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Sample records for air flotation unit

  1. CFD simulation and optimization of the capillary throttling of air-flotation unit

    NASA Astrophysics Data System (ADS)

    Bin, Huang; Yi, Jiajing; Tao, Jiayue; Lu, Rongsheng

    2016-01-01

    With respect to orifice throttling or compensating, capillary throttling has following advantages: smaller mass flow rate and stronger anti-interference ability. This paper firstly gives the required average pressure of air-film when shipping a piece of LCD glass. Then, dimensional flow model of the capillary throttling of air-flotation unit is established. Based on the model, we firstly analyze the flowing process of the lubricated air through the capillary. Secondly, the pressure distribution equation of air-film is derived from the Navier-Stokes Equation. Furthermore, the approximate functional relations between model parameters and static characteristics of the air-film, such as mass flow rate, static bearing capacity, are obtained and then influence of the former on the latter is analyzed . Finally, according to the continuity of air flow, the function relation between model parameters and pressure of core nodes in the air-film is also derived. On foundation of theoretical analysis, the impacts of each model parameter on static characteristics of the air-film flow field, are respectively simulated and analyzed by CFD software Fluent. Based on these simulations and analysis, radius and length of the capillary, density of the gas supply orifices and other model parameters are optimized. Finally, the best unit model is acquired, which greatly improves the static working performance of air-film in air-flotation unit. Research results of this paper can provide guidance and basis for the design and optimization of air-flotation transporting system.

  2. Dissolved air-flotation processes. Technical report

    SciTech Connect

    Krofta, M.; Wang, L.K.

    1986-11-05

    The theories and applications of various dissolved-air-flotation clarifiers (Supracell, Sandfloat, Floatpress, and Sedifloat) are presented. Supracell is a high-rate dissolved-air-flotation clarifier with only 3 to 5 minutes of detention time. Major application of Supracell is industrial-effluent treatment. Sandfloat is a package plant consisting of flocculation, dissolved-air floatation and automatic backwash filtration, and designed for either potable water treatment or tertiary wastewater-treatment. Sedifloat is a wastewater-treatment package plant consisting of both sedimentation and dissolved-air flotation. Floatpress consists of both dissolved air flotation and filter press and is specifically designed for sludge thickening. A Krofta Bargefloat is a floating lake-water clarification plant designed for acid-rain neutralization, phosphorus removal, algae removal and lake-water purification. Bargefloat has built-in chemical feeders, flocculator, dissolved-air-flotation clarifier and sand filter on a barge.

  3. Bubble performance of a novel dissolved air flotation(DAF) unit.

    PubMed

    Chen, Fu-tai; Peng, Feng-xian; Wu, Xiao-qing; Luan, Zhao-kun

    2004-01-01

    ES-DAF, a novel DAF with low cost, high reliability and easy controllability, was studied. Without a costly air saturator, ES-DAF consists of an ejector and a static mixer between the pressure side and suction side of the recycle rotary pump. The bubble size distribution in this novel unit was studied in detail by using a newly developed CCD imagination through a microscope. Compared with M-DAF under the same saturation pressure, ES-DAF can produce smaller bubble size and higher bubble volume concentration, especially in lower pressure. In addition, the bubble size decreases with the increase of reflux ratio or decrease of superficial air-water ratio. These results suggested that smaller bubbles will be formed when the initial number of nucleation sites increases by enhancing the turbulence intensity in the saturation system.

  4. Dissolved air flotation and me.

    PubMed

    Edzwald, James K

    2010-04-01

    This paper is mainly a critical review of the literature and an assessment of what we know about dissolved air flotation (DAF). A few remarks are made at the outset about the author's personal journey in DAF research, his start and its progression. DAF has been used for several decades in drinking water treatment as an alternative clarification method to sedimentation. DAF is particularly effective in treating reservoir water supplies; those supplies containing algae, natural color or natural organic matter; and those with low mineral turbidity. It is more efficient than sedimentation in removing turbidity and particles for these type supplies. Furthermore, it is more efficient in removing Giardia cysts and Cryptosporidium oocysts. In the last 20 years, fundamental models were developed that provide a basis for understanding the process, optimizing it, and integrating it into water treatment plants. The theories were tested through laboratory and pilot-plant studies. Consequently, there have been trends in which DAF pretreatment has been optimized resulting in better coagulation and a decrease in the size of flocculation tanks. In addition, the hydraulic loading rates have increased reducing the size of DAF processes. While DAF has been used mainly in conventional type water plants, there is now interest in the technology as a pretreatment step in ultrafiltration membrane plants and in desalination reverse osmosis plants.

  5. 21 CFR 880.5550 - Alternating pressure air flotation mattress.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Alternating pressure air flotation mattress. 880... Personal Use Therapeutic Devices § 880.5550 Alternating pressure air flotation mattress. (a) Identification. An alternating pressure air flotation mattress is a device intended for medical purposes...

  6. 21 CFR 880.5550 - Alternating pressure air flotation mattress.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Alternating pressure air flotation mattress. 880... Personal Use Therapeutic Devices § 880.5550 Alternating pressure air flotation mattress. (a) Identification. An alternating pressure air flotation mattress is a device intended for medical purposes...

  7. 21 CFR 880.5550 - Alternating pressure air flotation mattress.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Alternating pressure air flotation mattress. 880... Personal Use Therapeutic Devices § 880.5550 Alternating pressure air flotation mattress. (a) Identification. An alternating pressure air flotation mattress is a device intended for medical purposes...

  8. 21 CFR 880.5550 - Alternating pressure air flotation mattress.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Alternating pressure air flotation mattress. 880... Personal Use Therapeutic Devices § 880.5550 Alternating pressure air flotation mattress. (a) Identification. An alternating pressure air flotation mattress is a device intended for medical purposes...

  9. 21 CFR 880.5550 - Alternating pressure air flotation mattress.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Alternating pressure air flotation mattress. 880... Personal Use Therapeutic Devices § 880.5550 Alternating pressure air flotation mattress. (a) Identification. An alternating pressure air flotation mattress is a device intended for medical purposes...

  10. 33 CFR 183.112 - Flotation material and air chambers.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... SECURITY (CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Flotation Requirements for Inboard Boats, Inboard/Outdrive Boats, and Airboats § 183.112 Flotation material and air chambers. (a)...

  11. 33 CFR 183.112 - Flotation material and air chambers.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... SECURITY (CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Flotation Requirements for Inboard Boats, Inboard/Outdrive Boats, and Airboats § 183.112 Flotation material and air chambers. (a)...

  12. 33 CFR 183.112 - Flotation material and air chambers.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... SECURITY (CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Flotation Requirements for Inboard Boats, Inboard/Outdrive Boats, and Airboats § 183.112 Flotation material and air chambers. (a)...

  13. 33 CFR 183.112 - Flotation material and air chambers.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... SECURITY (CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Flotation Requirements for Inboard Boats, Inboard/Outdrive Boats, and Airboats § 183.112 Flotation material and air chambers. (a)...

  14. Improved algal harvesting using suspended air flotation.

    PubMed

    Wiley, Patrick E; Brenneman, Kristine J; Jacobson, Arne E

    2009-07-01

    Current methods to remove algae from a liquid medium are energy intensive and expensive. This study characterized algae contained within a wastewater oxidation pond and sought to identify a more efficient harvesting technique. Analysis of oxidation pond wastewater revealed that algae, consisting primarily of Chlorella and Scenedesmus, composed approximately 80% of the solids inventory during the study period. Results demonstrated that suspended air flotation (SAF) could harvest algae with a lower air:solids (A/S) ratio, lower energy requirements, and higher loading rates compared to dissolved air flotation (DAF) (P < 0.001). Identification of a more efficient algal harvesting system may benefit wastewater treatment plants by enabling cost effective means to reduce solids content of the final effluent. Furthermore, use of SAF to harvest commercially grown Chlorella and Scenedesmus may reduce manufacturing costs of algal-based products such as fuel, fertilizer, and fish food.

  15. Characterization of multiphase fluid flow during air-sparged hydrocyclone flotation by x-ray CT. Final report, 14 August 1990--13 August 1994

    SciTech Connect

    Miller, J.D.

    1994-10-18

    Air sparged hydrocyclone (ASH) flotation is a new particle separation technology that has been developed at the University of Utah. This technology combines froth flotation principles with the flow characteristics of a hydrocyclone such that the ASH system can perform flotation separations in less than a second. This feature provides the ASH with a high specific capacity, 100 to 600 times greater than the specific capacity of conventional flotation machines. In an effort to develop a more detailed understanding of ASH flotation, multiphase flow characteristics of the air sparged hydrocyclone were studied and the relationship of these characteristics with flotation performance was investigated. This investigation was divided into four phases. In the first phase, the time-averaged multiphase flow characteristics of the ASH during its steady state operation were studied using x-ray computed tomography (x-ray CT). In this regard, a model system, mono-sized quartz flotation with dodecyl amine as collector, using a 2 in. diameter ASH unit (ASH-2C), was selected for study. Various flow regimes, namely, the air core, the froth phase, and the swirl layer, were identified and their spatial extent established for different experimental conditions by x-ray CT analysis. In the second phase, a detailed parametric study of flotation response of the ASH for the same system was carried out in order to establish the effect of various operating variables on flotation response. The findings of this phase of investigation were then correlated with the multiphase flow characteristics as revealed by x-ray CT in the first phase. Thus, the impact of various operating variables on the flow regimes, and hence, on flotation response was established.

  16. Comparative study of flotation techniques for the treatment of liquid effluents.

    PubMed

    Puget, F P; Melo, M V; Massarani, G

    2004-01-01

    This work aimed to study the performance of three different induced air flotation units (flotation column, flotation tank and centrifugal flotation in hydrocyclone) for the treatment of a synthetic dairy effluent. Under continuous operation, it was possible to achieve removal efficiencies of milky material in suspension up to 90%, both for the flotation column and the flotation tank units. Using the centrifugal flotation unit in hydrocyclone, it was possible to decrease up to 45% of all suspended material in the effluent, with a clarified flow rate approximately three times greater than those found for the previous flotation units. In the centrifugal flotation unit, better results were obtained for air flow rate-feed flow rate ratios (Q(air)/Q(L)) greater than 0.15, and for underflow-overflow ratios (Qu/Qo) lower than 1.0.

  17. REACH. Air Conditioning Units.

    ERIC Educational Resources Information Center

    Garrison, Joe; And Others

    As a part of the REACH (Refrigeration, Electro-Mechanical, Air-Conditioning, Heating) electromechanical cluster, this student manual contains individualized instructional units in the area of air conditioning. The instructional units focus on air conditioning fundamentals, window air conditioning, system and installation, troubleshooting and…

  18. Use of coagulants in treatment of olive oil wastewater model solutions by induced air flotation.

    PubMed

    Meyssami, B; Kasaeian, A B

    2005-02-01

    Natural polyelectrolytes are suitable coagulants for the treatment of industrial and minicipal wastewaters because they are safe and have environmental benefits. Chitosan, a natural cationic polyelectrolyte, and other similar coagulants were used in the treatment of an olive oil water suspension as a model for the processing wastewater. The effect of chitosan, starch, alum and ferric chloride on the coagulation of oil droplets were determined by the jar test apparatus and turbidometric measurements. Olive oil emulsion samples were prepared by the use of surface active agents and other agents that could form stable oil water emulsions. The effect of parameters such as pH, ionic strength and optimum dosage of the coagulants were determined in the jar test experiments. Following the jar experiments, with the optimum concentration of the suitable coagulant, the emulsions were placed in an induced air flotation (IAF) cell to separate the coagulated oil droplets from solution. In the air flotation experiments, the effect of temperature, surfactant concentration and air flowrate were determined on the decrease of turbidity and COD of the emulsion samples. In the jar experiments, chitosan and alum used together at concentrations of 15 and 25 ppm, respectively, at pH 6 produced the lowest turbidity values. In the air flotation experiments, a concentration of 100 ppm of chitosan, an air flowrate of 3 l/min, aeration time of 45 s, temperature of 20 degrees C and pH 6 produced optimum levels. At optimum conditions of coagulation and flotation stages, the COD of the olive oil emulsion could be reduced by 95%.

  19. Effects of ozone and peroxone on algal separation via dispersed air flotation.

    PubMed

    Nguyen, Truc Linh; Lee, D J; Chang, J S; Liu, J C

    2013-05-01

    Effects of pre-oxidation on algal separation by dispersed air flotation were examined. Ozone (O3) and peroxone (O3 and H2O2) could induce cell lysis, release of intracellular organic matter (IOM), and mineralization of organic substances. Separation efficiency of algal cells improved when pre-oxidized. Total of 76.4% algal cells was separated at 40 mg/L of N-cetyl-N-N-N-trimethylammonium bromide (CTAB), while 95% were separated after 30-min ozonation. Pre-oxidation by ozone and peroxone also enhanced flotation separation efficiency of dissolved organic carbon (DOC), polysaccharide, and protein, in which peroxone process exerted more significantly than O3. Two main mechanisms were involved in flotation separation of unoxidized algal suspension, namely hydrophobic cell surface and cell flocculation resulting from CTAB adsorption. However, flocculation by CTAB was hindered for pre-oxidized algal suspensions. It implied that the compositional changes in extracellular organic matter (EOM) by pre-oxidation were more determined for flotation separation of pre-oxidized cells.

  20. Treatment of a dilute waste oil emulsion by chemical addition (CA)-dissolved air flotation (DAF)

    SciTech Connect

    Reed, B.E.; Carriere, P.; Zhu, X.; Lorkowski, T.

    1995-12-31

    Treatment of wastewater from aluminum rolling mill operations is an inherent problem in the aluminum fabrication industry. In this study, wastewater from the manufacturer`s processes was transferred to two holding ponds having a total capacity of about 5 million gallons and a detention time of about 10 days. In the holding ponds, free oil was allowed to rise to the surface where it was periodically removed. Wastewater from the holding ponds was withdrawn from about a depth of 9 ft. and used as influent to a variety of technologies. In this paper, results from the chemical addition (CA)-dissolved air flotation (DAF) portion of the treatability study are presented.

  1. Additive-free harvesting of oleaginous phagotrophic microalga by oil and air flotation.

    PubMed

    Hosseini, Majid; Starvaggi, Haley A; Ju, Lu-Kwang

    2016-07-01

    A unique oleaginous phagotrophic microalga Ochromonas danica is poised for effective lipid production from waste. Cell harvesting and dewatering are major costs in making algae-based products. In this work an effective additive-free harvesting method was developed, taking advantage of O. danica's comparatively more hydrophobic surface and larger size. The algal cells' partitioning to oil/water interface was evaluated. Recovery by flotation with waste cooking oil was optimized using an L-9 Taguchi orthogonal-array design. Further, additive-free cell collection and concentrating by air flotation was studied for the effects of both physical factors (column dimension, air-stone pore size, sample-to-column volume ratio) and culture properties (pH, culture growth stage, cell concentration, and pure versus impure cultures). The optimized process consistently achieved >90 % recovery in a single stage. 98+ % recovery could be achieved when starting concentrations were >10(8) cells/ml, or potentially using a two- or multi-stage process for diluter cultures. PMID:27025209

  2. Effects of dissolved air flotation hydraulic loading rate on water treatment performance

    SciTech Connect

    Tobiason, J.E.; Edzwald, J.K.; Amato, T.; Maggi, L.J.

    1999-07-01

    The performance of dissolved air flotation (DAF) followed by granular media filtration for water treatment was evaluated via pilot-scale studies for two water sources. The study focused on short flocculation times (5--8 minutes), high DAF hydraulic loading rates (17--44 m/hr (7--18 gpm/ft{sup 2})) and rapid rate filtration (10--20 m/hr (4--8 gpm/ft{sup 2})). Excellent treatment performance was achieved in terms of DAF clarified water turbidity, filtered water turbidity, organic matter removal and filtered water production. Bubble carryover from the DAF tank was mitigated by employing either internal or external air removal strategies. Overall, the results demonstrate the effectiveness of an integrated, high rate flocculation/DAF/filtration water treatment strategy.

  3. Hydrocarbon-oil encapsulated air bubble flotation of fine coal. Technical progress report for the third quarter, April 1, 1991--June 30, 1991

    SciTech Connect

    Peng, F.F.

    1995-01-01

    This report is concerned with the progress made during the third period of the two year project. A significant portion of this reporting period has been consumed in measurement of induction time of oil-free and oil-coated bubbles, modification of collector gasifier, hydrocarbon oil encapsulated flotation tests and float and sink analyses of various rank of coal samples, building a 1-inch column cell, as well as building the ultrasound collector emulsification apparatus. Induction time has been measured using an Electronic Induction Timer. The results indicate that alteration of chemical properties of air bubble by applying hydrocarbon oil or reagent can drastically improve the rate of flotation process. Various techniques have been employed in hydrocarbon oil encapsulated flotation processes to further enhance the selectivity of the process, which include: (1) gasified collector flotation with addition of gasified collector into the air stream in the initial stage; (2) two-stage (rougher-cleaner) gasified collector flotation; and (3) starvation gasified collector flotation by addition of gasified collector at various flotation times. Among these, three techniques used in hydrocarbon oil encapsulated flotation process, the starvation flotation technique provides the best selectivity.

  4. Influence of growth phase on harvesting of Chlorella zofingiensis by dissolved air flotation.

    PubMed

    Zhang, Xuezhi; Amendola, Pasquale; Hewson, John C; Sommerfeld, Milton; Hu, Qiang

    2012-07-01

    The effects of changes in cellular characteristics and dissolved organic matter (DOM) on dissolved air flotation (DAF) harvesting of Chlorella zofingiensis at the different growth phases were studied. Harvesting efficiency increased with Al(3+) dosage and reached more than 90%, regardless of growth phases. In the absence of DOM, the ratio of Al(3+) dosage to surface functional group concentration determined the harvesting efficiency. DOM in the culture medium competed with algal cell surface functional groups for Al(3+), and more Al(3+) was required for cultures with DOM than for DOM-free cultures to achieve the same harvesting efficiency. As the culture aged, the increase of Al(3+) dosage due to increased DOM was less than the decrease of Al(3+) dosage associated with reduced cell surface functional groups, resulting in overall reduced demand for Al(3+). The interdependency of Al(3+) dosage and harvesting efficiency on concentrations of cell surface functional groups and DOM was successfully modeled. PMID:22541950

  5. Seasonal influence of waste stabilisation pond effluent on DAF/F (dissolved air flotation/filtration) process operation.

    PubMed

    Buisine, F; Oemcke, D

    2003-01-01

    The Bolivar wastewater treatment plant (WWTP), North of Adelaide, South Australia encompasses the largest waste stabilisation pond (WSP) system in the Southern hemisphere. The wastewater effluent will ultimately be fully reused for agriculture irrigation. A dissolved air flotation/filtration (DAF/F) plant was installed for tertiary treatment downstream of the stabilisation lagoons for supply to the irrigation scheme. Chemical treatment in the form of coagulation and flocculation is required to assist the separation process. The DAF/F plant operation is highly dependent on the raw water algal population. Seasonal variations seem to be the main abiotic factors affecting the algal population growth. Significant doses of chemical can be required to respond to rapid changes of water quality. United Water International is currently assessing the appropriate chemical treatment for short-term response, and is also working with Flinders University of South Australia on determining ways to manage the lagoons and to control the water quality feeding the DAF/F plant in the long-term. This paper outlines the effect of seasonal variations of WSP effluent quality on the DAF/F process operation, the findings for an adapted chemical treatment, and the eventual possibilities for lagoon management.

  6. Critical evaluation and modeling of algal harvesting using dissolved air flotation. DAF Algal Harvesting Modeling

    SciTech Connect

    Zhang, Xuezhi; Hewson, John C.; Amendola, Pasquale; Reynoso, Monica; Sommerfeld, Milton; Chen, Yongsheng; Hu, Qiang

    2014-07-14

    In our study, Chlorella zofingiensis harvesting by dissolved air flotation (DAF) was critically evaluated with regard to algal concentration, culture conditions, type and dosage of coagulants, and recycle ratio. Harvesting efficiency increased with coagulant dosage and leveled off at 81%, 86%, 91%, and 87% when chitosan, Al3+, Fe3+, and cetyl trimethylammonium bromide (CTAB) were used at dosages of 70, 180, 250, and 500 mg g-1, respectively. The DAF efficiency-coagulant dosage relationship changed with algal culture conditions. In evaluating the influence of the initial algal concentration and recycle ratio revealed that, under conditions typical for algal harvesting, we found that it is possible that the number of bubbles is insufficient. A DAF algal harvesting model was developed to explain this observation by introducing mass-based floc size distributions and a bubble limitation into the white water blanket model. Moreover, the model revealed the importance of coagulation to increase floc-bubble collision and attachment, and the preferential interaction of bubbles with larger flocs, which limited the availability of bubbles to the smaller sized flocs. The harvesting efficiencies predicted by the model agree reasonably with experimental data obtained at different Al3+ dosages, algal concentrations, and recycle ratios. Based on this modeling, critical parameters for efficient algal harvesting were identified.

  7. A case study of dissolved air flotation for seasonal high turbidity water in Korea.

    PubMed

    Kwon, S B; Ahn, H W; Ahn, C J; Wang, C K

    2004-01-01

    A DAF (Dissolved-Air-Flotation) process has been designed considering raw water quality characteristics in Korea. Although direct filtration is usually operated, DAF is operated when freshwater algae blooms occur or raw water turbidity becomes high. Pre-sedimentation is operated in case when the raw water turbidity is very high due to rainstorms. A main feature of this plant is that the operation mode can be changed (controlled) based on the characteristics of the raw water to optimize the effluent quality and the operation costs. Treatment capacity (surface loading rate) and efficiency of DAF was found to be better than the conventional sedimentation process. Moreover, low-density particles (algae and alum flocs) are easily separated while the removal of them by sedimentation is more difficult. One of the main concerns for DAF operation is a high raw water turbidity. DAF is not adequate for raw water, which is more turbid than 100 NTU. In order to avoid this problem, pre-sedimentation basins are installed in the DAF plant to decrease the turbidity of the DAF inflow. For simulation of the actual operation, bench and full-scale tests were performed for highly turbid water conditions. Consequently, it is suggested that pre-sedimentation with optimum coagulation prior to DAF is the appropriate treatment scheme.

  8. Critical evaluation and modeling of algal harvesting using dissolved air flotation. DAF Algal Harvesting Modeling

    DOE PAGES

    Zhang, Xuezhi; Hewson, John C.; Amendola, Pasquale; Reynoso, Monica; Sommerfeld, Milton; Chen, Yongsheng; Hu, Qiang

    2014-07-14

    In our study, Chlorella zofingiensis harvesting by dissolved air flotation (DAF) was critically evaluated with regard to algal concentration, culture conditions, type and dosage of coagulants, and recycle ratio. Harvesting efficiency increased with coagulant dosage and leveled off at 81%, 86%, 91%, and 87% when chitosan, Al3+, Fe3+, and cetyl trimethylammonium bromide (CTAB) were used at dosages of 70, 180, 250, and 500 mg g-1, respectively. The DAF efficiency-coagulant dosage relationship changed with algal culture conditions. In evaluating the influence of the initial algal concentration and recycle ratio revealed that, under conditions typical for algal harvesting, we found that itmore » is possible that the number of bubbles is insufficient. A DAF algal harvesting model was developed to explain this observation by introducing mass-based floc size distributions and a bubble limitation into the white water blanket model. Moreover, the model revealed the importance of coagulation to increase floc-bubble collision and attachment, and the preferential interaction of bubbles with larger flocs, which limited the availability of bubbles to the smaller sized flocs. The harvesting efficiencies predicted by the model agree reasonably with experimental data obtained at different Al3+ dosages, algal concentrations, and recycle ratios. Based on this modeling, critical parameters for efficient algal harvesting were identified.« less

  9. Characteristic of flotation deinking using bio and synthetic surfactant at different air flow rate

    NASA Astrophysics Data System (ADS)

    Trismawati, Wardana, I. N. G.; Hamidi, Nurkholis; Sasongko, Mega Nur

    2016-03-01

    Flotation deinking has industrially applied but several problems keep unsolved because limitations have to compete with several variables present. Flotation deinking is multi variables process, so studying flotation deinking is still interesting. In this research, the amount of variables was reduced and focused to the performance comparison between flotation deinking of old newspaper (ONP) using biodegradable fatty acid of morinda citrifolia as the raw bio surfactant (RBS) and biodegradable fatty acid of palm oil that had been converted to be commercial surfactant (CS). The flotation was done at laboratory flotation cell equipped with orifice at different diameter (orifice number 20, 40 and 60) with adjustable airflow rate. Brightness and Effective Residual Ink Concentration (ERIC) of the deinked pulp were measured. The best results were achieved on orifice number 40 with the highest brightness of 41.96 °ISO and 40.96 °ISO when using CS and RBS respectively, and lowest ERIC of 896.82 ppm and 1001.72 ppm when using CS and RBS respectively. The percentage delta of deinking power characteristic between CS and RBS was 2.36% and 11.70% for brightness and ERIC, respectively.

  10. A model of particle removal in a dissolved air flotation tank: importance of stratified flow and bubble size.

    PubMed

    Lakghomi, B; Lawryshyn, Y; Hofmann, R

    2015-01-01

    An analytical model and a computational fluid dynamic model of particle removal in dissolved air flotation were developed that included the effects of stratified flow and bubble-particle clustering. The models were applied to study the effect of operating conditions and formation of stratified flow on particle removal. Both modeling approaches demonstrated that the presence of stratified flow enhanced particle removal in the tank. A higher air fraction was shown to be needed at higher loading rates to achieve the same removal efficiency. The model predictions showed that an optimum bubble size was present that increased with an increase in particle size.

  11. Flotation process for removal of precipitates from electrochemical chromate reduction unit

    DOEpatents

    DeMonbrun, James R.; Schmitt, Charles R.; Williams, Everett H.

    1976-01-01

    This invention is an improved form of a conventional electrochemical process for removing hexavalent chromium or other metal-ion contaminants from cooling-tower blowdown water. In the conventional process, the contaminant is reduced and precipitated at an iron anode, thus forming a mixed precipitate of iron and chromium hydroxides, while hydrogen being evolved copiously at a cathode is vented from the electrochemical cell. In the conventional process, subsequent separation of the fine precipitate has proved to be difficult and inefficient. In accordance with this invention, the electrochemical operation is conducted in a novel manner permitting a much more efficient and less expensive precipitate-recovery operation. That is, the electrochemical operation is conducted under an evolved-hydrogen partial pressure exceeding atmospheric pressure. As a result, most of the evolved hydrogen is entrained as bubbles in the blowdown in the cell. The resulting hydrogen-rich blowdown is introduced to a vented chamber, where the entrained hydrogen combines with the precipitate to form a froth which can be separated by conventional techniques. In addition to the hydrogen, two materials present in most blowdown act as flotation promoters for the precipitate. These are (1) air, with which the blowdown water becomes saturated in the course of normal cooling-tower operation, and (2) surfactants which commonly are added to cooling-tower recirculating-water systems to inhibit the growth of certain organisms or prevent the deposition of insoluble particulates.

  12. Lamella dissolved air flotation treatment of fish farming effluents as a part of an integrated farming and effluent treatment concept.

    PubMed

    Jokela, Petri; Lepistö, Raghida

    2014-01-01

    Nutrient emissions from fish farming can be reduced by a bag pen, i.e., a floating circular basin which serves simultaneously both as a fish cultivation tank and a swirl separation tank. Solid matter (excreta and uneaten feed) is collected at the bottom of the bag pen and pumped as an underflow to a dissolved air flotation (DAF) unit for nutrient removal. DAF equipped with lamella elements was studied in real conditions. Altogether 3000 rainbow trout females (2.0 kg each) were cultivated. Solid-water mixture was pumped from the bottom of the bag pen to an equalizing basin using a sequence of 2-min pumping followed by a 4-min pause. In some tests the influent was pumped directly and continuously from the bag pen to DAF. The influent quality changed substantially: average suspended solids (SS) and phosphorus (P) concentrations were 290 mg l⁻¹ ± 110 mg l⁻¹ and 3.2 mg l⁻¹ ± 1.2 mg l⁻¹, respectively. When the influent was fresh and P strongly associated with SS, DAF without precipitation chemicals produced up to 86% SS and 83% P removals. The influence of chemical doses was studied using 6.4-29.2 mg Fe l⁻¹ with hydraulic loadings (HLs) of 11.0-11.7 m h⁻¹. SS and P removal did not change substantially and the effluent concentration levelled at 30 mg SS l⁻¹ and 0.20-0.30 mg P l⁻¹, respectively. The lamella DAF, coupled with ferric precipitation, produced up to 90% P and 80% nitrogen reductions. HLs, excluding recycle water flow and lamella projection, up to 21 m h⁻¹ could be used. PMID:25176307

  13. Flotation: A promising microalgae harvesting and dewatering technology for biofuels production.

    PubMed

    Ndikubwimana, Theoneste; Chang, Jingyu; Xiao, Zongyuan; Shao, Wenyao; Zeng, Xianhai; Ng, I-Son; Lu, Yinghua

    2016-03-01

    Microalgal biomass as renewable energy source is believed to be of great potential for reliable and sustainable biofuels production. However, microalgal biomass production is pinned by harvesting and dewatering stage thus hindering the developing and growing microalgae biotechnology industries. Flotation technology applied in mineral industry could be potentially applied in microalgae harvesting and dewatering, however substantial knowledge on different flotation units is essential. This paper presents an overview on different flotation units as promising cost-effective technologies for microalgae harvesting thus bestowing for further research in development and commercialization of microalgae based biofuels. Dispersed air flotation was found to be less energy consuming. Moreover, Jameson cell flotation and dispersed ozone flotation are believed to be energy efficient microalgae flotation approaches. Microalgae harvesting and dewatering by flotation is still at embryonic stage, therefore extended studies with the focus on life cycle assessment, sustainability of the flotation unit, optimization of the operating parameters using different algal species is imperative. Though there are a number of challenges in microalgae harvesting and dewatering, with well designed and developed cultivation, harvesting/dewatering, extraction and conversion technologies, progressively, microalgae technology will be of great potential for biological carbon sequestration, biofuels and biochemicals production.

  14. Flotation: A promising microalgae harvesting and dewatering technology for biofuels production.

    PubMed

    Ndikubwimana, Theoneste; Chang, Jingyu; Xiao, Zongyuan; Shao, Wenyao; Zeng, Xianhai; Ng, I-Son; Lu, Yinghua

    2016-03-01

    Microalgal biomass as renewable energy source is believed to be of great potential for reliable and sustainable biofuels production. However, microalgal biomass production is pinned by harvesting and dewatering stage thus hindering the developing and growing microalgae biotechnology industries. Flotation technology applied in mineral industry could be potentially applied in microalgae harvesting and dewatering, however substantial knowledge on different flotation units is essential. This paper presents an overview on different flotation units as promising cost-effective technologies for microalgae harvesting thus bestowing for further research in development and commercialization of microalgae based biofuels. Dispersed air flotation was found to be less energy consuming. Moreover, Jameson cell flotation and dispersed ozone flotation are believed to be energy efficient microalgae flotation approaches. Microalgae harvesting and dewatering by flotation is still at embryonic stage, therefore extended studies with the focus on life cycle assessment, sustainability of the flotation unit, optimization of the operating parameters using different algal species is imperative. Though there are a number of challenges in microalgae harvesting and dewatering, with well designed and developed cultivation, harvesting/dewatering, extraction and conversion technologies, progressively, microalgae technology will be of great potential for biological carbon sequestration, biofuels and biochemicals production. PMID:26928758

  15. Evaluation of flow hydrodynamics in a pilot-scale dissolved air flotation tank: a comparison between CFD and experimental measurements.

    PubMed

    Lakghomi, B; Lawryshyn, Y; Hofmann, R

    2015-01-01

    Computational fluid dynamics (CFD) models of dissolved air flotation (DAF) have shown formation of stratified flow (back and forth horizontal flow layers at the top of the separation zone) and its impact on improved DAF efficiency. However, there has been a lack of experimental validation of CFD predictions, especially in the presence of solid particles. In this work, for the first time, both two-phase (air-water) and three-phase (air-water-solid particles) CFD models were evaluated at pilot scale using measurements of residence time distribution, bubble layer position and bubble-particle contact efficiency. The pilot-scale results confirmed the accuracy of the CFD model for both two-phase and three-phase flows, but showed that the accuracy of the three-phase CFD model would partly depend on the estimation of bubble-particle attachment efficiency.

  16. Importance of flow stratification and bubble aggregation in the separation zone of a dissolved air flotation tank.

    PubMed

    Lakghomi, B; Lawryshyn, Y; Hofmann, R

    2012-09-15

    The importance of horizontal flow patterns and bubble aggregation on the ability of dissolved air flotation (DAF) systems to improve bubble removal during drinking water treatment were explored using computational fluid dynamics (CFD) modeling. Both analytical and CFD analyses demonstrated benefits to horizontal flow. Two dimensional CFD modeling of a DAF system showed that increasing the amount of air in the system improved the bubble removal and generated a beneficial stratified horizontal flow pattern. Loading rates beyond a critical level disrupted the horizontal flow pattern, leading to significantly lower bubble removal. The results also demonstrated that including the effects of bubble aggregation in CFD modeling of DAF systems is an essential component toward achieving realistic modeling results.

  17. Application of Hydrodynamics in Design of Flotation Deinking Cell

    NASA Astrophysics Data System (ADS)

    Li, R. G.; Xie, X. F.; Wang, A. L.; Chen, K. F.

    Recovery and recycling of waste paper has become increasingly important with demand for paper products sharply growing. The flotation process is the predominant technology for the removal of inks from waste paper because of its advantages. Flotation cells may be very different in size and shape, but the key elements ensuring aeration, ink collection and bubble separation are always present. Different aeration systems have been developed by the equipment suppliers. The hydrodynamic method, based on the self suction and mixing of air according to the Venturi principle has become the most common aeration technique. Injectors of various sizes and designs have been investigated and constantly improved and adapted to different designs of flotation units. Step diffuser is a common and predominant injector used in the flotation deinking cell.

  18. Survey of dissolved air flotation system efficiency for reduce of pollution of vegetable oil industry wastewater.

    PubMed

    Keramati, H; Alidadi, H; Parvaresh, A R; Movahedian, H; Mahvi, A H

    2008-10-01

    The aim of this research was to sudy the reduction of pollution of vegetable oil manufacturing wastewater with DAF system. At first phase of this examination, the optimum dosage of the coagulants was determined. The coagulants that used in this study were Alum and Ferric Chloride. The second phase was flotation in this series of examinations, oil, COD, total solid, volatile solid, fixed solid and suspended solid measured in raw wastewater and the effluent of the DAF pilot. Optimum value of pH for alum and ferric chloride obtained 7.5 and 5.5, respectively. Optimum dosage for these obtained 30 and 32 mg L(-1) in this research. Mean removal for the parameters ofoil, COD, total solid, volatile solid, fixed solid and suspended solid obtained 75.85, 78.27, 77.32, 82.47, 73.52 and 85.53%, respectively. With pressure rising from 3 to 4 and 5 atm removing rate of COD, total solid, volatile solid, fixed solid parameters reduced, but oil and suspended solid have increase. In addition, following increase of flotation time up to 120 sec all of the measured parameters have increase in removing rate. Optimum A/S for removal of COD, total solid, volatile solid, fixed solid parameters obtained 0.001 and for oil and suspended solid obtained 0.0015.

  19. Flotation techniques for oily water treatment.

    PubMed

    Melo, M V; Sant'anna, G L; Massarani, G

    2003-07-01

    The aim of this work is to develop alternative techniques for the treatment of waters heavily contaminated by oil. Furthermore, the treatment system should achieve high removal efficiencies even under unfavorable conditions, when oil is finely dispersed in the water phase and oil droplet sizes range from 5-30 mm and concentrations are between 100 and 300 mg l(-1). The first experiments were carried out in an induced air flotation system where a flotation column performance was evaluated in batch and continuous operation. The second system investigated in this work focused on the association of centrifugal separation in a hydrocyclone and the flotation operation. The considered system is characterized by the association of these two processes, resulting the set-up in a compact unit (centrifugal flotation system). The bubbles generation and the droplet-bubble contact are performed through a gas-liquid ejector, while the separation of the phase rich in oil (froth phase) is promoted by a hydrocyclone. In both systems, it was possible to reduce the chemical demand of oxygen by more than 85% and the oil concentration of an emulsion containing droplets with sizes between 10 and 20 mm, using Polyacrilamide as destabilizing agent.

  20. Stable thermophilic anaerobic digestion of dissolved air flotation (DAF) sludge by co-digestion with swine manure.

    PubMed

    Creamer, K S; Chen, Y; Williams, C M; Cheng, J J

    2010-05-01

    Environmentally sound treatment of by-products in a value-adding process is an ongoing challenge in animal agriculture. The sludge produced as a result of the dissolved air flotation (DAF) wastewater treatment process in swine processing facilities is one such low-value residue. The objective of this study was to determine the fundamental performance parameters for thermophilic anaerobic digestion of DAF sludge. Testing in a semi-continuous stirred tank reactor and in batch reactors was conducted to determine the kinetics of degradation and biogas yield. Stable operation could not be achieved using pure DAF sludge as a substrate, possibly due to inhibition by long-chain fatty acids or to nutrient deficiencies. However, in a 1:1 ratio (w/w, dry basis) with swine manure, operation was both stable and productive. In the semi-continuous stirred reactor at 54.5 degrees Celsius, a hydraulic residence time of 10 days, and an organic loading rate of 4.68 gVS/day/L, the methane production rate was 2.19 L/L/day and the specific methane production rate was 0.47 L/gVS (fed). Maximum specific methanogenic activity (SMA) in batch testing was 0.15 mmoles CH(4) h(-1) gVS(-1) at a substrate concentration of 6.9 gVS L(-1). Higher substrate concentrations cause an initial lag in methane production, possibly due to long-chain fatty acid or nitrogen inhibition. PMID:20060713

  1. Hydrophobically-associating cationic polymers as micro-bubble surface modifiers in dissolved air flotation for cyanobacteria cell separation.

    PubMed

    Yap, R K L; Whittaker, M; Diao, M; Stuetz, R M; Jefferson, B; Bulmus, V; Peirson, W L; Nguyen, A V; Henderson, R K

    2014-09-15

    Dissolved air flotation (DAF), an effective treatment method for clarifying algae/cyanobacteria-laden water, is highly dependent on coagulation-flocculation. Treatment of algae can be problematic due to unpredictable coagulant demand during blooms. To eliminate the need for coagulation-flocculation, the use of commercial polymers or surfactants to alter bubble charge in DAF has shown potential, termed the PosiDAF process. When using surfactants, poor removal was obtained but good bubble adherence was observed. Conversely, when using polymers, effective cell removal was obtained, attributed to polymer bridging, but polymers did not adhere well to the bubble surface, resulting in a cationic clarified effluent that was indicative of high polymer concentrations. In order to combine the attributes of both polymers (bridging ability) and surfactants (hydrophobicity), in this study, a commercially-available cationic polymer, poly(dimethylaminoethyl methacrylate) (polyDMAEMA), was functionalised with hydrophobic pendant groups of various carbon chain lengths to improve adherence of polymer to a bubble surface. Its performance in PosiDAF was contrasted against commercially-available poly(diallyl dimethyl ammonium chloride) (polyDADMAC). All synthesised polymers used for bubble surface modification were found to produce positively charged bubbles. When applying these cationic micro-bubbles in PosiDAF, in the absence of coagulation-flocculation, cell removals in excess of 90% were obtained, reaching a maximum of 99% cell removal and thus demonstrating process viability. Of the synthesised polymers, the polymer containing the largest hydrophobic functionality resulted in highly anionic treated effluent, suggesting stronger adherence of polymers to bubble surfaces and reduced residual polymer concentrations.

  2. Testing of the 15-inch air-sparged hydrocyclone for fine coal flotation at the Homer City preparation plant

    SciTech Connect

    Miller, J.D.; Yi, Y.; Gopalakrishnan, S.; Battista, J.J.

    1993-12-31

    Previous plant testing had been limited to the processing of minus 100 mesh classifier overflow (Upper Freeport Coal {approximately} 20% ash) with the 6-inch air-sparged hydrocyclone (ASH-6C) as reported at Coal Prep 92. The ASH-6C unit was found to provide separation efficiencies equivalent, or superior, to separations with the ASH-2C system. During the summer of 1992 the construction of the first 15-inch air-sparged hydrocyclone prototype was completed by the Advanced Processing Technologies, Inc. Installation at the Homer City Coal Preparation Plant was accomplished and testing began in October 1992. The ASH-15C unit can operate at a flowrate as high as 1,000 gpm. Experimental results are reported with respect to capacity, combustible recovery and clean coal quality.

  3. IAQ and air handling unit design

    SciTech Connect

    Gill, K.E.

    1996-01-01

    Indoor air quality (IAQ) concerns are affecting the design of air handlers currently being offered by the manufacturers of equipment in the marketplace. These design changes are being driven by increased awareness, code changes, literature, and lawsuits within the HVAC industry. The design professionals who apply the manufacturers` products are acutely aware of the need to improve the quality of air within buildings. With the new awareness of indoor air quality issues come more options, different construction techniques, and modularity in air handling unit design.

  4. INDOOR AIR CONCENTRATION UNIT CONVERSIONS

    EPA Science Inventory

    Migration of volatile chemicals from the subsurface into overlying buildings is called vapor intrusion (VI). Volatile organic chemicals in contaminated soils or groundwater can emit vapors, which can migrate through subsurface soils and may enter the indoor air of overlying buil...

  5. Automation and optimization of froth flotation

    NASA Astrophysics Data System (ADS)

    Karr, C. L.; Stanley, D. A.; Scheiner, B. J.

    The U.S. Bureau of Mines is developing techniques to optimize the design of mineral processing equipment and to control the mineral processing sequence. Emphasis at the present time is on the optimization of froth flotation. The optimization of flotation devices, such as the air-injected hydrocyclone, has been accomplished using genetic algorithms. An expert system for the flotation of phosphate has been developed. Control of various operations in flotation is being studied using a combination of fuzzy logic and genetic algorithms. The combining of the control capabilities of fuzzy logic with the search capabilities of genetic algorithms make the production of an expert system that develops rules on-line a distinct possibility. Also, the use of computer vision for on-line analysis of processing streams in phosphate flotation is being investigated. This paper describes the progress to date on these processing problems.

  6. Air quality management in the United States

    SciTech Connect

    William Chameides; Daniel Greenbaum; Raymond Wassel; K. John Holmes; Karl Gustavson; Amanda Staudt

    2005-07-01

    In 2004, the National Research Council released Air Quality Management in the United States, a report prepared in response to a congressional request for an independent evaluation of the overall effectiveness of the Clean Air Act. Based on that report, this article summarizes the committee's findings and recommendations. 10 refs., 2 figs.

  7. Optimising dissolved air flotation/filtration treatment of algae-laden lagoon effluent using surface charge: a Bolivar treatment plant case study.

    PubMed

    Yap, Russell; Holmes, Michael; Peirson, William; Whittaker, Michael; Stuetz, Richard; Jefferson, Bruce; Henderson, Rita

    2012-01-01

    Dissolved air flotation (DAF) incorporating filtration (DAFF) is used at the Bolivar wastewater treatment plant (WWTP) to polish lagoon effluent for reuse. Elevated algal populations are frequently experienced and can lead to increased coagulant requirements and process control issues. Streaming current detectors (SCDs) and a charge demand analyser (CDA) were used to monitor the full-scale plant. This was followed by an optimisation study using a pilot plant with a CDA. It was found that the normal operational charge demand range for DAF at Bolivar was between -46 and -40 μeq L(-1). Decreasing the pH of coagulation reduced coagulant consumption and facilitated more sensitive CDA responses to changes in alum dose.

  8. United States Air Force Wipe Solvent Testing

    NASA Technical Reports Server (NTRS)

    Hornung, Steven D.; Beeson, Harold D.

    2000-01-01

    The Wright-Patterson Air Force Base (WPAFB), as part of the Air Force Material Command, requested that NASA Johnson Space Center (JSC) White Sands Test Facility (WSTF) conduct testing and analyses in support of the United States Air Force Wipe Solvent Development Project. The purpose of the wipe solvent project is to develop an alternative to be used by Air Force flight line and maintenance personnel for the wipe cleaning of oxygen equipment. This report provides material compatibility, liquid oxygen (LOX) mechanical impact, autogenous ignition temperature (AIT), and gauge cleaning test data for some of the currently available solvents that may be used to replace CFC-113 and methyl chloroform. It provides data from previous WSTF test programs sponsored by the Naval Sea Systems Command, the Kennedy Space Center, and other NASA programs for the purpose of assisting WP AFB in identifying the best alternative solvents for validation testing.

  9. Replacing synthetic with microbial surfactants as collectors in the treatment of aqueous effluent produced by acid mine drainage, using the dissolved air flotation technique.

    PubMed

    Menezes, Carlyle T B; Barros, Erilson C; Rufino, Raquel D; Luna, Juliana M; Sarubbo, Leonie A

    2011-02-01

    Dissolved air flotation (DAF) is a well-established separation process employing micro bubbles as a carrier phase. The application of this technique in the treatment of acid mine drainage, using three yeast biosurfactants as alternative collectors, is hereby analyzed. Batch studies were carried out in a 50-cm high acrylic column with an external diameter of 2.5 cm. High percentages (above 94%) of heavy metals Fe(III) and Mn(II) were removed by the biosurfactants isolated from Candida lipolytica and Candida sphaerica and the values were found to be similar to those obtained with the use of the synthetic sodium oleate surfactant. The DAF operation with both surfactant and biosurfactants, achieved acceptable turbidity values, in accordance with Brazilian standard limits. The best ones were obtained by the biosurfactant from C. lipolytica, which reached 4.8 NTU. The results obtained with a laboratory synthetic effluent were also satisfactory. The biosurfactants removed almost the same percentages of iron, while the removal percentages of manganese were slightly higher compared with those obtained in the acid mine drainage effluent. They showed that the use of low-cost biosurfactants as collectors in the DAF process is a promising technology for the mining industries.

  10. Flotation machine and process for removing impurities from coals

    DOEpatents

    Szymocha, K.; Ignasiak, B.; Pawlak, W.; Kulik, C.; Lebowitz, H.E.

    1995-12-05

    The present invention is directed to a type of flotation machine that combines three separate operations in a single unit. The flotation machine is a hydraulic separator that is capable of reducing the pyrite and other mineral matter content of a coal. When the hydraulic separator is used with a flotation system, the pyrite and certain other mineral particles that may have been entrained by hydrodynamic forces associated with conventional flotation machines and/or by the attachment forces associated with the formation of microagglomerates are washed and separated from the coal. 4 figs.

  11. Flotation machine and process for removing impurities from coals

    DOEpatents

    Szymocha, K.; Ignasiak, B.; Pawlak, W.; Kulik, C.; Lebowitz, H.E.

    1997-02-11

    The present invention is directed to a type of flotation machine that combines three separate operations in a single unit. The flotation machine is a hydraulic separator that is capable of reducing the pyrite and other mineral matter content of a coal. When the hydraulic separator is used with a flotation system, the pyrite and certain other minerals particles that may have been entrained by hydrodynamic forces associated with conventional flotation machines and/or by the attachment forces associated with the formation of microagglomerates are washed and separated from the coal. 4 figs.

  12. Flotation machine and process for removing impurities from coals

    DOEpatents

    Szymocha, Kazimierz; Ignasiak, Boleslaw; Pawlak, Wanda; Kulik, Conrad; Lebowitz, Howard E.

    1997-01-01

    The present invention is directed to a type of flotation machine that combines three separate operations in a single unit. The flotation machine is a hydraulic separator that is capable of reducing the pyrite and other mineral matter content of a coal. When the hydraulic separator is used with a flotation system, the pyrite and certain other minerals particles that may have been entrained by hydrodynamic forces associated with conventional flotation machines and/or by the attachment forces associated with the formation of microagglomerates are washed and separated from the coal.

  13. Flotation machine and process for removing impurities from coals

    DOEpatents

    Szymocha, Kazimierz; Ignasiak, Boleslaw; Pawlak, Wanda; Kulik, Conrad; Lebowitz, Howard E.

    1995-01-01

    The present invention is directed to a type of flotation machine that combines three separate operations in a single unit. The flotation machine is a hydraulic separator that is capable of reducing the pyrite and other mineral matter content of a coal. When the hydraulic separator is used with a flotation system, the pyrite and certain other minerals particles that may have been entrained by hydrodynamic forces associated with conventional flotation machines and/or by the attachment forces associated with the formation of microagglomerates are washed and separated from the coal.

  14. Oil removal from produced water by conjugation of flotation and photo-Fenton processes.

    PubMed

    da Silva, Syllos Santos; Chiavone-Filho, Osvaldo; de Barros Neto, Eduardo Lins; Foletto, Edson Luiz

    2015-01-01

    The present work investigates the conjugation of flotation and photo-Fenton techniques on oil removal performance from oilfield produced water. The experiments were conducted in a column flotation and annular lamp reactor for induced air flotation and photodegradation steps, respectively. A nonionic surfactant was used as a flotation agent. The flotation experimental data were analyzed in terms of a first-order kinetic rate model. Two experimental designs were employed to evaluate the oil removal efficiency: fractional experimental design and central composite rotational design (CCRD). Overall oil removal of 99% was reached in the optimum experimental condition after 10 min of flotation followed by 45 min of photo-Fenton. The results of the conjugation of induced air flotation and photo-Fenton processes allowed meeting the wastewater limits established by the legislations for disposal. PMID:25239685

  15. Efficiencies of residual organic pollutants removal from secondary effluent by switching of coagulation- air flotation -filtration processes.

    PubMed

    Huang, R; Zhang, J; Ma, L; Jiang, A; Kong, X J; Li, X K; Bao, L

    2006-01-01

    It is an essential task to remove the residual organic pollutants (ROP) from secondary effluent of a Wastewater Treatment Plant (WWTP) in wastewater reclamation and reuse processes. Four different compared flow schemes would be achieved for further purification of the secondary effluent by switching of different valves. In order to mainly remove non-biodegradable residual organic pollutants under various operating conditions, the optimum technology and economic process was obtained in the advanced purification flow scheme at a flow of 3200 m(3)/d in Harbin Wenchang WWTP. Conclusions under a lot of experiments show that: choosing the coagulation-settler plus biofilm filter for advanced purification process is reasonable; during the stable operation phase, this process showed good performance in removing the COD, BOD5, TP, NH3-N and SS; the removal rates are 50%, 39%, 67%, 50%, 80% respectively. The effluent is able to excel the requirements for wastewater reuse standards. The unit cost of the water is 0.542 yuan/m(3), which is far below the fee paid for supply water, long-distance transfer water or seawater desalination through economic analysis.

  16. Efficiencies of residual organic pollutants removal from secondary effluent by switching of coagulation- air flotation -filtration processes.

    PubMed

    Huang, R; Zhang, J; Ma, L; Jiang, A; Kong, X J; Li, X K; Bao, L

    2006-01-01

    It is an essential task to remove the residual organic pollutants (ROP) from secondary effluent of a Wastewater Treatment Plant (WWTP) in wastewater reclamation and reuse processes. Four different compared flow schemes would be achieved for further purification of the secondary effluent by switching of different valves. In order to mainly remove non-biodegradable residual organic pollutants under various operating conditions, the optimum technology and economic process was obtained in the advanced purification flow scheme at a flow of 3200 m(3)/d in Harbin Wenchang WWTP. Conclusions under a lot of experiments show that: choosing the coagulation-settler plus biofilm filter for advanced purification process is reasonable; during the stable operation phase, this process showed good performance in removing the COD, BOD5, TP, NH3-N and SS; the removal rates are 50%, 39%, 67%, 50%, 80% respectively. The effluent is able to excel the requirements for wastewater reuse standards. The unit cost of the water is 0.542 yuan/m(3), which is far below the fee paid for supply water, long-distance transfer water or seawater desalination through economic analysis. PMID:17302323

  17. Hydrocarbon-oil encapsulated bubble flotation of fine coal using 3-in. ID flotation column. Technical progress report for the eleventh quarter, April 1--June 30, 1993

    SciTech Connect

    Peng, F.F.

    1996-05-01

    There are four modes of the collector dispersion techniques. They are (1) direct liquid additions and stirring, (2) ultrasonic energy collector dispersion, (3) atomized collector dispersion, and (4) gasified collector transported in air stream. Among those collector dispersion techniques, the technique using the gasified collector transported in air phase can be used to enhance the flotation performance with substantial reduction in collector usage and selectivity, compared to the flotation using direct liquid addition (and mechanical agitation) technique. In this phase of study, two modes of collector addition techniques including gasified collector transported in gas phase and direct collector addition techniques were applied in the column flotation to demonstrate the selectivity of utilizing the hydrocarbon-oil encapsulated air bubbles in the fine coal flotation process. The 1-in. ID flotation column was used to scale-up to 3-in. ID flotation column. The initial starting point to operate the 3-in ID flotation column were determined using both 1-in. and 3-in. flotation columns based on the three phases of work plans and experiment design. A 3-in. flotation column was used to evaluate two modes of collector dispersion and addition techniques on the recovery and grade of fine coals using various ranks of coal.

  18. Separation of algal cells from water by column flotation

    SciTech Connect

    Liu, J.C.; Chen, Y.M.; Ju, Y.H.

    1999-08-01

    The dispersed air flotation (DiAF) process was utilized to separate algal cells (Chlorella sp.) from water. Two types of collector, cationic N-cetyl-N,N,N-trimethylammonium bromide (CTAB) and anionic sodium dodecylsulfate (SDS), were used. It was observed that 20% of cell removal was achieved in the presence of 40 mg/L of SDS, and ca. 86% of the cells were removed at 40 mg/L of CTAB. Upon the addition of 10 mg/L of chitosan, over 90% of the cells were removed when SDS (20 mg/L) was used as the collector. Air flow rate affected cell flotation slightly. Optimum pH values for cell flotation were from 4.0 to 5.0. Flotation efficiency decreased at high ionic strength. The electrostatic interaction between collector and cell surface plays a critical role in the separation processes.

  19. Canada/United States Air Quality Agreement: Progress report, 1996

    SciTech Connect

    1996-12-31

    This report builds on the 1992 and 1994 Canada/United States Air Quality Agreement Progress Reports. The report reviews the acid rain control programs, emissions forecasts, and scientific research in both countries; discusses new areas of concern, such as ground-level ozone (smog) and air toxics; and includes the first five-year review of the Air Quality Agreement.

  20. FORECASTING AIR QUALITY OVER THE UNITED STATES

    EPA Science Inventory

    Increased awareness of national air quality issues on the part of the media and the general public have recently led to more demand for short-term (1-2 day) air quality forecasts for use in assessing potential health impacts (e.g., on children, the elderly, and asthmatics) and po...

  1. Froth flotation of xenotime

    NASA Astrophysics Data System (ADS)

    Zhang, Yicheng

    Froth flotation as a fundamental method for processing complex minerals is commonly applied to the surface chemistry and beneficiation of rare-earth-bearing minerals. This is due to the fact that it is possible to process a wide range of fine particle sizes and the process can be tailored to the unique mineralogy of a given deposit. Flotation effectiveness is primarily controlled by the surface-chemical properties of the minerals and related adsorption phenomena at the liquid--solid interface. This research program was designed to investigate the principles of surface chemistry and froth flotation of xenotime and selected gangue minerals. This led to a better understanding of the factors affecting flotation performance and separation of xenotime from associated gangue minerals in an efficient way. This investigation includes MLA analysis, surface area measurement, zeta potential tests, and adsorption tests of xenotime, ilmenite, zircon, schorl, and staurolite under conditions of various reagent additions and different temperatures. Octano-hydroxamic acid, sodium oleate, sodium silicates, and ammonium lignosulfonate were used in microflotation behavior evaluation. Efforts were made to evaluate the effects of temperature, pH, concentration, addition order, and depressants in the microflotation of minerals with anionic collectors such as octano-hydroxamic acid and sodium oleate. Other factors, such as bubble surface tension and bubble particle size, are also discussed based on the literature review and lab observations.

  2. Intensification of flotation treatment by exposure to vibration.

    PubMed

    Ivanov, M V; Ksenofontov, B S

    2014-01-01

    In this paper, an intensification of wastewater flotation treatment by exposure to vibration is studied. Exposure to vibration results in the decrease of air bubble size, increase of air flow through the aerator and more even dispersion of air bubbles in water. This intensifies the aeration process, thus significantly improving the treatment efficiency. A multistage model of flotation kinetics has been applied in order to take into consideration the effects of vibration. The model gives a thorough explanation of the flotation process with consideration of 'air bubble - contaminant particle' aggregate formation. A large series of experiments was conducted with paint and varnish industry wastewaters. It is shown that vibroflotation results in an increase of treatment efficiency by up to three times. A comparison of the experimental data with the results of mathematical modeling is presented, showing a good correlation of theoretical and experimental results.

  3. Harvesting of Scenedesmus obliquus FSP-3 using dispersed ozone flotation.

    PubMed

    Cheng, Ya-Ling; Juang, Yu-Chuan; Liao, Guan-Yu; Tsai, Pei-Wen; Ho, Shih-Hsin; Yeh, Kuei-Ling; Chen, Chun-Yen; Chang, Jo-Shu; Liu, Jhy-Chern; Chen, Wen-Ming; Lee, Duu-Jong

    2011-01-01

    The Scenedesmus obliquus FSP-3, a species with excellent potential for CO(2) capture and lipid production, was harvested using dispersed ozone flotation. While air aeration does not, ozone produces effective solid-liquid separation through flotation. Ozone dose applied for sufficient algal flotation is similar to those used in practical drinking waterworks. The algae removal rate, surface charge, and hydrophobicity of algal cells, and fluorescence characteristics and proteins and polysaccharides contents of algogenic organic matter (AOM) were determined during ozonation. Proteins released from tightly bound AOM are essential to modifying the hydrophobicity of bubble surfaces for easy cell attachment and to forming a top froth layer for collecting floating cells. Humic substances in the suspension scavenge dosed ozone that adversely affects ozone flotation efficiency of algal cells.

  4. 14. NORTHEASTERN VIEW OF ORIGINAL DEMAG AIR COMPRESSOR UNIT FOR ...

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

    14. NORTHEASTERN VIEW OF ORIGINAL DEMAG AIR COMPRESSOR UNIT FOR THE LINDE 1000 TONS PER DAY HIGH PURITY OXYGEN MAKING PLANT. - U.S. Steel Duquesne Works, Fuel & Utilities Plant, Along Monongahela River, Duquesne, Allegheny County, PA

  5. Air Conditioning and Refrigeration Supplementary Units.

    ERIC Educational Resources Information Center

    Winston, Del; And Others

    This document contains supplemental materials for special needs high school students intended to facilitate their mainstreaming in regular air conditioning and refrigeration courses. Teacher's materials precede the materials for students and include general notes for the instructor, additional suggestions, two references, a questionnaire on the…

  6. [Air Pollution Unit, Edmonds School District.

    ERIC Educational Resources Information Center

    Edmonds School District 15, Lynnwood, WA.

    This interdisciplinary program, developed for secondary students, contains 16 air pollution activities that can either be used directly in, or as a supplement to, curriculum in Science, Photography, Mathematics, English, Social Studies, Industrial Arts and Home Economics. The topics to be investigated include: pollutants from automobiles, exhaust…

  7. Living History: Pioneering Bandswomen of the United States Air Force

    ERIC Educational Resources Information Center

    Nichols, Jeananne

    2015-01-01

    This narrative describes two United States Air Force bandswomen whose combined careers span the past sixty years. Cornetist Martha (Martye) Jean Awkerman joined the U.S. Women in the Air Force (WAF) Band in 1955. She served the WAF band as cornet soloist and principal trumpet until the band was disbanded in 1961. In 1983, tubist Jan Duga joined…

  8. Short haul air passenger data sources in the United States

    NASA Technical Reports Server (NTRS)

    Al-Kazily, J.; Gosling, G.; Horonjeff, R.

    1977-01-01

    The sources and characteristics of existing data on short haul air passenger traffic in the United States domestic air market are described along with data availability, processing, and costs. Reference is made to data derived from aircraft operations since these data can be used to insure that no short haul operators are omitted during the process of assembling passenger data.

  9. Micro-agglomerate flotation for deep cleaning of coal. Quarterly progress report, 1 April--30 June 1994

    SciTech Connect

    Chander, S.; Hogg, R.

    1994-07-01

    The authors are investigating the use of a hybrid process--Micro-agglomerate flotation--which is a combination of oil-agglomeration and froth flotation. The basic concepts is to use small quantities of oil to promote the formation of dense micro-agglomerates with minimal entrapment of water and mineral particles, and to use froth flotation to extract these micro-agglomerates from the water/dispersed-mineral phase. Since the floating units are agglomerates (about 30--50 {mu}m in size) rather than individual coal particles (1--10 {mu}m) the problems of froth overload water/mineral carryover should be significantly alleviated. The process involves at least five phases: two or more solids (coal and mineral), two liquids (oil and water) and one gas (air). It is necessary to maintain precise control over the chemistry of the liquid phases in order to promote the interfacial reactions and interactions between phases necessary to ensure selectivity. Kinetics as well as thermodynamic factors may be critical in determining overall system response. The research program has been organized into several specific tasks: Task 1, interfacial studies; Task 2, emulsification; Task 3, agglomerate growth and structure; and Task 4, agglomerate flotation. This report summarizes the status of Tasks 2, 3, and 4.

  10. AIR QUALITY OVER THE EASTERN UNITED STATES

    EPA Science Inventory

    Atmospheric concentrations of ozone and fine particulate matter continue to exceed their standards in many parts of the eastern United States. However, the peak concentration levels and number of ozone exceedances have decreased substantially in recent years due, in part, to the...

  11. Micro-agglomerate flotation for deep cleaning of coal. Final report

    SciTech Connect

    Chander, S.; Hogg, R.

    1997-01-15

    The development of practical technologies for the deep cleaning of coal has been seriously hampered by the problems of carrying out efficient coal/mineral separations at the very fine sizes (often finer than 10 {micro}m) needed to achieve adequate liberation of the mineral matter from the coal matrix. In this investigation a hybrid process--Micro-agglomerate flotation--which is a combination of oil-agglomeration and froth flotation was studied. The basic concept is to use small quantities of oil to promote the formation of dense micro-agglomerates with minimal entrapment of water and mineral particles and to use froth flotation to separate these micro-agglomerates from the water/dispersed-mineral phase. Since the floating units will be relatively large agglomerates (30--50 {micro}m in size) rather than fine coal particles (1--10 {micro}m) the problems of froth overload and water/mineral carryover should be significantly alleviated. There are, however, complications. The process involves at least five phases: two or more solids (coal and mineral), two liquids (oil and water) and one gas (air). It is demonstrated in this study that the process is very sensitive to fluctuations in operating parameters. It is necessary to maintain precise control over the chemistry of the liquid phases as well as the agitation conditions in order to promote selectivity. Both kinetics as well as thermodynamic factors play a critical role in determining overall system response.

  12. Transboundry air pollution along the United States - Mexico Border

    SciTech Connect

    Applegate, H.G.

    1984-01-01

    Data from the four border state agencies in the United States (Arizona Department of Health Services, California Air Resources Board, New Mexico Health and Environment Department and Texas Air Control Board) plus the Subsecretaria de Mejoramiento Del Ambiente and its successor Secretaria de Desarrollo Urbano y Ecologia in Mexico have been gathered for the past 20 years. In addition, county and city agencies in the United States plus universities in both countries have contributed data for various periods of time. These data are stored in a data bank at the University of Texas at El Paso and updated periodically. This paper is a distillation of the above data. Transfrontier air pollution has been documented only in El Paso/Cd. Juarez and San Diego/Tijuana along the southern border of the united states. Health effects have been documented only in El Paso/Cd. Juarez.

  13. Some physicochemical aspects of water-soluble mineral flotation.

    PubMed

    Wu, Zhijian; Wang, Xuming; Liu, Haining; Zhang, Huifang; Miller, Jan D

    2016-09-01

    Some physicochemical aspects of water-soluble mineral flotation including hydration phenomena, associations and interactions between collectors, air bubbles, and water-soluble mineral particles are presented. Flotation carried out in saturated salt solutions, and a wide range of collector concentrations for effective flotation of different salts are two basic aspects of water-soluble mineral flotation. Hydration of salt ions, mineral particle surfaces, collector molecules or ions, and collector aggregates play an important role in water-soluble mineral flotation. The adsorption of collectors onto bubble surfaces is suggested to be the precondition for the association of mineral particles with bubbles. The association of collectors with water-soluble minerals is a complicated process, which may include the adsorption of collector molecules or ions onto such surfaces, and/or the attachment of collector precipitates or crystals onto the mineral surfaces. The interactions between the collectors and the minerals include electrostatic and hydrophobic interactions, hydrogen bonding, and specific interactions, with electrostatic and hydrophobic interactions being the common mechanisms. For the association of ionic collectors with minerals with an opposite charge, electrostatic and hydrophobic interactions could have a synergistic effect, with the hydrophobic interactions between the hydrophobic groups of the previously associated collectors and the hydrophobic groups of oncoming collectors being an important attractive force. Association between solid particles and air bubbles is the key to froth flotation, which is affected by hydrophobicity of the mineral particle surfaces, surface charges of mineral particles and bubbles, mineral particle size and shape, temperature, bubble size, etc. The use of a collector together with a frother and the use of mixed surfactants as collectors are suggested to improve flotation. PMID:27346329

  14. Some physicochemical aspects of water-soluble mineral flotation.

    PubMed

    Wu, Zhijian; Wang, Xuming; Liu, Haining; Zhang, Huifang; Miller, Jan D

    2016-09-01

    Some physicochemical aspects of water-soluble mineral flotation including hydration phenomena, associations and interactions between collectors, air bubbles, and water-soluble mineral particles are presented. Flotation carried out in saturated salt solutions, and a wide range of collector concentrations for effective flotation of different salts are two basic aspects of water-soluble mineral flotation. Hydration of salt ions, mineral particle surfaces, collector molecules or ions, and collector aggregates play an important role in water-soluble mineral flotation. The adsorption of collectors onto bubble surfaces is suggested to be the precondition for the association of mineral particles with bubbles. The association of collectors with water-soluble minerals is a complicated process, which may include the adsorption of collector molecules or ions onto such surfaces, and/or the attachment of collector precipitates or crystals onto the mineral surfaces. The interactions between the collectors and the minerals include electrostatic and hydrophobic interactions, hydrogen bonding, and specific interactions, with electrostatic and hydrophobic interactions being the common mechanisms. For the association of ionic collectors with minerals with an opposite charge, electrostatic and hydrophobic interactions could have a synergistic effect, with the hydrophobic interactions between the hydrophobic groups of the previously associated collectors and the hydrophobic groups of oncoming collectors being an important attractive force. Association between solid particles and air bubbles is the key to froth flotation, which is affected by hydrophobicity of the mineral particle surfaces, surface charges of mineral particles and bubbles, mineral particle size and shape, temperature, bubble size, etc. The use of a collector together with a frother and the use of mixed surfactants as collectors are suggested to improve flotation.

  15. Canada/United States Air Quality Agreement: Progress report, 1998

    SciTech Connect

    1998-12-31

    Under the 1991 Air Quality Agreement, Canada and the United States have committed to addressing transboundary air pollution. To date, work under the agreement has focused on acid rain issues. The two governments have made significant reductions in emissions of the two major acid rain pollutants -- sulfur dioxide and nitrogen oxides. This report focuses on key scientific and technical trends related to air pollution, and the results of the acid rain control programs in each country. It also considers the increasing cooperation of both countries in addressing the emerging transboundary issues of ground-level ozone and particulate matter (PM).

  16. [Air conditioning units and warm air blankets in the operating room].

    PubMed

    Kerwat, Klaus; Piechowiak, Karolin; Wulf, Hinnerk

    2013-01-01

    Nowadays almost all operating rooms are equipped with air conditioning (AC units). Their main purpose is climatization, like ventilation, moisturizing, cooling and also the warming of the room in large buildings. In operating rooms they have an additional function in the prevention of infections, especially the avoidance of postoperative wound infections. This is achieved by special filtration systems and by the creation of specific air currents. Since hypothermia is known to be an unambiguous factor for the development of postoperative wound infections, patients are often actively warmed intraoperatively using warm air blankets (forced-air warming units). In such cases it is frequently discussed whether such warm air blankets affect the performance of AC units by changing the air currents or whether, in contrast, have exactly the opposite effect. However, it has been demonstrated in numerous studies that warm air blankets do not have any relevant effect on the functioning of AC units. Also there are no indications that their use increases the rate of postoperative wound infections. By preventing the patient from experiencing hypothermia, the rate of postoperative wound infections can even be decreased thereby.

  17. Removal of emulsified fuel oils from brackish and pond water by dissolved air flotation with and without polyelectrolyte use: pilot-scale investigation for estuarine and near shore applications.

    PubMed

    Tansel, Berrin; Pascual, Beth

    2011-11-01

    In coastal areas, estuaries, and inland waters, dispersant use after oil spills is not allowed due to sensitivity of the ecosystems. The purpose of this study was to investigate the removal of emulsified fuel oils from brackish and pond water by dissolved air flotation (DAF) with and without use of coagulants. Experiments were conducted with a 60L DAF system. Fuel oil-water emulsions were prepared with regular unleaded gasoline, jet fuel, and diesel fuel mixed at 1:1:1 (v/v/v) ratio. Batch and continuous runs were conducted at air pressurization of 354.6kPa. During both batch and continuous modes, significant petroleum hydrocarbon (PHC) removal was achieved within 10 min. Coagulant addition initially increased the PHC removal by about 5-15%. However, effectiveness of the coagulant was not significant after 20 min due to breakage of the aggregates. In general, the pond water had higher PHC removal than the brackish water. With longer run times, PHC removal improved slightly and the effluent contained increasing fractions of higher molecular weight compounds indicating that PHC removal was due to both DAF and stripping processes. Results indicate that DAF process can be effective both with and without the use of coagulants for removing PHCs from brackish and pond waters.

  18. 11. EXTERIOR VIEW OF UNITED STATES AIR FORCE MAN EXAMINING ...

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

    11. EXTERIOR VIEW OF UNITED STATES AIR FORCE MAN EXAMINING CONTENTS OF SHIELDING TANK AS FUEL ELEMENT ASSEMBLY IS RAISED AND LOWERED. INEL PHOTO NUMBER 65-6172, TAKEN NOVEMBER 10, 1965. - Idaho National Engineering Laboratory, Advanced Reentry Vehicle Fusing System, Scoville, Butte County, ID

  19. Aircraft: United States Air Force Child Care Program Activity Guide.

    ERIC Educational Resources Information Center

    Boggs, Juanita; Brant, Linda

    General information about United States' aircraft is provided in this program activity guide for teachers and caregivers in Air Force preschools and day care centers. The guide includes basic information for teachers and caregivers, basic understandings, suggested teaching methods and group activities, vocabulary, ideas for interest centers, and…

  20. Information Assurance within the United States Air Force

    ERIC Educational Resources Information Center

    Cherry, John D.

    2010-01-01

    According to the Department of Defense (DoD), a review of information assurance (IA) in the United States Air Force (USAF) in 2009, cyber security is jeopardized because of information loss. This situation has occurred in large part because of less than optimal training practices or adherence to training protocols. The purpose of this study was…

  1. Academic Integrity at the United States Air Force Academy

    ERIC Educational Resources Information Center

    Derby, LeAnn

    2006-01-01

    In troubled times, where threats to honor abound, it is essential that people support students who may have been enculturated in social dishonesty. The United States Air Force Academy (USAFA) has worked hard to put in place a number of supports to help cadets to grow beyond social norms where dishonesty may be tolerated. The academy seeks to…

  2. Eielson Air Force Base Operable Unit 2 baseline risk assessment

    SciTech Connect

    Lewis, R.E.; Jarvis, T.T.; Jarvis, M.R.; Whelan, G.

    1994-10-01

    Operable Unit 2 at Eielson Air Force Base (AFB) near Fairbanks, is one of several operable units characterized by petroleum, oil, and lubricant contamination, and by the presence of organic products floating at the water table, as a result of Air Force operations since the 1940s. The base is approximately 19,270 acres in size, and comprises the areas for military operations and a residential neighborhood for military dependents. Within Operable Unit 2, there are seven source areas. These source areas were grouped together primarily because of the contaminants released and hence are not necessarily in geographical proximity. Source area ST10 includes a surface water body (Hardfill Lake) next to a fuel spill area. The primary constituents of concern for human health include benzene, toluene, ethylbenzene, and xylenes (BTEX). Monitored data showed these volatile constituents to be present in groundwater wells. The data also showed an elevated level of trace metals in groundwater.

  3. China's international trade and air pollution in the United States.

    PubMed

    Lin, Jintai; Pan, Da; Davis, Steven J; Zhang, Qiang; He, Kebin; Wang, Can; Streets, David G; Wuebbles, Donald J; Guan, Dabo

    2014-02-01

    China is the world's largest emitter of anthropogenic air pollutants, and measurable amounts of Chinese pollution are transported via the atmosphere to other countries, including the United States. However, a large fraction of Chinese emissions is due to manufacture of goods for foreign consumption. Here, we analyze the impacts of trade-related Chinese air pollutant emissions on the global atmospheric environment, linking an economic-emission analysis and atmospheric chemical transport modeling. We find that in 2006, 36% of anthropogenic sulfur dioxide, 27% of nitrogen oxides, 22% of carbon monoxide, and 17% of black carbon emitted in China were associated with production of goods for export. For each of these pollutants, about 21% of export-related Chinese emissions were attributed to China-to-US export. Atmospheric modeling shows that transport of the export-related Chinese pollution contributed 3-10% of annual mean surface sulfate concentrations and 0.5-1.5% of ozone over the western United States in 2006. This Chinese pollution also resulted in one extra day or more of noncompliance with the US ozone standard in 2006 over the Los Angeles area and many regions in the eastern United States. On a daily basis, the export-related Chinese pollution contributed, at a maximum, 12-24% of sulfate concentrations over the western United States. As the United States outsourced manufacturing to China, sulfate pollution in 2006 increased in the western United States but decreased in the eastern United States, reflecting the competing effect between enhanced transport of Chinese pollution and reduced US emissions. Our findings are relevant to international efforts to reduce transboundary air pollution. PMID:24449863

  4. China's international trade and air pollution in the United States.

    PubMed

    Lin, Jintai; Pan, Da; Davis, Steven J; Zhang, Qiang; He, Kebin; Wang, Can; Streets, David G; Wuebbles, Donald J; Guan, Dabo

    2014-02-01

    China is the world's largest emitter of anthropogenic air pollutants, and measurable amounts of Chinese pollution are transported via the atmosphere to other countries, including the United States. However, a large fraction of Chinese emissions is due to manufacture of goods for foreign consumption. Here, we analyze the impacts of trade-related Chinese air pollutant emissions on the global atmospheric environment, linking an economic-emission analysis and atmospheric chemical transport modeling. We find that in 2006, 36% of anthropogenic sulfur dioxide, 27% of nitrogen oxides, 22% of carbon monoxide, and 17% of black carbon emitted in China were associated with production of goods for export. For each of these pollutants, about 21% of export-related Chinese emissions were attributed to China-to-US export. Atmospheric modeling shows that transport of the export-related Chinese pollution contributed 3-10% of annual mean surface sulfate concentrations and 0.5-1.5% of ozone over the western United States in 2006. This Chinese pollution also resulted in one extra day or more of noncompliance with the US ozone standard in 2006 over the Los Angeles area and many regions in the eastern United States. On a daily basis, the export-related Chinese pollution contributed, at a maximum, 12-24% of sulfate concentrations over the western United States. As the United States outsourced manufacturing to China, sulfate pollution in 2006 increased in the western United States but decreased in the eastern United States, reflecting the competing effect between enhanced transport of Chinese pollution and reduced US emissions. Our findings are relevant to international efforts to reduce transboundary air pollution.

  5. Low-Cost Sensor Units for Measuring Urban Air Quality

    NASA Astrophysics Data System (ADS)

    Popoola, O. A.; Mead, M.; Stewart, G.; Hodgson, T.; McLoed, M.; Baldovi, J.; Landshoff, P.; Hayes, M.; Calleja, M.; Jones, R.

    2010-12-01

    Measurements of selected key air quality gases (CO, NO & NO2) have been made with a range of miniature low-cost sensors based on electrochemical gas sensing technology incorporating GPS and GPRS for position and communication respectively. Two types of simple to operate sensors units have been designed to be deployed in relatively large numbers. Mobile handheld sensor units designed for operation by members of the public have been deployed on numerous occasions including in Cambridge, London and Valencia. Static sensor units have also been designed for long-term autonomous deployment on existing street furniture. A study was recently completed in which 45 sensor units were deployed in the Cambridge area for a period of 3 months. Results from these studies indicate that air quality varies widely both spatially and temporally. The widely varying concentrations found suggest that the urban environment cannot be fully understood using limited static site (AURN) networks and that a higher resolution, more dispersed network is required to better define air quality in the urban environment. The results also suggest that higher spatial and temporal resolution measurements could improve knowledge of the levels of individual exposure in the urban environment.

  6. New units for indoor air quality: decicarbdiox and decitvoc

    NASA Astrophysics Data System (ADS)

    Jokl, M. V.

    Two new units are proposed for the evaluation of indoor air quality using the decibel concept, which give a much better approximation of the human perception of odour intensity, compared to the CO2 and total volatile organic compounds (TVOC) concentration scales: the decicarbdiox and the devitvoc. On the psychophysical scale according to Yaglou, the weakest odour that can be detected by the human smell sensors is equal to one, and corresponds to the lower limit of percentage dissatisfaction (PD) of 5.8%. It is equivalent to: (1) a CO2 threshold concentration of 485 ppm - 0 dB (odour CO2) - 0 dCd (decicarbdiox), and (2) a TVOC threshold concentration of 50 µg m-3- 0 dB (odour TVOC) - 0 dTv (decitvoc). The upper limit is determined by the initial value of toxicity: (1) CO2- 15,000 ppm - 134 dCd, and (2) TVOC - 25,000 g/m-3- 135 dTv. Optimal pollutant values (corresponding to PD=20%) and admissible values (PD=30%) for unadapted and adapted persons are calculated. Long-term tolerable values (determining the sick building syndrome range) and short-term tolerable values (the beginning of the toxic range) are also stated. The same system used to evaluate noise can be used to evaluate air quality. Additionally, the contribution of the individual constituents (at present acoustic and odour) to the overall quality of the environment can be ascertained. The new units dCd and dTv can express an increase or decrease in air contamination, e.g. by the use of air cleaners, new building materials etc. The proposed system of using dCd and dTv is compatible with BSR/ASHRAE 62-1989 R which can be used to determine the required volume of fresh air for ventilation by an improved method, which takes into account different levels of required indoor air quality.

  7. Varying duty operation of air-cooled condenser units

    NASA Astrophysics Data System (ADS)

    Milman, O. O.; Kondratev, A. V.; Ptakhin, A. V.; Dunaev, S. N.; Kirjukhin, A. V.

    2016-05-01

    Results of experimental investigations of operation modes of air-cooled condensers (ACC) under design and varying duty conditions are presented. ACCs with varying cooling airflow rates under constant heat load and with constant cooling airflow under varying heat load are examined. Diagrams of heat transfer coefficients and condensation pressures on the heat load and cooling airflow are obtained. It is found that, if the relative heat load is in the range from 0.6 to 1.0 of the nominal value, the ACC heat transfer coefficient varies insignificantly, unlike that of the water-cooled surface condensers. The results of the determination of "zero points" are given, i.e., the attainable pressure in air-cooled condensing units (ACCU), if there is no heat load for several values of working water temperature at the input of water-jet ejectors and liquid ring vacuum pump. The results of the experimental determination of atmospheric air suction into the ACC vacuum system. The effect of additional air suctions in the steam pipe on ACCU characteristics is analyzed. The thermal mapping of ACC heat exchange surfaces from the cooling air inlet is carried out. The dependence of the inefficient heat exchange zone on the additional air suction into the ACC vacuum system is given. It is shown that, if there is no additional air suction into the ACC vacuum system, the inefficient heat exchange zone is not located at the bottom of the first pass tubes, and their portion adjacent to the bottom steam pipe works efficiently. Design procedures for the ACC varying duty of capacitors are presented, and their adequacy for the ACCU varying duty estimation is analyzed.

  8. Dry coolers and air-condensing units (Review)

    NASA Astrophysics Data System (ADS)

    Milman, O. O.; Anan'ev, P. A.

    2016-03-01

    The analysis of factors affecting the growth of shortage of freshwater is performed. The state and dynamics of the global market of dry coolers used at electric power plants are investigated. Substantial increase in number and maximum capacity of air-cooled condensers, which have been put into operation in the world in recent years, are noted. The key reasons facilitating the choice of developers of the dry coolers, in particular the independence of the location of thermal power plant from water sources, are enumerated. The main steam turbine heat removal schemes using air cooling are considered, their comparison of thermal efficiency is assessed, and the change of three important parameters, such as surface area of heat transfer, condensate pump flow, and pressure losses in the steam exhaust system, are estimated. It is shown that the most effective is the scheme of direct steam condensation in the heat-exchange tubes, but other schemes also have certain advantages. The air-cooling efficiency may be enhanced much more by using an air-cooling hybrid system: a combination of dry and wet cooling. The basic applied constructive solutions are shown: the arrangement of heat-exchange modules and the types of fans. The optimal mounting design of a fully shopassembled cooling system for heat-exchange modules is represented. Different types of heat-exchange tubes ribbing that take into account the operational features of cooling systems are shown. Heat transfer coefficients of the plants from different manufacturers are compared, and the main reasons for its decline are named. When using evaporative air cooling, it is possible to improve the efficiency of air-cooling units. The factors affecting the faultless performance of dry coolers (DC) and air-condensing units (ACU) and the ways of their elimination are described. A high velocity wind forcing reduces the efficiency of cooling systems and creates preconditions for the development of wind-driven devices. It is noted that

  9. Measuring turbulence in a flotation cell using electrical resistance tomography

    NASA Astrophysics Data System (ADS)

    Meng, Jun; Xie, Weiguo; Runge, Kym; Bradshaw, Dee

    2015-11-01

    Measuring turbulence in an industrial flotation environment has long been problematic due to the opaque, aggressive, and abrasive three-phase environment in a flotation cell. One of the promising measurement techniques is electrical resistance tomography (ERT). By measuring the conductivity distribution across a measurement area, ERT has been adopted by many researchers to monitor and investigate many processes involving multiphase flows. In the research outlined in this paper, a compact ERT probe was built and then used to measure the conductivity distribution within a 60 l flotation cell operated with water and air. Two approaches were then developed to process the ERT data and estimate turbulence-related parameters. One is a conductivity variance method and the other is based on the Green-Kubo relations. Both rely on and use the fluctuation in the ERT measurement caused by bubbles moving through the measurement area changing the density of the fluid. The results from both approaches were validated by comparing the results produced by the ERT probe in a 60l flotation cell operated at different air rates and impeller speeds to that measured using an alternative turbulence measurement device. The second approach is considered superior to the first as the first requires the development of auxiliary information which would not usually be known for a new system.

  10. 76 FR 82323 - Design, Inspection, and Testing Criteria for Air Filtration and Adsorption Units

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-30

    ....'' This guide applies to the design, inspection, and testing of air filtration and iodine adsorption units... the design, inspection, and testing of air filtration and iodine adsorption units of...

  11. 78 FR 6740 - Revisions to the California State Implementation Plan, San Joaquin Valley United Air Pollution...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-31

    ... Air Pollution Control District AGENCY: Environmental Protection Agency (EPA). ACTION: Final rule. SUMMARY: EPA is finalizing approval of revisions to the San Joaquin Valley United Air Pollution Control... CFR Part 52 Environmental protection, Air pollution control, Incorporation by...

  12. Selective flotation of inorganic sulfides from coal

    DOEpatents

    Miller, K.J.; Wen, Wu-Wey

    1988-05-31

    Pyritic sulfur is removed from coal or other carbonaceous material through the use of humic acid as a coal flotation depressant. Following the removal of coarse pyrite, the carbonaceous material is blended with humic acid, a pyrite flotation collector and a frothing agent within a flotation cell to selectively float pyritic sulfur leaving clean coal as an underflow. 1 fig., 2 tabs.

  13. 77 FR 19937 - Inflatable Personal Flotation Devices

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-03

    ... Personal Flotation Devices'' in the Federal Register. 76 FR 17561. We received three submissions in... Personal Flotation Devices); 60 FR 32836 (June 23, 1995). Subpart 160.076 incorporates by reference three... SECURITY Coast Guard 46 CFR Part 160 RIN 1625-AB60 Inflatable Personal Flotation Devices AGENCY:...

  14. 76 FR 60405 - Inflatable Personal Flotation Devices

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-29

    ... Flotation Devices'' in the Federal Register (76 FR 17561). The Coast Guard received three submissions in... SECURITY Coast Guard 46 CFR Part 160 RIN 1625-AB60 Inflatable Personal Flotation Devices AGENCY: Coast... performance standards for inflatable recreational personal flotation devices (PFDs) with current...

  15. 76 FR 17561 - Inflatable Personal Flotation Devices

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-30

    ... Final Agency Policy'' (67 FR 48244, July 23, 2002). This rule involves personal flotation device... SECURITY Coast Guard 46 CFR Part 160 RIN 1625-AB60 Inflatable Personal Flotation Devices AGENCY: Coast... flotation devices (PFDs) with current voluntary industry consensus standards. This direct final rule...

  16. Selective flotation of inorganic sulfides from coal

    DOEpatents

    Miller, Kenneth J.; Wen, Wu-Wey

    1989-01-01

    Pyritic sulfur is removed from coal or other carbonaceous material through the use of humic acid as a coal flotation depressant. Following the removal of coarse pyrite, the carbonaceous material is blended with humic acid, a pyrite flotation collector and a frothing agent within a flotation cell to selectively float pyritic sulfur leaving clean coal as an underflow.

  17. 33 CFR 183.322 - Flotation materials.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Flotation materials. 183.322 Section 183.322 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED... of 2 Horsepower or Less General § 183.322 Flotation materials. (a) Flotation materials must meet...

  18. 33 CFR 183.322 - Flotation materials.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false Flotation materials. 183.322 Section 183.322 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED... of 2 Horsepower or Less General § 183.322 Flotation materials. (a) Flotation materials must meet...

  19. 33 CFR 183.322 - Flotation materials.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false Flotation materials. 183.322 Section 183.322 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED... of 2 Horsepower or Less General § 183.322 Flotation materials. (a) Flotation materials must meet...

  20. Utilization of geothermal resources at United States Air Force bases

    SciTech Connect

    Grogger, P.K.

    1980-09-01

    The Air Force installations on the continental United States as well as Alaska and Hawaii, were evaluated as to the possibility of utilizing geothermal energy to develop electricity, produce process steam, or heat and/or cool buildings. Twenty-five bases have suspected geothermal resources available. Because of either need or available technology seven installations were rated priority I, six were rated priority II and priority III and IV totaled ten. Geological and geophysical data indicated further investigation of the priority I installations, Saylor Creek Range, Idaho, Ellsworth AFB, South Dakota, Charleston AFB, South Carolina, Kirkland AFB, New Mexico, Vandenberg AFB, California, Luke AFB, Arizona, and Williams AFB, Arizona, should be accomplished as soon as possible. The use of geothermal energy will decrease the need for fossil fuels by the USAF and during times of short supply allow such fuels to be used for the Air Force's primary mission, military defense.

  1. Achieved slime flotation in centrifugal force field by float-hydrocyclone

    SciTech Connect

    Guode Xuzhanxian; Gaozhenshen Songzhiwei

    1997-12-31

    Based on the theory of intensifying flotation in a centrifugal force field, float-hydrocyclone (FH) is developed, which is a new type of equipment for slime flotation and consists of an air bubble generator and the cylindrical section of a hydrocyclone. The combination of pulp and air bubbles is fed into the FH tangentially at a high speed to effect the separation of slime in the centrifugal force field. It offers many advantages over mechanically agitated flotation cells. Commercial test results show that slime, especially fine slime, can be perfectly floated in the FH with rapid flotation and fine froth size. The quality and quantity of concentrate and tailings can be adjusted conveniently within a certain range according to different requirements.

  2. A probabilistic method to diagnose faults of air handling units

    NASA Astrophysics Data System (ADS)

    Dey, Debashis

    Air handling unit (AHU) is one of the most extensively used equipment in large commercial buildings. This device is typically customized and lacks quality system integration which can result in hardwire failures and controller errors. Air handling unit Performance Assessment Rules (APAR) is a fault detection tool that uses a set of expert rules derived from mass and energy balances to detect faults in air handling units. APAR is computationally simple enough that it can be embedded in commercial building automation and control systems and relies only upon sensor data and control signals that are commonly available in these systems. Although APAR has many advantages over other methods, for example no training data required and easy to implement commercially, most of the time it is unable to provide the diagnosis of the faults. For instance, a fault on temperature sensor could be fixed bias, drifting bias, inappropriate location, complete failure. Also a fault in mixing box can be return and outdoor damper leak or stuck. In addition, when multiple rules are satisfied the list of faults increases. There is no proper way to have the correct diagnosis for rule based fault detection system. To overcome this limitation we proposed Bayesian Belief Network (BBN) as a diagnostic tool. BBN can be used to simulate diagnostic thinking of FDD experts through a probabilistic way. In this study we developed a new way to detect and diagnose faults in AHU through combining APAR rules and Bayesian Belief network. Bayesian Belief Network is used as a decision support tool for rule based expert system. BBN is highly capable to prioritize faults when multiple rules are satisfied simultaneously. Also it can get information from previous AHU operating conditions and maintenance records to provide proper diagnosis. The proposed model is validated with real time measured data of a campus building at University of Texas at San Antonio (UTSA).The results show that BBN is correctly able to

  3. New units for indoor air quality: decicarbdiox and decitvoc.

    PubMed

    Jokl, M V

    1998-12-01

    Two new units are proposed for the evaluation of indoor air quality using the decibel concept, which give a much better approximation of the human perception of odour intensity, compared to the CO2 and total volatile organic compounds (TVOC) concentration scales: the decicarbdiox and the devitvoc. On the psychophysical scale according to Yaglou, the weakest odour that can be detected by the human smell sensors is equal to one, and corresponds to the lower limit of percentage dissatisfaction (PD) of 5.8%. It is equivalent to: (1) a CO2 threshold concentration of 485 ppm-0 dB (odour CO2)-0 dCd (decicarbdiox), and (2) a TVOC threshold concentration of 50 micrograms m-3-0 dB (odour TVOC)-0 dTv (decitvoc). The upper limit is determined by the initial value of toxicity: (1) CO2-15,000 ppm-134 dCd, and (2) TVOC-25,000 g/m-3-135 dTv. Optimal pollutant values (corresponding to PD = 20%) and admissible values (PD = 30%) for unadapted and adapted persons are calculated. Long-term tolerable values (determining the sick building syndrome range) and short-term tolerable values (the beginning of the toxic range) are also stated. The same system used to evaluate noise can be used to evaluate air quality. Additionally, the contribution of the individual constituents (at present acoustic and odour) to the overall quality of the environment can be ascertained. The new units dCd and dTv can express an increase or decrease in air contamination, e.g. by the use of air cleaners, new building materials etc. The proposed system of using dCd and dTv is compatible with BSR/ASHRAE 62-1989 R which can be used to determine the required volume of fresh air for ventilation by an improved method, which takes into account different levels of required indoor air quality. PMID:9923202

  4. Window-mounted unit cleans air at hazardous waste site

    SciTech Connect

    Battaglia, J.M. ); Sawyer, P.

    1994-07-01

    Uncontrolled hazardous waste sites present the potential for exposure to numerous airborne chemicals--both identified and unidentified. This was the case at an Elizabeth, N.J., remediation project managed by a major environmental contractor. The four-acre site housed three active manufacturing facilities and was bordered by an operation commuter railroad line. About 6,300 drums of assorted organic chemicals, mostly acid chlorides and bromides, awaited sampling and removal. In addition, 120 tanks and vessels required sampling, characterization and removal. Due to site restrictions, support trailers were located relatively close to active work areas. Damaged drums littering the site contained water-reactive, organic acid chlorides and bromides, and released slight emissions during humid or rainy conditions. Shifting winds could (and did) carry trace releases or trace contaminants toward the trailers, potentially exposing unprotected workers. Efforts were begun to alleviate even trace contaminant at levels in the remediation site's temporary office trailers. One potential solution to managing trace contaminants at the site was to use a window-mounted, air conditioner-type unit that would replenish each trailer with filtered air three times an hour, and provide positive pressure in the trailer to compensate for repeated openings and closings of doors. The design uses common, off-the-shelf components to temper the approximately 10 percent makeup air, which provides positive pressure.

  5. Combined column and cell flotation process for the treatment of PAH contaminated hazardous wastes produced by an aluminium production plant.

    PubMed

    Dhenain, Aurélie; Mercier, Guy; Blais, Jean-François; Chartier, Myriam

    2009-06-15

    The aluminium electrolytic plants generate PAH and fluoride contaminated wastes which are usually classified as hazardous material. These residues are generally disposed in secure landfill sites. A flotation cell process was previously developed to remove PAH from these aluminium industry wastes. The tests were done on composite samples made of particle size fractions under 50mm. The efficiency of the flotation cell process was demonstrated but the high quantity of concentrate produced (14.0%) during the air injection period, because of the solid entrainment, raised the treatment cost. The aim of this study was to reduce the entrainment of fine particles in order to obtain an efficient and economic technology. The process initially developed was modified: the smallest particle size fraction (<0.5mm) of the composite sample was treated in a flotation column, whereas the other particle size fractions (0.5-50mm) were treated in a flotation cell. The separated treatment allowed to reduce the entrainment during the air injection period of the flotation cell step from 14.0% to 10.1%. The optimum total solids of the pulp and cocamidopropylhydroxysultaine (CAS) concentration were 3.33% and 0.50% (ww(-1)) for the flotation column, and 15% and 0.25% (ww(-1)) for the flotation cell. This combined flotation process minimized the total entrainment which allowed a 23.6% abatement of the concentrate quantity initially produced, and reduced the PAH concentrations of the wastes under the authorized limit of 1000 mg kg(-1).

  6. Observations on biofilm formation in industrial air-cooling units

    SciTech Connect

    Liebert, C.A.; Hood, M.A.; Winter, P.A.; Singleton, F.L.

    1983-01-01

    Observations on biofilm formation in industrial air-cooling units were made over a 60-day operational period. Methods employed included: epifluorescent direct counts of water and slime samples, enumeration of culturable bacteria in water and slime samples, and ultrastructural observations of microbial attachment to formvar coated grids and epoxy resin blocks. Acridine orange direct counts and culturable counts of bacteria in water samples remained constant over the 60-day cycle, while culturable counts in slime samples increased with time. Interfering fluorescent materials present in the slime made accurate direct counts difficult to obtain. Initial increases in numbers of bacteria on formvar coated grids and culturable counts of slime samples were positively correlated with time. However, after 14 days, the formvar deteriorated and direct transmission electron microscopic bacterial counts could no longer be obtained. Submersion of epoxy resin blocks, especially those with pitted surfaces, provided an excellent method for the observation of bacterial attachment and colonization. 21 references, 3 figures.

  7. Automated Proactive Techniques for Commissioning Air-Handling Units

    SciTech Connect

    Katipamula, Srinivas ); Brambley, Michael R. ); Luskay, Larry

    2003-08-30

    Many buildings today use sophisticated building automation systems (BASs) to manage a wide and varied range of building systems. Although the capabilities of the BASs seem to have increased over time, many buildings still are not properly commissioned, operated or maintained. Lack of or improper commissioning, the inability of the building operators to grasp the complex controls, and lack of proper maintenance leads to inefficient operations and reduced lifetimes of the equipment. If regularly scheduled manual maintenance or re-commissioning practices are adopted, they can be expensive and time consuming. Automated proactive commissioning and diagnostic technologies address two of the main barriers to commissioning: cost and schedules. Automated proactive continuous commissioning tools can reduce both the cost and time associated with commissioning, as well as enhance the persistence of commissioning fixes. In the long run, automation even offers the potential for automatically correcting problems by reconfiguring controls or changing control algorithms dynamically. This paper will discuss procedures and processes that can be used to automate and continuously commission the economizer operation and outdoor-air ventilation systems of an air-handling unit.

  8. The effects of global change upon United States air quality

    NASA Astrophysics Data System (ADS)

    Gonzalez-Abraham, R.; Chung, S. H.; Avise, J.; Lamb, B.; Salathé, E. P., Jr.; Nolte, C. G.; Loughlin, D.; Guenther, A.; Wiedinmyer, C.; Duhl, T.; Zhang, Y.; Streets, D. G.

    2015-11-01

    To understand more fully the effects of global changes on ambient concentrations of ozone and particulate matter with aerodynamic diameter smaller than 2.5 μm (PM2.5) in the United States (US), we conducted a comprehensive modeling effort to evaluate explicitly the effects of changes in climate, biogenic emissions, land use and global/regional anthropogenic emissions on ozone and PM2.5 concentrations and composition. Results from the ECHAM5 global climate model driven with the A1B emission scenario from the Intergovernmental Panel on Climate Change (IPCC) were downscaled using the Weather Research and Forecasting (WRF) model to provide regional meteorological fields. We developed air quality simulations using the Community Multiscale Air Quality Model (CMAQ) chemical transport model for two nested domains with 220 and 36 km horizontal grid cell resolution for a semi-hemispheric domain and a continental United States (US) domain, respectively. The semi-hemispheric domain was used to evaluate the impact of projected global emissions changes on US air quality. WRF meteorological fields were used to calculate current (2000s) and future (2050s) biogenic emissions using the Model of Emissions of Gases and Aerosols from Nature (MEGAN). For the semi-hemispheric domain CMAQ simulations, present-day global emissions inventories were used and projected to the 2050s based on the IPCC A1B scenario. Regional anthropogenic emissions were obtained from the US Environmental Protection Agency National Emission Inventory 2002 (EPA NEI2002) and projected to the future using the MARKet ALlocation (MARKAL) energy system model assuming a business as usual scenario that extends current decade emission regulations through 2050. Our results suggest that daily maximum 8 h average ozone (DM8O) concentrations will increase in a range between 2 to 12 parts per billion (ppb) across most of the continental US. The highest increase occurs in the South, Central and Midwest regions of the US due to

  9. 48 CFR 47.403-2 - Air transport agreements between the United States and foreign governments.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 48 Federal Acquisition Regulations System 1 2012-10-01 2012-10-01 false Air transport agreements....-Flag Carriers 47.403-2 Air transport agreements between the United States and foreign governments... attend, the use of a foreign-flag air carrier that provides transportation under an air...

  10. 48 CFR 47.403-2 - Air transport agreements between the United States and foreign governments.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 1 2011-10-01 2011-10-01 false Air transport agreements....-Flag Carriers 47.403-2 Air transport agreements between the United States and foreign governments... attend, the use of a foreign-flag air carrier that provides transportation under an air...

  11. 48 CFR 47.403-2 - Air transport agreements between the United States and foreign governments.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 1 2010-10-01 2010-10-01 false Air transport agreements....-Flag Carriers 47.403-2 Air transport agreements between the United States and foreign governments... attend, the use of a foreign-flag air carrier that provides transportation under an air...

  12. 48 CFR 47.403-2 - Air transport agreements between the United States and foreign governments.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 48 Federal Acquisition Regulations System 1 2013-10-01 2013-10-01 false Air transport agreements....-Flag Carriers 47.403-2 Air transport agreements between the United States and foreign governments... attend, the use of a foreign-flag air carrier that provides transportation under an air...

  13. Operational air quality forecast guidance for the United States

    NASA Astrophysics Data System (ADS)

    Stajner, Ivanka; Lee, Pius; Tong, Daniel; Pan, Li; McQueen, Jeff; Huang, Jinaping; Djalalova, Irina; Wilczak, James; Huang, Ho-Chun; Wang, Jun; Stein, Ariel; Upadhayay, Sikchya

    2016-04-01

    NOAA provides operational air quality predictions for ozone and wildfire smoke over the United States (U.S.) and predictions of airborne dust over the contiguous 48 states at http://airquality.weather.gov. These predictions are produced using U.S. Environmental Protection Agency (EPA) Community Model for Air Quality (CMAQ) and NOAA's HYSPLIT model (Stein et al., 2015) with meteorological inputs from the North American Mesoscale Forecast System (NAM). The current efforts focus on improving test predictions of fine particulate matter (PM2.5) from CMAQ. Emission inputs for ozone and PM2.5 predictions include inventory information from the U.S. EPA and recently added contributions of particulate matter from intermittent wildfires and windblown dust that rely on near real-time information. Current testing includes refinement of the vertical grid structure in CMAQ and inclusion of contributions of dust transport from global sources into the U.S. domain using the NEMS Global Aerosol Capability (NGAC). The addition of wildfire smoke and dust contributions in CMAQ reduced model underestimation of PM2.5 in summertime. Wintertime overestimation of PM2.5 was reduced by suppressing emissions of soil particles when the terrain is covered by snow or ice. Nevertheless, seasonal biases and biases in the diurnal cycle of PM2.5 are still substantial. Therefore, a new bias correction procedure based on an analog ensemble approach was introduced (Djalalova et al., 2015). It virtually eliminates biases in monthly means or in the diurnal cycle, but it also reduces day-to-day variability in PM2.5 predictions. Refinements to the bias correction procedure are being developed. Upgrades for the representation of wildfire smoke emissions within the domain and from global sources are in testing. Another area of active development includes approaches to scale emission inventories for nitrogen oxides in order to reproduce recent changes observed by the AirNow surface monitoring network and by

  14. 33 CFR 183.114 - Test of flotation materials.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... (CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Flotation Requirements for Inboard Boats, Inboard/Outdrive Boats, and Airboats § 183.114 Test of flotation materials. (a) Vapor test. The flotation...

  15. 33 CFR 183.114 - Test of flotation materials.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... (CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Flotation Requirements for Inboard Boats, Inboard/Outdrive Boats, and Airboats § 183.114 Test of flotation materials. (a) Vapor test. The flotation...

  16. A Simple Flotation De-Linking Experiment for the Recycling of Paper

    ERIC Educational Resources Information Center

    Venditti, Richard A.

    2004-01-01

    A laboratory exercise for the flotation de-linking of wastepaper is described, which consists of disintegrating printed wastepaper in a blender and then removing the ink or toner contaminants by pumping air bubbles through suspension using an aquarium pump or other source of air bubbles. The exercise has proven extremely reliable and consistent in…

  17. Sewage treatment-flotation apparatus

    SciTech Connect

    Hines, D.A.; Jones, R.T.; Roesler, F.C.

    1981-03-03

    Solids-liquid separation, wherein a solids-liquid mixture containing dissolved oxygen-containing gas is circulated around a circulatory system comprising a downcomer and a riser, part of the mixture in the riser being introduced into a flotation chamber in which the hydrostatic pressure gradually decreases as the mixture flows upwards, with consequent release from solution of gas bubbles which carry solid particles to the top of the mixture.

  18. Commercial tests of cationic flocculant in flotation treatment of waste water

    SciTech Connect

    Sokolov, V.P.; Chikunova, L.A.; Kudrina, L.A.; Gustov, V.A.

    1987-07-01

    This work has been aimed at testing the efficiency of a polyacrylamide with cationic properties in the flotation separation of oil matter from waste water under industrial conditions. The N-dimethylaminated polyacrylamide that they synthesized manifests the properties of a high-molecular-weight cationic polyelectrolyte. This particular flocculant was selected because of its relatively high flocculating power, the sharp reduction that it gives in the volume of slime (foam) in reagent flotation treatment of waste water, and the lower content of mineral salts in the treated water. Commercial tests of the cationic flocculant were performed at the Gor'kii petroleum oil plant. The treating facilities in this plant include the following: reagent section, pumping station, flotation unit, and section for gravitational compaction of oil slime rejected from the flotation cell.

  19. The effects of global change upon United States air quality

    NASA Astrophysics Data System (ADS)

    Gonzalez-Abraham, R.; Avise, J.; Chung, S. H.; Lamb, B.; Salathé, E. P., Jr.; Nolte, C. G.; Loughlin, D.; Guenther, A.; Wiedinmyer, C.; Duhl, T.; Zhang, Y.; Streets, D. G.

    2014-12-01

    To understand more fully the effects of global changes on ambient concentrations of ozone and particulate matter with aerodynamic diameter smaller than 2.5 μm (PM2.5) in the US, we conducted a comprehensive modeling effort to evaluate explicitly the effects of changes in climate, biogenic emissions, land use, and global/regional anthropogenic emissions on ozone and PM2.5 concentrations and composition. Results from the ECHAM5 global climate model driven with the A1B emission scenario from the Intergovernmental Panel on Climate Change (IPCC) were downscaled using the Weather Research and Forecasting (WRF) model to provide regional meteorological fields. We developed air quality simulations using the Community Multiscale Air Quality Model (CMAQ) chemical transport model for two nested domains with 220 and 36 km horizontal grid cell resolution for a semi-hemispheric domain and a continental United States (US) domain, respectively. The semi-hemispheric domain was used to evaluate the impact of projected Asian emissions changes on US air quality. WRF meteorological fields were used to calculate current (2000s) and future (2050s) biogenic emissions using the Model of Emissions of Gases and Aerosols from Nature (MEGAN). For the semi-hemispheric domain CMAQ simulations, present-day global emissions inventories were used and projected to the 2050s based on the IPCC A1B scenario. Regional anthropogenic emissions were obtained from the US Environmental Protection Agency National Emission Inventory 2002 (EPA NEI2002) and projected to the future using the MARKet ALlocation (MARKAL) energy system model assuming a business as usual scenario that extends current decade emission regulations through 2050. Our results suggest that daily maximum 8 h average ozone (DM8O) concentrations will increase in a range between 2 to 12 ppb across most of the continental US, with the highest increase in the South, Central, and Midwest regions of the US, due to increases in temperature, enhanced

  20. Microalgae harvesting by flotation using natural saponin and chitosan.

    PubMed

    Kurniawati, H Agnes; Ismadji, Suryadi; Liu, J C

    2014-08-01

    This study aims to investigate the harvesting of microalgae by dispersed air flotation (DiAF) using natural biosurfactant saponin as the collector and chitosan as the flocculant. Two types of microalgae, Chlorella vulgaris and Scenedesmus obliquus, were used in this study. It was observed that saponin was a good frother, but not an effective collector when used alone for flotation separation of algae. However, with the pre-flocculation of 5 mg/L of chitosan, separation efficiency of >93% microalgae cells was found at 20 mg/L of saponin. Removal efficiency of >54.4% and >73.0% was found for polysaccharide and protein, respectively at 20 mg/L of saponin and chitosan each. Experimental results show that DiAF using saponin and chitosan is effective for separation of microalgae, and algogenic organic matter (AOM). It can potentially be applied in the integrated microalgae-based biorefinery.

  1. Vision readiness in the United States Air Force revisited.

    PubMed

    Erneston, A G; Ricks, M R; Tate, T J; Ana, R S

    1996-01-01

    A study was conducted to determine the prevalence of substandard visual acuity in a sample of the diverse communities of the United States Air Force. In addition, mobility readiness (visual), ocular disease, time since last visual examination, and adherence to ocular requirements per AFR 160-43 were assessed. Comprehensive eye examinations were performed in the Optometry Clinic on 207 randomly chosen members scheduled by Squadron Schedulers using random computer lists of personnel generated by Military Personnel Flight. Of the 207 individuals, 112 (54%) had not had a professional eye examination in the last 2 years, 51 (24%) were not mobility ready, 6 (3%) had inadequate visual acuity per AFR 160-43, and 4 (1.9%) had ocular disease. The study reinforces the concept that comprehensive, periodic ocular examinations should be performed by an optometrist or ophthalmologist on all active duty members to ensure that they see properly to perform assigned duties, that members on mobility have required optical materials to be deployment ready, and that members who develop ocular disease are identified in a timely manner.

  2. 21 CFR 890.3175 - Flotation cushion.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Flotation cushion. 890.3175 Section 890.3175 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Prosthetic Devices § 890.3175 Flotation cushion....

  3. 21 CFR 890.3175 - Flotation cushion.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Flotation cushion. 890.3175 Section 890.3175 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Prosthetic Devices § 890.3175 Flotation cushion....

  4. 21 CFR 890.3175 - Flotation cushion.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Flotation cushion. 890.3175 Section 890.3175 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Prosthetic Devices § 890.3175 Flotation cushion....

  5. 21 CFR 890.3175 - Flotation cushion.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Flotation cushion. 890.3175 Section 890.3175 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Prosthetic Devices § 890.3175 Flotation cushion....

  6. 21 CFR 890.3175 - Flotation cushion.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Flotation cushion. 890.3175 Section 890.3175 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Prosthetic Devices § 890.3175 Flotation cushion....

  7. In-plant testing of microbubble column flotation

    SciTech Connect

    Yoon, R.H.; Luttrell, G.H.; Adel, G.T.; Mankosa, M.J.

    1991-07-31

    Microbubble column flotation (MCF) was developed at the Virginia Center for Coal and Minerals Processing (VCCMP) for the selective recovery of fine particles. Bench-scale test work conducted at VCCMP, largely under the sponsorship of the U.S. Department of Energy (DOE), showed that the technology worked well for both coal and mineral applications. For the technology to be commercially successful, however, a full-scale demonstration of the MCF technology was deemed necessary. This report summarizes the results of work performed under the DOE project entitled In-plant Testing of Microbubble Column Flotation.'' The objectives of this research and development effort were to duplicate the bench-scale performance of the MCF process in a full-scale unit, to verify the scale-up procedure developed in an earlier project, and to demonstrate the applicability of the MCF technology to the coal industry.

  8. In-plant testing of microbubble column flotation. Final report

    SciTech Connect

    Yoon, R.H.; Luttrell, G.H.; Adel, G.T.; Mankosa, M.J.

    1991-07-31

    Microbubble column flotation (MCF) was developed at the Virginia Center for Coal and Minerals Processing (VCCMP) for the selective recovery of fine particles. Bench-scale test work conducted at VCCMP, largely under the sponsorship of the U.S. Department of Energy (DOE), showed that the technology worked well for both coal and mineral applications. For the technology to be commercially successful, however, a full-scale demonstration of the MCF technology was deemed necessary. This report summarizes the results of work performed under the DOE project entitled ``In-plant Testing of Microbubble Column Flotation.`` The objectives of this research and development effort were to duplicate the bench-scale performance of the MCF process in a full-scale unit, to verify the scale-up procedure developed in an earlier project, and to demonstrate the applicability of the MCF technology to the coal industry.

  9. EXAMINING THE IMPACT OF CLIMATE CHANGE AND VARIABILITY OF REGIONAL AIR QUALITY OVER THE UNITED STATES

    EPA Science Inventory

    The United States has established a series of standards for criteria and other air pollutants to safeguard air quality to protect human health and the environment. The Climate Impact on Regional Air Quality (CIRAQ) project, a collaborative research effort involving multiple Fede...

  10. Air Pollution and Childhood Respiratory Allergies in the United States

    PubMed Central

    Parker, Jennifer D.; Akinbami, Lara J.; Woodruff, Tracey J.

    2009-01-01

    Background Childhood respiratory allergies, which contribute to missed school days and other activity limitations, have increased in recent years, possibly due to environmental factors. Objective In this study we examined whether air pollutants are associated with childhood respiratory allergies in the United States. Methods For the approximately 70,000 children from the 1999–2005 National Health Interview Survey eligible for this study, we assigned between 40,000 and 60,000 ambient pollution monitoring data from the U.S. Environmental Protection Agency, depending on the pollutant. We used monitors within 20 miles of the child’s residential block group. We used logistic regression models, fit with methods for complex surveys, to examine the associations between the reporting of respiratory allergy or hay fever and annual average exposure to particulate matter ≤ 2.5 μm in diameter (PM2.5), PM ≤ 10 μm in diameter, sulfur dioxide, and nitrogen dioxide and summer exposure to ozone, controlling for demographic and geographic factors. Results Increased respiratory allergy/hay fever was associated with increased summer O3 levels [adjusted odds ratio (AOR) per 10 ppb = 1.20; 95% confidence interval (CI), 1.15–1.26] and increased PM2.5 (AOR per 10 μg/m3 = 1.23; 95% CI, 1.10–1.38). These associations persisted after stratification by urban–rural status, inclusion of multiple pollutants, and definition of exposures by differing exposure radii. No associations between the other pollutants and the reporting respiratory allergy/hay fever were apparent. Conclusions These results provide evidence of adverse health for children living in areas with chronic exposure to higher levels of O3 and PM2.5 compared with children with lower exposures. PMID:19165401

  11. Microbial air-sampling equipment, part 1: meeting United States pharmacopeia chapter 797 standards.

    PubMed

    Kastango, Eric S

    2008-01-01

    The most recent changes to Chapter 797 of the United States Pharmcopeia-National Formulary initiated an intense controversy about the frequency of cleanroom air sampling that is required to prevent the contamination of sterile preparations. For compounders who must purchase an air sampler to use in the cleanroom, choices abound. Included in this article are a review of United States Pharmacopeia-National Formulary requirements that pertain to air sampling, a discussion of how recent revision to Chapter 797 affect air sampling and patient safety, and, for easy reference, a table that features specifications for various models of microbial air samplers.

  12. United States Air Force Child Care Center Infant Care Guide.

    ERIC Educational Resources Information Center

    Craig, Ardyn; And Others

    Intended to guide Air Force infant caregivers in providing high quality group care for infants 6 weeks to 6 months of age, this infant care guide must be used in conjunction with other Air Force regulations on day care, such as AFR 215-1, Volume VI (to be renumbered AFR 215-27). After a brief introductory chapter (Chapter I), Chapter II indicates…

  13. Enhanced phosphorus removal in the DAF process by flotation scum recycling for advanced treatment of municipal wastewater.

    PubMed

    Kwak, Dong-Heui; Lee, Ki-Cheol

    2015-01-01

    To remove phosphorus (P) from municipal wastewater, various types of advanced treatment processes are being actively applied. However, there is commonly a space limit in municipal wastewater treatment plants (MWTPs). For that reason, the dissolved air flotation (DAF), which is well known for small space and flexible application process, is preferred as an additive process to enhance the removal of P. A series of experiments were conducted to investigate the feasibility of flotation scum recycling for effective P removal from a MWTP using a DAF pilot plant over 1 year. The average increases in the removal efficiencies due to flotation scum recycling were 22.6% for total phosphorus (T-P) and 18.3% for PO4-P. A higher removal efficiency of T-P was induced by recycling the flotation scum because a significant amount of Al components remained in the flotation scum. The increase in T-P removal efficiency, due to the recycling of flotation scum, shifted from the boundary of the stoichiometric precipitate to the equilibrium control region. Flotation scum recycling may contribute to improving the quality of treated water and reducing treatment costs by minimizing the coagulant dosage required.

  14. Comprehensive national database of tree effects on air quality and human health in the United States.

    PubMed

    Hirabayashi, Satoshi; Nowak, David J

    2016-08-01

    Trees remove air pollutants through dry deposition processes depending upon forest structure, meteorology, and air quality that vary across space and time. Employing nationally available forest, weather, air pollution and human population data for 2010, computer simulations were performed for deciduous and evergreen trees with varying leaf area index for rural and urban areas in every county in the conterminous United States. The results populated a national database of annual air pollutant removal, concentration changes, and reductions in adverse health incidences and costs for NO2, O3, PM2.5 and SO2. The developed database enabled a first order approximation of air quality and associated human health benefits provided by trees with any forest configurations anywhere in the conterminous United States over time. Comprehensive national database of tree effects on air quality and human health in the United States was developed.

  15. Comprehensive national database of tree effects on air quality and human health in the United States.

    PubMed

    Hirabayashi, Satoshi; Nowak, David J

    2016-08-01

    Trees remove air pollutants through dry deposition processes depending upon forest structure, meteorology, and air quality that vary across space and time. Employing nationally available forest, weather, air pollution and human population data for 2010, computer simulations were performed for deciduous and evergreen trees with varying leaf area index for rural and urban areas in every county in the conterminous United States. The results populated a national database of annual air pollutant removal, concentration changes, and reductions in adverse health incidences and costs for NO2, O3, PM2.5 and SO2. The developed database enabled a first order approximation of air quality and associated human health benefits provided by trees with any forest configurations anywhere in the conterminous United States over time. Comprehensive national database of tree effects on air quality and human health in the United States was developed. PMID:27176764

  16. Termiticide use and indoor air quality in the United States.

    PubMed

    Savage, E P

    1989-01-01

    Organochlorine insecticides have been used extensively for the past 35 yr to reduce termite damage. The USEPA estimates that chlordane and heptachlor have been used in 24 million homes in the US. The pollution of air inside dwellings is a growing concern in the US because the population at risk includes the young and aged. Those exposed to pollutants in the home may be exposed for 24 hr instead of the usual 8 hr a day in the work place. Many of the halogenated aromatic hydrocarbons have been used as pesticides and have been reported as air contaminants inside buildings. Most of these chemicals are lipophilic, ubiquitous in the environment, and persistent. A number of chemicals found in indoor air have been reported to cause human health effects and some are carcinogenic. Many studies have been conducted using a variety of air samplers inside dwellings to determine levels of termiticides in indoor air. These include the Greenburg-Smith impinger, nylon chiffon screens, polyurethane foam plug samplers, and a Millipore miniature vacuum pump with a sampling tube containing Chromosorb 102 as the collecting medium. Chlordane and heptachlor have been widely used as termiticides and both have been implicated as serious problems. The US Air Force experienced several instances of contamination of houses with airborne chlordane following termite treatment, and numerous other studies have shown the magnitude of the problem. Because of increased instances of indoor air contamination, several new alternatives have been developed for termite control to reduce the potential for chemical exposure in indoor air of houses treated with termiticides. These new techniques include use of growth regulators and newer less hazardous chemicals. PMID:2692087

  17. Making the Environmental Justice Grade: The Relative Burden of Air Pollution Exposure in the United States

    PubMed Central

    Miranda, Marie Lynn; Edwards, Sharon E.; Keating, Martha H.; Paul, Christopher J.

    2011-01-01

    This paper assesses whether the Clean Air Act and its Amendments have been equally successful in ensuring the right to healthful air quality in both advantaged and disadvantaged communities in the United States. Using a method to rank air quality established by the American Lung Association in its 2009 State of the Air report along with EPA air quality data, we assess the environmental justice dimensions of air pollution exposure and access to air quality information in the United States. We focus on the race, age, and poverty demographics of communities with differing levels of ozone and particulate matter exposure, as well as communities with and without air quality information. Focusing on PM2.5 and ozone, we find that within areas covered by the monitoring networks, non-Hispanic blacks are consistently overrepresented in communities with the poorest air quality. The results for older and younger age as well as poverty vary by the pollution metric under consideration. Rural areas are typically outside the bounds of air quality monitoring networks leaving large segments of the population without information about their ambient air quality. These results suggest that substantial areas of the United States lack monitoring data, and among areas where monitoring data are available, low income and minority communities tend to experience higher ambient pollution levels. PMID:21776200

  18. Technology assessment of vertical and horizontal air drilling potential in the United States. Final report

    SciTech Connect

    Carden, R.S.

    1993-08-18

    The objective of the research was to assess the potential for vertical, directional and horizontal air drilling in the United States and to evaluate the current technology used in air drilling. To accomplish the task, the continental United States was divided into drilling regions and provinces. The map in Appendix A shows the divisions. Air drilling data were accumulated for as many provinces as possible. The data were used to define the potential problems associated with air drilling, to determine the limitations of air drilling and to analyze the relative economics of drilling with air versus drilling mud. While gathering the drilling data, operators, drilling contractors, air drilling contractors, and service companies were contacted. Their opinion as to the advantages and limitations of air drilling were discussed. Each was specifically asked if they thought air drilling could be expanded within the continental United States and where that expansion could take place. The well data were collected and placed in a data base. Over 165 records were collected. Once in the data base, the information was analyzed to determine the economics of air drilling and to determine the limiting factors associated with air drilling.

  19. Radioactive air emissions notice of construction portable temporary radioactive air emission units - August 1998

    SciTech Connect

    FRITZ, D.W.

    1999-07-22

    This notice of construction (NOC) requests a categorical approval for construction and operation of three types of portable/temporary radionuclide airborne emission units (PTRAEUs). These three types are portable ventilation-filter systems (Type I), mobile sample preparation facilities (Type II), and mobile sample screening and analysis facilities (Type 111). Approval of the NOC application is intended to allow construction and operation of the three types of PTRAEUs without prior project-specific approval. Environmental cleanup efforts on the Hanford Site often require the use of PTRAEUs. The PTRAEUs support site characterization activities, expedited response actions (ERAs), sampling and monitoring activities, and other routine activities. The PTRAEUs operate at various locations around the Hanford Site. Radiation Air Emissions Program, Washington Administrative Code (WAC) 246-247, requires that the Washington State Department of Health (WDOH) be notified before construction of any new emission that would release airborne radioactivity. The WDOH also must receive notification before any modification of an existing source. This includes changes in the source term or replacement of emission control equipment that might significantly contribute to the offsite maximum dose from a licensed facility. During site characterization activities, ERAs, sampling and monitoring activities, and other routine activities, the PTRAEUs might require startup immediately. The notification period hampers efforts to complete such activities in an effective and timely manner. Additionally, notification is to be submitted to the WDOH when the PTRAEUs are turned off. The U.S. Department of Energy, Richland Operations Office (DOE-RL) potentially could generate several notifications monthly. The WDOH would be required to review and provide approval on each NOC as well as review the notices of discontinued sources. The WDOH regulation also allows facilities the opportunity to request a

  20. Flotation Thickening. Sludge Treatment and Disposal Course #166. Instructor's Guide [and] Student Workbook.

    ERIC Educational Resources Information Center

    Klopping, Paul H.

    This lesson describes the process of dissolved air flotation thickening. The material is intended to acquaint students with the fundamental principles of operation, components found on a typical thickener, factors that affect operation, a comparison with other thickening processes, and the calculations and laboratory tests required in establishing…

  1. Parachute/flotation bag recovery system for a large RV nose cone

    SciTech Connect

    Pepper, W.M.

    1980-03-01

    This report describes the design and development of a single-stage recovery system consisting of a 6-ft dia guide surface parachute with a 3.5 ft/sup 3/ ram-air-filled flotation bag for ocean recovery of a 120-lb nose cone. Recovery procedures start with jettisoning a portion of the initial reentry mass before deploying the parachute.

  2. Nonambulatory cows: Duration of recumbency and quality of nursing care affect outcome of flotation therapy.

    PubMed

    Stojkov, J; Weary, D M; von Keyserlingk, M A G

    2016-03-01

    Cows that are unable or unwilling to stand and remain recumbent for ≥ 12 h are defined as nonambulatory. Care and management of nonambulatory cattle is considered a major animal welfare concern facing the livestock industry, particularly the dairy sector. Flotation therapy has gained interest as a means to promote recovery in nonambulatory cows and is based on the concept that by floating the cow in warm water, secondary pressure damage to muscles and nerves will be reduced. The objective of this study was to assess the physiological responses to stress related to the flotation therapy and to evaluate the effect of recumbency duration and nursing care on the outcome of the flotation therapy. The outcomes of 34 nonambulatory Holstein dairy cows were analyzed after they were subjected to flotation therapy. The duration of recumbency and quality of nursing care provided before initiation of the flotation treatment were assessed based on producer responses to survey questions, and from on-site observations by the researchers. A veterinarian examined all cows before flotation therapy began. The treatment was divided into 5 phases: baseline (before filling), manipulation (placing the cow into the tank), filling (the tank was filled with water), flotation (the cow was confined in the filled tank), and draining (water was removed from the tank). Stress responses to the procedure, excluding the manipulation portion, were assessed using heart rate variability. The high-frequency component (HF normalized units) decreased during the filling and draining phases (2.8 ± 0.2 and 3.1 ± 0.4, respectively) compared with the baseline and floating phase (5.1 ± 0.6 and 4.9 ± 0.3, [corrected] respectively). These results indicate that the stress related to the flotation therapy is greatest during the filling and draining phases of the treatment, when cows likely have to exert increased effort to transition to a standing position. The flotation therapy was less likely to be

  3. Radioactive air emissions notice of construction HEPA filtered vacuum radioactive air emission units

    SciTech Connect

    JOHNSON, R.E.

    1999-09-01

    This notice of construction (NOC) requests a categorical approval for construction and operation of certain portable high-efficiency particulate air (HEPA) filtered vacuum radionuclide airborne emission units (HVUs). Approval of this NOC application is intended to allow operation of the HVUs without prior project-specific approval. This NOC does not request replacement or supersedence of any previous agreements/approvals by the Washington State Department of Health for the use of vacuums on the Hanford Site. These previous agreement/approvals include the approved NOCs for the use of EuroClean HEPA vacuums at the T Plant Complex (routine technical meeting 12/10/96) and the Kelly Decontamination System at the Plutonium-Uranium Extraction (PUREX) Plant (routine technical meeting 06/25/96). Also, this NOC does not replace or supersede the agreement reached regarding the use of HEPA hand-held/shop-vacuum cleaners for routine cleanup activities conducted by the Environmental Restoration Project. Routine cleanup activities are conducted during the surveillance and maintenance of inactive waste sites (Radioactive Area Remedial Action Project) and inactive facilities. HEPA hand-held/shop-vacuum cleaners are used to clean up spot surface contamination areas found during outdoor radiological field surveys, and to clean up localized radiologically contaminated material (e.g., dust, dirt, bird droppings, animal feces, liquids, insects, spider webs, etc.). This agreement, documented in the October 12, 1994 Routine Meeting Minutes, is based on routine cleanup consisting of spot cleanup of low-level contamination provided that, in each case, the source term potential would be below 0.1 millirem per year.

  4. Results of fibre and toner flotation depending on oleic acid dosage.

    PubMed

    Trumic, Maja S; Trumic, Milan Z; Vujic, Bogdana; Andric, Ljubisa; Bogdanovic, Grozdanka

    2016-09-01

    The literature was reviewed with respect to deinking flotation methods with toner samples, specifically emphasizing the speciation of copy machine and laser printing, which produce an increasing quantity of paper that is difficult to recycle. Speciation here refers to the physical-chemical characteristics of the toner, which change because of the polymerization (fusion) and oxidation process, due to exposure to heat, light and oxygen (air) during the printing process. To simulate the deinking flotation, after the ideal disintegration process, samples of toner were prepared in order to provide free toner particles. Synthetic toner has iron content and the same physical-chemical features as free disintegrated printed toner particles.We report the toner (I) and fibre (Y) recovery and the brightness (B) of laboratory filter pads formed of deinked product as deinking efficiencies. The application of oleic acid as the collector in the flotation stage gives a better flotation recovery in alkaline than in acidic conditions. The highest brightness (BF = 93.66%) and flotation recoveries (I = 90, Y = 92.82%) were achieved during testing at an oleic acid concentration of 3.38·10(-6) mol l(-1), which is the lowest dose used. This makes the use of oleic acid economical and environmentally friendly. PMID:27354017

  5. EXAMINING THE IMPACT OF CLIMATE CHANGE ON REGIONAL AIR QUALITY OVER THE UNITED STATES

    EPA Science Inventory

    This presentation summarizes recent results produced in support of the assessment of climate change impacts on ozone and particulate matter over the continental United States. Preliminary findings of climate scenario, meteorologically-drive emissions and air quality simulation a...

  6. Foam flotation as a separation process

    NASA Technical Reports Server (NTRS)

    Currin, B. L.

    1986-01-01

    The basic principles of foam separation techniques are discussed. A review of the research concerning bubble-particle interaction and its role in the kinetics of the flotation process is given. Most of the research in this area deals with the use of theoretical models to predict the effects of bubble and particle sizes, of liquid flow, and of various forces on the aperture and retention of particles by bubbles. A discussion of fluid mechanical aspects of particle flotation is given.

  7. Evaluation of the TCE catalytic oxidation unit at Wurtsmith Air Force Base

    SciTech Connect

    Hylton, T.D. ); Marchand, E.G. )

    1991-01-01

    Remediation of VOC-contaminated groundwater is frequently performed by air stripping, a process that transfers the contaminants from the water phase to the air phase by contacting the phases countercurrently through a packed-bed column. Air stripping has proven to be effective and economic for removing volatile organic compounds (VOCs) from groundwater; in many cases, however, the states require the use of an emissions control device, such as a catalytic oxidation unit or a catalytic incinerator, in conjunction with the air stripping unit. Incineration is an attractive choice for emissions control since the contaminants are destroyed on site. Wurtsmith Air Force Base is the site of an air-stripping-with-emissions-control system to remove VOCs, chiefly trichloroethylene (TCE), from groundwater. A fluidized-bed catalytic oxidation unit treats the air stream to destroy the organic contaminants. The purpose of this study was to evaluate the performance of this unit and its catalyst for destroying halogenated organics with respect to catalyst bed temperature and operating time. The objectives included identification of any products of incomplete combustion formed and determination of the utility costs for the unit. Samples were collected over a period of {approximately}19 months with volatile organic sampling trains according to EPA Method 30. Samples were taken at catalyst bed temperatures of 315, 370, 425, and 480{degree}C. The results indicate that the incinerator was destroying the TCE with >97% efficiency when operated at 370{degree}C or greater. 6 refs., 9 figs., 2 tabs.

  8. Characterizing the Exposure of Regional-Scale Air Quality in the Northeastern United States

    EPA Science Inventory

    The Clean Air Act (CAA) requires that the United States (U.S.) Environmental Protection Agency (EPA) set National Ambient Air Quality Standards (NAAQS) for pollutants considered harmful to human health and the environment. Previous research has shown that high ambient ozone leve...

  9. Air and Weather Seychelles Integrated Science. [Teacher and Pupil Booklets]. Unit 2.

    ERIC Educational Resources Information Center

    Brophy, M.; Fryars, M.

    Seychelles Integrated Science (SIS), a 3-year laboratory-based science program for students (ages 11-15) in upper primary grades 7, 8, and 9, was developed from an extensive evaluation and modification of previous P7-P9 materials. This P7 SIS unit focuses on: (1) the importance of air and air pressure in students' everyday lives; (2) oxidation…

  10. The Contribution of Marine Organics to the Air Quality of the Western United States

    EPA Science Inventory

    The contribution of marine organic emissions to the air quality in coastal areas of the western United States is studied using the latest version of the US Environmental Protection Agency (EPA) regional-scale Community Multiscale Air Quality (CMAQv4.7) modeling system. Emissions ...

  11. Flotation separation of waste plastics for recycling-A review.

    PubMed

    Wang, Chong-qing; Wang, Hui; Fu, Jian-gang; Liu, You-nian

    2015-07-01

    The sharp increase of plastic wastes results in great social and environmental pressures, and recycling, as an effective way currently available to reduce the negative impacts of plastic wastes, represents one of the most dynamic areas in the plastics industry today. Froth flotation is a promising method to solve the key problem of recycling process, namely separation of plastic mixtures. This review surveys recent literature on plastics flotation, focusing on specific features compared to ores flotation, strategies, methods and principles, flotation equipments, and current challenges. In terms of separation methods, plastics flotation is divided into gamma flotation, adsorption of reagents, surface modification and physical regulation. PMID:25869841

  12. Flotation separation of waste plastics for recycling-A review.

    PubMed

    Wang, Chong-qing; Wang, Hui; Fu, Jian-gang; Liu, You-nian

    2015-07-01

    The sharp increase of plastic wastes results in great social and environmental pressures, and recycling, as an effective way currently available to reduce the negative impacts of plastic wastes, represents one of the most dynamic areas in the plastics industry today. Froth flotation is a promising method to solve the key problem of recycling process, namely separation of plastic mixtures. This review surveys recent literature on plastics flotation, focusing on specific features compared to ores flotation, strategies, methods and principles, flotation equipments, and current challenges. In terms of separation methods, plastics flotation is divided into gamma flotation, adsorption of reagents, surface modification and physical regulation.

  13. Engineering development of advanced physical fine coal cleaning technologies: Froth flotation

    SciTech Connect

    Not Available

    1991-01-01

    The design criteria for each unit operation have been developed based upon a number of variables. These variables, at this time, are based upon the best engineering design information available to industry. A number of assumptions utilized in the design criteria are uncertain. The uncertainties of inert atmospheres for grinding and flotation as well as pyrite depressants were answered by the Surface Control Project. It was determined that inerting was not required and no new'' reagents were presented that improved the flotation results. In addition, Tasks 5 and 6 results indicated the required reagent dosage for conventional flotation and advanced flotation. Task 5 results also indicated the need for a clean coal,thickener, the flocculent dosages for both the clean coal and refuse thickeners, and final dewatering requirements. The results from Tasks 5 and 6 and summarized in Task 7 indicate several uncertainties that require continuous long duration testing. The first is the possibility of producing a grab product for both the Pittsburgh and Illinois No. 6 coals in conventional flotation. Second what does long-term recirculation of clarified water do to the product quality The verification process and real data obtained from Tasks 5 and 6 greatly reduced the capital and operating costs for the process. This was anticipated and the test work indeed provided confirming data.

  14. Nanoparticle flotation collectors--the influence of particle softness.

    PubMed

    Yang, Songtao; Razavizadeh, Bi Bi Marzieh; Pelton, Robert; Bruin, Gerard

    2013-06-12

    The ability of polymeric nanoparticles to promote glass bead and pentlandite (Pn, nickel sulfide mineral) attachment to air bubbles in flotation was measured as a function of the nanoparticle glass transition temperature using six types of nanoparticles based on styrene/N-butylacrylate copolymers. Nanoparticle size, surface charge density, and hydrophobicity were approximately constant over the series. The ability of the nanoparticles to promote air bubble attachment and perform as flotation collectors was significantly greater for softer nanoparticles. We propose that softer nanoparticles were more firmly attached to the glass beads or mineral surface because the softer particles had a greater glass/polymer contact areas and thus stronger overall adhesion. The diameters of the contact areas between polymeric nanoparticles and glass surfaces were estimated with the Young-Laplace equation for soft, liquidlike particles, whereas JKR adhesion theory was applied to the harder polystyrene particles. The diameters of the contact areas were estimated to be more than an order of magnitude greater for the soft particles compared to harder polystyrene particles.

  15. Nanoparticle flotation collectors--the influence of particle softness.

    PubMed

    Yang, Songtao; Razavizadeh, Bi Bi Marzieh; Pelton, Robert; Bruin, Gerard

    2013-06-12

    The ability of polymeric nanoparticles to promote glass bead and pentlandite (Pn, nickel sulfide mineral) attachment to air bubbles in flotation was measured as a function of the nanoparticle glass transition temperature using six types of nanoparticles based on styrene/N-butylacrylate copolymers. Nanoparticle size, surface charge density, and hydrophobicity were approximately constant over the series. The ability of the nanoparticles to promote air bubble attachment and perform as flotation collectors was significantly greater for softer nanoparticles. We propose that softer nanoparticles were more firmly attached to the glass beads or mineral surface because the softer particles had a greater glass/polymer contact areas and thus stronger overall adhesion. The diameters of the contact areas between polymeric nanoparticles and glass surfaces were estimated with the Young-Laplace equation for soft, liquidlike particles, whereas JKR adhesion theory was applied to the harder polystyrene particles. The diameters of the contact areas were estimated to be more than an order of magnitude greater for the soft particles compared to harder polystyrene particles. PMID:23692163

  16. Winter operation of nation's largest potable flotation plant. Technical report

    SciTech Connect

    Krofta, M.; Wang, L.K.

    1987-09-20

    The heart of the Pittsfield (Massachusetts) water-supply system is two potable flotation plants: Ashley Plant (2 Sandfloats) and Cleveland Plant (4 Sandfloats). Each sandfloat unit has a capacity of 6.25 MGD (million gallons per day). Sandfloat is a package clarifier consisting of flocculation, flotation, and filtration. Complete chronological testing of Pittsfield's two plants in the winter period, December 1986 through March 1987, is documented. The technical and economical feasibilities of Sandfloat are presented. Cleveland raw water having sufficient alkalinity and low temperature in winter was treated satisfactorily by Sandfloat at 6.25 MGD per unit using the chemical combination of sodium aluminate, polymer, and alum at a cost of $0.02458/1000 gal. At Ashley Plant, the mixture of 28% Ashley raw water and 72% Farnham raw water, having moderate alkalinity and low winter temperature was treated adequately by Sandfloat at 5.5-5.8 MGD per unit using the same chemicals. When 100% Farnham raw water with extremely low alkalinity and low pH was treated at Ashley Plant, PAC, sodium aluminate and polymer 1849A was found to be the best chemical combination for clarification.

  17. Meeting the future challenges of air quality management in the United States.

    PubMed

    Bradley, Michael J

    2008-01-01

    The U.S. Clean Air Act (CAA, or the Act) and its amendments has achieved substantial progress in cleaning up the nation's air. Over the past 30 years, the CAA reduced emissions of the 6 principal ("criteria") pollutants by over 25%, even while gross domestic product (GDP) has increased over 150% and population and energy consumption rose by nearly 40%. However, despite the tremendous gains the Act has brought, the country's air quality management (AQM) system still faces substantial challenges. In response to a congressional request for an independent evaluation of the overall effectiveness of the CAA, the National Research Council formed the Committee on Air Quality Management. Composed of 25 members with diverse areas of air quality expertise, the committee was charged with developing scientific and technical recommendations for strengthening the nation's AQM system. In 2004, the National Academies published their recommendations in a text entitled Air Quality Management in the United States (National Research Council, 2004).

  18. Indoor-air assessment: An inventory of indoor-air-quality research in the United States: 1989-1990

    SciTech Connect

    Pierson, T.; Greenwood, D.

    1990-12-01

    A survey of indoor air quality research projects in the United States was undertaken using a standard form and keyword list. In response to the request for participation, 110 completed forms were received from 69 principal investigators at 34 institutions. Universities had the largest number of IAQ research projects (23), followed by EPA (20), other Federal agencies (18), state (18), national laboratories (15), and private research organizations (12). The results of the inventory will provide EPA and NATO-CCMS with information on the current directions and funding levels of IAQ research in the United States. Although the information is preliminary, it can be useful to EPA in planning future research.

  19. 46 CFR 25.25-13 - Personal flotation device lights.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Personal flotation device lights. 25.25-13 Section 25.25... Preservers and Other Lifesaving Equipment § 25.25-13 Personal flotation device lights. (a) This section... device intended to be worn, and each buoyant vest must have a personal flotation device light that...

  20. 46 CFR 25.25-13 - Personal flotation device lights.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 1 2011-10-01 2011-10-01 false Personal flotation device lights. 25.25-13 Section 25.25... Preservers and Other Lifesaving Equipment § 25.25-13 Personal flotation device lights. (a) This section... device intended to be worn, and each buoyant vest must have a personal flotation device light that...

  1. 33 CFR 183.105 - Quantity of flotation required.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... (CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Flotation Requirements for Inboard Boats, Inboard/Outdrive Boats, and Airboats § 183.105 Quantity of flotation required. (a) Each boat must have enough flotation to keep any portion of the boat above the surface of the water when the boat has been submerged...

  2. 33 CFR 183.105 - Quantity of flotation required.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... (CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Flotation Requirements for Inboard Boats, Inboard/Outdrive Boats, and Airboats § 183.105 Quantity of flotation required. (a) Each boat must have enough flotation to keep any portion of the boat above the surface of the water when the boat has been submerged...

  3. 33 CFR 183.105 - Quantity of flotation required.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... (CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Flotation Requirements for Inboard Boats, Inboard/Outdrive Boats, and Airboats § 183.105 Quantity of flotation required. (a) Each boat must have enough flotation to keep any portion of the boat above the surface of the water when the boat has been submerged...

  4. 33 CFR 183.105 - Quantity of flotation required.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... (CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Flotation Requirements for Inboard Boats, Inboard/Outdrive Boats, and Airboats § 183.105 Quantity of flotation required. (a) Each boat must have enough flotation to keep any portion of the boat above the surface of the water when the boat has been submerged...

  5. 33 CFR 175.15 - Personal flotation devices required.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Personal flotation devices... SECURITY (CONTINUED) BOATING SAFETY EQUIPMENT REQUIREMENTS Personal Flotation Devices § 175.15 Personal flotation devices required. Except as provided in § 175.17 and 175.25: (a) No person may use a...

  6. 46 CFR 25.25-13 - Personal flotation device lights.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 1 2012-10-01 2012-10-01 false Personal flotation device lights. 25.25-13 Section 25.25... Preservers and Other Lifesaving Equipment § 25.25-13 Personal flotation device lights. (a) This section... device intended to be worn, and each buoyant vest must have a personal flotation device light that...

  7. 46 CFR 25.25-13 - Personal flotation device lights.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 1 2013-10-01 2013-10-01 false Personal flotation device lights. 25.25-13 Section 25.25... Preservers and Other Lifesaving Equipment § 25.25-13 Personal flotation device lights. (a) This section... device intended to be worn, and each buoyant vest must have a personal flotation device light that...

  8. 46 CFR 25.25-13 - Personal flotation device lights.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 1 2014-10-01 2014-10-01 false Personal flotation device lights. 25.25-13 Section 25.25... Preservers and Other Lifesaving Equipment § 25.25-13 Personal flotation device lights. (a) This section... device intended to be worn, and each buoyant vest must have a personal flotation device light that...

  9. 14 CFR 121.340 - Emergency flotation means.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Emergency flotation means. 121.340 Section... Emergency flotation means. (a) Except as provided in paragraph (b) of this section, no person may operate an...(a)(1) or with an approved flotation means for each occupant. This means must be within easy reach...

  10. Physically absorbable reagents-collectors in elementary flotation

    SciTech Connect

    S.A. Kondrat'ev; I.G. Bochkarev

    2007-09-15

    Based on the reviewed researches held at the Institute of Mining, Siberian Branch, Russian Academy of Sciences, the effect of physically absorbable reagents-collectors on formation of a flotation complex and its stability in turbulent pulp flows in flotation machines of basic types is considered. The basic requirements for physically absorbable reagents-collectors at different flotation stages are established.

  11. Tree and forest effects on air quality and human health in the United States.

    PubMed

    Nowak, David J; Hirabayashi, Satoshi; Bodine, Allison; Greenfield, Eric

    2014-10-01

    Trees remove air pollution by the interception of particulate matter on plant surfaces and the absorption of gaseous pollutants through the leaf stomata. However, the magnitude and value of the effects of trees and forests on air quality and human health across the United States remains unknown. Computer simulations with local environmental data reveal that trees and forests in the conterminous United States removed 17.4 million tonnes (t) of air pollution in 2010 (range: 9.0-23.2 million t), with human health effects valued at 6.8 billion U.S. dollars (range: $1.5-13.0 billion). This pollution removal equated to an average air quality improvement of less than one percent. Most of the pollution removal occurred in rural areas, while most of the health impacts and values were within urban areas. Health impacts included the avoidance of more than 850 incidences of human mortality and 670,000 incidences of acute respiratory symptoms.

  12. Influence of a portable air treatment unit on health-related quality indicators of indoor air in a classroom.

    PubMed

    Scheepers, Paul T J; Cremers, Robbert; van Hout, Stef P R; Anzion, Rob B M

    2012-02-01

    During periods of two weeks in February and June 2010 the performance of portable air treatment units (PATUs) was evaluated in a primary school classroom using indicators of indoor air quality. Air samples were collected in an undisturbed setting on weekend days and in an occupied setting during teaching hours. In the first week PATUs were turned off and in the second week they were turned on. On weekend days PATUs reduced indoor levels of PM-10 by 87% in February and by 70% in June compared to weekend days when PATUs were turned off. On schooldays, indoor PM-10 was increased by 6% in February and reduced by 42% in June. For PM-2.5 reductions on weekend days were 89% in February and 80% in June. On school days PM-2.5 was increased by 15% in February and reduced by 83% in June. Turning on the PATUs reduced total VOC by 80% on weekend days and by 57% on school days (but not in June). No influence on formaldehyde, NO(2), O(3) and molds was observed. PATUs appeared to be less effective in removal of air pollutants when used in an occupied classroom compared to an unoccupied setting. Our study suggests that such devices should be tested in real-life settings to evaluate their influence on indoor air quality.

  13. United States International Air Transport Policy, the Promise and the Reality

    NASA Technical Reports Server (NTRS)

    Landry, J. E.; Phillips, G.

    1972-01-01

    The United States international air transportation policy is discussed. The major departure of the current policy lies in the relationship between scheduled and charter services. Various provisions of the transportation charter are analyzed to show the restrictions as well as the benefits the legislation holds for commercial aviation. It is stated that a group of full service carriers can meet the full spectrum of demands for air transportation more efficiently than two or more groups.

  14. 78 FR 77106 - U.S. Air Force Reminder Re: United Launch Alliance (ULA) Consent Order and Recent Change in...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-20

    ... Department of the Air Force U.S. Air Force Reminder Re: United Launch Alliance (ULA) Consent Order and Recent Change in Department of Defense (DOD) Compliance Officer AGENCY: Headquarters Air Force, Deputy Under Secretary of the Air Force (Space). ACTION: Publicize Consent Order, Notify Public of New DOD...

  15. 77 FR 66595 - U.S. Air Force Broadcast of Consent Order, and Determination of Interest Level for a United...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-06

    ... Department of the Air Force U.S. Air Force Broadcast of Consent Order, and Determination of Interest Level for a United Launch Alliance (ULA) Consent Order Industry Day AGENCY: Headquarters Air Force, Deputy Under Secretary of the Air Force (Space). ACTION: Publicize Consent Order, and Determine Level...

  16. Effect of microwave radiation on coal flotation

    SciTech Connect

    Ozbayoglu, G.; Depci, T.; Ataman, N.

    2009-07-01

    Most low-rank coals are high in moisture and acid functional groups, therefore showing poor floatability. Drying, which removes the water molecules trapped in the pores and adsorbed at the surface of coal, decreases the hydrophilic character and improves the floatability. Microwave heating, whose simplest application is drying, was applied at 0.9 kW power level for 60 sec exposure time in the experiments to decrease the moisture content of coal in order to enhance the hydrophobicity. The flotation tests of microwave-treated coal by using heptanol and octanol lead to a higher flotation yield and ash removal than original coal.

  17. Influence of Baseline Air Masses and Wildland Fires on Air Quality in the Western United States

    NASA Astrophysics Data System (ADS)

    Wigder, Nicole L.

    This dissertation focuses on several key uncertainties related to particulate matter (PM) and O3 concentrations in the western U.S. Each analysis conducted for this dissertation centers on data collected at the Mount Bachelor Observatory (MBO, 2.8 km a.s.l., 43.98° N, 121.69° W), a mountaintop research site in central Oregon, U.S. The first component of this dissertation is an analysis of the contribution of baseline O3 to observed O3 concentrations in two western U.S. urban areas, Enumclaw, Washington (WA) and Boise, Idaho, during 2004 -- 2010. I compared O3 data from two baseline sites (MBO and Cheeka Peak, WA) to O3 concentrations in the two urban areas on days when backward air mass trajectories showed transport between the baseline and urban sites. I found that the urban areas studied had relatively low O3 on the days with a strong influence from baseline air masses (28.3 -- 48.3 ppbv). These data suggested that there was low production of O3 from urban emissions on these days, which allowed me to quantify the impact of baseline O3 on urban O3 concentrations. A regression of the Boise and MBO O3 observations showed that free tropospheric air masses were diluted by 50% as they were entrained into the boundary layer at Boise. These air masses can contain high O3 concentrations (>70 ppbv) from Asian pollution sources or stratospheric intrusions, indicating that these sources can greatly contribute to urban surface O 3 concentrations. In addition, I found that the elevation and surface temperature of the urban areas studied impacted baseline O3 concentrations in these areas, with higher elevation and greater surface temperatures leading to greater O3 concentrations. The second and third components of this dissertation are analyses of the impact of wildland fires on PM and O3 concentrations in the western U.S. For both of these analyses, I calculated pollutant enhancement ratios for PM, O3, and other species in wildland fire plumes observed at MBO during 2004

  18. Multiscale air quality modeling of the Northeastern United States

    NASA Astrophysics Data System (ADS)

    Kumar, Naresh; Russell, Armistead G.

    The Urban and Regional Multiscale (URM) model has been used to study the ozone problem in the northeastern United States. The model was applied to a multiday ozone episode extending from 2 July 1988 to 8 July 1988. The URM model is particularly suitable for application to the Northeast as there is a dense network of urban centers along with large rural areas, and the model allows the use of variable grid sizes to effectively capture the pollutant dynamics while being computationally efficient. This study particularly concentrates on how spatial grid resolution affects results, particularly in the Northeast Corridor, a string of urban centers extending from Washington D.C. to Boston. Three different grid systems are employed in the model simulations to examine this issue. The most dynamic grid system uses grid sizes varying from 4.625 to 74 km, with the finest grids concentrated in the Northeast Corridor. The uniform grid system uses a uniform grid size of 18.5 km similar to that used in the regional oxidant model (ROM). The intermediate grid system uses grid sizes varying from 4.625 to 18.5 km. When finer grids are used over the urban areas, as in the intermediate and the most dynamic grid systems, the model predicted higher peak ozone concentrations with greater detail. Sensitivity calculations were performed to quantify the effect of various inputs on the predicted ozone. Effects of zeroing the initial conditions persisted until 7 July 1988. When using background levels of species concentrations as initial conditions, the effect lasted only for two days of simulation. Boundary conditions impacted the ozone concentrations near the boundary cells only. Emission inputs were the major factor in producing the large concentrations of ozone predicted in the Northeast Corridor. The URM model was also used to study ozone control strategy issues in the Northeast Corridor. A suite of simulations was performed where anthropogenic NO x and VOC emission levels were reducd

  19. United States Air Force 611th Air Support Group/Civil Engineering Squadron Elmendorf AFB, Alaska. Remedial investigation and feasibility study. Bullen Point Radar Installation, Alaska. Final report

    SciTech Connect

    Karmi, S.

    1996-03-18

    The United States Air Force (Air Force) has prepared this Remedial investigation/Feasibility Study (RI/FS) report as part of the Installation Restoration Program (IRP) to present results of RI/FS activities at five sites at the Bullen Point radar installation. The IRP provides for investigating, quantifying, and remediating environmental contamination from past waste management activities at Air Force installations throughout the United States.

  20. Carcinogenic Air Toxics Exposure and Their Cancer-Related Health Impacts in the United States

    PubMed Central

    Zhou, Ying; Li, Chaoyang; Huijbregts, Mark A. J.; Mumtaz, M. Moiz

    2015-01-01

    Public health protection from air pollution can be achieved more effectively by shifting from a single-pollutant approach to a multi-pollutant approach. To develop such multi-pollutant approaches, identifying which air pollutants are present most frequently is essential. This study aims to determine the frequently found carcinogenic air toxics or hazardous air pollutants (HAPs) combinations across the United States as well as to analyze the health impacts of developing cancer due to exposure to these HAPs. To identify the most commonly found carcinogenic air toxics combinations, we first identified HAPs with cancer risk greater than one in a million in more than 5% of the census tracts across the United States, based on the National-Scale Air Toxics Assessment (NATA) by the U.S. EPA for year 2005. We then calculated the frequencies of their two-component (binary), and three-component (ternary) combinations. To quantify the cancer-related health impacts, we focused on the 10 most frequently found HAPs with national average cancer risk greater than one in a million. Their cancer-related health impacts were calculated by converting lifetime cancer risk reported in NATA 2005 to years of healthy life lost or Disability-Adjusted Life Years (DALYs). We found that the most frequently found air toxics with cancer risk greater than one in a million are formaldehyde, carbon tetrachloride, acetaldehyde, and benzene. The most frequently occurring binary pairs and ternary mixtures are the various combinations of these four air toxics. Analysis of urban and rural HAPs did not reveal significant differences in the top combinations of these chemicals. The cumulative annual cancer-related health impacts of inhaling the top 10 carcinogenic air toxics included was about 1,600 DALYs in the United States or 0.6 DALYs per 100,000 people. Formaldehyde and benzene together contribute nearly 60 percent of the total cancer-related health impacts. Our study shows that although there are many

  1. Carcinogenic Air Toxics Exposure and Their Cancer-Related Health Impacts in the United States.

    PubMed

    Zhou, Ying; Li, Chaoyang; Huijbregts, Mark A J; Mumtaz, M Moiz

    2015-01-01

    Public health protection from air pollution can be achieved more effectively by shifting from a single-pollutant approach to a multi-pollutant approach. To develop such multi-pollutant approaches, identifying which air pollutants are present most frequently is essential. This study aims to determine the frequently found carcinogenic air toxics or hazardous air pollutants (HAPs) combinations across the United States as well as to analyze the health impacts of developing cancer due to exposure to these HAPs. To identify the most commonly found carcinogenic air toxics combinations, we first identified HAPs with cancer risk greater than one in a million in more than 5% of the census tracts across the United States, based on the National-Scale Air Toxics Assessment (NATA) by the U.S. EPA for year 2005. We then calculated the frequencies of their two-component (binary), and three-component (ternary) combinations. To quantify the cancer-related health impacts, we focused on the 10 most frequently found HAPs with national average cancer risk greater than one in a million. Their cancer-related health impacts were calculated by converting lifetime cancer risk reported in NATA 2005 to years of healthy life lost or Disability-Adjusted Life Years (DALYs). We found that the most frequently found air toxics with cancer risk greater than one in a million are formaldehyde, carbon tetrachloride, acetaldehyde, and benzene. The most frequently occurring binary pairs and ternary mixtures are the various combinations of these four air toxics. Analysis of urban and rural HAPs did not reveal significant differences in the top combinations of these chemicals. The cumulative annual cancer-related health impacts of inhaling the top 10 carcinogenic air toxics included was about 1,600 DALYs in the United States or 0.6 DALYs per 100,000 people. Formaldehyde and benzene together contribute nearly 60 percent of the total cancer-related health impacts. Our study shows that although there are many

  2. 76 FR 56294 - Inflatable Personal Flotation Devices

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-13

    ... issues in a notice of proposed rulemaking. DATES: The direct final rule published March 30, 2011, (76 FR... rule entitled ``Inflatable Personal Flotation Devices'' in the Federal Register (76 FR 17561). That..., or why it would be ineffective or unacceptable without a change (76 FR 17563). This...

  3. Plagioclase flotation and lunar crust formation

    NASA Technical Reports Server (NTRS)

    Walker, D.; Hays, J. F.

    1977-01-01

    Anorthitic plagioclase floats in liquids parental to the lunar highlands crust. The plagioclase enrichment that is characteristic of lunar highlands rocks can be the result of plagioclase flotation. Such rocks would form a gravitationally stable upper crust on their parental magma.

  4. Effectiveness of Germicidal UV Radiation for Reducing Fungal Contamination within Air-Handling Units

    PubMed Central

    Levetin, Estelle; Shaughnessy, Richard; Rogers, Christine A.; Scheir, Robert

    2001-01-01

    Levels of fungi growing on insulation within air-handling units (AHUs) in an office building and levels of airborne fungi within AHUs were measured before the use of germicidal UV light and again after 4 months of operation. The fungal levels following UV operation were significantly lower than the levels in control AHUs. PMID:11472952

  5. 77 FR 24156 - Proposed Amendment of Air Traffic Service Routes; Southwestern United States

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-23

    ... Policies and Procedures (44 FR 11034; February 26, 1979); and (3) does not warrant preparation of a... continues to read as follows: Authority: 49 U.S.C. 106(g), 40103, 40113, 40120; E.O. 10854, 24 FR 9565, 3... of Air Traffic Service Routes; Southwestern United States AGENCY: Federal Aviation...

  6. Commitment to Liberal Education at the United States Air Force Academy

    ERIC Educational Resources Information Center

    Enger, Rolf C.; Jones, Steven K.; Born, Dana H.

    2010-01-01

    Located just north of Colorado Springs, Colorado, the United States Air Force Academy (USAFA) is one of the nation's federally funded military service academies. With an enrollment of approximately 4,400 undergraduates, the academy offers an integrated four-year curriculum of academics, athletics, leadership and character development, military…

  7. Hydrocarbon-oil encapsulate bubble flotation of fine coal. Technical progress report for the twelfth quarter, July 1--September 30, 1993

    SciTech Connect

    Peng, F.F.

    1993-12-31

    Two modes of collector addition techniques including gasified collector transported in gas phase and direct collector addition techniques were applied in the column flotation to demonstrate the selectivity of utilizing the hydrocarbon-oil encapsulated air bubbles in the fine coal flotation process. A 3-in. flotation column was used to evaluate two modes of collector dispersion and addition techniques on the recovery and grade of fine coals using various ranks of coal. Five different coal samples were used in the column flotation test program. They are Mammoth, Lower Kittanning, Upper Freeport, Pittsburgh No. 8, and Illinois No. 6 seam coals, which correspond to anthracite-, low volatile-, medium volatile-, and high volatile-seam coals, respectively. In this quarterly report, the test results for the Upper Freeport seam coal and Pittsburgh No. 8 seam coal are reported.

  8. 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 ...

  9. The impact of marine organics on the air quality of the western United States

    NASA Astrophysics Data System (ADS)

    Gantt, B.; Meskhidze, N.; Carlton, A. G.

    2010-03-01

    The impact of marine organic emissions to the air quality in coastal areas of the western United States is studied using the latest version of the US Environmental Protection Agency (EPA) regional-scale Community Multiscale Air Quality (CMAQv4.7) modeling system. Emissions of marine isoprene, monoterpenes, and primary organic matter (POM) from the ocean are implemented into the model to provide a comprehensive view of the connection between ocean biology and atmospheric chemistry and air pollution. Model simulations show that marine organics can increase the concentration of PM2.5 by 0.1-0.3 μg m-3 (up to 5%) in coastal cities. This increase in the PM2.5 concentration is primarily attributed to the POM emissions, with small contributions from the marine isoprene and monoterpenes. When marine organic emissions are included, organic carbon (OC) concentrations over the remote ocean are increased by up to 50% (25% in coastal areas), values consistent with recent observational findings. This study is the first to quantify the air quality impacts from marine POM and monoterpenes for the United States, and highlights the need for inclusion of marine organic emissions in air quality models.

  10. The contribution of marine organics to the air quality of the western United States

    NASA Astrophysics Data System (ADS)

    Gantt, B.; Meskhidze, N.; Carlton, A. G.

    2010-08-01

    The contribution of marine organic emissions to the air quality in coastal areas of the western United States is studied using the latest version of the US Environmental Protection Agency (EPA) regional-scale Community Multiscale Air Quality (CMAQv4.7) modeling system. Emissions of marine isoprene, monoterpenes, and primary organic matter (POM) from the ocean are implemented into the model to provide a comprehensive view of the connection between ocean biology and atmospheric chemistry and air pollution. Model simulations show that marine organics can increase the concentration of PM2.5 by 0.1-0.3 μg m-3 (up to 5%) in some coastal cities such as San Francisco, CA. This increase in the PM2.5 concentration is primarily attributed to the POM emissions, with small contributions from the marine isoprene and monoterpenes. When marine organic emissions are included, organic carbon (OC) concentrations over the remote ocean are increased by up to 50% (25% in coastal areas), values consistent with recent observational findings. This study is the first to quantify the air quality impacts from marine POM and monoterpenes for the United States, and it highlights the need for inclusion of marine organic emissions in air quality models.

  11. Self-Correcting HVAC Controls: Algorithms for Sensors and Dampers in Air-Handling Units

    SciTech Connect

    Fernandez, Nicholas; Brambley, Michael R.; Katipamula, Srinivas

    2009-12-31

    This report documents the self-correction algorithms developed in the Self-Correcting Heating, Ventilating and Air-Conditioning (HVAC) Controls project funded jointly by the Bonneville Power Administration and the Building Technologies Program of the U.S. Department of Energy. The algorithms address faults for temperature sensors, humidity sensors, and dampers in air-handling units and correction of persistent manual overrides of automated control systems. All faults considered create energy waste when left uncorrected as is frequently the case in actual systems.

  12. International trade and air pollution: estimating the economic costs of air emissions from waterborne commerce vessels in the United States.

    PubMed

    Gallagher, Kevin P

    2005-10-01

    Although there is a burgeoning literature on the effects of international trade on the environment, relatively little work has been done on where trade most directly effects the environment: the transportation sector. This article shows how international trade is affecting air pollution emissions in the United States' shipping sector. Recent work has shown that cargo ships have been long overlooked regarding their contribution to air pollution. Indeed, ship emissions have recently been deemed "the last unregulated source of traditional air pollutants". Air pollution from ships has a number of significant local, national, and global environmental effects. Building on past studies, we examine the economic costs of this increasing and unregulated form of environmental damage. We find that total emissions from ships are largely increasing due to the increase in foreign commerce (or international trade). The economic costs of SO2 pollution range from dollars 697 million to dollars 3.9 billion during the period examined, or dollars 77 to dollars 435 million on an annual basis. The bulk of the cost is from foreign commerce, where the annual costs average to dollars 42 to dollars 241 million. For NOx emissions the costs are dollars 3.7 billion over the entire period or dollars 412 million per year. Because foreign trade is driving the growth in US shipping, we also estimate the effect of the Uruguay Round on emissions. Separating out the effects of global trade agreements reveals that the trade agreement-led emissions amounted to dollars 96 to dollars 542 million for SO2 between 1993 and 2001, or dollars 10 to dollars 60 million per year. For NOx they were dollars 745 million for the whole period or dollars 82 million per year. Without adequate policy responses, we predict that these trends and costs will continue into the future.

  13. Changes in the frequency of extreme air pollution events over the Eastern United States and Europe

    NASA Astrophysics Data System (ADS)

    Rieder, H. E.; Fiore, A. M.; Polvani, L. M.; Lamarque, J.-F.; Fang, Y.; Staehelin, J.

    2012-04-01

    Over the past few decades, thresholds for national air quality standards, intended to protect public health and welfare, have been lowered repeatedly. At the same time observations, over Europe and the Eastern U.S., demonstrate that extreme air pollution events (high O3 and PM2.5) are typically associated with stagnation events. Recent work showed that in a changing climate high air pollution events are likely to increase in frequency and duration. Within this work we examine meteorological and surface ozone observations from CASTNet over the U.S. and EMEP over Europe. With innovative statistical tools - i.e., statistics of extremes (EVT) - we analyze the frequency distribution of extreme air pollution events over the Eastern United States and Europe. The upper tail of observed values at individual stations (e.g., within the CASTNet), i.e., the extremes (maximum daily 8-hour average (MDA8) O3>60ppb) are poorly described by a Gaussian distribution. However, further analysis showed that applying Peak-Over-Threshold-models, better capture the extremes and allows us to estimate return levels of pollution events above certain threshold values of interest. The results show that changes in national ambient air quality standards had significant effect on the occurrence frequency of high air pollution episodes.

  14. Effects of air pollution on ecosystems and biological diversity in the eastern United States.

    PubMed

    Lovett, Gary M; Tear, Timothy H; Evers, David C; Findlay, Stuart E G; Cosby, B Jack; Dunscomb, Judy K; Driscoll, Charles T; Weathers, Kathleen C

    2009-04-01

    Conservation organizations have most often focused on land-use change, climate change, and invasive species as prime threats to biodiversity conservation. Although air pollution is an acknowledged widespread problem, it is rarely considered in conservation planning or management. In this synthesis, the state of scientific knowledge on the effects of air pollution on plants and animals in the Northeastern and Mid-Atlantic regions of the United States is summarized. Four air pollutants (sulfur, nitrogen, ozone, and mercury) and eight ecosystem types ranging from estuaries to alpine tundra are considered. Effects of air pollution were identified, with varying levels of certainty, in all the ecosystem types examined. None of these ecosystem types is free of the impacts of air pollution, and most are affected by multiple pollutants. In aquatic ecosystems, effects of acidity, nitrogen, and mercury on organisms and biogeochemical processes are well documented. Air pollution causes or contributes to acidification of lakes, eutrophication of estuaries and coastal waters, and mercury bioaccumulation in aquatic food webs. In terrestrial ecosystems, the effects of air pollution on biogeochemical cycling are also very well documented, but the effects on most organisms and the interaction of air pollution with other stressors are less well understood. Nevertheless, there is strong evidence for effects of nitrogen deposition on plants in grasslands, alpine areas, and bogs, and for nitrogen effects on forest mycorrhizae. Soil acidification is widespread in forest ecosystems across the eastern United States and is likely to affect the composition and function of forests in acid-sensitive areas over the long term. Ozone is known to cause reductions in photosynthesis in many terrestrial plant species. For the most part, the effects of these pollutants are chronic, not acute, at the exposure levels common in the eastern United States. Mortality is often observed only at experimentally

  15. Fortuitous consequence: The domestic politics of the 1991 Canada-United States agreement on air quality

    SciTech Connect

    Allison, J.E.

    1999-07-01

    Following more than a decade of negotiations, the Canada-United States Agreement on Air Quality entered into force on March 13, 1991, with the signatures of then-Canadian Prime Minister Brian Mulroney and US President George Bush. Why was it so difficult for Canadian and US negotiators to reach agreement? The author argues that Canadian and US domestic politics were the primary impediments to resolving the US-Canada acid rain dispute. This article thus casts the dispute in terms of a pair of domestic environmental policy problems, whose timely and complementary solution, furthermore, required executive initiative as the handmaiden of ecological crisis. Heightened public concern about the threat of acidic air pollution in Canada prompted Mulroney's efforts to reduce acid rain. In the US, a likewise critical change in the public's perception of air quality as a national emergency created the mass support necessary for Bush's federal acid rain control initiative.

  16. Stationary source sampling report: Ambient and source volatile organic compound testing, Production air stripper unit 1 (PASU-1) and pilot air stripper (PAS)

    SciTech Connect

    Not Available

    1984-09-05

    Tests were performed to measure the ambient concentrations of perchloroethylene, trichloroethylene, and 1,1,1-trichloroethane in the A/M area and to determine, for compliance purposes, the emissions and concentrations of those compounds issued from the Production Air Stripper Unit 1 (PASU-1) column and from the Pilot Air Stripper (PAS) column.

  17. Elk Valley coal implements smartcell flotation technology

    SciTech Connect

    Stirling, J.C.

    2008-06-15

    In anticipation of future raw coal containing higher fines content, Elk Valley Coal Corp.'s Greenhills Operations upgraded their fines circuit to include Wemco SmartCells in March 2007. Positive results were immediately achieved increasing the average flotation tailings ash by 16%. With this increase in yield the SmartCells project paid for itself in less than eight months. 2 figs., 1 tab., 1 photo.

  18. Spatial Cluster Detection of Air Pollution Exposure Inequities across the United States

    PubMed Central

    Zou, Bin; Peng, Fen; Wan, Neng; Mamady, Keita; Wilson, Gaines J.

    2014-01-01

    Air quality is known to be a key factor in affecting the wellbeing and quality of life of the general populous and there is a large body of knowledge indicating that certain underrepresented groups may be overexposed to air pollution. Therefore, a more precise understanding of air pollution exposure as a driving cause of health disparities between and among ethnic and racial groups is necessary. Utilizing 52,613 urban census tracts across the United States, this study investigates age, racial, educational attainment and income differences in exposure to benzene pollution in 1999 as a case. The study examines spatial clustering patterns of these inequities using logistic regression modeling and spatial autocorrelation methods such as the Global Moran's I index and the Anselin Local Moran's I index. Results show that the age groups of 0 to 14 and those over 60 years old, individuals with less than 12 years of education, racial minorities including Blacks, American Indians, Asians, some other races, and those with low income were exposed to higher levels of benzene pollution in some census tracts. Clustering analyses stratified by age, education, and race revealed a clear case of disparities in spatial distribution of exposure to benzene pollution across the entire United States. For example, people aged less than 4 years from the western south and the Pacific coastal areas exhibit statistically significant clusters. The findings confirmed that there are geographical-location based disproportionate pattern of exposures to benzene air pollution by various socio-demographic factors across the United States and this type of disproportionate exposure pattern can be effectively detected by a spatial autocorrelation based cluster analysis method. It is suggested that there is a clear and present need for programs and services that will reduce inequities and ultimately improve environmental conditions for all underrepresented groups in the United States. PMID:24647354

  19. Retrofitting Inefficient Rooftop Air-Conditioning Units Reduces U.S. Navy Energy Use (Fact Sheet)

    SciTech Connect

    Not Available

    2014-04-01

    As part of the U.S. Navy's overall energy strategy, the National Renewable Energy Laboratory (NREL) partnered with the Naval Facilities Engineering Command (NAVFAC) to demonstrate market-ready energy efficiency measures, renewable energy generation, and energy systems integration. One such technology - retrofitting rooftop air-conditioning units with an advanced rooftop control system - was identified as a promising source for reducing energy use and costs, and can contribute to increasing energy security.

  20. Future Tree Effects on Air Quality and Human Health in the United States

    NASA Astrophysics Data System (ADS)

    Hirabayashi, S.; Nowak, D.

    2014-12-01

    Trees are critical green infrastructure for mitigating adverse effects associated with human population, land use, and climate change (e.g. urban heat island, greenhouse gasses, air pollution, and floods). i-Tree (www.itreetools.org) is a suite of software tools developed by the USDA Forest Service and The Davey Institute that allows users to assess urban forest structure and the ecosystem services provided. Using i-Tree, the annual effects of trees on air quality and human health in urban and rural areas of counties across the conterminous United States have been quantified for 2010 (Nowak et al. 2014). Here, we extended the study to incorporate future forest structure scenarios using a model that accounts for tree growth, mortality and new plantings. Computer simulations using local environmental data and the possible leaf area index (LAI) for deciduous or evergreen tree covers were performed in urban and rural areas of counties across the conterminous United States. The result is a tree effects database on air pollutant removal (CO, NO2, O3, PM10, PM2.5 and SO2), biogenic emission of volatile organic compounds (VOCs), and monetary values associated with human health quantified per unit tree cover area with deciduous or evergreen trees and LAI ranging from 0 to 18 within each modeling domain. With these data, the potential annual effects that trees have on air quality and human health under future scenarios of urban forest extent can be readily derived for anywhere in the conterminous United States. The developed database will be integrated into i-Tree's suite in 2015 to enhance its functionality in estimating tree effects under the future scenarios.

  1. Spatial cluster detection of air pollution exposure inequities across the United States.

    PubMed

    Zou, Bin; Peng, Fen; Wan, Neng; Mamady, Keita; Wilson, Gaines J

    2014-01-01

    Air quality is known to be a key factor in affecting the wellbeing and quality of life of the general populous and there is a large body of knowledge indicating that certain underrepresented groups may be overexposed to air pollution. Therefore, a more precise understanding of air pollution exposure as a driving cause of health disparities between and among ethnic and racial groups is necessary. Utilizing 52,613 urban census tracts across the United States, this study investigates age, racial, educational attainment and income differences in exposure to benzene pollution in 1999 as a case. The study examines spatial clustering patterns of these inequities using logistic regression modeling and spatial autocorrelation methods such as the Global Moran's I index and the Anselin Local Moran's I index. Results show that the age groups of 0 to 14 and those over 60 years old, individuals with less than 12 years of education, racial minorities including Blacks, American Indians, Asians, some other races, and those with low income were exposed to higher levels of benzene pollution in some census tracts. Clustering analyses stratified by age, education, and race revealed a clear case of disparities in spatial distribution of exposure to benzene pollution across the entire United States. For example, people aged less than 4 years from the western south and the Pacific coastal areas exhibit statistically significant clusters. The findings confirmed that there are geographical-location based disproportionate pattern of exposures to benzene air pollution by various socio-demographic factors across the United States and this type of disproportionate exposure pattern can be effectively detected by a spatial autocorrelation based cluster analysis method. It is suggested that there is a clear and present need for programs and services that will reduce inequities and ultimately improve environmental conditions for all underrepresented groups in the United States.

  2. The Next Generation Air Particle Detectors for the United States Navy

    SciTech Connect

    Robert Hayes and Craig Marianno

    2007-06-24

    Design and testing of the United States Navy’s next generation air particle detector (NGAPD) is presently underway. The NGAPD is intended for use in nuclear applications for the United States Navy and is being designed to detect airborne Co-60 with a reduction in false alarms and improved ease of use. Features being developed include gamma compensation, low maintenance, commercial off-the-shelf electronics, and spectrum simulation for quality assurance and functional testing applications. By supplying a spectrum simulator, the radon stripping algorithm can be running when a simulated anthropogenic source spectrum (e.g., from Co-60 or transuranics) is superimposed on the radon progeny spectrum. This will allow alarm levels to be tested when the air flow is running and the radon stripping algorithm is providing the instrument response output. Modern units evaluate source spectra with the air flow off and the radon spectrum absent thereby not testing the true system performance which comes out of the radon stripping algorithm. Testing results of the preliminary prototype show promise along with computer simulations of source spectra. Primary testing results taken to date include gamma compensation, thermal insults, vibration and spectrum simulation.

  3. Air-chemistry studies over the Gulf of Mexico: a bilateral scientific cooperative project between the United States of America and the United States of Mexico. Technical memo

    SciTech Connect

    Parungo, F.; Miller, J.

    1988-02-01

    This report documents the scientific research of a bilateral cooperative project between the United States of America and The United States of America. In 1986 scientists from both nations joined a research cruise in the Gulf of Mexico to investigate the air chemistry over the water that the two nations share. Emphases were placed on natural air quality, anthropogenic air pollution, acid rain, air-sea-land exchanges of gases and aerosols. The investigation included in-situ measurements and post-cruise laboratory analyses. Chemical, physical, meteorological, and oceanographic analyses were conducted to survey temporal and spatial variations of diverse parameters throughout the Gulf. The data sets were analyzed, interpreted, and intercorrelated. The results show that during the cruise (20 July-22 August), the large-scale air trajectories were easterly from the Caribbean Sea at all levels; however, the Gulf air measured was highly polluted in general.

  4. Gas holdup in cyclone-static micro-bubble flotation column.

    PubMed

    Li, Xiaobing; Zhu, Wei; Liu, Jiongtian; Zhang, Jian; Xu, Hongxiang; Deng, Xiaowei

    2016-01-01

    The present work has been carried out to investigate the effect of process variables on gas holdup and develop an empirical equation and a neural network model for online process control of the gas holdup based on the operating variables. In this study, the effect of process variables (nozzle diameter, circulation pressure, aeration rate, and frother dosage) on gas holdup in a cyclone-static micro-bubble flotation column of an air/oily wastewater system was investigated. Gas holdup was estimated using a pressure difference method and an empirical equation was proposed to predict gas holdup. A general regression neural network (GRNN) model was also introduced to predict gas holdup for the cyclone-static micro-bubble flotation column. The predictions from the empirical equation and the GRNN are in good agreement with the experiment data for gas holdup, while the GRNN provides higher accuracy and stability compared with that of the empirical equation.

  5. Fungal spore concentrations in two haematopoietic stem cell transplantation (HSCT) units containing distinct air control systems.

    PubMed

    Brun, C P; Miron, D; Silla, L M R; Pasqualotto, A C

    2013-04-01

    Invasive fungal diseases have emerged as important causes of morbidity and mortality in haematological patients. In this study air samples were collected in two haematopoietic stem cell transplantation (HSCT) units, in which distinct air-control systems were in place. In hospital 1 no high-efficiency particulate air (HEPA) filter was available whereas in hospital 2 HSCT rooms were equipped with HEPA filters, with positive air pressure in relation to the corridor. A total of 117 samples from rooms, toilets and corridors were obtained during December 2009 to January 2011, using a six-stage Andersen sampler. In both hospitals, the concentration of potentially pathogenic fungi in the air was reduced in patients' rooms compared to corridors (P < 0·0001). Despite the presence of a HEPA filter in hospital 2, rooms in both hospitals showed similar concentrations of potentially pathogenic fungi (P = 0·714). These findings may be explained by the implementation of additional protective measures in hospital 1, emphasizing the importance of such measures in protected environments. PMID:22691688

  6. Test and evaluation of shale derived jet fuel by the United States Air Force

    SciTech Connect

    Delaney, C.L.

    1985-01-01

    In June 1980, the United States Congress passed the Energy Security Act which provided for the formation of the United States Synthetic Fuels Corporation and amended the Defense Production Act of 1950 to provide for synthetic fuels for the Department of Defense (DOD). A subsequent law, P.L., 96-304, appropriated up to $20 billion for financial incentives to foster a national synthetic fuel industry. The initial synthetic fuel project funded under the Energy Security Act is the Unocal Parachute Creek Project in Colorado with an expected shale oil production of 10,000 bbls/day. The Defense Fuel Supply Center (DFSC) contracted with Gary Energy Refining Company, Fruita, Colorado to provide approximately 5,000 bbls/day of shale JP-4 for the United States Air Force (USAF) using crude from the Parachute Creek Project, with initial deliveries to begin in 1985.

  7. A preliminary assessment of the Montreal process indicators of air pollution for the United States.

    PubMed

    Coulston, John W; Riitters, Kurt H; Smith, Gretchen C

    2004-07-01

    Air pollutants pose a risk to forest health and vitality in the United States. Here we present the major findings from a national scale air pollution assessment that is part of the United States' 2003 Report on Sustainable Forests. We examine trends and the percent forest subjected to specific levels of ozone and wet deposition of sulfate, nitrate, and ammonium. Results are reported by Resource Planning Act (RPA) reporting region and integrated by forest type using multivariate clustering. Estimates of sulfate deposition for forested areas had decreasing trends (1994-2000) across RPA regions that were statistically significant for North and South RPA regions. Nitrate deposition rates were relatively constant for the 1994 to 2000 period, but the South RPA region had a statistically decreasing trend. The North and South RPA regions experienced the highest ammonium deposition rates and showed slightly decreasing trends. Ozone concentrations were highest in portions of the Pacific Coast RPA region and relatively high across much of the South RPA region. Both the South and Rocky Mountain RPA regions had an increasing trend in ozone exposure. Ozone-induced foliar injury to sensitive species was recorded in all regions except for the Rocky Mountain region. The multivariate analysis showed that the oak-hickory and loblolly-shortleaf pine forest types were generally exposed to more air pollution than other forest types, and the redwood, western white pine, and larch forest types were generally exposed to less. These findings offer a new approach to national air pollution assessments and are intended to help focus research and planning initiatives related to air pollution and forest health. PMID:15195820

  8. A preliminary assessment of the Montreal process indicators of air pollution for the United States.

    PubMed

    Coulston, John W; Riitters, Kurt H; Smith, Gretchen C

    2004-07-01

    Air pollutants pose a risk to forest health and vitality in the United States. Here we present the major findings from a national scale air pollution assessment that is part of the United States' 2003 Report on Sustainable Forests. We examine trends and the percent forest subjected to specific levels of ozone and wet deposition of sulfate, nitrate, and ammonium. Results are reported by Resource Planning Act (RPA) reporting region and integrated by forest type using multivariate clustering. Estimates of sulfate deposition for forested areas had decreasing trends (1994-2000) across RPA regions that were statistically significant for North and South RPA regions. Nitrate deposition rates were relatively constant for the 1994 to 2000 period, but the South RPA region had a statistically decreasing trend. The North and South RPA regions experienced the highest ammonium deposition rates and showed slightly decreasing trends. Ozone concentrations were highest in portions of the Pacific Coast RPA region and relatively high across much of the South RPA region. Both the South and Rocky Mountain RPA regions had an increasing trend in ozone exposure. Ozone-induced foliar injury to sensitive species was recorded in all regions except for the Rocky Mountain region. The multivariate analysis showed that the oak-hickory and loblolly-shortleaf pine forest types were generally exposed to more air pollution than other forest types, and the redwood, western white pine, and larch forest types were generally exposed to less. These findings offer a new approach to national air pollution assessments and are intended to help focus research and planning initiatives related to air pollution and forest health.

  9. Evaluation of rhamnolipid (RL) as a biosurfactant for the removal of chromium from aqueous solutions by precipitate flotation.

    PubMed

    Salmani Abyaneh, Ali; Fazaelipoor, Mohammad Hassan

    2016-01-01

    Rhamnolipid (RL) is a biosurfactant which is produced by the bacterial species Pseudomonas aeruginosa. Although applications of this material have been examined in various fields, its applications in the flotation of heavy metals remain to be explored. In this research, rhamnolipid was applied as a collector in the flotation of Cr(III) from aqueous solutions. FeSO4 was used for the precipitation of Cr(VI) to Cr(III) which was subsequently removed by flotation. A two level full factorial design (with center points) was used to evaluate the effects of pH, air flow rate, RL/Cr and Fe/Cr molar ratios on the performance of the flotation system. The results showed that the biosurfactant was highly effective in the removal of chromium, and all of the factors had significant effects on the flotation performance. The chromium removal efficiencies of greater than 95% were obtained with the initial chromium concentration of 40 ppm within 5 min. Kinetic studies showed that a first order kinetic model was appropriate to describe the precipitate flotation of Cr(III) using rhamnolipid as a collector. The interference of NaCl, CaCl2, CaSO4, and CaCO3 on the Cr removal was also investigated, and it was demonstrated that CaSO4 and CaCO3 as sparingly water soluble salts, and CaCl2 as a contributor to water hardness had significant negative impacts on Cr removal efficiency of rhamnolipid.

  10. An investigation of variables in a fecal flotation technique.

    PubMed

    O'Grady, M R; Slocombe, J O

    1980-04-01

    Several variables in a standard vial fecal gravitational flotation technique were investigated. These were the specific gravity of the sodium nitrate flotation solution, duration of flotation and mesh sizes of strainers. The number of eggs which floated and adhered to a coverslip were counted and estimates of the number of eggs remaining in the strained fecal suspension and in the feces trapped on the strainer were made. Eggs from hookworms, Trichuris vulpis and Toxocara canis in feces from dogs, Nematodirus spp. from sheep and Parascaris equorum from horses floated equally well in solutions with specific gravities (SpGr) ranging from 1.22-1.38. Taenia spp. from dogs had a slightly narrower range (SpGr 1.27-1.38) for best recovery. Eggs from Haemonchus contortus from sheep appeared to float best between SpGr 1.22- 1.32. Strongyles from one horse floated best with SpGr 1.27-1.32 and from another with SpGr 1.11-1.38. Coccidial oocysts from sheep floated best in a narrow range of SpGr from 1.22-1.27. However, as the SpGr of the solution was increased the recognition of eggs under the coverslip was increasingly difficult and especially so at SpGr 1.38 with sheep feces. This was due to the increasing amount of debris and the more rapid formation of crystals with evaporation with solutions of higher SpGr. It appeared, therefore, that solutions with SpGr of 1.22-1.35 would be best for routine laboratory use. At specific gravity 1.27, there appeared to be no difference in the number of eggs recovered for a four, eight and 12 min flotation period. Only 3-7% of the eggs in 4 g of feces were counted under the coverslip. This poor efficacy resulted first because approximately 50% of the eggs were trapped in the feces and retained on the strainer. Secondly, only one half of the strained fecal suspension, containing approximately 25% of the eggs, was placed in the vial for examination. Thirdly, of those eggs in the vial only 16-29% were counted under the coverslip. When the

  11. An investigation of variables in a fecal flotation technique.

    PubMed

    O'Grady, M R; Slocombe, J O

    1980-04-01

    Several variables in a standard vial fecal gravitational flotation technique were investigated. These were the specific gravity of the sodium nitrate flotation solution, duration of flotation and mesh sizes of strainers. The number of eggs which floated and adhered to a coverslip were counted and estimates of the number of eggs remaining in the strained fecal suspension and in the feces trapped on the strainer were made. Eggs from hookworms, Trichuris vulpis and Toxocara canis in feces from dogs, Nematodirus spp. from sheep and Parascaris equorum from horses floated equally well in solutions with specific gravities (SpGr) ranging from 1.22-1.38. Taenia spp. from dogs had a slightly narrower range (SpGr 1.27-1.38) for best recovery. Eggs from Haemonchus contortus from sheep appeared to float best between SpGr 1.22- 1.32. Strongyles from one horse floated best with SpGr 1.27-1.32 and from another with SpGr 1.11-1.38. Coccidial oocysts from sheep floated best in a narrow range of SpGr from 1.22-1.27. However, as the SpGr of the solution was increased the recognition of eggs under the coverslip was increasingly difficult and especially so at SpGr 1.38 with sheep feces. This was due to the increasing amount of debris and the more rapid formation of crystals with evaporation with solutions of higher SpGr. It appeared, therefore, that solutions with SpGr of 1.22-1.35 would be best for routine laboratory use. At specific gravity 1.27, there appeared to be no difference in the number of eggs recovered for a four, eight and 12 min flotation period. Only 3-7% of the eggs in 4 g of feces were counted under the coverslip. This poor efficacy resulted first because approximately 50% of the eggs were trapped in the feces and retained on the strainer. Secondly, only one half of the strained fecal suspension, containing approximately 25% of the eggs, was placed in the vial for examination. Thirdly, of those eggs in the vial only 16-29% were counted under the coverslip. When the

  12. 33 CFR 183.325 - Flotation test for persons capacity.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Flotation test for persons capacity. 183.325 Section 183.325 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Flotation Requirements for Outboard Boats Rated for Engines of 2 Horsepower or...

  13. 33 CFR 183.225 - Flotation test for persons capacity.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Flotation test for persons capacity. 183.225 Section 183.225 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Flotation Requirements for Outboard Boats Rated for Engines of More Than 2...

  14. 33 CFR 183.202 - Flotation and certification requirements.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... SECURITY (CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Flotation Requirements for Outboard Boats Rated for Engines of More Than 2 Horsepower General § 183.202 Flotation and certification requirements. Each boat to which this subpart applies must be manufactured, constructed, or assembled to...

  15. 33 CFR 183.202 - Flotation and certification requirements.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... SECURITY (CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Flotation Requirements for Outboard Boats Rated for Engines of More Than 2 Horsepower General § 183.202 Flotation and certification requirements. Each boat to which this subpart applies must be manufactured, constructed, or assembled to...

  16. 46 CFR 170.245 - Foam flotation material.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... by reference; see 46 CFR 170.015), including the requirements for fire resistance. (3) A submergence... 46 Shipping 7 2012-10-01 2012-10-01 false Foam flotation material. 170.245 Section 170.245... REQUIREMENTS FOR ALL INSPECTED VESSELS Special Installations § 170.245 Foam flotation material....

  17. 46 CFR 170.245 - Foam flotation material.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... by reference; see 46 CFR 170.015), including the requirements for fire resistance. (3) A submergence... 46 Shipping 7 2011-10-01 2011-10-01 false Foam flotation material. 170.245 Section 170.245... REQUIREMENTS FOR ALL INSPECTED VESSELS Special Installations § 170.245 Foam flotation material....

  18. 46 CFR 170.245 - Foam flotation material.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 7 2014-10-01 2014-10-01 false Foam flotation material. 170.245 Section 170.245 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SUBDIVISION AND STABILITY STABILITY REQUIREMENTS FOR ALL INSPECTED VESSELS Special Installations § 170.245 Foam flotation material....

  19. Beneficiation of borax by reverse flotation in boron saturated brine.

    PubMed

    Cafer Cilek, Emin; Uresin, Hasan

    2005-10-15

    Flotation is one of the plausible methods for recovering borax fines discharged as fine waste to the tailings dam in the Kirka borax processing plant. A literature review dealing with the flotation behavior of boron minerals reveals that clay minerals in the boron ores coat boron minerals and thus deteriorate the quality of boron concentrates produced by direct flotation. The main objective of this study is therefore to recover borax fines from the tailings of the concentrator by reverse flotation. A three-level-factor experimental design was used to determine the main and interaction effects of variables selected on the metallurgical performance of reverse flotation. An analysis of variance for experimental results indicates that interaction effects of the variables for concentrate quality and recovery of B2O3 is nonsignificant and the most important variable for grade of concentrate and recovery is the collector dosage. It is shown that a concentrate assaying 11.25% B2O3 with 89.90% B2O3 recovery could be produced by means of single-stage (rougher) reverse flotation. Additionally, in order to produce a sufficient-quality concentrate, a multistage reverse flotation scheme involving rougher, scavenger, and two cleaners was devised. A final concentrate containing 23.47% B2O3 with 81.78% B2O3 recovery was obtained from these tests. The reverse flotation method can be thus considered as an important option for the beneficiation of borax fines.

  20. Pollution prevention opportunity assessment United States Naval Base Norfolk Naval Air Station. Project summary

    SciTech Connect

    Bowman, D.; DeWaters, J.

    1995-09-01

    The purposes of the WREAFS Program are to identify new technologies and techniques for reducing wastes from process operations and other activities at Federal sites, and to enhance the implementation of pollution prevention/waste minimization through technology transfer. New techniques and technologies for reducing waste generation are identified through waste minimization opportunity assessments and may be further evaluated through joint research, development, and demonstration projects. A cooling tower is an enclosed device designed for the evaporative cooling of water by direct contact with air. Cooling towers are used in conjunction with air conditioning and industrial process equipment, acting as the heat sink for these systems by providing a continuous source of cool water for process operations. Open-system recirculating cooling towers are typically chosen for operation with air conditioning and refrigeration equipment because they are relatively inexpensive and minimize heat rejection costs while conserving water. All of the cooling towers at the Norfolk Naval Air Station identified in this PPOA are of the recirculating, open-system type. The Navy and EPA are currently evaluating techniques and technologies to reduce wastes generated from cooling tower operations within the Norfolk NAS. Approximately 28 open-system recirculating cooling towers are currently operated at 18 buildings within the NAS. These units range in size from 5 to 300 tons, and are all associated with comfort cooling systems that operate on a seasonal basis (approximately 6 mo/yr).

  1. Method for simultaneous use of a single additive for coal flotation, dewatering and reconstitution

    SciTech Connect

    Wen, Wu-Wey; Gray, M.L.; Champagne, K.J.

    1993-11-09

    A single dose of additive contributes to three consecutive fine coal unit operations, i.e., flotation, dewatering and reconstitution, whereby the fine coal is first combined with water in a predetermined proportion so as to formulate a slurry. The slurry is then mixed with a heavy hydrocarbon-based emulsion in a second predetermined proportion and at a first predetermined mixing speed and for a predetermined period of time. The conditioned slurry is then cleaned by a froth flotation method to form a clean coal froth and then the froth is dewatered by vacuum filtration or a centrifugation process to form reconstituted products that are dried to dust-less clumps prior to combustion.

  2. Method for simultaneous use of a single additive for coal flotation, dewatering, and reconstitution

    DOEpatents

    Wen, Wu-Wey; Gray, McMahan L.; Champagne, Kenneth J.

    1995-01-01

    A single dose of additive contributes to three consecutive fine coal unit operations, i.e., flotation, dewatering and reconstitution, whereby the fine coal is first combined with water in a predetermined proportion so as to formulate a slurry. The slurry is then mixed with a heavy hydrocarbon-based emulsion in a second predetermined proportion and at a first predetermined mixing speed and for a predetermined period of time. The conditioned slurry is then cleaned by a froth flotation method to form a clean coal froth and then the froth is dewatered by vacuum filtration or a centrifugation process to form reconstituted products that are dried to dust-less clumps prior to combustion.

  3. Engineering development of advanced physical fine coal cleaning technologies: Froth flotation

    SciTech Connect

    Not Available

    1992-01-01

    In order to develop additional confidence in the conceptual design of the advanced froth flotation circuit, a 2-3 TPH Proof-of-Concept (POC) facility was necessary. During operation of this facility, the ICF KE team will demonstrate the ability of the conceptual flowsheets to meet the program goals of maximum pyritic sulfur reduction coupled with maximum energy recovery on three DOE specified coals. The POC circuit was designed to be integrated into the Ohio Coal Development's facility near Beverly, Ohio. OCDO's facility will provide the precleaning unit operations and ICF KE will add the advanced froth flotation circuitry. The work in this task will include the POC conceptual design, flowsheet development, equipment list, fabrication and construction drawings, procurement specifications and bid packages and a facilities.

  4. Air pollution response to changing weather and power plant emissions in the eastern United States

    NASA Astrophysics Data System (ADS)

    Bloomer, Bryan Jaye

    Air pollution in the eastern United States causes human sickness and death as well as damage to crops and materials. NOX emission reduction is observed to improve air quality. Effectively reducing pollution in the future requires understanding the connections between smog, precursor emissions, weather, and climate change. Numerical models predict global warming will exacerbate smog over the next 50 years. My analysis of 21 years of CASTNET observations quantifies a climate change penalty. I calculate, for data collected prior to 2002, a climate penalty factor of ˜3.3 ppb O3/°C across the power plant dominated receptor regions in the rural, eastern U.S. Recent reductions in NOX emissions decreased the climate penalty factor to ˜2.2 ppb O3/°C. Prior to 1995, power plant emissions of CO2, SO2, and NOX were estimated with fuel sampling and analysis methods. Currently, emissions are measured with continuous monitoring equipment (CEMS) installed directly in stacks. My comparison of the two methods show CO 2 and SO2 emissions are ˜5% lower when inferred from fuel sampling; greater differences are found for NOX emissions. CEMS are the method of choice for emission inventories and commodity trading and should be the standard against which other methods are evaluated for global greenhouse gas trading policies. I used CEMS data and applied chemistry transport modeling to evaluate improvements in air quality observed by aircraft during the North American electrical blackout of 2003. An air quality model produced substantial reductions in O3, but not as much as observed. The study highlights weaknesses in the model as commonly used for evaluating a single day event and suggests areas for further investigation. A new analysis and visualization method quantifies local-daily to hemispheric-seasonal scale relationships between weather and air pollution, confirming improved air quality despite increasing temperatures across the eastern U.S. Climate penalty factors indicate

  5. Learning Styles of Pilots Currently Qualified in United States Air Force Aircraft

    NASA Technical Reports Server (NTRS)

    Kanske, Craig A.

    2001-01-01

    Kolb's Learning Style Inventory was used to identify the predominant learning styles of pilots currently qualified in United States Air Force aircraft. The results indicate that these pilots show a significant preference for facts and things over people and feelings. By understanding the preferred learning styles of the target population, course material can be developed that take advantage of the strengths of these learning styles. This information can be especially useful in the future design of cockpit resource management training. The training program can be developed to demonstrate both that there are different learning styles and that it is possible to take advantage of the relative strengths of each of these learning styles.

  6. Air Quality Impacts of Increased Use of Ethanol under the United States' Energy Independence and Security Act

    EPA Science Inventory

    Increased use of ethanol in the United States fuel supply will impact emissions and ambient concentrations of greenhouse gases, “criteria” pollutants for which the U. S. EPA sets ambient air quality standards, and a variety of air toxic compounds. This paper focuses on impacts of...

  7. 14 CFR Special Federal Aviation... - Prohibition Against Certain Flights by Syrian Air Carriers to the United States

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... Syrian Air Carriers to the United States Federal Special Federal Aviation Regulation No. 104 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR TRAFFIC AND GENERAL OPERATING RULES GENERAL OPERATING AND FLIGHT RULES Pt. 91, SFAR No. 104 Special Federal...

  8. 14 CFR Special Federal Aviation... - Prohibition Against Certain Flights by Syrian Air Carriers to the United States

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... Syrian Air Carriers to the United States Federal Special Federal Aviation Regulation No. 104 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR TRAFFIC AND GENERAL OPERATING RULES GENERAL OPERATING AND FLIGHT RULES Pt. 91, SFAR No. 104 Special Federal...

  9. 14 CFR Special Federal Aviation... - Prohibition Against Certain Flights by Syrian Air Carriers to the United States

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Syrian Air Carriers to the United States Federal Special Federal Aviation Regulation No. 104 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR TRAFFIC AND GENERAL OPERATING RULES GENERAL OPERATING AND FLIGHT RULES Pt. 91, SFAR No. 104 Special Federal...

  10. 14 CFR Special Federal Aviation... - Prohibition Against Certain Flights by Syrian Air Carriers to the United States

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... Syrian Air Carriers to the United States Federal Special Federal Aviation Regulation No. 104 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR TRAFFIC AND GENERAL OPERATING RULES GENERAL OPERATING AND FLIGHT RULES Pt. 91, SFAR No. 104 Special Federal...

  11. 14 CFR Special Federal Aviation... - Prohibition Against Certain Flights by Syrian Air Carriers to the United States

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... Syrian Air Carriers to the United States Federal Special Federal Aviation Regulation No. 104 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR TRAFFIC AND GENERAL OPERATING RULES GENERAL OPERATING AND FLIGHT RULES Pt. 91, SFAR No. 104 Special Federal...

  12. Application of the Gestalt Theory of Learning in Teaching a Unit of Study Dealing with Air Pollution in Polk County.

    ERIC Educational Resources Information Center

    Nelson, Hershel H.

    This practicum was designed to demonstrate the value of Gestalt learning theory in teaching a unit of study on air pollution in Polk County, Florida. Students researched specific viewpoints based upon assigned positions in regard to air pollution (Cattlemen's Association, Florida Phosphate Council, Florida Citrus Mutual, Mid-State Lung…

  13. Visualized study on the interaction between single bubbles and curved solid surface in flotation separation process.

    PubMed

    Yang, Liwei; Zhao, Yue; Yang, Jingjing; Li, Yanpeng; Meng, Qinglong

    2014-01-01

    The present study has been devoted to bubble-curved solid surface interaction in water, which is critical to the separation of suspended particles by air flotation. For this purpose, two particular stages of the interaction (collision and attachment) have been examined visually using high-speed photography in a laboratory-scale flotation column. The effects of the surface material and surfactant concentration on these two stages have been also studied quantitatively. The considered solid materials are the cleaned glass as hydrophilic surface and Teflon as hydrophobic surface. The experimental results show that the presence of surfactant significantly affects the collision and rebound process of a gas bubble, while there is no obvious effect of the surface material on the rebound process. An increase in surfactant concentration has been observed to suppress the rebound number and maximal distance of the bubble from the surface. Moreover, the three-phase contact time of the bubble is a strong function of the surfactant concentration and surface hydrophobicity as well as of the bubble diameter. Another important finding is that the bubble attachment is only observed at the hydrophobic Teflon surface below the surfactant CMC (critical micelle concentration). Results of this study are relevant for deep understanding of the attachment mechanism and to determine the proper conditions for a selective flotation process.

  14. High Electricity Demand in the Northeast U.S.: PJM Reliability Network and Peaking Unit Impacts on Air Quality.

    PubMed

    Farkas, Caroline M; Moeller, Michael D; Felder, Frank A; Henderson, Barron H; Carlton, Annmarie G

    2016-08-01

    On high electricity demand days, when air quality is often poor, regional transmission organizations (RTOs), such as PJM Interconnection, ensure reliability of the grid by employing peak-use electric generating units (EGUs). These "peaking units" are exempt from some federal and state air quality rules. We identify RTO assignment and peaking unit classification for EGUs in the Eastern U.S. and estimate air quality for four emission scenarios with the Community Multiscale Air Quality (CMAQ) model during the July 2006 heat wave. Further, we population-weight ambient values as a surrogate for potential population exposure. Emissions from electricity reliability networks negatively impact air quality in their own region and in neighboring geographic areas. Monitored and controlled PJM peaking units are generally located in economically depressed areas and can contribute up to 87% of hourly maximum PM2.5 mass locally. Potential population exposure to peaking unit PM2.5 mass is highest in the model domain's most populated cities. Average daily temperature and national gross domestic product steer peaking unit heat input. Air quality planning that capitalizes on a priori knowledge of local electricity demand and economics may provide a more holistic approach to protect human health within the context of growing energy needs in a changing world. PMID:27385064

  15. High Electricity Demand in the Northeast U.S.: PJM Reliability Network and Peaking Unit Impacts on Air Quality.

    PubMed

    Farkas, Caroline M; Moeller, Michael D; Felder, Frank A; Henderson, Barron H; Carlton, Annmarie G

    2016-08-01

    On high electricity demand days, when air quality is often poor, regional transmission organizations (RTOs), such as PJM Interconnection, ensure reliability of the grid by employing peak-use electric generating units (EGUs). These "peaking units" are exempt from some federal and state air quality rules. We identify RTO assignment and peaking unit classification for EGUs in the Eastern U.S. and estimate air quality for four emission scenarios with the Community Multiscale Air Quality (CMAQ) model during the July 2006 heat wave. Further, we population-weight ambient values as a surrogate for potential population exposure. Emissions from electricity reliability networks negatively impact air quality in their own region and in neighboring geographic areas. Monitored and controlled PJM peaking units are generally located in economically depressed areas and can contribute up to 87% of hourly maximum PM2.5 mass locally. Potential population exposure to peaking unit PM2.5 mass is highest in the model domain's most populated cities. Average daily temperature and national gross domestic product steer peaking unit heat input. Air quality planning that capitalizes on a priori knowledge of local electricity demand and economics may provide a more holistic approach to protect human health within the context of growing energy needs in a changing world.

  16. Fault tree analysis for exposure to refrigerants used for automotive air conditioning in the United States.

    PubMed

    Jetter, J J; Forte, R; Rubenstein, R

    2001-02-01

    A fault tree analysis was used to estimate the number of refrigerant exposures of automotive service technicians and vehicle occupants in the United States. Exposures of service technicians can occur when service equipment or automotive air-conditioning systems leak during servicing. The number of refrigerant exposures of service technicians was estimated to be 135,000 per year. Exposures of vehicle occupants can occur when refrigerant enters passenger compartments due to sudden leaks in air-conditioning systems, leaks following servicing, or leaks caused by collisions. The total number of exposures of vehicle occupants was estimated to be 3,600 per year. The largest number of exposures of vehicle occupants was estimated for leaks caused by collisions, and the second largest number of exposures was estimated for leaks following servicing. Estimates used in the fault tree analysis were based on a survey of automotive air-conditioning service shops, the best available data from the literature, and the engineering judgement of the authors and expert reviewers from the Society of Automotive Engineers Interior Climate Control Standards Committee. Exposure concentrations and durations were estimated and compared with toxicity data for refrigerants currently used in automotive air conditioners. Uncertainty was high for the estimated numbers of exposures, exposure concentrations, and exposure durations. Uncertainty could be reduced in the future by conducting more extensive surveys, measurements of refrigerant concentrations, and exposure monitoring. Nevertheless, the analysis indicated that the risk of exposure of service technicians and vehicle occupants is significant, and it is recommended that no refrigerant that is substantially more toxic than currently available substitutes be accepted for use in vehicle air-conditioning systems, absent a means of mitigating exposure. PMID:11332544

  17. Fault tree analysis for exposure to refrigerants used for automotive air conditioning in the United States.

    PubMed

    Jetter, J J; Forte, R; Rubenstein, R

    2001-02-01

    A fault tree analysis was used to estimate the number of refrigerant exposures of automotive service technicians and vehicle occupants in the United States. Exposures of service technicians can occur when service equipment or automotive air-conditioning systems leak during servicing. The number of refrigerant exposures of service technicians was estimated to be 135,000 per year. Exposures of vehicle occupants can occur when refrigerant enters passenger compartments due to sudden leaks in air-conditioning systems, leaks following servicing, or leaks caused by collisions. The total number of exposures of vehicle occupants was estimated to be 3,600 per year. The largest number of exposures of vehicle occupants was estimated for leaks caused by collisions, and the second largest number of exposures was estimated for leaks following servicing. Estimates used in the fault tree analysis were based on a survey of automotive air-conditioning service shops, the best available data from the literature, and the engineering judgement of the authors and expert reviewers from the Society of Automotive Engineers Interior Climate Control Standards Committee. Exposure concentrations and durations were estimated and compared with toxicity data for refrigerants currently used in automotive air conditioners. Uncertainty was high for the estimated numbers of exposures, exposure concentrations, and exposure durations. Uncertainty could be reduced in the future by conducting more extensive surveys, measurements of refrigerant concentrations, and exposure monitoring. Nevertheless, the analysis indicated that the risk of exposure of service technicians and vehicle occupants is significant, and it is recommended that no refrigerant that is substantially more toxic than currently available substitutes be accepted for use in vehicle air-conditioning systems, absent a means of mitigating exposure.

  18. The sensitivity of direct faecal examination, direct faecal flotation, modified centrifugal faecal flotation and centrifugal sedimentation/flotation in the diagnosis of canine spirocercosis.

    PubMed

    Christie, J; Schwan, E V; Bodenstein, L L; Sommerville, J E M; van der Merwe, L L

    2011-06-01

    Several faecal examination techniques have shown variable sensitivity in demonstrating Spirocerca lupi (S. lupi) eggs. The objective of this study was to determine which faecal examination technique, including a novel modified centrifugal flotation technique, was most sensitive to diagnose spirocercosis. Ten coproscopic examinations were performed on faeces collected from 33 dogs confirmed endoscopically to have spirocercosis. The tests included a direct faecal examination, a faecal sedimentation/flotation test, 4 direct faecal flotations and 4 modified faecal centrifugal flotations. These latter 2 flotation tests utilised 4 different faecal flotation solutions: NaNO3 (SG 1.22), MgSO4 (SG 1.29), ZnSO4 (SG 1.30) and sugar (SG 1.27). The sensitivity of the tests ranged between 42% and 67%, with the NaNO3 solution showing the highest sensitivity in both the direct and modified-centrifugal flotations. The modified NaNO3 centrifugal method ranked 1st with the highest mean egg count (45.24 +/- 83), and was superior (i.e. higher egg count) and significantly different (P < 0.05) compared with the routine saturated sugar, ZnSO4 and MgSO4 flotation methods. The routine NaNO3 flotation method was also superior and significantly different (P < 0.05) compared with the routine ZnSO4 and MgSO4 flotation methods. Fifteen per cent (n = 5) of dogs had neoplastic oesophageal nodules and a further 18% (n = 6) had both neoplastic and non-neoplastic nodules. S. lupi eggs were demonstrated in 40% of dogs with neoplastic nodules only and 72.9% of the dogs with non-neoplastic nodules. The mean egg count in the non-neoplastic group (61) was statistically greater (P = 0.02) than that of the neoplastic group (1). The results show that faecal examination using a NaNO3 solution is the most sensitive in the diagnosis of spirocercosis. The modified centrifugal flotation faecal method using this solution has the highest egg count. The study also found that dogs with neoplastic nodules shed

  19. The removal of heavy metals from contaminated soil by a combination of sulfidisation and flotation.

    PubMed

    Vanthuyne, Mathias; Maes, André

    2002-05-01

    The possibility of removing cadmium, copper, lead and zinc from Belgian loamy soil by a combination of sulfidisation pre-treatment and Denver flotation was investigated. The potentially available--sulfide convertible--metal content of the metal polluted soil was estimated by EDTA (0.1 M, pH 4.65) extraction and BCR sequential extraction. EDTA extraction is better at approximating the metal percentage that is expected to be convertible into a metal sulfide phase, in contrast to the sequential extraction procedure of 'Int. J. Environ. Anal. Chem. 51 (1993) pp. 135-151' in which transition metals present as iron oxide co-precipitates are dissolved by hydroxylammoniumchloride in the second extraction step. To compare the surface characteristics of metal sulfides formed by sulfidisation with those of crystalline metal sulfides, two types of synthetic sediments were prepared and extracted with 0.1 M EDTA (pH 4.65) in anoxic conditions. Separate metal sulfides or co-precipitates with iron sulfide were formed by sulfide conditioning. The Denver flotation of both types of synthetic sediments (kerosene as collector at high background electrolyte concentrations) resulted in similar concentrating factors for freshly formed metal sulfides as for fine-grained crystalline metal sulfides. The selective flotation of metal sulfides after sulfide conditioning of a polluted soil, using kerosene or potassium ethyl xanthate as collectors and MIBC as frother, was studied at high background electrolyte concentrations. The sulfidisations were made in ambient air and inside an anoxic glove box. The concentrating factors corrected by the potentially available metal percentage, determined by 0.1 M EDTA extraction, lie between 2 and 3. The selective flotation of these finely dispersed, amorphous, metal sulfides can possibly be improved by optimising the bubble-particle interaction. PMID:12083717

  20. Climate Change and Health Risks from Extreme Heat and Air Pollution in the Eastern United States

    NASA Astrophysics Data System (ADS)

    Limaye, V.; Vargo, J.; Harkey, M.; Holloway, T.; Meier, P.; Patz, J.

    2013-12-01

    Climate change is expected to exacerbate health risks from exposure to extreme heat and air pollution through both direct and indirect mechanisms. Directly, warmer ambient temperatures promote biogenic emissions of ozone precursors and favor the formation of ground-level ozone, while an anticipated increase in the frequency of stagnant air masses will allow fine particulates to accumulate. Indirectly, warmer summertime temperatures stimulate energy demand and exacerbate polluting emissions from the electricity sector. Thus, while technological adaptations such as air conditioning can reduce risks from exposures to extreme heat, they can trigger downstream damage to air quality and public health. Through an interdisciplinary modeling effort, we quantify the impacts of climate change on ambient temperatures, summer energy demand, air quality, and public health. The first phase of this work explores how climate change will directly impact the burden of heat-related mortality. Climatic patterns, demographic trends, and epidemiologic risk models suggest that populations in the eastern United States are likely to experience an increasing heat stress mortality burden in response to rising summertime air temperatures. We use North American Regional Climate Change Assessment Program modeling data to estimate mid-century 2-meter air temperatures and humidity across the eastern US from June-August, and quantify how long-term changes in actual and apparent temperatures from present-day will affect the annual burden of heat-related mortality across this region. With the US Environmental Protection Agency's Environmental Benefits Mapping and Analysis Program, we estimate health risks using concentration-response functions, which relate temperature increases to changes in annual mortality rates. We compare mid-century summertime temperature data, downscaled using the Weather Research and Forecasting model, to 2007 baseline temperatures at a 12 km resolution in order to estimate

  1. Spinning Reserves from Controllable Packaged Through the Wall Air Conditioner (PTAC) Units

    SciTech Connect

    Kirby, B.J.

    2003-04-02

    This report summarizes the feasibility of providing spinning reserves from packaged through the wall air conditioning (PTAC) units. Spinning reserves, together with non-spinning reserves, compose the contingency reserves; the essential resources that the power system operator uses to restore the generation and load balance and maintain bulk power system reliability in the event of a major generation or transmission outage. Spinning reserves are the fastest responding and most expensive reserves. Many responsive load technologies could (and we hope will) be used to provide spinning reserve. It is also easier for many loads (including air conditioning loads) to provide the relatively shorter and less frequent interruptions required to respond to contingencies than it is for them to reduce consumption for an entire peak period. Oak Ridge National Laboratory (ORNL) is conducting research on obtaining spinning reserve from large pumping loads and from residential and small commercial thermostat controlled heating, ventilation and air conditioning (HVAC) units. The technology selected for this project, Digi-Log's retrofit PTAC controller, offers significant advantages. To evaluate the availability of spinning reserve capacity from responsive heating and air conditioning loads, ORNL obtained data from a number of units operating over a year at a motel in the TVA service territory. A total of 24 PTAC units in as many rooms were fitted with Digi-Log's supervisory control unit that could be controlled from the motel front desk. Twelve of the rooms formed the group in which the controller was controlled from the hotel front desk only. The remaining twelve rooms were controlled by the occupant and formed the uncontrolled group. This enables us to evaluate the spinning reserve capacity from PTACS that were operating normally and from those under active energy management. A second generation of the Digi-Log controller that will respond quickly enough to provide spinning reserve

  2. Lagrangian particle modeling of air pollution transport in southwestern United States

    SciTech Connect

    Uliasz, M.; Stocker, R.A.; Pielke, R.A.

    1994-12-31

    Several modeling techniques of various complexity and accuracy are applied in a numerical modeling study of regional air pollution transport being performed within the Measurement Of Haze And Visual Effect (MOHAVE) project. The goal of this study is to assess the impact of the Mohave Power Project (MPP) and other potential sources of air pollution to specific Class I areas located in the desert southwest United States including the Grand Canyon National Park. The Colorado State University team is performing the daily meteorological and dispersion simulations for a year long study using a nonhydrostatic mesoscale meteorological model; the Regional Atmospheric Modeling System (RAMS) coupled with a Lagrangian particle dispersion (LPD) model. The modeling domain covers the southwestern United States with its extremely complex terrain. Two complementary dispersion modeling techniques: a traditional source-oriented approach and receptor-oriented approach are used to calculate concentration and influence function fields, respectively. All computations are performed on two IBM RISC-6000 workstations dedicated to the project. The goal of this paper is to present our design for daily dispersion simulations with an emphasis on influence function calculations using examples from the winter and summer intensive periods of the MOHAVE project.

  3. Electrostatic augmentation of fabric filtration: Reverse-air pilot unit experience

    NASA Astrophysics Data System (ADS)

    Vanosdell, D. W.; Furlong, D. A.

    1984-08-01

    The use of a pilot unit (consisting of two baghouses in a parallel-flow arrangement on a slipstream from an industrial pulverized-coal boiler house) to test electrostatically augmented fabric filtration (ESFF) in a reverse-air cleaning model is described. The method is characterized by electrodes arranged about 2 cm apart around the circumference of the bag and running the length of the bag. An electric field of 2-4 kV/cm is maintained between the electrodes and perpendicular to the gas flow. Results showed that ESFF can reduce fabric filter pressure drops and may allow reverse-air filtration at a 2 cm/s face velocity, rather than the conventional 1 cm/s. A filter bag with stainless steel electrodes woven into the fabric was developed for the reverse-air tests as part of this research. The woven-in electrode and the potential for doubling the face velocity appear to make ESFF economically attractive for commercial baghouse users.

  4. Air Quality and Respiratory Health among Adolescents from the United Arab Emirates

    PubMed Central

    Dghaim, Rania

    2015-01-01

    Purpose. To examine the role of air quality in relation to chronic bronchitis, emphysema, asthma, wheeze, and dry cough among adolescents from the United Arab Emirates (UAE). Methods. A survey was administered on 6,363 adolescents from 9 UAE regions. Data consists of demographic, socioeconomic, residential, and behavioural variables, such as location of residence, residing near industry/gas stations/dumpsites/construction sites, residing near overhead power line/plants, exposure to tobacco, residential exposure, ethnicity, concern over air pollution, smoking, and purposely smelling gasoline fumes/glue/correctors/car exhaust/burning black ants. Logistic regression modeling was used to determine significant predictors of respiratory health. Results. Asthma prevalence was 12.3%, followed by chronic bronchitis (1.8%) and emphysema (0.5%). Overall 12.2% reported wheeze and 34.8% reported a dry nocturnal cough in the past year. Multivariate analyses suggest that sex is a significant predictor of asthma and dry cough. Exposure to tobacco and arts/crafts/ceramics/stain is significant predictor of respiratory health. Tobacco smoking and purposely smelling gasoline fumes/glue/correctors/car exhaust/burning black ants are significant predictors of wheeze and dry cough. Conclusions. This study suggests that exposure to air quality and behavioral factors such as smoking and purposely smelling gasoline fumes, glue, correctors, car exhaust, or burning black ants are significant predictors of respiratory health among UAE adolescents. PMID:26074980

  5. Removal of wax and stickies from OCC by flotation. Progress report No. 3, July 1--September 30, 1998

    SciTech Connect

    Dosh, M.R.; Dyer, J.; Heise, O.; Cao, B.

    1998-11-01

    In this quarter we completed low consistency laboratory pulping trials. Pulping results were analyzed in terms of defibering index or yield and the concentration of free wax. The objective of these trials is to identify pulping conditions that will give higher yield and higher concentration of free wax. The yields from low consistency pulping trials ranged from 90 to 99% based on 6-cut laboratory screen rejects. In general, high temperatures (140-150{degrees}F) and high pH (9.5-10) conditions resulted in higher yield and the generation of free wax. Factors such as rotor speed and the gap (between the rotor and grate) were not significant in affecting defibering. Generally, the turbidities of filtrates from wax-contaminated pulps increased with increase in temperature and/or pH. The filtrate turbidity indicated the relative concentration of finely dispersed wax that could be removed from pulp dewatered on a 30 {micro}m filter paper. Preliminary experiments were conducted to study flotation conditions necessary for effective removal of wax from pulp. Factors which are important for effective flotation include flotation time, volume of air, surfactant concentration and type, and low temperature. Future plans include additional flotation trials to better optimize conditions. Other contaminant types include pressure sensitive adhesives and hot melts will also be examined. This will be followed by pilot plant and mill trials.

  6. Removal of wax and stickies from OCC by flotation. Progress report No. 3, July 1--September 30, 1998

    SciTech Connect

    Doshi, M.R.; Dyer, J.; Heise, O.; Cao, B.

    1998-11-01

    In this quarter we completed low consistency laboratory pulping trials. Pulping results were analyzed in terms of defibering index or yield and the concentration of free wax. The objective of these trials is to identify pulping conditions that will give higher yield and higher concentration of free wax. The yields from low consistency pulping trials ranged from 90 to 99% based on 6-cut laboratory screen rejects. In general, high temperatures (140-150{degree}F) and high pH (9.5-10) conditions resulted in higher yield and the generation of free wax. Factors such as rotor speed and the gap (between the rotor and grate) were not significant in affecting defibering. Generally, the turbidities of filtrates from wax-contaminated pulps increased with increase in temperature and/or pH. The filtrate turbidity indicated the relative concentration of finely dispersed wax that could be removed from pulp dewatered on a 30 {micro}m filter paper. Preliminary experiments were conducted to study flotation conditions necessary for effective removal of wax from pulp. Factors which are important for effective flotation include flotation time, volume of air, surfactant concentration and type, and low temperature. Future plans include additional flotation trials to better optimize conditions. Other contaminant types include pressure sensitive adhesives and hot melts will also be examined. This will be followed by pilot plant and mill trials.

  7. Energy Savings and Economics of Advanced Control Strategies for Packaged Air-Conditioning Units with Gas Heat

    SciTech Connect

    Wang, Weimin; Katipamula, Srinivas; Huang, Yunzhi; Brambley, Michael R.

    2011-12-31

    Pacific Northwest National Laboratory (PNNL) with funding from the U.S. Department of Energy's Building Technologies Program (BTP) evaluated a number of control strategies that can be implemented in a controller, to improve the operational efficiency of the packaged air conditioning units. The two primary objectives of this research project are: (1) determine the magnitude of energy savings achievable by retrofitting existing packaged air conditioning units with advanced control strategies not ordinarily used for packaged units and (2) estimating what the installed cost of a replacement control with the desired features should be in various regions of the U.S. This document reports results of the study.

  8. Hot-Air Balloon Tours: Crash Epidemiology in the United States, 2000-2011

    PubMed Central

    Ballard, Sarah-Blythe; Beaty, Leland P.; Baker, Susan P.

    2016-01-01

    Introduction Hot-air balloon tours are FAR Part 91-governed balloon rides conducted for compensation or hire. Part 91, General Aviation, in general involves the least strict federal regulations and accounts for the majority of aviation crashes and fatalities. Methods National Transportation Safety Board reports of hot-air balloon tour crashes in the United States from 2000 through 2011 were read and analyzed. Results During the 12-yr period, 78 hot-air balloon tours crashed, involving 518 occupants. There were 91 serious injuries and 5 fatalities; 83% of crashes resulted in one or more serious or fatal outcomes. Of the serious injuries characterized, 56% were lower extremity fractures. Most crashes (81%) occurred during landing; 65% involved hard landings. Fixed object collisions contributed to 50% of serious injuries and all 5 fatalities. During landing sequences, gondola dragging, tipping, bouncing, and occupant ejection were associated with poor outcomes. Of the crashes resulting in serious or fatal outcomes, 20% of balloons were significantly damaged or destroyed. Discussion The incidence of morbidity and mortality is high among hot-air balloon tour crashes, and the proportion of balloon crashes attributed to paid rides appears to have increased over time. In addition to examining the role of restraint systems, personal protective equipment, and power line emergency procedures in ballooning, injury prevention efforts should target factors such hard landings, object strikes, gondola instability, and occupant ejections, which are associated with balloon injuries and deaths. Crash outcomes may also improve with vehicle engineering that enables balloons themselves to absorb impact forces. PMID:24279231

  9. SURFACTANT SPRAY: A NOVEL TECHNOLOGY TO IMPROVE FLOTATION DEINKING PERFORMANCE

    SciTech Connect

    Yulin Deng; Junyong Zhu

    2004-01-31

    Based on the fundamental understanding of ink removal and fiber loss mechanism in flotation deinking process, we developed this innovative technology using surfactant spray to improve the ink removal efficiency, reduce the water and fiber loss, reduce the chemical consumption and carry over in the flotation deinking. The innovative flotation deinking process uses a spray to deliver the frothing agent during flotation deinking to control several key process variables. The spray can control the foam stability and structure and modify the fluid dynamics to reduce the fibers entrapped in the froth layer. The froth formed at the top part of the flotation column will act as a physical filter to prevent the penetration of frothing agent into the pulp suspension to eliminate fiber contamination and unfavorable deinking surface chemistry modification due to surfactant adsorption on the fiber surface. Because of the filter effect, frothing agents will be better utilized. Under the sponsorships of the US Dept. of Energy (DOE) and the member companies of the Institute of Paper Science and Technology, we studied the chem-mechanical mechanism of surfactant spray for flotation deinking using different furnishes, chemicals, and flotation devices in the past four years. In the final year of the project, we successfully conducted mill trials at Abitibi-Consolidated, Inc., Snowflake paper recycling operation of 100% mixture of ONP/OMG. Results from laboratory, pilot-plant and mill trials indicated that surfactant spray technology can significantly reduce fiber loss in flotation deinking. It can be concluded that paper industry can profit greatly when this technology is commercialized in flotation deinking mills.

  10. Relationship between the merit factor of thermoelectric materials and the air conditioning unit of urban electric cars

    NASA Astrophysics Data System (ADS)

    Buffet, Jean

    1994-08-01

    The main benefit of electric cars is to reduce air pollution in cities that is thus desirable to equip them with non polluting air conditioning units and this rules out frigorific compressors operating with CFC. The planned replacement of CFC by HFC is at best an interim solution. The best solution is certainly to use thermoelectric air conditioning units, which are inherently pollution-free. However, these have a fairly low COPF when compared to traditional compressor units. We study the relationship between the cooling of the interior of urban electric cars and the merit factor of the thermoelectric material in their Peltier unit. This should help provide concrete target properties of future T E materials.

  11. Relationship between the merit factor of thermoelectric materials and the air conditioning unit of urban electric cars

    SciTech Connect

    Buffet, J.

    1994-08-10

    The main benefit of electric cars is to reduce air pollution in cities that is thus desirable to equip them with non polluting air conditioning units and this rules out frigorific compressors operating with CFC. The planned replacement of CFC by HFC is at best an interim solution. The best solution is certainly to use thermoelectric air conditioning units, which are inherently pollution-free. However, these have a fairly low COPF when compared to traditional compressor units. We study the relationship between the cooling of the interior of urban electric cars and the merit factor of the thermoelectric material in their Peltier unit. This should help provide concrete target properties of future T E materials. {copyright} {ital 1995} {ital American} {ital Institute} {ital of} {ital Physics}.

  12. Flotation Experiments with Seafloor-Sampled Pumice Lapilli, IODP 340 - Preliminary Results

    NASA Astrophysics Data System (ADS)

    Jutzeler, M.; Manga, M.; White, J. D.

    2012-12-01

    A 1.25-m-thick, unconsolidated unit of pink pumice lapilli was recovered at site U1396, IODP expedition 340. The drilling site lies at the top of an entirely submarine ridge in a back-arc of the Lesser Antilles volcanic arc, 35 km offshore from Montserrat Island. The unit was recovered from 122 m below sea floor, at a water depth of ~800 m. Preliminary biostratigraphy and paleomagnetic analysis yield an age of ~4 Ma. This age is much older than any rocks from the island of Montserrat, suggesting that the pumice lapilli unit may have submarine origin. In addition, the pumice lapilli unit has a grading and sorting that does not match conventional eruption-fed products from air-fall or turbidity currents. The pumice lapilli unit was recovered at two holes 40 m apart, and is identical in the two cores. The change in grain size in the stratigraphy of the unit defines a weak stratification. The pumice lapilli unit comprises two main sub-units, with four ash-rich intervals. The lower sub-unit is ~20 cm thick, framework-supported, and dominated by angular white tube-pumice lapilli (2-4 mm); dense lithic clasts (2 mm) are concentrated at the base of this sub-unit. The upper sub-unit is 1 m thick, and mostly composed of angular to sub-angular, white tube pumice lapilli (average 4 mm, max 32 mm), in a pink ash matrix. The ash is chiefly composed of micro-pumice clasts, feldspar and ferromagnesian crystal fragments, glass shards, and lithic clasts that commonly contain fresh pyrite. Three main parameters constrain the floatability of pumice clasts in water: vesicularity, clast size and shape, and clast temperature. The connected vesicularity of the pumice clasts was measured by subtracting the weight of dry pumice clasts from their water-saturated weight, and by functional stereology applied on SEM images. Clast-size distribution and clast shape were measured by particle size analyzer (CILAS) and sieving. We carried out pyroclast flotation and settling experiments in an

  13. Changes in the frequency of extreme air pollution events over the Eastern United States and Europe

    NASA Astrophysics Data System (ADS)

    Rieder, H. E.; Fiore, A. M.; Fang, Y.; Staehelin, J.

    2011-12-01

    Over the past few decades, thresholds for national air quality standards, intended to protect public health and welfare, have been lowered repeatedly. At the same time observations, over Europe and the Eastern U.S., demonstrate that extreme air pollution events (high O3 and PM2.5) are typically associated with stagnation events. Recent work showed that in a changing climate high air pollution events are likely to increase in frequency and duration. Within this work we examine meteorological and surface ozone observations from CASTNet over the U.S. and EMEP over Europe and "idealized" simulations with the GFDL AM3 chemistry-climate model, which isolate the role of climate change on air quality. Specifically, we examine an "idealized 1990s" simulation, forced with 20-year mean monthly climatologies for sea surface temperatures and sea ice from observations for 1981-2000, and an "idealized 2090s" simulation forced by the observed climatologies plus the multi-model mean changes in sea surface temperature and sea ice simulated by 19 IPCC AR-4 models under the A1B scenario for 2081-2100. With innovative statistical tools (empirical orthogonal functions (EOFs) and statistics of extremes (EVT)), we analyze the frequency distribution of past, present and future extreme air pollution events over the Eastern United States and Europe. The upper tail of observed values at individual stations (e.g., within the CASTNet), i.e., the extremes (maximum daily 8-hour average (MDA8) O3>60ppb) are poorly described by a Gaussian distribution. However, further analysis showed that applying Peak-Over-Threshold-models, better capture the extremes and allows us to estimate return levels of pollution events above certain threshold values of interest. We next apply EOF analysis to identify regions that vary coherently within the ground-based monitoring networks. Over the United States, the first EOF obtained from the model in both the 1990s and 2090s idealized simulations identifies the

  14. Swimming kinematic and flotation analysis of conscious and sedated dogs using 3 canine flotation devices.

    PubMed

    Corum, China Prentice; Wichtowski, Maja; Hetts, Suzanne; Estep, Dan; Bertone, Joseph J

    2014-12-01

    Canine flotation devices (CFDs) are very popular; however, their efficacy is still under debate. There is no oversight to standardize device testing, certification, or qualification for use. We set out to assess the biomechanical and behavioral effects of 3 CFDs on swim and flotation characteristics of dogs. High-speed video recordings were used to measure behavior, range of motion (ROM), maximum flexion angle, and cycles of motion per minute while swimming and roll, yaw, and fear or panic scoring while floating. Predictably, swimming with no CFD yielded the largest ROM and flexion angles. CFDINF was associated with the least ROM. During flotation, CFDAB and CFDRW caused significant rolling and fear, whereas CFDINF was the most stable. CFDAB was associated with cranial downpitch in 2 dogs. Interpretation of the kinematics for CFDAB and CFDRW suggests that decreased stability in the water leads to a greater forced ROM when the position of the dog was conducive to swimming. When positioning forced the dog into a downward pitch, ROM was decreased because of the increased effort for the dogs to keep their head above water. CFDINF was most stable overall owing to a decreased swim effort, with most dogs showing the lowest fear scores and absolute relaxation. CFDAB and CFDRW caused the dogs significant rolling, fear, and distress, with obvious fighting of sedation. We hope to disseminate these results to dog owners in the hopes of providing a valid assessment of these devices.

  15. Ranking Cancer Risks of Organic Hazardous Air Pollutants in the United States

    PubMed Central

    Loh, Miranda M.; Levy, Jonathan I.; Spengler, John D.; Houseman, E. Andres; Bennett, Deborah H.

    2007-01-01

    Background In this study we compared cancer risks from organic hazardous air pollutants (HAPs) based on total personal exposure summed across different microenvironments and exposure pathways. Methods We developed distributions of personal exposure concentrations using field monitoring and modeling data for inhalation and, where relevant, ingestion pathways. We calculated risks for a nonoccupationally exposed and nonsmoking population using U.S. Environmental Protection Agency (EPA) and California Office of Environmental Health and Hazard Assessment (OEHHA) unit risks. We determined the contribution to risk from indoor versus outdoor sources using indoor/outdoor ratios for gaseous compounds and the infiltration factor for particle-bound compounds. Results With OEHHA’s unit risks, the highest ranking compounds based on the population median are 1,3-butadiene, formaldehyde, benzene, and dioxin, with risks on the order of 10−4–10−5. The highest risk compounds with the U.S. EPA unit risks were dioxin, benzene, formaldehyde, and chloroform, with risks on a similar order of magnitude. Although indoor exposures are responsible for nearly 70% of risk using OEHHA’s unit risks, when infiltration is accounted for, inhalation of outdoor sources contributed 50% to total risk, on average. Additionally, 15% of risk resulted from exposures through food, mainly due to dioxin. Conclusions Most of the polycyclic aromatic hydrocarbon, benzene, acetaldehyde, and 1,3-butadiene risk came from outdoor sources, whereas indoor sources were primarily responsible for chloroform, formaldehyde, and naphthalene risks. The infiltration of outdoor pollution into buildings, emissions from indoor sources, and uptake through food are all important to consider in reducing overall personal risk to HAPs. PMID:17687442

  16. 77 FR 59391 - Delta Air Lines, Inc., Continental Airlines, Inc., JetBlue Airways Corporation, United Air Lines...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-27

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Delta Air Lines, Inc., Continental Airlines, Inc., JetBlue Airways...(a) and 343.2(c); Delta Air Lines, Inc., Continental Airlines, Inc., JetBlue Airways...

  17. An analysis of post-traumatic stress symptoms in United States Air Force drone operators.

    PubMed

    Chappelle, Wayne; Goodman, Tanya; Reardon, Laura; Thompson, William

    2014-06-01

    Remotely piloted aircraft (RPA), commonly referred to as "drones," have emerged over the past decade as an innovative warfighting tool. Given there is a paucity of empirical research assessing drone operators, the purpose of this study was to assess for the prevalence of PTSD symptoms among this cohort. Of the 1084 United States Air Force (USAF) drone operators that participated, a total of 4.3% endorsed a pattern of symptoms of moderate to extreme level of severity meeting criteria outlined in the Diagnostic and Statistical Manual of Mental Disorders-4th edition. The incidence of PTSD among USAF drone operators in this study was lower than rates of PTSD (10-18%) among military personnel returning from deployment but higher than incidence rates (less than 1%) of USAF drone operators reported in electronic medical records. Although low PTSD rates may be promising, limitations to this study are discussed.

  18. Effects of two ergonomic improvements in brazing coils of air-handler units.

    PubMed

    Loo, H S; Yeow, Paul H P

    2015-11-01

    The research aims to address the physically loading task and quality and productivity problems in the brazing of coils of air-handler units. Eight operators participated in two intervention studies conducted in a factory in Malaysia to compare the status quo brazing with (1) the use of a new twin-brazing torch that replaced the single-brazing gun and (2) brazing in a sitting position. The outcome measures are related to quality, productivity, monetary costs, body postures and symptoms. After baseline, Interventions I and II were applied for 3 months respectively. The results show a 58.9% quality improvement, 140% productivity increase and 113 times ROI. There was also a reduction in poor work postures e.g. in the raising of the arms and shoulders; bending, twisting and extending of the neck; and bending of left and right wrists, and the back. This research can be replicated in other factories that share similar processes.

  19. Eielson Air Force Base operable unit 2 and other areas record of decision

    SciTech Connect

    Lewis, R.E.; Smith, R.M.

    1994-10-01

    This decision document presents the selected remedial actions and no action decisions for Operable Unit 2 (OU2) at Eielson Air Force Base (AFB), Alaska, chosen in accordance with state and federal regulations. This document also presents the decision that no further action is required for 21 other source areas at Eielson AFB. This decision is based on the administrative record file for this site. OU2 addresses sites contaminated by leaks and spills of fuels. Soils contaminated with petroleum products occur at or near the source of contamination. Contaminated subsurface soil and groundwater occur in plumes on the top of a shallow groundwater table that fluctuates seasonally. These sites pose a risk to human health and the environment because of ingestion, inhalation, and dermal contact with contaminated groundwater. The purpose of this response is to prevent current or future exposure to the contaminated groundwater, to reduce further contaminant migration into the groundwater, and to remediate groundwater.

  20. An analysis of post-traumatic stress symptoms in United States Air Force drone operators.

    PubMed

    Chappelle, Wayne; Goodman, Tanya; Reardon, Laura; Thompson, William

    2014-06-01

    Remotely piloted aircraft (RPA), commonly referred to as "drones," have emerged over the past decade as an innovative warfighting tool. Given there is a paucity of empirical research assessing drone operators, the purpose of this study was to assess for the prevalence of PTSD symptoms among this cohort. Of the 1084 United States Air Force (USAF) drone operators that participated, a total of 4.3% endorsed a pattern of symptoms of moderate to extreme level of severity meeting criteria outlined in the Diagnostic and Statistical Manual of Mental Disorders-4th edition. The incidence of PTSD among USAF drone operators in this study was lower than rates of PTSD (10-18%) among military personnel returning from deployment but higher than incidence rates (less than 1%) of USAF drone operators reported in electronic medical records. Although low PTSD rates may be promising, limitations to this study are discussed. PMID:24907535

  1. Effects of two ergonomic improvements in brazing coils of air-handler units.

    PubMed

    Loo, H S; Yeow, Paul H P

    2015-11-01

    The research aims to address the physically loading task and quality and productivity problems in the brazing of coils of air-handler units. Eight operators participated in two intervention studies conducted in a factory in Malaysia to compare the status quo brazing with (1) the use of a new twin-brazing torch that replaced the single-brazing gun and (2) brazing in a sitting position. The outcome measures are related to quality, productivity, monetary costs, body postures and symptoms. After baseline, Interventions I and II were applied for 3 months respectively. The results show a 58.9% quality improvement, 140% productivity increase and 113 times ROI. There was also a reduction in poor work postures e.g. in the raising of the arms and shoulders; bending, twisting and extending of the neck; and bending of left and right wrists, and the back. This research can be replicated in other factories that share similar processes. PMID:26154237

  2. [Health problems in air-conditioned treatment rooms in a pediatric intensive care unit].

    PubMed

    Senkpiel, K; Ohgke, H; Beckert, J

    1994-04-01

    Personnel of a pediatric intensive care unit claimed health problems due to air draughts. Mucous membrane symptoms such as burning eyes, an increased number of colds as well as headaches and stiff necks were the most frequent complaints. According to our indoor climate analysis high turbulence intensities were the main cause for thermal discomfort (Tumax = 88%, Tumin = 50%, median = 58% at measuring position Nr. 7). The percentage of people dissatisfied due to draught (PD value) were for example PDmax = 31%, PDmin = 6.7%, median = 16% at measuring position Nr. 7. In addition the humidification device of the HVAC system was not run continuously resulting in relative humidities below existing standards (51% r.h. in summer and 28% r.h. during the heating period).

  3. Zircon-rutile-ilmenite froth flotation process

    SciTech Connect

    Schmidt, R.; Denham, D.L. Jr.

    1992-04-21

    This patent describes a method for separating a mixture of minerals comprising at least zircon, ilmenite and rutile. It comprises adding an acid solution to the mixture to acidify to a pH of between about 2.0 and 6.0; adding starch to the mixture to depress the ilmenite and the rutile; adding a source of fluoride ions to the mixture to provide a negative surface charge on the zircon surface to activate the zircon; adding an amine cationic collector to the mixture to float the activated zircon; subjecting the mixture containing the added acid solution, the fluoride ions, the starch and the cationic collector, to froth flotation; and withdrawing a float product comprising the zircon and a sink product comprising the ilmenite and rutile.

  4. The flotation column as a froth separator

    SciTech Connect

    Schultz, C.W.; Mehta, R.K.; Bates, J.B. )

    1991-12-01

    The Mineral Resources Institute, The University of Alabama, has for the past three years been engaged in a program to develop a beneficiation system for eastern (Devonian) oil shales. One objective of that program was to evaluate advanced technologies for effecting a kerogen-mineral matter separation. Column flotation was among the advanced technologies selected for evaluation. One observation made in the course of optimization testing was that introducing the feed into the froth (above the pulp- froth interface) resulted in an improved combination of concentrate grade and kerogen recovery. This observation was reported in a previous paper. Because the practice of maintaining the pulp froth interface below the feed point is contrary to conventional practice, it was decided to subject the observation to a systematic series of tests. This paper describes a recent series of tests and the results that were obtained.

  5. Revision of testing criteria for air cleaning unit of renovated APR-1000 and APR-1400 NPPS.

    PubMed

    Jeong, Seung-Young

    2011-07-01

    Designing Air Cleaning Units (ACU) of an Engineered Safety Feature and normal atmosphere clean-up system at the renovated APR-1000 and APR-1400 NPP, and fuel cycle facilities in Korea, is required to meet the standards of ASME AG-1 (1997), ASME N509/N510 (1989) and KEPIC-MH (2001) to enhance the removal efficiency of aerosols and particulates from the effluents. The revised ACU testing criteria are allowed to use alternative challenge agents of the dioctyl phthalate and Refrigerant-11 for in situ testing of high efficiency particulate air filters and adsorption banks. The operability testing time of engineered safety feature (ESF) trains was changed from 10 h to 15 min. The activated carbon in adsorption banks should undergo laboratory tests at a temperature of 30 °C and relative humidity 95 %. The removal criteria of methyl iodide should be over 99.5 % for ESF and 99 % for normal systems. This paper provides the background of the changed criteria for designing and testing of the ACU system in nuclear facilities.

  6. Operable Unit 1 remedial investigation report, Eielson Air Force Base, Alaska

    SciTech Connect

    Gilmore, T.J.; Fruland, R.M.; Liikala, T.L.

    1994-06-01

    This remedial investigation report for operable Unit 1 (OU-1) at Eielson Air Force Base presents data, calculations, and conclusions as to the nature and extent of surface and subsurface contamination at the eight source areas that make up OU-1. The information is based on the 1993 field investigation result and previous investigations. This report is the first in a set of three for OU-1. The other reports are the baseline risk assessment and feasibility study. The information in these reports will lead to a Record of Decision that will guide and conclude the environmental restoration effort for OU-1 at Eielson Air Force Base. The primary contaminants of concern include fuels and fuel-related contaminants (diesel; benzene, toluene, ethylbenzene, and xylene; total petroleum hydrocarbon; polycyclic aromatic hydrocarbons), maintenance-related solvents and cleaners (volatile chlorinated hydrocarbons such as trichloroothylene), polychlorinated biphenyls, and dichlorodiphenyltrichloroethane (DDT). The origins of contaminants of concern include leaks from storage tanks, drums and piping, and spills. Ongoing operations and past sitewide practices also contribute to contaminants of concern at OU-1 source areas. These include spraying mixed oil and solvent wastes on unpaved roads and aerial spraying of DDT.

  7. Thermodynamic and transport combustion properties of hydrocarbons with air. Part 1: Properties in SI units

    NASA Astrophysics Data System (ADS)

    Gordon, S.

    1982-07-01

    Thermodynamic and transport combustion properties were calculated for a wide range of conditions for the reaction of hydrocarbons with air. Three hydrogen-carbon atom ratios (H/C = 1.7, 2.0, 2.1) were selected to represent the range of aircraft fuels. For each of these H/C ratios, combustion properties were calculated for the following conditions: Equivalence ratio: 0, 0.25, 0.5, 0.75, 1.0, 1.25 Water - dry air mass ratio: 0, 0.03 Pressure, kPa: 1.01325, 10.1325, 101.325, 1013.25, 5066.25 (or in atm: 0.01, 0.1, 1, 10, 50) Temperature, K: every 10 degrees from 200 to 900 K; every 50 degrees from 900 to 3000 K Temperature, R: every 20 degrees from 360 to 1600 R; very 100 degrees from 1600 to 5400 R. The properties presented are composition, density, molecular weight, enthalphy, entropy, specific heat at constant pressure, volume derivatives, isentropic exponent, velocity of sound, viscosity, thermal conductivity, and Prandtl number. Property tables are based on composites that were calculated by assuming both: (1) chemical equilibrium (for both homogeneous and heterogeneous phases) and (2) constant compositions for all temperatures. Properties in SI units are presented in this report for the Kelvin temperature schedules.

  8. Analyzing a database of residential air leakage in the United States

    NASA Astrophysics Data System (ADS)

    Chan, Wanyu R.; Nazaroff, William W.; Price, Phillip N.; Sohn, Michael D.; Gadgil, Ashok J.

    We analyzed more than 70,000 air leakage measurements in houses across the United States to relate leakage area—the effective size of all penetrations of the building shell—to readily available building characteristics such as building size, year built, geographic region, and various construction characteristics. After adjusting for the lack of statistical representativeness of the data, we found that the distribution of leakage area normalized by floor area is approximately lognormal. Based on a classification tree analysis, year built and floor area are the two most significant predictors of leakage area: older and smaller houses tend to have higher normalized leakage areas than newer and larger ones. Multivariate regressions of normalized leakage are presented with respect to these two factors for three house classifications: low-income households, energy program houses, and conventional houses. We demonstrate a method of applying the regression model to housing characteristics from the American Housing Survey to derive a leakage-area distribution for all single-family houses in the US. The air exchange rates implied by these estimates agree reasonably well with published measurements.

  9. Thermodynamic and transport combustion properties of hydrocarbons with air. Part 1: Properties in SI units

    NASA Technical Reports Server (NTRS)

    Gordon, S.

    1982-01-01

    Thermodynamic and transport combustion properties were calculated for a wide range of conditions for the reaction of hydrocarbons with air. Three hydrogen-carbon atom ratios (H/C = 1.7, 2.0, 2.1) were selected to represent the range of aircraft fuels. For each of these H/C ratios, combustion properties were calculated for the following conditions: Equivalence ratio: 0, 0.25, 0.5, 0.75, 1.0, 1.25 Water - dry air mass ratio: 0, 0.03 Pressure, kPa: 1.01325, 10.1325, 101.325, 1013.25, 5066.25 (or in atm: 0.01, 0.1, 1, 10, 50) Temperature, K: every 10 degrees from 200 to 900 K; every 50 degrees from 900 to 3000 K Temperature, R: every 20 degrees from 360 to 1600 R; very 100 degrees from 1600 to 5400 R. The properties presented are composition, density, molecular weight, enthalphy, entropy, specific heat at constant pressure, volume derivatives, isentropic exponent, velocity of sound, viscosity, thermal conductivity, and Prandtl number. Property tables are based on composites that were calculated by assuming both: (1) chemical equilibrium (for both homogeneous and heterogeneous phases) and (2) constant compositions for all temperatures. Properties in SI units are presented in this report for the Kelvin temperature schedules.

  10. Effect and mechanism of siderite on reverse flotation of hematite

    NASA Astrophysics Data System (ADS)

    Yin, Wan-zhong; Li, Dong; Luo, Xi-mei; Yao, Jin; Sun, Qian-yu

    2016-04-01

    The effects of siderite on reverse flotation of hematite were investigated using micro flotation, adsorption tests, and Fourier transform infrared spectroscopy. The flotation results show that interactions between siderite and quartz are the main reasons that siderite significantly influences the floatability. The interactions are attributed to dissolved siderite species and fine siderite particles. The interaction due to the dissolved species is, however, dominant. Derjaguin-Landau-Verwey-Overbeek (DLVO) theoretical calculations reveal that adhesion on quartz increases when the siderite particle size decreases and that fine particles partly influence quartz floatability. Chemical solution calculations indicate that the dissolved species of siderite might convert the surface of active quartz to CaCO3 precipitates that can be depressed by starch. The theoretical calculations are in good agreement with the results of adsorption tests and FTIR spectroscopy and explain the reasons why siderite significantly influences reverse flotation of hematite.

  11. 33 CFR 183.114 - Test of flotation materials.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... vapor atmosphere for 30 days at a minimum temperature of 38 °C. (b) 24-hour gasoline test. The flotation... water. (h) The buoyant force reduction in paragraphs (a) through (g) of this section is measured...

  12. FLOTATION ROOM, LOOKING SOUTHWEST, WITH LEAD ROUGHER CELLS AT RIGHT ...

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

    FLOTATION ROOM, LOOKING SOUTHWEST, WITH LEAD ROUGHER CELLS AT RIGHT AND LEAD CLEANER CELLS AT LEFT. NOTE SUNNYSIDE GOLD CORP. "SG" LOGO ON ROUGHER CELL LAUNDER. - Shenandoah-Dives Mill, 135 County Road 2, Silverton, San Juan County, CO

  13. Coal desulfurization by bacterial treatment and column flotation. Final report

    SciTech Connect

    Kawatra, S.K.

    1994-06-01

    A review of the literature showed that bacterial leaching, using the microorganism Thiobacillus ferrooxidans, was a very effective technique for removing pyrite from coal, as it could dissolve even the finest pyrite particles without the need for expensive reagents or extreme processing conditions. Unfortunately, bacterial leaching is also rather slow, and so the initial goal of this research was to decrease the leaching time as much as possible. However, this still left the bacteria needing approximately a week to remove half of the pyritic sulfur, and so a faster technique was sought. Since it had been reported in the literature that T. ferrooxidans could be used to depress the flotation of pyrite during froth flotation of coal, this was investigated further. By studying the recovery mechanisms of coal-pyrite in froth flotation, it was found that pyrite was being recovered by entrainment and by locking to coal particles, not by true flotation of hydrophobic pyrite. Therefore, no pyrite depressant could be of any significant benefit for keeping pyrite out of the coal froth product, and it was much more important to prevent entrainment from occurring. Countercurrent flotation columns were invented to essentially eliminate entrainment effects, by washing the froth and reducing mixing of the froth and tailings products. Existing flotation columns tend to be quite simple, and in order to give reasonable product quality they must be very tall (typically 30--45 feet). As a result, they have difficulty in handling the high froth volumes which occur in coal flotation, and are awkward to install in existing plants. The bulk of this project therefore concentrated on developing an improved coal flotation column, and testing it under actual plant conditions.

  14. Cross flow cyclonic flotation column for coal and minerals beneficiation

    DOEpatents

    Lai, Ralph W.; Patton, Robert A.

    2000-01-01

    An apparatus and process for the separation of coal from pyritic impurities using a modified froth flotation system. The froth flotation column incorporates a helical track about the inner wall of the column in a region intermediate between the top and base of the column. A standard impeller located about the central axis of the column is used to generate a centrifugal force thereby increasing the separation efficiency of coal from the pyritic particles and hydrophillic tailings.

  15. Superfund record of decision (EPA Region 1): Otis Air National Guard (USAF), Operable Unit 3, Falmouth, MA, September 30, 1998

    SciTech Connect

    1999-03-01

    The Massachusetts Military Reservation (MMR) on Cape Cod, Massachusetts, lies within the boundaries of the towns of Falmouth, Mashpee, Sandwich, and Bourne. The Area of Contamination (AOC) known as Chemical Spill 3 United States Coast Guard (CS-3 (USCG)) is located on Lee Road, in the south central portion of the MMR. The Air Force Center for Environmental Excellence (AFCEE) Installation Restoration Program Office at Otis Air National Guard (ANG) Base, Massachusetts.

  16. Experimental tests and predictive model of an adsorptive air conditioning unit

    SciTech Connect

    Poyelle, F.; Guilleminot, J.J.; Meunier, F.

    1999-01-01

    An adsorption air conditioning unit has been built operating with a heat nd mass recovery cycle and a zeolite-water pair. A new consolidated adsorbent composite with good heat transfer properties has been developed and implemented in the adsorber. At an evaporating temperature of 4 C, the experimental specific cooling power (SCP) of 97 W/kg achieved represents a real improvement in comparison with those measured with a packed bed technology. At this evaporating pressure, the mass transfer resistance controls the process. Therefore, at higher evaporating temperature a COP of 0.68 and a SCP of 135 W/kg were experimentally achieved. A new model has been developed to take into account the mass transfer limitations. The model has been validated and can predict the average pressure inside the adsorber and the components temperature of the unit. A new high conductive material with enhanced mass transfer properties has been developed. The predictive model shows that a SCP of 600 W/kg and a COP of 0.74 could be achieved with this new material.

  17. Interfacial interactions between plastic particles in plastics flotation.

    PubMed

    Wang, Chong-qing; Wang, Hui; Gu, Guo-hua; Fu, Jian-gang; Lin, Qing-quan; Liu, You-nian

    2015-12-01

    Plastics flotation used for recycling of plastic wastes receives increasing attention for its industrial application. In order to study the mechanism of plastics flotation, the interfacial interactions between plastic particles in flotation system were investigated through calculation of Lifshitz-van der Waals (LW) function, Lewis acid-base (AB) Gibbs function, and the extended Derjaguin-Landau-Verwey-Overbeek potential energy profiles. The results showed that van der Waals force between plastic particles is attraction force in flotation system. The large hydrophobic attraction, caused by the AB Gibbs function, is the dominant interparticle force. Wetting agents present significant effects on the interfacial interactions between plastic particles. It is found that adsorption of wetting agents promotes dispersion of plastic particles and decreases the floatability. Pneumatic flotation may improve the recovery and purity of separated plastics through selective adsorption of wetting agents on plastic surface. The relationships between hydrophobic attraction and surface properties were also examined. It is revealed that there exists a three-order polynomial relationship between the AB Gibbs function and Lewis base component. Our finding provides some insights into mechanism of plastics flotation.

  18. Modelling Of Flotation Processes By Classical Mathematical Methods - A Review

    NASA Astrophysics Data System (ADS)

    Jovanović, Ivana; Miljanović, Igor

    2015-12-01

    Flotation process modelling is not a simple task, mostly because of the process complexity, i.e. the presence of a large number of variables that (to a lesser or a greater extent) affect the final outcome of the mineral particles separation based on the differences in their surface properties. The attempts toward the development of the quantitative predictive model that would fully describe the operation of an industrial flotation plant started in the middle of past century and it lasts to this day. This paper gives a review of published research activities directed toward the development of flotation models based on the classical mathematical rules. The description and systematization of classical flotation models were performed according to the available references, with emphasize exclusively given to the flotation process modelling, regardless of the model application in a certain control system. In accordance with the contemporary considerations, models were classified as the empirical, probabilistic, kinetic and population balance types. Each model type is presented through the aspects of flotation modelling at the macro and micro process levels.

  19. Boiling treatment of ABS and PS plastics for flotation separation.

    PubMed

    Wang, Chong-qing; Wang, Hui; Wu, Bao-xin; Liu, Qun

    2014-07-01

    A new physical method, namely boiling treatment, was developed to aid flotation separation of acrylonitrile-butadiene-styrene (ABS) and polystyrene (PS) plastics. Boiling treatment was shown to be effective in producing a hydrophilic surface on ABS plastic. Fourier Transform Infrared analysis was conducted to investigate the mechanism of boiling treatment of ABS. Surface rearrangement of polymer may be responsible for surface change of boiling treated ABS, and the selective influence of boiling treatment on the floatability of boiling treated plastics may be attributed to the difference in the molecular mobility of polymer chains. The effects of flotation time, frother concentration and particle size on flotation behavior of simple plastic were investigated. Based on flotation behavior of simple plastic, flotation separation of boiling treatment ABS and PS with different particle sizes was achieved efficiently. The purity of ABS and PS was up to 99.78% and 95.80%, respectively; the recovery of ABS and PS was up to 95.81% and 99.82%, respectively. Boiling treatment promotes the industrial application of plastics flotation and facilitates plastic recycling.

  20. Interfacial interactions between plastic particles in plastics flotation.

    PubMed

    Wang, Chong-qing; Wang, Hui; Gu, Guo-hua; Fu, Jian-gang; Lin, Qing-quan; Liu, You-nian

    2015-12-01

    Plastics flotation used for recycling of plastic wastes receives increasing attention for its industrial application. In order to study the mechanism of plastics flotation, the interfacial interactions between plastic particles in flotation system were investigated through calculation of Lifshitz-van der Waals (LW) function, Lewis acid-base (AB) Gibbs function, and the extended Derjaguin-Landau-Verwey-Overbeek potential energy profiles. The results showed that van der Waals force between plastic particles is attraction force in flotation system. The large hydrophobic attraction, caused by the AB Gibbs function, is the dominant interparticle force. Wetting agents present significant effects on the interfacial interactions between plastic particles. It is found that adsorption of wetting agents promotes dispersion of plastic particles and decreases the floatability. Pneumatic flotation may improve the recovery and purity of separated plastics through selective adsorption of wetting agents on plastic surface. The relationships between hydrophobic attraction and surface properties were also examined. It is revealed that there exists a three-order polynomial relationship between the AB Gibbs function and Lewis base component. Our finding provides some insights into mechanism of plastics flotation. PMID:26337962

  1. Effects of Automobile Emissions on Air Pollution in the United States

    NASA Astrophysics Data System (ADS)

    Cohen, Ryan; Singh, Ramesh

    2016-07-01

    Currently, about more than 253,000,000 automobiles and trucks, some are new, old, gas and electric, ply on the roads in the United States of America. Around the world, human activities and energy demand are the main sources for the air pollution and ozone depletion, causing dense haze, fog and smog especially during winter season in the country like China and India and also observed in different parts of the world. In recent years, automakers have been pushed by new governmental regulations and global expectations to create more fuel-efficient vehicles that burn less fossil fuels and create fewer harmful emissions. Automakers are exploring alternative fuel options such as hydrogen, natural gas, hybrids, and completely electric vehicles. Since the Nissan Leaf's introduction in 2010, fully electric vehicles have become widely produced and just fewer than 400,000 fully electric cars have been sold in the United States. Taking the influx of more fuel-efficient and alternative energy vehicles in the market into account, we have analyzed satellite and ground observed atmospheric pollution and greenhouse gases during 2009-2014 in the United States of America. Our results show that the increasing population of hybrid and fuel efficient vehicles have cut down the atmospheric pollution and greenhouse emissions in US in general, whereas in California the pollution level has increased as a result frequency of fog and haze events are seen during winter season. We will present a comparison of atmospheric pollution over US and California State in view of the increasing hybrid and fuel efficient vehicles.

  2. Microhydrodynamics of flotation processes in the sea surface layer

    NASA Astrophysics Data System (ADS)

    Grammatika, Marianne; Zimmerman, William B.

    2001-10-01

    The uppermost surface of the ocean forms a peculiarly important ecosystem, the sea surface microlayer (SML). Comprising the top 1-1000 μm of the ocean surface, the SML concentrates many chemical substances, particularly those that are surface active. Important economically as a nursery for fish eggs and larvae, the SML unfortunately is also especially vulnerable to pollution. Contaminants that settle out from the air, have low solubility, or attach to floatable matter tend to accumulate in the SML. Bubbles contribute prominently to the dynamics of air-sea exchanges, playing an important role in geochemical cycling of material in the upper ocean and SML. In addition to the movement of bubbles, the development of a bubble cloud interrelates with the single particle dynamics of all other bubbles and particles. In the early sixties, several in situ oceanographic techniques revealed an "unbelievably immense" number of coastal bubbles of radius 15-300 μm. The spatial and temporal variation of bubble numbers were studied; acoustical oceanographers now use bubbles as tracers to determine ocean processes near the ocean surface. Sea state and rain noises have both been definitively ascribed to the radiation from huge numbers of infant micro bubbles [The Acoustic Bubble. Academic Press, San Diego]. Our research programme aims at constructing a hydrodynamic model for particle transport processes occurring at the microscale, in multi-phase flotation suspensions. Current research addresses bubble and floc microhydrodynamics as building blocks for a microscale transport model. This paper reviews sea surface transport processes in the microlayer and the lower atmosphere, and identifies those amenable to microhydrodynamic modelling and simulation. It presents preliminary simulation results including the multi-body hydrodynamic mobility functions for the modelling of "dynamic bubble filters" and floc suspensions. Hydrodynamic interactions versus spatial anisotropy and size of

  3. United States Air Force 611th Air Support Group Civil Engineering Squadron, Elmendorf AFB, Alaska. Remedial investigation and feasibility study Point Lay Radar Installation, Alaska. Final report

    SciTech Connect

    Karmi, S.

    1996-03-04

    The United States Air Force (Air Force) has prepared this Remedial Investigation/Feasibility Study (RI/FS) report to present the results of RI/FS activities at four sites located at the Point Lay radar installation. The remedial investigation (RI) field activities were conducted at the Point Lay radar installation during the summer of 1993. The four sites at Point Lay were investigated because they were suspected of being contaminated with hazardous substances. RI activities were conducted using methods and procedures specified in the RI/FS Work Plan, Sampling and Analysis Plan (SAP), and Health and Safety Plan.

  4. The impacts of replacing air bubbles with microspheres for the clarification of algae from low cell-density culture.

    PubMed

    Ometto, Francesco; Pozza, Carlo; Whitton, Rachel; Smyth, Beatrice; Gonzalez Torres, Andrea; Henderson, Rita K; Jarvis, Peter; Jefferson, Bruce; Villa, Raffaella

    2014-04-15

    Dissolved Air Flotation (DAF) is a well-known coagulation-flotation system applied at large scale for microalgae harvesting. Compared to conventional harvesting technologies DAF allows high cell recovery at lower energy demand. By replacing microbubbles with microspheres, the innovative Ballasted Dissolved Air Flotation (BDAF) technique has been reported to achieve the same algae cell removal efficiency, while saving up to 80% of the energy required for the conventional DAF unit. Using three different algae cultures (Scenedesmus obliquus, Chlorella vulgaris and Arthrospira maxima), the present work investigated the practical, economic and environmental advantages of the BDAF system compared to the DAF system. 99% cells separation was achieved with both systems, nevertheless, the BDAF technology allowed up to 95% coagulant reduction depending on the algae species and the pH conditions adopted. In terms of floc structure and strength, the inclusion of microspheres in the algae floc generated a looser aggregate, showing a more compact structure within single cell alga, than large and filamentous cells. Overall, BDAF appeared to be a more reliable and sustainable harvesting system than DAF, as it allowed equal cells recovery reducing energy inputs, coagulant demand and carbon emissions.

  5. AUTOMOTIVE DIESEL MAINTENANCE 1. UNIT II, MAINTAINING THE AIR SYSTEM--DETROIT DIESEL ENGINES.

    ERIC Educational Resources Information Center

    Human Engineering Inst., Cleveland, OH.

    THIS MODULE OF A 30-MODULE COURSE IS DESIGNED TO DEVELOP AN UNDERSTANDING OF THE OPERATION AND MAINTENANCE OF THE DIESEL ENGINE AIR SYSTEM. TOPICS ARE (1) OPERATION AND FUNCTION, (2) AIR CLEANER, (3) AIR SHUT-DOWN HOUSING, (4) EXHAUST SYSTEM, (5) BLOWER, (6) TURBOCHARGER, AND (7) TROUBLE-SHOOTING TIPS ON THE AIR SYSTEM. THE MODULE CONSISTS OF A…

  6. Engineering development of advanced physical fine coal cleaning technologies: Froth flotation. Quarterly technical progress report No. 12, July 1, 1991--September 30, 1991

    SciTech Connect

    Not Available

    1991-12-31

    The design criteria for each unit operation have been developed based upon a number of variables. These variables, at this time, are based upon the best engineering design information available to industry. A number of assumptions utilized in the design criteria are uncertain. The uncertainties of inert atmospheres for grinding and flotation as well as pyrite depressants were answered by the Surface Control Project. It was determined that inerting was not required and no ``new`` reagents were presented that improved the flotation results. In addition, Tasks 5 and 6 results indicated the required reagent dosage for conventional flotation and advanced flotation. Task 5 results also indicated the need for a clean coal,thickener, the flocculent dosages for both the clean coal and refuse thickeners, and final dewatering requirements. The results from Tasks 5 and 6 and summarized in Task 7 indicate several uncertainties that require continuous long duration testing. The first is the possibility of producing a grab product for both the Pittsburgh and Illinois No. 6 coals in conventional flotation. Second what does long-term recirculation of clarified water do to the product quality? The verification process and real data obtained from Tasks 5 and 6 greatly reduced the capital and operating costs for the process. This was anticipated and the test work indeed provided confirming data.

  7. Removal of Wax and Stickies from OCC by Flotation

    SciTech Connect

    M. R. Doshi; J. Dyer

    2000-01-31

    Laboratory research indicates that wax is amenable to removal by froth flotation provided it is free or detached from the fiber. The only effective means, at this time, of maximizing detachment of wax is through the use of low consistency pulping at temperatures above the melting point of wax. Wax removal from WCC through washing, flotation, or a combination of both was approximately 90% in these laboratory studies, indicating that not all of the wax is detached from fibers. These results were summarized in Annual Report 1, December 1, 1997 to November 30, 1998. Pilot trials were conducted in which the authors simulated a conventional OCC repulping process with and without flotation. Additional aggressive washing and water clarification were also examined during the study. The inclusion of flotation in the OCC stock preparation system significantly improved the removal of wax spots and extractable material from the furnish. Based on this study, the authors predict that a compact flotation system with 2 lb surfactant/ton of fiber would improve the OCC pulp quality with regard to wax spots by 60% and would not negatively affect strength properties. Flotation losses would be in the 2-5% range. Two mill trials were conducted during the last quarter of the project. One trial was carried out at Green Bay Packaging, Green Bay, WI, and a second trial was conducted at Menasha Corporation, Otsego, MI. A 250-liter Voith Sulzer Ecocell was used to evaluate the removal of wax and stickies from the OCC processing systems at these two mills. The inclusion of flotation in the OCC stock preparation system significantly improved the removal of wax spots from the furnish. The data indicate that flotation was more effective in removing wax and stickies than reverse cleaners. The mill trials have demonstrated that flotation can be substituted for or replace existing reverse cleaning systems and, in some cases, can replace dispersion systems. In this manner, the use of flotation can

  8. SMA actuated vertical deploy air dam: part 2 operation and test performance of prototype unit

    NASA Astrophysics Data System (ADS)

    Browne, Alan L.; Johnson, Nancy L.; Brown, Jeffrey

    2013-03-01

    Airflow over/under/around a vehicle can affect many important aspects of vehicle performance including vehicle drag (fuel economy) and cooling/heat exchange for the vehicle powertrain and A/C systems. Devices in current use to control airflow, with the exception of a few active spoilers, are of fixed geometry, orientation, and stiffness. Such devices can thus not be relocated, reoriented, etc. as driving conditions change and thus vehicle airflow cannot be adjusted to better suit the changed driving condition. Additionally, under-vehicle airflow control devices also reduce ground clearance presenting a challenge to designers to provide the needed control of airflow while maintaining sufficient ground clearance. The collaborative study, whose second part is documented in this paper, was successful in developing an SMA actuator based approach to reversibly deploying an air dam through vertical translation of its structure. Beyond feasibility, vehicle mounted prototype fully functional units demonstrated that this approach would add little weight to the existing stationary system, and could potentially perform well in the harsh under vehicle environment due to a lack of exposed bearings and pivots. This demonstration showed that actuation speed, force, and cyclic stability all could meet the application requirements. The solution, a dual point balanced actuation approach based on shape memory alloy wires, uses straight linear actuation to produce a reversible height change of 50 mm. On vehicle wind tunnel and onroad tests verified the potential for a reversibly deployable air dam to meet the otherwise conflicting goals of large ground clearance for off-road performance and optimum lower ground clearance for optimum fuel economy benefits.

  9. Superfund Record of Decision (EPA Region 4): Naval Air Station Cecil Field, Operable Unit 6, Jacksonville, FL, September 1994

    SciTech Connect

    Not Available

    1994-09-01

    The site name is the Golf Course Pesticide Disposal Area, Site 11, Operable Unit (OU) 6. The site is located in a wooded area between the 11th fairway and the 17th green at the Naval Air Station (NAS) Cecil Field golf course, Jacksonville, Florida. The purpose of the interim remedial action is to remove buried containers of pesticides and associated contaminated soil.

  10. Superfund Record of Decision (EPA Region 1): Loring Air Force Base, Operable Unit 13, Limestone, ME, June 16, 1997

    SciTech Connect

    1997-11-01

    The former Loring Air Force Base (LAFB), in northeastern Maine, is bordered on the south and east by the Town of Limestone, on the north by the towns of Caswell and Connor, and on the west by the City of Caribou. This Record of Decision (ROD) relates to OU 13, the basewide surface water and sediment operable unit.

  11. Acanthamoeba belonging to T3, T4, and T11: genotypes isolated from air-conditioning units in Santiago, Chile.

    PubMed

    Astorga, Berbeli; Lorenzo-Morales, Jacob; Martín-Navarro, Carmen M; Alarcón, Verónica; Moreno, Johanna; González, Ana C; Navarrete, Elizabeth; Piñero, José E; Valladares, Basilio

    2011-01-01

    Free-living amoebae (FLA) of the genus Acanthamoeba are widely distributed in the environment, in the air, soil, and water, and have also been isolated from air-conditioning units. The objective of this work was to investigate the presence of this genus of FLA in the air-conditioning equipment at the Institute of Public Health of Chile in Santiago, Chile. Water and air samples were collected from air-conditioning systems and were checked for the presence of Acanthamoeba spp. Positive samples were further classified at the genotype level after sequencing the highly variable diagnostic fragment 3 (DF3) region of the 18S rRNA gene. This is the first report of the T3, T4, and T11 genotypes of Acanthamoeba in air-conditioning units from Chile. Overall, the widespread distribution of potentially pathogenic Acanthamoeba strains in the studied source demands more awareness within the public and health professionals in Chile as this pathogen is emerging as a risk for human health worldwide.

  12. National Patterns in Environmental Injustice and Inequality: Outdoor NO2 Air Pollution in the United States

    PubMed Central

    Clark, Lara P.; Millet, Dylan B.; Marshall, Julian D.

    2014-01-01

    We describe spatial patterns in environmental injustice and inequality for residential outdoor nitrogen dioxide (NO2) concentrations in the contiguous United States. Our approach employs Census demographic data and a recently published high-resolution dataset of outdoor NO2 concentrations. Nationally, population-weighted mean NO2 concentrations are 4.6 ppb (38%, p<0.01) higher for nonwhites than for whites. The environmental health implications of that concentration disparity are compelling. For example, we estimate that reducing nonwhites’ NO2 concentrations to levels experienced by whites would reduce Ischemic Heart Disease (IHD) mortality by ∼7,000 deaths per year, which is equivalent to 16 million people increasing their physical activity level from inactive (0 hours/week of physical activity) to sufficiently active (>2.5 hours/week of physical activity). Inequality for NO2 concentration is greater than inequality for income (Atkinson Index: 0.11 versus 0.08). Low-income nonwhite young children and elderly people are disproportionately exposed to residential outdoor NO2. Our findings establish a national context for previous work that has documented air pollution environmental injustice and inequality within individual US metropolitan areas and regions. Results given here can aid policy-makers in identifying locations with high environmental injustice and inequality. For example, states with both high injustice and high inequality (top quintile) for outdoor residential NO2 include New York, Michigan, and Wisconsin. PMID:24736569

  13. Experimental results and modeling tests of an adsorptive air-conditioning unit

    SciTech Connect

    Guilleminot, J.J.; Poyelle, F.; Meunier, F.

    1998-10-01

    Experimental tests have been performed on a zeolite-water adsorptive system suitable for air conditioning and consisting of two adsorbers filled with a consolidated composite made of zeolite mixed with a highly conductive matrix. This paper describes the experimental results of such a heat pump unit operating with a heat and mass recovery cycle. An important enhancement of the specific cooling power (SCP) has been achieved. At evaporating temperature T = 4 C, mass transfer resistance controls the process and limits the expected COP. Tests carried out at higher evaporating pressure make it possible to achieve the predicted COP and SCP. A predictive model developed and validated elsewhere in order to describe the temperature evolution of components and the heat and mass transfer in the adsorbers explains the mass transfer resistance in the adsorbent. Last, a new highly conductive adsorbent composite with good mass transfer properties is developed. The model is used to predict the performances of this new material. Very good SCP and COP can be achieved.

  14. Greenhouse gas emissions for refrigerant choices in room air conditioner units.

    PubMed

    Galka, Michael D; Lownsbury, James M; Blowers, Paul

    2012-12-01

    In this work, potential replacement refrigerants for window-mounted room air conditioners (RACs) in the U.S. have been evaluated using a greenhouse gas (GHG) emissions analysis. CO(2)-equivalent emissions for several hydrofluoroethers (HFEs) and other potential replacements were compared to the most widely used refrigerants today. Included in this comparison are pure refrigerants that make up a number of hydrofluorocarbon (HFC) mixtures, pure hydrocarbons, and historically used refrigerants such as propane and ammonia. GHG emissions from direct and indirect sources were considered in this thermodynamic analysis. Propylene, dimethyl ether, ammonia, R-152a, propane, and HFE-152a all performed effectively in a 1 ton window unit and produced slightly lower emissions than the currently used R-22 and R-134a. The results suggest that regulation of HFCs in this application would have some effect on reducing emissions since end-of-life emissions remain at 55% of total refrigerant charge despite EPA regulations that mandate 80% recovery. Even so, offsite emissions due to energy generation dominate over direct GHG emissions and all the refrigerants perform similarly in totals of indirect GHG emissions. PMID:23136858

  15. Uncertainty Analysis for a Virtual Flow Meter Using an Air-Handling Unit Chilled Water Valve

    SciTech Connect

    Song, Li; Wang, Gang; Brambley, Michael R.

    2013-04-28

    A virtual water flow meter is developed that uses the chilled water control valve on an air-handling unit as a measurement device. The flow rate of water through the valve is calculated using the differential pressure across the valve and its associated coil, the valve command, and an empirically determined valve characteristic curve. Thus, the probability of error in the measurements is significantly greater than for conventionally manufactured flow meters. In this paper, mathematical models are developed and used to conduct uncertainty analysis for the virtual flow meter, and the results from the virtual meter are compared to measurements made with an ultrasonic flow meter. Theoretical uncertainty analysis shows that the total uncertainty in flow rates from the virtual flow meter is 1.46% with 95% confidence; comparison of virtual flow meter results with measurements from an ultrasonic flow meter yielded anuncertainty of 1.46% with 99% confidence. The comparable results from the theoretical uncertainty analysis and empirical comparison with the ultrasonic flow meter corroborate each other, and tend to validate the approach to computationally estimating uncertainty for virtual sensors introduced in this study.

  16. National patterns in environmental injustice and inequality: outdoor NO2 air pollution in the United States.

    PubMed

    Clark, Lara P; Millet, Dylan B; Marshall, Julian D

    2014-01-01

    We describe spatial patterns in environmental injustice and inequality for residential outdoor nitrogen dioxide (NO2) concentrations in the contiguous United States. Our approach employs Census demographic data and a recently published high-resolution dataset of outdoor NO2 concentrations. Nationally, population-weighted mean NO2 concentrations are 4.6 ppb (38%, p<0.01) higher for nonwhites than for whites. The environmental health implications of that concentration disparity are compelling. For example, we estimate that reducing nonwhites' NO2 concentrations to levels experienced by whites would reduce Ischemic Heart Disease (IHD) mortality by ∼7,000 deaths per year, which is equivalent to 16 million people increasing their physical activity level from inactive (0 hours/week of physical activity) to sufficiently active (>2.5 hours/week of physical activity). Inequality for NO2 concentration is greater than inequality for income (Atkinson Index: 0.11 versus 0.08). Low-income nonwhite young children and elderly people are disproportionately exposed to residential outdoor NO2. Our findings establish a national context for previous work that has documented air pollution environmental injustice and inequality within individual US metropolitan areas and regions. Results given here can aid policy-makers in identifying locations with high environmental injustice and inequality. For example, states with both high injustice and high inequality (top quintile) for outdoor residential NO2 include New York, Michigan, and Wisconsin.

  17. Energy-Efficient Supermarket Heating, Ventilation, and Air Conditioning in Humid Climates in the United States

    SciTech Connect

    Clark, J.

    2015-03-01

    Supermarkets are energy-intensive buildings that consume the greatest amount of electricity per square foot of building of any building type in the United States and represent 5% of total U.S. commercial building primary energy use (EIA 2005). Refrigeration and heating, ventilation, and air-conditioning (HVAC) systems are responsible for a large proportion of supermarkets’ total energy use. These two systems sometimes work together and sometimes compete, but the performance of one system always affects the performance of the other. To better understand these challenges and opportunities, the Commercial Buildings team at the National Renewable Energy Laboratory investigated several of the most promising strategies for providing energy-efficient HVAC for supermarkets and quantified the resulting energy use and costs using detailed simulations. This research effort was conducted on behalf of the U.S. Department of Energy (DOE) Commercial Building Partnerships (CBP) (Baechler et al. 2012; Parrish et al. 2013; Antonopoulos et al. 2014; Hirsch et al. 2014). The goal of CBP was to reduce energy use in the commercial building sector by creating, testing, and validating design concepts on the pathway to net zero energy commercial buildings. Several CBP partners owned or operated buildings containing supermarkets and were interested in optimizing the energy efficiency of supermarket HVAC systems in hot-humid climates. These partners included Walmart, Target, Whole Foods Market, SUPERVALU, and the Defense Commissary Agency.

  18. 23-Valent Pneumococcal Polysaccharide Vaccine Uptake in the United States Air Force HIV Program.

    PubMed

    Ocampo, Thad F; Le, Tuan; Matthews, Peter E; Okulicz, Jason F

    2016-07-01

    Streptococcus pneumoniae infection is a predominant cause of bacterial infection in HIV-infected individuals. However, reported rates of pneumococcal vaccination with 23-valent polysaccharide vaccine (PPV23) are variable. We evaluated uptake of PPV23 in patients diagnosed with HIV between 1996 and 2012 (n = 507) in the United States Air Force, a centralized HIV program with free access to care including vaccines and medications. A total of 411 (81.1%) patients received at least 1 PPV23 dose. The PPV23 vaccination within 1 year of diagnosis was greater for those diagnosed between 2004 and 2012 (n = 184, 86%) compared with 1996 to 2003 (n = 104, 56.5%; P < .001). For those with ≥6 years of follow-up, receipt of a second recommended PPV23 dose was greater for those diagnosed between 1996 and 2003 (n = 52, 57.8%) compared with 2004 to 2012 (n = 9, 28.1%; P = .004). Although first PPV23 vaccination was high in recent years, process improvement efforts are underway to overcome barriers and improve uptake of pneumococcal vaccines in our program.

  19. Sources of Bacteria in Outdoor Air across Cities in the Midwestern United States ▿ †

    PubMed Central

    Bowers, Robert M.; Sullivan, Amy P.; Costello, Elizabeth K.; Collett, Jeff L.; Knight, Rob; Fierer, Noah

    2011-01-01

    Bacteria are abundant in the atmosphere, where they often represent a major portion of the organic aerosols. Potential pathogens of plants and livestock are commonly dispersed through the atmosphere, and airborne bacteria can have important effects on human health as pathogens or triggers of allergic asthma and seasonal allergies. Despite their importance, the diversity and biogeography of airborne microorganisms remain poorly understood. We used high-throughput pyrosequencing to analyze bacterial communities present in the aerosol fraction containing fine particulate matter of ≤2.5 μm from 96 near-surface atmospheric samples collected from cities throughout the midwestern United States and found that the communities are surprisingly diverse and strongly affected by the season. We also directly compared the airborne communities to those found in hundreds of samples representing potential source environments. We show that, in addition to the more predictable sources (soils and leaf surfaces), fecal material, most likely dog feces, often represents an unexpected source of bacteria in the atmosphere at more urbanized locations during the winter. Airborne bacteria are clearly an important, but understudied, component of air quality that needs to be better integrated into efforts to measure and model pollutants in the atmosphere. PMID:21803902

  20. Sources of bacteria in outdoor air across cities in the midwestern United States.

    PubMed

    Bowers, Robert M; Sullivan, Amy P; Costello, Elizabeth K; Collett, Jeff L; Knight, Rob; Fierer, Noah

    2011-09-01

    Bacteria are abundant in the atmosphere, where they often represent a major portion of the organic aerosols. Potential pathogens of plants and livestock are commonly dispersed through the atmosphere, and airborne bacteria can have important effects on human health as pathogens or triggers of allergic asthma and seasonal allergies. Despite their importance, the diversity and biogeography of airborne microorganisms remain poorly understood. We used high-throughput pyrosequencing to analyze bacterial communities present in the aerosol fraction containing fine particulate matter of ≤2.5 μm from 96 near-surface atmospheric samples collected from cities throughout the midwestern United States and found that the communities are surprisingly diverse and strongly affected by the season. We also directly compared the airborne communities to those found in hundreds of samples representing potential source environments. We show that, in addition to the more predictable sources (soils and leaf surfaces), fecal material, most likely dog feces, often represents an unexpected source of bacteria in the atmosphere at more urbanized locations during the winter. Airborne bacteria are clearly an important, but understudied, component of air quality that needs to be better integrated into efforts to measure and model pollutants in the atmosphere.

  1. Role of the collecting agent sorption forms in the elementary act of flotation

    SciTech Connect

    Abramov, A.A.

    2005-02-01

    A new hypothesis of flotation is substantiated based on the well-known hypotheses, theoretical analysis of the elementary act, and experimental results. The hypothesis presented allows the processes of flotation activation, depression, and intensification to be explained and optimized.

  2. CLIMATE CHANGE FUEL CELL PROGRAM UNITED STATES COAST GUARD AIR STATION CAPE COD BOURNE, MASSACHUSETTS

    SciTech Connect

    John K. Steckel Jr

    2004-06-30

    This report covers the first year of operation of a fuel cell power plant, installed by PPL Spectrum, Inc. (PPL) under contract with the United States Coast Guard (USCG), Research and Development Center (RDC). The fuel cell was installed at Air Station Cape Cod in Bourne, MA. The project had the support of the Massachusetts Technology Collaborative (MTC), the Department of Energy (DOE), and Keyspan Energy. PPL selected FuelCell Energy, Inc. (FCE) and its fuel cell model DFC{reg_sign}300 for the contract. Grant contributions were finalized and a contract between PPL and the USCG for the manufacture, installation, and first year's maintenance of the fuel cell was executed on September 24, 2001. As the prime contractor, PPL was responsible for all facets of the project. All the work was completed by PPL through various subcontracts, including the primary subcontract with FCE for the manufacture, delivery, and installation of the fuel cell. The manufacturing and design phases proceeded in a relatively timely manner for the first half of the project. However, during latter stages of manufacture and fuel cell testing, a variety of issues were encountered that ultimately resulted in several delivery delays, and a number of contract modifications. Final installation and field testing was completed in April and May 2003. Final acceptance of the fuel cell was completed on May 16, 2003. The fuel cell has operated successfully for more than one year. The unit achieved an availability rate of 96%, which exceeded expectations. The capacity factor was limited because the unit was set at 155 kW (versus a nameplate of 250 kW) due to the interconnection with the electric utility. There were 18 shutdowns during the first year and most were brief. The ability of this plant to operate in the island mode improved availability by 3 to 4%. Events that would normally be shutdowns were simply island mode events. The mean time between failure was calculated at 239 hours, or slightly less

  3. An Improved Calibration Method for Hydrazine Monitors for the United States Air Force

    SciTech Connect

    Korsah, K

    2003-07-07

    This report documents the results of Phase 1 of the ''Air Force Hydrazine Detector Characterization and Calibration Project''. A method for calibrating model MDA 7100 hydrazine detectors in the United States Air Force (AF) inventory has been developed. The calibration system consists of a Kintek 491 reference gas generation system, a humidifier/mixer system which combines the dry reference hydrazine gas with humidified diluent or carrier gas to generate the required humidified reference for calibrations, and a gas sampling interface. The Kintek reference gas generation system itself is periodically calibrated using an ORNL-constructed coulometric titration system to verify the hydrazine concentration of the sample atmosphere in the interface module. The Kintek reference gas is then used to calibrate the hydrazine monitors. Thus, coulometric titration is only used to periodically assess the performance of the Kintek reference gas generation system, and is not required for hydrazine monitor calibrations. One advantage of using coulometric titration for verifying the concentration of the reference gas is that it is a primary standard (if used for simple solutions), thereby guaranteeing, in principle, that measurements will be traceable to SI units (i.e., to the mole). The effect of humidity of the reference gas was characterized by using the results of concentrations determined by coulometric titration to develop a humidity correction graph for the Kintek 491 reference gas generation system. Using this calibration method, calibration uncertainty has been reduced by 50% compared to the current method used to calibrate hydrazine monitors in the Air Force inventory and calibration time has also been reduced by more than 20%. Significant findings from studies documented in this report are the following: (1) The Kintek 491 reference gas generation system (generator, humidifier and interface module) can be used to calibrate hydrazine detectors. (2) The Kintek system output

  4. Relationships in flotation recovery of thorium-containing anions

    SciTech Connect

    Skrylev, L.D.; Menchuk, V.V.; Seifullina, I.I.

    1981-11-20

    The possibility of flotation recovery of thorium from solutions was first pointed out by Sebba. He also proposed a flotation method for the separation of thorium and uranium, based on the formation of anionic complexes by uranium at levels of solution pH at which thorium is still in the form of simple cations. Later, Shakir carried out a detailed investigation of the flotation recovery of thorium from dilute aqueous solutions by means of cetyltrimethylammonium bromide and lauryl sulfate, and Jacobelli-Turi in media.Sekine applied flotation in the concentration of thorium in the form of a complex with arsenazo III, for analytical purposes. In our previous studies, we had shown that it was possible in principle to recover thorium from dilute sulfuric acid solutions by flotation with aliphatic amines. Here we are reporting on further studies of this process. The materials we chose as thorium collectors in our studies were AAK and primary aliphatic amines (typical cationic surfactants); this type of surfactant was chosen because thorium in sulfuric acid solutions exists in the form of complex anions.

  5. Air quality impacts of increased use of ethanol under the United States’ Energy Independence and Security Act

    NASA Astrophysics Data System (ADS)

    Cook, Rich; Phillips, Sharon; Houyoux, Marc; Dolwick, Pat; Mason, Rich; Yanca, Catherine; Zawacki, Margaret; Davidson, Ken; Michaels, Harvey; Harvey, Craig; Somers, Joseph; Luecken, Deborah

    2011-12-01

    Increased use of ethanol in the United States fuel supply will impact emissions and ambient concentrations of greenhouse gases, "criteria" pollutants for which the U. S. EPA sets ambient air quality standards, and a variety of air toxic compounds. This paper focuses on impacts of increased ethanol use on ozone and air toxics under a potential implementation scenario resulting from mandates in the U. S. Energy Independence and Security Act (EISA) of 2007. The assessment of impacts was done for calendar year 2022, when 36 billion gallons of renewable fuels must be used. Impacts were assessed relative to a baseline which assumed ethanol volumes mandated by the first renewable fuels standard promulgated by U. S. EPA in early 2007. This assessment addresses both impacts of increased ethanol use on vehicle and other engine emissions, referred to as "downstream" emissions, and "upstream" impacts, i.e., those connected with fuel production and distribution. Air quality modeling was performed for the continental United States using the Community Multi-scale Air Quality Model (CMAQ), version 4.7. Pollutants included in the assessment were ozone, acetaldehyde, ethanol, formaldehyde, acrolein, benzene, and 1,3-butadiene. Results suggest that increased ethanol use due to EISA in 2022 will adversely increase ozone concentrations over much of the U.S., by as much as 1 ppb. However, EISA is projected to improve ozone air quality in a few highly-populated areas that currently have poor air quality. Most of the ozone improvements are due to our assumption of increases in nitrogen oxides (NO x) in volatile organic compound (VOC)-limited areas. While there are some localized impacts, the EISA renewable fuel standards have relatively little impact on national average ambient concentrations of most air toxics, although ethanol concentrations increase substantially. Significant uncertainties are associated with all results, due to limitations in available data. These uncertainties are

  6. Impact of temporary freeway closure on regional air quality: a lesson from Carmageddon in Los Angeles, United States.

    PubMed

    Hong, Andy; Schweitzer, Lisa; Yang, Wan; Marr, Linsey C

    2015-03-01

    Large cities in the United States face multiple challenges in meeting federal air quality standards. One difficulty arises from the uncertainties in evaluating traffic-related air pollution, especially the formation of secondary pollutants such as ozone and some particulate matter. Current air quality models are not well suited to evaluate the impact of a short-term traffic change on air quality. Using regional traffic and ambient air quality data from Southern California, we examine the impact of a two-day freeway closure on traffic and several criteria air pollutants (CO, NO2, O3, PM10, PM2.5). The results indicate that regional traffic decreased about 14% on average during the closure. Daily average PM2.5 levels decreased by about 32%, and daily 8 h maximum ozone levels decreased by about 16%. However, the daily 1 h maximum NO2 concentration was higher at some sites during the closure. Despite the mixed results with NO2, this study provides empirical evidence to support traffic reduction as an effective strategy to address chronic air pollution problems, especially with regard to ozone, in Southern California. PMID:25629730

  7. Alcohol issues prior to training in the United States Air Force.

    PubMed

    Derefinko, Karen J; Klesges, Robert C; Bursac, Zoran; Little, Melissa A; Hryshko-Mullen, Ann; Talcott, Gerald W

    2016-07-01

    The negative impact of alcohol is a significant concern to the US military given the costs associated with alcohol-related offenses. Despite considerable research in active duty personnel, relatively little is known about the current extent of alcohol use among incoming recruits. We examined the history of alcohol use and harmful patterns of alcohol consumption among recruits entering the United States Air Force (USAF; N=50,549) over the span of 4 years (2010-2014). Across all years, drinking rates reflected national average trends for those aged 18-24 (NIDA, 2014). However, when abstainers were excluded, those under 21 (n=10,568) reported an average of 18.4 drinks per week, whereas those age 21 and over (n=14,188) reported an average of 14.1 drinks per week, suggesting that for those who drink, those under 21 are exhibiting more risky drinking rates. Alcohol Use Disorders Identification Task (AUDIT) scores for drinkers reflected these same trends. For those under 21, 58% scored in risk categories of 2 or higher (risky drinking warranting attention), compared with 40% for those age 21 and over. These scores indicate that for recruits in the USAF, approximately half report alcohol use immediately prior to basic training, resulting in the inheritance of these potential alcohol related issues for those conducting training of these recruits. Based upon these numbers, brief alcohol interventions could have a potential positive impact on individuals in their initial training stages of the USAF to prevent these baseline issues from resulting in problems later in their military careers. PMID:26945450

  8. Preparation and utilization of slurry fuel with flotation tailing

    SciTech Connect

    Jiang Shixin; Jiang Qiyun; Lui Qing; Shao Peozao; Wang Zuna; Guo Baoxin

    1993-12-31

    Most coal preparation plants treating metallurgical coal employ flotation process for recovering concentrate from -0.5mm fraction. For full utilization of combustibles, the common practice of flotation operation is to give a relatively low ash concentrate while leaving a medium ash tailing as an inferior fuel. In this case, the dilute flotation tailing is thickened and dewatered, giving a filtering cake containing about 20-30% moisture as the final product. Difficulties are confronted in handling of this sticky mass. Besides, combustion of such high-moisture inferior fuel would be less efficient and more pollutant. Ways have been sought to solve these problems. Conversion of such dewatered flotation tailing into slurry fuel is one of possible options in view of its good handleability and high efficiency of carbon burnout in combustion even in small outfits. In Chinese situation, a coal mine area always includes population points and associate utilities and consumes about 5% of coal produced, some of which should be of good quality. Clean and efficient usage of such coal sludge in-situ will be of benefit to the mine in that locally consumed coal could be substituted, which can be in turns loaded out as regular commodity or joining with the main stream to coal preparation plant for production of more premium coal. Datun Coal Preparation Plant employs jig-flotation process and produces concentrate for coking plants. It has a designed annual capacity of treating 1.8 Mt feed coal and the highest record of operation was 2.1 Mt. Average yield of flotation tailing in recent years is 3.5%. Economy would be the prime importance to be considered for converting this sludge into slurry fuel, as preparation of coal slurry is usually considered to be expensive.

  9. Influence of combined dust reducing carpet and compact air filtration unit on the indoor air quality of a classroom.

    PubMed

    Scheepers, Paul T J; de Hartog, Jeroen J; Reijnaerts, Judith; Beckmann, Gwendolyn; Anzion, Rob; Poels, Katrien; Godderis, Lode

    2015-02-01

    Primary schools mostly rely on natural ventilation but also have an interest in affordable technology to improve indoor air quality (IAQ). Laboratory tests show promising results for dust reducing carpets and compact air filtration systems but there is no information available on the performance of these interventions in actual operating classrooms. An exploratory study was performed to evaluate a combination of the two systems in a primary school. Measurements of PM-10 and PM-2.5 were performed by filter sampling and aerosol spectrometry. Other IAQ parameters included black smoke (BS), volatile organic compounds (VOC), nitrogen dioxide (NO2) and formaldehyde. Both interventions were introduced in one classroom during one week, using another classroom as a reference. In a second week the interventions were moved to the other classroom, using the first as a reference (cross-over design). In three remaining weeks the classrooms were compared without interventions. Indoor IAQ parameters were compared to the corresponding outdoor parameters using the indoor/outdoor (I/O) ratio. When the classrooms were occupied (teaching hours) interventions resulted in 27-43% reductions of PM-10, PM-2.5 and BS values. During the weekends the systems reduced these levels by 51-87%. Evaluations using the change in I/O ratios gave comparable results. Levels of VOC, NO2 and formaldehyde were rather low and a contribution of the interventions to the improvement of these gas phase IAQ parameters was inconclusive. PMID:25380291

  10. Influence of combined dust reducing carpet and compact air filtration unit on the indoor air quality of a classroom.

    PubMed

    Scheepers, Paul T J; de Hartog, Jeroen J; Reijnaerts, Judith; Beckmann, Gwendolyn; Anzion, Rob; Poels, Katrien; Godderis, Lode

    2015-02-01

    Primary schools mostly rely on natural ventilation but also have an interest in affordable technology to improve indoor air quality (IAQ). Laboratory tests show promising results for dust reducing carpets and compact air filtration systems but there is no information available on the performance of these interventions in actual operating classrooms. An exploratory study was performed to evaluate a combination of the two systems in a primary school. Measurements of PM-10 and PM-2.5 were performed by filter sampling and aerosol spectrometry. Other IAQ parameters included black smoke (BS), volatile organic compounds (VOC), nitrogen dioxide (NO2) and formaldehyde. Both interventions were introduced in one classroom during one week, using another classroom as a reference. In a second week the interventions were moved to the other classroom, using the first as a reference (cross-over design). In three remaining weeks the classrooms were compared without interventions. Indoor IAQ parameters were compared to the corresponding outdoor parameters using the indoor/outdoor (I/O) ratio. When the classrooms were occupied (teaching hours) interventions resulted in 27-43% reductions of PM-10, PM-2.5 and BS values. During the weekends the systems reduced these levels by 51-87%. Evaluations using the change in I/O ratios gave comparable results. Levels of VOC, NO2 and formaldehyde were rather low and a contribution of the interventions to the improvement of these gas phase IAQ parameters was inconclusive.

  11. Relative flotation response of zinc sulfide: Mineral and precipitate

    SciTech Connect

    Rao, S.R.; Finch, J.A.; Zhou, Z.; Xu, Z.

    1998-04-01

    Flotation continues to extend to nonmineral applications, including recycling of materials, soil remediation, and effluent treatment. A study has been conducted to compare the floatability of fine zinc sulfide (ZnS) precipitates and sphalerite particles. The floatability of the precipitates was significantly poorer compared to sphalerite particles when xanthate was used as the collector. The floatability was improved by using dodecylamine as the collector, and the difference in floatability between the precipitates was further improved significantly by incorporating a hydrodynamic cavitation tube in a conventional (mechanical) flotation cell. The improved kinetics was attributed to in-situ gas nucleation on the precipitates.

  12. Selective separation of virgin and post-consumer polymers (PET and PVC) by flotation method.

    PubMed

    Burat, Firat; Güney, Ali; Olgaç Kangal, M

    2009-06-01

    More and more polymer wastes are generated by industry and householders today. Recycling is an important process to reduce the amount of waste resulting from human activities. Currently, recycling technologies use relatively homogeneous polymers because hand-sorting waste is costly. Many promising technologies are being investigated for separating mixed thermoplastics, but they are still uneconomical and unreliable. At present, most waste polymers cause serious environmental problems. Burning polymers for recycling is not practiced since poisonous gases are released during the burning process. Particularly, polyvinyl chloride (PVC) materials among waste polymers generate hazardous HCl gas, dioxins containing Cl, etc., which lead to air pollution and shorten the life of the incinerator. In addition, they make other polymers difficult to recycle. Both polyethylene terephthalate (PET) and PVC have densities of 1.30-1.35g /cm(3) and cannot be separated using conventional gravity separation techniques. For this reason, polymer recycling needs new techniques. Among these techniques, froth flotation, which is also used in mineral processing, can be useful because of its low cost and simplicity. The main objective of this research is to recycle PET and PVC selectively from post-consumer polymer wastes and virgin polymers by using froth flotation. According to the results, all PVC particles were floated with 98.8% efficiency in virgin polymer separation while PET particles were obtained with 99.7% purity and 57.0% efficiency in post-consumer polymer separation.

  13. Selective separation of virgin and post-consumer polymers (PET and PVC) by flotation method

    SciTech Connect

    Burat, Firat; Gueney, Ali; Olgac Kangal, M.

    2009-06-15

    More and more polymer wastes are generated by industry and householders today. Recycling is an important process to reduce the amount of waste resulting from human activities. Currently, recycling technologies use relatively homogeneous polymers because hand-sorting waste is costly. Many promising technologies are being investigated for separating mixed thermoplastics, but they are still uneconomical and unreliable. At present, most waste polymers cause serious environmental problems. Burning polymers for recycling is not practiced since poisonous gases are released during the burning process. Particularly, polyvinyl chloride (PVC) materials among waste polymers generate hazardous HCl gas, dioxins containing Cl, etc., which lead to air pollution and shorten the life of the incinerator. In addition, they make other polymers difficult to recycle. Both polyethylene terephthalate (PET) and PVC have densities of 1.30-1.35 g/cm{sup 3} and cannot be separated using conventional gravity separation techniques. For this reason, polymer recycling needs new techniques. Among these techniques, froth flotation, which is also used in mineral processing, can be useful because of its low cost and simplicity. The main objective of this research is to recycle PET and PVC selectively from post-consumer polymer wastes and virgin polymers by using froth flotation. According to the results, all PVC particles were floated with 98.8% efficiency in virgin polymer separation while PET particles were obtained with 99.7% purity and 57.0% efficiency in post-consumer polymer separation.

  14. Development of the anode bipolar plate/membrane assembly unit for air breathing PEMFC stack using silicone adhesive bonding

    NASA Astrophysics Data System (ADS)

    Kim, Minkook; Lee, Dai Gil

    2016-05-01

    Polymer electrolyte membrane fuel cells (PEMFC) exhibit a wide power range, low operating temperature, high energy density and long life time. These advantages favor PEMFC for applications such as vehicle power sources, portable power, and backup power applications. With the push towards the commercialization of PEMFC, especially for portable power applications, the overall balance of plants (BOPs) of the systems should be minimized. To reduce the mass and complexity of the systems, air-breathing PEMFC stack design with open cathode channel configuration is being developed. However, the open cathode channel configuration incurs hydrogen leakage problem. In this study, the bonding strength of a silicon adhesive between the Nafion membrane and the carbon fiber/epoxy composite bipolar plate was measured. Then, an anode bipolar plate/membrane assembly unit which was bonded with the silicone adhesive was developed to solve the hydrogen leakage problem. The reliability of the anode bipolar plate/membrane assembly unit was estimated under the internal pressure of hydrogen by the FE analysis. Additionally, the gas sealability of the developed air breathing PEMFC unit cell was experimentally measured. Finally, unit cell performance of the developed anode bipolar plate/membrane assembly unit was tested and verified under operating conditions without humidity and temperature control.

  15. Method for enhancing selectivity and recovery in the fractional flotation of particles in a flotation column

    DOEpatents

    Klunder, Edgar B.

    2011-08-09

    The method relates to particle separation from a feed stream. The feed stream is injected directly into the froth zone of a vertical flotation column in the presence of a counter-current reflux stream. A froth breaker generates a reflux stream and a concentrate stream, and the reflux stream is injected into the froth zone to mix with the interstitial liquid between bubbles in the froth zone. Counter-current flow between the plurality of bubbles and the interstitial liquid facilitates the attachment of higher hydrophobicity particles to bubble surfaces as lower hydrophobicity particles detach. The height of the feed stream injection and the reflux ratio may be varied in order to optimize the concentrate or tailing stream recoveries desired based on existing operating conditions.

  16. A Critical Review of Air Pollution Index Systems in the United States and Canada

    ERIC Educational Resources Information Center

    Ott, Wayne R.; Thom, Gary C.

    1976-01-01

    An extensive survey of air pollution indices reveals great diversity in calculation and descriptor categories. This lack of uniformity creates confusion, suggests questionable technical validity, and discourages a national picture. The authors recombined indices currently in use to develop a Standardized Urban Air Quality Index for national use.…

  17. APPLICATION AND EVALUATION OF CMAQ IN THE UNITED STATES: AIR QUALITY FORECASTING AND RETROSPECTIVE MODELING

    EPA Science Inventory

    Presentation slides provide background on model evaluation techniques. Also included in the presentation is an operational evaluation of 2001 Community Multiscale Air Quality (CMAQ) annual simulation, and an evaluation of PM2.5 for the CMAQ air quality forecast (AQF) ...

  18. Superfund record of decision (EPA Region 9): Moffett Naval Air Station, operable unit 5, Mountain View, CA, June 28, 1996

    SciTech Connect

    1996-08-01

    This decision document presents the selected remedial action - groundwater extraction, treatment of the water using air stripping, and discharge - for Operable Unit 5 (OU5) at Moffett Field in Mountain View, California. The discharge method for OU5 is water reuse for irrigation purposes at the Moffett Field golf course. If water reuse is not possible, the discharge will be sent to a local publicly owned treatment works (POTW) or local off-site surface waters under an NPDES permit.

  19. Chemical and colloidal aspects of collectorless flotation behavior of sulfide and non-sulfide minerals.

    PubMed

    Aghazadeh, Sajjad; Mousavinezhad, Seyed Kamal; Gharabaghi, Mahdi

    2015-11-01

    Flotation has been widely used for separation of valuable minerals from gangues based on their surface characterizations and differences in hydrophobicity on mineral surfaces. As hydrophobicity of minerals widely differs from each other, their separation by flotation will become easier. Collectors are chemical materials which are supposed to make selectively valuable minerals hydrophobic. In addition, there are some minerals which based on their surface and structural features are intrinsically hydrophobic. However, their hydrophobicities are not strong enough to be floatable in the flotation cell without collectors such as sulfide minerals, coal, stibnite, and so forth. To float these minerals in a flotation cell, their hydrophobicity should be increased in specific conditions. Various parameters including pH, Eh, size distribution, mill types, mineral types, ore characterization, and type of reaction in flotation cells affect the hydrophobicity of minerals. Surface analysis results show that when sulfide minerals experience specific flotation conditions, the reactions on the surface of these minerals increase the amount of sulfur on the surface. These phenomenons improve the hydrophobicity of these minerals due to strong hydrophobic feature of sulfurs. Collectorless flotation reduces chemical material consumption amount, increases flotation selectivity (grade increases), and affects the equipment quantities; however, it can also have negative effects. Some minerals with poor surface floatability can be increased by adding some ions to the flotation system. Depressing undesirable minerals in flotation is another application of collectorless flotation.

  20. Prevalence of permanent threshold shifts in the United States Air Force hearing conservation program by career field, 2005-2011.

    PubMed

    Lloyd Soderlund, Laurel; McKenna, Elizabeth A; Tastad, Katie; Paul, Marika

    2016-01-01

    The purpose of this study was to describe changes in hearing, using the permanent threshold shift metric, among United States Air Force servicemembers, including active duty, Reserve and Air National Guard components, for demographics, job categories, and career fields. In the United States Air Force, only servicemembers who are occupationally exposed routinely to hazardous noise are monitored. Audiogram records and demographic variables were analyzed for servicemembers from 2005-2011 using data from the Department of Defense system that captures occupational hearing tests worldwide. Results suggest that occupational hearing loss was larger in males than females, in officers than enlisted populations, and in Reserve and Air National Guard than in active duty. Compared to similar civilian career fields, active duty has lower prevalence rates for occupational hearing loss overall, although Reserve and Air National Guard prevalence rates were more similar to the civilian reported rates. The proportion of personnel with permanent threshold shifts varied between 4.6-16.7% within active duty career fields, which includes 76% of the population for study timeframe. Permanent threshold shift was larger in small job categories, and in jobs that are not considered exposed to hazardous noise routinely which is comparative with results from civilian data analysis of occupational hearing loss. Further investigation into testing practices for Air Force specific groups, use of the system for nonoccupational hearing testing, and challenges to follow-up compliance is warranted. Increased surveillance procedures for occupational hearing loss are needed to address concerns on the prevalence of servicemember hearing loss, the role of recreational and lifestyle factors to contribute the high reported hearing loss prevalence of veterans compared to nonveterans. PMID:26720128

  1. Influence of surrounding structures upon the aerodynamic and acoustic performance of the outdoor unit of a split air-conditioner

    NASA Astrophysics Data System (ADS)

    Wu, Chengjun; Liu, Jiang; Pan, Jie

    2014-07-01

    DC-inverter split air-conditioner is widely used in Chinese homes as a result of its high-efficiency and energy-saving. Recently, the researches on its outdoor unit have focused on the influence of surrounding structures upon the aerodynamic and acoustic performance, however they are only limited to the influence of a few parameters on the performance, and practical design of the unit requires more detailed parametric analysis. Three-dimensional computational fluid dynamics(CFD) and computational aerodynamic acoustics(CAA) simulation based on FLUENT solver is used to study the influence of surrounding structures upon the aforementioned properties of the unit. The flow rate and sound pressure level are predicted for different rotating speed, and agree well with the experimental results. The parametric influence of three main surrounding structures(i.e. the heat sink, the bell-mouth type shroud and the outlet grille) upon the aerodynamic performance of the unit is analyzed thoroughly. The results demonstrate that the tip vortex plays a major role in the flow fields near the blade tip and has a great effect on the flow field of the unit. The inlet ring's size and throat's depth of the bell-mouth type shroud, and the through-flow area and configuration of upwind and downwind sections of the outlet grille are the most important factors that affect the aerodynamic performance of the unit. Furthermore, two improved schemes against the existing prototype of the unit are developed, which both can significantly increase the flow rate more than 6 %(i.e. 100 m3·h-1) at given rotating speeds. The inevitable increase of flow noise level when flow rate is increased and the advantage of keeping a lower rotating speed are also discussed. The presented work could be a useful guideline in designing the aerodynamic and acoustic performance of the split air-conditioner in engineering practice.

  2. An investigation of short haul air transportation in the southeastern United States

    NASA Technical Reports Server (NTRS)

    Kanafani, A.; Yuan, H. S.

    1977-01-01

    The specific objectives of this stage of the study are numerous. First, an attempt is made to characterize the travel patterns in the study region, both in terms of origin destination patterns, and connecting and through trip patterns. Second, the structure of the air service in the region is characterized in an attempt to develop an understanding of the evolution of the short haul air transportation network. Finally, a look is taken at the socioeconomic environment of Atlanta and the region in order to seek an explanation for the historic evolution of short haul air travel activities and the rather high growth rates experienced in recent years.

  3. Selective flotation of fossil resin from western coal

    SciTech Connect

    Jensen, G.F.; Miller, J.D.

    1992-03-20

    The test program has demonstrated that: (1) technically, the new flotation technologies discovered at the University of Utah and then improved upon by Advanced Processing Technologies, Inc. provide a highly efficient means to selectively recover fossil resin from coal. The proof-of-concept continuous flotation circuit resulted in fossil resin recovery with the same separation efficiency as was obtained from laboratory bench-scale testing (more than 80% recovery at about 80% concentrate grade); and (2) economically, the selective flotation process has been shown to be sufficiently profitable to justify the development of a fossil resin industry based on this new flotation process. The proof-of-concept testing has resulted in significant interest from several coal mining companies and has sparked the desire of local and state government to establish a fossil resin industry in the Wasatch Plateau coal field. In this view, the results from the current proof-of-concept testing program have been successful. This special report provides theoretical and analytical data on some surface chemistry work pertinent to fossil resin characterization, and other efforts carried out during the past months.

  4. 14 CFR 121.340 - Emergency flotation means.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 3 2014-01-01 2014-01-01 false Emergency flotation means. 121.340 Section 121.340 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED... airplane in any overwater operation unless it is equipped with life preservers in accordance with §...

  5. Beneficiation of U. S. oil shales by froth flotation

    SciTech Connect

    Krishnan, G.N.; Farley, E.P.; Murray, R.G.

    1983-04-01

    A bench-scale study of the beneficiation of western and eastern oil shales was conducted using ball mill grinding and froth flotation techniques. The liberation of organic and inorganic particles required reducing the particles to about 10-20 ..mu..m. Ball mill grinding energies were estimated to be about 50 kwh/ton for the western ''Anvil Points'' shale (13.5 wt% organics, 24 GPT) and 30 kwh/ton for the eastern ''Antrim'' shale (8 wt% organics, 7 GPT) for reduction to 20 ..mu..m. Froth flotation can increase the organic content of Anvil Points shale to about 27 wt% (50 GPT) at about 80% recovery. Froth flotation of finely ground Antrim shale produced concentrates containing 21 wt% organics (23 GPT) with 90% recovery. Higher grades of concentrates at lower recoveries can be obtained with additional stages of grinding and froth flotation. The separation efficiencies for the Anvil Points and Antrim shales were found to be 52% and 60% at the optimum conditions.

  6. 33 CFR 142.45 - Personal flotation devices.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... fall, they would likely fall into water, shall wear a work vest that meets the requirements of 33 CFR 146.20 or a life preserver that meets the requirements of 46 CFR 160.002, 160.005, or 160.055, except... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Personal flotation devices....

  7. 46 CFR 179.240 - Foam flotation material.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ..., see 46 CFR 175.600). The fire resistance test is not required. (2) Foam may be installed only in void spaces that are free of ignition sources, unless the foam complies with the requirements of 33 CFR 183... 46 Shipping 7 2012-10-01 2012-10-01 false Foam flotation material. 179.240 Section...

  8. 46 CFR 179.240 - Foam flotation material.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ..., see 46 CFR 175.600). The fire resistance test is not required. (2) Foam may be installed only in void spaces that are free of ignition sources, unless the foam complies with the requirements of 33 CFR 183... 46 Shipping 7 2011-10-01 2011-10-01 false Foam flotation material. 179.240 Section...

  9. High-efficiency flotation of coarse and fine coal

    SciTech Connect

    Atkinson, B.W.; Conway, C.J.; Jameson, G.J.

    1995-10-01

    The flotation of coal in the fine and coarse particle size ranges presents particular problems. Fine or ultra-fine coal less than 100 microns presents a challenge to conventional flotation machines because the rate of capture of the coal particles can be very low, so longer residence times are needed. Also, conventional mechanical cells are not normally designed with froth properties in mind. Froth drainage may be inadequate, leading to excessive entrainment of ash. The upper limit of flotation of coal is normally put at about 500 {micro}m (30 mesh). It appears that, in mechanical cells, coarser particles tend to be torn away from bubbles in the turbulent environment created by the impeller. In this paper, results are presented from plant trials of a high-intensity flotation column of novel design, namely the Jameson cell. Extensive trials have been conducted on coal slurries with a top size of around 1 mm. Size-by size analysis shows that it is possible to achieve high yields of low ash product over the whole particle size range.

  10. 46 CFR 179.240 - Foam flotation material.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... spaces that are free of ignition sources, unless the foam complies with the requirements of 33 CFR 183... 46 Shipping 7 2014-10-01 2014-10-01 false Foam flotation material. 179.240 Section 179.240 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SMALL PASSENGER VESSELS (UNDER 100...

  11. 33 CFR 183.225 - Flotation test for persons capacity.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    .... Flotation standard. When the conditions prescribed in § 183.220 are met, the boat must float in fresh, calm water as follows: (a) The angle of heel does not exceed 10 degrees from the horizontal. (b) Any point on either the forward or aft reference area is above the surface of the water. (c) The reference depth...

  12. 33 CFR 183.325 - Flotation test for persons capacity.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    .... Flotation standard. When the conditions prescribed in § 183.320 are met, the boat must float in fresh, calm water as follows: (a) The angle of heel does not exceed 10 degrees from the horizontal. (b) Any point on either the forward or aft reference area is above the surface of the water. (c) The reference depth...

  13. 33 CFR 183.325 - Flotation test for persons capacity.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    .... Flotation standard. When the conditions prescribed in § 183.320 are met, the boat must float in fresh, calm water as follows: (a) The angle of heel does not exceed 10 degrees from the horizontal. (b) Any point on either the forward or aft reference area is above the surface of the water. (c) The reference depth...

  14. 33 CFR 183.225 - Flotation test for persons capacity.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    .... Flotation standard. When the conditions prescribed in § 183.220 are met, the boat must float in fresh, calm water as follows: (a) The angle of heel does not exceed 10 degrees from the horizontal. (b) Any point on either the forward or aft reference area is above the surface of the water. (c) The reference depth...

  15. 33 CFR 183.325 - Flotation test for persons capacity.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    .... Flotation standard. When the conditions prescribed in § 183.320 are met, the boat must float in fresh, calm water as follows: (a) The angle of heel does not exceed 10 degrees from the horizontal. (b) Any point on either the forward or aft reference area is above the surface of the water. (c) The reference depth...

  16. 33 CFR 183.225 - Flotation test for persons capacity.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    .... Flotation standard. When the conditions prescribed in § 183.220 are met, the boat must float in fresh, calm water as follows: (a) The angle of heel does not exceed 10 degrees from the horizontal. (b) Any point on either the forward or aft reference area is above the surface of the water. (c) The reference depth...

  17. Engineering development of advanced froth flotation. Volume 2, Final report

    SciTech Connect

    Ferris, D.D.; Bencho, J.R.; Torak, E.R.

    1995-03-01

    This report is an account of findings related to the Engineering and Development of Advanced Froth Flotation project. The results from benchscale and proof-of-concept (POC) level testing are presented and the important results from this testing are used to refine a conceptual design and cost estimate for a 20 TPH Semi-Works Facility incorporating the final proposed technology.

  18. 21 CFR 890.5170 - Powered flotation therapy bed.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Powered flotation therapy bed. 890.5170 Section 890.5170 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Therapeutic Devices §...

  19. 21 CFR 890.5170 - Powered flotation therapy bed.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Powered flotation therapy bed. 890.5170 Section 890.5170 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Therapeutic Devices §...

  20. 21 CFR 890.5170 - Powered flotation therapy bed.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Powered flotation therapy bed. 890.5170 Section 890.5170 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Therapeutic Devices §...

  1. 21 CFR 890.5170 - Powered flotation therapy bed.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Powered flotation therapy bed. 890.5170 Section 890.5170 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Therapeutic Devices §...

  2. 21 CFR 890.5170 - Powered flotation therapy bed.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Powered flotation therapy bed. 890.5170 Section 890.5170 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Therapeutic Devices §...

  3. Surface chemistry control for selective fossil resin flotation

    DOEpatents

    Miller, J.D.; Yi, Y.; Yu, Q.

    1994-06-07

    A froth flotation method is disclosed for separating fine particles of fossil resin by use of frothing reagents which include an aliphatic organic compound having a polar group and containing not more than four carbon atoms. Butanol is an effective frothing reagent in this method. 12 figs.

  4. Surface chemistry control for selective fossil resin flotation

    DOEpatents

    Miller, Jan D.; Yi, Ye; Yu, Qiang

    1994-01-01

    A froth flotation method is disclosed for separating fine particles of fossil resin from by use of frothing reagents which include an aliphatic organic compound having a polar group and containing not more than four carbon atoms. Butanol is an effective frothing reagent in this method.

  5. 33 CFR 142.45 - Personal flotation devices.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... § 142.45 Personal flotation devices. Personnel, when working in a location such that, in the event of a fall, they would likely fall into water, shall wear a work vest that meets the requirements of 33 CFR 146.20 or a life preserver that meets the requirements of 46 CFR 160.002, 160.005, or 160.055,...

  6. Engineering development of advanced physical fine coal cleaning technologies: Froth flotation

    SciTech Connect

    Not Available

    1990-01-01

    An engineering development project was prepared to build upon the basic research effort conducted under a solicitation for research into Fine Coal Surface Control. The engineering development project is intended to use general plant design knowledge and conceptualize a plant to utilize advanced froth flotation technology to process coal and produce a product having maximum practical pyritic sulfur reduction consistent with maximum practical BTU recovery. This is being accomplished by utilization the basic research data on the surface properties of coal, mineral matter and pyrite obtained from the Coal Surface Control for Advanced Fine Coal Flotation Project, to develop this conceptual flowsheet. The conceptual flowsheet must be examined to identify critical areas that need additional design data. This data will then be developed using batch and semi-continuous bench scale testing. In addition to actual bench scale testing other unit operations from other industries processing fine material will be reviewed for potential application and incorporated into the design if appropriate. 31 figs., 22 tabs.

  7. Removal of arsenopyrite from complex sulfide minerals by froth flotation

    NASA Astrophysics Data System (ADS)

    Choi, Jin-young; Kim, Yang-soo; Kim, Dong-gyu; Han, Oh-hyung; Park, Chul-hyun

    2016-04-01

    Arsenic (As) is one of hazardous materials and a penalty element in metal concentrates and so metal concentrates containing arsenic of over 0.5% has been currently restricted in import and export trade. It also corrodes a smelting furnace as well as shortens its life cycle. In korea, Janggun mine that produces galena (PbS) /sphalerite (ZnS) concentrate containing arsenic of 1.78% charges a penalty of US 2/ton to LS-Nikko smelter. Hence in this work, flotation tests for removal of arsenopyrite (FeAsS) from sulfide mineral concentrates were carried out using lab scale flotation cell, which maintain grade and recovery of PbS and ZnS in comparison to flotation plant. Particularly, this study was focused on investigating the combination of several chemical reagents (depressant, collector, activator and etc.) that affect flotation performance. In the straight differential flotation for PbS, a PbS grade of 75.80% and a recovery of 90.12% could be obtained with FeAsS removal of 84.1% (0.2% As) under the conditions of 20% feed solids concentration, pH 8.5, 50g/t frother (AF65), 40g/t collector (AP242) and 800g/t As depressant (NaHSO3) and 600g/t Zn depressant (ZnSO4). In the ZnS flotation, the maximum separation achievable for ZnS using froth flotation has been shown to be a grade of 72.57% and a recovery of 95.43%. At this time, FeAsS removal of 87.8% (0.16% As) could be successfully accomplished under pH 11, and 800g/t Zn activator (CuSO4), 75g/t frother (AF65), 60g/t collector (AP211) and 600g/t As depressant (NaHSO3). Acknowledgments This work was supported by the Energy and Resources Engineering Program Grant funded by the Ministry of Trade, Industry and Energy, Korea

  8. Portable air quality sensor unit for participatory monitoring: an end-to-end VESNA-AQ based prototype

    NASA Astrophysics Data System (ADS)

    Vucnik, Matevz; Robinson, Johanna; Smolnikar, Miha; Kocman, David; Horvat, Milena; Mohorcic, Mihael

    2015-04-01

    Key words: portable air quality sensor, CITI-SENSE, participatory monitoring, VESNA-AQ The emergence of low-cost easy to use portable air quality sensors units is opening new possibilities for individuals to assess their exposure to air pollutants at specific place and time, and share this information through the Internet connection. Such portable sensors units are being used in an ongoing citizen science project called CITI-SENSE, which enables citizens to measure and share the data. The project aims through creating citizens observatories' to empower citizens to contribute to and participate in environmental governance, enabling them to support and influence community and societal priorities as well as associated decision making. An air quality measurement system based on VESNA sensor platform was primarily designed within the project for the use as portable sensor unit in selected pilot cities (Belgrade, Ljubljana and Vienna) for monitoring outdoor exposure to pollutants. However, functionally the same unit with different set of sensors could be used for example as an indoor platform. The version designed for the pilot studies was equipped with the following sensors: NO2, O3, CO, temperature, relative humidity, pressure and accelerometer. The personal sensor unit is battery powered and housed in a plastic box. The VESNA-based air quality (AQ) monitoring system comprises the VESNA-AQ portable sensor unit, a smartphone app and the remote server. Personal sensor unit supports wireless connection to an Android smartphone via built-in Wi-Fi. The smartphone in turn serves also as the communication gateway towards the remote server using any of available data connections. Besides the gateway functionality the role of smartphone is to enrich data coming from the personal sensor unit with the GPS location, timestamps and user defined context. This, together with an accelerometer, enables the user to better estimate ones exposure in relation to physical activities, time

  9. An Advanced Control System For Fine Coal Flotation

    SciTech Connect

    G. H. Luttrell; G. T. Adel

    1998-08-25

    A model-based flotation control scheme is being implemented to achieve optimal performance in the handling and treatment of fine coal. The control scheme monitors flotation performance through on-line analysis of ash content. Then, based on the economic and metallurgical performance of the circuit, variables such as collector dosage, frother dosage, and pulp level are adjusted using model-based control algorithms to compensate for feed variations and other process disturbances. Recent developments in sensor technology are being applied for on-line determination of slurry ash content. During the ninth quarter of this project, Task 3 (Model Building and Computer Simulation) and Task 4 (Sensor Testing) were nearly completed, and Task 6 (Equipment Procurement and Installation) was initiated. Previously, data collected from the plant sampling campaign (Task 2) were used to construct a population balance model to describe the steady-state and dynamic behavior of the flotation circuit. The details of this model were presented in the Eighth Quarterly Technical Progress Report. During the past quarter, a flotation circuit simulator was designed and used to evaluate control strategies. As a result of this work, a model-based control strategy has been conceived which will allow manipulated variables to be adjusted in response to disturbances to achieve a target incremental ash value in the last cell of the bank. This will, in effect, maximize yield at an acceptable product quality. During this same period, a video-based ash analyzer was installed on the flotation tailings stream at the Moss No. 3 preparation plant. A preliminary calibration curve was established, and data are continuing to be collected in order to improve the calibration of the analyzer.

  10. The Association of Ambient Air Pollution and Physical Inactivity in the United States

    PubMed Central

    Roberts, Jennifer D.; Voss, Jameson D.; Knight, Brandon

    2014-01-01

    Background Physical inactivity, ambient air pollution and obesity are modifiable risk factors for non-communicable diseases, with the first accounting for 10% of premature deaths worldwide. Although community level interventions may target each simultaneously, research on the relationship between these risk factors is lacking. Objectives After comparing spatial interpolation methods to determine the best predictor for particulate matter (PM2.5; PM10) and ozone (O3) exposures throughout the U.S., we evaluated the cross-sectional association of ambient air pollution with leisure-time physical inactivity among adults. Methods In this cross-sectional study, we assessed leisure-time physical inactivity using individual self-reported survey data from the Centers for Disease Control and Prevention's 2011 Behavioral Risk Factor Surveillance System. These data were combined with county-level U.S. Environmental Protection Agency air pollution exposure estimates using two interpolation methods (Inverse Distance Weighting and Empirical Bayesian Kriging). Finally, we evaluated whether those exposed to higher levels of air pollution were less active by performing logistic regression, adjusting for demographic and behavioral risk factors, and after stratifying by body weight category. Results With Empirical Bayesian Kriging air pollution values, we estimated a statistically significant 16–35% relative increase in the odds of leisure-time physical inactivity per exposure class increase of PM2.5 in the fully adjusted model across the normal weight respondents (p-value<0.0001). Evidence suggested a relationship between the increasing dose of PM2.5 exposure and the increasing odds of physical inactivity. Conclusions In a nationally representative, cross-sectional sample, increased community level air pollution is associated with reduced leisure-time physical activity particularly among the normal weight. Although our design precludes a causal inference, these results provide

  11. The US Air Force Aerial Spray Unit: a history of large area disease vector control operations, WWII through Katrina.

    PubMed

    Breidenbaugh, Mark; Haagsma, Karl

    2008-01-01

    The US Air Force has had a long history of aerial applications of pesticides to fulfill a variety of missions, the most important being the protection of troops through the minimization of arthropod vectors capable of disease transmission. Beginning in World War II, aerial application of pesticides by the military has effectively controlled vector and nuisance pest populations in a variety of environments. Currently, the military aerial spray capability resides in the US Air Force Reserve (USAFR), which operates and maintains C-130 airplanes capable of a variety of missions, including ultra low volume applications for vector and nuisance pests, as well as higher volume aerial applications of herbicides and oil-spill dispersants. The USAFR aerial spray assets are the only such fixed-wing aerial spray assets within the Department of Defense. In addition to troop protection, the USAFR Aerial Spray Unit has participated in a number of humanitarian/relief missions, most recently in the response to the 2005 Hurricanes Katrina and Rita, which heavily damaged the Gulf Coasts of Louisiana, Mississippi, and Texas. This article provides historical background on the Air Force Aerial Spray Unit and describes the operations in Louisiana in the aftermath of Hurricane Katrina. PMID:20088030

  12. The US Air Force Aerial Spray Unit: a history of large area disease vector control operations, WWII through Katrina.

    PubMed

    Breidenbaugh, Mark; Haagsma, Karl

    2008-01-01

    The US Air Force has had a long history of aerial applications of pesticides to fulfill a variety of missions, the most important being the protection of troops through the minimization of arthropod vectors capable of disease transmission. Beginning in World War II, aerial application of pesticides by the military has effectively controlled vector and nuisance pest populations in a variety of environments. Currently, the military aerial spray capability resides in the US Air Force Reserve (USAFR), which operates and maintains C-130 airplanes capable of a variety of missions, including ultra low volume applications for vector and nuisance pests, as well as higher volume aerial applications of herbicides and oil-spill dispersants. The USAFR aerial spray assets are the only such fixed-wing aerial spray assets within the Department of Defense. In addition to troop protection, the USAFR Aerial Spray Unit has participated in a number of humanitarian/relief missions, most recently in the response to the 2005 Hurricanes Katrina and Rita, which heavily damaged the Gulf Coasts of Louisiana, Mississippi, and Texas. This article provides historical background on the Air Force Aerial Spray Unit and describes the operations in Louisiana in the aftermath of Hurricane Katrina.

  13. An Air Mass Based Approach to the Establishment of Spring Season Synoptic Characteristics in the Northeast United States

    NASA Astrophysics Data System (ADS)

    Zander, R.; Messina, A.; Godek, M. L.

    2012-12-01

    The spring season is indicative of marked meteorological, ecological, and biological changes across the Northeast United States. The onset of spring coincides with distinct meteorological phenomena including an increase in severe weather events and snow meltwaters that can cause localized flooding and other costly damages. Increasing and variable springtime temperatures also influence Northeast tourist operations and agricultural productivity. Even with the vested interest of industry in the season and public awareness of the dynamic characteristics of spring, the definition of spring remains somewhat arbitrary. The primary goal of this research is to obtain a synoptic meteorological definition of the spring season through an assessment of air mass frequency over the past 60 years. A secondary goal examines the validity of recent speculations that the onset and termination of spring has changed in recent decades, particularly since 1975. The Spatial Synoptic Classification is utilized to define daily air masses over the region. Annual and seasonal baseline frequencies are identified and their differences are acquired to characterize the season. Seasonal frequency departures of the early and late segments of the period of record around 1975 are calculated and examined for practical and statistical significance. The daily boundaries of early and late spring are then isolated and frequencies are obtained for these periods. Boundary frequencies are assessed across the period of record to identify important changes in the season's initiation and termination through time. Results indicate that the Northeast spring season is dominated by dry air masses, mainly the Dry Moderate and Dry Polar types. Significant differences in seasonal air mass frequency are also observed through time. Prior to 1975, higher frequencies of polar air mass types are detected while after 1975 there is an increase in the frequencies of both moderate and tropical types. This finding is also

  14. Association between air pollution and daily consultations with general practitioners for allergic rhinitis in London, United Kingdom.

    PubMed

    Hajat, S; Haines, A; Atkinson, R W; Bremner, S A; Anderson, H R; Emberlin, J

    2001-04-01

    Few published studies have looked at the health effects of air pollution in the primary care setting, and most have concentrated on lower rather than upper respiratory diseases. The authors investigated the association of daily consultations with general practitioners for allergic rhinitis with air pollution in London, United Kingdom. Generalized additive models were used to regress time series of daily numbers of patients consulting for allergic rhinitis against 1992--1994 measures of air pollution, after control for possible confounders and adjustment for overdispersion and serial correlation. In children, a 10th--90th percentile increase in sulfur dioxide (SO(2)) levels 4 days prior to consultation (13-31 microg/m(3)) was associated with a 24.5% increase in consultations (95% confidence interval: 14.6, 35.2; p < 0.00001); a 10th--90th percentile increase in averaged ozone (O(3)) concentrations on the day of consultation and the preceding 3 days (6--29 parts per billion) was associated with a 37.6% rise (95% confidence interval: 23.3, 53.5; p < 0.00001). For adults, smaller effect sizes were observed for SO(2) and O(3). The association with SO(2) remained highly significant in the presence of other pollutants. This study suggests that air pollution worsens allergic rhinitis symptoms, leading to substantial increases in consultations. SO(2) and O(3) seem particularly responsible, and both seem to contribute independently. PMID:11282799

  15. Model validations for low-global warming potential refrigerants in mini-split air-conditioning units

    DOE PAGES

    Shen, Bo; Shrestha, Som; Abdelaziz, Omar

    2016-09-02

    To identify low GWP (global warming potential) refrigerants to replace R-22 and R-410A, extensive experimental evaluations were conducted for multiple candidates of refrigerant at the standard test conditions and at high-ambient conditions with outdoor temperature varying from 27.8 C to 55.0 C.. In the study, R-22 was compared to propane (R-290), DR-3, ARM-20B, N-20B and R-444B in a mini-split air conditioning unit originally designed for R-22; R-410A was compared to R-32, DR-55, ARM-71A, L41-2 (R-447A) in a mini-split unit designed for R-410A. To reveal physics behind the measured performance results, thermodynamic properties of the alternative refrigerants were analysed. In addition,more » the experimental data was used to calibrate a physics-based equipment model, i.e. ORNL Heat Pump Design Model (HPDM). The calibrated model translated the experimental results to key calculated parameters, i.e. compressor efficiencies, refrigerant side two-phase heat transfer coefficients, corresponding to each refrigerant. As a result, these calculated values provide scientific insights on the performance of the alternative refrigerants and are useful for other applications beyond mini-split air conditioning units.« less

  16. United States Air Force 611th Air Support Group/Civil Engineering Squadron, Elmendorf AFB, Alaska. Decision document for no further response action planned Oliktok Point Radar Installation, Alaska. Final report

    SciTech Connect

    Karmi, S.

    1996-06-03

    This Decision Document discusses the selection of no further action as the recommended action for four sites located at the Oliktok Point radar installation. The United States Air Force (Air Force) completed a Remedial Investigation/Feasibility Study and a Risk Assessment for the eight sites located at the Oliktok Point installation (U.S. Air Force 1996a,b). Based on the findings of these activities, four sites are recommended for no further action.

  17. United States Air Force 611th Air Support Group/Civil Engineering Squadron Elmendorf AFB, Alaska. Decision document for no further response action planned: Barter Island Radar Installation, Alaska. Final report, December 1995-May 1996

    SciTech Connect

    Karmi, S.; Madden, J.; Borsetti, R.

    1996-05-03

    This Decision Document discusses the selection of no further action as the recommended action for nine sites located at the Barter Island radar installation. The United States Air Force (Air Force) completed a Remedial Investigation/Feasibility Study and a Risk Assessment for the 14 sites located at the Barter Island installation (U.S. Air Force 1996a,b). Based on the findings of these activities, nine sites are recommended for no further action.

  18. Integrated Testing of a 4-Bed Molecular Sieve, Air-Cooled Temperature Swing Adsorption Compressor, and Sabatier Engineering Development Unit

    NASA Technical Reports Server (NTRS)

    Knox, James C.; Miller, Lee; Campbell, Melissa; Mulloth, Lila; Varghese, Mini

    2006-01-01

    Accumulation and subsequent compression of carbon dioxide that is removed from the space cabin are two important processes involved in a closed-loop air revitalization scheme of the International Space Station (ISS). The 4-Bed Molecular Sieve (4BMS) of ISS currently operates in an open loop mode without a compressor. The Sabatier Engineering Development Unit (EDU) processes waste CO2 to provide water to the crew. This paper reports the integrated 4BMS, air-cooled Temperature Swing Adsorption Compressor (TSAC), and Sabatier EDU testing. The TSAC prototype was developed at NASA Ames Research Center (ARC). The 4BMS was modified to a functionally flight-like condition at NASA Marshall Space Flight Center (MSFC). Testing was conducted at MSFC. The paper provides details of the TSAC operation at various CO2 loadings and corresponding performance of the 4BMS and Sabatier.

  19. The Dilemma of Teaching World History at the United States Air Force Academy.

    ERIC Educational Resources Information Center

    Shackleton, Deborah A.

    2000-01-01

    States that the lack of vision in world history teaching at the U.S. Air Force Academy is due to several factors including textbook selection, faculty resistance to teaching world history, the debate between teaching Western Civilization versus world history, and the educational background of the faculty. (CMK)

  20. Physical Therapy Career Ladder: United States Air Force Job Inventory. AFSCs 91330, 91350, 91370, and 91392.

    ERIC Educational Resources Information Center

    Air Force Personnel and Training Research Center, Lackland AFB, TX.

    The booklet is a checklist to provide information about the tasks of the physical therapist in the Air Force physical therapy career ladder. The first major section is on background information; there are multiple choice questions on job attitudes, places of employment, future plans, and general types of duty. From a list of 137 pieces of physical…

  1. POLLUTION PREVENTION OPPORTUNITY ASSESSMENT - UNITED STATES NAVAL BASE NORFOLK NAVAL AIR STATION

    EPA Science Inventory

    This report summarizes work conducted at the U.S. Navy's Naval Base Norfolk, Naval Air Station (NAS) located at Sewells Point in Norfolk, Virginia, under the U.S. Environmental Protection Agency's (EPA) Waste Reduction Evaluations at Federal Sites (WREAFS) Program. This project w...

  2. 77 FR 64414 - Approval and Promulgation of Air Quality Implementation Plans; United States Virgin Islands...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-22

    ... Islands regional haze FIP, the reader is referred to the June 25, 2012 proposal (77 FR 37842). EPA's... submit on January 15, 2009 (74 FR 2392), determining that the U.S. Virgin Islands failed to submit a SIP..., 2012 proposal (77 FR 37842). Air modeling ranks construction and road dust as the two...

  3. IMPACTS OF BIOMASS BURNING EMISSIONS ON AIR QUALITY AND PUBLIC HEALTH IN THE UNITED STATES

    EPA Science Inventory

    Wildfire is a natural disaster that claims human life and property. While most attention has been paid to direct life and health threats, mostly to firefighters, this work focuses on the indirect impact of wildfires on the general population due to degraded air quality. Using an ...

  4. AIR PERMIT COMPLIANCE FOR WASTE RETRIEVAL OEPRATIONS INVOLVING MULTI-UNIT OPERATIONS

    SciTech Connect

    SIMMONS FM

    2007-11-05

    Since 1970, approximately 38,000 suspect-transuranic and transuranic waste containers have been placed in retrievable storage on the Hanford Site in the 200 Areas burial grounds. Hanford's Waste Retrieval Project is retrieving these buried containers and processing them for safe storage and disposition. Container retrieval activities require an air emissions permit to account for potential emissions of radionuclides. The air permit covers the excavation activities as well as activities associated with assaying containers and installing filters in the retrieved transuranic containers lacking proper venting devices. Fluor Hanford, Inc. is required to track radioactive emissions resulting from the retrieval activities. Air, soil, and debris media contribute to the emissions and enabling assumptions allow for calculation of emissions. Each of these activities is limited to an allowed annual emission (per calendar year) and .contributes to the overall total emissions allowed for waste retrieval operations. Tracking these emissions is required to ensure a permit exceedance does not occur. A tracking tool was developed to calculate potential emissions in real time sense. Logic evaluations are established within the tracking system to compare real time data against license limits to ensure values are not exceeded for either an individual activity or the total limit. Data input are based on field survey and workplace air monitoring activities. This tracking tool is used monthly and quarterly to verify compliance to the license limits. Use of this tool has allowed Fluor Hanford, Inc. to successfully retrieve a significant number of containers in a safe manner without any exceedance of emission limits.

  5. Modeling and Qualification of a Modified Emission Unit for Radioactive Air Emissions Stack Sampling Compliance.

    PubMed

    Barnett, J Matthew; Yu, Xiao-Ying; Recknagle, Kurtis P; Glissmeyer, John A

    2016-11-01

    A planned laboratory space and exhaust system modification to the Pacific Northwest National Laboratory Material Science and Technology Building indicated that a new evaluation of the mixing at the air sampling system location would be required for compliance to ANSI/HPS N13.1-2011. The modified exhaust system would add a third fan, thereby increasing the overall exhaust rate out the stack, thus voiding the previous mixing study. Prior to modifying the radioactive air emissions exhaust system, a three-dimensional computational fluid dynamics computer model was used to evaluate the mixing at the sampling system location. Modeling of the original three-fan system indicated that not all mixing criteria could be met. A second modeling effort was conducted with the addition of an air blender downstream of the confluence of the three fans, which then showed satisfactory mixing results. The final installation included an air blender, and the exhaust system underwent full-scale tests to verify velocity, cyclonic flow, gas, and particulate uniformity. The modeling results and those of the full-scale tests show agreement between each of the evaluated criteria. The use of a computational fluid dynamics code was an effective aid in the design process and allowed the sampling system to remain in its original location while still meeting the requirements for sampling at a well mixed location. PMID:27682902

  6. PAST, PRESENT AND FUTURE AIR QUALITY MODELING AND ITS APPLICATIONS IN THE UNITED STATES

    EPA Science Inventory

    Since the inception of the Clean Air Act (CAA) in 1969, atmospheric models have been used to assess source-receptor relationships for sulfur dioxide and total suspended particulate matter (TSP) in the urban areas. The focus through the 1970's has been on the Gaussian dispersio...

  7. 78 FR 10608 - David Grant United States Air Force Medical Center Specialty Care Travel Reimbursement...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-14

    ... adequate clinical case mix of patients for approved Graduate Medical Education program functioning in the... demonstration would be initially conducted at DGMC and its satellite clinic, the McClellan Clinic (MCC) as well as the clinic located at Beale Air Force Base (Beale). However, it could be expanded to other...

  8. Increasing Anthropogenic Emissions in China Offset Air Quality Policy Efforts in Western United States: A Satellite and Modelling Perspective

    NASA Astrophysics Data System (ADS)

    Boersma, F. F.; Verstraeten, W. W.; Williams, J. E.; Neu, J. L.; Bowman, K. W.; Worden, J.

    2014-12-01

    Tropospheric ozone is an important greenhouse gas and a global air pollutant originating from photo-chemical oxidation of ozone precursors in the presence of NOX. Eastern Asia has the fastest growing anthropogenic emissions in the world, possibly affecting both the pollution in the local troposphere as well as in the trans-Pacific region. Local measurements over Asia show that tropospheric ozone has increased by 1 to 3% per year since the start of the millennium. This increase is often invoked to explain positive ozone trends observed in western United States, but to date there is no unambiguous evidence showing that enhanced Asian pollution is responsible for these trends. Here we interpret satellite measurements of tropospheric ozone and its precursor nitrate dioxide from the Aura Tropospheric Emission Spectrometer (TES) and Ozone Monitoring Instrument (OMI) using the TM5 global chemistry-transport model to directly show that tropospheric ozone over China has increased by ~10% from 2005-2010 in response to both a ~15% rise in Chinese emissions and an increased downward ozone transport from the stratosphere. What is more, we demonstrate that Chinese export of ozone and its precursors have offset one-third of the reduction in free tropospheric ozone over the western United States that should have occurred during 2005-2010 via emissions reductions associated with air quality policies in the United States. The issue of export and long-range transport of pollution from other countries indicates that global efforts may be required to address both the global as well as the regional air quality and climate change.

  9. Stable isotope composition of waters in the Great Basin, United States 1. Air-mass trajectories

    USGS Publications Warehouse

    Friedman, I.; Harris, J.M.; Smith, G.I.; Johnson, C.A.

    2002-01-01

    Isentropic trajectories, calculated using the NOAA/Climate Monitoring and Diagnostics Laboratory's isentropic transport model, were used to determine air-parcel origins and the influence of air mass trajectories on the isotopic composition of precipitation events that occurred between October 1991 and September 1993 at Cedar City, Utah, and Winnemucca, Nevada. Examination of trajectories that trace the position of air parcels backward in time for 10 days indicated five distinct regions of water vapor origin: (1) Gulf of Alaska and North Pacific, (2) central Pacific, (3) tropical Pacific, (4) Gulf of Mexico, and (5) continental land mass. Deuterium (??D) and oxygen-18 (??18O) analyses were made of precipitation representing 99% of all Cedar City events. Similar analyses were made on precipitation representing 66% of the precipitation falling at Winnemucca during the same period. The average isotopic composition of precipitation derived from each water vapor source was determined. More than half of the precipitation that fell at both sites during the study period originated in the tropical Pacific and traveled northeast to the Great Basin; only a small proportion traversed the Sierra Nevada. The isotopic composition of precipitation is determined by air-mass origin and its track to the collection station, mechanism of droplet formation, reequilibration within clouds, and evaporation during its passage from cloud to ground. The Rayleigh distillation model can explain the changes in isotopic composition of precipitation as an air mass is cooled pseudo-adiabatically during uplift. However, the complicated processes that take place in the rapidly convecting environment of cumulonimbus and other clouds that are common in the Great Basin, especially in summer, require modification of this model because raindrops that form in the lower portion of those clouds undergo isotopic change as they are elevated to upper levels of the clouds from where they eventually drop to the

  10. Historic and Future Response of Air Quality to Climate in the Eastern United States

    NASA Astrophysics Data System (ADS)

    Harkey, M.; Holloway, T.; Meier, P.; Limaye, V.; Patz, J.

    2013-12-01

    Both process-based models and observational analysis show relationships between health-relevant air pollutants and climate variables. Here, we evaluate how observed patterns in the response of O3, NO2, and PM2.5 may change in the future, based on an integrated analysis of model simulations, ground-based measurements, and satellite data. Our analysis builds confidence in model performance, and highlights the potential of satellite data to inform climate-chemistry processes. In addition to evaluating model performance in calculating climate and/or air quality variables directly, we present an analysis of total derivatives of change of a chemical constituent with respect to individual meteorological variables. We characterize spatial and temporal variability of observed and modeled "response factors," and evaluate whether the relationships are likely to change under future conditions. Although a range of factors could affect future change in air quality response factors, we consider here meteorological changes and the secondary effects of increases in electricity demand. We focus on changing climate and electrical demand on air quality in the Eastern U.S. in summertime. Observed chemistry-climate responses from ground-based measurements and satellite data are compared with simulations from the EPA Community Multiscale Air Quality (CMAQ) model. CMAQ is also used to evaluate future climate projections, selected for analysis from the North American Regional Climate Change Assessment Program (NARCCAP) simulation archive and downscaled with the Weather Research and Forecasting (WRF) model. Future electricity and emissions under a warmer climate are calculated with the MyPower model, based on region-specific building efficiencies and plant-by-plant electricity dispatch.

  11. Field Demonstration of a High-Efficiency Packaged Rooftop Air Conditioning Unit at Fort Gordon, Augusta, GA

    SciTech Connect

    Armstrong, Peter R.; Sullivan, Gregory P.; Parker, Graham B.

    2006-03-31

    As part of a larger program targeting the market transformation of packaged rooftop air conditioning, five high-efficiency rooftop air conditioning products were selected in 2002 by the U.S. Department of Energy (DOE) under the Unitary Air Conditioner (UAC) Technology Procurement (http://www.pnl.gov/uac). In February 2003, Fort Gordon in Augusta, Georgia was chosen as the demonstration site. With the goal of validating the field performance and operation of one of the awarded products, a 10-ton high-efficiency packaged rooftop unit (RTU) manufactured by Global Energy Group (GEG) was installed at Fort Gordon in October 2003. Following equipment installation, power metering, air- and refrigerant-side instrumentation was installed on the GEG RTU and a 4-year old typical-efficiency 20-ton RTU manufactured by AAON . The GEG and AAON units were instrumented identically and operated May through July, 2005, to observe performance under a range of conditions. Based on the data collected as part of this demonstration, the GEG equipment performed at least 8% better in stage-1 (single compressor running) cooling and at least 16% better in stage-2 (both compressors running) than the baseline AAON equipment. Performance comparisons are based on what we call application EER normalized to equivalent specific fan power. The full-load, specific-fan-power-normalized application EERs at ARI design conditions were 10.48 Btu/Wh for the GEG and 9.00 Btu/Wh for the baseline machine. With a cost premium of nearly 50%, and slightly higher maintenance costs, the life-cycle cost analysis shows that the GEG technology pays for itself--a positive net-present value (NPV)--only in climates and buildings with long cooling seasons. Manufacture of this equipment on a larger scale can be expected to reduce costs to the point where it is more broadly cost-effective. The assumed 10-ton baseline and new-technology unit costs are $3824.00 and $5525.00 respectively. If the new technology cost is assumed

  12. Flotation rate and residence time distribution in continuous coal froth flotation circuits and an evaluation of reagents and circuit variations for pyritic sulfur removal

    SciTech Connect

    Arnold, B.J.

    1989-01-01

    This thesis gives the results of research conducted on several aspects of coal froth flotation. The effect of operating variables on the residence time distribution in coal froth flotation cells is discussed, and a model of the residence time distribution is presented for use with flotation rate models in scaling up from laboratory to plant scale. Flotation rate models are also investigated in detail for continuous coal froth flotation circuits. Changes in operating variables were found to affect the mean residence time in cells, but they did not have much effect on the mixing behavior. The use of a time lag was found to be an important part of rate models for continuous froth flotation cells. An important aspect of the use of such rate and residence time equations is their application to the flotation of gangue constituents, which often enter the froth by water carry-over in addition to natural flotation or flotation as slime coatings. As such, water carry-over is also investigated in this thesis for the laboratory and the plant and for both ash-forming minerals and pyrite. Maintaining a constant froth factor, the percentage of froth above the weir, in both laboratory and plant tests is believed to be a critical factor in predicting plant results using a kinetic factor ratio documented in the literature. Removing the pyrite and ash-forming minerals from coal that may be recovered by the water carry-over or other mechanisms is an important goal in coal froth flotation. This thesis also contains the results of tests with pyrite depressants and circuit variations for removal of pyritic sulfur.

  13. An overview of oil-water separation using gas flotation systems.

    PubMed

    Saththasivam, Jayaprakash; Loganathan, Kavithaa; Sarp, Sarper

    2016-02-01

    Oil concentration levels in municipal waste water effluent streams are stringently regulated in most parts of the world. Apart from municipal waste, stricter oil/grease discharge limits are also enforced in oil and gas sectors as large volumes of produced water is being discharged to open ocean. One of the feasible, practical and established methods to remove oil substances from waste water sources is by gas flotation. In this overview, gas flotation technologies, namely dissolved and induced flotation systems, are discussed. Physico-chemical interaction between oil-water-gas during flotation is also summarized. In addition to a brief review on design advancements in flotation systems, enhancement of flotation efficiency by using pre-treatment methods, particularly coagulation-flocculation, is also presented.

  14. Improved flotation performance of hematite fines using citric acid as a dispersant

    NASA Astrophysics Data System (ADS)

    Luo, Xi-mei; Yin, Wan-zhong; Sun, Chuan-yao; Wang, Nai-ling; Ma, Ying-qiang; Wang, Yun-fan

    2016-10-01

    In this study, citric acid was used as a dispersant to improve the flotation performance of hematite fines. The effect and mechanism of citric acid on the reverse flotation of hematite fines were investigated by flotation tests, sedimentation experiments, scanning electron microscopy (SEM), zeta-potential measurements, and X-ray photoelectron spectroscopy (XPS). The results of SEM analysis and flotation tests reveal that a strong heterocoagulation in the form of slime coating or coagulation in hematite fine slurry affects the beneficiation of hematite ores by froth flotation. The addition of a small amount of citric acid (less than 300 g/t) favorably affects the reverse flotation of hematite fines by improving particle dispersion. The results of sedimentation experiments, zeta-potential measurements, and XPS measurements demonstrate that citric acid adsorbs onto hematite and quartz surfaces via hydrogen bonding, thereby reducing the zeta potentials of mineral surfaces, strengthening the electrical double-layer repulsion between mineral particles, and dispersing the pulp particles.

  15. An overview of oil-water separation using gas flotation systems.

    PubMed

    Saththasivam, Jayaprakash; Loganathan, Kavithaa; Sarp, Sarper

    2016-02-01

    Oil concentration levels in municipal waste water effluent streams are stringently regulated in most parts of the world. Apart from municipal waste, stricter oil/grease discharge limits are also enforced in oil and gas sectors as large volumes of produced water is being discharged to open ocean. One of the feasible, practical and established methods to remove oil substances from waste water sources is by gas flotation. In this overview, gas flotation technologies, namely dissolved and induced flotation systems, are discussed. Physico-chemical interaction between oil-water-gas during flotation is also summarized. In addition to a brief review on design advancements in flotation systems, enhancement of flotation efficiency by using pre-treatment methods, particularly coagulation-flocculation, is also presented. PMID:26408973

  16. Feasibility study of porous media compressed air energy storage in South Carolina, United States of America

    NASA Astrophysics Data System (ADS)

    Jarvis, Alexandra-Selene

    Renewable Energy Systems (RES) such as solar and wind, are expected to play a progressively significant role in electricity production as the world begins to move away from an almost total reliance on nonrenewable sources of power. In the US there is increasing investment in RES as the Department of Energy (DOE) expands its wind power network to encompass the use of offshore wind resources in places such as the South Carolina (SC) Atlantic Coastal Plain. Because of their unstable nature, RES cannot be used as reliable grid-scale power sources unless power is somehow stored during excess production and recovered at times of insufficiency. Only two technologies have been cited as capable of storing renewable energy at this scale: Pumped Hydro Storage and Compressed Air Energy Storage (CAES). Both CAES power plants in existence today use solution-mined caverns as their storage spaces. This project focuses on exploring the feasibility of employing the CAES method to store excess wind energy in sand aquifers. The numerical multiphase flow code, TOUGH2, was used to build models that approximate subsurface sand formations similar to those found in SC. Although the aquifers of SC have very low dips, less than 10, the aquifers in this study were modeled as flat, or having dips of 00. Cycle efficiency is defined here as the amount of energy recovered compared to the amount of energy injected. Both 2D and 3D simulations have shown that the greatest control on cycle efficiency is the volume of air that can be recovered from the aquifer after injection. Results from 2D simulations showed that using a dual daily peak load schedule instead of a single daily peak load schedule increased cycle efficiency as do the following parameters: increased anisotropy, screening the well in the upper portions of the aquifer, reduced aquifer thickness, and an initial water displacement by the continuous injection of air for at least 60 days. Aquifer permeability of 1x10-12 m2 produced a cycle

  17. Report on Preliminary Engineering Study for Installation of an Air Cooled Steam Condenser at Brawley Geothermal Plant, Unit No. 1

    SciTech Connect

    1982-03-01

    The Brawley Geothermal Project comprises a single 10 MW nominal geothermal steam turbine-generator unit which has been constructed and operated by the Southern California Edison Company (SCE). Geothermal steam for the unit is supplied through contract by Union Oil Company which requires the return of all condensate. Irrigation District (IID) purchases the electric power generated and provides irrigation water for cooling tower make-up to the plant for the first-five years of operation, commencing mid-1980. Because of the unavailability of irrigation water from IID in the future, SCE is investigating the application and installation of air cooled heat exchangers in conjunction with the existing wet (evaporative) cooling tower with make-up based on use of 180 gpm (nominal) of the geothermal condensate which may be made available by the steam supplier.

  18. A Review of the Current Geographic Distribution of and Debate Surrounding Electronic Cigarette Clean Air Regulations in the United States

    PubMed Central

    Kadowaki, Joy; Vuolo, Mike; Kelly, Brian C.

    2014-01-01

    In this article, we present the results of a systematic review of state, county, and municipal restrictions on the use of electronic cigarettes (e-cigarettes) in public spaces within the United States, alongside an overview of the current legal landscape. The lack of federal guidance leaves lower-level jurisdictions to debate the merits of restrictions on use in public spaces without sufficient scientific research. As we show through a geographic assessment of restrictions, this has resulted in an inconsistent patchwork of e-cigarette use bans across the United States of varying degrees of coverage. Bans have emerged over time in a manner that suggests a “bottom up” diffusion of e-cigarette clean air policies. Ultimately, the lack of clinical and scientific knowledge on the risks and potential harm reduction benefits has led to precautionary policymaking, which often lacks grounding in empirical evidence and results in spatially uneven diffusion of policy. PMID:25463920

  19. Impact of transpacific aerosol on air quality over the United States: A perspective from aerosol-cloud-radiation interactions

    NASA Astrophysics Data System (ADS)

    Tao, Zhining; Yu, Hongbin; Chin, Mian

    2016-01-01

    Observations have well established that aerosols from various sources in Asia, Europe, and Africa can travel across the Pacific and reach the contiguous United States (U.S.) at least on episodic bases throughout a year, with a maximum import in spring. The imported aerosol not only can serve as an additional source to regional air pollution (e.g., direct input), but also can influence regional air quality through the aerosol-cloud-radiation (ACR) interactions that change local and regional meteorology. This study assessed impacts of the transpacific aerosol on air quality, focusing on surface ozone and PM2.5, over the U.S. using the NASA Unified Weather Research Forecast model. Based on the results of 3-month (April to June of 2010) simulations, the impact of direct input (as an additional source) of transpacific aerosol caused an increase of surface PM2.5 concentration by approximately 1.5 μg m-3 over the west coast and about 0.5 μg m-3 over the east coast of the U.S. By influencing key meteorological processes through the ACR interactions, the transpacific aerosol exerted a significant effect on both surface PM2.5 (±6 μg m-3) and ozone (±12 ppbv) over the central and eastern U.S. This suggests that the transpacific transport of aerosol could either improve or deteriorate local air quality and complicate local effort toward the compliance with the U.S. National Ambient Air Quality Standards.

  20. Engineering development of advanced physical fine coal cleaning technologies: Froth flotation

    SciTech Connect

    Not Available

    1992-01-01

    A study conducted by Pittsburgh Energy Technology Center of sulfur emissions from about 1,300 United States coal-fired utility boilers indicated that half of the emissions were the result of burning coals having greater than 1.2 pounds of SO[sub 2] per million BTU. This was mainly attributed to the high pyritic sulfur content of the boiler fuel. A significant reduction in SO[sub 2] emissions could be accomplished by removing the pyrite from the coals by advanced physical fine coal cleaning. An engineering development project was prepared to build upon the basic research effort conducted under a solicitation for research into Fine Coal Surface Control. The engineering development project is intended to use general plant design knowledge and conceptualize a plant to utilize advanced froth flotation technology to process coal and produce a product having maximum practical pyritic sulfur reduction consistent with maximum practical BTU recovery.

  1. Air pollution control systems in WtE units: an overview.

    PubMed

    Vehlow, J

    2015-03-01

    All WtE (waste-to-energy) plants, based on combustion or other thermal processes, need an efficient gas cleaning for compliance with legislative air emission standards. The development of gas cleaning technologies started along with environment protection regulations in the late 1960s. Modern APC (air pollution control) systems comprise multiple stages for the removal of fly ashes, inorganic and organic gases, heavy metals, and dioxins from the flue gas. The main technologies and devices used for abatement of the various pollutants are described and their basic principles, their peculiarities, and their application are discussed. Few systems for cleaning of synthesis gas from waste gasification plants are included. Examples of APC designs in full scale plants are shown and cautious prospects for the future development of APC systems are made.

  2. United States: Canada memorandum of intent on transboundary air pollution. Atmospheric modeling, Work Group 2

    SciTech Connect

    Machta, L.

    1981-03-01

    The transport of air pollution from their sources to final deposition was investigated. Depositions in sensitive ecological areas are outlined. Several models were developed in both Canada and the U.S. for application in long range transport studies. The models describe sulfur deposition on an annual basis. A transfer matrix is adopted to establish a quantitative relationship between pollution emission and deposition in sensitive areas.

  3. Air Permit Compliance for Hanford Waste Retrieval Operations Involving Multi-Unit Emissions

    SciTech Connect

    Faulk, D.E.; Simmons, F.M.

    2008-07-01

    Since 1970, approximately 38,000 suspect-transuranic and transuranic waste containers have been placed in retrievable storage on the Hanford Site in the 200 Areas burial grounds. Hanford's Waste Retrieval Project is retrieving these buried containers and processing them for safe storage and disposition. Container retrieval activities require an air emissions permit to account for potential emissions of radionuclides. The air permit covers the excavation activities as well as activities associated with assaying containers and installing filters in the retrieved transuranic containers lacking proper venting devices. Fluor Hanford, Inc. is required to track radioactive emissions resulting from the retrieval activities. Air, soil, and debris media contribute to the emissions and enabling assumptions allow for calculation of emissions. Each of these activities is limited to an allowed annual emission (per calendar year) and contributes to the overall total emissions allowed for waste retrieval operations. Tracking these emissions is required to ensure a permit exceedance does not occur. A tracking tool was developed to calculate potential emissions in real time sense. Logic evaluations are established within the tracking system to compare real time data against license limits to ensure values are not exceeded for either an individual activity or the total limit. Data input are based on field survey and workplace air monitoring activities. This tracking tool is used monthly and quarterly to verify compliance to the license limits. Use of this tool has allowed Fluor Hanford, Inc. to successfully retrieve a significant number of containers in a safe manner without any exceedance of emission limits. (authors)

  4. On the Methodology of Nematode Extraction from Field Samples: Density Flotation Techniques

    PubMed Central

    Viglierchio, David R.; Yamashita, Tom T.

    1983-01-01

    Density flotation has been frequently used for the extraction of nematodes from field samples. Density flotation curves for four nematode species and five solutes have been prepared. The curves confirm that flotation was governed by several factors: solute density, solute osmotic activity, and physiological properties of the nematode species. Nematode viability and function can be adversely affected by improper selection of solute for density extraction of nematodes; nevertheless, some nematode species can be enriched from mixtures by density and solute selection. PMID:19295831

  5. Reporting air emissions from animal production activities in the United States.

    PubMed

    Centner, Terence J; Patel, Parag G

    2010-04-01

    Major releases of airborne ammonia and hydrogen sulfide from the decomposition of animal waste have the American public concerned about the health of persons near farms. Emissions of these hazardous substances are regulated by the US Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) and the Emergency Planning and Community Right-to-Know Act (EPCRA). Moreover, federal regulatory provisions delineate thresholds for reporting hazardous pollutants being released into the air. In 2008, the US Environmental Protection Agency (EPA) adopted a reporting exemption under which all farms were exempted from reporting air emissions under CERCLA and small farms were exempted under EPCRA. The US EPA's exemption poses questions about whether the rule is contrary to congressional mandates. Environmental and industry groups have challenged this exemption in federal circuit court, and the judiciary will need to decide whether the agency had authority to adopt the rule. To accord protection to humans from hazardous airborne emissions from farms producing livestock, state agencies may want to adopt scientifically-justified ambient air quality standards.

  6. Impacts of potential CO2-reduction policies on air quality in the United States.

    PubMed

    Trail, Marcus A; Tsimpidi, Alexandra P; Liu, Peng; Tsigaridis, Kostas; Hu, Yongtao; Rudokas, Jason R; Miller, Paul J; Nenes, Athanasios; Russell, Armistead G

    2015-04-21

    Impacts of emissions changes from four potential U.S. CO2 emission reduction policies on 2050 air quality are analyzed using the community multiscale air quality model (CMAQ). Future meteorology was downscaled from the Goddard Institute for Space Studies (GISS) ModelE General Circulation Model (GCM) to the regional scale using the Weather Research Forecasting (WRF) model. We use emissions growth factors from the EPAUS9r MARKAL model to project emissions inventories for two climate tax scenarios, a combined transportation and energy scenario, a biomass energy scenario and a reference case. Implementation of a relatively aggressive carbon tax leads to improved PM2.5 air quality compared to the reference case as incentives increase for facilities to install flue-gas desulfurization (FGD) and carbon capture and sequestration (CCS) technologies. However, less capital is available to install NOX reduction technologies, resulting in an O3 increase. A policy aimed at reducing CO2 from the transportation sector and electricity production sectors leads to reduced emissions of mobile source NOX, thus reducing O3. Over most of the U.S., this scenario leads to reduced PM2.5 concentrations. However, increased primary PM2.5 emissions associated with fuel switching in the residential and industrial sectors leads to increased organic matter (OM) and PM2.5 in some cities. PMID:25811418

  7. Reporting air emissions from animal production activities in the United States.

    PubMed

    Centner, Terence J; Patel, Parag G

    2010-04-01

    Major releases of airborne ammonia and hydrogen sulfide from the decomposition of animal waste have the American public concerned about the health of persons near farms. Emissions of these hazardous substances are regulated by the US Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) and the Emergency Planning and Community Right-to-Know Act (EPCRA). Moreover, federal regulatory provisions delineate thresholds for reporting hazardous pollutants being released into the air. In 2008, the US Environmental Protection Agency (EPA) adopted a reporting exemption under which all farms were exempted from reporting air emissions under CERCLA and small farms were exempted under EPCRA. The US EPA's exemption poses questions about whether the rule is contrary to congressional mandates. Environmental and industry groups have challenged this exemption in federal circuit court, and the judiciary will need to decide whether the agency had authority to adopt the rule. To accord protection to humans from hazardous airborne emissions from farms producing livestock, state agencies may want to adopt scientifically-justified ambient air quality standards. PMID:20056277

  8. Impacts of potential CO2-reduction policies on air quality in the United States.

    PubMed

    Trail, Marcus A; Tsimpidi, Alexandra P; Liu, Peng; Tsigaridis, Kostas; Hu, Yongtao; Rudokas, Jason R; Miller, Paul J; Nenes, Athanasios; Russell, Armistead G

    2015-04-21

    Impacts of emissions changes from four potential U.S. CO2 emission reduction policies on 2050 air quality are analyzed using the community multiscale air quality model (CMAQ). Future meteorology was downscaled from the Goddard Institute for Space Studies (GISS) ModelE General Circulation Model (GCM) to the regional scale using the Weather Research Forecasting (WRF) model. We use emissions growth factors from the EPAUS9r MARKAL model to project emissions inventories for two climate tax scenarios, a combined transportation and energy scenario, a biomass energy scenario and a reference case. Implementation of a relatively aggressive carbon tax leads to improved PM2.5 air quality compared to the reference case as incentives increase for facilities to install flue-gas desulfurization (FGD) and carbon capture and sequestration (CCS) technologies. However, less capital is available to install NOX reduction technologies, resulting in an O3 increase. A policy aimed at reducing CO2 from the transportation sector and electricity production sectors leads to reduced emissions of mobile source NOX, thus reducing O3. Over most of the U.S., this scenario leads to reduced PM2.5 concentrations. However, increased primary PM2.5 emissions associated with fuel switching in the residential and industrial sectors leads to increased organic matter (OM) and PM2.5 in some cities.

  9. Pellet coating by air suspension technique using a mini-model coating unit.

    PubMed

    Ganesan, M; Pal, T K; Jayakumar, M

    2003-09-01

    Air suspension coating is widely used in the pharmaceutical industry, as an attractive alternative to pan coating in that it can successfully coat small particles, pellets and tablets irrespective of size or shape with a wide variety of coating materials. The commercially available air suspension coating equipments require at least one kilogram of material for optimum efficiency of their working. Therefore, it is felt that there is a potential need for a small, compact air suspension coating instrument, which can work with gram quantities of material. The main objective of the present work is to design and evaluate a laboratory model top spray air suspension coating instrument. The performance of the instrument was evaluated for both, drug loading on to non-pareil pellets and coating of drug-loaded pellets. Terbutaline sulphate was selected as model drug, while Surelease (aqueous polymeric dispersion of ethyl cellulose) as representative coating material. The drug loading efficiency of the instrument was found to be around 82% with a pellet load of 10 g. The drug loading efficiency was found to be satisfactory and reproducible. Scanning electron micrographs of coated pellets indicated that coating was homogenous and uniform around the pellets. The maximum deviations observed in the in vitro drug release studies were +/- 2.7397% of the mean percent quantity of drug released, which is low enough for the coating to be considered uniform and reproducible. Reproducibility of the coating process was further confirmed by determining the 95% confidence interval for average difference in cumulative percentage drug release between two runs of each batch, which was found to be less than 5% set as the maximum allowable difference. The release data obtained were found to show best fit with first order kinetic model. A significant influence of coating thickness on the drug release rate was observed. From the results and observations of this work, it may be concluded that the

  10. Beneficiation of flotation tailing from Polish copper sulfide ores

    SciTech Connect

    Luszczkiewicz, A.; Sztaba, K.S.

    1995-12-31

    Flotation tailing of Polish copper sulfide ores represents more than 90% of the mass of run-of-mine ore. The tailing contains mainly quartz, dolomite, clay minerals, traces of sulfides, and some accessory minerals. Almost all minerals of the tailing are well liberated and, therefore, any further beneficiation process applied to the tailing is expected to be inexpensive. In this work, results of investigations on utilization of flotation tailing using classification and gravity concentration are presented. It is shown that due to classification of flotation tailing in hydrocyclones, the coarse fraction becomes suitable material for gravity separation providing backfill material for underground mines as well as heavy minerals, a source of valuable rare elements. It was also found that heavy minerals separated by gravity methods contain a significant amount of rare elements such as zirconium, titanium, silver, rare earth metals, and uranium. The light fraction of the gravity separation contains well deslimed quartz particles and meets strict requirements for hydraulic filling material used for structural support in underground mines. Evaluation of the cost of the proposed technology indicated that investment to implement the method would provide a return within 2--4 years.

  11. Flotation and flocculation chemistry of coal and oxidized coals

    SciTech Connect

    Somasundaran, P.

    1990-01-01

    The objective of this research project is to understand the fundamentals involved in the flotation and flocculation of coal and oxidized coals and elucidate mechanisms by which surface interactions between coal and various reagents enhance coal beneficiation. An understanding of the nature of the heterogeneity of coal surfaces arising from the intrinsic distribution of chemical moieties is fundamental to the elucidation of mechanism of coal surface modification and its role in interfacial processes such as flotation, flocculation and agglomeration. A new approach for determining the distribution in surface properties of coal particles was developed in this study and various techniques capable of providing such information were identified. Distributions in surface energy, contact angle and wettability were obtained using novel techniques such as centrifugal immersion and film flotation. Changes in these distributions upon oxidation and surface modifications were monitored and discussed. An approach to the modelling of coal surface site distributions based on thermodynamic information obtained from gas adsorption and immersion calorimetry is proposed. Polyacrylamide and dodecane was used to alter the coal surface. Methanol adsorption was also studied. 62 figs.

  12. Laboratory study of electro-coagulation-flotation for water treatment.

    PubMed

    Jiang, Jia-Qian; Graham, Nigel; André, Cecile; Kelsall, Geoff H; Brandon, Nigel

    2002-09-01

    An electro-coagulation-flotation process has been developed for water treatment. This involved an electrolytic reactor with aluminium electrodes and a separation/flotation tank. The water to be treated passed through the reactor and was subjected to coagulation/flotation, by Al(III) ions dissolved from the electrodes, the resulting flocs floating after being captured by hydrogen gas bubbles generated at cathode surfaces. Apparent current efficiencies for Al dissolution as aqueous Al(III) species at pH 6.5 and 7.8 were greater than unity. This was due to additional reactions occurring in parallel with Al dissolution: oxygen reduction at anodes and cathodes, and hydrogen evolution at cathodes, resulting in net (i.e. oxidation + reduction) currents at both anodes and cathodes. The specific electrical energy consumption of the reactor for drinking water treatment was as low as 20 kWh (kg Al)(-1) for current densities of 10-20A m(-2). The water treatment performance of the electrocoagulation process was found to be superior to that of conventional coagulation with aluminium sulphate for treating a model-coloured water, with 20% more dissolved organic carbon (DOC) being removed for the same Al(III) dose. However, for a lowland surface water sample, the two processes achieved a similar performance for DOC and UV-absorbance removal. In addition, an up-flow electrocoagulator configuration performed better than a horizontal flow configuration, with both bipolar and monopolar electrodes. PMID:12405415

  13. AN ADVANCED CONTROL SYSTEM FOR FINE COAL FLOTATION

    SciTech Connect

    G.H. Luttrell; G.T. Adel

    1999-01-11

    A model-based flotation control scheme is being implemented to achieve optimal performance in the handling and treatment of fine coal. The control scheme monitors flotation performance through on-line analysis of tailings ash content. Then, based on an on-line estimate of incremental ash, the pulp level is adjusted using a model-based control algorithm to compensate for feed variations and other process disturbances. Recent developments in sensor technology are being applied for on-line determination of slurry ash content. During the eleventh quarter of this project, Task 7 (Operation and Testing) was nearly completed through the efforts of J.A. Herbst and Associates, Virginia Tech, and Pittston Coal Company. As a result of this work, a model-based control system has now been installed which can predict incremental ash based on tailings ash content and general plant data, and adjust pulp level accordingly to maintain a target incremental ash. The system has gone through a shake-down period, training has been carried out for plant operators, and the bulk of the control logic testing has been completed with the results of these tests awaiting analysis under Task 8 (System Evaluation). The flotation model has been shown to predict incremental ash quite successfully, implying that this approach may provide the basis for a useful ''soft sensor'' for on-line incremental ash analysis.

  14. AN ADVANCED CONTROL SYSTEM FOR FINE COAL FLOTATION

    SciTech Connect

    1998-10-25

    A model-based flotation control scheme is being implemented to achieve optimal performance in the handling and treatment of fine coal. The control scheme monitors flotation performance through on-line analysis of tailings ash content. Then, based on an on-line estimate of incremental ash, the pulp level is adjusted using a model-based control algorithm to compensate for feed variations and other process disturbances. Recent developments in sensor technology are being applied for on-line determination of slurry ash content. During the tenth quarter of this project, Task 6 (Equipment Procurement and Installation) was completed through the efforts of J.A. Herbst and Associates, Virginia Tech, Pittston Coal Company, and FGR Automation. As a result of this work, a model-based control system is now in place which can predict incremental ash based on tailings ash content and general plant data, and adjust pulp level accordingly to maintain a target incremental ash. Testing of this control system is expected to be carried out during the next quarter, and the results of this testing will be reported in the Eleventh Quarterly report. In addition, calibration of the video-based ash analyzer was continued and an extensive set of calibration data were obtained showing that the plant is running remarkably well under manual control. This may be a result of increased attention being paid to froth flotation as a result of this project.

  15. Estimated water requirements for the conventional flotation of copper ores

    USGS Publications Warehouse

    Bleiwas, Donald I.

    2012-01-01

    This report provides a perspective on the amount of water used by a conventional copper flotation plant. Water is required for many activities at a mine-mill site, including ore production and beneficiation, dust and fire suppression, drinking and sanitation, and minesite reclamation. The water required to operate a flotation plant may outweigh all of the other uses of water at a mine site, [however,] and the need to maintain a water balance is critical for the plant to operate efficiently. Process water may be irretrievably lost or not immediately available for reuse in the beneficiation plant because it has been used in the production of backfill slurry from tailings to provide underground mine support; because it has been entrapped in the tailings stored in the TSF, evaporated from the TSF, or leaked from pipes and (or) the TSF; and because it has been retained as moisture in the concentrate. Water retained in the interstices of the tailings and the evaporation of water from the surface of the TSF are the two most significant contributors to water loss at a conventional flotation circuit facility.

  16. Laboratory study of electro-coagulation-flotation for water treatment.

    PubMed

    Jiang, Jia-Qian; Graham, Nigel; André, Cecile; Kelsall, Geoff H; Brandon, Nigel

    2002-09-01

    An electro-coagulation-flotation process has been developed for water treatment. This involved an electrolytic reactor with aluminium electrodes and a separation/flotation tank. The water to be treated passed through the reactor and was subjected to coagulation/flotation, by Al(III) ions dissolved from the electrodes, the resulting flocs floating after being captured by hydrogen gas bubbles generated at cathode surfaces. Apparent current efficiencies for Al dissolution as aqueous Al(III) species at pH 6.5 and 7.8 were greater than unity. This was due to additional reactions occurring in parallel with Al dissolution: oxygen reduction at anodes and cathodes, and hydrogen evolution at cathodes, resulting in net (i.e. oxidation + reduction) currents at both anodes and cathodes. The specific electrical energy consumption of the reactor for drinking water treatment was as low as 20 kWh (kg Al)(-1) for current densities of 10-20A m(-2). The water treatment performance of the electrocoagulation process was found to be superior to that of conventional coagulation with aluminium sulphate for treating a model-coloured water, with 20% more dissolved organic carbon (DOC) being removed for the same Al(III) dose. However, for a lowland surface water sample, the two processes achieved a similar performance for DOC and UV-absorbance removal. In addition, an up-flow electrocoagulator configuration performed better than a horizontal flow configuration, with both bipolar and monopolar electrodes.

  17. Symptoms of psychological distress and post-traumatic stress disorder in United States Air Force "drone" operators.

    PubMed

    Chappelle, Wayne L; McDonald, Kent D; Prince, Lillian; Goodman, Tanya; Ray-Sannerud, Bobbie N; Thompson, William

    2014-08-01

    The goal of this study is to repeat a survey administered in 2010 to assess for changes in mental health among United States Air Force aircrew operating Predator/Reaper remotely piloted aircraft, also commonly referred to as "drones." Participants were assessed for self-reported sources of occupational stress, levels of clinical distress using the Outcome Questionnaire-45.2, and symptoms of post-traumatic stress disorder (PTSD) using the PTSD Checklist-Military Version. A total of 1,094 aircrew responded to the web-based survey composed of the commercially available standardized instruments mentioned above. The survey also contained nonstandardized items asking participants to report the main sources of their occupational stress, as well as questions addressing demographics and work-related characteristics. The estimated response rate to the survey was 49%. Study results reveal the most problematic self-reported stressors are operational: low manning, extra duties/administrative tasks, rotating shift work, and long hours. The results also reveal 10.72% of operators self-reported experiencing high levels of distress and 1.57% reported high levels of PTSD symptomology. The results are lower than findings from the 2010 survey and from soldiers returning from Iraq and Afghanistan. Implications of the study and recommendations for United States Air Force line leadership and mental health providers are discussed.

  18. Corrective Action Decision Document for Corrective Action Unit 486: Double Tracks RADSAFE Area, Nellis Air Force Range, Nevada

    SciTech Connect

    ITLV

    1999-07-12

    This Corrective Action Decision Document (CADD) has been prepared for Corrective Action Unit (CAU) 486, Double Tracks Radiological Safety (RADSAFE) Area (DTRSA) in accordance with the Federal Facility Agreement and Consent Order (FFACO) of 1996 that was agreed to by the U.S. Department of Energy, Nevada Operations Office (DOE/NV); the Nevada Division of Environmental Protection (NDEP); and the U.S Department of Defense (FFACO, 1996). The CADD provides or references the specific information necessary to recommend a preferred corrective action for the single Corrective Action Site (CAS), 71-23-001-71DT, within CAU 486. Corrective Action Unit 486 is located on the Nellis Air Force Range 71 North, west of the Tonopah Test Range (TTR), Nevada. The TTR, located in the Nellis Air Force Range, is approximately 140 miles (mi) northwest of Las Vegas, Nevada (Figure 1-1). The DTRSA is located on the west side of the Cactus Range approximately 5 mi southwest of the Cactus Spring gate at the intersection of the Cactus Spring Road and the Double Tracks Control Point Road (Figure 1-2).

  19. The Air Quality and Economic Impact of Atmospheric Lead from General Aviation Aircraft in the United States

    NASA Astrophysics Data System (ADS)

    Wolfe, P. J.; Selin, N. E.; Barrett, S. R. H.

    2015-12-01

    While leaded fuels for automobiles were phased-out of use in the United States by 1996, lead (Pb) continues to be used as an anti-knock additive for piston-driven aircraft. We model the annual concentration of atmospheric lead attributable to piston driven aircraft emissions in the continental United States using the Community Multi-scale Air Quality (CMAQ) model. Using aircraft emissions inventories for 2008, we then calculate annual economic damages from lead as lifetime employment losses for a one-year cohort exposed to elevated atmospheric lead concentrations using a range of concentration response functions from literature. Mean and median estimates of annual damages attributable to lifetime lost earnings are 1.06 and 0.60 billion respectively. Economy-wide impacts of IQ-deficits on productivity and labor increase expected damages by 54%. Damages are sensitive to background lead concentrations; as emissions decrease from other sources, the damages attributable to aviation are expected to increase holding aviation emissions constant. The monetary impact of General Aviation lead emissions on the environment is the same order of magnitude as noise, climate change, and air quality degradation from all commercial operations.

  20. Symptoms of psychological distress and post-traumatic stress disorder in United States Air Force "drone" operators.

    PubMed

    Chappelle, Wayne L; McDonald, Kent D; Prince, Lillian; Goodman, Tanya; Ray-Sannerud, Bobbie N; Thompson, William

    2014-08-01

    The goal of this study is to repeat a survey administered in 2010 to assess for changes in mental health among United States Air Force aircrew operating Predator/Reaper remotely piloted aircraft, also commonly referred to as "drones." Participants were assessed for self-reported sources of occupational stress, levels of clinical distress using the Outcome Questionnaire-45.2, and symptoms of post-traumatic stress disorder (PTSD) using the PTSD Checklist-Military Version. A total of 1,094 aircrew responded to the web-based survey composed of the commercially available standardized instruments mentioned above. The survey also contained nonstandardized items asking participants to report the main sources of their occupational stress, as well as questions addressing demographics and work-related characteristics. The estimated response rate to the survey was 49%. Study results reveal the most problematic self-reported stressors are operational: low manning, extra duties/administrative tasks, rotating shift work, and long hours. The results also reveal 10.72% of operators self-reported experiencing high levels of distress and 1.57% reported high levels of PTSD symptomology. The results are lower than findings from the 2010 survey and from soldiers returning from Iraq and Afghanistan. Implications of the study and recommendations for United States Air Force line leadership and mental health providers are discussed. PMID:25102551

  1. A Longitudinal Investigation of Dropout from College in the United States. AIR 2002 Forum Paper.

    ERIC Educational Resources Information Center

    Ishitani, Terry T.; DesJardins, Stephen L.

    This study investigated the departure behavior of college students in the United States. Previous attrition studies have typically focused on dropout at specific points in time, such as the first year of enrollment. In this study, the timing of departure was examined over a 5-year period. It was found that factors affecting student attrition had…

  2. Developing and Implementing a Process for the Review of Nonacademic Units. AIR 1988 Annual Forum Paper.

    ERIC Educational Resources Information Center

    Brown, Marilyn K.

    The process of evaluating college academic-support units is described, and the experience of the University of Maryland (College Park) with such a program is discussed. A review of the literature discusses six models: the goal-attainment model, the systems model, the process model, the multiple-constituency approach, the Goodman and Pennings…

  3. 76 FR 72836 - Amendment and Establishment of Air Traffic Service Routes; Northeast United States

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-28

    ... United States (76 FR 57902). Subsequent to publication a more accurate alignment was calculated for the... coordinates for the CANDR waypoint as published in the Federal Register on September 19, 2011 (76 FR 57902) (FR Doc. 2011-23839) for RNAV route Q-480, is corrected under the description as follows:...

  4. 77 FR 35836 - Amendment of Air Traffic Service Routes; Southwestern United States

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-15

    ... routes in the southwestern United States (78 FR 24156). An NPRM correction published in the Federal Register of May 23, 2012 (77 FR 30437) corrected the description of VOR Federal airway V-16. Interested... and Procedures (44 FR 11034; February 26, 1979); and (3) does not warrant preparation of a...

  5. 77 FR 30437 - Proposed Amendment of Air Traffic Service Routes; Southwestern United States

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-23

    ... (77 FR 24156). The description of V-16 in the NPRM did not reflect a previous amendment of the route that was published on September 19, 2011 (76 FR 57902). The incorrect part of the V-16 description in...; Southwestern United States as published in the Federal Register of April 23, 2010 (77 FR 24156) FR Doc....

  6. Efficiency of Energy Use in the United States: Transportation, space heating, and air conditioning provide opportunities for large energy savings.

    PubMed

    Hirst, E; Moyers, J C

    1973-03-30

    We described three uses of energy for which greater efficiency is feasible: transportation, space heating, and air conditioning. Shifts to less energy-intensive transportation modes could substantially reduce energy consumption; the magnitude of such savings would, of course, depend on the extent of such shifts and possible load factor changes. The hypothetical transportation scenario described here results in a 22 percent savings in energy for transportation in 1970, a savings of 2800 trillion Btu. To the homeowner, increasing the amount of building insulation and, in some cases, adding storm windows would reduce energy consumption and provide monetary savings. If all homes in 1970 had the "economic optimum" amount of insulation, energy consumption for residential heating would have been 42 percent less than if the homes were insulated to meet the pre-1971 FHA standards, a savings of 3100 trillion Btu. Increased utilization of energy-efficient air conditioners and of building insulation would provide significant energy savings and help to reduce peak power demands during the summer. A 67 percent increase in energy efficiency for room air conditioners would have saved 15.8 billion kilowatt-hours in 1970. In conclusion, it is possible-from an engineering point of view-to effect considerable energy savings in the United States. Increases in the efficiency of energy use would provide desired end results with smaller energy inputs. Such measures will not reduce the level of energy consumption, but they could slow energy growth rates.

  7. Microbial communities related to volatile organic compound emission in automobile air conditioning units.

    PubMed

    Diekmann, Nina; Burghartz, Melanie; Remus, Lars; Kaufholz, Anna-Lena; Nawrath, Thorben; Rohde, Manfred; Schulz, Stefan; Roselius, Louisa; Schaper, Jörg; Mamber, Oliver; Jahn, Dieter; Jahn, Martina

    2013-10-01

    During operation of mobile air conditioning (MAC) systems in automobiles, malodours can occur. We studied the microbial communities found on contaminated heat exchanger fins of 45 evaporators from car MAC systems which were operated in seven different regions of the world and identified corresponding volatile organic compounds. Collected biofilms were examined by scanning electron microscopy and fluorescent in situ hybridization. The detected bacteria were loosely attached to the metal surface. Further analyses of the bacteria using PCR-based single-strand conformation polymorphism and sequencing of isolated 16S rRNA gene fragments identified highly divergent microbial communities with multiple members of the Alphaproteobacteriales, Methylobacteria were the prevalent bacteria. In addition, Sphingomonadales, Burkholderiales, Bacillales, Alcanivorax spp. and Stenotrophomonas spp. were found among many others depending on the location the evaporators were operated. Interestingly, typical pathogenic bacteria related to air conditioning systems including Legionella spp. were not found. In order to determine the nature of the chemical compounds produced by the bacteria, the volatile organic compounds were examined by closed loop stripping analysis and identified by combined gas chromatography/mass spectrometry. Sulphur compounds, i.e. di-, tri- and multiple sulphides, acetylthiazole, aromatic compounds and diverse substituted pyrazines were detected. Mathematical clustering of the determined microbial community structures against their origin identified a European/American/Arabic cluster versus two mainly tropical Asian clusters. Interestingly, clustering of the determined volatiles against the origin of the corresponding MAC revealed a highly similar pattern. A close relationship of microbial community structure and resulting malodours to the climate and air quality at the location of MAC operation was concluded.

  8. A review of lighter-than-air progress in the United States and its technological significance

    NASA Technical Reports Server (NTRS)

    Mayer, N. J.; Krida, R. H.

    1977-01-01

    Lighter-than-air craft for transportation and communications systems are discussed, with attention given to tethered balloons used to provide stable platforms for airborne surveillance equipment, freight-carrying balloons, manned scientific research balloons such as Atmosat, high-altitude superpressure aerostats employed in satellite communications systems, airport feeder airships, and naval surveillance airships. In addition, technical problems associated with the development of advanced aerostats, including the aerodynamics of hybrid combinations of large rotor systems and aerostat hulls, the application of composites to balloon shells, computer analyses of the complex geometrical structures of aerostats and propulsion systems for airships, are considered.

  9. A summary of lighter-than-air technology development and applications in the United States

    NASA Technical Reports Server (NTRS)

    Mayer, N. J.

    1979-01-01

    Recent studies indicate the promise of advanced LTA vehicles that can carry heavy loads and be capable of vertical takeoff and landing. Such airships may be combinations of aerostats and helicopters or modern versions of more conventional aircraft. These latter types would not be competitive with high speed modern jet air transports on established routes, but they would have a role in special situations and as long-endurance Naval and coastal surveillance aircraft. The most attractive and immediate market for modern airships in the field of short-range and heavy lift.

  10. Air quality extremes and trends over the United States: Effects of regional climate

    NASA Astrophysics Data System (ADS)

    Wang, Y.; Song, Y.; Loadholt, J.; Zhang, H.; Park, T.; Deng, Y.; Zhang, Y.

    2014-12-01

    We apply a suite of analysis methods, including statistical distribution and correlation, empirical orthogonal function (EOF), linear inverse modeling (LIM), and historical modeling using regional air quality and global chemistry-climate models, to analyze surface ozone (since 1980) and PM2.5 (since 2000) measurements from EPA observation networks. The overarching goal is to understand how regional climate and weather systems affect air quality trends and extreme events. Previous studies documented high or geographically specific ozone episodes and identified contributions from anticyclone, transport, or sub-decadal to decadal time scale patterns pertinent to the events. Here, an ensemble analysis of all events from single day to multi-day episodes in the past three decades places all episodes into a continuum of time and geospatial coordinates. Inter-annual patterns linked to source concentrations and seasonal transport are evident, but anomalies such as unseasonable and persistent anticyclones to winter events over snow cover can also be identified. Overlapping events between ozone and temperature extremes are identified. They tend to occur in eastern and western coast regions with significant local variability. The occurrence frequency of overlapping events decreased from 1980s to 2000s. PM2.5 extreme showed more sensitivity to extreme temperature than drought index. When being divided by two periods (2000-2004 and 2005-2009), the second period had more extreme PM events at lower temperature in winter time. An EOF analysis was conducted to examine how regional and hemispheric climate variability affects the ozone extreme events. A question explored here is how well EOF analysis that links ozone concentrations to climate variables explains the temporal and geospatial variability of extreme ozone events (days and episodes >= 75 ppbv). The seasonal change in controlling weather systems plays a key role in how regional climate affects air quality. We also show the

  11. Air pollution control systems in WtE units: An overview

    SciTech Connect

    Vehlow, J.

    2015-03-15

    Highlights: • The paper describes in brief terms the development of gas cleaning in waste incineration. • The main technologies for pollutant removal are described including their basic mechanisms. • Their respective efficiencies and their application are discussed. • A cautious outlook regarding future developments is made. - Abstract: All WtE (waste-to-energy) plants, based on combustion or other thermal processes, need an efficient gas cleaning for compliance with legislative air emission standards. The development of gas cleaning technologies started along with environment protection regulations in the late 1960s. Modern APC (air pollution control) systems comprise multiple stages for the removal of fly ashes, inorganic and organic gases, heavy metals, and dioxins from the flue gas. The main technologies and devices used for abatement of the various pollutants are described and their basic principles, their peculiarities, and their application are discussed. Few systems for cleaning of synthesis gas from waste gasification plants are included. Examples of APC designs in full scale plants are shown and cautious prospects for the future development of APC systems are made.

  12. United States-Canada air services: The role of alliances in a future bilateral agreement

    SciTech Connect

    Lewis, I.

    1995-12-01

    Transborder air services between the U.S. and Canada represent a mixing of two dynamic domestic markets whose relationships with each other is governed by a diplomatically negotiated agreement between governments. Trying to divide up the pie between the carriers of both nations while promoting economic growth is proving to be very difficult; four years of negotiations have yet to reach fruition. The Canadian government and carriers see the pie as fixed; there is only so much transborder traffic and Canadian airlines need their share. In contrast, U.S. carriers, airport operators, and government negotiators see the airline industry as a major instrument of economic growth. In this view, they are joined by many Canadian communities who believe that increased service can be of considerable benefit. More competition and better service can only lead to higher demand and passenger volume, from which Canadian airlines will benefit. Alliances between U.S. and Canadian carriers can help break the deadlock. The two governments need to recognize that their domestic airline industries are not distinct, and that they will share in any liberalization. Alliances need formal recognition, encouragement, and may be one of the few viable instruments available that will promote a greatly needed bilateral air services agreement between the U.S. and Canada.

  13. Air purging unit for an optical pyrometer of a gas turbine engine

    SciTech Connect

    Hurley, J.F.

    1981-12-22

    In order to measure the temperature of the mid-span first stage rotor blade of a gas turbine engine, an optical pyrometer is mounted in the inner casing of the gas turbine engine and includes an elongated sight tube extending from the optical lens of the pyrometer and through the wall of the engine separating the inner casing from the rotor. The sight tube includes an array of spaced apertures extending therethrough in the vicinity of the optical lens, with each aperture extending at an acute angle to the longitudinal axis of the sight tube away from the optical lens. Pressurized air within the inner casing passes through the array of apertures and effectively forms a conically-shaped fluid screen for preventing smoke, dust, fumes, or other contaminants from contaminating the optical lens. A second fluid screen may be provided by mounting the free end of the sight tube in an enlarged opening in the wall of the engine casing, whereby a secondary, generally cylindrical flow of air is developed for shielding the open end of the sight tube. The upstream edge of the sight tube may project into the flow path of the combustion gases flowing to the rotor stage whereby such combustion gases will be deflected and directed around the circumference of the sight tube to further inhibit contaminants from entering the sight tube and contaminating the optical lens.

  14. Sensitivity of air quality to potential future climate change and emissions in the United States and major cities

    NASA Astrophysics Data System (ADS)

    Trail, M.; Tsimpidi, A. P.; Liu, P.; Tsigaridis, K.; Rudokas, J.; Miller, P.; Nenes, A.; Hu, Y.; Russell, A. G.

    2014-09-01

    Simulated present and future air quality is compared for the years 2006-2010 and 2048-2052 over the contiguous United States (CONUS) using the Community Multi-scale Air Quality (CMAQ) model. Regionally downscaled present and future climate results are developed using GISS and the Weather Research Forecasting (WRF) model. Present and future emissions are estimated using MARKAL 9R model. O3 and PM2.5 sensitivities to precursor emissions for the years 2010 and 2050 are calculated using CMAQ-DDM (Direct Decoupled Method). We find major improvements in future U.S. air quality including generally decreased MDA8 (maximum daily 8-hr average O3) mixing ratios and PM2.5 concentrations and reduced frequency of NAAQS O3 standard exceedances in most major U.S. cities. The Eastern and Pacific U.S. experience the largest reductions in summertime seasonal average MDA8 (up to 12 ppb) with localized decreases in the 4th highest MDA8 of the year, decreasing by up to 25 ppb. Results from a Climate Penalty (CP) scenario isolate the impact of climate change on air quality and show that future climate change tends to increase O3 mixing ratios in some regions of the U.S., with climate change causing increases of over 10 ppb in the annual 4th highest MDA8 in Los Angeles. Seasonal average PM2.5 decreases (2-4 μg m-3) over the Eastern U.S. are accounted for by decreases in sulfate and nitrate concentrations resulting from reduced mobile and point source emissions of NOx and SOx.

  15. Impact of portable air filtration units on exposure of haematology-oncology patients to airborne Aspergillus fumigatus spores under field conditions.

    PubMed

    Engelhart, S; Hanfland, J; Glasmacher, A; Krizek, L; Schmidt-Wolf, I G H; Exner, M

    2003-08-01

    We undertook a one-year study to investigate the impact of the NSA model 7100A/B portable air filtration unit on exposure of haematology-oncology patients to airborne Aspergillus fumigatus spores under field conditions. Weekly measurements for airborne A. fumigatus were conducted in indoor and outdoor air, and surveillance for invasive aspergillosis was based on a combination of ward liaison, targeted chart review and consultation with the medical staff. The mean indoor A. fumigatus counts (8.1 cfu/m3; range, <0.8 to 42 cfu/m3) reflected the fungal load of outdoor air (9.4 cfu/m3; range, <0.8 to 50 cfu/m3), and were reduced by only about one third in rooms with portable air filtration units (5.3 cfu/m3; range, <0.8 to 41 cfu/m3). During the study period, a total of five cases (incidence density, 0.8 per 1000 patient-days) of invasive aspergillosis (one proven case, four suspected cases; case fatality rate 40%) were recorded. None of these five patients was allocated to a room with portable air filtration unit, however, the difference between incidence densities in rooms with and without portable air filtration units was non-significant (Fisher's exact test, P=0.33). Due to the noise level and thermal discomfort, patient compliance with the air filtration units was poor. We conclude that under field conditions this air filtration unit cannot be recommended for prevention of invasive aspergillosis in neutropenic haematology-oncology patients.

  16. AUTOMOTIVE DIESEL MAINTENANCE 1. UNIT XIV, I--MAINTAINING THE AIR SYSTEM, CUMMINS DIESEL ENGINE, II--UNIT REMOVAL--TRANSMISSION.

    ERIC Educational Resources Information Center

    Human Engineering Inst., Cleveland, OH.

    THIS MODULE OF A 30-MODULE COURSE IS DESIGNED TO DEVELOP AN UNDERSTANDING OF THE OPERATING PRINCIPLES AND MAINTENANCE OF THE DIESEL ENGINE AIR SYSTEM AND THE PROCEDURES FOR TRANSMISSION REMOVAL. TOPICS ARE (1) DEFINITION OF TERMS RELATED TO THE DIESEL AIR SYSTEM, (2) PRNCIPLES OF DIESEL AIR COMPRESSORS, (3) PRINCIPLES OF AIR STARTING MOTORS, (4)…

  17. Selective flotation of fossil resin from Western coal. Final report, July 1, 1990--May 25, 1992

    SciTech Connect

    Jensen, G.F.; Miller, J.D.

    1992-05-25

    The proof-of-concept test program was designed to clarify a number of concerns that have been raised by coal companies who own the valuable resin resource. First, from laboratory bench-scale flotation experiments, a froth product from cleaner flotation containing more than 80% hexane-extractable resin at higher than 80% recovery can be produced. Pilot-plant testing was initiated to demonstrate the selective flotation of fossil resin and to establish a better confidence level in the new technology. Second, pilot-plant testing was designed to evaluate the effect and impact of random variation in slurry solids concentration and feed grade on this new selective fossil resin flotation technology. The flotation performance obtained under these industrial conditions is more realistic for process evaluation. Third, more accurate operating cost data was to be obtained for economic analysis. Fourth, sufficient quantities of the fossil resin concentrate were to be produced from the test program for evaluation by potential industrial users. Fifth, and finally, optimum levels for the operating variables were to be established. Such information was required for eventual scale-up and design of a fossil resin flotation plant. The pilot-plant proof-of-concept testing of selective resinate flotation has demonstrated that: (1) technically, the new flotation technologies discovered at the University of Utah and then improved upon by Advanced Processing Technologies, Inc. provide a highly efficient means to selectively recover fossil resin from coal. The proof-of-concept continuous flotation circuit (about 0.1 tph) resulted in fossil resin recovery with the same separation efficiency as was obtained from laboratory bench-scale testing (more than 80% recovery at about 80% concentrate grade); and (2) economically, the selective flotation process has been shown to be sufficiently profitable to justify the development of a fossil resin industry based on this new flotation process.

  18. Design trends for Army/Air Force airplanes in the United States

    NASA Technical Reports Server (NTRS)

    Spearman, M. Leroy

    1990-01-01

    Some design trends in Army/Air Force airplane systems in the U.S. are traced from the pre-World War 2 era to the present time. Various types of aircraft systems are reviewed with a view toward noting design features that were used. Some observations concerning the design trends indicate that some may be driven by advanced technology and some by a need for new mission requirements. In addition, it is noted that some design trends are evolutionary and result in an extension of service life or utility of existing systems. In other cases the design trends may be more revolutionary with the intent of creating a system with a new capability. Some examples are included of designs that did not proceed to production for reasons that sometimes were technical and sometimes were not.

  19. Air liquide 1.8 K refrigeration units for CERN LHC project

    NASA Astrophysics Data System (ADS)

    Hilbert, Benoît; Gistau-Baguer, Guy M.; Caillaud, Aurélie

    2002-05-01

    The Large Hadron Collider (LHC) will be CERN's next research instrument for high energy physics. This 27 km long circular accelerator will make intensive use of superconducting magnets, operated below 2.0 K. It will thus require high capacity refrigeration below 2.0 K [1, 2]. Coupled to a refrigerator providing 18 kW equivalent at 4.5 K [3], these systems will be able to absorb a cryogenic power of 2.4 kW at 1.8 K in nominal conditions. Air Liquide has designed one Cold Compressor System (CCS) pre-series for CERN-preceding 3 more of them (among 8 in total located around the machine). These systems, making use of cryogenic centrifugal compressors in a series arrangement coupled to room temperature screw compressors, are presented. Key components characteristics will be given.

  20. National expenditures, jobs, and economic growth associated with indoor air quality in the United States.

    PubMed

    Mudarri, David H

    2014-05-01

    While a number of studies have addressed the economic cost associated with adverse health and productivity effects of poor indoor air quality (IAQ), few have addressed the value of economic expenditures and job creation associated with this industry. This article estimates that the annual sale of IAQ products and services is valued at $18-$30 billion and is associated with approximately 150,000-250,000 current jobs. Compared with other familiar industries, the IAQ market remains relatively small. Given the close association between good IAQ and both job performance of adults and learning performance of children, however, the expenditure to maintain good IAQ in commercial and educational facilities is a useful complement to programs designed to improve education and economic growth.

  1. Pesticides in Air and Rainwater in the Midcontinental United States, 1995 - Methods and Data

    USGS Publications Warehouse

    Majewski, Michael S.; Foreman, William T.; Coupe, Richard H.; Goolsby, Donald A.; Wiebe, Frank W.

    2008-01-01

    Weekly composite high-volume air and wet-only deposition samples were collected from April through September 1995 at paired urban and agricultural areas in Mississippi, Iowa, and Minnesota, and at a background site in Michigan?s Upper Peninsula. This report describes the methods used to collect, analyze, and quality assure the samples, and presents the results of all chemical analyses and quality control procedures. Each sample was analyzed for 49 compounds, including several pesticides not examined in previous atmospheric studies. Eighty-five percent of the herbicides, 70 percent of the insecticides, and 100 percent of the transformation products that were targeted for analysis were detected in one or more samples at each paired site.

  2. 1995 Area 1 bird survey/Zone 1, Operable Unit 2, Robins Air Force Base, Georgia

    SciTech Connect

    Wade, M.C.

    1995-08-01

    Robins Air Force Base is located in Warner Robins, Georgia, approximately 90 miles southeast of Atlanta, Georgia. As part of the Baseline Investigation (CDM Federal 1994) a two day bird survey was conducted by M. C. Wade (Oak Ridge National Laboratory) and B.A. Beatty (CDM Federal Programs) in May 1995. The subject area of investigation includes the sludge lagoon, Landfill No. 4, and the wetland area east of the landfill and west of Hannah Road (including two ponds). This is known as Area 1. The Area 1 wetlands include bottomland hardwood forest, stream, and pond habitats. The objectives of this survey were to document bird species using the Area I wetlands and to see if the change in hydrology (due to the installation of the Sewage Treatment Plant effluent diversion and stormwater runon control systems) has resulted in changes at Area 1 since the previous survey of May 1992 (CDM Federal 1994).

  3. Assessing air quality and climate impacts of future ground freight choice in United States

    NASA Astrophysics Data System (ADS)

    Liu, L.; Bond, T. C.; Smith, S.; Lee, B.; Ouyang, Y.; Hwang, T.; Barkan, C.; Lee, S.; Daenzer, K.

    2013-12-01

    The demand for freight transportation has continued to increase due to the growth of domestic and international trade. Emissions from ground freight (truck and railways) account for around 7% of the greenhouse gas emissions, 4% of the primary particulate matter emission and 25% of the NOx emissions in the U.S. Freight railways are generally more fuel efficient than trucks and cause less congestion. Freight demand and emissions are affected by many factors, including economic activity, the spatial distribution of demand, freight modal choice and routing decision, and the technology used in each modal type. This work links these four critical aspects of freight emission system to project the spatial distribution of emissions and pollutant concentration from ground freight transport in the U.S. between 2010 and 2050. Macroeconomic scenarios are used to forecast economic activities. Future spatial structure of employment and commodity demand in major metropolitan areas are estimated using spatial models and a shift-share model, respectively. Freight flow concentration and congestion patterns in inter-regional transportation networks are predicted from a four-step freight demand forecasting model. An asymptotic vehicle routing model is also developed to estimate delivery ton-miles for intra-regional freight shipment in metropolitan areas. Projected freight activities are then converted into impacts on air quality and climate. CO2 emissions are determined using a simple model of freight activity and fuel efficiency, and compared with the projected CO2 emissions from the Second Generation Model. Emissions of air pollutants including PM, NOx and CO are calculated with a vehicle fleet model SPEW-Trend, which incorporates the dynamic change of technologies. Emissions are projected under three economic scenarios to represent different plausible futures. Pollutant concentrations are then estimated using tagged chemical tracers in an atmospheric model with the emissions serving

  4. Model analyses of atmospheric mercury: present air quality and effects of transpacific transport on the United States

    NASA Astrophysics Data System (ADS)

    Lei, H.; Liang, X.-Z.; Wuebbles, D. J.; Tao, Z.

    2013-11-01

    Atmospheric mercury is a toxic air and water pollutant that is of significant concern because of its effects on human health and ecosystems. A mechanistic representation of the atmospheric mercury cycle is developed for the state-of-the-art global climate-chemistry model, CAM-Chem (Community Atmospheric Model with Chemistry). The model simulates the emission, transport, transformation and deposition of atmospheric mercury (Hg) in three forms: elemental mercury (Hg(0)), reactive mercury (Hg(II)), and particulate mercury (PHg). Emissions of mercury include those from human, land, ocean, biomass burning and volcano related sources. Land emissions are calculated based on surface solar radiation flux and skin temperature. A simplified air-sea mercury exchange scheme is used to calculate emissions from the oceans. The chemistry mechanism includes the oxidation of Hg(0) in gaseous phase by ozone with temperature dependence, OH, H2O2 and chlorine. Aqueous chemistry includes both oxidation and reduction of Hg(0). Transport and deposition of mercury species are calculated through adapting the original formulations in CAM-Chem. The CAM-Chem model with mercury is driven by present meteorology to simulate the present mercury air quality during the 1999-2001 period. The resulting surface concentrations of total gaseous mercury (TGM) are then compared with the observations from worldwide sites. Simulated wet depositions of mercury over the continental United States are compared to the observations from 26 Mercury Deposition Network stations to test the wet deposition simulations. The evaluations of gaseous concentrations and wet deposition confirm a strong capability for the CAM-Chem mercury mechanism to simulate the atmospheric mercury cycle. The general reproduction of global TGM concentrations and the overestimation on South Africa indicate that model simulations of TGM are seriously affected by emissions. The comparison to wet deposition indicates that wet deposition patterns

  5. Model analyses of atmospheric mercury: present air quality and effects of transpacific transport on the United States

    NASA Astrophysics Data System (ADS)

    Lei, H.; Liang, X.-Z.; Wuebbles, D. J.; Tao, Z.

    2013-04-01

    Atmospheric mercury is a toxic air and water pollutant that is of significant concern because of its effects on human health and ecosystems. A mechanistic representation of the atmospheric mercury cycle is developed for the state-of-the-art global climate-chemistry model, CAM-Chem (Community Atmospheric Model with Chemistry). The model simulates the emission, transport, transformation and deposition of atmospheric mercury (Hg) in three forms: elemental mercury (Hg(0)), reactive mercury (Hg(II)), and particulate mercury (PHg). Emissions of mercury include those from human, land, ocean, biomass burning and volcano related sources. Land emissions are calculated based on surface solar radiation flux and skin temperature. A simplified air-sea mercury exchange scheme is used to calculate emissions from the oceans. The chemistry mechanism includes the oxidation of Hg(0) in gaseous phase by ozone with temperature dependence, OH, H2O2 and chlorine. Aqueous chemistry includes both oxidation and reduction of Hg(0). Transport and deposition of mercury species are calculated through adapting the original formulations in CAM-Chem. The CAM-Chem model with mercury is driven by present meteorology to simulate the present mercury air quality during the 1999-2001 periods. The resulting surface concentrations of total gaseous mercury (TGM) are then compared with the observations from worldwide sites. Simulated wet depositions of mercury over the continental United States are compared to the observations from 26 Mercury Deposition Network stations to test the wet deposition simulations. The evaluations of gaseous concentrations and wet deposition confirm a strong capability for the CAM-Chem mercury mechanism to simulate the atmospheric mercury cycle. The results also indicate that mercury pollution in East Asia and Southern Africa is very significant with TGM concentrations above 3.0 ng m-3. The comparison to wet deposition indicates that wet deposition patterns of mercury are more

  6. Federal air travel restrictions for public health purposes--United States, June 2007-May 2008.

    PubMed

    2008-09-19

    Persons with communicable diseases who travel on commercial aircraft can pose a risk for infection to the traveling public. In June 2007, federal agencies developed a public health Do Not Board (DNB) list, enabling domestic and international public health officials to request that persons with communicable diseases who meet specific criteria and pose a serious threat to the public be restricted from boarding commercial aircraft departing from or arriving in the United States. The public health DNB list is managed by CDC and the U.S. Department of Homeland Security (DHS). To describe the experience with the public health DNB list since its inception, CDC analyzed data from June 2007 to May 2008. This report summarizes the results of that analysis, which indicated that CDC received requests for inclusion of 42 persons on the public health DNB list, all with suspected or confirmed pulmonary tuberculosis (TB). From the requests, 33 (79%) persons were included on the list. The public health DNB list enables public health officials to prevent travel on commercial aircraft by persons who pose a risk for infection to other travelers. State and local health departments in the United States and other countries should be aware of this new public health tool.

  7. Corrective Action Investigation Plan for Corrective Action Unit 486: Double Tracks RADSAFE Area Nellis Air Force Range, Nevada

    SciTech Connect

    IT Las Vegas

    1998-10-15

    This Corrective Action Investigation Plan (CAIP) has been developed in accordance with the Federal Facility Agreement and Consent Order (FFACO) that was agreed to by the US Department of Energy, Nevada Operations Office (DOE/NV); the State of Nevada Division of Environmental Protection (NDEP); and the US Department of Defense (FFACO, 1996). The CAIP is a document that provides or references all of the specific information for investigation activities associated with Corrective Action Units (CAUs) or Corrective Action Sites (CASs). According to the FFACO, CASs are sites potentially requiring corrective action(s) and may include solid waste management units or individual disposal or release sites (FFACO, 1996). Corrective Action Units consist of one or more CASs grouped together based on geography, technical similarity, or agency responsibility for the purpose of determining corrective actions. This CAIP contains the environmental sample collection objectives and the criteria for conducting site investigation activities at CAU 486, the Double Tracks Radiological Safety (RADSAFE) Area (DTRSA) which is located on the Nellis Air Force Range 71North (N), west of the Tonopah Test Range (TTR). The TTR, included in the Nellis Air Force Range Complex, is approximately 255 kilometers (km) (140 miles [mi]) northwest of Las Vegas, Nevada (Figure 1-1). Corrective Action Unit 486 is comprised of CAS 71-23-001-71DT consisting of two areas of concern referred to as the vehicle decontamination area and the animal burial pit. The DTRSA is located on the west side of the Cactus Range approximately 8 km (5 mi) southwest of the Cactus Spring gate at the intersection of the Cactus Spring Road and the Double Tracks Control Point Road (Figure 1-2). The DTRSA was used during May 1963 to decontaminate vehicles, equipment, personnel, and animals from the Double Tracks test. The DTRSA is one of three areas identified as a potential location for the disposal of radioactively contaminated

  8. Superfund record of decision (EPA Region 9): Williams Air Force Base, Operable Unit 2, Phoenix, AZ, December 1992

    SciTech Connect

    Not Available

    1992-12-01

    Williams Air Force Base (AFB) is located in Maricopa County, east of the City of Chandler, Arizona. Opreable Unit 2 (OU-2) of the Williams AFB National Priority List (NPL) site is located at the Base's Liquid Fuels Storage Area (LFSA), which is also referred to by its site designation 'ST-12'. Releases of Jet Propulsion Fuel Grade 4 (JP-4) and aviation gasoline (AVGAS) have contaminated soils and groundwater at OU-2. A variety of non-petroleum related CERCLA hazardous substances were also detected in OU-2 soils and groundwater. Actual or threatened releases of hazardous substances from this site, if not addressed by implementing the response actions selected in this ROD, may present an imminent and substantial endangerment to public health and the environment. Benzene, which is present in JP-4, is the most prevalent and mobile of the contaminants at OU-2.

  9. Superfund record of decision (EPA Region 9): Yuma Marine Corps Air Station, Operable Unit 2, Yuma, AZ, December 2, 1997

    SciTech Connect

    1998-10-01

    This Record of Decision (ROD) for Operable Unit (OU2) documents the remedial action plan for OU2 at Marine Corps Air Station (MCAS), Yuma, Arizona. On the basis of the data collected at the OU2 sites, no further action is necessary for 12 of the 18 CAOCs included in OU2, because these sites do not pose a threat to human health or the environment. However, remedial action is required to protect human health and comply with regulatory requirements at three of the CAOCs in OU2 because of the presence of ACM. Under this alternative, ACM fragment visible on soil surfaces would be collected manually. Collection would include removing approximately the upper inch of soil beneath the ACM to reduce the potential for asbestos fibers remaining behind in the soil. The ACM and soils would be stockpiled, manifested, loaded, transported, and disposed of at a permitted facility.

  10. Investigation of crossover processes in a unitized bidirectional vanadium/air redox flow battery

    NASA Astrophysics Data System (ADS)

    grosse Austing, Jan; Nunes Kirchner, Carolina; Komsiyska, Lidiya; Wittstock, Gunther

    2016-02-01

    In this paper the losses in coulombic efficiency are investigated for a vanadium/air redox flow battery (VARFB) comprising a two-layered positive electrode. Ultraviolet/visible (UV/Vis) spectroscopy is used to monitor the concentrations cV2+ and cV3+ during operation. The most likely cause for the largest part of the coulombic losses is the permeation of oxygen from the positive to the negative electrode followed by an oxidation of V2+ to V3+. The total vanadium crossover is followed by inductively coupled plasma mass spectroscopy (ICP-MS) analysis of the positive electrolyte after one VARFB cycle. During one cycle 6% of the vanadium species initially present in the negative electrolyte are transferred to the positive electrolyte, which can account at most for 20% of the coulombic losses. The diffusion coefficients of V2+ and V3+ through Nafion® 117 are determined as DV2+ ,N 117 = 9.05 ·10-6 cm2 min-1 and DV3+ ,N 117 = 4.35 ·10-6 cm2 min-1 and are used to calculate vanadium crossover due to diffusion which allows differentiation between vanadium crossover due to diffusion and migration/electroosmotic convection. In order to optimize coulombic efficiency of VARFB, membranes need to be designed with reduced oxygen permeation and vanadium crossover.

  11. 46 CFR 169.741 - Personal flotation devices and ring life buoys.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 7 2014-10-01 2014-10-01 false Personal flotation devices and ring life buoys. 169.741 Section 169.741 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL SCHOOLS SAILING... devices and ring life buoys. Each personal flotation device and ring life buoy must be marked with...

  12. 46 CFR 169.741 - Personal flotation devices and ring life buoys.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Personal flotation devices and ring life buoys. 169.741 Section 169.741 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL SCHOOLS SAILING... devices and ring life buoys. Each personal flotation device and ring life buoy must be marked with...

  13. 46 CFR 169.741 - Personal flotation devices and ring life buoys.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 7 2012-10-01 2012-10-01 false Personal flotation devices and ring life buoys. 169.741 Section 169.741 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL SCHOOLS SAILING... devices and ring life buoys. Each personal flotation device and ring life buoy must be marked with...

  14. 46 CFR 169.741 - Personal flotation devices and ring life buoys.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 7 2013-10-01 2013-10-01 false Personal flotation devices and ring life buoys. 169.741 Section 169.741 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL SCHOOLS SAILING... devices and ring life buoys. Each personal flotation device and ring life buoy must be marked with...

  15. 46 CFR 169.741 - Personal flotation devices and ring life buoys.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 7 2011-10-01 2011-10-01 false Personal flotation devices and ring life buoys. 169.741 Section 169.741 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL SCHOOLS SAILING... devices and ring life buoys. Each personal flotation device and ring life buoy must be marked with...

  16. 46 CFR 28.110 - Life preservers or other personal flotation devices.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 1 2014-10-01 2014-10-01 false Life preservers or other personal flotation devices. 28.110 Section 28.110 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY UNINSPECTED VESSELS REQUIREMENTS FOR COMMERCIAL FISHING INDUSTRY VESSELS Requirements for All Vessels § 28.110 Life preservers or other personal flotation devices. (a) Except...

  17. 46 CFR 28.110 - Life preservers or other personal flotation devices.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 1 2013-10-01 2013-10-01 false Life preservers or other personal flotation devices. 28.110 Section 28.110 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY UNINSPECTED VESSELS REQUIREMENTS FOR COMMERCIAL FISHING INDUSTRY VESSELS Requirements for All Vessels § 28.110 Life preservers or other personal flotation devices. (a) Except...

  18. 33 CFR 183.235 - Level flotation test without weights for persons capacity.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Level flotation test without weights for persons capacity. 183.235 Section 183.235 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Flotation Requirements for Outboard Boats Rated for Engines...

  19. 33 CFR 183.235 - Level flotation test without weights for persons capacity.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Level flotation test without weights for persons capacity. 183.235 Section 183.235 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Flotation Requirements for Outboard Boats Rated for Engines...

  20. 33 CFR 149.331 - What are the requirements for hybrid personal flotation devices?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... for them in 46 CFR 160.077-29, and all limitations, if any, marked on them. (b) All commercial hybrid... hybrid personal flotation devices? 149.331 Section 149.331 Navigation and Navigable Waters COAST GUARD... hybrid personal flotation devices? (a) The operator must ensure that the use and stowage of...

  1. 33 CFR 149.331 - What are the requirements for hybrid personal flotation devices?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... for them in 46 CFR 160.077-29, and all limitations, if any, marked on them. (b) All commercial hybrid... hybrid personal flotation devices? 149.331 Section 149.331 Navigation and Navigable Waters COAST GUARD... hybrid personal flotation devices? (a) The operator must ensure that the use and stowage of...

  2. 33 CFR 149.331 - What are the requirements for hybrid personal flotation devices?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... for them in 46 CFR 160.077-29, and all limitations, if any, marked on them. (b) All commercial hybrid... hybrid personal flotation devices? 149.331 Section 149.331 Navigation and Navigable Waters COAST GUARD... hybrid personal flotation devices? (a) The operator must ensure that the use and stowage of...

  3. 33 CFR 149.331 - What are the requirements for hybrid personal flotation devices?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... for them in 46 CFR 160.077-29, and all limitations, if any, marked on them. (b) All commercial hybrid... hybrid personal flotation devices? 149.331 Section 149.331 Navigation and Navigable Waters COAST GUARD... hybrid personal flotation devices? (a) The operator must ensure that the use and stowage of...

  4. 33 CFR 149.331 - What are the requirements for hybrid personal flotation devices?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... for them in 46 CFR 160.077-29, and all limitations, if any, marked on them. (b) All commercial hybrid... hybrid personal flotation devices? 149.331 Section 149.331 Navigation and Navigable Waters COAST GUARD... hybrid personal flotation devices? (a) The operator must ensure that the use and stowage of...

  5. Emissions and air quality impacts of truck-to-rail freight modal shifts in the Midwestern United States.

    PubMed

    Bickford, Erica; Holloway, Tracey; Karambelas, Alexandra; Johnston, Matt; Adams, Teresa; Janssen, Mark; Moberg, Claus

    2014-01-01

    We present an examination of the potential emissions and air quality benefits of shifting freight from truck to rail in the upper Midwestern United States. Using a novel, freight-specific emissions inventory (the Wisconsin Inventory of Freight Emissions, WIFE) and a three-dimensional Eulerian photochemical transport model (the Community Multiscale Air Quality Model, CMAQ), we quantify how specific freight mode choices impact ambient air pollution concentrations. Using WIFE, we developed two modal shift scenarios: one focusing on intraregional freight movements within the Midwest and a second on through-freight movements through the region. Freight truck and rail emissions inventories for each scenario were gridded to a 12 km × 12 km horizontal resolution as input to CMAQ, along with emissions from all other major sectors, and three-dimensional time-varying meteorology from the Weather Research and Forecasting model (WRF). The through-freight scenario reduced monthly mean (January and July) localized concentrations of nitrogen dioxide (NO2) by 28% (-2.33 ppbV) in highway grid cells, and reduced elemental carbon (EC) by 16% (-0.05 μg/m(3)) in highway grid cells. There were corresponding localized increases in railway grid cells of 25% (+0.83 ppbV) for NO2, and 22% (+0.05 μg/m(3)) for EC. The through-freight scenario reduced CO2 emissions 31% compared to baseline trucking. The through-freight scenario yields a July mean change in ground-level ambient PM2.5 and O3 over the central and eastern part of the domain (up to -3%).

  6. Evidence for an increase in the ozone photochemical lifetime in the eastern United States using a regional air quality model

    NASA Astrophysics Data System (ADS)

    Goldberg, Daniel L.; Vinciguerra, Timothy P.; Hosley, Kyle M.; Loughner, Christopher P.; Canty, Timothy P.; Salawitch, Ross J.; Dickerson, Russell R.

    2015-12-01

    Measures to control surface ozone rely on quantifying production attributable to local versus regional (upwind) emissions. Here we simulate the relative contribution of local (i.e., within a particular state) and regional sources of surface ozone in the eastern United States (66-94°W longitude) for July 2002, 2011, and 2018 using the Comprehensive Air-quality Model with Extensions (CAMx). To determine how emissions and chemistry within the domain affect the production, loss, lifetime, and transport of trace gases, we initialize our model with identical boundary conditions in each simulation. We find that the photochemical lifetime of ozone has increased as emissions have decreased. The contribution of ozone from outside the domain (boundary condition ozone, BCO3) to local surface mixing ratios increases in an absolute sense by 1-2 ppbv between 2002 and 2018 due to the longer lifetime of ozone. The photochemical lifetime of ozone lengthens because the two primary gas phase sinks for odd oxygen (Ox ≈ NO2 + O3)—attack by hydroperoxyl radicals (HO2) on ozone and formation of nitrate—weaken with decreasing pollutant emissions. The relative role of BCO3 will also increase. For example, BCO3 represents 34.5%, 38.8%, and 43.6% of surface ozone in the Baltimore, MD, region during July 2002, 2011, and 2018 means, respectively. This unintended consequence of air quality regulation impacts attainment of the National Ambient Air Quality Standard for surface ozone because the spatial and temporal scales of photochemical smog increase; the influence of pollutants transported between states and into the eastern U.S. will likely play a greater role in the future.

  7. Engineering development of advanced physical fine coal cleaning technologies: Froth flotation. Quarterly technical progress report No. 14, January 1, 1992--March 31, 1992

    SciTech Connect

    Not Available

    1992-12-31

    In order to develop additional confidence in the conceptual design of the advanced froth flotation circuit, a 2-3 TPH Proof-of-Concept (POC) facility was necessary. During operation of this facility, the ICF KE team will demonstrate the ability of the conceptual flowsheets to meet the program goals of maximum pyritic sulfur reduction coupled with maximum energy recovery on three DOE specified coals. The POC circuit was designed to be integrated into the Ohio Coal Development`s facility near Beverly, Ohio. OCDO`s facility will provide the precleaning unit operations and ICF KE will add the advanced froth flotation circuitry. The work in this task will include the POC conceptual design, flowsheet development, equipment list, fabrication and construction drawings, procurement specifications and bid packages and a facilities.

  8. Transmission of Mycobacterium chimaera from Heater-Cooler Units during Cardiac Surgery despite an Ultraclean Air Ventilation System.

    PubMed

    Sommerstein, Rami; Rüegg, Christian; Kohler, Philipp; Bloemberg, Guido; Kuster, Stefan P; Sax, Hugo

    2016-06-01

    Heater-cooler units (HCUs) were recently identified as a source of Mycobacterium chimaera causing surgical site infections. We investigated transmission of this bacterium from HCUs to the surgical field by using a thermic anemometer and particle counter, videotape of an operating room equipped with an ultraclean laminar airflow ventilation system, and bacterial culture sedimentation plates in a nonventilated room. Smoke from the HCU reached the surgical field in 23 s by merging with ultraclean air. The HCU produced on average 5.2, 139, and 14.8 particles/min in the surgical field at positions Off, On/oriented toward, and On/oriented away, respectively. Culture plates were positive for M. chimaera <5 m from the HCU in the test room. These experiments confirm airborne transmission of M. chimaera aerosols from a contaminated HCU to an open surgical field despite ultraclean air ventilation. Efforts to mitigate infectious risks during surgery should consider contamination from water sources and airflow-generating devices.

  9. Transmission of Mycobacterium chimaera from Heater–Cooler Units during Cardiac Surgery despite an Ultraclean Air Ventilation System

    PubMed Central

    Sommerstein, Rami; Rüegg, Christian; Kohler, Philipp; Bloemberg, Guido; Kuster, Stefan P.

    2016-01-01

    Heater–cooler units (HCUs) were recently identified as a source of Mycobacterium chimaera causing surgical site infections. We investigated transmission of this bacterium from HCUs to the surgical field by using a thermic anemometer and particle counter, videotape of an operating room equipped with an ultraclean laminar airflow ventilation system, and bacterial culture sedimentation plates in a nonventilated room. Smoke from the HCU reached the surgical field in 23 s by merging with ultraclean air. The HCU produced on average 5.2, 139, and 14.8 particles/min in the surgical field at positions Off, On/oriented toward, and On/oriented away, respectively. Culture plates were positive for M. chimaera <5 m from the HCU in the test room. These experiments confirm airborne transmission of M. chimaera aerosols from a contaminated HCU to an open surgical field despite ultraclean air ventilation. Efforts to mitigate infectious risks during surgery should consider contamination from water sources and airflow-generating devices. PMID:27070958

  10. Estimating daily air temperature across the Southeastern United States using high-resolution satellite data: A statistical modeling study.

    PubMed

    Shi, Liuhua; Liu, Pengfei; Kloog, Itai; Lee, Mihye; Kosheleva, Anna; Schwartz, Joel

    2016-04-01

    Accurate estimates of spatio-temporal resolved near-surface air temperature (Ta) are crucial for environmental epidemiological studies. However, values of Ta are conventionally obtained from weather stations, which have limited spatial coverage. Satellite surface temperature (Ts) measurements offer the possibility of local exposure estimates across large domains. The Southeastern United States has different climatic conditions, more small water bodies and wetlands, and greater humidity in contrast to other regions, which add to the challenge of modeling air temperature. In this study, we incorporated satellite Ts to estimate high resolution (1km×1km) daily Ta across the southeastern USA for 2000-2014. We calibrated Ts-Ta measurements using mixed linear models, land use, and separate slopes for each day. A high out-of-sample cross-validated R(2) of 0.952 indicated excellent model performance. When satellite Ts were unavailable, linear regression on nearby monitors and spatio-temporal smoothing was used to estimate Ta. The daily Ta estimations were compared to the NASA's Modern-Era Retrospective Analysis for Research and Applications (MERRA) model. A good agreement with an R(2) of 0.969 and a mean squared prediction error (RMSPE) of 1.376°C was achieved. Our results demonstrate that Ta can be reliably predicted using this Ts-based prediction model, even in a large geographical area with topography and weather patterns varying considerably.

  11. Transmission of Mycobacterium chimaera from Heater-Cooler Units during Cardiac Surgery despite an Ultraclean Air Ventilation System.

    PubMed

    Sommerstein, Rami; Rüegg, Christian; Kohler, Philipp; Bloemberg, Guido; Kuster, Stefan P; Sax, Hugo

    2016-06-01

    Heater-cooler units (HCUs) were recently identified as a source of Mycobacterium chimaera causing surgical site infections. We investigated transmission of this bacterium from HCUs to the surgical field by using a thermic anemometer and particle counter, videotape of an operating room equipped with an ultraclean laminar airflow ventilation system, and bacterial culture sedimentation plates in a nonventilated room. Smoke from the HCU reached the surgical field in 23 s by merging with ultraclean air. The HCU produced on average 5.2, 139, and 14.8 particles/min in the surgical field at positions Off, On/oriented toward, and On/oriented away, respectively. Culture plates were positive for M. chimaera <5 m from the HCU in the test room. These experiments confirm airborne transmission of M. chimaera aerosols from a contaminated HCU to an open surgical field despite ultraclean air ventilation. Efforts to mitigate infectious risks during surgery should consider contamination from water sources and airflow-generating devices. PMID:27070958

  12. Estimating daily air temperature across the Southeastern United States using high-resolution satellite data: A statistical modeling study.

    PubMed

    Shi, Liuhua; Liu, Pengfei; Kloog, Itai; Lee, Mihye; Kosheleva, Anna; Schwartz, Joel

    2016-04-01

    Accurate estimates of spatio-temporal resolved near-surface air temperature (Ta) are crucial for environmental epidemiological studies. However, values of Ta are conventionally obtained from weather stations, which have limited spatial coverage. Satellite surface temperature (Ts) measurements offer the possibility of local exposure estimates across large domains. The Southeastern United States has different climatic conditions, more small water bodies and wetlands, and greater humidity in contrast to other regions, which add to the challenge of modeling air temperature. In this study, we incorporated satellite Ts to estimate high resolution (1km×1km) daily Ta across the southeastern USA for 2000-2014. We calibrated Ts-Ta measurements using mixed linear models, land use, and separate slopes for each day. A high out-of-sample cross-validated R(2) of 0.952 indicated excellent model performance. When satellite Ts were unavailable, linear regression on nearby monitors and spatio-temporal smoothing was used to estimate Ta. The daily Ta estimations were compared to the NASA's Modern-Era Retrospective Analysis for Research and Applications (MERRA) model. A good agreement with an R(2) of 0.969 and a mean squared prediction error (RMSPE) of 1.376°C was achieved. Our results demonstrate that Ta can be reliably predicted using this Ts-based prediction model, even in a large geographical area with topography and weather patterns varying considerably. PMID:26717080

  13. United States Air Force 611th Air Support Group/Civil Engineering Squadron Elmendorf AFB, Alaska. Decision document for no further response action planned: Bullen Point Radar Installation, Alaska. Final report

    SciTech Connect

    Karmi, S.

    1996-05-24

    This Decision Document discusses the selection of no further action as the recommended action for two sites located at the Bullen Point radar installation. The United States Air Force (Air Force) completed a Remedial Investigation/Feasibility Study and a Risk Assessment for the five sites located at the Bullen Point installation (U.S. Air Force 1996a,b). Based on the findings of these activities, two sites are recommended for no further action. Sites at the Bullen Point radar installation recommended for no further action are: Old Landfill/Dump Site East (LF06) and Drum Storage Area (SS10).

  14. Fuel Efficient Strategies for Reducing Contrail Formations in United States Air Space

    NASA Technical Reports Server (NTRS)

    Sridhar, Banavar; Chen, Neil Y.; Ng, Hok K.

    2010-01-01

    This paper describes a class of strategies for reducing persistent contrail formation in the United States airspace. The primary objective is to minimize potential contrail formation regions by altering the aircraft's cruising altitude in a fuel-efficient way. The results show that the contrail formations can be reduced significantly without extra fuel consumption and without adversely affecting congestion in the airspace. The contrail formations can be further reduced by using extra fuel. For the day tested, the maximal reduction strategy has a 53% contrail reduction rate. The most fuel-efficient strategy has an 8% reduction rate with 2.86% less fuel-burnt compared to the maximal reduction strategy. Using a cost function which penalizes extra fuel consumed while maximizing the amount of contrail reduction provides a flexible way to trade off between contrail reduction and fuel consumption. It can achieve a 35% contrail reduction rate with only 0.23% extra fuel consumption. The proposed fuel-efficient contrail reduction strategy provides a solution to reduce aviation-induced environmental impact on a daily basis.

  15. Factors Regulating the Seasonal Cycle of Inter-continental Air Pollution Transport between Asia, the United States and Europe

    NASA Astrophysics Data System (ADS)

    Mauzerall, D. L.; Horowitz, L.; Kim, N.

    2002-12-01

    This talk will demonstrate the interdependency of air quality in the northern hemisphere on the emissions and subsequent transport of pollutants from each of the major industrialized continental regions. We examine the contribution that emissions from continental regions in the northern hemisphere make to the composition of the remote troposphere. We also examine the processes that control the concentration of reactive pollutants in continental boundary layers over the United States, Europe and East Asia and export from these boundary layers to the global troposphere. We use the MOZART-2 (Model of Ozone and Related Tracers, version 2) global chemical tracer model with tagged CO from fossil fuel and biomass burning emissions from each region. In conjunction with CO measurements from the Climate Monitoring and Diagnostic Lab (CMDL), we examine the influence that each regions' emissions have on remote surface locations in the northern hemisphere. We find that the remote troposphere of the northern hemisphere contains a mélange of CO emitted from different continental regions the contributions of which vary seasonally as a function of emissions, meteorology and atmospheric lifetime. To examine factors regulating the concentration distributions of O3, CO, NOx, PAN and HNO3 over the United States, Europe and Asia and their export to the global troposphere, we quantify and compare the seasonal contributions of chemistry, advection, convection and deposition to boundary layer concentrations of each chemical species and examine the horizontal and vertical fluxes of each species out of each regions boundary layer to the global troposphere.

  16. Dolomite flotation of high magnesium phosphate ores using fatty acid soap collectors

    NASA Astrophysics Data System (ADS)

    Gu, Zhengxing

    The separation of dolomite from apatite has been recognized as one of the most difficult subjects in mineral processing due to the similarities in their physiochemical properties. In this study, selective surfactants were used with a fatty acid soap collector to improve the flotation performance of separating dolomite from high magnesium phosphate ores. Three surfactants, diethyl phthalate (DP), Tween-80 (TW) and derivative of sulfonate salt (DSS1) were used. Hallimond cell flotation was conducted using pure dolomite sample to determine the effects of various factors including dosages, particle size, Ca2+ ions and slimes on the dolomite flotation recovery. The results showed that the surfactants can significantly improve dolomite flotation performance by increasing collecting ability and tolerating the effect of calcium ions and slime contents. The stirrer-tank cell batch flotation tests were carried out using two natural high magnesium phosphate ore samples containing 3.3% and 1.5% MgO. The test results showed that the surfactant DP could improve dolomite flotation at low dosages, and DSS1 could enhance the separation of dolomite from phosphate by improving both collecting ability and flotation selectivity. When 10% of DSS1 was used with the fatty acid soap as collector, at least 10% more dolomite can be removed with less P2O5 loss. The effectiveness of the surfactant DSS1 in enhancing dolomite flotation was further demonstrated in modified packed column flotation with natural dolomitic phosphate ore sample. The addition of the surfactant DSS1 into fatty acid soap collector could improve its frothability and froth stability, and reduce the bubble size. It has been found that the dolomite flotation performance has a close relationship with the frothability and froth stability of the collector.

  17. The kinetics of fossil resin extraction from a flotation concentrate

    SciTech Connect

    Li, L.; Yu, Q.; Miller, J.D.

    1995-11-01

    The kinetics of fossil resin extraction from a flotation concentrate by heptane were investigated as a function of process variables using monosize particles. Experimental results provide for a better understanding of the refining process and the basis for subsequent design and construction of a continuous resin refining circuit. Based on the effect of process variables (particle size, stirring speed, and temperature) the resin extraction rate appears to be controlled by surface solvation phenomena. The initial extraction rate was found to be inversely proportional to the initial particle size and a kinetic model is being developed to describe the experimental results.

  18. Improving the performance of conventional and column froth flotation cells

    SciTech Connect

    Arnold, B.J.

    1995-11-01

    Many existing mining operations hover on the brink of producing competitively priced fuel with marginally acceptable sulfur levels. To remain competitive, these operations need to improve the yield of their coal processing facilities, lower the sulfur content of their clean coal, or lower the ash content of their clean coal. Fine coal cleaning processes offer the best opportunity for coal producers to increase their yield of high quality product. Over 200 coal processing plants in the U.S. already employ some type of conventional or column flotation device to clean fines. an increase in efficiency in these existing circuits could be the margin required to make these coal producers competitive.

  19. Coal surface control for advanced fine coal flotation

    SciTech Connect

    Fuerstenau, D.W.; Hanson, J.S.; Diao, J.; Harris, G.H.; De, A.; Sotillo, F. ); Somasundaran, P.; Harris, C.C.; Vasudevan, T.; Liu, D.; Li, C. ); Hu, W.; Zou, Y.; Chen, W. ); Choudhry, V.; Shea, S.; Ghosh, A.; Sehgal, R. )

    1992-03-01

    The initial goal of the research project was to develop methods of coal surface control in advanced froth flotation to achieve 90% pyritic sulfur rejection, while operating at Btu recoveries above 90% based on run-of-mine quality coal. Moreover, the technology is to concomitantly reduce the ash content significantly (to six percent or less) to provide a high-quality fuel to the boiler (ash removal also increases Btu content, which in turn decreases a coal's emission potential in terms of lbs SO{sub 2}/million Btu). (VC)

  20. Pacific Northwest National Laboratory Site Dose-per-Unit-Release Factors for Use in Calculating Radionuclide Air Emissions Potential-to-Emit Doses

    SciTech Connect

    Barnett, J. Matthew; Rhoads, Kathleen

    2009-06-11

    This report documents assumptions and inputs used to prepare the dose-per-unit-release factors for the Pacific Northwest National Laboratory (PNNL) Site (including the buildings that make up the Physical Sciences Facility [PSF] as well as the Environmental Molecular Sciences Laboratory [EMSL]) calculated using the EPA-approved Clean Air Act Assessment Package 1988–Personal Computer (CAP88-PC) Version 3 software package. The dose-per-unit-release factors are used to prepare dose estimates for a maximum public receptor (MPR) in support of Radioactive Air Pollutants Notice of Construction (NOC) applications for the PNNL Site.

  1. Pacific Northwest National Laboratory Site Dose-per-Unit-Release Factors for Use in Calculating Radionuclide Air Emissions Potential-to-Emit Doses

    SciTech Connect

    Barnett, J. Matthew; Rhoads, Kathleen

    2008-09-29

    This report documents assumptions and inputs used to prepare the dose-per-unit-release factors for the Pacific Northwest National Laboratory (PNNL) Site (including the buildings that make up the Physical Sciences Facility [PSF] as well as the Environmental Molecular Sciences Laboratory [EMSL]) calculated using the EPA-approved Clean Air Act Assessment Package 1988–Personal Computer (CAP88-PC) Version 3 software package. The dose-per-unit-release factors are used to prepare dose estimates for a maximum public receptor (MPR) in support of Radioactive Air Pollutants Notice of Construction (NOC) applications for the PNNL Site.

  2. Initial testing of a dynamic column for fine coal flotation

    SciTech Connect

    Lai, R.W.; Patton, R.A.; He, D.X.; Joyce, T.; Chiang, S.H.

    1995-12-31

    This paper describes the design and initial performance of a dynamic column for fine coal column flotation. A dynamic column is a modified conventional column with the insertion of a series of draft tubes that provide individual mixing stages. The mixing is beneficial in generating small and uniform bubbles over a wide range of frother dosages. It is also beneficial in the control of flotation where the fluctuation of froth volume should be minimized. In the modified design, a vortex-inducing plate is attached to the top of each draft tube to create an artificial vortex. In theory the vortex action is desirable for collecting the light clean coal froth within the inner mixing zone, and for passing it upward to the next draft tube stage. The mineral laden slurry, particularly the pyrite, is accelerated outside the vortex zone by centrifugal force to reach the wall where it is carried downward to the bottom of the column. The draft tubes are arranged in a series to accomplish multistage cleaning. The experimental results showed that this dynamic column has the potential advantage of higher throughput and better product recovery as well as improved product quality.

  3. Inclusion flotation-driven channel segregation in solidifying steels

    PubMed Central

    Li, Dianzhong; Chen, Xing-Qiu; Fu, Paixian; Ma, Xiaoping; Liu, Hongwei; Chen, Yun; Cao, Yanfei; Luan, Yikun; Li, Yiyi

    2014-01-01

    Channel segregation, which is featured by the strip-like shape with compositional variation in cast materials due to density contrast-induced flow during solidification, frequently causes the severe destruction of homogeneity and some fatal damage. An investigation of its mechanism sheds light on the understanding and control of the channel segregation formation in solidifying metals, such as steels. Until now, it still remains controversial what composes the density contrasts and, to what extent, how it affects channel segregation. Here we discover a new force of inclusion flotation that drives the occurrence of channel segregation. It originates from oxide-based inclusions (Al2O3/MnS) and their sufficient volume fraction-driven flotation becomes stronger than the traditionally recognized inter-dendritic thermosolutal buoyancy, inducing the destabilization of the mushy zone and dominating the formation of channels. This study uncovers the mystery of oxygen in steels, extends the classical macro-segregation theory and highlights a significant technological breakthrough to control macrosegregation. PMID:25422943

  4. Application of geophysical methods to the delineation of paleochannels and missing confining units above the Castle Hayne Aquifer at US Marine Corps Air Station, Cherry Point, North Carolina

    USGS Publications Warehouse

    Daniel, C. C.; Miller, R.D.; Wrege, B.M.

    1995-01-01

    The U.S. Marine Corps Air Station, Cherry Point, North Carolina, is underlain by four freshwater-bearing aquifers--the surficial, Yorktown, and upper and lower Castle Hayne. The upper and lower Castle Hayne aquifers serve as the principal supply of freshwater for the Air Station. The potential for movement of contaminated water from the surficial aquifer downward to the water-supply aquifer is greatest in areas where clay confining units are missing. Missing confining units may indicate the presence of paleochannels filled with permeable material. Seismic-reflection techniques were successful in delinea- ting paleochannels of Quaternary and Tertiary age within unconsoli- dated sediments less than 180 feet deep at several locations. Continuous single-channel marine seismic-reflection profiling in the Neuse River was effective in delineating a large paleochannel complex consisting of at least two superimposed paleochannels within hydrogeologic units overlying the upper Castle Hayne aquifer. The complex was found immediately north of the Air Station and is thought to continue south beneath the Air Station. Shallow high-resolution land seismic-reflection techniques were used at the Air Station to delineate structures and correlate strati- graphy between the limestone of the upper Castle Hayne aquifer and the Yorktown confining unit. Three different land seismic-reflection techniques proved effective for the horizontal extrapolation of geo- logic features and identification of paleochannels at several locations. The northeastern margin of a large paleochannel was identified beneath the southern part of the Air Station. This feature strikes northwest to southeast and cuts through the Yorktown and upper Castle Hayne aquifer confining units.

  5. Air pollution and early deaths in the United States. Part I: Quantifying the impact of major sectors in 2005

    NASA Astrophysics Data System (ADS)

    Caiazzo, Fabio; Ashok, Akshay; Waitz, Ian A.; Yim, Steve H. L.; Barrett, Steven R. H.

    2013-11-01

    Combustion emissions adversely impact air quality and human health. A multiscale air quality model is applied to assess the health impacts of major emissions sectors in United States. Emissions are classified according to six different sources: electric power generation, industry, commercial and residential sources, road transportation, marine transportation and rail transportation. Epidemiological evidence is used to relate long-term population exposure to sector-induced changes in the concentrations of PM2.5 and ozone to incidences of premature death. Total combustion emissions in the U.S. account for about 200,000 (90% CI: 90,000-362,000) premature deaths per year in the U.S. due to changes in PM2.5 concentrations, and about 10,000 (90% CI: -1000 to 21,000) deaths due to changes in ozone concentrations. The largest contributors for both pollutant-related mortalities are road transportation, causing ∼53,000 (90% CI: 24,000-95,000) PM2.5-related deaths and ∼5000 (90% CI: -900 to 11,000) ozone-related early deaths per year, and power generation, causing ∼52,000 (90% CI: 23,000-94,000) PM2.5-related and ∼2000 (90% CI: -300 to 4000) ozone-related premature mortalities per year. Industrial emissions contribute to ∼41,000 (90% CI: 18,000-74,000) early deaths from PM2.5 and ∼2000 (90% CI: 0-4000) early deaths from ozone. The results are indicative of the extent to which policy measures could be undertaken in order to mitigate the impact of specific emissions from different sectors - in particular black carbon emissions from road transportation and sulfur dioxide emissions from power generation.

  6. Particulate Air Pollution, Exceptional Aging, and Rates of Centenarians: A Nationwide Analysis of the United States, 1980–2010

    PubMed Central

    Baccarelli, Andrea A.; Hales, Nick; Burnett, Richard T.; Jerrett, Michael; Mix, Carter; Dockery, Douglas W.; Pope, C. Arden

    2016-01-01

    Background: Exceptional aging, defined as reaching age 85 years, shows geographic inequalities that may depend on local environmental conditions. Links between particulate pollution—a well-recognized environmental risk factor—and exceptional aging have not been investigated. Objectives: We conducted a nationwide analysis of ~28 million adults in 3,034 United States counties to determine whether local PM2.5 levels (particulate matter < 2.5 μm in aerodynamic diameter) affected the probability of becoming 85- to 94-year-olds or centenarians (100- to 104-year-olds) in 2010 for individuals who were 55–64 or 70–74 years old, respectively, in 1980. Methods: We used population-weighted regression models including county-level PM2.5 from hybrid land-use regression and geostatistical interpolation, smoking, obesity, sociodemographic, and age-specific migration variables. Results: On average, 2,295 and 71.4 per 10,000 of the 55- to 64- and 70- to 74-year-olds in 1980, respectively, remained in the 85- to 94- and 100- to 104-year-old population in 2010. An interquartile range (4.19 μg/m3) increase in PM2.5 was associated with 93.7 fewer 85- to 94-year-olds (p < 0.001) and 3.5 fewer centenarians (p < 0.05). These associations were nearly linear, were stable to model specification, and were detectable below the annual PM2.5 national standard. Exceptional aging was strongly associated with smoking, with an interquartile range (4.77%) increase in population who smoked associated with 181.9 fewer 85- to 94-year-olds (p < 0.001) and 6.4 fewer centenarians (p < 0.001). Exceptional aging was also associated with obesity rates and median income. Conclusions: Communities with the most exceptional aging have low ambient air pollution and low rates of smoking, poverty, and obesity. Improvements in these determinants may contribute to increasing exceptional aging. Citation: Baccarelli AA, Hales N, Burnett RT, Jerrett M, Mix C, Dockery DW, Pope CA III. 2016. Particulate air

  7. Adsorption mechanism of mixed cationic/anionic collectors in feldspar-quartz flotation system.

    PubMed

    Vidyadhar, A; Hanumantha Rao, K

    2007-02-15

    The adsorption mechanism of mixed cationic alkyl diamine and anionic sulfonate/oleate collectors at acidic pH values was investigated on microcline and quartz minerals through Hallimond flotation, electrokinetic and diffuse reflectance FTIR studies. In the presence of anionic collectors, neither of the minerals responded to flotation but the diamine flotation of the minerals was observed to be pH and concentration dependent. The presence of sulfonate enhanced the diamine flotation of the minerals by its co-adsorption. The difference in surface charge between the minerals at pH 2 was found to be the basis for preferential feldspar flotation from quartz in mixed diamine/sulfonate collectors. The infrared spectra revealed no adsorption of sulfonate collector when used alone but displayed its co-adsorption as diamine-sulfonate complex when used with diamine. The presence of sulfonate increased the diamine adsorption due to a decrease in the electrostatic head-head repulsion between the adjacent surface ammonium ions and thereby increasing the lateral tail-tail hydrophobic bonds. The mole ratio of diamine/sulfonate was found to be an important factor in the orientation of alkyl chains and thus the flotation response of minerals. The increase in sulfonate concentration beyond diamine concentration leads to the formation of soluble 1:2 diamine-sulfonate complex or precipitate and the adsorption of these species decreased the flotation since the alkyl chains are in chaotical orientation with a conceivable number of head groups directing towards the solution phase.

  8. Air Quality and Exercise-Related Health Benefits from Reduced Car Travel in the Midwestern United States

    PubMed Central

    Spak, Scott N.; Holloway, Tracey; Stone, Brian; Mednick, Adam C.; Patz, Jonathan A.

    2011-01-01

    Background: Automobile exhaust contains precursors to ozone and fine particulate matter (PM ≤ 2.5 µm in aerodynamic diameter; PM2.5), posing health risks. Dependency on car commuting also reduces physical fitness opportunities. Objective: In this study we sought to quantify benefits from reducing automobile usage for short urban and suburban trips. Methods: We simulated census-tract level changes in hourly pollutant concentrations from the elimination of automobile round trips ≤ 8 km in 11 metropolitan areas in the upper midwestern United States using the Community Multiscale Air Quality (CMAQ) model. Next, we estimated annual changes in health outcomes and monetary costs expected from pollution changes using the U.S. Environmental Protection Agency Benefits Mapping Analysis Program (BenMAP). In addition, we used the World Health Organization Health Economic Assessment Tool (HEAT) to calculate benefits of increased physical activity if 50% of short trips were made by bicycle. Results: We estimate that, by eliminating these short automobile trips, annual average urban PM2.5 would decline by 0.1 µg/m3 and that summer ozone (O3) would increase slightly in cities but decline regionally, resulting in net health bene-fits of $4.94 billion/year [95% confidence interval (CI): $0.2 billion, $13.5 billion), with 25% of PM2.5 and most O3 bene-fits to populations outside metropolitan areas. Across the study region of approximately 31.3 million people and 37,000 total square miles, mortality would decline by approximately 1,295 deaths/year (95% CI: 912, 1,636) because of improved air quality and increased exercise. Making 50% of short trips by bicycle would yield savings of approximately $3.8 billion/year from avoided mortality and reduced health care costs (95% CI: $2.7 billion, $5.0 billion]. We estimate that the combined benefits of improved air quality and physical fitness would exceed $8 billion/year. Conclusion: Our findings suggest that significant health and

  9. Experiences with anaerobic treatment of fat-containing food waste liquids: two full scale studies with a novel anaerobic flotation reactor.

    PubMed

    Frijters, C T M J; Jorna, T; Hesselink, G; Kruit, J; van Schaick, D; van der Arend, R

    2014-01-01

    Fat-containing food waste can be effectively treated in a new type of reactor, the so-called BIOPAQ-Anaerobic Flotation Reactor or BIOPAQ(®) anaerobic flotation reactor (AFR). In the reactor a flotation unit is integrated to retain the sludge. In this study results from two plants with a 430 and 511 m(3)-AFR, respectively, are presented. In one reactor, which is fed with water originating from different food liquid streams, over 99% of fat and oils were removed. Over 90% of the chemical oxygen demand (COD) was removed. When the last solids were removed from the effluent with a tilted plate settler, 98% COD removal was attained. The effluent concentrations of extractable hydrolysed and non-hydrolysed fats were less than 40 mg/l. Apparently the variations in the liquid streams deriving from the tank cleaning activities did not disturb the system. Only extremely high concentrations of fats could disturb the system, but the inhibition was reversible. In the reactor treating water from an ice-cream factory, which contained fats up to approximately 50% of influent COD, a COD removal efficiency of 90% was achieved. At volumetric loading rates varying from 1 to 8 kg COD/m(3)/d, biogas was produced at an average specific gas production of 0.69 m(3)/kg COD-removed.

  10. Summary of Turbulence Data Obtained During United Air Lines Flight Evaluation of an Experimental C Band (5.5 cm) Airborne Weather Radar

    NASA Technical Reports Server (NTRS)

    Coe, E. C.; Fetner, M. W.

    1954-01-01

    Data on atmospheric turbulence in the vicinity of thunderstorms obtained during a flight evaluation of an experimental C band (5.5 cm) airborne radar are summarized. The turbulence data were obtained with an NACA VGH recorder installed in a United Air Lines DC-3 airplane.

  11. T & I--Air Conditioning, Refrigeration, and Heating--Heating Units. Kit No. 87. Instructor's Manual [and] Student Learning Activity Guide.

    ERIC Educational Resources Information Center

    Simmons, Mike

    An instructor's manual and student activity guide on air conditioning, refrigeration, and heating units are provided in this set of prevocational education materials which focuses on the vocational area of trade and industry. (This set of materials is one of ninety-two prevocational education sets arranged around a cluster of seven vocational…

  12. A Near-Road Modeling System for Community-Scale Assessments of Traffic-Related AirPollution in the United States

    EPA Science Inventory

    The Community Line Source (C-LINE) modeling system estimates emissions and dispersion of toxic air pollutants for roadways within the continental United States. It accesses publicly available traffic and meteorological datasets, and is optimized for use on community-sized areas (...

  13. Estimated 2017 Refrigerant Emissions of 2,3,3,3-Tetrafluoropropene (HFC-1234yf) in the United States Resulting from Automobile Air Conditioning

    EPA Science Inventory

    In response to recent regulations and concern over climate change, the global automotive community is evaluating alternatives to the current refrigerant used in automobile air conditioning units, 1,1,1,2-tetrafluoroethane, HFC-134a. One potential alternative is 2,3,3,3-tetrafluor...

  14. Assessment of microbiological air quality in hemato-oncology units and its relationship with the occurrence of invasive fungal infections: an integrative review.

    PubMed

    Menegueti, Mayra Gonçalves; Ferreira, Lécio Rodrigues; Silva, Magda Fabbri Isaac; Silva, Anderson Soares da; Bellissimo-Rodrigues, Fernando

    2013-01-01

    Worldwide aging of the human population has promoted an increase in the incidence of neoplasia, including hematological cancers, which render patients particularly vulnerable to invasive fungal infections. For this reason, air filtration in hematooncology units has been recommended. However, scarce literature has assessed the impact of microbiological air quality on the occurrence of fungal infections in this population. We performed an integrative review of studies in the MEDLINE database that were published between January 1980 and October 2012, using the following combinations of keywords: air × quality × HEPA, air × quality × hematology, and airborne fungal infections. The search yielded only 13 articles, suggesting that high-efficiency filtering of the ambient air in hemato-oncology units can prevent the incidence of invasive fungal infections. However, no randomized clinical trial was found to confirm this suggestion. Currently, there is no consensus about the maximum allowable count of fungi in the air, which complicates filtration monitoring, including filter maintenance and replacement, and needs to be addressed in future studies. PMID:23904085

  15. Evaluation of a seven-year air quality simulation using the Weather Research and Forecasting (WRF)/Community Multiscale Air Quality (CMAQ) models in the eastern United States.

    PubMed

    Zhang, Hongliang; Chen, Gang; Hu, Jianlin; Chen, Shu-Hua; Wiedinmyer, Christine; Kleeman, Michael; Ying, Qi

    2014-03-01

    The performance of the Weather Research and Forecasting (WRF)/Community Multi-scale Air Quality (CMAQ) system in the eastern United States is analyzed based on results from a seven-year modeling study with a 4-km spatial resolution. For 2-m temperature, the monthly averaged mean bias (MB) and gross error (GE) values are generally within the recommended performance criteria, although temperature is over-predicted with MB values up to 2K. Water vapor at 2-m is well-predicted but significant biases (>2 g kg(-1)) were observed in wintertime. Predictions for wind speed are satisfactory but biased towards over-prediction with 0

  16. Evaluation of a seven-year air quality simulation using the Weather Research and Forecasting (WRF)/Community Multiscale Air Quality (CMAQ) models in the eastern United States.

    PubMed

    Zhang, Hongliang; Chen, Gang; Hu, Jianlin; Chen, Shu-Hua; Wiedinmyer, Christine; Kleeman, Michael; Ying, Qi

    2014-03-01

    The performance of the Weather Research and Forecasting (WRF)/Community Multi-scale Air Quality (CMAQ) system in the eastern United States is analyzed based on results from a seven-year modeling study with a 4-km spatial resolution. For 2-m temperature, the monthly averaged mean bias (MB) and gross error (GE) values are generally within the recommended performance criteria, although temperature is over-predicted with MB values up to 2K. Water vapor at 2-m is well-predicted but significant biases (>2 g kg(-1)) were observed in wintertime. Predictions for wind speed are satisfactory but biased towards over-prediction with 0

  17. Modelling and calculation of flotation process in one-dimensional formulation

    NASA Astrophysics Data System (ADS)

    Amanbaev, Tulegen; Tilleuov, Gamidulla; Tulegenova, Bibigul

    2016-08-01

    In the framework of the assumptions of the mechanics of the multiphase media is constructed a mathematical model of the flotation process in the dispersed mixture of liquid, solid and gas phases, taking into account the degree of mineralization of the surface of the bubbles. Application of the constructed model is demonstrated on the example of one-dimensional stationary flotation and it is shown that the equations describing the process of ascent of the bubbles are singularly perturbed ("rigid"). The effect of size and concentration of bubbles and the volumetric content of dispersed particles on the flotation process are analyzed.

  18. Portable device for use in starting air-start-units for aircraft and having cable lead testing capability

    NASA Technical Reports Server (NTRS)

    Rosier, W. R.; Volk, G. G. (Inventor)

    1980-01-01

    A portable device for starting aircraft engines and the like is disclosed. The device includes a lead testing and motor starting circuit characterized by: (1) a direct current voltage source, (2) a pair of terminal plugs connected with the circuit (each being characterized by a first, second, and third terminal) (3) a pair of manually operable switches for connecting the first terminal of each plug of the pair to the positive side of the voltage source, (4) a circuit lead connecting to the second terminal of each plug the negative side of said source, (5) a pair of electrical cables adapted to connect said first and second terminals of each plug to an air-start unit, and means for connecting each cable of the pair of cables between the first terminal of one plug and the third terminal of the other plug of the pair, and (6) a second pair of manually operable switches for selectivity connecting the third terminal of each plug of the pair to the negative side of the voltage source.

  19. Dissemination of the Look AHEAD Lifestyle Intervention in the United States Air Force: Study Rationale, Design and Methods

    PubMed Central

    Krukowski, Rebecca A.; Hare, Marion E.; Talcott, Gerald W.; Johnson, Karen C.; Richey, Phyllis A.; Kocak, Mehmet; Balderas, Jennifer; Colvin, Lauren; Keller, Patrick L.; Waters, Teresa M.; Klesges, Robert C.

    2014-01-01

    Despite an increase in overweight and obesity similar to the civilian population, there have been few randomized controlled trials examining behavioral weight management interventions in the military settings. This paper describes the design, intervention development and analysis plan of the Fit Blue study, a randomized controlled behavioral weight loss trial taking place in the United States Air Force. This study compares two adapted versions of the efficacious Look AHEAD Intensive Lifestyle Intervention (ILI), a counselor-initiated condition and a self-paced condition. Also described are the unique steps required when conducting military-based health promotion research and adaptations made to the Look AHEAD intervention to accommodate the military environment. To our knowledge, this is the first translation of the Look AHEAD ILI in the military setting and one of the first translations of the ILI in general. If successful, this intervention could be disseminated to the entire U.S. Military as this project is designed to overcome the barriers and utilize the facilitators for weight loss that are unique to a military population. Programs validated in military populations can have a major public health impact given that with 1.4 million active duty personnel, the Department of Defense is the nation’s largest employer. However, while this intervention is designed for a military population and there are unique aspects of the military that may enhance weight loss interventions, the diversity of the study population should help inform obesity efforts in both civilian and military settings. PMID:25545025

  20. Finisher hog production in the Southeastern United States: Ancillary measurements derived from the National Air Emissions Monitoring Study (NAEMS)

    NASA Astrophysics Data System (ADS)

    Robarge, W. P.; Lee, S.; Walker, J. T.

    2010-12-01

    Measurements of emissions of gases and fine particulate matter from swine animal feeding operations (AFOs) in the southeastern US have typically been confined to relatively short periods (days to several weeks) and have generally focused on waste lagoons. Access to swine animal housing units and other ancillary information has been limited. The National Air Emissions Monitoring Study (NAEMS) provided a unique opportunity to characterize emissions from swine housing units for an extended period of time (~ 2 years), and allowed access to ancillary measurements regarding nutrient flows (feed amounts and composition), manure dynamics, animal inventories, water usage and farm management. Presented here is a summary of the observations made for a NAEMS finisher site (NC3B) selected as being representative of swine production in the southeastern US. Finisher hogs are raised in rotations (~ 140 days) with a target market weight of 123 kg/hog. Among the population during a rotation (700-800 hogs/barn) the actual growth rate varies with a series of “grade-outs” of market-weight hogs starting ~ 110 days from initial load-in. Derivation of the standing live-weight in the barns during a rotation therefore requires use of a growth model and summation over several different “populations” of hogs within a single barn. Up to 5 different feed formulations are fed during a rotation with %N content ranging from (3.4 to 2.2% N; total feed consumed 181,000 kg/barn). Across 4 complete rotations, N consumed was ~50 g N per hog/day. Of this amount, we estimate ~ 60% is excreted as fecal matter and urine. The TAN (NH3 + NH4+) content of the shallow pits is consistently higher (1880 ±390 mg TAN/L) than that found in the anaerobic lagoon (800 ±70 mg TAN/L), except immediately after recharge following pit-pull (pH of the two liquids was similar). The presence of a recalcitrant layer of sludge in the shallow pits (liquid height = 20 cm; sludge depth = 5-10 cm; TAN = 2500 mg N/L; total

  1. Coal flotation and flocculation in the presence of humic acids: Fianl report, January 1--December 31, 1988

    SciTech Connect

    Lalvani, S.B.

    1989-03-01

    The principle of coal cleaning using humic acid as follows. Humic acid is an anionic polyelectrolyte which possesses a high density of carboxyl groups. The mechanism of coal depression involves the selective adsorption of humic acid on the hydrophobic coal through hydrophobic bonding. Pyrite and ash are hydrophilic in nature and can be separated from the carbonaceous part of the coal, thus resulting in a cleaner coal. During the one-year period of investigation, the following tasks were accomplished: (1) determination of electrokinetic properties of coal; (2) depression of coal flotation due to the humic acid addition, (3) reversal of coal depression (originally caused by humic acid addition) by a sequential treatment of kerosene and MIBC, and (4) evaluation of coal cleaned as a function of the amount of humic acid added and air flow rate. It was found that the coal cleaned by this process has 24% lower ash content than the raw coal. 3 refs., 10 figs.

  2. [Treatment of high algae-laden water by step-recycle counter current flotation].

    PubMed

    Wang, Yu-Heng; Wang, Qi-Shan; Wu, Yu-Bao; Yue, Lin; Yang, Jian-Kang

    2008-11-01

    High algae-laden water was treated respectively by single-recycle and step-recycle counter current flotation. The results indicate that step-recycle mode of dissolved air water can strengthen capturing of bubbles and flocs association suspension bed, and extend the collision time of smaller flee and bubble because of reducing the thickness of suspension bed and increasing that of transition bed. Given the condition that other parameters were same, the biggest hydraulic loading of single-recycle could reach 11 m/h, and that of step-recycle could reach 17 m/h which is increased by 50%. Efficiency of treatment was improved by a large margin. The recycle ratio of two releasers and position of the pensile releaser influenced removal effect remarkably. The distance between settled releaser and inlet of raw water is 180 cm, and the range of distance between pensile releaser and inlet of raw water is 60-90 cm. The flow of pensile releaser is 2-3 times as much as settled releaser.

  3. Froth flotation of oil-bearing metal sulfide wastes

    SciTech Connect

    Miller, R.L. ); Atwood, R.L.; Ye, Yi )

    1991-01-01

    An industrial wastewater, including plating wastes, is treated with sodium sulfide and ferrous sulfate to form a sulfide-oxide precipitate containing chromium and other toxic metals. Hydrocarbons, in the water, coat the sulfide-oxide particles, impeding metal recovery. Froth flotation, without reagent addition, was found to recover 93.9% of the solids from the sludge with simultaneous rejection of 89% of the water. Methyl isobutyl carbinol (MIBC) improved recovery and potassium amyl xanthate improved both recovery and grade. The process design has wastewater feed (without MIBC) to the rougher circuit. The rougher concentrate is conditioned with MIBC and fed to a cleaner circuit to achieve a high grade concentrate. About 95% of the water is recirculated to the waste treatment plant. 3 refs., 3 figs., 4 tabs.

  4. Froth flotation of oil-bearing metal sulfide wastes

    SciTech Connect

    Miller, R.L.; Atwood, R.L.; Ye, Yi

    1991-12-01

    An industrial wastewater, including plating wastes, is treated with sodium sulfide and ferrous sulfate to form a sulfide-oxide precipitate containing chromium and other toxic metals. Hydrocarbons, in the water, coat the sulfide-oxide particles, impeding metal recovery. Froth flotation, without reagent addition, was found to recover 93.9% of the solids from the sludge with simultaneous rejection of 89% of the water. Methyl isobutyl carbinol (MIBC) improved recovery and potassium amyl xanthate improved both recovery and grade. The process design has wastewater feed (without MIBC) to the rougher circuit. The rougher concentrate is conditioned with MIBC and fed to a cleaner circuit to achieve a high grade concentrate. About 95% of the water is recirculated to the waste treatment plant. 3 refs., 3 figs., 4 tabs.

  5. Selective flotation of phosphate minerals with hydroxamate collectors

    DOEpatents

    Miller, Jan D.; Wang, Xuming; Li, Minhua

    2002-01-01

    A method is disclosed for separating phosphate minerals from a mineral mixture, particularly from high-dolomite containing phosphate ores. The method involves conditioning the mineral mixture by contacting in an aqueous in environment with a collector in an amount sufficient for promoting flotation of phosphate minerals. The collector is a hydroxamate compound of the formula; ##STR1## wherein R is generally hydrophobic and chosen such that the collector has solubility or dispersion properties it can be distributed in the mineral mixture, typically an alkyl, aryl, or alkylaryl group having 6 to 18 carbon atoms. M is a cation, typically hydrogen, an alkali metal or an alkaline earth metal. Preferably, the collector also comprises an alcohol of the formula, R'--OH wherein R' is generally hydrophobic and chosen such that the collector has solubility or dispersion properties so that it can be distributed in the mineral mixture, typically an alkyl, aryl, or alkylaryl group having 6 to 18 carbon atoms.

  6. Flotation purification of industrial wastewater by removing cyanide ions

    SciTech Connect

    Evtyugina, N.M.; Derbysheva, E.K.; Kopktova, L.A.

    1984-01-01

    One of the oldest and most common methods of purifying sewage by removing cyanide ions is binding them to nontoxic compounds of ferrous salts, principally divalent ferrous salts. Research in this direction has also been realized for the sewage of coking plants. One of the reasons why the method has not been introduced is tied to the difficulty of separating the finely-dispersed slime of the divalent ferrous cyanide K/sub 4/(Fe(CN)/sub 6/). This study investigates methods of producing complex compounds of cyanide ions with ferrous salts which have low solubility and, as far as possible, are easily extracted from water. To achieve this, it is suggested that one of the promising methods of water purification - flotation - be used and that the sludge extracted be utilized in accordance with wellknown plans.

  7. Nickel Ore Dispersion Evaluation and Consequences in Flotation Process

    NASA Astrophysics Data System (ADS)

    de São José, Fábio; Imbelloni, Alaine Moreira; Nogueira, Francielle Câmara; Pereira, Carlos Alberto

    2016-04-01

    Nickel ore dispersion before flotation using different reagents was investigated on a bench scale to improve metallurgical recovery and selectivity. The nickel ore had a content of 0.8 pct nickel and 14.5 pct MgO. A positive linear correlation between MgO and Ni was found. Carboxy methyl cellulose, both pure and combined with Na2CO3, was the best dispersant used. The most efficient collector was potassium amyl xanthate combined with mercaptobenzothiazole, and the addition of xanthate was decisive for this good result because it is normally more stable in the pH range used in the tests. A pH change from 7 to 9 resulted in a metal recovery increase of 49.3 pct, together with an increase of 6.25 pct of MgO in the concentrate.

  8. Statistical Evaluation and Optimization of Factors Affecting the Leaching Performance of Copper Flotation Waste

    PubMed Central

    Çoruh, Semra; Elevli, Sermin; Geyikçi, Feza

    2012-01-01

    Copper flotation waste is an industrial by-product material produced from the process of manufacturing copper. The main concern with respect to landfilling of copper flotation waste is the release of elements (e.g., salts and heavy metals) when in contact with water, that is, leaching. Copper flotation waste generally contains a significant amount of Cu together with trace elements of other toxic metals, such as Zn, Co, and Pb. The release of heavy metals into the environment has resulted in a number of environmental problems. The aim of this study is to investigate the leaching characteristics of copper flotation waste by use of the Box-Behnken experimental design approach. In order to obtain the optimized condition of leachability, a second-order model was examined. The best leaching conditions achieved were as follows: pH = 9, stirring time = 5 min, and temperature = 41.5°C. PMID:22629194

  9. 46 CFR 28.110 - Life preservers or other personal flotation devices.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... be equipped with at least one immersion suit, exposure suit, or wearable personal flotation device of... commercial fishing activities must meet the requirements of this paragraph. (b) Each wearable...

  10. 46 CFR 28.110 - Life preservers or other personal flotation devices.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... be equipped with at least one immersion suit, exposure suit, or wearable personal flotation device of... commercial fishing activities must meet the requirements of this paragraph. (b) Each wearable...

  11. Effects of particle size and chain length on flotation of quaternary ammonium salts onto kaolinite

    NASA Astrophysics Data System (ADS)

    Longhua, Xu; Yuehua, Hu; Faqin, Dong; Hao, Jiang; Houqin, Wu; Zhen, Wang; Ruohua, Liu

    2015-06-01

    Effects of particle size and chain length on flotation of quaternary ammonium salts (QAS) onto kaolinite have been investigated by flotation tests. Dodecyltrimethylammonium chloride (DTAC) and cetyltrimethylammonium chloride (CTAC) were used as collectors for kaolinite in different particle size fractions (0.075 ~ 0.01 mm, 0.045 ~ 0.075 mm, 0 ~ 0.045 mm). The anomalous flotation behavior of kaolinite have been further explained based on crystal structure considerations by adsorption tests and molecular dynamics (MD) simulation. The results show that the flotation recovery of kaolinite in all different particle size fractions decreases with an increase in pH. As the concentration of collectors increases, the flotation recovery increases. The longer the carbon chain of QAS is, the higher the recoveries of coarse kaolinite (0.075 ~ 0.01 mm and 0.045 ~ 0.075 mm) are. But the flotation recovery of the finest kaolinite (0 ~ 0.045 mm) decreases with chain lengths of QAS collectors increasing, which is consistent with the flotation results of unscreened kaolinite (0 ~ 0.075 mm). It is explained by the froth stability related to the residual concentration of QAS collector in mineral pulp. In lower residual concentration, the froth stability becomes worse. Within the range of flotation collector concentration, it's easy of CTAC to be completely adsorbed by kaolinite in the particle size fraction (0-0.045 mm), which led to lower flotation recovery. Moreover, it is interesting that the coarser particle size of kaolinite is, the higher flotation recovery is. The anomalous flotation behavior of kaolinite is rationalized based on crystal structure considerations. The results of MD simulations show that the (001) kaolinite surface has the strongest interaction with DTAC, compared with the (00 1) face, (010) and (110) edges. On the other hand, when particle size of kaolinite is altered, the number of basal planes and edge planes is changed. It is observed that the finer kaolinite

  12. Improving the Energy Performance of Multi-Unit Residential Buildings Using Air-Source Heat Pumps and Enclosed Balconies

    NASA Astrophysics Data System (ADS)

    Touchie, Marianne

    Existing multi-unit residential buildings (MURBs) are important assets for urban regions such as Toronto, Canada. These buildings provide high-density housing and allow for the efficient provision of public services and utilities. However, MURB energy-use imposes a significant environmental burden. A preliminary part of the study presented here found that the median energy intensity of MURBs in Toronto is 300ekWh/m2 and that this energy-use accounts for 17% of residential greenhouse gas (GHG) emissions in the City. To reduce this environmental burden, this work explores a novel energy retrofit strategy involving a suite-based air-source heat pump (ASHP) operating in an enclosed balcony space which serves as a thermal buffer zone (TBZ) to improve the cold-weather ASHP performance in a heating-dominated climate. More broadly, a methodology for assessing the impact of an energy retrofit measure is developed. First, energy-use and interior condition data were collected from a 1960s MURB over the course of one year. The subject building was found to have a higher-than-average energy intensity of 374ekWh/m2 and other operational issues including overheating of suites. These data were then used to calibrate an energy model so that the proposed retrofit strategy could be modeled. Next, the proposed retrofit strategy was tested in a mock apartment unit constructed in a climate-controlled chamber. The testing showed that the coefficient of performance of the ASHP could be improved by operating it in a TBZ with access to heat from solar gains. This finding was used to modify the subject building energy model which showed that applying the proposed retrofit could reduce the annual energy intensity and GHG emissions of the building by 39% and 45%, respectively. An estimate of the impact of applying this retrofit strategy to Toronto MURBs with energy intensities greater than the median results in a median sector energy intensity of 236ekWh/m 2.

  13. Heavy metals in the products of deinking flotation of digital offset prints.

    PubMed

    Barbaric-Mikocevic, Zeljka; Orescanin, Visnja; Bolanca, Zdenka; Lulic, Stipe; Rozic, Mirela

    2004-01-01

    This study was undertaken to investigate the suitability of applying the conventional method of chemical deinking flotation of digital offset prints and ecological implications of the disposal of digital offset prints, with special emphasis on the content of heavy metal cations. The EDXRF method was used to determine the concentrations of Pb, Zr, Sr, As, Co, Zn, Cu, Ni, Fe, Mn, Cr, V, Ti, Ca, and K cations in handsheet ashes after flotation as well as in ashes of foams separated from cellulose suspension in the flotation phase. The same method was applied to determine the concentrations of Pb, Cr, Mn, Fe, Ni, Cu, Zn, and Co in process water filtrates obtained from the cellulose suspension after flotation and in foam filtrates. Centrifuging and coagulation previously treated flotation process water, while foam filtrates were centrifuged. Concentrations of Pb, As, Sr, Zr, K, Ca, Ti, V, Cr, Mn, Fe, Cu, and Zn were determined in the sediments obtained by centrifuging process water. The trials were done with unprinted substrates without deinking chemicals, with unprinted substrates in the presence of deinking chemicals and with printed substrates in the presence of deinking chemicals. Cation analysis revealed that deinking chemicals facilitate release of cations from the substrate and their transition into process water. Concentrations of most cations in the flotation process water, in foam water as well as in the sediment of the process water of printed substrate flotation deinking were lower than those obtained by flotation of unprinted substrate suspension. Polymer particles of ElectroInk incompletely separated from cellulose fibers prevent release of cations from cellulose fibers into process water. Deinking chemicals do not affect release of cations from ElectroInk particles, so the substrate is the main source of increased concentration of cations in the water of digital offset print deinking. The major part of cations in process water is bound to the colloid

  14. Use of an index to reflect the aggregate burden of long-term exposure to criteria air pollutants in the United States.

    PubMed Central

    Kyle, Amy D; Woodruff, Tracey J; Buffler, Patricia A; Davis, Devra L

    2002-01-01

    Air pollution control in the United States for five common pollutants--particulate matter, ground-level ozone, sulfur dioxide, nitrogen dioxide, and carbon monoxide--is based partly on the attainment of ambient air quality standards that represent a level of air pollution regarded as safe. Regulatory and health agencies often focus on whether standards for short periods are attained; the number of days that standards are exceeded is used to track progress. Efforts to explain air pollution to the public often incorporate an air quality index that represents daily concentrations of pollutants. While effects of short-term exposures have been emphasized, research shows that long-term exposures to lower concentrations of air pollutants can also result in adverse health effects. We developed an aggregate index that represents long-term exposure to these pollutants, using 1995 monitoring data for metropolitan areas obtained from the U.S. Environmental Protection Agency's Aerometric Information Retrieval System. We compared the ranking of metropolitan areas under the proposed aggregate index with the ranking of areas by the number of days that short-term standards were exceeded. The geographic areas with the highest burden of long-term exposures are not, in all cases, the same as those with the most days that exceeded a short-term standard. We believe that an aggregate index of long-term air pollution offers an informative addition to the principal approaches currently used to describe air pollution exposures; further work on an aggregate index representing long-term exposure to air pollutants is warranted. PMID:11834467

  15. Relationships between stratospheric clear air turbulence and synoptic meteorological parameters over the western United States between 12-20 km altitude

    NASA Technical Reports Server (NTRS)

    Scoggins, J. R.; Clark, T. L.; Possiel, N. C.

    1975-01-01

    Procedures for forecasting clear air turbulence in the stratosphere over the western United States from rawinsonde data are described and results presented. Approaches taken to relate meteorological parameters to regions of turbulence and nonturbulence encountered by the XB-70 during 46 flights at altitudes between 12-20 km include: empirical probabilities, discriminant function analysis, and mountainwave theory. Results from these techniques were combined into a procedure to forecast regions of clear air turbulence with an accuracy of 70-80 percent. A computer program was developed to provide an objective forecast directly from the rawinsonde sounding data.

  16. Superfund Record of Decision (EPA Region 9): Williams Air Force Base, Operable Unit 5, Chandler, AZ, October 14, 1997

    SciTech Connect

    1998-10-01

    Williams Air Force Base (AFB) is located in Maricopa County, Mesa, Arizona. The following sites constitute Operable Unit (OU) 5: Airfield Underground Storage Tanks (UST) (ST-25); Paint Ship Leach Field (WP-27); Sewage Sludge Trenches (DP-28); Prime Beef Yard (SS-29); Golf Course Maintenance Area (SS-31); Building 1070 (SS-32); Munitions Incinerator (Facility 1119, SS-34); Concrete Hardfill Drum Removal Area (LF-26); Sewage Sludge Stockpile Area (Area 28); Facilities 1020 and 1051 (Site SS-21); Aboveground Storage Tanks (AST) 556 and 557 (Site ST-22); Building 1069 (Site SS-23); Building 1010 (Site SS-24); Concrete Hardfill Area (Site LF-26); Facility 1004 (Area 14). OU-5 addresses soil contamination actions at the nine sites listed in Section 1.1. OU-6 addresses soil and potential groundwater contamination at the Old Pesticide/Paint-Ship (Facility 724, Site SS-17). The USAF, EPA, and state of Arizona have approved ROD`s implementing cleanup remedies for OU-1, OU-2, and OU-3 sites. The deep soils at ST-12 (unsaturated soils below 25 feet) were included in an amendment to the OU-2 ROD. Investigations and feasibility study (FS) have been completed for OU-4 sites. Investigations, RI Report, Proposed Plan, and ROD are to be completed at OU-6. OU-5 is the subject of this ROD. This ROD recommends no action because previous removal actions resulting from the OU-5 action memorandum have either lowered the contamination levels below Arizona HBGL or EPA Region IX residential PRGs or the risk associated with the remaining contamination concentration will not pose an unacceptable risk to human health and the environment.

  17. Updated greenhouse gas and criteria air pollutant emission factors and their probability distribution functions for electricity generating units

    SciTech Connect

    Cai, H.; Wang, M.; Elgowainy, A.; Han, J.

    2012-07-06

    Greenhouse gas (CO{sub 2}, CH{sub 4} and N{sub 2}O, hereinafter GHG) and criteria air pollutant (CO, NO{sub x}, VOC, PM{sub 10}, PM{sub 2.5} and SO{sub x}, hereinafter CAP) emission factors for various types of power plants burning various fuels with different technologies are important upstream parameters for estimating life-cycle emissions associated with alternative vehicle/fuel systems in the transportation sector, especially electric vehicles. The emission factors are typically expressed in grams of GHG or CAP per kWh of electricity generated by a specific power generation technology. This document describes our approach for updating and expanding GHG and CAP emission factors in the GREET (Greenhouse Gases, Regulated Emissions, and Energy Use in Transportation) model developed at Argonne National Laboratory (see Wang 1999 and the GREET website at http://greet.es.anl.gov/main) for various power generation technologies. These GHG and CAP emissions are used to estimate the impact of electricity use by stationary and transportation applications on their fuel-cycle emissions. The electricity generation mixes and the fuel shares attributable to various combustion technologies at the national, regional and state levels are also updated in this document. The energy conversion efficiencies of electric generating units (EGUs) by fuel type and combustion technology are calculated on the basis of the lower heating values of each fuel, to be consistent with the basis used in GREET for transportation fuels. On the basis of the updated GHG and CAP emission factors and energy efficiencies of EGUs, the probability distribution functions (PDFs), which are functions that describe the relative likelihood for the emission factors and energy efficiencies as random variables to take on a given value by the integral of their own probability distributions, are updated using best-fit statistical curves to characterize the uncertainties associated with GHG and CAP emissions in life

  18. Flotation separation of polyvinyl chloride and polyethylene terephthalate plastics combined with surface modification for recycling.

    PubMed

    Wang, Chongqing; Wang, Hui; Fu, Jiangang; Zhang, Lingling; Luo, Chengcheng; Liu, Younian

    2015-11-01

    Surface modification with potassium permanganate (KMnO4) solution was developed for separation of polyvinyl chloride (PVC) and polyethylene terephthalate (PET) waste plastics. The floatability of PVC decreases with increasing of KMnO4 concentration, treatment time, temperature and stirring rate, while that of PET is unaffected. Fourier transform infrared (FT-IR) analysis confirms that mechanism of surface modification may be due to oxidization reactions occurred on PVC surface. The optimum conditions are KMnO4 concentration 1.25 mM/L, treatment time 50 min, temperature 60°C, stirring rate 300 r/min, frother concentration 17.5 g/L and flotation time 1 min. PVC and PET with different particle sizes were separated efficiently through two-stage flotation. Additionally, after ultrasonic assisted surface modification, separation of PVC and PET with different mass ratios was obtained efficiently through one-stage flotation. The purity and the recovery of the obtained products after flotation separation are up to 99.30% and 99.73%, respectively. A flotation process was designed for flotation separation of PVC and PET plastics combined with surface modification. This study provides technical insights into physical separation of plastic wastes for recycling industry.

  19. Ammonia modification for flotation separation of polycarbonate and polystyrene waste plastics.

    PubMed

    Wang, Chong-qing; Wang, Hui; Gu, Guo-hua; Lin, Qing-quan; Zhang, Ling-ling; Huang, Luo-luo; Zhao, Jun-yao

    2016-05-01

    A promising method, ammonia modification, was developed for flotation separation of polycarbonate (PC) and polystyrene (PS) waste plastics. Ammonia modification has little effect on flotation behavior of PS, while it changes significantly that of PC. The PC recovery in the floated product drops from 100% to 3.17% when modification time is 13min and then rises to 100% after longer modification. The mechanism of ammonia modification was studied by contact angle, and Fourier transform infrared (FT-IR) and X-ray photoelectron spectroscopy (XPS) measurements. Contact angle of PC indicates the decline of PC recovery in the floated product is ascribed to an increase in surface wettability. FT-IR and XPS spectra suggest that ammonia modification causes chemical reactions occurred on PC surface. Flotation behavior of ammonia-modified PC and PS was investigated with respect to flotation time, frother concentration and particle sizes. Flotation separation of PC and PS waste plastics was conducted based on the flotation behavior of single plastic. PC and PS mixtures with different particle sizes are separated efficiently, implying that the technology possesses superior applicability to particle sizes of plastics. The purity of PS and PC is up to 99.53% and 98.21%, respectively, and the recovery of PS and PC is larger than 92.06%. A reliable, cheap and effective process is proposed for separation of PC and PS waste plastics.

  20. Kinetic approach to the study of froth flotation applied to a lepidolite ore

    NASA Astrophysics Data System (ADS)

    Vieceli, Nathália; Durão, Fernando O.; Guimarães, Carlos; Nogueira, Carlos A.; Pereira, Manuel F. C.; Margarido, Fernanda

    2016-07-01

    The number of published studies related to the optimization of lithium extraction from low-grade ores has increased as the demand for lithium has grown. However, no study related to the kinetics of the concentration stage of lithium-containing minerals by froth flotation has yet been reported. To establish a factorial design of batch flotation experiments, we conducted a set of kinetic tests to determine the most selective alternative collector, define a range of pulp pH values, and estimate a near-optimum flotation time. Both collectors (Aeromine 3000C and Armeen 12D) provided the required flotation selectivity, although this selectivity was lost in the case of pulp pH values outside the range between 2 and 4. Cumulative mineral recovery curves were used to adjust a classical kinetic model that was modified with a non-negative parameter representing a delay time. The computation of the near-optimum flotation time as the maximizer of a separation efficiency (SE) function must be performed with caution. We instead propose to define the near-optimum flotation time as the time interval required to achieve 95%-99% of the maximum value of the SE function.