Wintering Sandhill Crane exposure to wind energy development in the central and southern Great Plains, USA

USGS Publications Warehouse

Pearse, Aaron T.; Brandt, David; Krapu, Gary

2016-01-01

Numerous wind energy projects have been constructed in the central and southern Great Plains, USA, the main wintering area for midcontinental Sandhill Cranes (Grus canadensis). In an initial assessment of the potential risks of wind towers to cranes, we estimated spatial overlap, investigated potential avoidance behavior, and determined the habitat associations of cranes. We used data from cranes marked with platform transmitting terminals (PTTs) with and without global positioning system (GPS) capabilities. We estimated the wintering distributions of PTT-marked cranes prior to the construction of wind towers, which we compared with current tower locations. Based on this analysis, we found 7% spatial overlap between the distributions of cranes and towers. When we looked at individually marked cranes, we found that 52% would have occurred within 10 km of a tower at some point during winter. Using data from cranes marked after tower construction, we found a potential indication of avoidance behavior, whereby GPS-marked cranes generally used areas slightly more distant from existing wind towers than would be expected by chance. Results from a habitat selection model suggested that distances between crane locations and towers may have been driven more by habitat selection than by avoidance, as most wind towers were constructed in locations not often selected by wintering cranes. Our findings of modest regional overlap and that few towers have been placed in preferred crane habitat suggest that the current distribution of wind towers may be of low risk to the continued persistence of wintering midcontinental Sandhill Cranes in the central and southern Great Plains.

Tracer concentration profiles measured in central London as part of the REPARTEE campaign

NASA Astrophysics Data System (ADS)

Martin, D.; Petersson, K. F.; White, I. R.; Henshaw, S. J.; Nickless, G.; Lovelock, A.; Barlow, J. F.; Dunbar, T.; Wood, C. R.; Shallcross, D. E.

2011-01-01

There have been relatively few tracer experiments carried out that have looked at vertical plume spread in urban areas. In this paper we present results from two tracer (cyclic perfluorocarbon) experiments carried out in 2006 and 2007 in central London centred on the BT Tower as part of the REPARTEE (Regent's Park and Tower Environmental Experiment) campaign. The height of the tower gives a unique opportunity to study vertical dispersion profiles and transport times in central London. Vertical gradients are contrasted with the relevant Pasquill stability classes. Estimation of lateral advection and vertical mixing times are made and compared with previous measurements. Data are then compared with a simple operational dispersion model and contrasted with data taken in central London as part of the DAPPLE campaign. This correlates dosage with non-dimensionalised distance from source. Such analyses illustrate the feasibility of the use of these empirical correlations over these prescribed distances in central London.

Advances in the Use of In Situ Flux Tower Measures of Canopy Structure and Function for Evaluation of MODIS and VIIRS Vegetation Indices and Phenology

NASA Astrophysics Data System (ADS)

Huete, A. R.; Ma, X.; Devadas, R.; Miura, T.; Obata, K.; Restrepo-Coupe, N.; Kato, A.

2016-12-01

Prior studies have linked tower-based measures of ecosystem productivity (GEP) and satellite vegetation indices (VIs) over primarily phenologically driven ecosystems. In situ flux towers are advantageous for satellite product assessments due to their comparable footprints and finer temporal resolution measurements. However, weaker relationships have been reported in meteorological driven ecosystems in which satellite and flux tower measures of productivity are asynchronous. This suggests that satellite derived biophysical measures are not a measure of GEP, but rather a proxy for ecosystem structure (e.g. LAI) and function. Here we investigate the use of flux tower measures of photosynthetic infrastructure, including photosynthetic capacity and light use efficiency, as more appropriate measures for the evaluation of satellite VI products and phenology. We related MODIS and VIIRS VIs (NDVI, EVI, EVI2) and phenology over a series of flux tower sites located across a climatically-diverse north to south gradient in central Australia, encompassing wet and dry subtropcal savannas, semi-arid shrub/grass, and temperate broadleaf evergreen forests. These represented environmental conditions where phenology and meteorology are not always synchronized. Our objectives were to (1) advance the use of in situ tower data for more accurate evaluation of satellite products and assess challenges and limitations of in situ tower networks; (2) intercompare cross-sensor VI products and derived phenology with tower measures across biomes to assess consistencies; and (3) better understand satellite and tower relationships to improve upon interpretation of satellite VI and phenology data. Our results show, that in contrast to measures of GEP, our measures of photosynthetic infrastructure were much better related to satellite VIs; they removed strong hysteresis influences on VI- productivity relationships across phenologic green-up and brown-down phases; and thus were better related to satellite phenology profiles. We conclude that flux tower networks offer a valuable source of in situ and consistent data that can be used for satellite time series continuity and cross sensor studies. This can also bring forward the validation of vegetation indices beyond simple reflectance-based accuracy assessments.

Tidal effects on net ecosystem exchange of carbon in an estuarine wetland

Treesearch

H. Guo; A. Noormets; B. Zhao; J. Chen; G. Sun; Y. Gu; B. Li; J. Chen

2009-01-01

One year of continuous data from two eddy-flux towers established along an elevation gradient incoastal Shanghai was analyzed to evaluate the tidal effect on carbon flux (Fc) over an estuarine wetland.The measured wavelet spectra and cospectra of Fc and other environmental factors demonstrated thatthe...

AmeriFlux US-SCg Southern California Climate Gradient - Grassland

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

Goulden, Mike

This is the AmeriFlux version of the carbon flux data for the site US-SCg Southern California Climate Gradient - Grassland. Site Description - Half hourly data are available at https://www.ess.uci.edu/~california/. This site is one of six Southern California Climate Gradient flux towers operated along an elevation gradient (sites are US-SCg, US-SCs, US-SCf, US-SCw, US-SCc, US-SCd). This site is a grassland that was historically dominated by exotic annuals and that underwent restoration with a focus on native bunch grasses in the 2010s. The site has historically burned every 10-20 years, with a wildfire in October 2007. The restoration involved several yearsmore » of mowing and herbicide application to suppress exotics followed by dense planting of Nasella bunch grasses.« less

Drop Tower Workshop

NASA Technical Reports Server (NTRS)

Urban, David

2013-01-01

Ground based microgravity facilities are an important proving ground for space experiments, ground-based research and space hardware risk mitigation. An overview of existing platforms will be discussed with an emphasis on drop tower capabilities. The potential for extension to partial gravity conditions will be discussed. Input will be solicited from attendees for their potential to use drop towers in the future and the need for enhanced capabilities (e.g. partial gravity)

Wind shear, sensible heat flux and atmospheric stability within a forest canopy

NASA Astrophysics Data System (ADS)

Piringer, M.; Polreich, E.

2009-09-01

The scientific project "ROSALIA”, carried out in co-operation between ZAMG and the Austrian Federal Research and Training Centre for Forests, Natural Hazards, and Landscape, investigated the meteorological impacts on pollen emission and spread in a typical Central European forest of mixed deciduous and coniferous trees. The study area is the "Lehrforst Rosalia” of BOKU University approx. 60 km south of the city of Vienna in undulating terrain (300 - 750 m altitude). In this area, two meteorological towers of similar construction, one at crest height, the other in the small valley of the river "Ofenbach” near a meteorological ground station, have been equipped with 3D ultrasonic anemometers: one has been placed on top of the upper tower to representatively measure the gradient flow; the tower in the valley has been equipped with 3 instruments, one at the lowermost platform near ground, the second in the middle of the forest canopy, the third on top of the tower situated within the transition zone between the canopy and the "free” boundary layer where the gradient winds dominate. The sonic anemometers measure the three-dimensional wind vector; in addition, the sound velocity is derived, from which the so-called "sonic temperature” is calculated to derive the sensible heat flux. Other quantities are the means, standard deviations, and covariances of the wind components and the momentum flux, the Monin-Obukhov stability parameter, and the friction velocity. In the sloping dense forest canopy surrounding the tower, complex meteorological conditions and frequent decoupling of above-canopy and within-canopy flow has to be expected. The presence of a thick leaf canopy results in a stronger decoupling between the flow above and inside the canopy. As the investigation period covers April and May 2009, this gives the opportunity to discern between leaf-off (at the beginning) and leaf-on periods, with a proposed increase in decoupling with time. The aim of the study is to derive characteristic patterns of wind and atmospheric stability within the forest canopy for leaf-off and leaf-on periods as well as for days of intense versus negligible pollen production.

Measurement of Ecosystem Metabolism across Climatic and Vegetation Gradients in California

NASA Astrophysics Data System (ADS)

DuBois, S.; Serbin, S.; Desai, A. R.; Kruger, E.; Kingdon, C.; Goulden, M.; Townsend, P. A.

2013-12-01

Terrestrial ecosystem models require information on vegetation structure, phenology, demographics, biochemistry, radiation properties, and physiology in order to accurately simulate the responses of ecosystem functioning to global change and disturbances. These models generally depend on a small number of intensive, fine-scaled point-based measurements from eddy covariance towers, detailed vegetation surveys, literature values, and site-scale data assimilation techniques to improve model calibration. However, the limited geographic and/or temporal scope of measurements can lead to inadequate model generalizations of modeled carbon (C), water, and energy fluxes across broad regions and relevant time periods. Remote sensing approaches, particularly imaging spectroscopy (IS) and thermal infrared (TIR) data, have the potential to provide the broad-scale spatial and temporal dynamics in many important vegetation properties related to ecosystem functioning. As part of the ongoing NASA HyspIRI Airborne Campaign (http://hyspiri.jpl.nasa.gov/airborne) we are assessing the potential of IS+TIR to generate spatially explicit estimates of two important parameters characterizing plant photosynthetic capacity: the maximum rate of CO2 carboxylation by RuBisCo (Vcmax), and the maximum rate of electron transport required for the regeneration of RuBP needed in Calvin Cycle processes (Jmax). These estimates are based on recent evidence that both properties can be predicted at the leaf level using spectroscopy techniques (Ainsworth et al. 2013 [http://tinyurl.com/n5xnzjg]; Serbin et al. 2012 [http://tinyurl.com/mhocmlz]). It follows that estimation of these variables from remotely sensed IS+TIR (i.e. AVIRIS & MASTER) could facilitate the prediction of seasonal C assimilation across large areas using data from the anticipated HyspIRI satellite mission. Our research focuses on two climate-elevation transects in California, which span a vegetation gradient from coastal sage and chaparral to oak woodlands and closed-canopy coniferous forests, as well as agro-ecosystems located throughout the Central and Imperial Valleys. We are also comparing remotely sensed estimates of ecosystem photosynthetic capacity with C flux data from a series of 10 eddy covariance towers. Results from the 2013 field season highlight the large range in sampled vegetation structure, optical properties (i.e. reflectance and transmittance) and physiology (i.e. Vcmax, Jmax, and cholorphyll fluorescence). Using approaches similar to Serbin et al. (2012) we have confirmed the ability of spectroscopy to estimate Vcmax and Jmax across these diverse and structurally complex vegetation types. Ecosystem products, such as gross primary productivity, estimated from flux towers highlight the relationship between climatic parameters and vegetation productivity. Multiple data-years allow this relationship to be examined under various climatic forcings including drought and heat stress. Based on these preliminary results, our next step is to scale leaf-level information to AVIRIS footprints using radiative transfer and statistical modeling approaches with ecosystem modeling in order to assess the IS data products against flux tower observations.

Flow-driven Assembly of Microcapsule Towers

NASA Astrophysics Data System (ADS)

Shum, Henry; Balazs, Anna

2016-11-01

Large populations of the slime mold, Dictyostelium discoideum, are able to aggregate over a surface and collectively form a long, vertical stalk. Inspired by this biological behavior, we develop a synthetic mechanism for assembling tower-like structures using microcapsules as the building blocks. We accomplish this in simulations by generating a fluid flow field that draws microcapsules together along a surface and lifts them up at a central point. We considered a fluid flow generated by the local release of a chemical species from a patch on the surface. The concentration gradient of the diffusing chemical species causes radial diffusioosmotic flow along the solid surface toward the patch. Adhesive interactions keep the microcapsules attached to the surface as they are drawn together above the patch. To build a tower-like structure, some of the microcapsules must detach from the surface but remain attached to the rest of the cluster. The upward directed fluid flow above the patch then draws out the cluster into a tower shape. The final morphology of the aggregate structure depends on the flow field, the adhesive capsule-capsule and capsule-surface interaction strengths, and the sedimentation force on the capsules. Tuning these factors changes the structures that are produced.

Using Cell-Phone Tower Signals for Detecting the Precursors of Fog

NASA Astrophysics Data System (ADS)

David, N.; Gao, H. O.

2018-01-01

In the last decade, published research has indicated the potential of commercial microwave links that comprise the data transmission infrastructure of cellular communication networks as an environmental monitoring technology. Different weather phenomena cause interference in the wireless communication links that can therefore essentially act as a low-cost sensor network, already deployed worldwide, for atmospheric monitoring. In this study we focus on the attenuation effect caused in commercial microwave networks due to gradients in the atmospheric refractive index with altitude as a result of the combination of temperature inversions and falls in the atmospheric humidity trapped beneath them. These conditions, when combined with high relative humidity near ground level, are precursors to the creation of fog. The current work utilizes this novel approach to demonstrate the potential for detecting these preconditions of fog, a phenomenon associated with severe visibility limitations that can lead to dangerous accidents, injuries, and loss of lives.

Evaluation of an Out-of-the-Window Air Traffic Control Tower Simulation for Controller Training

DOT National Transportation Integrated Search

1996-09-01

This study gathered evidence concerning the potential usefulness of out-of-the-window air traffic control tower : simulation for training tower controllers. Data were collected from all ten developmental controllers who completed : simulation trainin...

User's manual for the BNW-I optimization code for dry-cooled power plants. [AMCIRC

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

Braun, D.J.; Daniel, D.J.; De Mier, W.V.

1977-01-01

This appendix provides a listing, called Program AMCIRC, of the BNW-1 optimization code for determining, for a particular size power plant, the optimum dry cooling tower design using ammonia flow in the heat exchanger tubes. The optimum design is determined by repeating the design of the cooling system over a range of design conditions in order to find the cooling system with the smallest incremental cost. This is accomplished by varying five parameters of the plant and cooling system over ranges of values. These parameters are varied systematically according to techniques that perform pattern and gradient searches. The dry coolingmore » system optimized by program AMCIRC is composed of a condenser/reboiler (condensation of steam and boiling of ammonia), piping system (transports ammonia vapor out and ammonia liquid from the dry cooling towers), and circular tower system (vertical one-pass heat exchangers situated in circular configurations with cocurrent ammonia flow in the tubes of the heat exchanger). (LCL)« less

Minimizing Artifacts and Biases in Chamber-Based Measurements of Soil Respiration

NASA Astrophysics Data System (ADS)

Davidson, E. A.; Savage, K.

2001-05-01

Soil respiration is one of the largest and most important fluxes of carbon in terrestrial ecosystems. The objectives of this paper are to review concerns about uncertainties of chamber-based measurements of CO2 emissions from soils, to evaluate the direction and magnitude of these potential errors, and to explain procedures that minimize these errors and biases. Disturbance of diffusion gradients cause underestimate of fluxes by less than 15% in most cases, and can be partially corrected for with curve fitting and/or can be minimized by using brief measurement periods. Under-pressurization or over-pressurization of the chamber caused by flow restrictions in air circulating designs can cause large errors, but can also be avoided with properly sized chamber vents and unrestricted flows. Somewhat larger pressure differentials are observed under windy conditions, and the accuracy of measurements made under such conditions needs more research. Spatial and temporal heterogeneity can be addressed with appropriate chamber sizes and numbers and frequency of sampling. For example, means of 8 randomly chosen flux measurements from a population of 36 measurements made with 300 cm2 chambers in tropical forests and pastures were within 25% of the full population mean 98% of the time and were within 10% of the full population mean 70% of the time. Comparisons of chamber-based measurements with tower-based measurements of total ecosystem respiration require analysis of the scale of variation within the purported tower footprint. In a forest at Howland, Maine, the differences in soil respiration rates among very poorly drained and well drained soils were large, but they mostly were fortuitously cancelled when evaluated for purported tower footprints of 600-2100 m length. While all of these potential sources of measurement error and sampling biases must be carefully considered, properly designed and deployed chambers provide a reliable means of accurately measuring soil respiration in terrestrial ecosystems.

Feasibility Study on High Concentrating Photovoltaic Power Towers

NASA Astrophysics Data System (ADS)

Frohberger, Dirk; Jaus, Joachim; Wiesenfarth, Maike; Schramek, Philipp; Bett, Andreas W.

2010-10-01

This paper presents an analysis on the concept of high concentrating PV power towers. A feasibility study is conducted in order to evaluate the future potential of this technology. Objective of the analysis is to provide an improved basis for establishing research and development priorities for the PV power tower concept. Performance assessments and cost calculations for a 1 MW prototype PV tower power are derived. Based on the assumption of a highly homogeneously illuminated receiver, levelized costs of electricity of 0.29 €/kWh have been calculated for a prototype PV tower power.

Relationship between metal levels in the vent mussel Bathymodiolus azoricus and local microhabitat chemical characteristics of Eiffel Tower (Lucky Strike)

NASA Astrophysics Data System (ADS)

Martins, Inês; Cosson, Richard P.; Riou, Virginie; Sarradin, Pierre-Marie; Sarrazin, Jozée; Santos, Ricardo S.; Colaço, Ana

2011-03-01

The turbulent mixing of hydrothermal hot fluid with cold seawater creates large chemical gradients at a small spatial scale that may induce variable physiological and biochemical adaptations within the vent fauna. The adaptation to such a variable environment by the vent mussel Bathymodiolus azoricus relies on a dual symbiosis hosted in the gills, and digestion of particulate organic matter. The surrounding environment not only provides the necessary energy sources and suspended organic particles for the vent mussel nutrition, but also potentially toxic compounds such as metals. Our main goal was to see if there is a relation between metal accumulation in mussel organs and the chemical characteristics of their close environment. Mussels were collected at six locations in a cold part of the Eiffel Tower fluid-seawater mixing zone, characterized by distinct chemical compositions. Metals (Cd, Cu, Fe and Zn) and metallothioneins were quantified in the gills and digestive gland. The physiological condition of the sampled mussels was also evaluated using tissues and gill indices. Our study indicates that the accumulation of metals in B. azoricus is related to their spatial distribution and linked to fine scale environmental conditions that influence the physiological status of the organism.

Preliminary Design, Feasibility and Cost Evaluation of 1- to 15-Kilometer Height Steel Towers

NASA Technical Reports Server (NTRS)

Shanker, Ajay

2003-01-01

Design and construction of tall towers is an on-going research program of NASA. The agency has already done preliminary review in this area and has determined that multi-kilometer height towers are technically and economically feasible. The proposed towers will provide high altitude launch platforms reaching above eighty percent of Earth's atmosphere and provide tremendous gains in the potential energy as well as substantial reduction in aerodynamic drag. NASA has also determined that a 15-KM tower will have many useful applications in: (i)Meteorology,(ii)Oceanography, (iii)Astronomy, (iv)High Altitude Launch, (v)Physics Drop Tower, (vi) Biosphere Research, (vii) Nanotechnology, (viii) Energy/Power, (ix)Broadband Wireless Technology, (x)Space Transportation and (xi)Space Tourism.

Multi-Scale Approach for Measuring N2O and CH4 Emissions in Drainage Water Managed Corn-Soybean System

NASA Astrophysics Data System (ADS)

Hagedorn, J.; Zhu, Q.; Davidson, E. A.; Castro, M.

2017-12-01

Managing resources wisely while reducing environmental impact is the backbone of agricultural sustainability. Agricultural practices must develop strategies to effectively reduce nutrient runoff from farmed lands. Preliminary research suggests that one such strategy is drainage water management by which water levels are intentionally elevated following fertilization to favor subsoil denitrification and thereby reduce nitrogen leaching into groundwater and streams. Despite documented success in nitrate reduction, this best management practice (BMP) has not been widely adopted in part because users are not aware of the potential. But before extension agencies begin promoting this practice, evaluation of unintentional consequences must be studied. There is a risk that by elevating water levels for the purpose of creating suitable conditions for denitrification, more potent greenhouse gases such as nitrous oxide (N2O) and methane (CH4) could be produced, in which case the practice would be swapping one form of pollution for another. A multi-scale experimental design, using soil chambers and a tower-based gradient method, was implemented in a drainage water managed corn-soybean system on the Eastern Shore of Maryland. Emissions, soil moisture content, and soil nitrate measurements have been collected and analyzed to evaluate for differences between treatment and control plots as standard farm management practices, such as fertilization, occur. Preliminary results based on monthly sampling of transects of stationary soil chambers characterize the spatial heterogeneity of the fields and reveal that there are detectable differences in N2O and CH4 emissions between fields. There are also significant relationships between soil moisture, soil nitrate content and N2O emissions. The tower-based gradient method with micrometerological measurements provides high temporal resolution at the full field scale that complements the soil chamber work. This multi-scale resolution balance enables us to more accurately quantify this pollution swapping concern and demonstrates the efficacy of reducing nutrient runoff compared to risks of increased greenhouse gas emissions for a BMP that has transformative potential for sustainable agriculture.

Evapotranspiration estimates from eddy covariance towers and hydrologic modeling in managed forests in Northern Wisconsin, USA

Treesearch

Ge Sun; A. Noormets; J. Chen; S.G. McNulty

2008-01-01

Direct measurement of ecosystem evapotranspiration by the eddy covariance method and simulation modeling were employed to quantify the growing season (May–October) evapotranspiration (ET) of eight forest ecosystems representing a management gradient in dominant forest types and age classes in the Upper Great Lakes Region from 2002 to 2003. We measured net exchange of...

Effects of drop acceleration and deceleration on particle capture in a cross-flow gravity tower at intermediate drop Reynolds numbers.

PubMed

Kumar, Anoop; Gupta, S K; Kale, S R

2007-04-01

Cross-flow gravity towers are particle scrubbing devices in which water is sprayed from the top into particle-laden flow moving horizontally. Models for predicting particle capture assume drops traveling at terminal velocity and potential flow (ReD > 1000) around it, however, Reynolds numbers in the intermediate range of 1 to 1000 are common in gravity towers. Drops are usually injected at velocities greater than their terminal velocities (as in nozzles) or from near rest (perforated tray) and they accelerate/decelerate to their terminal velocity in the tower. Also, the effects of intermediate drop Reynolds number on capture efficiency have been simulated for (a) drops at their terminal velocity and (b) drops accelerating/decelerating to their terminal velocity. Tower efficiency based on potential flow about the drop is 40%-50% greater than for 200 mm drops traveling at their terminal velocity. The corresponding values for 500 mm drops are about 10%-20%. The drop injection velocity is important operating parameter. Increase in tower efficiency by about 40% for particles smaller than 5 mm is observed for increase in injection velocity from 0 to 20 m/s for 200 and 500mm drops.

Mycobacteria in Finnish cooling tower waters.

PubMed

Torvinen, Eila; Suomalainen, Sini; Paulin, Lars; Kusnetsov, Jaana

2014-04-01

Evaporative cooling towers are water systems used in, e.g., industry and telecommunication to remove excess heat by evaporation of water. Temperatures of cooling waters are usually optimal for mesophilic microbial growth and cooling towers may liberate massive amounts of bacterial aerosols. Outbreaks of legionellosis associated with cooling towers have been known since the 1980's, but occurrences of other potentially pathogenic bacteria in cooling waters are mostly unknown. We examined the occurrence of mycobacteria, which are common bacteria in different water systems and may cause pulmonary and other soft tissue infections, in cooling waters containing different numbers of legionellae. Mycobacteria were isolated from all twelve cooling systems and from 92% of the 24 samples studied. Their numbers in the positive samples varied from 10 to 7.3 × 10(4) cfu/L. The isolated species included M. chelonae/abscessus, M. fortuitum, M. mucogenicum, M. peregrinum, M. intracellulare, M. lentiflavum, M. avium/nebraskense/scrofulaceum and many non-pathogenic species. The numbers of mycobacteria correlated negatively with the numbers of legionellae and the concentration of copper. The results show that cooling towers are suitable environments for potentially pathogenic mycobacteria. Further transmission of mycobacteria from the towers to the environment needs examination. © 2013 APMIS. Published by John Wiley & Sons Ltd.

Potential errors in using one anemometer to characterize the wind power over an entire rotor disk

NASA Technical Reports Server (NTRS)

Simon, R. L.

1982-01-01

Wind data collected at four levels on a 90-m tower in a prospective wind farm area are used to evaluate how well the 10-m wind speed data with and without intermittent vertical profile measurements compare with the 90-m tower data. If a standard, or even predictable, wind speed profile existed, there would be no need for a large, expensive tower. This cost differential becomes even more significant if several towers are needed to study a prospective wind farm.

47 CFR 73.49 - AM transmission system fencing requirements.

Code of Federal Regulations, 2010 CFR

2010-10-01

.... Antenna towers having radio frequency potential at the base (series fed, folded unipole, and insulated... be provided to each antenna tower base for meter reading and maintenance purposes at all times...

47 CFR 73.49 - AM transmission system fencing requirements.

Code of Federal Regulations, 2011 CFR

2011-10-01

.... Antenna towers having radio frequency potential at the base (series fed, folded unipole, and insulated... be provided to each antenna tower base for meter reading and maintenance purposes at all times...

47 CFR 73.49 - AM transmission system fencing requirements.

Code of Federal Regulations, 2012 CFR

2012-10-01

.... Antenna towers having radio frequency potential at the base (series fed, folded unipole, and insulated... be provided to each antenna tower base for meter reading and maintenance purposes at all times...

Electric-dipole-induced universality for Dirac fermions in graphene.

PubMed

De Martino, Alessandro; Klöpfer, Denis; Matrasulov, Davron; Egger, Reinhold

2014-05-09

We study electric dipole effects for massive Dirac fermions in graphene and related materials. The dipole potential accommodates towers of infinitely many bound states exhibiting a universal Efimov-like scaling hierarchy. The dipole moment determines the number of towers, but there is always at least one tower. The corresponding eigenstates show a characteristic angular asymmetry, observable in tunnel spectroscopy. However, charge transport properties inferred from scattering states are highly isotropic.

Tower Illuminance Model

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

Ho, Clifford K.; Sims, Cianan

TIM is a real-time interactive concentrating solar field simulation. TIM models a concentrating tower (receiver), heliostat field, and potential reflected glare based on user-specified parameters such as field capacity, tower height and location. TIM provides a navigable 3D interface, allowing the user to “fly” around the field to determine the potential glare hazard from off-target heliostats. Various heliostat aiming strategies are available for specifying how heliostats behave when in standby mode. Strategies include annulus, point-per-group, up-aiming and single-point-focus. Additionally, TIM includes an avian path feature for approximating the irradiance and feather temperature of a bird flying through the field airspace.

Occurrence of Infected Free-Living Amoebae in Cooling Towers of Southern Brazil.

PubMed

Soares, Scheila S; Souza, Thamires K; Berté, Francisco K; Cantarelli, Vlademir V; Rott, Marilise B

2017-12-01

This study determined the occurrence of potentially pathogenic free-living amoebae (FLA) and bacteria associated with amoebae in air-conditioning cooling towers in southern Brazil. Water samples were collected from 36 cooling systems from air-conditioning in the state of Rio Grande do Sul, Brazil. The organisms were identified using polymerase chain reaction (PCR) and sequencing automated. The results showed that these aquatic environments, with variable temperature, are potential "hot spots" for emerging human pathogens like free-living amoebae and bacteria associated. In total, 92% of the cooling-tower samples analyzed were positive for FLA, and Acanthamoeba was the dominant genus by culture and PCR. Amoebal isolates revealed intracellular bacteria in 39.3% of them and all were confirmed as members of the genus Pseudomonas. The results obtained show the important role of cooling towers as a source of amoebae-associated pathogens.

Doppler lidar signal and turbulence study

NASA Technical Reports Server (NTRS)

Frost, W.; Huang, K. H.; Fitzjarrald, D. F.

1983-01-01

Comparison of the second moments of the Doppler lidar signal with aircraft and tower measured parameters is being carried out. Lidar binary data tapes were successfully converted to ASCII Code on the VAX 11/780. These data were used to develop the computer programs for analyzing data from the Marshall Space Flight Center field test. Raw lidar amplitude along the first 50 forward and backward beams of Run No. 2, respectively was plotted. Plotting techniques for the same beams except with the amplitude thresholded and range corrected were developed. Plotting routines for the corresponding lidar width of the first 50 forward and backward beams were also established. The relationship between raw lidar amplitude and lidar width was examined. The lidar width is roughly constant for lidar amplitudes less than 120 dB. A field test with the NASA/MSFC ground based Doppler lidar, the instrumented NASA B-57B gust gradient aircraft, and the NASA/MSFC eight tower array was carried out. The data tape for the lidar was received and read. The aircraft data and tower data are being digitized and converted to engineering units. Velocities computed sequentially along each of the lidar beams beginning at 16:40:00, May 12, 1983 were plotted for Run No. 1.

Cooling towers--a potential environmental source of slow-growing mycobacterial species.

PubMed

Black, Walter C; Berk, Sharon G

2003-01-01

Over the last decade a rise in the frequency of disease caused by nontuberculous mycobacteria (NTM) has occurred, especially among AIDS patients. The lack of evidence for person-to-person transmission indicates the environment is a source of infection. The ecology and environmental sources of NTMs are poorly understood, and many pathogenic strains have not been observed outside of clinical cases. Several species of NTMs have been reported from treated water distribution systems; however, one type of manmade environment that has not been examined for mycobacteria is that of cooling towers of air-conditioning systems. Such environments not only harbor a variety of microbial species, they also disseminate them in aerosols. The present investigation examined nine cooling towers from various locations in the United States. Cooling tower water was concentrated, treated with cetylpyridinium chloride, and plated onto Middlebrook 7H10 agar supplemented with OADC and cycloheximide. Colonies presumed to be mycobacterial species were isolated and acid-fast stained. Identification was made by amplifying and sequencing 1450 bp fragments of the 16S rRNA gene in both directions, and comparing resulting sequences with those in GenBank. Results showed that at least 75% of tower samples contained NTMs, and most of the isolates closely matched known mycobacterial pathogens. Isolates most closely matched the following GenBank sequences: Mycobacterium intracellulare, M. szulgai, M. bohemicum, M. gordonae, M. nonchromogenicum, and M. n. sp. "Fuerth 1999." This is the first report of specific NTMs in cooling tower water, and the first report of M. n. sp. "Fuerth 1999" from any environmental sample. Although cooling towers have a relatively high pH, they may favor the growth and dissemination of such potential pathogens, and future epidemiologic investigations should consider cooling towers as possible environmental sources of mycobacteria.

The Role of “Vortical” Hot Towers in the Formation of Tropical Cyclone Diana (1984).

NASA Astrophysics Data System (ADS)

Hendricks, Eric A.; Montgomery, Michael T.; Davis, Christopher A.

2004-06-01

A high-resolution (3-km horizontal grid spacing) near-cloud-resolving numerical simulation of the formation of Hurricane Diana (1984) is used to examine the contribution of deep convective processes to tropical cyclone formation. This study is focused on the 3-km horizontal grid spacing simulation because this simulation was previously found to furnish an accurate forecast of the later stages of the observed storm life cycle. The numerical simulation reveals the presence of vortical hot towers, or cores of deep cumulonimbus convection possessing strong vertical vorticity, that arise from buoyancy-induced stretching of local absolute vertical vorticity in a vorticity-rich prehurricane environment.At near-cloud-resolving scales, these vortical hot towers are the preferred mode of convection. They are demonstrated to be the most important influence to the formation of the tropical storm via a two-stage evolutionary process: (i) preconditioning of the local environment via diabatic production of multiple small-scale lower-tropospheric cyclonic potential vorticity (PV) anomalies, and (ii) multiple mergers and axisymmetrization of these low-level PV anomalies. The local warm-core formation and tangential momentum spinup are shown to be dominated by the organizational process of the diabatically generated PV anomalies; the former process being accomplished by the strong vertical vorticity in the hot tower cores, which effectively traps the latent heat from moist convection. In addition to the organizational process of the PV anomalies, the cyclogenesis is enhanced by the aggregate diabatic heating associated with the vortical hot towers, which produces a net influx of low-level mean angular momentum throughout the genesis.Simpler models are examined to elucidate the underlying dynamics of tropical cyclogenesis in this case study. Using the Sawyer Eliassen balanced vortex model to diagnose the macroscale evolution, the cyclogenesis of Diana is demonstrated to proceed in approximate gradient and hydrostatic balance at many instances, where local radial and vertical accelerations are small. Using a shallow water primitive equation model, a characteristic “moist” (diabatic) vortex merger in the cloud-resolving numerical simulation is captured in a large part by the barotropic model. Since a moist merger results in a stronger vortex and occurs twice as fast as a dry merger, it is inferred (consistent with related work) that a net low-level convergence can accelerate and intensify the merger process in the real atmosphere.Although the findings reported herein are based on a sole case study and thus cannot yet be generalized, it is believed the results are sufficiently interesting to warrant further idealized simulations of this nature.

The National Shipbuilding Research Program. Environmental Training Modules. Module 2 Shipyard Craft Specific Training

DTIC Science & Technology

1999-05-01

environmental liability. 4) Insecticides and Hazardous Metals Many antifouling coatings contain insecticides such as Tributyltin ( TBT ), and...of potentially toxic substances from shipyard welding operations. ASBESTOS OPERATIONS IN THE SHIPYARD (10ASBTOS.DOC) OBJECTIVE To ensure that...distillation operations. COOLING TOWERS (6-COOLIN.DOC) OBJECTIVE To minimize the potential for toxic emissions from cooling towers. VARNISH DIP TANKS (7

Potentially pathogenic amoeba-associated microorganisms in cooling towers and their control.

PubMed

Pagnier, Isabelle; Merchat, Michèle; La Scola, Bernard

2009-06-01

Cooling towers provide a favorable environment for the proliferation of microorganisms. Cooling towers generate a biofilm and often aerosolize contaminated water, thereby increasing the risk of microorganism dissemination by human inhalation. This pathogen dissemination was first revealed by the epidemics of Legionnaires' disease that were directly related to the presence of cooling towers, and since then, the ecology of Legionella pneumophila has been well studied. Each country has specific standards regarding the acceptable amount of microorganisms in cooling tower systems. However, those standards typically only concern L. pneumophila, even though many other microorganisms can also be isolated from cooling towers, including protozoa, bacteria and viruses. Microbiological control of the cooling tower system can be principally achieved by chemical treatments and also by improving the system's construction. Several new treatments are being studied to improve the efficiency of disinfection. However, as most of these treatments continue to focus solely on L. pneumophila, reports of other types of pathogens continue to increase. Therefore, how their dissemination affects the human populous health should be addressed now.

Occurrence of infected amoebae in cooling towers compared with natural aquatic environments: implications for emerging pathogens.

PubMed

Berk, S G; Gunderson, J H; Newsome, A L; Farone, A L; Hayes, B J; Redding, K S; Uddin, N; Williams, E L; Johnson, R A; Farsian, M; Reid, A; Skimmyhorn, J; Farone, M B

2006-12-01

Many species of bacteria pathogenic to humans, such as Legionella, are thought to have evolved in association with amoebal hosts. Several novel unculturable bacteria related to Legionella have also been found in amoebae, a few of which have been thought to be causes of nosocomial infections in humans. Because amoebae can be found in cooling towers, we wanted to know whether cooling tower environments might enhance the association between amoebae and bacterial pathogens of amoebae in order to identify potential "hot spots" for emerging human pathogens. To compare occurrence of infected amoebae in natural environments with those in cooling towers, 40 natural aquatic environments and 40 cooling tower samples were examined. Logistic regression analysis determined variables that were significant predictors of the occurrence of infected amoebae, which were found in 22 of 40 cooling tower samples but in only 3 of the 40 natural samples. An odds ratio showed that it is over 16 times more likely to encounter infected amoebae in cooling towers than in natural environments. Environmental data from cooling towers and natural habitats combined revealed dissolved organic carbon (DOC) and pH were predictors of the occurrence of the pathogens, however, when cooling tower data alone were analyzed, no variables accounted for the occurrence. Several bacteria have novel rRNA sequences, and most strains were not culturable outside of amoebae. Such pathogens of amoebae may spread to the environment via aerosols from cooling towers. Studies of emerging infectious diseases should strongly consider cooling towers as a source of amoeba-associated pathogens.

Characterization of a Quadrotor Unmanned Aircraft System for Aerosol-Particle-Concentration Measurements.

PubMed

Brady, James M; Stokes, M Dale; Bonnardel, Jim; Bertram, Timothy H

2016-02-02

High-spatial-resolution, near-surface vertical profiling of atmospheric chemical composition is currently limited by the availability of experimental platforms that can sample in constrained environments. As a result, measurements of near-surface gradients in trace gas and aerosol particle concentrations have been limited to studies conducted from fixed location towers or tethered balloons. Here, we explore the utility of a quadrotor unmanned aircraft system (UAS) as a sampling platform to measure vertical and horizontal concentration gradients of trace gases and aerosol particles at high spatial resolution (1 m) within the mixed layer (0-100 m). A 3D Robotics Iris+ autonomous quadrotor UAS was outfitted with a sensor package consisting of a two-channel aerosol optical particle counter and a CO2 sensor. The UAS demonstrated high precision in both vertical (±0.5 m) and horizontal positions (±1 m), highlighting the potential utility of quadrotor UAS drones for aerosol- and trace-gas measurements within complex terrain, such as the urban environment, forest canopies, and above difficult-to-access areas such as breaking surf. Vertical profiles of aerosol particle number concentrations, acquired from flights conducted along the California coastline, were used to constrain sea-spray aerosol-emission rates from coastal wave breaking.

76 FR 490 - Marking Meteorological Evaluation Towers

Federal Register 2010, 2011, 2012, 2013, 2014

2011-01-05

... of energy generation. Wind energy, converted into electrical energy by wind turbines, is widely... turbine or wind farm, companies erect METs. These towers are used to gather wind data necessary for site... if the targeted area represents a potential location for the installation of wind turbines...

NEON Data Products: Supporting the Validation of GCOS Essential Climate Variables

NASA Astrophysics Data System (ADS)

Petroy, S. B.; Fox, A. M.; Metzger, S.; Thorpe, A.; Meier, C. L.

2014-12-01

The National Ecological Observatory Network (NEON) is a continental-scale ecological observation platform designed to collect and disseminate data that contributes to understanding and forecasting the impacts of climate change, land use change, and invasive species on ecology. NEON will collect in-situ and airborne data over 60 sites across the US, including Alaska, Hawaii, and Puerto Rico. The NEON Biomass, Productivity, and Biogeochemistry protocols currently direct the collection of samples from distributed, gradient, and tower plots at each site, with sampling occurring either multiple times during the growing season, annually, or on three- or five-year centers (e.g. for coarse woody debris). These data are processed into a series of field-derived data products (e.g. Biogeochemistry, LAI, above ground Biomass, etc.), and when combined with the NEON airborne hyperspectral and LiDAR imagery, are used support validation efforts of algorithms for deriving vegetation characteristics from the airborne data. Sites are further characterized using airborne data combined with in-situ tower measurements, to create additional data products of interest to the GCOS community, such as Albedo and fPAR. Presented here are a summary of tower/field/airborne sampling and observation protocols and examples of provisional datasets collected at NEON sites that may be used to support the ongoing validation of GCOS Essential Climate Variables.

Controller and pilot error in airport operations : a review of previous research and analysis of safety data

DOT National Transportation Integrated Search

2001-01-01

The purpose of this study was to examine controller and pilot errors in airport operations to identify potential tower remedies. The : first part of the report contains a review of the literature of studies conducted of tower operationsand of efforts...

Impacts of chemical gradients on microbial community structure

PubMed Central

Chen, Jianwei; Hanke, Anna; Tegetmeyer, Halina E; Kattelmann, Ines; Sharma, Ritin; Hamann, Emmo; Hargesheimer, Theresa; Kraft, Beate; Lenk, Sabine; Geelhoed, Jeanine S; Hettich, Robert L; Strous, Marc

2017-01-01

Succession of redox processes is sometimes assumed to define a basic microbial community structure for ecosystems with oxygen gradients. In this paradigm, aerobic respiration, denitrification, fermentation and sulfate reduction proceed in a thermodynamically determined order, known as the ‘redox tower'. Here, we investigated whether redox sorting of microbial processes explains microbial community structure at low-oxygen concentrations. We subjected a diverse microbial community sampled from a coastal marine sediment to 100 days of tidal cycling in a laboratory chemostat. Oxygen gradients (both in space and time) led to the assembly of a microbial community dominated by populations that each performed aerobic and anaerobic metabolism in parallel. This was shown by metagenomics, transcriptomics, proteomics and stable isotope incubations. Effective oxygen consumption combined with the formation of microaggregates sustained the activity of oxygen-sensitive anaerobic enzymes, leading to braiding of unsorted redox processes, within and between populations. Analyses of available metagenomic data sets indicated that the same ecological strategies might also be successful in some natural ecosystems. PMID:28094795

Impacts of chemical gradients on microbial community structure.

PubMed

Chen, Jianwei; Hanke, Anna; Tegetmeyer, Halina E; Kattelmann, Ines; Sharma, Ritin; Hamann, Emmo; Hargesheimer, Theresa; Kraft, Beate; Lenk, Sabine; Geelhoed, Jeanine S; Hettich, Robert L; Strous, Marc

2017-04-01

Succession of redox processes is sometimes assumed to define a basic microbial community structure for ecosystems with oxygen gradients. In this paradigm, aerobic respiration, denitrification, fermentation and sulfate reduction proceed in a thermodynamically determined order, known as the 'redox tower'. Here, we investigated whether redox sorting of microbial processes explains microbial community structure at low-oxygen concentrations. We subjected a diverse microbial community sampled from a coastal marine sediment to 100 days of tidal cycling in a laboratory chemostat. Oxygen gradients (both in space and time) led to the assembly of a microbial community dominated by populations that each performed aerobic and anaerobic metabolism in parallel. This was shown by metagenomics, transcriptomics, proteomics and stable isotope incubations. Effective oxygen consumption combined with the formation of microaggregates sustained the activity of oxygen-sensitive anaerobic enzymes, leading to braiding of unsorted redox processes, within and between populations. Analyses of available metagenomic data sets indicated that the same ecological strategies might also be successful in some natural ecosystems.

AmeriFlux US-CZ4 Sierra Critical Zone, Sierra Transect, Subalpine Forest, Shorthair

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

Goulden, Michael

This is the AmeriFlux version of the carbon flux data for the site US-CZ4 Sierra Critical Zone, Sierra Transect, Subalpine Forest, Shorthair. Site Description - Half hourly data are available at https://www.ess.uci.edu/~california/. This site is one of four Southern Sierra Critical Zone Observatory flux towers operated along an elevation gradient (sites are USCZ1, USCZ2, USCZ3 and USCZ4). This site is a lodgepole pine subalpine woodland with no recent disturbance.

Molten salt power towers operating at 600–650 °C: Salt selection and cost benefits

DOE PAGES

Turchi, Craig S.; Vidal, Judith; Bauer, Matthew

2018-03-14

This analysis examines the potential benefit of adopting the supercritical carbon dioxide (sCO 2) Brayton cycle at 600-650 degrees C compared to the current state-of-the-art power tower operating a steam-Rankine cycle with solar salt at approximately 574 degrees C. The analysis compares a molten-salt power tower configuration using direct storage of solar salt (60:40 wt% sodium nitrate: potassium nitrate) or single-component nitrate salts at 600 degrees C or alternative carbonate- or chloride-based salts at 650 degrees C.

Molten salt power towers operating at 600–650 °C: Salt selection and cost benefits

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

Turchi, Craig S.; Vidal, Judith; Bauer, Matthew

This analysis examines the potential benefit of adopting the supercritical carbon dioxide (sCO 2) Brayton cycle at 600-650 degrees C compared to the current state-of-the-art power tower operating a steam-Rankine cycle with solar salt at approximately 574 degrees C. The analysis compares a molten-salt power tower configuration using direct storage of solar salt (60:40 wt% sodium nitrate: potassium nitrate) or single-component nitrate salts at 600 degrees C or alternative carbonate- or chloride-based salts at 650 degrees C.

ASSESSMENT OF DIOXIN INHALATION EXPOSURES AND POTENTIAL HEALTH IMPACTS FOLLOWING THE COLLAPSE OF THE WORLD TRADE CENTER TOWERS

EPA Science Inventory

In the days following the September 11, 2001, terrorist attack on New York City's World Trade Center (WTC) towers, EPA, other federal agencies, and New York City and New York State public health and environmental authorities initiated numerous air monitoring activities to better ...

Eddy-Covariance Observations and Large-Eddy-Simulations of Near-Shore Fluxes from Water Bodies

NASA Astrophysics Data System (ADS)

Bohrer, G.; Rey Sanchez, C.; Kenny, W.; Morin, T. H.

2017-12-01

Eddy covariance (EC) measurement techniques are increasingly used in the study of lakes and coastal ecosystems. The sharp water-shore transitions in energy forcing and surface roughness are challenging the validity of the EC approach at these sites. We discuss the results of two seasonal campaigns to measure CO2 and water-vapor fluxes in coastal environments - a small lake in Michigan, and the water over a coral reef in the Red, Sea, Israel. We show that in both environments, horizontal advection of CO2 and water vapor is responsible to a non-negligible component of the total flux to/from the water. We used a two-tower approach to measure fluxes from the water and from the shore and calculate the advection and flux divergence between the two. An empirical footprint model was used to filter the observations and keep only the times when interference from the shore-line transition is minimal. Observations of both vertical turbulent fluxes and advection were gapfilled with a neural-network model, based on their observed relationships with environmental forcing. Gap-filled observations were used to determine the seasonal net fluxes for the tow ecosystems. We used Large-Eddy Simulations (LES) to conduct a case study of airflow patterns associated with a small inland lake surrounded by forest (i.e. radius of lake only ten times the height of the forest). We combined LES outputs with scalar dispersion simulations to model potential biases in EC flux measurements due to the heterogeneity of surface fluxes and vertical advection. Our simulations show that the lake-to-forest transition can induce a non-zero vertical wind component, which will strongly affect the interpretation of wind and flux measurements. Furthermore, significant horizontal gradients of CO2 are generated by the forest carbon sink and lake carbon source, which are further transported by local roughness-induced circulation. We simulated six hypothetical flux tower locations along a downwind gradient at various heights and calculated the effects of both average vertical advection and average turbulent flux divergence of CO2 at each.

Simulating dynamics of δ13C of CO2 in the planetary boundary layer over a boreal forest region: covariation between surface fluxes and atmospheric mixing

NASA Astrophysics Data System (ADS)

Chen, Baozhang; Chen, Jing M.; Tans, Pieter P.; Huang, Lin

2006-11-01

Stable isotopes of CO2 contain unique information on the biological and physical processes that exchange CO2 between terrestrial ecosystems and the atmosphere. Ecosystem exchange of carbon isotopes with the atmosphere is correlated diurnally and seasonally with the planetary boundary layer (PBL) dynamics. The strength of this kind of covariation affects the vertical gradient of δ13C and thus the global δ13C distribution pattern. We need to understand the various processes involved in transport/diffusion of carbon isotope ratio in the PBL and between the PBL and the biosphere and the troposphere. In this study, we employ a one-dimensional vertical diffusion/transport atmospheric model (VDS), coupled to an ecosystem isotope model (BEPS-EASS) to simulate dynamics of 13CO2 in the PBL over a boreal forest region in the vicinity of the Fraserdale (FRD) tower (49°52'29.9''N, 81°34'12.3''W) in northern Ontario, Canada. The data from intensive campaigns during the growing season in 1999 at this site are used for model validation in the surface layer. The model performance, overall, is satisfactory in simulating the measured data over the whole course of the growing season. We examine the interaction of the biosphere and the atmosphere through the PBL with respect to δ13C on diurnal and seasonal scales. The simulated annual mean vertical gradient of δ13C in the PBL in the vicinity of the FRD tower was about 0.25‰ in 1999. The δ13C vertical gradient exhibited strong diurnal (29%) and seasonal (71%) variations that do not exactly mimic those of CO2. Most of the vertical gradient (96.5% +/-) resulted from covariation between ecosystem exchange of carbon isotopes and the PBL dynamics, while the rest (3.5%+/-) was contributed by isotopic disequilibrium between respiration and photosynthesis. This disequilibrium effect on δ13C of CO2 dynamics in PBL, moreover, was confined to the near surface layers (less than 350 m).

Analysis of Radiant Cooling System Configurations Integrated with Cooling Tower for Different Indian Climatic Zones

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

Mathur, Jyotirmay; Bhandari, Mahabir S; Jain, Robin

Radiant cooling system has proven to be a low energy consumption system for building cooling needs. This study describes the use of cooling tower in radiant cooling system to improve the overall system efficiency. A comprehensive simulation feasibility study of the application of cooling tower in radiant cooling system was performed for the fifteen cities in different climatic zones of India. It was found that in summer, the wet bulb temperature (WBT) of the different climatic zones except warm-humid is suitable for the integration of cooling tower with radiant cooling system. In these climates, cooling tower can provide on averagemore » 24 C to 27 C water In order to achieve the energy saving potential, three different configurations of radiant cooling system have been compared in terms of energy consumption. The different configurations of the radiant cooling system integrated with cooling tower are: (1) provide chilled water to the floor, wall and ceiling mounted tubular installation. (2) provide chilled water to the wall and ceiling mounted tabular installation. In this arrangement a separate chiller has also been used to provide chilled water at 16 C to the floor mounted tubular installation. (3) provide chilled water to the wall mounted tabular installation and a separate chiller is used to provide chilled water at 16 C to the floor and ceiling mounted tabular installation. A dedicated outdoor air system is also coupled for dehumidification and ventilation in all three configurations. A conventional all-air system was simulated as a baseline to compare these configurations for assessing the energy saving potential.« less

Engineering evaluation of magma cooling-tower demonstration at Nevada Power Company's Sunrise Station

NASA Astrophysics Data System (ADS)

1980-11-01

The Magma Cooling Tower (MCT) process utilizes a falling film heat exchanger integrated into an induced draft cooling tower to evaporate waste water. A hot water source such as return cooling water provides the energy for evaporation. Water quality control is maintained by removing potential scaling constituents to make concentrations of the waste water possible without scaling heat transfer surfaces. A pilot-scale demonstration test of the MCT process was performed from March 1979 through June 1979 at Nevada Power Company's Sunrise Station in Las Vegas, Nevada. The pilot unit extracted heat from the powerplant cooling system to evaporate cooling tower blowdown. Two water quality control methods were employed: makeup/sidestream softening and fluidized bed crystallization. The 11 week softening mode test was successful.

Evaluating the effectiveness of wildlife detection and observation technologies at a solar power tower facility

USGS Publications Warehouse

Diehl, Robert H.; Valdez, Ernest W.; Preston, Todd M.; Wellik, Mike J.; Cryan, Paul

2016-01-01

Solar power towers produce electrical energy from sunlight at an industrial scale. Little is known about the effects of this technology on flying animals and few methods exist for automatically detecting or observing wildlife at solar towers and other tall anthropogenic structures. Smoking objects are sometimes observed co-occurring with reflected, concentrated light (“solar flux”) in the airspace around solar towers, but the identity and origins of such objects can be difficult to determine. In this observational pilot study at the world’s largest solar tower facility, we assessed the efficacy of using radar, surveillance video, and insect trapping to detect and observe animals flying near the towers. During site visits in May and September 2014, we monitored the airspace surrounding towers and observed insects, birds, and bats under a variety of environmental and operational conditions. We detected and broadly differentiated animals or objects moving through the airspace generally using radar and near solar towers using several video imaging methods. Video revealed what appeared to be mostly small insects burning in the solar flux. Also, we occasionally detected birds flying in the solar flux but could not accurately identify birds to species or the types of insects and small objects composing the vast majority of smoking targets. Insect trapping on the ground was somewhat effective at sampling smaller insects around the tower, and presence and abundance of insects in the traps generally trended with radar and video observations. Traps did not tend to sample the larger insects we sometimes observed flying in the solar flux or found dead on the ground beneath the towers. Some of the methods we tested (e.g., video surveillance) could be further assessed and potentially used to automatically detect and observe flying animals in the vicinity of solar towers to advance understanding about their effects on wildlife.

Evaluating the Effectiveness of Wildlife Detection and Observation Technologies at a Solar Power Tower Facility.

PubMed

Diehl, Robert H; Valdez, Ernest W; Preston, Todd M; Wellik, Michael J; Cryan, Paul M

2016-01-01

Solar power towers produce electrical energy from sunlight at an industrial scale. Little is known about the effects of this technology on flying animals and few methods exist for automatically detecting or observing wildlife at solar towers and other tall anthropogenic structures. Smoking objects are sometimes observed co-occurring with reflected, concentrated light ("solar flux") in the airspace around solar towers, but the identity and origins of such objects can be difficult to determine. In this observational pilot study at the world's largest solar tower facility, we assessed the efficacy of using radar, surveillance video, and insect trapping to detect and observe animals flying near the towers. During site visits in May and September 2014, we monitored the airspace surrounding towers and observed insects, birds, and bats under a variety of environmental and operational conditions. We detected and broadly differentiated animals or objects moving through the airspace generally using radar and near solar towers using several video imaging methods. Video revealed what appeared to be mostly small insects burning in the solar flux. Also, we occasionally detected birds flying in the solar flux but could not accurately identify birds to species or the types of insects and small objects composing the vast majority of smoking targets. Insect trapping on the ground was somewhat effective at sampling smaller insects around the tower, and presence and abundance of insects in the traps generally trended with radar and video observations. Traps did not tend to sample the larger insects we sometimes observed flying in the solar flux or found dead on the ground beneath the towers. Some of the methods we tested (e.g., video surveillance) could be further assessed and potentially used to automatically detect and observe flying animals in the vicinity of solar towers to advance understanding about their effects on wildlife.

Evaluating the Effectiveness of Wildlife Detection and Observation Technologies at a Solar Power Tower Facility

PubMed Central

Diehl, Robert H.; Valdez, Ernest W.; Preston, Todd M.; Wellik, Michael J.; Cryan, Paul M.

2016-01-01

Solar power towers produce electrical energy from sunlight at an industrial scale. Little is known about the effects of this technology on flying animals and few methods exist for automatically detecting or observing wildlife at solar towers and other tall anthropogenic structures. Smoking objects are sometimes observed co-occurring with reflected, concentrated light (“solar flux”) in the airspace around solar towers, but the identity and origins of such objects can be difficult to determine. In this observational pilot study at the world’s largest solar tower facility, we assessed the efficacy of using radar, surveillance video, and insect trapping to detect and observe animals flying near the towers. During site visits in May and September 2014, we monitored the airspace surrounding towers and observed insects, birds, and bats under a variety of environmental and operational conditions. We detected and broadly differentiated animals or objects moving through the airspace generally using radar and near solar towers using several video imaging methods. Video revealed what appeared to be mostly small insects burning in the solar flux. Also, we occasionally detected birds flying in the solar flux but could not accurately identify birds to species or the types of insects and small objects composing the vast majority of smoking targets. Insect trapping on the ground was somewhat effective at sampling smaller insects around the tower, and presence and abundance of insects in the traps generally trended with radar and video observations. Traps did not tend to sample the larger insects we sometimes observed flying in the solar flux or found dead on the ground beneath the towers. Some of the methods we tested (e.g., video surveillance) could be further assessed and potentially used to automatically detect and observe flying animals in the vicinity of solar towers to advance understanding about their effects on wildlife. PMID:27462989

ASSESSMENT OF INHALATION EXPOSURES AND POTENTIAL HEALTH RISKS TO THE GENERAL POPULATION THAT RESULTED FROM THE COLLAPSE OF THE WORLD TRADE CENTER TOWERS

EPA Science Inventory

In the days following the collapse of the World Trade Center (WTC) towers on September 11, 2001 (9/11), the U.S. Environmental Protection Agency (EPA) initiated numerous air monitoring activities to better understand the ongoing impact of emissions from that disaster. Using these...

The Transmission Channel Tower Identification and Landslide Disaster Monitoring Based on Insar

NASA Astrophysics Data System (ADS)

Li, G.; Tan, Q.; Xie, C.; Fei, X.; Ma, X.; Zhao, B.; Ou, W.; Yang, Z.; Wang, J.; Fang, H.

2018-04-01

The transmission distance of transmission lines is long, the line affected by the diversity of climate and topography of the corridors of transmission lines, differences in regional geological structure conditions, variability of rock and soil types, and the complexity of groundwater. Under the influence of extreme weather conditions (ice-covered, strong wind, etc.) and sudden geological disasters (such as mudslides, flash floods, earthquakes, etc.), catastrophic damage and basic deformation problems of the tower foundations are prone, and even tower collapse accidents occur in severe cases, which affect the safe operation of transmission lines. Monitoring the deformation of power transmission towers and surrounding grounds, it is critical to ensuring the normal operation of transmission lines by assessing and controlling potential risks in advance. In this paper, using ALOS-2 PALSAR radar satellite data, differential interferometry was used to monitor surface deformation near the Sichuan Jinsu line transmission channel. The analysis found that a significant landslide hazard was found near the transmission channel tower in Yibin-Zhaotong section of Jinsu, Sichuan Province, the cumulative deformation reaches 9cm. The results of this paper can provide new monitoring means for safety monitoring of transmission towers.

Vertical profiles of ClNO2 at a remote terrestrial site: evidence of N2O5 dry deposition as a source of ClNO2?

NASA Astrophysics Data System (ADS)

McLaren, R.; Roberts, J. M.; Kercher, J. P.; Thornton, J. A.; Brown, S. S.; Edwards, P. M.; Young, C. J.; Dube, W. P.; Washenfelder, R. A.; Williams, E. J.; Holloway, J. S.; Bates, T. S.; Quinn, P.

2012-12-01

Recent observations of nitryl chloride (ClNO2) have suggested that this compound can accumulate to significant levels (several ppb) in the nocturnal boundary layer at night. Its photolytic loss the next day can be a significant source of chlorine atom radicals. The source of ClNO2 is largely thought to be the heterogeneous reaction of N2O5 with aerosol chloride, not just confined to coastal regions but also observed thousands of kilometers inland in urban areas. During the Uintah Basin Winter Ozone Study, we made measurements of ClNO2 by CIMS on a tower in a remote region of Utah. Levels of ClNO2 were surprisingly high at night (up to 2 ppb) even though sea salt aerosols were not present. Soils in the region were alkaline with high chloride content. To address the potential of N2O5 dry deposition as a source of ClNO2, we measured vertical profiles of ClNO2 from 1 to 12 m agl with a movable inlet. We observed negative gradients of ClNO2 and positive gradients of nitrate (a surrogate for N2O5), which suggests that dry deposition of N2O5 and reaction with Cl- in soils is a source of ClNO2 in this region.

Vertical profiles of ClNO2 measured in Utah: dry deposition of N2O5 as a source of ClNO2

NASA Astrophysics Data System (ADS)

McLaren, Robert; Roberts, James M.; Kercher, James P.; Thornton, Joel A.; Brown, Steven S.; Edwards, Peter M.; Young, Cora Y.; Dube, William P.; Washenfelder, Rebecca A.; Williams, Eric J.; Holloway, John S.; Bates, Timothy S.; Quinn, Patricia K.

2013-04-01

Several recent observations of nitryl chloride (ClNO2) have suggested that this compound can accumulate to significant levels (several ppb) in the nocturnal boundary layer at night. Its photolytic loss the next day can be a significant source of chlorine atom radicals. The source of ClNO2 is known to be the heterogeneous reaction of N2O5 with aerosol chloride, not just confined to coastal regions but also observed thousands of kilometers inland in urban areas. During the Uintah Basin Winter Ozone Study (2012), we made measurements of ClNO2 by CIMS on a tower in a remote region of Utah where intensive natural gas extraction operations via hydraulic fracturing were occurring. Levels of ClNO2 were surprisingly high at night (up to 2 ppb) even though coastal aerosols were not present. Soils in the region were alkaline with high chloride content. To address the potential of N2O5 dry deposition as a source of ClNO2, we measured vertical profiles of ClNO2 from 1 to 12 m agl with a movable inlet. We observed negative gradients of ClNO2 and positive gradients of N2O5, which suggest that dry deposition of N2O5 and reaction with soil chloride as a source of ClNO2.

Analysis the configuration of earthing system based on high-low and low-high soil structure

NASA Astrophysics Data System (ADS)

Ramani, A. N.; Ahmad, Abdul Rahman; Sulaima, M. F.; Nasir, M. N. M.; Ahmad, Arfah

2015-05-01

Each TNB transmission tower requires a tower footing resistance (TFR) with a lower grounding resistance value that depends on the transmission line voltage. For 132kV and 275kV tower, the TFR must less than 10Ω and 500kV tower must less than 5Ω. The TFR is changeable with variable factors such as soil resistivity. Low TFR provides essential protection to the fault such as lightning strike that may occur at any time. The fault current flow to the lowest resistance path and easily disperses to earth. Back flashover voltage across the insulator of transmission lines may occur when the TFR is high. The TFR is influenced by soil resistivity. There are three parameters affecting the soil resistivity; moisture content, salt content and temperature of the soil. High moisture content in soil will reduce the soil resistivity and resultant low TFR. Small scale moisture control by using Micro Reservoir (MR) irrigation with semi-permeable membranes have the power to offer the stable moisture in soil. By using osmosis concept, it is the process of net movement of water molecules from high potential water to lower potential water though a semi permeable membrane. The MR can withstand for 3 to 5 days without continuous water supply. The MR installed in the centre of the tower that contains a multiple parallel of electrode rods. The concentrated of electrode rods grounding configuration with a combination of MR will improve the TFR even at multilayer soil. As a result, MR gives a little improvement to TFR. The MR in area of concentrated electrode rod configuration to ensure the soil always wet and moist at all times. The changes in soil affect the tower-footing-resistance. The tower-footing-resistance measurement at afternoon is higher than at evening because of the temperature and moisture content in soil is change due to sun radiation.

Analysis the configuration of earthing system based on high-low and low-high soil structure

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

Ramani, A. N.; Ahmad, Abdul Rahman; Sulaima, M. F.

2015-05-15

Each TNB transmission tower requires a tower footing resistance (TFR) with a lower grounding resistance value that depends on the transmission line voltage. For 132kV and 275kV tower, the TFR must less than 10Ω and 500kV tower must less than 5Ω. The TFR is changeable with variable factors such as soil resistivity. Low TFR provides essential protection to the fault such as lightning strike that may occur at any time. The fault current flow to the lowest resistance path and easily disperses to earth. Back flashover voltage across the insulator of transmission lines may occur when the TFR is high.more » The TFR is influenced by soil resistivity. There are three parameters affecting the soil resistivity; moisture content, salt content and temperature of the soil. High moisture content in soil will reduce the soil resistivity and resultant low TFR. Small scale moisture control by using Micro Reservoir (MR) irrigation with semi-permeable membranes have the power to offer the stable moisture in soil. By using osmosis concept, it is the process of net movement of water molecules from high potential water to lower potential water though a semi permeable membrane. The MR can withstand for 3 to 5 days without continuous water supply. The MR installed in the centre of the tower that contains a multiple parallel of electrode rods. The concentrated of electrode rods grounding configuration with a combination of MR will improve the TFR even at multilayer soil. As a result, MR gives a little improvement to TFR. The MR in area of concentrated electrode rod configuration to ensure the soil always wet and moist at all times. The changes in soil affect the tower-footing-resistance. The tower-footing-resistance measurement at afternoon is higher than at evening because of the temperature and moisture content in soil is change due to sun radiation.« less

Thermal-Structural Analysis of PICA Tiles for Solar Tower Test

NASA Technical Reports Server (NTRS)

Agrawal, Parul; Empey, Daniel M.; Squire, Thomas H.

2009-01-01

Thermal protection materials used in spacecraft heatshields are subjected to severe thermal and mechanical loading environments during re-entry into earth atmosphere. In order to investigate the reliability of PICA tiles in the presence of high thermal gradients as well as mechanical loads, the authors designed and conducted solar-tower tests. This paper presents the design and analysis work for this tests series. Coupled non-linear thermal-mechanical finite element analyses was conducted to estimate in-depth temperature distribution and stress contours for various cases. The first set of analyses performed on isolated PICA tile showed that stresses generated during the tests were below the PICA allowable limit and should not lead to any catastrophic failure during the test. The tests results were consistent with analytical predictions. The temperature distribution and magnitude of the measured strains were also consistent with predicted values. The second test series is designed to test the arrayed PICA tiles with various gap-filler materials. A nonlinear contact method is used to model the complex geometry with various tiles. The analyses for these coupons predict the stress contours in PICA and inside gap fillers. Suitable mechanical loads for this architecture will be predicted, which can be applied during the test to exceed the allowable limits and demonstrate failure modes. Thermocouple and strain-gauge data obtained from the solar tower tests will be used for subsequent analyses and validation of FEM models.

Direct drive wind turbine

DOEpatents

Bywaters, Garrett Lee; Danforth, William; Bevington, Christopher; Stowell, Jesse; Costin, Daniel

2006-09-19

A wind turbine is provided that minimizes the size of the drive train and nacelle while maintaining the power electronics and transformer at the top of the tower. The turbine includes a direct drive generator having an integrated disk brake positioned radially inside the stator while minimizing the potential for contamination. The turbine further includes a means for mounting a transformer below the nacelle within the tower.

Direct drive wind turbine

DOEpatents

Bywaters, Garrett; Danforth, William; Bevington, Christopher; Jesse, Stowell; Costin, Daniel

2006-10-10

A wind turbine is provided that minimizes the size of the drive train and nacelle while maintaining the power electronics and transformer at the top of the tower. The turbine includes a direct drive generator having an integrated disk brake positioned radially inside the stator while minimizing the potential for contamination. The turbine further includes a means for mounting a transformer below the nacelle within the tower.

Direct drive wind turbine

DOEpatents

Bywaters, Garrett; Danforth, William; Bevington, Christopher; Stowell, Jesse; Costin, Daniel

2006-07-11

A wind turbine is provided that minimizes the size of the drive train and nacelle while maintaining the power electronics and transformer at the top of the tower. The turbine includes a direct drive generator having an integrated disk brake positioned radially inside the stator while minimizing the potential for contamination. The turbine further includes a means for mounting a transformer below the nacelle within the tower.

Direct drive wind turbine

DOEpatents

Bywaters, Garrett; Danforth, William; Bevington, Christopher; Jesse, Stowell; Costin, Daniel

2007-02-27

A wind turbine is provided that minimizes the size of the drive train and nacelle while maintaining the power electronics and transformer at the top of the tower. The turbine includes a direct drive generator having an integrated disk brake positioned radially inside the stator while minimizing the potential for contamination. The turbine further includes a means for mounting a transformer below the nacelle within the tower.

Influence of regional nighttime atmospheric regimes on canopy turbulence and gradients at a closed and open forest in mountain-valley terrain

DOE PAGES

Wharton, S.; Ma, S.; Baldocchi, D. D.; ...

2017-02-07

Stable stratification of the nocturnal lower boundary layer inhibits convective turbulence, such that turbulent vertical transfer of ecosystem carbon dioxide (CO 2), water vapor (H 2O) and energy is driven by mechanically forced turbulence, either from frictional forces near the ground or top of a plant canopy, or from shear generated aloft. The significance of this last source of turbulence on canopy flow characteristics in a closed and open forest canopy is addressed in this paper. We present micrometeorological observations of the lower boundary layer and canopy air space collected on nearly 200 nights using a combination of atmospheric lasermore » detection and ranging (lidar), eddy covariance (EC), and tower profiling instrumentation. Two AmeriFlux/Fluxnet sites in mountain-valley terrain in the Western U.S. are investigated: Wind River, a tall, dense conifer canopy, and Tonzi Ranch, a short, open oak canopy. On roughly 40% of nights lidar detected down-valley or downslope flows above the canopy at both sites. Nights with intermittent strong bursts of “top-down” forced turbulence were also observed above both canopies. The strongest of these bursts increased sub-canopy turbulence and reduced canopy virtual potential temperature (θv) gradient at Tonzi, but did not appear to change the flow characteristics within the dense Wind River canopy. At Tonzi we observed other times when high turbulence (via friction velocity, u*) was found just above the trees, yet CO2 and θv gradients remained large and suggested flow decoupling. These events were triggered by regional downslope flow. Lastly, a set of turbulence parameters is evaluated for estimating canopy turbulence mixing strength. The relationship between turbulence parameters and canopy θv gradients was found to be complex, although better agreement between the canopy θv gradient and turbulence was found for parameters based on the standard deviation of vertical velocity, or ratios of 3-D turbulence to mean flow, than for u*. These findings add evidence that the relationship between canopy turbulence, static stability, and canopy mixing is far from straightforward even within an open canopy.« less

Influence of regional nighttime atmospheric regimes on canopy turbulence and gradients at a closed and open forest in mountain-valley terrain

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

Wharton, S.; Ma, S.; Baldocchi, D. D.

Stable stratification of the nocturnal lower boundary layer inhibits convective turbulence, such that turbulent vertical transfer of ecosystem carbon dioxide (CO 2), water vapor (H 2O) and energy is driven by mechanically forced turbulence, either from frictional forces near the ground or top of a plant canopy, or from shear generated aloft. The significance of this last source of turbulence on canopy flow characteristics in a closed and open forest canopy is addressed in this paper. We present micrometeorological observations of the lower boundary layer and canopy air space collected on nearly 200 nights using a combination of atmospheric lasermore » detection and ranging (lidar), eddy covariance (EC), and tower profiling instrumentation. Two AmeriFlux/Fluxnet sites in mountain-valley terrain in the Western U.S. are investigated: Wind River, a tall, dense conifer canopy, and Tonzi Ranch, a short, open oak canopy. On roughly 40% of nights lidar detected down-valley or downslope flows above the canopy at both sites. Nights with intermittent strong bursts of “top-down” forced turbulence were also observed above both canopies. The strongest of these bursts increased sub-canopy turbulence and reduced canopy virtual potential temperature (θv) gradient at Tonzi, but did not appear to change the flow characteristics within the dense Wind River canopy. At Tonzi we observed other times when high turbulence (via friction velocity, u*) was found just above the trees, yet CO2 and θv gradients remained large and suggested flow decoupling. These events were triggered by regional downslope flow. Lastly, a set of turbulence parameters is evaluated for estimating canopy turbulence mixing strength. The relationship between turbulence parameters and canopy θv gradients was found to be complex, although better agreement between the canopy θv gradient and turbulence was found for parameters based on the standard deviation of vertical velocity, or ratios of 3-D turbulence to mean flow, than for u*. These findings add evidence that the relationship between canopy turbulence, static stability, and canopy mixing is far from straightforward even within an open canopy.« less

SENER molten salt tower technology. Ouarzazate NOOR III case

NASA Astrophysics Data System (ADS)

Relloso, Sergio; Gutiérrez, Yolanda

2017-06-01

NOOR III 150 MWe project is the evolution of Gemasolar (19.9 MWe) to large scale Molten Salt Tower plants. With more than 5 years of operational experience, Gemasolar lessons learned have been the starting point for the optimization of this technology, considered the leader of potential cost reduction in CSP. In addition, prototypes of plant key components (heliostat and receiver) were manufactured and thoroughly tested before project launch in order to prove the new engineering solutions adopted. The SENER proprietary technology of NOOR III will be applied in the next Molten Salt Tower plants that will follow in other countries, such as South Africa, Chile and Australia.

Dynamic analysis of horizontal axis wind turbine by thin-walled beam theory

NASA Astrophysics Data System (ADS)

Wang, Jianhong; Qin, Datong; Lim, Teik C.

2010-08-01

A mixed flexible-rigid multi-body mathematical model is applied to predict the dynamic performance of a wind turbine system. Since the tower and rotor are both flexible thin-walled structures, a consistent expression for their deformations is applied, which employs a successive series of transformations to locate any point on the blade and tower relative to an inertial coordinate system. The kinetic and potential energy terms of each flexible body and rigid body are derived for use in the Lagrange approach to formulate the wind turbine system's governing equation. The mode shapes are then obtained from the free vibration solution, while the distributions of dynamic stress and displacement of the tower and rotor are computed from the forced vibration response analysis. Using this dynamic model, the influence of the tower's stiffness on the blade tip deformation is studied. From the analysis, it is evident that the proposed model not only inherits the simplicity of the traditional 1-D beam element, but also able to provide detailed information about the tower and rotor response due to the incorporation of the flexible thin-walled beam theory.

Performance modeling and techno-economic analysis of a modular concentrated solar power tower with latent heat storage

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

Rea, Jonathan E.; Oshman, Christopher J.; Olsen, Michele L.

In this paper, we present performance simulations and techno-economic analysis of a modular dispatchable solar power tower. Using a heliostat field and power block three orders of magnitude smaller than conventional solar power towers, our unique configuration locates thermal storage and a power block directly on a tower receiver. To make the system dispatchable, a valved thermosyphon controls heat flow from a latent heat thermal storage tank to a Stirling engine. The modular design results in minimal balance of system costs and enables high deployment rates with a rapid realization of economies of scale. In this new analysis, we combinemore » performance simulations with techno-economic analysis to evaluate levelized cost of electricity, and find that the system has potential for cost-competitiveness with natural gas peaking plants and alternative dispatchable renewables.« less

Pay attention to reflux/feed entry design

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

Fleming, B.; Martin, G.R.; Hartman, E.L.

1996-01-01

Trays generally are forgiving pieces of equipment and can conceal the effects of poorly designed feed and reflux entries. When one tries to push a tower to its hydraulic limit, however, poor entry design can penalize the performance of the trays and result in a lower final capacity. Normally, new towers are not as susceptible to entry design problems as ones being revamped. This is because new towers usually have some degree of capacity oversizing.Standard design practices used for new columns having spare capacity, though, may not be suitable for revamped towers. In this article, the authors detail the basicmore » principles of reflux and feed entry design, good practices to follow, and poor practices to avoid. They also include a case study of a large-diameter light hydrocarbon splitter revamped with high capacity trays to illustrate the potential pitfalls associated with incorrectly designed reflux and feed entry arrangements.« less

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

Ma, Zhiwen; Eichman, Josh; Kurtz, Jennifer

This National Renewable Energy Laboratory industry-inspired Laboratory Directed Research and Development project evaluates the feasibility and economics of using fuel cell backup power systems in cell towers to provide grid services (e.g., balancing, ancillary services, demand response). The work is intended to evaluate the integration of thousands of under-utilized, clean, efficient, and reliable fuel cell systems that are already installed in cell towers for potential grid and ancillary services.

A multi-site analysis of random error in tower-based measurements of carbon and energy fluxes

Treesearch

Andrew D. Richardson; David Y. Hollinger; George G. Burba; Kenneth J. Davis; Lawrence B. Flanagan; Gabriel G. Katul; J. William Munger; Daniel M. Ricciuto; Paul C. Stoy; Andrew E. Suyker; Shashi B. Verma; Steven C. Wofsy; Steven C. Wofsy

2006-01-01

Measured surface-atmosphere fluxes of energy (sensible heat, H, and latent heat, LE) and CO2 (FCO2) represent the ``true?? flux plus or minus potential random and systematic measurement errors. Here, we use data from seven sites in the AmeriFlux network, including five forested sites (two of which include ``tall tower?? instrumentation), one grassland site, and one...

Applied Meteorology Unit (AMU) Quarterly Report First Quarter FY-14

NASA Technical Reports Server (NTRS)

Bauman, William Henry; Crawford, Winifred C.; Shafer, Jaclyn A.; Watson, Leela R.; Huddleston, Lisa L.; Decker, Ryan K.

2014-01-01

NASA's LSP and other programs at Vandenberg Air Force Base (VAFB) use wind forecasts issued by the 30th Operational Support Squadron (30 OSS) to determine if they need to limit activities or protect property such as a launch vehicle due to the occurrence of warning level winds at VAFB in California. The 30 OSS tasked the AMU to provide a wind forecasting capability to improve wind warning forecasts and enhance the safety of their customers' operations. This would allow 30 OSS forecasters to evaluate pressure gradient thresholds between pairs of regional observing stations to help determine the onset and duration of warning category winds. Development of such a tool will require that solid relationships exist between wind speed and the pressure gradient of one or more station pairs. As part of this task, the AMU will also create a statistical climatology of meteorological observations from the VAFB wind towers.

An attempt at estimating Paris area CO2 emissions from atmospheric concentration measurements

NASA Astrophysics Data System (ADS)

Bréon, F. M.; Broquet, G.; Puygrenier, V.; Chevallier, F.; Xueref-Rémy, I.; Ramonet, M.; Dieudonné, E.; Lopez, M.; Schmidt, M.; Perrussel, O.; Ciais, P.

2014-04-01

Atmospheric concentration measurements are used to adjust the daily to monthly budget of CO2 emissions from the AirParif inventory of the Paris agglomeration. We use 5 atmospheric monitoring sites including one at the top of the Eiffel tower. The atmospheric inversion is based on a Bayesian approach, and relies on an atmospheric transport model with a spatial resolution of 2 km with boundary conditions from a global coarse grid transport model. The inversion tool adjusts the CO2 fluxes (anthropogenic and biogenic) with a temporal resolution of 6 h, assuming temporal correlation of emissions uncertainties within the daily cycle and from day to day, while keeping the a priori spatial distribution from the emission inventory. The inversion significantly improves the agreement between measured and modelled concentrations. However, the amplitude of the atmospheric transport errors is often large compared to the CO2 gradients between the sites that are used to estimate the fluxes, in particular for the Eiffel tower station. In addition, we sometime observe large model-measurement differences upwind from the Paris agglomeration, which confirms the large and poorly constrained contribution from distant sources and sinks included in the prescribed CO2 boundary conditions These results suggest that (i) the Eiffel measurements at 300 m above ground cannot be used with the current system and (ii) the inversion shall rely on the measured upwind-downwind gradients rather than the raw mole fraction measurements. With such setup, realistic emissions are retrieved for two 30 day periods. Similar inversions over longer periods are necessary for a proper evaluation of the results.

Monitoring of biofilm-associated Legionella pneumophila on different substrata in model cooling tower system.

PubMed

Türetgen, Irfan; Cotuk, Aysin

2007-02-01

Cooling towers have the potential to develop infectious concentrations of Legionella pneumophila. Legionella counts increases where biofilm and warm water temperatures are present. In this study, biofilm associated L. pneumophila and heterotrophic bacteria were compared in terms of material dependence. Model cooling tower system was experimentally infected by L. pneumophila standard strain and monthly monitored. Different materials were tested for a period of 180 days. The lowest L. pneumophila and heterotrophic plate counts were measured on plastic polymers, whereas L. pneumophila and heterotrophic bacteria were accumulated rapidly on galvanized steel surfaces. It can be concluded that selection of plastic polymers, as a manufacturing material, are suitable for recirculating water systems.

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

Smith, C.; Brigmon, R.

Legionnaires disease is a pneumonia caused by the inhalation of the bacterium Legionella pneumophila. The majority of illnesses have been associated with cooling towers since these devices can harbor and disseminate the bacterium in the aerosolized mist generated by these systems. Historically, Savannah River Site (SRS) cooling towers have had occurrences of elevated levels of Legionella in all seasons of the year and in patterns that are difficult to predict. Since elevated Legionella in cooling tower water are a potential health concern a question has been raised as to the best control methodology. In this work we analyze available chemical,more » biological, and atmospheric data to determine the best method or key parameter for control. The SRS 4Q Industrial Hygiene Manual, 4Q-1203, 1 - G Cooling Tower Operation and the SRNL Legionella Sampling Program, states that 'Participation in the SRNL Legionella Sampling Program is MANDATORY for all operating cooling towers'. The resulting reports include L. pneumophila concentration information in cells/L. L. pneumophila concentrations >10{sup 7} cells/L are considered elevated and unsafe so action must be taken to reduce these densities. These remedial actions typically include increase biocide addition or 'shocking'. Sometimes additional actions are required if the problem persists including increase tower maintenance (e.g. cleaning). Evaluation of 14 SRS cooling towers, seven water quality parameters, and five Legionella serogroups over a three-plus year time frame demonstrated that cooling tower water Legionella densities varied widely though out this time period. In fact there was no one common consistent significant variable across all towers. The significant factors that did show up most frequently were related to suspended particulates, conductivity, pH, and dissolved oxygen, not chlorine or bromine as might be expected. Analyses of atmospheric data showed that there were more frequent significant elevated Legionella concentrations when the dew point temperature was high--a summertime occurrence. However, analysis of the three years of Legionella monitoring data of the 14 different SRS Cooling Towers demonstrated that elevated concentrations are observed at all temperatures and seasons. The objective of this study is to evaluate the ecology of L. pneumophila including serogroups and population densities, chemical, and atmospheric data, on cooling towers at SRS to determine whether relationships exist among water chemistry, and atmospheric conditions. The goal is to more fully understand the conditions which inhibit or encourage L. pneumophila growth and supply this data and associated recommendations to SRS Cooling Tower personnel for improved management of operation. Hopefully this information could then be used to help control L. pneumophila growth more effectively in SRS cooling tower water.« less

Aspects of cooling tower biocides and protozoa

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

Berk, S.G.; Ashburn, R.J.; Ting, R.S.

1998-12-31

Previous work has shown that certain cooling tower amoebae and ciliated protozoa are resistant to several cooling tower biocides, even at the manufacturer`s recommended dosages. For the present study, an Acunthumoeba species was isolated from a cooling tower in Australia. Suspensions of the trophozoites (feeding stages) were exposed to isothiazolones. Cysts were tested separately. The minimum lethal concentration (MLC) for trophozoites was between 31-62 ppm of the biocide product, which is slightly less than the MLC for an amoebae species from the United States; and cyst forms were twofold more resistant than those of the US species, with a MLCmore » of 62,500 ppm. A ciliate and an amoeba species were also exposed to bromochlorodimethylhydantoin. The MLC for the ciliate species was 1 ppm of the biocide product, and the MLC was 30--40 ppm for the amoeba trophozoites. Since amoebae can expel vesicles containing live Legionella, experiments were conducted to determine whether exposure of Acunthamoebu polyphugu to biocides influenced release of such potentially infectious particles. Vesicle release was not inhibited by any of the three biocides: quaternary ammonium compounds (QACs), isothiazolones, and a thiocarbamate compound. These results suggest that amoebae from various sources are resistant to recommended levels of biocides, and the amoebae may continue to release potentially infectious vesicles in the presence of biocides.« less

Aerodynamic roughness: A simple and alternative metric to detect the seasonality of canopy structure using flux-tower data

NASA Astrophysics Data System (ADS)

Chu, H.; Baldocchi, D. D.

2017-12-01

FLUXNET - the global network of eddy covariance tower sites provides valuable datasets of the direct and in situ measurements of fluxes and ancillary variables that are used across different disciplines and applications. Aerodynamic roughness (i.e., roughness length, zero plane displacement height) are one of the potential parameters that can be derived from flux-tower data and are crucial for the applications of land surface models and flux footprint models. As aerodynamic roughness are tightly associated with canopy structures (e.g., canopy height, leaf area), such parameters could potentially serve as an alternative metric for detecting the change of canopy structure (e.g., change of leaf areas in deciduous ecosystems). This study proposes a simple approach for deriving aerodynamic roughness from flux-tower data, and tests their suitability and robustness in detecting the seasonality of canopy structure. We run tests across a broad range of deciduous forests, and compare the seasonality derived from aerodynamic roughness (i.e., starting and ending dates of leaf-on period and peak-foliage period) against those obtained from remote sensing or in situ leaf area measurements. Our findings show aerodynamic roughness generally captures the timing of changes of leaf areas in deciduous forests. Yet, caution needs to be exercised while interpreting the absolute values of the roughness estimates.

An integrated system for the energy production and accumulation from renewable sources: a rural tower prototype

NASA Astrophysics Data System (ADS)

Di Francesco, Silvia; Petrozzi, Alessandro; Montesarchio, Valeria

2014-05-01

This research work presents the implementation of an architectural prototype aiming at the complete energy self-sufficiency through an integrated system based on renewable energy. It is suitable for historical buildings in rural areas, isolated but important from natural and architectonical point of view. In addition to the energy aspects, it is important to protect the impact in terms of land-use and environment. This idea is also especially powerful because in the rural countries there are many little building centers abandoned because they are devoid of a connection to the electric energy grid and methane piping. Thus, taking inspiration from dove towers, architectural typology widespread in central Italy, a virtual model has been developed as an integrated system for renewable energy production, storage and supply. While recovering the ancient tower, it is possible to design and assembly an integrated intelligent system, able to combine energy supply and demand: a new tower that should be flexible, efficient and replicable in other contexts as manufacturing, commercial and residential ones. The prototype has been applied to a real case of study, an ancient complex located in Umbria Region. The sources for electric production installed on the tower are photovoltaics, on the head and shaft of the tower, hydropower and a biomass gasifier providing thermal too. A tank at the head of the tower allows an available hydraulic potential energy, for the turbine at any time, to cover photovoltaic lacks, caused by sudden loss of production, for environmental causes. Conversely, photovoltaic peaks, otherwise unusable, can be used to reload the water from the receiving tank at the foot of the tower, up to the tank in the head. The same underground tank acts as a thermal flywheel to optimize the geothermal heat pumps for the heat and cold production. Keywords: hydropower, photovoltaics, dove tower.

Carbon dioxide effluxes and their environmental controls in sagebrush steppe ecosystems along an elevation gradient in the Reynolds Creek Critical Zone Observatory

NASA Astrophysics Data System (ADS)

Lohse, K. A.; Fellows, A.; Flerchinger, G. N.; Seyfried, M. S.

2017-12-01

The spatial and temporal variation of carbon dioxide effluxes and their environmental controls are poorly constrained in cold shrub steppe ecosystems. The objectives of this study were to 1) analyze environmental parameters in determining soil CO2 efflux, 2) assess the level of agreement between manual chambers and force diffusion (FD) soil CO2 efflux chambers, when both measurements are extrapolated across the growing season, and lastly to compare respiration fluxes to modeled ecosystem respiration fluxes. We installed FD chambers at four sites co-located with eddy covariance (EC) towers and soil moisture and temperature sensors along an elevation gradient in the Reynolds Creek Critical Zone Observatory in SW Idaho. FD chamber fluxes were collected continuously at 15-minute intervals. We sampled soil CO2 efflux with manual chambers at plant and interplant spaces in five plots at each site biweekly to monthly during the growing season. The sites included a Wyoming big sagebrush site, a low sagebrush site, a post-fire mountain big sagebrush site, and a mountain big sagebrush site located at elevations of 1425, 1680, 1808 and 2111 m. Climate variation followed the montane elevation gradient; mean annual precipitation (MAP) at the sites is 290, 337, 425, and 795 mm, respectively, and mean annual temperature is 8.9, 8.4, 6.1, 5.4°C. Automated force diffusion chambers detected large differences in carbon dioxide pulse dynamics along the elevation gradient. Growing season carbon dioxide fluxes were 3 times higher at the 425 mm MAP site compared than the lowest elevation sites at 290 and 337 MAP sites and >1.5 higher than the 795 mm MAP site over the same period. Manual fluxes showed similar seasonal patterns as FD chamber fluxes but often higher and greater spatial variability in fluxes than FD chamber fluxes. Plant and interplant flux differences were surprisingly similar, especially at higher elevations. Soil respiration ranged from 0.2-0.48 of ecosystem respiration suggesting that aboveground maintenance costs were relatively high at all of these sites. We conclude that coupled FD chamber, EC tower, and manual estimates hold promise in helping to partition and scale carbon fluxes from the plot to landscape scale.

Analysis of Wind Characteristics at United States Tall Tower Measurement Sites

NASA Astrophysics Data System (ADS)

Elliott, D.; Schwartz, M.; Scott, G.; Haymes, S.

2008-12-01

A major initiative of the U.S. Department of Energy (DOE) is to ensure that 20% of the country's electricity is produced by wind energy by the year 2030. An understanding of the boundary layer characteristics, especially at elevated heights greater than 80 meters (m) above the surface is a key factor for wind turbine design, wind plant layout, and identifying potential markets for advanced wind technology. The wind resource group at the DOE National Renewable Energy Laboratory is analyzing wind data collected at tall (80+ m) towers across the United States. The towers established by both public and private initiative, measure wind characteristics at multiple levels above the surface, with the highest measurement levels generally between 80 and 110 m. A few locations have measurements above 200 m. Measurements of wind characteristics over a wide range of heights are useful to: (1) characterize the local and regional wind climate; (2) validate wind resource estimates derived from numerical models; and (3) directly assess and analyze specific wind resource characteristics such as wind speed shear over the turbine blade swept area. The majority of the available public tall tower measurement sites are located between the Appalachian and Rocky Mountains. The towers are not evenly distributed among the states. The states with the largest number of towers include Indiana, Iowa, Missouri, and Kansas. These states have five or six towers collecting data. Other states with multiple tower locations include Texas, Oklahoma, Minnesota, and Ohio. The primary consideration when analyzing the data from the tall towers is identifying tower flow effects that not only can produce slightly misleading average wind speeds, but also significantly misleading wind speed shear values. In addition, the periods-of-record of most tall tower data are only one to two years in length. The short data collection time frame does not significantly affect the diurnal wind speed pattern though it does complicate analysis of seasonal wind patterns. The tall tower data analysis revealed some distinct regional features of wind shear climatology. For example, the wind shear exponent (alpha) at the towers in the Central Plains is generally between 0.15 and 0.25, greater than the commonly used 1/7 power law exponent value of 0.143. Another characteristic of Central Plains wind climatology was that winds from the south had alpha values of 0.2 to 0.3, while northerly winds had lower alpha values from 0.1 to 0.2. The wind resource at a particular tower is affected not only by the regional climatology but also by local conditions such as terrain, surface roughness, and structure of the lower boundary layer.

BOREAS TGB-1/TGB-3 Water Table and Peat Temperature Data over the NSA

NASA Technical Reports Server (NTRS)

Bubier, Jill L.; Comer, Neil; Moore, Tim R.; Hall, Forrest G. (Editor); Conrad, Sara K. (Editor)

2000-01-01

The BOREAS TGB-1 and TGB-3 teams collected several data sets that contributed to understanding the measured trace gas fluxes over sites in the NSA. This data set contains continuous and manual measurements of water level and air and soil temperatures at the four subsites within the NSA Tower Fen site complex. The measurements were taken to understand the thermal and hydrological gradients associated with each plant community present in the fen. Measurements were taken from May to September 1994 and May to October 1996. The data are provided in tabular ASCII files.

A field study of air flow and turbulent features of advection fog

NASA Technical Reports Server (NTRS)

Connell, J. D.

1979-01-01

The setup and initial operation of a set of specialized meteorological data collection hardware are described. To study the life cycle of advection fogs at a lake test site, turbulence levels in the fog are identified, and correlated with the temperature gradients and mean wind profiles. A meteorological tower was instrumented to allow multiple-level measurements of wind and temperature on a continuous basis. Additional instrumentation was: (1)hydrothermograph, (2)microbarograph, (3)transmissometers, and (4)a boundary layer profiler. Two types of fogs were identified, and important differences in the turbulence scales were noted.

Legionella species colonization in cooling towers: risk factors and assessment of control measures.

PubMed

Mouchtouri, Varvara A; Goutziana, Georgia; Kremastinou, Jenny; Hadjichristodoulou, Christos

2010-02-01

Cooling towers can be colonized by Legionella spp, and inhalation of aerosols generated by their operation may cause Legionnaires' disease in susceptible hosts. Environmental investigations of Legionnaires' disease outbreaks linked with cooling towers have revealed poorly maintained systems, lack of control measures, and failure of system equipment. The purpose of this study was to identify Legionella-contaminated cooling towers, identify risk factors for contamination, and assess the effectiveness of control measures. A total of 96 cooling towers of public buildings were registered and inspected, and 130 samples were collected and microbiologically tested. Microbiological test results were associated with characteristics of cooling towers, water samples, inspection results, and maintenance practices. Of the total 96 cooling towers examined, 47 (48.9%) were colonized by Legionella spp, and 22 (22.9%) required remedial action. A total of 65 samples (50.0%) were positive (> or = 500 cfu L(-1)), and 30 (23%) were heavily contaminated (> or = 10(4) cfu L(-1)). Of the 69 isolates identified, 55 strains (79.7.%) were L pneumophila. Legionella colonization was positively associated with the absence of training on Legionella control (relative risk [RR] = 1.66; P = .02), absence of regular Legionella testing (RR = 2.07: P = .002), absence of sunlight protection (RR = 1.63: P = .02), with samples in which the free residual chlorine level in the water sample was < 0.5 mg/L (RR = 2.23; P = .01), and with total plate count (P =.001). Colonization was negatively associated with chemical disinfection (RR = 0.2; P = .0003) and with the presence of a risk assessment and management plan (RR = 0.12; P = .0005). A statistically significant higher age (P =.01) was found in legionellae-positive cooling towers (median, 17 years; interquartile range [IQR] =5.0 to 26.0 years) compared with noncolonized cooling towers (median age, 6 years; IQR =1.0 to 13.5 years). After the 22 legionellae-positive cooling towers were disinfected with chlorine, 2 (9%) of them remained positive for Legionella spp with a concentration > or = 1000 cfu L(-1). Cooling towers can be heavily colonized by Legionella spp and thus present a potential risk for infection. This study demonstrates the importance of a risk assessment and management plan. Water chlorination effectively reduces legionellae contamination. Proper training of cooling tower operators is paramount. Copyright 2010 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Mosby, Inc. All rights reserved.

Legionella in Puerto Rico cooling towers

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

Negron-Alviro, A.; Perez-Suarez, I.; Hazen, T.C.

1988-12-31

Water samples from air conditioning cooling towers receiving different treatment protocols on five large municipal buildings in San Juan, Puerto Rico were assayed for various species and serogroups of Legionella spp. using direct immunofluorescence. Several water quality parameters were also measured with each sample. Guinea pigs were inoculated with water samples to confirm pathogenicity and recover viable organisms. Legionella pneumophila (1-6), L. bozemanii, L. micdadei, L. dumoffii, and L. gormanii were observed in at least one of the cooling towers. L. pneumophila was the most abundant species, reaching 10{sup 5} cells/ml, within the range that is considered potentially pathogenic tomore » humans. A significantly higher density of L. pneumophila was observed in the cooling tower water that was not being treated with biocides. Percent respiration (INT) and total cell activity (AODC), were inversely correlated with bacterial density. This study demonstrates that Legionella spp. are present in tropical air-conditioning cooling systems, and without continuous biocide treatment may reach densities that present a health risk.« less

Estimation of Regional Carbon Balance from Atmospheric Observations

NASA Astrophysics Data System (ADS)

Denning, S.; Uliasz, M.; Skidmore, J.

2002-12-01

Variations in the concentration of CO2 and other trace gases in time and space contain information about sources and sinks at regional scales. Several methods have been developed to quantitatively extract this information from atmospheric measurements. Mass-balance techniques depend on the ability to repeatedly sample the same mass of air, which involves careful attention to airmass trajectories. Inverse and adjoint techniques rely on decomposition of the source field into quasi-independent "basis functions" that are propagated through transport models and then used to synthesize optimal linear combinations that best match observations. A recently proposed method for regional flux estimation from continuous measurements at tall towers relies on time-mean vertical gradients, and requires careful trajectory analysis to map the estimates onto regional ecosystems. Each of these techniques is likely to be applied to measurements made during the North American Carbon Program. We have also explored the use of Bayesian synthesis inversion at regional scales, using a Lagrangian particle dispersion model driven by mesoscale transport fields. Influence functions were calculated for each hypothetical observation in a realistic diurnally-varying flow. These influence functions were then treated as basis functions for the purpose of separate inversions for daytime photosynthesis and 24-hour mean ecosystem respiration. Our results highlight the importance of estimating CO2 fluxes through the lateral boundaries of the model. Respiration fluxes were well constrained by one or two hypothetical towers, regardless of inflow fluxes. Time-varying assimilation fluxes were less well constrained, and much more dependent on knowledge of inflow fluxes. The small net difference between respiration and photosynthesis was the most difficult to determine, being extremely sensitive to knowledge of inflow fluxes. Finally, we explored the feasibility of directly incorporating mid-day concentration values measured at surface-layer flux towers in global inversions for regional surface fluxes. We found that such data would substantially improve the observational constraint on current carbon cycle models, especially if applied selectively to a well-designed subset of the current network of flux towers.

Parameter studies on the energy balance closure problem using large-eddy simulation

NASA Astrophysics Data System (ADS)

De Roo, Frederik; Banerjee, Tirtha; Mauder, Matthias

2017-04-01

The imbalance of the surface energy budget in eddy-covariance measurements is still a pending problem. A possible cause is the presence of land surface heterogeneity. Heterogeneities of the boundary layer scale or larger are most effective in influencing the boundary layer turbulence, and large-eddy simulations have shown that secondary circulations within the boundary layer can affect the surface energy budget. However, the precise influence of the surface characteristics on the energy imbalance and its partitioning is still unknown. To investigate the influence of surface variables on all the components of the flux budget under convective conditions, we set up a systematic parameter study by means of large-eddy simulation. For the study we use a virtual control volume approach, and we focus on idealized heterogeneity by considering spatially variable surface fluxes. The surface fluxes vary locally in intensity and these patches have different length scales. The main focus lies on heterogeneities of length scales of the kilometer scale and one decade smaller. For each simulation, virtual measurement towers are positioned at functionally different positions. We discriminate between the locally homogeneous towers, located within land use patches, with respect to the more heterogeneous towers, and find, among others, that the flux-divergence and the advection are strongly linearly related within each class. Furthermore, we seek correlators for the energy balance ratio and the energy residual in the simulations. Besides the expected correlation with measurable atmospheric quantities such as the friction velocity, boundary-layer depth and temperature and moisture gradients, we have also found an unexpected correlation with the temperature difference between sonic temperature and surface temperature. In additional simulations with a large number of virtual towers, we investigate higher order correlations, which can be linked to secondary circulations. In a companion presentation (EGU2017-2130) these correlations are investigated and confirmed with the help of micrometeorological measurements from the TERENO sites where the effects of landscape scale surface heterogeneities are deemed to be important.

Nocturnal Reversed Flows Above Parallel Ridges in Perdigão, Portugal

NASA Astrophysics Data System (ADS)

Krishnamurthy, R.; Fernando, H. J.; Leo, L. S.; Vassallo, D.; Hocut, C. M.; Creegan, E.; Rodriguez, C. V.; Palma, J. L.

2017-12-01

Prediction of topographically forced or induced wind events is extremely important for dispersion modeling and wind energy studies in complex terrain. To improve the current understanding of micro-scale processes over complex terrain, a large-scale field experiment was conducted in Perdigão, Portugal from May 1st, 2017 to June 15th, 2017. Measurements over a periodic valley were performed using 52 meteorological met-masts, 30 Doppler Lidars (scanning & vertical profilers), 2 tethered lifting systems and other remote sensing instruments (Sodar-rass, wind profilers & radiometer), and radiosondes were released every 6 hours over the period of study. The observations showed several cases of flow reversals confined to a thin layer of 70 - 100 m above the ridge under stably stratified conditions. These flow reversals were mostly observed during the lee wave formation over the periodic valley. It was observed that the flow reversal occurs predominantly under two atmospheric conditions: a) presence of large recirculation zones on the lee side of the hill causing a pressure gradient between the lee-side floor and the mountain ridge, and b) local change in the horizontal pressure gradient due to differential heating rates of the neighboring valley atmospheres. Microscale flow simulations could capture these observed flow reversals. Based on the network of tower instruments and remote sensing devices, the development, structure and occurrences of the flow reversals are being analyzed and quantified. Since these flow reversals are observed within the rotor swept area of modern wind turbines, they would drastically increase the fatigue loads on wind turbine blades. This presentation will include reversed flow observations from several synchronized scanning Doppler Lidars and meteorological towers and a theoretical framework for reverse flow over parallel valleys.

An attempt at estimating Paris area CO2 emissions from atmospheric concentration measurements

NASA Astrophysics Data System (ADS)

Bréon, F. M.; Broquet, G.; Puygrenier, V.; Chevallier, F.; Xueref-Remy, I.; Ramonet, M.; Dieudonné, E.; Lopez, M.; Schmidt, M.; Perrussel, O.; Ciais, P.

2015-02-01

Atmospheric concentration measurements are used to adjust the daily to monthly budget of fossil fuel CO2 emissions of the Paris urban area from the prior estimates established by the Airparif local air quality agency. Five atmospheric monitoring sites are available, including one at the top of the Eiffel Tower. The atmospheric inversion is based on a Bayesian approach, and relies on an atmospheric transport model with a spatial resolution of 2 km with boundary conditions from a global coarse grid transport model. The inversion adjusts prior knowledge about the anthropogenic and biogenic CO2 fluxes from the Airparif inventory and an ecosystem model, respectively, with corrections at a temporal resolution of 6 h, while keeping the spatial distribution from the emission inventory. These corrections are based on assumptions regarding the temporal autocorrelation of prior emissions uncertainties within the daily cycle, and from day to day. The comparison of the measurements against the atmospheric transport simulation driven by the a priori CO2 surface fluxes shows significant differences upwind of the Paris urban area, which suggests a large and uncertain contribution from distant sources and sinks to the CO2 concentration variability. This contribution advocates that the inversion should aim at minimising model-data misfits in upwind-downwind gradients rather than misfits in mole fractions at individual sites. Another conclusion of the direct model-measurement comparison is that the CO2 variability at the top of the Eiffel Tower is large and poorly represented by the model for most wind speeds and directions. The model's inability to reproduce the CO2 variability at the heart of the city makes such measurements ill-suited for the inversion. This and the need to constrain the budgets for the whole city suggests the assimilation of upwind-downwind mole fraction gradients between sites at the edge of the urban area only. The inversion significantly improves the agreement between measured and modelled concentration gradients. Realistic emissions are retrieved for two 30-day periods and suggest a significant overestimate by the AirParif inventory. Similar inversions over longer periods are necessary for a proper evaluation of the optimised CO2 emissions against independent data.

Bacterial community dynamics in a cooling tower with emphasis on pathogenic bacteria and Legionella species using universal and genus-specific deep sequencing.

PubMed

Pereira, Rui P A; Peplies, Jörg; Höfle, Manfred G; Brettar, Ingrid

2017-10-01

Cooling towers are the major source of outbreaks of legionellosis in Europe and worldwide. These outbreaks are mostly associated with Legionella species, primarily L. pneumophila, and its surveillance in cooling tower environments is of high relevance to public health. In this study, a combined NGS-based approach was used to study the whole bacterial community, specific waterborne and water-based bacterial pathogens, especially Legionella species, targeting the 16S rRNA gene. This approach was applied to water from a cooling tower obtained by monthly sampling during two years. The studied cooling tower was an open circuit cooling tower with lamellar cooling situated in Braunschweig, Germany. A highly diverse bacterial community was observed with 808 genera including 25 potentially pathogenic taxa using universal 16S rRNA primers. Sphingomonas and Legionella were the most abundant pathogenic genera. By applying genus-specific primers for Legionella, a diverse community with 85 phylotypes, and a representative core community with substantial temporal heterogeneity was observed. A high percentage of sequences (65%) could not be affiliated to an acknowledged species. L. pneumophila was part of the core community and the most abundant Legionella species reinforcing the importance of cooling towers as its environmental reservoir. Major temperature shifts (>10 °C) were the key environmental factor triggering the reduction or dominance of the Legionella species in the Legionella community dynamics. In addition, interventions by chlorine dioxide had a strong impact on the Legionella community composition but not on the whole bacterial community. Overall, the presented results demonstrated the value of a combined NGS approach for the molecular monitoring and surveillance of health related pathogens in man-made freshwater systems. Copyright © 2017 Elsevier Ltd. All rights reserved.

Constraints on Nitrous Oxide emissions within the US Corn Belt using tall tower observations and an Eulerian Modeling Approach

NASA Astrophysics Data System (ADS)

Chen, Z.; Griffis, T. J.; Lee, X.; Fu, C.; Dlugokencky, E. J.; Andrews, A. E.

2017-12-01

Mitigation of nitrous oxide (N2O) emissions requires a sound understanding of N2O production processes and a robust estimate of N2O budgets. It is critical to understand how emissions vary spatially and temporally, and how they are likely to change given future climate and land management decisions. To address these challenges we have coupled two models including WRF-Chem version 3.8.1 and CLM-GBC-CROP version 4.5 to simulate retrospective and future N2O emissions for the US Corn Belt. Using 7 years (2010-2016) of N2O mixing ratio data from 6 tall tower sites within the US Midwest, we ran the coupled model at a spatial resolution of 0.125o× 0.125o and tested and optimized the simulation of N2O emissions at hourly, seasonal, and inter-annual timescales. Our preliminary results indicate:1) The simulated tall tower mixing ratios for 6 tall towers were all significantly higher than the observations in the growing seasons, indicating a high bias of N2O emissions when using the default N2O production mechanisms in CLM. 2) Following the optimization of N2O production in CLM, the simulated tall tower mixing ratios were strongly correlated with the KCMP and WBI towers, and had moderate correlation with the BAO tower. Overall, the absolute biases in mixing ratios were relatively small. Our next step is to examine 7 years of simulations to assess the spatiotemporal variations of direct and indirect emissions within the US Corn Belt to help identify potential N2O hotspots and hot moments.

Characterizing the seasonal cycle and vertical structure of ozone in Paris, France using four years of ground based LIDAR measurements in the lowermost troposphere

NASA Astrophysics Data System (ADS)

Klein, Amélie; Ancellet, Gérard; Ravetta, François; Thomas, Jennie L.; Pazmino, Andrea

2017-10-01

Systematic ozone LIDAR measurements were completed during a 4 year period (2011-2014) in Paris, France to study the seasonal variability of the vertical structure of ozone in the urban boundary layer. In addition, we use in-situ measurements from the surface air quality network that is located in Paris (AIRPARIF). Specifically, we use ozone and NO2 measurements made at two urban stations: Paris13 (60 m ASL) and the Eiffel Tower (310 m ASL) to validate and interpret the LIDAR profiles. Remote sensed tropospheric NO2 integrated columns from the SAOZ instrument located in Paris are also used to interpret ozone measurements. Comparison between ozone LIDAR measurements averaged from 250 m to 500 m and the Eiffel Tower in-situ measurements shows that the accuracy of the LIDAR (originally ±14 μg·m-3) is significantly improved (±7 μg·m-3) when a small telescope with a wide angular aperture is used. Results for the seasonal cycle of the ozone vertical gradient are found to be similar using two methods: (1) measured differences between AIRPARIF stations with measurements at 60 m ASL and 310 m ASL and (2) using LIDAR profiles from 300 m to the top of the Planetary Boundary Layer (PBL). Ozone concentrations measured by the LIDAR increase with altitude within the PBL, with a steeper gradient in winter (60 μg·m-3·km-1) and a less strong gradient in summer (20 μg·m-3·km-1). Results show that in winter, there is a sharp positive gradient of ozone at the surface, which is explained by ozone titration by NO combined with increased atmospheric stability in winter. In the afternoon during summer, photochemistry and vertical mixing are large enough to compensate for ozone titration near the surface, where NOx is emitted, and there is no gradient in ozone observed. In contrast, in the summer during the morning, ozone has a sharper positive vertical gradient similar to the winter values. Comparison of the vertically averaged ozone concentrations up to (0-3 km) and urban layer (0-310 m) ozone concentrations shows that the ratio between these two quantities is the largest in summer (86%) and the lowest in winter (49%). We conclude that satellite measurements that represent the 0-3 km integrated ozone column are not necessarily a good proxy for surface ozone and may lead to incorrect conclusions about the surface ozone seasonal variability. The ratio between the urban layer NO2 average concentration and the boundary layer NO2 average concentration obtained from SAOZ NO2 tropospheric columns is always less than 50%, meaning NO2 does not decrease linearly in the PBL, but with a sharper decrease close to the surface.

Using Distributed Temperature Sensing for measuring vertical temperature profiles and air temperature variance in the roughness sublayer above a forest canopy

NASA Astrophysics Data System (ADS)

Schilperoort, B.; Coenders, M.; Savenije, H. H. G.

2017-12-01

In recent years, the accuracy and resolution of Distributed Temperature Sensing (DTS) machines has increased enough to expand its use in atmospheric sciences. With DTS the temperature of a fiber optic (FO) cable can be measured with a high frequency (1 Hz) and high resolution (0.30 m), for cable lengths up to kilometers. At our measurement site, a patch of 26 to 30 m tall Douglas Fir in mixed forest, we placed FO cables vertically along a 48 m tall flux tower. This gives a high resolution vertical temperature profile above, through, and below the canopy. By using a `bare' FO cable, with a diameter of 0.25 mm, we are able to measure variations in air temperature at a very small timescale, and are able to measure a vertical profile of the air temperature variance. The vertical temperature profiles can be used to study the formation of the stable boundary layer above and in the canopy at a high resolution. It also shows that a stable layer can develop below the canopy, which is not limited to night time conditions but also occurs during daytime. The high frequency measurements can be used to study the gradient of the variance of air temperature over the height. To study how the flux tower itself affects temperature variance measurements, the `bare' FO cable can be placed horizontally under a support structure away from the flux tower. Lastly, by using the hot-wire anemometer principle with DTS, the measurements can be expanded to also include vertical wind profile.

Snowpack Chemistry of Reactive Gases at Station Concordia, Antarctica

NASA Astrophysics Data System (ADS)

Helmig, Detlev; Mass, Alex; Hueber, Jacques; Fain, Xavier; Dommergue, Aurelien; Barbero, Albane; Savarino, Joel

2013-04-01

During December 2012 a new experiment for the study of snow photochemical processes and surface gas exchange was installed at Dome Concordia, Antarctica. The experiment consists of two sampling manifolds ('snow tower') which facilitate the withdrawal of interstitial firn air from four depths in the snowpack and from above the surface. One of these snow towers can be shaded for investigation of the dependency of snow chemistry on solar radiation. A nearby 12 m meteorological tower facilitates above surface turbulence and trace gas gradient measurements. Temperature profiles and UV and IR light penetration are monitored in the snowpack. Air samples are directed through sampling lines to a nearby underground laboratory that houses the experiment control system and gas monitors. The system is fully automated, sampling gases from the array of inlet ports sequentially, and is intended to be operated continuously for a full annual cycle. The computerized control system can be accessed remotely for data retrieval and quality control and for configuring experimental details. Continuous gas measurements include ozone, nitrogen oxides, methane, carbon monoxide, and gaseous elemental mercury. Whole air samples were sampled on four occasions for volatile organic compound analysis. The objective of this research is the study of the year-round snowpack gas chemistry and its dependency on snowpack and above surface physical and environmental conditions. A particular emphasis will be the investigation of the effects of increased UV radiation during the occurrence of the stratospheric ozone hole. We will present the conceptual design of the experiment and data examples from the first three months of the experiment.

Influence of strike object grounding on close lightning electric fields

NASA Astrophysics Data System (ADS)

Baba, Yoshihiro; Rakov, Vladimir A.

2008-06-01

Using the finite difference time domain (FDTD) method, we have calculated vertical electric field Ez, horizontal (radial) electric field Eh, and azimuthal magnetic field Hϕ produced on the ground surface by lightning strikes to 160-m- and a 553-m-high conical strike objects representing the Peissenberg tower (Germany) and the CN Tower (Canada), respectively. The fields were computed for a typical subsequent stroke at distances d' from the bottom of the object ranging from 5 to 100 m for the 160-m tower and from 10 to 300 m for the 553-m tower. Grounding of the 160-m object was assumed to be accomplished by its underground basement represented by a 10-m-radius and 8-m-long perfectly conducting cylinder with or without a reference ground plane located 2 m below. The reference ground plane simulates, to some extent, a higher-conducting ground layer that is expected to exist below the water table. The configuration without reference ground plane actually means that this plane is present, but is located at an infinitely large depth. Grounding of the 553-m object was modeled in a similar manner but in the absence of reference ground plane only. In all cases considered, waveforms of Eh and Hϕ are not much influenced by the presence of strike object, while waveforms of Ez are. Waveforms of Ez are essentially unipolar (as they are in the absence of strike object) when the ground conductivity σ is 10 mS/m (the equivalent transient grounding impedance is several ohms) or greater. Thus, for the CN Tower, for which σ ≥ 10 mS/m, the occurrence of Ez polarity change is highly unlikely. For the 160-m tower and for σ = 1 and 0.1 mS/m, waveforms of Ez become bipolar (exhibit polarity change) at d' ≤ 10 m and d' ≤ 50 m, respectively, regardless of the presence of the reference ground plane. The corresponding equivalent transient grounding impedances are about 30 and 50 Ω in the absence of the reference ground plane and smaller than 10 Ω in the presence of the reference ground plane. The source of opposite polarity Ez is the potential rise at the object base (at the air/ground interface) relative to the reference ground plane. For a given grounding electrode geometry, the strength of this source increases with decreasing σ, provided that the grounding impedance is linear. Potential rises at the strike object base for σ = 1 and 0.1 mS/m are some hundreds of kilovolts, which is sufficient to produce electrical breakdown from relatively sharp edges of the basement over a distance of several meters (or more) along the ground surface. The resultant ground surface arcs will serve to reduce the equivalent grounding impedance and, hence, potential rise. Therefore, the polarity change of Ez near the Peissenberg tower, for which σ is probably about 1 mS/m, should be a rare phenomenon, if it occurs at all. The equivalent transient grounding impedance of the cylindrical basement is similar to that of a hemispherical grounding electrode of the same radius. For the 160-m tower and for hemispherical grounding electrode, the transient grounding impedance is higher than its dc grounding resistance for σ = 10 and 1 mS/m, but lower for σ = 0.1 mS/m. For the 553-m tower, the transient grounding impedance of hemispherical electrode is equal to or larger than its dc resistance for all values of σ considered.

Ore controls in the Charters Towers goldfield, NE Australia: Constraints from geological, geophysical and numerical analyses

USGS Publications Warehouse

Kreuzer, O.P.; Blenkinsop, T.G.; Morrison, R.J.; Peters, S.G.

2007-01-01

The approach taken in this paper, namely synthesising a wealth of previous information with new data and a genetic model, in combination with integrated numerical analyses, led to new insights into the geological controls on the localisation of auriferous veins and residual prospectivity of the Charters Towers goldfield, NE Australia. The method also has implications for the assessment of other "mature" goldfields worldwide. Despite a number of different ore controls having operated within the Charters Towers goldfield, the controlling factors can be linked to a single genetic model for orogenic, granitoid-hosted lode-gold mineralisation in a brittle deformation regime (D4) of NE-SW to NNE-SSW shortening, under conditions of supralithostatic fluid pressure and low stress difference. Spatial autocorrelation results suggest district-scale alignment of the auriferous veins parallel to and overlapping with the ESE-WNW- to E-W-striking Charters Towers-Ravenswood lineament, a major crustal boundary in the basement to the Ravenswood batholith. At the camp-scale, auriferous veins have abundance and proximity relationships with NW-SE-, NNW-SSE-, NE-SW- and ENE-WSW-oriented lineaments, suggesting that structures that controlled gold deposition in one camp did not necessarily control mineralisation in other camps. Fractal dimensions obtained with the box-counting method range from 1.02 to 1.10, whereas veins in the Charters Towers City camp are characterised by a significantly higher fractal dimension of 1.28. This discrepancy may be taken to imply that most or all outcropping and near-surface deposits within the Charters Towers City camp have been found and that new discoveries are more likely to occur at greater levels of depth, or outside the boundaries of this camp. The new understanding has implications for the assessment of the residual prospectivity of the Charters Towers goldfield, where large areas of prospective rock types and structures (e.g., approximately 40% of the Charters Towers-Ravenswood lineament) are hidden under cover. This parameter space was inaccessible to the historic prospectors and has received relatively little attention from recent explorers. The following steps are suggested for the development of a targeting strategy for lode-gold exploration in areas of the goldfield under cover: (1) identify from geological and geophysical data the ENE-WSW (?? 15??) and NNW-SSE (?? 15??) striking structures and geological boundaries within a 20-km-wide corridor parallel to and centred upon the Charters Towers-Ravenswood lineament, the potential control on gold deposit distribution at the regional- to district-scale, (2) interpret from geological and geophysical data the distribution of pre-Middle Devonian granitoids within these areas that are the preferred host rocks of the payable gold deposits, (3) deduce from geophysical data the ENE-WSW (?? 15??) and NNW-SSE (?? 15??) striking structures that cut or bound the intrusions identified in step 2, (4) locate segments along the structures identified in step 3 that deviate most from the geometry of a straight line (e.g., potential bends or splays) and/or intersect other structures or geological contacts, or both, and (5) define and rank potential targets within the prospective areas identified in step 4 and systematically test the best ones. ?? 2006 Elsevier B.V. All rights reserved.

Flux agreement above a Scots pine plantation

NASA Astrophysics Data System (ADS)

Gay, L. W.; Vogt, R.; Bernhofer, Ch.; Blanford, J. H.

1996-03-01

The surface energy exchange of 12m high Scots pine plantation at Hartheim, Germany, was measured with a variety of methods during a 11-day period of fine weather in mid-May 1992. Net radiation and rate of thermal storage were measured with conventional net radiometers, soil heat flux discs and temperature-based storage models. The turbulent fluxes discussed in this report were obtained with an interchanging Bowen ratio energy budget system (BREB, at 14 m), two one-propeller eddy correlation systems (OPEC systems 1 and 2 at 17m), a 1-dimensional sonic eddy correlation system (SEC system 3) at 15 m, all on one “low” tower, and a 3-dimensional sonic eddy correlation system (SEC system 22) at 22 m on the “high” tower that was about 46 m distant. All systems measured sensible and latent heat (H and LE) directly, except for OPEC systems 1 and 2 which estimated LE as a residual term in the surface energy balance. Closure of turbulent fluxes from the two SEC systems was around 80% for daytime and 30% for night, with closure of 1-dimensional SEC system 3 exceeding that of 3-dimensional SEC system 22. The night measurements of turbulent fluxes contained considerable uncertainty, especially with the BREB system where measured gradients often yielded erroneous fluxes due to problems inherent in the method (i.e., computational instability as Bowen's ratio approaches -1). Also, both eddy correlation system designs (OPEC and SEC) appeared to underestimate |H| during stable conditions at night. In addition, both sonic systems (1- and 3-dimensional) underestimated |LE| during stable conditions. The underestimate of |H| at night generated residual estimates of OPEC LE containing a “phantom dew” error that erroneously decreased daily LE totals by about 10 percent. These special night problems are circumvented here by comparing results for daytime periods only, rather than for full days. To summarize, turbulent fluxes on the low tower from OPEC system 2 and the adjacent SEC system 3 were in reasonable agreement, while the BREB system appeared to overestimate H and underestimate LE; H and LE measured by SEC system 22 on the high tower were lower than from OPEC and SEC3 on the low tower. The turbulent flux measurements tended to converge, but the data exhibit unexplained differences between days, between systems, and between locations.

Estimation of tropical forest canopy temperatures, thermal response numbers, and evapotranspiration using an aircraft-based thermal sensor

NASA Technical Reports Server (NTRS)

Luvall, Jeffrey C.; Lieberman, Diana; Lieberman, Milton; Hartshorn, Gary S.; Peralta, Rodolfo

1990-01-01

Thermal infrared Multispectral Scanner (TIMS) data were collected at a resolution of 5 to 10 m from a tropical rain forest over an elevation gradient from 35 to 2700 m in the Braulio Carrillo National Park in Costa Rica. Flight lines were repeated with a 15 to 30 minute time difference for measurement of forest canopy thermal response over time. Concurrent radiosonde measurements of atmospheric profiles of air temperature and moisture provided inputs to LOWTRAN6 for atmospheric radiance corrections of the TIMS data. Techniques for using calibrated aircraft-based thermal scanner data to examine tropical forest canopy thermal properties are described. Forest canopy temperature changes over time assessed between repeated, duplicated flight lines were combined with estimates of surface radiative energy measurements from towers above the forest canopy to determine temperature spatial variability, calculate Thermal Response Numbers (TRN), and estimate evapotranspiration along the elevation gradient from selected one hectare forest inventory plots.

DIME Participant Builds a Potential Drop Tower Candidate

NASA Technical Reports Server (NTRS)

2002-01-01

A student assembles a Lego (TM) Challenge device designed to operate in the portable drop tower demonstrator as part of the second Dropping in a Microgravity Environment (DIME) competition held April 23-25, 2002, at NASA's Glenn Research Center. Competitors included two teams from Sycamore High School, Cincinnati, OH, and one each from Bay High School, Bay Village, OH, and COSI Academy, Columbus, OH. DIME is part of NASA's education and outreach activities. Details are on line at http://microgravity.grc.nasa.gov/DIME_2002.html.

AmeriFlux US-CZ2 Sierra Critical Zone, Sierra Transect, Ponderosa Pine Forest, Soaproot Saddle

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

Goulden, Michael

This is the AmeriFlux version of the carbon flux data for the site US-CZ2 Sierra Critical Zone, Sierra Transect, Ponderosa Pine Forest, Soaproot Saddle. Site Description - Half hourly data are available at https://www.ess.uci.edu/~california/. This site is one of four Southern Sierra Critical Zone Observatory flux towers operated along an elevation gradient (sites are USCZ1, USCZ2, USCZ3 and USCZ4). This site is an oak/pine forest, with occasional thinning and wildfire, a prescribed understory burn ~2012, and severe drought and ~80% canopy mortality in 2011-15

AmeriFlux US-CZ3 Sierra Critical Zone, Sierra Transect, Sierran Mixed Conifer, P301

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

Goulden, Michael

This is the AmeriFlux version of the carbon flux data for the site US-CZ3 Sierra Critical Zone, Sierra Transect, Sierran Mixed Conifer, P301. Site Description - Half hourly data are available at https://www.ess.uci.edu/~california/. This site is one of four Southern Sierra Critical Zone Observatory flux towers operated along an elevation gradient (sites are USCZ1, USCZ2, USCZ3 and USCZ4). This site is a pine/fir forest; it historically experienced logging and wildfire, was thinned in ~2012, and experienced severe drought and ~20% canopy mortality in 2011-15.

LCOE reduction potential of parabolic trough and solar tower CSP technology until 2025

NASA Astrophysics Data System (ADS)

Dieckmann, Simon; Dersch, Jürgen; Giuliano, Stefano; Puppe, Michael; Lüpfert, Eckhard; Hennecke, Klaus; Pitz-Paal, Robert; Taylor, Michael; Ralon, Pablo

2017-06-01

Concentrating Solar Power (CSP), with an installed capacity of 4.9 GW by 2015, is a young technology compared to other renewable power generation technologies. A limited number of plants and installed capacity in a small challenging market environment make reliable and transparent cost data for CSP difficult to obtain. The International Renewable Energy Agency (IRENA) and the DLR German Aerospace Center gathered and evaluated available cost data from various sources for this publication in order to yield transparent, reliable and up-to-date cost data for a set of reference parabolic trough and solar tower plants in the year 2015 [1]. Each component of the power plant is analyzed for future technical innovations and cost reduction potential based on current R&D activities, ongoing commercial developments and growth in market scale. The derived levelized cost of electricity (LCOE) for 2015 and 2025 are finally contrasted with published power purchase agreements (PPA) of the NOOR II+III power plants in Morocco. At 7.5% weighted average cost of capital (WACC) and 25 years economic life time, the levelized costs of electricity for plants with 7.5 (trough) respectively 9 (tower) full-load hours thermal storage capacity decrease from 14-15 -ct/kWh today to 9-10 -ct/kWh by 2025 for both technologies at direct normal irradiation of 2500 kWh/(m².a). The capacity factor increases from 41.1% to 44.6% for troughs and from 45.5% to 49.0% for towers. Financing conditions are a major cost driver and offer potential for further cost reduction with the maturity of the technology and low interest rates (6-7 - ct/kWh for 2% WACC at 2500 kWh/(m2.a) in 2025).

Distribution and spatial variation of hydrothermal faunal assemblages at Lucky Strike (Mid-Atlantic Ridge) revealed by high-resolution video image analysis

NASA Astrophysics Data System (ADS)

Cuvelier, Daphne; Sarrazin, Jozée; Colaço, Ana; Copley, Jon; Desbruyères, Daniel; Glover, Adrian G.; Tyler, Paul; Serrão Santos, Ricardo

2009-11-01

Whilst the fauna inhabiting hydrothermal vent structures in the Atlantic Ocean is reasonably well known, less is understood about the spatial distributions of the fauna in relation to abiotic and biotic factors. In this study, a major active hydrothermal edifice (Eiffel Tower, at 1690 m depth) on the Lucky Strike vent field (Mid-Atlantic Ridge (MAR)) was investigated. Video transects were carried out by ROV Victor 6000 and complete image coverage was acquired. Four distinct assemblages, ranging from dense larger-sized Bathymodiolus mussel beds to smaller-sized mussel clumps and alvinocaridid shrimps, and two types of substrata were defined based on high definition photographs and video imagery. To evaluate spatial variation, faunal distribution was mapped in three dimensions. A high degree of patchiness characterizes this 11 m high sulfide structure. The differences observed in assemblage and substratum distribution were related to habitat characteristics (fluid exits, depth and structure orientation). Gradients in community structure were observed, which coincided with an increasing distance from the fluid exits. A biological zonation model for the Eiffel Tower edifice was created in which faunal composition and distribution can be visually explained by the presence/absence of fluid exits.

Atmospheric stability analysis over statically and dynamically rough surfaces

NASA Astrophysics Data System (ADS)

Maric, Emina; Metzger, Meredith; Singha, Arindam; Sadr, Reza

2011-11-01

The ratio of buoyancy flux to turbulent kinetic energy production in the atmospheric surface layer is investigated experimentally for air flow over two types of surfaces characterized by static and dynamic roughness. In this study, ``static'' refers to the time-invariant nature of naturally-occurring roughness over a mud/salt playa; while, ``dynamic'' refers to the behavior of water waves along an air-water interface. In both cases, time-resolved measurements of the momentum and heat fluxes were acquired from synchronized 3D sonic anemometers mounted on a vertical tower. Field campaigns were conducted at two sites, representing the ``statically'' and ``dynamically'' rough surfaces, respectively: (1) the SLTEST facility in Utah's western desert, and (2) the new Doha airport in Qatar under construction along the coast of the Persian Gulf. Note, at site 2, anemometers were located directly above the water by extension from a tower secured to the end of a 1 km-long pier. Comparisons of the Monin-Obukhov length, flux Richardson number, and gradient Richardson number are presented, and discussed in the context of the observed evolution of the turbulent spectra in response to diurnal variations of atmospheric stability. Supported by the Qatar National Research Fund.

Marangoni bubble motion in zero gravity. [Lewis zero gravity drop tower

NASA Technical Reports Server (NTRS)

Thompson, R. L.; Dewitt, K. J.

1979-01-01

It was shown experimentally that the Marangoni phenomenon is a primary mechanism for the movement of a gas bubble in a nonisothermal liquid in a low gravity environment. A mathematical model consisting of the Navier-Stokes and thermal energy equations, together with the appropriate boundary conditions for both media, is presented. Parameter perturbation theory is used to solve this boundary value problem; the expansion parameter is the Marangoni number. The zeroth, first, and second order approximations for the velocity, temperature and pressure distributions in the liquid and in the bubble, and the deformation and terminal velocity of the bubble are determined. Experimental zero gravity data for a nitrogen bubble in ethylene glycol, ethanol, and silicone oil subjected to a linear temperature gradient were obtained using the NASA Lewis zero gravity drop tower. Comparison of the zeroth order analytical results for the bubble terminal velocity showed good agreement with the experimental measurements. The first and second order solutions for the bubble deformation and bubble terminal velocity are valid for liquids having Prandtl numbers on the order of one, but there is a lack of appropriate data to test the theory fully.

Legionella spp. in Puerto Rico cooling towers

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

Negron-Alvira, A.; Perez-Suarez, I.; Hazen, T.C.

1988-10-01

Water samples from air conditioning cooling towers receiving different treatment protocols on five large municipal buildings in San Juan, P.R., were assayed for various Legionella spp. and serogroups by using direct immunofluorescence. Several water quality parameters were also measured for each sample. Guinea pigs were inoculated with water samples to confirm pathogenicity and recover viable organisms. Legionella pneumophila serogroups 1 to 6, L. bozemanii, L. micdadei, L. dumoffii, and L. gormanii were observed in at least one of the cooling towers. L. pneumophila was the most abundant species; its density reached 10{sup 5} cells per ml, which is within themore » range that is considered potentially pathogenic to humans. A significantly higher density of L. pneumophila was observed in the cooling tower water that was not being treated with biocides. Percent respiration (INT) and total cell activity (acridine orange direct count) were inversely correlated with bacterial density. This study demonstrates that Legionella spp. are present in tropical air-conditioning cooling systems and that, without continuous biocide treatment, they may reach densities that present a health risk.« less

Dynamic in-plane potential gradients for actively controlling electrochemical reactions: Part I. Characterization of 1- and 2-component alkanethiol monolayer gradients on thin gold films. Part II. Applications of in-plane potential gradients

NASA Astrophysics Data System (ADS)

Balss, Karin Maria

The research contained in this thesis is focused on the formation and characterization of surface composition gradients on thin gold films that are formed by applications of in-plane potential gradients. Injecting milliamp currents into thin Au films yields significant in-plane voltage drops so that, rather than assuming a single value of potential, an in-plane potential gradient is imposed on the film which depends on the resistivity of the film, the cross sectional area and the magnitude of the potential drop. Furthermore, the in-plane electric potential gradient means that, relative to a solution reference couple, electrochemical reactions occurs at defined spatial positions corresponding to the local potential, V(x) ˜ E0. The spatial gradient in electrochemical potential can then produce spatially dependent electrochemistry. Surface-chemical potential gradients can be prepared by arranging the spread of potentials to span an electrochemical wave mediating redox-associated adsorption or desorption. Examples of reactions that can be spatially patterned include the electrosorption of alkanethiols and over-potential metal deposition. The unique advantage of this method for patterning spatial compositions is the control of surface coverage in both space and time. The thesis is organized into two parts. In Part I, formation and characterization of 1- and 2-component alkanethiol monolayer gradients is investigated. Numerous surface science tools are employed to examine the distribution in coverage obtained by application of in-plane potential gradients. Macroscopic characterization was obtained by sessile water drop contact angle measurements and surface plasmon resonance imaging. Gradients were also imaged on micron length scales with pulsed-force mode atomic force microscopy. Direct chemical evidence of surface compositions in aromatic thiol surface coverage was obtained by surface-enhanced Raman spectroscopy. In Part II, the applications of in-plane potential gradients is discussed. Electrochemical reactions other than electrosorption of alkanethiols were demonstrated with over-potential deposition of copper onto gold films. One application of these patterns is to control the movement of supermolecular objects. As a first step towards this goal, biological cells were seeded onto gradient patterns containing adhesion promoters and inhibitors. The morphology and adhesion was investigated as a function of concentration along the gradient.

Wind turbine tower for storing hydrogen and energy

DOEpatents

Fingersh, Lee Jay [Westminster, CO

2008-12-30

A wind turbine tower assembly for storing compressed gas such as hydrogen. The tower assembly includes a wind turbine having a rotor, a generator driven by the rotor, and a nacelle housing the generator. The tower assembly includes a foundation and a tubular tower with one end mounted to the foundation and another end attached to the nacelle. The tower includes an in-tower storage configured for storing a pressurized gas and defined at least in part by inner surfaces of the tower wall. In one embodiment, the tower wall is steel and has a circular cross section. The in-tower storage may be defined by first and second end caps welded to the inner surface of the tower wall or by an end cap near the top of the tower and by a sealing element attached to the tower wall adjacent the foundation, with the sealing element abutting the foundation.

The influence and analysis of natural crosswind on cooling characteristics of the high level water collecting natural draft wet cooling tower

NASA Astrophysics Data System (ADS)

Ma, Libin; Ren, Jianxing

2018-01-01

Large capacity and super large capacity thermal power is becoming the main force of energy and power industry in our country. The performance of cooling tower is related to the water temperature of circulating water, which has an important influence on the efficiency of power plant. The natural draft counter flow wet cooling tower is the most widely used cooling tower type at present, and the high cooling tower is a new cooling tower based on the natural ventilation counter flow wet cooling tower. In this paper, for high cooling tower, the application background of high cooling tower is briefly explained, and then the structure principle of conventional cooling tower and high cooling tower are introduced, and the difference between them is simply compared. Then, the influence of crosswind on cooling performance of high cooling tower under different wind speeds is introduced in detail. Through analysis and research, wind speed, wind cooling had little impact on the performance of high cooling tower; wind velocity, wind will destroy the tower inside and outside air flow, reducing the cooling performance of high cooling tower; Wind speed, high cooling performance of cooling tower has increased, but still lower than the wind speed.

A Numerical Model of Hercules A by Magnetic Tower

NASA Astrophysics Data System (ADS)

Nakamura, Masanori; Tregillis, I. L.; Li, H.; Li, S.

2009-01-01

We apply magnetohydrodynamic (MHD) modeling to the radio galaxy Hercules A for investigating the jet-driven shock, jet/lobe transition, wiggling, and magnetic field distribution associated with this source. The model consists of magnetic tower jets in a galaxy cluster environment. The profile of underlying ambient gas plays an important role in jet-lobe morphology. The balance between the magnetic pressure generated by axial current and the ambient gas pressure can determine the lobe radius. The jet body is confined jointly by the external pressure and gravity inside the cluster core radius, while outside this radius it expands radially to form fat lobes in a steeply decreasing ambient thermal pressure gradient. The current-carrying jets are responsible for generating a strong, tightly wound helical magnetic field. This magnetic configuration will be unstable against the current-driven kink mode and it visibly grows beyond the cluster core radius where a separation between the jet forward and return currents occurs. The reversed pinch profile of global magnetic field associated with the jet and lobes produces projected magnetic-vector distributions aligned with the jet flow and the lobe edge. AGN-driven shock powered by the expanding magnetic tower jet surrounds the jet/lobe structure and heats the ambient ICM. The lobes expand subsonically; no obvious hot spots are produced at the heads of lobes. Several key features in our MHD modeling may be qualitatively supported by the observations of Hercules A. This work was carried out under the auspices of the National Nuclear Security Administration of the U.S. Department of Energy at Los Alamos National Laboratory under Contract No. DE-AC52-06NA25396. It was supported by the Laboratory Directed Research and Development Program at LANL and by IGPP at LANL.

Spatiotemporal heterogeneity in carbon exchange at a restored peatland in Alberta, Canada

NASA Astrophysics Data System (ADS)

MacDonald, Scott; Strachan, Ian; Strack, Maria

2017-04-01

Boreal peatlands store a substantial portion of Earth's soil carbon, but the commercial peat extraction process upsets this carbon-sink dynamic. A best-practices restoration process has been developed that aims to return the vegetation and ecosystem functions of post-extraction peatlands. This includes the blocking and infilling of ditches, leveling of the peatland surface and re-introduction of vegetation through the moss layer transfer technique. The dynamics of carbon gas exchange in these restored peatlands are still poorly understood. We investigated ecosystem-scale and microscale carbon flux in a recently restored, post-extraction peatland near Seba Beach, Alberta, Canada. Two eddy covariance (EC) towers continuously measured CO2 and CH4 fluxes in hydrologically distinct parts of the peatland site. Here, we report on growing season measurements made during the fourth year following extraction. Regular static chamber measurements during June-August 2016 were also taken to study gas fluxes across an infilled drainage ditch on the site. Results suggest that if the peatland restoration process successfully returns high water table position, strong carbon uptake may be attained within several years of restoration. However, differences in peatland topography resulted spatial heterogeneity in carbon dynamics at this restored site. A gradient of revegetation success and attendant carbon-flux dynamics were observed, with much stronger net uptake of CO2 and substantial CH4 efflux measured at the tower with higher vegetation cover. Revegetation elsewhere was much sparser, and thus low CO2 uptake rates persisted at much of the peatland, though these conditions conversely inhibited substantial CH4 efflux. More broadly, the contrast in flux data between our two EC towers at the site suggests that attention be made to the selection of representative carbon flux values in similar restored peatlands.

Satellite Observations of Stratospheric Gravity Waves Associated With the Intensification of Tropical Cyclones

NASA Astrophysics Data System (ADS)

Hoffmann, Lars; Wu, Xue; Alexander, M. Joan

2018-02-01

Forecasting the intensity of tropical cyclones is a challenging problem. Rapid intensification is often preceded by the formation of "hot towers" near the eyewall. Driven by strong release of latent heat, hot towers are high-reaching tropical cumulonimbus clouds that penetrate the tropopause. Hot towers are a potentially important source of stratospheric gravity waves. Using 13.5 years (2002-2016) of Atmospheric Infrared Sounder observations of stratospheric gravity waves and tropical cyclone data from the International Best Track Archive for Climate Stewardship, we found empirical evidence that stratospheric gravity wave activity is associated with the intensification of tropical cyclones. The Atmospheric Infrared Sounder and International Best Track Archive for Climate Stewardship data showed that strong gravity wave events occurred about twice as often for tropical cyclone intensification compared to storm weakening. Observations of stratospheric gravity waves, which are not affected by obscuring tropospheric clouds, may become an important future indicator of storm intensification.

Piecewise Potential Vorticity Inversion for Intense Extratropical Cyclones

NASA Astrophysics Data System (ADS)

Seiler, C.; Zwiers, F. W.

2017-12-01

Global climate models (GCMs) tend to simulate too few intense extratropical cyclones (ETCs) in the Northern Hemisphere (NH) under historic climate conditions. This bias may arise from the interactions of multiple drivers, including surface temperature gradients, latent heating in the lower troposphere, and the upper-level jet stream. Previous attempts to quantify the importance of these drivers include idealized model experiments or statistical approaches. The first method however cannot easily be implemented for a multi-GCM ensemble, and the second approach does not disentangle the interactions among drivers, nor does it prove causality. An alternative method that overcomes these limitations is piecewise potential vorticity inversion (PPVI). PPVI derives the wind and geopotential height fields by inverting potential vorticity (PV) for discrete atmospheric levels. Despite being a powerful diagnostic tool, PPVI has primarily been used to study the dynamics of individual events only. This study presents the first PPVI climatology for the 5% most intense NH ETCs that occurred from 1980 to 2016. Conducting PPVI to 3273 ETC tracks identified in ERA-Interim reanalysis, we quantified the contributions from 3 atmospheric layers to ETC intensity. The respective layers are the surface (1000 hPa), a lower atmospheric level (700-850 hPa) and an upper atmospheric level (100-500 hPa) that are associated with the contributions from surface temperature gradients, latent heating, and the jet stream, respectively. Results show that contributions are dominated by the lower level (40%), followed by the upper level (20%) and the surface (17%), while the remaining 23% are associated with the background flow. Contributions from the surface and the lower level are stronger in the western ocean basins owed to the presence of the warm ocean currents, while contributions from the upper level are stronger in the eastern basins. Vertical cross sections of ETC-centered composites show an undulation of the dynamic tropopause and the formation of a PV tower with values exceeding 1 PV unit during maximum ETC intensity. The dominant contribution from the lower level underlines the importance of latent heating for intense ETCs. The ability of GCMs to reproduce this mechanism remains to be assessed.

Augmented Reality Tower Technology Assessment

NASA Technical Reports Server (NTRS)

Reisman, Ronald J.; Brown, David M.

2009-01-01

Augmented Reality technology may help improve Air Traffic Control Tower efficiency and safety during low-visibility conditions. This paper presents the assessments of five off-duty controllers who shadow-controlled' with an augmented reality prototype in their own facility. Initial studies indicated unanimous agreement that this technology is potentially beneficial, though the prototype used in the study was not adequate for operational use. Some controllers agreed that augmented reality technology improved situational awareness, had potential to benefit clearance, control, and coordination tasks and duties and could be very useful for acquiring aircraft and weather information, particularly aircraft location, heading, and identification. The strongest objections to the prototype used in this study were directed at aircraft registration errors, unacceptable optical transparency, insufficient display performance in sunlight, inadequate representation of the static environment and insufficient symbology.

DETAIL VIEW OF AERIAL TRAM SUPPORT TOWER SIX WITH TOWERS ...

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

DETAIL VIEW OF AERIAL TRAM SUPPORT TOWER SIX WITH TOWERS SEVEN,EIGHT, NINE, TEN, AND BREAK OVER TOWER IN DISTANCE, LOOKING NORTH. TOWER SIX IS THE LAST BEFORE A DEEP CHASM, AS IS SEEN BY THE DISTANCE BETWEEN TOWERS SIX AND SEVEN. SEE CA-291-48 (CT) FOR IDENTICAL COLOR TRANSPARENCY. - Keane Wonder Mine, Park Route 4 (Daylight Pass Cutoff), Death Valley Junction, Inyo County, CA

DETAIL VIEW OF AERIAL TRAM SUPPORT TOWER SIX WITH TOWERS ...

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

DETAIL VIEW OF AERIAL TRAM SUPPORT TOWER SIX WITH TOWERS SEVEN, EIGHT, NINE, TEN, AND BREAK OVER TOWER IN DISTANCE, LOOKING NORTH. TOWER SIX IS THE LAST BEFORE A DEEP CHASM, AS IS SEEN BY THE DISTANCE BETWEEN TOWERS SIX AND SEVEN. SEE CA-291-21 FOR IDENTICAL B&W NEGATIVE. - Keane Wonder Mine, Park Route 4 (Daylight Pass Cutoff), Death Valley Junction, Inyo County, CA

Biological amine transport in chromaffin ghosts. Coupling to the transmembrane proton and potential gradients.

PubMed

Johnson, R G; Pfister, D; Carty, S E; Scarpa, A

1979-11-10

The effect of the transmembrane proton gradient (delta pH) and potential gradient (delta psi) upon the rate and extent of amine accumulation was investigated in chromaffin ghosts. The chromaffin ghosts were formed by hypo-osmotic lysis of isolated bovine chromaffin granules and extensive dialysis in order to remove intragranular binding components and dissipate the endogenous electrochemical gradients. Upon ATP addition to suspensions of chromaffin ghosts, a transmembrane proton gradient alone, a transmembrane gradient alone, or both, could be established, depending upon the compositions of the media in which the ghosts were formed and resuspended. When chloride was present in the medium, addition of ATP resulted in the generation of a transmembrane proton gradient, acidic inside of 1 pH unit (measured by [14C]methylamine distribution), and no transmembrane potential (measured by [14C]-thiocyanate distribution). When ATP was added to chromaffin ghosts suspended in a medium in which chloride was substituted by isethionate, a transmembrane potential, inside positive, of 45 mV and no transmembrane proton gradient, was measured. In each medium, the addition of agents known to affect proton or potential gradients, respectively, exerted a predictable mechanism of action. Accumulation of [14C]epinephrine or [14C]5-hydroxytryptamine was over 1 order of magnitude greater in the presence of the transmembrane proton gradient or the transmembrane potential than in the absence of any gradient and, moreover, was related to the magnitude of the proton or potential gradient in a dose-dependent manner. When ghosts were added to a medium containing chloride and isethionate, both a delta pH and delta psi could be generated upon addition of ATP. In this preparation, the maximal rate of amine accumulation was observed. The results indicate that amine accumulation into chromaffin ghosts can occur in the presence of either a transmembrane proton gradient, or a transmembrane potential gradient, and that the maximal rate of accumulation may exist when both components of the protonmotive force are present.

Impacts of drought on regional carbon uptake dynamics in the Southwestern US, using the New Mexico Elevation Gradient of flux towers and the Temperature-Greenness model.

NASA Astrophysics Data System (ADS)

Krofcheck, D. J.; Lippitt, C.; Litvak, M. E.

2014-12-01

Semi-arid regions store approximately 568 Gt of carbon, roughly 18% of the global carbon reserves. Drought remains one of the largest sources of climatic stress in semi-arid regions globally. The impacts of these expansive, severe droughts on terrestrial productivity can be substantial and difficult to quantify spatially. The semi-arid Southwestern US suffered an expansive drought in 2011 which precipitated significant decline in ecosystem function and woody mortality across the region. We used the New Mexico Elevation Gradient (NMEG) cluster of flux towers, which provided in-situ measures of carbon flux via eddy-covariance to estimate the decreases in gross primary production across six dominant vegetation types in the region. Relative to a wet year, the largest decrease in cumulative carbon uptake we measured was 60% (a reduction of 200 g C /m2 annually) at the ponderosa pine site. The pattern of decreased carbon sequestration was consistent across the gradient, with the C4 grasslands shifting from carbon neutral to a source of 50 g C / m2 in response to the drought and desert shrublands sink strength reduced by 100%, (~50 g C /m2 annually). Juniper savannas, PJ woodlands, and mixed conifer subalpine woodlands all showed a decrease in carbon sequestration of roughly 100 g C /m2 annually. Rough scaling of these results suggest this drought could have resulted in a reduction of carbon uptake of 20 Tg C in NM alone. To more realistically estimate the decrease in carbon sequestration due to drought, we used results from the NMEG to parameterize the Temperature-Greenness model, a remote sensing based approach to scale these estimates to the region, focusing on the six dominant vegetation types represented by the NMEG (accounts for 60% of total land area in NM). This model is driven by 16-day averages of MODIS land surface temperature and the enhanced vegetation index. We used the Southwest Regional GAP analysis classification data to bin NM landcover into representative classes to most closely match the vegetation types measured by the NMEG. Given the spatial variability in vegetation structure and function within biomes, this approach provides more robust estimates of statewide carbon uptake patterns. We discuss these results in the context of recent droughts, future climate projections, and previous regional modeling results.

Potential Visual Impacts of Utility-Scale Solar Energy Development within Solar Energy Zones on Selected Viewpoints in Death Valley and Joshua Tree National Parks, and El Camino Real De Tierra Adentro National Historic Trail

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

Sullivan, Robert G.; Abplanalp, Jennifer M.; Cantwell, Brian L.

In connection with the Bureau of Land Management’s (BLM’s) Solar Programmatic Environmental Impact Statement (Solar PEIS), Argonne National Laboratory (Argonne) has conducted an extended visual impact analysis for selected key observation points (KOPs) within three National Park Service (NPS) units located within the 25-mi (40-km) viewshed of four solar energy zones (SEZs) identified in the Solar PEIS. The analysis includes only those NPS units that the Solar PEIS identified as potentially subject to moderate or strong visual contrasts associated with solar development within the SEZs. The NPS units included in the analysis are Death Valley and Joshua Tree National Parksmore » and El Camino Real De Tierra Adentro National Historic Trail. The analysis showed that certain KOPs in each of these NPS units could potentially be subject to major visual contrast and impacts from solar development within the SEZs, but many of the KOPs would likely be subject to moderate, minor, or negligible contrasts and impacts, generally because they were relatively distant from the relevant SEZ, had views of the SEZ partially blocked by intervening terrain, and/or had very low vertical angles of view toward the SEZ. For all three NPS units, power tower facilities were found to be major contributors to potential visual contrasts, primarily because of the long-distance visibility of intensely bright reflection of light from the receivers on the central towers, but also because of the height and strong vertical line of the tower structures and the potential for night-sky impacts from FAA-mandated hazard navigation lighting.« less

Isolation of a sulfide-producing bacterial consortium from cooling-tower water: Evaluation of corrosive effects on galvanized steel.

PubMed

Ilhan-Sungur, Esra; Ozuolmez, Derya; Çotuk, Ayşın; Cansever, Nurhan; Muyzer, Gerard

2017-02-01

Sulfidogenic Clostridia and sulfate reducing bacteria (SRB) often cohabit in nature. The presence of these microorganisms can cause microbially influenced corrosion (MIC) of materials in different ways. To investigate this aspect, bacteria were isolated from cooling tower water and used in corrosion tests of galvanized steel. The identity of the isolates was determined by comparative sequence analysis of PCR-amplified 16S rDNA gene fragments, separated by denaturing gradient gel electrophoresis (DGGE). This analysis showed that, in spite of the isolation process, colonies were not pure and consisted of a mixture of bacteria affiliated with Desulfosporosinus meridiei and Clostridium sp. To evaluate the corrosive effect, galvanized steel coupons were incubated with a mixed culture for 4, 8, 24, 72, 96, 168, 360 and 744 h, along with a control set in sterile culture medium only. The corrosion rate was determined by weight loss, and biofilm formation and corroded surfaces were observed by scanning electron microscopy (SEM). Although the sulfide-producing bacterial consortium led to a slight increase in the corrosion of galvanized steel coupons, when compared to the previous studies it can be said that Clostridium sp. can reduce the corrosive effect of the Desulfosporosinus sp. strain. Copyright © 2016 Elsevier Ltd. All rights reserved.

High-Frequency Response of the Atmospheric Electric Potential Gradient Under Strong and Dry Boundary-Layer Convection

NASA Astrophysics Data System (ADS)

Conceição, Ricardo; Silva, Hugo Gonçalves; Bennett, Alec; Salgado, Rui; Bortoli, Daniele; Costa, Maria João; Collares Pereira, Manuel

2018-01-01

The spectral response of atmospheric electric potential gradient gives important information about phenomena affecting this gradient at characteristic time scales ranging from years (e.g., solar modulation) to fractions of a second (e.g., turbulence). While long-term time scales have been exhaustively explored, short-term scales have received less attention. At such frequencies, space-charge transport inside the planetary boundary layer becomes a sizeable contribution to the potential gradient variability. For the first time, co-located (Évora, Portugal) measurements of boundary-layer backscatter profiles and the 100-Hz potential gradient are reported. Five campaign days are analyzed, providing evidence for a relation between high-frequency response of the potential gradient and strong dry convection.

Cavity enhanced spectroscopy for measurement of nitrogen oxides in the Anthropocene: results from the Seoul tower during MAPS 2015.

PubMed

Brown, Steven S; An, Hyunjin; Lee, Meehye; Park, Jeong-Hoo; Lee, Sang-Deok; Fibiger, Dorothy L; McDuffie, Erin E; Dubé, William P; Wagner, Nicholas L; Min, Kyung-Eun

2017-08-24

Cavity enhanced spectroscopy, CES, is a high sensitivity direct absorption method that has seen increasing utility in the last decade, a period also marked by increasing requirements for understanding human impacts on atmospheric composition. This paper describes the current NOAA six channel cavity ring-down spectrometer (CRDS, the most common form of CES) for measurement of nitrogen oxides and O 3 . It further describes the results from measurements from a tower 300 m above the urban area of Seoul in late spring of 2015. The campaign demonstrates the performance of the CRDS instrument and provides new data on both photochemistry and nighttime chemistry in a major Asian megacity. The instrument provided accurate, high time resolution data for N 2 O 5 , NO, NO 2 , NO y and O 3 , but suffered from large wall loss in the sampling of NO 3 , illustrating the requirement for calibration of the NO 3 inlet transmission. Both the photochemistry and nighttime chemistry of nitrogen oxides and O 3 were rapid in this megacity. Sustained average rates of O 3 buildup of 10 ppbv h -1 during recurring morning and early afternoon sea breezes led to a 50 ppbv average daily O 3 rise. Nitrate radical production rates, P(NO 3 ), averaged 3-4 ppbv h -1 in late afternoon and early evening, much greater than contemporary data from Los Angeles, a comparable U. S. megacity. These P(NO 3 ) were much smaller than historical data from Los Angeles, however. Nighttime data at 300 m above ground showed considerable variability in high time resolution nitrogen oxide and O 3 , likely resulting from sampling within gradients in the nighttime boundary layer structure. Apparent nighttime biogenic VOC oxidation rates of several ppbv h -1 were also likely influenced by vertical gradients. Finally, daytime N 2 O 5 mixing ratios of 3-35 pptv were associated with rapid daytime P(NO 3 ) and agreed well with a photochemical steady state calculation.

Solar tower enhanced natural draft dry cooling tower

NASA Astrophysics Data System (ADS)

Yang, Huiqiang; Xu, Yan; Acosta-Iborra, Alberto; Santana, Domingo

2017-06-01

Concentrating Solar Power (CSP) plants are located in desert areas where the Direct Normal Irradiance (DNI) value is very high. Since water resource is scarcely available, mechanical draft cooing technology is commonly used, with power consumption of mechanical fans being approximately 2% of the total power generated. Today, there is only one solar power plant (Khi Solar One in South Africa) uses a condenser installed in a Natural Draft Cooling (NDC) tower that avoids the windage loss of water occurring in wet cooling towers. Although, Khi Solar One is a cavity receiver power tower, the receivers can be hung onto the NDC tower. This paper looks at a novel integration of a NDC tower into an external molten salt receiver of a solar power plant, which is one of a largest commercial molten salt tower in China, with 100MWe power capacity. In this configuration study, the NDC tower surrounds the concrete tower of the receiver concentrically. In this way, the receiver concrete tower is the central support of the NDC tower, which consists of cable networks that are fixed to the concrete tower and suspended at a certain height over the floor. The cable networks support the shell of the NDC tower. To perform a preliminary analysis of the behavior of this novel configuration, two cases of numerical simulation in three dimensional (3D) models have been solved using the commercial Computational Fluid Dynamics (CFD) code, ANSYS Fluent 6.3. The results show that the integration of the NDC tower into an external central receiver tower is feasible. Additionally, the total heat transfer rate is not reduced but slightly increases when the molten salt receiver is in operation because of the additional natural draft induced by the high temperature of the receiver.

Summary of tower designs for large horizontal axis wind turbines

NASA Technical Reports Server (NTRS)

Frederick, G. R.; Savino, J. M.

1986-01-01

Towers for large horizontal axis wind turbines, machines with a rotor axis height above 30 meters and rated at more than 500 kW, have varied in configuration, materials of construction, type of construction, height, and stiffness. For example, the U.S. large HAWTs have utilized steel truss type towers and free-standing steel cylindrical towers. In Europe, the trend has been to use only free-standing and guyed cylindrical towers, but both steel and reinforced concrete have been used as materials of construction. These variations in materials of construction and type of construction reflect different engineering approaches to the design of cost effective towers for large HAWTs. Tower designs are the NASA/DOE Mod-5B presently being fabricated. Design goals and requirements that influence tower configuration, height and materials are discussed. In particular, experiences with United States large wind turbine towers are elucidated. Finally, current trends in tower designs for large HAWTs are highlighted.

13. INTERIOR VIEW OF TOWER OFFICE SHOWING CONTROL TOWER DESK, ...

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

13. INTERIOR VIEW OF TOWER OFFICE SHOWING CONTROL TOWER DESK, FACING NORTHWEST. - U.S. Naval Base, Pearl Harbor, Signal Tower, Corner of Seventh Street & Avenue D east of Drydock No. 1, Pearl City, Honolulu County, HI

Evaluation of dynamic response for monopole and hybrid wind mill tower

NASA Astrophysics Data System (ADS)

Shah, Hemal J.; Desai, Atul K.

2017-07-01

The wind mill towers are constructed using monopoles or lattice type tower. As the height of tower increases it gives more power but it becomes uneconomical, so in the present research work innovative wind mill tower such as combination of monopole and lattice tower is analyzed using FEM software. When the tall structures are constructed on soft soil it becomes dynamically sensitive so 3 types of soil such as hard, medium and soft soil is also modeled and the innovative tower is studied for different operating frequencies of wind turbine. From study it is concluded that the innovative tower will reduce resonance condition considering soil structure interaction.

Directed transport by surface chemical potential gradients for enhancing analyte collection in nanoscale sensors.

PubMed

Sitt, Amit; Hess, Henry

2015-05-13

Nanoscale detectors hold great promise for single molecule detection and the analysis of small volumes of dilute samples. However, the probability of an analyte reaching the nanosensor in a dilute solution is extremely low due to the sensor's small size. Here, we examine the use of a chemical potential gradient along a surface to accelerate analyte capture by nanoscale sensors. Utilizing a simple model for transport induced by surface binding energy gradients, we study the effect of the gradient on the efficiency of collecting nanoparticles and single and double stranded DNA. The results indicate that chemical potential gradients along a surface can lead to an acceleration of analyte capture by several orders of magnitude compared to direct collection from the solution. The improvement in collection is limited to a relatively narrow window of gradient slopes, and its extent strongly depends on the size of the gradient patch. Our model allows the optimization of gradient layouts and sheds light on the fundamental characteristics of chemical potential gradient induced transport.

Research on Condition Assessment Method of Transmission Tower Under the Action of Strong Wind

NASA Astrophysics Data System (ADS)

Huang, Ren-mou; An, Li-qiang; Zhang, Rong-lun; Wu, Jiong; Liang, Ya-feng

2018-03-01

Transmission towers are often subjected to the external damage of severe weather like strong wind and so on, which may cause the collapse due to the yield and fracture of the tower material. Aiming this issue, an assessment method was proposed in this paper to assess the operation condition of transmission towers under strong wind. With a reasonable assess index system established firstly, then the internal force of the tower material was solved and its stability was determined through the mechanical analysis of the transmission tower finite element model. Meanwhile, the condition risk level of the tower was finally determined by considering the difference among the influences of other factors like corrosion and loose of members, slope on the transmission tower through the analytic hierarchy process. The assessment method was applied to assess the wind-induced collapse of towers in 110kV Bao Yi II line in Wenchang City, Hainan Province, of which the result proves the method can assess the condition of transmission tower under strong wind and of guiding significance for improving the windproof capability of transmission towers.

Tower Temperature and Humidity Sensors (TWR) Handbook

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

Cook, DR

2010-02-01

Three tall towers are installed at the Atmospheric Radiation Measurement (ARM) Climate Research Facility: a 60-meter triangular tower at the Southern Great Plains (SGP) Central Facility (CF), a 21-meter walkup scaffolding tower at the SGP Okmulgee forest site (E21), and a 40-meter triangular tower at the North Slope of Alaska (NSA) Barrow site. The towers are used for meteorological, radiological, and other measurements.

SWECS tower dynamics analysis methods and results

NASA Technical Reports Server (NTRS)

Wright, A. D.; Sexton, J. H.; Butterfield, C. P.; Thresher, R. M.

1981-01-01

Several different tower dynamics analysis methods and computer codes were used to determine the natural frequencies and mode shapes of both guyed and freestanding wind turbine towers. These analysis methods are described and the results for two types of towers, a guyed tower and a freestanding tower, are shown. The advantages and disadvantages in the use of and the accuracy of each method are also described.

Characterization and Modeling of Dust Emissions from an Instrumented Mine Tailings Site

NASA Astrophysics Data System (ADS)

Betterton, E. A.; Stovern, M.; Saez, A.; Csavina, J. L.; Felix Villar, O. I.; Field, J. P.; Rine, K. P.; Russell, M. R.; Saliba, P.

2012-12-01

Mining operations are potential sources of airborne particulate metal and metalloid contaminants through both direct smelter emissions and wind erosion of mine tailings. The warmer, drier conditions predicted for the Southwestern US by climate models may make contaminated atmospheric dust and aerosols increasingly important, due to potential deleterious effects on human health and ecology. Dust emissions and dispersion of contaminants from the Iron King Mine tailings in Dewey-Humboldt, Arizona, a Superfund site, are currently being investigated through in situ field measurements and computational fluid dynamics modeling. These tailings are heavily contaminated with lead and arsenic. We report on the chemical characterization of atmospheric dust and aerosol sampled near the mine tailings. Instrumented eddy flux towers were also setup on the mine tailings to give both spatial and temporal dust observations. The eddy flux towers have multiple DUSTTRAK monitors as well as weather stations. These in situ observations allow us to assess spatial distribution of suspended particulate. Using the DUSTTRAK flux tower observations at 10-second resolution in conjunction with a computational fluid dynamics model, we have been able to model dust transport from the mine tailings to downwind areas. In order to improve the accuracy of the dust transport simulations both regional topographical features and local weather patterns have been incorporated into the model simulations.

5. View of south tower, facing northnortheast from south bank ...

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

5. View of south tower, facing north-northeast from south bank of the Columbia River. Center tower and north tower in background, lower right. - Pasco-Kennewick Transmission Line, Columbia River Crossing Towers, Columbia Drive & Gum Street, Kennewick, Benton County, WA

Pilot-scale cooling tower to evaluate corrosion, scaling, and biofouling control strategies for cooling system makeup water.

PubMed

Chien, S H; Hsieh, M K; Li, H; Monnell, J; Dzombak, D; Vidic, R

2012-02-01

Pilot-scale cooling towers can be used to evaluate corrosion, scaling, and biofouling control strategies when using particular cooling system makeup water and particular operating conditions. To study the potential for using a number of different impaired waters as makeup water, a pilot-scale system capable of generating 27,000 kJ∕h heat load and maintaining recirculating water flow with a Reynolds number of 1.92 × 10(4) was designed to study these critical processes under conditions that are similar to full-scale systems. The pilot-scale cooling tower was equipped with an automatic makeup water control system, automatic blowdown control system, semi-automatic biocide feeding system, and corrosion, scaling, and biofouling monitoring systems. Observed operational data revealed that the major operating parameters, including temperature change (6.6 °C), cycles of concentration (N = 4.6), water flow velocity (0.66 m∕s), and air mass velocity (3660 kg∕h m(2)), were controlled quite well for an extended period of time (up to 2 months). Overall, the performance of the pilot-scale cooling towers using treated municipal wastewater was shown to be suitable to study critical processes (corrosion, scaling, biofouling) and evaluate cooling water management strategies for makeup waters of complex quality.

Wet cooling towers: rule-of-thumb design and simulation

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

Leeper, Stephen A.

1981-07-01

A survey of wet cooling tower literature was performed to develop a simplified method of cooling tower design and simulation for use in power plant cycle optimization. The theory of heat exchange in wet cooling towers is briefly summarized. The Merkel equation (the fundamental equation of heat transfer in wet cooling towers) is presented and discussed. The cooling tower fill constant (Ka) is defined and values derived. A rule-of-thumb method for the optimized design of cooling towers is presented. The rule-of-thumb design method provides information useful in power plant cycle optimization, including tower dimensions, water consumption rate, exit air temperature,more » power requirements and construction cost. In addition, a method for simulation of cooling tower performance at various operating conditions is presented. This information is also useful in power plant cycle evaluation. Using the information presented, it will be possible to incorporate wet cooling tower design and simulation into a procedure to evaluate and optimize power plant cycles.« less

5. VIEW EAST, height finder radar towers, radar tower (unknown ...

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

5. VIEW EAST, height finder radar towers, radar tower (unknown function), prime search radar tower, operations building, and central heating plant - Fort Custer Military Reservation, P-67 Radar Station, .25 mile north of Dickman Road, east of Clark Road, Battle Creek, Calhoun County, MI

17. VIEW OF THE TOP OF THE TOWER SHOWING BASE ...

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

17. VIEW OF THE TOP OF THE TOWER SHOWING BASE OF TOWER MAST AND WOOD DECKING ON SIGNAL TOWER ROOF. - U.S. Naval Base, Pearl Harbor, Signal Tower, Corner of Seventh Street & Avenue D east of Drydock No. 1, Pearl City, Honolulu County, HI

Radiation Testing of PICA at the Solar Power Tower

NASA Technical Reports Server (NTRS)

White, Susan M.

2010-01-01

Sandia National Laboratory's Solar Power Tower was used to irradiate specimens of Phenolic Impregnated Carbon Ablator (PICA), in order to evaluate whether this thermal protection system material responded differently to potential shock layer radiative heating than to convective heating. Tests were run at 50, 100 and 150 Watts per square centimeter levels of concentrated solar radiation. Experimental results are presented both from spectral measurements on 1- 10 mm thick specimens of PICA, as well as from in-depth temperature measurements on instrumented thicker test specimens. Both spectral measurements and measured in-depth temperature profiles showed that, although it is a porous, low-density material, PICA does not exhibit problematic transparency to the tested high levels of NIR radiation, for all pragmatic cm-to-inch scale thicknesses. PICA acted as a surface absorber to efficiently absorb the incident visible and near infrared incident radiation in the top 2 millimeter layer in the Solar Power Tower tests up to 150 Watts per square centimeter.

Atmospheric considerations regarding the impact of heat dissipation from a nuclear energy center

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

Rotty, R.M.; Bauman, H.; Bennett, L.L.

1976-05-01

Potential changes in climate resulting from a large nuclear energy center are discussed. On a global scale, no noticeable changes are likely, but on both a regional and a local scale, changes can be expected. Depending on the cooling system employed, the amount of fog may increase, the amount and distribution of precipitation will change, and the frequency or location of severe storms may change. Very large heat releases over small surface areas can result in greater atmospheric instability; a large number of closely spaced natural-draft cooling towers have this disadvantage. On the other hand, employment of natural-draft towers makesmore » an increase in the occurrence of ground fog unlikely. The analysis suggests that the cooling towers for a large nuclear energy center should be located in clusters of four with at least 2.5-mile spacing between the clusters. This is equivalent to the requirement of one acre of land surface per each two megawatts of heat being rejected.« less

Use of Virtual Mission Operations Center Technology to Achieve JPDO's Virtual Tower Vision

NASA Technical Reports Server (NTRS)

Ivancic, William D.; Paulsen, Phillip E.

2006-01-01

The Joint Program Development Office has proposed that the Next Generation Air Transportation System (NGATS) consolidate control centers. NGATS would be managed from a few strategically located facilities with virtual towers and TRACONS. This consolidation is about combining the delivery locations for these services not about decreasing service. By consolidating these locations, cost savings in the order of $500 million have been projected. Evolving to spaced-based communication, navigation, and surveillance offers the opportunity to reduce or eliminate much of the ground-based infrastructure cost. Dynamically adjusted airspace offers the opportunity to reduce the number of sectors and boundary inconsistencies; eliminate or reduce "handoffs;" and eliminate the distinction between Towers, TRACONS, and Enroute Centers. To realize a consolidation vision for air traffic management there must be investment in networking. One technology that holds great potential is the use of Virtual Mission Operations Centers to provide secure, automated, intelligent management of the NGATS. This paper provides a conceptual framework for incorporating VMOC into the NGATS.

You're a What?: Tower Technician

ERIC Educational Resources Information Center

Vilorio, Dennis

2012-01-01

In this article, the author talks about the role and functions of a tower technician. A tower technician climbs up the face of telecommunications towers to remove, install, test, maintain, and repair a variety of equipment--from antennas to light bulbs. Tower technicians also build shelters and radiofrequency shields for electronic equipment, lay…

Vibration analysis of three guyed tower designs for intermediate size wind turbines

NASA Technical Reports Server (NTRS)

Christie, R. J.

1982-01-01

Three guyed tower designs were analyzed for intermediate size wind turbines. The four lowest natural frequencies of vibration of the three towers concepts were estimated. A parametric study was performed on each tower to determine the effect of varying such tower properties as the inertia and stiffness of the tower and guys, the inertia values of the nacelle and rotor, and the rotational speed of the rotor. Only the two lowest frequencies were in a range where they could be excited by the rotor blade passing frequencies. There two frequencies could be tuned by varying the guy stiffness, the guy attachment point on the tower, the tower and mass stiffness, and the nacelle/rotor/power train masses.

Lifting system and apparatus for constructing wind turbine towers

DOEpatents

Livingston, Tracy; Schrader, Terry; Goldhardt, James; Lott, James

2011-02-01

The disclosed invention is utilized for mounting a wind turbine and blade assembly on the upper end of a wind turbine tower. The invention generally includes a frame or truss that is pivotally secured to the top bay assembly of the tower. A transverse beam is connected to the frame or truss and extends fore of the tower when the frame or truss is in a first position and generally above the tower when in a second position. When in the first position, a wind turbine or blade assembly can be hoisted to the top of the tower. The wind turbine or blade assembly is then moved into position for mounting to the tower as the frame or truss is pivoted to a second position. When the turbine and blade assembly are secured to the tower, the frame or truss is disconnected from the tower and lowered to the ground.

2004 Savannah River Cooling Tower Collection (U)

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

Garrett, Alfred; Parker, Matthew J.; Villa-Aleman, E.

2005-05-01

The Savannah River National Laboratory (SRNL) collected ground truth in and around the Savannah River Site (SRS) F-Area cooling tower during the spring and summer of 2004. The ground truth data consisted of air temperatures and humidity inside and around the cooling tower, wind speed and direction, cooling water temperatures entering; inside adn leaving the cooling tower, cooling tower fan exhaust velocities and thermal images taken from helicopters. The F-Area cooling tower had six cells, some of which were operated with fans off during long periods of the collection. The operating status (fan on or off) for each of themore » six cells was derived from operations logbooks and added to the collection database. SRNL collected the F-Area cooling tower data to produce a database suitable for validation of a cooling tower model used by one of SRNL's customer agencies. SRNL considers the data to be accurate enough for use in a model validation effort. Also, the thermal images of the cooling tower decks and throats combined with the temperature measurements inside the tower provide valuable information about the appearance of cooling towers as a function of fan operating status and time of day.« less

Airport Surface Traffic Control Systems Deployment Analysis

DOT National Transportation Integrated Search

1974-01-01

The report summarizes the findings of an analysis of ASTC (Airport Surface Traffic Control) system requirements and develops estimates of the deployment potential of proposed system alternatives. The tower control problem areas were investigated by a...

The effect of a tall tower on flow and dispersion through a model urban neighborhood: part 2. Pollutant dispersion.

PubMed

Brixey, Laurie A; Heist, David K; Richmond-Bryant, Jennifer; Bowker, George E; Perry, Steven G; Wiener, Russell W

2009-12-01

This article is the second in a two-paper series presenting results from wind tunnel and computational fluid dynamics (CFD) simulations of flow and dispersion in an idealized model urban neighborhood. Pollutant dispersion results are presented and discussed for a model neighborhood that was characterized by regular city blocks of three-story row houses with a single 12-story tower located at the downwind edge of one of these blocks. The tower had three significant effects on pollutant dispersion in the surrounding street canyons: drawing the plume laterally towards the tower, greatly enhancing the vertical dispersion of the plume in the wake of the tower, and significantly decreasing the residence time of pollutants in the wake of the tower. In the wind tunnel, tracer gas released in the avenue lee of the tower, but several blocks away laterally, was pulled towards the tower and lifted in the wake of the tower. The same lateral movement of the pollutant was seen in the next avenue, which was approximately 2.5 tower heights downwind of the tower. The tower also served to ventilate the street canyon directly in its wake more rapidly than the surrounding areas. This was evidenced by CFD simulations of concentration decay where the residence time of pollutants lee of the 12-story tower was found to be less than half the residence time behind a neighboring three-story building. This same phenomenon of rapid vertical dispersion lee of a tower among an array of smaller buildings was also demonstrated in a separate set of wind tunnel experiments using an array of cubical blocks. A similar decrease in the residence time was observed when the height of one block was increased.

Tower Shielding Reactor II design and operation report: Vol. 2. Safety Analysis

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

Holland, L. B.; Kolb, J. O.

1970-01-01

Information on the Tower Shielding Reactor II is contained in the TSR-II Design and Operation Report and in the Tower Shielding Facility Manual. The TSR-II Design and Operating Report consists of three volumes. Volume 1 is Descriptions of the Tower Shielding Reactor II and Facility; Volume 2 is Safety analysis of the Tower Shielding Reactor II; and Volume 3 is the Assembly and Testing of the Tower Shielding Reactor II Control Mechanism Housing.

COOLING TOWER PUMP HOUSE, TRA606. THREE OF SIX SECTIONS OF ...

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

COOLING TOWER PUMP HOUSE, TRA-606. THREE OF SIX SECTIONS OF COOLING TOWER ARE VISIBLE ABOVE RAILING. PUMP HOUSE IN FOREGROUND IS ON SOUTH SIDE OF COOLING TOWER. NOTE THREE PIPES TAKING WATER FROM PUMP HOUSE TO HOT DECK OF COOLING TOWER. EMERGENCY WATER SUPPLY TOWER IS ALSO IN VIEW. INL NEGATIVE NO. 6197. Unknown Photographer, 6/27/1952 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

[Genotypic variability and persistence of Legionella pulsed-field gel electrophoresis patterns in 16 cooling towers in Shanghai, China].

PubMed

Chen, Ming-liang; Wang, Gang-yi; Chen, Min; Zhou, Hai-jian; Shao, Zhu-jun; Zhang, Xi; Wu, Fan

2010-07-01

To investigate the genotypic characteristics and persistence of Legionella pulsed-field gel electrophoresis (PFGE) patterns in 16 air-conditioner cooling towers in six different public sites of Shanghai. From May to October, continuous sampling was operated once per month in 2007. Legionella strains isolated from the 16 cooling towers were confirmed by serological and latex agglutination. PFGE was applied for the fingerprinting of the isolates, while the cluster results of PFGE were analyzed by BioNumerics software. 131 strains of Legionella were isolated, including L. pneumophila, L. bozemanae, L. micdadei and L. anisa. 52 distinguishable PFGE patterns were differentiated among the 16 cooling towers, with 37 patterns were owned by just one cooling tower, which was not shared with other cooling towers, while 15 patterns were shared by more than 2 cooling towers. All the cooling towers had ≥ 2 PFGE patterns, while in 13 cooling towers the same PFGE patterns were recovered during the six months. From June to October of 2007, 18 strains of Legionella belonging to the PFGE pattern of LPAs.SH0078 were isolated continuously from 6 cooling towers. This study demonstrated great genotypic diversity and complexity of Legionella in cooling towers. Persistence of the PFGE patterns was observed in 81.25% of the cooling towers. The PFGE pattern of LPAs. SH0078 was distributed widely, suggesting it might be the dominate strain in Shanghai.

78 FR 11146 - Utility Scale Wind Towers From the People's Republic of China: Antidumping Duty Order

Federal Register 2010, 2011, 2012, 2013, 2014

2013-02-15

... DEPARTMENT OF COMMERCE International Trade Administration [A-570-981] Utility Scale Wind Towers...''), the Department is issuing an antidumping duty order on utility scale wind towers (``wind towers... investigation of wind towers from the PRC.\\1\\ On February 8, 2013, the ITC notified the Department of its...

Advection and resulting CO2 exchange uncertainty in a tall forest in central Germany.

PubMed

Kutsch, Werner L; Kolle, Olaf; Rebmann, Corinna; Knohl, Alexander; Ziegler, Waldemar; Schulze, Ernst-Detlef

2008-09-01

Potential losses by advection were estimated at Hainich Forest, Thuringia, Germany, where the tower is located at a gentle slope. Three approaches were used: (1) comparing nighttime eddy covariance fluxes to an independent value of total ecosystem respiration by bottom-up modeling of the underlying processes, (2) direct measurements of a horizontal CO2 gradient and horizontal wind speed at 2 m height in order to calculate horizontal advection, and (3) direct measurements of a vertical CO2 gradient and a three-dimensional wind profile in order to calculate vertical advection. In the first approach, nighttime eddy covariance measurements were compared to independent values of total ecosystem respiration by means of bottom-up modeling of the underlying biological processes. Turbulent fluxes and storage term were normalized to the fluxes calculated by the bottom-up model. Below a u(*) threshold of 0.6 m/s the normalized turbulent fluxes decreased with decreasing u(*), but the flux to the storage increased only up to values less than 20% of the modeled flux at low turbulence. Horizontal advection was measured by a horizontal CO2 gradient over a distance of 130 m combined with horizontal wind speed measurements. Horizontal advection occurred at most of the evenings independently of friction velocity above the canopy. Nevertheless, horizontal advection was higher when u(*) was low. The peaks of horizontal advection correlated with changes in temperature. A full mass balance including turbulent fluxes, storage, and horizontal and vertical advection resulted in an increase of spikes and scatter but seemed to generally improve the results from the flux measurements. The comparison of flux data with independent bottom-up modeling results as well as the direct measurements resulted in strong indications that katabatic flows along the hill slope during evening and night reduces the measured apparent ecosystem respiration rate. In addition, anabatic flows may occur during the morning. We conclude that direct measurements of horizontal and vertical advection are highly necessary at sites located even on gentle hill slopes.

The shape of the Eiffel Tower

NASA Astrophysics Data System (ADS)

Gallant, Joseph

2002-02-01

The distinctive shape of the Eiffel Tower is based on simple physics and is designed so that the maximum torque created by the wind is balanced by the torque due to the Tower's weight. We use this idea to generate an equation for the shape of the Tower. The solution depends only on the width of the base and the maximum wind pressure. We parametrize the wind pressure and reproduce the shape of the Tower. We also discuss some of the Tower's interesting history and characteristics.

THE TOWER HOUSE, LOOKING WEST. The tower house provided a ...

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

THE TOWER HOUSE, LOOKING WEST. The tower house provided a water tank on the second floor that gravity fed water to the Kineth house and farm buildings. The one-story addition to the west of the tower provided workshop space. The hog shed is seen on the left of the image and the concrete foundation of the upright silo is in the foreground on the right. - Kineth Farm, Tower House, 19162 State Route 20, Coupeville, Island County, WA

Development of Meteorological Towers Using Advanced Composite Materials

NASA Astrophysics Data System (ADS)

Alshurafa, Sami A.

The research program involved both numerical and experimental work. The numerical analysis was conducted to simulate the static and dynamic behaviour of the 81 m meteorological FRP guyed tower under wind and ice loading. The FRP tower consisted of 16 segments each made of 3 cells connected together to form an equilateral triangle having equal sides of 450 mm. The segments were interconnected using internal sleeves. Various non-linear finite element models were developed to study a number of design parameters for the 81 m FRP tower such as, different laminates containing a variety of stacking sequences of laminate orientations with various thicknesses, different cable diameters, and appropriate guy cable spacing levels. The effect of pre-stressing the guy cables up to 10 % of their breaking strength was investigated. The effect of fibre volume fraction on the design of the FRP tower was also examined. Furthermore, an 8.6 m FRP tower segment was designed using the finite element analysis and subject to the same loading conditions experienced by the bottom section of the 81 m FRP tower. A modal analysis was carried out for both the 8.6 m FRP tower segment with and without a mass on the top as well as for the 81 m FRP guyed tower to evaluate the vibration performance of these towers. The experimental work involved extensive material testing to define the material properties for use in the analysis of the 81 m FRP tower. It also involved the design and fabrication of a special collapsible mandrel for fabricating the FRP cells for the 8.6 m tower segment. The 8.6 m tower was tested horizontally under static lateral loading to 80 % of its estimated failure load using a "whiffle tree" arrangement, in order to simulate a uniformly distributed wind loading. Later, the same FRP tower was erected in a vertical position and was tested with and without a mass on top under dynamic loading to obtain the natural frequencies. Lastly, a comparative study was conducted between two 81 m FRP towers having different fibre volume fractions and a steel tower having a circular cross section.

69. INTERIOR VIEW OF THE ABSORPTION TOWER BUILDING, ABSORPTION TOWER ...

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

69. INTERIOR VIEW OF THE ABSORPTION TOWER BUILDING, ABSORPTION TOWER UNDER CONSTRUCTION. (DATE UNKNOWN). - United States Nitrate Plant No. 2, Reservation Road, Muscle Shoals, Muscle Shoals, Colbert County, AL

Method and system for simulating heat and mass transfer in cooling towers

DOEpatents

Bharathan, Desikan; Hassani, A. Vahab

1997-01-01

The present invention is a system and method for simulating the performance of a cooling tower. More precisely, the simulator of the present invention predicts values related to the heat and mass transfer from a liquid (e.g., water) to a gas (e.g., air) when provided with input data related to a cooling tower design. In particular, the simulator accepts input data regarding: (a) cooling tower site environmental characteristics; (b) cooling tower operational characteristics; and (c) geometric characteristics of the packing used to increase the surface area within the cooling tower upon which the heat and mass transfer interactions occur. In providing such performance predictions, the simulator performs computations related to the physics of heat and mass transfer within the packing. Thus, instead of relying solely on trial and error wherein various packing geometries are tested during construction of the cooling tower, the packing geometries for a proposed cooling tower can be simulated for use in selecting a desired packing geometry for the cooling tower.

1. Light tower/keeper's house and abandoned light tower, view northwest, ...

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

1. Light tower/keeper's house and abandoned light tower, view northwest, south southeast and east northeast sides - Matinicus Rock Light Station, Matinicus Island, on Matinicus Rock, Matinicus, Knox County, ME

2. Abandoned light tower and keeper's house/light tower, view southeast, ...

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

2. Abandoned light tower and keeper's house/light tower, view southeast, north northwest and west southwest sides - Matinicus Rock Light Station, Matinicus Island, on Matinicus Rock, Matinicus, Knox County, ME

The Potential of Carbonyl Sulfide as a Tracer for Gross Primary Productivity at Flux Tower Sites

USDA-ARS?s Scientific Manuscript database

Regional/continental scale studies of atmospheric carbonyl sulfide (OCS) seasonal dynamics and leaf level studies of plant OCS uptake have shown a close relationship to CO2 dynamics and uptake, suggesting potential for OCS as a tracer for gross primary productivity (GPP). Canopy CO2 and OCS differen...

Wind turbine generator application places unique demands on tower design and materials

NASA Technical Reports Server (NTRS)

Kita, J. P.

1978-01-01

The most relevant contractual tower design requirements and goal for the Mod-1 tower are related to steel truss tower construction, cost-effective state-of-the-art design, a design life of 30 years, and maximum wind conditions of 120 mph at 30 feet elevation. The Mod-1 tower design approach was an iterative process. Static design loads were calculated and member sizes and overall geometry chosen with the use of finite element computer techniques. Initial tower dynamic characteristics were then combined with the dynamic properties of the other wind turbine components, and a series of complex dynamic computer programs were run to establish a dynamic load set and then a second tower design.

Some techniques for reducing the tower shadow of the DOE/NASA mod-0 wind turbine tower. [wind tunnel tests to measure effects of tower structure on wind velocity

NASA Technical Reports Server (NTRS)

Burley, R. R.; Savino, J. M.; Wagner, L. H.; Diedrich, J. H.

1979-01-01

Wind speed profile measurements to measure the effect of a wind turbine tower on the wind velocity are presented. Measurements were made in the wake of scale models of the tower and in the wake of certain full scale components to determine the magnitude of the speed reduction (tower shadow). Shadow abatement techniques tested on the towers included the removal of diagonals, replacement of diagonals and horizontals with round cross section members, installation of elliptical shapes on horizontal members, installation of airfoils on vertical members, and application of surface roughness to vertical members.

Evaluation of Tower Shadowing on Anemometer Measurements at Los Alamos National Laboratory

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

Bruggeman, David Alan

2016-06-14

The objective of this study is to evaluate the effect of tower shadowing from the meteorology towers at LANL during 2014. This study is in response to the Department of Energy Meteorological Coordinating Council visit in 2015 that recommended an evaluation of any biases in the wind data introduced by the tower and boom alignment at all meteorology towers.

Optimal Inflatable Space Towers with 3 - 100 km Height

NASA Technical Reports Server (NTRS)

Bolonkin, Alexander

2003-01-01

Theory and computations are provided for building inflatable space towers up to one hundred kilometers in height. These towers can be used for tourism, scientific observation of space, observation of the Earth's surface, weather and upper atmosphere, and for radio, television, and communication transmissions. These towers can also be used to launch space ships and Earth satellites. These projects are not expensive and do not require rockets. They require thin strong films composed from artificial fibers and fabricated by current industry. The towers can be built using present technology. The towers can be used (for tourism, communication, etc.) during the construction process and provide self-financing for further construction. The tower design does not require work at high altitudes; all construction can be done at the Earth's surface. The transport system for a tower consists of a small engine (used only for friction compensation) located at the Earth's surface. The tower is separated into sections and has special protection mechanisms in case of damage. Problems involving security, control, repair, and stability of the proposed towers are addressed in other publications. The author is prepared to discuss these and other problems with serious organizations desiring to research and develop these projects.

Tower Based Load Measurements for Individual Pitch Control and Tower Damping of Wind Turbines

NASA Astrophysics Data System (ADS)

Kumar, A. A.; Hugues-Salas, O.; Savini, B.; Keogh, W.

2016-09-01

The cost of IPC has hindered adoption outside of Europe despite significant loading advantages for large wind turbines. In this work we presented a method for applying individual pitch control (including for higher-harmonics) using tower-top strain gauge feedback instead of blade-root strain gauge feedback. Tower-top strain gauges offer hardware savings of approximately 50% in addition to the possibility of easier access for maintenance and installation and requiring a less specialised skill-set than that required for applying strain gauges to composite blade roots. A further advantage is the possibility of using the same tower-top sensor array for tower damping control. This method is made possible by including a second order IPC loop in addition to the tower damping loop to reduce the typically dominating 3P content in tower-top load measurements. High-fidelity Bladed simulations show that the resulting turbine spectral characteristics from tower-top feedback IPC and from the combination of tower-top IPC and damping loops largely match those of blade-root feedback IPC and nacelle- velocity feedback damping. Lifetime weighted fatigue analysis shows that the methods allows load reductions within 2.5% of traditional methods.

Recent Results From the NOAA/ESRL GMD Tall Tower Network

NASA Astrophysics Data System (ADS)

Andrews, A. E.; Tans, P. P.; Peters, W.; Hirsch, A.; Sweeney, C.; Petron, G.; Kofler, J.; Zhao, C.; Masarie, K.; Wofsy, S. C.; Matross, D. M.; Mahadevan, P.; Longo, M.; Gerbig, C.; Lin, J. C.

2006-12-01

We will present a summary of new results from NOAA Earth System Research Laboratory`s Tall Tower greenhouse gas monitoring network. The tower network is operated by the Global Monitoring Division, which also maintains the global Cooperative Air Sampling network and a network of aircraft profiling sites over North America. Tall tower CO2 mixing ratio measurements are sensitive to upwind fluxes over scales of hundreds of kilometers, and the primary objective of the tower network is to obtain regionally representative carbon flux estimates for the North American continent. Mixing ratios of CO2 and CO are measured semi-continuously at the towers, and the KWKT-TV tower site near Moody, TX has recently also been equipped with sensors to measure radon and O3. Daily flask samples are collected at the KWKT tower and analyzed for CO2, CO, CH4, SF6, N2O, H2, stable isotopes of CO2 and CH4, COS, and a variety of halocarbon and hydrocarbon species. Daily flask sampling will be implemented at all tower sites within the next few years. We have used the Stochastic Time Inverted Lagrangian Transport (STILT) model to investigate upwind influences on the tower observations. CO measurements provide an indicator of polluted air masses, and we will present a summary of the frequency and origin of pollution events observed at the towers. We will present an analysis of the primary factors contributing to observed CO2 variability along with average seasonal and diurnal cycles of CO2 at the tower sites. Tower measurements are being used to evaluate atmospheric transport models in the context of the Transcom Continuous experiment and are an important constraint for CO2 data assimilation systems that produce regional to global carbon flux estimates with up to weekly resolution.

DETAIL OF VALVE TOWER SHOWING SLUICE GATE ON EAST SIDE ...

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

DETAIL OF VALVE TOWER SHOWING SLUICE GATE ON EAST SIDE OF TOWER. VIEW FACING WEST - Schofield Barracks Military Reservation, Ku Tree Reservoir, Valve Tower, Kalakoa Stream, East Range, Wahiawa, Honolulu County, HI

Formation of protocell-like vesicles in a thermal diffusion column.

PubMed

Budin, Itay; Bruckner, Raphael J; Szostak, Jack W

2009-07-22

Many of the properties of bilayer membranes composed of simple single-chain amphiphiles seem to be well-suited for a potential role as primitive cell membranes. However, the spontaneous formation of membranes from such amphiphiles is a concentration-dependent process in which a significant critical aggregate concentration (cac) must be reached. Since most scenarios for the prebiotic synthesis of fatty acids and related amphiphiles would result in dilute solutions well below the cac, the identification of mechanisms that would lead to increased local amphiphile concentrations is an important aspect of defining reasonable conditions for the origin of cellular life. Narrow, vertically oriented channels within the mineral precipitates of hydrothermal vent towers have previously been proposed to act as natural Clusius-Dickel thermal diffusion columns, in which a strong transverse thermal gradient concentrates dilute molecules through the coupling of thermophoresis and convection. Here we experimentally demonstrate that a microcapillary acting as a thermal diffusion column can concentrate a solution of oleic acid. Upon concentration, self-assembly of large vesicles occurs in regions where the cac is exceeded. We detected vesicle formation by fluorescence microscopy of encapsulated dye cargoes, which simultaneously concentrated in our channels. Our findings suggest a novel means by which simple physical processes could have led to the spontaneous formation of cell-like structures from a dilute prebiotic reservoir.

Genotypic variability and persistence of Legionella pneumophila PFGE patterns in 34 cooling towers from two different areas.

PubMed

Sanchez, Inma; Garcia-Nuñez, Marian; Ragull, Sonia; Sopena, Nieves; Pedro-Botet, Maria Luisa; Estere, Maria; Rey-Joly, Celestino; Sabria, Miquel; Esteve, Maria

2008-02-01

Genotypic variability and clonal persistence are important concepts in molecular epidemiology as they facilitate the search for the source of sporadic cases or outbreaks of legionellosis. We studied the genotypic variability and persistence of Legionella pulsed-field gel electrophoresis (PFGE) patterns over time (period > 6 months) in 34 positive cooling towers from two different areas. In area A, radius of 70 km, 52 indistinguishable PFGE patterns were differentiated among the 27 cooling towers. In 13 cooling towers we observed >or= 2 PFGE patterns. Each cooling tower had its own indistinguishable Legionella PFGE pattern which was not shared with any other cooling tower. In area B, radius of 1 km, 10 indistinguishable PFGE patterns were obtained from the seven cooling towers. In four, we observed >or= 2 PFGE patterns. Three of these 10 indistinguishable PFGE patterns were shared by more than one cooling tower. In 27 of 34 cooling towers the same PFGE pattern was recovered after 6 months to up to 5 years of follow-up. The large genotypic diversity of Legionella observed in the cooling towers aids in the investigation of community outbreaks of Legionnaires' disease. However, shared patterns in small areas may confound the epidemiological investigation. The persistence of some PFGE patterns in cooling towers makes the recovery of the Legionella isolate causing the outbreak possible over time.

Effect of solar radiation on the performance of cross flow wet cooling tower in hot climate of Iran

NASA Astrophysics Data System (ADS)

Banooni, Salem; Chitsazan, Ali

2016-11-01

In some cities such as Ahvaz-Iran, the solar radiation is very high and the annual-mean-daily of the global solar radiation is about 17.33 MJ m2 d-1. Solar radiation as an external heat source seems to affect the thermal performance of the cooling towers. Usually, in modeling cooling tower, the effects of solar radiation are ignored. To investigate the effect of sunshade on the performance and modeling of the cooling tower, the experiments were conducted in two different states, cooling towers with and without sunshade. In this study, the Merkel's approach and finite difference technique are used to predict the thermal behavior of cross flow wet cooling tower without sunshade and the results are compared with the data obtained from the cooling towers with and without sunshade. Results showed that the sunshade is very efficient and it reduced the outlet water temperature, the approach and the water exergy of the cooling tower up to 1.2 °C, 15 and 1.1 %, respectively and increased the range and the efficiency of the cooling tower up to 29 and 37 %, respectively. Also, the sunshade decreased the error between the experimental data of the cooling tower with sunshade and the modeling results of the cooling tower without sunshade 1.85 % in average.

3. VIEW NORTHWEST, height finder radar towers, and radar tower ...

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

3. VIEW NORTHWEST, height finder radar towers, and radar tower (unknown function) - Fort Custer Military Reservation, P-67 Radar Station, .25 mile north of Dickman Road, east of Clark Road, Battle Creek, Calhoun County, MI

Cyanobacterial composition of microbial mats from an Australian thermal spring: a polyphasic evaluation.

PubMed

McGregor, Glenn B; Rasmussen, J Paul

2008-01-01

Cyanobacterial composition of microbial mats from an alkaline thermal spring issuing at 43-71 degrees C from tropical north-eastern Australia are described using a polyphasic approach. Eight genera and 10 species from three cyanobacterial orders were identified based on morphological characters. These represented taxa previously known as thermophilic from other continents. Ultrastructural analysis of the tower mats revealed two filamentous morphotypes contributed the majority of the biomass. Both types had ultrastructural characteristics of the family Pseudanabaenaceae. DNA extracts were made from sections of the tentaculiform towers and the microbial community analysed by 16S cyanobacteria-specific PCR and denaturing-gradient gel electrophoresis. Five significant bands were identified and sequenced. Two bands clustered closely with Oscillatoria amphigranulata isolated from New Zealand hot springs; one unique phylotype had only moderate similarity to a range of Leptolyngbya species; and one phylotype was closely related to a number of Geitlerinema species. Generally the approaches yielded complementary information, however the results suggest that species designation based on morphological and ultrastructural criteria alone often fails to recognize their true phylogenetic position. Conversely some molecular techniques may fail to detect rare taxa suggesting that the widest possible suite of techniques be applied when conducting analyses of cyanobacterial diversity of natural populations. This is the first polyphasic evaluation of thermophilic cyanobacterial communities from the Australian continent.

Effect of environmental conditions on the relationship between solar-induced fluorescence and gross primary productivity at an OzFlux grassland site

NASA Astrophysics Data System (ADS)

Verma, Manish; Schimel, David; Evans, Bradley; Frankenberg, Christian; Beringer, Jason; Drewry, Darren T.; Magney, Troy; Marang, Ian; Hutley, Lindsay; Moore, Caitlin; Eldering, Annmarie

2017-03-01

Recent studies have utilized coarse spatial and temporal resolution remotely sensed solar-induced fluorescence (SIF) for modeling terrestrial gross primary productivity (GPP) at regional scales. Although these studies have demonstrated the potential of SIF, there have been concerns about the ecophysiological basis of the relationship between SIF and GPP in different environmental conditions. Launched in 2014, the Orbiting Carbon Observatory-2 (OCO-2) has enabled fine-scale (1.3 by 2.5 km) retrievals of SIF that are comparable with measurements recorded at eddy covariance towers. In this study, we examine the effect of environmental conditions on the relationship of OCO-2 SIF with tower GPP over the course of a growing season at a well-characterized natural grassland site. Combining OCO-2 SIF and eddy covariance tower data with a canopy radiative transfer and an ecosystem model, we also assess the potential of OCO-2 SIF to constrain the estimates of Vcmax, one of the most important parameters in ecosystem models. Based on the results, we suggest that although environmental conditions play a role in determining the nature of relationship between SIF and GPP, overall, the linear relationship is more robust at ecosystem scale than the theory based on leaf-level processes might suggest. Our study also shows that the ability of SIF to constrain Vcmax is weak at the selected site.

Detecting Soil Moisture Related Impacts on Gross Primary Productivity using the MODIS-based Photochemical Reflectance Index

NASA Astrophysics Data System (ADS)

He, M.; Kimball, J. S.; Running, S. W.; Ballantyne, A.; Guan, K.; Huemmrich, K. F.

2016-12-01

Satellite remote sensing provides continuous observations of vegetation properties that can be used to estimate ecosystem gross primary production (GPP). The Photochemical Reflectance Index (PRI) has been shown to be sensitive to photosynthetic light use efficiency (LUE), GPP and canopy water-stress. The NASA EOS MODIS (Moderate Resolution Imaging Spectroradiometer) sensor provides potential PRI estimation globally at daily time step and 1-km spatial resolution for more than 10 years. Here, we use the MODIS based PRI with eddy covariance CO2 flux measurements and meteorological observations from 20 tower sites representing 5 major plant functional types (PFT) within the continental USA (CONUS) to assess GPP sensitivity to seasonal water supply variability. The sPRI (scaled PRI) derived using MODIS band 13 as a reference band (sPRI13) generally shows higher correspondence with tower GPP observations than other potential MODIS reference bands (MODIS band 1, 4, 10 and 12). The sPRI13 was used to represent soil moisture related water supply constraints to LUE within a terrestrial carbon flux model to estimate GPP (GPPPRI). The GPPPRI calculations show generally strong relationships with tower GPP observations (0.457 ≤ R2 ≤ 0.818), except for lower GPPPRI performance over evergreen needleleaf forest (ENF) sites. A regional model sensitivity analysis using the sPRI13 as a proxy for soil moisture related water supply limits indicated that water restrictions limit GPP over more than 21% of the CONUS domain, particularly in northwest and southwest CONUS subregions, and drier climate areas where atmospheric moisture deficits (VPD) alone are insufficient to represent both atmosphere demand and soil water supply controls affecting productivity. Our results indicate strong potential of the MODIS sPRI13 to represent GPP sensitivity to seasonal soil moisture related water supply variability, with enhanced (1-km resolution) delineation of these processes closer to the scale of in situ tower observations, providing an effective tool to characterize sub-grid spatial heterogeneity in soil moisture related water supply controls that inform coarser scale observations and estimates determined from other satellite observations and global carbon, and climate models.

A comment on towers for windmills. [structural and economic criteria

NASA Technical Reports Server (NTRS)

Budgen, H. P.

1973-01-01

Design considerations for windmill tower structures include the effects of normal wind forces on the rotor and on the tower. Circular tabular or masonry towers present a relatively simple aerodynamic solution. Economic factors establish the tubular tower as superior for small and medium sized windmills. Concrete and standard concrete block designs are cheaper than refabricated steel structures that have to be freighted.

Comparing MODIS and near-surface vegetation indexes for monitoring tropical dry forest phenology along a successional gradient using optical phenology towers

NASA Astrophysics Data System (ADS)

Rankine, C.; Sánchez-Azofeifa, G. A.; Guzmán, J. Antonio; Espirito-Santo, M. M.; Sharp, Iain

2017-10-01

Tropical dry forests (TDFs) present strong seasonal greenness signals ideal for tracking phenology and primary productivity using remote sensing techniques. The tightly synchronized relationship these ecosystems have with water availability offer a valuable natural experiment for observing the complex interactions between the atmosphere and the biosphere in the tropics. To investigate how well the MODIS vegetation indices (normalized difference vegetation index (NDVI) and the enhanced vegetation index (EVI)) represented the phenology of different successional stages of naturally regenerating TDFs, within a widely conserved forest fragment in the semi-arid southeast of Brazil, we installed several canopy towers with radiometric sensors to produce high temporal resolution near-surface vegetation greenness indices. Direct comparison of several years of ground measurements with a combined Aqua/Terra 8 day satellite product showed similar broad temporal trends, but MODIS often suffered from cloud contamination during the onset of the growing season and occasionally during the peak growing season. The strength of the in-situ and MODIS linear relationship was greater for NDVI than for EVI across sites but varied with forest stand age. Furthermore, we describe the onset dates and duration of canopy development phases for three years of in-situ monitoring. A seasonality analysis revealed significant discrepancies between tower and MODIS phenology transitions dates, with up to five weeks differences in growing season length estimation. Our results indicate that 8 and 16 day MODIS satellite vegetation monitoring products are suitable for tracking general patterns of tropical dry forest phenology in this region but are not temporally sufficient to characterize inter-annual differences in phenology phase onset dates or changes in productivity due to mid-season droughts. Such rapid transitions in canopy greenness are important indicators of climate change sensitivity of these already endangered forest ecosystems and should be further monitored using both ground and satellite approaches.

Observing BVOC Emissions, Oxidation, Deposition, and Interactions with Anthropogenic Pollutants to Form SOA in the Southeast United States

NASA Astrophysics Data System (ADS)

Goldstein, A. H.; Isaacman, G. A.; Misztal, P. K.; Yee, L.; Olson, K. F.; Moss, J.; Kreisberg, N. M.; Hering, S. V.; Park, J. H.; Kaser, L.; Seco, R.; Guenther, A. B.; Su, L.; Mak, J. E.; Holzinger, R.; Hu, W.; Campuzano Jost, P.; Palm, B. B.; Day, D. A.; Jimenez, J. L.; Koss, A.; De Gouw, J. A.

2014-12-01

Our overarching goals in the SOAS 2013 campaign were to 1) quantify biogenic VOC emission and VOC deposition to understand the processes controlling these bi-directional exchanges, 2) observe a broad suite of primary VOC and their oxidation products in the field and in controlled laboratory experiments, and 3) investigate their fate to understand how anthropogenic pollution alters oxidation pathways and secondary organic aerosol (SOA) formation. We pursued these goals through measurement of atmospheric organics ranging from very volatile (using in-situ GC-MS and proton transfer reaction time-of-flight MS, PTR-ToF-MS) to semi-volatile gas and particle phase compounds (using the Semi-Volatile Thermal desorption Aerosol Gas chromatograph, SV-TAG). Measured concentrations and fluxes of VOCs at the top of the SEARCH tower were coordinated with concentration gradients and fluxes at the AABC flux tower site, and vertical profiles using the Long-EZ aircraft to provide equivalent observations across sites. These results are informed through measurements using the same instrument during the FIXIT controlled laboratory oxidation study at CalTech that investigated oxidation pathways of BVOC with varying levels of anthropogenic pollutants. Measurements by SV-TAG of particle-phase and total gas-plus-particle-phase compounds at the SEARCH tower provide hourly quantification of semi-volatile compounds, including the oxidation products of measured VOCs. Derivatization of hydroxyl groups prior to GC analysis allows analysis of highly oxidized chemicals, including most known tracers. Methyl tetrols, an oxidation product of isoprene, had a significant day-time gas-phase component, and their abundance was strongly correlated with particle-phase sulfate, indicative of anthropogenic influence on the formation or partitioning processes. Similar observations of pinic acid (monterpene oxidation product) and many other BVOC oxidation products were made in both the gas and particle phases. Through measurements of specific chemical tracers across a wide range of volatilities, we explore the chemical lifecycle of BVOCs to understand anthropogenic-biogenic interactions in aerosol formation.

Aerosol Effects on Radiation and Climate: Column Closure Experiments with Towers, Aircraft, and Satellites

NASA Technical Reports Server (NTRS)

Russell, Philip B.

1994-01-01

Many theoretical studies have shown that anthropogenic aerosol particles can change the radiation balance in an atmospheric column and might thereby exert a significant effect on the Earth's climate. In particular, recent calculations have shown that sulfate particles from anthropogenic combustion may already exert a cooling influence on the Earth that partially offsets the warming caused by the greenhouse gases from the same combustion. Despite the potential climatic importance of anthropogenic aerosols, simultaneous measurements of anthropogenic aerosol properties and their effect on atmospheric radiation have been very rare. Successful comparisons of measured radiation fields with those calculated from aerosol measurements - now referred to as column closure comparisons - are required to improve the accuracy and credibility of climate predictions. This paper reviews the column closure experiment performed at the Mt. Sutro Tower in San Francisco in 1975, in which elevated radiometers measured the change in Earth-plus-atmosphere albedo caused by an aerosol layer, while a lidar, sunphotometer, nephelometer, and other radiometers measured properties of the responsible aerosol. The time-dependent albedo calculated from the measured aerosol properties agreed with that measured by the tower radiometers. Also presented are designs for future column closure studies using radiometers and aerosol instruments on the ground, aircraft, and satellites. These designs draw upon algorithms and experience developed in the Sutro Tower study, as well as more recent experience with current measurement and analysis capabilities.

Research approach and first results on agglomerate compaction in protoplanetary dust simulation in the Cloud Manipulation System

NASA Astrophysics Data System (ADS)

Vedernikov, Andrei; Blum, Jurgen; Ingo Von Borstel, Olaf; Schraepler, Rainer; Balapanov, Daniyar; Cecere, Anselmo

2016-07-01

Nanometre and micrometre-sized solid particles are ubiquitous in space and on Earth - from galaxies, interstellar space, protoplanetary and debris disks to planetary rings and atmospheres, planetary surfaces, comets, interplanetary space, Earth's atmosphere. Apparently, the most intriguing problem in the picture of the formation of planets is the transition from individual microscopic dust grains to kilometre-sized planetesimals. Revealing the mechanisms of this transition is one of the main tasks of the European Space Agency's project Interaction in Cosmic and Atmospheric Particle Systems (ICAPS). It was found that Brownian motion driven agglomeration could not provide the transition within reasonable time scale. As a result, at this stage top scientific goals shifted towards forced agglomeration and concentration of particles, targeting revealing the onset of compaction, experimental study of the evolution of fractal dimensions, size and mass distribution, occurrence of bouncing. The main tasks comprise 1) development of the rapid agglomeration model 2) development of the experimental facilities creating big fractal-type agglomerates from 10 to 1000 μm from a cloud of micrometre-size grains; 3) experimental realization of the rapid agglomeration in microgravity and ground conditions; and 4) in situ investigation of the morphology, mobility, mechanical and optical properties of the free-floating agglomerates, including investigation of thermophoresis, photophoresis of the agglomerates and of the two-phase flow phenomena. To solve the experimental part of the tasks we developed a Cloud Manipulation System, realized as a breadboard (CMS BB) for long duration microgravity platforms and a simplified laboratory version (CMS LV) mostly oriented on short duration microgravity and ground tests. The new system is based on the use of thermophoresis, most favourable for cloud manipulation without creating additional particle-particle forces in the cloud with a possibility of growing single agglomerate out of the whole cloud. The cloud manipulation system additionally provides temperature stabilization or, on the contrary, high temperature variation in the observation volume; formation of controlled temperature gradients, intensive three-dimensional periodic shear flow or three-dimensional gas density pulsations of the contraction-expansion type; application of electrostatic gradients including electro dynamic balancing; imposing of photophoretic force, etc. Their choice and/or combination depend upon particular experimental task. Experiments on forced agglomeration in short duration microgravity conditions of the Bremen drop tower succeeded in rapid growth of extended agglomerates, formation of complex three-dimensional cloud patterns, allowed observing controlled cloud displacement, cloud trapping, particle separation with respect to their electrical charge. The breadboard (CMS BB) and the laboratory version of the Cloud Manipulation System (CMS LV) are new types of scientific instrument with high scientific potential. ESA PRODEX program, the Belgian Federal Science Policy Office, DLR project 50WM1223, ZARM Drop Tower Operation and Service Company Ltd. are greatly acknowledged.

Model equations for the Eiffel Tower profile: historical perspective and new results

NASA Astrophysics Data System (ADS)

Weidman, Patrick; Pinelis, Iosif

2004-07-01

Model equations for the shape of the Eiffel Tower are investigated. One model purported to be based on Eiffel's writing does not give a tower with the correct curvature. A second popular model not connected with Eiffel's writings provides a fair approximation to the tower's skyline profile of 29 contiguous panels. Reported here is a third model derived from Eiffel's concern about wind loads on the tower, as documented in his communication to the French Civil Engineering Society on 30 March 1885. The result is a nonlinear, integro-differential equation which is solved to yield an exponential tower profile. It is further verified that, as Eiffel wrote, "in reality the curve exterior of the tower reproduces, at a determined scale, the same curve of the moments produced by the wind". An analysis of the actual tower profile shows that it is composed of two piecewise continuous exponentials with different growth rates. This is explained by specific safety factors for wind loading that Eiffel & Company incorporated in the design of the free-standing tower. To cite this article: P. Weidman, I. Pinelis, C. R. Mecanique 332 (2004).

Fire ants perpetually rebuild sinking towers.

PubMed

Phonekeo, Sulisay; Mlot, Nathan; Monaenkova, Daria; Hu, David L; Tovey, Craig

2017-07-01

In the aftermath of a flood, fire ants, Solenopsis invicta , cluster into temporary encampments. The encampments can contain hundreds of thousands of ants and reach over 30 ants high. How do ants build such tall structures without being crushed? In this combined experimental and theoretical study, we investigate the shape and rate of construction of ant towers around a central support. The towers are bell shaped, consistent with towers of constant strength such as the Eiffel tower, where each element bears an equal load. However, unlike the Eiffel tower, the ant tower is built through a process of trial and error, whereby failed portions avalanche until the final shape emerges. High-speed and novel X-ray videography reveal that the tower constantly sinks and is rebuilt, reminiscent of large multicellular systems such as human skin. We combine the behavioural rules that produce rafts on water with measurements of adhesion and attachment strength to model the rate of growth of the tower. The model correctly predicts that the growth rate decreases as the support diameter increases. This work may inspire the design of synthetic swarms capable of building in vertical layers.

Fire ants perpetually rebuild sinking towers

NASA Astrophysics Data System (ADS)

Phonekeo, Sulisay; Mlot, Nathan; Monaenkova, Daria; Hu, David L.; Tovey, Craig

2017-07-01

In the aftermath of a flood, fire ants, Solenopsis invicta, cluster into temporary encampments. The encampments can contain hundreds of thousands of ants and reach over 30 ants high. How do ants build such tall structures without being crushed? In this combined experimental and theoretical study, we investigate the shape and rate of construction of ant towers around a central support. The towers are bell shaped, consistent with towers of constant strength such as the Eiffel tower, where each element bears an equal load. However, unlike the Eiffel tower, the ant tower is built through a process of trial and error, whereby failed portions avalanche until the final shape emerges. High-speed and novel X-ray videography reveal that the tower constantly sinks and is rebuilt, reminiscent of large multicellular systems such as human skin. We combine the behavioural rules that produce rafts on water with measurements of adhesion and attachment strength to model the rate of growth of the tower. The model correctly predicts that the growth rate decreases as the support diameter increases. This work may inspire the design of synthetic swarms capable of building in vertical layers.

Fire ants perpetually rebuild sinking towers

PubMed Central

Phonekeo, Sulisay; Mlot, Nathan; Monaenkova, Daria; Tovey, Craig

2017-01-01

In the aftermath of a flood, fire ants, Solenopsis invicta, cluster into temporary encampments. The encampments can contain hundreds of thousands of ants and reach over 30 ants high. How do ants build such tall structures without being crushed? In this combined experimental and theoretical study, we investigate the shape and rate of construction of ant towers around a central support. The towers are bell shaped, consistent with towers of constant strength such as the Eiffel tower, where each element bears an equal load. However, unlike the Eiffel tower, the ant tower is built through a process of trial and error, whereby failed portions avalanche until the final shape emerges. High-speed and novel X-ray videography reveal that the tower constantly sinks and is rebuilt, reminiscent of large multicellular systems such as human skin. We combine the behavioural rules that produce rafts on water with measurements of adhesion and attachment strength to model the rate of growth of the tower. The model correctly predicts that the growth rate decreases as the support diameter increases. This work may inspire the design of synthetic swarms capable of building in vertical layers. PMID:28791170

Evaluating the relationships between solar-induced chlorophyll fluorescence from Orbiting Carbon Observatory-2 and gross primary productivity from eddy covariance flux towers

NASA Astrophysics Data System (ADS)

Li, X.; Xiao, J.; He, B.

2017-12-01

Solar-induced chlorophyll fluorescence (SIF) opens a new perspective on the monitoring of vegetation photosynthesis from space, and has been recently used to estimate gross primary productivity (GPP). However, previous studies on SIF were mainly based on satellite observations from the Greenhouse Gases Observing Satellite (GOSAT) and Global Ozone Monitoring Experiment-2 (GOME-2), and the evaluation of these coarse-resolution SIF measurements using GPP derived from eddy covariance (EC) flux towers has been hindered by the scale mismatch between satellite and tower footprints. We use new far-red SIF observations from the Orbiting Carbon Observatory-2 (OCO-2) satellite with much finer spatial resolution and GPP data from EC flux towers from 2014 to 2016 to examine the relationship between GPP and SIF for temperate forests. The OCO-2 SIF tracked tower GPP fairly well, and had strong correlation with tower GPP at both retrieval bands (757nm and 771nm) and both instantaneous (mid-day) and daily timescales. Daily SIF at 757nm (SIF757) exhibited much stronger correlation with tower GPP compared to MODIS enhanced vegetation index (EVI) and normalized difference vegetation index (NDVI) derived from either Terra or Aqua and had a similarly strong relationship as EVI based on the bidirectional reflectance distribution function (BRDF) corrected reflectance product (Terra+Aqua). Absorbed photosynthetically active radiation (APAR) explained 85% of the variance in SIF757, while the product of APAR and two environmental scalars - fTmin and fVPD (representing minimum temperature stress and water stress) explained slightly higher variance (92%) in SIF757. This suggests that SIF mainly depends on APAR and also contains information on light use efficiency (LUE) reflecting environmental stresses and physiological or biochemical variations of vegetation. The hyperbolic model based on SIF757 estimated GPP well (R2=0.81, p<0.0001; RMSE=1.11 gC m-2 d-1), and its performance was comparable to or slightly better than that of a LUE-based GPP model - the MODSI GPP algorithm. Our findings demonstrate the strong predictive ability of OCO-2 SIF in estimating GPP for temperate forests and its potential in future ecosystem functioning and carbon cycling studies.

High-precision quasi-continuous atmospheric greenhouse gas measurements at Trainou tower (Orléans forest, France)

NASA Astrophysics Data System (ADS)

Schmidt, M.; Lopez, M.; Yver Kwok, C.; Messager, C.; Ramonet, M.; Wastine, B.; Vuillemin, C.; Truong, F.; Gal, B.; Parmentier, E.; Cloué, O.; Ciais, P.

2014-07-01

Results from the Trainou tall tower measurement station installed in 2006 are presented for atmospheric measurements of CO2, CH4, N2O, SF6, CO, H2 mole fractions and radon-222 activity. Air is sampled from four sampling heights (180, 100, 50 and 5 m) of the Trainou 200 m television tower in the Orléans forest in France (47°57'53" N, 2°06'45" E, 131 m a.s.l.). The station is equipped with a custom-built CO2 analyser (CARIBOU), which is based on a commercial non-dispersive, infrared (NDIR) analyser (Licor 6252), and a coupled gas chromatography (GC) system equipped with an electron capture detector (ECD) and a flame ionization detector (FID) (HP6890N, Agilent) and a reduction gas detector (PP1, Peak Performer). Air intakes, pumping and air drying system are shared between the CARIBOU and the GC systems. The ultimately achieved short-term repeatability (1 sigma, over several days) for the GC system is 0.05 ppm for CO2, 1.4 ppb for CH4, 0.25 ppb for N2O, 0.08 ppb for SF6, 0.88 ppb for CO and 3.8 for H2. The repeatability of the CARIBOU CO2 analyser is 0.06 ppm. In addition to the in situ measurements, weekly flask sampling is performed, and flask air samples are analysed at the Laboratoire des Sciences du Climat et de l'Environnement (LSCE) central laboratory for the same species as well for stable isotopes of CO2. The comparison between in situ measurements and the flask sampling showed averaged differences of 0.08 ± 1.40 ppm for CO2, 0.7 ± 7.3 ppb for CH4, 0.6 ± 0.6 ppb for N2O, 0.01 ± 0.10 ppt for SF6, 1.5± 5.3 ppb for CO and 4.8± 6.9 ppb for H2 for the years 2008-2012. At Trainou station, the mean annual increase rates from 2007 to 2011 at the 180 m sampling height were 2.2 ppm yr-1 for CO2, 4 ppb yr-1 for CH4, 0.78 ppb yr-1 for N2O and 0.29 ppt yr-1 for SF6. For all species, the 180 m sampling level showed the smallest diurnal variation. Mean diurnal gradients between the 50 m and the 180 m sampling level reached up to 30 ppm CO2, 15 ppm CH4 or 0.5 ppb N2O during nighttime whereas the mean gradients are smaller than 0.5 ppm for CO2 and 1.5 ppb for CH4 during afternoon.

Changes in arctic and boreal ecosystem productivity in response to changes in growing season length

NASA Astrophysics Data System (ADS)

Hmimina, G.; Yu, R.; Billesbach, D. P.; Huemmrich, K. F.; Gamon, J. A.

2017-12-01

Large-scale greening and browning trends have been reported in northern terrestrial ecosystems over the last two decades. The greening is interpreted as an increased productivity in response to increases in temperature. Boreal and arctic ecosystem productivity is expected to increase as the length of growing seasons increases, resulting in a bigger northern carbon sink pool. While evidences of such greening based on the use of remotely-sensed vegetation indices are compelling, analysis over the sparse network of flux tower sites available in northern latitudes paint a more complex story, and raise some issues as to whether vegetation indices based on NIR reflectance at large spatial scales are suited to the analysis of very fragmented landscapes that exhibit strong patterns in snow and standing water cover. In a broader sense, whether "greenness" is a sufficiently good proxy of ecosystem productivity in northern latitudes is unclear. The current work focused on deriving continuous estimates of ecosystem potential productivity and photosynthesis limitation over a network of flux towers, and on analyzing the relationships between potential yearly productivity and the length of the growing season over time and space. A novel partitioning method was used to derive ecophysiological parameters from sparse carbon fluxes measurements, and those parameters were then used to delimit the growing season and to estimate potential yearly productivity over a wide range of ecosystems. The relationships obtained between those two metrics were then computed for each of the 23 studied sites, exhibiting a wide range of different responses to changes in growing season length. While an overall significant increasing productivity trend was found (R²=0.12) suggesting increased productivity, the more northern sites exhibited a consistent decreasing trend (0.11 The attribution of these trends to either changes in potential productivity or productivity limitation by abiotic factors will be discussed, as well as the potential of extending this analysis over space by using remote-sensing data along with flux tower data.

2. Southern Light Tower and Northern Light Tower, view north, ...

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

2. Southern Light Tower and Northern Light Tower, view north, south sides - Kennebec River Light Station, South side of Doubling Point Road, off State Highway 127, 1.8 miles south of U.S. Route 1, Arrowsic, Sagadahoc County, ME

Surface and Tower Meteorological Instrumentation at NSA Handbook - January 2006

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

MT Ritsche

2006-01-30

The Surface and Tower Meteorological Instrumentation at Atqasuk (METTWR2H) uses mainly conventional in situ sensors to measure wind speed, wind direction, air temperature, dew point and humidity mounted on a 10-m tower. It also obtains barometric pressure, visibility, and precipitation data from sensors at or near the base of the tower. In addition, a Chilled Mirror Hygrometer is located at 1 m for comparison purposes. Temperature and relative humidity probes are mounted at 2 m and 5 m on the tower. For more information, see the Surface and Tower Meteorological Instrumentation at Atqasuk Handbook.

Load-Direction-Derived Support Structures for Wind Turbines: A Lattice Tower Concept and Preparations for Future Certifications: Preprint

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

Jonkman, Jason; Damiani, Rick R; Struve, Achim

The call for more cost-effective and environmentally friendly tower concepts is motivated by tower costs [1] and tower CO2-emission contributions [2], which are high relative to the whole wind turbine system. The proposed rotatable tower concept with yaw bearing at the bottom instead of the top of the tower will provide beneficial economic and environmental impacts to the turbine system. This wind alignment capability indicates a load-direction-derived tower design. By combining this approach with a lattice concept, large material and cost savings for the tower can be achieved. This paper presents a way to analyze and verify the proposed designmore » through aero-servo-elastic simulations, which make future certifications of rotatable tower concepts viable. For this reason, the state-of-the-art, open-source lattice-tower finite-element-method (FEM) module SubDyn [10], developed by the National Renewable Energy Laboratory, has been modified to account for arbitrary member cross-sections. Required changes in the beam element stiffness and mass matrix formulation took place according to an energy method [13]. All validated adaptions will be usable within the aero-servo-elastic simulation framework FAST and are also beneficial for other nonrotatable lattice structures.« less

Mapping carbon flux uncertainty and selecting optimal locations for future flux towers in the Great Plains

USGS Publications Warehouse

Gu, Yingxin; Howard, Daniel M.; Wylie, Bruce K.; Zhang, Li

2012-01-01

Flux tower networks (e. g., AmeriFlux, Agriflux) provide continuous observations of ecosystem exchanges of carbon (e. g., net ecosystem exchange), water vapor (e. g., evapotranspiration), and energy between terrestrial ecosystems and the atmosphere. The long-term time series of flux tower data are essential for studying and understanding terrestrial carbon cycles, ecosystem services, and climate changes. Currently, there are 13 flux towers located within the Great Plains (GP). The towers are sparsely distributed and do not adequately represent the varieties of vegetation cover types, climate conditions, and geophysical and biophysical conditions in the GP. This study assessed how well the available flux towers represent the environmental conditions or "ecological envelopes" across the GP and identified optimal locations for future flux towers in the GP. Regression-based remote sensing and weather-driven net ecosystem production (NEP) models derived from different extrapolation ranges (10 and 50%) were used to identify areas where ecological conditions were poorly represented by the flux tower sites and years previously used for mapping grassland fluxes. The optimal lands suitable for future flux towers within the GP were mapped. Results from this study provide information to optimize the usefulness of future flux towers in the GP and serve as a proxy for the uncertainty of the NEP map.

The Drop Tower Bremen -Experiment Operation

NASA Astrophysics Data System (ADS)

Könemann, Thorben; von Kampen, Peter; Rath, Hans J.

The idea behind the drop tower facility of the Center of Applied Space Technology and Micro-gravity (ZARM) in Bremen is to provide an inimitable technical opportunity of a daily access to short-term weightlessness on earth. In this way ZARM`s european unique ground-based microgravity laboratory displays an excellent economic alternative for research in space-related conditions at low costs comparable to orbital platforms. Many national and international ex-perimentalists motivated by these prospects decide to benefit from the high-quality and easy accessible microgravity environment only provided by the Drop Tower Bremen. Corresponding experiments in reduced gravity could open new perspectives of investigation methods and give scientists an impressive potential for a future technology and multidisciplinary applications on different research fields like Fundamental Physics, Astrophysics, Fluid Dynamics, Combus-tion, Material Science, Chemistry and Biology. Generally, realizing microgravity experiments at ZARM`s drop tower facility meet new requirements of the experimental hardware and may lead to some technical constraints in the setups. In any case the ZARM Drop Tower Operation and Service Company (ZARM FAB mbH) maintaining the drop tower facility is prepared to as-sist experimentalists by offering own air-conditioned laboratories, clean rooms, workshops and consulting engineers, as well as scientific personal. Furthermore, ZARM`s on-site apartment can be used for accommodations during the experiment campaigns. In terms of approaching drop tower experimenting, consulting of experimentalists is mandatory to successfully accomplish the pursued drop or catapult capsule experiment. For this purpose there will be a lot of expertise and help given by ZARM FAB mbH in strong cooperation to-gether with the experimentalists. However, in comparison to standard laboratory setups the drop or catapult capsule setup seems to be completely different at first view. While defining a microgravity project at the Drop Tower Bremen, interesting experimentalists should keep in mind generally reducing dimensions and masses of their common laboratory setups to meet the capsule constraints: overall payload height 980mm/1730mm (short/long drop capsule) and 950mm (catapult capsule); area of each capsule platform 0,359sqm; maximum payload mass 274kg/234kg (short/long drop capsule) and 163,8kg (catapult capsule). The base equipments of each capsule are the Capsule Control System (CCS) to remote control the experiment and the rechargeable battery pack (24V/40A) for the experiment operation. Moreover, the exper-iment components must be able to withstand maximum decelerations of 50g while the short capsule impact of about 200ms, and maximum accelerations of 30g while catapult launch with a duration of about 300ms. In our second talk concerning ZARM`s drop tower facility we will go on with detailed infor-mations about the technical base setups of the drop and the catapult capsule structure to completely handle a freely falling experiment. Furthermore, we will summarize interesting current drop tower projects as an outlook to present you the range of opportunities at the ground-based short-term microgravity laboratory of ZARM.

Role of bacterial adhesion in the microbial ecology of biofilms in cooling tower systems.

PubMed

Liu, Yang; Zhang, Wei; Sileika, Tadas; Warta, Richard; Cianciotto, Nicholas P; Packman, Aaron

2009-01-01

The fate of the three heterotrophic biofilm forming bacteria, Pseudomonas aeruginosa, Klebsiella pneumoniae and Flavobacterium sp. in pilot scale cooling towers was evaluated both by observing the persistence of each species in the recirculating water and the formation of biofilms on steel coupons placed in each cooling tower water reservoir. Two different cooling tower experiments were performed: a short-term study (6 days) to observe the initial bacterial colonization of the cooling tower, and a long-term study (3 months) to observe the ecological dynamics with repeated introduction of the test strains. An additional set of batch experiments (6 days) was carried out to evaluate the adhesion of each strain to steel surfaces under similar conditions to those found in the cooling tower experiments. Substantial differences were observed in the microbial communities that developed in the batch systems and cooling towers. P. aeruginosa showed a low degree of adherence to steel surfaces both in batch and in the cooling towers, but grew much faster than K. pneumoniae and Flavobacterium in mixed-species biofilms and ultimately became the dominant organism in the closed batch systems. However, the low degree of adherence caused P. aeruginosa to be rapidly washed out of the open cooling tower systems, and Flavobacterium became the dominant microorganism in the cooling towers in both the short-term and long-term experiments. These results indicate that adhesion, retention and growth on solid surfaces play important roles in the bacterial community that develops in cooling tower systems.

Role of bacterial adhesion in the microbial ecology of biofilms in cooling tower systems

PubMed Central

Liu, Yang; Zhang, Wei; Sileika, Tadas; Warta, Richard; Cianciotto, Nicholas P.; Packman, Aaron

2009-01-01

The fate of the three heterotrophic biofilm forming bacteria, Pseudomonas aeruginosa, Klebsiella pneumoniae and Flavobacterium sp. in pilot scale cooling towers was evaluated both by observing the persistence of each species in the recirculating water and the formation of biofilms on steel coupons placed in each cooling tower water reservoir. Two different cooling tower experiments were performed: a short-term study (6 days) to observe the initial bacterial colonization of the cooling tower, and a long-term study (3 months) to observe the ecological dynamics with repeated introduction of the test strains. An additional set of batch experiments (6 days) was carried out to evaluate the adhesion of each strain to steel surfaces under similar conditions to those found in the cooling tower experiments. Substantial differences were observed in the microbial communities that developed in the batch systems and cooling towers. P. aeruginosa showed a low degree of adherence to steel surfaces both in batch and in the cooling towers, but grew much faster than K. pneumoniae and Flavobacterium in mixed-species biofilms and ultimately became the dominant organism in the closed batch systems. However, the low degree of adherence caused P. aeruginosa to be rapidly washed out of the open cooling tower systems, and Flavobacterium became the dominant microorganism in the cooling towers in both the short-term and long-term experiments. These results indicate that adhesion, retention and growth on solid surfaces play important roles in the bacterial community that develops in cooling tower systems. PMID:19177226

8. VIEW OF THE EAST BASE CONNECTION OF ANTENNA TOWER ...

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

8. VIEW OF THE EAST BASE CONNECTION OF ANTENNA TOWER S-111 FACING NORTHEAST. BUILDING 1 AND ANTENNA TOWER S-110 IN THE BACKGROUND. - U.S. Naval Base, Pearl Harbor, Lualualei Radio Transmitter, Edison & Tower Drives, Pearl City, Honolulu County, HI

8. GENERAL VIEW OF TOWER 32, LEFT, AND TOWER 31, ...

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

8. GENERAL VIEW OF TOWER 32, LEFT, AND TOWER 31, RIGHT. VIEW LOOKING NORTH SHOWING AERIAL WIRE DESIGN WITH VERTICAL 'TOP HAT' WIRES IN CENTER. - Chollas Heights Naval Radio Transmitting Facility, 6410 Zero Road, San Diego, San Diego County, CA

Taking advantage of modern turbines

NASA Astrophysics Data System (ADS)

Thresher, Robert

2018-06-01

Wind facilities have generally deployed turbines of the same power and height in regular uniform arrays. Now, the modern generation of turbines, with customer-selectable tower heights and larger rotors, can significantly increase wind energy's economic potential using less land to generate cheaper electricity.

Microwave Tower Deflection Monitor

NASA Astrophysics Data System (ADS)

Truax, Bruce E.

1980-10-01

This paper describes an instrument which is capable of monitoring both the twist and lateral motion of a microwave tower. The Microwave Tower Deflection Monitor (MTDM) gives designers the capability of evaluating towers, both for troubleshooting purposes and comparison with design theory. The MTDM has been designed to operate on a broad range of tower structures in a variety of weather conditions. The instrument measures tower motion by monitoring the position of two retroreflectors mounted on the top of the tower. The two retroreflectors are located by scanning a laser beam in a raster pattern in the vicinity of the reflector. When a retroreflector is struck its position is read by a microprocessor and stored on a magnetic tape. Position resolution of better than .5 cm at 200 ft. has been observed in actual tests.

KSC-99pp1239

NASA Image and Video Library

1999-10-14

KENNEDY SPACE CENTER, FLA. — Two 34-year-old towers on Launch Complex 41, Cape Canaveral Air Station, fall to the ground amid the black smoke from explosives set to topple them. Weighing two million pounds, the umbilical tower (left) was approximately 200 feet high. The taller 300-foot Mobile Service Tower (right) weighs five million pounds. About 200 pounds of linear-shaped charges were used to topple the towers so that the materials can be recycled. Adjacent to the towers are lightning protection structures, which will remain on the site. The towers are being demolished to make room for Lockheed Martin's 14-acre Vehicle Integration Facility (VIF), under construction. The implosion and removal of the tower debris is expected to be completed in two months. The VIF will be used for Lockheed Martin's Atlas V Launch System.

KSC-99pp1238

NASA Image and Video Library

1999-10-14

KENNEDY SPACE CENTER, FLA. — Two 34-year-old towers on Launch Complex 41, Cape Canaveral Air Station, lie on the ground amid the black smoke from explosives set to topple them. Weighing two million pounds, the umbilical tower (left) was approximately 200 feet high. The taller 300-foot Mobile Service Tower (right) weighs five million pounds. About 200 pounds of linear-shaped charges were used to topple the towers so that the materials can be recycled. Adjacent to the towers are lightning protection structures, which will remain on the site. The towers are being demolished to make room for Lockheed Martin's 14-acre Vehicle Integration Facility (VIF), under construction. The implosion and removal of the tower debris is expected to be completed in two months. The VIF will be used for Lockheed Martin's Atlas V Launch System.

PBF Cooling Tower and it Auxiliary Building (PER624) to left ...

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

PBF Cooling Tower and it Auxiliary Building (PER-624) to left of tower. Camera facing west and the east louvered face of the tower. Details include secondary coolant water riser piping and flow control valves (butterfly valves) to distribute water evenly to all sections of tower. Photographer: Holmes. Date: May, 20, 1970. INEEL negative no. 70-2322 - Idaho National Engineering Laboratory, SPERT-I & Power Burst Facility Area, Scoville, Butte County, ID

2. VIEW SOUTHWEST, prime search radar tower, height finder radar ...

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

2. VIEW SOUTHWEST, prime search radar tower, height finder radar towards, height finder radar towers, and radar tower (unknown function) - Fort Custer Military Reservation, P-67 Radar Station, .25 mile north of Dickman Road, east of Clark Road, Battle Creek, Calhoun County, MI

4. VIEW NORTHEAST, radar tower (unknown function), prime search radar ...

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

4. VIEW NORTHEAST, radar tower (unknown function), prime search radar tower, emergency power building, and height finder radar tower - Fort Custer Military Reservation, P-67 Radar Station, .25 mile north of Dickman Road, east of Clark Road, Battle Creek, Calhoun County, MI

3. View from former light tower to Cape Elizabeth Light ...

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

3. View from former light tower to Cape Elizabeth Light Tower, view northeast, southwest side of Cape Elizabeth Tower - Cape Elizabeth Light Station, Near Two Lights State Park at end of Two Lights Road, off State Highway 77, Cape Elizabeth, Cumberland County, ME

Grassland and cropland net ecosystem production of the U.S. Great Plains: Regression tree model development and comparative analysis

USGS Publications Warehouse

Wylie, Bruce K.; Howard, Daniel; Dahal, Devendra; Gilmanov, Tagir; Ji, Lei; Zhang, Li; Smith, Kelcy

2016-01-01

This paper presents the methodology and results of two ecological-based net ecosystem production (NEP) regression tree models capable of up scaling measurements made at various flux tower sites throughout the U.S. Great Plains. Separate grassland and cropland NEP regression tree models were trained using various remote sensing data and other biogeophysical data, along with 15 flux towers contributing to the grassland model and 15 flux towers for the cropland model. The models yielded weekly mean daily grassland and cropland NEP maps of the U.S. Great Plains at 250 m resolution for 2000–2008. The grassland and cropland NEP maps were spatially summarized and statistically compared. The results of this study indicate that grassland and cropland ecosystems generally performed as weak net carbon (C) sinks, absorbing more C from the atmosphere than they released from 2000 to 2008. Grasslands demonstrated higher carbon sink potential (139 g C·m−2·year−1) than non-irrigated croplands. A closer look into the weekly time series reveals the C fluctuation through time and space for each land cover type.

The optimal operation of cooling tower systems with variable-frequency control

NASA Astrophysics Data System (ADS)

Cao, Yong; Huang, Liqing; Cui, Zhiguo; Liu, Jing

2018-02-01

This study investigates the energy performance of chiller and cooling tower systems integrated with variable-frequency control for cooling tower fans and condenser water pumps. With regard to an example chiller system serving an office building, Chiller and cooling towers models were developed to assess how different variable-frequency control methods of cooling towers fans and condenser water pumps influence the trade-off between the chiller power, pump power and fan power under various operating conditions. The matching relationship between the cooling tower fans frequency and condenser water pumps frequency at optimal energy consumption of the system is introduced to achieve optimum system performance.

Main photoautotrophic components of biofilms in natural draft cooling towers.

PubMed

Hauer, Tomáš; Čapek, Petr; Böhmová, Petra

2016-05-01

While photoautotrophic organisms are an important component of biofilms that live in certain regions of natural draft cooling towers, little is known about these communities. We therefore examined 18 towers at nine sites to identify the general patterns of community assembly in three distinct tower parts, and we examined how community structures differ depending on geography. We also compared the newly acquired data with previously published data. The bottom sections of draft cooling towers are mainly settled by large filamentous algae, primarily Cladophora glomerata. The central portions of towers host a small amount of planktic algae biomass originating in the cooling water. The upper fourths of towers are colonized by biofilms primarily dominated by cyanobacteria, e.g., members of the genera Gloeocapsa and Scytonema. A total of 41 taxa of phototrophic microorganisms were identified. Species composition of the upper fourth of all towers was significantly affected by cardinal position. There was different species composition at positions facing north compared to positions facing south. West- and east-facing positions were transitory and highly similar to each other in terms of species composition. Biofilms contribute to the degradation of paint coatings inside towers.

The Quality Control Algorithms Used in the Process of Creating the NASA Kennedy Space Center Lightning Protection System Towers Meteorological Database

NASA Technical Reports Server (NTRS)

Orcutt, John M.; Brenton, James C.

2016-01-01

The methodology and the results of the quality control (QC) process of the meteorological data from the Lightning Protection System (LPS) towers located at Kennedy Space Center (KSC) launch complex 39B (LC-39B) are documented in this paper. Meteorological data are used to design a launch vehicle, determine operational constraints, and to apply defined constraints on day-of-launch (DOL). In order to properly accomplish these tasks, a representative climatological database of meteorological records is needed because the database needs to represent the climate the vehicle will encounter. Numerous meteorological measurement towers exist at KSC; however, the engineering tasks need measurements at specific heights, some of which can only be provided by a few towers. Other than the LPS towers, Tower 313 is the only tower that provides observations up to 150 m. This tower is located approximately 3.5 km from LC-39B. In addition, data need to be QC'ed to remove erroneous reports that could pollute the results of an engineering analysis, mislead the development of operational constraints, or provide a false image of the atmosphere at the tower's location.

Monitoring potential ecological impacts of a utility-scale photovoltaic panel facility on a creosote-bursage plant community

NASA Astrophysics Data System (ADS)

Apodaca, L.; Devitt, D. A.

2016-12-01

High energy demands and greater financial viability have propelled recent growth in the solar energy market. Southern Nevada is poised to become a major contributor of green energy through the commissioning of public and private lands for solar development, but there exists a pressing need to better understand the ecological consequences of these facilities as documentation of the impacts of large-scale solar operations on surrounding environments is severely lacking. The Copper Mountain 2 (CM2) solar facility in Eldorado Valley, Nevada, USA utilizes nearly 1.8 square kilometers of photovoltaic panels to generate enough energy to power about 50,000 homes and is situated within a predominately creosote (Larrea tridentata) and white bursage (Ambrosia dumosa) habitat. Currently, the potential impacts on the local environment related to this massive development are being studied from two perspectives: microclimate effects and alteration of surface hydrology. A series of meteorological towers and ibuttons are being used to monitor microclimate changes in the area of CM2 and the adjacent natural habitat as localized climate within the facility may be altering growing conditions in nearby desert plant communities. Because the placement of CM2 represents a major obstacle to established surface water flow, a transect of soil moisture probe access tubes have been placed in association with creosote plants along a downslope gradient from the facility to observe changes to soil water storage. Individual creosote and bursage plant physiologies are also being monitored to study any potential increase in plant stress influenced by the CM2 solar facility. Most measurements have been ongoing for at least one year. Greater details on the research infrastructure will be presented along with the latest observational data.

An Estimate of Avian Mortality at Communication Towers in the United States and Canada

PubMed Central

Longcore, Travis; Rich, Catherine; Mineau, Pierre; MacDonald, Beau; Bert, Daniel G.; Sullivan, Lauren M.; Mutrie, Erin; Gauthreaux, Sidney A.; Avery, Michael L.; Crawford, Robert L.; Manville, Albert M.; Travis, Emilie R.; Drake, David

2012-01-01

Avian mortality at communication towers in the continental United States and Canada is an issue of pressing conservation concern. Previous estimates of this mortality have been based on limited data and have not included Canada. We compiled a database of communication towers in the continental United States and Canada and estimated avian mortality by tower with a regression relating avian mortality to tower height. This equation was derived from 38 tower studies for which mortality data were available and corrected for sampling effort, search efficiency, and scavenging where appropriate. Although most studies document mortality at guyed towers with steady-burning lights, we accounted for lower mortality at towers without guy wires or steady-burning lights by adjusting estimates based on published studies. The resulting estimate of mortality at towers is 6.8 million birds per year in the United States and Canada. Bootstrapped subsampling indicated that the regression was robust to the choice of studies included and a comparison of multiple regression models showed that incorporating sampling, scavenging, and search efficiency adjustments improved model fit. Estimating total avian mortality is only a first step in developing an assessment of the biological significance of mortality at communication towers for individual species or groups of species. Nevertheless, our estimate can be used to evaluate this source of mortality, develop subsequent per-species mortality estimates, and motivate policy action. PMID:22558082

Analysis of wind-resistant and stability for cable tower in cable-stayed bridge with four towers

NASA Astrophysics Data System (ADS)

Meng, Yangjun; Li, Can

2017-06-01

Wind speed time history simulation methods have been introduced first, especially the harmonic synthesis method introduced in detail. Second, taking Chishi bridge for example, choosing the particular sections, and combined with the design wind speed, three-component coefficient simulate analysis between -4°and 4°has been carry out with the Fluent software. The results show that drag coefficient reaches maximum when the attack Angle is 1°. According to measured wind speed samples,time history curves of wind speed at bridge deck and tower roof have been obtained,and wind-resistant time history analysis for No.5 tower has been carry out. Their results show that the dynamic coefficients are different with different calculation standard, especially transverse bending moment, pulsating crosswind load does not show a dynamic amplification effect.Under pulsating wind loads at bridge deck or tower roof, the maximum displacement at the top of the tower and the maximum stress at the bottom of the tower are within the allowable range. The transverse stiffness of tower is greater than that of the longitudinal stiffness, therefore wind-resistant analysis should give priority to the longitudinal direction. Dynamic coefficients are different with different standard, the maximum dynamic coefficient should be used for the pseudo-static analysis.Finally, the static stability of tower is analyzed with different load combinations, and the galloping stabilities of cable tower is proved.

An estimate of avian mortality at communication towers in the United States and Canada.

PubMed

Longcore, Travis; Rich, Catherine; Mineau, Pierre; MacDonald, Beau; Bert, Daniel G; Sullivan, Lauren M; Mutrie, Erin; Gauthreaux, Sidney A; Avery, Michael L; Crawford, Robert L; Manville, Albert M; Travis, Emilie R; Drake, David

2012-01-01

Avian mortality at communication towers in the continental United States and Canada is an issue of pressing conservation concern. Previous estimates of this mortality have been based on limited data and have not included Canada. We compiled a database of communication towers in the continental United States and Canada and estimated avian mortality by tower with a regression relating avian mortality to tower height. This equation was derived from 38 tower studies for which mortality data were available and corrected for sampling effort, search efficiency, and scavenging where appropriate. Although most studies document mortality at guyed towers with steady-burning lights, we accounted for lower mortality at towers without guy wires or steady-burning lights by adjusting estimates based on published studies. The resulting estimate of mortality at towers is 6.8 million birds per year in the United States and Canada. Bootstrapped subsampling indicated that the regression was robust to the choice of studies included and a comparison of multiple regression models showed that incorporating sampling, scavenging, and search efficiency adjustments improved model fit. Estimating total avian mortality is only a first step in developing an assessment of the biological significance of mortality at communication towers for individual species or groups of species. Nevertheless, our estimate can be used to evaluate this source of mortality, develop subsequent per-species mortality estimates, and motivate policy action.

KSC-99pp1240

NASA Image and Video Library

1999-10-14

KENNEDY SPACE CENTER, FLA. — Two 34-year-old towers on Launch Complex 41, Cape Canaveral Air Station, fall to the ground amid the black smoke from explosives set to topple them. Weighing two million pounds, the umbilical tower (left) was approximately 200 feet high. The taller 300-foot Mobile Service Tower (right), still falling, weighs five million pounds. About 200 pounds of linear-shaped charges were used to topple the towers so that the materials can be recycled. Adjacent to the towers are lightning protection structures, which will remain on the site. The towers are being demolished to make room for Lockheed Martin's 14-acre Vehicle Integration Facility (VIF), under construction. The implosion and removal of the tower debris is expected to be completed in two months. The VIF will be used for Lockheed Martin's Atlas V Launch System.

78 FR 11152 - Utility Scale Wind Towers from the People's Republic of China: Countervailing Duty Order

Federal Register 2010, 2011, 2012, 2013, 2014

2013-02-15

... DEPARTMENT OF COMMERCE International Trade Administration [C-570-982] Utility Scale Wind Towers...''), the Department is issuing a countervailing duty order on utility scale wind towers (``wind towers..., 2012, the Department published the final determination in the countervailing duty investigation of wind...

10. VIEW OF ANTENNA TOWER S111 FROM THE NORTHEAST SIDE ...

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

10. VIEW OF ANTENNA TOWER S-111 FROM THE NORTHEAST SIDE LOOKING UP. A PARABLOIC ANTENNA MOUNTED ON THE TOWER IS LOCATED IN THE LOWER LEFT OF PHOTO. - U.S. Naval Base, Pearl Harbor, Lualualei Radio Transmitter, Edison & Tower Drives, Pearl City, Honolulu County, HI

14 CFR 170.13 - Airport Traffic Control Tower (ATCT) establishment criteria.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Airport Traffic Control Tower (ATCT... AIR TRAFFIC CONTROL SERVICES AND NAVIGATIONAL FACILITIES Airport Traffic Control Towers § 170.13 Airport Traffic Control Tower (ATCT) establishment criteria. (a) The following criteria along with general...

Taking advantage of modern turbines

DOE PAGES

Thresher, Robert

2018-05-14

Here, wind facilities have generally deployed turbines of the same power and height in regular uniform arrays. Now, the modern generation of turbines, with customer-selectable tower heights and larger rotors, can significantly increase wind energy's economic potential using less land to generate cheaper electricity.

Taking advantage of modern turbines

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

Thresher, Robert

Here, wind facilities have generally deployed turbines of the same power and height in regular uniform arrays. Now, the modern generation of turbines, with customer-selectable tower heights and larger rotors, can significantly increase wind energy's economic potential using less land to generate cheaper electricity.

Binding in pair potentials of liquid simple metals from nonlocality in electronic kinetic energy

NASA Technical Reports Server (NTRS)

Perrot, F.; March, N. H.

1990-01-01

The paper presents an explicit expression for the pair potential in liquid simple metals from low-order density-gradient theory when the superposition of single-center displaced charges is employed. Numerical results are presented for the gradient expansion pair interaction in liquid Na and Be. The low-order density-gradient equation for the pair potential is presented.

Assessing submarine gas hydrate at active seeps on the Hikurangi Margin, New Zealand, using controlled source electromagnetic data with constraints from seismic, geochemistry, and heatflow data

NASA Astrophysics Data System (ADS)

Schwalenberg, K.; Haeckel, M.; Pecher, I. A.; Toulmin, S. J.; Hamdan, L. J.; Netzeband, G.; Wood, W.; Poort, J.; Jegen, M. D.; Coffin, R. B.

2009-12-01

Electrical resistivity is one of the key properties useful for evaluating submarine gas hydrate deposits. Gas hydrates are electrically insulating in contrast to the conductive pore fluid. Where they form in sufficient quantities the bulk resistivity of the sub-seafloor is elevated. CSEM data were collected in 2007 as part of the German - International “New Vents” project on R/V Sonne, cruise SO191, at three target areas on the Hikurangi subduction margin, New Zealand. The margin is characterized by widespread bottom simulating reflectors (BSR), seep structures, and active methane and fluid venting indicating the potential for gas hydrate formation. Opouawe Bank is one of the ridge and basin systems on the accretionary wedge and is located off the Wairarapa coast at water depths of 1000-1100 m. The first observed seep sites (North Tower, South Tower, Pukeko, Takahe, and Tui) were identified from individual gas flares in hydro-acoustic data and video observations during voyages on R/V Tangaroa. Seismic reflection data collected during SO191 subsequently identified more than 25 new seep structures. Two intersecting CSEM profiles have been surveyed across North Tower, South Tower, and Takahe. 1-D inversion of the data reveals anomalously high resistivities at North Tower and South Tower, moderately elevated resistivities at Takahe, and normal background resistivities away from the seeps. The high resistivities are attributed to gas hydrate layers at intermediate depths beneath the seeps. At South Tower the hydrate concentration could be possibly as much as 25% of the total sediment volume within a 50m thick layer. This conforms with geochemical pore water analyses which show a trend of increased methane flux towards South Tower. At Takahe, gas pockets and patchy gas hydrate, as well as sediment heterogeneities and carbonates, or temperature driven upward fluid flow indicated by the observed higher heat flow at this site may explain the resistivity pattern. Porangahau Ridge is located further north on the margin in water depths of 1900-2000m. A high amplitude reflection zone extending from the BSR around 700mbsf towards the seafloor has been observed at the western flank of the ridge. This is attributed to local shoaling at the base of the hydrate stability zone caused by upward migrating warm fluids. A CSEM profile was surveyed across the same seismic line. The data reveal a pronounced resistivity anomaly at the western rim suggesting a zone of concentrated gas hydrate above the reflection band. Heat flow and geochemistry data collected along the same transect show concave temperature profiles indicating mildly advective heat flow and massive gas and fluid transport on the western flank, particularly at the location where the resistivity anomaly has been observed.

Carbon Nanotube Tower-Based Supercapacitor

NASA Technical Reports Server (NTRS)

Meyyappan, Meyya (Inventor)

2012-01-01

A supercapacitor system, including (i) first and second, spaced apart planar collectors, (ii) first and second arrays of multi-wall carbon nanotube (MWCNT) towers or single wall carbon nanotube (SWCNT) towers, serving as electrodes, that extend between the first and second collectors where the nanotube towers are grown directly on the collector surfaces without deposition of a catalyst and without deposition of a binder material on the collector surfaces, and (iii) a porous separator module having a transverse area that is substantially the same as the transverse area of at least one electrode, where (iv) at least one nanotube tower is functionalized to permit or encourage the tower to behave as a hydrophilic structure, with increased surface wettability.

KSC-99pp1220

NASA Image and Video Library

1999-10-14

KENNEDY SPACE CENTER, FLA. -- Live TV trucks (far right) from local channels merge at the site of the fallen Mobile Service Tower (MST) and umbilical tower nearby after their demolition. The towers were demolished to make room for Lockheed Martin's 14-acre Vehicle Integration Facility (VIF), under construction. Weighing two million pounds, the umbilical tower was approximately 200 feet high. The taller 300-foot MST weighed five million pounds. About 200 pounds of linear-shaped charges were used to bring down the towers so that the materials can be recycled. The implosion and removal of the tower debris is expected to be completed in two months. The VIF will be used for Lockheed Martin's Atlas V Launch System.

KSC-99pp1219

NASA Image and Video Library

1999-10-14

KENNEDY SPACE CENTER, FLA. -- Live TV trucks from local channels merge at the site of the fallen Mobile Service Tower (MST) and umbilical tower nearby after their demolition. The towers were demolished to make room for Lockheed Martin's 14-acre Vehicle Integration Facility (VIF), under construction. Weighing two million pounds, the umbilical tower was approximately 200 feet high. The taller 300-foot MST weighed five million pounds. About 200 pounds of linear-shaped charges were used to bring down the towers so that the materials can be recycled. The implosion and removal of the tower debris is expected to be completed in two months. The VIF will be used for Lockheed Martin's Atlas V Launch System.

The influence of liquid-gas velocity ratio on the noise of the cooling tower

NASA Astrophysics Data System (ADS)

Yang, Bin; Liu, Xuanzuo; Chen, Chi; Zhao, Zhouli; Song, Jinchun

2018-05-01

The noise from the cooling tower has a great influence on psychological performance of human beings. The cooling tower noise mainly consists of fan noise, falling water noise and mechanical noise. This thesis used DES turbulence model with FH-W model to simulate the flow and sound pressure field in cooling tower based on CFD software FLUENT and analyzed the influence of different kinds noise, which affected by diverse factors, on the cooling tower noise. It can be concluded that the addition of cooling water can reduce the turbulence and vortex noise of the rotor fluid field in the cooling tower at some extent, but increase the impact noise of the liquid-gas two phase. In general, the cooling tower noise decreases with the velocity ratio of liquid to gas increasing, and reaches the lowest when the velocity ratio of liquid to gas is close to l.

Dynamic Responses and Vibration Control of the Transmission Tower-Line System: A State-of-the-Art Review

PubMed Central

Chen, Bo; Guo, Wei-hua; Li, Peng-yun; Xie, Wen-ping

2014-01-01

This paper presented an overview on the dynamic analysis and control of the transmission tower-line system in the past forty years. The challenges and future developing trends in the dynamic analysis and mitigation of the transmission tower-line system under dynamic excitations are also put forward. It also reviews the analytical models and approaches of the transmission tower, transmission lines, and transmission tower-line systems, respectively, which contain the theoretical model, finite element (FE) model and the equivalent model; shows the advances in wind responses of the transmission tower-line system, which contains the dynamic effects under common wind loading, tornado, downburst, and typhoon; and discusses the dynamic responses under earthquake and ice loads, respectively. The vibration control of the transmission tower-line system is also reviewed, which includes the magnetorheological dampers, friction dampers, tuned mass dampers, and pounding tuned mass dampers. PMID:25105161

Visibility analysis of fire lookout towers in the Boyabat State Forest Enterprise in Turkey.

PubMed

Kucuk, Omer; Topaloglu, Ozer; Altunel, Arif Oguz; Cetin, Mehmet

2017-07-01

For a successful fire suppression, it is essential to detect and intervene forest fires as early as possible. Fire lookout towers are crucial assets in detecting forest fires, in addition to other technological advancements. In this study, we performed a visibility analysis on a network of fire lookout towers currently operating in a relatively fire-prone region in Turkey's Western Black Sea region. Some of these towers had not been functioning properly; it was proposed that these be taken out of the grid and replaced with new ones. The percentage of visible areas under the current network of fire lookout towers was 73%; it could rise to 81% with the addition of newly proposed towers. This study was the first research to conduct a visibility analysis of current and newly proposed fire lookout towers in the Western Black Sea region and focus on its forest fire problem.

77 FR 9700 - Utility Scale Wind Towers From China and Vietnam

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-17

...)] Utility Scale Wind Towers From China and Vietnam Determinations On the basis of the record \\1\\ developed... threatened with material injury by reason of imports from China of utility scale wind towers, provided for in... with material injury by reason of imports from Vietnam of utility scale wind towers, provided for in...

78 FR 10210 - Utility Scale Wind Towers From China and Vietnam

Federal Register 2010, 2011, 2012, 2013, 2014

2013-02-13

...)] Utility Scale Wind Towers From China and Vietnam Determinations On the basis of the record \\1\\ developed... with material injury by reason of imports of utility scale wind towers from China and Vietnam, provided... of imports of utility scale wind towers from China and Vietnam. Commissioner Dean A. Pinkert...

Convection towers

DOEpatents

Prueitt, Melvin L.

1996-01-01

Convection towers which are capable of cleaning the pollution from large quantities of air, of generating electricity, and of producing fresh water utilize the evaporation of water sprayed into the towers to create strong airflows and to remove pollution from the air. Turbines in tunnels at the skirt section of the towers generate electricity, and condensers produce fresh water.

Convection towers

DOEpatents

Prueitt, Melvin L.

1995-01-01

Convection towers which are capable of cleaning the pollution from large quantities of air, of generating electricity, and of producing fresh water utilize the evaporation of water sprayed into the towers to create strong airflows and to remove pollution from the air. Turbines in tunnels at the skirt section of the towers generate electricity, and condensers produce fresh water.

Convection towers

DOEpatents

Prueitt, M.L.

1996-01-16

Convection towers which are capable of cleaning the pollution from large quantities of air, of generating electricity, and of producing fresh water utilize the evaporation of water sprayed into the towers to create strong airflows and to remove pollution from the air. Turbines in tunnels at the skirt section of the towers generate electricity, and condensers produce fresh water. 6 figs.

14 CFR 139.329 - Pedestrians and ground vehicles.

Code of Federal Regulations, 2010 CFR

2010-01-01

... by an employee, tenant, or contractor; (c) When an air traffic control tower is in operation, ensure... between the tower and the pedestrian, vehicle, or escort; (d) When an air traffic control tower is not in operation, or there is no air traffic control tower, provide adequate procedures to control pedestrians and...

15. GENERAL EASTERN VIEW OF LINDE 1000 TONS PER DAY ...

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

15. GENERAL EASTERN VIEW OF LINDE 1000 TONS PER DAY HIGH PURITY OXYGEN MAKING PLANT SHOWING TWIN OXYGEN FRACTIONATING TOWER (ON RIGHT), VERMICULITE STORAGE TOWERS (ON LEFT FOREGROUND), AND AN ARGON FRACTIONATING TOWER (BEHIND VERMICULITE STORAGE TOWER). - U.S. Steel Duquesne Works, Fuel & Utilities Plant, Along Monongahela River, Duquesne, Allegheny County, PA

Airborne LIDAR point cloud tower inclination judgment

NASA Astrophysics Data System (ADS)

liang, Chen; zhengjun, Liu; jianguo, Qian

2016-11-01

Inclined transmission line towers for the safe operation of the line caused a great threat, how to effectively, quickly and accurately perform inclined judgment tower of power supply company safety and security of supply has played a key role. In recent years, with the development of unmanned aerial vehicles, unmanned aerial vehicles equipped with a laser scanner, GPS, inertial navigation is one of the high-precision 3D Remote Sensing System in the electricity sector more and more. By airborne radar scan point cloud to visually show the whole picture of the three-dimensional spatial information of the power line corridors, such as the line facilities and equipment, terrain and trees. Currently, LIDAR point cloud research in the field has not yet formed an algorithm to determine tower inclination, the paper through the existing power line corridor on the tower base extraction, through their own tower shape characteristic analysis, a vertical stratification the method of combining convex hull algorithm for point cloud tower scarce two cases using two different methods for the tower was Inclined to judge, and the results with high reliability.

The Effect Analysis of Strain Rate on Power Transmission Tower-Line System under Seismic Excitation

PubMed Central

Wang, Wenming

2014-01-01

The effect analysis of strain rate on power transmission tower-line system under seismic excitation is studied in this paper. A three-dimensional finite element model of a transmission tower-line system is created based on a real project. Using theoretical analysis and numerical simulation, incremental dynamic analysis of the power transmission tower-line system is conducted to investigate the effect of strain rate on the nonlinear responses of the transmission tower and line. The results show that the effect of strain rate on the transmission tower generally decreases the maximum top displacements, but it would increase the maximum base shear forces, and thus it is necessary to consider the effect of strain rate on the seismic analysis of the transmission tower. The effect of strain rate could be ignored for the seismic analysis of the conductors and ground lines, but the responses of the ground lines considering strain rate effect are larger than those of the conductors. The results could provide a reference for the seismic design of the transmission tower-line system. PMID:25105157

The Role of Transmural Repolarization Gradient in the Inversion of Cardiac Electric Field: Model Study of ECG in Hypothermia.

PubMed

Arteyeva, Natalia V; Azarov, Jan E

2017-01-01

The changes in ventricular repolarization gradients lead to significant alterations of the electrocardiographic body surface T waves up to the T wave inversion. However, the contribution of a specific gradient remains to be elucidated. The objective of the present investigation was to study the role of the transmural repolarization gradient in the inversion of the body surface T wave with a mathematical model of the hypothermia-induced changes of ventricular repolarization. By means of mathematical simulation, we set the hypothermic action potential duration (APD) distribution on the rabbit ventricular epicardium as it was previously experimentally documented. Then the parameters of the body surface potential distribution were tested with the introduction of different scenarios of the endocardial and epicardial APD behavior in hypothermia resulting in the unchanged, reversed or enlarged transmural repolarization gradient. The reversal of epicardial repolarization gradients (apicobasal, anterior-posterior and interventricular) caused the inversion of the T waves regardless of the direction of the transmural repolarization gradient. However, the most realistic body surface potentials were obtained when the endocardial APDs were not changed under hypothermia while the epicardial APDs prolonged. This produced the reversed and increased transmural repolarization gradient in absolute magnitude. The body surface potentials simulated under the unchanged transmural gradient were reduced in comparison to those simulated under the reversed transmural gradient. The simulations demonstrated that the transmural repolarization gradient did not play a crucial role in the cardiac electric field inversion under hypothermia, but its magnitude and direction contribute to the T wave amplitude. © 2016 Wiley Periodicals, Inc.

Collapse and pull - down analysis of high voltage electricity transmission towers subjected to cyclonic wind

NASA Astrophysics Data System (ADS)

Ahmed, Ammar; Arthur, Craig; Edwards, Mark

2010-06-01

Bulk electricity transmission lines are linear assets that can be very exposed to wind effects, particularly where they traverse steep topography or open coastal terrain in cyclonic regions. Interconnected nature of the lattice type towers and conductors also, present complex vulnerabilities. These relate to the direction of wind attack to the conductors and the cascading failure mechanisms in which the failure of a single tower has cascading effects on neighbouring towers. Such behaviour is exacerbated by the finely tuned nature of tower design which serves to minimize cost and reserve strength at design wind speeds. There is a clear need to better quantify the interdependent vulnerabilities of these critical infrastructure assets in the context of the severe wind hazard. This paper presents a novel methodology developed for the Critical Infrastructure Protection Modelling and Analysis (CIPMA) capability for assessing local wind speeds and the likelihood of tower failure for a range of transmission tower and conductor types. CIPMA is a program managed by the Federal Attorney-General's Department and Geoscience Australia is leading the technical development. The methodology then involves the development of heuristically derived vulnerability models that are consistent with Australian industry experience and full-scale static tower testing results, considering isolated tower loss along with three interdependent failure mechanisms to give overall likelihoods of failure.

Energy conservation strategies, the ignored cooling towers

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

Burger, R.

1997-06-01

Because of their apparent lack of sophistication, cooling towers are usually considered orphans of the facilities operation. Historically, cooling towers have been neglected in refrigeration air conditioning systems, electric power generating stations, manufacturing plants, and chemical process plants. Operators are aware of the importance of their sophisticated equipment but, they take the apparently simple cooling towers and cold water returning for granted, Since the box looks sturdy and the fans are rotating, the operators think all is well and ignore the quality of water coming off the tower. A cooling tower is purchased for Design Conditions of performance which aremore » specified. Design Conditions relate to the volume of circulating water (GPM), hot water temperature (HWT), cold water temperature (CWT) discharge, and wet bulb temperature (WBT). The WBT consisting of ambient temperature and relative humidity. After the tower is on line and the CWT becomes inadequate, many engineers look to solutions other than the obvious. All cooling towers are purchased to function at 100% of capability in accordance with Design Condition. In the real world of on-stream utilization, the level of operation is lower. It can be deficient as much as 30% due to a variety of reasons which are not necessarily due to the failure of the performance of the tower.« less

Convective Cloud Towers and Precipitation Initiation, Frequency and Intensity

NASA Astrophysics Data System (ADS)

Vant-hull, B.; Mahani, S. E.; Autones, F.; Rabin, R.; Mecikalski, J. R.; Khanbilvardi, R.

2012-12-01

: Geosynchronous satellite retrieval of precipitation is desirable because it would provide continuous observation throughout most of the globe in regions where radar data is not available. In the current work the distribution of precipitation rates is examined as a function of cloud tower area and cloud top temperature. A thunderstorm tracking algorithm developed at Meteo-France is used to track cumulus towers that are matched up with radar data at 5 minute 1 km resolution. It is found that roughly half of the precipitation occurs in the cloud mass that surrounds the towers, and when a tower is first detected the precipitation is already in progress 50% of the time. The average density of precipitation per area is greater as the towers become smaller and colder, yet the averaged shape of the precipitation intensity distribution is remarkably constant in all convective situations with cloud tops warmer than 220 K. This suggests that on average all convective precipitation events look the same, unaffected by the higher frequency of occurrence per area inside the convective towers. Only once the cloud tops are colder than 220 K does the precipitation intensity distribution become weighted towards higher instantaneous intensities. Radar precipitation shown in shades of green to blue, lightning in orange; black diamonds are coldest points in each tower. Ratio of number of pixels of given precipitation inside versus outside the convective towers, for various average cloud top temperatures. A flat plot indicates the distribution of rainfall inside and outside the towers has the same shape.

Identification of tower-wake distortions using sonic anemometer and lidar measurements

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

McCaffrey, Katherine; Quelet, Paul T.; Choukulkar, Aditya

The eXperimental Planetary boundary layer Instrumentation Assessment (XPIA) field campaign took place in March through May 2015 at the Boulder Atmospheric Observatory, utilizing its 300 m meteorological tower, instrumented with two sonic anemometers mounted on opposite sides of the tower at six heights. This allowed for at least one sonic anemometer at each level to be upstream of the tower at all times and for identification of the times when a sonic anemometer is in the wake of the tower frame. Other instrumentation, including profiling and scanning lidars aided in the identification of the tower wake. Here we compare pairsmore » of sonic anemometers at the same heights to identify the range of directions that are affected by the tower for each of the opposing booms. The mean velocity and turbulent kinetic energy are used to quantify the wake impact on these first- and second-order wind measurements, showing up to a 50% reduction in wind speed and an order of magnitude increase in turbulent kinetic energy. Comparisons of wind speeds from profiling and scanning lidars confirmed the extent of the tower wake, with the same reduction in wind speed observed in the tower wake, and a speed-up effect around the wake boundaries. Wind direction differences between pairs of sonic anemometers and between sonic anemometers and lidars can also be significant, as the flow is deflected by the tower structure. Comparisons of lengths of averaging intervals showed a decrease in wind speed deficit with longer averages, but the flow deflection remains constant over longer averages. Furthermore, asymmetry exists in the tower effects due to the geometry and placement of the booms on the triangular tower. An analysis of the percentage of observations in the wake that must be removed from 2 min mean wind speed and 20 min turbulent values showed that removing even small portions of the time interval due to wakes impacts these two quantities. Furthermorew, a vast majority of intervals have no observations in the tower wake, so removing the full 2 or 20 min intervals does not diminish the XPIA dataset.« less

Identification of tower-wake distortions using sonic anemometer and lidar measurements

DOE PAGES

McCaffrey, Katherine; Quelet, Paul T.; Choukulkar, Aditya; ...

2017-02-02

The eXperimental Planetary boundary layer Instrumentation Assessment (XPIA) field campaign took place in March through May 2015 at the Boulder Atmospheric Observatory, utilizing its 300 m meteorological tower, instrumented with two sonic anemometers mounted on opposite sides of the tower at six heights. This allowed for at least one sonic anemometer at each level to be upstream of the tower at all times and for identification of the times when a sonic anemometer is in the wake of the tower frame. Other instrumentation, including profiling and scanning lidars aided in the identification of the tower wake. Here we compare pairsmore » of sonic anemometers at the same heights to identify the range of directions that are affected by the tower for each of the opposing booms. The mean velocity and turbulent kinetic energy are used to quantify the wake impact on these first- and second-order wind measurements, showing up to a 50% reduction in wind speed and an order of magnitude increase in turbulent kinetic energy. Comparisons of wind speeds from profiling and scanning lidars confirmed the extent of the tower wake, with the same reduction in wind speed observed in the tower wake, and a speed-up effect around the wake boundaries. Wind direction differences between pairs of sonic anemometers and between sonic anemometers and lidars can also be significant, as the flow is deflected by the tower structure. Comparisons of lengths of averaging intervals showed a decrease in wind speed deficit with longer averages, but the flow deflection remains constant over longer averages. Furthermore, asymmetry exists in the tower effects due to the geometry and placement of the booms on the triangular tower. An analysis of the percentage of observations in the wake that must be removed from 2 min mean wind speed and 20 min turbulent values showed that removing even small portions of the time interval due to wakes impacts these two quantities. Furthermorew, a vast majority of intervals have no observations in the tower wake, so removing the full 2 or 20 min intervals does not diminish the XPIA dataset.« less

Seismic response of a full-scale wind turbine tower using experimental and numerical modal analysis

NASA Astrophysics Data System (ADS)

Kandil, Kamel Sayed Ahmad; Saudi, Ghada N.; Eltaly, Boshra Aboul-Anen; El-khier, Mostafa Mahmoud Abo

2016-12-01

Wind turbine technology has developed tremendously over the past years. In Egypt, the Zafarana wind farm is currently generating at a capacity of 517 MW, making it one of the largest onshore wind farms in the world. It is located in an active seismic zone along the west side of the Gulf of Suez. Accordingly, seismic risk assessment is demanded for studying the structural integrity of wind towers under expected seismic hazard events. In the context of ongoing joint Egypt-US research project "Seismic Risk Assessment of Wind Turbine Towers in Zafarana wind Farm Egypt" (Project ID: 4588), this paper describes the dynamic performance investigation of an existing Nordex N43 wind turbine tower. Both experimental and numerical work are illustrated explaining the methodology adopted to investigate the dynamic behavior of the tower under seismic load. Field dynamic testing of the full-scale tower was performed using ambient vibration techniques (AVT). Both frequency domain and time domain methods were utilized to identify the actual dynamic properties of the tower as built in the site. Mainly, the natural frequencies, their corresponding mode shapes and damping ratios of the tower were successfully identified using AVT. A vibration-based finite element model (FEM) was constructed using ANSYS V.12 software. The numerical and experimental results of modal analysis were both compared for matching purpose. Using different simulation considerations, the initial FEM was updated to finally match the experimental results with good agreement. Using the final updated FEM, the response of the tower under the AQABA earthquake excitation was investigated. Time history analysis was conducted to define the seismic response of the tower in terms of the structural stresses and displacements. This work is considered as one of the pioneer structural studies of the wind turbine towers in Egypt. Identification of the actual dynamic properties of the existing tower was successfully performed based on AVT. Using advanced techniques in both the field testing and the numerical investigations produced reliable FEM specific for the tested tower, which can be further used in more advanced structural investigations for improving the design of such special structures.

How many flux towers are enough? How tall is a tower tall enough? How elaborate a scaling is scaling enough?

NASA Astrophysics Data System (ADS)

Xu, K.; Sühring, M.; Metzger, S.; Desai, A. R.

2017-12-01

Most eddy covariance (EC) flux towers suffer from footprint bias. This footprint not only varies rapidly in time, but is smaller than the resolution of most earth system models, leading to a systemic scale mismatch in model-data comparison. Previous studies have suggested this problem can be mitigated (1) with multiple towers, (2) by building a taller tower with a large flux footprint, and (3) by applying advanced scaling methods. Here we ask: (1) How many flux towers are needed to sufficiently sample the flux mean and variation across an Earth system model domain? (2) How tall is tall enough for a single tower to represent the Earth system model domain? (3) Can we reduce the requirements derived from the first two questions with advanced scaling methods? We test these questions with output from large eddy simulations (LES) and application of the environmental response function (ERF) upscaling method. PALM LES (Maronga et al. 2015) was set up over a domain of 12 km x 16 km x 1.8 km at 7 m spatial resolution and produced 5 hours of output at a time step of 0.3 s. The surface Bowen ratio alternated between 0.2 and 1 among a series of 3 km wide stripe-like surface patches, with horizontal wind perpendicular to the surface heterogeneity. A total of 384 virtual towers were arranged on a regular grid across the LES domain, recording EC observations at 18 vertical levels. We use increasing height of a virtual flux tower and increasing numbers of virtual flux towers in the domain to compute energy fluxes. Initial results show a large (>25) number of towers is needed sufficiently sample the mean domain energy flux. When the ERF upscaling method was applied to the virtual towers in the LES environment, we were able to map fluxes over the domain to within 20% precision with a significantly smaller number of towers. This was achieved by relating sub-hourly turbulent fluxes to meteorological forcings and surface properties. These results demonstrate how advanced scaling techniques can decrease the number of towers, and thus experimental expense, required for domain-scaling over heterogeneous surface.

Planning performance in schizophrenia patients: a meta-analysis of the influence of task difficulty and clinical and sociodemographic variables.

PubMed

Knapp, F; Viechtbauer, W; Leonhart, R; Nitschke, K; Kaller, C P

2017-08-01

Despite a large body of research on planning performance in adult schizophrenia patients, results of individual studies are equivocal, suggesting either no, moderate or severe planning deficits. This meta-analysis therefore aimed to quantify planning deficits in schizophrenia and to examine potential sources of the heterogeneity seen in the literature. The meta-analysis comprised outcomes of planning accuracy of 1377 schizophrenia patients and 1477 healthy controls from 31 different studies which assessed planning performance using tower tasks such as the Tower of London, the Tower of Hanoi and the Stockings of Cambridge. A meta-regression analysis was applied to assess the influence of potential moderator variables (i.e. sociodemographic and clinical variables as well as task difficulty). The findings indeed demonstrated a planning deficit in schizophrenia patients (mean effect size: ; 95% confidence interval 0.56-0.78) that was moderated by task difficulty in terms of the minimum number of moves required for a solution. The results did not reveal any significant relationship between the extent of planning deficits and sociodemographic or clinical variables. The current results provide first meta-analytic evidence for the commonly assumed impairments of planning performance in schizophrenia. Deficits are more likely to become manifest in problem items with higher demands on planning ahead, which may at least partly explain the heterogeneity of previous findings. As only a small fraction of studies reported coherent information on sample characteristics, future meta-analyses would benefit from more systematic reports on those variables.

FUGITIVE EMISSION SOURCES AND BATCH OPERATIONS IN SYNTHETIC ORGANIC CHEMICAL PRODUCTION

EPA Science Inventory

This survey report was developed for the EPA for use in assessing the potential magnitude of fugitive volatile organic compound (VOC) emissions from agitator seals, cooling towers and batch operations in the production of 378 designated chemicals. The information presented in thi...

Comparison-based optical study on a point-line-coupling-focus system with linear Fresnel heliostats.

PubMed

Dai, Yanjun; Li, Xian; Zhou, Lingyu; Ma, Xuan; Wang, Ruzhu

2016-05-16

Concentrating the concept of a beam-down solar tower with linear Fresnel heliostat (PLCF) is one of the feasible choices and has great potential in reducing spot size and improving optical efficiency. Optical characteristics of a PLCF system with the hyperboloid reflector are introduced and investigated theoretically. Taking into account solar position and optical surface errors, a Monte Carlo ray-tracing (MCRT) analysis model for a PLCF system is developed and applied in a comparison-based study on the optical performance between the PLCF system and the conventional beam-down solar tower system with flat and spherical heliostats. The optimal square facet of linear Fresnel heliostat is also proposed for matching with the 3D-CPC receiver.

ASSESSMENT OF DIOXIN INHALATION EXPOSURES AND ...

EPA Pesticide Factsheets

In the days following the September 11, 2001, terrorist attack on New York City's World Trade Center (WTC) towers, EPA, other federal agencies, and New York City and New York State public health and environmental authorities initiated numerous air monitoring activities to better understand the ongoing impact of emissions from that disaster. Using these data, EPA conducted an inhalation exposure and human health risk assessment. The overall evaluation focused on particulate matter, metals, polychlorinated biphenyls, dioxin-like compounds, asbestos, and volatile organic compounds. This paper reports on the analysis of dioxin-like compounds only.Lorber, M. 2003. Assessment of Dioxin Inhalation Exposures and Potential Health Impacts Following the Collapse of the World Trade Center Towers. Organohalogen Compounds 63 (no page numbers). journal article

Simulation of hybrid solar power plants

NASA Astrophysics Data System (ADS)

Dieckmann, Simon; Dersch, Jürgen

2017-06-01

Hybrid solar power plants have the potential to combine advantages of two different technologies at the cost of increased complexity. The present paper shows the potential of the software greenius for the techno-economic evaluation of hybrid solar power plants and discusses two exemplary scenarios. Depreciated Concentrated Solar Power (CSP) plants based on trough technology can be retrofitted with solar towers in order to reach higher steam cycle temperatures and hence efficiencies. Compared to a newly built tower plant the hybridization of a depreciated trough plant causes about 30% lower LCOE reaching 104 /MWh. The second hybrid scenario combines cost-efficient photovoltaics with dispatchable CSP technology. This hybrid plant offers very high capacity factors up to 69% based on 100% load from 8am to 11pm. The LCOE of the hybrid plant are only slightly lower (174 vs. 186 /MWh) compared to the pure CSP plant because the capital expenditure for thermal storage and power block remains the same while the electricity output is much lower.

Fuel Cell Backup Power System for Grid Service and Micro-Grid in Telecommunication Applications: Preprint

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

Ma, Zhiwen; Eichman, Joshua D; Kurtz, Jennifer M

This paper presents the feasibility and economics of using fuel cell backup power systems in telecommunication cell towers to provide grid services (e.g., ancillary services, demand response). The fuel cells are able to provide power for the cell tower during emergency conditions. This study evaluates the strategic integration of clean, efficient, and reliable fuel cell systems with the grid for improved economic benefits. The backup systems have potential as enhanced capability through information exchanges with the power grid to add value as grid services that depend on location and time. The economic analysis has been focused on the potential revenuemore » for distributed telecommunications fuel cell backup units to provide value-added power supply. This paper shows case studies on current fuel cell backup power locations and regional grid service programs. The grid service benefits and system configurations for different operation modes provide opportunities for expanding backup fuel cell applications responsive to grid needs.« less

Dimensions of Air Traffic Control Tower Information Needs: From Information Requests to Display Design

ERIC Educational Resources Information Center

Durso, Francis T.; Johnson, Brian R.; Crutchfield, Jerry M.

2010-01-01

In an effort to determine the information needs of tower air traffic controllers, instructors from the Federal Aviation Administration's Academy in Oklahoma City were asked to control traffic in a high-fidelity tower cab simulator. Information requests were made apparent by eliminating access to standard tower information sources. Instead,…

Convection towers

DOEpatents

Prueitt, Melvin L.

1994-01-01

Convection towers which are capable of cleaning the pollution from large quantities of air and of generating electricity utilize the evaporation of water sprayed into the towers to create strong airflows and to remove pollution from the air. Turbines in tunnels at the skirt section of the towers generate electricity. Other embodiments may also provide fresh water, and operate in an updraft mode.

Convection towers

DOEpatents

Prueitt, M.L.

1994-02-08

Convection towers which are capable of cleaning the pollution from large quantities of air and of generating electricity utilize the evaporation of water sprayed into the towers to create strong airflows and to remove pollution from the air. Turbines in tunnels at the skirt section of the towers generate electricity. Other embodiments may also provide fresh water, and operate in an updraft mode. 5 figures.

Ivory Basements and Ivory Towers

ERIC Educational Resources Information Center

Fitzgerald, Tanya

2012-01-01

The metaphors of the ivory tower and ivory basement are used in this chapter to reflect how many women understand and experience the academy. The ivory tower signifies a place that is protected, a place of privilege and authority and a place removed from the outside world (and consequently the rigours of the market place). The ivory tower, by…

Cell-Phone Tower Power System Prototype Testing for Verizon Wireless |

Science.gov Websites

Verizon Wireless Cell-Phone Tower Power System Prototype Testing for Verizon Wireless For Verizon Wireless Advanced Manufacturing Research | NREL Cell-Phone Tower Power System Prototype Testing for , NREL tested a new cell-phone tower power system prototype based on DC interconnection and photovoltaics

VIEW OF BUILDING 215A, THE WATER TOWER, LOOKING WEST, SOUTHWEST. ...

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

VIEW OF BUILDING 215A, THE WATER TOWER, LOOKING WEST, SOUTHWEST. CONSTRUCTION ON BUILDING 215A BEGAN IN 1952. THE WATER TOWER IS 155 FEET TALL AND IS THE TALLEST STRUCTURE AT THE ROCKY FLATS PLANT - Rocky Flats Plant, Water Tower, Northwest quadrant of Plant near west terminus of Central Avenue, Golden, Jefferson County, CO

77 FR 3440 - Utility Scale Wind Towers From the People's Republic of China and the Socialist Republic of...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-01-24

... Exhibit II-12. Petitioner determined labor costs using the labor consumption rates of the Wind Tower... natural gas costs using the natural gas consumption rates derived from the Wind Tower Producer's.... Petitioner determined labor costs using the labor consumption rates of the Wind Tower Producer. See Volume IV...

Approximate method for calculating free vibrations of a large-wind-turbine tower structure

NASA Technical Reports Server (NTRS)

Das, S. C.; Linscott, B. S.

1977-01-01

A set of ordinary differential equations were derived for a simplified structural dynamic lumped-mass model of a typical large-wind-turbine tower structure. Dunkerley's equation was used to arrive at a solution for the fundamental natural frequencies of the tower in bending and torsion. The ERDA-NASA 100-kW wind turbine tower structure was modeled, and the fundamental frequencies were determined by the simplified method described. The approximate fundamental natural frequencies for the tower agree within 18 percent with test data and predictions analyzed.

System and method for aligning heliostats of a solar power tower

DOEpatents

Convery, Mark R.

2013-01-01

Disclosed is a solar power tower heliostat alignment system and method that includes a solar power tower with a focal area, a plurality of heliostats that each reflect sunlight towards the focal area of the solar power tower, an off-focal area location substantially close to the focal area of the solar power tower, a communication link between the off-focal area location and a misaligned heliostat, and a processor that interprets the communication between the off-focal area location and the misaligned heliostat to identify the misaligned heliostat from the plurality of heliostats and that determines a correction for the identified misaligned heliostat to realign the misaligned heliostat to reflect sunlight towards the focal area of the solar power tower.

Control of Carbon Nanotube Density and Tower Height in an Array

NASA Technical Reports Server (NTRS)

Delzeit, Lance D. (Inventor); Schipper, John F. (Inventor)

2010-01-01

A method for controlling density or tower height of carbon nanotube (CNT) arrays grown in spaced apart first and second regions on a substrate. CNTs having a first density range (or first tower height range) are grown in the first region using a first source temperature range for growth. Subsequently or simultaneously, CNTs having a second density range (or second tower height range), having an average density (or average tower height) in the second region different from the average density (or average tower height) for the first region, are grown in the second region, using supplemental localized hearing for the second region. Application for thermal dissipation and/or dissipation of electrical charge or voltage in an electronic device are discussed.

The Damaging Effects of Earthquake Excitation on Concrete Cooling Towers

NASA Astrophysics Data System (ADS)

Abedi-Nik, Farhad; Sabouri-Ghomi, Saeid

2008-07-01

Reinforced concrete cooling towers of hyperbolic shell configuration find widespread application in utilities engaged in the production of electric power. In design of critical civil infrastructure of this type, it is imperative to consider all the possible loading conditions that the cooling tower may experience, an important loading condition in many countries is that of the earthquake excitation, whose influence on the integrity and stability of cooling towers is profound. Previous researches have shown that the columns supporting a cooling tower are sensitive to earthquake forces, as they are heavily loaded elements that do not possess high ductility, and understanding the behavior of columns under earthquake excitation is vital in structural design because they provide the load path for the self weight of the tower shell. This paper presents the results of a finite element investigation of a representative "dry" cooling tower, using realistic horizontal and vertical acceleration data obtained from the recent and widely-reported Tabas, Naghan and Bam earthquakes in Iran. The results of both linear and nonlinear analyses are reported in the paper, the locations of plastic hinges within the supporting columns are identified and the ramifications of the plastic hinges on the stability of the cooling tower are assessed. It is concluded that for the (typical) cooling tower configuration analyzed, the columns that are instrumental in providing a load path are influenced greatly by earthquake loading, and for the earthquake data used in this study the representative cooling tower would be rendered unstable and would collapse under the earthquake forces considered.

The Damaging Effects of Earthquake Excitation on Concrete Cooling Towers

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

Abedi-Nik, Farhad; Sabouri-Ghomi, Saeid

2008-07-08

Reinforced concrete cooling towers of hyperbolic shell configuration find widespread application in utilities engaged in the production of electric power. In design of critical civil infrastructure of this type, it is imperative to consider all the possible loading conditions that the cooling tower may experience, an important loading condition in many countries is that of the earthquake excitation, whose influence on the integrity and stability of cooling towers is profound. Previous researches have shown that the columns supporting a cooling tower are sensitive to earthquake forces, as they are heavily loaded elements that do not possess high ductility, and understandingmore » the behavior of columns under earthquake excitation is vital in structural design because they provide the load path for the self weight of the tower shell. This paper presents the results of a finite element investigation of a representative 'dry' cooling tower, using realistic horizontal and vertical acceleration data obtained from the recent and widely-reported Tabas, Naghan and Bam earthquakes in Iran. The results of both linear and nonlinear analyses are reported in the paper, the locations of plastic hinges within the supporting columns are identified and the ramifications of the plastic hinges on the stability of the cooling tower are assessed. It is concluded that for the (typical) cooling tower configuration analyzed, the columns that are instrumental in providing a load path are influenced greatly by earthquake loading, and for the earthquake data used in this study the representative cooling tower would be rendered unstable and would collapse under the earthquake forces considered.« less

Simulation of Pressure-swing Distillation for Separation of Ethyl Acetate-Ethanol-Water

NASA Astrophysics Data System (ADS)

Yang, Jing; Zhou, Menglin; Wang, Yujie; Zhang, Xi; Wu, Gang

2017-12-01

In the light of the azeotrope of ethyl acetate-ethanol-water, a process of pressure-swing distillation is proposed. The separation process is simulated by Aspen Plus, and the effects of theoretical stage number, reflux ratio and feed stage about the pressure-swing distillation are optimized. Some better process parameters are as follows: for ethyl acetate refining tower, the pressure is 500.0 kPa, theoretical stage number is 16, reflux ratio is 0.6, feed stage is 5; for crude ethanol tower, the pressure is 101.3 kPa, theoretical stage number is 15, reflux ratio is 0.3, feed stage is 4; for ethanol tower, the pressure is 101.3 kPa, theoretical stage number is 25, reflux ratio is 1.2, feed stage is 10. The mass fraction of ethyl acetate in the bottom of the ethyl acetate refining tower reaches 0.9990, the mass fraction of ethanol in the top of the ethanol tower tower reaches 0.9017, the mass fraction of water in the bottom of the ethanol tower tower reaches 0.9622, and there is also no ethyl acetate in the bottom of the ethanol tower. With laboratory tests, experimental results are in good agreement with the simulation results, which indicates that the separation of ethyl acetate ethanol water can be realized by the pressure-swing distillation separation process. Moreover, it has certain practical significance to industrial practice.

2. Signal Tower, looking east. Delaware, Lackawanna & Western ...

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

2. Signal Tower, looking east. - Delaware, Lackawanna & Western Railroad, Scranton Yards, Mattes Street Signal Tower, 80 feet Southwest of Railroad Alley & Cedar Avenue, Scranton, Lackawanna County, PA

Performance Evaluation of a Mechanical Draft Cross Flow Cooling Towers Employed in a Subtropical Region

NASA Astrophysics Data System (ADS)

Muthukumar, Palanisamy; Naik, Bukke Kiran; Goswami, Amarendra

2018-02-01

Mechanical draft cross flow cooling towers are generally used in a large-scale water cooled condenser based air-conditioning plants for removing heat from warm water which comes out from the condensing unit. During this process considerable amount of water in the form of drift (droplets) and evaporation is carried away along with the circulated air. In this paper, the performance evaluation of a standard cross flow induced draft cooling tower in terms of water loss, range, approach and cooling tower efficiency are presented. Extensive experimental studies have been carried out in three cooling towers employed in a water cooled condenser based 1200 TR A/C plant over a period of time. Daily variation of average water loss and cooling tower performance parameters have been reported for some selected days. The reported average water loss from three cooling towers is 4080 l/h and the estimated average water loss per TR per h is about 3.1 l at an average relative humidity (RH) of 83%. The water loss during peak hours (2 pm) is about 3.4 l/h-TR corresponding to 88% of RH and the corresponding efficiency of cooling towers varied between 25% and 45%.

Finite Element Analysis of the Maximum Stress at the Joints of the Transmission Tower

NASA Astrophysics Data System (ADS)

Itam, Zarina; Beddu, Salmia; Liyana Mohd Kamal, Nur; Bamashmos, Khaled H.

2016-03-01

Transmission towers are tall structures, usually a steel lattice tower, used to support an overhead power line. Usually, transmission towers are analyzed as frame-truss systems and the members are assumed to be pin-connected without explicitly considering the effects of joints on the tower behavior. In this research, an engineering example of joint will be analyzed with the consideration of the joint detailing to investigate how it will affect the tower analysis. A static analysis using STAAD Pro was conducted to indicate the joint with the maximum stress. This joint will then be explicitly analyzed in ANSYS using the Finite Element Method. Three approaches were used in the software which are the simple plate model, bonded contact with no bolts, and beam element bolts. Results from the joint analysis show that stress values increased with joint details consideration. This proves that joints and connections play an important role in the distribution of stress within the transmission tower.

Investigation of flow characteristics of a single and two-adjacent natural draft dry cooling towers under cross wind condition

NASA Astrophysics Data System (ADS)

Mekanik, Abolghasem; Soleimani, Mohsen

2007-11-01

Wind effect on natural draught cooling towers has a very complex physics. The fluid flow and temperature distribution around and in a single and two adjacent (tandem and side by side) dry-cooling towers under cross wind are studied numerically in the present work. Cross-wind can significantly reduce cooling efficiency of natural-draft dry-cooling towers, and the adjacent towers can affect the cooling efficiency of both. In this paper we will present a complex computational model involving more than 750,000 finite volume cells under precisely defined boundary condition. Since the flow is turbulent, the standard k-ɛ turbulence model is used. The numerical results are used to estimate the heat transfer between radiators of the tower and air surrounding it. The numerical simulation explained the main reason for decline of the thermo-dynamical performance of dry-cooling tower under cross wind. In this paper, the incompressible fluid flow is simulated, and the flow is assumed steady and three-dimensional.

'Towers in the Tempest' Computer Animation Submission

NASA Technical Reports Server (NTRS)

Shirah, Greg

2008-01-01

The following describes a computer animation that has been submitted to the ACM/SIGGRAPH 2008 computer graphics conference: 'Towers in the Tempest' clearly communicates recent scientific research into how hurricanes intensify. This intensification can be caused by a phenomenon called a 'hot tower.' For the first time, research meteorologists have run complex atmospheric simulations at a very fine temporal resolution of 3 minutes. Combining this simulation data with satellite observations enables detailed study of 'hot towers.' The science of 'hot towers' is described using: satellite observation data, conceptual illustrations, and a volumetric atmospheric simulation data. The movie starts by showing a 'hot tower' observed by NASA's Tropical Rainfall Measuring Mission (TRMM) spacecraft's three dimensional precipitation radar data of Hurricane Bonnie. Next, the dynamics of a hurricane and the formation of 'hot towers' are briefly explained using conceptual illustrations. Finally, volumetric cloud, wind, and vorticity data from a supercomputer simulation of Hurricane Bonnie are shown using volume techniques such as ray marching.

Minimizing corrosion in coal liquid distillation

DOEpatents

Baumert, Kenneth L.; Sagues, Alberto A.; Davis, Burtron H.

1985-01-01

In an atmospheric distillation tower of a coal liquefaction process, tower materials corrosion is reduced or eliminated by introduction of boiling point differentiated streams to boiling point differentiated tower regions.

3. West elevation of Signal Tower. Delaware, Lackawanna & ...

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

3. West elevation of Signal Tower. - Delaware, Lackawanna & Western Railroad, Scranton Yards, Mattes Street Signal Tower, 80 feet Southwest of Railroad Alley & Cedar Avenue, Scranton, Lackawanna County, PA

Enumeration of Legionella pneumophila in cooling tower water systems.

PubMed

Türetgen, Irfan; Sungur, Esra Ilhan; Cotuk, Aysin

2005-01-01

Legionella pneumophila, the causative agent of Legionnaires' disease, is known to colonise and frequently grow in cooling tower waters. Disease is acquired by inhaling aerosol contaminated by legionellae. Determination of the count of Legionella pneumophila in cooling tower waters may, therefore, be useful for risk assessment. In our survey, 103 water samples from 50 cooling towers were examined over a five-year period to indicate the seasonal distribution and the ecology of L. pneumophila, as regards temperature and pH. L. pneumophila serogroup 1 was found in 44% of the isolated strains, which is primarily responsible for the majority of Legionnaires' disease. The large majority of examined towers had levels of L. pneumophila in the high-risk category. These cooling towers have been linked to many outbreaks of Legionnaires' disease.

Movement planning reflects skill level and age changes in toddlers

PubMed Central

Chen, Yu-ping; Keen, Rachel; Rosander, Kerstin; von Hofsten, Claes

2010-01-01

Kinematic measures of children’s reaching were found to reflect stable differences in skill level for planning for future actions. Thirty-five toddlers (18–21 months) were engaged in building block towers (precise task) and in placing blocks into an open container (imprecise task). Sixteen children were re-tested on the same tasks a year later. Longer deceleration as the hand approached the block for pickup was found in the tower task compared to the imprecise task, indicating planning for the second movement. More skillful toddlers who could build high towers had a longer deceleration phase when placing blocks on the tower than toddlers who built low towers. Kinematic differences between the groups remained a year later when all children could build high towers. PMID:21077868

Health risks from exposure to Legionella in reclaimed water aerosols: Toilet flushing, spray irrigation, and cooling towers.

PubMed

Hamilton, Kerry A; Hamilton, Mark T; Johnson, William; Jjemba, Patrick; Bukhari, Zia; LeChevallier, Mark; Haas, Charles N

2018-05-01

The use of reclaimed water brings new challenges for the water industry in terms of maintaining water quality while increasing sustainability. Increased attention has been devoted to opportunistic pathogens, especially Legionella pneumophila, due to its growing importance as a portion of the waterborne disease burden in the United States. Infection occurs when a person inhales a mist containing Legionella bacteria. The top three uses for reclaimed water (cooling towers, spray irrigation, and toilet flushing) that generate aerosols were evaluated for Legionella health risks in reclaimed water using quantitative microbial risk assessment (QMRA). Risks are compared using data from nineteen United States reclaimed water utilities measured with culture-based methods, quantitative PCR (qPCR), and ethidium-monoazide-qPCR. Median toilet flushing annual infection risks exceeded 10 -4 considering multiple toilet types, while median clinical severity infection risks did not exceed this value. Sprinkler and cooling tower risks varied depending on meteorological conditions and operational characteristics such as drift eliminator performance. However, the greatest differences between risk scenarios were due to 1) the dose response model used (infection or clinical severity infection) 2) population at risk considered (residential or occupational) and 3) differences in laboratory analytical method. Theoretical setback distances necessary to achieve a median annual infection risk level of 10 -4 are proposed for spray irrigation and cooling towers. In both cooling tower and sprinkler cases, Legionella infection risks were non-trivial at potentially large setback distances, and indicate other simultaneous management practices could be needed to manage risks. The sensitivity analysis indicated that the most influential factors for variability in risks were the concentration of Legionella and aerosol partitioning and/or efficiency across all models, highlighting the importance of strategies to manage Legionella occurrence in reclaimed water. Copyright © 2018 Elsevier Ltd. All rights reserved.

Gradient Measurements of Nitrous Acid (hono)

NASA Astrophysics Data System (ADS)

Kleffmann, J.; Kurtenbach, R.; Lörzer, J.; Wiesen, P.; Kalthoff, N.; Vogel, B.; Vogel, H.

Nitrous acid (HONO) plays an important role in photochemical air pollution due to its photodissociation by solar UV radiation into hydroxyl radicals and thus significantly enhances photooxidation processes. Furthermore, HONO is an important indoor pol- lutant, which can react with amines leading to nitrosamines, which are known to be carcinogenic. Despite its importance in atmospheric chemistry the mechanisms lead- ing to HONO formation are still not completely understood at present. Although it is commonly proposed that HONO is formed by heterogeneous processes, i.e. by the conversion of NO2 on wet surfaces, it is still under discussion whether HONO produc- tion is dominated by the surface of particles or by the ground surface. Simultaneous vertical profile measurements of HONO, the precursor NO2 and the aerosol surface area, which could answer this question are not available at present. Accordingly, in the present study night-time HONO, NO2 and particle surface area gradients in the altitude range 10-190 m were measured on the meteorological tower at the Forschungszentrum Karlsruhe/Germany using a new, very sensitive HONO in- strument (LOPAP), a commercial NOx monitor and a SMPS system. For all gradient measurements during the campaign it was observed that the [HONO]/[NO2] ratio decreased with increasing altitude. In contrast, the particle sur- face area was found to be more or less constant. Accordingly, no correlation between the [HONO]/[NO2] ratio and the particle surface area was observed showing that HONO formation was dominated by processes on ground surfaces and that signifi- cant HONO formation on particle surfaces could be excluded for the measurement site.

Regional recovery of the disturbing gravitational potential by inverting satellite gravitational gradients

NASA Astrophysics Data System (ADS)

Pitoňák, Martin; Šprlák, Michal; Hamáčková, Eliška; Novák, Pavel

2016-04-01

Regional recovery of the disturbing gravitational potential in the area of Central Europe from satellite gravitational gradients data is discussed in this contribution. The disturbing gravitational potential is obtained by inverting surface integral formulas which transform the disturbing gravitational potential onto disturbing gravitational gradients in the spherical local north-oriented frame. Two numerical approaches that solve the inverse problem are considered. In the first approach, the integral formulas are rigorously decomposed into two parts, that is, the effects of the gradient data within near and distant zones. While the effect of the near zone data is sought as an inverse problem, the effect of the distant zone data is synthesized from the global gravitational model GGM05S using spectral weights given by truncation error coefficients up to the degree 150. In the second approach, a reference gravitational field up to the degree 180 is applied to reduce and smooth measured gravitational gradients. In both cases we recovered the disturbing gravitational potential from each of the four well-measured gravitational gradients of the GOCE satellite separately as well as from their combination. Obtained results are compared with the EGM2008, DIR-r2, TIM-r2 and SPW-r2 global gravitational models. The best fit was achieved for EGM2008 and the second approach combining all four well-measured gravitational gradients with rms of 1.231 m2 s-2.

VALVE TOWER FROM HIGH GROUND NEAR APPROACH BRIDGE. VIEW FACING ...

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

VALVE TOWER FROM HIGH GROUND NEAR APPROACH BRIDGE. VIEW FACING NORTHEAST - Schofield Barracks Military Reservation, Ku Tree Reservoir, Valve Tower, Kalakoa Stream, East Range, Wahiawa, Honolulu County, HI

PBF Cooling Tower. Hot deck of Cooling Tower with fan ...

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

PBF Cooling Tower. Hot deck of Cooling Tower with fan motors in place. Fan's propeller blades (not in view) rotate within lower portion of vents. Inlet pipe is a left of view. Contractor's construction buildings in view to right. Photographer: Larry Page. Date: June 30, 1969. INEEL negative no. 69-3781 - Idaho National Engineering Laboratory, SPERT-I & Power Burst Facility Area, Scoville, Butte County, ID

Some extemporaneous comments on our experiences with towers for wind generators

NASA Technical Reports Server (NTRS)

Hutter, U.

1973-01-01

A wind generator tower must be designed to withstand fatigue forces and gust winds loads. Optimum tower height depends on the energy cost to the customer because an increase in height results in an increase in the cost of the plant. It is suggested that costs are minimum for the shortest tower possible and that the rotor should be as large as possible.

Application of micro-PIV to the study of staphylococci bacteria bio-film dynamics

NASA Astrophysics Data System (ADS)

Sherman, Erica; Bayles, Kenneth; Moormeier, Derek; Wei, Timothy

2012-11-01

Staphylococci bacteria are recognized as the most frequent cause of biofilm-associated infections. Although humans are regularly exposed to staphylococcus bacteria without consequence, a localized staph infection has the potential to enter the bloodstream and lead to serious infections such as endocarditis, pneumonia, or toxic shock syndrome. The mechanics of staphylococci biofilm formation and dispersion through the bloodstream are not well known. It has recently been observed that under certain flow conditions, bacteria grow in stable bio-films. Under other conditions, they organize in tower-like structures which break and are transported downstream by the flow. The fundamental questions addressed in this study are i) whether or not fluid mechanics plays a role in differentiating between film or tower formation and ii) whether or not the faulty towers are a bio-film propagation mechanism. This talk focuses on the application of micro-PIV to study this problem. Bacteria were cultured in a glass microchannel and subjected to a range of steady shear rates. Micro-PIV measurements were made to map the flow over and around different types of bio-film structures. Measurements and control volume analysis will be presented quantifying forces acting on these structures.

Estimating Carcass Persistence and Scavenging Bias in a Human Influenced Landscape

USGS Publications Warehouse

Flint, Paul L.; Lance, Ellen W.; Sowl, Kristine M.; Donnelly, Tyrone F.

2010-01-01

We examined variation in persistence rates of waterfowl carcasses placed along a series of transects in tundra habitats in western Alaska. This study was designed to assess the effects of existing tower structures and was replicated with separate trials in winter, summer and fall as both the resident avian population and the suite of potential scavengers varied seasonally. Carcass persistence rates were uniformly low, with <50% of carcasses persisting for more than a day on average. Persistence rate varied by carcass age, carcass size, among transects and was lowest in the fall and highest in the summer. We found little support for models where persistence varied in relation to the presence of tower structures. We interpret this as evidence that scavengers were not habituated to searching for carcasses near these structures. Our data demonstrate that only a small fraction of bird carcasses are likely to persist between searches, and if not appropriately accounted for, scavenging bias could significantly influence bird mortality estimates. The variation that we documented suggests that persistence rates should not be extrapolated among tower locations or across time periods as the variation in carcass persistence will result in biased estimates of total bird strike mortality.

OVERVIEW OF VALVE TOWER FROM NORTHERN SIDE OF BASIN. VIEW ...

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

OVERVIEW OF VALVE TOWER FROM NORTHERN SIDE OF BASIN. VIEW FACING SOUTHWEST - Schofield Barracks Military Reservation, Ku Tree Reservoir, Valve Tower, Kalakoa Stream, East Range, Wahiawa, Honolulu County, HI

Geology of Devils Tower National Monument, Wyoming

USGS Publications Warehouse

Robinson, Charles Sherwood

1956-01-01

Devils Tower is a steep-sided mass of igneous rock that rises above the surrounding hills and the valley of the Belle Fourche River in Crook County, Wyo. It is composed of a crystalline rock, classified as phonolite porphyry, that when fresh is gray but which weathers to green or brown. Vertical joints divide the rock mass into polygonal columns that extend from just above the base to the top of the Tower. The hills in the vicinity and at the base of the Tower are composed of red, yellow, green, or gray sedimentary rocks that consist of sandstone, shale, or gypsum. These rocks, in aggregate about 400 feet thick, include, from oldest to youngest, the upper part of the Spearfish formation, of Triassic age, the Gypsum Spring formation, of Middle Jurassic age, and the Sundance formation, of Late Jurassic age. The Sundance formation consists of the Stockade Beaver shale member, the Hulett sandstone member, the Lak member, and the Redwater shale member. The formations have been only slightly deformed by faulting and folding. Within 2,000 to 3.000 feet of the Tower, the strata for the most part dip at 3 deg - 5 deg towards the Tower. Beyond this distance, they dip at 2 deg - 5 deg from the Tower. The Tower is believed to have been formed by the intrusion of magma into the sedimentary rocks, and the shape of the igneous mass formed by the cooled magma is believed to have been essentially the same as the Tower today. Devils Tower owes its impressiveness to its resistance to erosion as compared with the surrounding sedimentary rocks, and to the contrast of the somber color of the igneous column to the brightly colored bands of sedimentary rocks.

Problems in air traffic management. V., Identification and potential aptitude test measures for selection of tower air traffic controller trainees.

DOT National Transportation Integrated Search

1965-07-01

A study of over 200 Terminal Air Traffic Control Specialists indicated that their training performance could be well predicted by a composite of four aptitude tests measuring: numerical ability, non-verbal abstract reasoning, ability to solve simplif...

Molecular characterization and pathogenicity of fungal isolates for use against the small hive beetle (Aethina tumida)

USDA-ARS?s Scientific Manuscript database

The analysis of DNA sequences from fungal pathogens obtained from cadavers of the small hive beetle (SHB) collected from several apiaries in Florida revealed a mixture of saprobes and two potential primary entomopathogens, Metarhizium anisopliae and Beauveria bassiana. Spray tower bioassays indicate...

28. WEST CONFEDERATE AVENUE, OBSERVATION TOWER, VIEW FROM THE TOP ...

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

28. WEST CONFEDERATE AVENUE, OBSERVATION TOWER, VIEW FROM THE TOP OF TOWER TO SOUTH. NOTE FOREST AND AGRICULTURAL LANDSCAPES. VIEW S. - Gettysburg National Military Park Tour Roads, Gettysburg, Adams County, PA

6. View of south tower, facing south from Clover Island, ...

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

6. View of south tower, facing south from Clover Island, across boat moorage channel. - Pasco-Kennewick Transmission Line, Columbia River Crossing Towers, Columbia Drive & Gum Street, Kennewick, Benton County, WA

1. Perspective of Mattes Street Signal Tower looking southwest. ...

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

1. Perspective of Mattes Street Signal Tower looking southwest. - Delaware, Lackawanna & Western Railroad, Scranton Yards, Mattes Street Signal Tower, 80 feet Southwest of Railroad Alley & Cedar Avenue, Scranton, Lackawanna County, PA

7. Detail of first floor doorway to Signal Tower. ...

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

7. Detail of first floor doorway to Signal Tower. - Delaware, Lackawanna & Western Railroad, Scranton Yards, Mattes Street Signal Tower, 80 feet Southwest of Railroad Alley & Cedar Avenue, Scranton, Lackawanna County, PA

Evaporation Tower With Prill Nozzles

NASA Technical Reports Server (NTRS)

Du Fresne, E. R.

1984-01-01

Tower more efficient than conventional evaporation equipment. Liquids such as milk and fruit juice concentrated by passing them through tiny nozzle to form droplets, then allowing droplets to fall through evacuated tower with cooled walls.

2. Detail of tower foundation with lightning transfer wire, southeast ...

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

2. Detail of tower foundation with lightning transfer wire, southeast corner - Cold Mountain Fire Lookout Station, Lookout Tower, Krassel District, Frank Church River of No Return Wilderness, Dixie, Idaho County, ID

Flux Sampling Errors for Aircraft and Towers

NASA Technical Reports Server (NTRS)

Mahrt, Larry

1998-01-01

Various errors and influences leading to differences between tower- and aircraft-measured fluxes are surveyed. This survey is motivated by reports in the literature that aircraft fluxes are sometimes smaller than tower-measured fluxes. Both tower and aircraft flux errors are larger with surface heterogeneity due to several independent effects. Surface heterogeneity may cause tower flux errors to increase with decreasing wind speed. Techniques to assess flux sampling error are reviewed. Such error estimates suffer various degrees of inapplicability in real geophysical time series due to nonstationarity of tower time series (or inhomogeneity of aircraft data). A new measure for nonstationarity is developed that eliminates assumptions on the form of the nonstationarity inherent in previous methods. When this nonstationarity measure becomes large, the surface energy imbalance increases sharply. Finally, strategies for obtaining adequate flux sampling using repeated aircraft passes and grid patterns are outlined.

Legionnaires' Disease Outbreak at a Long-Term Care Facility Caused by a Cooling Tower Using an Automated Disinfection System--Ohio, 2013.

PubMed

Quinn, Celia; Demirjian, Alicia; Watkins, Louise Francois; Tomczyk, Sara; Lucas, Claressa; Brown, Ellen; Kozak-Muiznieks, Natalia; Benitez, Alvaro; Garrison, Laurel E; Kunz, Jasen; Brewer, Scott; Eitniear, Samantha; DiOrio, Mary

2015-12-01

On July 9, 2013, an outbreak of Legionnaires' disease (LD) was identified at Long-Term Care Facility A in central Ohio. This article describes the investigation of the outbreak and identification of the outbreak source, a cooling tower using an automated biocide delivery system. In total, 39 outbreak LD cases were identified; among these, six patients died. Water samples from a cooling tower were positive for Legionella pneumophila serogroup 1, reactive to monoclonal antibody 2, with matching sequence type to a patient isolate. An electronic control system turned off cooling tower pumps during low-demand periods, preventing delivery of disinfectant by a timed-release system, and leading to amplification of Legionella in the cooling tower. Guidelines for tower maintenance should address optimal disinfection when using automated systems.

A Meso-Climatology Study of the High-Resolution Tower Network Over the Florida Spaceport

NASA Technical Reports Server (NTRS)

Case, Jonathan L.; Bauman, William H., III

2004-01-01

Forecasters at the US Air Force 45th Weather Squadron (45 WS) use wind and temperature data from the tower network over the Kennedy Space Center (KSC) and Cape Canaveral Air Force Station (CCAFS) to evaluate Launch Commit Criteria and to issue and verify temperature and wind advisories, watches, and warnings for ground operations. The Spaceflight Meteorology Group at the Johnson Space Center in Houston, TX also uses these data when issuing forecasts for shuttle landings at the KSC Shuttle Landing Facility. Systematic biases in these parameters at any of the towers could adversely affect an analysis, forecast, or verification for all of these operations. In addition, substantial geographical variations in temperature and wind speed can occur under specific wind directions. Therefore, the Applied Meteorology Unit (AMU), operated by ENSCO Inc., was tasked to develop a monthly and hourly climatology of temperatures and winds from the tower network, and identify the geographical variation, tower biases, and the magnitude of those biases. This paper presents a sub-set of results from a nine-year climatology of the KSC/CCAFS tower network, highlighting the geographical variations based on location, month, times of day, and specific wind direction regime. Section 2 provides a description of the tower mesonetwork and instrumentation characteristics. Section 3 presents the methodology used to construct the tower climatology including QC methods and data processing. The results of the tower climatology are presented in Section 4 and Section 5 summarizes the paper.

Research Based on the Acoustic Emission of Wind Power Tower Drum Dynamic Monitoring Technology

NASA Astrophysics Data System (ADS)

Zhang, Penglin; Sang, Yuan; Xu, Yaxing; Zhao, Zhiqiang

Wind power tower drum is one of the key components of the wind power equipment. Whether the wind tower drum performs safety directly affects the efficiency, life, and performance of wind power equipment. Wind power tower drum in the process of manufacture, installation, and operation may lead to injury, and the wind load and gravity load and long-term factors such as poor working environment under the action of crack initiation or distortion, which eventually result in the instability or crack of the wind power tower drum and cause huge economic losses. Thus detecting the wind power tower drum crack damage and instability is especially important. In this chapter, acoustic emission is used to monitor the whole process of wind power tower drum material Q345E steel tensile test at first, and processing and analysis tensile failure signal of the material. And then based on the acoustic emission testing technology to the dynamic monitoring of wind power tower drum, the overall detection and evaluation of the existence of active defects in the whole structure, and the acoustic emission signals collected for processing and analysis, we could preliminarily master the wind tower drum mechanism of acoustic emission source. The acoustic emission is a kind of online, efficient, and economic method, which has very broad prospects for work. The editorial committee of nondestructive testing qualification and certification of personnel teaching material of science and technology industry of national defense, "Acoustic emission testing" (China Machine Press, 2005.1).

Enhanced Precision Geolocation in 4G Wireless Networks

DTIC Science & Technology

2013-03-01

years has implemented a National Emergency Warning System using text messages delivered to cell phones [5]. The November 1999 FCC E911 regulations...statistical theory of passive geolocation of emitters may be found in [18]. Papers that survey methods of geolocation applied to cell phones include [4...where to put the tower % n: which tower to place %randomTowers(obj,dispersion, seperation ): generates % random towers for the network % obj: the network

Roughness Length Variability over Heterogeneous Surfaces

DTIC Science & Technology

2010-03-01

urban areas, marshes, temperate forests , barrier islands, sheltered inland waters, and the Atlantic Ocean . Depending upon the strength and direction of...32. Satellite photograph showing the proximity of Tower 0002 to the Atlantic Ocean . The tower is less than 1 km from the ocean in sector 120°–180...proximity of Tower 0110 to the Banana River and Atlantic Ocean . Red "X" marks the tower location. Image ©2010 Google

Challenges and Solutions in Fabrication of Silica-Based Photonic Crystal Fibers: An Experimental Study

NASA Astrophysics Data System (ADS)

Amouzad Mahdiraji, G.; Chow, Desmond M.; Sandoghchi, S. R.; Amirkhan, F.; Dermosesian, E.; Shien Yeo, Kwok; Kakaei, Z.; Ghomeishi, M.; Poh, Soo Yong; Gang, Shee Yu; Mahamd Adikan, F. R.

2014-01-01

The fabrication process of photonic crystal fibers based on a stack-and-draw method is presented in full detail in this article. In addition, improved techniques of photonic crystal fiber preform preparation and fabrication are highlighted. A new method of connecting a handle to a preform using only a fiber drawing tower is demonstrated, which eliminates the need for a high-temperature glass working lathe. Also, a new technique of modifying the photonic crystal fiber structural pattern by sealing air holes of the photonic crystal fiber cane is presented. Using the proposed methods, several types of photonic crystal fibers are fabricated, which suggests potential for rapid photonic crystal fibers fabrication in laboratories equipped with and limited to only a fiber drawing tower.

KSC-99pp1217

NASA Image and Video Library

1999-10-14

KENNEDY SPACE CENTER, FLA. -- Workers are dwarfed by the fallen 300-foot, five-million-pound Mobile Service Tower (MST) on Launch Complex 41, Cape Canaveral Air Force Station. The MST and a 200-foot-high umbilical tower nearby were demolished to make room for Lockheed Martin's 14-acre Vehicle Integration Facility (VIF), under construction. Only lightning protection towers remain standing at the site. About 200 pounds of linear-shaped charges were used to bring down the towers so that the materials can be recycled. The implosion and removal of the tower debris is expected to be completed in two months. The VIF will be used for Lockheed Martin's Atlas V Launch System.

Active tower damping and pitch balancing - design, simulation and field test

NASA Astrophysics Data System (ADS)

Duckwitz, Daniel; Shan, Martin

2014-12-01

The tower is one of the major components in wind turbines with a contribution to the cost of energy of 8 to 12% [1]. In this overview the load situation of the tower will be described in terms of sources of loads, load components and fatigue contribution. Then two load reduction control schemes are described along with simulation and field test results. Pitch Balancing is described as a method to reduce aerodynamic asymmetry and the resulting fatigue loads. Active Tower Damping is reducing the tower oscillations by applying appropiate pitch angle changes. A field test was conducted on an Areva M5000 wind turbine.

Surface Development and Test Facility (SDTF) New R&D Simulator for Airport Operations

NASA Technical Reports Server (NTRS)

Dorighi, Nancy S.

1997-01-01

A new simulator, the Surface Development and Test Facility (SDTF) is under construction at the NASA Ames Research Center in Mountain View, California. Jointly funded by the FAA (Federal Aviation Administration) and NASA, the SDTF will be a testbed for airport surface automation technologies of the future. The SDTF will be operational in the third quarter of 1998. The SDTF will combine a virtual tower with simulated ground operations to allow evaluation of new technologies for safety, effectiveness, reliability, and cost benefit. The full-scale level V tower will provide a seamless 360 degree high resolution out-the-window view, and a full complement of ATC (air traffic control) controller positions. The imaging system will be generated by two fully-configured Silicon Graphics Onyx Infinite Reality computers, and will support surface movement of up to 200 aircraft and ground vehicles. The controller positions, displays and consoles can be completely reconfigured to match the unique layout of any individual airport tower. Dedicated areas will accommodate pseudo-airport ramp controllers, pseudo-airport operators, and pseudo-pilots. Up to 33 total personnel positions will be able to participate in simultaneous operational scenarios. A realistic voice communication infrastructure will emulate the intercom and telephone communications of a real airport tower. Multi-channel audio and video recording and a sophisticated data acquisition system will support a wide variety of research and development areas, such as evaluation of automation tools for surface operations, human factors studies, integration of terminal area and airport technologies, and studies of potential airport physical and procedural modifications.

1. View of north tower, facing northwest from dike on ...

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

1. View of north tower, facing northwest from dike on north bank of the Columbia River. - Pasco-Kennewick Transmission Line, Columbia River Crossing Towers, Columbia Drive & Gum Street, Kennewick, Benton County, WA

Interior of the mine observation tower building, showing the steel ...

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

Interior of the mine observation tower building, showing the steel compass ring in the tower. View facing east - U.S. Naval Base, Pearl Harbor, Waipio Peninsula, Waipo Peninsula, Pearl City, Honolulu County, HI

Tower-supported solar-energy collector

NASA Technical Reports Server (NTRS)

Selcuk, M. K.

1977-01-01

Multiple-collector tower system supports three receiver/concentrators that absorb solar energy reflected from surrounding field of heliostats. System overcomes disadvantages of tower-supported collectors. Booms can be lowered during heavy winds to protect arms and collectors.

TOWER, WEST ELEVATION, SHOWING CONNECTION PIPES FOR TURNOUTS 22 (FOREGROUND) ...

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

TOWER, WEST ELEVATION, SHOWING CONNECTION PIPES FOR TURNOUTS 22 (FOREGROUND) AND 24. NOTE “LAZY JACK” TEMPERATURE COMPENSATOR IN FOREGROUND. - Baltimore & Ohio Railroad, Z Tower, State Route 46, Keyser, Mineral County, WV

6. Detail of windows in north wall of Signal Tower. ...

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

6. Detail of windows in north wall of Signal Tower. - Delaware, Lackawanna & Western Railroad, Scranton Yards, Mattes Street Signal Tower, 80 feet Southwest of Railroad Alley & Cedar Avenue, Scranton, Lackawanna County, PA

4. VIEW, LOOKING SOUTHEAST, SHOWING NORTHWEST ELEVATION OF TOWER ND ...

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

4. VIEW, LOOKING SOUTHEAST, SHOWING NORTHWEST ELEVATION OF TOWER ND SIGNAL BRIDGE No. 6 AND DWARF SIGNAL IN FOREGROUND - South Station Tower No. 1 & Interlocking System, Dewey Square, Boston, Suffolk County, MA

Concentrating Solar Power Gen3 Demonstration Roadmap

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

Mehos, Mark; Turchi, Craig; Vidal, Judith

Today's power-tower concentrating solar power (CSP) technology exists in large part as a result of Department of Energy (DOE) and utility industry funding of demonstration systems in the 1980s and 1990s. Today's most advanced towers are integrated with molten-salt thermal energy storage, delivering thermal energy at 565 degrees C for integration with conventional steam-Rankine cycles. The supercritical carbon dioxide power cycle has been identified as a likely successor to the steam-Rankine power cycle due to its potential for high efficiency when operating at elevated temperatures of 700 degrees C or greater. Over the course of the SunShot Initiative, DOE hasmore » supported a number of technology pathways that can operate efficiently at these temperatures and that hold promise to be reliable and cost effective. Three pathways - molten salt, particle, and gaseous - were selected for further investigation based on a two-day workshop held in August of 2016. The information contained in this roadmap identifies research and development challenges and lays out recommended research activities for each of the three pathways. DOE foresees that by successfully addressing the challenges identified in this roadmap, one or more technology pathways will be positioned for demonstration and subsequent commercialization within the next ten years. Based on current knowledge of the three power tower technologies, all three have the potential to achieve the SunShot goal of 6 cents/kilowatt-hour. Further development, modeling, and testing are now required to bring one or more of the technologies to a stage where integrated system tests and pilot demonstrations are feasible.« less

Diabatic processes and the evolution of two contrasting extratropical cyclones

NASA Astrophysics Data System (ADS)

Methven, John; Martinez-Alvarado, Oscar; Gray, Suzanne

2017-04-01

Extratropical cyclones are typically weaker and less frequent in summer as a result of differences in the background state flow and diabatic processes with respect to other seasons. Two extratropical cyclones were observed in summer 2012 with a research aircraft during the DIAMET (DIAbatic influences on Mesoscale structure in ExTratropical storms) field campaign. The first cyclone deepened only down to 995 hPa; the second cyclone deepened down to 978 hPa and formed a potential vorticity (PV) tower, a frequent signature of intense cyclones. The cyclones were analyzed through numerical simulations incorporating tracers for the effects of diabatic processes on potential temperature and PV. It was found that the observed maximum vapor flux in the stronger cyclone was twice as strong as in the weaker cyclone; the water vapor mass flow along the warm conveyor belt of the stronger cyclone was over half that typical in winter even though the flow was weaker. Did the greater water transport and latent heat release associated with condensation result in the greater circulation in the PV tower case? A cyclone-centred integral framework is introduced relating the tracers with cross-isentropic mass transport and circulation around the cyclone. It is shown that the circulation increases much more slowly than the amplitude of the diabatically-generated PV tower at its centre. This effect is explained using the PV impermeability theorem and the influence of diabatic heating on circulation around a cyclone is shown to scale with Rossby number. The implication is that the stronger a cyclone becomes (larger Rossby number), the stronger the influence of latent heating on circulation.

8. LOOKING EAST FROM TOP OF WATER TOWER: VIEW SHOWS ...

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

8. LOOKING EAST FROM TOP OF WATER TOWER: VIEW SHOWS BUILDING #626 AND PORTION OF QUADRANGLE - Fort Sam Houston, San Antonio Depot, Water-Watch Tower, Grayson Street & New Braunfels Avenue, San Antonio, Bexar County, TX

3. View of north tower, facing north across the main ...

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

3. View of north tower, facing north across the main channel of the Columbus River from Clover Island. - Pasco-Kennewick Transmission Line, Columbia River Crossing Towers, Columbia Drive & Gum Street, Kennewick, Benton County, WA

29. Photocopy of 1921 photograph. Glass Negative Box IX, Tower ...

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

29. Photocopy of 1921 photograph. Glass Negative Box IX, Tower Grove, Missouri Botanical Garden. ITALIAN GARDEN AND NEW PALM HOUSE (DEMOLISHED), LOOKING NORTHEAST - Missouri Botanical Garden, 2345 Tower Grove Avenue, Saint Louis, Independent City, MO

Oblique view of the mine observation tower and transformer buildings, ...

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

Oblique view of the mine observation tower and transformer buildings, with the tower building behind. View facing south-southeast - U.S. Naval Base, Pearl Harbor, Waipio Peninsula, Waipo Peninsula, Pearl City, Honolulu County, HI

4. View of center tower at Clover Island, facing northeast. ...

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

4. View of center tower at Clover Island, facing northeast. Pasco-Kennewick automobile bridge in background, lower right. - Pasco-Kennewick Transmission Line, Columbia River Crossing Towers, Columbia Drive & Gum Street, Kennewick, Benton County, WA

OVERVIEW OF VALVE TOWER FROM EASTERN SIDE OF BASIN SHOWING ...

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

OVERVIEW OF VALVE TOWER FROM EASTERN SIDE OF BASIN SHOWING BRIDGE SUPPORTS ON HILLTOP. VIEW FACING WEST - Schofield Barracks Military Reservation, Ku Tree Reservoir, Valve Tower, Kalakoa Stream, East Range, Wahiawa, Honolulu County, HI

View of the southwest guard tower, cell blocks seven and ...

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

View of the southwest guard tower, cell blocks seven and eight, administration building west tower, and Fairmount Avenue, looking from the administration building facing west - Eastern State Penitentiary, 2125 Fairmount Avenue, Philadelphia, Philadelphia County, PA

12. GENERAL INTERIOR VIEW OF SIGNAL TOWER OFFICE FACING NORTH. ...

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

12. GENERAL INTERIOR VIEW OF SIGNAL TOWER OFFICE FACING NORTH. - U.S. Naval Base, Pearl Harbor, Signal Tower, Corner of Seventh Street & Avenue D east of Drydock No. 1, Pearl City, Honolulu County, HI

ETR COOLING TOWER. PUMP HOUSE (TRA645) IN SHADOW OF TOWER ...

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

ETR COOLING TOWER. PUMP HOUSE (TRA-645) IN SHADOW OF TOWER ON LEFT. AT LEFT OF VIEW, HIGH-BAY BUILDING IS ETR. ONE STORY ATTACHMENT IS ETR ELECTRICAL BUILDING. STACK AT RIGHT IS ETR STACK; MTR STACK IS TOWARD LEFT. CAMERA FACING NORTHEAST. INL NEGATIVE NO. 56-3799. Jack L. Anderson, 11/26/1956 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

Continuous multi-plot measurements of CO2, CH4, N2O and H2O in a managed boreal forest - The importance of accounting for all greenhouse gases

NASA Astrophysics Data System (ADS)

Vestin, P.; Mölder, M.; Sundqvist, E.; Båth, A.; Lehner, I.; Weslien, P.; Klemedtsson, L.; Lindroth, A.

2015-12-01

In order to assess the effects of different management practices on the exchange of greenhouse gases (GHG), it is desirable to perform repeated and parallel measurements on both experimental and control plots. Here we demonstrate how a system system combining eddy covariance and gradient techniques can be used to perform this assessment in a managed forest ecosystem.The net effects of clear-cutting and stump harvesting on GHG fluxes were studied at the ICOS site Norunda, Sweden. Micrometeorological measurements (i.e., flux-gradient measurements in 3 m tall towers) allowed for quantification of CO2, CH4 and H2O fluxes (from May 2010) as well as N2O and H2O fluxes (from June 2011) at two stump harvested plots and two control plots. There was one wetter and one drier plot of each treatment. Air was continuously sampled at two heights in the towers and gas concentrations were analyzed for CH4, CO2, H2O (LGR DLT-100, Los Gatos Research) and N2O, H2O (QCL Mini Monitor, Aerodyne Research). Friction velocities and sensible heat fluxes were measured by sonic anemometers (Gill Windmaster, Gill Instruments Ltd). Automatic chamber measurements (CO2, CH4, H2O) were carried out in the adjacent forest stand and at the clear-cut during 2010.Average CO2 emissions for the first year ranged between 14.4-20.2 ton CO2 ha-1 yr-1. The clear-cut became waterlogged after harvest and a comparison of flux-gradient data and chamber data (from the adjacent forest stand) indicated a switch from a weak CH4 sink to a significant source at all plots. The CH4 emissions ranged between 0.8-4.5 ton CO2-eq. ha-1 yr-1. N2O emissions ranged between 0.4-2.6 ton CO2-eq. ha-1 yr-1. Enhanced N2O emission on the drier stump harvested plot was the only clear treatment effect on GHG fluxes that was observed. Mean CH4 and N2O emissions for the first year of measurements amounted up to 29% and 20% of the mean annual CO2 emissions, respectively. This highlights the importance of including all GHGs when assessing the climate impacts of different forest management options. Our results show that continuous multi-plot measurements of the main GHGs are possible also at sites where GHG fluxes are low, at a reasonable cost and with reduced plot inter-comparison uncertainties.

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

Danguy des Deserts, L.M.J.; Michael, D.; Sedillot, F.G.

An oscillating platform is described for work at sea, the platform having a weight, comprising a deck, a lattice tower having an upper part and a lower part, the tower further having a total buoyancy center, and a center of gravity, an articulation formed by flexible piles. The articulation has a center; the flexible piles are driven into the sea bed and fixed to the upper part of the tower; the tower comprising floaters in its upper part and a ballast compartment in its lower part, as well as means for resisting shear forces; the product of the total buoyancymore » of the tower by the distance between the buoyancy center of the tower and the center of the articulation are at least equal to 1.25 times the product of the weight of the platform by the distance between the center of gravity of the platform and the center of the articulation.« less

Antenna structures and cloud-to-ground lightning location: 1995-2015

NASA Astrophysics Data System (ADS)

Kingfield, Darrel M.; Calhoun, Kristin M.; de Beurs, Kirsten M.

2017-05-01

Spatial analyses of cloud-to-ground (CG) lightning occurrence due to a rapid expansion in the number of antenna towers across the United States are explored by gridding 20 years of National Lightning Detection Network data at 500 m spatial resolution. The 99.8% of grid cells with ≥100 CGs were within 1 km of an antenna tower registered with the Federal Communications Commission. Tower height is positively correlated with CG occurrence; towers taller than 400 m above ground level experience a median increase of 150% in CG lightning density compared to a region 2 km to 5 km away. In the northern Great Plains, the cumulative CG lightning density near the tower was around 138% (117%) higher than a region 2 to 5 km away in the September-February (March-August) months. Higher CG frequencies typically also occur in the first full year following new tower construction, creating new lightning hot spots.

Modified shape of the Eiffel Tower determined for an atmospheric boundary-layer wind profile

NASA Astrophysics Data System (ADS)

Weidman, P. D.

2009-06-01

The design and construction of the Eiffel Tower was based, in part, on a uniform horizontal wind model giving 300 kg m-2 kinematic pressure acting on the surface of the tower. Eiffel received a patent for his method of construction that eliminates the need for diagonal trellis bars used to resist the moment of an oncoming wind. At the end of the 19th century boundary-layer theory, laminar or turbulent, was nonexistent. Now, however, models for atmospheric flow over rough landscapes are available, the simplest being a power-law distribution of velocity with height. In this paper we deduce the shape of the tower had Eiffel incorporated this information into the design and construction of his world famous tower. Moreover, we prove Eiffel's observation that the tower profile conforms to the moment distribution wrought by the wind.

Wind tower service lift

DOEpatents

Oliphant, David; Quilter, Jared; Andersen, Todd; Conroy, Thomas

2011-09-13

An apparatus used for maintaining a wind tower structure wherein the wind tower structure may have a plurality of legs and may be configured to support a wind turbine above the ground in a better position to interface with winds. The lift structure may be configured for carrying objects and have a guide system and drive system for mechanically communicating with a primary cable, rail or other first elongate member attached to the wind tower structure. The drive system and guide system may transmit forces that move the lift relative to the cable and thereby relative to the wind tower structure. A control interface may be included for controlling the amount and direction of the power into the guide system and drive system thereby causing the guide system and drive system to move the lift relative to said first elongate member such that said lift moves relative to said wind tower structure.

Hospital-acquired legionellosis originating from a cooling tower during a period of thermal inversion.

PubMed

Engelhart, Steffen; Pleischl, Stefan; Lück, Christian; Marklein, Günter; Fischnaller, Edith; Martin, Sybille; Simon, Arne; Exner, Martin

2008-07-01

A case of hospital-acquired legionellosis occurred in a 75-year-old male patient who underwent surgery due to malignant melanoma. Legionellosis was proven by culture of Legionella pneumophila serogroup 1 from bronchoalveolar lavage (BAL) fluid. Being a chronic smoker the patient used to visit the sickroom balcony that was located about 90 m to the west of a hospital cooling tower. Routine cooling tower water samples drawn during the presumed incubation period revealed 1.0x10(4) CFU/100 ml (L. pneumophila serogroup 1). One of three isolates from the cooling tower water matched the patient's isolate by monoclonal antibody (mab)- and genotyping (sequence-based typing). Horizontal transport of cooling tower aerosols probably was favoured by meteorological conditions with thermal inversion. The case report stresses the importance of routine maintenance and microbiological control of hospital cooling towers.

Water potential gradient in a tall sequoiadendron.

PubMed

Tobiessen, P

1971-09-01

With an elevator installed in a 90-meter tall Sequoiadendron to collect the samples, xylem pressure potential measurements were made approximately every 15 meters along 60 meters of the tree's height. The measured gradient was about -0.8 bar per 10 meters of height, i.e., less than the hydrostatic gradient. Correction of the xylem pressure potential data by calibration against a thermocouple psychrometer confirmed this result. Similar gradients are described in the literature in tall conifers at times of low transpiration, although a different sampling technique was used. If the data in the present study and those supporting it are typical, they imply a re-evaluation of either the use of the pressure chamber to estimate water potential or the present theories describing water transport in tall trees.

Water Potential Gradient in a Tall Sequoiadendron

PubMed Central

Tobiessen, Peter; Rundel, Philip W.; Stecker, R. E.

1971-01-01

With an elevator installed in a 90-meter tall Sequoiadendron to collect the samples, xylem pressure potential measurements were made approximately every 15 meters along 60 meters of the tree's height. The measured gradient was about −0.8 bar per 10 meters of height, i.e., less than the hydrostatic gradient. Correction of the xylem pressure potential data by calibration against a thermocouple psychrometer confirmed this result. Similar gradients are described in the literature in tall conifers at times of low transpiration, although a different sampling technique was used. If the data in the present study and those supporting it are typical, they imply a re-evaluation of either the use of the pressure chamber to estimate water potential or the present theories describing water transport in tall trees. PMID:16657786

Use of Plant Hydraulic Theory to Predict Ecosystem Fluxes Across Mountainous Gradients in Environmental Controls and Insect Disturbances

NASA Astrophysics Data System (ADS)

Ewers, B. E.; Pendall, E.; Reed, D. E.; Barnard, H. R.; Whitehouse, F.; Frank, J. M.; Massman, W. J.; Brooks, P. D.; Biederman, J. A.; Harpold, A. A.; Naithani, K. J.; Mitra, B.; Mackay, D. S.; Norton, U.; Borkhuu, B.

2011-12-01

While mountainous areas are critical for providing numerous ecosystem benefits at the regional scale, the strong gradients in environmental controls make predictions difficult. A key part of the problem is quantifying and predicting the feedback between mountain gradients and plant function which then controls ecosystem cycling. The emerging theory of plant hydraulics provides a rigorous yet simple platform from which to generate testable hypotheses and predictions of ecosystem pools and fluxes. Plant hydraulic theory predicts that plant controls over carbon, water, energy and nutrient fluxes can be derived from the limitation of plant water transport from the soil through xylem and out of stomata. In addition, the limit to plant water transport can be predicted by combining plant structure (e.g. xylem diameters or root-to-shoot ratios) and plant function (response of stomatal conductance to vapor pressure deficit or root vulnerability to cavitation). We evaluate the predictions of the plant hydraulic theory by testing it against data from a mountain gradient encompassing sagebrush steppe through subalpine forests (2700 to 3400 m). We further test the theory by predicting the carbon, water and nutrient exchanges from several coniferous trees in the same gradient that are dying from xylem dysfunction caused by blue-stain fungi carried by bark beetles. The common theme of both of these data sets is a change in water limitation caused by either changing precipitation along the mountainous gradient or lack of access to soil water from xylem-occluding fungi. Across all of the data sets which range in scale from individual plants to hillslopes, the data fit the predictions of plant hydraulic theory. Namely, there was a proportional tradeoff between the reference canopy stomatal conductance to water vapor and the sensitivity of that conductance to vapor pressure deficit that quantitatively fits the predictions of plant hydraulic theory. Incorporating this result into whole plant mass and energy exchange models allows prediction of plant carbon, energy and nitrogen exchange that fits recently collected data including plant sap flux, leaf gas exchange, eddy covariance towers and stand and watershed-scale biogeochemistry measurements. The results of our work will allow the next generation of ecosystem to regional scale coupled-biogeochemistry models to incorporate a simple plant hydraulic mechanism that will enable defensible predictions of carbon, water, energy and nutrient cycling with changing climate and land use.

Test of Monin-Obukhov similarity theory using distributed temperature sensing

NASA Astrophysics Data System (ADS)

Cheng, Y.; Sayde, C.; Li, Q.; Gentine, P.

2017-12-01

Monin-Obukhov similarity theory [Monin and Obukhov, 1954] (MOST) has been widely used to calculate atmospheric surface fluxes applying the structure correction functions [Stull, 1988]. The exact forms of the structure correction functions for momentum and heat, which depend on the vertical gradient velocity and temperature, have been determined empirically mostly from the Kansas experiment [Kaimal et al., 1972]. However, due to the limitation of point measurement, the vertical gradient of temperature and horizontal wind speed are not well captured. Here we propose a way to measure the vertical gradient of temperature and horizontal wind speed with high resolution in space (every 12.7 cm) and time (every second) using the Distributed Temperature Sensing [Selker et al., 2006] (DTS), thus determining the exact form of the structure correction functions of MOST under various stability conditions. Two parallel vertical fiber optics will be placed on a tower at the central facility of ARM SGP site. Vertical air temperature will be measured every 12.7 cm by the fiber optics and horizontal wind speed along fiber will be measured. Then vertical gradient of temperature and horizontal wind speed will be calculated and stability correction functions for momentum and heat will be determined. ReferencesKaimal, J. C., Wyngaard, J. C., Izumi, Y., and Cote, O. R. (1972), Spectral characteristics of surface-layer turbulence, Quarterly Journal of the Royal Meteorological Society, 98(417), 563-589, doi: 10.1002/qj.49709841707. Monin, A., and Obukhov, A. (1954), Basic laws of turbulent mixing in the surface layer of the atmosphere, Contrib. Geophys. Inst. Acad. Sci. USSR, 24(151), 163-187. Selker, J., Thévenaz, L., Huwald, H., Mallet, A., Luxemburg, W., van de Giesen, N., Stejskal, M., Zeman, J., Westhoff, M., and Parlange, M. B. (2006), Distributed fiber-optic temperature sensing for hydrologic systems, Water Resources Research, 42, W12202, doi: 10.1029/2006wr005326. Stull, R. (1988), An Introduction to Boundary Layer Meteorology, pp. 666, Kluwer Academic Publishers, Dordrecht.

Influence of advection on measurements of the net ecosystem-atmosphere exchange of CO2 from a very tall tower

NASA Astrophysics Data System (ADS)

Yi, C.; Davis, K. J.; Bakwin, P. S.; Berger, B. W.; Marr, L. C.

2000-04-01

In most studies of the net ecosystem-atmosphere exchange of CO2 (NEE) using tower-based eddy covariance (EC) systems it has been assumed that advection is negligible. In this study we use a scalar conservation budget method to estimate the contribution of advection to NEE measurements from a very tall tower in northern Wisconsin. We examine data for June-August 1997. Measured NEE0, calculated as the sum of the EC flux plus the rate of change of storage below the EC measurement level, is expected to be constant with measurement height, and we take the differences between levels as a measure of advection. We find that the average difference in total advection ΔFCadtot between 30 and 122 m is as large as 6 μmol m-2s-1 during the morning transition from stable to convective conditions and the average difference ΔFCadtot between 122 and 396 m is as large as 4 μmol m-2s-1 during daytime. For the month of July, advection between 30 and 122 m is 27% of the diurnally integrated NEE0 at 122 m, and advection between 122 and 396 m accounts for 5% of the NEE0 observed at 396 m. The observed differences of advection often have significant correlation with the vertical integral of wind speed within the same layer. This indicates that the horizontal advection contribution to NEE could be significant. Direct observations of the vertical gradient in CO2 show that ΔFCadtot cannot be explained by vertical advection alone. It is hypothesized that differing flux footprints and pooling of CO2 in the heterogeneous landscape causes the advection contribution. The magnitudes of the total advection component FCadtot of NEE at the 30 m level are roughly estimated by a linear extrapolation. A peak in FCadtot at 30 m of ˜ 3 μmol m-2 s-1 during the morning transition is predicted for all three months. The July integrated FCadtot is estimated to be 10% of the diurnally integrated NEE0 at 30 m.

Visual appearance of wind turbine tower at long range measured using imaging system

NASA Astrophysics Data System (ADS)

Gustafsson, K. Ove S.; Möller, Sebastian

2013-10-01

Wind turbine towers affect the visual appearance of the landscape, as an example in the touristic woodland of Dalecarlia, and the fear is that the visual impact will be too negative to the important tourist trade. The landscape analysis, developed by municipalities around Lake Siljan, limited expansion of wind power, due to the strong visual impression of wind turbine towers. In order to facilitate the assessment of the visual impact of towers a view, from Tällberg, over the ring of height on the other side of Lake Siljan, has been photographed every ten minutes for a year (34,727 images, about 65% of the possible number during a year). Four towers are possible to see in the photos, three of them have been used in the assessment of visual impression. This contribution presents a method to assess visibility of wind turbine towers from photographs, describing the measuring situation (location and equipment) as well as the analytical method and results of the analysis. The towers are possible to see in about 48% of analyzed images taken during daytime with the used equipment. During the summer (winter) months the towers were apparent in 49% (46%) of the images. At least one red warning light was possible to see on towers in about 66% of the night images. One conclusion of this work is that the method to assess the visibility within digital photographs and translate it into the equivalent of a normal eye can only provide an upper limit for visibility of an object.

GANTRY SIGNAL EAST OF TOWER AT MILEPOST 203.0, LOOKING WEST, ...

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

GANTRY SIGNAL EAST OF TOWER AT MILEPOST 203.0, LOOKING WEST, EQUIPPED WITH B&O COLOR-POSITION-LIGHT SIGNAL HEAD FOR WESTBOUND TRAINS. - Baltimore & Ohio Railroad, Z Tower, State Route 46, Keyser, Mineral County, WV

SIGNAL BRIDGE WEST OF TOWER AT MILEPOST 203.2, LOOKING WEST, ...

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

SIGNAL BRIDGE WEST OF TOWER AT MILEPOST 203.2, LOOKING WEST, EQUIPPED WITH B&O COLOR-POSITION-LIGHT SIGNAL HEADS FOR EASTBOUND TRAINS. - Baltimore & Ohio Railroad, Z Tower, State Route 46, Keyser, Mineral County, WV

26. Evening view of concrete mixing plant, concrete placement tower, ...

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

26. Evening view of concrete mixing plant, concrete placement tower, cableway tower, power line and derrick. Photographer unknown, 1927. Source: MWD. - Waddell Dam, On Agua Fria River, 35 miles northwest of Phoenix, Phoenix, Maricopa County, AZ

4. Keeper's house and light tower, view south southeast, west ...

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

4. Keeper's house and light tower, view south southeast, west side of house, north and west sides of tower - Rockland Breakwater Light Station, At end of granite breakwater extending south from Jameson Point, Rockland, Knox County, ME

Tower-Related Major System Development Programs

DOT National Transportation Integrated Search

1978-03-01

This report is devoted to the present and near future states of the tower cab environment, addresses those MSDP systems which may have an impact on the current tower cab environment, systems and/or operations. The systems included are: Discrete Addre...

View of EPA Farm metal weather tower, facing east, showing ...

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

View of EPA Farm metal weather tower, facing east, showing thirty-acre irrigated field - Nevada Test Site, Environmental Protection Agency Farm, Weather Tower, Area 15, Yucca Flat, 10-2 Road near Circle Road, Mercury, Nye County, NV

1. VIEW NORTHWEST, operations building, height finder radar tower, and ...

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

1. VIEW NORTHWEST, operations building, height finder radar tower, and radar tower (unknown function) - Fort Custer Military Reservation, P-67 Radar Station, .25 mile north of Dickman Road, east of Clark Road, Battle Creek, Calhoun County, MI

Characterization of Current Tower Cab Environments

DOT National Transportation Integrated Search

1977-11-01

This report describes the general tower cab environment in terms of: (a) the evolution of the tower cab, current cab classification and staffing levels, and the basic flow of ATC data relevant to cab operations, (b) a breakdown of functions performed...

14. CLOSEUP VIEW OF WINDOW IN SIGNAL TOWER OFFICE FACING ...

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

14. CLOSE-UP VIEW OF WINDOW IN SIGNAL TOWER OFFICE FACING WEST. - U.S. Naval Base, Pearl Harbor, Signal Tower, Corner of Seventh Street & Avenue D east of Drydock No. 1, Pearl City, Honolulu County, HI

10. ENTRANCE VIEW OF ELEVATOR SHAFT AT TOP OF TOWER ...

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

10. ENTRANCE VIEW OF ELEVATOR SHAFT AT TOP OF TOWER FACING SOUTHEAST. - U.S. Naval Base, Pearl Harbor, Signal Tower, Corner of Seventh Street & Avenue D east of Drydock No. 1, Pearl City, Honolulu County, HI

1. Keeper's house and light tower, view northwest, south and ...

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

1. Keeper's house and light tower, view northwest, south and east sides of keeper's house, southwest and southeast sides of light tower - Curtis Island Light Station, Curtis Island, at entrance to Camden Harbor, Camden, Knox County, ME

The Potential of Tropospheric Gradients for Regional Precipitation Prediction

NASA Astrophysics Data System (ADS)

Boisits, Janina; Möller, Gregor; Wittmann, Christoph; Weber, Robert

2017-04-01

Changes of temperature and humidity in the neutral atmosphere cause variations in tropospheric path delays and tropospheric gradients. By estimating zenith wet delays (ZWD) and gradients using a GNSS reference station network the obtained time series provide information about spatial and temporal variations of water vapour in the atmosphere. Thus, GNSS-based tropospheric parameters can contribute to the forecast of regional precipitation events. In a recently finalized master thesis at TU Wien the potential of tropospheric gradients for weather prediction was investigated. Therefore, ZWD and gradient time series at selected GNSS reference stations were compared to precipitation data over a period of six months (April to September 2014). The selected GNSS stations form two test areas within Austria. All required meteorological data was provided by the Central Institution for Meteorology and Geodynamics (ZAMG). Two characteristics in ZWD and gradient time series can be anticipated in case of an approaching weather front. First, an induced asymmetry in tropospheric delays results in both, an increased magnitude of the gradient and in gradients pointing towards the weather front. Second, an increase in ZWD reflects the increased water vapour concentration right before a precipitation event. To investigate these characteristics exemplary test events were processed. On the one hand, the sequence of the anticipated increase in ZWD at each GNSS station obtained by cross correlation of the time series indicates the direction of the approaching weather front. On the other hand, the corresponding peak in gradient time series allows the deduction of the direction of movement as well. To verify the results precipitation data from ZAMG was used. It can be deduced, that tropospheric gradients show high potential for predicting precipitation events. While ZWD time series rather indicate the orientation of the air mass boundary, gradients rather indicate the direction of movement of an approaching weather front. Additionally our investigations have shown that gradients are able to capture the characteristics of an approaching weather front twenty to thirty hours before the precipitation event, which allows a first indication well in advance. Thus in conclusion, the utilization of GNSS tropospheric parameters, in particular tropospheric gradients, has the potential to contribute substantially to weather forecasting models.

KM3NeT tower data acquisition and data transport electronics

NASA Astrophysics Data System (ADS)

Nicolau, C. A.; Ameli, F.; Biagioni, A.; Capone, A.; Frezza, O.; Lonardo, A.; Masullo, R.; Mollo, C. M.; Orlando, A.; Simeone, F.; Vicini, P.

2016-04-01

In the framework of the KM3Net European project, the production stage of a large volume underwater neutrino telescope has started. The forthcoming installation includes 8 towers and 24 strings, that will be installed 100 km off-shore Capo Passero (Italy) at 3500 m depth. The KM3NeT tower, whose layout is strongly based on the NEMO Phase-2 prototype tower deployed in March 2013, has been re-engineered and partially re-designed in order to optimize production costs, power consumption, and usability. This contribution gives a description of the main electronics, including front-end, data transport and clock distribution system, of the KM3NeT tower detection unit.

KSC-99pp1216

NASA Image and Video Library

1999-10-14

KENNEDY SPACE CENTER, FLA. -- The 300-foot, five-million-pound Mobile Service Tower (MST) on Launch Complex 41, Cape Canaveral Air Force Station, lies on its side after being demolished. The MST and a 200-foot-high umbilical tower nearby were demolished to make room for Lockheed Martin's 14-acre Vehicle Integration Facility (VIF), under construction. Only lightning protection towers, such as the one seen behind the MST, remain standing at the site. About 200 pounds of linear-shaped charges were used to bring down the towers so that the materials can be recycled. The implosion and removal of the tower debris is expected to be completed in two months. The VIF will be used for Lockheed Martin's Atlas V Launch System.

Local stellar kinematics from RAVE data—VIII. Effects of the Galactic disc perturbations on stellar orbits of red clump stars

NASA Astrophysics Data System (ADS)

Önal Taş, Ö.; Bilir, S.; Plevne, O.

2018-02-01

We aim to probe the dynamic structure of the extended Solar neighborhood by calculating the radial metallicity gradients from orbit properties, which are obtained for axisymmetric and non-axisymmetric potential models, of red clump (RC) stars selected from the RAdial Velocity Experiment's Fourth Data Release. Distances are obtained by assuming a single absolute magnitude value in near-infrared, i.e. M_{Ks}=-1.54±0.04 mag, for each RC star. Stellar orbit parameters are calculated by using the potential functions: (i) for the MWPotential2014 potential, (ii) for the same potential with perturbation functions of the Galactic bar and transient spiral arms. The stellar age is calculated with a method based on Bayesian statistics. The radial metallicity gradients are evaluated based on the maximum vertical distance (z_{max}) from the Galactic plane and the planar eccentricity (ep) of RC stars for both of the potential models. The largest radial metallicity gradient in the 0< z_{max} ≤0.5 kpc distance interval is -0.065±0.005 dex kpc^{-1} for a subsample with ep≤0.1, while the lowest value is -0.014±0.006 dex kpc^{-1} for the subsample with ep≤0.5. We find that at z_{max}>1 kpc, the radial metallicity gradients have zero or positive values and they do not depend on ep subsamples. There is a large radial metallicity gradient for thin disc, but no radial gradient found for thick disc. Moreover, the largest radial metallicity gradients are obtained where the outer Lindblad resonance region is effective. We claim that this apparent change in radial metallicity gradients in the thin disc is a result of orbital perturbation originating from the existing resonance regions.

Vortex-augmented cooling tower-windmill combination

DOEpatents

McAllister, Jr., John E.

1985-01-01

A cooling tower for cooling large quantities of effluent water from a production facility by utilizing natural wind forces includes the use of a series of helically directed air inlet passages extending outwardly from the base of the tower to introduce air from any direction in a swirling vortical pattern while the force of the draft created in the tower makes it possible to place conventional power generating windmills in the air passages to provide power as a by-product.

Vortex-augmented cooling tower - windmill combination

DOEpatents

McAllister, J.E. Jr.

1982-09-02

A cooling tower for cooling large quantities of effluent water from a production facility by utilizing natural wind forces includes the use of a series of helically directed air inlet passages extending outwardly from the base of the tower to introduce air from any direction in a swirling vortical pattern while the force of the draft created in the tower makes it possible to place conventional power generating windmills in the air passage to provide power as a by-product.

Blasting response of the Eiffel Tower

NASA Astrophysics Data System (ADS)

Horlyck, Lachlan; Hayes, Kieran; Caetano, Ryan; Tahmasebinia, Faham; Ansourian, Peter; Alonso-Marroquin, Fernando

2016-08-01

A finite element model of the Eiffel Tower was constructed using Strand7 software. The model replicates the existing tower, with dimensions justified through the use of original design drawings. A static and dynamic analysis was conducted to determine the actions of the tower under permanent, imposed and wind loadings, as well as under blast pressure loads and earthquake loads due to an explosion. It was observed that the tower utilises the full axial capacity of individual members by acting as a `truss of trusses'. As such, permanent and imposed loads are efficiently transferred to the primary columns through compression, while wind loads induce tensile forces in the windward legs and compressive forces in the leeward. Under blast loading, the tower experienced both ground vibrations and blast pressures. Ground vibrations induced a negligibly small earthquake loading into the structure which was ignored in subsequent analyses. The blast pressure was significant, and a dynamic analysis of this revealed that further research is required into the damping qualities of the structure due to soil and mechanical properties. In the worst case scenario, the blast was assumed to completely destroy several members in the adjacent leg. Despite this weakened condition, it was observed that the tower would still be able to sustain static loads, at least for enough time for occupant evacuation. Further, an optimised design revealed the structure was structurally sound under a 46% reduction of the metal tower's mass.

Improved reliability of wind turbine towers with active tuned mass dampers (ATMDs)

NASA Astrophysics Data System (ADS)

Fitzgerald, Breiffni; Sarkar, Saptarshi; Staino, Andrea

2018-04-01

Modern multi-megawatt wind turbines are composed of slender, flexible, and lightly damped blades and towers. These components exhibit high susceptibility to wind-induced vibrations. As the size, flexibility and cost of the towers have increased in recent years, the need to protect these structures against damage induced by turbulent aerodynamic loading has become apparent. This paper combines structural dynamic models and probabilistic assessment tools to demonstrate improvements in structural reliability when modern wind turbine towers are equipped with active tuned mass dampers (ATMDs). This study proposes a multi-modal wind turbine model for wind turbine control design and analysis. This study incorporates an ATMD into the tower of this model. The model is subjected to stochastically generated wind loads of varying speeds to develop wind-induced probabilistic demand models for towers of modern multi-megawatt wind turbines under structural uncertainty. Numerical simulations have been carried out to ascertain the effectiveness of the active control system to improve the structural performance of the wind turbine and its reliability. The study constructs fragility curves, which illustrate reductions in the vulnerability of towers to wind loading owing to the inclusion of the damper. Results show that the active controller is successful in increasing the reliability of the tower responses. According to the analysis carried out in this paper, a strong reduction of the probability of exceeding a given displacement at the rated wind speed has been observed.

Hexcrete Tower for Harvesting Wind Energy at Taller Hub Heights - Budget Period 2

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

Sritharan, Sri

Interest in designing taller towers for wind energy production in the United States (U.S.) has been steadily growing. In May 2015, it was revealed that taller towers will make wind energy production a reality in all 50 states, including some states that have nearly zero renewables in their energy portfolio. Facilitating wind energy production feasibility in all 50 states will no doubt contribute to increasing the electricity produced by wind from 4.5% in 2013 to a targeted scenario of 35% by 2050 in the Wind Vision report. This project focuses on the Hexcrete tower concept developed for tall towers usingmore » High Strength Concrete (HSC) and/or Ultra-High Performance Concrete (UHPC). Among other benefits, the Hexcrete concept overcomes transportation and logistical challenges, thus facilitating construction of towers with hub heights of 100-m (328-ft) and higher. The goal of this project is to facilitate widespread deployment of Hexcrete towers for harvesting wind energy at 120 to 140-m (394 to 459-ft) hub heights and reduce the Levelized Cost of Energy (LCOE) of wind energy production in the U.S. The technical scope of the project includes detailed design and optimization of at least three wind turbine towers using the Hexcrete concept together with experimental validation and LCOE analyses and development of a commercialization plan.« less

Bridging the Scales from Field to Region with Practical Tools to Couple Time- and Space-Synchronized Data from Flux Towers and Networks with Proximal and Remote Sensing Data

NASA Astrophysics Data System (ADS)

Burba, G. G.; Avenson, T.; Burkart, A.; Gamon, J. A.; Guan, K.; Julitta, T.; Pastorello, G.; Sakowska, K.

2017-12-01

Many hundreds of flux towers are presently operational as standalone projects and as parts of regional networks. However, the vast majority of these towers do not allow straightforward coupling with remote sensing (drone, aircraft, satellite, etc.) data, and even fewer have optical sensors for validation of remote sensing products, and upscaling from field to regional levels. In 2016-2017, new tools to collect, process, and share time-synchronized flux data from multiple towers were developed and deployed globally. Originally designed to automate site and data management, and to streamline flux data analysis, these tools allow relatively easy matching of tower data with remote sensing data: GPS-driven PTP time protocol synchronizes instrumentation within the station, different stations with each other, and all of these to remote sensing data to precisely align remote sensing and flux data in time Footprint size and coordinates computed and stored with flux data help correctly align tower flux footprints and drone, aircraft or satellite motion to precisely align optical and flux data in space Full snapshot of the remote sensing pixel can then be constructed, including leaf-level, ground optical sensor, and flux tower measurements from the same footprint area, closely coupled with the remote sensing measurements to help interpret remote sensing data, validate models, and improve upscaling Additionally, current flux towers can be augmented with advanced ground optical sensors and can use standard routines to deliver continuous products (e.g. SIF, PRI, NDVI, etc.) based on automated field spectrometers (e.g., FloX and RoX, etc.) and other optical systems. Several dozens of new towers already operational globally can be readily used for the proposed workflow. Over 500 active traditional flux towers can be updated to synchronize their data with remote sensing measurements. This presentation will show how the new tools are used by major networks, and describe how this approach can be utilized for matching remote sensing and tower data to aid in ground truthing, improve scientific interactions, and promote joint grant writing and other forms of collaboration between the flux and remote sensing communities.

15. VIEW OF COAL TOWER No. 2, LOOKING WEST TO ...

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

15. VIEW OF COAL TOWER No. 2, LOOKING WEST TO EAST FROM COAL TOWER No. 1 (FLOOR BELOW CRANE CONTROL) - Delaware County Electric Company, Chester Station, Delaware River at South end of Ward Street, Chester, Delaware County, PA

47 CFR 10.340 - Digital television transmission towers retransmission capability.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 47 Telecommunication 1 2013-10-01 2013-10-01 false Digital television transmission towers retransmission capability. 10.340 Section 10.340 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL WIRELESS EMERGENCY ALERTS System Architecture § 10.340 Digital television transmission towers...

47 CFR 10.340 - Digital television transmission towers retransmission capability.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 47 Telecommunication 1 2012-10-01 2012-10-01 false Digital television transmission towers retransmission capability. 10.340 Section 10.340 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL COMMERCIAL MOBILE ALERT SYSTEM System Architecture § 10.340 Digital television transmission towers...

47 CFR 10.340 - Digital television transmission towers retransmission capability.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 47 Telecommunication 1 2014-10-01 2014-10-01 false Digital television transmission towers retransmission capability. 10.340 Section 10.340 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL WIRELESS EMERGENCY ALERTS System Architecture § 10.340 Digital television transmission towers...

2. Light tower and keeper's house, view southwest, north northeast ...

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

2. Light tower and keeper's house, view southwest, north northeast side of tower, northeast and northwest sides of keeper's house - Wood Island Light Station, East end of Wood Island, at mouth of Soo River, Biddeford Pool, York County, ME

Executive Summary : Tower Cab System Integration Analysis

DOT National Transportation Integrated Search

1978-08-01

This report summarizes the principal results of the study of the integration into the tower cab of the systems being developed under the Major Systems Development Program (MSDP). The impact of these systems on the tower cab is analyzed from several p...

47 CFR 10.340 - Digital television transmission towers retransmission capability.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 47 Telecommunication 1 2011-10-01 2011-10-01 false Digital television transmission towers retransmission capability. 10.340 Section 10.340 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL COMMERCIAL MOBILE ALERT SYSTEM System Architecture § 10.340 Digital television transmission towers...

1. ENVIRONMENT, FROM NORTHWEST, SHOWING B&P INTERLOCKING TOWER AND POWER ...

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

1. ENVIRONMENT, FROM NORTHWEST, SHOWING B&P INTERLOCKING TOWER AND POWER SUBSTATIONS - Baltimore & Potomac Interlocking Tower, Adjacent to AMTRAK railroad tracks in block bounded by Howard Street, Jones Falls Expressway, Maryland Avenue & Falls Road, Baltimore, Independent City, MD

3. View looking E from top of World Trade Tower ...

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

3. View looking E from top of World Trade Tower with World Trade Tower parapet in foreground. Jet Lowe, photographer, 1982. - Brooklyn Bridge, Spanning East River between Park Row, Manhattan and Sands Street, Brooklyn, New York County, NY

Cell block one and southeast guard tower, looking from the ...

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

Cell block one and southeast guard tower, looking from the central guard tower, facing southeast (note view also includes cell block ten (left) and cell block nine (right)) - Eastern State Penitentiary, 2125 Fairmount Avenue, Philadelphia, Philadelphia County, PA

50. NORTHERN VIEW OF NONEVAPORATIVE WASTE WATER TREATMENT COOLING TOWERS ...

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

50. NORTHERN VIEW OF NON-EVAPORATIVE WASTE WATER TREATMENT COOLING TOWERS IN CENTER, AND EVAPORATIVE WASTE WATER COOLING TOWERS ON RIGHT. (Jet Lowe) - U.S. Steel Duquesne Works, Blast Furnace Plant, Along Monongahela River, Duquesne, Allegheny County, PA

9. VIEW OF ENTRANCE TO SIGNAL TOWER OFFICE AT TOP ...

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

9. VIEW OF ENTRANCE TO SIGNAL TOWER OFFICE AT TOP OF ELEVATOR FACING NORTHWEST. - U.S. Naval Base, Pearl Harbor, Signal Tower, Corner of Seventh Street & Avenue D east of Drydock No. 1, Pearl City, Honolulu County, HI

Bracing for Disaster

ERIC Educational Resources Information Center

Schaffhauser, Dian

2011-01-01

A freak blizzard, a mentally ill and armed student, a record-breaking flood. No matter how idyllic a campus may feel, no matter how cocooned the ivory tower, disaster can strike. If a campus is unprepared, it comes like a sucker punch, potentially turning a crisis into a tragedy of unimagined proportions--and causing reverberations that will be…

The Quality Control Algorithms Used in the Creation of NASA Kennedy Space Center Lightning Protection System Towers Meteorological Database

NASA Technical Reports Server (NTRS)

Orcutt, John M.; Brenton, James C.

2016-01-01

An accurate database of meteorological data is essential for designing any aerospace vehicle and for preparing launch commit criteria. Meteorological instrumentation were recently placed on the three Lightning Protection System (LPS) towers at Kennedy Space Center (KSC) launch complex 39B (LC-39B), which provide a unique meteorological dataset existing at the launch complex over an extensive altitude range. Data records of temperature, dew point, relative humidity, wind speed, and wind direction are produced at 40, 78, 116, and 139 m at each tower. The Marshall Space Flight Center Natural Environments Branch (EV44) received an archive that consists of one-minute averaged measurements for the period of record of January 2011 - April 2015. However, before the received database could be used EV44 needed to remove any erroneous data from within the database through a comprehensive quality control (QC) process. The QC process applied to the LPS towers' meteorological data is similar to other QC processes developed by EV44, which were used in the creation of meteorological databases for other towers at KSC. The QC process utilized in this study has been modified specifically for use with the LPS tower database. The QC process first includes a check of each individual sensor. This check includes removing any unrealistic data and checking the temporal consistency of each variable. Next, data from all three sensors at each height are checked against each other, checked against climatology, and checked for sensors that erroneously report a constant value. Then, a vertical consistency check of each variable at each tower is completed. Last, the upwind sensor at each level is selected to minimize the influence of the towers and other structures at LC-39B on the measurements. The selection process for the upwind sensor implemented a study of tower-induced turbulence. This paper describes in detail the QC process, QC results, and the attributes of the LPS towers meteorological database.

Measurement and modeling of CO2 exchange over forested landscapes in India: an overview

NASA Astrophysics Data System (ADS)

Kushwaha, S.; Dadhwal, V.

2009-04-01

The increasing atmospheric CO2 concentration and its potential impact on global climate change is the subject of worldwide studies, political debates and international discussions. The concern led to the establishment of the Kyoto Protocol to curtail emissions and mitigate the possible global warming. The studies so far suggest that terrestrial biological sinks might be the low cost options for carbon sequestration, which can be used to partially offset the industrial CO2 emissions globally. In past, the effectiveness of terrestrial sink and the quantitative estimates of their sink strengths have relied mainly on the measurements of changes in carbon stocks across the world. Recent developments in flux tower based measurement techniques such as Eddy Covariance for assessing the CO2, H2O and energy fluxes provide tools for quantifying the net ecosystem exchange (NEE) of CO2 on a continuous basis. These near real time measurements, when integrated with remote sensing, enable the up-scaling of the carbon fluxes to regional scale. More than 470 towers exist worldwide as of now. Indian subcontinent was not having any tower-based CO2 flux measurement system so far. The Indian Space Research Organization under its Geosphere Biosphere Programme is funding five eddy covariance towers for terrestrial CO2 flux measurements in different ecological regions of the country. The tower sites already planned are: (i) a mixed forest plantation (Dalbergia sissoo, Acacia catechu, Holoptelia integrifolia) at Haldwani in collaboration with DISAFRI, University of Tuscia, Italy and the Indian Council for Forestry Research and Education (ICFRE), Dehradun, (ii) a sal (Shorea robusta) forest in Doon valley Himalayan state of Uttarakhand in northern India, (ii) a teak (Tectona grandis) mixed forest at Betul in Madhya Pradesh in central India, (iv) an old teak plantation at Dandeli, and (v) a semi-evergreen forest at Nagarhole in Karnataka state in southern India. The three towers have been procured and the eddy covariance equipment installation on Haldwani tower will be completed this month. The equipment for ground based studies such as soil respiration system, soil moisture and temperature measurement system, PAR sensor, hemi view, light use efficiency measurement system etc. have been already procured. The spatial database containing a variety of information on soil types, rainfall, temperature, forest cover PAR, vegetation indices etc. has been prepared using remote sensing and other means. The temporal ground inventory of the vegetation and soil parameters is also under progress. Each site will involve a team leader, one research student and one master degree student. The Forest Departments of above mentioned states of India are actively collaborating in this research. Various universities and research institutions have also expressed interest to cooperate in the programme.

Comparison of the efficacy of free residual chlorine and monochloramine against biofilms in model and full scale cooling towers.

PubMed

Türetgen, Irfan

2004-04-01

The presence of microbial cells on surfaces results in the formation of biofilms, which may also give rise to microbiologically influenced corrosion. Biofilms accumulate on all submerged industrial and environmental surfaces. The efficacy of disinfectants is usually evaluated using planktonic cultures, which often leads to an underestimate of the concentration required to control a biofilm. The aim of this study was to investigate the efficacy of monochloramine on biofilms developed in a cooling tower. The disinfectants selected for the study were commercial formulations recommended for controlling microbial growth in cooling towers. A cooling tower and a laboratory model recirculating water system were used as biofilm reactors. Although previous studies have evaluated the efficacy of free chlorine and monochloramine for controlling biofilm growth, there is a lack of published data concerning the use monochloramine in cooling towers. Stainless steel coupons were inserted in each tower basin for a period of 30 d before removal. Monochloramine and free chlorine were tested under identical conditions on mixed biofilms which had been allowed to grow on coupons. Monochloramine was found to be significantly more effective than free chlorine against cooling tower biofilms.

Droplet combustion experiment drop tower tests using models of the space flight apparatus

NASA Technical Reports Server (NTRS)

Haggard, J. B.; Brace, M. H.; Kropp, J. L.; Dryer, F. L.

1989-01-01

The Droplet Combustion Experiment (DCE) is an experiment that is being developed to ultimately operate in the shuttle environment (middeck or Spacelab). The current experiment implementation is for use in the 2.2 or 5 sec drop towers at NASA Lewis Research Center. Initial results were reported in the 1986 symposium of this meeting. Since then significant progress was made in drop tower instrumentation. The 2.2 sec drop tower apparatus, a conceptual level model, was improved to give more reproducible performance as well as operate over a wider range of test conditions. Some very low velocity deployments of ignited droplets were observed. An engineering model was built at TRW. This model will be used in the 5 sec drop tower operation to obtain science data. In addition, it was built using the flight design except for changes to accommodate the drop tower requirements. The mechanical and electrical assemblies have the same level of complexity as they will have in flight. The model was tested for functional operation and then delivered to NASA Lewis. The model was then integrated into the 5 sec drop tower. The model is currently undergoing initial operational tests prior to starting the science tests.

An evaluation of the efficacy of Aqualox for microbiological control of industrial cooling tower systems.

PubMed

Prince, E L; Muir, A V G; Thomas, W M; Stollard, R J; Sampson, M; Lewis, J A

2002-12-01

A comprehensive sampling protocol was employed to evaluate the efficacy of Aqualox, a biocide based on electrochemically activated water, against legionellae and heterotrophic bacteria in two industrial cooling tower systems. Both of the towers in the study remained free from evidence of Legionella spp. contamination throughout a five-month evaluation period, despite the previously demonstrated presence of legionellae in one of the test towers, and in two other towers on the same site, at levels well in excess of UK Health and Safety Commission (HSC) Approved Code of Practice and Guidance (ACOP) upper action limits. Levels of heterotrophic bacteria were controlled below 10(4) cfu/mL in both towers throughout most of the trial. Results also provided indirect evidence of significant activity against biofilm bacteria, with biofilm removal beginning almost immediately after commissioning of the Aqualox treatment systems. The results were particularly encouraging as the two towers studied had a long history of poor microbiological control using conventional bromine-based biocide products. Significant differences were observed between laboratory measurements of total viable counts on frequent liquid samples and those obtained from dip slides following HSC recommendations. Copyright 2002 The Hospital Infection Society

Fluid dynamic effects on staphylococci bacteria biofilms

NASA Astrophysics Data System (ADS)

Sherman, Erica; Bayles, Kenneth; Endres, Jennifer; Wei, Timothy

2016-11-01

Staphylococcus aureus bacteria are able to form biofilms and distinctive tower structures that facilitate their ability to tolerate treatment and to spread within the human body. The formation of towers, which break off, get carried downstream and serve to initiate biofilms in other parts of the body are of particular interest here. It is known that flow conditions play a role in the development, dispersion and propagation of biofilms in general. The influence of flow on tower formation, however, is not at all understood. This work is focused on the effect of applied shear on tower development. The hypothesis being examined is that tower structures form within a specific range of shear stresses and that there is an as yet ill defined fluid dynamic phenomenon that occurs hours before a tower forms. In this study, a range of shear stresses is examined that brackets 0.6 dynes/cm2, the nominal shear stress where towers seem most likely to form. This talk will include µPTV measurements and cell density data indicating variations in flow and biofilm evolution as a function of the applied shear. Causal relations between flow and biofilm development will be discussed.

Optical fiber science and technology: Novel fibers and fiber sensors

NASA Astrophysics Data System (ADS)

Morse, T. F.

1988-02-01

This equipment grant has permitted the purchase of a complete optical fiber draw facility and auxilliary equipment for our fiber characterization laboratory. The draw tower has been erected in a specially prepared laboratory. It is a 7.8 m automated tower with a 20 kw carbon induction furnace, and sufficient room for two UV coating stages, or a UV coating stage, and a thermal curing stage. The tower installation took perhaps somewhat more time than initially anticipated, largely due to difficulties in the site preparation. The tower itself has been installed on a reinforced concrete pad, with appropriate vibration isolation. For about six months, we have been gaining experience in the use of the tower, and have been drawing kilometer lengths of fiber that range in diameter from 50 microns to 250 microns with a tolerance of the order of a few microns. In anticipation of expanding the coating capabilities of our draw tower, a vacuum system was purchased for use with radio frequency sputtering on-line on the tower. This will be particularly useful for ceramic coated fibers in the study of the behavior of fiber strengthened composite materials.

AmeriFlux US-Wrc Wind River Crane Site

DOE Data Explorer

Bible, Ken [University of Washington; Wharton, Sonia [Lawrence Livermore National Laboratory

2016-01-01

This is the AmeriFlux version of the carbon flux data for the site US-Wrc Wind River Crane Site. Site Description - Wind River Field Station flux tower site is located in the T.T. Munger Research Area of the Wind River Ranger District in the Gifford Pinchot National Forest. Protected since 1926, the T.T. Munger Research Natural Area (RNA) is administered by the USDA Forest Service Pacific Northwest Research Station and Gifford Pinchot National Forest. The Douglas-fir/western hemlock dominant stand is approximately 500 years old and represents end points of several ecological gradients including age, biomass, structural complexity, and density of the dominant overstory species. A complete stand replacement fire, approximately 450-500 years ago, resulted in the initial establishment. No significant disturbances have occurred since the fire aside from those confined to small groups of single trees, such as overturn from high wind activity and mechanical damage from winter precipitation.

14. WEST ELEVATION OF COAL TOWER No. 2, LOOKING WEST ...

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

14. WEST ELEVATION OF COAL TOWER No. 2, LOOKING WEST TO EAST FROM COAL TOWER No. 1 (FLOOR BELOW THE CRANE CONTROL) - Delaware County Electric Company, Chester Station, Delaware River at South end of Ward Street, Chester, Delaware County, PA

1. Keeper's house and light tower, view north northeast, southwest ...

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

1. Keeper's house and light tower, view north northeast, southwest and southeast sides of house, northwest and southwest sides of tower - Wood Island Light Station, East end of Wood Island, at mouth of Soo River, Biddeford Pool, York County, ME

Systems Integration Analysis for Future Tower Cab Configurations/Systems

DOT National Transportation Integrated Search

1978-06-01

This report presents the results of the analysis of various aspects of the integration of future ATC systems into the tower cab. The impact on the tower cab environment is analyzed from several points of view: how the systems information and displays...

348. Caltrans, Photographer December 27, 1935 "TOWER E3"; VIEW OF ...

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

348. Caltrans, Photographer December 27, 1935 "TOWER E-3"; VIEW OF TOWER E-3 AND CANTILEVER TRUSS EAST ANCHOR ARM UNDER CONSTRUCTION. 7-1128 - San Francisco Oakland Bay Bridge, Spanning San Francisco Bay, San Francisco, San Francisco County, CA

BOREAS TF-5 SSA-OJP Tower Flux and Meteorological Data

NASA Technical Reports Server (NTRS)

Baldocchi, Dennis; Vogel, Christoph; Hall, Forrest G. (Editor); Huemmrich, Karl (Editor)

2000-01-01

The BOReal Ecosystem-Atmosphere Study Tower Flux (BOREAS TF-5) team collected tower flux data at the BOREAS Southern Study Area Old Jack Pine (SSA-OJP) site through the growing season of 1994. The data are available in tabular ASCII files.

37. VIEW LOOKING SOUTH AT THE STATIC TEST TOWER. THIS ...

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

37. VIEW LOOKING SOUTH AT THE STATIC TEST TOWER. THIS VIEW SHOWS TWO MAJOR CHANGES TO THE STATIC TEST TOWER: THE ADDITION OF THE NASA LOGO TO THE FACADE AND THE ADDITION OF THE UPPER STAGES TO THE JUPITER MISSILE IN THE WEST POSITION ON THE TOWER TO REPRESENT THE JUNO II CONFIGURATION. 1961, PHOTOGRAPHER UNKNOWN, FRED ORDWAY COLLECTION, U. S. SPACE AND ROCKET CENTER, HUNTSVILLE, AL. - Marshall Space Flight Center, Saturn Propulsion & Structural Test Facility, East Test Area, Huntsville, Madison County, AL

Aircraft- and tower-based fluxes of carbon dioxide, latent, and sensible heat

NASA Technical Reports Server (NTRS)

Desjardins, R. L.; Hart, R. L.; Macpherson, J. I.; Schuepp, P. H.; Verma, S. B.

1992-01-01

Fluxes of carbon dioxide, water vapor, and sensible heat obtained over a grassland ecosystem, during the First International Satellite Land Surface Climatology Project (ISLSCP) Field Experiment (FIFE), using an aircraft- and two tower-based systems are compared for several days in 1987 and in 1989. The tower-based cospectral estimates of CO2, sensible heat, water vapor, and momentum, expressed as a function of wavenumber K times sampling height z, are relatively similar to the aircraft-based estimates for K x z greater than 0.1. A measurable contribution to the fluxes is observed by tower-based systems at K x z less than 0.01 but not by the aircraft-based system operating at an altitude of approximately 100 m over a 15 x 15 km area. Using all available simultaneous aircraft and tower data, flux estimates by both systems were shown to be highly correlated. As expected from the spatial variations of the greenness index, surface extrapolation of airborne flux estimates tended to lie between those of the two tower sites. The average fluxes obtained, on July 11, 1987, and August 4, 1989, by flying a grid pattern over the FIFE site agreed with the two tower data sets for CO2, but sensible and latent heat were smaller than those obtained by the tower-based systems. However, in general, except for a small underestimation due to the long wavelength contributions and due to flux divergence with height, the differences between the aircraft- and tower-based surface estimates of fluxes appear to be mainly attributable to differences in footprint, that is, differences in the area contributing to the surface flux estimates.

Siting Background Towers to Characterize Incoming Air for Urban Greenhouse Gas Estimation: A Case Study in the Washington, DC/Baltimore Area

NASA Astrophysics Data System (ADS)

Mueller, K.; Yadav, V.; Lopez-Coto, I.; Karion, A.; Gourdji, S.; Martin, C.; Whetstone, J.

2018-03-01

There is increased interest in understanding urban greenhouse gas (GHG) emissions. To accurately estimate city emissions, the influence of extraurban fluxes must first be removed from urban greenhouse gas (GHG) observations. This is especially true for regions, such as the U.S. Northeastern Corridor-Baltimore/Washington, DC (NEC-B/W), downwind of large fluxes. To help site background towers for the NEC-B/W, we use a coupled Bayesian Information Criteria and geostatistical regression approach to help site four background locations that best explain CO2 variability due to extraurban fluxes modeled at 12 urban towers. The synthetic experiment uses an atmospheric transport and dispersion model coupled with two different flux inventories to create modeled observations and evaluate 15 candidate towers located along the urban domain for February and July 2013. The analysis shows that the average ratios of extraurban inflow to total modeled enhancements at urban towers are 21% to 36% in February and 31% to 43% in July. In July, the incoming air dominates the total variability of synthetic enhancements at the urban towers (R2 = 0.58). Modeled observations from the selected background towers generally capture the variability in the synthetic CO2 enhancements at urban towers (R2 = 0.75, root-mean-square error (RMSE) = 3.64 ppm; R2 = 0.43, RMSE = 4.96 ppm for February and July). However, errors associated with representing background air can be up to 10 ppm for any given observation even with an optimal background tower configuration. More sophisticated methods may be necessary to represent background air to accurately estimate urban GHG emissions.

Legionnaires' disease from a cooling tower in a community outbreak in Lidköping, Sweden- epidemiological, environmental and microbiological investigation supported by meteorological modelling.

PubMed

Ulleryd, Peter; Hugosson, Anna; Allestam, Görel; Bernander, Sverker; Claesson, Berndt E B; Eilertz, Ingrid; Hagaeus, Anne-Christine; Hjorth, Martin; Johansson, Agneta; de Jong, Birgitta; Lindqvist, Anna; Nolskog, Peter; Svensson, Nils

2012-11-21

An outbreak of Legionnaires' Disease took place in the Swedish town Lidköping on Lake Vänern in August 2004 and the number of pneumonia cases at the local hospital increased markedly. As soon as the first patients were diagnosed, health care providers were informed and an outbreak investigation was launched. Classical epidemiological investigation, diagnostic tests, environmental analyses, epidemiological typing and meteorological methods. Thirty-two cases were found. The median age was 62 years (range 36 - 88) and 22 (69%) were males. No common indoor exposure was found. Legionella pneumophila serogroup 1 was found at two industries, each with two cooling towers. In one cooling tower exceptionally high concentrations, 1.2 × 109 cfu/L, were found. Smaller amounts were also found in the other tower of the first industry and in one tower of the second plant. Sero- and genotyping of isolated L. pneumophila serogroup 1 from three patients and epidemiologically suspected environmental strains supported the cooling tower with the high concentration as the source. In all, two L. pneumophila strains were isolated from three culture confirmed cases and both these strains were detected in the cooling tower, but one strain in another cooling tower as well. Meteorological modelling demonstrated probable spread from the most suspected cooling tower towards the town centre and the precise location of four cases that were stray visitors to Lidköping. Classical epidemiological, environmental and microbiological investigation of an LD outbreak can be supported by meteorological modelling methods.The broad competence and cooperation capabilities in the investigation team from different authorities were of paramount importance in stopping this outbreak.

Legionnaires’ disease from a cooling tower in a community outbreak in Lidköping, Sweden- epidemiological, environmental and microbiological investigation supported by meteorological modelling

PubMed Central

2012-01-01

Background An outbreak of Legionnaires’ Disease took place in the Swedish town Lidköping on Lake Vänern in August 2004 and the number of pneumonia cases at the local hospital increased markedly. As soon as the first patients were diagnosed, health care providers were informed and an outbreak investigation was launched. Methods Classical epidemiological investigation, diagnostic tests, environmental analyses, epidemiological typing and meteorological methods. Results Thirty-two cases were found. The median age was 62 years (range 36 – 88) and 22 (69%) were males. No common indoor exposure was found. Legionella pneumophila serogroup 1 was found at two industries, each with two cooling towers. In one cooling tower exceptionally high concentrations, 1.2 × 109 cfu/L, were found. Smaller amounts were also found in the other tower of the first industry and in one tower of the second plant. Sero- and genotyping of isolated L. pneumophila serogroup 1 from three patients and epidemiologically suspected environmental strains supported the cooling tower with the high concentration as the source. In all, two L. pneumophila strains were isolated from three culture confirmed cases and both these strains were detected in the cooling tower, but one strain in another cooling tower as well. Meteorological modelling demonstrated probable spread from the most suspected cooling tower towards the town centre and the precise location of four cases that were stray visitors to Lidköping. Conclusions Classical epidemiological, environmental and microbiological investigation of an LD outbreak can be supported by meteorological modelling methods. The broad competence and cooperation capabilities in the investigation team from different authorities were of paramount importance in stopping this outbreak. PMID:23171054

Use of cooling tower blow down in ethanol fermentation.

PubMed

Rajagopalan, N; Singh, V; Panno, B; Wilcoxon, M

2010-01-01

Reducing water consumption in bioethanol production conserves an increasingly scarce natural resource, lowers production costs, and minimizes effluent management issues. The suitability of cooling tower blow down water for reuse in fermentation was investigated as a means to lower water consumption. Extensive chemical characterization of the blow down water revealed low concentrations of toxic elements and total dissolved solids. Fermentation carried out with cooling tower blow down water resulted in similar levels of ethanol and residual glucose as a control study using deionized water. The study noted good tolerance by yeast to the specific scale and corrosion inhibitors found in the cooling tower blow down water. This research indicates that, under appropriate conditions, reuse of blow down water from cooling towers in fermentation is feasible.

How tall can gelatin towers be? An introduction to elasticity and buckling

NASA Astrophysics Data System (ADS)

Taberlet, Nicolas; Ferrand, Jérémy; Camus, Élise; Lachaud, Léa; Plihon, Nicolas

2017-12-01

The stability of elastic towers is studied through simple hands-on experiments. Using gelatin-based stackable bricks, one can investigate the maximum height a simple structure can reach before collapsing. We show through experiments and by using the classical linear elastic theory that the main limitation to the height of such towers is the buckling of the elastic structures under their own weight. Moreover, the design and architecture of the towers can be optimized to greatly improve their resistance to self-buckling. To this aim, the maximum height of hollow and tapered towers is investigated. The experimental and theoretical developments presented in this paper can help students grasp the fundamental concepts in elasticity and mechanical stability.

KSC-99pp1218

NASA Image and Video Library

1999-10-14

KENNEDY SPACE CENTER, FLA. -- The fallen 300-foot, five-million-pound Mobile Service Tower (MST) on Launch Complex 41, Cape Canaveral Air Force Station, looms over the head of a worker on the ground beside it. The MST and a 200-foot-high umbilical tower nearby were demolished to make room for Lockheed Martin's 14-acre Vehicle Integration Facility (VIF), under construction. Only lightning protection towers, such as the one seen behind the MST, remain standing at the site. About 200 pounds of linear-shaped charges were used to bring down the towers so that the materials can be recycled. The implosion and removal of the tower debris is expected to be completed in two months. The VIF will be used for Lockheed Martin's Atlas V Launch System.

Dual pressure-dual temperature isotope exchange process

DOEpatents

Babcock, D.F.

1974-02-12

A liquid and a gas stream, each containing a desired isotope, flow countercurrently through two liquid-gas contacting towers maintained at different temperatures and pressures. The liquid is enriched in the isotope in one tower while the gas is enriched within the other and a portion of at least one of the enriched streams is withdrawn from the system for use or further enrichment. The tower operated at the lower temperature is also maintained at the lower pressure to prevent formation of solid solvates. Gas flow between the towers passes through an expander-compressor apparatas to recover work from the expansion of gas to the lower pressure and thereby compress the gas returning to the tower of higher pressure. (Official Gazette)

Chankillo

NASA Astrophysics Data System (ADS)

Ghezzi, Iván; Ruggles, Clive L. N.

A line of thirteen rectangular towers, built along a north-south hilltop ridge within a ceremonial complex in coastal Peru dating to c. 300 BC, appears to represent the oldest known solar observation device in the Americas. The fact that this device functions throughout the seasonal year, and still functions today, makes it unique on the planet. The broader archaeological evidence suggests that observations of sunrise and sunset against the thirteen towers served to regulate a social and ritual calendar while reinforcing a solar cult that helped to lend legitimacy and authority to a rising warrior elite. Recent archaeoastronomical work has identified a wider range of potentially significant alignments, possibly including some lunar ones, visible from publicly accessible places rather than just by a few high-status individuals. The site and its interpretation also illustrate some fundamental issues of archaeoastronomical methodology and practice that are of broader significance.

Background and system description of the Mod 1 wind turbine generator

NASA Technical Reports Server (NTRS)

Ernst, E. H.

1978-01-01

The Mod-1 wind turbine considered is a large utility-class machine, operating in the high wind regime, which has the potential for generation of utility grade power at costs competitive with other alternative energy sources. A Mod-1 wind turbine generator (WTG) description is presented, taking into account the two variable-pitch steel blades of the rotor, the drive train, power generation/control, the Nacelle structure, and the yaw drive. The major surface elements of the WTG are the ground enclosure, the back-up battery system, the step-up transformer, elements of the data system, cabling, area lighting, and tower foundation. The final system weight (rotor, Nacelle, and tower) is expected to be about 650,000 pounds. The WTG will be capable of delivering 1800 kW to the utility grid in a wind-speed above 25 mph.

2. ENVIRONMENT, FROM SOUTHEAST, SHOWING B&P INTERLOCKING TOWER, AUXILIARY INTERLOCKING ...

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

2. ENVIRONMENT, FROM SOUTHEAST, SHOWING B&P INTERLOCKING TOWER, AUXILIARY INTERLOCKING BUILDING, AND POWER SUBSTATION - Baltimore & Potomac Interlocking Tower, Adjacent to AMTRAK railroad tracks in block bounded by Howard Street, Jones Falls Expressway, Maryland Avenue & Falls Road, Baltimore, Independent City, MD

32. VIEW LOOKING EAST AT THE STATIC TEST TOWER WHILE ...

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

32. VIEW LOOKING EAST AT THE STATIC TEST TOWER WHILE A JUPITER MISSILE IS BEING POSITIONED ONTO THE TEST TOWER. DATE AND PHOTOGRAPHER UNKNOWN, MSFC PHOTO LAB. - Marshall Space Flight Center, Saturn Propulsion & Structural Test Facility, East Test Area, Huntsville, Madison County, AL

78 FR 17183 - Information Collection: Grey Towers Visitor Comment Card

Federal Register 2010, 2011, 2012, 2013, 2014

2013-03-20

... DEPARTMENT OF AGRICULTURE Forest Service Information Collection: Grey Towers Visitor Comment Card... request: (1) An extension from the Office of Management and Budget; and (2) to merge the currently approved information collection 0596- 0222, ``Grey Towers Visitor Comment Card'' with 0596-0226, ``Forest...

36. EASTERN VIEW OF BOTTOM CONE OF GAS COOLING TOWER ...

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

36. EASTERN VIEW OF BOTTOM CONE OF GAS COOLING TOWER No. 1 AND TWO GAS COOLING TOWER SERVICE WATER PUMPS IN THE GAS WASHER PUMP HOUSE. - U.S. Steel Duquesne Works, Basic Oxygen Steelmaking Plant, Along Monongahela River, Duquesne, Allegheny County, PA

2. Light tower and oil house, view west, southeast and ...

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

2. Light tower and oil house, view west, southeast and northeast sides of tower and south side of oil house - Goat Island Light Station, Goat Island, next to entrance to Cape Porpoise Harbor, just south of Trott Island, Cape Porpoise, York County, ME

2. Fog signal house and light tower, view west southwest, ...

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

2. Fog signal house and light tower, view west southwest, southeast and northeast sides of signal house, east and north sides of tower - Libby Island Light Station, At southern tip of Libby Island at entrance to Machias Bay, Machiasport, Washington County, ME

1. Light tower and fog signal house, view south southeast, ...

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

1. Light tower and fog signal house, view south southeast, east and north sides of tower, northeast and northwest sides of signal house - Libby Island Light Station, At southern tip of Libby Island at entrance to Machias Bay, Machiasport, Washington County, ME

15. TYPICAL VIEW OF PEARL HARBOR FROM SIGNAL TOWER OFFICE, ...

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

15. TYPICAL VIEW OF PEARL HARBOR FROM SIGNAL TOWER OFFICE, LOOKING OUT TOWARD ARIZONA MEMORIAL AND FORD ISLAND. - U.S. Naval Base, Pearl Harbor, Signal Tower, Corner of Seventh Street & Avenue D east of Drydock No. 1, Pearl City, Honolulu County, HI

An experimental study of windturbine noise from blade-tower wake interaction

NASA Astrophysics Data System (ADS)

Marcus, E. N.; Harris, W. L.

1983-04-01

A program of experiments has been conducted to study the impulsive noise of a horizontal axis windturbine. These tests were performed on a 1/53 scale model of the DOE-NASA MOD-1 windturbine. Experiments were performed in the M.I.T. 5 x 7-1/2 ft Anechoic Windtunnel Facility. The impulsive noise of a horizontal axis windturbine is observed to result from repeated blade passage through the mean velocity deficit induced in the lee of the windturbine support tower. The two factors which most influence this noise are rotation speed and tower drag coefficient. The intensity of noise from blade tower wake interaction is predicted to increase with the fourth power of the RPM and the second power of the tower drag coefficient. These predictions are confirmed in experiments. Further experiments are also presented in order to observe directionality of the acoustic field as well as the acoustic influence of tower shape and blade number.

Supplement Analysis for the Transmission System Vegetation Management Program FEIS (DOE/EIS-0285/SA-120 Hanford-Ostrander Corridor Maintenance

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

Hutchinson, Ken

2003-02-10

Vegetation Management for the Hanford-Ostrander Transmission Line Corridor from Tower 10/4 to Tower 17/2 + 770. The line is a 500kV Single Circuit Transmission Line having an easement width of 300 feet. The proposed work will be accomplished in the indicated sections of the transmission line corridor as referenced on the attached checklist. The work will include the performance of road maintenance and tower pad maintenance along the Hanford-Ostrander transmission line. Maintenance will be performed from Tower 10/1, close to Army Loop road near the northeast corner of 200 West Area of the Hanford Nuclear Reservation to the western edgemore » of the Arid Lands Ecological Reserve (ALE) at Tower 17/2 + 700. Total distance of the work is approximately 7.5 miles. The planned work includes spraying with herbicides to minimize vegetation regrowth along the access roads and removing shrubs from within 50 feet of each transmission tower.« less

Integrating fluid dynamic and biologic effects on staphylococci bacteria biofilms

NASA Astrophysics Data System (ADS)

Sherman, Erica; Endres, Jennifer; Bayles, Kenneth; Wei, Timothy

2017-11-01

Staphylococcus aureus bacteria are able to form biofilms and distinctive tower structures that facilitate their ability to tolerate treatment and to spread within the human body. The formation of towers, which break off, get carried downstream and serve to initiate biofilms in other parts of the body are of particular interest here. In previous work on biofilm growth and evolution in steady, laminar microchannel flows, it has been established that tower formation occurs around a very limited range of applied shear stresses centered on 0.6 dynes/cm2. Quantifying cell density characteristics as a function of time during biofilm formation reveals indicators of tower development hours before towers actually form and become visible. The next step in this research is to explore biological factors that might explain why this specific shear is so important. Additional studies with mutants, e.g. ica-A, that have been tied to tower formation have been conducted. The shear dependence of these mutants and their correlation to the behavior of wild type S. aureus is examined.

Cooling towers, the neglected energy conservations and money making machine

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

Burger, R.

1996-12-31

The heat Rejection Industry defines a nominal cooling tower as circulating three gallons of water per minute (GPM) per ton of refrigeration from entering the tower at 95 {degrees}F, Hot Water temperature (HWT), Leaving at 85{degrees}F Cold Water Temperature (CWT) at a Design Wet Bulb of 70{degrees}F (WBT). Manufacturers then provide a selection chart based on various wet bulb temperatures and HWTs. The wet bulb fluctuates and varies throughout the world since it is the combination ambient temperature, relative humidity, and/or dew point. Different HWT and CWT requirements are usually charted as they change, so that the user can selectmore » the nominal cooling tower model recommended by the manufacturer. In the specification of cooling towers it is necessary to clearly understand the definition of nominal cooling tower, and to make sure the specification you need addressed can be met by the system you purchase. This should be tested prior to final acceptance.« less

Stimulatory effect of cooling tower biocides on amoebae.

PubMed

Srikanth, S; Berk, S G

1993-10-01

Two species of amoebae were isolated from the cooling tower of an air-conditioning system and examined for effects of exposure to four cooling tower biocides, a thiocarbamate compound, tributyltin neodecanoate mixed with quaternary ammonium compounds, another quaternary ammonium compound alone, and an isothiazolin derivative. The amoebae isolated were Acanthamoeba hatchetti and a Cochliopodium species. Two other amoeba cultures, an A. hatchetti culture and Cochliopodium bilimbosum, were obtained from the American Type Culture Collection (ATCC) and were also tested. The cooling tower isolates were more resistant to most of the biocides than the ATCC isolates were. The isothiazolin derivative was the least inhibitory to all four amoeba isolates, and tributyltin neodecanoate mixed with quaternary ammonium compounds was the most inhibitory to three of the four isolates. After exposure to lower concentrations of the biocides, including for one strain the manufacturer's recommended concentration of one biocide, the cooling tower amoeba populations increased significantly compared with unexposed controls, whereas the ATCC isolates were not stimulated at any of the concentrations tested. In some cases, concentrations which stimulated cooling tower amoebae inhibited the growth of the ATCC isolates. These results suggest that cooling tower amoebae may adapt to biocides, underscoring the need to use freshly isolated cooling tower organisms rather than organisms from culture collections for testing the efficacy of such biocides. The stimulatory effect of biocides on amoeba populations is an alarming observation, since these organisms may be reservoirs for legionellae. Biocides used to control microbial growth may actually enhance populations of host organisms for pathogenic bacteria.

Sampling and detection of Legionella pneumophila aerosols generated from an industrial cooling tower.

PubMed

Ishimatsu, S; Miyamoto, H; Hori, H; Tanaka, I; Yoshida, S

2001-08-01

Cooling tower water has frequently been cited as a source of infection in outbreaks of Legionnaires' disease. However, there have been few reports on the presence of legionellae in aerosols from cooling towers. This paper describes our use of an impinger or a six-stage microbial impactor for detecting legionellae in air around a cooling tower contaminated with L. pneumophila (1.2+/-0.3x10(5) CFU/100 ml). Phosphate-buffered saline, Page's saline, 2% yeast extract solution and buffered yeast extract (BYE) broth were tested to evaluate their collection efficiency. These solutions were compared in laboratory experiments using an aerosol of L. pneumophila serogroup (SG) 1. Because BYE broth was the most efficient and storable collecting fluid among them, it was used for outdoor air sampling. In the outdoor air sampling, aerosolized L. pneumophila SG 6 was detected in the air around the cooling tower by the impinger (0.09 CFU/l. air). No legionellae were detected by the impactor with Legionella-selective agar plates (WYOalpha) because the plates were overgrown with fungi. Repetitive element PCR (rep-PCR) and arbitrarily primed PCR (AP-PCR) were employed to assess the epidemiological relationship among Legionella isolates from the air sample and the cooling tower water samples. L. pneumophila SG 6 isolated from the aerosols produced rep-PCR and AP-PCR fingerprints identical to those of L. pneumophila SG 6 strains from the cooling tower water, suggesting that the bacterium was aerosolized from the cooling tower.

Small Liquid Hydrogen Tank for Drop Tower Tests

NASA Image and Video Library

1964-11-21

A researcher fills a small container used to represent a liquid hydrogen tank in preparation for a microgravity test in the 2.2-Second Drop Tower at the National Aeronautics and Space Administration (NASA) Lewis Research Center. For over a decade, NASA Lewis endeavored to make liquid hydrogen a viable propellant. Hydrogen’s light weight and high energy made it very appealing for rocket propulsion. One of the unknowns at the time was the behavior of fluids in the microgravity of space. Rocket designers needed to know where the propellant would be inside the fuel tank in order to pump it to the engine. NASA Lewis utilized sounding rockets, research aircraft, and the 2.2 Second Drop Tower to study liquids in microgravity. The drop tower, originally built as a fuel distillation tower in 1948, descended into a steep ravine. By early 1961 the facility was converted into an eight-floor, 100-foot tower connected to a shop and laboratory space. Small glass tanks, like this one, were installed in experiment carts with cameras to film the liquid’s behavior during freefall. Thousands of drop tower tests in the early 1960s provided an increased understanding of low-gravity processes and phenomena. The tower only afforded a relatively short experiment time but was sufficient enough that the research could be expanded upon using longer duration freefalls on sounding rockets or aircraft. The results of the early experimental fluid studies verified predictions made by Lewis researchers that the total surface energy would be minimized in microgravity.

Nitrous acid (HONO) measurements during winter haze events in Beijing

NASA Astrophysics Data System (ADS)

Bloss, W.; Kramer, L. J.; Crilley, L.; Lee, J. D.; Squires, F. A.; Tong, S.

2017-12-01

Daytime HONO levels can reach several parts per billion in megacities during winter haze events and hence act as the dominant (primary) precursor to OH radicals in the urban boundary layer, and affect NOx abundance. Understanding the sources of HONO is therefore important to quantify atmospheric oxidative capacity and secondary pollutant formation during such haze events. Despite decades of research, there are still large uncertainties in HONO formation mechanisms, and as a result models often substantially underestimate peak HONO levels. In this study, measurements of HONO were performed at the Institute of Atmospheric Physics (IAP) site located in central Beijing during Nov/Dec 2016, across both haze and non-haze events. Using a commercial long-path absorption photometer (LOPAP), vertical profiles of HONO concentrations up to a height of 260 m on the IAP Meteorological Tower were performed, as well as continuous near-surface measurements. Preliminary results showed that HONO levels near the ground were very high during the winter haze events with concentrations over 10 ppbV observed. Typically, during the vertical profiles a negative gradient was observed, indicating a large HONO source close to the surface. However, during some of the profiles elevated HONO concentrations were also observed at higher altitudes pointing to a strong source within the boundary layer. Co-located NOx and SO2 measurements are used to elucidate potential HONO sources from direct emissions, homogeneous gas phase reactions and heterogeneous conversion of NO2 on surfaces. Results from ground level HONO/NOx ratios show a midday peak during clean periods indicating a photo-enhanced process, which was not apparent during hazy days. The potential impact of these findings on the OH radical budget in wintertime Beijing will be discussed.

Disentangling Climate and Land-use Impacts on Grassland Carbon and Water Fluxes

NASA Astrophysics Data System (ADS)

Brunsell, N. A.; Nippert, J. B.

2014-12-01

Regional climate and land cover interact in a complex, non-linear manner to alter the local cycling of mass and energy. It is often difficult to isolate the role of either mechanism on the resultant fluxes. Here, we attempt to isolate these mechanisms through the use of network of 4 Ameriflux eddy covariance towers installed over different land cover and land use classes along a pronounced rainfall gradient. The land cover types include: annually burned C4 grassland, a 4 year burn site experiencing woody encroachment, an abandoned agricultural field and a new perennial agricultural site. We investigated the impact of rainfall variability, drought, and heat waves on the water and carbon budgets using data analysis, remote sensing, and modeling approaches. In addition, we have established a network of mini-meteorological stations at the annually and 4-year burn sites to assess micro-scale variability within the footprints of the towers as a function of topographic position, soil depth and soil water availability. Through the use of a wavelet multiscale decomposition and information theory metrics, we have isolated the role of environmental factors (temperature, humidity, soil moisture, etc.) on the fluxes across the different sites. By applying a similar analysis to model output, we can assess the ability of land-surface models to recreate the observed sensitity. Results indicate the utility of a network of measurement systems used in conjunction with land surface modeling and time series analysis to assess differential impacts to similar regional scale climate forcings. Implications for the role of land cover class in regional and global scale modeling systems will also be discussed.

An Error-Reduction Algorithm to Improve Lidar Turbulence Estimates for Wind Energy

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

Newman, Jennifer F.; Clifton, Andrew

2016-08-01

Currently, cup anemometers on meteorological (met) towers are used to measure wind speeds and turbulence intensity to make decisions about wind turbine class and site suitability. However, as modern turbine hub heights increase and wind energy expands to complex and remote sites, it becomes more difficult and costly to install met towers at potential sites. As a result, remote sensing devices (e.g., lidars) are now commonly used by wind farm managers and researchers to estimate the flow field at heights spanned by a turbine. While lidars can accurately estimate mean wind speeds and wind directions, there is still a largemore » amount of uncertainty surrounding the measurement of turbulence with lidars. This uncertainty in lidar turbulence measurements is one of the key roadblocks that must be overcome in order to replace met towers with lidars for wind energy applications. In this talk, a model for reducing errors in lidar turbulence estimates is presented. Techniques for reducing errors from instrument noise, volume averaging, and variance contamination are combined in the model to produce a corrected value of the turbulence intensity (TI), a commonly used parameter in wind energy. In the next step of the model, machine learning techniques are used to further decrease the error in lidar TI estimates.« less

Application of micro-PIV to the study of staphylococci bacteria biofilm dynamics

NASA Astrophysics Data System (ADS)

Sherman, Erica; Moormeier, Derek; Bayles, Kenneth; Wei, Timothy

2014-11-01

Staphylococci bacteria are recognized as the most frequent cause of biofilm-associated infections. A localized staph infection has the potential to enter the bloodstream and lead to serious infections such as endocarditis, pneumonia, or toxic shock syndrome. Changes in flow conditions, such as shear stress, can lead to stable biofilm growth or the dispersion of portions of the biofilm downstream. Exploration of biofilm physiology indicates a link between production of a specific enzyme called nuclease and biofilm architecture -; however the physical impact of this enzyme in directing the location and behavior of biofilm growth remains unclear. This talk investigates the link between sites of nuclease production and the development of biofilm tower structures using the application of micro-PIV and fluorescently labeled bacterial cells producing nuclease. Staphylococcus aureus bacteria were cultured in a BioFlux1000 square microchannel of a 65 by 65 um cross section, and subjected to a steady shear rate of 0.6 dynes. Micro-PIV and nuclease production measurements were taken to quantify the flow over a biofilm tower structure prior and during development. Data were recorded around the structure at a series of two dimensional planes, which when stacked vertically show a two dimensional flow field as a function of tower height.

On the applicability of surrogate-based Markov chain Monte Carlo-Bayesian inversion to the Community Land Model: Case studies at flux tower sites: SURROGATE-BASED MCMC FOR CLM

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

Huang, Maoyi; Ray, Jaideep; Hou, Zhangshuan

2016-07-04

The Community Land Model (CLM) has been widely used in climate and Earth system modeling. Accurate estimation of model parameters is needed for reliable model simulations and predictions under current and future conditions, respectively. In our previous work, a subset of hydrological parameters has been identified to have significant impact on surface energy fluxes at selected flux tower sites based on parameter screening and sensitivity analysis, which indicate that the parameters could potentially be estimated from surface flux observations at the towers. To date, such estimates do not exist. In this paper, we assess the feasibility of applying a Bayesianmore » model calibration technique to estimate CLM parameters at selected flux tower sites under various site conditions. The parameters are estimated as a joint probability density function (PDF) that provides estimates of uncertainty of the parameters being inverted, conditional on climatologically-average latent heat fluxes derived from observations. We find that the simulated mean latent heat fluxes from CLM using the calibrated parameters are generally improved at all sites when compared to those obtained with CLM simulations using default parameter sets. Further, our calibration method also results in credibility bounds around the simulated mean fluxes which bracket the measured data. The modes (or maximum a posteriori values) and 95% credibility intervals of the site-specific posterior PDFs are tabulated as suggested parameter values for each site. Analysis of relationships between the posterior PDFs and site conditions suggests that the parameter values are likely correlated with the plant functional type, which needs to be confirmed in future studies by extending the approach to more sites.« less

On the applicability of surrogate-based MCMC-Bayesian inversion to the Community Land Model: Case studies at Flux tower sites

DOE PAGES

Huang, Maoyi; Ray, Jaideep; Hou, Zhangshuan; ...

2016-06-01

The Community Land Model (CLM) has been widely used in climate and Earth system modeling. Accurate estimation of model parameters is needed for reliable model simulations and predictions under current and future conditions, respectively. In our previous work, a subset of hydrological parameters has been identified to have significant impact on surface energy fluxes at selected flux tower sites based on parameter screening and sensitivity analysis, which indicate that the parameters could potentially be estimated from surface flux observations at the towers. To date, such estimates do not exist. In this paper, we assess the feasibility of applying a Bayesianmore » model calibration technique to estimate CLM parameters at selected flux tower sites under various site conditions. The parameters are estimated as a joint probability density function (PDF) that provides estimates of uncertainty of the parameters being inverted, conditional on climatologically average latent heat fluxes derived from observations. We find that the simulated mean latent heat fluxes from CLM using the calibrated parameters are generally improved at all sites when compared to those obtained with CLM simulations using default parameter sets. Further, our calibration method also results in credibility bounds around the simulated mean fluxes which bracket the measured data. The modes (or maximum a posteriori values) and 95% credibility intervals of the site-specific posterior PDFs are tabulated as suggested parameter values for each site. As a result, analysis of relationships between the posterior PDFs and site conditions suggests that the parameter values are likely correlated with the plant functional type, which needs to be confirmed in future studies by extending the approach to more sites.« less

Estimating rice yield related traits and quantitative trait loci analysis under different nitrogen treatments using a simple tower-based field phenotyping system with modified single-lens reflex cameras

NASA Astrophysics Data System (ADS)

Naito, Hiroki; Ogawa, Satoshi; Valencia, Milton Orlando; Mohri, Hiroki; Urano, Yutaka; Hosoi, Fumiki; Shimizu, Yo; Chavez, Alba Lucia; Ishitani, Manabu; Selvaraj, Michael Gomez; Omasa, Kenji

2017-03-01

Application of field based high-throughput phenotyping (FB-HTP) methods for monitoring plant performance in real field conditions has a high potential to accelerate the breeding process. In this paper, we discuss the use of a simple tower based remote sensing platform using modified single-lens reflex cameras for phenotyping yield traits in rice under different nitrogen (N) treatments over three years. This tower based phenotyping platform has the advantages of simplicity, ease and stability in terms of introduction, maintenance and continual operation under field conditions. Out of six phenological stages of rice analyzed, the flowering stage was the most useful in the estimation of yield performance under field conditions. We found a high correlation between several vegetation indices (simple ratio (SR), normalized difference vegetation index (NDVI), transformed vegetation index (TVI), corrected transformed vegetation index (CTVI), soil-adjusted vegetation index (SAVI) and modified soil-adjusted vegetation index (MSAVI)) and multiple yield traits (panicle number, grain weight and shoot biomass) across a three trials. Among all of the indices studied, SR exhibited the best performance in regards to the estimation of grain weight (R2 = 0.80). Under our tower-based field phenotyping system (TBFPS), we identified quantitative trait loci (QTL) for yield related traits using a mapping population of chromosome segment substitution lines (CSSLs) and a single nucleotide polymorphism data set. Our findings suggest the TBFPS can be useful for the estimation of yield performance during early crop development. This can be a major opportunity for rice breeders whom desire high throughput phenotypic selection for yield performance traits.

On the applicability of surrogate-based MCMC-Bayesian inversion to the Community Land Model: Case studies at Flux tower sites

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

Huang, Maoyi; Ray, Jaideep; Hou, Zhangshuan

The Community Land Model (CLM) has been widely used in climate and Earth system modeling. Accurate estimation of model parameters is needed for reliable model simulations and predictions under current and future conditions, respectively. In our previous work, a subset of hydrological parameters has been identified to have significant impact on surface energy fluxes at selected flux tower sites based on parameter screening and sensitivity analysis, which indicate that the parameters could potentially be estimated from surface flux observations at the towers. To date, such estimates do not exist. In this paper, we assess the feasibility of applying a Bayesianmore » model calibration technique to estimate CLM parameters at selected flux tower sites under various site conditions. The parameters are estimated as a joint probability density function (PDF) that provides estimates of uncertainty of the parameters being inverted, conditional on climatologically average latent heat fluxes derived from observations. We find that the simulated mean latent heat fluxes from CLM using the calibrated parameters are generally improved at all sites when compared to those obtained with CLM simulations using default parameter sets. Further, our calibration method also results in credibility bounds around the simulated mean fluxes which bracket the measured data. The modes (or maximum a posteriori values) and 95% credibility intervals of the site-specific posterior PDFs are tabulated as suggested parameter values for each site. As a result, analysis of relationships between the posterior PDFs and site conditions suggests that the parameter values are likely correlated with the plant functional type, which needs to be confirmed in future studies by extending the approach to more sites.« less

Solar Tower Experiments for Radiometric Calibration and Validation of Infrared Imaging Assets and Analysis Tools for Entry Aero-Heating Measurements

NASA Technical Reports Server (NTRS)

Splinter, Scott C.; Daryabeigi, Kamran; Horvath, Thomas J.; Mercer, David C.; Ghanbari, Cheryl M.; Ross, Martin N.; Tietjen, Alan; Schwartz, Richard J.

2008-01-01

The NASA Engineering and Safety Center sponsored Hypersonic Thermodynamic Infrared Measurements assessment team has a task to perform radiometric calibration and validation of land-based and airborne infrared imaging assets and tools for remote thermographic imaging. The IR assets and tools will be used for thermographic imaging of the Space Shuttle Orbiter during entry aero-heating to provide flight boundary layer transition thermography data that could be utilized for calibration and validation of empirical and theoretical aero-heating tools. A series of tests at the Sandia National Laboratories National Solar Thermal Test Facility were designed for this task where reflected solar radiation from a field of heliostats was used to heat a 4 foot by 4 foot test panel consisting of LI 900 ceramic tiles located on top of the 200 foot tall Solar Tower. The test panel provided an Orbiter-like entry temperature for the purposes of radiometric calibration and validation. The Solar Tower provided an ideal test bed for this series of radiometric calibration and validation tests because it had the potential to rapidly heat the large test panel to spatially uniform and non-uniform elevated temperatures. Also, the unsheltered-open-air environment of the Solar Tower was conducive to obtaining unobstructed radiometric data by land-based and airborne IR imaging assets. Various thermocouples installed on the test panel and an infrared imager located in close proximity to the test panel were used to obtain surface temperature measurements for evaluation and calibration of the radiometric data from the infrared imaging assets. The overall test environment, test article, test approach, and typical test results are discussed.

On the applicability of surrogate-based Markov chain Monte Carlo-Bayesian inversion to the Community Land Model: Case studies at flux tower sites

NASA Astrophysics Data System (ADS)

Huang, Maoyi; Ray, Jaideep; Hou, Zhangshuan; Ren, Huiying; Liu, Ying; Swiler, Laura

2016-07-01

The Community Land Model (CLM) has been widely used in climate and Earth system modeling. Accurate estimation of model parameters is needed for reliable model simulations and predictions under current and future conditions, respectively. In our previous work, a subset of hydrological parameters has been identified to have significant impact on surface energy fluxes at selected flux tower sites based on parameter screening and sensitivity analysis, which indicate that the parameters could potentially be estimated from surface flux observations at the towers. To date, such estimates do not exist. In this paper, we assess the feasibility of applying a Bayesian model calibration technique to estimate CLM parameters at selected flux tower sites under various site conditions. The parameters are estimated as a joint probability density function (PDF) that provides estimates of uncertainty of the parameters being inverted, conditional on climatologically average latent heat fluxes derived from observations. We find that the simulated mean latent heat fluxes from CLM using the calibrated parameters are generally improved at all sites when compared to those obtained with CLM simulations using default parameter sets. Further, our calibration method also results in credibility bounds around the simulated mean fluxes which bracket the measured data. The modes (or maximum a posteriori values) and 95% credibility intervals of the site-specific posterior PDFs are tabulated as suggested parameter values for each site. Analysis of relationships between the posterior PDFs and site conditions suggests that the parameter values are likely correlated with the plant functional type, which needs to be confirmed in future studies by extending the approach to more sites.

34. SITE BUILDING 002 SCANNER BUILDING ROOM 105 ...

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

34. SITE BUILDING 002 - SCANNER BUILDING - ROOM 105 - CHILLER ROOM, SHOWING SINGLE COMPRESSOR, LIQUID CHILLERS AND "CHILLED WATER RETURN", COOLING TOWER 'TOWER WATER RETURN" AND 'TOWER WATER SUPPLY" LINES. - Cape Cod Air Station, Technical Facility-Scanner Building & Power Plant, Massachusetts Military Reservation, Sandwich, Barnstable County, MA

2. Keeper's house, light tower and oil house, view north, ...

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

2. Keeper's house, light tower and oil house, view north, south and east sides of keeper's house, south side of tower and oil house - Owl's Head Light Station, Off State Highway 73 just east of Rockland on Owl's Head Bay, Owls Head, Knox County, ME

10. INDIAN HOUSE TOWER, FROM, THE EAST. ALSO SHOWS THE ...

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

10. INDIAN HOUSE TOWER, FROM, THE EAST. ALSO SHOWS THE BALCONY AND ARCADE OF THE WEST WING. THE TOWER WAS ADDED IN 1916. - Moravian Pottery & Tile Works, Southwest side of State Route 313 (Swamp Road), Northwest of East Court Street, Doylestown, Bucks County, PA

1. Oil house, keeper's house, Southern Light Tower and Northern ...

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

1. Oil house, keeper's house, Southern Light Tower and Northern Light Tower, view northwest, south and east sides - Kennebec River Light Station, South side of Doubling Point Road, off State Highway 127, 1.8 miles south of U.S. Route 1, Arrowsic, Sagadahoc County, ME

7. Keeper's house, fog signal house and light tower, view ...

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

7. Keeper's house, fog signal house and light tower, view north northeast, west and south sides of keeper's house and tower, southwest and southeast sides of fog signal house - West Quoddy Head Light Station, At eastern tip of West Quaddy Head, Lubec, Washington County, ME

2. Barn, light tower and keeper's house, view southeast, west ...

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

2. Barn, light tower and keeper's house, view southeast, west and north sides of barn, northwest side of light tower, and west northwest and north northeast sides of keeper's house - Curtis Island Light Station, Curtis Island, at entrance to Camden Harbor, Camden, Knox County, ME

KENNEDY SPACE CENTER, FLA. -- A new control tower is nearing completion at the KSC Shuttle Landing Facility. It will replace the old tower in use since 1987. The old tower stands only 20 feet above the runway surface, too low to see the launch pads to the east. During nighttime landing operations, those inside the tower have been hindered by the eight-billion candlepower xenon lights that illuminate the runway. The new control tower is built atop an existing mound, rising nearly 100 feet over the midpoint of the runway. The height gives controllers a spectacular 360-degree view of NASA-KSC and northern Brevard County. The new facility will also replace the SLF Operations Building. The operations building is home to the Military Radar Unit that monitors NASA-KSC airspace 24 hours a day, as well as runway light controls, navigational aids, weather and wind speed instrumentation, and gate controls. In the new tower, the computer displays will be fully modernized to Federal Aviation Administration standards with touch-screen technology. Construction on the new facility began in February 2003 and is nearly ready for occupancy. Only some final inspections and approvals remain. A support building and Public Affairs viewing deck, to be used for observing future landing operations, will be added and are already in work.

NASA Image and Video Library

2003-12-17

KENNEDY SPACE CENTER, FLA. -- A new control tower is nearing completion at the KSC Shuttle Landing Facility. It will replace the old tower in use since 1987. The old tower stands only 20 feet above the runway surface, too low to see the launch pads to the east. During nighttime landing operations, those inside the tower have been hindered by the eight-billion candlepower xenon lights that illuminate the runway. The new control tower is built atop an existing mound, rising nearly 100 feet over the midpoint of the runway. The height gives controllers a spectacular 360-degree view of NASA-KSC and northern Brevard County. The new facility will also replace the SLF Operations Building. The operations building is home to the Military Radar Unit that monitors NASA-KSC airspace 24 hours a day, as well as runway light controls, navigational aids, weather and wind speed instrumentation, and gate controls. In the new tower, the computer displays will be fully modernized to Federal Aviation Administration standards with touch-screen technology. Construction on the new facility began in February 2003 and is nearly ready for occupancy. Only some final inspections and approvals remain. A support building and Public Affairs viewing deck, to be used for observing future landing operations, will be added and are already in work.

Drop Tower Physics

ERIC Educational Resources Information Center

Dittrich, William A.

2014-01-01

The drop towers of yesteryear were used to make lead shot for muskets, as described in "The Physics Teacher" in April 2012. However, modern drop towers are essentially elevators designed so that the cable can "break" on demand, creating an environment with microgravity for a short period of time, currently up to nine seconds at…

47 CFR 5.109 - Antenna and tower requirements.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 47 Telecommunication 1 2011-10-01 2011-10-01 false Antenna and tower requirements. 5.109 Section 5... BROADCAST) Technical Standards and Operating Requirements § 5.109 Antenna and tower requirements. (a) Applicants with fixed stations that use antennas that exceed 6 meters in height above the ground level or...

47 CFR 5.109 - Antenna and tower requirements.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 47 Telecommunication 1 2010-10-01 2010-10-01 false Antenna and tower requirements. 5.109 Section 5... BROADCAST) Technical Standards and Operating Requirements § 5.109 Antenna and tower requirements. (a) Applicants with fixed stations that use antennas that exceed 6 meters in height above the ground level or...

47 CFR 5.109 - Antenna and tower requirements.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 47 Telecommunication 1 2012-10-01 2012-10-01 false Antenna and tower requirements. 5.109 Section 5... BROADCAST) Technical Standards and Operating Requirements § 5.109 Antenna and tower requirements. (a) Applicants with fixed stations that use antennas that exceed 6 meters in height above the ground level or...

PBF Cooling Tower Auxiliary Building (PER624) interior. Camera facing north. ...

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

PBF Cooling Tower Auxiliary Building (PER-624) interior. Camera facing north. Deluge valves and automatic fire protection piping for Cooling Tower. Photographer: Holmes. Date: May 20, 1970. INEEL negative no. 70-2323 - Idaho National Engineering Laboratory, SPERT-I & Power Burst Facility Area, Scoville, Butte County, ID

40 CFR 63.1329 - Process contact cooling towers provisions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... DDD, shall maintain an ethylene glycol concentration in the process contact cooling tower at or below... to the process contact cooling tower. (1) To determine the ethylene glycol concentration, owners or... procedures specified in 40 CFR 60.564(j)(1)(i). An average ethylene glycol concentration by weight shall be...

16. TYPICAL VIEW OF PEARL HARBOR FROM SIGNAL TOWER OFFICE, ...

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

16. TYPICAL VIEW OF PEARL HARBOR FROM SIGNAL TOWER OFFICE, LOOKING OUT AT MAIN CHANNEL ENTRANCE, WITH FORD ISLAND ON THE RIGHT. - U.S. Naval Base, Pearl Harbor, Signal Tower, Corner of Seventh Street & Avenue D east of Drydock No. 1, Pearl City, Honolulu County, HI

1. Keeper's house, small boathouse, and light tower, view east, ...

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

1. Keeper's house, small boathouse, and light tower, view east, west and south sides of keeper's house, west side of boathouse and tower - Great Duck Island Light Station, At southern tip of Great Duck Island southeast of Bass Harbor & northeast of Frenchboro, Frenchboro, Hancock County, ME

Design, fabrication, and initial test of a fixture for reducing the natural frequency of the Mod-O wind turbine tower

NASA Technical Reports Server (NTRS)

Winemiller, J. R.; Sullivan, T. L.; Sizemore, R. L.; Yee, S. T.

1979-01-01

It was desired to observe the behavior of a two bladed wind turbine where the tower first bending natural frequency is less than twice the rotor speed. The system then passes through resonance when accelerating to operating speed. The frequency of the original Mod-O tower was reduced by placing it on a spring fixture. The fixture is adjustable to provide a range of tower bending frequencies. Fixture design details are given and behavior during initial operation is described.

Visual Features Involving Motion Seen from Airport Control Towers

NASA Technical Reports Server (NTRS)

Ellis, Stephen R.; Liston, Dorion

2010-01-01

Visual motion cues are used by tower controllers to support both visual and anticipated separation. Some of these cues are tabulated as part of the overall set of visual features used in towers to separate aircraft. An initial analyses of one motion cue, landing deceleration, is provided as a basis for evaluating how controllers detect and use it for spacing aircraft on or near the surface. Understanding cues like it will help determine if they can be safely used in a remote/virtual tower in which their presentation may be visually degraded.

FAA Air Traffic Control Operations Concepts. Volume 7. ATCT (Airport Traffic Control Towers) Tower Controllers

DTIC Science & Technology

1989-04-21

kift rIn FAA AIR TRAFFIC CONTROL OPERATIONS CONCEPTS V olum e V iI:.................... ATCT Tower Controllers AmELECTE JUL 2 11989 21 April 1989 A...01 022.3013209-87-B 11 a FAA AIR TRAFFIC CONTROL OPERATIONS CONCEPTS VOLUME VII: ATCT TOWER CONTROLLERS CDRL Bl 12, VOL. VII CONTRACT DTF-AO1-85-Y...INCORPORATED 7150 Campus Drive, Suite 100 Colorado Springs, CO 80920 (719) 590-5100 DOT/FAA/AP-87-0i (VOL#7) 21 April 1989 FAA AIR TRAFFIC CONTROL OPERATIONS

KSC-04PD-0610

NASA Technical Reports Server (NTRS)

2004-01-01

KENNEDY SPACE CENTER, FLA. -- Launch Umbilical Tower No. 1 (LUT- 1) stored in the Industrial Area of KSC is being demolished with a Caterpillar excavator and 48-inch shear attachment. Seen is the base of tower; the upright tower extended more than 398 feet above the launch pad. The LUT-1 was part of the launch system used for Apollo-Saturn V, launching Apollo 8, Apollo 11, Skylab manned missions and the Apollo-Soyuz Test Project. The shear is one used in the deconstruction of the Twin Towers in New York City after 9/11.

KSC-04PD-0612

NASA Technical Reports Server (NTRS)

2004-01-01

KENNEDY SPACE CENTER, FLA. -- Launch Umbilical Tower No. 1 (LUT- 1) stored in the Industrial Area of KSC is being demolished with the Caterpillar excavator and 48-inch shear attachment. Seen is the base of tower; the upright tower extended more than 398 feet above the launch pad. The LUT-1 was part of the launch system used for Apollo-Saturn V, launching Apollo 8, Apollo 11, Skylab manned missions and the Apollo-Soyuz Test Project. The shear is one used in the deconstruction of the Twin Towers in New York City after 9/11.

KSC-04PD-0604

NASA Technical Reports Server (NTRS)

2004-01-01

KENNEDY SPACE CENTER, FLA. -- Launch Umbilical Tower No. 1 (LUT- 1), stored in the Industrial Area of KSC, is being demolished using a Caterpillar excavator and 48-inch shear attachment. Seen is the base of tower; the upright tower extended more than 398 feet above the launch pad. The LUT-1 was part of the launch system used for Apollo-Saturn V, launching Apollo 8, Apollo 11, Skylab manned missions and the Apollo-Soyuz Test Project. The shear being used for demolition is one used in the deconstruction of the Twin Towers in New York City after 9/11.

KSC-04PD-0607

NASA Technical Reports Server (NTRS)

2004-01-01

KENNEDY SPACE CENTER, FLA. -- Launch Umbilical Tower No. 1 (LUT- 1) stored in the Industrial Area of KSC is being demolished with a Caterpillar excavator and 48-inch shear attachment. Seen is the base of tower; the upright tower extended more than 398 feet above the launch pad. The LUT-1 was part of the launch system used for Apollo-Saturn V, launching Apollo 8, Apollo 11, Skylab manned missions and the Apollo-Soyuz Test Project. The shear is one used in the deconstruction of the Twin Towers in New York City after 9/11.

KSC-04PD-0608

NASA Technical Reports Server (NTRS)

2004-01-01

KENNEDY SPACE CENTER, FLA. -- Launch Umbilical Tower No. 1 (LUT- 1) stored in the Industrial Area of KSC is being demolished with a Caterpillar excavator and 48-inch shear attachment. Seen is the base of tower; the upright tower extended more than 398 feet above the launch pad. The LUT-1 was part of the launch system used for Apollo-Saturn V, launching Apollo 8, Apollo 11, Skylab manned missions and the Apollo-Soyuz Test Project. The shear is one used in the deconstruction of the Twin Towers in New York City after 9/11.

Design and Manufacturing of Composite Tower Structure for Wind Turbine Equipment

NASA Astrophysics Data System (ADS)

Park, Hyunbum

2018-02-01

This study proposes the composite tower design process for large wind turbine equipment. In this work, structural design of tower and analysis using finite element method was performed. After structural design, prototype blade manufacturing and test was performed. The used material is a glass fiber and epoxy resin composite. And also, sand was used in the middle part. The optimized structural design and analysis was performed. The parameter for optimized structural design is weight reduction and safety of structure. Finally, structure of tower will be confirmed by structural test.

Crosswinds Effect on the Thermal Performance of Wet Cooling Towers Under Variable Operating Conditions

NASA Astrophysics Data System (ADS)

Chen, You Liang; Shi, Yong Feng; Hao, Jian Gang; Chang, Hao; Sun, Feng Zhong

2018-01-01

In order to quantitatively analyze the influence of the variable operating parameters on the cooling performance of natural draft wet cooling towers (NDWCTs), a hot model test system was set up with adjustable ambient temperature and humidity, circulating water flowrate and temperature. In order to apply the hot model test results to the real tower, the crosswind Froude number is defined. The results show that the crosswind has a negative effect on the thermal performance of the cooling tower, and there is a critical crosswind velocity corresponding to the lowest cooling efficiency. According to the crosswind Froude number similarity, when the ambient temperature decreases, or the circulating water flowrate and temperature increase, the cooling tower draft force will increase, and the critical crosswind velocity will increase correspondingly.

Parametric study of closed wet cooling tower thermal performance

NASA Astrophysics Data System (ADS)

Qasim, S. M.; Hayder, M. J.

2017-08-01

The present study involves experimental and theoretical analysis to evaluate the thermal performance of modified Closed Wet Cooling Tower (CWCT). The experimental study includes: design, manufacture and testing prototype of a modified counter flow forced draft CWCT. The modification based on addition packing to the conventional CWCT. A series of experiments was carried out at different operational parameters. In view of energy analysis, the thermal performance parameters of the tower are: cooling range, tower approach, cooling capacity, thermal efficiency, heat and mass transfer coefficients. The theoretical study included develops Artificial Neural Network (ANN) models to predicting various thermal performance parameters of the tower. Utilizing experimental data for training and testing, the models simulated by multi-layer back propagation algorithm for varying all operational parameters stated in experimental test.

Legionella longbeachae detected in an industrial cooling tower linked to a legionellosis outbreak, New Zealand, 2015; possible waterborne transmission?

PubMed

Thornley, C N; Harte, D J; Weir, R P; Allen, L J; Knightbridge, K J; Wood, P R T

2017-08-01

A legionellosis outbreak at an industrial site was investigated to identify and control the source. Cases were identified from disease notifications, workplace illness records, and from clinicians. Cases were interviewed for symptoms and risk factors and tested for legionellosis. Implicated environmental sources were sampled and tested for legionella. We identified six cases with Legionnaires' disease and seven with Pontiac fever; all had been exposed to aerosols from the cooling towers on the site. Nine cases had evidence of infection with either Legionella pneumophila serogroup (sg) 1 or Legionella longbeachae sg1; these organisms were also isolated from the cooling towers. There was 100% DNA sequence homology between cooling tower and clinical isolates of L. pneumophila sg1 using sequence-based typing analysis; no clinical L. longbeachae isolates were available to compare with environmental isolates. Routine monitoring of the towers prior to the outbreak failed to detect any legionella. Data from this outbreak indicate that L. pneumophila sg1 transmission occurred from the cooling towers; in addition, L. longbeachae transmission was suggested but remains unproven. L. longbeachae detection in cooling towers has not been previously reported in association with legionellosis outbreaks. Waterborne transmission should not be discounted in investigations for the source of L. longbeachae infection.

FLUXNET: A Global Network of Eddy-Covariance Flux Towers

NASA Astrophysics Data System (ADS)

Cook, R. B.; Holladay, S. K.; Margle, S. M.; Olsen, L. M.; Gu, L.; Heinsch, F.; Baldocchi, D.

2003-12-01

The FLUXNET global network was established to aid in understanding the mechanisms controlling the exchanges of carbon dioxide, water vapor, and energy across a variety of terrestrial ecosystems. Flux tower data are also being used to validate ecosystem model outputs and to provide information for validating remote sensing based products, including surface temperature, reflectance, albedo, vegetation indices, leaf area index, photosynthetically active radiation, and photosynthesis derived from MODIS sensors on the Terra and Aqua satellites. The global FLUXNET database provides consistent and complete flux data to support global carbon cycle science. Currently FLUXNET consists of over 210 sites, with most flux towers operating continuously for 4 years or longer. Gap-filled data are available for 53 sites. The FLUXNET database contains carbon, water vapor, sensible heat, momentum, and radiation flux measurements with associated ancillary and value-added data products. Towers are located in temperate conifer and broadleaf forests, tropical and boreal forests, crops, grasslands, chaparral, wetlands, and tundra on five continents. Selected MODIS Land products in the immediate vicinity of the flux tower are subsetted and posted on the FLUXNET Web site for 169 flux-towers. The MODIS subsets are prepared in ASCII format for 8-day periods for an area 7 x 7 km around the tower.

Studies of the low-energy quasiparticle excitations in high-temperature superconducting cuprates with scanning tunneling spectroscopy and magnetization measurements

NASA Astrophysics Data System (ADS)

Boev, Ivan Krasimirov

In the present PhD work, three sophisticated models based on the "Engineering" modeling approach have been utilized to conveniently describe and thoroughly analyze details of Lightning events at the CN Tower. Both the CN Tower and the Lightning Channel are represented by a number of connected in series Transmission Line sections in order to account for the variations in the shape of the tower and for plasma processes that take place within the Lightning Channel. A sum of two Heidler functions is used to describe the "uncontaminated" Return Stroke current, which is injected at the attachment point between the CN Tower and the Lightning Channel. Reflections and refractions at all points of mismatched impedances are considered until their contribution becomes less than 1% of the originally injected current wave. In the proposed models, the problem with the current discontinuity at the Lightning Channel front, commonly taken care of by introducing a "turn-on" term when computing radiation fields, is uniquely treated by introducing reflected and transmitted components. For the first time, variable speed of propagation of the Return Stroke current front has been considered and its influence upon the predicted current distributions along the whole Lightning Channel path and upon the radiated distant fields analyzed. Furthermore, as another novelty, computation of the electromagnetic field is accomplished in Cartesian Coordinates. This fact permits to relax the requirement on the verticality of the Lightning Channel, normally imposed in Cylindrical Coordinates. Therefore, it becomes possible to study without difficulty the influence of a slanted Lightning Channel upon the surrounding electromagnetic field. Since the proposed sophisticated Five-Section Model has the capability to represent very closely the structure of the CN Tower and to emulate faithfully the shape of, as well as physical processes within the Lightning Channel, it is believed to have the potential of truthfully reproducing observed fields. The developed modeling approach can be easily adapted to study the anticipated radiated fields at tall structures even before construction.

EO-1 Hyperion Reflectance Time Series at Calibration and Validation Sites: Stability and Sensitivity to Seasonal Dynamics

NASA Technical Reports Server (NTRS)

Campbell, Petya K. Entcheva; Middleton, Elizabeth M.; Thome, Kurt J.; Kokaly, Raymond F.; Huemmrich, Karl Fred; Lagomasino, David; Novick, Kimberly A.; Brunsell, Nathaniel A.

2013-01-01

This study evaluated Earth Observing 1 (EO-1) Hyperion reflectance time series at established calibration sites to assess the instrument stability and suitability for monitoring vegetation functional parameters. Our analysis using three pseudo-invariant calibration sites in North America indicated that the reflectance time series are devoid of apparent spectral trends and their stability consistently is within 2.5-5 percent throughout most of the spectral range spanning the 12-plus year data record. Using three vegetated sites instrumented with eddy covariance towers, the Hyperion reflectance time series were evaluated for their ability to determine important variables of ecosystem function. A number of narrowband and derivative vegetation indices (VI) closely described the seasonal profiles in vegetation function and ecosystem carbon exchange (e.g., net and gross ecosystem productivity) in three very different ecosystems, including a hardwood forest and tallgrass prairie in North America, and a Miombo woodland in Africa. Our results demonstrate the potential for scaling the carbon flux tower measurements to local and regional landscape levels. The VIs with stronger relationships to the CO2 parameters were derived using continuous reflectance spectra and included wavelengths associated with chlorophyll content and/or chlorophyll fluorescence. Since these indices cannot be calculated from broadband multispectral instrument data, the opportunity to exploit these spectrometer-based VIs in the future will depend on the launch of satellites such as EnMAP and HyspIRI. This study highlights the practical utility of space-borne spectrometers for characterization of the spectral stability and uniformity of the calibration sites in support of sensor cross-comparisons, and demonstrates the potential of narrowband VIs to track and spatially extend ecosystem functional status as well as carbon processes measured at flux towers.

Bioengineered silver nanoparticles as potent anti-corrosive inhibitor for mild steel in cooling towers.

PubMed

Narenkumar, Jayaraman; Parthipan, Punniyakotti; Madhavan, Jagannathan; Murugan, Kadarkarai; Marpu, Sreekar Babu; Suresh, Anil Kumar; Rajasekar, Aruliah

2018-02-01

Silver nanoparticle-aided enhancement in the anti-corrosion potential and stability of plant extract as ecologically benign alternative for microbially induced corrosion treatment is demonstrated. Bioengineered silver nanoparticles (AgNPs) surface functionalized with plant extract material (proteinacious) was generated in vitro in a test tube by treating ionic AgNO 3 with the leaf extract of Azadirachta indica that acted as dual reducing as well as stabilizing agent. Purity and crystallinity of the AgNPs, along with physical and surface characterizations, were evaluated by performing transmission electron microscopy, Fourier transform infrared spectroscopy, energy dispersive x-ray spectra, single-area electron diffractions, zeta potential, and dynamic light scattering measurements. Anti-corrosion studies against mild steel (MS1010) by corrosion-inducive bacterium, Bacillus thuringiensis EN2 isolated from cooling towers, were evaluated by performing electrochemical impedance spectroscopy (EIS), weight loss analysis, and surface analysis by infrared spectroscopy. Our studies revealed that AgNPs profoundly inhibited the biofilm on MS1010 surface and reduced the corrosion rates with the CR of 0.5 mm/y and an inhibition efficiency of 77% when compared to plant extract alone with a CR of 2.2 mm/y and an inhibition efficiency of 52%. Further surface analysis by infrared spectra revealed that AgNPs formed a protective layer of self-assembled film on the surface of MS1010. Additionally, EIS and surface analysis revealed that the AgNPs have inhibited the bacterial biofilm and reduced the pit on MS1010. This is the first report disclosing the application of bioengineered AgNP formulations as potent anti-corrosive inhibitor upon forming a protective layer over mild steel in cooling water towers. Graphical Abstract ᅟ.

EO-1 Hyperion reflectance time series at calibration and validation sites: stability and sensitivity to seasonal dynamics

USGS Publications Warehouse

Campbell, P.K.E.; Middleton, E.M.; Thome, K.J.; Kokaly, Raymond F.; Huemmrich, K.F.; Novick, K.A.; Brunsell, N.A.

2013-01-01

This study evaluated Earth Observing 1 (EO-1) Hyperion reflectance time series at established calibration sites to assess the instrument stability and suitability for monitoring vegetation functional parameters. Our analysis using three pseudo-invariant calibration sites in North America indicated that the reflectance time series are devoid of apparent spectral trends and their stability consistently is within 2.5-5 percent throughout most of the spectral range spanning the 12+ year data record. Using three vegetated sites instrumented with eddy covariance towers, the Hyperion reflectance time series were evaluated for their ability to determine important variables of ecosystem function. A number of narrowband and derivative vegetation indices (VI) closely described the seasonal profiles in vegetation function and ecosystem carbon exchange (e.g., net and gross ecosystem productivity) in three very different ecosystems, including a hardwood forest and tallgrass prairie in North America, and a Miombo woodland in Africa. Our results demonstrate the potential for scaling the carbon flux tower measurements to local and regional landscape levels. The VIs with stronger relationships to the CO2 parameters were derived using continuous reflectance spectra and included wavelengths associated with chlorophyll content and/or chlorophyll fluorescence. Since these indices cannot be calculated from broadband multispectral instrument data, the opportunity to exploit these spectrometer-based VIs in the future will depend on the launch of satellites such as EnMAP and HyspIRI. This study highlights the practical utility of space-borne spectrometers for characterization of the spectral stability and uniformity of the calibration sites in support of sensor cross-comparisons, and demonstrates the potential of narrowband VIs to track and spatially extend ecosystem functional status as well as carbon processes measured at flux towers.

Estimating fuel consumption for the upper coastal plain of South Carolina

Treesearch

S.L. Goodrick; D. Shea; J. Blake

2010-01-01

Recent changes in air quality regulations present a potential obstacle to continued use of prescribed fire as a land management tool. towering of the acceptable daily concentration of particulate matter from 6510 35 jig/m' will bring much closer scrutiny of prescribed burning practices from the air quality community. To work within this narrow window, land...

The Potential of Carbonyl Sulfide as a Proxy for Gross Primary Production at Flux Tower Sites

USDA-ARS?s Scientific Manuscript database

Regional and continental scale studies of the seasonal dynamics of atmospheric carbonyl sulfide (OCS) mole fractions and leaf-level studies of plant OCS exchange have shown a close relationship with those for CO2. CO2 has sinks and sources within terrestrial ecosystems, but the primary terrestrial e...

Mechanical properties of gypsum board at elevated temperatures

Treesearch

S.M. Cramer; O.M. Friday; R.H. White; G. Sriprutkiat

2003-01-01

Gypsum board is a common fire barrier used in house and general building construction. Recently, evaluation of the collapses of the World Trade Center Towers highlighted the potential role and failure of gypsum board in containing the fires and resisting damage. The use of gypsum board as primary fire protection of light-flame wood or steel construction is ubiquitous....

On the geological origin of Devils Tower (WY, USA)

NASA Astrophysics Data System (ADS)

Zavada, P.; Dedecek, P.; Holloway, S. D.; Chang, J. C.; Crain, K.; Keller, G. R.

2011-12-01

The Devils Tower is an exceptional igneous rock formation and a dominating landmark of the northern plains in Wyoming (USA). It rises 250 m above the surrounding sedimentary formations. Previous hypotheses suggested that the Devils Tower was originally part of a magmatic intrusion; volcanic conduit, magmatic stock or a laccolith. Our review of the geological evidence suggests that the Devils Tower is a remnant of an eroded lava lake that filled a broad phreatomagmatic volcano crater. Our hypothesis is based on a detailed study of a similar phonolite landmark in Czech Republic, called Boren, and analogue modeling, finite element numerical modeling of cooling for various shapes of volcanic bodies, and results of field and gravity surveys of the area. The Devils Tower together with a group of five phonolite bodies called Missouri Buttes, located 6 km NW from the Devils Tower, represent the easternmost products of the Tertiary tectonomagmatic events related to the lithospheric-scale uplift of the Black hills monocline. The phreatomagmatic deposits in the surroundings of the Missouri Buttes and the Devils Tower suggest that these phonolite bodies were originally emplaced into phreatomagmatic maar-diatreme volcanoes. To reveal the original shape of the Devils Tower, we employed the analogue modeling using plaster of Paris as analogue for phonolite magma to study internal fabrics and shapes of extrusive/intrusive magmatic bodies emplaced into the maar-diatreme volcanoes. Then, the resulting shapes of analogue magmatic bodies were used for the Finite Element thermal numerical models of their cooling using the thermophysical parameters of the phonolite magma and the rock units surrounding the Devils Tower and Missouri Buttes. Because the columnar joints grow perpendicular to the isotherms in cooling igneous and volcanic bodies, we analyzed the match between the thermal structure of the FE models and the columnar jointing pattern on the Devils Tower. The best fit of the thermal structure and the inverted fan columnar jointing pattern on Devils Tower was found for one of the models that produced a lava lake filling the entire maar crater of the phreatomagmatic volcano. The Devils Tower represents the central part of the lake just above the feeding conduit. After emplacement and solidification of the lava lake, erosion first removed the weakly consolidated phreatomagmatic deposits in the tuff ring around the lake. Then the lava body eroded laterally due to the formation of ice in the columnar joints, pushing columns away from the neighboring columns into the open space. The remnant of the solidified lake (Devils Tower) represents a structure, which is resistant to this kind of erosion, because its base is formed by columns that lean against each other and towards the center of the Tower. In contrast, the Missouri Buttes most probably represent a remnant of a branched intrusion producing several extrusive domes on the maar-crater periphery that can form by subsequent emplacement of different magma batches (e.g. from a stratified magma chamber), each with relatively lower yield strength owing to decreasing crystal content.

The Drop Tower Bremen -An Overview

NASA Astrophysics Data System (ADS)

von Kampen, Peter; Könemann, Thorben; Rath, Hans J.

The Center of Applied Space Technology and Microgravity (ZARM) was founded in 1985 as an institute of the University of Bremen, which focuses on research on gravitational and space-related phenomena. In 1988, the construction of ZARM`s drop tower began. Since its inau-guration in September 1990, the eye-catching Drop Tower Bremen with a height of 146m and its characteristic glass roof has become twice a landmark on the campus of the University of Bremen and the emblem of the technology park Bremen. As such an outstanding symbol of space science in Bremen the drop tower provides an european unique facility for experiments under conditions of high-quality weightlessness with residual gravitational accelerations in the microgravity regime. The period of maximum 4.74s of each freely falling experiment at the Drop Tower Bremen is only limited by the height of the drop tower vacuum tube, which was fully manufactured of steal and enclosed by an outer concrete shell. Thus, the pure free fall height of each microgravity drop experiment is approximately 110m. By using the later in-stalled catapult system established in 2004 ZARM`s short-term microgravity laboratory is able to nearly double the time of free fall. This world-wide inimitable capsule catapult system meets scientists` demand of extending the period of weightlessness. During the catapult operation the experiment capsule performs a vertical parabolic flight within the drop tower vacuum tube. In this way the time of microgravity can be extended to slightly over 9s. Either in the drop or in the catapult operation routine the repetition rates of microgravity experiments at ZARM`s drop tower facility are the same, generally up to 3 times per day. In comparison to orbital platforms the ground-based laboratory Drop Tower Bremen represents an economic alternative with a permanent access to weightlessness on earth. Moreover, the exceptional high quality of weightlessness in order of 1e-6 g (in the frequency range below 100Hz) demonstrates a perfect experimental environment for unperturbed investigations of scientific phenomena. Motivated by these prospects many national and international groups have initialized research programs taking advantage of this drop tower facility. In respect thereof the spectrum of research fields and technologies in space-related conditions can be continuously enhanced at ZARM. In the first of our two talks we will give you an overview about the inner structure of ZARM, as well as the service and the operation offered by the ZARM Drop Tower Operation and Service Company (ZARM FAB mbH). The ZARM FAB mbH owned by the State Government of Bremen is a public company maintaining the drop tower facility and supporting experimentalists in scientific and technical questions before, during and after their drop or catapult campaigns. In detail, we will present you important technical drop tower informations, our support and the idea, how you can proceed with your microgravity-related experiment including all your requirements to successfully accomplish an entire drop or catapult campaign. In summary, we will illustrate the complete procedure, how to drop or to catapult an experiment capsule at the Drop Tower Bremen.

Quantifying the local influence at a tall tower site in nocturnal conditions

DOE PAGES

Werth, David; Buckley, Robert; Zhang, Gengsheng; ...

2015-10-17

The influence of the local terrestrial environment on nocturnal atmospheric CO 2 measurements at a 329-m television transmitter tower (and a component of a CO 2 monitoring network) was estimated in this paper with a tracer release experiment and a subsequent simulation of the releases. This was done to characterize the vertical transport of emissions from the surface to the uppermost tower level and how it is affected by atmospheric stability. The tracer release experiment was conducted over two nights in May of 2009 near the Department of Energy’s Savannah River Site (SRS) in South Carolina. Tracer was released onmore » two contrasting nights—slightly stable and moderately stable—from several upwind surface locations. Measurements at the 329-m level on both nights indicate that tracer was able to mix vertically within a relatively short (~24 km) distance, implying that nocturnal stable conditions do not necessarily prevent vertical dispersion in the boundary layer and that CO 2 measurements at the tower are at least partly influenced by nearby emissions. A simulation of the tracer release is used to calculate the tower footprint on the two nights to estimate the degree to which the local domain affects the tower readings. The effect of the nocturnal boundary layer on the area sampled by the tower can be seen clearly, as the footprints were affected by changes in stability. Finally, the contribution of local sources to the measurements at the tower was minimal, however, suggesting that nocturnal concentrations at upper levels are contributed mostly by regional sources.« less

Adaptation of amoebae to cooling tower biocides.

PubMed

Srikanth, S; Berk, S G

1994-05-01

Adaptation of amoebae to four cooling tower Biocides, which included a thiocarbamate compound, tributyltin neodecanoate mixed with quaternary ammonium compounds (TBT/QAC), another QAC alone, and an isothiazolin derivative, was studied. Previously we found that amoebae isolated from waters of cooling towers were more resistant to cooling tower biocides than amoebae from other habitats. Acanthamoeba hatchetti and Cochliopodium bilimbosum, obtained from American Type Culture Collection and used in the previous studies, were tested to determine whether they could adapt to cooling tower Biocides. A. hatchetti was preexposed to subinhibitory concentrations of the four Biocides for 72h, after which they were tested for their resistance to the same and other biocides. C. bilimbosum was exposed to only two biocides, as exposure to the other two was lethal after 72 h. Preexposure to the subinhibitory concentrations of the Biocides increased the resistance of the amoebae, as indicated by a significant increase in the minimum inhibitory concentration (up to 30-fold). In addition, cross-resistance was also observed, i.e., exposure to one biocide caused resistance to other biocides. These results show that amoebae can adapt to biocides in a short time. The phenomenon of cross-resistance indicates that regularly alternating biocides, as is done to control microbial growth in cooling towers, may not be effective in keeping amoeba populations in check. On the contrary, exposure to one biocide may boost the amoebae's resistance to a second biocide before the second biocide is used in the cooling tower. Since amoebae may harbor Legionella, or alone cause human diseases, these results may be important in designing effective strategies for controlling pathogens in cooling towers.

Quantifying the local influence at a tall tower site in nocturnal conditions

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

Werth, David; Buckley, Robert; Zhang, Gengsheng

The influence of the local terrestrial environment on nocturnal atmospheric CO 2 measurements at a 329-m television transmitter tower (and a component of a CO 2 monitoring network) was estimated with a tracer release experiment and a subsequent simulation of the releases. This was done to characterize the vertical transport of emissions from the surface to the uppermost tower level and how it is affected by atmospheric stability. The tracer release experiment was conducted over two nights in May of 2009 near the Department of Energy’s Savannah River Site (SRS) in South Carolina. Tracer was released on two contrasting nights—slightlymore » stable and moderately stable—from several upwind surface locations. Measurements at the 329-m level on both nights indicate that tracer was able to mix vertically within a relatively short (~24 km) distance, implying that nocturnal stable conditions do not necessarily prevent vertical dispersion in the boundary layer and that CO 2 measurements at the tower are at least partly influenced by nearby emissions. A simulation of the tracer release is used to calculate the tower footprint on the two nights to estimate the degree to which the local domain affects the tower readings. The effect of the nocturnal boundary layer on the area sampled by the tower can be seen clearly, as the footprints were affected by changes in stability. The contribution of local sources to the measurements at the tower was minimal, however, suggesting that nocturnal concentrations at upper levels are contributed mostly by regional sources.« less

Quantifying the local influence at a tall tower site in nocturnal conditions

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

Werth, David; Buckley, Robert; Zhang, Gengsheng

The influence of the local terrestrial environment on nocturnal atmospheric CO 2 measurements at a 329-m television transmitter tower (and a component of a CO 2 monitoring network) was estimated in this paper with a tracer release experiment and a subsequent simulation of the releases. This was done to characterize the vertical transport of emissions from the surface to the uppermost tower level and how it is affected by atmospheric stability. The tracer release experiment was conducted over two nights in May of 2009 near the Department of Energy’s Savannah River Site (SRS) in South Carolina. Tracer was released onmore » two contrasting nights—slightly stable and moderately stable—from several upwind surface locations. Measurements at the 329-m level on both nights indicate that tracer was able to mix vertically within a relatively short (~24 km) distance, implying that nocturnal stable conditions do not necessarily prevent vertical dispersion in the boundary layer and that CO 2 measurements at the tower are at least partly influenced by nearby emissions. A simulation of the tracer release is used to calculate the tower footprint on the two nights to estimate the degree to which the local domain affects the tower readings. The effect of the nocturnal boundary layer on the area sampled by the tower can be seen clearly, as the footprints were affected by changes in stability. Finally, the contribution of local sources to the measurements at the tower was minimal, however, suggesting that nocturnal concentrations at upper levels are contributed mostly by regional sources.« less

Atmospheric stability effects on wind fields and scalar mixing within and just above a subalpine forest in sloping terrain

USGS Publications Warehouse

Burns, Sean P.; Sun, Jielun; Lenschow, D.H.; Oncley, S.P.; Stephens, B.B.; Yi, C.; Anderson, D.E.; Hu, Jiawen; Monson, Russell K.

2011-01-01

Air temperature Ta, specific humidity q, CO2 mole fraction ??c, and three-dimensional winds were measured in mountainous terrain from five tall towers within a 1 km region encompassing a wide range of canopy densities. The measurements were sorted by a bulk Richardson number Rib. For stable conditions, we found vertical scalar differences developed over a "transition" region between 0.05 < Rib < 0.5. For strongly stable conditions (Rib > 1), the vertical scalar differences reached a maximum and remained fairly constant with increasing stability. The relationships q and ??c have with Rib are explained by considering their sources and sinks. For winds, the strong momentum absorption in the upper canopy allows the canopy sublayer to be influenced by pressure gradient forces and terrain effects that lead to complex subcanopy flow patterns. At the dense-canopy sites, soil respiration coupled with wind-sheltering resulted in CO2 near the ground being 5-7 ??mol mol-1 larger than aloft, even with strong above-canopy winds (near-neutral conditions). We found Rib-binning to be a useful tool for evaluating vertical scalar mixing; however, additional information (e.g., pressure gradients, detailed vegetation/topography, etc.) is needed to fully explain the subcanopy wind patterns. Implications of our results for CO2 advection over heterogenous, complex terrain are discussed. ?? 2010 Springer Science+Business Media B.V.

Modification of pure oxygen absorption equipment for concurrent stripping of carbon dioxide

USGS Publications Warehouse

Watten, B.J.; Sibrell, P.L.; Montgomery, G.A.; Tsukuda, S.M.

2004-01-01

The high solubility of carbon dioxide precludes significant desorption within commercial oxygen absorption equipment. This operating characteristic of the equipment limits its application in recirculating water culture systems despite its ability to significantly increase allowable fish loading rates (kg/(L min)). Carbon dioxide (DC) is typically removed by air stripping. This process requires a significant energy input for forced air movement, air heating in cold climates and water pumping. We developed a modification for a spray tower that provides for carbon dioxide desorption as well as oxygen absorption. Elimination of the air-stripping step reduces pumping costs while allowing dissolved nitrogen to drop below saturation concentrations. This latter response provides for an improvement in oxygen absorption efficiency within the spray tower. DC desorption is achieved by directing head-space gases from the spray tower (O2, N2, CO2) through a sealed packed tower scrubber receiving a 2 N NaOH solution. Carbon dioxide is selectively removed from the gas stream, by chemical reaction, forming the product Na 2CO3. Scrubber off-gas, lean with regard to carbon dioxide but still rich with oxygen, is redirected through the spray tower for further stripping of DC and absorption of oxygen. Make-up NaOH is metered into the scrubbing solution sump on an as needed basis as directed by a feedback control loop programmed to maintain a scrubbing solution pH of 11.4-11.8. The spent NaOH solution is collected, then regenerated for reuse, in a batch process that requires relatively inexpensive hydrated lime (Ca(OH)2). A by-product of the regeneration step is an alkaline filter cake, which may have use in bio-solids stabilization. Given the enhanced gas transfer rates possible with chemical reaction, the required NaOH solution flow rate through the scrubber represents a fraction of the spray tower water flow rate. Further, isolation of the water being treated from the atmosphere (1), allows for an improvement in oxygen absorption efficiency by maintaining DN well below local saturation concentrations (2), minimizes building energy requirements related to heating and ventilation and (3), reduces the potential for pathogen transmittance. We report on the performance of a test scrubber evaluated over a range of NaOH solution temperatures, pH, packing irrigation rates, and gas stream compositions. We also describe our experience with the process in a pilot scale recirculating water (trout) production system.

10 CFR Appendix J to Part 110 - Illustrative List of Uranium Conversion Plant Equipment and Plutonium Conversion Plant Equipment...

Code of Federal Regulations, 2010 CFR

2010-01-01

... reactors, flame tower reactors, liquid centrifuges, distillation columns and liquid-liquid extraction... to UF6 is performed by exothermic reaction with fluorine in a tower reactor. UF6 is condensed from..., flame tower reactors, liquid centrifuges, distillation columns and liquid-liquid extraction columns. Hot...

PBF Cooling Tower. View of stairway to fan deck. Vents ...

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

PBF Cooling Tower. View of stairway to fan deck. Vents are made of redwood. Camera facing southwest toward north side of Cooling Tower. Siding is corrugated asbestos concrete. Photographer: Kirsh. Date: June 6, 1969. INEEL negative no. 69-3463 - Idaho National Engineering Laboratory, SPERT-I & Power Burst Facility Area, Scoville, Butte County, ID

Detail of conning tower atop the submarine. Note the wire ...

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

Detail of conning tower atop the submarine. Note the wire rope wrapped around the base of the tower, which may have been used in an attempt to pull the submarine offshore. - Sub Marine Explorer, Located along the beach of Isla San Telmo, Pearl Islands, Isla San Telmo, Former Panama Canal Zone, CZ

PBF. Oblique and contextual view of PBF Cooling Tower, PER720. ...

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

PBF. Oblique and contextual view of PBF Cooling Tower, PER-720. Camera facing northeast. Auxiliary Building (PER-624) abuts Cooling Tower. Demolition equipment has arrived. Date: August 2003. INEEL negative no. HD-35-11-2 - Idaho National Engineering Laboratory, SPERT-I & Power Burst Facility Area, Scoville, Butte County, ID

PBF Cooling Tower contextual view. Camera facing southwest. West wing ...

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

PBF Cooling Tower contextual view. Camera facing southwest. West wing and north facade (rear) of Reactor Building (PER-620) is at left; Cooling Tower to right. Photographer: Kirsh. Date: November 2, 1970. INEEL negative no. 70-4913 - Idaho National Engineering Laboratory, SPERT-I & Power Burst Facility Area, Scoville, Butte County, ID

1. OVERALL VIEW OF ANTENNA TOWERS S109, S110 AND S111 ...

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

1. OVERALL VIEW OF ANTENNA TOWERS S-109, S-110 AND S-111 FACING NORTH. TRANSMITTER BUILDING (BLDG NO. 1) IN THE CENTER OF PHOTO AND THE WAIANAE MOUNTAIN RANGE IN THE BACKGROUND. - U.S. Naval Base, Pearl Harbor, Lualualei Radio Transmitter, Edison & Tower Drives, Pearl City, Honolulu County, HI

Sequoias, Mavericks, Open Doors...Composing Joan Tower

ERIC Educational Resources Information Center

Allsup, Randall Everett

2011-01-01

This essay interview with Joan Tower is a meditation on the importance of composing, understood as a process larger than the making of new sound combinations or musical scores, suggesting that the compositional act is self-educative and self-forming. Tower's musical life, one of teaching and learning, one of composing and self-composing, is an…

76 FR 67059 - Addition of Certain Persons on the Entity List: Addition of Persons Acting Contrary to the...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-10-31

... Room 1702, Tower B, Honesty Building, Humen, Dongguan, Guangdong, China (See alternate addresses under...Tian District, Shenzhen, China; and Room 1702, Tower B, Honesty Building, Humen, Dongguan, Guangdong...., CaiTian Rd., FuTian District, Shenzhen, China; and Room 1702, Tower B, Honesty Building, Humen...

PBF Cooling Tower. Camera facing southwest. Round piers will support ...

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

PBF Cooling Tower. Camera facing southwest. Round piers will support Tower's wood "fill" or "packing." Black-topped stack in far distance is at Idaho Chemical Processing Plant. Photographer: John Capek. Date: October 16, 1968. INEEL negative no. 68-4097 - Idaho National Engineering Laboratory, SPERT-I & Power Burst Facility Area, Scoville, Butte County, ID

Concentrating Solar Power Projects - Golden Tower 100MW Molten Salt project

Science.gov Websites

| Concentrating Solar Power | NREL Golden Tower 100MW Molten Salt project Status Date Turbine Capacity: Net: 100.0 Gross: 100.0 Status: Under development Do you have more information , corrections, or comments? Background Technology: Power tower Status: Under development Country: China City

Concentrating Solar Power Projects - Yumen 100MW Molten Salt Tower CSP

Science.gov Websites

project | Concentrating Solar Power | NREL 100MW Molten Salt Tower CSP project Status Date Turbine Capacity: Net: 100.0 MW Gross: 100.0 MW Status: Under development Do you have more information , corrections, or comments? Background Technology: Power tower Status: Under development Country: China City

BOREAS TF-3 NSA-OBS Tower Flux, Meteorological, and Soil Temperature Data

NASA Technical Reports Server (NTRS)

Wofsy, Steven; Sutton, Doug; Goulden, Mike; Hall, Forrest G. (Editor); Huemmrich, Karl (Editor)

2000-01-01

The BOReal Ecosystem-Atmosphere Study Tower Flux (BOREAS TF-3) team collected tower flux, surface meteorological, and soil temperature data at the BOREAS Northern Study Area-Old Black Spruce (NSA-OBS) site continuously from the March 1994 through October 1996. The data are available in tabular ASCII files.

84. INDIAN HOUSE TOWER, FROM THE EAST. ALSO SHOWS THE ...

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

84. INDIAN HOUSE TOWER, FROM THE EAST. ALSO SHOWS THE BALCONY AND ARCADE OF THE WEST WING. THE TOWER WAS ADDED IN 1916. SAME VIEW AS PA-107-10. - Moravian Pottery & Tile Works, Southwest side of State Route 313 (Swamp Road), Northwest of East Court Street, Doylestown, Bucks County, PA

In Hot Water: A Cooling Tower Case Study

ERIC Educational Resources Information Center

Cochran, Justin; Raju, P. K.; Sankar, Chetan

2005-01-01

Problem Statement: Vogtle Electric Generating Plant operated by Southern Nuclear Operating Company, a subsidiary of Southern Company, has found itself at a decision point. Vogtle depends on their natural draft cooling towers to remove heat from the power cycle. Depending on the efficiency of the towers, the cycle can realize more or less power…

Confusion at the Tower

ERIC Educational Resources Information Center

Li, Loretta F.

2014-01-01

This study will explore the omission of the Tower of Babel narrative from middle and secondary school world history, world studies, and world geography textbooks and will consider what might be learned from inclusion of the story in the curriculum. A total of 17 textbooks are analyzed. The Tower of Babel narrative is examined within the context of…

OVERVIEW OF AERIAL TRAM SUPPORT TOWERS NINE, TEN, AND DEEP ...

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

OVERVIEW OF AERIAL TRAM SUPPORT TOWERS NINE, TEN, AND DEEP RAVINE,LOOKING SOUTH FROM BREAK OVER TOWER LOCATION. A SINGLE ORE BUCKET HANGS FROM THE CABLE AT CENTER. DEATH VALLEY'S FLOOR IS IN THE DISTANCE (TOP). - Keane Wonder Mine, Park Route 4 (Daylight Pass Cutoff), Death Valley Junction, Inyo County, CA

14 CFR 91.127 - Operating on or in the vicinity of an airport in Class E airspace.

Code of Federal Regulations, 2010 CFR

2010-01-01

... established for that airport in part 93 of this chapter. (c) Communications with control towers. Unless... airport having an operational control tower unless two-way radio communications are maintained between that aircraft and the control tower. Communications must be established prior to 4 nautical miles from...

47 CFR 87.349 - Frequencies.

Code of Federal Regulations, 2010 CFR

2010-10-01

... stations on a noninterference basis at airports which have a part-time control tower, part-time RCO or part-time FAA flight service station and a unicom. (c) At airports which have a unicom but no control tower... described in subpart G of this part. (d) At airports which have no control tower, RCO, flight service...

A Strategy of Suppressing the Underground Impact Scattered Current in Power Grid by Using Insulation Baffle

NASA Astrophysics Data System (ADS)

Zhan, Qinghua; Chen, Zhucheng; Li, Hongtao; Liu, Yijun; Mei, Cheng; He, Zhijie

2017-05-01

In order to solve the accidents happened in the ponds or other special places around the tower which were caused by the diffusion current after lightning stroke the transmission tower, the protection measures for the problem tower in the area of Guangdong Province which occurred dead fish in the pond in thunderstorm weather were studied in this paper. The COMSOL mutiphysics simulation software was used in order to calculate the electromagnetic environment of the diffusion situation by grounding device after lightning stroke the power transmission tower. Study concluded that the safe distance between the fish pond and grounding device of transmission tower is 14 meter. The effects of the length and depth or stayed a gap of the insulation baffle on the fish in the fish pond were discussed. The protection method of the insulation baffle has important practical significance to the protection of the grounding device for diffusion current, and can provide some engineering guidance and basis for the grounding arrangement and transformation of the high voltage transmission line tower.

Seismic risk assessment of Trani's Cathedral bell tower in Apulia, Italy

NASA Astrophysics Data System (ADS)

Diaferio, Mariella; Foti, Dora

2017-09-01

The present paper deals with the evaluation of the seismic vulnerability of slender historical buildings; these structures, in fact, may manifest a high risk with respect to seismic actions as usually they have been designed to resist to gravitational loads only, and are characterized by a high flexibility. To evaluate this behavior, the bell tower of the Trani's Cathedral is investigated. The tower is 57 m tall and is characterized by an unusual building typology, i.e., the walls are composed of a concrete core coupled with external masonry stones. The dynamic parameters and the mechanical properties of the tower have been evaluated on the basis of an extensive experimental campaign that made use of ambient vibration tests and ground penetrating radar tests. Such data have been utilized to calibrate a numerical model of the examined tower. A linear static analysis, a dynamic analysis and a nonlinear static analysis have been carried out on such model to evaluate the displacement capacity of the tower and the seismic risk assessment in accordance with the Italian guidelines.

Floating wind turbine system

NASA Technical Reports Server (NTRS)

Viterna, Larry A. (Inventor)

2009-01-01

A floating wind turbine system with a tower structure that includes at least one stability arm extending therefrom and that is anchored to the sea floor with a rotatable position retention device that facilitates deep water installations. Variable buoyancy for the wind turbine system is provided by buoyancy chambers that are integral to the tower itself as well as the stability arm. Pumps are included for adjusting the buoyancy as an aid in system transport, installation, repair and removal. The wind turbine rotor is located downwind of the tower structure to allow the wind turbine to follow the wind direction without an active yaw drive system. The support tower and stability arm structure is designed to balance tension in the tether with buoyancy, gravity and wind forces in such a way that the top of the support tower leans downwind, providing a large clearance between the support tower and the rotor blade tips. This large clearance facilitates the use of articulated rotor hubs to reduced damaging structural dynamic loads. Major components of the turbine can be assembled at the shore and transported to an offshore installation site.

The nominal cooling tower

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

Burger, R.

1995-12-31

The heat Rejection Industry defines a nominal cooling tower as circulating three gallons of water per minute (GPM) per ton of refrigeration from entering the tower at 95{degrees}F. Hot Water temperature (HWT) Leaving at 85{degrees}F Cold Water Temperature (CWT) at a Design Wet Bulb of 70{degrees}F (WBT). Manufacturers then provide a selection chart based on various wet bulb temperatures and HWTs. The wet bulb fluctuates and varies through out the world since it is the combination ambient temperature, relative humidity, and/or dew point. Different HWT and CWT requirements are usually charted as they change, so that the user can selectmore » the nominal cooling tower model recommended by the manufacturer. Ask any HVAC operator, refinery manager, power generating station operator what happens when the Wet Bulb reaches or exceeds the design WBT of the area. He probably will tell you, {open_quotes}My cooling tower works quite well, but in the summer time, I usually have trouble with it.{close_quotes} This occurs because he is operating a nominal cooling tower.« less

Pressure gradients fail to predict diffusio-osmosis

NASA Astrophysics Data System (ADS)

Liu, Yawei; Ganti, Raman; Frenkel, Daan

2018-05-01

We present numerical simulations of diffusio-osmotic flow, i.e. the fluid flow generated by a concentration gradient along a solid-fluid interface. In our study, we compare a number of distinct approaches that have been proposed for computing such flows and compare them with a reference calculation based on direct, non-equilibrium molecular dynamics simulations. As alternatives, we consider schemes that compute diffusio-osmotic flow from the gradient of the chemical potentials of the constituent species and from the gradient of the component of the pressure tensor parallel to the interface. We find that the approach based on treating chemical potential gradients as external forces acting on various species agrees with the direct simulations, thereby supporting the approach of Marbach et al (2017 J. Chem. Phys. 146 194701). In contrast, an approach based on computing the gradients of the microscopic pressure tensor does not reproduce the direct non-equilibrium results.

Applications to determine the shortest tower BTS distance using Dijkstra algorithm

NASA Astrophysics Data System (ADS)

Mardana, Herwin; Maharani, Septya; Hatta, Heliza Rahmania

2017-02-01

Telecommunications Tower or so-called BTS (Base Transceiver System) Toweris one of the main components in the network infrastructure that has experienced an increase in the number of construction. Telecommunications tower function as a place to put the antenna signal transmitter (access network) to provide communication services to customers around the tower. In addition, other use of telecommunications tower also to place the transmission signal antenna (transport network using microwave technology) for connecting customers with a central area. Therefore, in needed of a decision support system that can provide recommendations planting route of fiber optic cable with the shortest distance in purpose the use of fiber optic cable becoming more efficient. The results of the research were the shortest rule information, showing the distance to be travelled and the map view to enabling users to look at these.

The development of the architectural form of a tower derived from a traditional and philosophical symbol, realized by solutions of high-class technologies. The case of the Bitexco Financial Tower

NASA Astrophysics Data System (ADS)

Van Khai, Tran

2018-03-01

The Bitexco Financial Tower, majestically standing tall in the heart of Ho Chi Minh City, Vietnam, rejects the box-shaped, abstract forms of modernism, incorporating an innovative idea of contemporary architecture. Based on the inspiration from the Bitexco Group, a renowned architect designedthe tower that became an iconic landmark of the city in the form of a lotus bud, one of the most iconic symbols of Vietnamese culture since ancient times. High class structural system solution designed by top international professional teams enable the building to rise high with its graceful, statuesque design of the lotus flower shape. CNNGo recently ranked the Bitexco Financial Tower fifth in their listing of the world's 20 most-iconic skyscrapers.

Ground Monitoring Neotropical Dry Forests: A Sensor Network for Forest and Microclimate Dynamics in Semi-Arid Environments (Enviro-Net°)

NASA Astrophysics Data System (ADS)

Rankine, C. J.; Sánchez-Azofeifa, G.

2011-12-01

In the face of unprecedented global change driven by anthropogenic pressure on natural systems it has become imperative to monitor and better understand potential shifts in ecosystem functioning and services from local to global scales. The utilization of automated sensors technologies offers numerous advantages over traditional on-site ecosystem surveying techniques and, as a result, sensor networks are becoming a powerful tool in environmental monitoring programs. Tropical forests, renowned for their biodiversity, are important regulators of land-atmosphere fluxes yet the seasonally dry tropical forests, which account for 40% of forested ecosystems in the American tropics, have been severely degraded over the past several decades and not much is known of their capacity to recover. With less than 1% of these forests protected, our ability to monitor the dynamics and quantify changes in the remaining primary and recovering secondary tropical dry forests is vital to understanding mechanisms of ecosystem stress responses and climate feedback with respect to annual productivity and desertification processes in the tropics. The remote sensing component of the Tropi-Dry: Human and Biophysical Dimensions of Tropical Dry Forests in the Americas research network supports a network of long-term tropical ecosystem monitoring platforms which focus on the dynamics of seasonally dry tropical forests in the Americas. With over 25 sensor station deployments operating across a latitudinal gradient in Mexico, Costa Rica, Brazil, and Argentina continuously collecting hyper-temporal sensory input based on standardized deployment parameters, this monitoring system is unique among tropical environments. Technologies used in the network include optical canopy phenology towers, understory wireless sensing networks, above and below ground microclimate stations, and digital cameras. Sensory data streams are uploaded to a cyber-infrastructure initiative, denominated Enviro-Net°, for data storage, management, visualization, and retrieval for further analysis. The use of tower and ground-based optical sensor networks and meteorological monitoring instrumentation has proven effective in capturing seasonal growth patterns in primary and secondary forest stands. Furthermore, the observed trends in above and below ground microclimate variables are shown to closely correlate with in-situ vegetative indices (NDVI and EVI) across study sites. These long-term environmental sensory data streams provide valuable insights as to how these threatened semi-arid ecosystems regenerate after disturbances and how they respond to environmental stress such as climate change in the tropical and sub-tropical latitudes.

Validation of the Dynamic Wake Meander model with focus on tower loads

NASA Astrophysics Data System (ADS)

Larsen, T. J.; Larsen, G. C.; Pedersen, M. M.; Enevoldsen, K.; Madsen, H. A.

2017-05-01

This paper presents a comparison between measured and simulated tower loads for the Danish offshore wind farm Nysted 2. Previously, only limited full scale experimental data containing tower load measurements have been published, and in many cases the measurements include only a limited range of wind speeds. In general, tower loads in wake conditions are very challenging to predict correctly in simulations. The Nysted project offers an improved insight to this field as six wind turbines located in the Nysted II wind farm have been instrumented to measure tower top and tower bottom moments. All recorded structural data have been organized in a database, which in addition contains relevant wind turbine SCADA data as well as relevant meteorological data - e.g. wind speed and wind direction - from an offshore mast located in the immediate vicinity of the wind farm. The database contains data from a period extending over a time span of more than 3 years. Based on the recorded data basic mechanisms driving the increased loading experienced by wind turbines operating in offshore wind farm conditions have been identified, characterized and modeled. The modeling is based on the Dynamic Wake Meandering (DWM) approach in combination with the state-of-the-art aeroelastic model HAWC2, and has previously as well as in this study shown good agreement with the measurements. The conclusions from the study have several parts. In general the tower bending and yaw loads show a good agreement between measurements and simulations. However, there are situations that are still difficult to match. One is tower loads of single-wake operation near rated ambient wind speed for single wake situations for spacing’s around 7-8D. A specific target of the study was to investigate whether the largest tower fatigue loads are associated with a certain downstream distance. This has been identified in both simulations and measurements, though a rather flat optimum is seen in the measurements.

Quantifying the contribution of root systems to community and individual drought resilience in the Amazon rainforest

NASA Astrophysics Data System (ADS)

Agee, E.; Ivanov, V. Y.; Oliveira, R. S.; Brum, M., Jr.; Saleska, S. R.; Bisht, G.; Prohaska, N.; Taylor, T.; Oliveira Junior, R. C.; Restrepo-Coupe, N.

2017-12-01

The increased intensity and severity of droughts within the Amazon Basin region has emphasized the question of vulnerability and resilience of tropical forests to water limitation. During the recent 2015-2016 drought caused by the anomalous El Nino episode, we monitored a large, diverse sample of trees within the Tapajos National Forest, Brazil, in the footprint of the K67 eddy covariance tower. The observed trees exhibited differential responses in terms of stem water potential and sap flow among species: their regulation of ecophysiological strategies varied from very conservative (`isohydric') behavior, to much less restrained, atmosphere-controlled (`anisohydric') type of response. While much attention has been paid to forest canopies, it remains unclear how the regulation of individual tree root system and root spatial interactions contribute to the emergent individual behavior and the ecosystem-scale characterization of drought resilience. Given the inherent difficulty in monitoring below-ground phenomena, physically-based models are valuable for examining different strategies and properties to reduce the uncertainty of characterization. We use a modified version of the highly parallel DOE PFLOTRAN model to simulate the three-dimensional variably saturated flows and root water uptake for over one thousand individuals within a two-hectare area. Root morphology and intrinsic hydraulic properties are assigned based on statistical distributions developed for tropical trees, which account for the broad spectrum of hydraulic strategies in biodiverse environments. The results demonstrate the dynamic nature of active zone of root water uptake based on local soil water potential gradients. The degree of the corresponding shifts in uptake and root collar potential depend not only on assigned hydraulic properties but also on spatial orientation and size relative to community members. This response highlights the importance of not only tree individual hydraulic traits, but also dynamic spatial interactions in assessing forest drought resilience.

Combination film/splash fill for overcoming film fouling

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

Phelps, P.M.; Minett, T.O.

1995-02-01

In summary, this large cooling tower user has found the Phelps film/splash Stack-Pack fill design to attain a substantial improvement in capability of their existing crossflow cooling towers, without increasing fan power or tower size. The lack of fouling in the film fill component of this fill design is due to the use of film fill with large (1 inch) spacing between sheets, coupled with effective water treatment as provided by Nalco. This combination of factors provides a proven method for significantly increasing crossflow or counterflow cooling tower capability while minimizing chances of serious fill fouling.

Distinct difference of flaA genotypes of Legionella pneumophila between isolates from bath water and cooling tower water.

PubMed

Amemura-Maekawa, Junko; Kura, Fumiaki; Chang, Bin; Suzuki-Hashimoto, Atsuko; Ichinose, Masayuki; Endo, Takuro; Watanabe, Haruo

2008-09-01

To investigate the genetic difference of Legionella pneumophila in human-made environments, we collected isolates of L. pneumophila from bath water (n = 167) and cooling tower water (n = 128) primarily in the Kanto region in 2001 and 2005. The environmental isolates were serogrouped and sequenced for a target region of flaA. A total of 14 types of flaA genotypes were found: 10 from cooling tower water and nine from bath water. The flaA genotypes of isolates from cooling tower water were quite different from those of bath water.

KSC-2010-1367

NASA Image and Video Library

2010-01-19

CAPE CANAVERAL, Fla. – At NASA's Kennedy Space Center in Florida, preparations are under way to install the ninth tower segment of a new mobile launcher, or ML, being constructed to support the Constellation Program, on the top of the growing tower. When completed, the tower will be approximately 345 feet tall and have multiple platforms for personnel access. Its base is being made lighter than space shuttle mobile launcher platforms so the crawler-transporter can pick up the heavier load of the tower and a taller rocket. For information on the Constellation Program, visit http://www.nasa.gov/constellation. Photo credit: NASA/Jack Pfaller

LDSD on the Launch Tower

NASA Image and Video Library

2015-06-05

NASA's Low-Density Supersonic Decelerator (LDSD) hangs from a launch tower at U.S. Navy's Pacific Missile Range Facility in Kauai, Hawaii. The saucer-shaped vehicle will test two devices for landing heavy payloads on Mars: an inflatable donut-shaped device and a supersonic parachute. The launch tower helps link the vehicle to a balloon; once the balloon floats up, the vehicle is released from the tower and the balloon carries it to high altitudes. The vehicle's rocket takes it to even higher altitudes, to the top of the stratosphere, where the supersonic test begins. http://photojournal.jpl.nasa.gov/catalog/PIA19343