94 results on '"Terry Johnson"'
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2. Ultra low Rdson LDMOS with 12V BVDSS
- Author
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Brendan Toner, Hafizah Binti Abdul Malik, Darin Davis, Gary Dolny, Terry Johnson, and William Richards
- Published
- 2022
3. Improved subsalt imaging in Brazil Campos basin — Cascaded application of hybrid interbed demultiple, P- and S-salt velocity joint migration, and subsalt converted wave suppression
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Riaz Alai, Faqi Liu, Darrell Armentrout, David Brookes, Terry Johnson, Milos Cvetkovic, Gundogan Coskun, Shah Sulaiman, Kien Kok Lee, Afiq Mokhtar, Christopher Lee Slind, Hafizan Wahab, Wan Ching Low, and Ali Andrea B. Hashim
- Published
- 2022
4. Longer-term temporal trends in PFAS concentrations in Midwestern landfill leachate
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Terry Johnson, James Obereiner, and Milind V Khire
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Environmental Engineering ,Pollution - Abstract
It is well documented that per- and polyfluoroalkyl substances (PFAS) are routinely detected in leachate from municipal solid waste (MSW) landfills. PFAS-containing products are ubiquitous in society and in end-of-life discarded materials. While considerable data have been generated in recent years for PFAS concentrations in landfill leachate, little published information exists concerning longer-term trends in leachate concentrations. In this study, we examine a ten-year dataset for three MSW landfills located in the upper Midwestern United States where leachate PFAS testing has been performed on a quarterly basis. The significance of these data are considered in light of phase-out initiatives implemented in the US manufacturing companies for longer-chain PFAS including perfluorooctanoic acid (PFOA), perfluorooctane sulphonate (PFOS) and perfluorononanoic acid (PFNA). Findings from this study indicate that the average concentration of longer-chain PFOA in the three landfills decreased from 2400 to 1900 ng/L and the average PFOS concentrations decreased from 1000 to 370 ng/L. This may be indicative of reduced domestic production and use of these compounds. The phase-out of long-chain PFAS has also led to the introduction of shorter-chain replacement compounds such as perfluorobutanoic acid, perfluorobutane sulphonate and perfluorohexanoic acid, and this paper also examines long-term trends in leachate concentrations of these compounds.
- Published
- 2023
5. Field Temperatures and Geothermal Modeling of an MSW Landfill Located in Humid Climate
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Milind V. Khire, Terry Johnson, William Meyer, and Richard Holt
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- 2022
6. Heat Loss in Landfills as a Function of Landfill Size
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Milind V. Khire, Terry Johnson, and Richard Holt
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- 2022
7. Addressing the challenges of sub-50nm channel LDMOS
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Gary M. Dolny, William R. Richards, Brendan Toner, Terry Johnson, Christoph Ellmers, Stefan Eisenbrandt, Liu Zhengchao, and Darin Davis
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010302 applied physics ,LDMOS ,Computer science ,020208 electrical & electronic engineering ,Transistor ,Process (computing) ,Silicon on insulator ,02 engineering and technology ,Integrated circuit ,01 natural sciences ,law.invention ,law ,0103 physical sciences ,0202 electrical engineering, electronic engineering, information engineering ,Key (cryptography) ,Electronic engineering ,Body region ,Communication channel - Abstract
Low on-resistance LDMOS transistors frequently utilize a self-aligned body to minimize resistance and size of the device. This paper discusses the challenges associated with ultra-short channels and proposes contrarian solutions to address them while maintaining key operating characteristics. These include a retrograde body for e-field modulation and an elegant, cost effective process flow incorporating a self-aligned body and hybrid source. The novel architectures are illustrated by simulation and 12V n-LDMOS implementation on a 0.18um SOI platform.
- Published
- 2021
8. The Winners by Julio Cortázar
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Terry, Johnson King, Johnson King, Terry, Responsable del archivo: Josserand Colla, Sylvie, Responsable científico: Gómez, Susana, Editor científico: Idmhand, Fatiha, Autor del análisis: Alí, María Alejandra, Autores de la reseña: Gómez, Susana, Passion, Laurent, and IDMHAND, Fatiha
- Subjects
Literatura argentina ,"Los Premios" - Abstract
Notas: Documento pegado a una hoja en blanco., Tipo de publicación: Periódico, Título de la publicación: The Miami News, Periodicidad: Diario
- Published
- 2021
9. Schottky Source LDMOS - Electrical SOA Improvement through BJT Suppression
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Darin Davis, Terry Johnson, Lutz Steinbeck, Brendan Toner, Ralf Granzner, Gary M. Dolny, William R. Richards, Stefan Eisenbrandt, and Markus Frank
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010302 applied physics ,LDMOS ,Materials science ,business.industry ,020208 electrical & electronic engineering ,Bipolar junction transistor ,Transistor ,Schottky diode ,02 engineering and technology ,01 natural sciences ,law.invention ,Safe operating area ,law ,0103 physical sciences ,0202 electrical engineering, electronic engineering, information engineering ,Optoelectronics ,Breakdown voltage ,Current (fluid) ,business ,Voltage - Abstract
This paper introduces the first application of a Schottky source approach for the purpose of expanding the Electrical Safe Operating Area (E-SOA) of a HV Transistor. Replacing the conventional PN source with a Schottky source suppresses the parasitic BJT enabling significant improvement in the E-SOA, particularly for very fast pulses. Under these conditions, improvement in the trigger voltage and current of a 40V n-LDMOS is 5.6% and 117% respectively. The breakdown voltage of 57V is maintained and a competitive on-resistance of 31.5 mOhm.mm2 achieved.
- Published
- 2020
10. Geothermal Modeling of Elevated Temperature Landfills
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Terry Johnson, Richard Holt, and Milind V. Khire
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Waste management ,Environmental science ,Geothermal gradient - Published
- 2020
11. Field-Scale Evaluation of Evapotranspiration from a Landfill Cover
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Terry Johnson, Milind V. Khire, Mike Caldwell, and Banafsheh Saghaei
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Hydrology ,Scale (ratio) ,Evapotranspiration ,Environmental science ,Cover (algebra) ,Field (geography) - Published
- 2020
12. Application of wavestrapping statistical technique to estimate an extreme value in train aerodynamics
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António Ramos Andrade, Julian Stow, and Terry Johnson
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Renewable Energy, Sustainability and the Environment ,Computer science ,020209 energy ,Mechanical Engineering ,Airspeed ,02 engineering and technology ,Aerodynamics ,01 natural sciences ,Signal ,010305 fluids & plasmas ,Wavelet ,0103 physical sciences ,0202 electrical engineering, electronic engineering, information engineering ,Slipstream ,Peak value ,Extreme value theory ,Algorithm ,Bootstrapping (statistics) ,Civil and Structural Engineering - Abstract
This paper explores the application of a statistical analysis technique known as ‘wavestrapping’ to a railway data analysis problem in train aerodynamics. This simulation technique is used to reproduce/reconstruct signals with the same statistical properties of the initial signal(s) and to estimate an extreme value in train aerodynamics. This technique is compared with the method currently used in practice to estimate the peak value of slipstream air speed, according to the European standard EN 14067.
- Published
- 2018
13. Boatyard Hazards: Tips for protecting worker safety and health
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Terry Johnson
- Published
- 2019
14. Train overturning in high winds
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David Soper, Mark Sterling, Andrew Quinn, Christopher Baker, Hassan Hemida, Dominic Flynn, and Terry Johnson
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Moment (mathematics) ,Aerodynamic force ,Scale (ratio) ,Computer science ,business.industry ,Range (statistics) ,Full scale ,Train ,Computational fluid dynamics ,business ,Marine engineering ,Crosswind - Abstract
This chapter considers the effects of high winds on train operation. The various issues that arise from trains in high crosswinds are first outlined and a generic methodology is proposed for the consideration of these issues. Firstly, methods are outlined for determining the aerodynamic force and moment coefficients through the use of full-scale testing, physical model testing and CFD calculations. It is clear that the nature of the crosswind flow around trains at full scale is very complex, and model scale measurements and CFD calculations only provide a limited representation of the full-scale situation. Nonetheless, the force and moment coefficients from such tests are adequate for the overall calculation methodology. Such measurements have been made for a wide variety of trains in many different situations. These are tabulated in Appendix 2 , and this chapter provides a simple method of parameterising the results. A range of methods for simulating the natural wind are then critically presented, and the manner in which these simulations are combined with the force and moment coefficients and models of the vehicle dynamic system are set out to calculate the characteristic wind curve, which is used for train authorisation purposes. A simple methodology for calculating such curves is then described. Methods are then outlined for the calculation of the probability of a wind-induced accident occurring along an entire route. Finally, methods of reducing this accident risk, both through physical interventions and operational strategies, are discussed.
- Published
- 2019
15. Tunnel aerodynamics issues
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Terry Johnson, Christopher Baker, Mark Sterling, David Soper, Andrew Quinn, Dominic Flynn, and Hassan Hemida
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Drag ,Inlet pressure ,Range (aeronautics) ,Aural pressure ,Environmental science ,Train ,Transient (oscillation) ,Aerodynamics ,Marine engineering - Abstract
This chapter, building on the description of tunnel pressures and flows in Chapter 6 , discusses a range of practical issues associated with aerodynamic effects in railway tunnels. Firstly, pressure transients in tunnels are considered, and the range of methods used for calculating pressure transients in tunnels is set out, together with their input requirements. Aural pressure comfort is then considered, and the pressure transient limits specified by standards are described, together with an overview of the experiments from which these standards were derived. A probability-based approach to assessing aural comfort is also provided. Methods of reducing these pressure transients are then presented – through modification of tunnel geometry and train operating conditions, through the provision of airshafts or through the sealing of trains. Secondly, the emission of micropressure waves from tunnels is considered. Methods to reduce the inlet pressure gradients (and thus to reduce the magnitudes of these waves) are described – tunnel entrance hoods, elongated train noses, provision of cross shafts and the use of both passive and active aerodynamic damping devices. Finally, the chapter describes a range of other tunnel aerodynamic issues – train drag in tunnels, structural loading in tunnels and on trains and the very specific problems associated with long tunnels.
- Published
- 2019
16. Aerodynamic effects on pantographs and overhead wire systems
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Dominic Flynn, Hassan Hemida, Christopher Baker, David Soper, Andrew Quinn, Terry Johnson, and Mark Sterling
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Lift (force) ,Aerodynamic force ,business.industry ,Drag ,Computer science ,Pantograph ,Structural engineering ,Aerodynamics ,Computational fluid dynamics ,business ,Overhead line ,Wind tunnel - Abstract
This chapter considers the aerodynamic behaviour of pantographs and overhead line systems. After an introduction to the geometry of such systems, the mechanical and aerodynamic forces on the overhead wire are set out. The static and dynamic displacement of the wire due to wind effects is described. Wire instabilities caused by galloping are then discussed at length and the circumstances under which these instabilities might occur are derived. The different types of pantograph are then discussed and the types of mechanical and aerodynamic forces experienced by pantographs are outlined. Full-scale measurements, wind tunnel measurements and CFD calculations of pantograph aerodynamic characteristics are considered. The important issue of pantograph aerodynamic optimisation is then discussed at length for both lift forces and drag forces. Finally, methods are described for analysing the dewirement problem and for predicting the risk of such incidents.
- Published
- 2019
17. Fluid mechanics concepts
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Dominic Flynn, Christopher Baker, David Soper, Mark Sterling, Andrew Quinn, Hassan Hemida, and Terry Johnson
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Physics::Fluid Dynamics ,Flow (mathematics) ,Computer science ,Turbulence ,Equations of motion ,Energy–momentum relation ,Fluid mechanics ,Aerodynamics ,Mechanics ,Conservation of mass ,Wind speed - Abstract
This chapter sets out some basic fluid mechanics concepts that are required in the study of train aerodynamics and that will be referred to later in this book. Dimensionless analysis and dimensionless variables are described, and this is followed by a discussion of two different frames of reference – the ground and train frames. Qualitative descriptions are then given of the principles of conservation of mass, momentum and energy, and of the concepts of free flows, boundary layers, turbulence, separated flows and wakes. This leads into a more quantitative discussion of the equations of motion in a variety of different forms, which will all be referred to later in this book. This section attempts to show the interrelated nature of many of the practical problems in train aerodynamics that might otherwise appear quite diverse. The nature of flow turbulence is then discussed in more detail, and this is followed by a description of the natural wind close to the ground, including wind speed probabilities, wind speed and turbulence profiles and turbulence spectra.
- Published
- 2019
18. The flow around trains in the open air
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Dominic Flynn, Christopher Baker, David Soper, Andrew Quinn, Terry Johnson, Mark Sterling, and Hassan Hemida
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Boundary layer ,business.industry ,Flow (psychology) ,Train ,Computational fluid dynamics ,Wake ,business ,Wind speed ,Geology ,Vortex ,Marine engineering ,Crosswind - Abstract
This chapter gives an introduction to the flow around trains in the open air and provides the basic description of the flow field on which the discussion of the applications in Part 2 is based. The discussion is built on the results of full-scale experiments, for a wide range of different train types, with data from model-scale experiments and computational fluid dynamics being used where no full-scale data are available. Firstly, the flow around trains on level ground is discussed, and the five basic flow regions are introduced – the nose region, the boundary layer region, the near wake region, the far wake region and the underbody flow region. Each of these regions is then analysed in turn, and data for typical pressure and velocity fields are presented. Information is presented on nose peak-to-peak pressure coefficients: train side, roof and underbody boundary layer parameters and roof and underbody skin friction for different train types. The unsteady vortex flow in the near wake region of high-speed trains is discussed in qualitative terms. The discussion then moves on to consider the flow around trains on level ground in crosswinds, considering both low and high wind speed conditions. The complexity and transient nature of these flow fields is emphasised. Finally, the flow around trains in a range of different environments is presented, and the effects of ballast platform height, embankments, viaducts and different station environments are discussed.
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- 2019
19. Trains in tunnels
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Christopher Baker, David Soper, Mark Sterling, Hassan Hemida, Andrew Quinn, Terry Johnson, and Dominic Flynn
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Condensed Matter::Superconductivity ,Flow (psychology) ,Train ,Aerodynamics ,Mechanics ,Condensed Matter::Mesoscopic Systems and Quantum Hall Effect ,Geology ,Entry pressure ,Sonic boom - Abstract
This chapter describes the nature of the flow in railway tunnels and forms the basis for the consideration of a number of practical issues in tunnel aerodynamics in Chapter 12 . The nature of the pressure transients caused by trains passing through tunnels is discussed in detail, and in particular the large changes in pressure as the train enters the tunnel are described. The concept of wave diagrams is presented, and the way it can be used to describe wave interactions is illustrated. The various factors that are associated with tunnel pressure changes are set out and discussed. In addition to the pressure changes, velocity changes in tunnels as trains pass through are also presented. The effects of airshafts on both tunnel pressures and velocities are then considered. Finally, the issue of micropressure waves (or sonic booms) from the exits of tunnels is discussed – both in terms of their generation through the steepening of entry pressure transients and their radiation outside the tunnel.
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- 2019
20. Computational techniques
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Chris Baker, Terry Johnson, Dominic Flynn, Hassan Hemida, Andrew Quinn, David Soper, and Mark Sterling
- Published
- 2019
21. Aerodynamic loads on trackside structures, passing trains and people
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David Soper, Andrew Quinn, Mark Sterling, Dominic Flynn, Hassan Hemida, Christopher Baker, and Terry Johnson
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Computer science ,business.industry ,Range (aeronautics) ,Pressure load ,Slipstream ,Ranging ,Train ,Aerodynamics ,Computational fluid dynamics ,Track (rail transport) ,business ,Marine engineering - Abstract
This chapter considers the aerodynamic loads caused by passing trains on trackside structure, people and other trains. These loads are of two forms – pressure loads and slipstream loads. Pressure loads are considered first and then the ways of quantifying the peak-to-peak pressure transients are described. The use of full-scale measurements, physical model measurements and CFD calculations to calculate these transients are then described, and the role of simple analytical methods are discussed. A range of correlations of pressure load data from standards is then presented, primarily concerned with loads on vertical structures next to the track and horizontal surfaces above the track. Pressure loads in station environments and on passing trains are also considered. The ways in which these pressure loads can be used to calculate structural loading are then described, ranging from simple static methods through to fully dynamic methods. With regard to slipstream loads, full-scale measurements require the measurement of slipstream gust speeds from a large number of train passes and the formation of an ensemble of gust speeds. Both physical model tests and CFD have some limitations in providing similar data. A collation of gust velocities for a wide range of train types is presented. The application of these gust speeds to loading of people and objects is then considered. A number of different approaches can be used and an overall framework that shows the interaction between these approaches is set out and described.
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- 2019
22. Testing techniques
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Chris Baker, Terry Johnson, Dominic Flynn, Hassan Hemida, Andrew Quinn, David Soper, and Mark Sterling
- Published
- 2019
23. Historical context
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Chris Baker, Terry Johnson, Dominic Flynn, Hassan Hemida, Andrew Quinn, David Soper, and Mark Sterling
- Published
- 2019
24. Aerodynamic drag
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Chris Baker, Terry Johnson, Dominic Flynn, Hassan Hemida, Andrew Quinn, David Soper, and Mark Sterling
- Published
- 2019
25. Emerging issues
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Chris Baker, Terry Johnson, Dominic Flynn, Hassan Hemida, Andrew Quinn, David Soper, and Mark Sterling
- Published
- 2019
26. Insignificance
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Terry Johnson
- Published
- 2018
27. Cries from the Mammal House
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Terry Johnson
- Published
- 2018
28. Crosswind sensitivity assessment of a representative Europe-wide range of conventional vehicles
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Terry Johnson, Kaspar Schroeder-Bodenstein, Marc Stiepel, Peter Deeg, Mikael Sima, Remi Gregoire, Ander Blanco, Gianluca Zanetti, and Nicolas Paradot
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Transport engineering ,Engineering ,business.industry ,Mechanical Engineering ,media_common.cataloged_instance ,European union ,business ,Stock (geology) ,media_common ,Crosswind - Abstract
The European Union Seventh Framework Programme research project AeroTRAIN aimed at delivering limit criteria for crosswinds to the ‘Rolling stock – locomotives and passenger rolling stock’ Technical Specification for Interoperability (CR LOC&PAS TSI) and for class 2 trains of the high-speed rolling stock TSI (HS RST TSI). A first objective was the assessment of characteristic wind curve (CWC) for identified class 2 and conventional vehicles with low, but sufficient, crosswind stability (as proven by their safe operational records) on the EN 14067-6: 2010 single track with ballast and rails (STBR) standard configuration. In the same manner, and as a second objective, Reference CWC and limit criteria for class 1 trains of HS RST TSI were planned to be determined. For all these trains, the aerodynamic coefficients were obtained in a unique wind tunnel campaign using the STBR ground configuration. Their crosswind sensitivity was assessed against a calculated CWC obtained from vehicle dynamics simulations. The resulting database will allow the derivation of the relevant limit criteria still needed for vehicle authorization regarding crosswind stability.
- Published
- 2015
29. Modeling the effects of vegetation on methane oxidation and emissions through soil landfill final covers across different climates
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Tarek Kormi, Lei Yuan, Tarek Abichou, Terry Johnson, and Escobar Francisco
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Climate ,Biomass ,Methane ,Soil ,chemistry.chemical_compound ,Waste Management ,Organic matter ,Organic Chemicals ,Waste Management and Disposal ,chemistry.chemical_classification ,Air Pollutants ,Macropore ,Environmental engineering ,Vegetation ,Models, Theoretical ,Plants ,United States ,Waste Disposal Facilities ,chemistry ,Soil water ,Anaerobic oxidation of methane ,Soil horizon ,Environmental science ,Oxidation-Reduction ,Environmental Monitoring - Abstract
Plant roots are reported to enhance the aeration of soil by creating secondary macropores which improve the diffusion of oxygen into soil as well as the supply of methane to bacteria. Therefore, methane oxidation can be improved considerably by the soil structuring processes of vegetation, along with the increase of organic biomass in the soil associated with plant roots. This study consisted of using a numerical model that combines flow of water and heat with gas transport and oxidation in soils, to simulate methane emission and oxidation through simulated vegetated and non-vegetated landfill covers under different climatic conditions. Different simulations were performed using different methane loading flux (5–200 g m−2 d−1) as the bottom boundary. The lowest modeled surface emissions were always obtained with vegetated soil covers for all simulated climates. The largest differences in simulated surface emissions between the vegetated and non-vegetated scenarios occur during the growing season. Higher average yearly percent oxidation was obtained in simulations with vegetated soil covers as compared to non-vegetated scenario. The modeled effects of vegetation on methane surface emissions and percent oxidation were attributed to two separate mechanisms: (1) increase in methane oxidation associated with the change of the physical properties of the upper vegetative layer and (2) increase in organic matter associated with vegetated soil layers. Finally, correlations between percent oxidation and methane loading into simulated vegetated and non-vegetated covers were proposed to allow decision makers to compare vegetated versus non-vegetated soil landfill covers. These results were obtained using a modeling study with several simplifying assumptions that do not capture the complexities of vegetated soils under field conditions.
- Published
- 2015
30. Use of Evapotranspiration (ET) Landfill Covers to Reduce Methane Emissions from Municipal Solid Waste Landfills
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Terry Johnson, Tarek Kormi, Tarek Abichou, Cheng Wang, Haykel Melaouhia, and Stephen Dwyer
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Hydrology ,Water balance ,chemistry.chemical_compound ,Municipal solid waste ,Macropore ,chemistry ,Greenhouse gas ,Evapotranspiration ,Soil water ,Anaerobic oxidation of methane ,Environmental engineering ,Environmental science ,Methane - Abstract
Solid waste landfills need to have final covers to 1) reduce the infiltration of rainfall into the waste mass and 2) reduce surface greenhouse gas emissions. Most regulations require that such final covers include hydraulic barriers, such as compacted clays with or without geomembrane. Significant research has been undertaken to allow the use of evapotranspiration-based covers (often termed: Evapotranspiration (ET) Cover, Water Balance Covers, or Phyto Covers) as an alternative to the barrier concept covers. ET covers are designed so that they have the capacity to store water by the soil and also have plants or vegetation to remove the stored water. In ET covers, plant roots can enhance the aeration of soil by creating secondary macropores which improve the diffusion of oxygen into soil. Therefore, biological methane oxidation (a natural process in landfill soils) can be improved considerably by the soil structuring processes of vegetation, along with the increase of organic biomass in the soil associated with plant roots. This paper summarizes a study to investigate the capacity of an ET cover to reduce surface greenhouse gas emissions when implemented on a solid waste landfill. This study consisted of using a numerical model to estimate methane emission and oxidation through an ET cover under average climatic conditions in Bennignton, Nebraska, USA. Different simulations were performed using different methane loading flux (5 to 200 gm-2·d-1) as the bottom boundary. For all simulations, surface emissions were the lowest during the growing season and during warmer days of the year. Percent oxidation is the highest during the growing season and during warmer days. The lowest modeled surface emissions were always obtained during the growing season. Finally, correlations between percent oxidation and methane loading into simulated ET covers were proposed to estimate methane emissions and methane oxidation in ET covers.
- Published
- 2015
31. Transient aerodynamic pressures and forces on trackside and overhead structures due to passing trains. Part 1: Model-scale experiments; Part 2: Standards applications
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Sarah Jordan, Mark Sterling, Timothy Gilbert, Terry Johnson, Andrew Quinn, John Lane, and Christopher Baker
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Measure (data warehouse) ,Engineering ,Scale (ratio) ,business.industry ,Position (vector) ,Mechanical Engineering ,Overhead (computing) ,Train ,Structural engineering ,Transient (oscillation) ,Aerodynamics ,business ,Scale model - Abstract
This is the first part of a two-part paper that describes the results of an experimental investigation to measure the aerodynamic pressure forces on structures in the vicinity of railway tracks. The investigations were carried out in order to obtain a fundamental understanding of the nature of the phenomenon and to obtain data for a variety of railway infrastructure geometries of particular relevance to the UK situation, in order to provide material for a National Annex to the relevant Eurocode. The experiments were carried out on the moving model TRAIN Rig, with models of three different sorts of trains with different nose types, and a variety of infrastructures types: vertical hoardings, overbridges, station canopies and trestle platforms. The transient loads that were measured had a characteristic form: a positive pressure peak followed by a negative pressure peak. In general the magnitudes of the two peaks were different, and varied with infrastructure type and position, as well as with train type. As would be expected, the more streamlined the train, the lower were the magnitudes of the pressure transients. A comparison of the experimental results was made with a variety of existing model- scale and full-scale data and a broad consistency was demonstrated, within the limits that the rather different experimental conditions in the various cases would allow. An analysis of the scaling of these pressure transients was carried out, and it was shown that whilst there was a reasonable coalescence around a theoretical formulation, the complexity of the flows involved meant that a general scaling formulation could not be achieved. Part 2 of this paper will consider the application of the results to the development of revised standards formulations.
- Published
- 2014
32. Solid- State H2 Storage System Engineering: Direct H2 Refueling
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Terry Johnson and Pierre Bénard
- Subjects
business.industry ,Computer data storage ,Solid-state ,Environmental science ,Process engineering ,business - Published
- 2016
33. A study of the slipstreams of high-speed passenger trains and freight trains
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Terry Johnson, Christopher Baker, Sarah Jordan, and Mark Sterling
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Transport engineering ,Engineering ,Identification (information) ,business.industry ,Mechanical Engineering ,Scale (chemistry) ,Interoperability ,Container (abstract data type) ,Flow (psychology) ,Train ,Railway engineering ,business ,Boundary (real estate) - Abstract
As the speeds of both passenger and freight trains increase, there is increasing concern that the unsteady gusts generated in train boundary layers and wakes will become more of for a risk to passengers waiting on platforms and for trackside workers. In addition, the demands of interoperability make this a problem of growing relevance to railway operators across Europe. A number of model scale and full-scale experiments have been carried out in recent years that have provided robust experimental data to quantify these flows. This paper considers all the available datasets for high-speed passenger trains and container freight trains, and in making a comparison between them, arrives at a number of conclusions concerning the characteristics of train slipstreams. It is concluded that the identification of a number of distinct flow regions in earlier work is generally valid and forms a useful framework for the consideration of the problem. The flow characteristics are different in each region, and, depending upon the train type, the measurement distance from the train and height above ground, the observed peak gusts for a train may occur at any time during the train passage or in its wake. It is also concluded that results obtained from measurements around small scale moving models are in good agreement with the full scale measurements and reproduce all the important flow features.
- Published
- 2008
34. Stormwater Sediment Filtration Using Sand versus Synthetic Fibers
- Author
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Terry Johnson, Mark Verwiel, Milind V. Khire, Christopher Prucha, and Duraisamy S. Saravanathiiban
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Clogging ,Hydraulic conductivity ,law ,Bentonite ,Environmental engineering ,Sediment ,Turbidity ,Effluent ,Geology ,Filtration ,Filter (aquarium) ,law.invention - Abstract
Ottawa sand and a synthetic fiber were tested for filtration of stormwater sediments. Laboratory column tests were performed using water spiked with Bentonite clay as a surrogate for sediment. Filter media column height was varied from 20 cm to 90 cm. 10 to 20 pore volumes of Bentonite spiked water was permeated through each filter medium. Influent turbidity and effluent turbidity were monitored. Ratios of effluent turbidity to influent turbidity and hydraulic conductivity as a function of pore volumes of flow were evaluated for each filter medium as an indicator of hydraulic efficiency. Hydraulic conductivity of Ottawa sand and Synthetic Fiber were 0.08 cm/sec. and 0.20 cm/sec., respectively. Increase in filter column height of Ottawa sand increased the filtration efficiency as quantified by lower turbidity effluent vs. pore volume. However, hydraulic conductivity decreased with increasing filtration efficiency for Ottawa sand due to clogging. Compared to Ottawa sand, filtration efficiency and hydraulic conductivity of synthetic fibers was higher throughout the experiments.
- Published
- 2015
35. A PROACTIVE APPROACH TO MANAGING NUTRIENT LOADS IN LAS VEGAS BAY AND LAKE MEAD
- Author
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Caroline E. Scruggs, Ira Rackley, Terry Johnson, and Doug Karafa
- Subjects
Hydrology ,Nutrient ,Las vegas ,General Engineering ,Environmental science ,Bay - Published
- 2005
36. Certification assays for HIV-1-based vectors: frequent passage of gag sequences without evidence of replication-competent viruses
- Author
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Kunal Desai, Yi Xu, David Rissing, Jonathan Marsh, Kenneth Cornetta, Lakshmi Sastry, and Terry Johnson
- Subjects
Quality Control ,Time Factors ,Genetic Vectors ,Green Fluorescent Proteins ,Molecular Sequence Data ,Gene Products, gag ,Enzyme-Linked Immunosorbent Assay ,Polymerase Chain Reaction ,Cell Line ,law.invention ,chemistry.chemical_compound ,Transduction (genetics) ,Viral Envelope Proteins ,Transduction, Genetic ,law ,Cell Line, Tumor ,Drug Discovery ,Genetics ,Humans ,Molecular Biology ,Polymerase chain reaction ,chemistry.chemical_classification ,Pharmacology ,Membrane Glycoproteins ,Base Sequence ,Models, Genetic ,biology ,Reverse Transcriptase Polymerase Chain Reaction ,HEK 293 cells ,Gene Transfer Techniques ,biology.organism_classification ,Virology ,Molecular biology ,Luminescent Proteins ,chemistry ,Vesicular stomatitis virus ,Cell culture ,Lentivirus ,HIV-1 ,Molecular Medicine ,Glycoprotein ,DNA ,HeLa Cells - Abstract
A principal concern regarding the safety of HIV-1-based vectors is replication-competent lentivirus (RCL). We have developed two PCR assays for detecting RCL; the first detects recombination between gag regions in the transfer vector and the packaging construct (sensitivity of detection approximately 10-100 copies of target sequence). The second assay uses real-time PCR to detect vesicular stomatitis virus glycoprotein (VSVG) envelope DNA (sensitivity approximately 5-50 VSVG sequences). In an attempt to amplify any RCL, test vectors were used to transduce C8166 and 293 cells, which were then screened weekly for 3 weeks. Psi-gag recombinants were routinely detected (20 of 21 analyses) in four transductions using the RRL-CMV-GFP vector. In contrast, VSVG sequences were detected only once in 21 analyses. Interestingly, p24 levels (as measured by ELISA) were occasionally detectable after 3 weeks of culture. To determine if a true RCL was present, 21-day cell-free medium was used to transduce naïve cells. No evidence of psi-gag or VSVG transfer was detected, indicating that the recombination events were insufficient to reconstitute a true RCL. These findings have important implications for the design and safety of HIV-1-based vectors intended for clinical applications.
- Published
- 2003
- Full Text
- View/download PDF
37. Palm Beach County Florida Uses Innovative Cloth-Media Tertiary Filtration To Meet its Reuse Requirements
- Author
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David Dalton and Terry Johnson
- Subjects
Waste management ,law ,General Engineering ,Environmental science ,Reuse ,Palm ,Filtration ,law.invention - Published
- 2001
38. Die Aufsichtsbehörde prüft – was nun?
- Author
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Terry Johnson
- Published
- 2013
39. Evaluation of the efficiency of an experimental biocover to reduce BTEX emissions from landfill biogas
- Author
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Waldir Nagel Schirmer, Terry Johnson, Alexandre R. Cabral, Abderrahim Lakhouit, and Hubert Cabana
- Subjects
Canada ,Environmental Engineering ,Health, Toxicology and Mutagenesis ,BTEX ,Xylenes ,Methane ,chemistry.chemical_compound ,Human health ,Biogas ,Benzene Derivatives ,Environmental Chemistry ,Humans ,Benzene ,Air quality index ,Air Pollutants ,Volatile Organic Compounds ,Waste management ,Chemistry ,Xylene ,Public Health, Environmental and Occupational Health ,General Medicine ,General Chemistry ,Pollution ,Refuse Disposal ,Waste Disposal Facilities ,Biofuel ,Environmental chemistry ,Toluene - Abstract
Landfill emissions include volatile organic compounds (VOCs) and, particularly, benzene, toluene, ethyl-benzene and xylene isomers (collectively called BTEX). The latter are the most common VOCs found in landfill biogas. BTEX affect air quality and may be harmful to human health. In conjunction with a study aiming to evaluate the efficiency of passive methane oxidizing biocovers, a complementary project was developed with the specific goal of evaluating the reduction in VOC emissions due to the installation of a biocover. One of the biocovers constructed at the Saint-Nicephore (Quebec, Canada) landfill site was instrumented for this purpose. The total BTEX concentration in the raw biogas ranged from 28.7 to 65.4ppmv, and the measured concentration of BTEX in biogas emitted through the biocover ranged from below the limit of detection (BLD) to 2.1ppmv. The other volatile organic compounds (OVOCs) concentration varied from 18.8 to 40.4ppmv and from 0.8 to 1.2ppmv in the raw biogas and in the emitted biogas, respectively. The results obtained showed that the biocover effectiveness ranged from 67% to 100% and from 96% to 97% for BTEX and OVOC, respectively.
- Published
- 2013
40. Expertise and the state
- Author
-
Terry Johnson
- Subjects
Sociology ,State (computer science) ,Law and economics - Published
- 2013
41. Changing Fisheries of the Russian Far East
- Author
-
Terry Johnson
- Subjects
Economics and Econometrics ,Government ,Geography, Planning and Development ,Fishing ,Planned economy ,Demise ,Management, Monitoring, Policy and Law ,Oceanography ,Creative financing ,Domestic market ,Fishery ,Economic restructuring ,Business ,Communism - Abstract
Since the demise of the Soviet Union, and creation of the Russian Federation in 1992, the fishing industries of the Russian Far East (RFE) have undergone dramatic change.1 The Soviet Union was once the world's top fishing nation, and the fleets of the RFE produced some 70% of the total catch, which peaked in 1988 and 1989 at more than ten million metric tons (mmt). Current production is closer to 4.5 mmt, or about three-quarters of the volume of America's Pacific fisheries (including Alaska). Conversion from a command economy, where the Communist Party set production targets,2 to a market economy continues to occur throughout the industry. This conversion is accompanied by large-scale privatization of the capital resources of the country. Because the economic restructuring occurred largely as a result of the Soviet state's worsening financial condition, there has been little government aid available to struggling state enterprises, which previously made up the bulk of the fisheries production capacity, and little financial assistance available to the newlyconstituted private enterprises. This financial pinch initially has had several effects. One was a shortage of fuel, which kept many vessels in port. For example, in Petropavlovsk-Kamchatsky in 1993, dozens of trawlers, crabbers, and processors lay at the dock or anchored in scenic Avacha Bay due to a lack of fuel. Another was an inability to replace obsolete harvesting and processing equipment. At a time when Japanese importers were paying handsome prices for quality frozen sockeye salmon, Russian processors were forced to salt or can their fish for the low-priced domestic market if they could even obtain sufficient cans or salt to do the job. However, Russian entrepreneurs soon devised creative financing schemes, or entered into various kinds of joint ventures with foreigners. Fuel supplies are now adequate (in part because of purchases from Alaska), production is increasing, and revitalization of the industry is underway. In Kamchatka, fish production in 1995 was up 33% from the previous year, contributing to a 15% increase in overall indus
- Published
- 1996
42. Analysis of H2 storage needs for early market non-motive fuel cell applications
- Author
-
Terry Johnson, Marcina Moreno, Marco Arienti, Joseph Pratt, Leo Shaw, and Leonard Klebanoff
- Published
- 2012
43. The Russian salmon fishery: Alaska's next big threat?
- Author
-
Mark Herrman, Terry Johnson, Joshua Greenberg, and Andrei Streletsky
- Subjects
Economics and Econometrics ,business.industry ,Geography, Planning and Development ,International trade ,Competition (economics) ,Econometric model ,Economy ,Agriculture ,Economics ,Animal Science and Zoology ,Salmon fishery ,Soviet union ,Far East ,business ,Agronomy and Crop Science ,Food Science - Abstract
The recent breakup of the Soviet Union has brought hope and opportunity to many Americans. It has also brought the possibility of new competition to some US agricultural and resource-based industries. Recent concern in the western regions of the United States and Canada has centered on the increased possibility of salmon exports from the Russia Far East to traditional Western markets fueled, in a large part, from Russia- Japanese joint ventures. A dynamic econometric model of the world salmon markets was utilized to simulate future Russian salmon export scenarios. It was found that the Alaska pink salmon industry may suffer devastating consequences from increased Russian exports of pink salmon while the sockeye industry will suffer somewhat less from increased Russian exports of sockeye salmon. © 1994 by John Wiley & sons, Inc.
- Published
- 1994
44. Absorption, distribution, metabolism, and excretion of [1-¹⁴C]-perfluorohexanoate ([¹⁴C]-PFHx) in rats and mice
- Author
-
Shawn A, Gannon, Terry, Johnson, Diane L, Nabb, Tessa L, Serex, Robert C, Buck, and Scott E, Loveless
- Subjects
Male ,Fluorocarbons ,Guinea Pigs ,Rats ,Rats, Sprague-Dawley ,Mice ,Intestinal Absorption ,Area Under Curve ,Hepatocytes ,Animals ,Female ,Tissue Distribution ,Carbon Radioisotopes ,Caproates ,Half-Life - Abstract
The absorption, tissue distribution, elimination, and metabolism of [1-¹⁴C]-PFHx in rats and mice dosed orally at 2 or 100 mg/kg was evaluated following a single dose or after 14 consecutive doses. Absorption was rapid in rats as evidenced by a short time to maximum concentration (C(max)) of 30 min in male rats and 15 min in female rats at both the 2 and 100mg/kg dose level. The plasma elimination half-life was somewhat longer in males (1.5-1.7 h) than in females (0.5-0.7 h). Absorption in the mouse was also rapid with the maximum plasma concentration occurring between 15 and 30 min after dosing. The maximum concentration was not appreciably different between male and female mice (8 μg equiv./g at 2 mg/kg; ~350 μg equiv./g at 100 mg/kg). The primary route of elimination was via the urine. PFHx was not metabolized in rat or mouse hepatocytes, nor were any metabolites observed after oral dosing in either rodent species. Essentially 100% of the dose was eliminated in urine within 24 h demonstrating that PFHx is readily absorbed and bioavailability approaches 100%, even at a dose as high as 100 mg/kg. The route and extent of elimination was unchanged after 14 days of daily dosing. Tissues were collected at three time points (rat: 0.5, 2, and 24 h; mice: 0.25, 1, and 24 h) after dosing to investigate the tissue clearance kinetics of PFHx following a single dose at 2 or 100 mg/kg. In all tissues except skin, PFHx was not quantifiable 24 h after dosing in both sexes of the two species.
- Published
- 2011
45. Lysimeters versus Actual Earthen Caps: Numerical Assessment of Soil Water Storage
- Author
-
Terry Johnson, Ramil G. Mijares, and Milind V. Khire
- Subjects
Hydrology ,Water balance ,Hydraulics ,law ,Lysimeter ,Percolation ,Evapotranspiration ,Vadose zone ,Soil water ,Water storage ,Environmental science ,Soil science ,law.invention - Abstract
Lysimeters are commonly used for field-scale assessment of water balance of earthen caps, commonly referred to as evapotranspirative (ET) caps. While lysimeters are the only direct tool to measure percolation through a cap, the lower hydraulic boundary of a lysimeter is significantly different compared to an actual ET cap. In this study, numerical simulations of water balance of lysimeters and ET caps were carried out using Vadose/W for a range of hydraulic properties of the soils and waste. The numerical results suggest that due to the presence of waste below the cap, the soil water storage of an ET cap is greater than an equivalent lysimeter. This greater water storage capacity in an actual ET cap results in lower percolation than for an equivalent lysimeter.
- Published
- 2010
46. Developing a Design Approach to Reduce Methane Emissions from California Landfills
- Author
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Jeffrey P. Chanton, Koen Mahieu, Terry Johnson, Imane Mansouri, Mehrez Romdhane, and Tarek Abichou
- Subjects
Methane emissions ,chemistry.chemical_compound ,Bioreactor landfill ,chemistry ,Waste management ,Water flow ,Airflow ,Environmental engineering ,Environmental science ,Water content ,Methane ,Heat flow - Published
- 2010
47. Clean Boating for Alaskans
- Author
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Terry Johnson
- Published
- 2009
48. Rat Control for Alaska Waterfront Facilities
- Author
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Terry Johnson
- Subjects
Engineering ,business.industry ,Environmental protection ,Control (management) ,business ,Environmental planning - Published
- 2008
49. Fishermen's Direct Marketing Manual
- Author
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Terry Johnson
- Subjects
Direct marketing ,business.industry ,Advertising ,Marketing ,business - Published
- 2007
50. Responsible Marine Wildlife Viewing in Alaska
- Author
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Terry Johnson
- Subjects
Fishery ,Geography ,Environmental protection ,Wildlife - Published
- 2006
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