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Sample records for air stripping tower

  1. Analysis of mass transfer performance in an air stripping tower

    SciTech Connect

    Chung, T.W.; Lai, C.H.; Wu, H.

    1999-10-01

    The carryover of working solution in a traditional stripping tower is of serious concern in real applications. A U-shaped spray tower to prevent carryover has been designed to study the stripping of water vapor from aqueous desiccant solutions of 91.8 to 95.8 wt% triethylene glycol. In this study, water vapor was removed from the diluted desiccant solution by heating the solution and stripping it with the ambient air. Therefore, the solution was concentrated to a desired concentration. This spray tower was capable of handling air flow rates from 3.2 to 5.13 kg/min and liquid flow rates from 1.6 to 2.76 kg/min. Since the literature data on air stripping towers are limited, studies on the mass transfer coefficient and other mass transfer parameters were carried out in this study. Under the operating conditions, the overall mass transfer coefficient calculated from the experimental data varied from 0.053 to 0.169 mol/m{sup 3}{center{underscore}dot}s. These corresponded to heights of a transfer unit of 2.3 to 0.71 m, respectively. The rates of stripping in this spray tower were typically varied from 2.28 to 12.15 kg H{sub 2}O/h. A correlation of the mass transfer coefficient for the air stripping process was also developed in this study.

  2. Cross-flow versus counterflow air-stripping towers

    SciTech Connect

    Little, J.C.; Marinas, B.J.

    1997-07-01

    Mass-transfer and pressure-drop packing performance correlations are used together with tower design equations and detailed cost models to compare the effectiveness of cross-flow and counterflow air stripping towers over a wide range of contaminant volatility. Cross-flow towers are shown to offer a significant economic advantage over counterflow towers when stripping low volatility organic contaminants primarily due to savings in energy costs. These savings increase as contaminant volatility decreases and as water flow rate increases. A further advantage of the cross-flow configuration is that it extends the feasible operating range for air stripping as cross-flow towers can accommodate higher air-to-water flow ratios than conventional counterflow towers. Finally it is shown that the optimized least-cost design for both counterflow and cross-flow towers varies with Henry`s law constant, water flow rate, and percent removal, but that the optimum is virtually insensitive to other cost and operating variables. This greatly simplifies the tower design procedure.

  3. Stripping of phenols in model cooling towers

    SciTech Connect

    Turner, C.D.; Moe, T.A.; Wentz, C.A.

    1987-01-01

    Cooling towers are used to remove waste heat from unit operations in chemical processing plants. Using cooling towers for wastewater treatment and disposal through internal recycling has become an important alternative because of stricter wastewater discharge standards, the expense of specialized wastewater treatment systems and the limited availability and cost of water in arid regions. Designs for synfuels plants must address the problem of wastewater disposal. Alternative systems under consideration usually include zero discharge designs that incorporate evaporative cooling towers in the system. The mechanisms for contaminant removal in cooling towers are biological oxidation, stripping and chemical precipitation. Chemical precipitation is generally considered undesirable because of losses in heat transfer efficiency. Predicting whether stripping or biological oxidation will be the primary removal mechanism for phenolic compounds from coal conversion wastewaters used as makeup in cooling towers does not appear to be possible based on the results of these tests. The tests do indicate that the biological oxidation of phenol is possible in forced draft cooling towers.

  4. Air stripping industrial wastewater

    SciTech Connect

    Lamarre, B.; Shearouse, D.

    1994-09-01

    Industrial wastewater can be quickly, efficiently and economically treated using air strippers. Air stripping removes a range of volatile and semi-volatile contaminants from water. And the performance of various types and sizes of tray-type air stripper for treating contaminated water now is highly predictable because of laboratory studies. Air stripping can be a fast, efficient and economical approach to treating industrial wastewater. However, since every industrial wastewater stream is unique, each must be evaluated to determine its constituents, its potentially adverse effects on treatability, and any pretreatment steps necessary to ensure desired results. The general principles of air stripping are simple. In an air stripper, the surfaces area of a film of contaminated water is maximized while air is directed across it. Contaminants at the air/water interface volatilize and are discharged to the atmosphere or to an off-gas treatment system.

  5. Membrane air-stripping: Effects of pretreatment

    SciTech Connect

    Castro, K. ); Zander, A.K. . Dept. of Civil and Environmental Engineering)

    1995-03-01

    As a result of the Safe Drinking Water Act and its 1986 amendments, the number of regulated volatile organic chemicals (VOCs) has increased substantially. The discovery of drinking water supply sources contaminated by VOCs is also increasing. These factors have led to the development of alternative treatment methods for control of VOCs. Microporous polypropylene hollow-fiber membranes offer significant advantages over packed-tower aeration for removing volatile organic chemicals. A laboratory study assessed the performance of membrane air-stripping in continuous operation, while exposed to various pretreatments. Results indicate that membrane air-stripping is compatible with low-pH or low-chlorine waters but not with waters of high pH or high-chlorine concentration or those that are ozonated.

  6. Crossflow air stripping with catalytic oxidation. Final report, 1 October 1990-30 September 1994

    SciTech Connect

    Kim, B.C.; Gavaskar, A.R.; Ong, S.K.; Rosansky, S.H.; Cummings, C.A.

    1994-09-30

    A novel air stripping technique was tested on a pilot scale at Dover Air Force Base. Groundwater contaminated with 1,2-dichloroethane was subjected to air stripping in two towers: the novel crossflow tower and the conventional countercurrent tower. The crossflow tower was found to require higher airflow rates but much lower pressure drops to effect the same removal efficiency. The airstream from the towers was directed into bench-scale and pilot-scale commercial catalytic units. An innovative photocatalytic unit also was tested. Five of the six catalysts tested performed well. Air stripping in conjunction with catalytic oxidation was found to be a good technique for remediation of groundwater containing low levels of organics. However the crossflow air stripper did not offer any cost advantages over conventional counterflow air stripping.

  7. Membrane air stripping utilizing a plate and frame configuration

    SciTech Connect

    Boswell, S.T.

    1991-01-01

    Membrane air stripping has recently been proposed as a possible method to remove volatile organic chemicals (VOCs) and radon from drinking water supplies. Current and anticipated regulatory requirements, driven by health consequences, make the removal of these contaminants mandatory. This work examines the use of plate and frame membrane air stripping for the removal of VOCs and radon from a water supply. The theoretical basis of membrane air stripping and a literature review are included. The advantages of membrane air stripping versus other methods of removal, as well as the advantages of a plate and frame configuration versus a hollow fiber configuration for membrane air stripping are discussed. Multiple regression/correlation techniques are used to model mass transfer coefficients and fluid resistances. An economic evaluation is performed using the developed models. The costs of comparable membrane and packed tower air stripping systems are 4.86 cents per thousand gallons versus 4.36 cents per thousand gallons, respectively. This work indicates that plate and frame membrane air stripping may, in fact, prove to be an economical alternative to packed tower aeration and carbon adsorption for the removal of VOCs and radon.

  8. Laboratory investigations of cascade crossflow packed towers for air stripping of volatile organics from ground-water. Final report, 21 Apr 86-24 Aug 89

    SciTech Connect

    Harrison, D.P.; Valsaraj, K.T.; Thibodeaus, L.J.

    1990-12-01

    This report evaluates the effectiveness of a cascade crossflow air stripper for the removal of Volatile Organic Compounds (VOCs) from simulated groundwater. Experimental tests were conducted on four VOCs-methylene chloride, chloroform, 1,2-dichloroethane and carbon tetrachloride - on both a 6-inch internal diameter laboratory scale column and a 12-inch internal diameter pilot-scale column. The additional variable, alpha, which is the ratio of gas to liquid flow areas was investigated. Experimental data on stripping efficiencies were used to obtain mass transfer coefficients in crossflow operation. These mass transfer coefficients were compared with literature correlations obtained for conventional countercurrent operation, but modified appropriately for crossflow. For liquid phase controlled chemicals, the modified Onda's correlation satisfactorily predicted the crossflow mass transfer coefficient.

  9. Air stripping of contaminated water sources - air emissions and controls. Final report

    SciTech Connect

    Vancit, M.A.; Howle, R.H.; Herndon, D.J.; Shareef, S.A.

    1987-08-01

    Air-stripping towers are being used to remove low concentrations of organic contaminants from water. The report describes the technology and methods used to control air pollution resulting from this procedure. The cost of the controls is presented along with other positive and negative impacts of the technology.

  10. Air stripping for treatment of produced water

    SciTech Connect

    Fang, C.S.; Lin, J.H.

    1988-05-01

    In a laboratory study, air stripping shows a promising potential for treatment of produced water to meet new government regulations on total organic carbon (TOC). Reservoir hydrocarbons dissolved in water, such as volatile paraffins and aromatics, can be removed by air stripping through interphase mass transfer. However, air stripping cannot remove many chemicals added to crude oil by the operator.

  11. Air stripping VOCs from groundwater: Process design considerations

    SciTech Connect

    Ball, B.R.; Edwards, M.D. )

    1992-02-01

    Considerations for evaluating and designing the air stripping process are presented by case study. The case study involves the design of an air stripping process to remediate groundwater contaminated with volatile organic compounds (VOCs) at a National Priorities List site in Tacoma, WA. Design objectives included developing a tower with minimum volume and energy requirements while complying with discharge air and water quality standards. A two-phase resistance model using Onda Correlations to determine liquid- and gas-phase mass transfer coefficients was used to assist in the evaluation and design. Considerations for applying the two-phase resistance model to air stripping tower design are presented. The ability of the model to simulate process performance is demonstrated by comparison with actual data for 11 priority pollutant list VOCs evaluated during an onsite pilot study. Design procedures with which to develop a tower with minimum volume and energy requirements are described. Other considerations involving the evaluation of VOC emissions and the precipitation and buildup of inorganic constituents within the internal packing media are described.

  12. Air stripping of ammonia in a water-sparged aerocyclone reactor.

    PubMed

    Quan, Xuejun; Wang, Fuping; Zhao, Qinghua; Zhao, Tiantao; Xiang, Jinxin

    2009-10-30

    Air stripping of ammonia is a widely used process for the pretreatment of wastewater. Scaling and fouling on the packing surface in packed towers and a lower stripping efficiency are the two major problems in this process. New equipment that is suitable for the air stripping of wastewater with suspended solids has been developed. Air stripping of ammonia from water with Ca(OH)2 was performed in the newly designed gas-liquid contactor, a water-sparged aerocyclone (WSA). WSA exhibited a higher air stripping efficiency and an excellent mass transfer performance, it also consumed less air compared with stripping tanks and packed towers. In addition, no scaling and fouling was observed in the inner structure of the WSA. During the stripping process, the stripping efficiency and mass transfer coefficient naturally increases with the liquid phase temperature and air flow rate. There is a critical value for the air flow rate over which stripping efficiency and the mass transfer coefficient increases rapidly. An efficient air stripping of ammonia should be conducted at a higher ambient temperature (>25 degrees C), and a higher air flow rate (>1.4 l/s).

  13. Crossflow air stripping and catalytic oxidation of chlorinated hydrocarbons from groundwater

    SciTech Connect

    Gavaskar, A.R.; Kim, B.C.; Rosansky, S.H.; Ong, S.K.; Marchand, E.G.

    1995-02-01

    This paper describes air stripping of chlorinated hydrocarbon contaminants from groundwater in a crossflow air stripping tower and destruction of the organic compounds by catalytic oxidation. Crossflow stripping has an advantage over conventional countercurrent stripping. In typical stripping operations, the mass transfer coefficient is insensitive to the velocity of the gas stream. The crossflow stripping tower is a geometry that increases the cross section of gas flow while making minimal disturbances to the liquid flow, allowing high gas-liquid ratios without flooding. By increasing the flow cross section for the gas stream, pressure drop (and thus fan power) can be reduced significantly. A field demonstration of the crossflow column was performed at a contaminated groundwater site. The groundwater was pumped out and sent to two 17-ft-high (5.2-m) towers in a parallel arrangement. One tower was a crossflow air stripper and the other a conventional countercurrent design. The performance of the two was compared. The key organic species targeted was dichloroethane, which has a low Henry`s law constant. Three different baffle configurations were tested in the crossflow tower. The results of this demonstration were used to develop design criteria for crossflow air strippers to be used for destruction of halogenated hydrocarbons. 4 refs., 15 figs., 2 tabs.

  14. Air stripping of aqueous solutions. Engineering bulletin

    SciTech Connect

    Not Available

    1991-10-01

    Air stripping is a means to transfer contaminants from aqueous solutions to air. Contaminants are not destroyed by air stripping but are physically separated from the aqueous solutions. Contaminant vapors are transferred into the air stream and, if necessary, can be treated by incineration, adsorption, or oxidation. Most frequently, contaminants are collected in carbon adsorption systems and then treated or destroyed in this concentrated form. The concentrated contaminants may be recovered, incinerated for waste heat recovery, or destroyed by other treatment technologies. Generally, air stripping is used as one in a series of unit operations and can reduce the overall cost for managing a particular site. Air stripping is applicable to volatile and semivolatile organic compounds. It is not applicable for treating metals and inorganic compounds. The bulletin provides information on the technology applicability, the technology limitations, a description of the technology, the types of residuals produced, site requirements, the latest performance data, the status of the technology, and sources of further information.

  15. ENGINEERING BULLETIN: AIR STRIPPING OF AQUEOUS SOLUTIONS

    EPA Science Inventory

    Air striding is a means to transfer contaminants from aqueous solutions to air. ontaminants are not destroyed by air stripping but are physically separated from the aqueous solutions. ontaminant vapors are transferred into the air stream and, if necessary, can be treated by incin...

  16. Ammonia removal from landfill leachate by air stripping and absorption.

    PubMed

    Ferraz, Fernanda M; Povinelli, Jurandyr; Vieira, Eny Maria

    2013-01-01

    An old landfill leachate was pre-treated in a pilot-scale aerated packed tower operated in batch mode for total ammoniacal nitrogen (TAN) removal. The stripped ammonia was recovered with a 0.4 mol L(-1) H2SO4 solution, deionized water and tap water. Ca(OH)2 (95% purity) or commercial hydrated lime was added to the raw leachate to adjust its pH to 11, causing removal of colour (82%) and heavy metals (70-90% for Zn, Fe and Mn). The 0.4 molL(-1) H2SO4 solution was able to neutralize 80% of the stripped ammonia removed from 12 L of leachate. The effectiveness of the neutralization of ammonia with deionized water was 75%. Treating 100 L of leachate, the air stripping tower removed 88% of TAN after 72 h of aeration, and 87% of the stripped ammonia was recovered in two 31 L pilot-scale absorption units filled with 20 L of tap water.

  17. Ammonia removal from landfill leachate by air stripping and absorption.

    PubMed

    Ferraz, Fernanda M; Povinelli, Jurandyr; Vieira, Eny Maria

    2013-01-01

    An old landfill leachate was pre-treated in a pilot-scale aerated packed tower operated in batch mode for total ammoniacal nitrogen (TAN) removal. The stripped ammonia was recovered with a 0.4 mol L(-1) H2SO4 solution, deionized water and tap water. Ca(OH)2 (95% purity) or commercial hydrated lime was added to the raw leachate to adjust its pH to 11, causing removal of colour (82%) and heavy metals (70-90% for Zn, Fe and Mn). The 0.4 molL(-1) H2SO4 solution was able to neutralize 80% of the stripped ammonia removed from 12 L of leachate. The effectiveness of the neutralization of ammonia with deionized water was 75%. Treating 100 L of leachate, the air stripping tower removed 88% of TAN after 72 h of aeration, and 87% of the stripped ammonia was recovered in two 31 L pilot-scale absorption units filled with 20 L of tap water. PMID:24350487

  18. Air stripping of organics from groundwater

    SciTech Connect

    Harrison, D.P.; Valsaraj, K.T.; Wetzel, D.M. . Dept. of Chemical Engineering)

    1993-01-01

    As awareness of the problem of contaminated ground water increases, the demand for reliable and cost-effective treatment processes will also increase. Although a number of treatment options exist or are under development, air stripping using counter current flow in packed columns is the current technology of choice in many situations. This paper reviews the basic principles of packed-column design and defines the limits of counter current contacting when applied to situations in which the resistance to mass transfer in the gas phase is important. The cascade crossflow configuration allows water and air flow to be varied independently, providing added design flexibility. Reductions in pressure drop by as much as two orders of magnitude result in stable column operation at air and water flow rates which would cause flooding in a counter current column. Mass transfer efficiencies comparable to, and in some cases greater than, counter current operation have been measured. Experimental results for cascade crossflow air stripping of 1,2-dichloroethane and methyl ethyl ketone are presented. The gas-phase, mass-transfer resistance is important for both compounds due to their small Henry's constants, 1,2-dichloroethane is considered to be difficult to strip using counter current contacting, while high efficiency air stripping of methyl ethyl ketone is impractical at ambient temperature.

  19. Air stripping. (Latest citations from the NTIS database). Published Search

    SciTech Connect

    Not Available

    1993-04-01

    The bibliography contains citations concerning the application of air stripping techniques to water treatment, including groundwater decontamination and wastewater purification. The advantages and disadvantages of air stripping over other water treatment processes are discussed. Cleanup of the organic emissions generated by air stripping is also considered. The primary applications of air stripping are in groundwater and soil cleanup. (Contains a minimum of 71 citations and includes a subject term index and title list.)

  20. Within compound, from Guard Tower, looking north Beale Air ...

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

    Within compound, from Guard Tower, looking north - Beale Air Force Base, Perimeter Acquisition Vehicle Entry Phased-Array Warning System, End of Spencer Paul Road, north of Warren Shingle Road (14th Street), Marysville, Yuba County, CA

  1. Catalytic treatment of air-stripping effluents

    SciTech Connect

    Kosusko, M.; Mullins, M.E.; Rogers, T.N.; Ramanathan, K.

    1987-12-01

    The paper reviews the applicability of catalytic oxidation to control ground-water air-stripping gaseous effluents with emphasis on system designs and case histories. The contaminants and catalyst poisons encountered in stripping operations are also reviewed. Vapor-phase carbon adsorption and thermal incineration, the treatment methods that have been applied most often, have some disadvantages: adsorption merely transfers the contaminant to a solid phase, which in turn requires disposal or regeneration; and thermal incineration may be expensive, since it requires a substantial energy input to destroy dilute gas-phase contaminants. A new alternative is appearing in the form of catalytic oxidation. Like thermal incineration, it is an ultimate disposal method, but the energy costs are lower.

  2. Source-emissions testing of the air-stripping process, Vance Air Force Base, Oklahoma. Final report, 21 May-25 May 1990

    SciTech Connect

    Binovi, R.D.; Vaughn, R.W.

    1990-08-01

    At the request of HQ ATC/DEEV through HQ ATC/SGPB, source emissions testing for methylene chloride emissions in the air stripping tower vent and tower influent and effluent was performed at the pretreatment facility at Vance AFB on 21-25 May 90. Testing was conducted to provide data for the air quality permit to operate the pretreatment facility's air stripping tower as required by the Oklahoma State Department of Health. Results show the plant has operational problems, based on the percent removal calculations from the wastewater stream. The pretreatment plant is also not meeting the Federal pretreatment standard limits for methylene chloride from a new facility treating metal finishing waste (40 CFR 433.17). Recommendations included: (1) optimizing the plant operations by determining proper coagulant dosage and cleaning the stripping tower; (2) contacting the manufacturer to determine the design efficiency of the stripping tower; if not efficient enough, additional treatment such as carbon absorption needs to be added; and (3) completing another round of emissions testing after the plant's operation has been optimized.

  3. Cascade air-stripping system for removal of low and semi-volatile organic contaminants

    SciTech Connect

    Jang, Won.

    1989-01-01

    Many hazardous waste sites have been known to have groundwaters contaminated with low volatile, hazardous compounds such as bromoform 1,1,2,2-tetrachloroethane, 1,2-dibromo-3-chloropropane (DBCP), napthalene, and polychlorinated biphenyls (PCBs). In addition, a large number of public water supplies have been reported to have taste and odor problems in drinking water, which are attributed primarily to naturally occurring compounds, such as 2-methylisoborneol (MIB), geosmin, etc. These classes of compounds have very low Henry's Constant, H{sub c}, in the range of 1 to 50 atm. Air-stripping in countercurrent packed towers is a well accepted treatment process for removing volatile organic chemicals (VOCs) from water. The USEPA has identified packed countercurrent air-stripping as not only the least-cost, but also one of the best available technologies for the removal of VOCs. However, the economic viability of this process is limited to volatile compounds of H{sub c} value greater than SO atm. A novel modification of the conventional countercurrent air-stripping process, introduced as cascade air-stripping was proposed for cost effective removal of these classes of compounds from water and at hazardous waste spill-sites. The main objectives of this study were to demonstrate the concept of cascade air-stripping; to compare cascade air-stripping with conventional air-stripping under identical conditions; and to verify the hypothesis that the cascade system is superior to the conventional system at the pilot and prototype scales. Results of the pilot and prototype study showed that the cascade airstrip ping system was a viable and economical approach to remove low and semi-volatile organic compounds from water. The cascade system consistently showed higher removals than the conventional system for both pilot and prototype scale study.

  4. Groundwater air stripping: Effect on water toxicity

    SciTech Connect

    Eldridge, R.B.; Simpson, C.W.; Elliott, D.J.

    1995-02-01

    An air stripping unit was designed to reduce groundwater hydrocarbon content and biotoxicity to acceptable levels. A pilot plant study was conducted to determine the water treatability and to optimize the commercial unit design conditions. A measurement of the pilot plant effluent toxicity was obtained from {open_quotes}Microtox{close_quotes} analysis and rigorous bio-assays. These results indicated that reduction of the water hydrocarbon content to permitted discharge limits was accompanied by the elimination of water toxicity. The Onda mass transfer model was used to prepare the commercial unit design. A post-installation evaluation indicated that the model gave a good representation of the commercial unit performance. Toxicity reductions observed in the pilot plant were also observed in the commercial unit. 3 refs., 5 figs., 3 tabs.

  5. Air-stripping effects on cell growth with volatile substrates.

    PubMed

    Singh, N; Hill, G A

    1987-09-01

    The removal of substate molecules from aerobic microbial cultures is due to both consumption by microorganisms and stripping by the air stream. The air stripping component can be described by a constant parameter for low concentrations of volatile substrates. This air stripping parameter was found to have a value of 0.0033 h(-1) for phenol molecules in a typical fermentation situation. The determination and inclusion of this constant is important for modeling microbial growth. For Pseudomonas putida growing on phenol, it is shown that air stripping is responsible for all of the original decline in phenol concentration. Further, the kinetic inhibition constant is sensitive to both the value of the air stripping parameter and the value of the initial concentration of bacteria. The experimental data for Pseudomonas putida growing on phenol was fit by a non-linear, least squares technique to isolate the inhibition constant between 100 and 600 ppm.

  6. Ultralow Concentration Mercury Treatment Using Chemical Reduction and Air Stripping

    SciTech Connect

    Looney, B.B.

    2001-05-21

    Field, laboratory and engineering data confirmed the efficacy of chemical reduction and air stripping as an ultralow concentration mercury treatment concept for water containing Hg(II). The simple process consists of dosing the water with low levels of stannous chloride (Sn(II)) to cover the mercury to Hg degrees. This mercury species can easily be removed from the water by air stripping or sparging.

  7. Air stripping & photocatalytic oxidation: A winning team for groundwater remediation

    SciTech Connect

    Kittrell, J.R.; Quinlan, C.W.

    1995-09-01

    The Dover AFB Groundwater Reclamation Project demonstrated advanced technologies to control groundwater contamination, including comparisons of traditional countercurrent air atrippers to a crossflow air stripping technology. Another demonstration involved an advanced photocatalytic VOC destruction technology, which operates on the effluent air from the stripper. The combination of air stripping and photocatalytic destruction was shown to be effective for remediation of groundwater contaminated with chlorinated organic compounds, both because of its low cost and its ability to prevent toxic air emissions. A detailed performance comparison of stripper designs shows that the crossflow air stripper design was comparable in effectiveness to the conventional countercurrent air stripper at high air-to-water ratios, but at a substantially lower pressure drop.

  8. Sulfide-oxidizing bacteria: Their role during air-stripping

    SciTech Connect

    Dell`Orco, M.J.; Chadik, P.A.; Bitton, G.; Neumann, R.P.

    1998-10-01

    Air-stripping, used to remove hydrogen sulfide naturally present in many groundwater supplies, commonly causes sulfide-oxidizing bacteria to proliferate. The role of sulfide-oxidizing bacteria during air-stripping was investigated in a diffused-air pilot reactor modeled after an existing treatment facility. Visible bacterial filaments and biofilm developed within a few days and increased both the sulfide removed from and turbidity in the effluent. Total sulfide, dissolved oxygen, pH, and electrode potential were monitored at eight locations in the reactor to characterize the process.

  9. 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,…

  10. Distillation and Air Stripping Designs for the Lunar Surface

    NASA Technical Reports Server (NTRS)

    Boul, Peter J.; Lange, Kevin E.; Conger, Bruce; Anderson, Molly

    2009-01-01

    Air stripping and distillation are two different gravity-based methods, which may be applied to the purification of wastewater on the lunar base. These gravity-based solutions to water processing are robust physical separation techniques, which may be advantageous to many other techniques for their simplicity in design and operation. The two techniques can be used in conjunction with each other to obtain high purity water. The components and feed compositions for modeling waste water streams are presented in conjunction with the Aspen property system for traditional stage distillation models and air stripping models. While the individual components for each of the waste streams will vary naturally within certain bounds, an analog model for waste water processing is suggested based on typical concentration ranges for these components. Target purity levels for the for recycled water are determined for each individual component based on NASA s required maximum contaminant levels for potable water Distillation processes are modeled separately and in tandem with air stripping to demonstrate the potential effectiveness and utility of these methods in recycling wastewater on the Moon. Optimum parameters such as reflux ratio, feed stage location, and processing rates are determined with respect to the power consumption of the process. Multistage distillation is evaluated for components in wastewater to determine the minimum number of stages necessary for each of 65 components in humidity condensate and urine wastewater mixed streams. Components of the wastewater streams are ranked by Henry s Law Constant and the suitability of air stripping in the purification of wastewater in terms of component removal is evaluated. Scaling factors for distillation and air stripping columns are presented to account for the difference in the lunar gravitation environment. Commercially available distillation and air stripping units which are considered suitable for Exploration Life Support

  11. Treatment of contaminated groundwaters with granular activated carbon and air stripping

    SciTech Connect

    Stenzel, M.H.; Gupta, U.S.

    1985-01-01

    Over the past several years there have been increasing reports of cases of contaminated groundwater. Many cases were caused by leaking from surface impoundments or landfills, or leakage from underground storage tanks. Treatment of groundwater use, discharge or recharge into the aquifer is becoming a major concern. Two widely used treatment techniques are adsorption with granular activated carbon and packed tower air stripping. Granular activated carbon is often applied when organic contaminants need to be removed to nondetectable levels, and should be a part of the process if nonvolatile contaminants are present. Air stripping is capable of 95-99% reduction of volatile contaminants and can be a cost effective treatment technology if nondetectable contaminant levels are not required and air pollution is not a factor. Should off-gas from an air stripper require treatment for removal of organic contaminants, granular activated carbon adsorption can be effectively applied as it was in the water phase. Selection of a groundwater treatment technology depends on factors such as contaminant type, end use of the water and air pollution concern, and each case requires consideration of these factors to arrive at the most cost effective solution.

  12. Air stripping. (Latest citations from the NTIS bibliographic database). Published Search

    SciTech Connect

    1995-02-01

    The bibliography contains citations concerning the application of air stripping techniques to water treatment, including groundwater decontamination and wastewater purification. The advantages and disadvantages of air stripping over other water treatment processes are discussed. Cleanup of the organic emissions generated by air stripping is also considered. The primary applications of air stripping are in groundwater and soil cleanup. (Contains a minimum of 89 citations and includes a subject term index and title list.)

  13. Air stripping. (Latest citations from the NTIS bibliographic database). Published Search

    SciTech Connect

    Not Available

    1994-02-01

    The bibliography contains citations concerning the application of air stripping techniques to water treatment, including groundwater decontamination and wastewater purification. The advantages and disadvantages of air stripping over other water treatment processes are discussed. Cleanup of the organic emissions generated by air stripping is also considered. The primary applications of air stripping are in groundwater and soil cleanup. (Contains a minimum of 83 citations and includes a subject term index and title list.)

  14. Air stripping. (Latest citations from the NTIS bibliographic database). Published Search

    SciTech Connect

    1995-12-01

    The bibliography contains citations concerning the application of air stripping techniques to water treatment, including groundwater decontamination and wastewater purification. The advantages and disadvantages of air stripping over other water treatment processes are discussed. Cleanup of the organic emissions generated by air stripping is also considered. The primary applications of air stripping are in groundwater and soil cleanup. (Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

  15. Air stripping. (Latest citations from the NTIS bibliographic database). Published Search

    SciTech Connect

    1997-03-01

    The bibliography contains citations concerning the application of air stripping techniques to water treatment, including groundwater decontamination and wastewater purification. The advantages and disadvantages of air stripping over other water treatment processes are discussed. Cleanup of the organic emissions generated by air stripping is also considered. The primary applications of air stripping are in groundwater and soil cleanup. (Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

  16. Simulations of in situ air stripping demonstration at Savannah River

    SciTech Connect

    Robinson, B.A.; Rosenberg, N.D.; Zyvoloski, G.A.; Viswanathan, H.

    1994-06-01

    This report assesses the performance of the in situ air stripping technology demonstrated at the Savannah River Integrated Demonstration (SRID) site. This technology is a combination of air injection below the water table and vacuum extraction in the vadose zone, using a pair of horizontal wells. Our approach is based on the construction of a site-specific numerical model using the FEHM flow and transport code. We use the model as a tool to investigate improvements to performance, to improve the prediction of the performance of this technology over longer periods of time and at different sites, and to compare performance with other remediation technologies.

  17. Air/Superfund national technical guidance study series: Estimation of air impacts for air stripping of contaminated water

    SciTech Connect

    Eklund, B.; Smith, S.; Hunt, M.

    1991-05-01

    Analysis of the air impacts associated with the alternatives to cleaning up Superfund sites is frequently required for planning purposes prior to actual cleanup. Such analyses depend on estimates rather than on field measurements. The report provides procedures for estimating the emissions and ambient air concentrations associated with air stripping - a widely used technique for removing volatile organic compounds (VOC) from contaminated water. Procedures are given to evaluate the effect of the concentration of contaminants in water, the stripping efficiency and the stripping rate on the emission rates and on the ambient air concentrations at selected distances from the air stripper. Henry's Law constants are provided for over 130 compounds to assist in determining stripping efficiencies. Health-based action levels are also provided for the 130 compounds for comparison to the estimated ambient air concentrations. Action levels are also expressed in terms of water concentrations using conservative estimates of emissions and dispersion.

  18. On the performance of a cascade crossflow air stripping column

    SciTech Connect

    Akiyama, Y.; Valsaraj, K.T.; Wetzel, D.M.; Harrison, D.P.

    1996-10-01

    The cascade crossflow packed column is an innovative design that offers the separation advantages of countercurrent flow while avoiding flooding limitations. Liquid and gas cross-sectional flow areas and path length in contact with packing may be controlled independently. These features are illustrated by studying the air stripping of methylene chloride (MeCl), 1,2-dichloroethane (1,2-DCA), and methyl ethyl ketone (MEK). Stripping efficiencies in the cascade crossflow column were generally slightly smaller than in countercurrent flow at equal liquid and gas flow rates. However larger gas-to-liquid ratios were possible in crossflow, permitting larger maximum stripping efficiencies to be attained. The experimental mass transfer coefficients were smaller than predicted by the Onda correlation. Modifications to the gas-phase Onda correlation are proposed that reduce the magnitude of the average deviation between experiment and prediction for 40 tests to about 12%. Experimental values of 38 of 40 tests were within {+-}30% of modified Onda correlation predictions. Additional applications for the cascade crossflow concept are suggested, such as vacuum distillation columns and trickle-bed reactors, which require low pressure drop and/or large gas-to-liquid ratios.

  19. Water treatment: Air stripping. (Latest citations from the Selected Water Resources Abstracts database). Published Search

    SciTech Connect

    Not Available

    1993-07-01

    The bibliography contains citations concerning the use of air stripping techniques for wastewater, groundwater, and soil decontamination. The advantages and disadvantages of air stripping over other water treatment processes are discussed. The cleanup of organic emissions generated by air stripping is also considered. Other water treatment processes are discussed in separate bibliographies. (Contains a minimum of 212 citations and includes a subject term index and title list.)

  20. Water treatment: Air stripping. (Latest citations from the Selected Water Resources Abstracts database). Published Search

    SciTech Connect

    Not Available

    1993-11-01

    The bibliography contains citations concerning the use of air stripping techniques for wastewater, groundwater, and soil decontamination. The advantages and disadvantages of air stripping over other water treatment processes are discussed. The cleanup of organic emissions generated by air stripping is also considered. Other water treatment processes are discussed in separate bibliographies. (Contains a minimum of 225 citations and includes a subject term index and title list.)

  1. Water treatment: Air stripping. (Latest citations from the Selected Water Resources Abstracts data base). Published Search

    SciTech Connect

    Not Available

    1992-04-01

    The bibliography contains citations concerning the use of air stripping techniques for wastewater, groundwater, and soil decontamination. The advantages and disadvantages of air stripping over other water treatment processes are discussed. The cleanup of organic emissions generated by air stripping is also considered. Other water treatment processes are discussed in separate bibliographies. (Contains a minimum of 129 citations and includes a subject term index and title list.)

  2. Modeling Air Stripping of Ammonia in an Agitated Vessel

    SciTech Connect

    Kofi, Adu-Wusu; Martino, Christopher J.; Wilmarth, William R.; Bennett, William M.; Peters, Robert s.

    2005-11-29

    A model has been developed to predict the rate of removal of ammonia (NH{sub 3}) from solution in a sparged agitated vessel. The model is first-order with respect to liquid-phase concentration of NH{sub 3}. The rate constant for the first-order equation is a function of parameters related to the vessel/impeller characteristics, the air/liquid properties as well as the process conditions. However, the vessel/impeller characteristics, the air/liquid properties, and the process conditions reduce the rate constant dependence to only three parameters, namely, the air sparge rate, the liquid volume or batch size, and the Henry's law constant of NH{sub 3} for the liquid or solution. Thus, the rate of removal is not mass-transfer limited. High air sparge rates, high temperatures, and low liquid volumes or batch sizes increase the rate of removal of NH{sub 3} from solution. The Henry's law constant effect is somewhat reflected in the temperature since Henry's law constant increases with increasing temperature. Data obtained from actual air stripping operation agree fairly well with the model predictions.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. Cleaning contaminated soil using electrical heating and air stripping

    SciTech Connect

    Buettner, H.M.; Daily, W.D.

    1995-08-01

    In the summer of 1992, a proof-of-concept demonstration of direct electrical heating and air stripping was conducted for enhancing the removal of a volatile organic contaminant, trichloroethylene (TCSE), from soil. Six electrodes were buried in shallow boreholes so that a target region 6.1 m in diameter and 3.05 m in height was heated by ohmic dissipation of power-line-frequency electrical currents supplied by a diesel generator. Air stripping of TCE contamination from the same region was accomplished from a single well at the center of the heated volume. The electrical energy used during the demonstration was 3.46 {times} 10{sup 10} J (9,600 kW {center_dot} h), and the temperature of the extracted air rose from 16 C to 38 C. An energy balance shows that input energy is consistent with the temperature rise in the target volume and the amount of water vaporized at the electrodes. Prior to heating, the TCE concentration in the vapor decreased from about 80 parts per million by volume (ppm{sub v}) to around 60 ppm{sub v}. As soon as electrical heating started, TCE concentrations began to increase. Some concentration data were lost shortly after electrical heating began. After the system was repaired, the TCE concentration fell rapidly from about 140 ppm{sub v} to 5 ppm{sub v} over a period of about 25 days. A simple two-dimensional model for calculation of heating rates is also presented and verified experimentally. Finally some of the operation and safety issues associated with electrical heating are discussed.

  8. Air stripping. January 1980-February 1992 (Citations from the NTIS Data Base). Rept. for Jan 80-Feb 92

    SciTech Connect

    Not Available

    1992-02-01

    The bibliography contains citations concerning the application of air stripping techniques to water treatment, including groundwater decontamination and wastewater purification. The advantages and disadvantages of air stripping over other water treatment processes are discussed. Cleanup of the organic emissions generated by air stripping is also considered. The primary applications of air stripping are in groundwater and soil cleanup. (Contains 58 citations with title list and subject index.)

  9. The odour of digested sewage sludge--determination and its abatement by air stripping.

    PubMed

    Winter, P; Jones, N; Asaadi, M; Bowman, L

    2004-01-01

    This paper describes a project to investigate the odour of sewage sludge after anaerobic digestion. The impact of air stripping on the odour of liquid sludge and on the quality of the dewatered product was evaluated at a full-scale sludge treatment installation. A continuous and a batch air-stripping mode were tested. Odour samples were collected during air stripping from the liquid sludge and from the biosolids surface during long term storage. The biosolids were also analysed for hedonic tone and for their potential odour expressed as an odour unit per unit mass. The odour emission profiles for continuous and batch air stripping demonstrated a reduction in the overall (time weighted) emissions during a 24 hr-period compared with emissions from the quiescent liquid storage tank. The averaged specific odour emission rate (Esp) of the biosolids derived from the continuous process was only 13% of the Esp of the biosolids derived from unaerated liquid sludge during the first month of storage. The results of the total potential odour and the hedonic tone of the biosolids underpin the beneficial effects of the air stripping. Odour dispersion modelling showed a noticeable reduction in overall odour impact from the sludge centre when air stripping was applied. The reduction was primarily associated with the reduced odour from stockpiled biosolids. The continuous air-stripping mode appeared to provide the greatest benefits in terms of odour impact from site operations.

  10. Treatment of MTBE by air stripping, carbon adsorption, and advanced oxidation: technical and economic comparison for five groundwaters.

    PubMed

    Sutherland, J; Adams, C; Kekobad, J

    2004-01-01

    An investigation was made of the treatability of methyl tert-butyl ether (MTBE) in five groundwaters with highly varied water quality characteristics. Air stripping, granular activated carbon (GAC) adsorption, and the O(3)/H(2)O(2) and UV/H(2)O(2) advanced oxidation processes were compared in a mobile water treatment pilot plant under a variety of process conditions. Air stripping was shown to have the lower unit treatment costs for higher flowrates (i.e., 3800L/min), although relatively tall towers were required for greater treatment requirements. At low flowrates (i.e., 38L/min), advanced oxidation provided the lowest treatment costs for four of five waters (but was ineffective for a high chemical oxygen demand water). Both the O(3)/H(2)O(2) and UV/H(2)O(2) processes were more efficient at pH 7 versus 9 due in part to increased scavenging at higher pH. GAC was examined using rapid small-scale column tests (RSSCT). GAC was effective at most conditions, although it was also the most costly alternative for most waters. The results of this study can help to provide specific guidance into process selection for treating MTBE in contaminated groundwaters.

  11. Evaluation and quantification of the impact of cooling tower emissions on indoor air quality

    SciTech Connect

    Vanderheyden, M.D.; Schuyler, G.D.

    1994-12-31

    Assessment of the potential impact of outdoor pollutant sources on indoor air quality through the reentrainment of pollutants vis-a-vis air-handling units, doorways, and windows has mainly focused on the evaluation of fume hood, boiler, diesel generator, and vehicular pollutant emissions. In recent years, however, gaseous and waterborne pollutants emitted from cooling towers have become an increasing source of concern. Chemicals such as biocides and corrosion and scale inhibitors are used to reduce and/or eliminate algae blooms, decrease bacterial and fungal growth, and reduce the corrosion of equipment. When added to the water used in cooling towers, these chemicals are emitted in both the gaseous phase and as pollutants dissolved in or suspended in water droplets. A qualitative evaluation of exhaust dispersion and droplet deposition rates associated with cooling towers is necessary when conducting an overall review of the environmental impact on indoor air quality. This paper identifies source emission rates to be used in assessing emissions of chemical additives in cooling towers, presents provisional design criteria for evaluating the impact of the chemical additives, and evaluates alternative methodologies for quantifying impact concentrations. These alternative assessment methodologies include numerical models, physical wind tunnel simulations, and computational fluid dynamics (CFD) simulations. Parameters used in comparing the methodologies include relative accuracy (order of magnitude) and modeling and simulation limitations.

  12. 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.

  13. Air stripping and emissions control technologies: Field testing of countercurrent packings, rotary air stripping, catalytic oxidation, and adsorption materials. Final report, April 1987-June 1989

    SciTech Connect

    Wilson, J.H.; Counce, R.M.; Lucero, A.J.; Jennings, H.L.; Singh, S.P.

    1992-05-01

    The objective of this activity was to field test innovative air stripping with emissions control technologies. The scale of the various components used in these tests was selected such that results would be useful for better predicting the performance of application-scale equipment. The goal of this effort was to provide managers and engineers with necessary information so that decisions relating to the application of this technology can proceed on a rational basis. Conventional countercurrent air stripping (with 4 different packing materials) were compared to a centrifugal contactor, also known as a rotary air stripper. Emissions control tests showed that the activity of the noble metal catalyst was lost before any useful abatement results were obtained. This loss in activity was attributed to poisoning by sulfur stripped from the groundwater. Control of the emissions by activated carbon was achieved. Significant quantities of lighter hydrocarbons were noted in the stripper effluent that were not effectively adsorbed by the carbon. No generally useful results ere obtained for control of emissions by molecular sieves.... Air stripping, Rotary air stripper, VOCs, Fuel contamination, Catalytic oxidations, Carbon adsorption, Molecular sieves.

  14. Air Stripping Designs and Reactive Water Purification Processes for the Lunar Surface

    NASA Technical Reports Server (NTRS)

    Boul, Peter J.; Lange, Kevin; Conger, Bruce; Anderson, Molly

    2010-01-01

    Air stripping designs are considered to reduce the presence of volatile organic compounds in the purified water. Components of the wastewater streams are ranked by Henry's Law Constant and the suitability of air stripping in the purification of wastewater in terms of component removal is evaluated. Distillation processes are modeled in tandem with air stripping to demonstrate the potential effectiveness and utility of these methods in recycling wastewater on the Moon. Scaling factors for distillation and air stripping columns are presented to account for the difference in the lunar gravitation environment. Commercially available distillation and air stripping units which are considered suitable for Exploration Life Support are presented. The advantages to the various designs are summarized with respect to water purity levels, power consumption, and processing rates. An evaluation of reactive distillation and air stripping is presented with regards to the reduction of volatile organic compounds in the contaminated water and air. Among the methods presented, an architecture is presented for the evaluation of the simultaneous oxidation of organics in air and water. These and other designs are presented in light of potential improvements in power consumptions and air and water purities for architectures which include catalytic activity integrated into the water processor. In particular, catalytic oxidation of organics may be useful as a tool to remove contaminants that more traditional distillation and/or air stripping columns may not remove. A review of the current leading edge at the commercial level and at the research frontier in catalytically active materials is presented. Themes and directions from the engineering developments in catalyst design are presented conceptually in light of developments in the nanoscale chemistry of a variety of catalyst materials.

  15. Indoor air quality assessment in the air traffic control tower of the Athens Airport, Greece.

    PubMed

    Helmis, Costas G; Assimakopoulos, Vasiliki D; Flocas, Helena A; Stathopoulou, Ourania I; Sgouros, George; Hatzaki, Maria

    2009-01-01

    In this study, an assessment of indoor air quality (IAQ) and thermal comfort in the Athens Traffic Control Tower (ATCT) offices of Hellinicon building complex, which is mechanically ventilated, is presented. Measurements of PM(10), PM(2.5), TVOCs and CO(2) concentrations were performed during three experimental cycles, while the Thom Discomfort Index was calculated to describe the employees' feeling of discomfort. The aim of the first cycle was to identify the IAQ status, the second to investigate the effectiveness of certain measures taken, and the third to continuously monitor and control IAQ. During the first two cycles, daily spot measurements of TVOCs and CO(2) were performed at various indoor locations and at the respective outdoor air intake positions, in addition with mean 24-h spot measurements of indoor PM(10) and PM(2.5). Results revealed that pollution levels vary according to the occupancy and the kind of activity. Following that, an automated system (IMAS) was designed and employed to continuously monitor indoor and outdoor CO(2), TVOCs, temperature and relative humidity. The ultimate scope was to control the IAQ and offer acceptable comfort conditions to the employees, whose work is of special nature and extremely demanding. Intervention scenarios were formulated and applied to the system to improve indoor conditions, when and where necessary. Regarding the third cycle, 1-year measurements collected from the system to examine its effectiveness. While it was shown that discomfort may be attributed to co-existence of unsatisfactory thermal comfort conditions and IAQ, usually the sole predominant factor of discomfort feeling is thermal comfort.

  16. Performance of air stripping and GAC (granular activated carbon) for SOC (synthetic organic chemical) and VOC (volatile organic chemical) removal from ground water. Final report, October 1983-November 1987

    SciTech Connect

    Hand, D.W.; Crittenden, J.C.; Miller, J.M.; Gehin, J.L.

    1988-09-01

    This study compares the ability and cost-effectiveness of granular activated carbon and packed-tower aeration (air stripping) in removing synthetic organic and volatile organic chemicals (SOCs and VOCs) from a contaminated groundwater source in Wausau, WI. Among the SOCs and VOCs identified and targeted for removal were cis-1,2-dichloroethene, trichloroethene, tetrachlorethene, and toluene. A liquid-phase GAC pilot-plant, full-scale GAS adsorber, and a full-scale air-stripping tower were designed, built, and operated to provide data so that the process performance could be evaluated. Extensive laboratory studies were performed. Mathematical models and correlations for obtaining kinetic parameters and single-solute isotherm parameters were developed and tested by comparing their results to those obtained from the pilot plant. Possible surrogate parameters were investigated. Cost estimates are compared.

  17. Multipass membrane air-stripping (MAS) for removing volatile organic compounds (VOCs) from surfactant micellar solutions.

    PubMed

    Cheng, Hefa; Hu, Yuanan; Luo, Jian; Sabatini, David A

    2009-10-30

    Air-stripping is one of the most effective technologies for removing volatile organic compounds (VOCs) from surfactant solutions, although the presence of surfactant poses some unique challenges. This study evaluated the effect of a mixed surfactant system on the apparent Henry's law constant of tetrachloroethylene (PCE) and the efficiency of PCE removal from surfactant solutions using a lab-scale hollow fiber membrane contactor. Results show that the presence of surfactant significantly reduced the apparent Henry's law constant of PCE, and the reduction was proportional to the total surfactant concentration. PCE removal efficiency by membrane air-stripping (MAS) decreased as the surfactant system transitioned from solubilization to supersolubilization. Besides significantly reducing the apparent volatility of VOCs, the presence of surfactant brings additional mass transfer resistance in air-stripping, which makes it difficult to achieve high levels of contaminant removal, even at very high air/liquid (A/L) ratios. In contrast, multipass/multistage MAS operated at low A/L ratios could achieve near 100% contaminant removal because of less mass transfer limitation during each stripping pass/stage. Experimental results, together with model calculations demonstrate multipass (and multistage) air-stripping as a cost-effective alternative for removing VOCs from surfactant micellar solutions compared to the options of using large air strippers or operating at high A/L ratios.

  18. Development Of Chemical Reduction And Air Stripping Processes To Remove Mercury From Wastewater

    SciTech Connect

    Jackson, Dennis G.; Looney, Brian B.; Craig, Robert R.; Thompson, Martha C.; Kmetz, Thomas F.

    2013-07-10

    This study evaluates the removal of mercury from wastewater using chemical reduction and air stripping using a full-scale treatment system at the Savannah River Site. The existing water treatment system utilizes air stripping as the unit operation to remove organic compounds from groundwater that also contains mercury (C ~ 250 ng/L). The baseline air stripping process was ineffective in removing mercury and the water exceeded a proposed limit of 51 ng/L. To test an enhancement to the existing treatment modality a continuous dose of reducing agent was injected for 6-hours at the inlet of the air stripper. This action resulted in the chemical reduction of mercury to Hg(0), a species that is removable with the existing unit operation. During the injection period a 94% decrease in concentration was observed and the effluent satisfied proposed limits. The process was optimized over a 2-day period by sequentially evaluating dose rates ranging from 0.64X to 297X stoichiometry. A minimum dose of 16X stoichiometry was necessary to initiate the reduction reaction that facilitated the mercury removal. Competing electron acceptors likely inhibited the reaction at the lower 1 doses, which prevented removal by air stripping. These results indicate that chemical reduction coupled with air stripping can effectively treat large-volumes of water to emerging part per trillion regulatory standards for mercury.

  19. VOCs removal from industrial wastewater via air stripping - an operating experience

    SciTech Connect

    Ansari, M.A.; Hsieh, D.T.

    1996-12-31

    This paper presents design criteria and operating experience of an air stripping unit installed to remove volatile organic compounds (VOCs) from process wastewater in a phenol and acetone manufacturing facility. The unit also removes contaminants from the ground water within the plant for OCSPF compliance. The desorbed hydrocarbon are destroyed in a thermal oxidizer. Air stripping is a fast, efficient, and economical approach to treating waste streams with varying characteristics such as contaminant strength and flows. Evaluation of some of the alternatives to an air stripping process is also discussed. The system was installed in Allied Signal`s chemical manufacturing in Philadelphia, PA., in 1991 and has been operating satisfactorily. Some of the post start-up problems and their solutions, and necessary process modification are also discussed.

  20. In situ air stripping using horizontal wells. Innovative technology summary report

    SciTech Connect

    1995-04-01

    In-situ air stripping employs horizontal wells to inject or sparge air into the ground water and vacuum extract VOC`S from vadose zone soils. The horizontal wells provide better access to the subsurface contamination, and the air sparging eliminates the need for surface ground water treatment systems and treats the subsurface in-situ. A full-scale demonstration was conducted at the Savannah River Plant in an area polluted with trichloroethylene and tetrachloroethylene. Results are described.

  1. Innovative technology summary report: in situ air stripping using horizontal wells

    SciTech Connect

    1995-04-01

    In situ air stripping (ISAS) technology was developed to remediate soils and ground water contaminated with volatile organic compounds (VOCs) both above and below the water table. ISAS employs horizontal wells to inject (sparge) air into the ground water and vacuum extract VOCs from vadose zone soils. The innovation is creation of a system that combines two somewhat innovative technologies, air sparging and horizontal wells, with a baseline technology, soil vapor extraction, to produce a more efficient in situ remediation system.

  2. Requirements analysis for an air traffic control tower surface surveillance enhanced vision system

    NASA Astrophysics Data System (ADS)

    Ruffner, John W.; Deaver, Dawne M.; Henry, Daniel J.

    2003-09-01

    Tower controllers are responsible for maintaining separation between aircraft and expediting the flow of traffic in the air. On the airport surface, they also are responsible for maintaining safe separation between aircraft, ground equipment, and personnel. They do this by sequencing departing and arriving aircraft, and controlling the location and movement of aircraft, vehicles, equipment, and personnel on the airport surface. The local controller and ground controller are responsible for determining aircraft location and intent, and for ensuring that aircraft, vehicles, and other surface objects maintain a safe separation distance. During nighttime or poor visibility conditions, controllers' situation awareness is significantly degraded, resulting in lower safety margins and increased errors. Safety and throughput can be increased by using an Enhanced Vision System, based upon state-of-the-art infrared sensor technology, to restore critical visual cues. We discuss the results of an analysis of tower controller critical visual tasks and information requirements. The analysis identified: representative classes of ground obstacles/targets (e.g., aircraft, vehicles, wildlife); sample airport layouts and tower-to-runway distances; and obstacle subtended visual angles. We performed NVTherm modeling of candidate sensors and field data collections. This resulted in the identification of design factors for an airport surface surveillance Enhanced Vision System.

  3. Hydrophilic strips for preventing air bubble formation in a microfluidic chamber.

    PubMed

    Choi, Munseok; Na, Yang; Kim, Sung-Jin

    2015-12-01

    In a microfluidic chamber, unwanted formation of air bubbles is a critical problem. Here, we present a hydrophilic strip array that prevents air bubble formation in a microfluidic chamber. The array is located on the top surface of the chamber, which has a large variation in width, and consists of a repeated arrangement of super- and moderately hydrophilic strips. This repeated arrangement allows a flat meniscus (i.e. liquid front) to form when various solutions consisting of a single stream or two parallel streams with different hydrophilicities move through the chamber. The flat meniscus produced by the array completely prevents the formation of bubbles. Without the array in the chamber, the meniscus shape is highly convex, and bubbles frequently form in the chamber. This hydrophilic strip array will facilitate the use of a microfluidic chamber with a large variation in width for various microfluidic applications. PMID:26382942

  4. Novel closed-loop air-stripping process for VOC removal from contaminated water. Final report

    SciTech Connect

    Bhowmick, M.; Sontag, T.K.; Semmens, M.J.

    1990-12-05

    The study presents an approach for the treatment of contaminated groundwater, which includes Volatile Organic Compounds (VOCs) stripped from the water using hollow fiber membranes or using conventional air stripping technology and then the VOCs are oxidized in the gas phase using UV oxidation or a combination of photooxidation and photo-catalysis with Titanium Dioxide (TiO2). The work on the photooxidation of VOCs is applicable to both water and soil treatment techniques, such as air stripping and in-situ vacuum extraction. The study is divided into five major segments: Each segment includes relevant sections on the experimental methods employed, the results from the tests conducted, the development of models, and the conclusions which were drawn from the work.

  5. Hydrophilic strips for preventing air bubble formation in a microfluidic chamber.

    PubMed

    Choi, Munseok; Na, Yang; Kim, Sung-Jin

    2015-12-01

    In a microfluidic chamber, unwanted formation of air bubbles is a critical problem. Here, we present a hydrophilic strip array that prevents air bubble formation in a microfluidic chamber. The array is located on the top surface of the chamber, which has a large variation in width, and consists of a repeated arrangement of super- and moderately hydrophilic strips. This repeated arrangement allows a flat meniscus (i.e. liquid front) to form when various solutions consisting of a single stream or two parallel streams with different hydrophilicities move through the chamber. The flat meniscus produced by the array completely prevents the formation of bubbles. Without the array in the chamber, the meniscus shape is highly convex, and bubbles frequently form in the chamber. This hydrophilic strip array will facilitate the use of a microfluidic chamber with a large variation in width for various microfluidic applications.

  6. APPLICATIONS ANALYSIS REPORT: TOXIC TREATMENTS, IN-SITU STEAM/HOT-AIR STRIPPING TECHNOLOGY

    EPA Science Inventory

    This document is an evaluation of the performance of the Toxic Treatments (USA), Inc., (TTUSA) in situ steam/hot-air stripping technology and its applicability as an on-site treatment technique for hazardous waste site soil cleanup of volatile and semivolatile contaminants. Both ...

  7. DEMONSTRATION BULLETIN: IN-SITU STEAM/HOT AIR SOIL STRIPPING TOXIC TREATMENT (USA) INC.

    EPA Science Inventory

    This technology uses steam and hot air to strip volatile organics from contaminated soil. The treatment equipment is mobile and treats the soil in-situ without need for soil excavation or transportation. The organic contaminants volatilized from the soil are condensed and col...

  8. INTEGRATION OF PHOTOCATALYTIC OXIDATION WITH AIR STRIPPING OF CONTAMINATED AQUIFERS

    EPA Science Inventory

    Bench scale laboratory studies and pilot scale studies in a simulated field-test situation were performed to evaluate the integration of gas-solid ultaviolet (UV) photocatalytic oxidation (PCO) downstream if an air stripper unit as a technology for cost-effectively treating water...

  9. Problems Found Using a Radon Stripping Algorithm for Retrospective Assessment of Air Filter Samples

    SciTech Connect

    Robert Hayes

    2008-04-01

    An evaluation of a large number of air sample filters was undertaken using a commercial alpha and beta spectroscopy system employing a passive implanted planar silicon (PIPS) detector. Samples were only measured after air flow through the filters had ceased. Use of a commercial radon stripping algorithm was implemented to discriminate anthropogenic alpha activity on the filters from the radon progeny. When uncontaminated air filters were evaluated, the results showed that there was a time-dependent bias in both average estimates and measurement dispersion of anthropogenic activity estimates with the relative bias being small compared to the dispersion, indicating that the system would not give false positive indications for an appropriately set decision level. By also measuring environmental air sample filters simultaneously with electroplated alpha filters, use of the radon stripping algorithm demonstrated a number of substantial unexpected deviations from calibrated values indicating that the system would give false negative indications. Use of the current algorithm is, therefore, not recommended for general assay applications. Use of the PIPS detector should only be utilized for gross counting without appropriate modifications to the curve-fitting algorithm. As a screening method, the radon stripping algorithm might be expected to see elevated alpha activities on air sample filters (not due to radon progeny) around the 200 disintegrations per minute level.

  10. Use of a Radon Stripping Algorithm for Retrospective Assessment of Air Filter Samples

    SciTech Connect

    Robert Hayes

    2009-01-23

    An evaluation of a large number of air sample filters was undertaken using a commercial alpha and beta spectroscopy system employing a passive implanted planar silicon (PIPS) detector. Samples were only measured after air flow through the filters had ceased. Use of a commercial radon stripping algorithm was implemented to discriminate anthropogenic alpha and beta activity on the filters from the radon progeny. When uncontaminated air filters were evaluated, the results showed that there was a time-dependent bias in both average estimates and measurement dispersion with the relative bias being small compared to the dispersion. By also measuring environmental air sample filters simultaneously with electroplated alpha and beta sources, use of the radon stripping algorithm demonstrated a number of substantial unexpected deviations. Use of the current algorithm is therefore not recommended for assay applications and so use of the PIPS detector should only be utilized for gross counting without appropriate modifications to the curve fitting algorithm. As a screening method, the radon stripping algorithm might be expected to see elevated alpha and beta activities on air sample filters (not due to radon progeny) around the 200 dpm level.

  11. Membrane air stripping: A process for removal of organics from aqueous solutions

    SciTech Connect

    Mahmud, H.; Kumar, A.; Narbaitz, R.M.; Matsuura, T.

    1998-10-01

    The membrane air-stripping (MAS) process using microporous polypropylene hollow fiber membranes has shown potential for the removal of volatile organics from aqueous streams over conventional treatment processes, particularly in reducing the size of the equipment. This paper reviews the theoretical aspects and experimental investigations on the performance of these membranes in terms of overall mass transfer capabilities in the removal of organics from aqueous solutions. The reported findings of the effect of pH, ozone, chlorine, influence of packing density and possible fouling on the performance of these hollow fibers membranes are presented. The fate of the stripped air is discussed. Other possible applications as well as the future research needs are highlighted, along with critical assessment of the reported work.

  12. Evaporation and air-stripping to assess and reduce ethanolamines toxicity in oily wastewater.

    PubMed

    Libralato, G; Ghirardini, A Volpi; Avezzù, F

    2008-05-30

    Toxicity from industrial oily wastewater remains a problem even after conventional activated sludge treatment process, because of the persistence of some toxicant compounds. This work verified the removal efficiency of organic and inorganic pollutants and the effects of evaporation and air-stripping techniques on oily wastewater toxicity reduction. In a lab-scale plant, a vacuum evaporation procedure at three different temperatures and an air-stripping stage were tested on oily wastewater. Toxicity reduction/removal was observed at each treatment step via Microtox bioassay. A case study monitoring real scale evaporation was also done in a full-size wastewater treatment plant (WWTP). To implement part of a general project of toxicity reduction evaluation, additional investigations took into account the monoethanolamine (MEA), diethanolamine (DEA) and triethanolamine (TEA) role in toxicity definition after the evaporation phase, both as pure substances and mixtures. Only MEA and TEA appeared to contribute towards effluent toxicity.

  13. Air stripping of volatile organic chlorocarbons: System development, performance, and lessons learned

    SciTech Connect

    McKillip, S.T.; Sibley, K.L.; Horvath, J.G.

    1991-12-31

    The Savannah River Site, which has been in operation since the 1950`s, is a 780-square kilometer reservation that produces tritium for the national defense program. As a result of past waste handling practices, the ground water at several locations on the Site has become contaminated with solvents, metals, and radionuclides. In 1981, the ground water located under the Site`s fuel and target rod fabrication area (M-Area) was found to be contaminated with degreasing solvents, specifically trichloroethylene (TCE) and tetrachloroethylene (PCE). In 1983, a program was started to evaluate air stripping and determine its applicability to cleanup of M-Area contamination. Lessons learned regarding the efficiency and effectiveness of air stripping technology are presented.

  14. [Air stripping-UASB process for the treatment of evaporator condensate from a Kraft pulp mill].

    PubMed

    Zhou, Wei-li; Qin, Xiao-peng; Yu, Jun; Imai, Tsuyoshi; Ukita, Masao

    2006-04-01

    Evaporator condensate from a kraft pulp mill is characterized by high temperature, high strength, poor nutrition, and some odor and inhibitive materials. In this study, air stripping-UASB process was developed to treat the wastewater from a kraft pulp mill. The lab scale study demonstrated that air stripping process removed 70%-80% of the volatile organic sulfur compounds. After that, the UASB reactor showed high efficiency, at the organic loading rate (COD) of 30 kg x (m3 x d)(-1), COD removal was retained about 95%. On the other hand, the inoculated granules were broken in the new surroundings and were replaced with the newly formed granules The scanning electronic microscope (SEM) observation showed wide difference of the predominant anaerobic microorganisms in the seed and newly formed granules.

  15. Air stripping of volatile organic chlorocarbons: System development, performance, and lessons learned

    SciTech Connect

    McKillip, S.T.; Sibley, K.L.; Horvath, J.G.

    1991-01-01

    The Savannah River Site, which has been in operation since the 1950's, is a 780-square kilometer reservation that produces tritium for the national defense program. As a result of past waste handling practices, the ground water at several locations on the Site has become contaminated with solvents, metals, and radionuclides. In 1981, the ground water located under the Site's fuel and target rod fabrication area (M-Area) was found to be contaminated with degreasing solvents, specifically trichloroethylene (TCE) and tetrachloroethylene (PCE). In 1983, a program was started to evaluate air stripping and determine its applicability to cleanup of M-Area contamination. Lessons learned regarding the efficiency and effectiveness of air stripping technology are presented.

  16. Economic evaluation of air stripping to remove volatile organic compounds from water. Final report

    SciTech Connect

    Zaghloul, H.H.; Ball, R.O.; Maloney, S.W.

    1987-12-01

    This report documents the results of a study conducted to provide a basis for estimating the costs of installing and using air stripping to remove volatile organic compounds (VOCs) from water. The air-stripping technology was found to be a very economical and efficient method for contaminant removal. The technology is simple, relatively inexpensive to install, and has low labor and maintenance requirements. VOC removal rates range from 90 to 99.99%. Estimated costs, in terms of percentage of total production costs, were found to be 40% for capital costs, 50% for operational costs, and 10% for maintenance costs, according to literature sources. Results of a survey conducted during this study generally agree with these percentages, except that maintenance costs reported on the survey were lower due to the highly automated nature of new installations.

  17. Model for in situ air stripping of contaminated soils: Effects of hydrocarbon adsorption

    SciTech Connect

    Mehrotra, A.K.; Karan, K.; Chakma, A.

    1996-01-01

    Soil contamination due to organic compounds is a widespread problem. The contaminants enter the soil subsurface by a number of routes, such as the disposal of wastes in landfills, spills during transportation of chemicals, plant operation, and leakage from underground storage. Air stripping as a means of soil remediation has gained popularity in recent years. In this in situ process, clean air is injected into the contaminated soil zone to volatilize and strip the contaminants, which are then removed by the carrier gas. The process has been found to be effective especially for treating the vadose zone of the soil contaminated with volatile and semivolatile organics. Nitrogen adsorption/desorption experiments in this study were performed on a soil sample to establish its desorption characteristics. A field-scale model for the air stripping process has been developed to simulate the removal of semivolatile hydrocarbons. The numerical results show that the interphase contaminant transport from the sorbed to the vapor phase plays a dominant role in influencing the process effectiveness.

  18. Applying membrane technology to air stripping effluent for remediation of groundwater contaminated with volatile organic compounds

    SciTech Connect

    Brown, J.J.; Erickson, M.D.; Beskid, N.J.

    1993-12-31

    Remediation groundwater contaminated by volatile organic compounds (VOCs) requires cost- and technically-effective solutions. This paper reviews the options for VOC removal from remediation air streams, focusing on membrane separation. The basic separation science and technology, results of performance tests, and results of cost studies for membrane separation are presented. Competing technologies are discussed and compared with membrane separation. Membrane separation combined with air stripping will provide an economically and environmentally safe technology for remediation of VOC-contaminated groundwater and, as it matures, may become the preferred method. 9 refs., 6 figs., 2 tabs.

  19. Startup of air-cooled condensers and dry cooling towers at low temperatures of the cooling air

    NASA Astrophysics Data System (ADS)

    Milman, O. O.; Ptakhin, A. V.; Kondratev, A. V.; Shifrin, B. A.; Yankov, G. G.

    2016-05-01

    The problems of startup and performance of air-cooled condensers (ACC) and dry cooling towers (DCT) at low cooling air temperatures are considered. Effects of the startup of the ACC at sub-zero temperatures are described. Different options of the ACC heating up are analyzed, and examples of existing technologies are presented (electric heating, heating up with hot air or steam, and internal and external heating). The use of additional heat exchanging sections, steam tracers, in the DCT design is described. The need for high power in cases of electric heating and heating up with hot air is noted. An experimental stand for research and testing of the ACC startup at low temperatures is described. The design of the three-pass ACC unit is given, and its advantages over classical single-pass design at low temperatures are listed. The formation of ice plugs inside the heat exchanging tubes during the start-up of ACC and DCT at low cooling air temperatures is analyzed. Experimental data on the effect of the steam flow rate, steam nozzle distance from the heat-exchange surface, and their orientation in space on the metal temperature were collected, and test results are analyzed. It is noted that the surface temperature at the end of the heat up is almost independent from its initial temperature. Recommendations for the safe start-up of ACCs and DCTs are given. The heating flow necessary to sufficiently heat up heat-exchange surfaces of ACCs and DCTs for the safe startup is estimated. The technology and the process of the heat up of the ACC with the heating steam external supply are described by the example of the startup of the full-scale section of the ACC at sub-zero temperatures of the cooling air, and the advantages of the proposed start-up technology are confirmed.

  20. Remediation of MTBE from drinking water: air stripping followed by off-gas adsorption.

    PubMed

    Ramakrishnan, Balaji; Sorial, George A; Speth, Thomas F; Clark, Patrick; Zaffiro, Alan; Patterson, Craig; Hand, David W

    2004-05-01

    The widespread use of methyl tertiary butyl ether (MTBE) as an oxygenate in gasoline has resulted in the contamination of a large number of ground and surface water sources. Even though air stripping has been proven to be an effective treatment technology for MTBE removal, off-gas treatment often is required in conjunction with it. This study evaluated the combined treatment technologies of air stripping followed by off-gas adsorption on a pilot scale for the treatment of MTBE-contaminated water. The effect of air/water ratios on the treatment efficiency was studied, and the mass transfer coefficient was determined. Air/water ratios of 105:1, 151:1, 177:1, 190:1, 202:1, and 206:1 were used, and a treatment efficiency of >99% was achieved for all the runs conducted. The depth of packing required to achieve maximum treatment efficiency decreased with increasing air/water ratio. Relative humidity (RH) impacts on the MTBE adsorption capacity of a granular activated carbon (GAC) and carbonaceous resin were determined from pilot plant studies. Breakthrough profiles obtained from the pilot plant studies conducted at 20, 30, and 50% RH indicated that GAC has a higher adsorptive capacity than resin. The adsorptive capacity of GAC decreased with increasing RH, whereas RH did not impact the resin adsorptive capacity.

  1. Reactive Distillation and Air Stripping Processes for Water Recycling and Trace Contaminant Control

    NASA Technical Reports Server (NTRS)

    Boul, Peter J.; Lange, Kevin E.; Conger, Bruce; Anderson, Molly

    2009-01-01

    Reactive distillation designs are considered to reduce the presence of volatile organic compounds in the purified water. Reactive distillation integrates a reactor with a distillation column. A review of the literature in this field has revealed a variety of functional reactive columns in industry. Wastewater may be purified by a combination of a reactor and a distiller (e.g., the EWRS or VPCAR concepts) or, in principle, through a design which integrates the reactor with the distiller. A review of the literature in reactive distillation has identified some different designs in such combinations of reactor and distiller. An evaluation of reactive distillation and reactive air stripping is presented with regards to the reduction of volatile organic compounds in the contaminated water and air. Among the methods presented, an architecture is presented for the evaluation of the simultaneous oxidation of organics in air and water. These and other designs are presented in light of potential improvements in power consumptions and air and water purities for architectures which include catalytic activity integrated into the water processor. In particular, catalytic oxidation of organics may be useful as a tool to remove contaminants that more traditional distillation and/or air stripping columns may not remove. A review of the current leading edge at the commercial level and at the research frontier in catalytically active materials is presented. Themes and directions from the engineering developments in catalyst design are presented conceptually in light of developments in the nanoscale chemistry of a variety of catalyst materials.

  2. Ultralow Level Mercury Treatment Using Chemical Reduction and Air Stripping: Scoping Report

    SciTech Connect

    Looney, B.B.

    2000-08-18

    Data collected during the first stage of a Savannah River Technology Center (SRTC) Strategic Research and Development Project confirmed the efficacy of chemical reduction and air stripping/sparging as an ultralow level mercury treatment concept for waters containing Hg(II). The process consists of dosing the water with low levels of stannous chloride to convert the mercury to Hg. This form of mercury can easily be removed from the water by air stripping or sparging. Samples of Savannah River Site (SRS) groundwater containing approximately 130 ng/L of total mercury (as Hg(II)) were used for the study. In undosed samples, sparging removed 0 percent of the initial mercury. In the dosed samples, all of the removals were greater than 94 percent, except in one water type at one dose. This sample, which was saturated with dissolved oxygen, showed a 63 percent reduction in mercury following treatment at the lowest dose. Following dosing at minimally effective levels and sparging, treated water contained less than 10 ng/L total mercury. In general, the data indicate that the reduction of mercury is highly favored and that stannous chloride reagent efficiently targets the Hg(II) contaminant in the presence of competing reactions. Based on the results, the authors estimated that the costs of implementing and operating an ultralow level mercury treatment process based on chemical reduction and stripping/sparging are 10 percent to 20 percent of traditional treatment technologies.

  3. Micellar-enhanced ultrafiltration and air stripping for surfactant-contaminant separation and surfactant reuse

    SciTech Connect

    Lipe, K.M.; Sabatini, D.A.; Hasegawa, M.A.; Harwell, J.H.

    1996-05-01

    Micellar-enhanced ultrafiltration (MEUF) and air stripping were evaluated for surfactant-contaminant separation and surfactant recovery. Two linear alkyl diphenyloxide disulfonate (DPDS) surfactants were evaluated with the contaminants naphthalene and trichloroethylene. A separation model developed from micellar partitioning principles showed a good correlation to batch MEUF studies, whereas flux analysis highlighted concentration polarization effects in relation to hydrophobe length. MEUF effectively concentrated the surfactant-contaminant system (93 to 99% retention); however, this did not result in surfactant-contaminant separation. Batch and continuous flow air stripping models were developed based upon air/water ratio, surfactant concentration, and micellar partitioning; model predictions were validated by experimental data. Sensitivity analyses illustrated the decline in contaminant-surfactant separation with increasing surfactant concentration (e.g., TCE removal efficiency declines from 83% to 37% as C-16 DPDS concentration increases from 0 to 55 mM). This effect is greater for more hydrophobic contaminants (naphthalene vs. TCE) and surfactants with greater solubilization potential (C16-DPDS vs. C-12 DPDS). The resulting design equations can account for this effect and thus properly size air strippers to achieve the desired removal efficiency in the presence of surfactant micelles. Proper selection and design of surfactant-contaminant separation and surfactant recovery systems are integral to optimizing surfactant-enhanced subsurface remediation.

  4. Crosshole shear-wave seismic monitoring of an in situ air stripping waste remediation process

    SciTech Connect

    Elbring, G.J.

    1992-02-01

    Crosshole shear-wave seismic surveys have been used to monitor the distribution of injected air in the subsurface during an in situ air stripping waste remediation project at the Savannah River site in South Carolina. To remove the contaminant, in this case TCE's from a leaking sewer line, two horizontal wells were drilled at depths of 20 m and 52 m. Air was pumped into the lower well and a vacuum was applied to the upper well to extract the injected air. As the air passed through the subsurface, TCE's were dissolved into the gas and brought out the extraction well. Monitoring of the air injection by crosshole shear wave seismics is feasible due to the changes in soil saturation during injection resulting in a corresponding change in seismic velocities. Using a downhole shear-wave source and clamped downhole receiver, two sets of shear-wave data were taken. The first data were taken before the start of air injection, and the second taken during. The difference in travel times between the two data sets were tomographically inverted to obtain velocity differences. Velocity changes ranging up to 3% were mapped corresponding to saturation changes up to 24%. The distribution of these changes shows a desaturation around the position of the injection well with a plume extending in the direction of the extraction well. Layers with higher clay content show distinctively less change in saturation than the regions with higher sand content.

  5. Crosshole shear-wave seismic monitoring of an in situ air stripping waste remediation process

    SciTech Connect

    Elbring, G.J.

    1992-02-01

    Crosshole shear-wave seismic surveys have been used to monitor the distribution of injected air in the subsurface during an in situ air stripping waste remediation project at the Savannah River site in South Carolina. To remove the contaminant, in this case TCE`s from a leaking sewer line, two horizontal wells were drilled at depths of 20 m and 52 m. Air was pumped into the lower well and a vacuum was applied to the upper well to extract the injected air. As the air passed through the subsurface, TCE`s were dissolved into the gas and brought out the extraction well. Monitoring of the air injection by crosshole shear wave seismics is feasible due to the changes in soil saturation during injection resulting in a corresponding change in seismic velocities. Using a downhole shear-wave source and clamped downhole receiver, two sets of shear-wave data were taken. The first data were taken before the start of air injection, and the second taken during. The difference in travel times between the two data sets were tomographically inverted to obtain velocity differences. Velocity changes ranging up to 3% were mapped corresponding to saturation changes up to 24%. The distribution of these changes shows a desaturation around the position of the injection well with a plume extending in the direction of the extraction well. Layers with higher clay content show distinctively less change in saturation than the regions with higher sand content.

  6. Hydrocarbon removal from bilgewater by a combination of air-stripping and photocatalysis.

    PubMed

    Cazoir, D; Fine, L; Ferronato, C; Chovelon, J-M

    2012-10-15

    In order to prevent hydrocarbon discharge at sea from the bilge of ships, the International Maritime Organization (IMO) enacted the MARPOL 73/78 convention in which effluents are now limited to those with maximum oil content of 15 ppmv. Thus, photocatalysis and air-stripping were combined for the hydrocarbon removal from a real oily bilgewater sample and an original monitoring of both aqueous and gaseous phases was performed by GC/MS to better understand the process. Our results show that the hydrocarbon oil index [HC] can be reduced to its maximum permissible value of 15 ppmv (MARPOL) in only 8.5h when photocatalysis and air-stripping are used together in a synergistic way, as against 17 h when photocatalysis is used alone. However, this air-assisted photocatalytic process emits a large quantity of volatile organic compounds (VOC) and, within the first four hours, ca. 10% of the hydrocarbon removal in the aqueous phase is actually just transferred into the gaseous one. Finally, we highlight that the n-alkanes with a number of carbon atoms higher than 15 (N(C)>15) are those which most decrease the rate of [HC] removal.

  7. Application of pig slurry to soils. Effect of air stripping treatment on nitrogen and TOC leaching.

    PubMed

    Bolado-Rodríguez, Silvia; García-Sinovas, David; Alvarez-Benedí, Javier

    2010-12-01

    The effect of physical-chemical slurry treatment on the mobility and transformation of nitrogen and organic matter from pig slurry after soil application is evaluated. Two different pig slurries (one treated by stripping with air at pH=9 and another non-treated) were applied at the top of a soil column, containing approximately 100 kg of soil. Effluents were monitored measuring concentration values of ammonia, nitrites, nitrates and total organic carbon (TOC). The breakthrough curves were modelled using STANMOD and HYDRUS 1D codes. Low concentrations of ammonia were detected in the effluent recovered at the bottom of the soil profile for both types of slurry. Nitrate concentration in effluent was lower and more homogenous over time when applying stripping treated pig slurry. In N modelling, adsorption of ammonia by soil proved an important process, nitrite and nitrate adsorption being less significant, although not negligible. Transformation from ammonia to nitrite controls the kinetics of the nitrification process. Total organic carbon in the column effluent was higher in the experiment using treated pig slurry, which can be attributed to organic matter solubilisation in the stripping treatment process.

  8. Legionella detection and subgrouping in water air-conditioning cooling tower systems in Kuwait.

    PubMed

    Al-Matawah, Qadreyah; Al-Zenki, Sameer; Al-Azmi, Ahmad; Al-Waalan, Tahani; Al-Salameen, Fadila; Hejji, Ahmad Ben

    2015-07-01

    The main aim of the study was to test for the presence of Legionnaires' disease-causing microorganisms in air-conditioned buildings in Kuwait using molecular technologies. For this purpose, 547 samples were collected from 38 cooling towers for the analysis of Legionella pneumophila. These samples included those from water (n = 178), air (n = 231), and swabs (n = 138). Out of the 547 samples, 226 (41%) samples were presumptive positive for L. pneumophila, with L. pneumophila viable counts in the positive water samples ranging from 1 to 88 CFU/ml. Of the Legionella culture-positive samples, 204 isolates were examined by latex agglutination. These isolates were predominately identified as L. pneumophila serogroup (sg) 2-14. Using the Dresden panel of monoclonal antibodies, 74 representatives isolates were further serogrouped. Results showed that 51% of the isolates belonged to serogroup 7 followed by 1 (18%) and 3 (18%). Serogroups 4 (4%) and 10 (7%) were isolated at a lower frequency, and two isolates could not be assigned to a serogroup. These results indicate the wide prevalence of L. pneumophila serogroup 7 as the predominant serogroup at the selected sampling sites. Furthermore, the 74 L. pneumophila (sg1 = 13; sg3 = 13; sg4 = 3; sg7 = 38; sg10 = 5; sgX = 2) isolates were genotyped using the seven gene protocol sequence-based typing (SBT) scheme developed by the European Working Group for Legionella Infections (EWGLI). The results show that Legionella isolates were discriminated into nine distinct sequence typing (ST) profiles, five of which were new to the SBT database of EWGLI. Additionally, all of the ST1 serogroup 1 isolates were of the OLDA/Oxford subgroup. These baseline data will form the basis for the development of a Legionella environmental surveillance program and used for future epidemiological investigations.

  9. Legionella detection and subgrouping in water air-conditioning cooling tower systems in Kuwait.

    PubMed

    Al-Matawah, Qadreyah; Al-Zenki, Sameer; Al-Azmi, Ahmad; Al-Waalan, Tahani; Al-Salameen, Fadila; Hejji, Ahmad Ben

    2015-07-01

    The main aim of the study was to test for the presence of Legionnaires' disease-causing microorganisms in air-conditioned buildings in Kuwait using molecular technologies. For this purpose, 547 samples were collected from 38 cooling towers for the analysis of Legionella pneumophila. These samples included those from water (n = 178), air (n = 231), and swabs (n = 138). Out of the 547 samples, 226 (41%) samples were presumptive positive for L. pneumophila, with L. pneumophila viable counts in the positive water samples ranging from 1 to 88 CFU/ml. Of the Legionella culture-positive samples, 204 isolates were examined by latex agglutination. These isolates were predominately identified as L. pneumophila serogroup (sg) 2-14. Using the Dresden panel of monoclonal antibodies, 74 representatives isolates were further serogrouped. Results showed that 51% of the isolates belonged to serogroup 7 followed by 1 (18%) and 3 (18%). Serogroups 4 (4%) and 10 (7%) were isolated at a lower frequency, and two isolates could not be assigned to a serogroup. These results indicate the wide prevalence of L. pneumophila serogroup 7 as the predominant serogroup at the selected sampling sites. Furthermore, the 74 L. pneumophila (sg1 = 13; sg3 = 13; sg4 = 3; sg7 = 38; sg10 = 5; sgX = 2) isolates were genotyped using the seven gene protocol sequence-based typing (SBT) scheme developed by the European Working Group for Legionella Infections (EWGLI). The results show that Legionella isolates were discriminated into nine distinct sequence typing (ST) profiles, five of which were new to the SBT database of EWGLI. Additionally, all of the ST1 serogroup 1 isolates were of the OLDA/Oxford subgroup. These baseline data will form the basis for the development of a Legionella environmental surveillance program and used for future epidemiological investigations. PMID:25701245

  10. Water treatment: Air stripping. December 1981-July 1989 (Citations from the Selected Water Resources Abstracts data base). Report for December 1981-July 1989

    SciTech Connect

    Not Available

    1989-10-01

    This bibliography contains citations concerning the application of air stripping techniques to water treatment, including ground-water decontamination and waste-water purification. The advantages and disadvantages of air stripping over other water-treatment processes are discussed. Cleanup of the organic emissions generated by air stripping is also considered. The primary applications of air stripping are in ground-water and soil cleanup. Other water treatment processes are discussed in separate bibliographies. (Contains 74 citations fully indexed and including a title list.)

  11. Influence of liquid and gas flow rates on sulfuric acid mist removal from air by packed bed tower

    PubMed Central

    2012-01-01

    The possible emission of sulfuric acid mists from a laboratory scale, counter-current packed bed tower operated with a caustic scrubbing solution was studied. Acid mists were applied through a local exhaust hood. The emissions from the packed bed tower were monitored in three different categories of gas flow rate as well as three liquid flow rates, while other influencing parameters were kept almost constant. Air sampling and sulfuric acid measurement were carried out iso-kinetically using USEPA method 8. The acid mists were measured by the barium-thorin titration method. According to the results when the gas flow rate increased from 10 L/s to 30 L/s, the average removal efficiency increased significantly (p < 0.001) from 76.8 ± 1.8% to 85.7 ± 1.2%. Analysis of covariance method followed by Tukey post-hoc test of 92 tests did not show a significant change in removal efficiency between liquid flow rates of 1.5, 2.5 and 3.5 L/min (p = 0.811). On the other hand, with fixed pressure loss across the tower, by increasing the liquid/gas (L/G) mass ratio, the average removal efficiency decreased significantly (p = 0.001) from 89.9% at L/G of <2 to 83.1% at L/G of 2–3 and further to 80.2% at L/G of >3, respectively. L/G of 2–3 was recommended for designing purposes of a packed tower for sulfuric acid mists and vapors removal from contaminated air stream. PMID:23369487

  12. Use of an air-fluid exchange system to promote graft adhesion during Descemet's stripping automated endothelial keratoplasty.

    PubMed

    Meisler, David M; Dupps, William J; Covert, Douglas J; Koenig, Steven B

    2007-05-01

    Dislocation of the graft is a well-recognized complication of Descemet's stripping automated endothelial keratoplasty (DSAEK). We describe a technique to promote adhesion of the graft during DSAEK using an anterior chamber air-fluid infusion and exchange for direct control of the pressure and medium used to tamponade the graft against the host stroma.

  13. In-well air stripping/bioventing study at Tyndall Air Force Base, Florida. Final technical report, 13 September 1991-30 November 1995

    SciTech Connect

    Alleman, B.C.

    1996-01-03

    This study was conducted to determine the feasibility of incorporating in-well air stripping systems into the design of bioventing systems to effectively extend bioventing to simultaneously remediate hydrocarbon contamination in both the vadose and saturated zones. The field study was conducted for 12 months between June 1994 and June 1995. The data demonstrated that the in-well air stripping systems were able to circulate the groundwater throughout the 25-foot radius of influence. The well systems were shown to be effective at remediating the benzene, toluene, ethylbenzene, and xylenes (BTEX) of the hydrocarbon contamination in the groundwater within the treatment cell. Conclusions made included: (1) the air lift pumping mechanism was capable of circulating groundwater in the aquifer; (2) the volatile compounds were effectively stripped from the groundwater; (3) anoxic groundwater entering the well was sufficiently oxygenated during air lift; (4) the residual oxygen in the off-gas from the in-well air stripping system was sufficient for supporting bioventing in the vadose zone; (5) volatile compounds in the off-gas from the well system were degraded in the vadose zone through bioventing when the mass loading did not exceed the degradative capacity of the microorganisms; and (6) bioventing was very effective for remediating residual hydrocarbon contamination in the vadose zone.

  14. Ground water and soil remediation: In situ air stripping using horizontal wells

    SciTech Connect

    Kaback, D.S.; Looney, B.B.; Eddy, C.A.; Hazen, T.C.

    1990-12-31

    An innovative environmental restoration technology, in situ air stripping, has been demonstrated at the US Department of Energy (DOE) Savannah River Site (SRS) in South Carolina. This process, using horizontal wells, is designed to concurrently remediate unsaturated-zone soils and ground water containing Volatile Organic Compounds (VOC). In situ technologies have the potential to substantially reduce costs and time required for remediation as well as improve effectiveness of remediation. Horizontal wells were selected to deliver and extract fluids from the subsurface because their geometry can maximize the efficiency of a remediation system and they have great potential for remediating contaminant sources under existing facilities. The first demonstration of this new technology was conducted for a period of twenty weeks. A vacuum was first drawn on the vadose zone well until a steady-state removal of VOCs was obtained. Air was then injected at three different rates and at two different temperatures. An extensive characterization program was conducted at the site and an extensive monitoring network was installed prior to initiation of the test. Significant quantities of VOCs have been removed from the subsurface (equivalent to an eleven-well, 500-gpm, pump-and-treat system at the same site). Concentrations of VOCs in the ground water have been significantly reduced in a number of the monitoring wells.

  15. Ground water and soil remediation: In situ air stripping using horizontal wells

    SciTech Connect

    Kaback, D.S.; Looney, B.B.; Eddy, C.A.; Hazen, T.C.

    1990-01-01

    An innovative environmental restoration technology, in situ air stripping, has been demonstrated at the US Department of Energy (DOE) Savannah River Site (SRS) in South Carolina. This process, using horizontal wells, is designed to concurrently remediate unsaturated-zone soils and ground water containing Volatile Organic Compounds (VOC). In situ technologies have the potential to substantially reduce costs and time required for remediation as well as improve effectiveness of remediation. Horizontal wells were selected to deliver and extract fluids from the subsurface because their geometry can maximize the efficiency of a remediation system and they have great potential for remediating contaminant sources under existing facilities. The first demonstration of this new technology was conducted for a period of twenty weeks. A vacuum was first drawn on the vadose zone well until a steady-state removal of VOCs was obtained. Air was then injected at three different rates and at two different temperatures. An extensive characterization program was conducted at the site and an extensive monitoring network was installed prior to initiation of the test. Significant quantities of VOCs have been removed from the subsurface (equivalent to an eleven-well, 500-gpm, pump-and-treat system at the same site). Concentrations of VOCs in the ground water have been significantly reduced in a number of the monitoring wells.

  16. Preliminary Design and Evaluation of Portable Electronic Flight Progress Strips

    NASA Technical Reports Server (NTRS)

    Doble, Nathan A.; Hansman, R. John

    2002-01-01

    There has been growing interest in using electronic alternatives to the paper Flight Progress Strip (FPS) for air traffic control. However, most research has been centered on radar-based control environments, and has not considered the unique operational needs of the airport air traffic control tower. Based on an analysis of the human factors issues for control tower Decision Support Tool (DST) interfaces, a requirement has been identified for an interaction mechanism which replicates the advantages of the paper FPS (e.g., head-up operation, portability) but also enables input and output with DSTs. An approach has been developed which uses a Portable Electronic FPS that has attributes of both a paper strip and an electronic strip. The prototype flight strip system uses Personal Digital Assistants (PDAs) to replace individual paper strips in addition to a central management interface which is displayed on a desktop computer. Each PDA is connected to the management interface via a wireless local area network. The Portable Electronic FPSs replicate the core functionality of paper flight strips and have additional features which provide a heads-up interface to a DST. A departure DST is used as a motivating example. The central management interface is used for aircraft scheduling and sequencing and provides an overview of airport departure operations. This paper will present the design of the Portable Electronic FPS system as well as preliminary evaluation results.

  17. Removing a small quantity of THT from gas storage groundwater through air stripping and gas-phase carbon adsorption

    SciTech Connect

    Girod, J.F.; Leclerc, J.P.; Muhr, H.

    1996-12-31

    This paper deals with the response to a case of contaminated groundwater located in France. The natural gas is stored during summer in porous underground rocks. When energy requirements increase (particularly in winter), gas is drawn off, but water is also pumped during this operation. The water has a strong characteristic odour of the TetraHydroThiophene (THT), which has been used by Gaz de France as an additive in order to detect gas leakages because of its strong odour. Unfortunately, the presence of THT in medium other than natural gas can be responsible for safety problems. Gas stripping combined with adsorption on granular activated carbon was chosen to obtain removal of THT from the groundwater. The gas to water ratio for stripping column is higher than usual and the gas used for stripping was recycled in order to prevent air pollution. Carbon consumption is approximately 3 tons a year. 8 refs., 5 figs., 2 tabs.

  18. A study of air-to-ground sound propagation using an instrumented meteorological tower

    NASA Technical Reports Server (NTRS)

    Kasper, P. K.; Pappa, R. S.; Keefe, L. R.; Sutherland, L. C.

    1975-01-01

    The results of an exploratory NASA study, leading to a better understanding of the effects of meteorological conditions on the propagation of aircraft noise, are reported. The experimental program utilized a known sound source fixed atop an instrumented meteorological tower. The basic experimental scheme consisted of measuring the amplitude of sound radiated toward the ground along a line of microphones fixed to a tower guy wire. Experimental results show the feasibility of this approach in the acquisition of data indicating the variations encountered in the time-averaged and instantaneous amplitudes of propagated sound. The investigation included a consideration of ground reflections, a comparison of measured attenuations with predicted atmospheric absorption losses, and an evaluation of the amplitude fluctuations of recorded sound pressures.

  19. Use of Oriented Spray Nozzles to Set the Vapor-Air Flow in Rotary Motion in the Superspray Space of the Evaporative Chimney-Type Tower

    NASA Astrophysics Data System (ADS)

    Dobrego, K. V.; Davydenko, V. F.; Koznacheev, I. A.

    2016-01-01

    The present paper considers the problem of upgrading the thermal efficiency of chimney-type evaporative cooling towers due to the rotary motion of the vapor-air flow in the superspray space. To set the vapor-air flow in rotary motion, we propose to use the momentum of the sprayed water. It has been shown that the existing parameters of spray nozzles permit setting up to 30% of the water flow momentum in translatory motion, which is enough for changing considerably the aerodynamics of the vapor-air flow in the superspray space and improving the operation of the cooling tower. The optimal angle of axial inclination of the spray cone has been estimated. Recommendations are given and problems have been posed for engineering realization of the proposed technologies in a chimney-type cooling tower.

  20. Flow Alteration and Chemical Reduction: Air Stripping to Lessen Subsurface Discharges of Mercury to Surface Water

    NASA Astrophysics Data System (ADS)

    Brooks, S. C.; Bogle, M.; Liang, L.; Miller, C. L.; Peterson, M.; Southworth, G. R.; Spalding, B. P.

    2009-12-01

    process water. Greater than 90% of the mercury in that discharge was converted to the highly volatile dissolved Hg(0) by dechlorinating the streamflow with ascorbic acid and then treating it with a near stoichiometric concentration of the chemical reductant stannous chloride. Preliminary engineering evaluations indicate that once converted to Hg(0), mercury in the stream discharge could be removed by in-situ air stripping at the discharge point or perhaps within the enclosed stormdrain network upstream. If chemical reduction:air stripping was eventualy able to remove 80% or more of Hg from water, input to the stream from that source could be lowered from 6 - 8 g/d to 1 - 2 g/d. Together, these two strategies have the potential to eliminate much of the remaining dissolved Hg input to the creek.

  1. Stripping organics from groundwater and wastewater

    SciTech Connect

    Lamarre, B.; Shearouse, D.

    1996-03-01

    At thousands of installations worldwide, air stripping has been used as an efficient method for removing volatile and semi-volatile contaminants from water -- both groundwater and industrial wastewater streams. In addition to numerous field installations, extensive laboratory analysis has confirmed the performance of various types and sizes of air strippers, and has made the practice highly predictable for a wide range of contaminants. The general principles of air stripping are quite simple. Within an air stripper, an air stream is directed across a thin film of contaminated water. Contaminants at the air-water interface volatilize and are discharged to the atmosphere, or to an off-gas treatment system. The two main types of air strippers are packed towers and try-type strippers. In many cases, air stripping can be a fast, efficient and economical approach to treating organics-laden water streams. However, since different wastewater streams can vary significantly, each must be evaluated to characterize its constitutents, determine each constituent`s potential affinity or resistance to being volatilized, and identify any pre-treatment steps that need to be taken to produce the desired results.

  2. Application of ultrasound and air stripping for the removal of aromatic hydrocarbons from spent sulfidic caustic for use in autotrophic denitrification as an electron donor.

    PubMed

    Lee, Jae-Ho; Park, Jeung-Jin; Choi, Gi-Choong; Byun, Im-Gyu; Park, Tae-Joo; Lee, Tae-Ho

    2013-01-01

    Spent sulfidic caustic (SSC) produced from petroleum industry can be reused to denitrify nitrate-nitrogen via a biological nitrogen removal process as an electron donor for sulfur-based autotrophic denitrification, because it has a large amount of dissolved sulfur. However, SSC has to be refined because it also contains some aromatic hydrocarbons, typically benzene, toluene, ethylbenzene, xylene (BTEX) and phenol that are recalcitrant organic compounds. In this study, laboratory-scale ultrasound irradiation and air stripping treatment were applied in order to remove these aromatic hydrocarbons. In the ultrasound system, both BTEX and phenol were exponentially removed by ultrasound irradiation during 60 min of reaction time to give the greatest removal efficiency of about 80%. Whereas, about 95% removal efficiency of BTEX was achieved, but not any significant phenol removal, within 30 min in the air stripping system, indicating that air stripping was a more efficient method than ultrasound irradiation. However, since air stripping did not remove any significant phenol, an additional process for degrading phenol was required. Accordingly, we applied a combined ultrasound and air stripping process. In these experiments, the removal efficiencies of BTEX and phenol were improved compared to the application of ultrasound and air stripping alone. Thus, the combined ultrasound and air stripping treatment is appropriate for refining SSC.

  3. Program plan: Testing of vacuum extraction and in-situ air stripping technologies

    SciTech Connect

    Kaback, D.S.; Looney, B.B.

    1987-07-24

    Recent hydrological investigations at the Savannah River Plant (SRP) have shown that operation of the plant has resulted in contamination of the groundwater and the vadose zone in various locations across the plant. Volatile organic solvent (VOC) contamination has been observed at a number of locations across SRP. A remedial action program consisting of above-ground air stripping of groundwater is underway to address contamination in M Area. A recent pilot study to clean up the soils above the water table was completed in M Area (for location see Figure 1). A new technique, in-situ vacuum extraction, successfully removed significant quantities of trichloroethylene and tetrachloroethylene from the soils along a portion of the abandoned process-sewer line in M Area. The vacuum-extraction test was conducted for a period of three weeks. It is calculated that almost 1500 pounds of solvents were removed from the soils during the test. The radius of influence for the vacuum process is estimated to be greater than 75 feet. 5 figs.

  4. Field demonstration of in-situ air stripping using horizontal wells

    SciTech Connect

    Looney, B.B.; Kaback, D.S.

    1991-12-31

    Under sponsorship from the US Department of Energy, technical personnel from the Savannah River Laboratory and other DOE laboratories, universities and private industry have completed a full scale demonstration of environmental remediation using horizontal wells. The 139 day long test was designed to remove volatile chlorinated solvents from the subsurface using two horizontal wells. One well, approximately 90m long and 45m deep drilled below a contaminant plume in the groundwater, was used to inject air and strip the contaminants from the groundwater. A second horizontal well, approximately 50m long and 20m deep in the vadose zone, was used to extract residual contamination in the vadose zone along with the material purged from the groundwater. The test successfully removed approximately 7250 kg of contaminants. A large amount of characterization and monitoring data was collected to aid in interpretation of the test and to provide the information needed for future environmental restorations that employ directionally drilled wells as extraction or delivery systems.

  5. Field demonstration of in-situ air stripping using horizontal wells

    SciTech Connect

    Looney, B.B.; Kaback, D.S.

    1991-01-01

    Under sponsorship from the US Department of Energy, technical personnel from the Savannah River Laboratory and other DOE laboratories, universities and private industry have completed a full scale demonstration of environmental remediation using horizontal wells. The 139 day long test was designed to remove volatile chlorinated solvents from the subsurface using two horizontal wells. One well, approximately 90m long and 45m deep drilled below a contaminant plume in the groundwater, was used to inject air and strip the contaminants from the groundwater. A second horizontal well, approximately 50m long and 20m deep in the vadose zone, was used to extract residual contamination in the vadose zone along with the material purged from the groundwater. The test successfully removed approximately 7250 kg of contaminants. A large amount of characterization and monitoring data was collected to aid in interpretation of the test and to provide the information needed for future environmental restorations that employ directionally drilled wells as extraction or delivery systems.

  6. Optimization of the integrated citric acid-methane fermentation process by air stripping and glucoamylase addition.

    PubMed

    Xu, Jian; Chen, Yang-Qiu; Zhang, Hong-Jian; Wang, Ke; Tang, Lei; Zhang, Jian-Hua; Chen, Xu-Sheng; Mao, Zhong-Gui

    2015-03-01

    To solve the problem of extraction wastewater in citric acid industry, an integrated citric acid-methane fermentation process was proposed. In the integrated process, extraction wastewater was treated by mesophilic anaerobic digestion and then reused to make mash for the next batch of citric acid fermentation. In this study, an Aspergillus niger mutant strain exhibiting resistance to high metal ions concentration was used to eliminate the inhibition of 200 mg/L Na(+) and 300 mg/L K(+) in anaerobic digestion effluent (ADE) and citric acid production increased by 25.0 %. Air stripping was used to remove ammonium, alkalinity, and part of metal ions in ADE before making mash. In consequence, citric acid production was significantly improved but still lower by 6.1 % than the control. Results indicated that metal ions in ADE synergistically inhibited the activity of glucoamylase, thus reducing citric acid production. When 130 U/g glucoamylase was added before fermentation, citric acid production was 141.5 g/L, which was even higher than the control (140.4 g/L). This process could completely eliminate extraction wastewater discharge and reduce water resource consumption.

  7. Aquarius: Tower Rollback

    NASA Video Gallery

    The mobile service tower at NASA's Launch Complex-2 at Vandenberg Air Force Base in California is being moved away from the ULA Delta II rocket with the Aquarius/SAC-D spacecraft atop, in preparati...

  8. Nitrogen potential recovery and concentration of ammonia from swine manure using electrodialysis coupled with air stripping.

    PubMed

    Ippersiel, D; Mondor, M; Lamarche, F; Tremblay, F; Dubreuil, J; Masse, L

    2012-03-01

    The practice of intensive animal production in certain areas has resulted in excessive manure production for the available regional land base. Consequently, there is a need to develop treatment technologies to recover the valuable nutrients that manure contains so that the resulting product can be transported and used as fertilizer on agricultural land. The project presented here used electrodialysis in a dilution/concentration configuration to transfer the manure ammonia in the diluate solution by electromigration to an adjacent solution separated by an ion-exchange membrane under the driving force of an electrical potential. Then, air stripping from the electrodialysis-obtained concentrate solution without pH modification was used to isolate the ammonia in an acidic solution. An optimal process operating voltage of 17.5 V was first determined on the basis of current efficiency and total energy consumption. During the process, the swine manure pH varied from 8.5 to 8.2, values favourable for NH(4)(+) electromigration. Total ammonia nitrogen reached 21,352 mg/L in the concentrate solution, representing approximately seven times the concentration in the swine manure. Further increases in concentration were limited by water transfer from the diluate solution due to electroosmosis and osmosis. Applying vacuum to the concentrate reservoir was found to be more efficient than direct concentrate solution aeration for NH(3) recuperation in the acid trap, given that the ammonia recuperated under vacuum represented 14.5% of the theoretical value of the NH(3) present in the concentrate solution as compared to 6.2% for aeration. However, an excessively low concentrate solution pH (8.6-8.3) limited NH(3)volatilization toward the acid trap. These results suggest that the concentrate solution pH needs to be raised to promote the volatile NH(3) form of total ammonia nitrogen.

  9. Impact of nocturnal planetary boundary layer on urban air pollutants: measurements from a 250-m tower over Tianjin, China.

    PubMed

    Han, Suqin; Bian, Hai; Tie, Xuexi; Xie, Yiyang; Sun, Meiling; Liu, Aixia

    2009-02-15

    It is well known that nocturnal planetary boundary layer (NPBL) has important effects on urban air pollutants. However, the direct measurements of the interactions between the NPBL height and urban air pollutants are normally difficult, because such measurements require continuous vertical profiles of air pollutants and meteorological parameters. This paper provides an unique data, which temperature, NPBL, NO(x) and O(3) concentrations are measured at a 250-m meteorological tower in the city of Tianjin, China (a much polluted city located in central-eastern China). The results are analyzed to study the trend of NPBL and the impacts of NPBL on air pollutants in the city. The results show that the measured NPBL height ranges from 100m to 150m. The measurement of 10-year trend of the NPBL height suggests that the averaged NPBL height increases by about 20% between 1995 and 2006. The results also show that the NPBL height has important effects on air pollutants. This study suggests that NO(x) and O(3) concentrations are strongly anti-correlated inside of the NPBL height. During nighttime, NO(x) is directly emitted from the surface and is limited to inside of NPBL (40m), resulting in high NO(x) concentrations near the surface. The high NO(x) concentrations depress O(3), producing low O(3) concentrations near the surface. The measurements of vertical gradient of O(3) show that about 30-50ppbv of O(3) concentrations are chemically destroyed due to the surface emission of NO(x) during nighttime, suggesting that NPBL plays important roles in regulating the diurnal cycle of O(3) at the surface.

  10. Evaluation of pH, alkalinity and temperature during air stripping process for ammonia removal from landfill leachate.

    PubMed

    Campos, Juacyara Carbonelli; Moura, Denise; Costa, Ana Paula; Yokoyama, Lidia; Araujo, Fabiana Valeria da Fonseca; Cammarota, Magali Christe; Cardillo, Luigi

    2013-01-01

    The objective of this research was to evaluate the air stripping technology for the removal of ammonia from landfill leachates. In this process, pH, temperature, airflow rate and operation time were investigated. Furthermore, the relationship between the leachate alkalinity and the ammonia removal efficiency during the process was studied. The leachate used in the tests was generated in the Gramacho Municipal Solid Waste Landfill (Rio de Janeiro State, Brazil). The best results were obtained with a temperature of 60(o)C, and they were independent of the pH value for 7 h of operation (the ammonia nitrogen removal was greater than 95%). A strong influence of the leachate alkalinity on the ammonia nitrogen removal was observed; as the alkalinity decreased, the ammonia concentration also decreased because of prior CO2 removal, which increased the pH and consequently favored the NH3 stripping. The air flow rate, in the values evaluated (73, 96 and 120 L air.h(-1).L(-1) of leachate), did not influence the results.

  11. Acute and sub-lethal toxicity of landfill leachate towards two aquatic macro-invertebrates: demonstrating the remediation potential of air stripping.

    PubMed

    Bloor, M C; Banks, C J

    2005-10-01

    A specific leachate that contained 1.036 mg l(-1) of 2-chlorobiphenyl was used in the study (255 mg l(-1) COD and 133 mg l(-1) BOD5). Bench scale (20 l) air stripping trials were used to simulate on a small-scale the treatment potential of this method. Air stripping effectively reduced the leachates COD concentration. Regardless of the volume of air supplied (1-5 l of air per minute) the leachates COD reached a <50 mg l(-1) equilibrium after 96-h exposure, however, increasing the volume of air accelerated the process. In untreated leachate, the LC50 for Asellus aquaticus was 57% v/v leachate in deionised water and 5% for Gammarus pulex (96-h, static LC50 tests without nutrition and oxygen depleting conditions). After being exposed to air stripping, these values rose from 90% to below the LC50 threshold for Asellus when 1-5 l of air per minute were applied and 30-90% for Gammarus. Furthermore, in sub-lethal concentrations of air stripped leachate (leachate that had been exposed to 5-l of air per minute for 96-h) the population dynamics of both test species remained unaltered.

  12. Detecting CO2 and CH4 Urban Emissions using Column-Integrated Dry Air mole Fractions, In-Situ Tower Dry Air Mole Fractions, and WRF Modeling

    NASA Astrophysics Data System (ADS)

    Hillyard, P. W.; Lauvaux, T.; Podolske, J. R.; Iraci, L. T.; Miles, N. L.; Richardson, S.; Davis, K.; Roehl, C. M.; Wunch, D.; Wennberg, P. O.; Blavier, J. F.; Allen, N.; Barrow, E.; Deng, A.

    2015-12-01

    Total column measurements of atmospheric gases are important because of their ability to be performed via satellites that provide global coverage. Here we will present measurements of CO2 and CH4 dry air mole fractions obtained using a Fourier Transform Spectrometer (FTS) as part of the Total Carbon Column Observing Nework (TCCON). These measurements were performed in Indianapolis as part of the Indianapolis Flux Experiment (INFLUX). We will extract urban emission signals using high resolution modeling and in-situ tower measurements of CO2 and CH4 mixing ratios. In addition to quantifying the influence of surface emissions on the column measurements, we will also decompose the atmospheric columns into sub-layers to identify the origin of air masses at various altitudes. We will show that the variability in the origins of air masses increases the complexity of the observed signals in the column, which limits our ability to combine surface and column measurements. This work will also highlight the potential application of using total column measurements to detect local urban signals. We conclude that the deployment of multiple column sensors is required in order to measure the upwind (background) and downwind (urban) conditions. Such work provides a test case for using these methods with satellite measurements such as GOSAT and OCO-2 that provide global coverage.

  13. Ant Tower

    NASA Astrophysics Data System (ADS)

    Mlot, Nathan; Shinotsuka, Sho; Hu, David

    2010-11-01

    Ants walk via adhesive drops of fluid extruded by their feet. They also use these drops as mortar to build structures such as rafts, bridges and towers, each composed of thousands of ants linked together. We investigate experimentally the construction of triangular ant towers braced by hydrophobic walls. Particular attention is paid to the relationship between tower height and contact angle hysteresis of the wall. We rationalize tower height according to ant adhesion, and tower shape according to the constraints on a column of constant strength.

  14. Effect of CO{sub 2} air mixtures on the pH of air-stripped water at Treatment Facility D

    SciTech Connect

    Krauter, P.W.; Harrar, J.E.; Orloff, S.P.

    1998-01-01

    A small-scale model of the air stripping tanks at TFD was constructed and tested to determine the effect of carbon dioxide additions, to the stripper air, on system water pH. The objective was to determine whether this technique could be used to control and minimize CaCO{sub 3} scale formation. It was found that a concentration of 0.7 vol. % CO{sub 2} is required to maintain the water at its original, influent pH value of 7.4, but lower concentrations may be effective in controlling scale. There is also a possibility of reducing CO{sub 2} consumption by recycling the CO{sub 2}-rich air. The use of CO{sub 2} injection at Site 300 water treatment is reviewed.

  15. Outfall 51 air stripping feasibility study for the Reduction of Mercury in Plant Effluent (RMPE) Project. Revision 1

    SciTech Connect

    1997-01-01

    Within the US Department of Energy`s Oak Ridge Y-12 Plant there are a number of industrial wastewater discharge points or outfalls that empty into East Fork Poplar Creek (EFPC). EFPC originates within and runs continuously throughout the plant site and subsequently flows out the east end of the Y-12 Plant into the City of Oak Ridge. Mercury is present in outfall discharges due to contact of water with the soils surrounding past mercury-use buildings. As a result, the Reduction of Mercury in Plant Effluent (RMPE) Project was developed to achieve and maintain environmental compliance with regards to mercury, and, in particular with the National Pollutant Discharge Elimination System permit for the Y-12 Plant. To achieve a reduction in mercury loading to EFPC, a number of options have already been studied and implemented as part of the RMPE project. With the successful implementation of these options, Outfall 51 remains as a significant contributor to mercury load to EFPC. The primary purpose of this project is to determine the feasibility of removing mercury from contaminated spring water using air stripping. In order to accomplish this goal, a number of different areas were addressed. A pilot-scale unit was tested in the field using actual mercury-contaminated source water. Properties which impact the mercury removal via air stripping were reviewed to determine their effect. Also, enhanced testing was performed to improve removal efficiencies. Finally, the variable outfall flow was studied to size appropriate processing equipment for full-scale treatment.

  16. Toxic treatments 'in-situ' steam/hot-air stripping technology. Applications analysis report. Rept. for Jun 89-Jun 90

    SciTech Connect

    Jackson, T.

    1991-03-01

    A SITE Demonstration of the Toxic Treatment (USA) Inc. in-situ steam/hot-air stripping technology (Detoxifier) was conducted beginning in the fall of 1989 at the GATX Annex Terminal site located in San Pedro, CA. The chemical storage and transfer facility was contaminated with various solvents due to spillage and a fire. Contamination extended into the salt water table (1.8 meters). Based on the SITE Demonstration and other data, it was concluded that 85% of the volatile organic compounds and 50% of the semivolatile organic compounds were removed from the soil. Fugitive air emissions are very low, and lateral and downward migration of contaminants due to the treatment were minimal. Finally, it was concluded that this in-situ process is cost competitive.

  17. Niche for steam stripping in treating dilute SOC-contaminated waters

    SciTech Connect

    Dvorak, B.I.; Lawler, D.F.; Speitel, G.E. Jr.

    1996-09-01

    As regulatory limits for contaminants in air and water become increasingly stringent, interest in steam stripping to remove synthetic organic compounds (SOCs) from industrial waters has increased. To identify situations in which steam stripping could be a cost-competitive option for treating waters contaminated with low concentrations (<10 mg/L) of synthetic organic chemicals, the performance and cost of steam-stripping towers were modeled, and a range of hypothetical contaminated waters was examined. The cost of steam stripping was compared to that of air stripping, liquid-phase carbon adsorption, and air stripping with off-gas adsorption. Steam stripping was found to be a highly specialized treatment technology that will not frequently be cost-effective, but it does have a small niche in the environmental remediation market. Steam stripping is cost-effective when site-specific factors significantly reduce capital or operating costs, or when the target chemical is only marginally volatile, adsorbable, and biodegradable, effectively making all other conventional treatment methods more expensive.

  18. Windmill tower

    SciTech Connect

    Schachle, C.; Schachle, E.C.; Schachle, J.R.; Schachle, P.J.

    1982-04-06

    A windmill tower supports a propeller and a platform that in turn supports a propeller feather control system and a generator system. The entire tower rotates at its base under changes in wind direction so the rotating propeller is constantly maintained upwind of the tower. The tower is a rigid structure that withstands cyclic thrust and torque loading sufficiently to reduce resonant vibrations of the tower as the propeller rotates under the influence of the wind. The resonant frequency of the tower can be higher than the passing frequency of the rotating propeller blades. The tower includes a pair of generally upright fore legs that converge upwardly toward a first apex on the propeller axis of rotation near the front of the platform immediately behind the propeller hub. A diagonal bracing strut extends downwardly from the first apex away from the plane of the fore legs and toward the rear of the tower. The bottoms of the fore legs and the diagonal bracing strut are rigidly interconnected by base plane truss members. A pair of upwardly converging aft legs extend diagonally upwardly from the bottoms of the fore legs toward a second apex aft of the first apex at the rear of the platform. At regular vertical intervals, stiffening trusses add rigidity to the main upright members of the tower structure. The natural frequency of the tower is raised by the fore legs and the diagonal bracing strut being interconnected in a rigid base plane truss. The diagonal bracing strut resists thrust loading on the tower, and the fore legs and aft legs resist torsional forces produced at the top of the tower.

  19. Post-test evaluation of the geology, geochemistry, microbiology, and hydrology of the in situ air stripping demonstration site at the Savannah River Site

    SciTech Connect

    Eddy Dilek, C.A.; Looney, B.B.; Hazen, T.C.; Nichols, R.L.; Fliermans, C.B.; Parker, W.H.; Dougherty, J.M.; Kaback, D.S.; Simmons, J.L.

    1993-07-01

    A full-scale demonstration of the use of horizontal wells for in situ air stripping for environment restoration was completed as part of the Savannah River Integrated Demonstration Program. The demonstration of in situ air stripping was the first in a series of demonstrations of innovative remediation technologies for the cleanup of sites contaminated with volatile organic contaminants. The in situ air stripping system consisted of two directionally drilled wells that delivered gases to and extract contamination from the subsurface. The demonstration was designed to remediate soils and sediments in the unsaturated and saturated zones as well as groundwater contaminated with volatile organic compounds. The demonstration successfully removed significant quantities of solvent from the subsurface. The field site and horizontal wells were subsequently used for an in situ bioremediation demonstration during which methane was added to the injected air. The field conditions documented herein represent the baseline status of the site for evaluating the in situ bioremediation as well as the post-test conditions for the in situ air stripping demonstration. Characterization activities focused on documenting the nature and distribution of contamination in the subsurface. The post-test characterization activities discussed herein include results from the analysis of sediment samples, three-dimensional images of the pretest and post-test data, contaminant inventories estimated from pretest and post-test models, a detailed lithologic cross sections of the site, results of aquifer testing, and measurements of geotechnical parameters of undisturbed core sediments.

  20. AIR STRIPPING AND OFF-GAS ADSORPTION FOR THE REMOVAL OF MTBE FROM DRINKING WATER

    EPA Science Inventory

    Methyl-tertiary butyl ether (MTBE) is a synthetic organic chemical, primarily used for oxgenating fuel. The 1990 Federal Clean Air Act Amendments mandated the use of fuel oxgenates in areas where air quality did not meet national standards, which led to widespread use of MTBE in...

  1. Full scale field test of the in situ air stripping process at the Savannah River integrated demonstration test site

    SciTech Connect

    Looney, B.B.; Hazen, T.C.; Kaback, D.S.; Eddy, C.A.

    1991-06-29

    Under sponsorship from the US Department of Energy, technical personnel from the Savannah River Laboratory (SRL) and other DOE laboratories, universities and private industry have completed a full scale demonstration of environmental remediation using horizontal wells. This demonstration was performed as Phase I of an Integrated Demonstration Project designed to evaluate innovative remediation technologies for environmental restoration of sites contaminated with organic contaminants. The demonstration utilized two directionally drilled horizontal wells to deliver gases and extract contaminants from the subsurface. The resulting in situ air stripping process was designed to remediate soils and sediments above and below the water table as well as groundwater contaminated with volatile organic contaminants. The 139 day long test successfully removed volatile chlorinated solvents from the subsurface using the two horizontal wells. One well, approximately 300 ft (90m) long and 165 ft (50m) deep drilled below a contaminant plume in the groundwater, was used to inject air and strip the contaminants from the groundwater. A second horizontal well, approximately 175 ft (53m) long and 75 ft (23m) deep in the vadose zone, was used to extract residual contamination in the vadose zone along with the material purged from the groundwater. Pretest and posttest characterization data and monitoring data during the demonstration were collected to aid in interpretation of the test and to provide the information needed for future environmental restoration that employ directionally drilled wells as extraction or delivery systems. Contaminant concentration data and microbiological monitoring data are summarized in this report; the characterization data and geophysical monitoring data are documented in a series of related project reports.

  2. Characterization of dissolved organic matter in landfill leachate during the combined treatment process of air stripping, Fenton, SBR and coagulation.

    PubMed

    Liu, ZhiPing; Wu, WenHui; Shi, Ping; Guo, JinSong; Cheng, Jin

    2015-07-01

    A combined treatment process of air stripping+Fenton+sequencing batch reactor (SBR)+ coagulation was performed to remove the pollutants in landfill leachate. Molecular weight (MW) distribution and fractions of dissolved organic matter (DOM) were discussed to study the characteristics. The experiment showed that the removal rate of chemical oxygen demand (COD), five day biological oxygen demand (BOD5) and ammonia nitrogen (NH3N) by the combined process were 92.8%, 87.8% and 98.0%, respectively. Humic acid (HA) and fulvic acid (FA) were the main fractions in raw leachate with 81.8% of the total COD concentration, while hydrophilic organic matter (HyI) was the dominant fraction in the final effluent of the combined process with 63.5% of the total COD concentration. After the combined treatment process, the removal rate of DOM and fractions HA, FA, HyI were 91.9%, 97.1%, 95.8% and 71.7%, respectively. Organic matters of MW<2k and MW>100k were removed with 90.5% and 97.9% COD concentration after the treatment. The ultraviolet-visible spectra (UV-vis), Fourier transform infrared spectra (FTIR) and three-dimensional excitation-emission matrices spectra (EEMs) indicated that benzene materials and phenol compounds were preferentially removed in air stripping. High MW matters, aromatic rings, conjugated moieties and some functional groups were mainly removed by Fenton. While smallMW fractions, carboxylic acids, alcohols and protein-like materials were preferentially biodegraded via SBR. Fulvic-like and humic-like materials were mainly destroyed via Fenton oxidation and coagulation.

  3. Characterization of dissolved organic matter in landfill leachate during the combined treatment process of air stripping, Fenton, SBR and coagulation

    SciTech Connect

    Liu, ZhiPing; Wu, WenHui; Shi, Ping; Guo, JinSong; Cheng, Jin

    2015-07-15

    Highlights: • DOM fractions spectra analysis during the whole treatment process. • Efficient method was achieved to remove organic matters in landfill leachate. • Molecular weight distribution and fractions were discussed. - Abstract: A combined treatment process of air stripping + Fenton + sequencing batch reactor (SBR)+ coagulation was performed to remove the pollutants in landfill leachate. Molecular weight (MW) distribution and fractions of dissolved organic matter (DOM) were discussed to study the characteristics. The experiment showed that the removal rate of chemical oxygen demand (COD), five day biological oxygen demand (BOD{sub 5}) and ammonia nitrogen (NH{sub 3}−N) by the combined process were 92.8%, 87.8% and 98.0%, respectively. Humic acid (HA) and fulvic acid (FA) were the main fractions in raw leachate with 81.8% of the total COD concentration, while hydrophilic organic matter (HyI) was the dominant fraction in the final effluent of the combined process with 63.5% of the total COD concentration. After the combined treatment process, the removal rate of DOM and fractions HA, FA, HyI were 91.9%, 97.1%, 95.8% and 71.7%, respectively. Organic matters of MW < 2 k and MW > 100 k were removed with 90.5% and 97.9% COD concentration after the treatment. The ultraviolet–visible spectra (UV–vis), Fourier transform infrared spectra (FTIR) and three-dimensional excitation-emission matrices spectra (EEMs) indicated that benzene materials and phenol compounds were preferentially removed in air stripping. High MW matters, aromatic rings, conjugated moieties and some functional groups were mainly removed by Fenton. While small MW fractions, carboxylic acids, alcohols and protein-like materials were preferentially biodegraded via SBR. Fulvic-like and humic-like materials were mainly destroyed via Fenton oxidation and coagulation.

  4. Characterization of dissolved organic matter in landfill leachate during the combined treatment process of air stripping, Fenton, SBR and coagulation.

    PubMed

    Liu, ZhiPing; Wu, WenHui; Shi, Ping; Guo, JinSong; Cheng, Jin

    2015-07-01

    A combined treatment process of air stripping+Fenton+sequencing batch reactor (SBR)+ coagulation was performed to remove the pollutants in landfill leachate. Molecular weight (MW) distribution and fractions of dissolved organic matter (DOM) were discussed to study the characteristics. The experiment showed that the removal rate of chemical oxygen demand (COD), five day biological oxygen demand (BOD5) and ammonia nitrogen (NH3N) by the combined process were 92.8%, 87.8% and 98.0%, respectively. Humic acid (HA) and fulvic acid (FA) were the main fractions in raw leachate with 81.8% of the total COD concentration, while hydrophilic organic matter (HyI) was the dominant fraction in the final effluent of the combined process with 63.5% of the total COD concentration. After the combined treatment process, the removal rate of DOM and fractions HA, FA, HyI were 91.9%, 97.1%, 95.8% and 71.7%, respectively. Organic matters of MW<2k and MW>100k were removed with 90.5% and 97.9% COD concentration after the treatment. The ultraviolet-visible spectra (UV-vis), Fourier transform infrared spectra (FTIR) and three-dimensional excitation-emission matrices spectra (EEMs) indicated that benzene materials and phenol compounds were preferentially removed in air stripping. High MW matters, aromatic rings, conjugated moieties and some functional groups were mainly removed by Fenton. While smallMW fractions, carboxylic acids, alcohols and protein-like materials were preferentially biodegraded via SBR. Fulvic-like and humic-like materials were mainly destroyed via Fenton oxidation and coagulation. PMID:25899801

  5. Air stripping of ammonia from pig slurry: characterisation and feasibility as a pre- or post-treatment to mesophilic anaerobic digestion.

    PubMed

    Bonmatí, August; Flotats, Xavier

    2003-01-01

    The objective of the present paper has been to study the effect of pig slurry waste type, fresh or anaerobically digested, and the effect of initial pH on ammonia air stripping from pig slurry waste at high temperature (80 degrees C). Stripping process as pre- or post-treatment to anaerobic digestion has been also evaluated. Treatment performances differ according to pig slurry type. When fresh pig slurry is used, despite working at 80 degrees C, a high initial pH (11.5) is required for complete ammonia removal. On the other hand, for digested pig slurry, complete ammonia removal without pH modification is possible and organic matter significantly less contaminates recovered ammonia salt. Batch anaerobic tests showed that ammonia air stripping is not an advisable pre-treatment to pig slurry anaerobic digestion.

  6. 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.

  7. Collapsible Towers

    NASA Technical Reports Server (NTRS)

    1976-01-01

    NASA needed a means of orbiting a large radio telescope antenna. Astro Research Corporation developed a new structure that was strong, lightweight, folded into a small storage space, and could be erected by rotation. Later they adapted it to commercial use. Today the "Astromast" tower consists of tubular aluminum alloy and stainless steel members that deploy into small three-sided bays, each made rigid by six diagonal cables. All joints are flexible to permit folding and unfolding. Tower packs into container 5% of its height, can be erected without tools and is reusable. Tower has won "Design of the Year" award from Machine Design. Variations include portable emergency bridges and commercial scaffolding.

  8. The TALE Tower Detector

    NASA Astrophysics Data System (ADS)

    Bergman, D. R.

    The TA Low Energy Extension will include a Tower FluorescenceDetector. Extensive air showers at the lowest usful energies for fluorescence detectors will in general be close to the detector. This requires viewing all elevation angles to be able to reconstruct showers. The TALE Tower Detector, operating in conjunction with other TALE detectors will view elevation angles up to above 70 degrees, with an azimuthal coverage of about 90 degrees. Results from a prototype mirror operated in conjunction with the HiRes detector will also be presented.

  9. Simultaneous stripping recovery of ammonia-nitrogen and precipitation of manganese from electrolytic manganese residue by air under calcium oxide assist.

    PubMed

    Chen, Hongliang; Liu, Renlong; Shu, Jiancheng; Li, Wensheng

    2015-01-01

    Leaching tests of electrolytic manganese residue (EMR) indicated that high contents of soluble manganese and ammonia-nitrogen posed a high environmental risk. This work reports the results of simultaneous stripping recovery of ammonia-nitrogen and precipitation of manganese by air under calcium oxide assist. The ammonia-nitrogen stripping rate increased with the dosage of CaO, the air flow rate and the temperature of EMR slurry. Stripped ammonia-nitrogen was absorbed by a solution of sulfuric acid and formed soluble (NH4)2SO4 and (NH4)3H(SO4)3. The major parameters that effected soluble manganese precipitation were the dosage of added CaO and the slurry temperature. Considering these two aspects, the efficient operation conditions should be conducted with 8 wt.% added CaO, 60°C, 800 mL min(-1) air flow rate and 60-min reaction time. Under these conditions 99.99% of the soluble manganese was precipitated as Mn3O4, which was confirmed by XRD and SEM-EDS analyses. In addition, the stripping rate of ammonia-nitrogen was 99.73%. Leaching tests showed the leached toxic substances concentrations of the treated EMR met the integrated wastewater discharge standard of China (GB8978-1996).

  10. Simultaneous stripping recovery of ammonia-nitrogen and precipitation of manganese from electrolytic manganese residue by air under calcium oxide assist.

    PubMed

    Chen, Hongliang; Liu, Renlong; Shu, Jiancheng; Li, Wensheng

    2015-01-01

    Leaching tests of electrolytic manganese residue (EMR) indicated that high contents of soluble manganese and ammonia-nitrogen posed a high environmental risk. This work reports the results of simultaneous stripping recovery of ammonia-nitrogen and precipitation of manganese by air under calcium oxide assist. The ammonia-nitrogen stripping rate increased with the dosage of CaO, the air flow rate and the temperature of EMR slurry. Stripped ammonia-nitrogen was absorbed by a solution of sulfuric acid and formed soluble (NH4)2SO4 and (NH4)3H(SO4)3. The major parameters that effected soluble manganese precipitation were the dosage of added CaO and the slurry temperature. Considering these two aspects, the efficient operation conditions should be conducted with 8 wt.% added CaO, 60°C, 800 mL min(-1) air flow rate and 60-min reaction time. Under these conditions 99.99% of the soluble manganese was precipitated as Mn3O4, which was confirmed by XRD and SEM-EDS analyses. In addition, the stripping rate of ammonia-nitrogen was 99.73%. Leaching tests showed the leached toxic substances concentrations of the treated EMR met the integrated wastewater discharge standard of China (GB8978-1996). PMID:26301855

  11. Solar-Powered Air Stripping at the Rocky Flats Site, Colorado - 12361

    SciTech Connect

    Boylan, John A.

    2012-07-01

    . Initially, several alternatives such as commercial air strippers and cascade aerators were evaluated; resulting cost estimates exceeded $100,000. After several simpler alternatives were considered and prototype testing was conducted, the existing effluent metering manhole was converted to house a spray-nozzle based, solar-powered air stripper, at a cost of approximately $20,000. About two-thirds of this cost was for the solar power system, which was initially designed to only provide power for 12 hours per day. Performance data are being collected and adjustments made to optimize the design, determine maintenance requirements, and establish power needs for continuous operation. Analytical data confirm the air stripper is sharply reducing concentrations of residual contaminants. (authors)

  12. Advances in air-stripper technology

    SciTech Connect

    Wilson, J.H.; Singh, S.P. ); Lucero, A.J.; Thomas, C.O. . Dept. of Chemical Engineering); Ashworth, R.A.; Elliott, M.G. ); Counce, R.M. Tennessee Univ., Knoxville, TN . Dept. of Chemical Engineering)

    1990-01-01

    The cost for application of air-stripping technology for removal of volatile organic compounds (VOC's) from groundwater has been shown to be relatively insensitive to the cost of the installed capital equipment. In light of this observation, the basis for selection of air stripping equipment may include site-specific requirements without major economic penalties. In this paper, potential advantages for the use of highly efficient packings for traditional packed towers and a commercial rotary gas-liquid contactor are pointed out, and a basis for design is provided. 11 refs., 10 figs.

  13. The pathway of in-situ ammonium removal from aerated municipal solid waste bioreactor: nitrification/denitrification or air stripping?

    PubMed

    Hao, Yong-Jun; Ji, Min; Chen, Ying-Xu; Wu, Wei-Xiang; Hao, Yong-Jun; Zhang, Shu-Guang; Liu, Han-Qiao

    2010-12-01

    In-situ ammonium removal from municipal solid waste (MSW) landfill is an attractive method due to its economic advantages. In this study, two simulated MSW bioreactors with different degrees of initial bio-stabilization were utilized to investigate the effects of intermittent aeration mode and the addition of activated sludge on the removal of ammonium. The results showed that up to 90% of ammonium could be removed and the amount of NO(x)-N produced was less than 1% of NH4 (+)-N removed in both reactors. The pH values increased rapidly and finally arrived at a high level of 8.5-8.8. The efficiency of ammonium removal was improved by increasing the continuous aeration time, but it was not affected by the addition of activated sludge. A portion of liquid escaped from the reactors in the form of vapour, and as high as 195-258 mg L(-1) of NH(4) ( +)-N was detected in the vapour collector. According to calculation, nitrification was inhibited by the high level of free ammonia in the bioreactors. As a result, air stripping was enhanced and became the primary pathway of ammonium removal. Therefore, controlling free ammonia concentration was essential in ammonium removal from the aerated MSW bioreactor.

  14. Air stripping of volatile organic compounds from groundwater: An evaluation of a centrifugal vapor-liquid contractor

    SciTech Connect

    Singh, S.P.

    1989-01-01

    The performance of a centrifugal vapor-liquid contactor equipped with high specific surface area packing (>2,000 m{sup 2}/m{sup 3}) was evaluated for air stripping of jet fuel components from groundwater. Hydraulic test data indicated that the Sherwood flooding correlation which has been proposed for use in designing centrifugal vapor-liquid contactors overestimates the rotational speeds at which flooding occurs. For the mass transfer performance, a concept of area of a transfer unit (ATU) was introduced to account for the change in fluid loading with radius of the packing torus. The ATU was found to be a strong function of the specific surface area of the packing and to a lesser extent a function of rotor speed and liquid flow rate. A correlation based on the specific surface area of the packing is proposed for predicting the ATU. A simple empirical model is also proposed for determining the power consumed in turning the packing torus at various operating conditions. Previous claims in the literature that centrifugal vapor-liquid contactor is resistant to fouling because of high shear force were found not to be valid for groundwater with high iron content.

  15. Tower counts

    USGS Publications Warehouse

    Woody, Carol Ann; Johnson, D.H.; Shrier, Brianna M.; O'Neal, Jennifer S.; Knutzen, John A.; Augerot, Xanthippe; O'Neal, Thomas A.; Pearsons, Todd N.

    2007-01-01

    Counting towers provide an accurate, low-cost, low-maintenance, low-technology, and easily mobilized escapement estimation program compared to other methods (e.g., weirs, hydroacoustics, mark-recapture, and aerial surveys) (Thompson 1962; Siebel 1967; Cousens et al. 1982; Symons and Waldichuk 1984; Anderson 2000; Alaska Department of Fish and Game 2003). Counting tower data has been found to be consistent with that of digital video counts (Edwards 2005). Counting towers do not interfere with natural fish migration patterns, nor are fish handled or stressed; however, their use is generally limited to clear rivers that meet specific site selection criteria. The data provided by counting tower sampling allow fishery managers to determine reproductive population size, estimate total return (escapement + catch) and its uncertainty, evaluate population productivity and trends, set harvest rates, determine spawning escapement goals, and forecast future returns (Alaska Department of Fish and Game 1974-2000 and 1975-2004). The number of spawning fish is determined by subtracting subsistence, sport-caught fish, and prespawn mortality from the total estimated escapement. The methods outlined in this protocol for tower counts can be used to provide reasonable estimates ( plus or minus 6%-10%) of reproductive salmon population size and run timing in clear rivers. 

  16. Evaluation of rotary air stripping for removal of volatile organics from groundwater. Final report, 1 March 1985-1 September 1986

    SciTech Connect

    Dietrich, C.; Treichler, D.; Armstrong, J.

    1987-02-01

    Rotary air stripping was researched and developed to remove volatile organic contaminants from groundwater. The Traverse Group, Inc, Ann Arbor MI, was contracted under a joint funding venture by the US Coast Guard and the US Air Force to evaluate feasibility of using rotary air stripping to treat water contaminated with benzene, toluene, xylenes, trichloroethylene, 1,2,dichloroethane, and tetrachloroethylene. A site of groundwater contamination at the US Coast Guard Station, Traverse City MI provided a readily available source of contaminated water for this work. A prototype rotary air stripper (RAS), manufactured specifically for this project, was installed onsite in Traverse City MI. The RAS (consisting of a packed-bed 1.7 feet in diameter by 1.2 feet thick) was evaluated over a range of contaminant concentrations (63 to 19,000 ppb), liquid flow rates (50 to 120 gpm), air-to-water ratios (10:1 to 170:1 vol/vol), and rotor speeds (365 to 875 rpms). The effect of each parameter on removal efficiency was analyzed. Generally, removal efficiencies in excess of 99 percent were achieved for all contaminants (except 1,2-DCE) at an air-to-water ratio and rotor speed of 30:1 vol/vol and 435 rpms, respectively.

  17. Preliminary evaluation of the control of microbial fouling by laboratory and pilot-scale air-stripping columns. Final report, March-December 1984

    SciTech Connect

    Seekins, D.; Rogers, M.R.

    1985-03-01

    The U.S. Army Natick Research, Development and Engineering Center (Natick) undertook a study to investigate the buildup of microbial slimes primarily pseudomonas, bacillus and azotobacter in Air Stripping Columns that are used by the military to remove volatile compounds from contaminated groundwater. The air-stripping and carbon-adsorption columns were previously used at the Anniston Army Depot (ANAD) to treat groundwater that had been contaminated with chemical solvents and metal-plating wastes. The major groundwater contaminants were: trichloroethylene (TCE), dichloroethylene (DCE), methylene chloride (MeCl), phenol, and chromium. The results of the study will provide the basis for recommendations on preventative or control measures to be taken in future applications of these water-treatment methods. Measures to prevent buildup of microbial slimes will allow for longer column life and reduction in costs. Treatment of the laboratory-scale column with 3% and 15% hydrogen peroxide reduced total microbial counts but was not successful at disinfecting the column. It was concluded that to prevent microbial fouling of air-stripping columns, the packing material should be disinfected prior to use and should be shock-chlorinated during use if microbial fouling should start to occur. The column should be run continuously if possible to keep the inside temperature as low as possible to retard the growth of microorganisms. If iron fouling should occur, the column should be treated with dilute HCl to clear the packing material of the hydroxide buildup.

  18. Rapunzel's Tower

    ERIC Educational Resources Information Center

    Depp, Sheryl

    2007-01-01

    Children's literature often inspires the author's lessons, and reading to her primary students motivates their participation. In this article, the author presents and describes her lesson which is based on the book "Falling for Rapunzel" by Leah Wilcox. Students created a fairy tale tower in this lesson, which took place over three class periods.…

  19. Stripping with dry ice

    NASA Astrophysics Data System (ADS)

    Malavallon, Olivier

    1995-04-01

    Mechanical-type stripping using dry ice (solid CO2) consists in blasting particles of dry ice onto the painted surface. This surface can be used alone or in duplex according to type of substrate to be treated. According to operating conditions, three physical mechanisms may be involved when blasting dry ice particles onto a paint system: thermal shock, differential thermal contraction, and mechanical shock. The blast nozzle, nozzle travel speed, blast angle, stripping distance, and compressed air pressure and media flow rate influence the stripping quality and the uniformity and efficiency obtained.

  20. Control tower northwest corner of building 29. View southward shows ...

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

    Control tower northwest corner of building 29. View southward shows tower and stairway built onto door outrigger structure. - Naval Air Station North Island, Seaplane Hangars, Roe Street, North Island, San Diego, San Diego County, CA

  1. Experimental study of organically contaminated water in a cooling tower

    SciTech Connect

    Goldstein, D.J.; Aiyegbusi, O.

    1982-12-01

    A pilot model cooling system was set up and run so as to simultaneously cool heat exchanger tubes and biologically degrade phenol in the makeup water. The cooling tower used 1 ft/sup 2/ by 3 ft high, wetted film, polygrid, PVC packing. Water was circulated at 2.5 gpm (5.6 ft/sec) through two parallel heat exchange tubes immersed in a water bath controlled at 150/sup 0/F. Total water flow was 5 gpm/ft/sup 2/ of tower. Air was forced through the tower to give a liquid to gas mass ratio of 1.3. The cooling water circulated with an average temperature rise of 10/sup 0/F and an average approach to the air wet bulb temperature of 12/sup 0/F. Conclusions of this study are: (1) The pilot cooling tower was successfully operated to simultaneously cool and biodegrade phenol in the makeup water. Operation was not difficult and the experiments were reasonably reproducible. (2) An equivalent average concentration of phenol in the makeup water of 165 ppM (300 ppM BOD) should present little problem in commercial practice. An equivalent average concentration of up to 600 ppM phenol (1200 ppM BOD) may be acceptable in practice. Concentrations higher than 600 ppM phenol will cause such rapid biofouling and such rapid production of suspended solids in the circulating water as to be impractical. (3) More than 85 percent of the phenol removed was by biodegradation. Not more than 15 percent was stripped into the atmosphere. 12 figures, 12 tables.

  2. An Air-Stripping Packed Bed Combined with a Biofilm-Type Biological Process for Treating BTEX and Total Petroleum Hydrocarbon Contaminated Groudwater

    NASA Astrophysics Data System (ADS)

    Hong, U.; Park, S.; Lim, J.; Lee, W.; Kwon, S.; Kim, Y.

    2009-12-01

    In this study, we examined the removal efficiency of a volatile compound (e.g. toluene) and a less volatile compound [e.g. total petroleum hydrocarbon (TPH)] using an air stripping packed bed combined with a biofilm-type biological process. We hypothesized that this system might be effective and economical to simultaneously remove both volatile and less volatile compounds. The gas-tight reactor has 5.9-inch-diameter and 48.8-inch-height. A spray nozzle was installed at the top cover to distribute the liquid evenly through reactor. The reactor was filled with polypropylene packing media for the increase of volatilization surface area and the growth of TPH degrading facultative aerobic bacteria on the surface of the packing media. In air stripping experiments, 45.6%, 71.7%, 72.0%, and 75.4% of toluene was removed at air injection rates of 0 L/min, 2.5 L/min, 4 L/min, and 6 L/min, respectively. Through the result, we confirmed that toluene removal efficiency increased by injecting higher amounts of air. TPH removal by stripping was minimal. To remove a less volatile TPH by commercial TPH degrading culture (BIO-ZYME B-52), 15-times diluted culture was circulated through the reactor for 2-3 days to build up a biofilm on the surface of packing media with 1 mg-soluble nitrogen source /L-water per 1 ppm of TPH. Experiments evaluating the degree of TPH biodegradation in this system are carrying out.

  3. 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

  4. Simultaneous removal of ammonia, P and COD from anaerobically digested piggery wastewater using an integrated process of chemical precipitation and air stripping.

    PubMed

    Quan, Xuejun; Ye, Changying; Xiong, Yanqi; Xiang, Jinxin; Wang, Fuping

    2010-06-15

    The paper presented an efficient integrated physicochemical process, which consists of chemical precipitation and air stripping, for the simultaneous removal of NH(3)-N, total P and COD from anaerobically digested piggery wastewater. In the integrated process, Ca(OH) (2) was used as the precipitant for NH(4)(+), PO(4)(3-) and organic phosphorous compounds, and as the pH adjuster for the air stripping of residual ammonia. The possibility of the suggested process and the related mechanisms were first investigated through a series of equilibrium tests. Laboratory scale tests were carried out to validate the application possibility of the integrated process using a new-patented water sparged aerocyclone reactor (WSA). The WSA could be effectively used for the simultaneous removal of NH(3)-N, total P and COD. 3g/L of Ca(OH) (2) is a proper dosage for the simultaneous removal. The simultaneous removal of NH(3)-N, total P and COD in the WSA reactor could be easily optimized by selecting a proper air inlet velocity and a proper jet velocity of the liquid phase. In all the cases, the removal efficiencies of the NH(3)-N, total P and COD were over 91%, 99.2% and 52% for NH(3)-N, total P and COD, respectively. The formed precipitates in the process could be easily settled down from the suspension system. Therefore, the integrated process provided an efficient alternative for the simultaneous removal of NH(3)-N, total P and COD from the wastewater.

  5. 2004 Savannah River Cooling Tower Collection (U)

    SciTech Connect

    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 the 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.

  6. Stripping of organic compounds from wastewater as an auxiliary fuel of regenerative thermal oxidizer.

    PubMed

    Chang, Meng-Wen; Chern, Jia-Ming

    2009-08-15

    Organic solvents with different volatilities are widely used in various processes and generate air and water pollution problems. In the cleaning processes of electronics industries, most volatile organic compounds (VOCs) are vented to air pollution control devices while most non-volatile organic solvents dissolve in the cleaning water and become the major sources of COD in wastewater. Discharging a high-COD wastewater stream to wastewater treatment facility often disturbs the treatment performance. A pretreatment of the high-COD wastewater is therefore highly desirable. This study used a packed-bed stripping tower in combination with a regenerative thermal oxidizer to remove the COD in the wastewater from a printed circuit board manufacturing process and to utilize the stripped organic compounds as the auxiliary fuel of the RTO. The experimental results showed that up to 45% of the COD could be removed and 66% of the RTO fuel could be saved by the combined treatment system.

  7. Removal of organic pollutants from 2,2',5,5'-tetrachlorobenzidine (TCB) industrial wastewater by micro-electrochemical oxidation and air-stripping.

    PubMed

    Shibin, Xia; Shuichun, Xia; Changqing, Zhu

    2007-06-01

    A feasible method for treatment of the wastewater from the two-staged neutralization in 2,2',5,5'-tetrachlorobenzidine (TCB) manufacturing processes, a refractory dye intermediate effluents, based on combined micro-electrochemical oxidation or iron-chipping filtration (ICF) and air-stripping reactor (ASR), was developed. On conditions of HRT 1h, pH 3.0 in ICF and HRT 38 h, gas-liquid ratio 15, pH 6.0-8.65, temperature 26 degrees C in ASR, the overall COD, color, TCB and NH(4)(+)-N removal were 96.8%, 91%, 87.61% and 62%, respectively, during the treatment of TCB wastewater from the two-staged neutralization dissolved by methanol. The averaged 18.3%, 81.7% of the total degraded COD, 35.2%, 64.8% of TCB were carried out in ICF and ASR, respectively. NH(4)(+)-N removal was finished mainly in ASR. The experimental results indicated that the combined micro-electrochemical oxidation and air-stripping process performed good treatment of COD, color, TCB and NH(4)(+)-N removal in TCB wastewater from the two-staged neutralization dissolved by ethanol or acetone, came up the discharge standard in China. But the TCB wastewater from the two-staged neutralization dissolved by methanol should be deeply treated before discharged.

  8. Laboratory batch experiments of the combined effects of ultrasound and air stripping in removing CCl4 and 1,1,1-TCA from water.

    PubMed

    Ayyildiz, Onder; Anderson, Paul R; Peters, Robert W

    2005-04-11

    Ultrasonic and air-stripping techniques for removal of carbon tetrachloride (CCl4) and 1,1,1-trichloroethane (1,1,1-TCA) from water were studied in batch experiments. Ultrasound (US) is effective for destroying organic compounds in aqueous solutions whereas air stripping (AS) efficiently transfers volatile compounds from the liquid to the gas phase. In simultaneous US and AS experiments, synergistic effects were observed and attributed to the effect of US on the mass transfer process. Using a photographic method, ultrasonic break up of gas bubbles and changes in gas holdup ratios were examined. In the two different gas-sparging systems studied, ultrasonic waves did not break up gas bubbles. In contrast, bubbles from the smaller porous size diffuser were coalesced due to sonication. In addition, both photographic and gas holdup experiments demonstrated that ultrasonic irradiation increased the gas holdup ratio. The enhancement observed in the removal of the compounds appeared to be due to this greater ultrasonic gas holdup ratio.

  9. Characterization of the geology, geochemistry, hydrology and microbiology of the in-situ air stripping demonstration site at the Savannah River Site

    SciTech Connect

    Eddy, C.A.; Looney, B.B.; Dougherty, J.M.; Hazen, T.C.; Kaback, D.S.

    1991-05-01

    The Savannah River Site is the location of an Integrated Demonstration Project designed to evaluate innovative remediation technologies for environmental restoration at sites contaminated with volatile organic contaminants. This demonstration utilizes directionally drilled horizontal wells to deliver gases and extract contaminants from the subsurface. Phase I of the Integrated Demonstration focused on the application and development of in-situ air stripping technologies to remediate soils and sediments above and below the water table as well as groundwater contaminated with volatile organic contaminants. The objective of this report is to provide baseline information on the geology, geochemistry, hydrology, and microbiology of the demonstration site prior to the test. The distribution of contaminants in soils and sediments in the saturated zone and groundwater is emphasized. These data will be combined with data collected after the demonstration in order to evaluate the effectiveness of in-situ air stripping. New technologies for environmental characterization that were evaluated include depth discrete groundwater sampling (HydroPunch) and three-dimensional modeling of contaminant data.

  10. Removal of organic pollutants from 2,2',5,5'-tetrachlorobenzidine (TCB) industrial wastewater by micro-electrochemical oxidation and air-stripping.

    PubMed

    Shibin, Xia; Shuichun, Xia; Changqing, Zhu

    2007-06-01

    A feasible method for treatment of the wastewater from the two-staged neutralization in 2,2',5,5'-tetrachlorobenzidine (TCB) manufacturing processes, a refractory dye intermediate effluents, based on combined micro-electrochemical oxidation or iron-chipping filtration (ICF) and air-stripping reactor (ASR), was developed. On conditions of HRT 1h, pH 3.0 in ICF and HRT 38 h, gas-liquid ratio 15, pH 6.0-8.65, temperature 26 degrees C in ASR, the overall COD, color, TCB and NH(4)(+)-N removal were 96.8%, 91%, 87.61% and 62%, respectively, during the treatment of TCB wastewater from the two-staged neutralization dissolved by methanol. The averaged 18.3%, 81.7% of the total degraded COD, 35.2%, 64.8% of TCB were carried out in ICF and ASR, respectively. NH(4)(+)-N removal was finished mainly in ASR. The experimental results indicated that the combined micro-electrochemical oxidation and air-stripping process performed good treatment of COD, color, TCB and NH(4)(+)-N removal in TCB wastewater from the two-staged neutralization dissolved by ethanol or acetone, came up the discharge standard in China. But the TCB wastewater from the two-staged neutralization dissolved by methanol should be deeply treated before discharged. PMID:17118553

  11. Status of in-situ air stripping tests and proposed modifications: Horizontal wells AMH-1 and AMH-2 Savannah River Site

    SciTech Connect

    Kaback, D.S.; Looney, B.B.

    1989-08-01

    A project to drill and install two horizontal vapor extraction/air injection wells at the Savannah River Site (SRS), Aiken, South Carolina, was performed in September and October of 1988. The project was performed to test the feasibility of horizontal drilling technologies in shallow unconsolidated sediments. Additional study to evaluate the effectiveness of in-situ air stripping of volatile organics from the ground water and unsaturated soils is planned. This status report contains (1) a short summary of the construction details of the two horizontal wells and (2) proposed modifications to the original program plan (Kaback and Looney 1988; Looney and Kaback, 1988). The modifications include added pressure monitoring and use of an inert tracer gas (helium) to better evaluate system performance. This paper contains sections that provide information requested by the South Carolina Department Health and Environmental Control as part of the underground injection well permitting process. 3 refs., 6 figs.

  12. 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.

  13. Performance specification for control tower display systems

    NASA Astrophysics Data System (ADS)

    Aleva, Denise L.; Meyer, Frederick M.

    2003-09-01

    Personnel in airport control towers monitor and direct the takeoff of outgoing aircraft, landing of incoming aircraft and all movements of aircraft on the ground. Although the primary source of information for the Local Controller, Assistant Local Controller and the Ground Controller is the real world viewed through the windows of the control tower, electronic displays are also used to provide situation awareness. Due to the criticality of the work to be performed by the controllers and the rather unique environment of the air traffic control tower, display hardware standards, which have been developed for general use, are not directly applicable. The Federal Aviation Administration (FAA) requested assistance of Air Force Research Laboratory Human Effectiveness Directorate in producing a document which can be adopted as a Tower Display Standard usable by display engineers, human factors practitioners and system integrators. Particular emphasis was placed on human factors issues applicable to the control tower environment and controller task demands.

  14. Development of solar tower observatories

    NASA Astrophysics Data System (ADS)

    Wolfschmidt, Gudrun

    Because the horizontal solar telescope, the Snow Telescope in Yerkes Observatory, was affected by air-currents from the warmed-up soil, George Ellery Hale had the idea of a tower telescope. In 1904, the 60-foot tower in Mt. Wilson was ready, in 1908 the 150-foot tower was built with the help of the Carnegie foundation. After World War I, Germany made heavy efforts to regain its former strong position in the field of science. Already in December 1919 - after the spectacular result of the English eclipse expedition in October 1919 - Erwin Finlay-Freundlich started a successful fund raising (“Einstein-Stiftungrdquo;) among German industrialists. The company Zeiss in Jena was responsible for the instrumentation of the 20-m solar tower, built in 1920-22. The optical design of the Einstein Tower in respect to light intensity surpassed even the Mt. Wilson solar observatory. Also abroad solar tower observatories were built in the 1920s: Utrecht,The Netherlands (1922), Canberra, Australia (1924), Arcetri, Italy (1926), Pasadena, California (1926) and Tokyo, Japan (1928). In the thirties, solar physics became important because of the solar maximum in 1938 and the new observational possibilities created by Bernard Lyot. At the end of the 1930s, Karl-Otto Kiepenheuer proposed to establish a solar tower observatory on Wendelstein in order to improve the predictions of radio interference by observing sunspots. By stressing the importance of the solar research for war efforts, Otto Heckmann of Göttingen observatory finally succeeded in winning the “Reichsluftfahrtministerium” to finance several solar observatories, like Wendelstein, Hainberg/Göttingen, Kanzelhöhe/Villach, and Schauinsland/Freiburg. Solar astronomy profited by the foundation of the new observatories - four of them existed still after the war. Abroad only the solar observatories of Oxford (1935) and the 50 foot tower of the McMath-Hulbert Observatory, University of Michigan (1936) should be mentioned. Only

  15. Drop tower with no aerodynamic drag

    NASA Technical Reports Server (NTRS)

    Kendall, J. M., Jr.

    1981-01-01

    Cooling air accelerated to match velocity of falling object eliminates drag. 3 meter drop tower with suction fan and specific geometry causes air to accelerate downward at 1 g. Although cooling of molten material released from top is slow because surrounding air moves with it, drop remains nearly spherical.

  16. Salt in the Air during the Nitrogen, Aerosol Composition, and Halogens on a Tall Tower (NACHTT) Campaign

    NASA Astrophysics Data System (ADS)

    Pszenny, A.; Keene, W. C.; Sander, R.; Bearekman, R.; Deegan, B.; Maben, J. R.; Warrick-Wriston, C.; Young, A.

    2011-12-01

    Bulk and size-segregated aerosol samples were collected 22 m AGL at the Boulder Atmospheric Observatory (40°N, 105°W, 1563 m ASL) from 18 February to 13 March 2011. Total concentrations of Na, Mg, Al, Cl, V, Mn, Br and I in bulk samples were determined by neutron activation analysis. Ionic composition of all size-segregated and a subset of bulk samples was determined by ion chromatography of aqueous extracts. Mg, Al, V and Mn mass concentrations were highly correlated and present in ratios similar to those in Denver area surface soils. Na and Cl were less well correlated with these soil elements but, after correction for soil contributions, highly correlated with each other. Linear regression of non-soil Cl vs. non-soil Na yielded a slope of 1.69 ± 0.09 (95% C.I.; n = 173), a value between the mass ratios of sea salt (1.80) and halite (1.54). The median Na and Cl concentrations (6.8 and 6.6 nmol m-3 STP, respectively) were factors of 25 to 35 less than those typically measured in the marine boundary layer. Br and I were somewhat correlated and appeared to represent a third aerosol component. The average bulk Cl-:total Cl ratio was 0.99 ± 0.03 (n = 44) suggesting that essentially all aerosol chlorine was water-soluble. Na+ and Cl- mass distributions were bimodal with most of the masses (medians 75% and 78%, respectively, n = 45) in supermicrometer particles. Possible origins of the "salt" component will be discussed based on consideration of 5-day HYSPLIT back trajectories and other information on sampled air mass characteristics.

  17. Opacification of a hydrophilic acrylic intraocular lens with a hydrophobic surface after air injection in Descemet-stripping automated endothelial keratoplasty in a patient with Fuchs dystrophy.

    PubMed

    Mojzis, Peter; Studeny, Pavel; Werner, Liliana; Piñero, David P

    2016-03-01

    A 71-year-old woman with Fuchs endothelial dystrophy in the right eye had uneventful phacoemulsification cataract surgery with implantation of a single-piece intraocular lens (IOL) (CT47S) in January 2012. Because of corneal problems and vision loss, uneventful Descemet-stripping automated endothelial keratoplasty (DSAEK) was performed in May 2013. Four months later, a new corneal lamella (repeat DSAEK) was implanted with reinjection of an air bubble into the anterior chamber. Six months after the initial DSAEK, the patient complained of blurred vision. On examination, the cornea was transparent but the IOL presented opacification in the central area. The opacified IOL was explanted and analyzed by light microscopy, which showed the presence of thin granular deposits distributed in an overall round pattern that stained positive for calcium. The opacification of hydrophilic acrylic IOLs is a complication that can occur after uneventful endothelial keratoplasty, especially when rebubbling is necessary. PMID:27006326

  18. Technical and economic evaluation of air stripping for volatile organic compound (VOC) removal from contaminated ground water at selected Army sites. Final report, Sep 89-May 91

    SciTech Connect

    Holt, M.T.; Brown, C.W.

    1991-07-01

    This report provides a process and economic evaluation of the use of air stripping to remove VOC's from contaminated groundwater on or near three existing U.S. Army facilities. The three sites visited were: (1) Twin Cities Army Ammunition Plant (TCAAP), Minneapolis, Minnesota; (2) Letterkenny Army Depot (LEAD), Chambersburg, Pennsylvania, and (3) Sharpe Army Depot (SHAD), Lathrop, California. The evaluation focused on the economics of each site to determine (1) the total capital cost for the existing treatment facilities, (2) the operating costs for each existing facility, and (3) to identify the significant cost drives for each facility. The installed costs of each facility were determined and compared using total life cycle costing (TLCC) analysis based on 1,000 gallons of water treated over the life of each plant. The operating costs were also determined and compared based on 1,000 gallons of water treated.

  19. Treatment of pretreated coking wastewater by flocculation, alkali out, air stripping, and three-dimensional electrocatalytic oxidation with parallel plate electrodes.

    PubMed

    Wen-wu, Liu; Xiu-ping, Wang; Xue-yan, Tu; Chang-yong, Wang

    2014-10-01

    The coking wastewater generally comprises highly concentrated, recalcitrant, and toxic organic pollutants, so its treatment has been of great importance to prevent living beings and their environment from these hazardous contaminations. The treatment of pretreated coking wastewater by flocculation-coagulation, alkali out, air stripping, and three-dimensional (3-D) electrocatalytic oxidation was performed (gap between the used β-PbO2/Ti anode and titanium cathode, 12 mm; mass ratio of Cu-Mn/granular activated carbon (GAC) to effluent, 1:4; cell voltage, 7 V). The results showed that the pH adjusting from 3.7 to 6.1 was necessary for coagulants; alkali out played an important role because it brought up precipitation containing higher fatty acids as well as other contaminants to decrease the chemical oxygen demand (COD) in the effluent, and it had also forced the reduction of ammonia nitrogen (NH3-N) by incorporating with air stripping; for 3-D electrocatalytic oxidation with a bleaching liquid assisting, the initial pH 8.5 of effluent was suitable for Cu-Mn/GAC; moreover, it was considered that its Cu component was dedicated to the decrease of COD and NH3-N, while the Mn component specialized in the decay of NH3-N. The residual COD and NH3-N values in the final effluent with pH 6.5 were 95.8 and 8.8 mg/L, respectively, demonstrating that the whole processes applied were feasible and low in cost.

  20. Typical Mid Tower Elevation & Section, Typical Mid Tower Footing ...

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

    Typical Mid Tower Elevation & Section, Typical Mid Tower Footing Section & Elevation, South Tower Section & Elevation, and North Tower Sections & Elevation - Cape Arago Light Station Footbridge, Gregory Point, Charleston, Coos County, OR

  1. Surface and Tower Meteorological Instrumentation at NSA Handbook - January 2006

    SciTech Connect

    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.

  2. Radon data acquisition: An automated system for radon analysis of both ground air and tower air and for the simultaneous logging of meteorological data

    SciTech Connect

    Martins, S.

    1990-10-01

    A system to acquire radon data was developed at Lawrence Livermore National Laboratory (LLNL) to provide information about the effect of weather conditions on the release of radon gas from soils into air. One of the system criteria that drive other design considerations was the need for operation at remote sites where the availability of 120-volt AC power was problematic. As a consequence, all components were selected or designed to run on +12 and/or {minus}12 volts DC. PC-based laptop computers were used for all data acquisition because of their availability, their low power consumption, and the abundance of software written for this platform. The system is comprised of four major sub-systems that are linked by laptop computers: radon-monitor controller, HANDAR 540 data-capture platform, radon-detection units, and barometric pressure unit. Using this system, we successfully collected data at an LLNL field site during 1990. Data from meteorological sensors and radon-concentration profiles from both air and soil were acquired simultaneously and logged on MS-DOS computers for data reduction at a future time. This document describes the functions, hardware, firmware, and software of this system.

  3. Cellular Phone Towers

    MedlinePlus

    ... the call. How are people exposed to the energy from cellular phone towers? As people use cell ... where people can be exposed to them. The energy from a cellular phone tower antenna, like that ...

  4. An economical solution to cooling tower drift

    SciTech Connect

    Pedersen, G.C.; Lamkin, V.K.; Seich, M.

    1987-01-01

    Most processes one encounters in the refining and petrochemical industries require the rejection of waste heat. The most economical and effective means of accomplishing this is through the use of cooling towers. Heat is transferred by convection and evaporation (mass transfer) by the direct contact of the atmospheric air and water. This results in a major environmental concern of cooling towers - DRIFT, which is discussed in this paper.

  5. Integration of photocatalytic oxidation with air stripping of contaminated aquifers. Report for 1 October 1993--30 June 1997

    SciTech Connect

    Changrani, R.; Raupp, G.B.; Turchi, C.

    1998-12-01

    The global objective of this work was to evaluate the integration of gas-solid ultraviolet (UV) photocatalytic oxidation (PCO) downstream of an air stripper as a technology for cost-effectively treating water pumped from an aquifer contaminated with chlorinated volatile organic compounds (VOCs). Experimental work was performed at the bench-scale in the laboratory during the first phase of the project, and at the pilot-scale in a simulated field-test situation during the second phase.

  6. 4. SOUTHWEST CORNER OF METEOROLOGICAL TOWER; SOUTH FACE OF SLC3W ...

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

    4. SOUTHWEST CORNER OF METEOROLOGICAL TOWER; SOUTH FACE OF SLC-3W MST IN BACKGROUND - Vandenberg Air Force Base, Space Launch Complex 3, Meteorological Shed & Tower, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

  7. TOP OF STRAND ANNEALING TOWER, ONE OF FIVE SUCH STRUCTURES ...

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

    TOP OF STRAND ANNEALING TOWER, ONE OF FIVE SUCH STRUCTURES THE BUFFALO PLANT OF AMERICAN BRASS. HEAVIER-GAUGE STRIP IS CONTINUOUSLY ANNEALED TO GIVE THE PRODUCT A MORE UNIFORM GRAIN SIZE AND RENDER IT MORE DUCTILE. - American Brass Foundry, 70 Sayre Street, Buffalo, Erie County, NY

  8. Robotic Stripping

    NASA Technical Reports Server (NTRS)

    2000-01-01

    UltraStrip Systems, Inc.'s M-200 removes paint from the hulls of ships faster than traditional grit-blasting methods. And, it does so without producing toxic airborne particles common to traditional methods. The M-2000 magnetically attaches itself to the hull of the ship. Its water jets generate 40,000 pounds of pressure per square inch, blasting away paint down to the ships steel substrate. The only by product is water and dried paint chips and these are captured by a vacuum system so no toxic residue can escape. It was built out of a partnership between the Jet Propulsion Laboratory and the National Robotics Engineering Consortium.

  9. Measurement and characterization of emissions from a gas liquor fed cooling tower

    NASA Astrophysics Data System (ADS)

    Galegher, Sheila J.; Mann, Michael D.

    Phase I cooling tower testing at the University of North Dakota Energy Research Center (UNDERC) was designed to use solvent extracted and steam stripped wastewater from fixed-bed gasification of lignite as makeup. The objective of this test was to simulate the proposed mode of operation at the Great Plains Gasification Associates (GPGA) plant. A crucial part of this study was the characterization of emissions from a stripped gas liquor (SGL) fed cooling tower. Several types of sampling equipment including a multicyclone, cooled impingers, and an XAD resin trap were used for the collection and retention of components in the tower evaporate. Results of this study indicated that a significant portion of the phenol and ammonia, and also some methanol, in the tower makeup stream were stripped into the atmosphere. Concentration levels of 26,900 μg m -3 ammonia, 8000 μg m -3 phenol and 2500 μ m -3 methanol were detected in the lower exhaust.

  10. Combined air stripper/membrane vapor separation systems. Final report

    SciTech Connect

    Wijmans, J.G.; Baker, R.W.; Kamaruddin, H.D.; Kaschemekat, J.; Olsen, R.P.; Rose, M.E.; Segelke, S.V.

    1992-11-01

    Air stripping is an economical and efficient method of removing dissolved volatile organic compounds (VOCs) from contaminated groundwater. Air strippers, however, produce a vent air stream, which must meet the local air quality limits. If the VOC content exceeds the limits, direct discharge is not possible; therefore, a carbon adsorption VOC capture system is used to treat the vent air. This treatment step adds a cost of at least $50/lb of VOC captured. In this program, a combined air stripper/membrane vapor separation system was constructed and demonstrated in the laboratory. The membrane system captures VOCs from the stripper vent stream at a projected cost of $15/lb VOC for a water VOC content of 5 ppmw, and $75/lb VOC for a water VOC content of 1 ppmw. The VOCs are recovered as a small, concentrated liquid fraction for disposal or solvent recycling. The concept has been demonstrated in experiments with a system capable of handling up to 150,000 gpd of water. The existing demonstration system is available for field tests at a DOE facility or remediation site. Replacement of the current short air stripping tower (effective height 3 m) with a taller tower is recommended to improve VOC removal.

  11. 7. SOUTHWEST CORNER OF EAST PHOTO TOWER. CLOSED WINDOW ON ...

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

    7. SOUTHWEST CORNER OF EAST PHOTO TOWER. CLOSED WINDOW ON WEST SIDE; ELECTRICAL POWER BOX ON EAST SIDE OF PHOTO TOWER. - Vandenberg Air Force Base, Space Launch Complex 3, Launch Pad 3 East, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

  12. NORTH FRONT AND WEST SIDE, HIGH ENCLOSED METAL OBSERVATION TOWER ...

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

    NORTH FRONT AND WEST SIDE, HIGH ENCLOSED METAL OBSERVATION TOWER LOCATED APPROXIMATELY 1800 FEET SOUTH OF TRACK. Looking southeast - Edwards Air Force Base, South Base Sled Track, Observation Tower, South of west end of Sled Track, Lancaster, Los Angeles County, CA

  13. Within compound, from Guard Tower (Building 5762), looking southwest, Technical ...

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

    Within compound, from Guard Tower (Building 5762), looking southwest, Technical Equipment Building (Building 5760) to left, Microwave Tower (associated with Building 5769) and Civil Engineering Storage Building (Building 5766) to left - Beale Air Force Base, Perimeter Acquisition Vehicle Entry Phased-Array Warning System, End of Spencer Paul Road, north of Warren Shingle Road (14th Street), Marysville, Yuba County, CA

  14. 8. SOUTH SIDE OF EAST PHOTO TOWER; ELECTRICAL POWER BOX ...

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

    8. SOUTH SIDE OF EAST PHOTO TOWER; ELECTRICAL POWER BOX ON RIGHT. LEFT TO RIGHT IN BACKGROUND: A STORAGE SHED (BLDG. 776), METEOROLOGICAL TOWER, PYROTECHNIC SHED (BLDG. 757), AND SLC-3W MST. - Vandenberg Air Force Base, Space Launch Complex 3, Launch Pad 3 East, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

  15. 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…

  16. Leaning Tower of PESA

    ERIC Educational Resources Information Center

    Clark, John

    2009-01-01

    There is a certain similarity between the Philosophy of Education Society of Australasia (PESA) and the leaning tower of Pisa. Both have a certain presence on the landscape: the tower has a commanding appearance on the Italian countryside while PESA has left its mark on the academic fabric of Australasia. Both are much loved: Pisa by visiting…

  17. 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…

  18. 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.

  19. 14 CFR 170.13 - Airport Traffic Control Tower (ATCT) establishment criteria.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 3 2013-01-01 2013-01-01 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...

  20. Credit BG. View looking north northwest (324°) at Control Tower, ...

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

    Credit BG. View looking north northwest (324°) at Control Tower, in context with Building 4505 at right. Shed beneath tower is Building 4501; to the immediate left is an unnumbered structure - Edwards Air Force Base, North Base, Radio & Control Tower T-65, Northeast of A Street, Boron, Kern County, CA

  1. Ammonia stripping of biologically treated liquid manure.

    PubMed

    Alitalo, Anni; Kyrö, Aleksis; Aura, Erkki

    2012-01-01

    A prerequisite for efficient ammonia removal in air stripping is that the pH of the liquid to be stripped is sufficiently high. Swine manure pH is usually around 7. At pH 7 (at 20°C), only 0.4% of ammonium is in ammonia form, and it is necessary to raise the pH of swine slurry to achieve efficient ammonia removal. Because manure has a very high buffering capacity, large amounts of chemicals are needed to change the slurry pH. The present study showed that efficient air stripping of manure can be achieved with a small amount of chemicals and without strong bases like NaOH. Slurry was subjected to aerobic biological treatment to raise pH before stripping. This facilitated 8 to 32% ammonia removal without chemical treatment. The slurry was further subjected to repeated cycles of stripping with MgO and Ca(OH)(2) additions after the first and second strippings, respectively, to raise slurry pH in between the stripping cycles. After three consecutive stripping cycles, 59 to 86% of the original ammonium had been removed. It was shown that the reduction in buffer capacity of the slurry was due to ammonia and carbonate removal during the stripping cycles.

  2. Robotic sensors for aircraft paint stripping

    NASA Astrophysics Data System (ADS)

    Weniger, Richard J.

    1990-10-01

    Aircraft of all types need to have paint routinely removed from their outer surfaces. Any method needs to be controlled to remove all the paint and not damage the surface of the aircraft. Human operators get bored with the monotonous task of stripping paint from an aircraft and thus do not control the process very well. This type of tedious operation tends itself to robotics. A robot that strips paint from aircraft needs to have feedback as to the state of the stripping process, its location in respect to the aircraft, and the availability of stripping material. This paper describes the sensors used on the paint stripping robot being developed for the United States Air Force's Manufacturing Technology Program. Particular attention is given to the paint sensor which is the feedback element for determining the state of the stripping process.

  3. View of Nevada rim towers from Arizona side. Left tower ...

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

    View of Nevada rim towers from Arizona side. Left tower supports Circuit 6, middle tower supports Circuit 5, and right tower supports Circuits 4 and 15, view north - Hoover Dam, Circuits 1-15, U.S. Highway 93, Boulder City, Clark County, NV

  4. 13. INTERIOR OF NORTHEAST PHOTO TOWER WITH WINDOW OPEN; ELECTRICAL ...

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

    13. INTERIOR OF NORTHEAST PHOTO TOWER WITH WINDOW OPEN; ELECTRICAL POWER BOX BELOW WINDOW - Vandenberg Air Force Base, Space Launch Complex 3, Launch Pad 3 East, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

  5. 5. SOUTHEAST CORNER OF EAST TELEVISION CAMERA TOWER. SOUTHEAST FACE ...

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

    5. SOUTHEAST CORNER OF EAST TELEVISION CAMERA TOWER. SOUTHEAST FACE OF MST IN BACKGROUND. - Vandenberg Air Force Base, Space Launch Complex 3, Launch Pad 3 East, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

  6. 8. View of power plant and radar tower, looking southwest ...

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

    8. View of power plant and radar tower, looking southwest - Naval Air Station Fallon, Power Plant, 800 Complex, off Carson Road near intersection of Pasture & Berney Roads, Fallon, Churchill County, NV

  7. 1. View of east elevation of power plant, radar tower ...

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

    1. View of east elevation of power plant, radar tower in background, looking west - Naval Air Station Fallon, Power Plant, 800 Complex, off Carson Road near intersection of Pasture & Berney Roads, Fallon, Churchill County, NV

  8. WINGS OF BUILDING EXTENDING FROM TOWER SECTION, VIEW FACING SOUTHSOUTHEAST. ...

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

    WINGS OF BUILDING EXTENDING FROM TOWER SECTION, VIEW FACING SOUTH-SOUTHEAST. - Naval Air Station Barbers Point, Administrative Office Building, Lexington Avenue north of Midway Street, Ewa, Honolulu County, HI

  9. Interior view at top of parachute drying tower showing original ...

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

    Interior view at top of parachute drying tower showing original steel wall-mounted ladder, facing southwest. - Albrook Air Force Station, Parachute & Armament Building, 200 feet north of Andrews Boulevard, Balboa, Former Panama Canal Zone, CZ

  10. Oblique view of south and east sides showing parachute tower, ...

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

    Oblique view of south and east sides showing parachute tower, facing northwest. - Albrook Air Force Station, Parachute & Armament Building, 200 feet north of Andrews Boulevard, Balboa, Former Panama Canal Zone, CZ

  11. Detail of parachute tower showing integration with main roof form, ...

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

    Detail of parachute tower showing integration with main roof form, facing southwest. - Albrook Air Force Station, Parachute & Armament Building, 200 feet north of Andrews Boulevard, Balboa, Former Panama Canal Zone, CZ

  12. Tower Camera Handbook

    SciTech Connect

    Moudry, D

    2005-01-01

    The tower camera in Barrow provides hourly images of ground surrounding the tower. These images may be used to determine fractional snow cover as winter arrives, for comparison with the albedo that can be calculated from downward-looking radiometers, as well as some indication of present weather. Similarly, during spring time, the camera images show the changes in the ground albedo as the snow melts. The tower images are saved in hourly intervals. In addition, two other cameras, the skydeck camera in Barrow and the piling camera in Atqasuk, show the current conditions at those sites.

  13. 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

  14. 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

  15. Airport Remote Tower Sensor Systems

    NASA Technical Reports Server (NTRS)

    Maluf, David A.; Gawdiak, Yuri; Leidichj, Christopher; Papasin, Richard; Tran, Peter B.; Bass, Kevin

    2006-01-01

    Networks of video cameras, meteorological sensors, and ancillary electronic equipment are under development in collaboration among NASA Ames Research Center, the Federal Aviation Administration (FAA), and the National Oceanic Atmospheric Administration (NOAA). These networks are to be established at and near airports to provide real-time information on local weather conditions that affect aircraft approaches and landings. The prototype network is an airport-approach-zone camera system (AAZCS), which has been deployed at San Francisco International Airport (SFO) and San Carlos Airport (SQL). The AAZCS includes remotely controlled color video cameras located on top of SFO and SQL air-traffic control towers. The cameras are controlled by the NOAA Center Weather Service Unit located at the Oakland Air Route Traffic Control Center and are accessible via a secure Web site. The AAZCS cameras can be zoomed and can be panned and tilted to cover a field of view 220 wide. The NOAA observer can see the sky condition as it is changing, thereby making possible a real-time evaluation of the conditions along the approach zones of SFO and SQL. The next-generation network, denoted a remote tower sensor system (RTSS), will soon be deployed at the Half Moon Bay Airport and a version of it will eventually be deployed at Los Angeles International Airport. In addition to remote control of video cameras via secure Web links, the RTSS offers realtime weather observations, remote sensing, portability, and a capability for deployment at remote and uninhabited sites. The RTSS can be used at airports that lack control towers, as well as at major airport hubs, to provide synthetic augmentation of vision for both local and remote operations under what would otherwise be conditions of low or even zero visibility.

  16. 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)

  17. Tower Mesonetwork Climatology and Interactive Display Tool

    NASA Technical Reports Server (NTRS)

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

    2004-01-01

    Forecasters at the 45th Weather Squadron and Spaceflight Meteorology Group use data from the tower network over the Kennedy Space Center (KSC) and Cape Canaveral Air Force Station (CCAFS) to evaluate Launch Commit Criteria, and issue and verify forecasts for ground operations. Systematic biases in these parameters could adversely affect an analysis, forecast, or verification. Also, substantial geographical variations in temperature and wind speed can occur under specific wind directions. To address these concerns, the Applied Meteorology Unit (AMU) developed a climatology of temperatures and winds from the tower network, and identified the geographical variation and significant tower biases. The mesoclimate is largely driven by the complex land-water interfaces across KSC/CCAFS. Towers with close proximity to water typically had much warmer nocturnal temperatures and higher wind speeds throughout the year. The strongest nocturnal wind speeds occurred from October to March whereas the strongest mean daytime wind speeds occurred from February to May. These results of this project can be viewed by forecasters through an interactive graphical user interface developed by the AMU. The web-based interface includes graphical and map displays of mean, standard deviation, bias, and data availability for any combination of towers, variables, months, hours, and wind directions.

  18. Approximate strip exchanging.

    PubMed

    Roy, Swapnoneel; Thakur, Ashok Kumar

    2008-01-01

    Genome rearrangements have been modelled by a variety of primitives such as reversals, transpositions, block moves and block interchanges. We consider such a genome rearrangement primitive Strip Exchanges. Given a permutation, the challenge is to sort it by using minimum number of strip exchanges. A strip exchanging move interchanges the positions of two chosen strips so that they merge with other strips. The strip exchange problem is to sort a permutation using minimum number of strip exchanges. We present here the first non-trivial 2-approximation algorithm to this problem. We also observe that sorting by strip-exchanges is fixed-parameter-tractable. Lastly we discuss the application of strip exchanges in a different area Optical Character Recognition (OCR) with an example.

  19. Combined air stripper/membrane vapor separation systems. [Volatile organic compounds

    SciTech Connect

    Wijmans, J.G.; Baker, R.W.; Kamaruddin, H.D.; Kaschemekat, J.; Olsen, R.P.; Rose, M.E.; Segelke, S.V.

    1992-11-01

    Air stripping is an economical and efficient method of removing dissolved volatile organic compounds (VOCs) from contaminated groundwater. Air strippers, however, produce a vent air stream, which must meet the local air quality limits. If the VOC content exceeds the limits, direct discharge is not possible; therefore, a carbon adsorption VOC capture system is used to treat the vent air. This treatment step adds a cost of at least $50/lb of VOC captured. In this program, a combined air stripper/membrane vapor separation system was constructed and demonstrated in the laboratory. The membrane system captures VOCs from the stripper vent stream at a projected cost of $15/lb VOC for a water VOC content of 5 ppmw, and $75/lb VOC for a water VOC content of 1 ppmw. The VOCs are recovered as a small, concentrated liquid fraction for disposal or solvent recycling. The concept has been demonstrated in experiments with a system capable of handling up to 150,000 gpd of water. The existing demonstration system is available for field tests at a DOE facility or remediation site. Replacement of the current short air stripping tower (effective height 3 m) with a taller tower is recommended to improve VOC removal.

  20. METHODOLOGIES FOR ESTIMATING AIR EMISSIONS FROM THREE NON-TRADITIONAL SOURCE CATEGORIES: OIL SPILLS, PETROLEUM VESSEL LOADING & UNLOADING, AND COOLING TOWERS

    EPA Science Inventory

    The report discusses part of EPA's program to identify and characterize emissions sources not currently accounted for by either the existing Aerometric Information Retrieval System (AIRS) or State Implementation Plan (sip) area source methodologies and to develop appropriate emis...

  1. 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

  2. DETAIL VIEW OF AERIAL TRAM SUPPORT TOWER TWO, WITH TOWERS ...

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

    DETAIL VIEW OF AERIAL TRAM SUPPORT TOWER TWO, WITH TOWERS THREE,FOUR, FIVE AND SIX IN DISTANCE, LOOKING NORTHEAST. - Keane Wonder Mine, Park Route 4 (Daylight Pass Cutoff), Death Valley Junction, Inyo County, CA

  3. 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

  4. 26. STATIC TEST TOWER CONTROL PANELS AT REAR OF TOWER ...

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

    26. STATIC TEST TOWER CONTROL PANELS AT REAR OF TOWER UNDERNEATH SHED ROOF. - Marshall Space Flight Center, Saturn Propulsion & Structural Test Facility, East Test Area, Huntsville, Madison County, AL

  5. 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

  6. 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

  7. 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

  8. Solar thermal power towers

    NASA Astrophysics Data System (ADS)

    Kreith, F.; Meyer, R. T.

    1984-07-01

    The solar thermal central receiver technology, known as solar power towers, is rapidly evolving to a state of near-term energy availability for electrical power generation and industrial process heat applications. The systems consist of field arrays of heliostat reflectors, a central receiver boiler, short term thermal storage devices, and either turbine-generators or heat exchangers. Fluid temperatures up to 550 C are currently achievable, and technology developments are underway to reach 1100 C. Six solar power towers are now under construction or in test operation in five countries around the world.

  9. Engineering photochemical smog through convection towers

    SciTech Connect

    Elliott, S.; Prueitt, M.L.; Bossert, J.E.; Mroz, E.J.; Krakowski, R.A.; Miller, R.L.; Jacobson, M.Z.; Turco, R.P. |

    1995-02-01

    Reverse convection towers have attracted attention as a medium for cleansing modern cities. Evaporation of an aqueous mist injected at the tower opening could generate electrical power by creating descent, and simultaneously scavenge unsightly and unhealthful particulates. The study offered here assesses the influence to tower water droplets on the photochemical component of Los Angeles type smog. The primary radical chain initiator OH is likely removed into aqueous phases well within the residence time of air in the tower, and then reacts away rapidly. Organics do not dissolve, but nighttime hydrolysis of N{sub 2}O{sub 5} depletes the nitrogen oxides. A lack of HOx would slow hydrocarbon oxidation and so also ozone production. Lowering of NOx would also alter ozone production rates, but the direction is uncertain. SO{sub 2} is available in sufficient quantities in some urban areas to react with stable oxidants, and if seawater were the source of the mist, the high pH would lead to fast sulfur oxidation kinetics. With an accommodation coefficient of 10{sup {minus}3}, however, ozone may not enter the aqueous phase efficiently. Even if ozone is destroyed or its production suppressed, photochemical recovery times are on the order of hours, so that tower processing must be centered on a narrow midday time window. The cost of building the number of structures necessary for this brief turnover could be prohibitive. The increase in humidity accompanying mist evaporation could be controlled with condensers, but might otherwise counteract visibility enhancements by recreating aqueous aerosols. Quantification of the divergent forcings convection towers must exert upon the cityscape would call for coupled three dimensional modeling of transport, microphysics, and photochemistry. 112 refs.

  10. 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.

  11. 40 CFR Table 4 to Subpart F of... - Organic Hazardous Air Pollutants Subject to Cooling Tower Monitoring Requirements in § 63.104

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Hazardous Air Pollutants From the Synthetic Organic Chemical Manufacturing Industry Pt. 63, Subpt. F, Table... Monitoring Requirements in § 63.104 Chemical name CASNumber a Acetaldehyde 75070 Acetonitrile 75058...-) 108383 Xylene (o-) 95476 Xylene (p-) 106423 a CAS Number=Chemical Abstract Service number....

  12. 40 CFR Table 4 to Subpart F of... - Organic Hazardous Air Pollutants Subject to Cooling Tower Monitoring Requirements in § 63.104

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Hazardous Air Pollutants From the Synthetic Organic Chemical Manufacturing Industry Pt. 63, Subpt. F, Table... Monitoring Requirements in § 63.104 Chemical name CASNumber a Acetaldehyde 75070 Acetonitrile 75058...-) 108383 Xylene (o-) 95476 Xylene (p-) 106423 a CAS Number=Chemical Abstract Service number....

  13. 40 CFR Table 4 to Subpart F of... - Organic Hazardous Air Pollutants Subject to Cooling Tower Monitoring Requirements in § 63.104

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Hazardous Air Pollutants From the Synthetic Organic Chemical Manufacturing Industry Pt. 63, Subpt. F, Table... Monitoring Requirements in § 63.104 Chemical name CASNumber a Acetaldehyde 75070 Acetonitrile 75058...-) 108383 Xylene (o-) 95476 Xylene (p-) 106423 a CAS Number=Chemical Abstract Service number....

  14. PBF Cooling Tower detail. Camera facing southwest into north side ...

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

    PBF Cooling Tower detail. Camera facing southwest into north side of Tower. Five horizontal layers of splash bars constitute fill decks, which will break up falling water into droplets, promoting evaporative cooling. Louvered faces, through which air enters tower, are on east and west sides. Louvers have been installed. Support framework for one of two venturi-shaped fan stacks (or "vents") is in center top. Orifices in hot basins (not in view) will distribute water over fill. Photographer: Kirsh. Date: May 15, 1969. INEEL negative no. 69-3032 - Idaho National Engineering Laboratory, SPERT-I & Power Burst Facility Area, Scoville, Butte County, ID

  15. 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.

  16. 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…

  17. Air

    MedlinePlus

    ... do to protect yourself from dirty air . Indoor air pollution and outdoor air pollution Air can be polluted indoors and it can ... this chart to see what things cause indoor air pollution and what things cause outdoor air pollution! Indoor ...

  18. Credit BG. West elevation of Test Stand "D" tower, with ...

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

    Credit BG. West elevation of Test Stand "D" tower, with workshop on left, and tunnel entrance at right. Tower is accessed by exterior steel stairway; the vertical vacuum cell (Dv Cell) is obscured behind large square sunscreen. Below the sunscreen can be seen the end of the horizontal vacuum duct leading from the vacuum cell - Jet Propulsion Laboratory Edwards Facility, Test Stand D, Edwards Air Force Base, Boron, Kern County, CA

  19. Windmill tower shadow eliminator

    SciTech Connect

    Randolph, A.J.

    1984-04-17

    In a wind driven propeller system an airfoil support for the shaft of a propeller having an even number of blades extends above and below the shaft a distance at least equal to the blade length and pivots with the propeller into the wind for substantially eliminating tower shadow effects on the propeller.

  20. Cell Towers and Songbirds

    ERIC Educational Resources Information Center

    Klosterman, Michelle; Mesa, Jennifer; Milton, Katie

    2009-01-01

    This article describes how our common addiction to cell phones was used to launch a discussion about their use, impacts on the environment, and connections to issues of civic concern. By encouraging middle school science students to adopt the perspectives of special-interest groups debating communication tower restrictions designed to protect…

  1. The Ivory Tower Revisited

    ERIC Educational Resources Information Center

    Chantler, Abigail

    2016-01-01

    The corollary of the concept of the "ivory tower", as reflected in the writings of Plato and Newman amongst others, was, paradoxically, the vital importance of the university for wider society. Nevertheless from the mid-twentieth century, the esteem in which a "liberal" university education was held was diminished by rising…

  2. The Towers of Hanoi

    ERIC Educational Resources Information Center

    Morris, George C.

    2007-01-01

    This article presents an investigation carried out with a group of able mathematics students who were studying at a level 1 year in advance of their peers. The purpose was to investigate the extension of usual three peg Towers of Hanoi to four pegs and attempt to find a rule that could be used to predict the minimum number of moves required to…

  3. Wet/dry cooling tower and method

    DOEpatents

    Glicksman, Leon R.; Rohsenow, Warren R.

    1981-01-01

    A wet/dry cooling tower wherein a liquid to-be-cooled is flowed along channels of a corrugated open surface or the like, which surface is swept by cooling air. The amount of the surface covered by the liquid is kept small compared to the dry part thereof so that said dry part acts as a fin for the wet part for heat dissipation.

  4. Lateral flow strip assay

    DOEpatents

    Miles, Robin R.; Benett, William J.; Coleman, Matthew A.; Pearson, Francesca S.; Nasarabadi, Shanavaz L.

    2011-03-08

    A lateral flow strip assay apparatus comprising a housing; a lateral flow strip in the housing, the lateral flow strip having a receiving portion; a sample collection unit; and a reagent reservoir. Saliva and/or buccal cells are collected from an individual using the sample collection unit. The sample collection unit is immersed in the reagent reservoir. The tip of the lateral flow strip is immersed in the reservoir and the reagent/sample mixture wicks up into the lateral flow strip to perform the assay.

  5. Low-head air stripper treats oil tanker ballast water

    SciTech Connect

    Goldman, M. )

    1992-02-01

    Prototype tests conducted during the winter of 1989/90 have successfully demonstrated an economical design for air stripping volatile hydrocarbons from oily tanker ballast water. The prototype air stripper, developed for Alyeska's Ballast Water Treatment (BWT) facility in Valdez, Alaska, ran continuously for three months with an average removal of 88% of the incoming volatile organics. Initially designed to remove oil and grease compounds from tanker ballast water, the BWT system has been upgraded to a three-step process to comply with new, stringent regulations. The BWT biological oxidation process enhances the growth of bacteria present in the incoming ballast water through nutrient addition, aeration, and recirculation within a complete-mixed bioreactor. The average removal of BETX is over 95%, however, occassional upsets required the placement of a polishing air stripper downstream of the aeration tanks. Packed-tower air stripping was investigated but deemed economically unfeasible for a facility that would only occasionally be used. Twelve feet of excess gravity head in the existing BWT hydraulic gradeline were employed to drive the air stripper feed. This limited the stripper packing depth to 8 feet and imposed constraints on the design of the inlet water and air distributors. Water distribution, air flow, temperature effects, and fouling from constituents in the ballast water were investigated. The prototype was operated under water and air flow conditions similar to those specified for the full-scale unit, and at a range of test conditions above and below the normal design conditions.

  6. 1. VIEW OF SOUTHEAST CORNER OF MOBILE SERVICE TOWER (MST). ...

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

    1. VIEW OF SOUTHEAST CORNER OF MOBILE SERVICE TOWER (MST). CABLE TRAY SHED IN FOREGROUND. MICROWAVE ANTENNAS AND AIR-CONDITIONING PORCH ON EAST SIDE OF MST. - Vandenberg Air Force Base, Space Launch Complex 3, Launch Pad 3 East, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

  7. Successfully troubleshoot distillation towers

    SciTech Connect

    Hasbrouck, J.F. ); Kunesh, J.G. ); Smith, V.C. )

    1993-03-01

    Distillation dominates separation services in the chemical process industries. With this widespread use, not surprisingly, operating problems are common. Because distillation columns frequently are limiting factors in plant capacity or product quality, correcting these problems usually is urgent. The paper describes the steps to be taken to start to correct problems on distillation towers: understand the ground rules, understand the people and procedures, and understand the plant. Then observe the actual operation, monitor the system, collect required data, and analyze the data. The paper discusses how to determine the problem area, broadening the search, focusing on the distillation tower and its internals, confirming the specific problem, extending the troubleshooting activities, and dealing with tougher problems.

  8. Utility avoids cooling tower

    SciTech Connect

    1994-08-01

    After more than four years of often rancorous debate, New Jersey late last month approved a plan that permits the state`s largest utility to reclaim and restore Delaware Bay marshland instead of constructing a costly cooling tower for two nuclear power units. Environmental interests say they`ll appeal the wetlands proposal, calling it an {open_quotes}unproven experiment{close_quotes} that violates Clean Water Act provisions.

  9. Anatomy comic strips.

    PubMed

    Park, Jin Seo; Kim, Dae Hyun; Chung, Min Suk

    2011-01-01

    Comics are powerful visual messages that convey immediate visceral meaning in ways that conventional texts often cannot. This article's authors created comic strips to teach anatomy more interestingly and effectively. Four-frame comic strips were conceptualized from a set of anatomy-related humorous stories gathered from the authors' collective imagination. The comics were drawn on paper and then recreated with digital graphics software. More than 500 comic strips have been drawn and labeled in Korean language, and some of them have been translated into English. All comic strips can be viewed on the Department of Anatomy homepage at the Ajou University School of Medicine, Suwon, Republic of Korea. The comic strips were written and drawn by experienced anatomists, and responses from viewers have generally been favorable. These anatomy comic strips, designed to help students learn the complexities of anatomy in a straightforward and humorous way, are expected to be improved further by the authors and other interested anatomists.

  10. Legionella spp. in Puerto Rico cooling towers

    SciTech Connect

    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 the 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.

  11. Legionella in Puerto Rico cooling towers

    SciTech Connect

    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 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 (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.

  12. Legionella spp. in Puerto Rico cooling towers.

    PubMed Central

    Negrón-Alvíra, A; Pérez-Suarez, I; Hazen, T C

    1988-01-01

    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(5) cells per ml, which is within the 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. PMID:3202625

  13. Surface and Tower Meteorological Instrumentation at Atqasuk (METTWR2H) Handbook

    SciTech Connect

    Ritsche, MT

    2006-01-01

    The Atqasuk meteorology station (AMET) 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 (CMH) is located at 1 m for comparison purposes. Temperature and relative humidity (RH) probes are mounted at 2 m and 5 m on the tower.

  14. The use of an electrical-fluid dynamic parameter in cooling tower

    SciTech Connect

    Sirena, J.A.

    1999-11-01

    An Electrical-Fluid Dynamic quality parameter is defined for a mechanical draft type cooling tower. It allows to evaluate the efficiency of the transformation of the electrical power input into kinetic energy of the air flow. It could also be used to calculate the active electrical power of the tower at different working conditions. Results obtained through tests in a small counterflow water cooling tower are shown.

  15. Delta XTE Spacecraft Arrives at CCAS Skid Strip

    NASA Technical Reports Server (NTRS)

    1995-01-01

    Footage shows the U.S Air Force Aircraft "Air Mobility Command" approaching, and landing at the Cape Canaveral Air Station Skid Strip (CCAS). The truck carrying the Delta XTE Spacecraft is also shown as it leaves the Air Mobility Command.

  16. Peak Wind Forecasts for the Launch-Critical Wind Towers on Kennedy Space Center/Cape Canaveral Air Force Station, Phase IV

    NASA Technical Reports Server (NTRS)

    Crawford, Winifred

    2011-01-01

    This final report describes the development of a peak wind forecast tool to assist forecasters in determining the probability of violating launch commit criteria (LCC) at Kennedy Space Center (KSC) and Cape Canaveral Air Force Station (CCAFS). The peak winds arc an important forecast clement for both the Space Shuttle and Expendable Launch Vehicle (ELV) programs. The LCC define specific peak wind thresholds for each launch operation that cannot be exceeded in order to ensure the safety of the vehicle. The 45th Weather Squadron (45 WS) has found that peak winds are a challenging parameter to forecast, particularly in the cool season months of October through April. Based on the importance of forecasting peak winds, the 45 WS tasked the Applied Meteorology Unit (AMU) to update the statistics in the current peak-wind forecast tool to assist in forecasting LCC violations. The tool includes onshore and offshore flow climatologies of the 5-minute mean and peak winds and probability distributions of the peak winds as a function of the 5-minute mean wind speeds.

  17. Performance of the Integrated Tracker Towers of the GLAST Large Area Telescope

    SciTech Connect

    Brigida, M.; Caliandro, A.; Favuzzi, C.; Fusco, P.; Gargano, F.; Giglietto, N.; Giordano, F.; Loparco, F.; Marangelli, B.; Mazziotta, M.N.; Mirizzi, N.; Raino, S.; Spinelli, P.; /Bari U. /INFN, Bari

    2007-02-15

    The GLAST Large Area Telescope (LAT) is a high energy gamma ray observatory, mounted on a satellite that will be own in 2007. The LAT tracker consists of an array of tower modules, equipped with planes of silicon strip detectors (SSDs) interleaved with tungsten converter layers. Photon detection is based on the pair conversion process; silicon strip detectors will reconstruct tracks of electrons and positrons. The instrument is actually being assembled. The first towers have been already tested and integrated at Stanford Linear Accelerator Center (SLAC). An overview of the integration stages of the main components of the tracker and a description of the pre-launch tests will be given. Experimental results on the performance of the tracker towers will be also discussed.

  18. The Physics of Shot Towers

    NASA Astrophysics Data System (ADS)

    Lipscombe, Trevor C.; Mungan, Carl E.

    2012-04-01

    In the late 18th and throughout the 19th century, lead shot for muskets was prepared by use of a shot tower. Molten lead was poured from the top of a tower and, during its fall, the drops became spherical under the action of surface tension. In this article, we ask and answer the question: How does the size of the lead shot depend on the height of the tower? In the process, we explain the basic technology underlying an important historical invention (the shot tower) and use simple physics (Newtonian mechanics and the thermodynamic laws of cooling) to model its operation.

  19. Prefix Stripping Revisited.

    ERIC Educational Resources Information Center

    Taft, Marcus

    1981-01-01

    Presents and analyzes three experiments on prefix stripping. Results show that pseudoprefixed words are indiscriminately treated as prefixed words and concludes that prefix stripping does occur in word recognition and that prefixed words are accessed through a representation of their stem. (Author/BK)

  20. Anatomy Comic Strips

    ERIC Educational Resources Information Center

    Park, Jin Seo; Kim, Dae Hyun; Chung, Min Suk

    2011-01-01

    Comics are powerful visual messages that convey immediate visceral meaning in ways that conventional texts often cannot. This article's authors created comic strips to teach anatomy more interestingly and effectively. Four-frame comic strips were conceptualized from a set of anatomy-related humorous stories gathered from the authors' collective…

  1. Science Comic Strips

    ERIC Educational Resources Information Center

    Kim, Dae Hyun; Jang, Hae Gwon; Shin, Dong Sun; Kim, Sun-Ja; Yoo, Chang Young; Chung, Min Suk

    2012-01-01

    Science comic strips entitled Dr. Scifun were planned to promote science jobs and studies among professionals (scientists, graduate and undergraduate students) and children. To this end, the authors collected intriguing science stories as the basis of scenarios, and drew four-cut comic strips, first on paper and subsequently as computer files.…

  2. Towers of hybrid mesons

    SciTech Connect

    Semay, Claude; Buisseret, Fabien; Silvestre-Brac, Bernard

    2009-05-01

    A hybrid meson is a quark-antiquark pair in which, contrary to ordinary mesons, the gluon field is in an excited state. In the framework of constituent models, the interaction potential is assumed to be the energy of an excited string. An approximate, but accurate, analytical solution of the Schroedinger equation with such a potential is presented. When applied to hybrid charmonia and bottomonia, towers of states are predicted in which the masses are a linear function of a harmonic oscillator band number for the quark-antiquark pair. Such a formula could be a reliable guide for the experimental detection of heavy hybrid mesons.

  3. 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

  4. FLORIDA TOWER FOOTPRINT EXPERIMENTS

    SciTech Connect

    WATSON,T.B.; DIETZ, R.N.; WILKE, R.; HENDREY, G.; LEWIN, K.; NAGY, J.; LECLERC, M.

    2007-01-01

    The Florida Footprint experiments were a series of field programs in which perfluorocarbon tracers were released in different configurations centered on a flux tower to generate a data set that can be used to test transport and dispersion models. These models are used to determine the sources of the CO{sub 2} that cause the fluxes measured at eddy covariance towers. Experiments were conducted in a managed slash pine forest, 10 km northeast of Gainesville, Florida, in 2002, 2004, and 2006 and in atmospheric conditions that ranged from well mixed, to very stable, including the transition period between convective conditions at midday to stable conditions after sun set. There were a total of 15 experiments. The characteristics of the PFTs, details of sampling and analysis methods, quality control measures, and analytical statistics including confidence limits are presented. Details of the field programs including tracer release rates, tracer source configurations, and configuration of the samplers are discussed. The result of this experiment is a high quality, well documented tracer and meteorological data set that can be used to improve and validate canopy dispersion models.

  5. Pontiac fever outbreak associated with a cooling tower.

    PubMed Central

    Friedman, S; Spitalny, K; Barbaree, J; Faur, Y; McKinney, R

    1987-01-01

    In late April 1984, an outbreak of Pontiac fever was investigated in an office building in lower Manhattan (New York City). The outbreak was characterized by a high attack rate (78 per cent overall); the predominant symptoms were myalgias, chills, fatigue, fever, and headache. There was a clustering of cases in an office that was air cooled by a dedicated cooling tower separate from the remainder of the building. A high concentration of live L. Pneumophila cells in the cooling tower was quantified. Airborne spread via settle plates placed along the air intake system and within the office was demonstrated. Legionella pneumophila serogroup 1 antigen was found in the urine of two cases, and identical monoclonal antibody reactivity patterns of isolates from all sources was observed. Difficulty was experienced in eliminating the organism from the tower. PMID:3565648

  6. Short Duration Reduced Gravity Drop Tower Design and Development

    NASA Astrophysics Data System (ADS)

    Osborne, B.; Welch, C.

    The industrial and commercial development of space-related activities is intimately linked to the ability to conduct reduced gravity research. Reduced gravity experimentation is important to many diverse fields of research in the understanding of fundamental and applied aspects of physical phenomena. Both terrestrial and extra-terrestrial experimental facilities are currently available to allow researchers access to reduced gravity environments. This paper discusses two drop tower designs, a 2.0 second facility built in Australia and a proposed 2.2 second facility in the United Kingdom. Both drop towers utilise a drag shield for isolating the falling experiment from the drag forces of the air during the test. The design and development of The University of Queensland's (Australia) 2.0 second drop tower, including its specifications and operational procedures is discussed first. Sensitive aspects of the design process are examined. Future plans are then presented for a new short duration (2.2 sec) ground-based reduced gravity drop tower. The new drop tower has been designed for Kingston University (United Kingdom) to support teaching and research in the field of reduced gravity physics. The design has been informed by the previous UQ drop tower design process and utilises a catapult mechanism to increase test time and also incorporates features to allow participants for a variety of backgrounds (from high school students through to university researchers) to learn and experiment in reduced gravity. Operational performance expectations for this new facility are also discussed.

  7. Droplet size of cooling tower fog.

    PubMed

    Rothman, T; Ledbetter, J O

    1975-01-01

    Fog from cooling towers causes problems of visibility and icing along roadways adjacent to the towers; moreover, the visible plume from the towers offers difficulty in that it is equated by much of the public with air pollution. It is desirable to know the size of the fog droplets in order to plan abatement procedures and to determine the airborne lifetimes of such fogs. The methodology involved capturing the droplets on slides coated with a vaseline-mineral oil mixture, making photomicrographs of the droplets, counting and sizing the droplets into eight droplet diameter increments; namely less than 5 mum, 5-10 mum, 10-20 mum, 20-40 mum, 40-60 mum, 60-80 mum, 80-100 mum, and greater than 100 mum. The resulting distribution was similar to that for natural fogs and clouds; i.e., it was bi-modal, the first mode at less than 5 mum containing the vast majority of the droplets, and the second at 20-40 mum. This study agrees with others that the size distribution of a fog in a saturated environment is continuously changing, with the smaller droplets tending to evaporate and the larger ones tending to grow, thus shifting the second mode toward larger sizes.

  8. 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

  9. Within compound, from Guard Tower, looking southeast, Power Plant (Building ...

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

    Within compound, from Guard Tower, looking southeast, Power Plant (Building 5761) to left, Satellite Communications Terminal (Building 5771) center, Supply Warehouse (Building 5768) to left - Beale Air Force Base, Perimeter Acquisition Vehicle Entry Phased-Array Warning System, End of Spencer Paul Road, north of Warren Shingle Road (14th Street), Marysville, Yuba County, CA

  10. Exterior, looking west, Equipment Building to left, Tower at center, ...

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

    Exterior, looking west, Equipment Building to left, Tower at center, Civil Engineering Storage Building (Building 5765) at left - Beale Air Force Base, Perimeter Acquisition Vehicle Entry Phased-Array Warning System, Microwave Equipment Building, End of Spencer Paul Road, north of Warren Shingle Road (14th Street), Marysville, Yuba County, CA

  11. 169. PORTLAND FILTER FLOOR FROM SOUTHEAST. CYANIDE FEED TOWER TO ...

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

    169. PORTLAND FILTER FLOOR FROM SOUTHEAST. CYANIDE FEED TOWER TO SUMP, LOWER RIGHT QUADRANT. DIAGONAL PIPE IN UPPER RIGHT IS AIR LINE TO AGITATORS. LAUNDER PARALLEL TO LEFT EDGE (FILLED WITH DEBRIS) RUNS FROM PRIMARY THICKENER No. 2 TO GOLD TANK No. 2 - Bald Mountain Gold Mill, Nevada Gulch at head of False Bottom Creek, Lead, Lawrence County, SD

  12. 90. PORTLAND FILTER FLOOR FROM SOUTHEAST. CYANIDE FEED TOWER TO ...

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

    90. PORTLAND FILTER FLOOR FROM SOUTHEAST. CYANIDE FEED TOWER TO SUMP, LOWER RIGHT QUADRANT. DIAGONAL PIPE IN UPPER RIGHT IS AIR LINE TO AGITATORS. LAUNDER PARALLEL TO LEFT EDGE (FILLED WITH DEBRIS) RUNS FROM PRIMARY THICKENER No. 2 TO GOLD TANK No. 2. - Bald Mountain Gold Mill, Nevada Gulch at head of False Bottom Creek, Lead, Lawrence County, SD

  13. 6. SOUTH SIDE OF EAST TELEVISION CAMERA TOWER. A STORAGE ...

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

    6. SOUTH SIDE OF EAST TELEVISION CAMERA TOWER. A STORAGE SHED (BLDG. 776), THE PYROTECHNIC SHED (BLDG. 757), AND SLC-3W MST IN BACKGROUND. - Vandenberg Air Force Base, Space Launch Complex 3, Launch Pad 3 East, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

  14. Within compound, looking southwest, Guard Tower (Building 5762) and Technical ...

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

    Within compound, looking southwest, Guard Tower (Building 5762) and Technical Equipment Building (Building 5760) - Beale Air Force Base, Perimeter Acquisition Vehicle Entry Phased-Array Warning System, End of Spencer Paul Road, north of Warren Shingle Road (14th Street), Marysville, Yuba County, CA

  15. Indiana State University Graduates to Advanced Plastic Cooling Towers

    ERIC Educational Resources Information Center

    Sullivan, Ed

    2012-01-01

    Perhaps more than many other industries, today's universities and colleges are beset by dramatically rising costs on every front. One of the areas where overhead can be contained or reduced is in the operation of the chilled water systems that support air conditioning throughout college campuses, specifically the cooling towers. Like many…

  16. Interior view at top of parachute drying tower showing Lbeams ...

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

    Interior view at top of parachute drying tower showing L-beams and holes for hanging parachutes, and wooden roof construction, facing northeast. - Albrook Air Force Station, Parachute & Armament Building, 200 feet north of Andrews Boulevard, Balboa, Former Panama Canal Zone, CZ

  17. Hydrocarbon product stripping

    SciTech Connect

    Harandi, M.N.; Owen, H.; Siuta, M.T.

    1989-04-18

    A method is described for stripping light gasiform components from the liquid effluent of a catalytic hydrodesulfurization process, which comprises separating the liquid effluent containing relatively low boiling hydrocarbon components, relatively high boiling hydrocarbon components, hydrogen, and hydrogen sulfide.

  18. Subdue solids in towers

    SciTech Connect

    Sloley, A.W.; Martin, G.R.

    1995-01-01

    Many distillation, absorption, and stripping columns operate with solids present in the system. The presence of solids may be either intentional or unintentional. But, in all cases, the solids must be handled or tolerated by the vapor/liquid mass-transfer equipment. Such solids should be dealt with by a combination of four methods. From most favorable to least favorable, these are: (1) keep the solids out; (2) keep the solids moving; (3) put the solids somewhere harmless; and (4) make it easier to clean the hardware. The key precept for all these approaches is the realization that solids present in a system just don't disappear. In this article, the authors review the techniques and design issues involved in making a vapor/liquid mass-transfer system operate with solids present. They assume that the solids cannot be kept out, eliminating the first choice. The type of mass-transfer service does not matter. The same principles apply equally well to distillation, adsorption, and stripping. They include equipment design criteria based on the methods outlined above, as well as detailed recommendations for each of the major equipment choices that can be made for mass-transfer devices. Then, they illustrate the approach via an example--a vinyl chloride monomer (VCM) unit having solids as an inherent part of its feed.

  19. 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

  20. 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…

  1. CFD MODELING ANALYSIS OF MECHANICAL DRAFT COOLING TOWER

    SciTech Connect

    Lee, S; Alfred Garrett, A; James02 Bollinger, J; Larry Koffman, L

    2008-03-03

    Industrial processes use mechanical draft cooling towers (MDCT's) to dissipate waste heat by transferring heat from water to air via evaporative cooling, which causes air humidification. The Savannah River Site (SRS) has a MDCT consisting of four independent compartments called cells. Each cell has its own fan to help maximize heat transfer between ambient air and circulated water. The primary objective of the work is to conduct a parametric study for cooling tower performance under different fan speeds and ambient air conditions. The Savannah River National Laboratory (SRNL) developed a computational fluid dynamics (CFD) model to achieve the objective. The model uses three-dimensional steady-state momentum, continuity equations, air-vapor species balance equation, and two-equation turbulence as the basic governing equations. It was assumed that vapor phase is always transported by the continuous air phase with no slip velocity. In this case, water droplet component was considered as discrete phase for the interfacial heat and mass transfer via Lagrangian approach. Thus, the air-vapor mixture model with discrete water droplet phase is used for the analysis. A series of the modeling calculations was performed to investigate the impact of ambient and operating conditions on the thermal performance of the cooling tower when fans were operating and when they were turned off. The model was benchmarked against the literature data and the SRS test results for key parameters such as air temperature and humidity at the tower exit and water temperature for given ambient conditions. Detailed results will be presented here.

  2. Cell-tower deployment of counter-sniper sensors

    NASA Astrophysics Data System (ADS)

    Storch, Michael T.

    2004-09-01

    Cellular telephone antenna towers are evaluated as sites for rapid, effective & efficient deployment of counter-sniper sensors, especially in urban environments. They are expected to offer a suitable density, excellent LOS, and a generally limited variety of known or readily-characterized mechanical interfaces. Their precise locations are easily mapped in advance of deployment, are easily accessible by ground and air, and are easily spotted by deployment teams in real-time. We survey issues of EMI & RFI, susceptibility to denial & ambush in military scenarios, and the impact of trends in cell tower design & construction.

  3. Ozonation of cooling tower waters

    NASA Technical Reports Server (NTRS)

    Humphrey, M. F.; French, K. R.; Howe, R. D. (Inventor)

    1979-01-01

    Continuous ozone injection into water circulating between a cooling tower and heat exchanger with heavy scale deposits inhibits formation of further deposits, promotes flaking of existing deposits, inhibits chemical corrosion and controls algae and bacteria.

  4. Tower Temperature and Humidity Sensors (TWR) Handbook

    SciTech Connect

    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.

  5. The Physics of Shot Towers

    ERIC Educational Resources Information Center

    Lipscombe, Trevor C.; Mungan, Carl E.

    2012-01-01

    In the late 18th and throughout the 19th century, lead shot for muskets was prepared by use of a shot tower. Molten lead was poured from the top of a tower and, during its fall, the drops became spherical under the action of surface tension. In this article, we ask and answer the question: "How does the size of the lead shot depend on the height…

  6. 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.

  7. Virtual Environment Design for Low/Zero Visibility Tower Tools

    NASA Technical Reports Server (NTRS)

    Reisman, Ron; Farouk, Ahmed; Edwards, Thomas A. (Technical Monitor)

    1998-01-01

    This paper describes prototype software for three-dimensional display of aircraft movement based on realtime radar and other Air Traffic Control (ATC) information. This prototype can be used to develop operational tools for controllers in ATC Towers who cannot view aircraft in low or zero visibility (LZV) weather conditions. The controller could also use the software to arbitrarily reposition his virtual eyepoint to overcome physical obstructions or increase situation awareness. The LZV Tower tool prototype consists of server and client components. The server interfaces to operational ATC radar and communications systems, sending processed data to a client process written in java. This client process runs under Netscape Communicator to provide an interactive perspective display of aircraft in the airport environment. Prototype VRML airport models were derived from 3-D databases used in FAA-certified high fidelity flight-simulators. The web-based design offers potential efficiency increases and decreased costs in the development and deployment of operational LZV Tower tools.

  8. Mastering Interproximal Stripping: With Innovations in Slenderization

    PubMed Central

    Shrivastav, Sunita S; Hazarey, Pushpa V

    2012-01-01

    ABSTRACT Crowding and irregularity remain a consistent problem for children. Management of space problems continues to play an important role in a dental practice. It also represents an area of major interaction between the primary provider and the specialists. Proximal stripping is routinely carried out to avoid extraction in borderline cases where space discrepancy is less and in cases where there is a discrepancy between the mesio- distal width of maxillary and mandibular teeth to satisfy Bolton ratio. Proximal stripping is carried out using of metallic abrasive strip, safe sided carborundum disk, or with long thin tapered fissure burs with air rotor. The use of rotary cutting instrument can harm the pulp by exposure of mechanical vibration and heat generation (in some cases). Whereas, the large diameter of the disk obstructs vision of the working area. Also fracturing away a portion is a common problem with disk. Tapered fissure burs cut the tooth structure as the width of bur or overcutting may occur of the tooth structure due to high speed. The use of metallic abrasive strip is the safest procedure amongst the above. The strip can be placed in the anterior region without any difficulty but using it in the posterior region is difficult as, it is difficult to hold it with fingers while stripping the posterior teeth. To avoid this inconvenience here with a simple and economical way of fabricating strip holder from routine lab material is presented. Clinical implications: Proper management of space in the primary and mixed dentitions can prevent unnecessary loss in arch length. Diagnosing and treating space problems requires an understanding of the etiology of crowding and the development of the dentition to render treatment for the mild, moderate and severe crowding cases. Most crowding problems with less than 4.5 mm can be resolved through preservation of the leeway space, regaining space or limited expansion in the late mixed dentition. In cases with 5 to 9 mm

  9. Influence of the gas composition on the efficiency of ammonia stripping of biogas digestate.

    PubMed

    Bousek, J; Scroccaro, D; Sima, Jan; Weissenbacher, Norbert; Fuchs, W

    2016-03-01

    Impact of strip gas composition on side stream ammonia stripping, a technology aiming at the reduction of high ammonia levels in anaerobic reactors, was investigated. Evaluation of the effect of oxygen contact during air stripping showed a distinct, though lower than perceived, inhibition of anaerobic microflora. To circumvent, the feasibility and possible constraints of biogas and flue gas as alternatives in side stream stripping were studied. Experiments, with ammonia bicarbonate model solution and digestate, were conducted. It was demonstrated that the stripping performance is negatively correlated to the CO2 level in the strip gas with a progressive performance loss towards higher concentrations. In contrast to biogas with its high CO2 content, the efficiency reduction observed for flue gas was significantly less pronounced. The later provides the additional benefit that its high thermal energy can be re-utilized in the stripping unit and it is therefore considered a viable alternative for air.

  10. Deployable tensegrity towers

    NASA Astrophysics Data System (ADS)

    Pinaud, Jean-Paul

    The design of a complete tensegrity system involves the analysis of static equilibria, the mechanical properties of the configuration, the deployment of the structure, and the regulation and dynamics of the system. This dissertation will explore these steps for two different types of structures. The first structure is the traditional Snelson Tower, where struts are disjointed, and is referred to as a Class 1 tensegrity. The second structure of interest is referred to as a Class 2 structure, where two struts come in contact at a joint. The first part of the thesis involves the dynamics of these tensegrity structures. Two complete nonlinear formulations for the dynamics of tensegrity systems are derived. In addition, a general formulation for the statics for an arbitrary tensegrity structure resulted from one of the dynamic formulations and is presented with symmetric and nonsymmetric tensegrity configurations. The second part of the thesis involves statics. The analysis of static equilibria and the implementation of this analysis into an open loop control law that will deploy the tensegrity structures along an equilibrium manifold are derived. The analysis of small stable tensegrity units allow for a modular design, where a collection of these units can be assembled into a larger structure that obeys the same control laws for deployment concepts. In addition, a loaded structure is analyzed to determine the optimal number of units required to obtain a minimal mass configuration. The third part of the thesis involves laboratory hardware that demonstrates the practical use of the methodology presented. A Class 2 symmetric structure is constructed, deployed, and stowed using the analysis from part two. In addition, the static equilibria of a Class 1 structure is computed to obtain nonsymmetric reconfigurations. The final part of the thesis involves the attenuation of white noise disturbances acting on nodes of both structures. The structures are simulated using linear

  11. Retractable barrier strip

    DOEpatents

    Marts, D.J.; Barker, S.G.; McQueen, M.A.

    1996-04-16

    A portable barrier strip is described having retractable tire-puncture means for puncturing a vehicle tire. The tire-puncture means, such as spikes, have an armed position for puncturing a tire and a retracted position for not puncturing a tire. The strip comprises a plurality of barrier blocks having the tire-puncture means removably disposed in a shaft that is rotatably disposed in each barrier block. The shaft removably and pivotally interconnects the plurality of barrier blocks. Actuation cables cause the shaft to rotate the tire-puncture means to the armed position for puncturing a vehicle tire and to the retracted position for not puncturing the tire. Each tire-puncture means is received in a hollow-bed portion of its respective barrier block when in the retracted position. The barrier strip rests in its deployed position and substantially motionless as a tire rolls thereon and over. The strip is rolled up for retrieval, portability, and storage purposes, and extended and unrolled in its deployed position for use. 13 figs.

  12. Retractable barrier strip

    DOEpatents

    Marts, Donna J.; Barker, Stacey G.; Wowczuk, Andrew; Vellenoweth, Thomas E.

    2002-01-01

    A portable barrier strip having retractable tire-puncture spikes for puncturing a vehicle tire. The tire-puncture spikes have an armed position for puncturing a tire and a retracted position for not puncturing a tire. The strip comprises a plurality of barrier blocks having the tire-puncture spikes removably disposed in a shaft that is rotatably disposed in each barrier block. The plurality of barrier blocks hare hingedly interconnected by complementary hinges integrally formed into the side of each barrier block which allow the strip to be rolled for easy storage and retrieval, but which prevent irregular or back bending of the strip. The shafts of adjacent barrier blocks are pivotally interconnected via a double hinged universal joint to accommodate irregularities in a roadway surface and to transmit torsional motion of the shaft from block to block. A single flexshaft cable is connected to the shaft of an end block to allow a user to selectively cause the shafts of a plurality of adjacently connected barrier blocks to rotate the tire-puncture spikes to the armed position for puncturing a vehicle tire, and to the retracted position for not puncturing the tire. The flexshaft is provided with a resiliently biased retracting mechanism, and a release latch for allowing the spikes to be quickly retracted after the intended vehicle tire is punctured.

  13. Retractable barrier strip

    DOEpatents

    Marts, Donna J.; Barker, Stacey G.; McQueen, Miles A.

    1996-01-01

    A portable barrier strip having retractable tire-puncture means for puncturing a vehicle tire. The tire-puncture means, such as spikes, have an armed position for puncturing a tire and a retracted position for not puncturing a tire. The strip comprises a plurality of barrier blocks having the tire-puncture means removably disposed in a shaft that is rotatably disposed in each barrier block. The shaft removably and pivotally interconnects the plurality of barrier blocks. Actuation cables cause the shaft to rotate the tire-puncture means to the armed position for puncturing a vehicle tire and to the retracted position for not puncturing the tire. Each tire-puncture means is received in a hollow-bed portion of its respective barrier block when in the retracted position. The barrier strip rests stable in its deployed position and substantially motionless as a tire rolls thereon and over. The strip is rolled up for retrieval, portability, and storage purposes, and extended and unrolled in its deployed position for use.

  14. Towers for Offshore Wind Turbines

    NASA Astrophysics Data System (ADS)

    Kurian, V. J.; Narayanan, S. P.; Ganapathy, C.

    2010-06-01

    Increasing energy demand coupled with pollution free production of energy has found a viable solution in wind energy. Land based windmills have been utilized for power generation for more than two thousand years. In modern times wind generated power has become popular in many countries. Offshore wind turbines are being used in a number of countries to tap the energy from wind over the oceans and convert to electric energy. The advantages of offshore wind turbines as compared to land are that offshore winds flow at higher speed than onshore winds and the more available space. In some land based settings, for better efficiency, turbines are separated as much as 10 rotor diameters from each other. In offshore applications where only two wind directions are likely to predominate, the distances between the turbines arranged in a line can be shortened to as little as two or four rotor diameters. Today, more than a dozen offshore European wind facilities with turbine ratings of 450 kw to 3.6 MW exist offshore in very shallow waters of 5 to 12 m. Compared to onshore wind turbines, offshore wind turbines are bigger and the tower height in offshore are in the range of 60 to 80 m. The water depths in oceans where offshore turbines can be located are within 30 m. However as the distance from land increases, the costs of building and maintaining the turbines and transmitting the power back to shore also increase sharply. The objective of this paper is to review the parameters of design for the maximum efficiency of offshore wind turbines and to develop types offshore towers to support the wind turbines. The methodology of design of offshore towers to support the wind turbine would be given and the environmental loads for the design of the towers would be calculated for specific cases. The marine corrosion on the towers and the methods to control the corrosion also would be briefly presented. As the wind speeds tend to increase with distance from the shore, turbines build father

  15. Strip interpolation in silicon and germanium strip detectors.

    SciTech Connect

    Wulf, E. A.; Phlips, B. F.; Johnson, W. N.; Kurfess, J. D.; Lister, C. J.; Kondev, F.; Physics; Naval Research Lab.

    2004-01-01

    The position resolution of double-sided strip detectors is limited by the strip pitch and a reduction in strip pitch necessitates more electronics. Improved position resolution would improve the imaging capabilities of Compton telescopes and PET detectors. Digitizing the preamplifier waveform yields more information than can be extracted with regular shaping electronics. In addition to the energy, depth of interaction, and which strip was hit, the digitized preamplifier signals can locate the interaction position to less than the strip pitch of the detector by looking at induced signals in neighboring strips. This allows the position of the interaction to be interpolated in three dimensions and improve the imaging capabilities of the system. In a 2 mm thick silicon strip detector with a strip pitch of 0.891 mm, strip interpolation located the interaction of 356 keV gamma rays to 0.3 mm FWHM. In a 2 cm thick germanium detector with a strip pitch of 5 mm, strip interpolation of 356 keV gamma rays yielded a position resolution of 1.5 mm FWHM.

  16. 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.

  17. Ammonia stripping for enhanced biomethanization of piggery wastewater.

    PubMed

    Zhang, Lei; Lee, Yong-Woo; Jahng, Deokjin

    2012-01-15

    In this study, the effects of ammonia removal by air stripping as a pretreatment on the anaerobic digestion of piggery wastewater were investigated. Ammonia stripping results indicated that ammonia removal was strongly dependent on pH and aeration rate, and the ammonia removal rate followed the pseudo-first-order kinetics. A significant enhancement of biomethanization was observed for wastewaters of which ammonia was air-stripped at pH 9.5 and pH 10.0. The methane productivity increased from 0.23 ± 0.08 L CH(4)/Ld of the control (raw piggery wastewater) to 0.75 ± 0.11 L CH(4)/Ld (ammonia-stripped at pH 9.5) and 0.57 ± 0.04 L CH(4)/Ld (ammonia-stripped at pH 10.0). However, the improvement of methane production from the piggery wastewater pretreated at pH 11.0 was negligible compared to the control, which was thought to be due to the high concentration of sodium ions supplied from sodium hydroxide for pH adjustment. From these results, it was concluded that ammonia removal through air stripping at the alkaline pH could be a viable option for preventing the failure of anaerobic digestion of the raw piggery wastewater. Additionally, it was also found that a high concentration of sodium ion originated from sodium hydroxide for pH adjustment inhibited methane production.

  18. Emissions characteristics of cooling towers using reclaimed wastewater in california. Final report, July 1979-July 1981

    SciTech Connect

    Rogozen, M.B.; Phillips, A.R.; Guttman, M.A.; Shokes, R.F.; Fargo, L.

    1981-08-11

    Present and planned use of reclaimed municipal wastewater, industrial process water, and geothermal condensate as makeup to cooling towers have raised questions about the potential for atmospheric emissions of pathogenic microorganisms, organic compounds, heavy metals, and other wastewater constituents. In this study, the makeup and circulating water of six towers were sampled and analyzed for indicator bacteria and virus, volatile and nonvolatile organic compounds, metals, and other components of potential concern. Further water sampling and exhaust air emissions tests were then conducted on four of the towers; for the microbiological emissions tests, a special isokinetic sampling device was developed and employed.

  19. Gated strip proportional detector

    DOEpatents

    Morris, Christopher L.; Idzorek, George C.; Atencio, Leroy G.

    1987-01-01

    A gated strip proportional detector includes a gas tight chamber which encloses a solid ground plane, a wire anode plane, a wire gating plane, and a multiconductor cathode plane. The anode plane amplifies the amount of charge deposited in the chamber by a factor of up to 10.sup.6. The gating plane allows only charge within a narrow strip to reach the cathode. The cathode plane collects the charge allowed to pass through the gating plane on a set of conductors perpendicular to the open-gated region. By scanning the open-gated region across the chamber and reading out the charge collected on the cathode conductors after a suitable integration time for each location of the gate, a two-dimensional image of the intensity of the ionizing radiation incident on the detector can be made.

  20. Gated strip proportional detector

    DOEpatents

    Morris, C.L.; Idzorek, G.C.; Atencio, L.G.

    1985-02-19

    A gated strip proportional detector includes a gas tight chamber which encloses a solid ground plane, a wire anode plane, a wire gating plane, and a multiconductor cathode plane. The anode plane amplifies the amount of charge deposited in the chamber by a factor of up to 10/sup 6/. The gating plane allows only charge within a narrow strip to reach the cathode. The cathode plane collects the charge allowed to pass through the gating plane on a set of conductors perpendicular to the open-gated region. By scanning the open-gated region across the chamber and reading out the charge collected on the cathode conductors after a suitable integration time for each location of the gate, a two-dimensional image of the intensity of the ionizing radiation incident on the detector can be made.

  1. Investigation of Natural Draft Cooling Tower Performance Using Neural Network

    NASA Astrophysics Data System (ADS)

    Mahdi, Qasim S.; Saleh, Saad M.; Khalaf, Basima S.

    In the present work Artificial Neural Network (ANN) technique is used to investigate the performance of Natural Draft Wet Cooling Tower (NDWCT). Many factors are affected the rang, approach, pressure drop, and effectiveness of the cooling tower which are; fill type, water flow rate, air flow rate, inlet water temperature, wet bulb temperature of air, and nozzle hole diameter. Experimental data included the effects of these factors are used to train the network using Back Propagation (BP) algorithm. The network included seven input variables (Twi, hfill, mw, Taiwb, Taidb, vlow, vup) and five output variables (ma, Taowb, Two, Δp, ɛ) while hidden layer is different for each case. Network results compared with experimental results and good agreement was observed between the experimental and theoretical results.

  2. View of first bank of circuit towers on Arizona side ...

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

    View of first bank of circuit towers on Arizona side of canyon. Left tower supports Circuit 12, second from left tower supports Circuit 11, middle tower supports Circuit 10, second from right tower supports Circuit 9, and right tower supports Circuit 8, view west - Hoover Dam, Circuits 1-15, U.S. Highway 93, Boulder City, Clark County, NV

  3. View of Arizona rim towers from top of power plant. ...

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

    View of Arizona rim towers from top of power plant. Left tower supports Circuit 3, second tower from left supports Circuit 12, middle tower supports Circuit 10, second tower from right supports Circuit 9, and right tower supports Circuit 8, view southeast - Hoover Dam, Circuits 1-15, U.S. Highway 93, Boulder City, Clark County, NV

  4. 30 CFR 57.10006 - Tower guards.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Tower guards. 57.10006 Section 57.10006 Mineral... HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Aerial Tramways § 57.10006 Tower guards. Towers shall be suitably protected from swaying buckets....

  5. 30 CFR 56.10006 - Tower guards.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Tower guards. 56.10006 Section 56.10006 Mineral... HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Aerial Tramways § 56.10006 Tower guards. Towers shall be suitably protected from swaying buckets....

  6. 30 CFR 56.10006 - Tower guards.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Tower guards. 56.10006 Section 56.10006 Mineral... HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Aerial Tramways § 56.10006 Tower guards. Towers shall be suitably protected from swaying buckets....

  7. 30 CFR 57.10006 - Tower guards.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Tower guards. 57.10006 Section 57.10006 Mineral... HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Aerial Tramways § 57.10006 Tower guards. Towers shall be suitably protected from swaying buckets....

  8. 30 CFR 57.10006 - Tower guards.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Tower guards. 57.10006 Section 57.10006 Mineral... HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Aerial Tramways § 57.10006 Tower guards. Towers shall be suitably protected from swaying buckets....

  9. 30 CFR 56.10006 - Tower guards.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Tower guards. 56.10006 Section 56.10006 Mineral... HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Aerial Tramways § 56.10006 Tower guards. Towers shall be suitably protected from swaying buckets....

  10. Surface and Tower Meteorological Instrumentation at Barrow (METTWR4H) Handbook

    SciTech Connect

    Ritsche, MT

    2008-04-01

    The Barrow meteorology station (BMET) uses mainly conventional in situ sensors mounted at four different heights (2m, 10m, 20m and 40m) on a 40 m tower to obtain profiles of wind speed, wind direction, air temperature, dew point and humidity. It also obtains barometric pressure, visibility and precipitation data from sensors at the base of the tower. Additionally, a Chilled Mirror Hygrometer and an Ultrasonic wind speed sensor are located near the 2m level for comparison purposes.

  11. Use of Air2Air Technology to Recover Fresh-Water from the Normal Evaporative Cooling Loss at Coal-Based Thermoelectric Power Plants

    SciTech Connect

    Ken Mortensen

    2009-06-30

    This program was undertaken to build and operate the first Air2Air{trademark} Water Conservation Cooling Tower at a power plant, giving a validated basis and capability for water conservation by this method. Air2Air{trademark} water conservation technology recovers a portion of the traditional cooling tower evaporate. The Condensing Module provides an air-to-air heat exchanger above the wet fill media, extracting the heat from the hot saturated moist air leaving in the cooling tower and condensing water. The rate of evaporate water recovery is typically 10%-25% annually, depending on the cooling tower location (climate).

  12. Plant Vogtle cooling tower studies

    SciTech Connect

    O'Steen, L.

    2000-01-26

    Intensive ground-based field studies of plumes from two large, natural-draft cooling towers were conducted in support of the MTI modeling effort. Panchromatic imagery, IR imagery, meteorological data, internal tower temperatures and plant power data were collected during the field studies. These data were used to evaluate plume simulations, plume radioactive transfer calculations and plume volume estimation algorithms used for power estimation. Results from six field studies indicate that a 3-D atmospheric model at sufficient spatial resolution can effectively simulate a cooling tower plume if the plume is of sufficient size and the ambient meteorology is known and steady. Small plumes and gusty wind conditions degrade the agreement between the simulated and observed plumes. Thermal radiance calculations based on the simulated plumes produced maximum IR temperatures (near tower exit) which were in good agreement with measured IR temperatures for the larger plumes. For the smaller plumes, the calculated IR temperature was lower than the measured temperature by several degrees. Variations in maximum IR plume temperature with decreasing power (one reactor was undergoing a shutdown process), were clearly observed in the IR imagery and seen in the simulations. These temperature changes agreed with those calculated from an overall tower energy and momentum balance. Plume volume estimates based on camcorder images at three look angles were typically 20--30 percent larger than the plume volumes derived from the simulations, although one estimate was twice the simulated volume. Volume overestimation is expected and will have to be accounted for to some degree if plume volume is to be a useful diagnostic quantity in power estimation. Volume estimation with MTI imagery will require a large, stable plume and two looks in the visible bands (5m GSD) along with a solar shadow.

  13. 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.

  14. ASDC: A microcomputer-based program for air stripper design and costing. Revision. Final report, March 1990-August 1991

    SciTech Connect

    Dzombak, D.A.; Fang, H.J.; Roy, S.B.

    1993-10-01

    Packed-tower, counter-current air stripping is a treatment process that can be employed for removal of volatile organic compounds (VOCs) from water and wastewater. The design of an air stripper is performed using a well-developed mathematical model of the process. However, the number of variables involved exceeds the number of constraining equations by two, with the result that a number of alternative air stripper designs exist for a particular water treatment goal. In selecting the optimum design among the various alternatives, it is important to consider the capital and operating costs associated with each alternative. This report describes an interactive, microcomputer-based program - the Air Stripper Design and Costing (ASDC) program - that enables rapid evaluation of alternative air stripper designs and approximate costs associated with these designs for user-specified treatment scenarios. The various components of the program are described in detail, a guide to program operation is provided along with example applications, and results of some verification tests are presented. Air Stripping, Computer design, Water Treatment, Volatile organic compound.

  15. Air/Superfund National Technical Guidance Study Series. Comparisons of air-stripper simulations and field-performance data. Final report

    SciTech Connect

    Saunders, G.L.

    1990-02-01

    One of the more common problems noted at Superfund sites is the contamination of ground water by volatile organic compounds (VOCs). One remedial alternative that is used to reduce or remove the VOC contamination from water is air stripping in a tower that uses either packing media or trays. The ability to strip a compound from the water depends on several factors, including the air/water ratio, the packing or tray type, and the Henry's Law value for the compounds of interest. The objective is to remove the VOCs from the water. When being considered for remediation purposes, the air stripper design should be evaluated for removal efficiency and cost of operation. The purpose of the project was to collect available design and operating data on operating air strippers and to input the design and operating parameters into the ASPEN simulator through a user interface program. The results from the ASPEN simulator were compared to the operating data gathered for the sites to determine the relative accuracy of the ASPEN model results when compared with the actual performance data.

  16. Air-stripper design and costing computer program

    SciTech Connect

    Dzombak, D.A.; Roy, S.B. ); Fang, H.J. )

    1993-10-01

    Packed-tower, countercurrent air-stripping is widely used to remove volatile organic compounds from contaminated water. An air stripper is designed using a well-developed mathematical model of the process. However, the number of variables in the model exceeds the number of constraining equations by two, with the result that a number of alternative air-stripper designs are possible for a particular water treatment objective. To select one or several designs associated with minimum capital and operating costs, it is necessary to develop a large number of possible designs and to estimate the costs associated with each. The air-stripper design and costing (ASDC) program, a microcomputer-based public-domain program, automates the iterative design and cost calculations and thus enables rapid, preliminary evaluation of alternative air-stripper designs and associated costs. In this article, the design methodology and cost-estimation techniques incorporated in ASDC are described, and ASDC cost predictions are compared with costs reported for actual operating air strippers.

  17. Spray Rolling Aluminum Strip

    SciTech Connect

    Lavernia, E.J.; Delplanque, J-P; McHugh, K.M.

    2006-05-10

    Spray forming is a competitive low-cost alternative to ingot metallurgy for manufacturing ferrous and non-ferrous alloy shapes. It produces materials with a reduced number of processing steps, while maintaining materials properties, with the possibility of near-net-shape manufacturing. However, there are several hurdles to large-scale commercial adoption of spray forming: 1) ensuring strip is consistently flat, 2) eliminating porosity, particularly at the deposit/substrate interface, and 3) improving material yield. Through this program, a new strip/sheet casting process, termed spray rolling, has been developed, which is an innovative manufacturing technique to produce aluminum net-shape products. Spray rolling combines the benefits of twin-roll casting and conventional spray forming, showing a promising potential to overcome the above hurdles associated with spray forming. Spray rolling requires less energy and generates less scrap than conventional processes and, consequently, enables the development of materials with lower environmental impacts in both processing and final products. Spray Rolling was developed as a collaborative project between the University of California-Davis, the Colorado School of Mines, the Idaho National Engineering and Environmental Laboratory, and an industry team. The following objectives of this project were achieved: (1) Demonstration of the feasibility of the spray rolling process at the bench-scale level and evaluation of the materials properties of spray rolled aluminum strip alloys; and (2) Demonstration of 2X scalability of the process and documentation of technical hurdles to further scale up and initiate technology transfer to industry for eventual commercialization of the process.

  18. Paresev on Taxi Strip

    NASA Technical Reports Server (NTRS)

    1962-01-01

    Test pilot Milton Thompson sitting in NASA Flight Research Center-built Paresev 1 (Paraglider Research Vehicle) on the taxi strip in front of the NASA Flight Research Center in 1962. In this photo the control stick can be seen coming from overhead and hanging in front of the pilot. The control system was a direct link with the wing membrane made of doped Irish linen. By maintaining simplicity during construction, it was possible to make control and configuration changes overnight and, in many instances, in minutes.

  19. About NICADD extruded scintillating strips

    SciTech Connect

    Dyshkant, A.; Beznosko, D.; Blazey, G.; Chakraborty, D.; Francis, K.; Kubik, D.; Lima, J.G.; Rykalin, V.; Zutshi, v.; Baldina, E.; Bross, A.; Deering, P.; Nebel, T.; Pla-Dalmau, A.; Schellpfeffer, J.; Serritella, C.; Zimmerman, J.; /Fermilab

    2005-04-01

    The results of control measurements of extruded scintillating strip responses to a radioactive source Sr-90 are provided, and details of strip choice, preparation, and method of measurement are included. About four hundred one meter long extruded scintillating strips were measured at four different points. These results were essential for prototyping a tail catcher and muon tracker for a future international electron positron linear collider detector.

  20. Strip casting apparatus and method

    DOEpatents

    Williams, R.S.; Baker, D.F.

    1988-09-20

    Strip casting apparatus including a molten-metal-holding container and a nozzle to deposit molten metal onto a moving chill drum to directly cast continuous metallic strip. The nozzle body includes a slot bounded between a back and a front lip. The slot width exceeds about 20 times the gap distance between the nozzle and the chill drum surface. Preferably, the slot width exceeds 0.5 inch. This method of strip casting minimizes pressure drop, insuring better metal-to-chill-drum contact which promotes heat transfer and results in a better quality metallic strip. 6 figs.

  1. Strip casting apparatus and method

    DOEpatents

    Williams, Robert S.; Baker, Donald F.

    1988-01-01

    Strip casting apparatus including a molten-metal-holding container and a nozzle to deposit molten metal onto a moving chill drum to directly cast continuous metallic strip. The nozzle body includes a slot bounded between a back and a front lip. The slot width exceeds about 20 times the gap distance between the nozzle and the chill drum surface. Preferably, the slot width exceeds 0.5 inch. This method of strip casting minimizes pressure drop, insuring better metal-to-chill-drum contact which promotes heat transfer and results in a better quality metallic strip.

  2. Spiral Galaxies Stripped Bare

    NASA Astrophysics Data System (ADS)

    2010-10-01

    Six spectacular spiral galaxies are seen in a clear new light in images from ESO's Very Large Telescope (VLT) at the Paranal Observatory in Chile. The pictures were taken in infrared light, using the impressive power of the HAWK-I camera, and will help astronomers understand how the remarkable spiral patterns in galaxies form and evolve. HAWK-I [1] is one of the newest and most powerful cameras on ESO's Very Large Telescope (VLT). It is sensitive to infrared light, which means that much of the obscuring dust in the galaxies' spiral arms becomes transparent to its detectors. Compared to the earlier, and still much-used, VLT infrared camera ISAAC, HAWK-I has sixteen times as many pixels to cover a much larger area of sky in one shot and, by using newer technology than ISAAC, it has a greater sensitivity to faint infrared radiation [2]. Because HAWK-I can study galaxies stripped bare of the confusing effects of dust and glowing gas it is ideal for studying the vast numbers of stars that make up spiral arms. The six galaxies are part of a study of spiral structure led by Preben Grosbøl at ESO. These data were acquired to help understand the complex and subtle ways in which the stars in these systems form into such perfect spiral patterns. The first image shows NGC 5247, a spiral galaxy dominated by two huge arms, located 60-70 million light-years away. The galaxy lies face-on towards Earth, thus providing an excellent view of its pinwheel structure. It lies in the zodiacal constellation of Virgo (the Maiden). The galaxy in the second image is Messier 100, also known as NGC 4321, which was discovered in the 18th century. It is a fine example of a "grand design" spiral galaxy - a class of galaxies with very prominent and well-defined spiral arms. About 55 million light-years from Earth, Messier 100 is part of the Virgo Cluster of galaxies and lies in the constellation of Coma Berenices (Berenice's Hair, named after the ancient Egyptian queen Berenice II). The third

  3. Airport Remote Tower Sensor Systems

    NASA Technical Reports Server (NTRS)

    Papasin, Richard; Gawdiak, Yuri; Maluf, David A.; Leidich, Christopher; Tran, Peter B.

    2001-01-01

    Remote Tower Sensor Systems (RTSS) are proof-of-concept prototypes being developed by NASA/Ames Research Center (NASA/ARC) with collaboration with the FAA (Federal Aviation Administration) and NOAA (National Oceanic Atmospheric Administration). RTSS began with the deployment of an Airport Approach Zone Camera System that includes real-time weather observations at San Francisco International Airport. The goal of this research is to develop, deploy, and demonstrate remotely operated cameras and sensors at several major airport hubs and un-towered airports. RTSS can provide real-time weather observations of airport approach zone. RTSS will integrate and test airport sensor packages that will allow remote access to realtime airport conditions and aircraft status.

  4. Ozone Treatment For Cooling Towers

    NASA Technical Reports Server (NTRS)

    Blackwelder, Rick; Baldwin, Leroy V.; Feeney, Ellen S.

    1990-01-01

    Report presents results of study of cooling tower in which water treated with ozone instead of usual chemical agents. Bacteria and scale reduced without pollution and at low cost. Operating and maintenance costs with treatment about 30 percent of those of treatment by other chemicals. Corrosion rates no greater than with other chemicals. Advantage of ozone, even though poisonous, quickly detected by smell in very low concentrations.

  5. Electronic rumble strip

    NASA Astrophysics Data System (ADS)

    Stauffer, Donald R.; Lenz, James

    1997-02-01

    Single vehicle run-off-road accidents are responsible for significant numbers of injuries and fatalities, and significant property damage. This fact spurs interest in warning systems to alert drivers that vehicles are drifting towards the edge of the road, and that a run-off road accident is imminent. An early attempt at such a warning system is the use of machined grooves on the shoulder to create a rumble strip. Such a system only provides warning, however, as the vehicle actually leaves the traffic lane. More desirable is a system that warns in anticipation of such departure. Honeywell has under development a magnetic lateral guidance system that couples a sensitive magnetoresistive transducer with a magnetic traffic marking tape being developed by 3M. While this development was initially undertaken for use in automated highways, or for special tasks such as guiding snowplow owners, the system can provide an effective, all-weather warning system to provide alert of impending departure from the roadway. This electronic rumble strip is actually a simpler system than the baseline guidance system, and can monitor both distance from the traffic lane edge and the speed of approach to the edge with a low cost sensor.

  6. Economic and technical assessment of the desiccant wheel effect on the thermal performance of cross flow cooling towers in variable wet bulb temperature

    NASA Astrophysics Data System (ADS)

    Banooni, Salem; Chitsazan, Ali

    2014-05-01

    Performance improvements of cross flow cooling towers in variable wet bulb temperature were performed. A conventional mathematical model is used to predict desiccant wheel effect on the performance of cooling tower. It is found that by using optimum parameters of desiccant wheel, the inlet air wet bulb temperature into the cooling tower would decrease more than 6 °C and outlet water temperature would decrease more than 4 °C.

  7. Use of treated gasification wastewater in a pilot cooling tower. Phase I. Final report for the period ending January 31, 1984

    SciTech Connect

    Willson, W.G.; Hendrikson, J.G.; Mann, M.D.; Galegher, S.J.; Gallagher, J.R.; Mayer, G.G.; Thomas, W.C.; Winton, S.L.; Nelson, D.F.

    1984-05-16

    During the UNDERC cooling tower tests, data were colleced and evaluated in five major areas: characterization of cooling tower streams, process performance, biofouling, corrosion, and inorganic/organic fouling. A summary of the results and conclusions for each area is presented. Recommendations are provided for research and development programs to further define the pretreatment and operating requirements for the use of wastewater as cooling tower makeup. The results of the Phase I-Pilot Cooling Tower test have revealed several potential problems that may arise from the use of a relatively high organic content gas liquor as cooling tower makeup. Most of the problems identified are related to the presence of organics in the wastewater which promote biofouling/fouling, corrosion, and emissions from the cooling tower. The Phase II-Pilot Cooling Tower Test will address this issue by identifying the advantages of further treatment of stripped gas liquor to reduce the organic content to a lower level before use in the cooling tower. This test will parallel the Phase I test using the same system and monitoring procedures. Comparison of the results of Phase I and Phase II tests will provide an indication of how well problem areas can be avoided with additional makeup water pretreatment. 39 references, 34 tables, and 25 figures.

  8. Susceptibility of Legionella pneumophila to three cooling tower microbicides

    SciTech Connect

    Grace, R.D.; Dewar, N.E.; Barnes, W.G.; Hodges, G.R.

    1981-01-01

    Investigation of epidemic outbreaks of Legionnaires disease by Center for Disease Control personnel has resulted in the isolation of Legionella pneumophila from water in the air-conditioning cooling towers or evaporative condensers at the site of the outbreak. It is suspected that improperly maintained open, recirculating water systems may play a role in the growth and dissemination of this pathogen. The objective of this study was to determine the antimicrobial activity of three chemically different, commercially available, cooling tower microbicides against L. pneumophila. Using two in vitro test systems, a combination of N-alkyl dimethyl benzyl ammonium chloride and bis (tri-n-butyltin) oxide was found to kill L. pneumophila at a concentration 25 times less than the minimum recommended use concentration, whereas N-alkyl 1,3-propanediamine and methylene bis(thiocyanate) were active at concentrations equal to or greater than the concentrations recommended for use by the manufacturer.

  9. Credit BG. Test Stand "D" tower as seen looking northeast ...

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

    Credit BG. Test Stand "D" tower as seen looking northeast (See caption for CA-163-F-18). To the right of the view is the stainless steel dome top for Dv Cell (see CA-163-F-22 for view into cell), behind which rests a spherical accumulator--an electrically heated steam generator for powering the vacuum system at "C" and Test Stand "D." Part of the ejector system can be seen on the right corner of the tower, other connections include electrical ducts (thin, flat metal members) and fire protection systems. Note the stand in the foreground with lights used to indicate safety status of the stand during tests - Jet Propulsion Laboratory Edwards Facility, Test Stand D, Edwards Air Force Base, Boron, Kern County, CA

  10. Susceptibility of Legionella pneumophila to three cooling tower microbicides.

    PubMed Central

    Grace, R D; Dewar, N E; Barnes, W G; Hodges, G R

    1981-01-01

    Investigation of epidemic outbreaks of Legionnaires disease by Center for Disease Control personnel has resulted in the isolation of Legionella pneumophila from water in the air-conditioning cooling towers or evaporative condensers at the site of the outbreak. It is suspected that improperly maintained open, recirculating water systems may play a role in the growth and dissemination of this pathogen. The objective of this study was to determine the antimicrobial activity of three chemically different, commercially available, cooling tower microbicides against L. pneumophila. Using two in vitro test systems, a combination of N-alkyl dimethyl benzyl ammonium chloride and bis (tri-n-butyltin) oxide was found to kill L. pneumophila at a concentration 25 times less than the minimum recommended use concentration, whereas N-alkyl 1,3-propanediamine and methylene bis (thiocyanate) were active at concentrations equal to or greater than the concentrations recommended for use by the manufacturer. PMID:7224623

  11. '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.

  12. Bismuth-based electrochemical stripping analysis

    DOEpatents

    Wang, Joseph

    2004-01-27

    Method and apparatus for trace metal detection and analysis using bismuth-coated electrodes and electrochemical stripping analysis. Both anodic stripping voltammetry and adsorptive stripping analysis may be employed.

  13. Stripping volatile organic compounds and petroleum hydrocarbons from water

    SciTech Connect

    LaBranche, D.F.; Collins, M. R.

    1996-05-01

    Volatile organic compounds (VOCs) and petroleum products are ubiquitous groundwater contaminants. Petroleum products, for example, diesel fuel, contain a wide array of volatile, semivolatile, and large-chain hydrocarbon compounds. This research sought to determine whether air stripping can provide a site-specific treatment solution for petroleum-contaminated groundwaters and to document the abilities and limitations of tray-type (ShallowTray{sup TM}) air-stripping technology. Full factorial experimental trials were conducted to determine the influence of inlet water flow rate and temperature on trichloroethylene (TCE), perchloroethylene (PCE), and total petroleum hydrocarbon (TPH) removal. As expected, TPH removal controlled air stripper performance, and liquid temperature affected removal more than flow rate. The mass-transfer rate of TCE and PCE from water to air was controlled by the compound`s volatility, whereas the TPH mass-transfer rate was controlled by the compound`s concentration gradient. Results indicate that economical air stripping of VOC and TPH compounds can be achieved using low liquid flow rates (20 to 75 L/min), high air/water ratios (225 to 898), and medium liquid temperatures (16{degree}C to 28{degree}C) in tray-type air strippers. 19 refs., 7 figs., 6 tabs.

  14. 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

  15. 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

  16. Stripped Crater Floor

    NASA Technical Reports Server (NTRS)

    2004-01-01

    10 February 2004 This full-resolution Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows details on the floor of an ancient meteor crater in the northeastern part of Noachis Terra. After the crater formed, layers of material--perhaps sediment--were deposited in the crater. These materials became somewhat solidified, but later were eroded to form the patterns shown here. Many windblown ripples in the scene indicate the presence of coarse-grained sediment that was not completely stripped away by wind. The picture is located near 22.1oS, 307.0oW. Sunlight illuminates this scene from the left/upper left; the image covers an area 3 km (1.9 mi) wide.

  17. Effects of Airport Tower Controller Decision Support Tool on Controllers Head-Up Time

    NASA Technical Reports Server (NTRS)

    Hayashi, Miwa; Cruz Lopez, Jose M.

    2013-01-01

    Despite that aircraft positions and movements can be easily monitored on the radar displays at major airports nowadays, it is still important for the air traffic control tower (ATCT) controllers to look outside the window as much as possible to assure safe operations of traffic management. The present paper investigates whether an introduction of the NASA's proposed Spot and Runway Departure Advisor (SARDA), a decision support tool for the ATCT controller, would increase or decrease the controllers' head-up time. SARDA provides the controller departure-release schedule advisories, i.e., when to release each departure aircraft in order to minimize individual aircraft's fuel consumption on taxiways and simultaneously maximize the overall runway throughput. The SARDA advisories were presented on electronic flight strips (EFS). To investigate effects on the head-up time, a human-in-the-loop simulation experiment with two retired ATCT controller participants was conducted in a high-fidelity ATCT cab simulator with 360-degree computer-generated out-the-window view. Each controller participant wore a wearable video camera on a side of their head with the camera facing forward. The video data were later used to calculate their line of sight at each moment and eventually identify their head-up times. Four sessions were run with the SARDA advisories, and four sessions were run without (baseline). Traffic-load levels were varied in each session. The same set of user interface - EFS and the radar displays - were used in both the advisory and baseline sessions to make them directly comparable. The paper reports the findings and discusses their implications.

  18. Microtube Strip Heat Exchanger

    SciTech Connect

    Doty, F.D.

    1990-12-27

    Doty Scientific (DSI) believes their Microtube-Strip Heat Exchanger will contribute significantly to (a) the closed Brayton cycles being pursued at MIT, NASA, and elsewhere; (b) reverse Brayton cycle cryocoolers, currently being investigated by NASA for space missions, being applied to MRI superconducting magnets; and (c) high-efficiency cryogenic gas separation schemes for CO{sub 2} removal from exhaust stacks. The goal of this current study is to show the potential for substantial progress in high-effectiveness, low-cost, gas-to-gas heat exchangers for diverse applications at temperatures from below 100 K to above 1000 K. To date, the highest effectiveness measured is about 98%, and relative pressure drops below 0.1% with a specific conductance of about 45 W/kgK are reported. During the pre-award period DSI built and tested a 3-module heat exchanger bank using 103-tube microtube strip (MTS) modules. To add to their analytical capabilities, DSI has acquired computational fluid dynamics (CFD) software. This report describes the pre-award work and the status of the ten tasks of the current project, which are: analyze flow distribution and thermal stresses within individual modules; design a heat exchanger bank of ten modules with 400 microtube per module; obtain production quality tubestrip die and AISI 304 tubestrips; obtain production quality microtubing; construct revised MTS heat exchanger; construct dies and fixtures for prototype heat exchanger; construct 100 MTS modules; assemble 8-10 prototype MTS heat exchangers; test prototype MTS heat exchanger; and verify test through independent means. 7 refs., 9 figs. 1 tab. (CK)

  19. Optimal Inflatable Space Towers of High Height

    NASA Astrophysics Data System (ADS)

    Bolonkin, Alexander

    2002-01-01

    Author provides theory and computations for building inflatable space towers up to a hundred km in height. These towers can be used for tourism; scientific observation of space, earth's surface, weather, top atmosphere, as well as 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. Towers can be built using present technology. 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 this tower consists a small engine (used only for friction compensation) located at the earth's surface. The tower is separated into sections and has special protection mechanism in case of a damage. Problems involving security, control, repair, and stability of the proposed towers are addressed in subsequent publications. The author is prepared to discuss these and other problems with serious organizations desiring to research and develop these projects.

  20. Optimal inflatable space towers of high height

    NASA Astrophysics Data System (ADS)

    Bolonkin, A.

    Author suggested, developed theory, and computed some projects of an optimal inflatable space tower of the heights some hundreds km. These towers can be used for tourism, scientist observation of space, Earth surface, Earth weather, Earth top atmosphere, and for radio, TV, communication transmissions. These towers can be used for launching of the space ships and Earth s atellites. The computed projects not expensive, do not request rockets. They need only in thin strong films composed from the artificial fibers and fabricated by a current industry. Towers can be built by a current technology. Towers can be explored (for tourism, communication, etc.) in a time of the construction process and give a profit, self- financing for further constriction. They can permanent increase their height. The tower design does not request a work at the high altitudes. All construction works will be making at the Earth surface. Author suggests the transport system for this tower of a high capability, which does not request a power energy issue. The small engine (only for a friction compensation) is located at the Earth surface. The tower is separated on sections and has a special protection of a case of a damage. It is considered also the problems of security, control, repair, etc. of the suggested towers. The author has also solved additional problems, which appear in these projects and which can look as difficult for the given proposal and current technology. The author is prepared to discuss the problems with serious organizations, which want to research and develop these projects.

  1. European Sail Tower SPS concept

    NASA Astrophysics Data System (ADS)

    Seboldt, W.; Klimke, M.; Leipold, M.; Hanowski, N.

    2001-03-01

    Based on a DLR-study in 1998/99 on behalf of ESA/ESTEC called "System Concepts, Architectures and Technologies for Space Exploration and Utilization (SE&U)" a new design for an Earth-orbiting Solar Power Satellite (SPS) has been developed. The design is called "European Sail Tower SPS" and consists mainly of deployable sail-like structures derived from the ongoing DLR/ESA solar sail technology development activity. Such a SPS satellite features an extremely light-weight and large tower-like orbital system and could supply Europe with significant amounts of electrical power generated by photovoltaic cells and subsequently transmitted to Earth via microwaves. In order to build up the sail tower, 60 units - each consisting of a pair of square-shaped sails - are moved from LEO to GEO with electric propulsion and successively assembled in GEO robotically on a central strut. Each single sail has dimensions of 150m × 150 m and is automatically deployed, using four diagonal light-weight carbon fiber (CFRP) booms which are initially rolled up on a central hub. The electric thrusters for the transport to GEO could also be used for orbit and attitude control of the assembled tower which has a total length of about 15 km and would be mainly gravity gradient stabilized. Employing thin film solar cell technology, each sail is used as a solar array and produces an electric power in orbit of about 3.7 MW e. A microwave antenna with a diameter of 1 km transmits the power to a 10 km rectenna on the ground. The total mass of this 450 MW SPS is about 2100 tons. First estimates indicate that the costs for one kWh delivered in this way could compete with present day energy costs, if launch costs would decrease by two orders of magnitude. Furthermore, mass production and large numbers of installed SPS systems must be assumed in order to lower significantly the production costs and to reduce the influence of the expensive technology development. The paper presents the technical concept

  2. Drop Tower and Aircraft Capabilities

    NASA Technical Reports Server (NTRS)

    Urban, David L.

    2015-01-01

    This presentation is a brief introduction to existing capabilities in drop towers and low-gravity aircraft that will be presented as part of a Symposium: Microgravity Platforms Other Than the ISS, From Users to Suppliers which will be a half day program to bring together the international community of gravity-dependent scientists, program officials and technologists with the suppliers of low gravity platforms (current and future) to focus on the future requirements and use of platforms other than the International Space Station (ISS).

  3. Range gated strip proximity sensor

    DOEpatents

    McEwan, Thomas E.

    1996-01-01

    A range gated strip proximity sensor uses one set of sensor electronics and a distributed antenna or strip which extends along the perimeter to be sensed. A micro-power RF transmitter is coupled to the first end of the strip and transmits a sequence of RF pulses on the strip to produce a sensor field along the strip. A receiver is coupled to the second end of the strip, and generates a field reference signal in response to the sequence of pulse on the line combined with received electromagnetic energy from reflections in the field. The sensor signals comprise pulses of radio frequency signals having a duration of less than 10 nanoseconds, and a pulse repetition rate on the order of 1 to 10 MegaHertz or less. The duration of the radio frequency pulses is adjusted to control the range of the sensor. An RF detector feeds a filter capacitor in response to received pulses on the strip line to produce a field reference signal representing the average amplitude of the received pulses. When a received pulse is mixed with a received echo, the mixing causes a fluctuation in the amplitude of the field reference signal, providing a range-limited Doppler type signature of a field disturbance.

  4. Range gated strip proximity sensor

    DOEpatents

    McEwan, T.E.

    1996-12-03

    A range gated strip proximity sensor uses one set of sensor electronics and a distributed antenna or strip which extends along the perimeter to be sensed. A micro-power RF transmitter is coupled to the first end of the strip and transmits a sequence of RF pulses on the strip to produce a sensor field along the strip. A receiver is coupled to the second end of the strip, and generates a field reference signal in response to the sequence of pulse on the line combined with received electromagnetic energy from reflections in the field. The sensor signals comprise pulses of radio frequency signals having a duration of less than 10 nanoseconds, and a pulse repetition rate on the order of 1 to 10 MegaHertz or less. The duration of the radio frequency pulses is adjusted to control the range of the sensor. An RF detector feeds a filter capacitor in response to received pulses on the strip line to produce a field reference signal representing the average amplitude of the received pulses. When a received pulse is mixed with a received echo, the mixing causes a fluctuation in the amplitude of the field reference signal, providing a range-limited Doppler type signature of a field disturbance. 6 figs.

  5. Wind turbine tower for storing hydrogen and energy

    DOEpatents

    Fingersh, Lee Jay

    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.

  6. View second bank of circuit towers on Arizona side of ...

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

    View second bank of circuit towers on Arizona side of canyon. Left tower supports Circuit 10 and right tower supports Circuit 11, view north - Hoover Dam, Circuits 1-15, U.S. Highway 93, Boulder City, Clark County, NV

  7. APPROACH BRIDGE PORTION OF VALVE TOWER FOOT BRIDGE, AS SEEN ...

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

    APPROACH BRIDGE PORTION OF VALVE TOWER FOOT BRIDGE, AS SEEN FROM BELOW, SHOWING VALVE TOWER TO RIGHT. VIEW FACING NORTH - Schofield Barracks Military Reservation, Ku Tree Reservoir, Valve Tower Foot Bridge, Kalakoa Stream, East Range, Wahiawa, Honolulu County, HI

  8. 157. Copy of Louis Rosenberg Etching (original in the Tower ...

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

    157. Copy of Louis Rosenberg Etching (original in the Tower City Development Office) TERMINAL TOWER UNDER CONSTRUCTION, STEEL FRAMEWORK OF THE SOUTHWEST WING, VIEW WEST TO EAST - Terminal Tower Building, Cleveland Union Terminal, 50 Public Square, Cleveland, Cuyahoga County, OH

  9. Analysis/design of strip reinforced random composites (strip hybrids)

    NASA Technical Reports Server (NTRS)

    Chamis, C. C.; Sinclair, J. H.

    1978-01-01

    Advanced analysis methods and composite mechanics were applied to a strip-reinforced random composite square panel with fixed ends to illustrate the use of these methods for the a priori assessment of the composite panel when subjected to complex loading conditions. The panel was assumed to be of E-glass random composite. The strips were assumed to be of three advanced unidirectional composites to cover a range of low, intermediate, and high modulus stiffness. The panels were assumed to be subjected to complex loadings to assess their adequacy as load-carrying members in auto body, aircraft engine nacelle and windmill blade applications. The results show that strip hybrid panels can be several times more structurally efficient than the random composite base materials. Some of the results are presented in graphical form and procedures are described for use of these graphs as guides for preliminary design of strip hybrids.

  10. Analysis/design of strip reinforced random composites /strip hybrids/

    NASA Technical Reports Server (NTRS)

    Chamis, C. C.; Sinclair, J. H.

    1978-01-01

    Results are described which were obtained by applying advanced analysis methods and composite mechanics to a strip-reinforced random composite square panel with fixed ends. This was done in order to illustrate the use of these methods for the apriori assessment of the composite panel when subjected to complex loading conditions. The panel was assumed to be of E-Glass/Random Composite. The strips were assumed to be of three advanced unidirectional composites to cover a range of low, intermediate, and high modulus stiffness. The panels were assumed to be subjected to complex loadings to assess their adequacy as load-carrying members in auto body, aircraft engine nacelle, and windmill blade applications. The results show that strip hybrid panels can be several times more structurally efficient than the random composite base materials. Some of the results are presented in graphical form and procedures are described for use of these graphs as guides for preliminary design of strip hybrids.

  11. Investigation of the effect of packing location on performance of closed wet cooling tower based on exergy analysis

    NASA Astrophysics Data System (ADS)

    Qasim, S. M.; Hayder, M. J.

    2016-08-01

    In this paper, the effect of packing location on thermal performance of Closed Wet Cooling Tower (CWCT) based on exergy analysis has been studied. The experimental study incorporates design, manufacture and testing of a modified counter flow forced draft CWCT prototype. The modification based on addition packing to the conventional CWCT. The variation of spray water temperature, air dry bulb temperature, air wet bulb temperature, enthalpy and relative humidity of air for different position along the tower are measured experimentally. Applying the exergy destruction method for the cooling tower; exergy destruction, exergy efficiency, exergy of water and air were calculated for two cases: CWCT with packing below the heat exchanger and CWCT with packing above the heat exchanger. It is highly important to analyze the exergy along the cooling tower height. Therefore, the exergy analysis of different elements along the height of the tower is carried out. Results show that the total exergy destruction of modified CWCT is higher when the heat exchanger is located above the packing at the highest point of the tower.

  12. Improvement to Air2Air Technology to Reduce Fresh-Water Evaporative Cooling Loss at Coal-Based Thermoelectric Power Plants

    SciTech Connect

    Ken Mortensen

    2011-12-31

    This program was undertaken to enhance the manufacturability, constructability, and cost of the Air2Air{TM} Water Conservation and Plume Abatement Cooling Tower, giving a validated cost basis and capability. Air2Air{TM} water conservation technology recovers a portion of the traditional cooling tower evaporate. The Condensing Module provides an air-to-air heat exchanger above the wet fill media, extracting the heat from the hot saturated moist air leaving in the cooling tower and condensing water. The rate of evaporate water recovery is typically 10% - 25% annually, depending on the cooling tower location (climate). This program improved the efficiency and cost of the Air2Air{TM} Water Conservation Cooling Tower capability, and led to the first commercial sale of the product, as described.

  13. View of first bank of circuit towers on Arizona side ...

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

    View of first bank of circuit towers on Arizona side of canyon. Photograph taken from Nevada side of canyon. Left tower supports Circuit 8, second from left tower supports Circuit 9, middle tower supports Circuit 10, second from right tower supports Circuit 11, and right tower supports Circuit 12, view southeast. - Hoover Dam, Circuits 1-15, U.S. Highway 93, Boulder City, Clark County, NV

  14. The lateral tarsal strip revisited. The enhanced tarsal strip.

    PubMed

    Jordan, D R; Anderson, R L

    1989-04-01

    The lateral tarsal strip procedure was originally designed for the treatment of upper and lower eyelid laxity, or lateral canthal tendon laxity or malposition. Despite the excellent results with a standard tarsal strip procedure for those eyelids with laxity and excess skin, we have encountered a number of patients with lower eyelid or canthal malpositions or both who would benefit from a tarsal strip, but who do not have lax tissues (especially skin), and may in fact have a shortage of skin. These include cases of lower lid retraction or canthal malposition following trauma, blepharoplasty, or other operations, and patients with tendency toward or having cicatricial ectropion. Any anterior lamella removal in such patients would aggravate the lid malposition and weaken the lateral canthal tissues to be sutured. We suggest a modification of the tarsal strip (developed by one of us [R.L.A.]) to treat many such patients without requiring additional anterior lamella (skin graft) or more formidable procedures. We refer to this technique as the "enhanced tarsal strip" technique, and we use this technique more frequently than the original tarsal strip procedure.

  15. The Solar lake/condensation tower system (SL/CT System)

    SciTech Connect

    deLangen, L.H.

    1983-08-01

    The system is basically an ammonia cycle between the hot water of a lake, covered with floating heat collectors and the cold air at great height of the atmosphere, only attainable by a high tower. Below, ammonia is evaporated by the water of the lake; at high level, air-cooled condensers take care of the condensation of the ammonia vapour. The system offers a possibility to be combined with a multi-stage sea-water distillation plant, enabling irrigation of deserts and steppes. In the paper attention is given to the design of the tower. Results of calculations are given about attainable energy production, quantities of building materials needed to build the tower and installations, the surface of the lake, the quantities of produced water and the surface of irrigated land.

  16. Tower Water-Vapor Mixing Ratio

    SciTech Connect

    Guastad, Krista; Riihimaki, Laura; none,

    2013-04-01

    The purpose of the Tower Water-Vapor Mixing Ratio (TWRMR) value-added product (VAP) is to calculate water-vapor mixing ratio at the 25-meter and 60-meter levels of the meteorological tower at the Southern Great Plains (SGP) Central Facility.

  17. In-well vapor stripping drilling and characterization work plan

    SciTech Connect

    Koegler, K.J.

    1994-03-13

    This work plan provides the information necessary for drilling, sampling, and hydrologic testing of wells to be completed in support of a demonstration of the in-well vapor stripping system. The in-well vapor stripping system is a remediation technology designed to preferentially extract volatile organic compounds (VOCs) from contaminated groundwater by converting them to a vapor phase. Air-lift pumping is used to lift and aerate groundwater within the well. The volatiles escaping the aerated water are drawn off by a slight vacuum and treated at the surface while the water is allowed to infiltrate the vadose zone back to the watertable.

  18. Three years of vertically resolved CO2/CH4/CO measurements at the tallest tower in the Amazon - Amazonian Tall Tower Observatory (ATTO, Brazil)

    NASA Astrophysics Data System (ADS)

    Valentin Lavrič, Jošt; Winderlich, Jan; Walter, David; Chi, Xuguang; Andreae, Meinrat O.; Heimann, Martin

    2015-04-01

    The 330 m-tall tower that is currently in its final phase of construction at the Amazonian Tall Tower Observatory (ATTO, Brazil; 2° 08'S, 59° 00'W), is the counterpart of the 304 m-tall tower of the Zotino Tall Tower Observatory tower (ZOTTO), located in central Siberia (Russia; 60° 48'N, 89° 21'E). The ATTO tall tower will extend above the atmospheric surface layer and the nocturnal stable boundary layer, and aims at delivering ground breaking findings that will be the basis for improved climate models. While awaiting the completion of the tall tower, a number of campaign or continuous pilot measurements are taking place on the ATTO site at and around the currently tallest Amazonian tower and mast (80 m a.g.l.). Since March 2012, we run continuous high precision CO2/CH4/CO measurements in an air-conditioned container at the foot of the 80 m tower. The sample air inlets are installed at five levels; 79, 53, 38, 24, and 4 m a.g.l. Two frequently calibrated CRDS analyzers (G1301 and G1302; Picarro Inc., USA) are used for measuring CO2/CH4 and CO/CO2, respectively. Even if due to proximity of our measurements to the canopy (~ 35 m a.g.l.) the data is influenced by local sources and sinks, it still provides a valuable insight into the diurnal and seasonal variations of the measured gas species. Additionally, the data set has proven to be also interesting combined with the parameters that are measured by other groups at the site in parallel either continuously or during intensive observation periods (e.g. VOCs, reactive trace gases, aerosols). A first analysis of the available data is presented. Our work was performed within the frame of the German-Brazilian project ATTO and supported by the federal government agencies BMBF and MCT (Grant number BMBF 01LB1001A). We acknowledge the fundamental support by the Max Planck Society, INPA and UEA. Special thanks go to the Amazonas State SDS/CEUC-RDS Uatumã.

  19. 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.

  20. 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.

  1. Upgrading the performance of groudwater VOC air strippers

    SciTech Connect

    Nelson, A.D.; Schmitt, R.J.; Dickeson, D.

    1997-12-31

    Rocketdynes Santa Susana Field Laboratory has been treating groundwater to remove chlorinated solvents since 1987. Six air stripping treatment installations, using vapor-phase carbon to control air emissions, have consistently met effluent quality standards over nine years of operation. In 1995, Rocketdyne embarked on an inspection and maintenance program to thoroughly check tower equipment and packing condition and to improve treatment efficiency using new packing technology now available. Baseline removal efficiency measurements were made on one large-capacity air stripper, which was then shut down for inspection. The original random packing was found to be fouled, and had settled too far below the level of the spray nozzle. The packing was removed, and replaced with a newer, high-efficiency packing. As a result, single-stage removal efficiency for trichloroethylene increased from 98.5% to > 99.60%. Aside from demonstrating the improvement attainable by upgrading the packing media, Rocketdyne`s maintenance program also highlighted the critical importance of proper liquid distribution. At one point, the refurbished air stripper was overpacked, resulting in concentration of the water spray near the center of the packed section. The liquid distribution was found to remain grossly nonuniform even after the water had trickled down over 8.2 meters of packing in a 91-cm diameter column. 4 refs., 1 fig., 5 tabs.

  2. Nineteenth century Parisian smoke variations inferred from Eiffel Tower atmospheric electrical observations

    NASA Astrophysics Data System (ADS)

    Harrison, R. G.; Aplin, K. L.

    Atmospheric electrical measurements provide proxy data from which historic smoke pollution levels can be determined. This approach is applied to infer autumnal Parisian smoke levels in the 1890s, based on atmospheric electric potential measurements made at the surface and the summit of the Eiffel Tower (48.7°N, 2.4°E). A theoretical model of the development of the autumn convective boundary layer is used to determine when local pollution effects dominated the Eiffel Tower potential measurements. The diurnal variation of the Eiffel Tower potential showed a single oscillation, but it differs from the standard oceanic air potential gradient (PG) variations during the period 09-17 UT, when the model indicates that the Eiffel Tower summit should be within the boundary layer. Outside these hours, the potential changes closely follow the clean air PG variation: this finding is used to calibrate the Eiffel Tower measurements. The surface smoke pollution concentration found during the morning maximum was 60±30 μg m -3, substantially lower than the values previously inferred for Kew in 1863. A vertical smoke profile was also derived using a combination of the atmospheric electrical data and boundary layer meteorology theory. Midday smoke concentration decreased with height from 60 μg m -3 at the surface to 15 μg m -3 at the top of the Eiffel Tower. The 19th century PG measurements in both polluted and clean Parisian air present a unique resource for European air pollution and atmospheric composition studies, and early evidence of the global atmospheric electrical circuit.

  3. The Tower Shielding Facility: Its glorious past

    SciTech Connect

    Muckenthaler, F.J.

    1997-05-07

    The Tower Shielding Facility (TSF) is the only reactor facility in the US that was designed and built for radiation-shielding studies in which both the reactor source and shield samples could be raised into the air to allow measurements to be made without interference from ground scattering or other spurious effects. The TSF proved its usefulness as many different programs were successfully completed. It became active in work for the Defense Atomic Support Agency (DASA) Space Nuclear Auxiliary Power, Defense Nuclear Agency, Liquid Metal Fast Breeder Reactor Program, the Gas-Cooled and High-Temperature Gas-Cooled Reactor programs, and the Japanese-American Shielding Program of Experimental Research, just to mention a few of the more extensive ones. The history of the TSF as presented in this report describes the various experiments that were performed using the different reactors. The experiments are categorized as to the programs which they supported and placed in corresponding chapters. The experiments are described in modest detail, along with their purpose when appropriate. Discussion of the results is minimal, but references are given to more extensive topical reports.

  4. Mobius Strip underlying Nonlinear Oscillators

    NASA Astrophysics Data System (ADS)

    Lopaz, Edaurdo; Satija, Indubala

    2004-03-01

    Geometrical and topolgocial aspects of phase space orbits of driven nonlinear oscillators are shown to share many features with the circuits on the mobius strips. Most important characteristic shared by nonlinear oscillators and the mobius strip is the first order geometrical phase transition characterized in terms of local variable torsion and the global variable the geometrical phase . These geometrical transitions are geometrical resonances and lead to geometrical localization that underlie not only limit cycles but also the strange attractors.

  5. Tall Tower Wind Energy Monitoring and Numerical Model Validation in Northern Nevada

    SciTech Connect

    Koracin, D.; Kaplan, M.; Smith, C.; McCurdy, G.; Wolf, A.; McCord, T.; King, K.; Belu, R.; Horvath, K.

    2015-10-01

    The main objectives of this project were to conduct a tall-tower and sodar field campaign in complex terrain, investigate wind properties relevant to wind energy assessment, and evaluate high-resolution models with fixed and adaptive grid structures. Two 60-m towers at Virginia Peak ridges near Washoe Valley, Nevada, were instrumented with cup and vane anemometers as well as sonic anemometers, and an acoustic sounder (hereafter sodar) was installed near one of the towers. The towers were located 2,700 m apart with a vertical distance of 140 m elevation between their bases. Each tower had a downhill exposure of rolling complex terrain, with the nearby valley floor 3,200 m to the west and 800 m below the summit. Cup anemometers were installed at both towers at 20, 40, and 60 m, wind vanes at 20 and 60 m, and sonic anemometers at 20 and 60 m. The sodar measurements were nominally provided every 10 m in vertical distance from 40 to 200 m with the quality of the data generally decreasing with height. Surface air temperature, atmospheric pressure, and radiation measurements were conducted at 1.5 m AGL at both of the towers. Although the plan was to conduct a 1-year period of data collection, we extended the period (October 5, 2012 through February 24, 2014) to cover for possible data loss from instrument or communication problems. We also present a preliminary analysis of the towers and sodar data, including a detailed inventory of available and missing data as well as outliers. The analysis additionally includes calculation of the Weibull parameters, turbulence intensity, and initial computation of wind power density at various heights.

  6. The Dark Side of the Moebius Strip.

    ERIC Educational Resources Information Center

    Schwarz, Gideon E.

    1990-01-01

    Discussed are various models proposed for the Moebius strip. Included are a discussion of a smooth flat model and two smooth flat algebraic models, some results concerning the shortest Moebius strip, the Moebius strip of least elastic energy, and some observations on real-world Moebius strips. (KR)

  7. Operational cooling tower model (CTTOOL V1.0)

    SciTech Connect

    Aleman, S.; LocalDomainServers, L.; Garrett, A.

    2015-01-01

    Mechanical draft cooling towers (MDCT’s) are widely used to remove waste heat from industrial processes, including suspected proliferators of weapons of mass destruction (WMD). The temperature of the air being exhausted from the MDCT is proportional to the amount of thermal energy being removed from the process cooling water, although ambient weather conditions and cooling water flow rate must be known or estimated to calculate the rate of thermal energy dissipation (Q). It is theoretically possible to derive MDCT air exhaust temperatures from thermal images taken from a remote sensor. A numerical model of a MDCT is required to translate the air exhaust temperature to a Q. This report describes the MDCT model developed by the Problem Centered Integrated Analysis (PCIA) program that was designed to perform those computational tasks. The PCIA program is a collaborative effort between the Savannah River National Laboratory (SRNL), the Northrop-Grumman Corporation (NG) and the Aerospace Corporation (AERO).

  8. Legionella adelaidensis, a new species isolated from cooling tower water.

    PubMed Central

    Benson, R F; Thacker, W L; Lanser, J A; Sangster, N; Mayberry, W R; Brenner, D J

    1991-01-01

    A Legionella-like organism (strain 1762-AUS-E) was isolated from a cooling tower of an air-conditioning system in Adelaide, South Australia, Australia. The isolate was presumptively identified as a Legionella strain by its growth requirement for L-cysteine and its cellular branched-chain fatty acids. Strain 1762-AUS-E was serologically distinct in the slide agglutination test with absorbed antisera. DNA hybridization confirmed that it is a new Legionella species for which the name Legionella adelaidensis is proposed. PMID:2056032

  9. Static and Motion-Based Visual Features Used by Airport Tower Controllers: Some Implications for the Design of Remote or Virtual Towers

    NASA Technical Reports Server (NTRS)

    Ellis, Stephen R.; Liston, Dorion B.

    2011-01-01

    Visual motion and other visual cues are used by tower controllers to provide important support for their control tasks at and near airports. These cues are particularly important for anticipated separation. Some of them, which we call visual features, have been identified from structured interviews and discussions with 24 active air traffic controllers or supervisors. The visual information that these features provide has been analyzed with respect to possible ways it could be presented at a remote tower that does not allow a direct view of the airport. Two types of remote towers are possible. One could be based on a plan-view, map-like computer-generated display of the airport and its immediate surroundings. An alternative would present a composite perspective view of the airport and its surroundings, possibly provided by an array of radially mounted cameras positioned at the airport in lieu of a tower. An initial more detailed analyses of one of the specific landing cues identified by the controllers, landing deceleration, is provided as a basis for evaluating how controllers might detect and use it. Understanding other such cues will help identify the information that may be degraded or lost in a remote or virtual tower not located at the airport. Some initial suggestions how some of the lost visual information may be presented in displays are mentioned. Many of the cues considered involve visual motion, though some important static cues are also discussed.

  10. First Results From GLAST-LAT Integrated Towers Cosmic Ray Data Taking And Monte Carlo Comparison

    SciTech Connect

    Brigida, M.; Caliandro, A.; Favuzzi, C.; Fusco, P.; Gargano, F.; Giordano, F.; Giglietto, N.; Loparco, F.; Marangelli, B.; Mazziotta, M.N.; Mirizzi, N.; Raino, S.; Spinelli, P.; /Bari U. /INFN, Bari

    2007-02-15

    GLAST Large Area Telescope (LAT) is a gamma ray telescope instrumented with silicon-strip detector planes and sheets of converter, followed by a calorimeter (CAL) and surrounded by an anticoincidence system (ACD). This instrument is sensitive to gamma rays in the energy range between 20 MeV and 300 GeV. At present, the first towers have been integrated and pre-launch data taking with cosmic ray muons is being performed. The results from the data analysis carried out during LAT integration will be discussed and a comparison with the predictions from the Monte Carlo simulation will be shown.

  11. Strip casting with fluxing agent applied to casting roll

    DOEpatents

    Williams, Robert S.; O'Malley, Ronald J.; Sussman, Richard C.

    1997-01-01

    A strip caster (10) for producing a continuous strip (24) includes a tundish (12) for containing a melt (14), a pair of horizontally disposed water cooled casting rolls (22) and devices (29) for electrostatically coating the outer peripheral chill surfaces (44) of the casting rolls with a powder flux material (56). The casting rolls are juxtaposed relative to one another for forming a pouting basin (18) for receiving the melt through a teeming tube (16) thereby establishing a meniscus (20) between the rolls for forming the strip. The melt is protected from the outside air by a non-oxidizing gas passed through a supply line (28) to a sealing chamber (26). A preferred flux is boron oxide having a melting point of about 550.degree. C. The flux coating enhances wetting of the steel melt to the casting roll and dissolves any metal oxide formed on the roll.

  12. Strip casting with fluxing agent applied to casting roll

    DOEpatents

    Williams, R.S.; O`Malley, R.J.; Sussman, R.C.

    1997-07-29

    A strip caster for producing a continuous strip includes a tundish for containing a melt, a pair of horizontally disposed water cooled casting rolls and devices for electrostatically coating the outer peripheral chill surfaces of the casting rolls with a powder flux material. The casting rolls are juxtaposed relative to one another for forming a pouting basin for receiving the melt through a teeming tube thereby establishing a meniscus between the rolls for forming the strip. The melt is protected from the outside air by a non-oxidizing gas passed through a supply line to a sealing chamber. A preferred flux is boron oxide having a melting point of about 550 C. The flux coating enhances wetting of the steel melt to the casting roll and dissolves any metal oxide formed on the roll. 3 figs.

  13. "Tower, Am I Cleared to Land?": Problematic Communication in Aviation Discourse

    ERIC Educational Resources Information Center

    Howard, John W., III

    2008-01-01

    This study examined problematic communication in pilot-air traffic controller (ATC) interaction. More than 15 hours of pilot-ATC dialogue were collected by monitoring control tower frequencies at 15 U.S. airports. The transcribed data yielded a total of 34 ATCs, 270 pilots, and 1,799 turns of talk. Analyses revealed that (a) communication…

  14. EVALUATING THE COSTS OF PACKED-TOWER AERATION AND GAC FOR CONTROLLING SELECTED ORGANICS

    EPA Science Inventory

    This article focuses on a preliminary cost analysis that compares liquid-phase granular activated carbon (GAC) treatment with packed-tower aeration (PTA) treatment, with and without air emissions control. The sensitivity of cost to design and operating variables is also discussed...

  15. 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.

  16. 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.

  17. 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.

  18. View of second bank of circuit towers on Arizona side ...

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

    View of second bank of circuit towers on Arizona side of canyon. Left tower supports Circuit 8, middle tower supports Circuit 9, and right tower supports Circuit 10, view northwest - Hoover Dam, Circuits 1-15, U.S. Highway 93, Boulder City, Clark County, NV

  19. View of Nevada rim towers from top of power plant. ...

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

    View of Nevada rim towers from top of power plant. Left tower supports Circuits 7 and 14, middle tower supports Circuit 6, and right tower supports Circuit 5, view west - Hoover Dam, Circuits 1-15, U.S. Highway 93, Boulder City, Clark County, NV

  20. 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

  1. 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

  2. Investigation of HV/HR-CMOS technology for the ATLAS Phase-II Strip Tracker Upgrade

    NASA Astrophysics Data System (ADS)

    Fadeyev, V.; Galloway, Z.; Grabas, H.; Grillo, A. A.; Liang, Z.; Martinez-Mckinney, F.; Seiden, A.; Volk, J.; Affolder, A.; Buckland, M.; Meng, L.; Arndt, K.; Bortoletto, D.; Huffman, T.; John, J.; McMahon, S.; Nickerson, R.; Phillips, P.; Plackett, R.; Shipsey, I.; Vigani, L.; Bates, R.; Blue, A.; Buttar, C.; Kanisauskas, K.; Maneuski, D.; Benoit, M.; Di Bello, F.; Caragiulo, P.; Dragone, A.; Grenier, P.; Kenney, C.; Rubbo, F.; Segal, J.; Su, D.; Tamma, C.; Das, D.; Dopke, J.; Turchetta, R.; Wilson, F.; Worm, S.; Ehrler, F.; Peric, I.; Gregor, I. M.; Stanitzki, M.; Hoeferkamp, M.; Seidel, S.; Hommels, L. B. A.; Kramberger, G.; Mandić, I.; Mikuž, M.; Muenstermann, D.; Wang, R.; Zhang, J.; Warren, M.; Song, W.; Xiu, Q.; Zhu, H.

    2016-09-01

    ATLAS has formed strip CMOS project to study the use of CMOS MAPS devices as silicon strip sensors for the Phase-II Strip Tracker Upgrade. This choice of sensors promises several advantages over the conventional baseline design, such as better resolution, less material in the tracking volume, and faster construction speed. At the same time, many design features of the sensors are driven by the requirement of minimizing the impact on the rest of the detector. Hence the target devices feature long pixels which are grouped to form a virtual strip with binary-encoded z position. The key performance aspects are radiation hardness compatibility with HL-LHC environment, as well as extraction of the full hit position with full-reticle readout architecture. To date, several test chips have been submitted using two different CMOS technologies. The AMS 350 nm is a high voltage CMOS process (HV-CMOS), that features the sensor bias of up to 120 V. The TowerJazz 180 nm high resistivity CMOS process (HR-CMOS) uses a high resistivity epitaxial layer to provide the depletion region on top of the substrate. We have evaluated passive pixel performance, and charge collection projections. The results strongly support the radiation tolerance of these devices to radiation dose of the HL-LHC in the strip tracker region. We also describe design features for the next chip submission that are motivated by our technology evaluation.

  3. Critical point wetting drop tower experiment

    NASA Technical Reports Server (NTRS)

    Kaukler, W. F.; Tcherneshoff, L. M.; Straits, S. R.

    1984-01-01

    Preliminary results for the Critical Point Wetting CPW Drop Tower Experiment are produced with immiscible systems. Much of the observed phenomena conformed to the anticipated behavior. More drops will be needed to test the CPW theory with these immiscible systems.

  4. Using ozone to treat cooling tower water

    SciTech Connect

    Webster, L.

    1995-07-01

    Ozone is a controversial but promising alternative to chemicals for treating water in cooling towers. A powerful disinfectant, ozone can prevent biofouling of heat exchange surfaces, and may mitigate scale and corrosion. Ozone treatment of cooling towers can cut costs for energy, water, sewage, and regulatory compliance. Ozone treatment is an electrotechnology, but ozone equipment represents only a small electric load. Although ozone has provided excellent results in some cooling tower applications, its effectiveness has not been proven conclusively. Less than 1,000 cooling towers use ozone water treatment in the United States. Acceptance of this technology is increasing, however, as indicated by its use by such large firms as IBM, AT and T, DuPont, and Xerox, and by its adoption by some chemical water treatment suppliers. The energy efficiency implications of ozone treatment are being researched. Southern California Edison found that in some systems, ozone treatment improved chiller efficiency up to 20 percent due to cleaner heat exchange surfaces.

  5. Another Look at the Tower of Hanoi

    ERIC Educational Resources Information Center

    Shwarger, Michael

    1977-01-01

    Through the use of sequences, geometric progressions and permutations, the author investigates some interesting and unusual questions concerning the number of moves required by each disc in solving the Tower of Hanoi puzzle. (JT)

  6. Ozone inhibits corrosion in cooling towers

    NASA Technical Reports Server (NTRS)

    French, K. R.; Howe, R. D.; Humphrey, M. F.

    1980-01-01

    Commercially available corona discharge ozone generator, fitted onto industrial cooling tower, significantly reduces formation of scales (calcium carbonate) and corrosion. System also controls growth of algae and other microorganisms. Modification lowers cost and improves life of cooling system.

  7. Rock Creek Tower Painting Project : Environmental Assessment.

    SciTech Connect

    United States. Bonneville Power Administration.

    1988-10-01

    Bonneville Power Administration (BPA) built a 500-kV line across Rock Creek, a Class I trout stream about 20 miles east of Missoula, MT. Two 190-foot towers rise on either side of the Rock Creek valley, and the line between is suspended 600 feet over the valley floor. The crossing poses a hazard to passing airplanes and disrupts the natural landscape. The area where the line crosses Rock Creek is prized for its scenic beauty. In response to public demand that BPA protect the visual beauty of this area, BPA painted the towers gray to blend them best in with their natural surroundings. The issue now is to decide between either two gray towers or two orange-and-white towers. The underlying need is to resolve the conflict of pilot safety against scenic intrusion. The proposed action is to paint the gray tower aeronautical orange and white. Alternatives are to paint the orange-and-white tower back to its original gray; or leave the dilemma unresolved (the ''no-action'' alternative). 9 refs., 3 figs.

  8. Concentration, serotypic profiles, and infectivity of Legionnaires' Disease bacteria populations in cooling towers

    SciTech Connect

    Tyndall, R.L.

    1982-01-01

    At the Philadelphia American Legion Convention in 1976 nearly two hundred people developed pulmonary infection. Of these, twenty-eight died. The causative bacterial agent was subsequently isolated and identified as a previously undiscovered human pathogen, that is, Legionnaires' Disease Bacterium (LDB). Currently it is estimated that over one hundred thousand cases of Legionella occur annually. Cooling towers have been shown to be the source of LDB in some of the outbreaks. Ecological information indicates that the bacteria are present in many natural waters. Moreover, there is strong evidence that algal products can stimulate the growth of LDB. Because cooling tower environments may be conducive for growth and/or dispersal of LDB, a survey of both industrial and air-conditioning cooling towers for the presence of LDB was undertaken.

  9. TECHNOLOGY ASSESSMENT OF SOIL VAPOR EXTRACTION AND AIR SPARGING

    EPA Science Inventory

    Air sparging, also called "in situ air stripping and in situ volatilization" injects air into the saturated zone to strip away volatile organic compounds (VOCs) dissolved in groundwater and adsorbed to soil. hese volatile contaminants transfer in a vapor phase to the unsaturated ...

  10. Characteristics of laminates with delamination control strips

    NASA Technical Reports Server (NTRS)

    Sun, C. T.; Goering, J. C.; Alper, J. M.; Gause, L. W.

    1992-01-01

    Tough resin is needed to resist delamination crack propagation. However, modulus often has to be compromised because it is difficult to retain both high modulus and toughness in a matrix material. A potential solution is to use a hybrid system in which tough resin strips are included within a conventional matrix composite. By adjusting the spacing of the tough resin strips, maximum delamination size can be controlled. Experimental results for impact damage and subsequent damage propagation in laminates containing tough resin strips are reported. Plain adhesive strips and fiber-reinforced tough resin composite strips were used in constructing the hybrid laminates. Test results indicated that size of delamination inflicted by impact was confined between the tough resin strips. As a result, significantly increased residual compressive strength was obtained. Impacted laminates containing tough resin strips were also fatigue tested. It was found that these strips reduced the growth of the impact damage area relative to the growth seen in coupons with no tough resin strips. Damage growth from an open hole under tension fatigue was evaluated using both tough resin strips and glass fiber reinforced tough resin strips. Unreinforced tough resin strips retarded delamination growth from the open hole, but did not stop matrix cracks growing in the fiber direction. Fiber reinforced tough resin strips did not contain axial delamination growth from the open hole. However, they did act as crack arresters, stopping the through-the-thickness tension crack originating from the hole.

  11. Assessing the environmental health relevance of cooling towers--a systematic review of legionellosis outbreaks.

    PubMed

    Walser, Sandra M; Gerstner, Doris G; Brenner, Bernhard; Höller, Christiane; Liebl, Bernhard; Herr, Caroline E W

    2014-03-01

    Bioaerosols from cooling towers are often suspected to cause community-acquired legionellosis outbreaks. Although Legionella infections can mostly be assigned to the emission sources, uncertainty exists about the release and distribution into the air, the occurrence of the respirable virulent form and the level of the infective concentration. Our study aimed to evaluate studies on legionellosis outbreaks attributed to cooling towers published within the last 11 years by means of a systematic review of the literature. 19 legionellosis outbreaks were identified affecting 12 countries. Recurring events were observed in Spain and Great Britain. In total, 1609 confirmed cases of legionellosis and a case-fatality rate of approximately 6% were reported. Duration of outbreaks was 65 days on average. For diagnosis the urinary antigen test was mainly used. Age, smoking, male sex and underlying diseases (diabetes, immunodeficiency) could be confirmed as risk factors. Smoking and underlying diseases were the most frequent risk factors associated with legionellosis in 11 and 10 of the 19 studies, respectively. The meteorological conditions varied strongly. Several studies reported a temporal association of outbreaks with inadequate maintenance of the cooling systems. A match of clinical and environmental isolates by serotyping and/or molecular subtyping could be confirmed in 84% of outbreaks. Legionella-contaminated cooling towers as environmental trigger, in particular in the neighbourhood of susceptible individuals, can cause severe health problems and even death. To prevent and control Legionella contamination of cooling towers, maintenance actions should focus on low-emission cleaning procedures of cooling towers combined with control measurements of water and air samples. Procedures allowing rapid detection and risk assessment in the case of outbreaks are essential for adequate public health measures. Systematic registration of cooling towers will facilitate the

  12. The Perils of Strip Searches.

    ERIC Educational Resources Information Center

    Trotter, Andrew

    1995-01-01

    Every year, a few administrators mishandle school searches and create spectacles similar to the New Castle, Pennsylvania, incident involving six illegally strip-searched students. Principals using "cops-and-robber" techniques to unearth contraband may not realize the potential for infringing on students' constitutional privacy rights. Strip…

  13. Bimaterial Thermal Strip With Increased Flexing

    NASA Technical Reports Server (NTRS)

    Morrison, Andrew D.

    1994-01-01

    In proposed bimaterial thermal strip, one layer has negative coefficient of thermal expansion, thereby increasing difference between coefficients of thermal expansion of two outer layers and consequently increasing flexing caused by change in temperature. Proposed bimaterial strips used in thermostats.

  14. 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.

  15. Pretreatment of anaerobic digestion effluent with ammonia stripping and biogas purification.

    PubMed

    Lei, Xiaohui; Sugiura, Norio; Feng, Chuanping; Maekawa, Takaaki

    2007-07-16

    In this study, ammonia stripping was optimized for pretreating anaerobic digestion effluent from an anaerobic digestion plant, and the possibility of using CO(2) stripping and biogas injection for adjusting the pH of the effluent before and after the ammonia stripping process was also investigated. For ammonia stripping, the results showed that an overdose of calcium hydroxide, i.e., 27.5g/L wastewater, achieved higher ammonia, phosphorus, chemical oxygen demand, suspended solids, and turbidity removal efficiency. An air flow rate of 5L/min for 1L of wastewater was thought as suitable for engineering application. The pH of the anaerobic digestion effluent can be increased from about 7 to about 9 by CO(2) stripping, however which is insufficient for ammonia stripping. For 1L of wastewater treated after ammonia stripping, the pH can be neutralized to about 7 from greater than 11 through biogas injection at 1L/min for less than 30min, and continuous injection does not decrease the pH. It was roughly estimated that 43m(3) of biogas (CH(4):CO(2) approximately 60%:40%) produced daily could be purified to CH(4):CO(2) approximately 74%:26% by neutralizing the pH of the 5m(3) anaerobic digestion effluent pretreated by ammonia stripping. PMID:17178436

  16. 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.

  17. 33 CFR 157.128 - Stripping system.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false Stripping system. 157.128 Section... of the following devices for stripping oil from each cargo tank: (1) A positive displacement pump. (2... positive displacement pump or a self-priming centrifugal pump, the stripping system must have the...

  18. 33 CFR 157.128 - Stripping system.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false Stripping system. 157.128 Section... of the following devices for stripping oil from each cargo tank: (1) A positive displacement pump. (2... positive displacement pump or a self-priming centrifugal pump, the stripping system must have the...

  19. Using Comic Strips in Language Classes

    ERIC Educational Resources Information Center

    Csabay, Noémi

    2006-01-01

    The author believes that using comic strips in language-learning classes has three main benefits. First, comic strips motivate younger learners. Second, they provide a context and logically connected sentences to help language learning. Third, their visual information is helpful for comprehension. The author argues that comic strips can be used in…

  20. 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 100

  1. Tilts of the Master Equatorial Tower

    NASA Astrophysics Data System (ADS)

    Ahlstrom, H. G., Jr.; Gawronski, W.; Girdner, D.; Noskoff, E.; Sommerville, J. N.

    2000-07-01

    At the center of the DSS-14 antenna, a tower reaches to the focal point of the antenna dish. The master equatorial (ME) instrument is located at the top of the tower. This instrument precisely (with an accuracy that exceeds that of the antenna) follows the commanded trajectory. Through the optical coupling, the antenna focal point follows the ME. One factor of the antenna pointing precision is the movement of the ME base, i.e., the top of the tower. For this reason, measurements of the ME tower tilts have been taken in order to quantify the tilts, to determine possible causes of the tilting, and to update the antenna pointing budget. They were conducted under three antenna operating modes: during tracking, slewing, and antenna stowing. The measurements indicate that the ME tower tilts introduce significant pointing errors that exceed the required 32-GHz (Ka-band) pointing precision (estimated as 0.8 mdeg for a 0.1-dB gain loss). Four different sources of tilt were identified and require verification.

  2. 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. PMID:23937212

  3. Analyzing the possibility of achieving more efficient cooling of water in the evaporative cooling towers of the Armenian NPP

    NASA Astrophysics Data System (ADS)

    Petrosyan, V. G.; Yeghoyan, E. A.

    2015-10-01

    The specific features of the service cooling water system used at the Armenian NPP and modifications made in the arrangement for supplying water to the water coolers in order to achieve more efficient cooling are presented. The mathematical model applied in carrying out the analyses is described, the use of which makes it possible to investigate the operation of parallel-connected cooling towers having different hydraulic and thermal loads. When the third standby cooling tower is put into operation (with the same flow rate of water supplied to the water coolers), the cooled water temperature is decreased by around 2-3°C in the range of atmospheric air temperatures 0-35°C. However, the introduced water distribution arrangement with a decreased spraying density has limitation on its use at negative outdoor air temperatures due to the hazard intense freezing of the fill in the cooling tower peripheral zone. The availability of standby cooling towers in the shutdown Armenian NPP power unit along with the planned full replacement of the cooling tower process equipment create good possibilities for achieving a deeper water cooling extent and better efficiency of the NPP. The present work was carried out with the aim of achieving maximally efficient use of existing possibilities and for elaborating the optimal cooling tower modernization version. Individual specific heat-andmass transfer processes in the chimney-type evaporative cooling towers are analyzed. An improved arrangement for distributing cooled water over the cooling tower spraying area (during its operation with a decreased flow rate) is proposed with the aim of cooling water to a deeper extent and preserving the possibility of using the cooling towers in winter. The main idea behind improving the existing arrangement is to exclude certain zones of the cooling tower featuring inefficient cooling from operation. The effectiveness of introducing the proposed design is proven by calculations (taking as an

  4. Fast variation method for elastic strip calculation.

    PubMed

    Biryukov, Sergey V

    2002-05-01

    A new, fast, variation method (FVM) for determining an elastic strip response to stresses arbitrarily distributed on the flat side of the strip is proposed. The remaining surface of the strip may have an arbitrary form, and it is free of stresses. The FVM, as well as the well-known finite element method (FEM), starts with the variational principle. However, it does not use the meshing of the strip. A comparison of FVM results with the exact analytical solution in the special case of shear stresses and a rectangular strip demonstrates an excellent agreement.

  5. CFD MODELING AND ANALYSIS FOR A-AREA AND H-AREA COOLING TOWERS

    SciTech Connect

    Lee, S.; Garrett, A.; Bollinger, J.

    2009-09-02

    Mechanical draft cooling towers are designed to cool process water via sensible and latent heat transfer to air. Heat and mass transfer take place simultaneously. Heat is transferred as sensible heat due to the temperature difference between liquid and gas phases, and as the latent heat of the water as it evaporates. Mass of water vapor is transferred due to the difference between the vapor pressure at the air-liquid interface and the partial pressure of water vapor in the bulk of the air. Equations to govern these phenomena are discussed here. The governing equations are solved by taking a computational fluid dynamics (CFD) approach. The purpose of the work is to develop a three-dimensional CFD model to evaluate the flow patterns inside the cooling tower cell driven by cooling fan and wind, considering the cooling fans to be on or off. Two types of the cooling towers are considered here. One is cross-flow type cooling tower located in A-Area, and the other is counterflow type cooling tower located in H-Area. The cooling tower located in A-Area is mechanical draft cooling tower (MDCT) consisting of four compartment cells as shown in Fig. 1. It is 13.7m wide, 36.8m long, and 9.4m high. Each cell has its own cooling fan and shroud without any flow communications between two adjacent cells. There are water distribution decks on both sides of the fan shroud. The deck floor has an array of about 25mm size holes through which water droplet falls into the cell region cooled by the ambient air driven by fan and wind, and it is eventually collected in basin area. As shown in Fig. 1, about 0.15-m thick drift eliminator allows ambient air to be humidified through the evaporative cooling process without entrainment of water droplets into the shroud exit. The H-Area cooling tower is about 7.3 m wide, 29.3 m long, and 9.0 m high. Each cell has its own cooling fan and shroud, but each of two corner cells has two panels to shield wind at the bottom of the cells. There is some

  6. Antenna structure with distributed strip

    DOEpatents

    Rodenbeck, Christopher T.

    2008-10-21

    An antenna comprises electrical conductors arranged to form a radiating element including a folded line configuration and a distributed strip configuration, where the radiating element is in proximity to a ground conductor. The folded line and the distributed strip can be electrically interconnected and substantially coplanar. The ground conductor can be spaced from, and coplanar to, the radiating element, or can alternatively lie in a plane set at an angle to the radiating element. Embodiments of the antenna include conductor patterns formed on a printed wiring board, having a ground plane, spacedly adjacent to and coplanar with the radiating element. Other embodiments of the antenna comprise a ground plane and radiating element on opposed sides of a printed wiring board. Other embodiments of the antenna comprise conductors that can be arranged as free standing "foils". Other embodiments include antennas that are encapsulated into a package containing the antenna.

  7. Antenna structure with distributed strip

    DOEpatents

    Rodenbeck, Christopher T.

    2008-03-18

    An antenna comprises electrical conductors arranged to form a radiating element including a folded line configuration and a distributed strip configuration, where the radiating element is in proximity to a ground conductor. The folded line and the distributed strip can be electrically interconnected and substantially coplanar. The ground conductor can be spaced from, and coplanar to, the radiating element, or can alternatively lie in a plane set at an angle to the radiating element. Embodiments of the antenna include conductor patterns formed on a printed wiring board, having a ground plane, spacedly adjacent to and coplanar with the radiating element. Other embodiments of the antenna comprise a ground plane and radiating element on opposed sides of a printed wiring board. Other embodiments of the antenna comprise conductors that can be arranged as free standing "foils". Other embodiments include antennas that are encapsulated into a package containing the antenna.

  8. Cooling tower water conditioning study. [using ozone

    NASA Technical Reports Server (NTRS)

    Humphrey, M. F.; French, K. R.

    1979-01-01

    Successful elimination of cooling tower treatment chemicals was demonstrated. Three towers functioned for long periods of time with ozone as the only treatment for the water. The water in the systems was reused as much as 30 times (cycles of concentration) without deleterious effects to the heat exchangers. Actual system blow-down was eliminated and the only makeup water added was that required to replace the evaporation and mist entrainment losses. Minimum water savings alone are approximately 75.1 1/kg/year. Cost estimates indicate that a savings of 55 percent was obtained on the systems using ozone. A major problem experienced in the use of ozone for cooling tower applications was the difficulty of accurate concentration measurements. The ability to control the operational characteristics relies on easily and accurately determined concentration levels. Present methods of detection are subject to inaccuracies because of interfering materials and the rapid destruction of the ozone.

  9. Simple model of a cooling tower plume

    NASA Astrophysics Data System (ADS)

    Jan, Cizek; Jiri, Nozicka

    2016-06-01

    This article discusses the possibilities in the area of modeling of the so called cooling tower plume emergent at operating evaporating cooling systems. As opposed to recent publication, this text focuses on the possibilities of a simplified analytic description of the whole problem where this description shall - in the future - form the base of a calculation algorithms enabling to simulate the efficiency of systems reducing this cooling tower plume. The procedure is based on the application of basic formula for the calculation of the velocity and concentration fields in the area above the cooling tower. These calculation is then used to determine the form and the total volume of the plume. Although this approach does not offer more exact results, it can provide a basic understanding of the impact of individual quantities relating to this problem.

  10. Drop Tower Facility at Queensland University of Technology

    NASA Astrophysics Data System (ADS)

    Plagens, Owen; Castillo, Martin; Steinberg, Theodore; Ong, Teng-Cheong

    The Queensland University of Technology (QUT) Drop Tower Facility is a {raise.17exscriptstyle˜}2.1 second, 21.3 m fall, dual capsule drop tower system. The dual capsule comprises of an uncoupled exterior hollow drag shield that experiences drag by the ambient atmosphere with the experimental capsule falling within the drag shield. The dual capsule system is lifted to the top of the drop tower via a mechanical crane and the dropping process is initiated by the cutting of a wire coupling the experimental package and suspending the drag shield. The internal experimental capsule reaches the bottom of the drag shield floor just prior to the deceleration stage at the air bag and during this time experience gravity levels of {raise.17exscriptstyle˜}10textsuperscript{-6} g. The deceleration system utilizes an inflatable airbag where experimental packages can be designed to experience a maximum deceleration of {raise.17exscriptstyle˜}10textsuperscript{18} g for {raise.17exscriptstyle˜}0.1 seconds. The drag shield can house experimental packages with a maximum diameter of 0.8 m and height of 0.9 m. The drag shield can also be used in foam mode, where the walls are lined with foam and small experiments can be dropped completely untethered. This mode is generally used for the study of microsatellite manipulation. Payloads can be powered by on-board power systems with power delivered to the experiment until free fall occurs. Experimental data that can be collected includes but is not limited to video, temperature, pressure, voltage/current from the power supply, and triggering mechanisms outputs which are simultaneously collected via data logging systems and high speed video recording systems. Academic and commercial projects are currently under investigation at the QUT Drop Tower Facility and collaboration is openly welcome at this facility. Current research includes the study of heterogeneously burning metals in oxygen which is aimed at fire safety applications and

  11. Analysis of a simple biodegradation process for the removal of volatile organic chemicals from wastewater based on a gas stripping principle.

    PubMed

    Dahlan, M H; Xing, X H; Yoshikawa, Y; Matsumoto, K

    1999-01-01

    A simple biodegradation system consisting of an air stripping tank and a bioreactor was proposed for the treatment of volatile organic chemicals in wastewater. Toluene was used as a model of volatile organic chemicals. An aqueous solution of toluene and a basic mineral medium were placed in the air stripping tank and bioreactor, respectively. Toluene was stripped by supplying compressed air into the stripping tank through a sparger, and the stripped toluene was degraded by Pseudomonas putida mt-2 (ATCC 33015) in the bioreactor under aerobic conditions. The effect of the air stripping rate on bacterial growth was examined. A quantitative relationship was found between the air flow rate in the air stripping tank (Qa) and the stripping rate constant. During cultivation, the bacterial cells grew by utilizing toluene as the sole carbon source, and reached their maximum cell concentration (Xm) at the stationary phase. Xm showed a gradual decrease with increase in Qa from 1.8 to 7.2 l/h, indicating a decrease in the rate of toluene degradation with increasing Qa. The Xm at Qa=1.8 l/h was the highest among the experiments under different values of Qa, which was almost twice that at Qa=7.2 l/h. Mathematical analysis taking the growth kinetics and mass transfer of toluene into consideration satisfactorily explained the system performance.

  12. Lessons learned from the Lena guyed tower

    SciTech Connect

    Finn, L.D.; Maus, L.D.

    1984-10-01

    The design, fabrication, and installation of the Lena guyed tower required the development of new offshore technology in several areas. Lessons learned from this experience include an understanding of the consequences of major design decisions and insight into the interactive behavior of the structural components. The guyed tower is now a proven deepwater production platform concept for the Gulf of Mexico and is also judged to be applicable for a wide range of water depths and deck loads in the North Sea and other areas of the world.

  13. The new Drop Tower catapult system

    NASA Astrophysics Data System (ADS)

    von Kampen, Peter; Kaczmarczik, Ulrich; Rath, Hans J.

    2006-07-01

    The Center of Applied Space Technology and Microgravity (ZARM) was founded in 1985 as an institute of the University Bremen, which focuses on research on gravitational and space-related phenomena. In 1988, the construction of the "Drop Tower" began. Since then, the eye-catching tower with a height of 146 m and its characteristic glass roof has become the emblem of the technology centre in Bremen. The Drop Tower Bremen provides a facility for experiments under conditions of weightlessness. Items are considered weightless, when they are in "free fall", i.e. moving without propulsion within the gravity field of the earth. The height of the tower limits the simple "free fall" experiment period to max. 4.74 s. With the inauguration of the catapult system in December 2004, the ZARM is entering a new dimension. This world novelty will meet scientists' demands of extending the experiment period up to 9.5 s. Since turning the first sod on May 3rd, 1988, the later installation of the catapult system has been taken into account by building the necessary chamber under the tower. The catapult system is located in a chamber 10 m below the base of the tower. This chamber is almost completely occupied by 12 huge pressure tanks. These tanks are placed around the elongation of the vacuum chamber of the drop tube. In its centre there is the pneumatic piston that accelerates the drop capsule by the pressure difference between the vacuum inside the drop tube and the pressure inside the tanks. The acceleration level is adjusted by means of a servo hydraulic breaking system controlling the piston velocity. After only a quarter of a second the drop capsule achieves its lift-off speed of 175 km/h. With this exact speed, the capsule will rise up to the top of the tower and afterwards fall down again into the deceleration unit which has been moved under the drop tube in the meantime. The scientific advantages of the doubled experiment time are obvious: during almost 10 s of high

  14. 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

  15. 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

  16. 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

  17. 2. Slacking Tower south side, view to the northnortheast. ...

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

    2. Slacking Tower south side, view to the north-northeast. - Washington Water Power Clark Fork River Noxon Rapids Hydroelectric Development, Slacking Tower, South bank of Clark Fork River at Noxon Rapids, Noxon, Sanders County, MT

  18. 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

  19. 1. General view of crossing gate tower, taken in 1916 ...

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

    1. General view of crossing gate tower, taken in 1916 (courtesy of Erie Railroad Company) (photocopy) - Erie Railway, Crossing Gate Tower, West side of Lincoln Street, 100 feet South of Concord Street, Union City, Erie County, PA

  20. 39. View from top of Brooklyn Tower looking SW at ...

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

    39. View from top of Brooklyn Tower looking SW at tower cornice, main cable and stay cables. Jet Lowe, photographer, 1982. - Brooklyn Bridge, Spanning East River between Park Row, Manhattan and Sands Street, Brooklyn, New York County, NY

  1. 54. Angled view looking up at Brooklyn Tower showing juncture ...

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

    54. Angled view looking up at Brooklyn Tower showing juncture of deck superstructure with the tower and diagonal cables. Jet Lowe, photographer, 1982. - Brooklyn Bridge, Spanning East River between Park Row, Manhattan and Sands Street, Brooklyn, New York County, NY

  2. 1. Keeper's house and light tower, view north, south and ...

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

    1. Keeper's house and light tower, view north, south and east sides of keeper's house, southwest and southeast sides of tower - Whitehead Light Station, Whitehead Island, East northeast of Tenants Harbor, Spruce Head, Knox County, ME

  3. 2. Light tower, keeper's house and shed, view south southwest, ...

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

    2. Light tower, keeper's house and shed, view south southwest, northwest and northeast sides of tower, east and north sides of keeper's house and shed - Whitehead Light Station, Whitehead Island, East northeast of Tenants Harbor, Spruce Head, Knox County, ME

  4. 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

  5. Steam sand dryer in northeast part of sand tower. View ...

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

    Steam sand dryer in northeast part of sand tower. View to northeast - Duluth & Iron Range Rail Road Company Shops, Sand Tower, Southwest of downtown Two Harbors, northwest of Agate Bay, Two Harbors, Lake County, MN

  6. 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

  7. 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.

  8. 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

  9. TOWER S389, MAGAZINES IN BACKGROUND. Naval Magazine Lualualei, West ...

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

    TOWER S389, MAGAZINES IN BACKGROUND. - Naval Magazine Lualualei, West Loch Branch, Guard-Watch Tower Type, Near A Avenue between Fourth & Sixth Streets, Ninth Street & D Avenue intersection, & F Avenue, Pearl City, Honolulu County, HI

  10. TOWER 450 WITH POLE. Naval Magazine Lualualei, West Loch ...

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

    TOWER 450 WITH POLE. - Naval Magazine Lualualei, West Loch Branch, Guard-Watch Tower Type, Near A Avenue between Fourth & Sixth Streets, Ninth Street & D Avenue intersection, & F Avenue, Pearl City, Honolulu County, HI

  11. S316, GUARD TOWER INTERIOR. Naval Magazine Lualualei, Headquarters Branch, ...

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

    S316, GUARD TOWER INTERIOR. - Naval Magazine Lualualei, Headquarters Branch, Guard-Watch Tower Type, Off Dent Road & on Kolekole Road near north boundary of installation, Pearl City, Honolulu County, HI

  12. 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

  13. S316, GUARD TOWER ON KOLEKOLE PASS RD. Naval Magazine ...

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

    S316, GUARD TOWER ON KOLEKOLE PASS RD. - Naval Magazine Lualualei, Headquarters Branch, Guard-Watch Tower Type, Off Dent Road & on Kolekole Road near north boundary of installation, Pearl City, Honolulu County, HI

  14. TOWER S389, WITH POLE. MAGAZINES IN BACKGROUND. Naval Magazine ...

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

    TOWER S389, WITH POLE. MAGAZINES IN BACKGROUND. - Naval Magazine Lualualei, West Loch Branch, Guard-Watch Tower Type, Near A Avenue between Fourth & Sixth Streets, Ninth Street & D Avenue intersection, & F Avenue, Pearl City, Honolulu County, HI

  15. 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

  16. 27. STATIC TEST TOWER CLOSEUP VIEW OF CONTROL PANEL AT ...

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

    27. STATIC TEST TOWER CLOSE-UP VIEW OF CONTROL PANEL AT REAR OF TOWER UNDER SHED ROOF. - Marshall Space Flight Center, Saturn Propulsion & Structural Test Facility, East Test Area, Huntsville, Madison County, AL

  17. 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

  18. 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

  19. INTERIOR OF SA WETSIDE BUILDING. TOP OF CARBONATION TOWERS (SOLVAY ...

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

    INTERIOR OF SA WETSIDE BUILDING. TOP OF CARBONATION TOWERS (SOLVAY TOWERS) PROBABLY SAME LEVEL AS NY-300-D-6 BUT OPPOSITE VIEW. - Solvay Process Company, SA Wetside Building, Between Willis & Milton Avenue, Solvay, Onondaga County, NY

  20. 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

  1. APPROACH BRIDGE PORTION OF VALVE TOWER FOOT BRIDGE, AS SEEN ...

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

    APPROACH BRIDGE PORTION OF VALVE TOWER FOOT BRIDGE, AS SEEN FROM ENTRY. VIEW FACING NORTHWEST - Schofield Barracks Military Reservation, Ku Tree Reservoir, Valve Tower Foot Bridge, Kalakoa Stream, East Range, Wahiawa, Honolulu County, HI

  2. 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

  3. 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

  4. 5. Detail of tower bottom step and stairway structure, facing ...

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

    5. Detail of tower bottom step and stairway structure, facing southeast - Cold Mountain Fire Lookout Station, Lookout Tower, Krassel District, Frank Church River of No Return Wilderness, Dixie, Idaho County, ID

  5. View uphill of single chair lift, tower 15 in foreground, ...

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

    View uphill of single chair lift, tower 15 in foreground, TOWERS 16 and 17 in the distance, LOOKING SOUTH. - Mad River Glen, Single Chair Ski Lift, 62 Mad River Glen Resort Road, Fayston, Washington County, VT

  6. 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

  7. 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

  8. Low-cost Triangular Lattice Towers for Small Wind Turbines

    NASA Astrophysics Data System (ADS)

    Adhikari, Ram Chandra

    This thesis focuses on the study of low-cost steel and bamboo triangular lattice towers for small wind turbines. The core objective is to determine the material properties of bamboo and assess the feasibility of bamboo towers. Using the experimentally determined buckling resistance, elastic modulus, and Poisson's ratio, a 12 m high triangular lattice tower for a 500W wind turbine has been modeled as a tripod to formulate the analytical solutions for the stresses and tower deflections, which enables design of the tower based on buckling strength of tower legs. The tripod formulation combines the imposed loads, the base distance between the legs and tower height, and cross-sectional dimensions of the tower legs. The tripod model was used as a reference for the initial design of the bamboo tower and extended to finite element analysis. A 12 m high steel lattice tower was also designed for the same turbine to serve as a comparison to the bamboo tower. The primary result of this work indicates that bamboo is a valid structural material. The commercial software package ANSYS APDL was used to carry out the tower analysis, evaluate the validity of the tripod model, and extend the analysis for the tower design. For this purpose, a 12 m high steel lattice tower for a 500 W wind turbine was examined. Comparison of finite element analysis and analytical solution has shown that tripod model can be accurately used in the design of lattice towers. The tower designs were based on the loads and safety requirements of international standard for small wind turbine safety, IEC 61400-2. For connecting the bamboo sections in the lattice tower, a steel-bamboo adhesive joint combined with conventional lashing has been proposed. Also, considering the low durability of bamboo, periodic replacement of tower members has been proposed. The result of this study has established that bamboo could be used to construct cost-effective and lightweight lattice towers for wind turbines of 500 Watt

  9. Utility Towers, Insulator Detail, Front Elevation, Side Elevation, Elevation, Double ...

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

    Utility Towers, Insulator Detail, Front Elevation, Side Elevation, Elevation, Double Pole Tower, Single Pole Tower - La Bajada Historic Trails and Roads, Approximately 1 mile East/Northeast of intersection of State Highway 16 and Indian Service Road 841, La Bajada, Santa Fe County, NM

  10. 1. Slacking Tower north side, view to the southsouthwest. The ...

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

    1. Slacking Tower north side, view to the south-southwest. The tower was used for dredging the river downstream of the powerhouse. - Washington Water Power Clark Fork River Noxon Rapids Hydroelectric Development, Slacking Tower, South bank of Clark Fork River at Noxon Rapids, Noxon, Sanders County, MT

  11. 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

  12. 78 FR 17183 - Information Collection: Grey Towers Visitor Comment Card

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-20

    ... Forest Service Information Collection: Grey Towers Visitor Comment Card AGENCY: Forest Service, USDA... collection 0596- 0222, ``Grey Towers Visitor Comment Card'' with 0596-0226, ``Forest Service Generic.... SUPPLEMENTARY INFORMATION: Title: Grey Towers Visitor Comment Card. OMB Number: 0596-0222. Expiration Date...

  13. 38. View from top of Brooklyn Tower showing man walking ...

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

    38. View from top of Brooklyn Tower showing man walking up main cable, stay cables radiating from top of tower and tower cornice. Jet Lowe, photographer, 1982. - Brooklyn Bridge, Spanning East River between Park Row, Manhattan and Sands Street, Brooklyn, New York County, NY

  14. 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

  15. 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

  16. View of second bank of circuit towers on Arizona side ...

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

    View of second bank of circuit towers on Arizona side of canyon. Left tower supports Circuit 10 and right tower supports Circuit 11, view north - Hoover Dam, Circuits 1-15, U.S. Highway 93, Boulder City, Clark County, NV

  17. DETAIL VIEW OF AERIAL TRAM SUPPORT TOWERS THREE AND FOUR ...

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

    DETAIL VIEW OF AERIAL TRAM SUPPORT TOWERS THREE AND FOUR WITH TOWERS FIVE AND SIX IN THE DISTANCE, LOOKING NORTHEAST. THE TWO INTACT CABLES RUNNING ALONG TOP OF THE TOWERS ARE FIXED. WHILE THE MOVING CABLE IS LYING SLACK ON THE GROUND. - Keane Wonder Mine, Park Route 4 (Daylight Pass Cutoff), Death Valley Junction, Inyo County, CA

  18. 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

  19. CONCRETE PAD AND SUSPENSION BRIDGE TOWERS FOR CABLES FORMERLY SUPPORTING ...

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

    CONCRETE PAD AND SUSPENSION BRIDGE TOWERS FOR CABLES FORMERLY SUPPORTING THE SUSPENSION BRIDGE PORTION OF VALVE TOWER FOOT BRIDGE. VIEW FACING NORTHEAST - Schofield Barracks Military Reservation, Ku Tree Reservoir, Valve Tower Foot Bridge, Kalakoa Stream, East Range, Wahiawa, Honolulu County, HI

  20. ASDC: A microcomputer-based program for air stripper design and costing. Final report, March 1990-August 1991

    SciTech Connect

    Dzombak, D.A.; Fang, H.J.; Roy, S.B.

    1991-12-01

    Packed-tower, counter-current air stripping is a treatment process that can be employed for removal of volatile organic compounds (VOCS) from water and wastewater. The design of an air stripper is performed using a well-developed mathematical model of the process. However, the number of variables involved exceeds the number of constraining equations by two, with the result that a number of alternative air stripper designs exist for a particular water treatment goal. In selecting the optimum design among the various alternatives, it is important to consider the capital and operating costs associated with each alternative. This report describes an interactive, microcomputer-based program - the Air Stripper Design and Costing (ASDC) program - that enables rapid evaluation of alternative air stripper designs and approximate costs associated with these designs for user-specified treatment scenarios. The various components of the program are described in detail, a guide to program operation is provided along with example applications, and results of some verification tests are presented.

  1. Ignition, Burning, and Extinction of a Strained Fuel Strip

    NASA Technical Reports Server (NTRS)

    Selerland, T.; Karagozian, A. R.

    1996-01-01

    Flame structure and ignition and extinction processes associated with a strained fuel strip are explored numerically using detailed transport and complex kinetics for a propane-air reaction. Ignition modes are identified that are similar to those predicted by one-step activation energy asymptotics, i.e., modes in which diffusion flames can ignite as independent or dependent interfaces, and modes in which single premixed or partially premixed flames ignite. These ignition modes are found to be dependent on critical combinations of strain rate, fuel strip thickness, and initial reactant temperatures. Extinction in this configuration is seen to occur due to fuel consumption by adjacent flames, although viscosity is seen to have the effect of delaying extinction by reducing the effective strain rate and velocity field experienced by the flames.

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

    SciTech Connect

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

    2016-01-01

    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 average 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.

  3. The Legacy of the Texas Tower Sniper

    ERIC Educational Resources Information Center

    Lavergne, Gary

    2007-01-01

    In this article, the author relates the incident that happened at the University of Texas to the tragedy that took place at Virginia Tech. On August 1, 1966, Charles Joseph Whitman ascended the University of Texas Tower, in Austin, and in 96 minutes fired 150 high-powered rounds of ammunition down upon an unsuspecting university family. The…

  4. The Tower and Glass Marbles Problem

    ERIC Educational Resources Information Center

    Denman, Richard T.; Hailey, David; Rothenberg, Michael

    2010-01-01

    The Catseye Marble company tests the strength of its marbles by dropping them from various levels of their office tower, to find the highest floor from which a marble will not break. We find the smallest number of drops required and from which floor each drop should be made. We also find out how these answers change if a restriction is placed on…

  5. 29 CFR 1926.1435 - Tower cranes.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... registered professional engineer familiar with the equipment must not be exceeded. (c) Signs. The size and location of signs installed on tower cranes must be in accordance with manufacturer specifications. Where... must approve in writing the size and location of any signs. (d) Safety devices. (1) Section...

  6. The Tower of Hanoi and Inductive Logic

    ERIC Educational Resources Information Center

    Merrotsy, Peter

    2015-01-01

    In the "Australian Curriculum," the concept of mathematical induction is first met in the senior secondary subject Specialist Mathematics. This article details an example, the Tower of Hanoi problem, which provides an enactive introduction to the inductive process before moving to more abstract and cognitively demanding representations.…

  7. 29 CFR 1926.1435 - Tower cranes.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... following brakes, which must automatically set in the event of pressure loss or power failure, are required: (A) A hoist brake on all hoists. (B) Swing brake. (C) Trolley brake. (D) Rail travel brake. (viii...) Hoist drum lower limiting device. Tower cranes manufactured after November 8, 2011 must be equipped...

  8. Tower Power: Producing Fuels from Solar Energy

    ERIC Educational Resources Information Center

    Antal, M. J., Jr.

    1976-01-01

    This article examines the use of power tower technologies for the production of synthetic fuels. This process overcomes the limitations of other processes by using a solar furnace to drive endothermic fuel producing reactions and the resulting fuels serve as a medium for storing solar energy. (BT)

  9. Balsa Tower Walls Brave "Big Buster"

    ERIC Educational Resources Information Center

    Granlund, George

    2008-01-01

    Like many technology teachers, the author, a technology education teacher at Arthur Hill High School in Saginaw, Michigan, tries to stretch his budget by "milking" each student activity for maximum benefit. In the technology department, they use balsa wood towers to teach the basics of structural engineering. To get the most from their materials,…

  10. 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

  11. 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 ...

  12. Update on the Purdue University 2-second Drop Tower

    NASA Astrophysics Data System (ADS)

    Collicott, Steven

    an update on progress for the micro-gravity community. The most noticeable current activity is testing of the air-bag decelerator. The tower is one that will use a free-falling experiment inside of a drag shield to avoid most aerodynamic drag. The airbag is designed from experiences of others yet the small, triangular room in which the tower terminates imposes challenges. The airbag is approximately 1.5m diameter and 1.5m tall. Initial testing led to a desire to increase vent area, and just this week the bag has returned from the shop that was modifying it. On-board computer, battery packs, lighting, and cameras have been acquired. Thanks to Lockheed Martin, one camera is 500 frames per second with 1.3 million 12-bit gray scale pixels per frame. The Spincraft company donated steel hemisphere-cylinders to serve as the nose of the drag shield. Wind tunnel and CFD modeling of the drag shield has been performed by Purdue undergraduate aerospace students. Currently the drag shield structure and experiment package structure are being design and analyzed. The experiment volume is approximately a cylinder 0.45m diameter and 0.6m tall. Tower operation is intended to commence in fall 2010 with inert package drops at full mass and full height. Developing the operations procedures, especially operational safety, are the goals of this work. First science is then expected in the winter. References 1. Y. Chen, "A Study of Capillary Flow in a Vane-wall Gap in Zero Gravity," Ph.D. thesis, School of Aeronautics and Astronautics, Purdue University. August 2003. 2. Y. Chen and S. H. Collicott, "Investigation of the Symmetric Wetting of a Vane-Wall Gap in Propellant Tanks," AIAA Journal, 42, No. 2, pp. 305-314, February 2004. 3. Y. Chen, and S. H. Collicott, "Experimental Study on the Capillary Flow in a Vane-Wall Gap Geometry," AIAA Journal, 43, No. 11, pp. 2395-2403, November, 2005. 4. Y. Chen and S. H. Collicott, "Study of Wetting in an Asymmetrical Vane-Wall Gap in Propellant Tanks

  13. Update on the Purdue University 2-second Drop Tower

    NASA Astrophysics Data System (ADS)

    Collicott, Steven

    an update on progress for the micro-gravity community. The most noticeable current activity is testing of the air-bag decelerator. The tower is one that will use a free-falling experiment inside of a drag shield to avoid most aerodynamic drag. The airbag is designed from experiences of others yet the small, triangular room in which the tower terminates imposes challenges. The airbag is approximately 1.5m diameter and 1.5m tall. Initial testing led to a desire to increase vent area, and just this week the bag has returned from the shop that was modifying it. On-board computer, battery packs, lighting, and cameras have been acquired. Thanks to Lockheed Martin, one camera is 500 frames per second with 1.3 million 12-bit gray scale pixels per frame. The Spincraft company donated steel hemisphere-cylinders to serve as the nose of the drag shield. Wind tunnel and CFD modeling of the drag shield has been performed by Purdue undergraduate aerospace students. Currently the drag shield structure and experiment package structure are being design and analyzed. The experiment volume is approximately a cylinder 0.45m diameter and 0.6m tall. Tower operation is intended to commence in fall 2010 with inert package drops at full mass and full height. Developing the operations procedures, especially operational safety, are the goals of this work. First science is then expected in the winter. References 1. Y. Chen, "A Study of Capillary Flow in a Vane-wall Gap in Zero Gravity," Ph.D. thesis, School of Aeronautics and Astronautics, Purdue University. August 2003. 2. Y. Chen and S. H. Collicott, "Investigation of the Symmetric Wetting of a Vane-Wall Gap in Propellant Tanks," AIAA Journal, 42, No. 2, pp. 305-314, February 2004. 3. Y. Chen, and S. H. Collicott, "Experimental Study on the Capillary Flow in a Vane-Wall Gap Geometry," AIAA Journal, 43, No. 11, pp. 2395-2403, November, 2005. 4. Y. Chen and S. H. Collicott, "Study of Wetting in an Asymmetrical Vane-Wall Gap in Propellant Tanks

  14. Buffer strips in composites at elevated temperature

    NASA Technical Reports Server (NTRS)

    Bigelow, C. A.

    1983-01-01

    The composite material 'buffer strip' concept is presently investigated at elevated temperatures for the case of graphite/polyimide buffer strip panels using a (45/0/45/90)2S layup, where the buffer strip material was 0-deg S-glass/polyimide. Each panel was loaded in tension until it failed, and radiographs and crack opening displacements were recorded during the tests to determine fracture onset, fracture arrest, and the extent of damage in the buffer strip after crack arrest. At 177 + or - 3 C, the buffer strips increased the panel strength by at least 40 percent in comparison with panels without buffer strips. Compared to similar panels tested at room temperature, those tested at elevated temperature had lower residual strengths, but higher failure strains.

  15. Studies of NICADD Extruded Scintillator Strips

    SciTech Connect

    Dychkant, Alexandre; et al.

    2005-03-01

    About four hundred one meter long, 10 cm wide and 5 mm thick extruded scintillating strips were measured at four different points. The results of measurements strip responses to a radioactive source {sup 90}Sr are provided, and details of strip choice, preparation, and method of measurement are included. This work was essential for prototyping a tail catcher and muon tracker for a future international electron positron linear collider detector.

  16. Quantifiable Lateral Flow Assay Test Strips

    NASA Technical Reports Server (NTRS)

    2003-01-01

    As easy to read as a home pregnancy test, three Quantifiable Lateral Flow Assay (QLFA) strips used to test water for E. coli show different results. The brightly glowing control line on the far right of each strip indicates that all three tests ran successfully. But the glowing test line on the middle left and bottom strips reveal their samples were contaminated with E. coli bacteria at two different concentrations. The color intensity correlates with concentration of contamination.

  17. Method of stripping metals from organic solvents

    DOEpatents

    Todd, Terry A.; Law, Jack D.; Herbst, R. Scott; Romanovskiy, Valeriy N.; Smirnov, Igor V.; Babain, Vasily A.; Esimantovski, Vyatcheslav M.

    2009-02-24

    A new method to strip metals from organic solvents in a manner that allows for the recycle of the stripping agent. The method utilizes carbonate solutions of organic amines with complexants, in low concentrations, to strip metals from organic solvents. The method allows for the distillation and reuse of organic amines. The concentrated metal/complexant fraction from distillation is more amenable to immobilization than solutions resulting from current practice.

  18. Strip of heat-recoverable articles

    SciTech Connect

    McLoughlin, R.H.; Kirkham, S.W.

    1985-01-29

    A strip of hollow heat-recoverable articles formed side-by-side by tear welding two lengths of polymeric material together at intervals so that individual articles may be torn off. A preferred method of making the strip involves cross-linking after the tear welding, heating the strip, and inflating the hollow articles to render them heat-recoverable by introducing pressure via an interconnecting passage formed for that purpose during the tear welding.

  19. Experimental optimization of cooling-tower-fan control based on field data. Master's thesis

    SciTech Connect

    Herman, D.L.

    1991-04-01

    Energy costs continue to play an important role in the decision-making process for building design and operation. Since the chiller, cooling tower fans, and associated pumps consume the largest fraction of energy in a heating, ventilating, and air-conditioning (HVAC) system, the control of these components is of major importance in determining building energy use. A significant control parameter for the chilled water system is the minimum entering condenser water set point temperature at which the cooling tower fans are cycled on and off, several studies have attempted to determine the optimum value for this minimum set point temperature, but direct measurements are not available to validate these studies. The purpose of this study was to experimentally determine the optimum minimum entering condenser water set point temperature from field data based on minimum energy consumption and to validate a chilled water system analytical model previously developed in earlier work. The total chiller system electrical consumption (chiller and cooling tower fan energy) was measured for four entering condensor water set point temperatures (70, 75, 80, and 85 deg F). The field results were compared to results obtained using an analytical model previously developed in a thesis entitled Optimized Design of a Commercial Building Chiller/Cooling Tower System, written by Joyce.

  20. Innovative Air Conditioning and Climate Control

    NASA Technical Reports Server (NTRS)

    Graf, John

    2015-01-01

    NASA needed to develop a desiccant wheel based humidity removal system to enable the long term testing of the Orion CO2 scrubber on the International Space Station. In the course of developing that system, we learned three things that are relevant to energy efficient air conditioning of office towers. NASA developed a conceptual design for a humidity removal system for an office tower environment. We are looking for interested partners to prototype and field test this concept.

  1. Groundwater treatment with zero air emissions

    SciTech Connect

    Cheuvront, D.A. ); Giggy, C.L.; Loven, C.G. ); Swett, G.H. )

    1990-08-01

    Air emissions from the treatment of volatile organic compound (VOC) - contaminated groundwater are a growing problem in the US. Historically, air stripping has been used to remove VOCs from contaminated groundwater. Air stripping technology is a cross media treatment technique, i.e., it solves a groundwater problem by transferring contamination to the atmosphere. In response to the air pollution problem created by air stripping, the public, air quality regulatory agencies, the federal government and private industry are exerting pressure to eliminate and/or reduce air emissions from the clean-up of contaminated groundwater. These forces make it desirable to consider alternative and innovative technologies for the treatment of groundwater contaminated with VOCs.

  2. Bonded orthotropic strips with cracks

    NASA Technical Reports Server (NTRS)

    Delale, F.; Erdogan, F.

    1979-01-01

    The elastostatic problem for a nonhomogeneous plane which consists of two sets of periodically arranged dissimilar orthotropic strips is considered. It is assumed that the plane contains a series of collinear cracks perpendicular to the interfaces and is loaded in tension away from and perpendicular to the cracks. The problem of cracks fully imbedded into the homogeneous strips is considered. The singular behavior of the stresses for two special crack geometries is studied. The first is the case of a broken laminate in which the crack tips touch the interfaces. The second is the case of cracks crossing the interfaces. An interesting result found from the analysis of the latter is that for certain orthotropic material combinations the stress state at the point of intersection of a crack and an interface may be bounded whereas in isotropic materials at this point stresses are always singular. A number of numerical examples are worked out to separate the primary material parameters influencing the stress intensity factors and the powers of stress singularity, and to determine the trends regarding the influence of the secondary parameters. Some numerical results are given for the stress intensity factors in certain basic crack geometries and for typical material combinations.

  3. The Whipple Strip Sky Survey

    NASA Astrophysics Data System (ADS)

    Kertzman, M. P.

    As part of the normal operation of the Whipple 10m Gamma Ray telescope, ten minute drift scan “zenith” runs are made each night of observation for use as calibration. Most of the events recorded during a zenith run are due to the background of cosmic ray showers. However, it would be possible for a hitherto unknown source of gamma rays to drift through the field. This paper reports the results of a search for serendipitous high energy gamma ray sources in the Whipple 10m nightly calibration zenith data. From 2000-2004 nightly calibration runs were taken at an elevation of 89 º. A 2- D analysis of these drift scan runs produces a strip of width ~ 3.5º in declination and spanning the full range of right ascension. In the 2004-05 observing season the calibration runs were taken at elevations of 86° and 83°. Beginning in the 2005-06 season, the nightly calibration runs were taken at an elevation of 80º. Collectively, these drift scans cover a strip approximately 12.5º wide in declination, centered at declination 37.18º, and spanning the full range of RA. The analysis procedures developed for drift scan data, the sensitivity of the method, and the results will be presented.

  4. Simulating a Measurement of the 2nd Knee in the Cosmic Ray Spectrum with an Atmospheric Fluorescence Telescope Tower Array

    PubMed Central

    Liu, Jiali; Yang, Qunyu; Bai, Yunxiang; Cao, Zhen

    2014-01-01

    A fluorescence telescope tower array has been designed to measure cosmic rays in the energy range of 1017–1018 eV. A full Monte Carlo simulation, including air shower production, light generation and propagation, detector response, electronics, and trigger system, has been developed for that purpose. Using such a simulation tool, the detector configuration, which includes one main tower array and two side-trigger arrays, 24 telescopes in total, has been optimized. The aperture and the event rate have been estimated. Furthermore, the performance of the Xmax⁡ technique in measuring composition has also been studied. PMID:24737964

  5. Simulating a measurement of the 2nd knee in the cosmic ray spectrum with an atmospheric fluorescence telescope tower array.

    PubMed

    Liu, Jiali; Yang, Qunyu; Bai, Yunxiang; Cao, Zhen

    2014-01-01

    A fluorescence telescope tower array has been designed to measure cosmic rays in the energy range of 10(17)-10(18) eV. A full Monte Carlo simulation, including air shower production, light generation and propagation, detector response, electronics, and trigger system, has been developed for that purpose. Using such a simulation tool, the detector configuration, which includes one main tower array and two side-trigger arrays, 24 telescopes in total, has been optimized. The aperture and the event rate have been estimated. Furthermore, the performance of the X max technique in measuring composition has also been studied.

  6. Exterior, looking west Beale Air Force Base, Perimeter Acquisition ...

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

    Exterior, looking west - Beale Air Force Base, Perimeter Acquisition Vehicle Entry Phased-Array Warning System, Guard Tower, End of Spencer Paul Road, north of Warren Shingle Road (14th Street), Marysville, Yuba County, CA

  7. Exterior, detail, showing spiral stair, looking northwest Beale Air ...

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

    Exterior, detail, showing spiral stair, looking northwest - Beale Air Force Base, Perimeter Acquisition Vehicle Entry Phased-Array Warning System, Guard Tower, End of Spencer Paul Road, north of Warren Shingle Road (14th Street), Marysville, Yuba County, CA

  8. Interior, looking west Beale Air Force Base, Perimeter Acquisition ...

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

    Interior, looking west - Beale Air Force Base, Perimeter Acquisition Vehicle Entry Phased-Array Warning System, Guard Tower, End of Spencer Paul Road, north of Warren Shingle Road (14th Street), Marysville, Yuba County, CA

  9. Air Controlman 1 & C: Rate Training Manual.

    ERIC Educational Resources Information Center

    Naval Training Command, Pensacola, FL.

    The manual is designed for use in preparing for advancement within the Navy Air Controlman rating, which designates a professional air traffic controller, unlike the more specialized center or tower controllers. However, minimum qualifications for the rating include completion of the Federal Aviation Administration (FAA) written examination for…

  10. Kaluza-Klein towers on general manifolds

    NASA Astrophysics Data System (ADS)

    Hinterbichler, Kurt; Levin, Janna; Zukowski, Claire

    2014-04-01

    A higher dimensional universe with compactified extra dimensions admits a four-dimensional description consisting of an infinite Kaluza-Klein tower of fields. We revisit the problem of describing the free part of the complete Kaluza-Klein tower of gauge fields, p forms, gravity, and flux compactifications. In contrast to previous studies, we work with a generic internal manifold of any dimension, completely at the level of the action, in a gauge-invariant formulation and without resorting to the equations of motion or analysis of propagators. We demonstrate that the physical fields and Stückelberg fields are naturally described by ingredients of the Hodge decomposition and its analog for symmetric tensors. The spectrum of states and stability conditions, in terms of the eigenvalues of various Laplacians on the internal manifold, is easily read from the action.

  11. Optical study of solar tower power plants

    NASA Astrophysics Data System (ADS)

    Eddhibi, F.; Ben Amara, M.; Balghouthi, M.; Guizani, A.

    2015-04-01

    The central receiver technology for electricity generation consists of concentrating solar radiation coming from the solar tracker field into a central receiver surface located on the top of the tower. The heliostat field is constituted of a big number of reflective mirrors; each heliostat tracks the sun individually and reflects the sunlight to a focal point. Therefore, the heliostat should be positioned with high precision in order to minimize optical losses. In the current work, a mathematical model for the analysis of the optical efficiency of solar tower field power plant is proposed. The impact of the different factors which influence the optical efficiency is analyzed. These parameters are mainly, the shading and blocking losses, the cosine effect, the atmospheric attenuation and the spillage losses. A new method for the calculation of blocking and shadowing efficiency is introduced and validated by open literature.

  12. Dynamic analysis of the Milad Tower

    NASA Astrophysics Data System (ADS)

    Wilhelm, Edwin; Ford, Mitchell; Coelho, Darren; Lawler, Lachlan; Ansourian, Peter; Alonso-Marroquin, Fernando; Tahmasebinia, Faham

    2016-08-01

    This report involves the modelling of the Milad Tower using the finite element analysis program Strand7. A dynamic analysis was performed on the structure in order to understand the deflections and stresses as a result of earthquake and wind loading. In particular, Linear Static as well as Natural Frequency and Spectral Response solvers were used to determine the behaviour of the structure under loading. The findings of the report highlight that the structure was modelled accurately with the outputs representing realistic values. The report suggests that the design of the beams, columns, slabs and all structural members was sufficient enough to support the tower during maximum loading cases. The governing load case was earthquake loading.

  13. In-situ conditioning of a strip casting roll

    DOEpatents

    Williams, Robert S.; Campbell, Steven L.

    1997-01-01

    A strip caster (10) for producing a continuous strip (24) has a tundish (12) for containing a melt (14) and a pair of horizontally disposed water cooled casting rolls (22). The casting rolls are juxtaposed relative to one another for forming a pouring basin (18) for receiving the melt through a teeming tube (16) thereby establishing a meniscus (20) between the rolls for forming a strip (24). The melt is protected from the outside air by a non-oxidizing gas passed through a supply line (28) to a sealing chamber (26). Devices (29) for conditioning the outer peripheral chill surfaces of the casting rolls includes grit blasting nozzles (30A, 30B, 30C, 30D), a collection trough (32) for gathering the grit, a line (34) for recycling the grit to a bag house (36), a feeder (38) and a pressurized distributor (40) for delivering the grit to the nozzles. The conditioning nozzles remove dirt, metal oxides and surface imperfections providing a clean surface readily wetted by the melt.

  14. In-situ conditioning of a strip casting roll

    DOEpatents

    Williams, R.S.; Campbell, S.L.

    1997-07-29

    A strip caster (10) for producing a continuous strip (24) has a tundish (12) for containing a melt (14) and a pair of horizontally disposed water cooled casting rolls (22). The casting rolls are juxtaposed relative to one another for forming a pouring basin (18) for receiving the melt through a teeming tube (16) thereby establishing a meniscus (20) between the rolls for forming a strip (24). The melt is protected from the outside air by a non-oxidizing gas passed through a supply line (28) to a sealing chamber (26). Devices (29) for conditioning the outer peripheral chill surfaces of the casting rolls includes grit blasting nozzles (30A, 30B, 30C, 30D), a collection trough (32) for gathering the grit, a line (34) for recycling the grit to a bag house (36), a feeder (38) and a pressurized distributor (40) for delivering the grit to the nozzles. The conditioning nozzles remove dirt, metal oxides and surface imperfections providing a clean surface readily wetted by the melt.

  15. Side Stream Filtration for Cooling Towers

    SciTech Connect

    2012-10-20

    This technology evaluation assesses side stream filtration options for cooling towers, with an objective to assess key attributes that optimize energy and water savings along with providing information on specific technology and implementation options. This information can be used to assist Federal sites to determine which options may be most appropriate for their applications. This evaluation provides an overview of the characterization of side stream filtration technology, describes typical applications, and details specific types of filtration technology.

  16. Aspects of cooling tower biocides and protozoa

    SciTech Connect

    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 MLC 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.

  17. Water-conserving cooling tower treatment

    SciTech Connect

    Mathie, A.J.

    1996-12-31

    Water conservation in cooling towers and evaporative coolers can finally become a reality. Also, fouled closed hot and chilled water systems can be restored to near original efficiency using the same technology. The barrier limiting the traditional water treatment industry from serious involvement in water conservation is the lack of a really good chemical to control scale. Poor scale inhibitors are the reason for a heavy bleed. Minerals concentrated by evaporation is wasted to the sewer while low solids make-up water fills the tower. Water conservation is important because of the increasing usable water shortage, the cost to add infrastructure to deliver increasing amounts of water to accommodate growth and the limitations imposed on disposal to the sewer. Now, due to innovations in chemical treatment, users of cooling towers and evaporative coolers can conserve water. In this presentation the author assumes the audience has some knowledge of traditional water treatment. Except for a few general references to establish common understanding, the author confines his remarks to discussing an advanced technology developed by DIAS, Inc., and the economics of its use.

  18. Aromatic hydrocarbon emissions in the United States deduced from tall tower measurements

    NASA Astrophysics Data System (ADS)

    Hu, L.; Millet, D. B.; Griffis, T. J.; Tessum, C.; Travis, K.

    2013-12-01

    Aromatic compounds including benzene (C6H6), toluene (C7H8), and xylenes (C8H10) are important anthropogenic precursors of secondary organic aerosol and ground-level ozone. In addition, benzene has been classified as a Group 1 carcinogen by the International Agency for Research on Cancer (IARC). However, their emissions remain poorly constrained. Here we present a full year (2011) of continuous aromatic hydrocarbon measurements by PTR-MS at the University of Minnesota tall tower Tracer Gas Observatory (KCMP tall tower, 244 m a.g.l, 44.689°N, 93.073°W). We interpret the tall tower data with a 0.5° ×0.667° GEOS-Chem nested grid simulation to constrain US sources of benzene, toluene, and xylenes. The tall tower observations reveal a clear high bias in the model, with model: measurement slopes of 1.8, 5.3, and 2.9 for benzene, toluene, and xylenes, respectively. The high bias reflects an overestimate of aromatic hydrocarbon emissions in the model, which are based on the RETRO emission Inventory. In this work, we employ a Bayesian inversion to interpret the KCMP tall tower measurements in terms of quantitative constraints on US aromatic sources and the importance of sectors such as on-road transportation, waste treatment and disposal, solvent use, etc. We discuss our findings relative to other emission estimates (e.g., the EPA NEI) and in terms of their implications for air quality modeling.

  19. Smooth Muscle Strips for Intestinal Tissue Engineering

    PubMed Central

    Walthers, Christopher M.; Lee, Min; Wu, Benjamin M.; Dunn, James C. Y.

    2014-01-01

    Functionally contracting smooth muscle is an essential part of the engineered intestine that has not been replicated in vitro. The purpose of this study is to produce contracting smooth muscle in culture by maintaining the native smooth muscle organization. We employed intact smooth muscle strips and compared them to dissociated smooth muscle cells in culture for 14 days. Cells isolated by enzymatic digestion quickly lost maturity markers for smooth muscle cells and contained few enteric neural and glial cells. Cultured smooth muscle strips exhibited periodic contraction and maintained neural and glial markers. Smooth muscle strips cultured for 14 days also exhibited regular fluctuation of intracellular calcium, whereas cultured smooth muscle cells did not. After implantation in omentum for 14 days on polycaprolactone scaffolds, smooth muscle strip constructs expressed high levels of smooth muscle maturity markers as well as enteric neural and glial cells. Intact smooth muscle strips may be a useful component for engineered intestinal smooth muscle. PMID:25486279

  20. Ultrasonic examination of JBK-75 strip material

    SciTech Connect

    Cook, K.V.; Cunningham, R.A. Jr.; Lewis, J.C.; McClung, R.W.

    1982-12-01

    An ultrasonic inspection system was assembled to inspect the JBK-75 stainless steel sheath material (for the Large Coil Project) for the Westinghouse-Airco superconducting magnet program. The mechanical system provided for handling the 180-kg (400-lb) coils of strip material (1.6 mm thick by 78 mm wide by 90 to 120 m long (0.064 by 3.07 in. by 300 to 400 ft)), feeding the strip through the ultrasonic inspection and cleaning stations, and respooling the coils. We inspected 54 coils of strip for both longitudinal and laminar flaws. Simulated flaws were used to calibrate both inspections. Saw-cut notches (0.28 mm deep (0.011 in., about 17% of the strip thickness)) were used to calibrate the longitudinal flaw inspections; 1.59-mm-diam (0.063-in.) flat-bottom holes drilled halfway through a calibration strip were used to calibrate the laminar flaw tests.

  1. Reuse of pretreated coal gasification condensate in a pilot scale cooling tower

    SciTech Connect

    Johnson, M.D.; Schweitzer, G.W.

    1987-01-01

    The recycle of wastewaters to cooling water systems is practiced in many industrial sectors. The Great Plains Gasification Plant (GPGP) located near Beulah, North Dakota, for example, was designed to reuse treated gas liquor as the primary source of makeup water. In other industrial plants, the concentration of contaminants in the makeup water is very low or the wastewater comprises only a small fraction of the total makeup to the cooling system. The Great Plains system is unique in that the stripped gas liquor (SGL) used as makeup contains relatively high concentrations of dissolved organics, ammonia and acid gases. In addition, the SGL constitutes over 90% of the total makeup to the system. The use of pretreated gas liquor in open, circulating cooling systems is an untried approach to wastewater recycle. The plant not only eliminates a large discharge problem but gains a valuable makeup source for the cooling towers. Because of the large heat duties for the cooling system in these types of plants and their location of regions of water shortages, this approach can be very beneficial. However, there are several environmental and operational concerns that have yet to be resolved. These include atmospheric emissions, fouling of heat transfer surfaces and cooling tower equipment, and excessive corrosion of system components.

  2. Conceptual Design Gamma-Ray Large Area Space Telescope (GLAST) Tower Structure

    SciTech Connect

    Jennings, Chad

    2002-07-18

    The main objective of this work was to develop a conceptual design and engineering prototype for the Gamma-ray Large Area Space Telescope (GLAST) tower structure. This thesis describes the conceptual design of a GLAST tower and the fabrication and testing of a prototype tower tray. The requirements were that the structure had to support GLAST's delicate silicon strip detector array through ground handling, launch and in orbit operations as well as provide for thermal and electrical pathways. From the desired function and the given launch vehicle for the spacecraft that carries the GLAST detector, an efficient structure was designed which met the requirements. This thesis developed in three stages: design, fabrication, and testing. During the first stage, a general set of specifications was used to develop the initial design, which was then analyzed and shown to meet or exceed the requirements. The second stage called for the fabrication of prototypes to prove manufacturability and gauge cost and time estimates for the total project. The last step called for testing the prototypes to show that they performed as the analysis had shown and prove that the design met the requirements. As a spacecraft engineering exercise, this project required formulating a solution based on engineering judgment, analyzing the solution using advanced engineering techniques, then proving the validity of the design and analysis by the manufacturing and testing of prototypes. The design described here met all the requirements set out by the needs of the experiment and operating concerns. This strawman design is not intended to be the complete or final design for the GLAST instrument structure, but instead examines some of the main challenges involved and demonstrates that there are solutions to them. The purpose of these tests was to prove that there are solutions to the basic mechanical, electrical and thermal problems presented with the GLAST project.

  3. Credit BG. View looking northeast down from the tower onto ...

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

    Credit BG. View looking northeast down from the tower onto the two horizontal test stations at Test Stand "D." Station Dy is at the far left (Dy vacuum cell out of view), with in-line exhaust gas cooling sections and steam-driven "air ejector" (or evacuator) discharging engine exhausts to the east. The Dd cell is visible at the lower left, and the Dd exhaust train has the same functions as at Dy. The spherical tank is an electrically heated "accumulator" which supplies steam to the ejectors at Dv, Dd, and Dy stations. Other large piping delivered cooling water to the horizontal train cooling sections. The horizontal duct at the "Y" branch in the Dd train connects the Dd ejector to the Dv and Cv vacuum duct system (a blank can be bolted into this duct to isolate the Dd system). The shed roof for the Dpond test station appears at bottom center of this image. The open steel frame to the lower left of the image supports a hoist and crane for installing or removing test engines from the Dd test cell - Jet Propulsion Laboratory Edwards Facility, Test Stand D, Edwards Air Force Base, Boron, Kern County, CA

  4. Another solid rocket booster is lifted at the tower at LP17A, CCAS

    NASA Technical Reports Server (NTRS)

    1999-01-01

    A Boeing Delta II rocket sits on Launch Pad 17A (left), Cape Canaveral Air Station, before mating with its final Solid Rocket Booster, in the tower at right. In the background is Pad 17B with its two launch tower components. The Delta II rocket will carry the Stardust satellite into space for a close encounter with the comet Wild 2 in January 2004. Using a medium called aerogel, Stardust will capture comet particles flying off the nucleus of the comet, plus collect interstellar dust for later analysis. The collected samples will return to Earth in a Sample Return Capsule to be jettisoned as Stardust swings by Earth in January 2006. Stardust is scheduled to be launched on Feb. 6, 1999.

  5. Transfusion and blood donation in comic strips.

    PubMed

    Lefrère, Jean-Jacques; Danic, Bruno

    2013-07-01

    The representation of blood transfusion and donation of blood in the comic strip has never been studied. The comic strip, which is a relatively recent art, emerged in the 19th century before becoming a mass medium during the 20th century. We have sought, by calling on collectors and using the resources of Internet, comic strips devoted, wholly or in part, to the themes of transfusion and blood donation. We present some of them here in chronologic order, indicating the title, country of origin, year of publication, and names of authors. The theme of the superhero using transfusion to transmit his virtues or his powers is repeated throughout the 20th century in North American comic strips. More recently, comic strips have been conceived from the outset with a promotional aim. They perpetuate positive images and are directed toward a young readership, wielding humor to reduce the fear of venipuncture. Few comic strips denounce the abuse of the commercialization of products derived from the human body. The image of transfusion and blood donation given by the comic strips is not to be underestimated because their readership is primarily children, some of whom will become blood donors. Furthermore, if some readers are transfused during their lives, the impact of a memory more or less conscious of these childhood readings may resurface, both in hopes and in fears.

  6. A Strip Cell in Pyroelectric Devices.

    PubMed

    Siao, An-Shen; Chao, Ching-Kong; Hsiao, Chun-Ching

    2016-01-01

    The pyroelectric effect affords the opportunity to convert temporal temperature fluctuations into usable electrical energy in order to develop abundantly available waste heat. A strip pyroelectric cell, used to enhance temperature variation rates by lateral temperature gradients and to reduce cell capacitance to further promote the induced voltage, is described as a means of improving pyroelectric energy transformation. A precision dicing saw was successfully applied in fabricating the pyroelectric cell with a strip form. The strip pyroelectric cell with a high-narrow cross section is able to greatly absorb thermal energy via the side walls of the strips, thereby inducing lateral temperature gradients and increasing temperature variation rates in a thicker pyroelectric cell. Both simulation and experimentation show that the strip pyroelectric cell improves the electrical outputs of pyroelectric cells and enhances the efficiency of pyroelectric harvesters. The strip-type pyroelectric cell has a larger temperature variation when compared to the trenched electrode and the original type, by about 1.9 and 2.4 times, respectively. The measured electrical output of the strip type demonstrates a conspicuous increase in stored energy as compared to the trenched electrode and the original type, by of about 15.6 and 19.8 times, respectively. PMID:26999134

  7. A Strip Cell in Pyroelectric Devices

    PubMed Central

    Siao, An-Shen; Chao, Ching-Kong; Hsiao, Chun-Ching

    2016-01-01

    The pyroelectric effect affords the opportunity to convert temporal temperature fluctuations into usable electrical energy in order to develop abundantly available waste heat. A strip pyroelectric cell, used to enhance temperature variation rates by lateral temperature gradients and to reduce cell capacitance to further promote the induced voltage, is described as a means of improving pyroelectric energy transformation. A precision dicing saw was successfully applied in fabricating the pyroelectric cell with a strip form. The strip pyroelectric cell with a high-narrow cross section is able to greatly absorb thermal energy via the side walls of the strips, thereby inducing lateral temperature gradients and increasing temperature variation rates in a thicker pyroelectric cell. Both simulation and experimentation show that the strip pyroelectric cell improves the electrical outputs of pyroelectric cells and enhances the efficiency of pyroelectric harvesters. The strip-type pyroelectric cell has a larger temperature variation when compared to the trenched electrode and the original type, by about 1.9 and 2.4 times, respectively. The measured electrical output of the strip type demonstrates a conspicuous increase in stored energy as compared to the trenched electrode and the original type, by of about 15.6 and 19.8 times, respectively. PMID:26999134

  8. 10. Photocopy of photograph of tower as constructed at Cape ...

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

    10. Photocopy of photograph of tower as constructed at Cape Henlopen, Delaware, September 1926 (original photograph in National Archives and Records Service, Still Pictures Branch, RG 26, 26-LG-22-A), photographer G.W. Hitchens, September 10, 1926. "New Tower. Camera Station West 100 ft." - Mispillion Lighthouse, Beacon Tower, South bank of Mispillion River at it confluence with Delaware River at northeast end of County Road 203, 7 miles east of Milford, Milford, Sussex County, DE

  9. Technical Evaluation of Side Stream Filtration for Cooling Towers

    SciTech Connect

    2012-10-01

    Cooling towers are an integral component of many refrigeration systems, providing comfort or process cooling across a broad range of applications. Cooling towers represent the point in a cooling system where heat is dissipated to the atmosphere through evaporation. Cooling towers are commonly used in industrial applications and in large commercial buildings to release waste heat extracted from a process or building system through evaporation of water.

  10. 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

  11. Retractable spiked barrier strip for law enforcement

    SciTech Connect

    Marts, D.J.; Barker, S.G.

    1995-03-01

    The Idaho National Engineering Laboratory has designed an laboratory tested a prototype retractable spiked barrier strip for law enforcement. The proposed system, which is ready for controlled field testing, expands the functionality of existing spiked barrier strips. A retractable barrier strip, one that can place the spikes in either the active (vertical) or passive (horizontal) position, would allow law enforcement personnel to lay the unobtrusive strip across a road far in advance of a fleeing vehicle. No damage occurs to passing vehicles until the spikes are activated, and that can be done from a safe distance and at a strategic location when the offending vehicle is close to the strip. The concept also allows the strips to be place safely across several roadways that are potential paths of a fleeing vehicle. Since they are not activated until needed, they are harmless to nonoffending vehicles. The laboratory tests conducted on the system indicate that it will puncture tires only when the spikes are rotated to the active position and is safe to travel over when the spikes are in the down position. The strip itself will not cause instability to a vehicle driving over it, nor is the strip disturbed or adversely affected by vehicles driving over it. The spikes can be quickly rotated between the active (vertical) and passive (horizontal) position. However, the laboratory tests have only demonstrated that the retractable spiked barrier strip can perform its intended function in a laboratory environment. Field tests are needed to finalize the design and develop the system into a functional law enforcement tool.

  12. Stripping volatile organic compounds and petroleum hydrocarbons from water by tray aeration

    SciTech Connect

    Labranche, D.F.; Collins, M.R.

    1997-03-01

    Volatile organic compounds (VOCS) and petroleum products are ubiquitous groundwater contaminants. Petroleum products, e.g., diesel fuel, contain a wide array of volatile, semivolatile, and long chain hydrocarbon compounds. This research sought to determine whether air stripping can provide a site specific treatment solution for petroleum contaminated groundwaters and to document the abilities and limitations of tray type (Shallow Tray) air stripping technology. Full factorial experimental trials were conducted to determine the influence of inlet water flow rate and temperature on trichloroethylene (TCE), perchloroethylene (PCE) and total petroleum hydrocarbon (TPH) removal. As expected, TPH removal controlled air stripper performance, and liquid temperature affected removal more than flow rate. The mass transfer rate of TCE and PCE from water to air was controlled by the compound`s volatility, while the TPH mass transfer rate was controlled by the compound`s concentration gradient. Results indicate that economical air stripping of VOC and TPH compounds can be achieved using low liquid flow rates (20-75 L/min) and medium liquid temperatures (16-28 deg C) in tray type air strippers.

  13. 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.

  14. Interior detail of tower space; camera facing southwest. Mare ...

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

    Interior detail of tower space; camera facing southwest. - Mare Island Naval Shipyard, Defense Electronics Equipment Operating Center, I Street, terminus west of Cedar Avenue, Vallejo, Solano County, CA

  15. 93. TOWER STAIRHALL, SOUTH WALL, WEST TABERNACLE FRAME. DETAIL OF ...

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

    93. TOWER STAIRHALL, SOUTH WALL, WEST TABERNACLE FRAME. DETAIL OF DOG EAR AND TRUSS (BRACKET) - Independence Hall Complex, Independence Hall, 500 Chestnut Street, Philadelphia, Philadelphia County, PA

  16. 8. STATIC TEST TOWER NORTHWEST ELEVATION FROM THE POWER ...

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

    8. STATIC TEST TOWER - NORTHWEST ELEVATION FROM THE POWER PLANT TEST STAND. - Marshall Space Flight Center, Saturn Propulsion & Structural Test Facility, East Test Area, Huntsville, Madison County, AL

  17. The Damaging Effects of Earthquake Excitation on Concrete Cooling Towers

    SciTech Connect

    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 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.

  18. Detail of towers at southwest corner; camera facing northeast. ...

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

    Detail of towers at southwest corner; camera facing northeast. - Mare Island Naval Shipyard, Hospital Wards, Cedar Avenue, eat side between Fourteenth Avenue & Cossey Street, Vallejo, Solano County, CA

  19. View of commissary, central guard tower, and cell block five, ...

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

    View of commissary, central guard tower, and cell block five, looking from the chapel stairs, facing southeast - Eastern State Penitentiary, 2125 Fairmount Avenue, Philadelphia, Philadelphia County, PA

  20. 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.