Accident Investigation Board report, a plug repair kit has been developed to enable astronauts to repair the space shuttle's wing leading edge (WLE) during orbit. The plug repair kit consists of several 17.78- cm-diameter carbon/silicon carbide (C/SiC) cover plates of various curvatures that can be attached to the refractory carbon-carbon WLE panels using a TZM refractory metal attach mechanism. The attach mechanism is inserted through the damage in the WLE panel and, as it is tightened, the cover plate flexes to conform to the curvature of the WLE panel within 0.050 mm. An astronaut installs the repair during an extravehicular activity (EVA). After installing the plug repair, edge gaps are checked and the perimeter of the repair is sealed using a proprietary material, developed to fill cracks and small holes in the WLE.

  15. Distal false lumen occlusion in aortic dissection with a homemade extra-large vascular plug: the candy-plug technique.

    PubMed

    Kölbel, Tilo; Lohrenz, Christina; Kieback, Arne; Diener, Holger; Debus, Eike Sebastian; Larena-Avellaneda, Axel

    2013-08-01

    To report a technique to create an extra-large vascular plug for occlusion of a large distal false lumen in chronic aortic dissection. The "candy-plug" technique is demonstrated in a 58-year-old multimorbid man with a history of complicated acute type B aortic dissection and a 9-cm chronic thoracic false lumen aneurysm. The patient underwent a staged repair with a cervical debranching procedure as a first step and a thoracic endovascular aortic repair from the innominate artery to the celiac artery as a second step. To occlude the large false lumen from a distal route, a stent-graft was modified on-table with a diameter-restricting suture, giving it a wrapped candy-like shape. This plug was deployed into the false lumen, and the remaining opening was occluded with a standard vascular plug. On 3-month follow-up imaging, the thoracic false lumen aneurysm remained completely thrombosed. The candy-plug technique can facilitate complete occlusion of chronic thoracic false lumen aneurysm by prohibiting distal false lumen backflow.

  16. Eddy Current Minimizing Flow Plug for Use in Flow Conditioning and Flow Metering

    NASA Technical Reports Server (NTRS)

    England, John Dwight (Inventor); Kelley, Anthony R. (Inventor)

    2015-01-01

    An eddy-current-minimizing flow plug has open flow channels formed between the plug's inlet and outlet. Each open flow channel includes (i) a first portion that originates at the inlet face and converges to a location within the plug that is downstream of the inlet, and (ii) a second portion that originates within the plug and diverges to the outlet. The diverging second portion is approximately twice the length of the converging first portion. The plug is devoid of planar surface regions at its inlet and outlet, and in fluid flow planes of the plug that are perpendicular to the given direction of a fluid flowing therethrough.

  17. Versatile Friction Stir Welding/Friction Plug Welding System

    NASA Technical Reports Server (NTRS)

    Carter, Robert

    2006-01-01

    A proposed system of tooling, machinery, and control equipment would be capable of performing any of several friction stir welding (FSW) and friction plug welding (FPW) operations. These operations would include the following: Basic FSW; FSW with automated manipulation of the length of the pin tool in real time [the so-called auto-adjustable pin-tool (APT) capability]; Self-reacting FSW (SRFSW); SR-FSW with APT capability and/or real-time adjustment of the distance between the front and back shoulders; and Friction plug welding (FPW) [more specifically, friction push plug welding] or friction pull plug welding (FPPW) to close out the keyhole of, or to repair, an FSW or SR-FSW weld. Prior FSW and FPW systems have been capable of performing one or two of these operations, but none has thus far been capable of performing all of them. The proposed system would include a common tool that would have APT capability for both basic FSW and SR-FSW. Such a tool was described in Tool for Two Types of Friction Stir Welding (MFS- 31647-1), NASA Tech Briefs, Vol. 30, No. 10 (October 2006), page 70. Going beyond what was reported in the cited previous article, the common tool could be used in conjunction with a plug welding head to perform FPW or FPPW. Alternatively, the plug welding head could be integrated, along with the common tool, into a FSW head that would be capable of all of the aforementioned FSW and FPW operations. Any FSW or FPW operation could be performed under any combination of position and/or force control.

  18. Plug and Play PV Systems for American Homes

    SciTech Connect

    Hoepfner, Christian

    2016-12-22

    The core objectives of the Plug & Play PV Systems Project were to develop a PV system that can be installed on a residential rooftop for less than $1.50/W in 2020, and in less than 10 hours (from point of purchase to commissioning). The Fraunhofer CSE team’s approach to this challenge involved a holistic approach to system design – hardware and software – that make Plug & Play PV systems: • Quick, easy, and safe to install • Easy to demonstrate as code compliant • Permitted, inspected, and interconnected via an electronic process Throughout the three years of work during this Department of Energy SunShot funded project, the team engaged in a substantive way with inspectional services departments and utilities, manufacturers, installers, and distributors. We received iterative feedback on the system design and on ideas for how such systems can be commercialized. This ultimately led us to conceiving of Plug & Play PV Systems as a framework, with a variety of components compatible with the Plug & Play PV approach, including string or microinverters, conventional modules or emerging lightweight modules. The framework enables a broad group of manufacturers to participate in taking Plug & Play PV Systems to market, and increases the market size for such systems. Key aspects of the development effort centered on the system hardware and associated engineering work, the development of a Plug & Play PV Server to enable the electronic permitting, inspection and interconnection process, understanding the details of code compliance and, on occasion, supporting applications for modifications to the code to allow lightweight modules, for example. We have published a number of papers on our testing and assessment of novel technologies (e.g., adhered lightweight modules) and on the electronic architecture.

  19. Bio-based production of C2-C6 platform chemicals.

    PubMed

    Jang, Yu-Sin; Kim, Byoungjin; Shin, Jae Ho; Choi, Yong Jun; Choi, Sol; Song, Chan Woo; Lee, Joungmin; Park, Hye Gwon; Lee, Sang Yup

    2012-10-01

    Platform chemicals composed of 2-6 carbons derived from fossil resources are used as important precursors for making a variety of chemicals and materials, including solvents, fuels, polymers, pharmaceuticals, perfumes, and foods. Due to concerns regarding our environment and the limited nature of fossil resources, however, increasing interest has focused on the development of sustainable technologies for producing these platform chemicals from renewable resources. The techniques and strategies for developing microbial strains for chemicals production have advanced rapidly, and it is becoming feasible to develop microbes for producing additional types of chemicals, including non-natural molecules. In this study, we review the current status of the bio-based production of major C2-C6 platform chemicals, focusing on the microbial production of platform chemicals that have been used for the production of chemical intermediates, building block compounds, and polymers. Copyright © 2012 Wiley Periodicals, Inc.

  20. My contribution to broadening the base of chemical engineering.

    PubMed

    Sargent, Roger W H

    2011-01-01

    This paper is a short account, from a personal viewpoint, of the various contributions I have made to expand the academic basis of chemical engineering from its origin in the unifying concept of unit operations, focussed on process design, to encompassing all the professional activities of industrial chemical engineers. This includes all aspects of planning and scheduling the operations as well as designing and controlling the process plant. The span of my career also happens to include the birth of the age of computing, with all the consequential implications.

  1. Photopolymerization-based fabrication of chemical sensing films

    SciTech Connect

    Yang, Xiaoguang; Swanson, Basil I.; Du, Xian-Xian

    2003-12-30

    A photopolymerization method is disclosed for attaching a chemical microsensor film to an oxide surface including the steps of pretreating the oxide surface to form a functionalized surface, coating the functionalized surface with a prepolymer solution, and polymerizing the prepolymer solution with ultraviolet light to form the chemical microsensor film. The method also allows the formation of molecular imprinted films by photopolymerization. Formation of multilayer sensing films and patterned films is allowed by the use of photomasking techniques to allow patterning of multiple regions of a selected sensing film, or creating a sensor surface containing several films designed to detect different compounds.

  2. Gravimetric chemical sensors based on silica-based mesoporous organic-inorganic hybrids.

    PubMed

    Xu, Jiaqiang; Zheng, Qi; Zhu, Yongheng; Lou, Huihui; Xiang, Qun; Cheng, Zhixuan

    2014-09-01

    Silica-based mesoporous organic-inorganic hybrid material modified quartz crystal microbalance (QCM) sensors have been examined for their ability to achieve highly sensitive and selective detection. Mesoporous silica SBA-15 serves as an inorganic host with large specific surface area, facilitating gas adsorption, and thus leads to highly sensitive response; while the presence of organic functional groups contributes to the greatly improved specific sensing property. In this work, we summarize our efforts in the rational design and synthesis of novel sensing materials for the detection of hazardous substances, including simulant nerve agent, organic vapor, and heavy metal ion, and develop high-performance QCM-based chemical sensors.

  3. Selectively plugging subterranean formations with a hydrocarbon soluble fluid

    SciTech Connect

    Falk, D. O.

    1984-11-13

    Highly permeable zones in a subterranean formation vertically bounded by a relatively less permeable zone are selectively plugged by injecting an emulsion of melamine and formaldehyde in an alcohol medium via a well into the highly permeable zones. The emulsion is hydrocarbon soluble are preferentially envelops the highly permeable zones where it reacts to form a resin at a temperature of from about 80/sup 0/ C. to about 250/sup 0/ C. and a pH of from about 7 to 12 and over a period of from about 1 to 4 days. The resulting resin substantially plugs the highly permeable zones in the formation.

  4. Process for selectively plugging subterranean formations with a melamine resin

    SciTech Connect

    Falk, D.O.

    1984-09-25

    Highly permeable zones in a subterranean formation are selectively plugged by injecting a melamine formaldehyde solution via a well into the highly permeable zones. The solution is water soluble and preferentially enters water-containing zones where it reacts to form a resin at a temperature of from about 25/sup 0/ C. to about 120/sup 0/ C. and a pH of from about 7 to 12 and over a period of from about 1 to 4 days. The resulting resin substantially plugs the highly permeable zones in the formation.

  5. Implantation of the AMPLATZER™ Cardiac Plug: tips and tricks.

    PubMed

    Park, Jai-Wun

    2013-03-01

    The AMPLATZER™ Cardiac Plug device is designed for percutaneous occlusion of the left atrial appendage (LAA) for stroke prophylaxis in patients with atrial fibrillation (AF) who are contraindicated or intolerant to oral anticoagulation. While updated guidelines start to refer to this therapy (Camm A, Eur Heart J, doi:10.1093/eurheartj/ehs253, 2012) and operators gain experience with this relatively new technique, continuing efforts are focused on maximizing the safety of the implantation procedure. This paper is aimed at explaining and illustrating the distinct steps and specific considerations related to the implantation of the AMPLATZER™ Cardiac Plug.

  6. Method for preventing plugging in the pyrolysis of agglomerative coals

    DOEpatents

    Green, Norman W.

    1979-01-23

    To prevent plugging in a pyrolysis operation where an agglomerative coal in a nondeleteriously reactive carrier gas is injected as a turbulent jet from an opening into an elongate pyrolysis reactor, the coal is comminuted to a size where the particles under operating conditions will detackify prior to contact with internal reactor surfaces while a secondary flow of fluid is introduced along the peripheral inner surface of the reactor to prevent backflow of the coal particles. The pyrolysis operation is depicted by two equations which enable preselection of conditions which insure prevention of reactor plugging.

  7. A plug and play polymeric template driven by supramolecular interactions.

    PubMed

    Xiao, Wang; Chen, Wei-Hai; Li, Cao; Chen, Jin-Xiao; Zhang, Xian-Zheng; Zhuo, Ren-Xi

    2012-01-01

    A new "plug and play" polymeric template with the driving force of host-guest interaction between β-CD and naphthalene-modified functional groups was designed and studied. Multiple functional groups can be loaded into the template directly and conveniently. Importantly, the "plug and play" effect of the polymeric template is reversible and the functional groups could be removed from the polymeric template conveniently by adding AD-HCl. The studies on the cell viability and phagocytosis proved that the loading and unloading process of this template could be realized in vitro. Copyright © 2011 Wiley Periodicals, Inc.

  8. A Decision Analytic Approach to Exposure-Based Chemical Prioritization

    EPA Science Inventory

    The manufacture of novel synthetic chemicals has increased in volume and variety, but often the environmental and health risks are not fully understood in terms of toxicity and, in particular, exposure. While efforts to assess risks have generally been effective when sufficient d...

  9. Pharmacokinetically based mapping device for chemical space navigation.

    PubMed

    Oprea, Tudor I; Zamora, Ismael; Ungell, Anna-Lena

    2002-01-01

    ChemGPS, the chemical global positioning system, is a tool that combines rules (equivalent to dimensions) and objects (chemical structures) to provide a consistent chemical space map (Oprea, T. I.; Gottfries, J. J. Comb. Chem. 2001, 3, 157-166.). Rules included, initially, general properties such as size, lipophilicity, and hydrogen bond capacity, while objects include "satellites", intentionally placed outside the druglike space, as well as "core" objects, mostly orally available drugs. ChemGPS molecules (objects) were used in conjunction with the VolSurf (http://www.moldiscovery.com) descriptors (rules), which are relevant for ADME (absorption, distribution, metabolism, and excretion) properties. The combination of ChemGPS and VolSurf, GPSVS, was investigated with respect to the biopharmaceutics classification system, which is recommended by the Food and Drug Administration (FDA) (http://www.fda.gov/cder/OPS/BCS_guidance.htm), in particular with respect to permeability and solubility. The first GPSVS principal component correlates, with no further training, to passive transcellular permeability, as illustrated for the Caco-2, ghost erythrocyte, and blood-brain barrier datasets, respectively. The second GPSVS principal component correlates, without prior training, to solubility, as shown for the octanol-water partition and intrinsic solubility datasets, respectively. Although derived from principal component analysis, the two property axes rotate and form an angle of approximately 43 degrees, thus being no longer orthogonal. GPSVS can be used to map the chemical space with respect to permeability and solubility, as recommended by FDA's biopharmaceutics classification system.

  10. Ex Priori: Exposure-based Prioritization across Chemical Space

    EPA Science Inventory

    EPA's Exposure Prioritization (Ex Priori) is a simplified, quantitative visual dashboard that makes use of data from various inputs to provide rank-ordered internalized dose metric. This complements other high throughput screening by viewing exposures within all chemical space si...

  11. A four-component organogel based on orthogonal chemical interactions.

    PubMed

    Luisier, Nicolas; Schenk, Kurt; Severin, Kay

    2014-09-14

    A thermoresponsive organogel was obtained by orthogonal assembly of four compounds using dynamic covalent boronate ester and imine bonds, as well as dative boron-nitrogen bonds. It is shown that the gel state can be disrupted or reinforced by chemicals which undergo exchange reactions with the gel components.

  12. A Decision Analytic Approach to Exposure-Based Chemical Prioritization

    EPA Science Inventory

    The manufacture of novel synthetic chemicals has increased in volume and variety, but often the environmental and health risks are not fully understood in terms of toxicity and, in particular, exposure. While efforts to assess risks have generally been effective when sufficient d...

  13. Ex Priori: Exposure-based Prioritization across Chemical Space

    EPA Science Inventory

    EPA's Exposure Prioritization (Ex Priori) is a simplified, quantitative visual dashboard that makes use of data from various inputs to provide rank-ordered internalized dose metric. This complements other high throughput screening by viewing exposures within all chemical space si...

  14. Carbon Nanostructure-Based Field-Effect Transistors for Label-Free Chemical/Biological Sensors

    PubMed Central

    Hu, PingAn; Zhang, Jia; Li, Le; Wang, Zhenlong; O’Neill, William; Estrela, Pedro

    2010-01-01

    Over the past decade, electrical detection of chemical and biological species using novel nanostructure-based devices has attracted significant attention for chemical, genomics, biomedical diagnostics, and drug discovery applications. The use of nanostructured devices in chemical/biological sensors in place of conventional sensing technologies has advantages of high sensitivity, low decreased energy consumption and potentially highly miniaturized integration. Owing to their particular structure, excellent electrical properties and high chemical stability, carbon nanotube and graphene based electrical devices have been widely developed for high performance label-free chemical/biological sensors. Here, we review the latest developments of carbon nanostructure-based transistor sensors in ultrasensitive detection of chemical/biological entities, such as poisonous gases, nucleic acids, proteins and cells. PMID:22399927

  15. An Integrated Surface Acoustic Wave-Based Chemical Microsensor Array for Gas-Phase Chemical Analysis Microsystems

    SciTech Connect

    Casalnuovo, stephen A.; Frye-Mason, Gregory C.; Heller, Edwin J.; Hietala, Vincent M.; Kottenstette, Richard J.; Lewis, Patrick R.; Manginell, Ronald P.; Matzke, Carolyn M.

    1999-07-20

    This paper describes preliminary results in the development of an acoustic wave (SAW) microsensor array. The array is based on a novel configuration that allows for three sensors and a phase reference. Two configurations of the integrated array are discussed: a hybrid multichip-module based on a quartz SAW sensor with GaAs microelectronics and a fully monolithic GaAs-based SAW. Preliminary data are also presented for the use of the integrated SAW array in a gas-phase chemical micro system that incorporates microfabricated sample collectors and concentrators along with gas chromatography (GC) columns.

  16. Relationship between first-order decay coefficients in ponds, for plug flow, CSTR and dispersed flow regimes.

    PubMed

    von, Sperling M

    2002-01-01

    Adequate consideration of the hydraulic regime of a pond is essential in the analysis of BOD and coliform removal, and considerable divergence exists in the literature when reporting removal coefficients. This paper aims at integrating the existing approaches, by quantifying the relationship between the first-order removal coefficients K from the three main hydraulic regimes (CSTR, plug flow and dispersed flow) adopted in the design and performance evaluation of ponds. Based on theoretical considerations and statistical regression analyses, the relationship between the K values is investigated, quantified and modelled. Two tables are presented and two equations are proposed, which allow conversion of K values obtained for dispersed flow to (a) K for CSTR and (b) K for plug flow, based on the hydraulic detention time t and the dispersion number d. These coefficients, when applied in the CSTR or plug-flow equations, will give approximately the same prediction of the effluent concentration as that obtained when using the dispersed-flow model with its proper coefficient. With this approach designers can apply, and researchers can report, K values for the two idealised flow patterns (CSTR and plug flow).

  17. GTKDynamo: a PyMOL plug-in for QC/MM hybrid potential simulations

    PubMed Central

    Bachega, José Fernando R.; Timmers, Luís Fernando S.M.; Assirati, Lucas; Bachega, Leonardo R.; Field, Martin J.; Wymore, Troy

    2014-01-01

    Hybrid quantum chemical (QC)/molecular mechanical (MM) potentials are very powerful tools for molecular simulation. They are especially useful for studying processes in condensed phase systems, such as chemical reactions, that involve a relatively localized change in electronic structure and where the surrounding environment contributes to these changes but can be represented with more computationally efficient functional forms. Despite their utility, however, these potentials are not always straightforward to apply since the extent of significant electronic structure changes occurring in the condensed phase process may not be intuitively obvious. To facilitate their use we have developed an open-source graphical plug-in, GTKDynamo, that links the PyMOL visualization program and the pDynamo QC/MM simulation library. This article describes the implementation of GTKDynamo and its capabilities and illustrates its application to QC/MM simulations. PMID:24137667

  18. 30 CFR 250.1712 - What information must I submit before I permanently plug a well or zone?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... production of oil, gas, or sulfur; (b) Recent well test data and pressure data, if available; (c) Maximum...) in each casing annulus; (6) Plug locations; (7) Plug types; (8) Plug lengths; (9) Properties of mud...

  19. Commercializing light-duty plug-in/plug-out hydrogen-fuel-cell vehicles: "Mobile electricity" technologies, early California household markets, and innovation management

    NASA Astrophysics Data System (ADS)

    Williams, Brett David

    Starting from the premise that new consumer value must drive hydrogen-fuel-cell-vehicle (H2FCV) commercialization, a group of opportunities collectively called "Mobile Electricity" (Me-) is characterized. Me- redefines H2 FCVs as innovative products able to provide home recharging and mobile power, for example for tools, mobile activities, emergencies, and electric-grid-support services. To characterize such opportunities, this study first integrates and extends previous analyses of H2FCVs, plug-in hybrids, and vehicle-to-grid (V2G) power. It uses a new model to estimate zero-emission-power vs. zero-emission-driving tradeoffs, costs, and grid-support revenues for various electric-drive vehicle types and levels of infrastructure service. Next, the initial market potential for Me- enabled vehicles, such as H2FCVs and plug-in hybrids, is estimated by eliminating unlikely households from consideration for early adoption. 5.2 million of 33.9 million Californians in the 2000 Census live in households pre-adapted to Me-, 3.9 million if natural gas is required for home refueling. The possible sales base represented by this population is discussed. Several differences in demographic and other characteristics between the target market and the population as a whole are highlighted, and two issues related to the design of H2FCVs and their supporting infrastructure are discussed: vehicle range and home hydrogen refueling. These findings argue for continued investigation of this and similar target segments-which represent more efficient research populations for subsequent study by product designers and other decision-makers wishing to understand the early market dynamics facing Me- innovations. Next, Me-H2FCV commercialization issues are raised from the perspectives of innovation, product development, and strategic marketing. Starting with today's internalcombustion hybrids, this discussion suggests a way to move beyond the battery vs. fuel-cell zero-sum game and towards the

  20. Neural Network Based PID Gain Tuning of Chemical Plant Controller

    NASA Astrophysics Data System (ADS)

    Abe, Yoshihiro; Konishi, Masami; Imai, Jun; Hasegawa, Ryusaku; Watanabe, Masamori; Kamijo, Hiroaki

    In these years, plant control systems are highly automated and applied to many industries. The control performances change with the passage of time, because of the deterioration of plant facilities. This is why human experts tune the control system to improve the total plant performances. In this study, PID control system for the oil refining chemical plant process is treated. In oil refining, there are thousands of the control loops in the plant to keep the product quality at the desired value and to secure the safety of the plant operation. According to the ambiguity of the interference between control loops, it is difficult to estimate the plant dynamical model accurately. Using neuro emulator and recurrent neural networks model (RNN model) for emulation and tuning parameters, PID gain tuning system of chemical plant controller is constructed. Through numerical experiments using actual plant data, effect of the proposed method was ascertained.

  1. Conductometric chemical sensor based on individual CuO nanowires

    NASA Astrophysics Data System (ADS)

    Li, Dongdong; Hu, Jun; Wu, Ruqian; Lu, Jia G.

    2010-12-01

    CuO nanowires with high crystalline quality are synthesized via a simple thermal oxidation method. Charge conduction on individual nanowires under a transverse electric field exhibits an intrinsic p-type semiconducting behavior. Variations in signal transducer in different chemical gas environments are measured on individual CuO nanowire field effect transistors. They demonstrate good performance to both NO2 and ethanol gasses. In particular, the nanowire chemical sensor reveals a reverse response to ethanol vapor under temperature variation. Experimental results and first-principles calculations indicate that ethanol is oxidized in air at high temperature, resulting in the production of CO2 and H2O. The strong H2O adsorption leads to the reversal behavior, due to the electron transfer from H2O molecules to the CuO surface.

  2. Aperture-Tolerant, Chemical-Based Methods to Reduce Channeling

    SciTech Connect

    Randall S. Seright

    2007-09-30

    This final technical progress report describes work performed from October 1, 2004, through May 16, 2007, for the project, 'Aperture-Tolerant, Chemical-Based Methods to Reduce Channeling'. We explored the potential of pore-filling gels for reducing excess water production from both fractured and unfractured production wells. Several gel formulations were identified that met the requirements--i.e., providing water residual resistance factors greater than 2,000 and ultimate oil residual resistance factors (F{sub rro}) of 2 or less. Significant oil throughput was required to achieve low F{sub rro} values, suggesting that gelant penetration into porous rock must be small (a few feet or less) for existing pore-filling gels to provide effective disproportionate permeability reduction. Compared with adsorbed polymers and weak gels, strong pore-filling gels can provide greater reliability and behavior that is insensitive to the initial rock permeability. Guidance is provided on where relative-permeability-modification/disproportionate-permeability-reduction treatments can be successfully applied for use in either oil or gas production wells. When properly designed and executed, these treatments can be successfully applied to a limited range of oilfield excessive-water-production problems. We examined whether gel rheology can explain behavior during extrusion through fractures. The rheology behavior of the gels tested showed a strong parallel to the results obtained from previous gel extrusion experiments. However, for a given aperture (fracture width or plate-plate separation), the pressure gradients measured during the gel extrusion experiments were much higher than anticipated from rheology measurements. Extensive experiments established that wall slip and first normal stress difference were not responsible for the pressure gradient discrepancy. To explain the discrepancy, we noted that the aperture for gel flow (for mobile gel wormholing through concentrated immobile

  3. Chemical bases for medicinal plant use in Oaxaca, Mexico.

    PubMed

    Ortiz de Montellano, B R; Browner, C H

    1985-03-01

    Fifty-eight medicinal plants used for the management of reproduction and the treatment of women's reproductive health problems in an indigenous community in southern Mexico are described. The efficacy of these plants is assessed according to both community members' understandings of the therapeutic effects they seek and the standards of conventional Western medicine. The majority of the plants contain chemicals which would appear to enable them to accomplish their intended effects in either or both the popular and the conventional medical systems.

  4. Healing of apical rarefaction of three nonvital open apex anterior teeth using a white portland cement apical plug

    PubMed Central

    Chakraborty, Amitabha; Dey, Bibhas; Dhar, Reema; Sardar, Prabir

    2012-01-01

    The major challenge of performing root canal treatment in an open apex pulp-less tooth is to obtain a good apical seal. MTA has been successfully used to achieve a good apical seal, wherein the root canal obturation can be done immediately. MTA and White Portland Cement has been shown similarity in their physical, chemical and biological properties and has also shown similar outcome when used in animal studies and human trials. In our study, open apex of three non vital upper central incisors has been plugged using modified white Portland cement. 3 to 6 months follow up revealed absence of clinical symptoms and disappearance of peri-apical rarefactions. The positive clinical outcome may encourage the future use of white Portland cement as an apical plug material in case of non vital open apex tooth as much cheaper substitute of MTA. PMID:23230357

  5. Analysis of supersonic plug nozzle flowfield and heat transfer

    NASA Technical Reports Server (NTRS)

    Murthy, S. N. B.; Sheu, W. H.

    1988-01-01

    A number of problems pertaining to the flowfield in a plug nozzle, designed as a supersonic thruster nozzle, with provision for cooling the plug with a coolant stream admitted parallel to the plug wall surface, were studied. First, an analysis was performed of the inviscid, nonturbulent, gas dynamic interaction between the primary hot stream and the secondary coolant stream. A numerical prediction code for establishing the resulting flowfield with a dividing surface between the two streams, for various combinations of stagnation and static properties of the two streams, was utilized for illustrating the nature of interactions. Secondly, skin friction coefficient, heat transfer coefficient and heat flux to the plug wall were analyzed under smooth flow conditions (without shocks or separation) for various coolant flow conditions. A numerical code was suitably modified and utilized for the determination of heat transfer parameters in a number of cases for which data are available. Thirdly, an analysis was initiated for modeling turbulence processes in transonic shock-boundary layer interaction without the appearance of flow separation.

  6. 6. Front of northern kiln group, looking west. Vents, plugged ...

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

    6. Front of northern kiln group, looking west. Vents, plugged with loose bricks and clay, are distinguishable in the nearest and farthest kilns, slightly above current grade. - Warren King Charcoal Kilns, 5 miles west of Idaho Highway 28, Targhee National Forest, Leadore, Lemhi County, ID

  7. Plug-In Electric Vehicle Handbook for Fleet Managers (Brochure)

    SciTech Connect

    Not Available

    2012-04-01

    Plug-in electric vehicles (PEVs) are entering the automobile market and are viable alternatives to conventional vehicles. This guide for fleet managers describes the basics of PEV technology, PEV benefits for fleets, how to select the right PEV, charging a PEV, and PEV maintenance.

  8. Plug-in Sensors for Air Pollution Monitoring.

    ERIC Educational Resources Information Center

    Shaw, Manny

    Faristors, a type of plug-in sensors used in analyzing equipment, are described in this technical report presented at the 12th Conference on Methods in Air Pollution and Industrial Hygiene Studies, University of Southern California, April, 1971. Their principles of operation, interchangeability, and versatility for measuring air pollution at…

  9. A mixed plug flow anaerobic digester for dairy manure

    SciTech Connect

    Cournoyer, M.S.; Delisle, U.; Ferland, D.; Chagnon, R.

    1985-01-01

    In 1982, a ''mixed plug-flow'' anaerobic digester has been built to produce biogas from the manure of 350 dairy cows and, subsequently, to produce electricity for on-farm use only. This paper describes the digester and presents the main results of one year of technical follow-up.

  10. Transient motion of mucus plugs in respiratory airways

    NASA Astrophysics Data System (ADS)

    Zamankhan, Parsa; Hu, Yingying; Helenbrook, Brian; Takayama, Shuichi; Grotberg, James B.

    2011-11-01

    Airway closure occurs in lung diseases such as asthma, cystic fibrosis, or emphysema which have an excess of mucus that forms plugs. The reopening process involves displacement of mucus plugs in the airways by the airflow of respiration. Mucus is a non-Newtonian fluid with a yield stress; therefore its behavior can be approximated by a Bingham fluid constitutive equation. In this work the reopening process is approximated by simulation of a transient Bingham fluid plug in a 2D channel. The governing equations are solved by an Arbitrary Lagrangian Eulerian (ALE) finite element method through an in-house code. The constitutive equation for the Bingham fluid is implemented through a regularization method. The effects of the yield stress on the flow features and wall stresses are discussed with applications to potential injuries to the airway epithelial cells which form the wall. The minimum driving pressure for the initiation of the motion is computed and its value is related to the mucus properties and the plug shape. Supported by HL84370 and HL85156.

  11. Plug-in Sensors for Air Pollution Monitoring.

    ERIC Educational Resources Information Center

    Shaw, Manny

    Faristors, a type of plug-in sensors used in analyzing equipment, are described in this technical report presented at the 12th Conference on Methods in Air Pollution and Industrial Hygiene Studies, University of Southern California, April, 1971. Their principles of operation, interchangeability, and versatility for measuring air pollution at…

  12. Plug-In Electric Vehicle Handbook for Consumers (Brochure)

    SciTech Connect

    Not Available

    2011-09-01

    Plug-in electric vehicles (PEVs) are entering the automobile market and are viable alternatives to conventional vehicles. This guide for consumers describes the basics of PEV technology, PEV benefits, how to select the right PEV, charging a PEV, and PEV maintenance.

  13. Folding tool for preparing FCC molded-plug terminations

    NASA Technical Reports Server (NTRS)

    Campbell, E. C.; Chambers, C. M.

    1971-01-01

    Assemblies consist of window piece, conductor spacer, insulator, outer seal, and molded portion that integrates all components. Preparation of FCC for molded plug termination requires that terminated ends of conductors in each cable be accurately folded simultaneously into spacer end and groove.

  14. Seating tool for preparing molded-plug terminations on FCC

    NASA Technical Reports Server (NTRS)

    Chambers, C. M.; Corum, C. C.

    1971-01-01

    Hand-operated tool positions and seats window piece and conductor spacer onto conductors of two stripped cables during process of terminating cables with molded plug. Tool accommodates cables up to 3 in. wide and is used in conjunction with folding tools.

  15. Inert plug formation in the DDT of granular energetic materials

    SciTech Connect

    Son, S.F.; Asay, B.W.; Bdzil, J.B.

    1996-05-01

    A mechanism is proposed to explain the {open_quotes}plugs{close_quotes} that have been observed in deflagration-to-detonation transition (DDT) of granular explosives. Numerical simulations are performed that demonstrate the proposed mechanism. Observed trends are reproduced. {copyright} {ital 1996 American Institute of Physics.}

  16. Valley plugs, land use, and phytogeomorphic response: Chapter 14

    USGS Publications Warehouse

    Pierce, A.R.; King, Sammy L.; Shroder, John F.

    2013-01-01

    Anthropogenic alteration of fluvial systems can disrupt functional processes that provide valuable ecosystem services. Channelization alters fluvial parameters and the connectivity of river channels to their floodplains which is critical for productivity, nutrient cycling, flood control, and biodiversity. The effects of channelization can be exacerbated by local geology and land-use activities, resulting in dramatic geomorphic readjustments including the formation of valley plugs. Considerable variation in the response of abiotic processes, including surface hydrology, subsurface hydrology, and sedimentation dynamics, to channelization and the formation of valley plugs. Altered abiotic processes associated with these geomorphic features and readjustments influence biotic processes including species composition, abundance, and successional processes. Considerable interest exists for restoring altered fluvial systems and their floodplains because of their social and ecological importance. Understanding abiotic and biotic responses of channelization and valley-plug formation within the context of the watershed is essential to successful restoration. This chapter focuses on the primary causes of valley-plug formation, resulting fluvial-geomorphic responses, vegetation responses, and restoration and research needs for these systems.

  17. Plug identification in drainage system using electromagnetic wave

    NASA Astrophysics Data System (ADS)

    Hijriani, Arifa; Utama, Aji Surya; Boas, Andrianus; Mukti, M. Ridho; Widodo

    2017-07-01

    The evaluation of drainage system's performance is an important thing to do to prevent flooding. Conventionally the Government evaluates the drainage system by opening one by one the lid of drainage and detects the plug manually. This method is not effective and efficient because this method need many people, much time and relatively expensive. The purpose of this paper is to identify plugs in drainage system in G St. at Bandung Institute of Technology by using electromagnetic wave. Ground Penetrating Radar (GPR) is one of geophysics method that using electromagnetic wave with high frequency. GPR is a non-destructive method with high resolution imaging for shallow depth (˜100m) and relatively cheap. We could identify the plug without opening the lid manually so that we could save much time. GPR's sensitivity is depends on resistivity, magnetic permeability, and permittivity of an object. The result of this research is we could identify the plug on the radargram that observed by a build-up amplitude anomaly.

  18. Axicell design for the end plugs of MFTF-B

    SciTech Connect

    Thomassen, K.I.; Karpenko, V.N.

    1982-04-23

    Certain changes in the end-plug design in the Mirror Fusion Test Facility (MFTF-B) are described. The Laboratory (LLNL) proposes to implement these changes as soon as possible in order to construct the machine in an axicell configuration. The present physics and technology goals as well as the project cost and schedule will not be affected by these changes.

  19. Spatial and temporal variations of microbial community in a mixed plug-flow loop reactor fed with dairy manure

    PubMed Central

    Li, Yueh-Fen; Chen, Po-Hsu; Yu, Zhongtang

    2014-01-01

    Mixed plug-flow loop reactor (MPFLR) has been widely adopted by the US dairy farms to convert cattle manure to biogas. However, the microbiome in MPFLR digesters remains unexplored. In this study, the microbiome in a MPFLR digester operated on a mega-dairy farm was examined thrice over a 2 month period. Within 23 days of retention time, 55–70% of total manure solid was digested. Except for a few minor volatile fatty acids (VFAs), total VFA concentration and pH remained similar along the course of the digester and over time. Metagenomic analysis showed that although with some temporal variations, the bacterial community was rather stable spatially in the digester. The methanogenic community was also stable both spatially and temporally in the digester. Among methanogens, genus Methanosaeta dominated in the digester. Quantitative polymerase chain reaction (qPCR) analysis and metagenomic analysis yielded different relative abundance of individual genera of methanogens, especially for Methanobacterium, which was predominant based on qPCR analysis but undetectable by metagenomics. Collectively, the results showed that only small microbial and chemical gradients existed within the digester, and the digestion process occurred similarly throughout the MPFLR digester. The findings of this study may help improve the operation and design of this type of manure digesters. PMID:24690147

  20. Spatial and temporal variations of microbial community in a mixed plug-flow loop reactor fed with dairy manure.

    PubMed

    Li, Yueh-Fen; Chen, Po-Hsu; Yu, Zhongtang

    2014-07-01

    Mixed plug-flow loop reactor (MPFLR) has been widely adopted by the US dairy farms to convert cattle manure to biogas. However, the microbiome in MPFLR digesters remains unexplored. In this study, the microbiome in a MPFLR digester operated on a mega-dairy farm was examined thrice over a 2 month period. Within 23 days of retention time, 55-70% of total manure solid was digested. Except for a few minor volatile fatty acids (VFAs), total VFA concentration and pH remained similar along the course of the digester and over time. Metagenomic analysis showed that although with some temporal variations, the bacterial community was rather stable spatially in the digester. The methanogenic community was also stable both spatially and temporally in the digester. Among methanogens, genus Methanosaeta dominated in the digester. Quantitative polymerase chain reaction (qPCR) analysis and metagenomic analysis yielded different relative abundance of individual genera of methanogens, especially for Methanobacterium, which was predominant based on qPCR analysis but undetectable by metagenomics. Collectively, the results showed that only small microbial and chemical gradients existed within the digester, and the digestion process occurred similarly throughout the MPFLR digester. The findings of this study may help improve the operation and design of this type of manure digesters.

  1. Fiscal Year 1993 Well Plugging and Abandonment Program Summary Report Y-12 Plant, Oak Ridge, Tennessee

    SciTech Connect

    1994-09-01

    This report is a synopsis of the progress of the well plugging and abandonment program at the Y-12 Plant, Oak Ridge, Tennessee, from October 1993 through August 1994. A total of 57 wells and borings were plugged and abandoned during the period of time covered in this report. All wells and borings were plugged and abandoned in accordance with the Monitoring Well Plugging and Abandonment Plan for the U.S. Department of Energy, Y-12 Plant, Oak Ridge, Tennessee.

  2. Initial experience of treating anal fistula with the Surgisis anal fistula plug.

    PubMed

    Chan, S; McCullough, J; Schizas, A; Vasas, P; Engledow, A; Windsor, A; Williams, A; Cohen, C R

    2012-06-01

    Complex anal fistulas remain a challenge for the colorectal surgeon. The anal fistula plug has been developed as a simple treatment for fistula-in-ano. We present and evaluate our experience with the Surgisis anal fistula plug from two centres. Data were prospectively collected and analysed from consecutive patients undergoing insertion of a fistula plug between January 2007 and October 2009. Fistula plugs were inserted according to a standard protocol. Data collected included patient demographics, fistula characteristics and postoperative outcome. Forty-four patients underwent insertion of 62 plugs (27 males, mean age 45.6 years), 25 of whom had prior fistula surgery. Mean follow-up was 10.5 months Twenty-two patients (50%) had successful healing following the insertion of plug with an overall success rate of 23 out of 62 plugs inserted (35%). Nineteen out of 29 patients healed following first-time plug placement, whereas repeated plug placement was successful in 3 out of 15 patients (20%; p = 0.0097). There was a statistically significant difference in the healing rate between patients who had one or less operations prior to plug insertion (i.e. simple fistulas) compared with patients who needed multiple operations (18 out of 24 patients vs. 4 out of 20 patients; p = 0.0007). Success of treatment with the Surgisis anal fistula plug relies on the eradication of sepsis prior to plug placement. Plugs inserted into simple tracts have a higher success rate, and recurrent insertion of plugs following previous plug failure is less likely to be successful. We suggest the fistula plug should remain a first-line treatment for primary surgery and simple tracts.

  3. Fiscal year 1993 well plugging and abandonment program, Y-12 Plant, Oak Ridge, Tennessee

    SciTech Connect

    Not Available

    1993-09-01

    This report is a synopsis of the progress of the well plugging and abandonment program at the Y-12 Plant, Oak Ridge, Tennessee, from December 1992 through August 20, 1993. A total of 70 wells and borings were plugged and abandoned during the period of time covered in this report. All wells and borings were plugged and abandoned in accordance with the Monitoring Well Plugging and Abandonment Plan for the US Department of Energy, Y-12 Plant, Oak Ridge, Tennessee (HSW, Inc. 1991).

  4. Aeroacoustics of contoured and solid/porous conical plug-nozzle supersonic jet flows

    NASA Technical Reports Server (NTRS)

    Dosanjh, D. S.; Das, I. S.

    1985-01-01

    The acoustic far field, the shock-associated noise and characteristics of the repetitive shock structure of supersonic jet flows issuing from a contoured plug-nozzle and uncontoured plug-nozzle having a short conical plug of either a solid or a combination of solid/porous surface with pointed termination operated at a range of supercritical pressure are reported. The contoured and the uncontoured plug-nozzles had the same throat area and the same annular-radius ratio.

  5. A modular hierarchy-based theory of the chemical origins of life based on molecular complementarity.

    PubMed

    Root-Bernstein, Robert

    2012-12-18

    Albert Szent-Gyorgyi once defined discovery as seeing what everyone else sees and thinking what no one else thinks. I often find that phenomena that are obvious to other people are not obvious to me. Molecular complementarity is one of these phenomena: while rare among any random set of compounds, it is ubiquitous in living systems. Because every molecule in a living system binds more or less specifically to several others, we now speak of "interactomes". What explains the ubiquity of molecular complementarity in living systems? What might such an explanation reveal about the chemical origins of life and the principles that have governed its evolution? Beyond this, what might complementarity tell us about the optimization of integrated systems in general? My research combines theoretical and experimental approaches to molecular complementarity relating to evolution from prebiotic chemical systems to superorganismal interactions. Experimentally, I have characterized complementarity involving specific binding between small molecules and explored how these small-molecule modules have been incorporated into macromolecular systems such as receptors and transporters. Several general principles have emerged from this research. Molecules that bind to each other almost always alter each other's physiological effects; and conversely, molecules that have antagonistic or synergistic physiological effects almost always bind to each other. This principle suggests a chemical link between biological structure and function. Secondly, modern biological systems contain an embedded molecular paleontology based on complementarity that can reveal their chemical origins. This molecular paleontology is often manifested through modules involving small, molecularly complementary subunits that are built into modern macromolecular structures such as receptors and transporters. A third principle is that complementary modules are conserved and repurposed at every stage of evolution. Molecular

  6. Oscillation of an isolated liquid plug inside a dry capillary

    NASA Astrophysics Data System (ADS)

    Srinivasan, Vyas; Kumar, Siddhartha; Asfer, Mohammed; Khandekar, Sameer

    2017-06-01

    The present work reports an experimental study on the dynamics of partially wetting isolated liquid plug (DI water), which is made to oscillate inside a square, glass capillary tube (1 mm × 1 mm; 60 mm length). The liquid plug is made to oscillate pneumatically at two different frequencies (0.25 and 0.35 Hz), using a cam-follower mechanism. Bright field imaging is used to visualize the three-phase contact line behavior, while, micro-Particle Imaging Velocimetry (PIV) apparatus is used to discern the nature of flow inside the oscillating liquid plug. During a cycle, due to the partial wetting nature of DI water, the three-phase contact line at the menisci gets pinned at the extreme end of each stroke, where the dynamic apparent contact angle gets drastically altered before the initiation of the next stroke. The difference between the apparent contact angle of the front and rear meniscus are seen to be a function of the oscillating frequency; the difference increasing with increasing frequency. The flow inside the liquid plug reveals unique non-Poiseuille flow features near the meniscus, due to free-slip boundary condition, which leads to formation of distinct vortex pairs behind it. The vortices too change their direction during each stroke of the oscillation, eventually leading to an alternating recirculation pattern inside the plug. The results clearly indicate that improved mathematical models are required for predicting transport parameters in such flows, which are important in engineering systems such as pulsating heat pipes, lab-on-chip devices and PEM fuel cells.

  7. Alternate tube plugging criteria for steam generator tubes

    SciTech Connect

    Cueto-Felgueroso, C.; Aparicio, C.B.

    1997-02-01

    The tubing of the Steam Generators constitutes more than half of the reactor coolant pressure boundary. Specific requirements governing the maintenance of steam generator tubes integrity are set in Plant Technical Specifications and in Section XI of the ASME Boiler and Pressure Vessel Code. The operating experience of Steam Generator tubes of PWR plants has shown the existence of some types of degradatory processes. Every one of these has an specific cause and affects one or more zones of the tubes. In the case of Spanish Power Plants, and depending on the particular Plant considered, they should be mentioned the Primary Water Stress Corrosion Cracking (PWSCC) at the roll transition zone (RTZ), the Outside Diameter Stress Corrosion Cracking (ODSCC) at the Tube Support Plate (TSP) intersections and the fretting with the Anti-Vibration Bars (AVBs) or with the Support Plates in the preheater zone. The In-Service Inspections by Eddy Currents constitutes the standard method for assuring the SG tubes integrity and they permit the monitoring of the defects during the service life of the plant. When the degradation reaches a determined limit, called the plugging limit, the SG tube must be either repaired or retired from service by plugging. Customarily, the plugging limit is related to the depth of the defect. Such depth is typically 40% of the wall thickness of the tube and is applicable to any type of defect in the tube. In its origin, that limit was established for tubes thinned by wastage, which was the predominant degradation in the seventies. The application of this criterion for axial crack-like defects, as, for instance, those due to PWSCC in the roll transition zone, has lead to an excessive and unnecessary number of tubes being plugged. This has lead to the development of defect specific plugging criteria. Examples of the application of such criteria are discussed in the article.

  8. Filter-based chemical sensors for hazardous materials

    NASA Astrophysics Data System (ADS)

    Major, Kevin J.; Ewing, Kenneth J.; Poutous, Menelaos K.; Sanghera, Jasbinder S.; Aggarwal, Ishwar D.

    2014-05-01

    The development of new techniques for the detection of homemade explosive devices is an area of intense research for the defense community. Such sensors must exhibit high selectivity to detect explosives and/or explosives related materials in a complex environment. Spectroscopic techniques such as FTIR are capable of discriminating between the volatile components of explosives; however, there is a need for less expensive systems for wide-range use in the field. To tackle this challenge we are investigating the use of multiple, overlapping, broad-band infrared (IR) filters to enable discrimination of volatile chemicals associated with an explosive device from potential background interferants with similar chemical signatures. We present an optical approach for the detection of fuel oil (the volatile component in ammonium nitrate-fuel oil explosives) that relies on IR absorption spectroscopy in a laboratory environment. Our proposed system utilizes a three filter set to separate the IR signals from fuel oil and various background interferants in the sample headspace. Filter responses for the chemical spectra are calculated using a Gaussian filter set. We demonstrate that using a specifically chosen filter set enables discrimination of pure fuel oil, hexanes, and acetone, as well as various mixtures of these components. We examine the effects of varying carrier gasses and humidity on the collected spectra and corresponding filter response. We study the filter response on these mixtures over time as well as present a variety of methods for observing the filter response functions to determine the response of this approach to detecting fuel oil in various environments.

  9. Raman-spectroscopy-based chemical contaminant detection in milk powder

    NASA Astrophysics Data System (ADS)

    Dhakal, Sagar; Chao, Kuanglin; Qin, Jianwei; Kim, Moon S.

    2015-05-01

    Addition of edible and inedible chemical contaminants in food powders for purposes of economic benefit has become a recurring trend. In recent years, severe health issues have been reported due to consumption of food powders contaminated with chemical substances. This study examines the effect of spatial resolution used during spectral collection to select the optimal spatial resolution for detecting melamine in milk powder. Sample depth of 2mm, laser intensity of 200mw, and exposure time of 0.1s were previously determined as optimal experimental parameters for Raman imaging. Spatial resolution of 0.25mm was determined as the optimal resolution for acquiring spectral signal of melamine particles from a milk-melamine mixture sample. Using the optimal resolution of 0.25mm, sample depth of 2mm and laser intensity of 200mw obtained from previous study, spectral signal from 5 different concentration of milk-melamine mixture (1%, 0.5%, 0.1%, 0.05%, and 0.025%) were acquired to study the relationship between number of detected melamine pixels and corresponding sample concentration. The result shows that melamine concentration has a linear relation with detected number of melamine pixels with correlation coefficient of 0.99. It can be concluded that the quantitative analysis of powder mixture is dependent on many factors including physical characteristics of mixture, experimental parameters, and sample depth. The results obtained in this study are promising. We plan to apply the result obtained from this study to develop quantitative detection model for rapid screening of melamine in milk powder. This methodology can also be used for detection of other chemical contaminants in milk powders.

  10. CHEMICAL SOLUTION DEPOSITION BASED OXIDE BUFFERS AND YBCO COATED CONDUCTORS

    SciTech Connect

    Paranthaman, Mariappan Parans

    2011-01-01

    We have reviewed briefly the growth of buffer and high temperature superconducting oxide thin films using a chemical solution deposition (CSD) method. In the Rolling-Assisted Biaxially Textured Substrates (RABiTS) process, developed at Oak Ridge National Laboratory, utilizes the thermo mechanical processing to obtain the flexible, biaxially oriented copper, nickel or nickel-alloy substrates. Buffers and Rare Earth Barium Copper Oxide (REBCO) superconductors have been deposited epitaxially on the textured nickel alloy substrates. The starting substrate serves as a template for the REBCO layer, which has substantially fewer weak links. Buffer layers play a major role in fabricating the second generation REBCO wire technology. The main purpose of the buffer layers is to provide a smooth, continuous and chemically inert surface for the growth of the REBCO film, while transferring the texture from the substrate to the superconductor layer. To achieve this, the buffer layers need to be epitaxial to the substrate, i.e. they have to nucleate and grow in the same bi-axial texture provided by the textured metal foil. The most commonly used RABiTS multi-layer architectures consist of a starting template of biaxially textured Ni-5 at.% W (Ni-W) substrate with a seed (first) layer of Yttrium Oxide (Y2O3), a barrier (second) layer of Yttria Stabilized Zirconia (YSZ), and a Cerium Oxide (CeO2) cap (third) layer. These three buffer layers are generally deposited using physical vapor deposition (PVD) techniques such as reactive sputtering. On top of the PVD template, REBCO film is then grown by a chemical solution deposition. This article reviews in detail about the list of oxide buffers and superconductor REBCO films grown epitaxially on single crystal and/or biaxially textured Ni-W substrates using a CSD method.

  11. A MEMS Based Hybrid Preconcentrator/Chemiresistor Chemical Sensor

    SciTech Connect

    HUGHES,ROBERT C.; PATEL,SANJAY V.; MANGINELL,RONALD P.

    2000-06-12

    A hybrid of a microfabricated planar preconcentrator and a four element chemiresistor array chip has been fabricated and the performance as a chemical sensor system has been demonstrated. The close proximity of the chemiresistor sensor to the preconcentrator absorbent layer allows for fast transfer of the preconcentrated molecules during the heating and resorption step. The hybrid can be used in a conventional flow sampling system for detection of low concentrations of analyte molecules or in a pumpless/valveless mode with a grooved lid to confine the desorption plume from the preconcentrator during heating.

  12. Space-Based Chemical Lasers in Strategic Defense

    DTIC Science & Technology

    2007-11-02

    using <fJ*™’™ „, „,,„,,; rrÄr^ÄSXnceuea. MlRACL Chemical laser at White planned for 1995. ssssSS Sands New Mexico ^f Tit:*n s«ron»1 «>ta<J*’f...AsswnHY P«o Su<«y CS2 Secwios CaoaMitv LPE 10,412 OPE 12.323 S/C with Test Objects 12,382 Subtotal 35,117 Titan IVA Margin !32.7°.o

  13. Investigation of opening switch mechanisms based on chemically reactive plasmas

    NASA Astrophysics Data System (ADS)

    Lapatovich, W. P.; Piejak, R. B.; Proud, J. M.

    1985-11-01

    An investigation of discharge-induced chemical reactions resulting in high-density product vapors containing strongly attaching gases has been conducted to evaluate the feasibility and potential of such reactions in rapid opening plasma switches. This new concept of employing such reactions to limit and/or interrupt large currents on a microsecond time scale was studied in two element (electrodeless and electroded) devices and in three element (electroded) devices. Bimolecular and unimolecular reactions were considered. The plasma reaction between AlCl sub 3 and SiO sub 2 was studied. The electrical properties of one of the reaction products (SiCl sub 4) is reported.

  14. Surfactant-Based Chemical and Biological Agent Decontaminating Solution Development

    DTIC Science & Technology

    2003-11-19

    10^8 4 PAA in uEm 10^8 8 (1) C10 Amine oxide (2) di-C10 Amine oxide ! Peracetic Acid (PAA) Found to Be an Effective Disinfectant Decon Conf 11-03...Utilize as Environmentally Green Reactant for Both Chemical and Biological Agents – Some Peracids Available in Neat Form ( Peracetic acid ) and In-Situ...Formulation Components – Peroxygen Compounds and Catalysts Oxidation of Calmagite Dye by Peracetic Acid TAML FeMB Catalyst 0 20 40 60 80 100 120 0 2 4 6

  15. Non-allergic cutaneous reactions in airborne chemical sensitivity--a population based study.

    PubMed

    Berg, Nikolaj Drimer; Linneberg, Allan; Thyssen, Jacob Pontoppidan; Dirksen, Asger; Elberling, Jesper

    2011-06-01

    Multiple chemical sensitivity (MCS) is characterised by adverse effects due to exposure to low levels of chemical substances. The aetiology is unknown, but chemical related respiratory symptoms have been found associated with positive patch test. The purpose of this study was to investigate the relationship between cutaneous reactions from patch testing and self-reported severity of chemical sensitivity to common airborne chemicals. A total of 3460 individuals participating in a general health examination, Health 2006, were patch tested with allergens from the European standard series and screened for chemical sensitivity with a standardised questionnaire dividing the participants into four severity groups of chemical sensitivity. Both allergic and non-allergic cutaneous reactions--defined as irritative, follicular, or doubtful allergic reactions--were analysed in relationship with severity of chemical sensitivity. Associations were controlled for the possible confounding effects of sex, age, asthma, eczema, atopic dermatitis, psychological and social factors, and smoking habits. In unadjusted analyses we found associations between allergic and non-allergic cutaneous reactions on patch testing and the two most severe groups of self-reported sensitivity to airborne chemicals. When adjusting for confounding, associations were weakened, and only non-allergic cutaneous reactions were significantly associated with individuals most severely affected by inhalation of airborne chemicals (odds ratio = 2.5, p = 0.006). Our results suggest that individuals with self-reported chemical sensitivity show increased non-allergic cutaneous reactions based on day 2 readings of patch tests.

  16. PLUG STORAGE BUILDING, TRA611, AWAITS SHIELDING SOIL TO BE PLACED ...

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

    PLUG STORAGE BUILDING, TRA-611, AWAITS SHIELDING SOIL TO BE PLACED OVER PLUG STORAGE TUBES. WING WALLS WILL SUPPORT EARTH FILL. MTR, PROCESS WATER BUILDING, AND WORKING RESERVOIR IN VIEW BEYOND PLUG STORAGE. CAMERA FACES NORTHEAST. INL NEGATIVE NO. 2949. Unknown Photographer, 7/30/1951 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  17. Sizing community energy storage systems to reduce transformer overloading with emphasis on plug-in electric vehicle loads

    NASA Astrophysics Data System (ADS)

    Trowler, Derik Wesley

    The research objective of this study was to develop a sizing method for community energy storage systems with emphasis on preventing distribution transformer overloading due to plug-in electric vehicle charging. The method as developed showed the formulation of a diversified load profile based upon residential load data for several customers on the American Electric Power system. Once a load profile was obtained, plug-in electric vehicle charging scenarios which were based upon expected adoption and charging trends were superimposed on the load profile to show situations where transformers (in particular 25 kVA, 50 kVA, and 100 kVA) would be overloaded during peak hours. Once the total load profiles were derived, the energy and power requirements of community energy storage systems were calculated for a number of scenarios with different combinations of numbers of homes and plug-in electric vehicles. The results were recorded and illustrated into charts so that one could determine the minimum size per application. Other topics that were covered in this thesis were the state of the art and future trends in plug-in electric vehicle and battery chemistry adoption and development. The goal of the literature review was to confirm the already suspected notion that Li-ion batteries are best suited and soon to be most cost-effective solution for applications requiring small, efficient, reliable, and light-weight battery systems such as plug-in electric vehicles and community energy storage systems. This thesis also includes a chapter showing system modeling in MATLAB/SimulinkRTM. All in all, this thesis covers a wide variety of considerations involved in the designing and deploying of community energy storage systems intended to mitigate the effects of distribution transformer overloading.

  18. Plug-In Hybrid Urban Delivery Truck Technology Demonstration

    SciTech Connect

    Miyasato, Matt; Impllitti, Joseph; Pascal, Amar

    2015-07-31

    The I-710 and CA-60 highways are key transportation corridors in the Southern California region that are heavily used on a daily basis by heavy duty drayage trucks that transport the cargo from the ports to the inland transportation terminals. These terminals, which include store/warehouses, inland-railways, are anywhere from 5 to 50 miles in distance from the ports. The concentrated operation of these drayage vehicles in these corridors has had and will continue to have a significant impact on the air quality in this region whereby significantly impacting the quality of life in the communities surrounding these corridors. To reduce these negative impacts it is critical that zero and near-zero emission technologies be developed and deployed in the region. A potential local market size of up to 46,000 trucks exists in the South Coast Air Basin, based on near- dock drayage trucks and trucks operating on the I-710 freeway. The South Coast Air Quality Management District (SCAQMD), California Air Resources Board (CARB) and Southern California Association of Governments (SCAG) — the agencies responsible for preparing the State Implementation Plan required under the federal Clean Air Act — have stated that to attain federal air quality standards the region will need to transition to broad use of zero and near zero emission energy sources in cars, trucks and other equipment (Southern California Association of Governments et al, 2011). SCAQMD partnered with Volvo Trucks to develop, build and demonstrate a prototype Class 8 heavy-duty plug-in hybrid drayage truck with significantly reduced emissions and fuel use. Volvo’s approach leveraged the group’s global knowledge and experience in designing and deploying electromobility products. The proprietary hybrid driveline selected for this proof of concept was integrated with multiple enhancements to the complete vehicle in order to maximize the emission and energy impact of electrification. A detailed review of all

  19. GPU-based flow simulation with detailed chemical kinetics

    NASA Astrophysics Data System (ADS)

    Le, Hai P.; Cambier, Jean-Luc; Cole, Lord K.

    2013-03-01

    The current paper reports on the implementation of a numerical solver on the Graphic Processing Units (GPUs) to model reactive gas mixtures with detailed chemical kinetics. The solver incorporates high-order finite volume methods for solving the fluid dynamical equations coupled with stiff source terms. The chemical kinetics are solved implicitly via an operator-splitting method. We explored different approaches in implementing a fast kinetics solver on the GPU. The detail of the implementation is discussed in the paper. The solver is tested with two high-order shock capturing schemes: MP5 (Suresh and Huynh, 1997) [9] and ADERWENO (Titarev and Toro, 2005) [10]. Considering only the fluid dynamics calculation, the speed-up factors obtained are 30 for the MP5 scheme and 55 for ADERWENO scheme. For the fully-coupled solver, the performance gain depended on the size of the reaction mechanism. Two different examples of chemistry were explored. The first mechanism consisted of 9 species and 38 reactions, resulting in a speed-up factor up to 35. The second, larger mechanism, consisted of 36 species and 308 reactions, resulting in a speed-up factor of up to 40.

  20. Thermo-sensitive polymer nanospheres as a smart plugging agent for shale gas drilling operations.

    PubMed

    Wang, Wei-Ji; Qiu, Zheng-Song; Zhong, Han-Yi; Huang, Wei-An; Dai, Wen-Hao

    2017-01-01

    Emulsifier-free poly(methyl methacrylate-styrene) [P(MMA-St)] nanospheres with an average particle size of 100 nm were synthesized in an isopropyl alcohol-water medium by a solvothermal method. Then, through radical graft copolymerization of thermo-sensitive monomer N-isopropylacrylamide (NIPAm) and hydrophilic monomer acrylic acid (AA) onto the surface of P(MMA-St) nanospheres at 80 °C, a series of thermo-sensitive polymer nanospheres, named SD-SEAL with different lower critical solution temperatures (LCST), were prepared by adjusting the mole ratio of NIPAm to AA. The products were characterized by Fourier transform infrared spectroscopy, transmission electron microscopy, thermogravimetric analysis, particle size distribution, and specific surface area analysis. The temperature-sensitive behavior was studied by light transmittance tests, while the sealing performance was investigated by pressure transmission tests with Lungmachi Formation shales. The experimental results showed that the synthesized nanoparticles are sensitive to temperature and had apparent LCST values which increased with an increase in hydrophilic monomer AA. When the temperature was higher than its LCST value, SD-SEAL played a dual role of physical plugging and chemical inhibition, slowed down pressure transmission, and reduced shale permeability remarkably. The plugged layer of shale was changed to being hydrophobic, which greatly improved the shale stability.