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Sample records for biological oxygen demand

  1. Estimation of Biological Oxygen Demand and Chemical Oxygen Demand for Combined Sewer Systems Using Synchronous Fluorescence Spectra

    Directory of Open Access Journals (Sweden)

    Dae-Hee Park

    2010-03-01

    Full Text Available Real-time monitoring of water quality for sewer system is required for efficient sewer network design because it provides information on the precise loading of pollutant to wastewater treatment facilities and the impact of loading on receiving water. In this study, synchronous fluorescence spectra and its first derivatives were investigated using a number of wastewater samples collected in sewer systems in urban and non-urban areas, and the optimum fluorescence feature was explored for the estimation of biochemical oxygen demand (BOD and chemical oxygen demand (COD concentrations of sewer samples. The temporal variations in BOD and COD showed a regular pattern for urban areas whereas they were relatively irregular for non-urban areas. Irrespective of the sewer pipes and the types of the areas, two distinct peaks were identified from the synchronous fluorescence spectra, which correspond to protein-like fluorescence (PLF and humic-like fluorescence (HLF, respectively. HLF in sewer samples appears to be associated with fluorescent whitening agents. Five fluorescence characteristics were selected from the synchronous spectra and the first-derivatives. Among the selected fluorescence indices, a peak in the PLF region (i.e., Index I showed the highest correlation coefficient with both BOD and COD. A multiple regression approach based on suspended solid (SS and Index I used to compensate for the contribution of SS to BOD and COD revealed an improvement in the estimation capability, showing good correlation coefficients of 0.92 and 0.94 for BOD and COD, respectively.

  2. Seasonal contribution of terrestrial organic matter and biological oxygen demand to the Baltic Sea from three contrasting river catchments

    DEFF Research Database (Denmark)

    Reader, H. E.; Stedmon, C. A.; Kritzberg, E. S.

    2014-01-01

    on the same order of magnitude for all three catchments. Biological oxygen demand (BOD) was used as a proxy for the lability of carbon in the system. The range of BOD values was similar for all three catchments, however, the ratio of BOD to DOC (an indication of the labile fraction) in Ume river was four...... times higher than in the southern two catchments. Total annual BOD loading to the Baltic Sea was twice as high in the northern catchment than in the two southern catchments. Lower winter temperatures and preservation of organic matter in the northern catchment combined with an intense spring flood help...

  3. High removal of chemical and biochemical oxygen demand from tequila vinasses by using physicochemical and biological methods.

    Science.gov (United States)

    Retes-Pruneda, Jose Luis; Davila-Vazquez, Gustavo; Medina-Ramírez, Iliana; Chavez-Vela, Norma Angelica; Lozano-Alvarez, Juan Antonio; Alatriste-Mondragon, Felipe; Jauregui-Rincon, Juan

    2014-08-01

    The goal of this research is to find a more effective treatment for tequila vinasses (TVs) with potential industrial application in order to comply with the Mexican environmental regulations. TVs are characterized by their high content of solids, high values of biochemical oxygen demand (BODs), chemical oxygen demand (COD), low pH and intense colour; thus, disposal of untreated TVs severely impacts the environment. Physicochemical and biological treatments, and a combination of both, were probed on the remediation of TVs. The use of alginate for the physicochemical treatment of TVs reduced BOD5 and COD values by 70.6% and 14.2%, respectively. Twenty white-rot fungi (WRF) strains were tested in TV-based solid media. Pleurotus ostreatus 7992 and Trametes trogii 8154 were selected due to their ability to grow on TV-based solid media. Ligninolytic enzymes' production was observed in liquid cultures of both fungi. Using the selected WRF for TVs' bioremediation, both COD and BOD5 were reduced by 88.7% and 89.7%, respectively. Applying sequential physicochemical and biological treatments, BOD5 and COD were reduced by 91.6% and 93.1%, respectively. Results showed that alginate and selected WRF have potential for the industrial treatment of TVs.

  4. Influence of biological oxygen demand degradation patterns on water-quality modeling for rivers running through urban areas.

    Science.gov (United States)

    Fan, Chihhao; Wang, Wei-Shen

    2008-10-01

    Water-quality modeling has been used as a support tool for water-resources management. The Streeter-Phelps (SP) equation is one often-used algorithm in river water-quality simulation because of its simplicity and ease in use. To characterize the river dissolved oxygen (DO) sag profile, it only considers that the first-order biological oxygen demand (BOD) degradation and atmospheric reaeration are the sink and source in a river, respectively. In the river water-quality calculation, the assumption may not always provide satisfactory simulation due to an inappropriate description of BOD degradation. In the study, various patterns of BOD degradation were combined with the oxygen reaeration to simulate the DO sag profile in a river. Different BOD degradation patterns used include the first-order decay, mixed second-order decay, and oxygen-inhibition decay. The results shows that the oxygen-inhibition SP equation calculates higher BOD and DO concentration, while the mixed second SP equation calculates the least among the three tested models. In river-water calculation of Keelung River, the SP and oxygen-inhibition SP equations calculate similar BOD and DO concentrations, and the mixed second SP equation calculates the least BOD and DO concentration. The pollution loading of BOD and atmospheric reaeration constant are the two important factors that have significant impacts on aqueous DO concentration. In the field application, it is suggested that the mixed second SP equation be employed in water-quality simulation when the monitoring data exhibits a faster trend in BOD decay. The oxygen-inhibition SP equation may calculate the water quality more accurately when BOD decay is slower.

  5. Sediment oxygen demand in eastern Kansas streams, 2014 and 2015

    Science.gov (United States)

    Foster, Guy M.; King, Lindsey R.; Graham, Jennifer L.

    2016-08-29

    Dissolved oxygen concentrations in streams are affected by physical, chemical, and biological factors in the water column and streambed, and are an important factor for the survival of aquatic organisms. Sediment oxygen demand (SOD) rates in Kansas streams are not well understood. During 2014 and 2015, the U.S. Geological Survey, in cooperation with the Kansas Department of Health and Environment, measured SOD at eight stream sites in eastern Kansas to quantify SOD rates and variability with respect to season, land use, and bottom-sediment characteristics. Sediment oxygen demand rates (SODT) ranged from 0.01 to 3.15 grams per square meter per day at the ambient temperature of the measurements. The summer mean SOD rate was 3.0-times larger than the late fall mean rate, likely because of increased biological activity at warm water temperatures. Given the substantial amount of variability in SOD rates possible within sites, heterogeneity of substrate type is an important consideration when designing SOD studies and interpreting the results. Sediment oxygen demand in eastern Kansas streams was correlated with land use and streambed-sediment characteristics, though the strength of relations varied seasonally. The small number of study sites precluded a more detailed analysis. The effect of basin land use and streambed sediment characteristics on SOD is currently (2016) not well understood, and there may be many contributing factors including basin influences on water quality that affect biogeochemical cycles and the biological communities supported by the stream.

  6. Methods for assessing biochemical oxygen demand (BOD): a review.

    Science.gov (United States)

    Jouanneau, S; Recoules, L; Durand, M J; Boukabache, A; Picot, V; Primault, Y; Lakel, A; Sengelin, M; Barillon, B; Thouand, G

    2014-02-01

    The Biochemical Oxygen Demand (BOD) is one of the most widely used criteria for water quality assessment. It provides information about the ready biodegradable fraction of the organic load in water. However, this analytical method is time-consuming (generally 5 days, BOD5), and the results may vary according to the laboratory (20%), primarily due to fluctuations in the microbial diversity of the inoculum used. Work performed during the two last decades has resulted in several technologies that are less time-consuming and more reliable. This review is devoted to the analysis of the technical features of the principal methods described in the literature in order to compare their performances (measuring window, reliability, robustness) and to identify the pros and the cons of each method.

  7. Sediment oxygen demand of wetlands in the oil sands region of northeastern Alberta

    International Nuclear Information System (INIS)

    Sediment oxygen demand (SOD) can significantly influence the dissolved oxygen concentrations in shallow water bodies. This study discussed the types of sediments used to reclaim wetlands and their influence on SOD, successional processes, and ecosystem trajectories. The study hypothesized that oil sands process material (OSPM) affected wetlands would support cyanobacterial biofilms as opposed to submergent macrophytes as a result of insufficient phosphorus levels. SOD was assessed by monitoring dissolved oxygen concentrations within domes placed on the sediment surface for a 3-hour period. Gas flux and composition analyses were used to quantify the biological SOD components. Chemical SOD components were then determined by subtraction. Concentrations of phosphorus bioavailable to the macrophytes were estimated using plant root simulator probes. The study showed that OSPM wetlands exhibited higher chemical SOD and SOD than reference wetlands, and supported benthic biofilms as opposed to the submergent macrophyte communities typically found in northeastern Alberta wetlands.

  8. Inhibitory effect of nitrobenzene on oxygen demand in lake sediments

    Institute of Scientific and Technical Information of China (English)

    Xiaohong Zhou; Xuying Wang; Hanchang Shi

    2012-01-01

    Nitrobenzene is an important raw material and product,which presents a heavy threat to the ecosystem.The potential impacts of nitrobenzene on sediment oxygen demand (SOD) were studied in lake sediment simulating reactors receiving relatively low inputs of nitrobenzene.Oxygen microprofiles were measured in these sediment reactors using microelectrodes.After an initial microprofile measurement as a control,nitrobenzene was added to the overlying water resulting in concentrations of 0,50,100,and 150 μg/L.Microprofiles were measured on day 1,2,4 and 7 following the addition of nitrobenzene.SODs were determined from the microprofiles using a reaction-diffusion model.Results showed that the SODs increased relative to the initial values measured in the pre-treatment period in reactors exposed to all nitrobenzene concentrations on day 1.However,the values decreased gradually on the following days,which eventually resulted in a 50% loss in SODs after 7 days of exposure to nitrobenzene in all reactors.In addition,the inhibition effect of nitrobenzene on SOD exhibited a weak relationship with its concentration.The microscopic observation and count of algae in the sediment showed that the exposure to nitrobenzene did not change the composition of algae greatly,however,it decreased the number of dominant algae species sharply after 7 days of exposure.These results suggested that nitrobenzene could significantly alter SOD in lakes,which could ultimately affect the pollutant recovery in aquatic-sediment systems.

  9. Chitosan on Reducing Chemical Oxygen Demands in Laundry Waste Water

    Directory of Open Access Journals (Sweden)

    Tri Joko

    2016-09-01

    Full Text Available Laundry liquid waste contains several chemical substances in detergent raw materials such as phosphate, surfactants, ammonia, and total suspended solids. The existence of detergent in high concentrations and exceeds the quality standards that have been estabilished in a body of water can lead to cases of enviromental pollution in the form of increased turbidity an Chemical Oxygen Demands (COD levels. Therefore in order to maintain and to ensure the availabillity of water in terms of quality, it requires coagulation-flocculation process to laundry liquid waste before discharging into water bodies. This study aims to determine the decrease of COD levels and turbidity level in laundry liquid waste using chitosan coagulant in “X” laundry, Tembalang District, Semarang. The research is a quasi experimental study with pretest-posttest with control group research design with 6 times replication. The total samples are 60 in wich 24 tested for the levels of turbidity and 6 controls. The test results of Kruskal-Wallis with significance p-value < 0,05 indicates that dosage variation (p=0,000 gives different levels of COD and dosage variation (p=0,000 provide 755,97 mg/l and the advantage levels of turbidity before treatment was 516,20 NTU. The optimum dosage of chitosan coagulant is on the dose of 200 mg/l with the effectiveness decrease of COD levels and turbidity levels on 72,67% an 98,67% respectively.

  10. Correlation between Biochemical Oxygen Demand and Chemical Oxygen Demand for Various Wastewater Treatment Plants in Egypt to Obtain the Biodegradability Indices

    OpenAIRE

    Khaled Zaher Abdallah; Gina Hammam

    2014-01-01

    Biochemical Oxygen Demand (BOD5) and Chemical Oxygen Demand (COD) are the most commonly used parameters for the characterization of wastewaters. Both of these parameters have advantages and disadvantages, and the choice usually depends on many factors such as the time period required to determine each one of them. It is essential to obtain a correlation between BOD5 and COD for various wastewater treatment plants, to help in the design and operation of these plants. In this paper, the biodegr...

  11. Oxygen saturations of medical inpatients in a Malawian hospital: cross-sectional study of oxygen supply and demand

    Directory of Open Access Journals (Sweden)

    Hywel-Gethin Tudur Evans

    2012-05-01

    Full Text Available Normal 0 false false false EN-GB JA X-NONE Oxygen is a World Health Organisation listed essential drug yet provision of oxygen in developing countries often fails to meet demand.  The aim of this study was to evaluate the need for supplementary oxygen against oxygen delivery capacity at a large teaching hospital in Malawi.  A cross‐sectional study of all adult medical inpatients and assessment of oxygen provision over a 24‐hour period was conducted.    144 patients were included in the study, 14 of whom met local and international criteria for oxygen therapy (oxygen saturations of <90%.  Four were receiving oxygen.  Of the 8 oxygen concentrators available, only 4 were functional.  In conclusion, we identified a need for oxygen that was greater than the supply.

  12. Southern Ocean biological impacts on global ocean oxygen

    Science.gov (United States)

    Keller, David P.; Kriest, Iris; Koeve, Wolfgang; Oschlies, Andreas

    2016-06-01

    Southern Ocean (SO) physical and biological processes are known to have a large impact on global biogeochemistry. However, the role that SO biology plays in determining ocean oxygen concentrations is not completely understood. These dynamics are investigated here by shutting off SO biology in two marine biogeochemical models. The results suggest that SO biological processes reduce the ocean's oxygen content, mainly in the deep ocean, by 14 to 19%. However, since these processes also trap nutrients that would otherwise be transported northward to fuel productivity and subsequent organic matter export, consumption, and the accompanying oxygen consumption in midlatitude to low-latitude waters, SO biology helps to maintain higher oxygen concentrations in these subsurface waters. Thereby, SO biology can influence the size of the tropical oxygen minimum zones. As a result of ocean circulation the link between SO biological processes and remote oxygen changes operates on decadal to centennial time scales.

  13. Watershed modeling of dissolved oxygen and biochemical oxygen demand using a hydrological simulation Fortran program.

    Science.gov (United States)

    Liu, Zhijun; Kieffer, Janna M; Kingery, William L; Huddleston, David H; Hossain, Faisal

    2007-11-01

    Several inland water bodies in the St. Louis Bay watershed have been identified as being potentially impaired due to low level of dissolved oxygen (DO). In order to calculate the total maximum daily loads (TMDL), a standard watershed model supported by U.S. Environmental Protection Agency, Hydrological Simulation Program Fortran (HSPF), was used to simulate water temperature, DO, and bio-chemical oxygen demand (BOD). Both point and non-point sources of BOD were included in watershed modeling. The developed model was calibrated at two time periods: 1978 to 1986 and 2000 to 2001 with simulated DO closely matched the observed data and captured the seasonal variations. The model represented the general trend and average condition of observed BOD. Water temperature and BOD decay are the major factors that affect DO simulation, whereas nutrient processes, including nitrification, denitrification, and phytoplankton cycle, have slight impacts. The calibrated water quality model provides a representative linkage between the sources of BOD and in-stream DO\\BOD concentrations. The developed input parameters in this research could be extended to similar coastal watersheds for TMDL determination and Best Management Practice (BMP) evaluation.

  14. Effects of arteriovenous fistulas on cardiac oxygen supply and demand

    NARCIS (Netherlands)

    Bos, W.J.W.; Zietse, R.; Wesseling, K.H.; Westerhof, N.

    1999-01-01

    Background. Arteriovenous (AV) fistulas used for hemodialysis access may affect cardiac load by increasing the preload while decreasing the afterload. In dogs, AV fistulas have also been shown to affect coronary perfusion negatively. We investigated the net effect of AV fistulas on cardiac oxygen su

  15. COMPARISON OF METHODS TO DETERMINE OXYGEN DEMAND FOR BIOREMEDIATION OF A FUEL CONTAMINATED AQUIFER

    Science.gov (United States)

    Four analytical methods were compared for estimating concentrations of fuel contaminants in subsurface core samples. The methods were total organic carbon, chemical oxygen demand, oil and grease, and a solvent extraction of fuel hydrocarbons combined with a gas chromatographic te...

  16. Determination of Biochemical Oxygen Demand of Area Waters: A Bioassay Procedure for Environmental Monitoring

    Science.gov (United States)

    Riehl, Matthew

    2012-01-01

    A graphical method for determining the 5-day biochemical oxygen demand (BOD5) for a body of water is described. In this bioassay, students collect a sample of water from a designated site, transport it to the laboratory, and evaluate the amount of oxygen consumed by naturally occurring bacteria during a 5-day incubation period. An accuracy check,…

  17. Sediment oxygen demand in a constructed lake in south-eastern Australia.

    Science.gov (United States)

    Wallace, Todd A; Ganf, George G; Brookes, Justin D

    2016-10-01

    The occurrence of hypoxia and anoxia in aquatic environments is increasing, driven by changes in land use and alteration of flow regimes. Periods of low oxygen impact biodiversity and water quality for both recreational and consumptive users. We use the Torrens Lake as a case study to assess pelagic, benthic and resuspended sediment oxygen demand, and the release of sediment bound phosphorus to determine the relative role of internal and external loading on water quality in a lake within a heavily urbanised landscape. Our results indicate temporal shifts in the dominant oxygen demanding process in the lake. During periods of no-inflow, sediment oxygen demand is the dominant process; during periods of inflow resulting from wet weather conditions, pelagic rather than sediment derived oxygen demand becomes the governing process. The inlet end of the lake is a depositional zone for stormwater borne sediments. Resuspended sediments at the inlet end of the lake exert a higher oxygen demand than those from the outlet, and represent a larger pool of potentially mobile phosphorus compared to sediments at the outlet end of the lake. However, external rather than internal loading appears to be the dominant driver of water quality in this lake. PMID:27420167

  18. Application of Ozone and Oxygen to Reduce Chemical Oxygen Demand and Hydrogen Sulfide from a Recovered Paper Processing Plant

    Directory of Open Access Journals (Sweden)

    Patricia A. Terry

    2010-01-01

    Full Text Available A pilot study was performed at the Fox River Fiber recovered paper processing company in DePere, Wisconsin, to determine the extent to which injection of oxygen and ozone could reduce the high chemical oxygen demand, COD, in the effluent and the effectiveness of the ozone/oxygen stream in suppressing production of hydrogen sulfide gas in downstream sewage lines. Adaptive Ozone Solutions, LLC, supplied the oxygen/ozone generation and injection system. Samples were analyzed both before and after oxygen/ozone injection. Hydrogen sulfide gas was continuously monitored at sewer stations downstream of Fox River Fiber. Results showed that with a very short contact time, effluent COD was reduced by over 15%. A simple kinetic model predicts that a contact time of fewer than 30 minutes could reduce COD by as much as 60%. In addition, downstream hydrogen sulfide gas production in the sewage mains was also better controlled, such that costly Bioxide applications could be reduced.

  19. In situ global method for measurement of oxygen demand and mass transfer

    Energy Technology Data Exchange (ETDEWEB)

    Klasson, K.T. [Oak Ridge National Lab., TN (United States). Chemical Technology Div.; Lundbaeck, K.M.O.; Clausen, E.C.; Gaddy, J.L. [Univ. of Arkansas, Fayetteville, AR (United States). Dept. of Chemical Engineering

    1997-05-01

    Two aerobic microorganisms, Saccharomycopsis lipolytica and Brevibacterium lactofermentum, have been used in a study of mass transfer and oxygen uptake from a global perspective using a closed gas system. Oxygen concentrations in the gas and liquid were followed using oxygen electrodes, and the results allowed for easy calculation of in situ oxygen transport. The cell yields on oxygen for S. lipolytica and B. lactofermentum were 1.01 and 1.53 g/g respectively. The mass transfer coefficient was estimated as 10 h{sup {minus}1} at 500 rpm for both fermentations. The advantages with this method are noticeable since the use of model systems may be avoided, and the in situ measurements of oxygen demand assure reliable data for scale-up.

  20. Analytical applications of microbial fuel cells. Part I: Biochemical oxygen demand.

    Science.gov (United States)

    Abrevaya, Ximena C; Sacco, Natalia J; Bonetto, Maria C; Hilding-Ohlsson, Astrid; Cortón, Eduardo

    2015-01-15

    Microbial fuel cells (MFCs) are bio-electrochemical devices, where usually the anode (but sometimes the cathode, or both) contains microorganisms able to generate and sustain an electrochemical gradient which is used typically to generate electrical power. In the more studied set-up, the anode contains heterotrophic bacteria in anaerobic conditions, capable to oxidize organic molecules releasing protons and electrons, as well as other by-products. Released protons could reach the cathode (through a membrane or not) whereas electrons travel across an external circuit originating an easily measurable direct current flow. MFCs have been proposed fundamentally as electric power producing devices or more recently as hydrogen producing devices. Here we will review the still incipient development of analytical uses of MFCs or related devices or set-ups, in the light of a non-restrictive MFC definition, as promising tools to asset water quality or other measurable parameters. An introduction to biological based analytical methods, including bioassays and biosensors, as well as MFCs design and operating principles, will also be included. Besides, the use of MFCs as biochemical oxygen demand sensors (perhaps the main analytical application of MFCs) is discussed. In a companion review (Part 2), other new analytical applications are reviewed used for toxicity sensors, metabolic sensors, life detectors, and other proposed applications. PMID:24856922

  1. IN-SITU DETERMINATION OF SEDIMENT OXYGEN DEMAND IN CULTIVATION PONDS

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    This paper presents a method for in-situ determining sediment oxygen demand (SOD) in cultivation pond. This method based on sediment surface structure, temperature, and other determining conditions like those in shrimp cultivation environments, overcomes defects of old methods and provides more accurate estimation of SOD's effect on dissolved oxygen in culture waters. Our experiment shows that the sediment surface structure and temperature had important effect on SOD in culture water. Different SOD values were derived from different parts of oxygen consumption curves of sediment, because the curves were not linear. According to the oxygen consumption curves of sediment and saturated DO in culture water, it was thought more suitable to calculate SOD with dissolved oxygen reduction from 5.0 to 2.0 mg/l. This method to determine the SOD of shrimp ponds yielded satisfactory results.

  2. Geostatistical Modeling of the Spatial Distribution of Sediment Oxygen Demand Within a Coastal Plain Blackwater Watershed

    Science.gov (United States)

    Blackwater streams of the Georgia Coastal Plain are often listed as impaired due to chronically low DO levels. Previous research has shown that high sediment oxygen demand (SOD) values, a hypothesized cause of lowered DO within these waters, are significantly positively correlated with TOC within th...

  3. Ultimate biochemical oxygen demand in semi-intensively managed shrimp pond waters

    Science.gov (United States)

    Three independent studies were conducted to quantified ultimate biochemical oxygen demand (UBOD) and the corresponding decomposition rate constant for production pond (average 21.5 ha each) waters and effluents on six semi-intensively managed marine shrimp (Litopenaeus vannamei) farms in Honduras. S...

  4. Alternative aircraft anti-icing formulations with reduced aquatic toxicity and biochemical oxygen demand

    Science.gov (United States)

    Gold, Harris; Joback, Kevin; Geis, Steven; Bowman, George; Mericas, Dean; Corsi, Steven R.; Ferguson, Lee

    2010-01-01

    The current research was conducted to identify alternative aircraft and pavement deicer and anti-icer formulations with improved environmental characteristics compared to currently used commercial products (2007). The environmental characteristics of primary concern are the biochemical oxygen demand (BOD) and aquatic toxicity of the fully formulated products. Except when the distinction among products is necessary for clarity, “deicer” will refer to aircraft-deicing fluids (ADFs), aircraft anti-icing fluids (AAFs), and pavementdeicing materials (PDMs).

  5. Evaluation of Three Flow Injection Analysis Methods for the Determination of Chemical Oxygen Demand

    OpenAIRE

    Korenaga, Takashi; Moriwake, Tosio; Takahashi, Teruo

    1984-01-01

    Three methods for determining chemical oxygen demand (COD) by means of flow injection analysis (FIA) with potassium permanganate, potassium dichromate, or cerium(IV) sulfate as oxidant, developed in this laboratory, are described from the point of view of their operating properties. The permanganate method is the most sensitive and common, but forms manganese(IV) oxide precipitate which blocks the FIA lines and connectors. Addition of phosphoric acid in the reagent system is, however, effecti...

  6. Myocardial Ischemia: Lack of Coronary Blood Flow or Myocardial Oxygen Supply/Demand Imbalance?

    Science.gov (United States)

    Heusch, Gerd

    2016-07-01

    Regional myocardial blood flow and contractile function in ischemic myocardium are well matched, and there is no evidence for an oxygen supply/demand imbalance. Thus, myocardial ischemia is lack of coronary blood flow with electric, functional, metabolic, and structural consequences for the myocardium. All therapeutic interventions must aim to improve blood flow to ischemic myocardium as much and as quickly as possible. PMID:27390331

  7. Oxygen demand during mineralization of aquatic macrophytes from an oxbow lake.

    Science.gov (United States)

    Bianchini Jr, I; Cunha-Santino, M B; Peret, A M

    2008-02-01

    This study presents a kinetic model of oxygen consumption during aerobic decomposition of detritus from seven species of aquatic macrophytes: Cabomba furcata, Cyperus giganteus, Egeria najas, Eichhornia azurea, Salvinia auriculata, Oxycaryum cubense and Utricularia breviscapa. The aquatic macrophytes were collected from Oleo Lagoon situated in the Mogi-Guaçu river floodplain (SP, Brazil). Mineralization experiments were performed using the closed bottles method. Incubations made with lake water and macrophytes detritus (500 mL and 200 mg.L(-1) (DM), respectively) were maintained during 45 to 80 days at 20 degrees C under aerobic conditions and darkness. Carbon content of leachates from aquatic macrophytes detritus and dissolved oxygen concentrations were analyzed. From the results we concluded that: i) the decomposition constants differ among macrophytes; these differences being dependent primarily on molecular and elemental composition of detritus and ii) in the short term, most of the oxygen demand seems to depend upon the demineralization of the dissolved carbon fraction. PMID:18470379

  8. Non-steady response of BOD biosensor for the determination of biochemical oxygen demand in wastewater.

    Science.gov (United States)

    Velling, Siiri; Mashirin, Alexey; Hellat, Karin; Tenno, Toomas

    2011-01-01

    A biochemical oxygen demand (BOD) biosensor for effective and expeditious BOD(7) estimations was constructed and the non-steady phase of the output signal was extensively studied. The modelling approach introduced allows response curve reconstruction and a curve fitting procedure of good quality, resulting in parameters indicating the relationship between response and organic substrate concentration and stability properties of the BOD biosensor. Also, the immobilization matrixes of different thicknesses were characterized to determine their suitability for bio-sensing measurements in non-stationary conditions, as well as for the determination of the mechanical durability of the BOD biosensor in time. The non-steady response of the experimental output of the BOD biosensor was fitted according to the developed model that enables to determine the stability of the biosensor output and dependency on biodegradable organic substrate concentration. The calibration range of the studied BOD biosensor in OECD synthetic wastewater was 15-110 mg O(2) L(-1). Repeatability tests showed relative standard deviation (RSD) values of 2.8% and 5.8% for the parameter τ(d), characterizing the transient output of the amperometric oxygen sensor in time, and τ(s), describing the dependency of the transient response of the BOD biosensor on organic substrate concentration, respectively. BOD biosensor experiments for the evaluation of the biochemical oxygen demand of easily degradable and refractory municipal wastewater showed good concurrence with traditional BOD(7) analysis.

  9. Rapid Determination of the Chemical Oxygen Demand of Water Using a Thermal Biosensor

    OpenAIRE

    Na Yao; Jinqi Wang; Yikai Zhou

    2014-01-01

    In this paper we describe a thermal biosensor with a flow injection analysis system for the determination of the chemical oxygen demand (COD) of water samples. Glucose solutions of different concentrations and actual water samples were tested, and their COD values were determined by measuring the heat generated when the samples passed through a column containing periodic acid. The biosensor exhibited a large linear range (5 to 3000 mg/L) and a low detection limit (1.84 mg/L). It could tolerat...

  10. Total, chemical, and biological oxygen consumption of the sediments in the Ziya River watershed, China.

    Science.gov (United States)

    Rong, Nan; Shan, Baoqing

    2016-07-01

    Sediment oxygen demand (SOD) is a critical dissolved oxygen (DO) sink in many rivers. Understanding the relative contributions of the biological and chemical components of SOD would improve our knowledge of the potential environmental harm SOD could cause and allow appropriate management systems to be developed. A various inhibitors addition technique was conducted to measure the total, chemical, and biological SOD of sediment samples from 13 sites in the Ziya River watershed, a severely polluted and anoxic river system in the north of China. The results showed that the major component of SOD was chemical SOD due to iron predominate. The ferrous SOD accounted for 21.6-78.9 % of the total SOD and 33.26-96.79 % of the chemical SOD. Biological SOD represented 41.13 % of the overall SOD averagely. Sulfide SOD accounted for 1.78-45.71 % of the total SOD and it was the secondary predominate of the chemical SOD. Manganous SOD accounted for 1.2-16.6 % of the total SOD and it was insignificant at many sites. Only four kinds of benthos were collected in the Ziya River watershed, resulting from the low DO concentration in the sediment surface due to SOD. This study would be helpful for understanding and preventing the potential sediment oxygen depletion during river restoration.

  11. Benthic Oxygen Demand in Three Former Salt Ponds Adjacent to South San Francisco Bay, California

    Science.gov (United States)

    Topping, Brent R.; Kuwabara, James S.; Athearn, Nicole D.; Takekawa, John Y.; Parcheso, Francis; Henderson, Kathleen D.; Piotter, Sara

    2009-01-01

    Sampling trips were coordinated in the second half of 2008 to examine the interstitial water in the sediment and the overlying bottom waters of three shallow (average depth 2 meters). The water column at all deployment sites was monitored with dataloggers for ancillary water-quality parameters (including dissolved oxygen, salinity, specific conductance, temperature, and pH) to facilitate the interpretation of benthic-flux results. Calculated diffusive benthic flux of dissolved (0.2-micron filtered) oxygen was consistently negative (that is, drawn from the water column into the sediment) and ranged between -0.5 x 10-6 and -37 x 10-6 micromoles per square centimeter per second (site averages depicted in table 2). Assuming pond areas of 1.0, 1.4, and 2.3 square kilometers for ponds A16, A14, and A3W, respectively, this converts to an oxygen mass flux into the ponds' sediment ranging from -1 to -72 kilograms per day. Diffusive oxygen flux into the benthos (listed as negative) was lowest in pond A14 (-0.5 x 10-6 to -1.8 x 10-6 micromoles per square centimeter per second) compared with diffusive flux estimates for ponds A16 and A3W (site averages -26 x 10-6 to -35 x 10-6 and -34 x 10-6 to -37 x 10-6 micromoles per square centimeter per second, respectively). These initial diffusive-flux estimates are of the order of magnitude of those measured in the South Bay using core-incubation experiments (Topping and others, 2004), which include bioturbation and bioirrigation effects. Estimates of benthic oxygen demand reported herein, based on molecular diffusion, serve as conservative estimates of benthic flux because solute transport across the sediment-water interface can be enhanced by multidisciplinary processes including bioturbation, bioirrigation, ground-water advection, and wind resuspension (Kuwabara and others, 2009).

  12. Ethanol Demand in United States Production of Oxygenate-limited Gasoline

    Energy Technology Data Exchange (ETDEWEB)

    Hadder, G.R.

    2000-08-16

    Ethanol competes with methyl tertiary butyl ether (MTBE) to satisfy oxygen, octane, and volume requirements of certain gasolines. However, MTBE has water quality problems that may create significant market opportunities for ethanol. Oak Ridge National Laboratory (ORNL) has used its Refinery Yield Model to estimate ethanol demand in gasolines with restricted use of MTBE. Reduction of the use of MTBE would increase the costs of gasoline production and possibly reduce the gasoline output of U.S. refineries. The potential gasoline supply problems of an MTBE ban could be mitigated by allowing a modest 3 vol percent MTBE in all gasoline. In the U.S. East and Gulf Coast gasoline producing regions, the 3 vol percent MTBE option results in costs that are 40 percent less than an MTBE ban. In the U.S. Midwest gasoline producing region, with already high use of ethanol, an MTBE ban has minimal effect on ethanol demand unless gasoline producers in other regions bid away the local supply of ethanol. The ethanol/MTBE issue gained momentum in March 2000 when the Clinton Administration announced that it would ask Congress to amend the Clean Air Act to provide the authority to significantly reduce or eliminate the use of MTBE; to ensure that air quality gains are not diminished as MTBE use is reduced; and to replace the existing oxygenate requirement in the Clean Air Act with a renewable fuel standard for all gasoline. Premises for the ORNL study are consistent with the Administration announcement, and the ethanol demand curve estimates of this study can be used to evaluate the impact of the Administration principles and related policy initiatives.

  13. Estimation of Biological Oxygen Demand and Chemical Oxygen Demand for Combined Sewer Systems Using Synchronous Fluorescence Spectra

    OpenAIRE

    Dae-Hee Park; Tae-Hwan Lee; Bo-Mi Lee; Jin Hur

    2010-01-01

    Real-time monitoring of water quality for sewer system is required for efficient sewer network design because it provides information on the precise loading of pollutant to wastewater treatment facilities and the impact of loading on receiving water. In this study, synchronous fluorescence spectra and its first derivatives were investigated using a number of wastewater samples collected in sewer systems in urban and non-urban areas, and the optimum fluorescence feature was explored for the es...

  14. Performance of on-site pilot static granular bed reactor (SGBR) for treating dairy processing wastewater and chemical oxygen demand balance modeling under different operational conditions.

    Science.gov (United States)

    Oh, Jin Hwan; Park, Jaeyoung; Ellis, Timothy G

    2015-02-01

    The performance and operational stability of a pilot-scale static granular bed reactor (SGBR) for the treatment of dairy processing wastewater were investigated under a wide range of organic and hydraulic loading rates and temperature conditions. The SGBR achieved average chemical oxygen demand (COD), biological oxygen demand (BOD), and total suspended solids (TSS)-removal efficiencies higher than 90% even at high loading rates up to 7.3 kg COD/m(3)/day, with an hydraulic retention time (HRT) of 9 h, and at low temperatures of 11 °C. The average methane yield of 0.26 L CH4/g COD(removed) was possibly affected by a high fraction of particulate COD and operation at low temperatures. The COD mass balance indicated that soluble COD was responsible for most of the methane production. The reactor showed the capacity of the methanogens to maintain their activity and withstand organic and hydraulic shock loads.

  15. Study on Determination of Chemical Oxygen Demand in Water with Ion Chromatography

    Institute of Scientific and Technical Information of China (English)

    ZHANG Zhong-Hai; DING Hong-Chun; FANG Yan-Ju; XIAN Yue-Zhong; JIN Li-Tong

    2007-01-01

    A new method for determining chemical oxygen demand (COD) value in water using ion chromatography coupled with nano TiO2-K2S2O8 co-existing system was described. The photocatalytic oxidation system and nano TiO2-K2S2O8 co-existing system could degrade the organic compounds in water. All sulfur-containing species in the reactive solution were eventually transformed to sulfate which could be determined by conductivity detector in ion chromatography. The change of conductivity of sulfate was proportional to COD value. The optimal experimental conditions and the mechanism of the detection were discussed. The application range was 10.0-300.0 mg·L -1 and the lowest limit of detection was 3.5 mg·L -1. It was considered that the value obtained could be reliably correlated with the COD value obtained using the conventional methods.

  16. Soft Computing of Biochemical Oxygen Demand Using an Improved T-S Fuzzy Neural Network☆

    Institute of Scientific and Technical Information of China (English)

    Junfei Qiao; Wei Li; Honggui Han

    2014-01-01

    It is difficult to measure the online values of biochemical oxygen demand (BOD) due to the characteristics of nonlinear dynamics, large lag and uncertainty in wastewater treatment process. In this paper, based on the knowledge representation ability and learning capability, an improved T–S fuzzy neural network (TSFNN) is in-troduced to predict BOD values by the soft computing method. In this improved TSFNN, a K-means clustering is used to initialize the structure of TSFNN, including the number of fuzzy rules and parameters of membership function. For training TSFNN, a gradient descent method with the momentum item is used to adjust antecedent parameters and consequent parameters. This improved TSFNN is applied to predict the BOD values in effluent of the wastewater treatment process. The simulation results show that the TSFNN with K-means clustering algorithm can measure the BOD values accurately. The algorithm presents better approximation performance than some other methods.

  17. Chemical Oxygen Demand of Seawater Determined with a Microwave Heating Method

    Institute of Scientific and Technical Information of China (English)

    LIU Li; JI Hongwei; LIU Ying; XIN Huizhen

    2005-01-01

    This paper investigates a microwave heating method for the determination of chemical oxygen demand (COD) in seawater. The influences of microwave-power, heating time and standard substances on the results are studied. Using the proposed method, we analyzed the glucose standard solution, the coefficient of variation being less than 2%. Compared with the traditional electric stove heating method, the results of F-test and T-test showed that there was no significant difference between the two methods, but the microwave method had slightly higher precision and reproducibility than the electric stove method. With the microwave heating method, several seawater samples from Jiaozhou Bay and the South Yellow Sea were also analyzed. The recovery was between 97.5% and 104.3%. This new method has the advantages of shortening the heating time, improving the working efficiency and having simple operation and therefore can be used to analyze the COD in seawater.

  18. Improvement of the analysis of the biochemical oxygen demand (BOD) of Mediterranean seawater by seeding control.

    Science.gov (United States)

    Simon, F Xavier; Penru, Ywann; Guastalli, Andrea R; Llorens, Joan; Baig, Sylvie

    2011-07-15

    Biochemical oxygen demand (BOD) is a useful parameter for assessing the biodegradability of dissolved organic matter in water. At the same time, this parameter is used to evaluate the efficiency with which certain processes remove biodegradable natural organic matter (NOM). However, the values of BOD in seawater are very low (around 2 mgO(2)L(-1)) and the methods used for its analysis are poorly developed. The increasing attention given to seawater desalination in the Mediterranean environment, and related phenomena such as reverse osmosis membrane biofouling, have stimulated interest in seawater BOD close to the Spanish coast. In this study the BOD analysis protocol was refined by introduction of a new step in which a critical quantity of autochthonous microorganisms, measured as adenosine triphosphate, is added. For the samples analyzed, this improvement allowed us to obtain reliable and replicable BOD measurements, standardized with solutions of glucose-glutamic acid and acetate. After 7 days of analysis duration, more than 80% of ultimate BOD is achieved, which in the case of easily biodegradable compounds represents nearly a 60% of the theoretical oxygen demand. BOD(7) obtained from the Mediterranean Sea found to be 2.0±0.3 mgO(2)L(-1) but this value decreased with seawater storage time due to the rapid consumption of labile compounds. No significant differences were found between two samples points located on the Spanish coast, since their organic matter content was similar. Finally, the determination of seawater BOD without the use of inoculum may lead to an underestimation of BOD. PMID:21645736

  19. Improvement of the analysis of the biochemical oxygen demand (BOD) of Mediterranean seawater by seeding control.

    Science.gov (United States)

    Simon, F Xavier; Penru, Ywann; Guastalli, Andrea R; Llorens, Joan; Baig, Sylvie

    2011-07-15

    Biochemical oxygen demand (BOD) is a useful parameter for assessing the biodegradability of dissolved organic matter in water. At the same time, this parameter is used to evaluate the efficiency with which certain processes remove biodegradable natural organic matter (NOM). However, the values of BOD in seawater are very low (around 2 mgO(2)L(-1)) and the methods used for its analysis are poorly developed. The increasing attention given to seawater desalination in the Mediterranean environment, and related phenomena such as reverse osmosis membrane biofouling, have stimulated interest in seawater BOD close to the Spanish coast. In this study the BOD analysis protocol was refined by introduction of a new step in which a critical quantity of autochthonous microorganisms, measured as adenosine triphosphate, is added. For the samples analyzed, this improvement allowed us to obtain reliable and replicable BOD measurements, standardized with solutions of glucose-glutamic acid and acetate. After 7 days of analysis duration, more than 80% of ultimate BOD is achieved, which in the case of easily biodegradable compounds represents nearly a 60% of the theoretical oxygen demand. BOD(7) obtained from the Mediterranean Sea found to be 2.0±0.3 mgO(2)L(-1) but this value decreased with seawater storage time due to the rapid consumption of labile compounds. No significant differences were found between two samples points located on the Spanish coast, since their organic matter content was similar. Finally, the determination of seawater BOD without the use of inoculum may lead to an underestimation of BOD.

  20. Oxygen demand of aircraft and airfield pavement deicers and alternative freezing point depressants

    Science.gov (United States)

    Corsi, Steven R.; Mericas, Dean; Bowman, George

    2012-01-01

    Aircraft and pavement deicing formulations and other potential freezing point depressants were tested for biochemical oxygen demand (BOD) and chemical oxygen demand (COD). Propylene glycol-based aircraft deicers exhibited greater BOD5 than ethylene glycol-based aircraft deicers, and ethylene glycol-based products had lower degradation rates than propylene glycol-based products. Sodium formate pavement deicers had lower COD than acetate-based pavement deicers. The BOD and COD results for acetate-based pavement deicers (PDMs) were consistently lower than those for aircraft deicers, but degradation rates were greater in the acetate-based PDM than in aircraft deicers. In a 40-day testing of aircraft and pavement deicers, BOD results at 20°C (standard) were consistently greater than the results from 5°C (low) tests. The degree of difference between standard and low temperature BOD results varied among tested products. Freshwater BOD test results were not substantially different from marine water tests at 20°C, but glycols degraded slower in marine water than in fresh water for low temperature tests. Acetate-based products had greater percentage degradation than glycols at both temperatures. An additive component of the sodium formate pavement deicer exhibited toxicity to the microorganisms, so BOD testing did not work properly for this formulation. BOD testing of alternative freezing point depressants worked well for some, there was little response for some, and for others there was a lag in response while microorganisms acclimated to the freezing point depressant as a food source. Where the traditional BOD5 test performed adequately, values ranged from 251 to 1,580 g/kg. Where the modified test performed adequately, values of BOD28 ranged from 242 to 1,540 g/kg.

  1. Peroxone mineralization of chemical oxygen demand for direct potable water reuse: Kinetics and process control.

    Science.gov (United States)

    Wu, Tingting; Englehardt, James D

    2015-04-15

    Mineralization of organics in secondary effluent by the peroxone process was studied at a direct potable water reuse research treatment system serving an occupied four-bedroom, four bath university residence hall apartment. Organic concentrations were measured as chemical oxygen demand (COD) and kinetic runs were monitored at varying O3/H2O2 dosages and ratios. COD degradation could be accurately described as the parallel pseudo-1st order decay of rapidly and slowly-oxidizable fractions, and effluent COD was reduced to below the detection limit (water, and a relationship is proposed and demonstrated to estimate the pseudo-first order rate constant for design purposes. At this O3/H2O2 mass ratio, ORP and dissolved ozone were found to be useful process control indicators for monitoring COD mineralization in secondary effluent. Moreover, an average second order rate constant for OH oxidation of secondary effluent organics (measured as MCOD) was found to be 1.24 × 10(7) ± 0.64 × 10(7) M(-1) S(-1). The electric energy demand of the peroxone process is estimated at 1.73-2.49 kW h electric energy for removal of one log COD in 1 m(3) secondary effluent, comparable to the energy required for desalination of medium strength seawater. Advantages/disadvantages of the two processes for municipal wastewater reuse are discussed.

  2. Peroxone mineralization of chemical oxygen demand for direct potable water reuse: Kinetics and process control.

    Science.gov (United States)

    Wu, Tingting; Englehardt, James D

    2015-04-15

    Mineralization of organics in secondary effluent by the peroxone process was studied at a direct potable water reuse research treatment system serving an occupied four-bedroom, four bath university residence hall apartment. Organic concentrations were measured as chemical oxygen demand (COD) and kinetic runs were monitored at varying O3/H2O2 dosages and ratios. COD degradation could be accurately described as the parallel pseudo-1st order decay of rapidly and slowly-oxidizable fractions, and effluent COD was reduced to below the detection limit (process control indicators for monitoring COD mineralization in secondary effluent. Moreover, an average second order rate constant for OH oxidation of secondary effluent organics (measured as MCOD) was found to be 1.24 × 10(7) ± 0.64 × 10(7) M(-1) S(-1). The electric energy demand of the peroxone process is estimated at 1.73-2.49 kW h electric energy for removal of one log COD in 1 m(3) secondary effluent, comparable to the energy required for desalination of medium strength seawater. Advantages/disadvantages of the two processes for municipal wastewater reuse are discussed. PMID:25704155

  3. Protozoan biomass relation to nutrient and chemical oxygen demand removal in activated sludge mixed liquor.

    Science.gov (United States)

    Akpor, Oghenerobor B; Momba, Maggy N B; Okonkwo, Jonathan O

    2008-08-01

    The relationship between biomass concentration to nutrient and chemical oxygen demand (COD) removal in mixed liquor supplemented with sodium acetate was investigated, using three protozoan isolates and three different initial biomass concentrations (10(1), 10(2) and 10(3) cells/mL). The study was carried out in a shaking flask environment at a shaking speed of 100 rpm for 96 h at 25 degrees C. Aliquot samples were taken periodically for the determination of phosphate, nitrate, COD and dissolved oxygen, using standard methods. The results revealed remarkable phosphate removal of 82-95% at biomass concentration of 10(3)cells/mL. A high nitrate removal of over 87% was observed at all initial biomass concentration in mixed liquor. There was an observed COD increase of over 50% in mixed liquor in at the end of 96-h incubation and this was irrespective of initial biomass concentration used for inoculation. The study shows the trend in nutrient and COD removal at different biomass concentrations of the test isolates in mixed liquor.

  4. An integrated mathematical model for chemical oxygen demand (COD) removal in moving bed biofilm reactors (MBBR) including predation and hydrolysis.

    Science.gov (United States)

    Revilla, Marta; Galán, Berta; Viguri, Javier R

    2016-07-01

    An integrated mathematical model is proposed for modelling a moving bed biofilm reactor (MBBR) for removal of chemical oxygen demand (COD) under aerobic conditions. The composite model combines the following: (i) a one-dimensional biofilm model, (ii) a bulk liquid model, and (iii) biological processes in the bulk liquid and biofilm considering the interactions among autotrophic, heterotrophic and predator microorganisms. Depending on the values for the soluble biodegradable COD loading rate (SCLR), the model takes into account a) the hydrolysis of slowly biodegradable compounds in the bulk liquid, and b) the growth of predator microorganisms in the bulk liquid and in the biofilm. The integration of the model and the SCLR allows a general description of the behaviour of COD removal by the MBBR under various conditions. The model is applied for two in-series MBBR wastewater plant from an integrated cellulose and viscose production and accurately describes the experimental concentrations of COD, total suspended solids (TSS), nitrogen and phosphorous obtained during 14 months working at different SCLRs and nutrient dosages. The representation of the microorganism group distribution in the biofilm and in the bulk liquid allow for verification of the presence of predator microorganisms in the second reactor under some operational conditions.

  5. An integrated mathematical model for chemical oxygen demand (COD) removal in moving bed biofilm reactors (MBBR) including predation and hydrolysis.

    Science.gov (United States)

    Revilla, Marta; Galán, Berta; Viguri, Javier R

    2016-07-01

    An integrated mathematical model is proposed for modelling a moving bed biofilm reactor (MBBR) for removal of chemical oxygen demand (COD) under aerobic conditions. The composite model combines the following: (i) a one-dimensional biofilm model, (ii) a bulk liquid model, and (iii) biological processes in the bulk liquid and biofilm considering the interactions among autotrophic, heterotrophic and predator microorganisms. Depending on the values for the soluble biodegradable COD loading rate (SCLR), the model takes into account a) the hydrolysis of slowly biodegradable compounds in the bulk liquid, and b) the growth of predator microorganisms in the bulk liquid and in the biofilm. The integration of the model and the SCLR allows a general description of the behaviour of COD removal by the MBBR under various conditions. The model is applied for two in-series MBBR wastewater plant from an integrated cellulose and viscose production and accurately describes the experimental concentrations of COD, total suspended solids (TSS), nitrogen and phosphorous obtained during 14 months working at different SCLRs and nutrient dosages. The representation of the microorganism group distribution in the biofilm and in the bulk liquid allow for verification of the presence of predator microorganisms in the second reactor under some operational conditions. PMID:27085154

  6. Development and characterization of microbial biosensors for evaluating low biochemical oxygen demand in rivers.

    Science.gov (United States)

    Chee, Gab-Joo

    2013-12-15

    Five microorganisms were used to construct a biosensor for the evaluation of low biochemical oxygen demand (BOD) in rivers. Characterization and comparison of BOD biosensors were performed using two standard solutions: glucose and glutamic acid (GGA) and artificial wastewater (AWW). Pseudomonas putida SG10 demonstrated the best response when using AWW. Trichosporon cutaneum IFO10466, however, had an extremely poor response. When evaluating the biosensor response to each component of AWW, all of the microorganisms except T. cutaneum displayed the highest response to tannic acid. In a comparison of the two standard solutions for all the microorganisms, the biosensor responses of GGA were approximately three times higher than those of AWW were. In the BOD determination of environmental samples, the biosensor BOD values evaluated using AWW were slightly lower or equivalent to BOD5 values, whereas the biosensor BOD values evaluated using GGA were considerably lower. These results suggest that GGA is suitable for the detection of high BOD in industrial wastewaters and factory effluents, while AWW is suitable for the detection of low BOD in rivers. PMID:24209354

  7. A portable photoelectrochemical probe for rapid determination of chemical oxygen demand in wastewaters.

    Science.gov (United States)

    Zhang, Shanqing; Li, Lihong; Zhao, Huijun

    2009-10-15

    A photoelectrochemical probe for rapid determination of chemical oxygen demand (COD) is developed using a nanostructured mixed-phase TiO2 photoanode, namely PeCOD probe. A UV-LED light source and a USB mircroelectrochemical station are powered and controlled by a laptop computer, which makes the probe portable for onsite COD analyses. The photoelectrochemical measurement of COD was optimized in terms of light intensity, applied bias, and pH. Under the optimized conditions, the net steady state currents originated from the oxidation of organic compounds were found to be directly proportional to COD concentrations. A practical detection limit of 0.2 ppm COD and a linear range of 0-120 ppm COD were achieved. The analytical method using the portable PeCOD probe has the advantages of being rapid, low cost, robust, user-friendly, and environmental friendly. It has been successfully applied to determine the COD values of the synthetic samples consisting of potassium hydrogen phthalate, D-glucose, glutamic acid, glutaric acid, succinic acid, and malonic acid, and real samples from various industries, such as bakery, oil and grease manufacturer, poultry, hotel, fine food factory, and fresh food producer, commercial bread manufacturer. Excellent agreement between the proposed method and the conventional COD method (dichromate) was achieved. PMID:19921898

  8. A Novel Biosensor for the Rapid Determination of Biochemical Oxygen Demand

    Institute of Scientific and Technical Information of China (English)

    JIN-SONG CHEN; LI-SHENG ZHANG; JIAN-LONG WANG

    2007-01-01

    Objective To investigate the function of a novel biosensor used for the rapid determination of biochemical oxygen demand (BOD) which is developed by our research group based on suspended immobilized microbial cell system in a completely mixed determining chamber as a substitute of the traditional membrane system. Methods Activated sludge was immobilized by PVA gel and used as a bio-sensing element. The novel biosensor was used to measure the short time BOD value and the conventional cultivation method was used for BOD5 measurement. Results A linear relationship was observed for the difference between the current and the concentration of glucose-glutamic acid (GGA) solution below 200mg/L with a correlation coefficient of 0.995. The optimal response of the sensor was obtained at pH 7.0 and 30℃. The sensor response was within 15 min and was reproducible within ±5% of the mean in a series of eight samples containing 75 mg/L BOD using standard GGA solution. The novel sensor response was found to be fairly constant over a period of 0days, with ±5% fluctuations. Conclusion A relatively good agreement is found between BOD estimated by the novel BOD biosensor and that determined by the conventional 5-day BOD method. This novel BOD biosensor has good sensitivity, stability and reproducibility.

  9. Chemical oxygen demand reduction in coffee wastewater through chemical flocculation and advanced oxidation processes

    Institute of Scientific and Technical Information of China (English)

    ZAYAS Pérez Teresa; GEISSLER Gunther; HERNANDEZ Fernando

    2007-01-01

    The removal of the natural organic matter present in coffee processing wastewater through chemical coagulation-flocculatio and advanced oxidation processes(AOP)had been studied.The effectiveness of the removal of natural organic matter using commercial flocculants and UV/H202,UVO3 and UV/H-H202/O3 processes was determined under acidic conditions.For each of these processes,different operational conditions were explored to optimize the treatment efficiency of the coffee wastewater.Coffee wastewater is characterized by a high chemical oxygen demand(COD)and low total suspended solids.The outcomes of coffee wastewater reeatment using coagulation-flocculation and photodegradation processes were assessed in terms of reduction of COD,color,and turbidity.It was found that a reductiOn in COD of 67%could be realized when the coffee wastewater was treated by chemical coagulation-flocculatlon witll lime and coagulant T-1.When coffee wastewater was treated by coagulation-flocculation in combination with UV/H202,a COD reduction of 86%was achieved,although only after prolonged UV irradiation.Of the three advanced oxidation processes considered,UV/H202,uv/03 and UV/H202/03,we found that the treatment with UV/H2O2/O3 was the most effective,with an efficiency of color,turbidity and further COD removal of 87%,when applied to the flocculated coffee wastewater.

  10. WO3/W Nanopores Sensor for Chemical Oxygen Demand (COD Determination under Visible Light

    Directory of Open Access Journals (Sweden)

    Xuejin Li

    2014-06-01

    Full Text Available A sensor of a WO3 nanopores electrode combined with a thin layer reactor was proposed to develop a Chemical Oxygen Demand (COD determination method and solve the problem that the COD values are inaccurately determined by the standard method. The visible spectrum, e.g., 420 nm, could be used as light source in the sensor we developed, which represents a breakthrough by limiting of UV light source in the photoelectrocatalysis process. The operation conditions were optimized in this work, and the results showed that taking NaNO3 solution at the concentration of 2.5 mol·L−1 as electrolyte under the light intensity of 214 μW·cm−2 and applied bias of 2.5 V, the proposed method is accurate and well reproducible, even in a wide range of pH values. Furthermore, the COD values obtained by the WO3 sensor were fitted well with the theoretical COD value in the range of 3–60 mg·L−1 with a limit value of 1 mg·L−1, which reveals that the proposed sensor may be a practical device for monitoring and controlling surface water quality as well as slightly polluted water.

  11. Influence of Chemical Oxygen Demand Concentrations on Anaerobi Ammonium Oxidation by Granular Sludge From EGSB Reactor

    Institute of Scientific and Technical Information of China (English)

    JING KANG; JIAN-LONG WANG

    2006-01-01

    Objective To investigate the effect of chemical oxygen demand (COD) concentrations on the anaerobic ammonium oxidation (ANAMMOX). Methods An Expanded Granular Sludge Bed (EGSB) reactor was used to cultivate the granular sludge and to perform the ANAMMOX reaction in the bench scale experiment. NH4+-N and NO2--N were measured by usingcolorimetric method. NO3--N was analyzed by using the UV spectrophotometric method. COD measurement was based on digestion with potassium dichromate in concentrated sulphuric acid. Results When the COD concentrations in the reactors were 0 mg/L, 200 mg/L, 350 mg/L, and 550 mg/L, respectively, the NH4+-N removal efficiency was 12.5%, 14.2%, 14.3%, and 23.7%; the removal amount of NO2--N was almost the same; the nitrate removal efficiency was 16.8%, 94.5%, 86.6%, and 84.2% and TN removal efficiency was 16.3%, 50.7%, 46.9%, and 50.4%, moreover, the COD removal efficiency concentrations have a significant influence on anaerobic ammonium oxidation by granular sludge.

  12. Chemical oxygen demand reduction in coffee wastewater through chemical flocculation and advanced oxidation processes.

    Science.gov (United States)

    Zayas Pérez, Teresa; Geissler, Gunther; Hernandez, Fernando

    2007-01-01

    The removal of the natural organic matter present in coffee processing wastewater through chemical coagulation-flocculation and advanced oxidation processes (AOP) had been studied. The effectiveness of the removal of natural organic matter using commercial flocculants and UV/H2O2, UV/O3 and UV/H2O2/O3 processes was determined under acidic conditions. For each of these processes, different operational conditions were explored to optimize the treatment efficiency of the coffee wastewater. Coffee wastewater is characterized by a high chemical oxygen demand (COD) and low total suspended solids. The outcomes of coffee wastewater treatment using coagulation-flocculation and photodegradation processes were assessed in terms of reduction of COD, color, and turbidity. It was found that a reduction in COD of 67% could be realized when the coffee wastewater was treated by chemical coagulation-flocculation with lime and coagulant T-1. When coffee wastewater was treated by coagulation-flocculation in combination with UV/H2O2, a COD reduction of 86% was achieved, although only after prolonged UV irradiation. Of the three advanced oxidation processes considered, UV/H2O2, UV/O3 and UV/H2O2/O3, we found that the treatment with UV/H2O2/O3 was the most effective, with an efficiency of color, turbidity and further COD removal of 87%, when applied to the flocculated coffee wastewater. PMID:17918591

  13. Rapid Determination of the Chemical Oxygen Demand of Water Using a Thermal Biosensor

    Directory of Open Access Journals (Sweden)

    Na Yao

    2014-06-01

    Full Text Available In this paper we describe a thermal biosensor with a flow injection analysis system for the determination of the chemical oxygen demand (COD of water samples. Glucose solutions of different concentrations and actual water samples were tested, and their COD values were determined by measuring the heat generated when the samples passed through a column containing periodic acid. The biosensor exhibited a large linear range (5 to 3000 mg/L and a low detection limit (1.84 mg/L. It could tolerate the presence of chloride ions in concentrations of 0.015 M without requiring a masking agent. The sensor was successfully used for detecting the COD values of actual samples. The COD values of water samples from various sources were correlated with those obtained by the standard dichromate method; the linear regression coefficient was found to be 0.996. The sensor is environmentally friendly, economical, and highly stable, and exhibits good reproducibility and accuracy. In addition, its response time is short, and there is no danger of hazardous emissions or external contamination. Finally, the samples to be tested do not have to be pretreated. These results suggest that the biosensor is suitable for the continuous monitoring of the COD values of actual wastewater samples.

  14. Development and characterization of microbial biosensors for evaluating low biochemical oxygen demand in rivers.

    Science.gov (United States)

    Chee, Gab-Joo

    2013-12-15

    Five microorganisms were used to construct a biosensor for the evaluation of low biochemical oxygen demand (BOD) in rivers. Characterization and comparison of BOD biosensors were performed using two standard solutions: glucose and glutamic acid (GGA) and artificial wastewater (AWW). Pseudomonas putida SG10 demonstrated the best response when using AWW. Trichosporon cutaneum IFO10466, however, had an extremely poor response. When evaluating the biosensor response to each component of AWW, all of the microorganisms except T. cutaneum displayed the highest response to tannic acid. In a comparison of the two standard solutions for all the microorganisms, the biosensor responses of GGA were approximately three times higher than those of AWW were. In the BOD determination of environmental samples, the biosensor BOD values evaluated using AWW were slightly lower or equivalent to BOD5 values, whereas the biosensor BOD values evaluated using GGA were considerably lower. These results suggest that GGA is suitable for the detection of high BOD in industrial wastewaters and factory effluents, while AWW is suitable for the detection of low BOD in rivers.

  15. Estimation of Biochemical Oxygen Demand Based on Dissolved Organic Carbon, UV Absorption, and Fluorescence Measurements

    Directory of Open Access Journals (Sweden)

    Jihyun Kwak

    2013-01-01

    Full Text Available Determination of 5-d biochemical oxygen demand (BOD5 is the most commonly practiced test to assess the water quality of surface waters and the waste loading. However, BOD5 is not a good parameter for the control of water or wastewater treatment processes because of its long test period. It is very difficult to produce consistent and reliable BOD5 results without using careful laboratory quality control practices. This study was performed to develop software sensors to predict the BOD5 of river water and wastewater. The software sensors were based on the multiple regression analysis using the dissolved organic carbon (DOC concentration, UV light absorbance at 254 nm, and synchronous fluorescence spectra. River water samples and wastewater treatment plant (WWTP effluents were collected at 1-hour interval to evaluate the feasibility of the software sensors. In short, the software sensors developed in this study could well predict the BOD5 of river water (r=0.78 and for the WWTP effluent (r=0.90.

  16. Compensatory vasodilatation during hypoxic exercise: mechanisms responsible for matching oxygen supply to demand

    Science.gov (United States)

    Casey, Darren P; Joyner, Michael J

    2012-01-01

    Hypoxia can have profound influences on the circulation. In humans, acute exposure to moderate hypoxia has been demonstrated to result in vasodilatation in the coronary, cerebral, splanchnic and skeletal muscle vascular beds. The combination of submaximal exercise and hypoxia produces a ‘compensatory’ vasodilatation and augmented blood flow in contracting skeletal muscles relative to the same level of exercise under normoxic conditions. This augmented vasodilatation exceeds that predicted by a simple sum of the individual dilator responses to hypoxia alone and normoxic exercise. Additionally, this enhanced hypoxic exercise hyperaemia is proportional to the hypoxia-induced fall in arterial oxygen (O2) content, thus preserving muscle O2 delivery and ensuring it is matched to demand. Several vasodilator pathways have been proposed and examined as likely regulators of skeletal muscle blood flow in response to changes in arterial O2 content. The purpose of this review is to put into context the present evidence regarding mechanisms responsible for the compensatory vasodilatation observed during hypoxic exercise in humans. Along these lines, this review will highlight the interactions between various local metabolic and endothelial derived substances that influence vascular tone during hypoxic exercise. PMID:22988134

  17. Environmental capacity of chemical oxygen demand in the Bohai Sea: modeling and calculation

    Institute of Scientific and Technical Information of China (English)

    ZHAO Xixi; WANG Xiulin; SHI Xiaoyong; LI Keqiang; DING Dongsheng

    2011-01-01

    A three-dimensional advection-diffusion model coupled with the degradation process is established for describing the transport of chemical oxygen demand (COD). Comparison of the simulated distribution of COD at the surface in the Bohai Sea in August, 2001 with field observations, shows that the model simulates the dataset reasonably well. The Laizhou Bay, Bohai Bay, and Liaodong Bay were contaminated heavily near shore. Based on the optimal discharge flux method, the Environmental Capacity (EC) and allocated capacities of COD in the Bohai Sea are calculated. For seawater of Grades I to IV of the Chinese National Standard, the ECs of COD in the Bohai Sea were 77×104t/a, 116×l04t/a, 154×l04t/a and 193×104t/a, respectively. The Huanghe (Yellow) River pollutant discharge accounted for the largest percentage of COD at 14.3%, followed by that of from the Liugu River (11.5%), and other nine local rivers below 10%. The COD level in 2005 was worse than that of Grade II seawater and was beyond the environmental capacity. In average, 35% COD reduction is called to meet the standard of Grade I seawater.

  18. Photocatalytic Reactive Oxygen Species Formation by Semiconductor-Metal Hybrid Nanoparticles. Toward Light-Induced Modulation of Biological Processes.

    Science.gov (United States)

    Waiskopf, Nir; Ben-Shahar, Yuval; Galchenko, Michael; Carmel, Inbal; Moshitzky, Gilli; Soreq, Hermona; Banin, Uri

    2016-07-13

    Semiconductor-metal hybrid nanoparticles manifest efficient light-induced spatial charge separation at the semiconductor-metal interface, as demonstrated by their use for hydrogen generation via water splitting. Here, we pioneer a study of their functionality as efficient photocatalysts for the formation of reactive oxygen species. We observed enhanced photocatalytic activity forming hydrogen peroxide, superoxide, and hydroxyl radicals upon light excitation, which was significantly larger than that of the semiconductor nanocrystals, attributed to the charge separation and the catalytic function of the metal tip. We used this photocatalytic functionality for modulating the enzymatic activity of horseradish peroxidase as a model system, demonstrating the potential use of hybrid nanoparticles as active agents for controlling biological processes through illumination. The capability to produce reactive oxygen species by illumination on-demand enhances the available peroxidase-based tools for research and opens the path for studying biological processes at high spatiotemporal resolution, laying the foundation for developing novel therapeutic approaches. PMID:27224678

  19. On-Demand Targeting: Investigating Biology with Proximity-Directed Chemistry.

    Science.gov (United States)

    Long, Marcus J C; Poganik, Jesse R; Aye, Yimon

    2016-03-23

    Proximity enhancement is a central chemical tenet underpinning an exciting suite of small-molecule toolsets that have allowed us to unravel many biological complexities. The leitmotif of this opus is "tethering"-a strategy in which a multifunctional small molecule serves as a template to bring proteins/biomolecules together. Scaffolding approaches have been powerfully applied to control diverse biological outcomes such as protein-protein association, protein stability, activity, and improve imaging capabilities. A new twist on this strategy has recently appeared, in which the small-molecule probe is engineered to unleash controlled amounts of reactive chemical signals within the microenvironment of a target protein. Modification of a specific target elicits a precisely timed and spatially controlled gain-of-function (or dominant loss-of-function) signaling response. Presented herein is a unique personal outlook conceptualizing the powerful proximity-enhanced chemical biology toolsets into two paradigms: "multifunctional scaffolding" versus "on-demand targeting". By addressing the latest advances and challenges in the established yet constantly evolving multifunctional scaffolding strategies as well as in the emerging on-demand precision targeting (and related) systems, this Perspective is aimed at choosing when it is best to employ each of the two strategies, with an emphasis toward further promoting novel applications and discoveries stemming from these innovative chemical biology platforms.

  20. On-Demand Targeting: Investigating Biology with Proximity-Directed Chemistry.

    Science.gov (United States)

    Long, Marcus J C; Poganik, Jesse R; Aye, Yimon

    2016-03-23

    Proximity enhancement is a central chemical tenet underpinning an exciting suite of small-molecule toolsets that have allowed us to unravel many biological complexities. The leitmotif of this opus is "tethering"-a strategy in which a multifunctional small molecule serves as a template to bring proteins/biomolecules together. Scaffolding approaches have been powerfully applied to control diverse biological outcomes such as protein-protein association, protein stability, activity, and improve imaging capabilities. A new twist on this strategy has recently appeared, in which the small-molecule probe is engineered to unleash controlled amounts of reactive chemical signals within the microenvironment of a target protein. Modification of a specific target elicits a precisely timed and spatially controlled gain-of-function (or dominant loss-of-function) signaling response. Presented herein is a unique personal outlook conceptualizing the powerful proximity-enhanced chemical biology toolsets into two paradigms: "multifunctional scaffolding" versus "on-demand targeting". By addressing the latest advances and challenges in the established yet constantly evolving multifunctional scaffolding strategies as well as in the emerging on-demand precision targeting (and related) systems, this Perspective is aimed at choosing when it is best to employ each of the two strategies, with an emphasis toward further promoting novel applications and discoveries stemming from these innovative chemical biology platforms. PMID:26907082

  1. On-Demand Targeting: Investigating Biology with Proximity-Directed Chemistry

    Science.gov (United States)

    2016-01-01

    Proximity enhancement is a central chemical tenet underpinning an exciting suite of small-molecule toolsets that have allowed us to unravel many biological complexities. The leitmotif of this opus is “tethering”—a strategy in which a multifunctional small molecule serves as a template to bring proteins/biomolecules together. Scaffolding approaches have been powerfully applied to control diverse biological outcomes such as protein–protein association, protein stability, activity, and improve imaging capabilities. A new twist on this strategy has recently appeared, in which the small-molecule probe is engineered to unleash controlled amounts of reactive chemical signals within the microenvironment of a target protein. Modification of a specific target elicits a precisely timed and spatially controlled gain-of-function (or dominant loss-of-function) signaling response. Presented herein is a unique personal outlook conceptualizing the powerful proximity-enhanced chemical biology toolsets into two paradigms: “multifunctional scaffolding” versus “on-demand targeting”. By addressing the latest advances and challenges in the established yet constantly evolving multifunctional scaffolding strategies as well as in the emerging on-demand precision targeting (and related) systems, this Perspective is aimed at choosing when it is best to employ each of the two strategies, with an emphasis toward further promoting novel applications and discoveries stemming from these innovative chemical biology platforms. PMID:26907082

  2. The Effect of H2O2 Interference in Chemical Oxygen Demand Removal During Advanced Oxidation Processes

    Directory of Open Access Journals (Sweden)

    Afsane Chavoshani

    2016-07-01

    Full Text Available Hydrogen peroxide (H2O2 is one of the most oxidants in AOPs. By H2O2 dissociation, hydroxyl radical with a standard oxidation potential of 2.7 is produced. It is reported H2O¬ residual in AOPs has been led to interference in chemical oxygen demand (COD test and it is able to hinder biological treatment of waste water. Because of high mixed organic load of solid waste leachate, this study investigated effect of H2O2 interference in COD removal from solid waste leachate. In this study effect of parameters such as pH (3,5,7,12, H2O2 dose (0.01, 0.02, 0.03, 0.04 mol l-1, and time reaction(10,20,30,40,50,60 min evaluated on H2O2 interference in COD removal from solid waste leachate. Optimum pH and concentration were 3 and 0.02 moll-1 respectively. With increasing reaction time, COD removal was increased. The false COD obtained between 0.49mg per 1mg of H2O2. The average of COD removal by H2O2 for 60 min was 6.57%. Also reaction rate of this process was 0.0029 min-1. The presence of H2O2 leads to overestimation of COD values after reaction time because it consumes the oxidation agent. The extent of H2O2 interference in COD analysis was proportional to the remaining H2O2 concentration at the moment of sampling.

  3. Validation of MIKE 11 Model Simulated Data for Biochemical and Chemical Oxygen Demands Transport

    Directory of Open Access Journals (Sweden)

    Mahdieh Eisakhani

    2012-01-01

    Full Text Available Problem statement: The aim of the study was to model the discharge, biochemical and chemical oxygen demands (BOD and COD loads in each cross section of Bertam River in Cameron Highlands, Malaysia. Cameron Highlands form the headwater catchment for two major rivers of the lowlands; Pahang River and Perak River. On the other hand, Cameron Highlands is undergoing rapid development as a popular tourist destination and an area exploited for growing of temperature vegetables, fruits and flowers. It is also a mountainous area subjected to torrential tropical showers. The condition of Bertam River as one of the main rivers in Cameron Highlands has degraded over the years in terms of water pollution and river environment. Approach: Therefore, MIKE 11 a one-dimensional hydrodynamic simulation program was utilized to model stream flow transport and water quality processing in the river system. The model was used to generate the river outflow and simulate BOD and COD concentrations in each cross section of Bertam River. Hydrodynamic Module (HD which uses an implicit, finite difference solver was applied to calculate water level and flow for the river. Next, Rainfall-Runoff Module (RR which is include unit hydrograph method and lumped conceptual continuous hydrological model was used to combine the meteorological data of the study area to MIKE 11 simulation system. Finally, Advection-Dispersion Module (AD was used for transported BOD and COD concentrations calculation. Results: Water quality results show the BOD5 varies from 1-2 mg L-1 during pre-monsoon and from 4-10 mg L-1 during post-monsoon. The COD between 39-49 mg L-1 was observed during High Water Flow (HWF. Much lower concentration was detected during Average Water Flow (AWF which was between 10-14 mg L-1. The comparative analysis between measured and simulated data showed that MIKE 11 is able to predict sufficiently accurate BOD and COD loads at the catchment outlet especially during AWF. Conclusion

  4. Efficiency of horizontal roughing filter in removing nitrate, phosphate and chemical oxygen demand from effluent of waste stabilization pond

    OpenAIRE

    Seyed Mostafa Khezri; Gharib Majidi; Hossein Jafari Mansoorian; Mohsen Ansari; Farideh Atabi; Taha Tohidi Mogaddam; Nahid Rashtchi

    2015-01-01

    Background: The effective size of the end grain of horizontal roughing filters (HRFs) is larger than 2 mm. This study aimed to examine the efficiency of HRFs in removing nitrate, phosphate, and chemical oxygen demand (COD) from effluent of a wastewater stabilization pond. Methods: This experimental study was conducted in 2013. The pilot project was transferred to the Karaj wastewater treatment plant (stabilization pond), and the installation, equipping, and start-up of the system began usi...

  5. Enhanced response of microbial fuel cell using sulfonated poly ether ether ketone membrane as a biochemical oxygen demand sensor.

    Science.gov (United States)

    Ayyaru, Sivasankaran; Dharmalingam, Sangeetha

    2014-03-25

    The present study is focused on the development of single chamber microbial fuel cell (SCMFC) using sulfonated poly ether ether ketone (SPEEK) membrane to determine the biochemical oxygen demand (BOD) matter present in artificial wastewater (AW). The biosensor produces a good linear relationship with the BOD concentration up to 650 ppm when using artificial wastewater. This sensing range was 62.5% higher than that of Nafion(®). The most serious problem in using MFC as a BOD sensor is the oxygen diffusion into the anode compartment, which consumes electrons in the anode compartment, thereby reducing the coulomb yield and reducing the electrical signal from the MFC. SPEEK exhibited one order lesser oxygen permeability than Nafion(®), resulting in low internal resistance and substrate loss, thus improving the sensing range of BOD. The system was further improved by making a double membrane electrode assembly (MEA) with an increased electrode surface area which provide high surface area for electrically active bacteria.

  6. Characterization of water quality and simulation of temperature, nutrients, biochemical oxygen demand, and dissolved oxygen in the Wateree River, South Carolina, 1996-98

    Science.gov (United States)

    Feaster, Toby D.; Conrads, Paul A.

    2000-01-01

    In May 1996, the U.S. Geological Survey entered into a cooperative agreement with the Kershaw County Water and Sewer Authority to characterize and simulate the water quality in the Wateree River, South Carolina. Longitudinal profiling of dissolved-oxygen concentrations during the spring and summer of 1996 revealed dissolved-oxygen minimums occurring upstream from the point-source discharges. The mean dissolved-oxygen decrease upstream from the effluent discharges was 2.0 milligrams per liter, and the decrease downstream from the effluent discharges was 0.2 milligram per liter. Several theories were investigated to obtain an improved understanding of the dissolved-oxygen dynamics in the upper Wateree River. Data suggest that the dissolved-oxygen concentration decrease is associated with elevated levels of oxygen-consuming nutrients and metals that are flowing into the Wateree River from Lake Wateree. Analysis of long-term streamflow and water-quality data collected at two U.S. Geological Survey gaging stations suggests that no strong correlation exists between streamflow and dissolved-oxygen concentrations in the Wateree River. However, a strong negative correlation does exist between dissolved-oxygen concentrations and water temperature. Analysis of data from six South Carolina Department of Health and Environmental Control monitoring stations for 1980.95 revealed decreasing trends in ammonia nitrogen at all stations where data were available and decreasing trends in 5-day biochemical oxygen demand at three river stations. The influence of various hydrologic and point-source loading conditions on dissolved-oxygen concentrations in the Wateree River were determined by using results from water-quality simulations by the Branched Lagrangian Transport Model. The effects of five tributaries and four point-source discharges were included in the model. Data collected during two synoptic water-quality samplings on June 23.25 and August 11.13, 1997, were used to calibrate

  7. Removal of color and chemical oxygen demand using a coupled coagulation-electrocoagulation-ozone treatment of industrial wastewater that contains offset printing dyes

    International Nuclear Information System (INIS)

    Industrial offset printing processes generate wastewater with highly colored obtaining values of 5 x 106Pt-Co units and great values of chemical oxygen demand (COD) 5.3 x 10-5 mg L-1. Thus, conventional technologies such as biologicals treatment fail in reaching the discharge limits. In this research, a sequential treatment was applied: coagulation with aluminum hydroxychloride (AHC), electrocoagulation with Al anodes and finally ozonation. Optimal conditions are found when adding 20 mg L-1 AHC, followed by electrocoagulation at 4 A for 50 min, and finally alkaline ozonation for 15 min, resulting in an overall color removal of 99.99% color and 99.35 COD. The sludge generated by the coagulation process was analyzed by scanning electron microscopy and energy dispersive X-ray (EDX) microanalysis. (Author)

  8. Removal of color and chemical oxygen demand using a coupled coagulation-electrocoagulation-ozone treatment of industrial wastewater that contains offset printing dyes

    Energy Technology Data Exchange (ETDEWEB)

    Roa M, G.; Barrera D, C.; Balderas H, P.; Zaldumbide O, F. [Centro Conjunto de Investigacion en Quimica Sustentable UAEM-UNAM, Km 14.5 Carretera Toluca-Atlacomulco, 50200 San Cayetano-Toluca, Estado de Mexico (Mexico); Reyes P, H. [Universidad Autonoma del Estado de Mexico, Facultad de Quimica, Paseo Colon y Paseo Tollocan s/n, 50120 Toluca, Estado de Mexico (Mexico); Bilyeu, B., E-mail: groam@uaemex.mx [Xavier University of Louisiana, Department of Chemistry, 1 Drexel Drive, New Orleans, LA 70125 (United States)

    2014-07-01

    Industrial offset printing processes generate wastewater with highly colored obtaining values of 5 x 10{sup 6}Pt-Co units and great values of chemical oxygen demand (COD) 5.3 x 10{sup -5} mg L{sup -1}. Thus, conventional technologies such as biologicals treatment fail in reaching the discharge limits. In this research, a sequential treatment was applied: coagulation with aluminum hydroxychloride (AHC), electrocoagulation with Al anodes and finally ozonation. Optimal conditions are found when adding 20 mg L{sup -1} AHC, followed by electrocoagulation at 4 A for 50 min, and finally alkaline ozonation for 15 min, resulting in an overall color removal of 99.99% color and 99.35 COD. The sludge generated by the coagulation process was analyzed by scanning electron microscopy and energy dispersive X-ray (EDX) microanalysis. (Author)

  9. Control of voluntary feed intake in fish: a role for dietary oxygen demand in Nile tilapia (Oreochromis niloticus) fed diets with different macronutrient profiles.

    Science.gov (United States)

    Saravanan, S; Geurden, I; Figueiredo-Silva, A C; Kaushik, S J; Haidar, M N; Verreth, J A J; Schrama, J W

    2012-10-28

    It has been hypothesised that, at non-limiting water oxygen conditions, voluntary feed intake (FI) in fish is limited by the maximal physiological capacity of oxygen use (i.e. an 'oxystatic control of FI in fish'). This implies that fish will adjust FI when fed diets differing in oxygen demand, resulting in identical oxygen consumption. Therefore, FI, digestible energy (DE) intake, energy balance and oxygen consumption were monitored at non-limiting water oxygen conditions in Nile tilapia fed diets with contrasting macronutrient composition. Diets were formulated in a 2 × 2 factorial design in order to create contrasts in oxygen demand: two ratios of digestible protein (DP):DE ('high' v. 'low'); and a contrast in the type of non-protein energy source ('starch' v. 'fat'). Triplicate groups of tilapia were fed each diet twice daily to satiation for 48 d. FI (g DM/kg(0·8) per d) was significantly lower (9·5%) in tilapia fed the starch diets relative to the fat diets. The DP:DE ratio affected DE intakes (P demand of these diets. Indeed, DE intakes of fish showed an inverse linear relationship with dietary oxygen demand (DOD; R 2 0·81, P theory), oxygen consumption of fish was identical among three out of the four diets. Altogether, these results demonstrate the involvement of metabolic oxygen use and DOD in the control of FI in tilapia.

  10. Enhanced response of microbial fuel cell using sulfonated poly ether ether ketone membrane as a biochemical oxygen demand sensor

    Energy Technology Data Exchange (ETDEWEB)

    Ayyaru, Sivasankaran; Dharmalingam, Sangeetha, E-mail: sangeetha@annauniv.edu

    2014-03-01

    Graphical abstract: - Highlights: • Sulfonated poly ether ether ketone (SPEEK) membrane in SCMFC used to determine the BOD. • The biosensor produces a good linear relationship with the BOD concentration up to 650 ppm. • This sensing range was 62.5% higher than that of Nafion{sup ®}. • SPEEK exhibited one order lesser oxygen permeability than Nafion{sup ®}. • Nafion{sup ®} shows high anodic internal resistance (67 Ω) than the SPEEK (39 Ω). - Abstract: The present study is focused on the development of single chamber microbial fuel cell (SCMFC) using sulfonated poly ether ether ketone (SPEEK) membrane to determine the biochemical oxygen demand (BOD) matter present in artificial wastewater (AW). The biosensor produces a good linear relationship with the BOD concentration up to 650 ppm when using artificial wastewater. This sensing range was 62.5% higher than that of Nafion{sup ®}. The most serious problem in using MFC as a BOD sensor is the oxygen diffusion into the anode compartment, which consumes electrons in the anode compartment, thereby reducing the coulomb yield and reducing the electrical signal from the MFC. SPEEK exhibited one order lesser oxygen permeability than Nafion{sup ®}, resulting in low internal resistance and substrate loss, thus improving the sensing range of BOD. The system was further improved by making a double membrane electrode assembly (MEA) with an increased electrode surface area which provide high surface area for electrically active bacteria.

  11. Discriminating between west-side sources of nutrients and organiccarbon contributing to algal growth and oxygen demand in the San JoaquinRiver

    Energy Technology Data Exchange (ETDEWEB)

    Wstringfellow@lbl.gov

    2002-07-24

    The purpose of this study was to investigate the Salt and Mud Slough tributaries as sources of oxygen demanding materials entering the San Joaquin River (SJR). Mud Slough and Salt Slough are the main drainage arteries of the Grasslands Watershed, a 370,000-acre area west of the SJR, covering portions of Merced and Fresno Counties. Although these tributaries of the SJR are typically classified as agricultural, they are also heavily influenced by Federal, State and private wetlands. The majority of the surface water used for both irrigation and wetland management in the Grassland Watershed is imported from the Sacramento-San Joaquin Delta through the Delta-Mendota Canal. In this study, they measured algal biomass (as chlorophyll a), organic carbon, ammonia, biochemical oxygen demand (BOD), and other measures of water quality in drainage from both agricultural and wetland sources at key points in the Salt Slough and Mud Slough tributaries. This report includes the data collected between June 16th and October 4th, 2001. The objective of the study was to compare agricultural and wetland drainage in the Grasslands Watershed and to determine the relative importance of each return flow source to the concentration and mass loading of oxygen demanding materials entering the SJR. Additionally, they compared the quality of water exiting our study area to water entering our study area. This study has demonstrated that Salt and Mud Sloughs both contribute significant amounts of oxygen demand to the SJR. Together, these tributaries could account for 35% of the oxygen demand observed below their confluence with the SJR. This study has characterized the sources of oxygen demanding materials entering Mud Slough and evaluated the oxygen demand conditions in Salt Slough. Salt Slough was found to be the dominant source of oxygen demand load in the study area, because of the higher flows in this tributary. The origins of oxygen demand in Salt Slough still remain largely uninvestigated

  12. Cryptic photosynthesis, Extrasolar planetary oxygen without a surface biological signature

    CERN Document Server

    Cockell, C S; Raven, J A

    2008-01-01

    On the Earth, photosynthetic organisms are responsible for the production of nearly all of the oxygen in the atmosphere. On the land, vegetation reflects in the visible, leading to a red edge which has been proposed as a biosignature for life on extrasolar planets. However, in many regions of the Earth, and particularly where surface conditions are extreme, for example in hot and cold deserts, photosynthetic organisms can be driven into and under substrates where light is still sufficient for photosynthesis. These communities exhibit no detectable surface spectral signature. The same is true of the assemblages of photosynthetic organisms at more than a few meters depth in water bodies. These communities are widespread and dominate local photosynthetic productivity. We review known cryptic photosynthetic communities and their productivity. We use a radiative transfer model to link geomicrobiology with observational astronomy and calculate the disk-averaged spectra and identify detectable features that would re...

  13. A sensitive and environmentally friendly method for determination of chemical oxygen demand using NiCu alloy electrode

    International Nuclear Information System (INIS)

    Highlights: ► NiCu alloy modified electrode is used to determine chemical oxygen demand. ► NiCu alloy can effectively oxidize a wide range of organic compounds. ► Compared with the existing methods, this method has wide linear range and high sensitivity. ► The results are linearly correlated to those by the classic dichromate method. ► The proposed method has an excellent practical perspective in water quality control. - Abstract: A simple, sensitive and environmentally friendly method was developed for determination of chemical oxygen demand (COD) by cyclic voltammetry using nickel–copper (NiCu) alloy electrode. The structure and the electrochemical behavior of NiCu alloy electrode were investigated by atomic force microscope, energy dispersive X-ray spectrometer, and cyclic voltammetry, respectively. The results indicated that NiCu alloy film with high quality was stably modified on the surface of glass carbon (GC) electrode, which could effectively oxidize a wide range of organic compounds. Subsequently, the parameters affecting the analytical performance were investigated, including pH, dissolved oxygen and concentration of chloride ion. Under optimized conditions, the linear range was 10–1533 mg L−1 and the detection limit was 1.0 mg L−1. The results obtained from the proposed method were linearly correlated to those by the classic dichromate method (r = 0.9978, p < 0.01, n = 13). Finally, the validated method was used to determine the COD values of surface water, reclaimed water and wastewater. It was shown that the proposed method had an excellent practical perspective on determination of COD in water quality control and pollution evaluation.

  14. A 400 kyr record of combustion oxygen demand in the western equatorial Pacific: Evidence for a precessionally forced climate response

    Science.gov (United States)

    Perks, Helen M.; Keeling, Ralph F.

    1998-02-01

    We have developed a combustion analysis technique for sediments which measures the amount of O2 consumed by the reduced species. We have measured this quantity, which we call "combustion oxygen demand (COD)," on a carbonate-rich sediment core from the Ontong-Java Plateau in the western equatorial Pacific back to marine oxygen isotope stage 11. The precision of the COD technique is ±6.3 µmol O2 g-1, which corresponds to ˜±0.0076% wt Corg, assuming oxidation of organic carbon dominates the signal. The COD time series is characterized by values which are about twice as high during glacials as during interglacials, the largest shift occurring from 401 µmol O2 g-1 in midstage 6 to 144 µmol O2 g-1 at 5e, and is coherent with the oxygen isotope curve of Globigerinoides sacculifer in the same core at the Milankovitch frequencies of 100 and 41 kyr. Pronounced variations in the 19-23 kyr band suggest that the climate of the western equatorial Pacific is sensitive to precessional forcing, a response not apparent from other records obtained in this region.

  15. Heart rate and oxygen demand of powered exoskeleton–assisted walking in persons with paraplegia

    Directory of Open Access Journals (Sweden)

    Pierre Asselin, MS

    2015-06-01

    Full Text Available Historically, persons with paralysis have limited options for overground ambulation. Recently, powered exoskeletons, which are systems that translate the user’s body movements to activate motors that move the lower limbs through a predetermined gait pattern, have become available. As part of an ongoing clinical study (NCT01454570, eight nonambulatory persons with paraplegia were trained to ambulate with a powered exoskeleton. Measurements of oxygen uptake (VO2 and heart rate (HR were recorded for 6 min each during each maneuver while sitting, standing, and walking. The average value of VO2 during walking (11.2 +/– 1.7 mL/kg/min was significantly higher than for sitting and standing (3.5 +/– 0.4 and 4.3 +/– 0.9 mL/kg/min, respectively; p < 0.001. The HR response during walking was significantly greater than that of either sitting or standing (118 +/– 21 vs 70 +/– 10 and 81 +/– 12 beats per minute, respectively; p < 0.001. Persons with paraplegia were able to ambulate efficiently using the powered exoskeleton for overground ambulation, providing the potential for functional gain and improved fitness.

  16. Singlet molecular oxygen generated in dark biological process.

    Science.gov (United States)

    Di Mascio, Paolo; Medeiros, Marisa H G

    2014-10-01

    Ultraweak chemiluminescence arising from biomolecules oxidation has been attributed to the radiative deactivation of singlet molecular oxygen [(1)O2] and electronically excited triplet carbonyl products involving dioxetane intermediates. As examples, we will discuss the generation of (1)O2 from lipid hydroperoxides, which involves a cyclic mechanism from a linear tetraoxide intermediate. The generation of (1)O2 in aqueous solution via energy transfer from the excited triplet acetone arising from the thermodecomposition of dioxetane a chemical source, and horseradish peroxidase-catalyzed oxidation of 2-methylpropanal, as an enzymatic source, will also be discussed. The approach used to unequivocally demonstrate the generation of (1)O2 in these reactions is the use of (18)O-labeled hydroperoxide / triplet dioxygen ((18)[(3)O2]), the detection of labeled compounds by HPLC coupled to tandem mass spectrometry (HPLC-MS/MS) and the direct spectroscopic detection and characterization of (1)O2 light emission. Characteristic light emission at 1,270nm, corresponding to the singlet delta state monomolecular decay was observed. Using(18)[(3)O2], we observed the formation of (18)O-labeled (1)O2 ((18)[(1)O2]) by the chemical trapping of (18)[(1)O2]with the anthracene-9,10-diyldiethane-2,1-diyl disulfate disodium salt (EAS) and detected the corresponding (18)O-labeled EAS endoperoxide usingHPLC-MS/MS. The combined use of the thermolysis of a water-soluble naphthalene endoperoxide as a generator of (18)O labeled (1)O2 and the sensitivity of HPLC-MS/MS allowed the study of (1)O2reactivity toward biomolecules. Photoemission properties and chemical trapping clearly demonstrate that the production of hydroperoxide and excited carbonyls generates (18)[(1)O2], and points to the involvement of (1)O2 in physiological and pathophysiological mechanism. Supported by FAPESP (2012/12663-1), CAPES, INCT Redoxoma (FAPESP/CNPq/CAPES; 573530/2008-4), NAP Redoxoma (PRPUSP; 2011.1.9352.1.8), CEPID

  17. Effects of chitosan on growth of an aquatic plant (Hydrilla verticillata) in polluted waters with different chemical oxygen demands

    Institute of Scientific and Technical Information of China (English)

    XU Qiu-jin; NIAN Yue-gang; JIN Xiang-can; YAN Chang-zhou; LIU Jin; Jiang Gao-ming

    2007-01-01

    Effects of chitosan on a submersed plant, Hydrilla verticillata, were investigated. Results indicated that H. verticillata could prevent ultrastructure phytotoxicities and oxidativereaction from polluted water with high chemical oxygen demand (COD). Superoxide dismutase (SOD) activity and malondialdehyde (MDA) contents in H. verticillata treated with 0.1% chitosan in wastewater increased with high COD (980 mg/L) and decreased with low COD (63 mg/L), respectively. Ultrastructural analysis showed that the stroma and grana of chloroplast basically remained normal. However, plant cells from the control experiment (untreated with chitosan) were vacuolated and the cell interval increased. The relict of protoplast moved to the center, with cells tending to disjoint. Our findings indicate that wastewater with high COD concentration can cause a substantial damage to submersed plant, nevertheless, chitosan probably could alleviate the membrane lipid peroxidization and ultrastructure phytotoxicities, and protect plant cells from stress of high COD concentration polluted water.

  18. Using electro-flotation/oxidation for reducing chemical oxygen demand, total organic carbon and total solids in vinasses

    Directory of Open Access Journals (Sweden)

    Javier Dávila Rincón

    2010-05-01

    Full Text Available The high chemical oxygen demand (COD of vinasses from ethanol distilleries (greater than 130,000 mg/L has led to exploring alternative treatments enabling their final disposition. The electro-flotation/oxidation of vinasses was thus experimentally evalua-ted regarding initial pH, electrolytic support (NaCl and hydrogen peroxide concentration (H2O2, current density (CD and se-veral electrodes: iron, aluminum and galvanized steel. Its effect on reducing COD and total organic carbon (TOC was studied, an initial 214,000 ppm COD value being reduced to 90,000 ppm, thereby representing a 58% reduction. The greatest reduc-tions were achieved with galvanized steel electrodes, basic pH, 20 mA/cm2 and 60,000 ppm H2O2.

  19. Oxygen demand for the stabilization of the organic fraction of municipal solid waste in passively aerated bioreactors

    Energy Technology Data Exchange (ETDEWEB)

    Kasinski, Slawomir, E-mail: slawomir.kasinski@uwm.edu.pl; Wojnowska-Baryla, Irena

    2014-02-15

    Highlights: • The use of an passively aerated reactor enables effective stabilization of OFMSW. • Convective air flow does not inhibit the aerobic stabilization of waste. • The use of an passively aerated reactor reduces the heat loss due to convection. • The volume of supplied air exceeds 1.7–2.88 times the microorganisms demand. - Abstract: Conventional aerobic waste treatment technologies require the use of aeration devices that actively transport air through the stabilized waste mass, which greatly increases operating costs. In addition, improperly operated active aeration systems, may have the adverse effect of cooling the stabilized biomass. Because active aeration can be a limiting factor for the stabilization process, passive aeration can be equally effective and less expensive. Unfortunately, there are few reports documenting the use of passive aeration systems in municipal waste stabilization. There have been doubts raised as to whether a passive aeration system provides enough oxygen to the organic matter mineralization processes. In this paper, the effectiveness of aeration during aerobic stabilization of four different organic fractions of municipal waste in a reactor with an integrated passive ventilation system and leachate recirculation was analyzed. For the study, four fractions separated by a rotary screen were chosen. Despite the high temperatures in the reactor, the air flow rate was below 0.016 m{sup 3}/h. Using Darcy’s equation, theoretical values of the air flow rate were estimated, depending on the intensity of microbial metabolism and the amount of oxygen required for the oxidation of organic compounds. Calculations showed that the volume of supplied air exceeded the microorganisms demand for oxidation and endogenous activity by 1.7–2.88-fold.

  20. Development of Biological Oxygen Demand Biosensor for Monitoring the Fermentation Industry Effluent

    OpenAIRE

    Neelam Verma; Ashish Kumar Singh

    2012-01-01

    A biosensor was developed for the determination of BOD value of fermentation industry effluent. The developed biosensor was fabricated by immobilizing the microbial consortium on cellulose acetate (CA) membrane in close proximity to a DO probe electrode. The microbial consortium was harvested from the fermentation industry effluent. The BOD biosensor was calibrated by using a solution containing the equivalent amount of glucose/glutamic acid (GGA) as a standard sample solution. The response t...

  1. Intraspecific individual variation of temperature tolerance associated with oxygen demand in the European sea bass (Dicentrarchus labrax).

    Science.gov (United States)

    Ozolina, Karlina; Shiels, Holly A; Ollivier, Hélène; Claireaux, Guy

    2016-01-01

    The European sea bass (Dicentrarchus labrax) is an economically important fish native to the Mediterranean and Northern Atlantic. Its complex life cycle involves many migrations through temperature gradients that affect the energetic demands of swimming. Previous studies have shown large intraspecific variation in swimming performance and temperature tolerance, which could include deleterious and advantageous traits under the evolutionary pressure of climate change. However, little is known of the underlying determinants of this individual variation. We investigated individual variation in temperature tolerance in 30 sea bass by exposing them to a warm temperature challenge test. The eight most temperature-tolerant and eight most temperature-sensitive fish were then studied further to determine maximal swimming speed (U CAT), aerobic scope and post-exercise oxygen consumption. Finally, ventricular contractility in each group was determined using isometric muscle preparations. The temperature-tolerant fish showed lower resting oxygen consumption rates, possessed larger hearts and initially recovered from exhaustive exercise faster than the temperature-sensitive fish. Thus, whole-animal temperature tolerance was associated with important performance traits. However, the temperature-tolerant fish also demonstrated poorer maximal swimming capacity (i.e. lower U CAT) than their temperature-sensitive counterparts, which may indicate a trade-off between temperature tolerance and swimming performance. Interestingly, the larger relative ventricular mass of the temperature-tolerant fish did not equate to greater ventricular contractility, suggesting that larger stroke volumes, rather than greater contractile strength, may be associated with thermal tolerance in this species. PMID:27382468

  2. Gas production, oxygen demand and microbial activity in sediments of wetlands constructed with oil sands mine tailings

    International Nuclear Information System (INIS)

    Changes in sediment oxygen demand (SOD) in 2 reference and 9 oil sands process material (OSPM) impacted wetlands were evaluated. The wetlands were constructed in 1992. SOD was measured by determining the rate of O2 depletion in in-situ test chambers placed on the sediment surface within the test pond areas. The study showed that SOD measurements conducted in 2008-2009 showed a slower rate of oxygen consumption than measurements conducted in 1993. Results suggested that sediment-associated reducing compounds were depleted. Carbon dioxide (CO2) was dominantly respired by methanogens using the carbon as a terminal electron acceptor in conjunction with hydrogen to produce methane (CH4). Gases analyzed in situ from the wetland sediments suggested that OSPM-affected sediments promote the growth of methanogenic bacteria. Samples of evolved gas, pore water, and intact sediment cores were collected at each wetland site in order to determine if significant differences in biogeochemical composition have developed. Further research is being conducted to characterize the relationship between the microbes and the sediments of the reclaimed wetlands.

  3. The effects of graded changes in oxygen and carbon dioxide tension on coronary blood velocity independent of myocardial energy demand.

    Science.gov (United States)

    Boulet, Lindsey M; Stembridge, Mike; Tymko, Michael M; Tremblay, Joshua C; Foster, Glen E

    2016-08-01

    In humans, coronary blood flow is tightly regulated by microvessels within the myocardium to match myocardial energy demand. However, evidence regarding inherent sensitivity of the microvessels to changes in arterial partial pressure of carbon dioxide and oxygen is conflicting because of the accompanied changes in myocardial energy requirements. This study aimed to investigate the changes in coronary blood velocity while manipulating partial pressures of end-tidal CO2 (Petco2) and O2 (Peto2). It was hypothesized that an increase in Petco2 (hypercapnia) or decrease in Peto2 (hypoxia) would result in a significant increase in mean blood velocity in the left anterior descending artery (LADVmean) due to an increase in both blood gases and energy demand associated with the concomitant cardiovascular response. Cardiac energy demand was assessed through noninvasive measurement of the total left ventricular mechanical energy. Healthy subjects (n = 13) underwent a euoxic CO2 test (Petco2 = -8, -4, 0, +4, and +8 mmHg from baseline) and an isocapnic hypoxia test (Peto2 = 64, 52, and 45 mmHg). LADVmean was assessed using transthoracic Doppler echocardiography. Hypercapnia evoked a 34.6 ± 8.5% (mean ± SE; P < 0.01) increase in mean LADVmean, whereas hypoxia increased LADVmean by 51.4 ± 8.8% (P < 0.05). Multiple stepwise regressions revealed that both mechanical energy and changes in arterial blood gases are important contributors to the observed changes in LADVmean (P < 0.01). In summary, regulation of the coronary vasculature in humans is mediated by metabolic changes within the heart and an inherent sensitivity to arterial blood gases.

  4. The effects of graded changes in oxygen and carbon dioxide tension on coronary blood velocity independent of myocardial energy demand.

    Science.gov (United States)

    Boulet, Lindsey M; Stembridge, Mike; Tymko, Michael M; Tremblay, Joshua C; Foster, Glen E

    2016-08-01

    In humans, coronary blood flow is tightly regulated by microvessels within the myocardium to match myocardial energy demand. However, evidence regarding inherent sensitivity of the microvessels to changes in arterial partial pressure of carbon dioxide and oxygen is conflicting because of the accompanied changes in myocardial energy requirements. This study aimed to investigate the changes in coronary blood velocity while manipulating partial pressures of end-tidal CO2 (Petco2) and O2 (Peto2). It was hypothesized that an increase in Petco2 (hypercapnia) or decrease in Peto2 (hypoxia) would result in a significant increase in mean blood velocity in the left anterior descending artery (LADVmean) due to an increase in both blood gases and energy demand associated with the concomitant cardiovascular response. Cardiac energy demand was assessed through noninvasive measurement of the total left ventricular mechanical energy. Healthy subjects (n = 13) underwent a euoxic CO2 test (Petco2 = -8, -4, 0, +4, and +8 mmHg from baseline) and an isocapnic hypoxia test (Peto2 = 64, 52, and 45 mmHg). LADVmean was assessed using transthoracic Doppler echocardiography. Hypercapnia evoked a 34.6 ± 8.5% (mean ± SE; P < 0.01) increase in mean LADVmean, whereas hypoxia increased LADVmean by 51.4 ± 8.8% (P < 0.05). Multiple stepwise regressions revealed that both mechanical energy and changes in arterial blood gases are important contributors to the observed changes in LADVmean (P < 0.01). In summary, regulation of the coronary vasculature in humans is mediated by metabolic changes within the heart and an inherent sensitivity to arterial blood gases. PMID:27233761

  5. Increase in water column denitrification during the deglaciation controlled by oxygen demand in the eastern equatorial Pacific

    Directory of Open Access Journals (Sweden)

    P. Martinez

    2009-05-01

    Full Text Available Here we present organic export production and isotopic nitrogen results over the last 30 000 years from one core localized off Costa Rica (ODP Site 1242 on the leading edge of the oxygen minimum zone of the Eastern Tropical North Pacific. Marine export production reveals glacial-interglacial variations with low organic matter (total organic carbon and total nitrogen contents during warm intervals, twice more during cold episodes and double peaked maximum during the deglaciation, between ~15.5–18.5 and 11–13 ka BP. When this new export production record is compared with four nearby cores localized within the Eastern Pacific along the Equatorial divergence, a good agreement between all the cores is observed, with the major feature being a maximum of export during the early deglaciation. As for export production, water-column denitrification represented by sedimentary δ15N records along the Eastern tropical North and South Pacific between 15° N and 36° S is coherent as well over the last deglaciation period. The whole isotopic nitrogen profiles indicate that denitrification increased abruptly at 19 ka BP to a maximum during the early deglaciation, confirming a typical Antarctic timing. It is proposed that the increase in export production and then in subsurface oxygen demand lead to an intensification of water-column denitrification within the oxygen minimum zones in the easternmost Pacific at the time of the last deglaciation. The triggering mechanism would have been primarily linked to an increase in preformed nutrients contents feeding the Equatorial Undercurrent driven by the resumption of overturning in the Southern Ocean and the return of nutrients from the deep ocean to the sea-surface. An increase in equatorial wind-driven upwelling of sub-surface nutrient-rich waters could have played the role of an amplifier.

  6. A flow injection analysis system with encapsulated high-density Saccharomyces cerevisiae cells for rapid determination of biochemical oxygen demand.

    Science.gov (United States)

    Seo, Kyo Seong; Choo, Kwang Ho; Chang, Ho Nam; Park, Joong Kon

    2009-05-01

    The biochemical oxygen demand (BOD) determination was studied using a novel flow injection analysis (FIA) system with encapsulated Saccharomyces cerevisiae cells and an oxygen electrode and was compared with conventional 5-day BOD tests. S. cerevisiae cells were packed in a calcium alginate capsule at a dry cell weight of 250 g/l of capsule core. The level of dissolved oxygen (DO) was reduced due to the enhanced respiratory activity of the microbial cells when the injected nutrient passed through the bioreactor. The decrease in DO (DeltaDO) was intensified with the amount of microbial cells packed in the bioreactor. However, the specific DeltaDO decreased as the amount of cells loaded in the bioreactor increased. The DeltaDO value was dependent on the pH and temperature of the mobile phase and reached its maximum value at 35 degrees C and pH 7-8. Also, DeltaDO became larger at longer response times as the flow rate of the mobile phase decreased. The measurement of DeltaDO was repeated more than six times consecutively using a 20-ppm standard glucose and glutamic acid solution, which confirmed the reproducibility with a standard deviation of 0.95%. A strong linear correlation between DeltaDO and BOD was also observed. The 5-day BOD values of actual water and wastewater samples were in accordance with the BOD values obtained by this FIA method using encapsulated S. cerevisiae cells. Unlike the cell-immobilized bead system, there was no contamination of the bioreactor resulting from any leak of yeast cells from the sensor capsules during BOD measurements. PMID:19153729

  7. Constructed Wetlands Systems Batch: removal of Biochemical Oxygen Demand and pH regulation for treatment dairy effluent

    Directory of Open Access Journals (Sweden)

    Henrique Vieira de Mendonça

    2015-04-01

    Full Text Available This work assessed the effectiveness of using constructed wetlands (CW's to treat dairy effluent. The purpose of the research was to evaluate the influence of substrates and cultivated plants on the efficiency of Biochemical Oxygen Demand (BOD removal and pH regulation in six experimental units operating at pilot scale. Six CW's for dairy sewage treatment were constructed in 100-liter High-Density Polyethylene Ethylene (HDPE tanks. Three constructed wetlands containing fine gravel (0 mm and another three with a mix of 20% sand and 80% fine gravel (0 mm were used in the filtering stage. Four experimental units were planted with the macrophytes Typha dominguensis (cattail and Hedychium coronarium (pond lily, the selected plants for this study, and two others were maintained as control units. A minimum average of 77.8% and a maximum of 95.2% BOD efficiency removal were achieved and a pH range of 5 to 9 was maintained as required by the Brazilian Resolution CONAMA N. 430 /2011 in order to release the effluent into a waterway. The six treatments showed similar removal of biodegradable carbonaceous compounds with no significant differences between the treatments at a 95% confidence level. This work showed that CW’s operating in batch can be used to treat dairy raw water for BOD removal and pH regulation.

  8. Efficiency of horizontal roughing filter in removing nitrate, phosphate and chemical oxygen demand from effluent of waste stabilization pond

    Directory of Open Access Journals (Sweden)

    Seyed Mostafa Khezri

    2015-06-01

    Full Text Available Background: The effective size of the end grain of horizontal roughing filters (HRFs is larger than 2 mm. This study aimed to examine the efficiency of HRFs in removing nitrate, phosphate, and chemical oxygen demand (COD from effluent of a wastewater stabilization pond. Methods: This experimental study was conducted in 2013. The pilot project was transferred to the Karaj wastewater treatment plant (stabilization pond, and the installation, equipping, and start-up of the system began using an effluent treatment plant. Sampling was done from March to August in 3 rates, 0.5, 1 and 1.5 m/h, and included simultaneous sampling from inlet and outlet filtering to determine the concentrations of nitrate, phosphate, and COD. Results: At filtration rates of 0.5, 1, and 1.5 m/h, the average nitrate removal equaled 25%, 32%, and 34%, respectively, average phosphate removal equaled 29%, 26%, and 28%, respectively, and the average COD removal at filtration rates of 0.5, 1, and 1.5 m/h equaled 62%, 66%, and 68%, respectively. Outlet values of phosphate and nitrate were lower than the standards set by the Environmental Standards Organization (ESO (P < 0.05. Conclusion: According to the results of this study, the HRF function was approximately adequate in COD removal, but its efficiency in nitrate and phosphate removal was lower.

  9. A sensitive ferricyanide-mediated biochemical oxygen demand assay for analysis of wastewater treatment plant influents and treated effluents.

    Science.gov (United States)

    Jordan, Mark A; Welsh, David T; John, Richard; Catterall, Kylie; Teasdale, Peter R

    2013-02-01

    Representative and fast monitoring of wastewater influent and effluent biochemical oxygen demand (BOD) is an elusive goal for the wastewater industry and regulatory bodies alike. The present study describes a suitable assay, which incorporates activated sludge as the biocatalyst and ferricyanide as the terminal electron acceptor for respiration. A number of different sludges and sludge treatments were investigated, primarily to improve the sensitivity of the assay. A limit of detection (LOD) (2.1 mg BOD₅ L⁻¹) very similar to that of the standard 5-day BOD₅ method was achieved in 4 h using raw influent sludge that had been cultured overnight as the biocatalyst. Reducing the microbial concentration was the most effective means to improve sensitivity and reduce the contribution of the sludge's endogenous respiration to total ferricyanide-mediated (FM) respiration. A strong and highly significant relationship was found (n = 33; R = 0.96; p treatment plant (WWTP) influent and treated effluent, as well as several grey water samples. The activated sludge FM-BOD assay presented here is an exceptional surrogate method to the standard BOD₅ assay, providing representative, same-day BOD analysis of WWTP samples with a comparable detection limit, a 4-fold greater analytical range and much faster analysis time. The industry appeal of such an assay is tremendous given that ~90% of all BOD₅ analysis is dedicated to measurement of WWTP samples, for which this assay is specifically designed. PMID:23200506

  10. Treatment of textile industry effluents using orange waste: a proposal to reduce color and chemical oxygen demand.

    Science.gov (United States)

    de Farias Silva, Carlos Eduardo; da Silva Gonçalves, Andreza Heloiza; de Souza Abud, Ana Karla

    2016-01-01

    Various agricultural residues have been tested as biosorbents due to their low cost, high surface area, and favorable surface chemistry. In this work, a sweet orange albedo was tested as a biosorbent for treatment of real textile effluents. The orange albedo powder was prepared by drying the residue at 50 °C and milling to 30 mesh, and then used for dye adsorption from a alkaline (pH = 10.71) effluent. The adsorption process was studied in batch experiments at 30 °C by measuring color removal and chemical oxygen demand (COD). The color removal was found not to be significantly altered when the effluent was used in its raw state, while COD increased probably due to albedo degradation. For the effluent diluted to 60% (Veffluent VH2O(-1)), color and COD removal percentages of approximately 89% were obtained. It was found that pH played a very significant role on the adsorption process, as the treated albedo displayed a relative pHPZC* of 4.61, and the highest dye removal efficiencies were reached at pH lower than 2. The COD was strongly influenced by the effluent dilution. The effectiveness in eliminating color and COD shows that orange albedo can be potentially used as a biosorbent to treat textile wastewater. PMID:27533873

  11. A sensitive ferricyanide-mediated biochemical oxygen demand assay for analysis of wastewater treatment plant influents and treated effluents.

    Science.gov (United States)

    Jordan, Mark A; Welsh, David T; John, Richard; Catterall, Kylie; Teasdale, Peter R

    2013-02-01

    Representative and fast monitoring of wastewater influent and effluent biochemical oxygen demand (BOD) is an elusive goal for the wastewater industry and regulatory bodies alike. The present study describes a suitable assay, which incorporates activated sludge as the biocatalyst and ferricyanide as the terminal electron acceptor for respiration. A number of different sludges and sludge treatments were investigated, primarily to improve the sensitivity of the assay. A limit of detection (LOD) (2.1 mg BOD₅ L⁻¹) very similar to that of the standard 5-day BOD₅ method was achieved in 4 h using raw influent sludge that had been cultured overnight as the biocatalyst. Reducing the microbial concentration was the most effective means to improve sensitivity and reduce the contribution of the sludge's endogenous respiration to total ferricyanide-mediated (FM) respiration. A strong and highly significant relationship was found (n = 33; R = 0.96; p BOD₅ and FM-BOD equivalent values for a diverse range of samples including wastewater treatment plant (WWTP) influent and treated effluent, as well as several grey water samples. The activated sludge FM-BOD assay presented here is an exceptional surrogate method to the standard BOD₅ assay, providing representative, same-day BOD analysis of WWTP samples with a comparable detection limit, a 4-fold greater analytical range and much faster analysis time. The industry appeal of such an assay is tremendous given that ~90% of all BOD₅ analysis is dedicated to measurement of WWTP samples, for which this assay is specifically designed.

  12. Removal of chemical oxygen demand and dissolved nutrients by a sunken lawn infiltration system during intermittent storm events.

    Science.gov (United States)

    Hou, Lizhu; Yang, Huan; Li, Ming

    2014-01-01

    Urban surface water runoff typically contains high but varying amounts of organic matter and nutrients that require removal before reuse. Infiltration systems such as sunken lawns can improve water quality. However, there is currently insufficient information describing the treatment efficiency of lawn-based infiltration systems. In this study, novel sunken lawn infiltration systems (SLISs) were designed and their pollutant removal effectiveness was assessed. The results revealed that SLISs with Poa pratensis and Lolium perenne effectively removed most chemical oxygen demand (CODCr) and dissolved nutrients. Average CODCr, total nitrogen (TN), ammonium-nitrogen (NH4(+)-N) and total phosphorus (TP) concentrations were reduced by 78.93, 66.64, 71.86 and 75.83%, respectively, and the corresponding effluent concentrations met the standard for urban miscellaneous water consumption in China. The NH4(+)-N in the synthetic runoff was shown to be removed by adsorption during the stormwater dosing and nitrification during subsequent dry days, as well as through uptake by plants. Phosphorus was mainly removed by adsorption and chemical precipitation. The NH4(+)-N and phosphorus Langmuir isotherm model fitted the clay loam soil adsorption process better than the Freundlich model. Overall, these results indicate that an SLIS provides an alternative means of removing runoff pollutants owing to its efficiency, easy operation and maintenance. PMID:24473312

  13. Miniaturized and green method for determination of chemical oxygen demand using UV-induced oxidation with hydrogen peroxide and single drop microextraction

    International Nuclear Information System (INIS)

    We report on a green method for the determination of low levels of chemical oxygen demand. It is based on the combination of (a) UV-induced oxidation with hydrogen peroxide, (b) headspace single-drop microextraction with in-drop precipitation, and (c) micro-turbidimetry. The generation of CO2 after photolytic oxidation followed by its sequestration onto a microdrop of barium hydroxide gives rise to a precipitate of barium carbonate which is quantified by turbidimetry. UV-light induced oxidation was studied in the absence and presence of H2O2, ultrasound, and ferrous ion. Determinations of chemical oxygen demand were performed using potassium hydrogen phthalate as a model compound. The optimized method gives a calibration curve that is linear between 3.4 and 20 mg L−1 oxygen. The detection limit was 1.2 mg L−1 of oxygen, and the repeatability (as relative standard deviation) was around 5 %. The method was successfully applied to the determination of chemical oxygen demand in different natural waters and a synthetic wastewater. (author)

  14. Activation of methanogenesis in arid biological soil crusts despite the presence of oxygen.

    Directory of Open Access Journals (Sweden)

    Roey Angel

    Full Text Available Methanogenesis is traditionally thought to occur only in highly reduced, anoxic environments. Wetland and rice field soils are well known sources for atmospheric methane, while aerated soils are considered sinks. Although methanogens have been detected in low numbers in some aerated, and even in desert soils, it remains unclear whether they are active under natural oxic conditions, such as in biological soil crusts (BSCs of arid regions. To answer this question we carried out a factorial experiment using microcosms under simulated natural conditions. The BSC on top of an arid soil was incubated under moist conditions in all possible combinations of flooding and drainage, light and dark, air and nitrogen headspace. In the light, oxygen was produced by photosynthesis. Methane production was detected in all microcosms, but rates were much lower when oxygen was present. In addition, the δ(13C of the methane differed between the oxic/oxygenic and anoxic microcosms. While under anoxic conditions methane was mainly produced from acetate, it was almost entirely produced from H(2/CO(2 under oxic/oxygenic conditions. Only two genera of methanogens were identified in the BSC-Methanosarcina and Methanocella; their abundance and activity in transcribing the mcrA gene (coding for methyl-CoM reductase was higher under anoxic than oxic/oxygenic conditions, respectively. Both methanogens also actively transcribed the oxygen detoxifying gene catalase. Since methanotrophs were not detectable in the BSC, all the methane produced was released into the atmosphere. Our findings point to a formerly unknown participation of desert soils in the global methane cycle.

  15. Control of nitratation in an oxygen-limited autotrophic nitrification/denitrification rotating biological contactor through disc immersion level variation.

    Science.gov (United States)

    Courtens, Emilie N P; Boon, Nico; De Clippeleir, Haydée; Berckmoes, Karla; Mosquera, Mariela; Seuntjens, Dries; Vlaeminck, Siegfried E

    2014-03-01

    With oxygen supply playing a crucial role in an oxygen-limited autotrophic nitrification/denitrification (OLAND) rotating biological contactor (RBC), its controlling factors were investigated in this study. Disc rotation speeds (1.8 and 3.6rpm) showed no influence on the process performance of a lab-scale RBC, although abiotic experiments showed a significant effect on the oxygenation capacity. Estimations of the biological oxygen uptake rate revealed that 85-89% of the oxygen was absorbed by the microorganisms during the air exposure of the discs. Indeed, increasing the disc immersion (50 to 75-80%) could significantly suppress undesired nitratation, on the short and long term. The presented results demonstrated that nitratation could be controlled by the immersion level and revealed that oxygen control in an OLAND RBC should be predominantly based on the atmospheric exposure percentage of the discs.

  16. Co-Digestion of Palm Oil Mill Effluent and Refined Glycerin Wash Water for Chemical Oxygen Demand Removal and Methane Production

    Directory of Open Access Journals (Sweden)

    A. Sulaiman

    2009-01-01

    Full Text Available Problem statement: Refined Glycerin Wash Water (RGWW from the oleochemical industry contains high Chemical Oxygen Demand (COD and requires proper treatment before disposal. Unfortunately the wash water also contains high concentration of sodium chloride (NaCl that could cause inhibition to the normal biological treatment process. However, there is feasibility of co-digesting the RGWW and Palm Oil Mill Effluent (POME for its treatment and methane recovery. Approach: A large 500 m3 semi-commercial closed digester tank was used to study the effect of co-digesting POME and RGWW under mesophilic condition at different RGWW percentage. The digester performance in terms of COD removal efficiency and methane production rate and stability based on total Volatile Fatty Acids (VFA accumulation, Mixed Liquor Volatile Suspended Solid (MLVSS and pH were evaluated. Results: At 1.0% of RGWW co-digested, both COD removal efficiency and methane production rate showed satisfactory results with higher than 90% and 505 m3 day-1, respectively. However, once the percentage was increased to a maximum of 5.25%, COD removal efficiency remains high but the methane production rate reduced significantly down to 307 m3 day-1. At this stage, the digester was already unstable with high total VFA recorded of 913 mg L-1 and low cells concentration of 8.58 g L-1. This was probably due to the effect of plasmolysis on the methanogens at high concentration of NaCl in the digester of nearly 4000 mg L-1. Conclusion: Co-digesting of RGWW with high NaCl content and POME is satisfactory for COD removal but not for increasing the methane production.

  17. Ability of the aquatic fern Azolla to remove chemical oxygen demand and polyphenols from olive mill wastewater

    Directory of Open Access Journals (Sweden)

    Sacchi, Angelo

    2007-03-01

    Full Text Available We investigated the biofiltration ability of the aquatic fern Azolla to remove polyphenols and chemical oxygen demand (COD from olive mill wastewater (OMWw collected from the traditional (TS and continuous (CS extraction systems. Azolla biomass was packed into five sequential Imhoff cones and five sequential columns. In both experiments, the filtrates collected from the 5th biofilter showed a decrease in polyphenol contents: from 7650 mg l–1 to 3610 mg l–1 in TS OMWw and from 3852 mg l–1 to 1351 mg l–1 in CS OMWw. The COD contents decreased from 110200 mg L–1 to 52400 mg L–1 in TS OMWw and from 41600 mg L–1 to 2300 mg L–1 in CS OMWw. A 5:1 OMWw to Azolla-fresh-weight ratio was optimal for both polyphenol and COD removal. The biofiltration ability of alfalfa was compared with that of Azolla, but the treatment with alfalfa did not result in the reduction of COD or polyphenols.La eficacia del helecho de agua azolla para eliminar polifenoles y reducir la demanda química de oxígeno (DQO de los alpechines obtenidos en el proceso de obtención tradicional y continuo del aceite de oliva, fue investigado mediante ensayos de filtración. Cinco conos secuenciales de Imhoff y cinco columnas secuenciales se rellenaron de biomasa de Azolla. En ambos experimentos, el filtrado procedente de la quinta extracción mostró una disminución en el contenido de polifenoles de 7650 mg L–1 a 3610 mg L–1en el alpechín obtenido mediante el sistema tradicional y de 3852 mg L–1 a 1351 mg L–1en el alpechín del sistema continuo. La demanda química de oxígeno del alpechín del sistema tradicional disminuyó de 110200 mg L–1 a 52400 mg L–1 en y de 41600 mg L–1a 2300 mg L–1en el procedente del sistema continuo. Una proporción en peso 5:1 de alpechín: Azolla fue la óptima tanto para la reducción de los polifenoles como para la de la DQO. La eficiencia del tratamiento biológico con alfalfa se comparó con la obtenida con Azolla. Los

  18. A pilot scale trickling filter with pebble gravel as media and its performance to remove chemical oxygen demand from synthetic brewery wastewater*

    OpenAIRE

    Habte Lemji, Haimanot; Eckstädt, Hartmut

    2013-01-01

    Evaluating the performance of a biotrickling filter for the treatment of wastewaters produced by a company manufacturing beer was the aim of this study. A pilot scale trickling filter filled with gravel was used as the experimental biofilter. Pilot scale plant experiments were made to evaluate the performance of the trickling filter aerobic and anaerobic biofilm systems for removal of chemical oxygen demand (COD) and nutrients from synthetic brewery wastewater. Performance evaluation data of ...

  19. Effect of spent cotton stalks on color removal and chemical oxygen demand lowering in olive oil mill wastewater by white rot fungi.

    Science.gov (United States)

    Kahraman, S; Yeşilada, O

    1999-01-01

    Wastewater from olive oil mill was decolorized (and its chemical oxygen demand reduced in static cultivation) using the fungi Coriolus versicolor, Funalia trogii, Phanerochaete chrysosporium and Pleurotus sajor-caju. The effect of cotton stalk on decolorizing and COD removing capability was demonstrated. P. chrysosporium (in 20% medium with cotton stalk) reduced the COD by 48% and color by 58%, F. trogii (in 30% medium with cotton stalk)) by 51 and 55%, respectively.

  20. Biological Apatite Formed from Polyphosphate and Alkaline Phosphatase May Exchange Oxygen Isotopes from Water through Carbonate

    Science.gov (United States)

    Omelon, S. J.; Stanley, S. Y.; Gorelikov, I.; Matsuura, N.

    2011-12-01

    The oxygen isotopic composition in bone mineral phosphate is known to reflect the local water composition, environmental humidity, and diet1. Once ingested, biochemical processes presumably equilibrate PO43- with "body water" by the many biochemical reactions involving PO43- 2. Blake et al. demonstrated that enzymatic release of PO43- from organophosphorus compounds, and microbial metabolism of dissolved orthophosphate, significantly exchange the oxygen in precipitated apatite within environmental water3,4, which otherwise does not exchange with water at low temperatures. One of the enzymes that can cleave phosphates from organic substrates is alkaline phosphastase5, the enzyme also associated with bone mineralization. The literature often states that the mineral in bone in hydroxylapatite, however the mineral in bone is carbonated apatite that also contains some fluoride6. Deprotonation of HPO32- occurs at pH 12, which is impossibly high for biological system, and the predominate carbonate species in solution at neutral pH is HCO3-. To produce an apatite mineral without a significant hydroxyl content, it is possible that apatite biomineralization occurs through a polyphosphate pathway, where the oxygen atom required to transform polyphosphate into individual phosphate ions is from carbonate: [PO3-]n + CO32- -> [PO3-]n-1 + PO43- + CO2. Alkaline phosphatase can depolymerise polyphosphate into orthophosphate5. If alkaline phosphatase cleaves an oxygen atom from a calcium-carbonate complex, then there is no requirement for removing a hydrogen atom from the HCO3- or HPO43- ions of body water to form bioapatite. A mix of 1 mL of 1 M calcium polyphosphate hydogel, or nano-particles of calcium polyphosphate, and amorphous calcium carbonate were reacted with alkaline phosphatase, and maintained at neutral to basic pH. After two weeks, carbonated apatite and other calcium phosphate minerals were identified by powder x-ray diffraction. Orthophosphate and unreacted

  1. Occurrence, pathways and implications of biological production of reactive oxygen species in natural waters

    Science.gov (United States)

    Zhang, T.; Hansel, C. M.; Voelker, B. M.; Lamborg, C. H.

    2014-12-01

    Reactive oxygen species (ROS), such as superoxide (O2-) and hydrogen peroxide (H2O2) play a critical role in the redox cycling of both toxic (e.g., Hg) and nutrient (e.g., Fe) metals. Despite the discovery of extracellular ROS production in various microbial cultures, including fungi, algae and bacteria, photo-dependent processes are generally considered as the predominant source of ROS in natural waters. Here we show that biological production of ROS is ubiquitous and occurs at a significant rate in freshwater and brackish water environments. Water samples were collected from three freshwater and one brackish water ponds in Cape Cod, Massachusetts, USA, periodically from 2012 to 2014. Production of O2- and H2O2 were measured in dark incubations of natural water using a chemiluminescent and a colorimetric probe, respectively. Rates of biological ROS production were obtained by comparing unfiltered with 0.2-μm filtered samples. The role of biological activity in ROS production was confirmed by the cessation of ROS production upon addition of formaldehyde. In surface water, production rates of O2- ranged from undetectable to 96.0 ± 30.0 nmol L-1 h-1, and production rates of H2O2 varied between 9.9 ± 1.3 nmol L-1 h-1 and 145.6 ± 11.2 nmol L-1 h-1. The maximum production rates of both ROS were observed in mid-summer 2013, which coincides with peak biological activity. ROS production in the water from aphotic zone was greater than in the water from photic zone. Thus, non-light dependent biological processes are likely the major contributors to ROS production in this system. Moreover, O2- production appeared to be enhanced by NADH and inhibited by proteinase-K, suggesting the possible involvement of NADH oxidoreductases in this process. The potential role of different microbial communities in ROS production, and the implications of biological ROS production for mercury speciation will also be discussed.

  2. Renal Doppler Resistive Index as a Marker of Oxygen Supply and Demand Mismatch in Postoperative Cardiac Surgery Patients

    Directory of Open Access Journals (Sweden)

    Francesco Corradi

    2015-01-01

    Full Text Available Background and Objective. Renal Doppler resistive index (RDRI is a noninvasive index considered to reflect renal vascular perfusion. The aim of this study was to identify the independent hemodynamic determinants of RDRI in mechanically ventilated patients after cardiac surgery. Methods. RDRI was determined in 61 patients by color and pulse Doppler ultrasonography of the interlobar renal arteries. Intermittent thermodilution cardiac output measurements were obtained and blood samples taken from the tip of pulmonary artery catheter to measure hemodynamics and mixed venous oxygen saturation (SvO2. Results. By univariate analysis, RDRI was significantly correlated with SvO2, oxygen extraction ratio, left ventricular stroke work index, and cardiac index, but not heart rate, central venous pressure, mean artery pressure, pulmonary capillary wedge pressure, systemic vascular resistance index, oxygen delivery index, oxygen consumption index, arterial lactate concentration, and age. However, by multivariate analysis RDRI was significantly correlated with SvO2 only. Conclusions. The present data suggests that, in mechanically ventilated patients after cardiac surgery, RDRI increases proportionally to the decrease in SvO2, thus reflecting an early vascular response to tissue hypoxia.

  3. Quality improvement in determination of chemical oxygen demand in samples considered difficult to analyze, through participation in proficiency-testing schemes

    DEFF Research Database (Denmark)

    Raposo, Francisco; Fernández-Cegrí, V.; De la Rubia, M.A.;

    2010-01-01

    test the performance achievable in the participants laboratories, so we carried out a second PT of COD determination in samples considered ‘‘difficult’’ to analyze (i.e. solid samples and liquid samples with high concentrations of suspended solids). The results obtained (based on acceptable z......Chemical oxygen demand (COD) is a critical analytical parameter in waste and wastewater treatment, more specifically in anaerobic digestion, although little is known about the quality of measuring COD of anaerobic digestion samples. Proficiency testing (PT) is a powerful tool that can be used to...

  4. Developing mononuclear copper-active-oxygen complexes relevant to reactive intermediates of biological oxidation reactions.

    Science.gov (United States)

    Itoh, Shinobu

    2015-07-21

    Active-oxygen species generated on a copper complex play vital roles in several biological and chemical oxidation reactions. Recent attention has been focused on the reactive intermediates generated at the mononuclear copper active sites of copper monooxygenases such as dopamine β-monooxygenase (DβM), tyramine β-monooxygenase (TβM), peptidylglycine-α-hydroxylating monooxygenase (PHM), and polysaccharide monooxygenases (PMO). In a simple model system, reaction of O2 and a reduced copper(I) complex affords a mononuclear copper(II)-superoxide complex or a copper(III)-peroxide complex, and subsequent H(•) or e(-)/H(+) transfer, which gives a copper(II)-hydroperoxide complex. A more reactive species such as a copper(II)-oxyl radical type species could be generated via O-O bond cleavage of the peroxide complex. However, little had been explored about the chemical properties and reactivity of the mononuclear copper-active-oxygen complexes due to the lack of appropriate model compounds. Thus, a great deal of effort has recently been made to develop efficient ligands that can stabilize such reactive active-oxygen complexes in synthetic modeling studies. In this Account, I describe our recent achievements of the development of a mononuclear copper(II)-(end-on)superoxide complex using a simple tridentate ligand consisting of an eight-membered cyclic diamine with a pyridylethyl donor group. The superoxide complex exhibits a similar structure (four-coordinate tetrahedral geometry) and reactivity (aliphatic hydroxylation) to those of a proposed reactive intermediate of copper monooxygenases. Systematic studies based on the crystal structures of copper(I) and copper(II) complexes of the related tridentate supporting ligands have indicated that the rigid eight-membered cyclic diamine framework is crucial for controlling the geometry and the redox potential, which are prerequisites for the generation of such a unique mononuclear copper(II)-(end-on)superoxide complex

  5. Removal of oxygen demand and nitrogen using different particle-sizes of anthracite coated with nine kinds of LDHs for wastewater treatment

    Science.gov (United States)

    Zhang, Xiangling; Guo, Lu; Wang, Yafen; Ruan, Congying

    2015-10-01

    This paper reports the application of anthracite particles of different sizes and coated with nine kinds of layered double hydroxides (LDHs) varying in MII-MIII cations, as alternative substrates in the simulated vertical-flow constructed wetland columns. Effects of LDHs-coating and particle size of modified anthracites were examined to evaluate their abilities in removing oxygen demand and nitrogen from sewage wastewater. Results showed that LDHs modification effectively enhanced the removal of nitrogen and organics. The removal efficiencies of total nitrogen (TN) , ammonia and chemical oxygen demand (COD) were best improved by 28.5%, 11.9% and 4.1% for the medium particle size (1-3 mm), followed by 9.2%, 5.5% and 13.6% for the large size (3-5 mm), respectively. Only TN removal was improved up to 16.6% for the small particle size (0.5-1 mm). Nitrate tended to accumulate and fluctuate greatly across all the treatments, probably due to the dominancy of aerobic condition in the vertical-flow columns. Overall, MgFe-LDHs was selected as the best-modified coating for anthracite. The results suggested LDHs modification would be one of the promising strategies to provide new-types of highly efficient and lasting wetland substrates.

  6. Improving the simultaneous removal of chemical oxygen demand and terephthalic acid in a cross-flow aerobic sludge reactor by using response surface methodology.

    Science.gov (United States)

    Hu, Dong-Xue; Tian, Yu; Chen, Zhao-Bo; Ge, Hui; Cui, Yu-Bo; Ran, Chun-Qiu

    2015-01-01

    Central composite design and response surface methodology (RSM) were implemented to optimize the operational parameters for a cross-flow aerobic sludge reactor (CFASR) in remedying mixed printing and dyeing wastewater (MPDW). The individual and interactive effects of three variables, hydraulic retention time (HRT), pH and sludge loading rate (SLR), on chemical oxygen demand (COD) and terephthalic acid (TA) removal rates were evaluated. For HRT of 15.3-19.8 hours, pH of 7.2-8.1 and SLR of 0.4-0.6 kg chemical oxygen demand (COD) per kg mixed liquor suspended solids per day, COD and TA removal rates of the CFASR exceeded 85% and 90%, respectively. The check experiment revealed that the effluent from the optimized CFASR was stable below the limitation of 100 mg COD/L and the TA concentration decreased by 6.0% compared to the usual CFASR. The results verified that the RSM was useful for optimizing the operation parameters of the CFASR in remedying MPDW.

  7. Interconnection of reactive oxygen species chemistry across the interfaces of atmospheric, environmental, and biological processes.

    Science.gov (United States)

    Anglada, Josep M; Martins-Costa, Marilia; Francisco, Joseph S; Ruiz-López, Manuel F

    2015-03-17

    Oxidation reactions are ubiquitous and play key roles in the chemistry of the atmosphere, in water treatment processes, and in aerobic organisms. Ozone (O3), hydrogen peroxide (H2O2), hydrogen polyoxides (H2Ox, x > 2), associated hydroxyl and hydroperoxyl radicals (HOx = OH and HO2), and superoxide and ozonide anions (O2(-) and O3(-), respectively) are the primary oxidants in these systems. They are commonly classified as reactive oxygen species (ROS). Atmospheric chemistry is driven by a complex system of chain reactions of species, including nitrogen oxides, hydroxyl and hydroperoxide radicals, alkoxy and peroxy radicals, and ozone. HOx radicals contribute to keeping air clean, but in polluted areas, the ozone concentration increases and creates a negative impact on plants and animals. Indeed, ozone concentration is used to assess air quality worldwide. Clouds have a direct effect on the chemical composition of the atmosphere. On one hand, cloud droplets absorb many trace atmospheric gases, which can be scavenged by rain and fog. On the other hand, ionic species can form in this medium, which makes the chemistry of the atmosphere richer and more complex. Furthermore, recent studies have suggested that air-cloud interfaces might have a significant impact on the overall chemistry of the troposphere. Despite the large differences in molecular composition, concentration, and thermodynamic conditions among atmospheric, environmental, and biological systems, the underlying chemistry involving ROS has many similarities. In this Account, we examine ROS and discuss the chemical characteristics common to all of these systems. In water treatment, ROS are key components of an important subset of advanced oxidation processes. Ozonation, peroxone chemistry, and Fenton reactions play important roles in generating sufficient amounts of hydroxyl radicals to purify wastewater. Biochemical processes within living organisms also involve ROS. These species can come from pollutants in

  8. Interconnection of reactive oxygen species chemistry across the interfaces of atmospheric, environmental, and biological processes.

    Science.gov (United States)

    Anglada, Josep M; Martins-Costa, Marilia; Francisco, Joseph S; Ruiz-López, Manuel F

    2015-03-17

    Oxidation reactions are ubiquitous and play key roles in the chemistry of the atmosphere, in water treatment processes, and in aerobic organisms. Ozone (O3), hydrogen peroxide (H2O2), hydrogen polyoxides (H2Ox, x > 2), associated hydroxyl and hydroperoxyl radicals (HOx = OH and HO2), and superoxide and ozonide anions (O2(-) and O3(-), respectively) are the primary oxidants in these systems. They are commonly classified as reactive oxygen species (ROS). Atmospheric chemistry is driven by a complex system of chain reactions of species, including nitrogen oxides, hydroxyl and hydroperoxide radicals, alkoxy and peroxy radicals, and ozone. HOx radicals contribute to keeping air clean, but in polluted areas, the ozone concentration increases and creates a negative impact on plants and animals. Indeed, ozone concentration is used to assess air quality worldwide. Clouds have a direct effect on the chemical composition of the atmosphere. On one hand, cloud droplets absorb many trace atmospheric gases, which can be scavenged by rain and fog. On the other hand, ionic species can form in this medium, which makes the chemistry of the atmosphere richer and more complex. Furthermore, recent studies have suggested that air-cloud interfaces might have a significant impact on the overall chemistry of the troposphere. Despite the large differences in molecular composition, concentration, and thermodynamic conditions among atmospheric, environmental, and biological systems, the underlying chemistry involving ROS has many similarities. In this Account, we examine ROS and discuss the chemical characteristics common to all of these systems. In water treatment, ROS are key components of an important subset of advanced oxidation processes. Ozonation, peroxone chemistry, and Fenton reactions play important roles in generating sufficient amounts of hydroxyl radicals to purify wastewater. Biochemical processes within living organisms also involve ROS. These species can come from pollutants in

  9. Extracorporeal blood oxygenation and ozonation: clinical and biological implications of ozone therapy.

    Science.gov (United States)

    Di Paolo, N; Gaggiotti, E; Galli, F

    2005-01-01

    Some lines of evidence have suggested that the challenge to antioxidants and biomolecules provoked by pro-oxidants such as ozone may be used to generate a controlled stress response of possible therapeutic relevance in some immune dysfunctions and chronic, degenerative conditions. Immune and endothelial cells have been proposed to be elective targets of the positive molecular effects of ozone and its derived species formed during blood ozonation. On the bases of these underlying principles and against often prejudicial scepticism and concerns about its toxicity, ozone has been used in autohemotherapy (AHT) for four decades with encouraging results. However, clinical application and validation of AHT have been so far largely insufficient. Latterly, a new and more effective therapeutic approach to ozone therapy has been established, namely extracorporeal blood oxygenation and ozonation (EBOO). This technique, first tested in vitro and then in vivo in sheep and humans (more than 1200 treatments performed in 82 patients), is performed with a high-efficiency apparatus that makes it possible to treat with a mixture of oxygen-ozone (0.5-1 microg/ml oxygen) in 1 h of extracorporeal circulation up to 4800 ml of heparinized blood without technical or clinical problems, whereas only 250 ml of blood can be treated with ozone by AHT. The EBOO technique can be easily adapted for use in hemodialysis also. The standard therapeutic cycle lasts for 7 weeks in which 14 treatment sessions of 1 h are performed. After a session of EBOO, the interaction of ozone with blood components results in 4-5-fold increased levels of thiobarbituric acid reactants and a proportional decrease in plasma protein thiols without any appreciable erythrocyte haemolysis. On the basis of preliminary in vitro evidence, these simple laboratory parameters may represent a useful complement in the routine monitoring of biological compliance to the treatment. The clinical experience gained so far confirms the

  10. A comparative study of technologies for the continuous measurements of the biochemical demand for oxygen and toxicity of water; Estudio comparativo de tecnologias de medicion en continuo de la demanda bioquimica de oxigeno y de la toxicidad en aguas

    Energy Technology Data Exchange (ETDEWEB)

    Diez-Caballero Arnau, T.; Rodriguez Albalat, G.; Rosa de la Garcia, S.; Jimenez Bono, M.; Millan Navarro, C.; prats, R.; Serramia, A.; Miguel, S. de

    2002-07-01

    The Prevention and Integrated Control of Contamination Act (Ley de Prevencion y control Integrado de la Contaminacion) was passed by the Spanish parliament on 13 June. the basic purpose of this law is to prevent, reduce and control contamination of the atmosphere, water and soil caused by the most contaminating industrial activities. Public sector bodies and private companies in Spanish have been invited by the European Union to adopt new technologies in their production processes with a view to cutting down emissions, minimising or re-using waste, and pre-treating or purifying effluents. I t is therefore extremely appropriate to make available information on new tools of analysis that allow users to take preventive measures to reduce the impact their activity may have on the environment. A fundamental parameter in monitoring water is the Biological Demand for Oxygen (BOD). Various different chemical, physical and biological techniques have been developed to solve the problem of continuously monitoring the BOD and toxicity of water. This study carried out a comparative analysis of these techniques, describing the advantages and disadvantages of applying them to water quality control. At the present time it can be said that the BOD microbiosensor. Multisens 304 is the best available technology for monitoring this parameter. The articles tells us why. (Author) 8 refs.

  11. Gill morphometrics of the thresher sharks (Genus Alopias): Correlation of gill dimensions with aerobic demand and environmental oxygen.

    Science.gov (United States)

    Wootton, Thomas P; Sepulveda, Chugey A; Wegner, Nicholas C

    2015-05-01

    Gill morphometrics of the three thresher shark species (genus Alopias) were determined to examine how metabolism and habitat correlate with respiratory specialization for increased gas exchange. Thresher sharks have large gill surface areas, short water-blood barrier distances, and thin lamellae. Their large gill areas are derived from long total filament lengths and large lamellae, a morphometric configuration documented for other active elasmobranchs (i.e., lamnid sharks, Lamnidae) that augments respiratory surface area while limiting increases in branchial resistance to ventilatory flow. The bigeye thresher, Alopias superciliosus, which can experience prolonged exposure to hypoxia during diel vertical migrations, has the largest gill surface area documented for any elasmobranch species studied to date. The pelagic thresher shark, A. pelagicus, a warm-water epi-pelagic species, has a gill surface area comparable to that of the common thresher shark, A. vulpinus, despite the latter's expected higher aerobic requirements associated with regional endothermy. In addition, A. vulpinus has a significantly longer water-blood barrier distance than A. pelagicus and A. superciliosus, which likely reflects its cold, well-oxygenated habitat relative to the two other Alopias species. In fast-swimming fishes (such as A. vulpinus and A. pelagicus) cranial streamlining may impose morphological constraints on gill size. However, such constraints may be relaxed in hypoxia-dwelling species (such as A. superciliosus) that are likely less dependent on streamlining and can therefore accommodate larger branchial chambers and gills. PMID:25703507

  12. The Metropolis-Hastings algorithm, a handy tool for the practice of environmental model estimation : illustration with biochemical oxygen demand data

    Directory of Open Access Journals (Sweden)

    Franck Torre

    2001-02-01

    Full Text Available Environmental scientists often face situations where: (i stimulus-response relationships are non-linear; (ii data are rare or imprecise; (iii facts are uncertain and stimulus-responses relationships are questionable. In this paper, we focus on the first two points. A powerful and easy-to-use statistical method, the Metropolis-Hastings algorithm, allows the quantification of the uncertainty attached to any model response. This stochastic simulation technique is able to reproduce the statistical joint distribution of the whole parameter set of any model. The Metropolis-Hastings algorithm is described and illustrated on a typical environmental model: the biochemical oxygen demand (BOD. The aim is to provide a helpful guideline for further, and ultimately more complex, models. As a first illustration, the MH-method is also applied to a simple regression example to demonstrate to the practitioner the ability of the algorithm to produce valid results.

  13. Spatial distribution and diurnal variation of chemical oxygen demand at the beginning of the rainy season in the Changjiang (Yangtze) River Estuary

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A field observation was carried out in the Changjiang (Yangtze) River Estuary from May 19 to 26, 2003. A total of 29 stations, including 2 anchored stations, were occupied through almost the whole salinity gradient. Based on the observation data, biogeochemistry of chemical oxygen demand (COD) was examined. Spatial distribution pattern of COD shows that it decreased downstream. The COD concentration varied generally within a narrow range of 1.24-1.60 mg/L in the zone around the river mouth, beyond which it decreased rapidly to 0.20 mg/L. In the mixed water zone, the fluctuation in COD was smaller at 2 m above the bottom layer than at the surface layer in 48 h. In the seawater zone, the 48-h fluctuation at the surface was the largest, followed by that of 5 m below the surface and 2 m above the bottom layers in a range of from 2.50 to 0.55 mg/L. Freshwater discharge was the dominant source of COD in the estuary. The average COD beyond the river mouth was 2.7 rog/L, which accorded with the Chinese seawater quality Grade I. Relationships between dissolved oxygen and biogeochemical parameters such as suspended particulate matter, dissolved organic matter and chlorophyll-a were also discussed.

  14. Treatment of a slaughterhouse wastewater: effect of internal recycle rate on chemical oxygen demand, total Kjeldahl nitrogen and total phosphorus removal.

    Science.gov (United States)

    Fongsatitkul, P; Wareham, D G; Elefsiniotis, P; Charoensuk, P

    2011-12-01

    This study investigated the ability of an anaerobic/anoxic/oxic (A2/O) system to treat a slaughterhouse wastewater. The system employed two identical continuous-flow reactors (101 total liquid volume each) running in parallel with the main operational variable, being the internal recycle (IR) rate. The chemical oxygen demand (COD), total Kjeldahl nitrogen (TKN) and total phosphorus (TP) performance was evaluated as the IR flowrate was increased from a Q of 151d(-1) to 4Q at a system hydraulic retention time of 16 h and a solids retention time of 10 d. The COD:TKN and COD:TP ratios were 8.2:1 and 54:1, which supported both nitrogen and phosphorus removal. For all IR multiples of Q, the COD removal was in excess of 90%. The TKN removal showed a modest improvement (a 4-5% increase, depending on the dissolved oxygen (DO)) as the IR doubled from Q to 2Q, but no further increase was observed at the 4Q IR rate. The TP removal reached its optimum (around 85%-89% (again depending on the DO)) at the 2Q rate. PMID:22439562

  15. Effects of chemical oxygen demand (COD)/N ratios on pollutants removal in the subsurface wastewater infiltration systems with/without intermittent aeration.

    Science.gov (United States)

    Song, Siyu; Pan, Jing; Wu, Shiwei; Guo, Yijing; Yu, Jingxiao; Shan, Qingchi

    2016-01-01

    The matrix oxidation reduction potential level, organic pollutants and nitrogen removal performances of eight subsurface wastewater infiltration systems (SWISs) (four with intermittent aeration, four without intermittent aeration) fed with influent chemical oxygen demand (COD)/N ratio of 3, 6, 12 and 18 were investigated. Nitrification of non-aerated SWISs was poor due to oxygen deficiency while higher COD/N ratios further led to lower COD and nitrogen removal rate. Intermittent aeration achieved almost complete nitrification, which successfully created aerobic conditions in the depth of 50 cm and did not change anoxic or anaerobic conditions in the depth of 80 and 110 cm. The sufficient carbon source in high COD/N ratio influent greatly promoted denitrification in SWISs with intermittent aeration. High average removal rates of COD (95.68%), ammonia nitrogen (NH4(+)-N) (99.32%) and total nitrogen (TN) (89.65%) were obtained with influent COD/N ratio of 12 in aerated SWISs. The results suggest that intermittent aeration was a reliable option to achieve high nitrogen removal in SWISs, especially with high COD/N ratio wastewater.

  16. Effect of different carbon sources on the biological phosphorus removal by a sequencing batch reactor using pressurized pure oxygen

    OpenAIRE

    Wei, Jie; Imai, Tsuyoshi; Higuchi, Takaya; Arfarita, Novi; YAMAMOTO, Koichi; Sekine, Masahiko; Kanno, Ariyo

    2014-01-01

    The effect of different carbon source on the efficiency of enhanced biological phosphorus removal (EBPR) from synthetic wastewater with acetate and two ratios of acetate/starch as a carbon source was investigated. Three pressurized pure oxygen sequencing batch reactor (POSBR) experiments were operated. The reactors (POSBR1, POSBR2 and POSBR3) were developed and studied at different carbon source ratios of 100% acetate, 75% acetate plus 25% starch and 50% acetate plus 50% starch, respectively....

  17. Laser-induced luminescence of singlet molecular oxygen: generation by drugs and pigments of biological importance

    Science.gov (United States)

    Egorov, Sergei Y.; Krasnovsky, Alexander A., Jr.

    1991-05-01

    The photon counting technique and flashlaser excitation were applied to the timeresolved measurement of photosensitized singlet oxygen luminescence in organic and aqueous media. The quantum yields for singlet oxygen generation have been measured in solutions of photosynthetic pigments synthetic and natural porphyrins porphyrins conjugated with monoclonal antibodies furocoumarins flavins fluorescein tetracycline and endogenous photosensitizers of human lens. The data obtained indicate that the measurement of the singlet oxygen luminescence is a reliable tool to study the photosensitizing activity of drugs and to elucidate primary mechanisms of photodynamic destruction. 1.

  18. Effect of nickel loading on hydrogen production and chemical oxygen demand (COD) destruction from glucose oxidation and gasification in supercritical water

    International Nuclear Information System (INIS)

    minutes of reaction time increased the hydrogen yield from 0.618 mol/mol to 1.45 mol/mol. Chemical oxygen demand (COD) removal efficiency was 75 % in presence of both commercial and synthesized catalysts and 90 % without catalyst. This study showed that the same hydrogen yield can be obtained from the synthesized low nickel alumina loading (18 wt %) catalyst with (65 wt %) nickel on silica-alumina loading commercial catalyst. (author)

  19. Tide-related biological rhythm in the oxygen consumption rate of ghost shrimp (Neotrypaea uncinata).

    Science.gov (United States)

    Leiva, Félix P; Niklitschek, Edwin J; Paschke, Kurt; Gebauer, Paulina; Urbina, Mauricio A

    2016-07-01

    The effects of tidal height (high and low), acclimation to laboratory conditions (days in captivity) and oxygen level (hypoxia and normoxia) were evaluated in the oxygen consumption rate (OCR) of the ghost shrimp Neotrypaea uncinata We evaluated the hypothesis that N. uncinata reduces its OCR during low tide and increases it during high tide, regardless of oxygen level or acclimation. Additionally, the existence of an endogenous rhythm in OCR was explored, and we examined whether it synchronized with tidal, diurnal or semidiurnal cycles. Unexpectedly, high OCRs were observed at low tide, during normoxia, in non-acclimated animals. Results from a second, longer experiment under normoxic conditions suggested the presence of a tide-related metabolic rhythm, a response pattern not yet demonstrated for a burrowing decapod. Although rhythms persisted for only 2 days after capture, their period of 12.8 h closely matched the semidiurnal tidal cycle that ghost shrimp confront inside their burrows. PMID:27099365

  20. Metabolic scaling theory in plant biology and the three oxygen paradoxa of aerobic life.

    Science.gov (United States)

    Kutschera, Ulrich; Niklas, Karl J

    2013-12-01

    Alfred Russell Wallace was a field naturalist with a strong interest in general physiology. In this vein, he wrote that oxygen (O2), produced by green plants, is "the food of protoplasm, without which it cannot continue to live". Here we summarize current models relating body size to respiration rates (in the context of the metabolic scaling theory) and show that oxygen-uptake activities, measured at 21 vol.% O2, correlate closely with growth patterns at the level of specific organs within the same plant. Thus, whole plant respiration can change ontogenetically, corresponding to alterations in the volume fractions of different tissues. Then, we describe the evolution of cyanobacterial photosynthesis during the Paleoarchean, which changed the world forever. By slowly converting what was once a reducing atmosphere to an oxidizing one, microbes capable of O2-producing photosynthesis modified the chemical nature and distribution of the element iron (Fe), slowly drove some of the most ancient prokaryotes to extinction, created the ozone (O3) layer that subsequently shielded the first terrestrial plants and animals from harmful UV radiation, but also made it possible for Earth's forest to burn, sometimes with catastrophic consequences. Yet another paradox is that the most abundant protein (i.e., the enzyme Rubisco, Ribulose-1,5-biphosphate carboxylase/oxygenase) has a greater affinity for oxygen than for carbon dioxide (CO2), even though its function is to bind with the latter rather than the former. We evaluate this second "oxygen paradox" within the context of photorespiratory carbon loss and crop yield reduction in C3 vs. C4 plants (rye vs. maize). Finally, we analyze the occurrence of reactive oxygen species (ROS) as destructive by-products of cellular metabolism, and discuss the three "O2-paradoxa" with reference to A. R. Wallace's speculations on "design in nature".

  1. NADPH Oxidases: A Perspective on Reactive Oxygen Species Production in Tumor Biology

    OpenAIRE

    Meitzler, Jennifer L.; Antony, Smitha; Wu, Yongzhong; Juhasz, Agnes; Liu, Han; Jiang, Guojian; LU, JIAMO; ROY, KRISHNENDU; Doroshow, James H.

    2014-01-01

    Significance: Reactive oxygen species (ROS) promote genomic instability, altered signal transduction, and an environment that can sustain tumor formation and growth. The NOX family of NADPH oxidases, membrane-bound epithelial superoxide and hydrogen peroxide producers, plays a critical role in the maintenance of immune function, cell growth, and apoptosis. The impact of NOX enzymes in carcinogenesis is currently being defined and may directly link chronic inflammation and NOX ROS-mediated tum...

  2. Comparison of Poly Aluminum Chloride and Chlorinated Cuprous for Chemical Oxygen Demand and Color Removal from Kashan Textile Industries Company Wastewater

    Directory of Open Access Journals (Sweden)

    Hoseindoost Gh.1 MSPH,

    2016-08-01

    Full Text Available Aims Textile wastewaters are the most important health and environmental problems in Kashan. This research was aimed to compare the poly aluminum chloride and chlorinated cuprous efficiency for removal of Chemical Oxygen Demand (COD and color from Kashan Textile Industries Company wastewater. Materials & Methods This experimental bench scale study in a batch system was conducted on 20 composed wastewater samples collected from Kashan Textile Industries Company raw wastewater. During 5 months, in the beginning of every week a day was selected randomly and in the day a composed sample was taken and studied. PAC at the doses of 10, 20, 30, 40 and 50mg.l-1 and chlorinated cuprous at the doses of 100, 200, 300, 400 and 500mg.l-1 were applied. The optimum pH also optimum concentration of PAC and chlorinated cuprous were determined using Jar test. The data was analyzed by SPSS 16 using descriptive statistics and Fisher Exact test. Findings The average concentration of COD in the raw textile wastewater was 2801.56±1398.29mg.l-1. The average COD concentration has been decreased to 1125.47±797.55mg.l-1. There was a significant difference between the effects of these two coagulants efficiency (p<0.05. The average COD removal efficiency for chlorinated cuprous and PAC was 58.52% and 72.56%, respectively. Also, the average color removal efficiency by chlorinated cuprous and PAC were 17.23 and 64.45%, respectively. Conclusion PAC is more efficient than chlorinated cuprous for both COD and color removal from KTIC wastewater.

  3. Long-term effects of antibiotics on the elimination of chemical oxygen demand, nitrification, and viable bacteria in laboratory-scale wastewater treatment plants.

    Science.gov (United States)

    Schmidt, Susan; Winter, Josef; Gallert, Claudia

    2012-10-01

    Antibiotics and other pharmaceuticals are contaminants of the environment because of their widespread use and incomplete removal by microorganisms during wastewater treatment. The influence of a mixture of ciprofloxacin (CIP), gentamicin (GM), sulfamethoxazole (SMZ)/trimethoprim (TMP), and vancomycin (VA), up to a final concentration of 40 mg/L, on the elimination of chemical oxygen demand (COD), nitrification, and survival of bacteria, as well as the elimination of the antibiotics, was assessed in a long-term study in laboratory treatment plants (LTPs). In the presence of 30 mg/L antibiotics, nitrification of artificial sewage by activated sludge ended at nitrite. Nitrate formation was almost completely inhibited. No nitrification at all was possible in the presence of 40 mg/L antibiotics. The nitrifiers were more sensitive to antibiotics than heterotrophic bacteria. COD elimination in antibiotic-stressed LTPs was not influenced by ≤20 mg/L antibiotics. Addition of 30 mg/L antibiotic mixture decreased COD removal efficiency for a period, but the LTPs recovered. Similar results were obtained with 40 mg/L antibiotic mixture. The total viable count of bacteria was not affected negatively by the antibiotics. It ranged from 2.2 × 10(6) to 8.2 × 10(6) colony-forming units per milliliter (CFU/mL) compared with the control at 1.4 × 10(6)-6.3 × 10(6) CFU/mL. Elimination of the four antibiotics during phases of 2.4-30 mg/L from the liquid was high for GM (70-90 %), much lower for VA, TMP, and CIP (0-50 %), and highly fluctuating for SMZ (0-95 %). The antibiotics were mainly adsorbed to the sludge and not biodegraded. PMID:22622431

  4. Development of variable pathlength UV-vis spectroscopy combined with partial-least-squares regression for wastewater chemical oxygen demand (COD) monitoring.

    Science.gov (United States)

    Chen, Baisheng; Wu, Huanan; Li, Sam Fong Yau

    2014-03-01

    To overcome the challenging task to select an appropriate pathlength for wastewater chemical oxygen demand (COD) monitoring with high accuracy by UV-vis spectroscopy in wastewater treatment process, a variable pathlength approach combined with partial-least squares regression (PLSR) was developed in this study. Two new strategies were proposed to extract relevant information of UV-vis spectral data from variable pathlength measurements. The first strategy was by data fusion with two data fusion levels: low-level data fusion (LLDF) and mid-level data fusion (MLDF). Predictive accuracy was found to improve, indicated by the lower root-mean-square errors of prediction (RMSEP) compared with those obtained for single pathlength measurements. Both fusion levels were found to deliver very robust PLSR models with residual predictive deviations (RPD) greater than 3 (i.e. 3.22 and 3.29, respectively). The second strategy involved calculating the slopes of absorbance against pathlength at each wavelength to generate slope-derived spectra. Without the requirement to select the optimal pathlength, the predictive accuracy (RMSEP) was improved by 20-43% as compared to single pathlength spectroscopy. Comparing to nine-factor models from fusion strategy, the PLSR model from slope-derived spectroscopy was found to be more parsimonious with only five factors and more robust with residual predictive deviation (RPD) of 3.72. It also offered excellent correlation of predicted and measured COD values with R(2) of 0.936. In sum, variable pathlength spectroscopy with the two proposed data analysis strategies proved to be successful in enhancing prediction performance of COD in wastewater and showed high potential to be applied in on-line water quality monitoring.

  5. InfoBiology by printed arrays of microorganism colonies for timed and on-demand release of messages.

    Science.gov (United States)

    Palacios, Manuel A; Benito-Peña, Elena; Manesse, Mael; Mazzeo, Aaron D; Lafratta, Christopher N; Whitesides, George M; Walt, David R

    2011-10-01

    This paper presents a proof-of-principle method, called InfoBiology, to write and encode data using arrays of genetically engineered strains of Escherichia coli with fluorescent proteins (FPs) as phenotypic markers. In InfoBiology, we encode, send, and release information using living organisms as carriers of data. Genetically engineered systems offer exquisite control of both genotype and phenotype. Living systems also offer the possibility for timed release of information as phenotypic features can take hours or days to develop. We use growth media and chemically induced gene expression as cipher keys or "biociphers" to develop encoded messages. The messages, called Steganography by Printed Arrays of Microbes (SPAM), consist of a matrix of spots generated by seven strains of E. coli, with each strain expressing a different FP. The coding scheme for these arrays relies on strings of paired, septenary digits, where each pair represents an alphanumeric character. In addition, the photophysical properties of the FPs offer another method for ciphering messages. Unique combinations of excited and emitted wavelengths generate distinct fluorescent patterns from the Steganography by Printed Arrays of Microbes (SPAM). This paper shows a new form of steganography based on information from engineered living systems. The combination of bio- and "photociphers" along with controlled timed-release exemplify the capabilities of InfoBiology, which could enable biometrics, communication through compromised channels, easy-to-read barcoding of biological products, or provide a deterrent to counterfeiting.

  6. Biological nitrogen fixation is not a major contributor to the nitrogen demand of a commercially growth South African sugarcane cultivar

    NARCIS (Netherlands)

    Hoefsloot, G.; Termorshuizen, A.J.; Watt, D.A.; Cramer, M.D.

    2005-01-01

    It has previously been reported that endophytic diazotrophic bacteria contribute significantly to the nitrogen budgets of some graminaceous species. In this study the contribution of biological nitrogen fixation to the N-budget of a South African sugarcane cultivar was evaluated using 15N natural ab

  7. Assessment of Biological Kinetics in a Conventional Municipal WWTP by Means of the Oxygen Uptake Rate Method

    Directory of Open Access Journals (Sweden)

    Vincenzo Torretta

    2014-04-01

    Full Text Available Pollution control of surface water bodies requires stringent checks on wastewater treatment plants performances. The satisfactory operation of biological treatment, commonly performed by means of activated sludge processes, requires a number of controlling and monitoring procedures. Suitable respirometric techniques for the determination of the kinetic parameters that regulate biological processes have been implemented in order to achieve this aim. This paper describes the results of an experimental research carried out in a conventional Italian municipal wastewater treatment plant. Particularly, the research has been finalized to both evaluate the biological process for the removal of biodegradable pollutants, such as carbonaceous substrates and ammonia nitrogen, and to collect data in order to evaluate a possible plant upgrade. Heterotrophic and autotrophic biomass kinetic parameters have been examined using respirometric techniques based on oxygen uptake measurements. The research performed makes a valuable contribution toward verifying the reliability of the values proposed in the literature for some kinetic parameters, which have been commonly used for a long time.

  8. Determination of biological transport of oxygen-15 and carbon-11 generated in rats

    International Nuclear Information System (INIS)

    The distribution of induced 15O and 11C activity in live and dead rats was determined following local irradiation with a 32 MeV proton beam. Results indicate that rapid biological redistribution of some of the induced activity occurs within a minute following irradiation. Sufficient activity remains, bound in the intracellular water, to define the proton beam in tissue. Thus, mapping of the induced 15O activity proves to be a valid means of beam localization

  9. The emerging role of reactive oxygen and nitrogen species in redox biology and some implications for plasma applications to medicine and biology

    International Nuclear Information System (INIS)

    Reactive oxygen species (ROS) and the closely related reactive nitrogen species (RNS) are often generated in applications of atmospheric pressure plasmas intended for biomedical purposes. These species are also central players in what is sometimes referred to as ‘redox’ or oxidation-reduction biology. Oxidation-reduction biochemistry is fundamental to all of aerobic biology. ROS and RNS are perhaps best known as disease-associated agents, implicated in diabetes, cancer, heart and lung disease, autoimmune disease and a host of other maladies including ageing and various infectious diseases. These species are also known to play active roles in the immune systems of both animals and plants and are key signalling molecules, among many other important roles. Indeed, the latest research has shown that ROS/RNS play a much more complex and nuanced role in health and ageing than previously thought. Some of the most potentially profound therapeutic roles played by ROS and RNS in various medical interventions have emerged only in the last several years. Recent research suggests that ROS/RNS are significant and perhaps even central actors in the actions of antimicrobial and anti-parasite drugs, cancer therapies, wound healing therapies and therapies involving the cardiovascular system. Understanding the ways ROS/RNS act in established therapies may help guide future efforts in exploiting novel plasma medical therapies. The importance of ROS and RNS to plant biology has been relatively little appreciated in the plasma biomedicine community, but these species are just as important in plants. It appears that there are opportunities for useful applications of plasmas in this area as well. (topical review)

  10. The emerging role of reactive oxygen and nitrogen species in redox biology and some implications for plasma applications to medicine and biology

    Science.gov (United States)

    Graves, David B.

    2012-07-01

    Reactive oxygen species (ROS) and the closely related reactive nitrogen species (RNS) are often generated in applications of atmospheric pressure plasmas intended for biomedical purposes. These species are also central players in what is sometimes referred to as ‘redox’ or oxidation-reduction biology. Oxidation-reduction biochemistry is fundamental to all of aerobic biology. ROS and RNS are perhaps best known as disease-associated agents, implicated in diabetes, cancer, heart and lung disease, autoimmune disease and a host of other maladies including ageing and various infectious diseases. These species are also known to play active roles in the immune systems of both animals and plants and are key signalling molecules, among many other important roles. Indeed, the latest research has shown that ROS/RNS play a much more complex and nuanced role in health and ageing than previously thought. Some of the most potentially profound therapeutic roles played by ROS and RNS in various medical interventions have emerged only in the last several years. Recent research suggests that ROS/RNS are significant and perhaps even central actors in the actions of antimicrobial and anti-parasite drugs, cancer therapies, wound healing therapies and therapies involving the cardiovascular system. Understanding the ways ROS/RNS act in established therapies may help guide future efforts in exploiting novel plasma medical therapies. The importance of ROS and RNS to plant biology has been relatively little appreciated in the plasma biomedicine community, but these species are just as important in plants. It appears that there are opportunities for useful applications of plasmas in this area as well.

  11. The stability of the reactive oxygen metabolites (d-ROMs) and biological antioxidant potential (BAP) tests on stored horse blood.

    Science.gov (United States)

    Celi, P; Sullivan, M; Evans, D

    2010-02-01

    Increasing interest in the role of oxidative stress (OS) in equine medicine has highlighted the need to develop reliable methods to quantify it. In this study we describe the effect of refrigeration (at 4 degrees C) on the stability of the reactive oxygen metabolites (d-ROMs) and biological antioxidant potential (BAP) tests carried out on 15 healthy horses. Blood samples, collected from the jugular vein, were immediately placed on ice and analysed using both the d-ROMs and BAP tests. Samples were also refrigerated at 4 degrees C and tested after 3, 7 and 24 h. The average results were similar for up to 24 h and minimal variations were found for each horse. The findings suggest that refrigeration is suitable for preserving equine blood samples for these assays and this approach will provide veterinarians with a technically simple, reliable test to measure OS under field conditions.

  12. Determination of singlet oxygen quenching and protection of biological systems by various extracts from seed of Rumex crispus L.

    Science.gov (United States)

    Suh, Hwa-Jin; Lee, Kyung-Seok; Kim, Seong-Ryul; Shin, Myoung-Ho; Park, Sanggyu; Park, Shin

    2011-02-01

    The 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging effect and total phenolic contents were evaluated for the screening of singlet oxygen ((1)O(2)) quenching efficacy of various seed extracts from Rumex crispus L. The butanol and ethyl-acetate extracts displayed remarkable effect of DPPH as compared to positive control ascorbic acid. The concentrations (QC(50)) of butanol and ethyl-acetate extracts required to exert 50% reducing effect on (1)O(2) were found to be 116 and 82 μg mL(-1), respectively. Both extracts were also found to protect the in vitro biological system from the detrimental effect of (1)O(2) on type II photosensitization in Escherichia coli, red blood cell, lactate dehydrogenase and histidine. Among all the tested extracts, the ethyl-acetate and butanol extracts contained higher amount of total phenolic contents. The results suggest that our study may contribute to the development of new bioactive products with potential applications to reduce photo-produced oxidative stress involving reactive oxygen species in living organisms. PMID:21185197

  13. Mitochondrial Flash: Integrative Reactive Oxygen Species and pH Signals in Cell and Organelle Biology

    Science.gov (United States)

    Gong, Guohua; Wang, Xianhua; Wei-LaPierre, Lan; Cheng, Heping; Dirksen, Robert

    2016-01-01

    Abstract Significance: Recent breakthroughs in mitochondrial research have advanced, reshaped, and revolutionized our view of the role of mitochondria in health and disease. These discoveries include the development of novel tools to probe mitochondrial biology, the molecular identification of mitochondrial functional proteins, and the emergence of new concepts and mechanisms in mitochondrial function regulation. The discovery of “mitochondrial flash” activity has provided unique insights not only into real-time visualization of individual mitochondrial redox and pH dynamics in live cells but has also advanced understanding of the excitability, autonomy, and integration of mitochondrial function in vivo. Recent Advances: The mitochondrial flash is a transient and stochastic event confined within an individual mitochondrion and is observed in a wide range of organisms from plants to Caenorhabditis elegans to mammals. As flash events involve multiple transient concurrent changes within the mitochondrion (e.g., superoxide, pH, and membrane potential), a number of different mitochondrial targeted fluorescent indicators can detect flash activity. Accumulating evidence indicates that flash events reflect integrated snapshots of an intermittent mitochondrial process arising from mitochondrial respiration chain activity associated with the transient opening of the mitochondrial permeability transition pore. Critical Issues: We review the history of flash discovery, summarize current understanding of flash biology, highlight controversies regarding the relative roles of superoxide and pH signals during a flash event, and bring forth the integration of both signals in flash genesis. Future Directions: Investigations using flash as a biomarker and establishing its role in cell signaling pathway will move the field forward. Antioxid. Redox Signal. 25, 534–549. PMID:27245241

  14. Oxygen in human health from life to death – An approach to teaching redox biology and signaling to graduate and medical students

    Directory of Open Access Journals (Sweden)

    Margaret M. Briehl

    2015-08-01

    Full Text Available In the absence of oxygen human life is measured in minutes. In the presence of oxygen, normal metabolism generates reactive species (ROS that have the potential to cause cell injury contributing to human aging and disease. Between these extremes, organisms have developed means for sensing oxygen and ROS and regulating their cellular processes in response. Redox signaling contributes to the control of cell proliferation and death. Aberrant redox signaling underlies many human diseases. The attributes acquired by altered redox homeostasis in cancer cells illustrate this particularly well. This teaching review and the accompanying illustrations provide an introduction to redox biology and signaling aimed at instructors of graduate and medical students.

  15. An assessment of oxygen transfer efficiency in a gas permeable hollow fibre membrane biological reactor.

    Science.gov (United States)

    Soreanu, G; Lishman, L; Dunlop, S; Behmann, H; Seto, P

    2010-01-01

    The clean water oxygen transfer efficiency (OTE) of a full scale non-porous hollow fibre gas permeable (GP) membrane (surface area of 500 m(2)) was evaluated at inlet air pressures of 1.2, 1.4, and 1.8 atm using two established testing methods. To form a basis of comparison with traditional aeration technologies, additional testing was done with conventional aerators (fine bubble and coarse bubble diffusers) replacing the GP membrane. OTE can be established based on the re-aeration of deoxygenated water or by monitoring the catalytic oxidation of a sodium sulphite (Na(2)SO(3)) solution. In this study, OTE values determined by sulphite oxidation (SOTE(S)) were consistently higher than those established during re-aeration (SOTE(R)) suggesting that the chemical reaction was enhancing the mass transfer. The chemical reaction was sufficiently fast in the case of the GP membrane, that the gas phase limited the mass transfer. The GP membrane operating at 1.2 atm had a SOTE(S) of 70.6% and a SOTER of 52.2%. SOTE(R) for the coarse bubble and fine bubble diffusers were 3.8% and 23.6%, respectively. This is comparable to the manufacturer's values, corrected for depth of 3.4% and 18.3%, respectively. Particularly, the derived OTE values were used to evaluate differences in energy consumption for a conventional treatment plant achieving carbon removal and nitrification. This analysis highlights the potential energy efficiency of GP membranes, which could be considered for the design of the membrane modules. PMID:20220238

  16. Biological and physical induced oxygen dynamics in melting sea ice of the Fram Strait

    DEFF Research Database (Denmark)

    Glud, Ronnie; Rysgaard, Søren; Turner, Gavin;

    2014-01-01

    We investigated the production, consumption, and exchange of O2 in melting sea ice to assess the biological- and physical-induced O2 turnover. The underside of the ice was covered with 5–20 cm3 large, buoyant algal aggregates. Their gross primary production amounted to 0.49 mmol C m−2 d−1, which...... that the aggregates were formed from agglutinated algae released from the melting ice. At the prevailing light conditions, the sea ice–encrusted communities were almost at metabolic balance, while the aggregates were net heterotrophic. Together, the two communities were responsible for an overall O2 consumption of 0.......32 mmol m−2 d−1. The sea ice–associated communities thereby represent a southward-drifting carbon source that is being exhausted by sea ice–affiliated food webs. The sea ice volume decreased rapidly, releasing meltwater at a rate 25 L m−2 d−1, but no surface melt ponds were formed. Aquatic eddy...

  17. Carbon, oxygen and biological productivity in the Southern Ocean in and out the Kerguelen plume: CARIOCA drifter results

    Directory of Open Access Journals (Sweden)

    L. Merlivat

    2014-12-01

    Full Text Available The Kerguelen Plateau region in the Indian sector of the Southern Ocean supports annually a large-scale phytoplankton bloom which is naturally fertilized with iron. As part of the second Kerguelen Ocean and Plateau compared Study expedition (KEOPS2 in austral spring (October–November 2011, one Carioca buoy was deployed east of the Kerguelen plateau. It drifted eastward downstream in the Kerguelen plume. Hourly surface measurements of pCO2, O2 and ancillary observations were collected between 1 November 2011 to 12 February 2012 with the aim of characterizing the spatial and temporal variability of the biological Net Community Production (NCP downstream the Kerguelen plateau, assess the impact of iron-induced productivity on the biological carbon consumption and consequently on the CO2 flux exchanged at the air–sea interface. The trajectory of the buoy until mid-December was within the longitude range, 72–83° E, close to the polar front and then in the polar frontal zone, PFZ, until 97° E. From 17 November to 16 December, the buoy drifted within the Kerguelen plume following a filament carrying dissolved iron, DFe, for a total distance of 700 km. In the first part of the trajectory, the ocean surface waters are a sink for CO2 and a source for CO2, with fluxes of respective mean values equal to −8 and +38 mmol CO2 m−2 d−1. Eastward, as the buoy escapes the iron enriched filament, the fluxes are in opposite direction, with respective mean values of +5 and −48 mmol O2 m−2 d−1. These numbers clearly indicate the strong impact of biological processes on the biogeochemistry in the surface waters within the Kerguelen plume in November-mid-December, while it is undetectable eastward in the PFZ from mid-December to mid-February. While the buoy follows the Fe enriched filament, simultaneous observations of dissolved inorganic carbon, DIC, and dissolved oxygen, O2, highlight biological events lasting from 2 to 4 days. Stoichiometric

  18. Light and Dark of Reactive Oxygen Species for Vascular Function: 2014 ASVB (Asian Society of Vascular Biology).

    Science.gov (United States)

    Shimokawa, Hiroaki; Satoh, Kimio

    2015-05-01

    Vascular-derived hydrogen peroxide (H2O2) serves as an important signaling molecule in the cardiovascular system and contributes to vascular homeostasis. H2O2 is a second messenger, transducing the oxidative signal into biological responses through posttranslational protein modification. The balance between oxidant and antioxidant systems regulates intracellular redox status, and their imbalance causes oxidative or reductive stress, leading to cellular damage in cardiovascular systems. Excessive H2O2 deteriorates vascular functions and promotes vascular disease through multiple pathways. The RhoA/Rho-kinase pathway plays an important role in various fundamental cellular functions, including production of excessive reactive oxygen species, leading to the development of cardiovascular diseases. Rho-kinase (ROCK1 and ROCK2) belongs to the family of serine/threonine kinases and is an important downstream effector of the small GTP-binding protein RhoA. Rho-kinase plays a crucial role in the pathogenesis of vasospasm, arteriosclerosis, ischemia/reperfusion injury, hypertension, pulmonary hypertension, stroke, and heart failure. Thus, Rho-kinase inhibitors may be useful for the treatment of cardiovascular diseases in humans. In this review, we will briefly discuss the roles of vascular-derived H2O2 and review the recent progress in the translational research on the therapeutic importance of the Rho-kinase pathway in cardiovascular medicine.

  19. The imbalance between oxygen demand and supply as a potential mechanism in the pathophysiology of heart failure : The role of microvascular growth and abnormalities

    NARCIS (Netherlands)

    De Boer, RA; Pinto, YM; van Veldhuisen, DJ

    2003-01-01

    In heart failure., a deficient oxygen supply often is a primary cause for myocardial dysfunction. The reverse however, may also be true; the changes that occur in the failing heart may predispose for the existence of tissue hypoxia, which further affects the function of the heart. Specifically, myoc

  20. Energy Demand

    NARCIS (Netherlands)

    Stehfest, E. et al.

    2014-01-01

    Key policy issues – How will energy demand evolve particularly in emerging and medium- and low- income economies? – What is the mix of end-use energy carriers to meet future energy demand? – How can energy efficiency contribute to reducing the growth rate of energy demand and mitigate pressures on t

  1. Energy Demand

    OpenAIRE

    Stehfest, E. et al.

    2014-01-01

    Key policy issues – How will energy demand evolve particularly in emerging and medium- and low- income economies? – What is the mix of end-use energy carriers to meet future energy demand? – How can energy efficiency contribute to reducing the growth rate of energy demand and mitigate pressures on the global environment?

  2. Role of H2O2 in the fluctuating patterns of COD (chemical oxygen demand) during the treatment of palm oil mill effluent (POME) using pilot scale triple frequency ultrasound cavitation reactor.

    Science.gov (United States)

    Manickam, Sivakumar; Abidin, Norhaida binti Zainal; Parthasarathy, Shridharan; Alzorqi, Ibrahim; Ng, Ern Huay; Tiong, Timm Joyce; Gomes, Rachel L; Ali, Asgar

    2014-07-01

    Palm oil mill effluent (POME) is a highly contaminating wastewater due to its high chemical oxygen demand (COD) and biochemical oxygen demand (BOD). Conventional treatment methods require longer residence time (10-15 days) and higher operating cost. Owing to this, finding a suitable and efficient method for the treatment of POME is crucial. In this investigation, ultrasound cavitation technology has been used as an alternative technique to treat POME. Cavitation is the phenomenon of formation, growth and collapse of bubbles in a liquid. The end process of collapse leads to intense conditions of temperature and pressure and shock waves which assist various physical and chemical transformations. Two different ultrasound systems i.e. ultrasonic bath (37 kHz) and a hexagonal triple frequency ultrasonic reactor (28, 40 and 70 kHz) of 15 L have been used. The results showed a fluctuating COD pattern (in between 45,000 and 60,000 mg/L) while using ultrasound bath alone, whereas a non-fluctuating COD pattern with a final COD of 27,000 mg/L was achieved when hydrogen peroxide was introduced. Similarly for the triple frequency ultrasound reactor, coupling all the three frequencies resulted into a final COD of 41,300 mg/L compared to any other individual or combination of two frequencies. With the possibility of larger and continuous ultrasonic cavitational reactors, it is believed that this could be a promising and a fruitful green process engineering technique for the treatment of POME.

  3. Biologic

    CERN Document Server

    Kauffman, L H

    2002-01-01

    In this paper we explore the boundary between biology and the study of formal systems (logic). In the end, we arrive at a summary formalism, a chapter in "boundary mathematics" where there are not only containers but also extainers ><, entities open to interaction and distinguishing the space that they are not. The boundary algebra of containers and extainers is to biologic what boolean algebra is to classical logic. We show how this formalism encompasses significant parts of the logic of DNA replication, the Dirac formalism for quantum mechanics, formalisms for protein folding and the basic structure of the Temperley Lieb algebra at the foundations of topological invariants of knots and links.

  4. Synthesis, characterization and biological relevance of some metal (II) complexes with oxygen, nitrogen and oxygen (ONO) donor Schiff base ligand derived from thiazole and 2-hydroxy-1-naphthaldehyde

    Science.gov (United States)

    Nagesh, G. Y.; Mruthyunjayaswamy, B. H. M.

    2015-04-01

    The novel Schiff base ligand 2-((2-hydroxynaphthalen-1-yl)methylene)-N-(4-phenylthiazol-2-yl)hydrazinecarboxamide (L) obtained by the condensation of N-(4-phenylthiazol-2-yl)hydrazinecarboxamide with 2-hydroxy-1-naphthaldehyde and its newly synthesized Cu(II), Co(II), Ni(II), Zn(II) and Cd(II) complexes have been characterized by microanalysis, molar conductance, IR, 1H NMR, ESI-mass, UV-Visible, TGA/DTA, ESR and powder X-ray diffraction data to explicate their structures. The IR results confirmed the tridentate binding of the ligand involving oxygen atom of amide carbonyl, azomethine nitrogen and naphthol oxygen. 1H NMR spectral data of the ligand (L) and its Zn(II) complex agreed well with the proposed structures. Thermogravimetric studies for Cu(II) and Ni(II) complexes indicated the presence of coordinated water molecules and the final product is the metal oxide. In order to appraise the effect of antimicrobial activity of metal ions upon chelation, the newly synthesized ligand and its metal complexes were screened for their antimicrobial activity by minimum inhibitory concentration (MIC) method. The DNA cleavage activities were studied using plasmid DNA pBR322 (Bangal re Genei, Bengaluru, Cat. No 105850) as a target molecule by agarose gel electrophoresis method. The brine shrimp bioassay was also carried out to study the in vitro cytotoxicity properties against Artemia salina. Furthermore, the antioxidant activity were determined in vitro by reduction of 1,1-diphenyl-2-picryl hydrazyl (DPPH). The ligand exhibited better in vitro-antioxidant activity than its metal complexes.

  5. 三种快速测定石油污水中COD方法的比较%Comparison of three methods for determination of chemical oxygen demand of petroleum polluted water

    Institute of Scientific and Technical Information of China (English)

    贾锦霞; 郭景玉

    2011-01-01

    以新疆乌鲁木齐石化总厂石油污水研究对象,采用标准法从消解时间、取样量、催化剂用量三方面考察测定了COD的最佳实验条件,并在两实验室间验证其可靠性。分别利用重铬酸钾快速法、密封消解法、HACH法测定石油污水的COD值,并与标准法进行比对。结果表明:(1)取样量相同时,重铬酸钾快速法比标准法耗酸量还要多,仅仅只是缩短了回流时间;(2)密封消解法具有省时、省试制、工作效率高的特点,可以作为标准法的替代方法;(3)HACH方法在实际操作中不经济。%The national standard method was used to detect chemical oxygen demand of petroleum -polluted water from Urumchi petrochemistry company.The elimination time, sample Volume and catalyst consumption of the chemical oxygen demand was determined. The optimal experimental condition of the were determined and verified by practical water sample between two Laboratories.Three kinds of methods were Compared with the standard method.It was shown that.(1)In the same condition,The catalyst amount of K_2Cr_2O_7 rapid detecting were more than national standard.(2)the standard method was replaced of the sealed elimination by saving time,saving drugs and high efficiency.(3)In practice,HACH was uneconomic.

  6. Biological oxygen sensing via two-photon absorption by an Ir(III) complex using a femtosecond fiber laser

    Science.gov (United States)

    Moritomo, Hiroki; Fujii, Akinari; Suzuki, Yasutaka; Yoshihara, Toshitada; Tobita, Seiji; Kawamata, Jun

    2016-09-01

    Near-infrared two-photon absorption of the phosphorescent Ir(III) complex (2,4-pentanedionato-κO 2,κO 4)bis[2-(6-phenanthridinyl-κN)benzo[b]thien-3-yl-κC]iridium (BTPHSA) was characterized. It exhibited a 800-1200 nm two-photon absorption band, and thus could be electronically excited by 1030-nm femtosecond Ti:sapphire and Yb-doped fiber lasers. By using BTPHSA, oxygen concentrations in human embryonic kidney 293 (HEK293) cells were imaged. These results demonstrate two-photon oxygen sensing of live tissues via easily operable excitation sources.

  7. STUDY OF PHYSIO-CHEMICAL CHARACTERISTICS AND BIOLOGICAL TREATMENT OF MOLASSES-BASED DISTILLERY EFFLUENT

    OpenAIRE

    Anupama Chaudhary* AK Sharma and Birbal Singh

    2013-01-01

    Molasses based distilleries are recognized as of major polluting industries with a large amount of annual effluent production. Modi Distillery, located at Modi Nagar in western Uttar Pradesh, is a molasses-based distillery with a capacity of 26 KLPD. Being an alcohol-processing unit, we estimated capacity and efficiency of Modi distillery that discharges highly polluted effluent to small drainage with a very high biological oxygen demand (BOD) (42,000-51,000mg/ltr) and chemical oxygen demand ...

  8. Demand Uncertainty

    DEFF Research Database (Denmark)

    Nguyen, Daniel Xuyen

    This paper presents a model of trade that explains why firms wait to export and why many exporters fail. Firms face uncertain demands that are only realized after the firm enters the destination. The model retools the timing of uncertainty resolution found in productivity heterogeneity models...... the high rate of exit seen in the first years of exporting. Finally, when faced with multiple countries in which to export, some firms will choose to sequentially export in order to slowly learn more about its chances for success in untested markets....

  9. Low pressure radio-frequency oxygen plasma induced oxidation of titanium--surface characteristics and biological effects.

    Directory of Open Access Journals (Sweden)

    Wan-Yu Tseng

    Full Text Available OBJECTIVE: This research was designed to investigate the effects of low pressure radio-frequency (RF oxygen plasma treatment (OPT on the surface of commercially pure titanium (CP-Ti and Ti6Al4V. Surface topography, elemental composition, water contact angle, cell viability, and cell morphology were surveyed to evaluate the biocompatibility of titanium samples with different lengths of OP treating time. MATERIALS AND METHODS: CP-Ti and Ti6Al4V discs were both classified into 4 groups: untreated, treated with OP generated by using oxygen (99.98% for 5, 10, and 30 min, respectively. After OPT on CP-Ti and Ti6Al4V samples, scanning probe microscopy, X-ray photoelectron spectrometry (XPS, and contact angle tests were conducted to determine the surface topography, elemental composition and hydrophilicity, respectively. The change of surface morphology was further studied using sputtered titanium on silicon wafers. 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT assay and F-actin immunofluorescence stain were performed to investigate the viability and spreading behavior of cultivated MG-63 cells on the samples. RESULTS: The surface roughness was most prominent after 5 min OPT in both CP-Ti and Ti6Al4V, and the surface morphology of sputtered Ti sharpened after the 5 min treatment. From the XPS results, the intensity of Ti(°, Ti(2+, and Ti(3+ of the samples' surface decreased indicating the oxidation of titanium after OPT. The water contact angles of both CP-Ti and Ti6Al4V were increased after 5 min OPT. The results of MTT assay demonstrated MG-63 cells proliferated best on the 5 min OP treated titanium sample. The F-actin immunofluorescence stain revealed the cultivated cell number of 5 min treated CP-Ti/Ti6Al4V was greater than other groups and most of the cultivated cells were spindle-shaped. CONCLUSIONS: Low pressure RF oxygen plasma modified both the composition and the morphology of titanium samples' surface. The CP-Ti/Ti6Al4V

  10. Brain Oxygenation Monitoring.

    Science.gov (United States)

    Kirkman, Matthew A; Smith, Martin

    2016-09-01

    A mismatch between cerebral oxygen supply and demand can lead to cerebral hypoxia/ischemia and deleterious outcomes. Cerebral oxygenation monitoring is an important aspect of multimodality neuromonitoring. It is increasingly deployed whenever intracranial pressure monitoring is indicated. Although there is a large body of evidence demonstrating an association between cerebral hypoxia/ischemia and poor outcomes, it remains to be determined whether restoring cerebral oxygenation leads to improved outcomes. Randomized prospective studies are required to address uncertainties about cerebral oxygenation monitoring and management. This article describes the different methods of monitoring cerebral oxygenation, their indications, evidence base, limitations, and future perspectives. PMID:27521197

  11. Oxygen Therapy

    Science.gov (United States)

    Oxygen therapy is a treatment that provides you with extra oxygen. Oxygen is a gas that your body ... machine in your home. A different kind of oxygen therapy is called hyperbaric oxygen therapy. It uses oxygen ...

  12. Serratia Secondary Metabolite Prodigiosin Inhibits Pseudomonas aeruginosa Biofilm Development by Producing Reactive Oxygen Species that Damage Biological Molecules

    Science.gov (United States)

    Kimyon, Önder; Das, Theerthankar; Ibugo, Amaye I.; Kutty, Samuel K.; Ho, Kitty K.; Tebben, Jan; Kumar, Naresh; Manefield, Mike

    2016-01-01

    Prodigiosin is a heterocyclic bacterial secondary metabolite belonging to the class of tripyrrole compounds, synthesized by various types of bacteria including Serratia species. Prodigiosin has been the subject of intense research over the last decade for its ability to induce apoptosis in several cancer cell lines. Reports suggest that prodigiosin promotes oxidative damage to double-stranded DNA (dsDNA) in the presence of copper ions and consequently leads to inhibition of cell-cycle progression and cell death. However, prodigiosin has not been previously implicated in biofilm inhibition. In this study, the link between prodigiosin and biofilm inhibition through the production of redox active metabolites is presented. Our study showed that prodigiosin (500 μM) (extracted from Serratia marcescens culture) and a prodigiosin/copper(II) (100 μM each) complex have strong RNA and dsDNA cleaving properties while they have no pronounced effect on protein. Results support a role for oxidative damage to biomolecules by H2O2 and hydroxyl radical generation. Further, it was demonstrated that reactive oxygen species scavengers significantly reduced the DNA and RNA cleaving property of prodigiosin. P. aeruginosa cell surface hydrophobicity and biofilm integrity were significantly altered due to the cleavage of nucleic acids by prodigiosin or the prodigiosin/copper(II) complex. In addition, prodigiosin also facilitated the bactericidal activity. The ability of prodigiosinto cause nucleic acid degradation offers novel opportunities to interfere with extracellular DNA dependent bacterial biofilms. PMID:27446013

  13. Serratia secondary metabolite prodigiosin inhibit Pseudomonas aeruginosa biofilm development by producing reactive oxygen species that damage biological molecules.

    Directory of Open Access Journals (Sweden)

    Onder eKimyon

    2016-06-01

    Full Text Available Prodigiosin is a heterocyclic bacterial secondary metabolite belonging to the class of tripyrrole compounds, synthesized by various types of bacteria including Serratia species. Prodigiosin has been the subject of intense research over the last decade for its ability to induce apoptosis in several cancer cell lines. Reports suggest that prodigiosin promotes oxidative damage to double-stranded DNA (dsDNA in the presence of copper ions and consequently leads to inhibition of cell-cycle progression and cell death. However, prodigiosin has not been previously implicated in biofilm inhibition. In this study, the link between prodigiosin and biofilm inhibition through the production of redox active metabolites is presented. Our study showed that prodigiosin (500 µM (extracted from Serratia marcescens culture and a prodigiosin/copper(II (100 µM each complex have strong RNA and dsDNA cleaving properties while they have no pronounced effect on protein. Results support a role for oxidative damage to biomolecules by H2O2 and hydroxyl radical generation. Further, it was demonstrated that reactive oxygen species scavengers significantly reduced the DNA and RNA cleaving property of prodigiosin. P. aeruginosa cell surface hydrophobicity and biofilm integrity were significantly altered due to the cleavage of nucleic acids by prodigiosin or the prodigiosin/copper(II complex. In addition, prodigiosin also facilitated the bactericidal activity. The ability of prodigiosin to cause nucleic acid degradation offers novel opportunities to interfere with extracellular DNA dependent bacterial biofilms.

  14. The relative biological effectiveness for carbon and oxygen ion beams using the raster-scanning technique in hepatocellular carcinoma cell lines.

    Directory of Open Access Journals (Sweden)

    Daniel Habermehl

    Full Text Available BACKGROUND: Aim of this study was to evaluate the relative biological effectiveness (RBE of carbon (12C and oxygen ion (16O-irradiation applied in the raster-scanning technique at the Heidelberg Ion beam Therapy center (HIT based on clonogenic survival in hepatocellular carcinoma cell lines compared to photon irradiation. METHODS: Four human HCC lines Hep3B, PLC, HepG2 and HUH7 were irradiated with photons, 12C and 16O using a customized experimental setting at HIT for in-vitro trials. Cells were irradiated with increasing physical photon single doses of 0, 2, 4 and 6 Gy and heavy ion-single doses of 0, 0.125, 0.5, 1, 2, 3 Gy (12C and 16O. SOBP-penetration depth and extension was 35 mm +/-4 mm and 36 mm +/-5 mm for carbon ions and oxygen ions respectively. Mean energy level and mean linear energy transfer (LET were 130 MeV/u and 112 keV/um for 12C, and 154 MeV/u and 146 keV/um for 16O. Clonogenic survival was computated and relative biological effectiveness (RBE values were defined. RESULTS: For all cell lines and both particle modalities α- and β-values were determined. As expected, α-values were significantly higher for 12C and 16O than for photons, reflecting a steeper decline of the initial slope of the survival curves for high-LET beams. RBE-values were in the range of 2.1-3.3 and 1.9-3.1 for 12C and 16O, respectively. CONCLUSION: Both irradiation with 12C and 16O using the raster-scanning technique leads to an enhanced RBE in HCC cell lines. No relevant differences between achieved RBE-values for 12C and 16O were found. Results of this work will further influence biological-adapted treatment planning for HCC patients that will undergo particle therapy with 12C or 16O.

  15. HYDRO BIOLOGICAL ASSESSMENT OF WATER BODIES FROM MIRAJ TAHSIL MAHARASHTRA: A COMPARATIVE STUDY

    Directory of Open Access Journals (Sweden)

    A. B. Sarwade

    2014-09-01

    Full Text Available Physicochemical features of freshwater bodies were regulated by number of factors. It includes temperature, turbidity, pH, total alkalinity, carbondioxide, dissolved oxygen, biological oxygen demand, chemical oxygen demand, phosphate, chloride and hardness. Present study focused on the determination of hydrobiological parameters during different seasons in January, 2011 – December, 2013 in three lakes of Miraj tahsil. The study indicated marked variation in some of the factors as turbidity, CO₂, DO, COD, Alkalinity etc. Obtained data showed, variations in pollution status of three lakes. As per observations and analysis contamination of lakes was Bharatnagar > Mhaishal > Brahmanath lake.

  16. Oxygen therapy reduces postoperative tachycardia

    DEFF Research Database (Denmark)

    Stausholm, K; Kehlet, H; Rosenberg, J

    1995-01-01

    Concomitant hypoxaemia and tachycardia in the postoperative period is unfavourable for the myocardium. Since hypoxaemia per se may be involved in the pathogenesis of postoperative tachycardia, we have studied the effect of oxygen therapy on tachycardia in 12 patients randomly allocated to blinded...... air or oxygen by facemask on the second or third day after major surgery. Inclusion criteria were arterial hypoxaemia (oxygen saturation 90 beat.min-1). Each patient responded similarly to oxygen therapy: an increase in arterial oxygen saturation and a decrease...... in heart rate (p oxygen has a positive effect on the cardiac oxygen delivery and demand balance....

  17. 利用微生物电解池构建新型BOD快速测定生物传感器%A NovelBiosensor Based on Microbial Electrolysis Cells for Rapid Determination of Biochemical Oxygen Demand

    Institute of Scientific and Technical Information of China (English)

    蒋海明; 司万童; 潘建刚

    2015-01-01

    基于微生物电解池构建了新型生化需氧量(BOD)快速测定生物传感器,以葡萄糖-谷氨酸溶液为模拟废水对传感器的性能进行了评估。结果表明:(1)当外加电压保持为0.7 V,传感器的最大电流与BOD浓度在10~400 mgL1内符合Monod方程,且传感器的最大电流和BOD浓度在10~100 mgL1呈线性关系;(2)传感器的测量时间短,BOD浓度在10~400 mgL1测量时间约为10 min;(3)传感器的重复性(±SD<±12.2%,n=6)和稳定性(±SD<±6%,12 d)好。结论:基于微生物电解池开发新型 BOD 生物传感器是可行的,且传感器具有灵敏度高、线性范围宽、检测时间短、重复性及稳定性好等优点,并能快速测定BOD。%A novel microbial electrolysis cell (MEC) based biosensor for rapid determination of biochemical oxygen demand (BOD) was developed, and its performance was evaluated with glucose-glutamic acid containing artificial wastewater. The results show that when the applied voltage is kept at 0.7 V, the maximum current of the biosensor follows Monod equation under BOD concentration of 10~400 mgL1, and the maximum current has linear relationship with BOD when the BOD concentration is in the range of 10~100 mgL1. The results also indicate that the measurement time is about 10 min when the BOD concentration is in the range of 10~400 mgL1. The relative standard deviation of repeatability was less than ±12.2%, while the relative standard deviation of stability was less than ±6% over a period of 12 days. These results demonstrate that the development of novel biosensors based on MEC for rapid determination of BOD is feasible, and the biosensor has advantages of high sensitivity, wide linear range, short detection time, good repeatability and good stability.

  18. Microbial sensor for measurement of biochemical oxygen demand based on ferrocene-grafted mediator%基于接枝二茂铁介体的BOD微生物传感器

    Institute of Scientific and Technical Information of China (English)

    胡磊; 李轶

    2012-01-01

    开发出以接枝二茂铁为介体的微生物传感器测量BOD,将二茂铁(ferrocene,Fc)通过缩合反应接枝到大分子介孔材料SBA-15的表面,作为微生物生化反应传递电子的介体,与活性污泥微生物 混合固定化于聚乙烯醇(PVA)里,制备成微生物敏感膜,并与玻碳电极耦合,构建三电极传感系统,用于快速测量水样的BOD质量浓度.结果表明,传感器测量的质量浓度线性范围为2~ 300 mg/L,连续测量20个样品的精密度为4.2%,能连续工作35 d.讨论pH、温度和重金属对传感器响应的影响.实际水样的测试结果表明,由微生物传感器测得的BOD与BOD5的具有良好的相关度.%A novel microbial sensor using a ferrocene (Fc)-grafted SBA-15 mediator immobilized in a PVA matrix was developed for measurement of the biochemical oxygen demand (BOD). Fc was grafted onto the SBA-15 surface via ion-association and the product was labeled as SBA-15-Fc, and applied to a modified glassy carbon electrode for measuring BOD rapidly in the three-electrode system. The results showed a linear relationship between the anodic current responses and glucose/glutamate (GGA) concentration ranging from 2 mg/L to 300 mg/L. The reproducibility of a single sensor measuring 20 samples was less than 4.2%, and the sensor could continuously work for 35 days. The effects of pH, temperature, and heavy metal on the BOD response were studied. The detection results of real samples show that the BOD measured by the microbial sensor was in good correlation with that obtained with the BOD5 method.

  19. Rapid Determination of Biochemical Oxygen Demand(BOD) in Wastewater with Ferrocene (Fc) Grafted Mediator Microbial Sensor%接枝二茂铁介体微生物传感器对污水BOD的快速测定

    Institute of Scientific and Technical Information of China (English)

    胡磊; 李轶

    2012-01-01

    采用接枝二茂铁为介体的微生物传感器测量污水的BOD.将二茂铁(ferrocene,Fc)通过缩合反应接枝到大分子介孔材料SBA-15的表面用作微生物生化反应传递电子的介体,与活性污泥提取的微生物混合,并用聚乙烯醇(PVA)进行固定化,以此制备成微生物敏感膜,并与玻碳电极耦合,构建三电极传感系统,用于快速测量污水水样的BOD.结果表明,传感器的线性范围为2~300 mg/L,连续测量20个样品的精密度为4.2%,能连续工作35 d.并讨论了pH,温度和重金属对传感器响应的影响.通过对实际水样的测试表明,测得的BOD与BOD5的具有良好的相关性.%A novel biochemical oxygen demand(BOD) detecting method employing a ferrocene(Fc) grafted SBA-1S mediator immobilized in PVA matrix was developed. Fc was combined with SBA-15 via ion-association and the product was labeled as SBA-15-Fc, which was employed for a modified glassy carbon electrode. In a three-electrode system, a linear relationship between the anodic current responses and glucose/glutamate(GGA) concentration was 2~300 mg/L. Single sensor (measuring 20 samples) reproducibility were less than 4.2 %, and the sensor can works for 35 days continuously. The effects of pH, temperature and heavy metal on the BOD responses were studied. Comparaiion of detecting the BOD and BOD; of real samples showed a good correlation

  20. Effect of Nano-ZnO Particle on the Chemical Oxygen Demand in Water of Dianchi Lake%纳米氧化锌对滇池水COD的影响

    Institute of Scientific and Technical Information of China (English)

    施在从; 李成季; 施丽美; 杨奕; 陈芮

    2014-01-01

    化学需氧量( COD)作为一种常用的评价水体污染程度的综合性指标,能够反映水体受还原性物质污染的程度。 COD数值越高,表明水质有机污染越严重。本文以Zn(NO3)2·6H2O为主要原料,Na2CO3·10H2O为沉淀剂,采用溶液直接沉淀法制得纳米ZnO。以纳米ZnO作为吸附剂和杀菌剂,采用酸性高锰酸钾法测定纳米ZnO对滇池水COD值的影响。结果表明:纳米ZnO的加入量为8 mg/L(滇池水)、吸附时间2 h时,滇池水COD值降低效果显著。%Chemical oxygen demand ( COD) was considered as the value to assess the pollution degree of water. Using Zn(NO3)2·6H2O as main reagent and Na2CO3·10H2O as precipitant, nano-zinc oxide was obtained by di-rect precipitation from solution. Using nano-zinc oxide as absorbent and disinfectant, the effect of nano-zinc oxide on the COD in water of Dianchi Lake was discussed in detail by acidic potassium permanganate method. The result showed that the added amount of nano-zinc oxide and the absorption time had influence on the value of COD. The further research was shown that the value of COD could be remarkably decreased when the added amount of nano-zinc oxide was 8 mg/L and the absorption time was 2 h, which was considered to be optimum condition on cleansing the water of Dianchi Lake.

  1. Biologically synthesized silver nanoparticles induce neuronal differentiation of SH-SY5Y cells via modulation of reactive oxygen species, phosphatases, and kinase signaling pathways.

    Science.gov (United States)

    Dayem, Ahmed Abdal; Kim, BongWoo; Gurunathan, Sangiliyandi; Choi, Hye Yeon; Yang, Gwangmo; Saha, Subbroto Kumar; Han, Dawoon; Han, Jihae; Kim, Kyeongseok; Kim, Jin-Hoi; Cho, Ssang-Goo

    2014-07-01

    Nano-scale materials are noted for unique properties, distinct from those of their bulk material equivalents. In this study, we prepared spherical silver nanoparticles (AgNPs) with an average size of about 30 nm and tested their potency to induce neuronal differentiation of SH-SY5Y cells. Human neuroblastoma SH-SY5Y cells are considered an ideal in vitro model for studying neurogenesis, as they can be maintained in an undifferentiated state or be induced to differentiate into neuron-like phenotypes in vitro by several differentiation-inducing agents. Treatment of SH-SY5Y cells by biologically synthesized AgNPs led to cell morphological changes and significant increase in neurite length and enhanced the expression of neuronal differentiation markers such as Map-2, β-tubulin III, synaptophysin, neurogenin-1, Gap-43, and Drd-2. Furthermore, we observed an increase in generation of intracellular reactive oxygen species (ROS), activation of several kinases such as ERK and AKT, and downregulation of expression of dual-specificity phosphatases (DUSPs) in AgNPs-exposed SH-SY5Y cells. Our results suggest that AgNPs modulate the intracellular signaling pathways, leading to neuronal differentiation, and could be applied as promising nanomaterials for stem cell research and therapy. PMID:24827677

  2. Biologically synthesized silver nanoparticles induce neuronal differentiation of SH-SY5Y cells via modulation of reactive oxygen species, phosphatases, and kinase signaling pathwayss.

    Science.gov (United States)

    Dayem, Ahmed Abdal; Kim, Bongwoo; Gurunathan, Sangiliyandi; Choi, Hye Yeon; Yang, Gwangmo; Saha, Subbroto Kumar; Han, Dawoon; Han, Jihae; Kim, Kyeongseok; Kim, Jin-Hoi; Cho, Ssang-Goo

    2014-04-22

    The relevant in vitro cellular model resembling functional neurons is important for the mechanistic research on various neuronal diseases. Human neuroblastoma SH-SY5Y cells may be considered one of the ideal in vitro models for studying neuroscience, as they can be maintained in an undifferentiated state or be induced to differentiate into neuron-like phenotypes in vitro by several differentiation-inducing agents. In this study, we prepared spherical silver nanoparticles (AgNPs) with an average size of about 30 nm and tested their potency to induce neuronal differentiation of SH-SY5Y cells. Treatment of SH-SY5Y cells by biologically synthesized AgNPs led to cell morphological changes and significant increase in neurite length and enhanced the expression of neuronal differentiation markers such as Map-2, β-tubulin III, synaptophysin, neurogenin-1, Gap-43, and Drd-2. Furthermore, we observed an increase in generation of intracellular reactive oxygen species (ROS), activation of several kinases such as ERK and AKT, and down-regulation of expression of dual-specificity phosphatases (DUSPs) in AgNPs-exposed SH-SY5Y cells. Our results suggest that AgNPs could modulate the intracellular signaling pathways to lead to neuronal differentiation, and could be applied as promising nanomaterials for stem cell research and therapy. PMID:24753441

  3. Separation of metabolic supply and demand: aerobic glycolysis as a normal physiological response to fluctuating energetic demands in the membrane

    Science.gov (United States)

    2014-01-01

    Background Cancer cells, and a variety of normal cells, exhibit aerobic glycolysis, high rates of glucose fermentation in the presence of normal oxygen concentrations, also known as the Warburg effect. This metabolism is considered abnormal because it violates the standard model of cellular energy production that assumes glucose metabolism is predominantly governed by oxygen concentrations and, therefore, fermentative glycolysis is an emergency back-up for periods of hypoxia. Though several hypotheses have been proposed for the origin of aerobic glycolysis, its biological basis in cancer and normal cells is still not well understood. Results We examined changes in glucose metabolism following perturbations in membrane activity in different normal and tumor cell lines and found that inhibition or activation of pumps on the cell membrane led to reduction or increase in glycolysis, respectively, while oxidative phosphorylation remained unchanged. Computational simulations demonstrated that these findings are consistent with a new model of normal physiological cellular metabolism in which efficient mitochondrial oxidative phosphorylation supplies chronic energy demand primarily for macromolecule synthesis and glycolysis is necessary to supply rapid energy demands primarily to support membrane pumps. A specific model prediction was that the spatial distribution of ATP-producing enzymes in the glycolytic pathway must be primarily localized adjacent to the cell membrane, while mitochondria should be predominantly peri-nuclear. The predictions were confirmed experimentally. Conclusions Our results show that glycolytic metabolism serves a critical physiological function under normoxic conditions by responding to rapid energetic demand, mainly from membrane transport activities, even in the presence of oxygen. This supports a new model for glucose metabolism in which glycolysis and oxidative phosphorylation supply different types of energy demand. Cells use efficient but

  4. Oxygen Therapy

    Science.gov (United States)

    Oxygen therapy is a treatment that provides you with extra oxygen. Oxygen is a gas that your body needs to function. Normally, your lungs absorb oxygen from the air you breathe. But some conditions ...

  5. Experimental Study on the Contribution and Impact of Chemical Oxygen Demand Caused by Flotation Reagents%不同矿山化学药剂对水体COD贡献和影响的试验研究

    Institute of Scientific and Technical Information of China (English)

    李伟新

    2012-01-01

    矿山选矿药剂的使用已经引起了严重的水体污染,为了可持续利用矿区水资源,选择了常见的5种浮选药剂和3种起泡剂进行了其对水体化学需氧量(COD)贡献和影响的试验研究。研究结果表明:不同浓度范围的乙黄原酸盐(乙黄)、丁黄原酸盐(丁黄)、聚丙烯酰胺(PAM)、乙硫氮、Ds对水体COD的贡献不一样,并且同一种浮选药剂在不同浓度条件下对应的c0D并不呈现线性关系。总体来看,5种药剂中丁黄对COD贡献最大,而乙硫氮对COD贡献最小。不同来源起泡剂对水体COD的贡献有较大差异,总体来看GY2”要比SD2”及ZLZZ2”的COD贡献大。起泡剂的GC—MS仪器分析结果显示起泡剂中多环化合物或者杂环化合物占的比例越大,其对废水COI)贡献越多,因此研制以直链状为主要成分的“环保型”起泡剂显得尤为迫切。%Mineral mining has caused the use of agents to serious water pollution, in order to protect the sustainable use of water resources in miningarea, this paper uses the familiar five kinds of flotation agents and three kinds of foaming agents on the contribution and impact on the water body of its chemical oxygen demand (COD). The results showed that range of different concentrations of ethyl xauthogeuic acid, xanghogenate, polyacrylamide(PAM), diethyldithioearbamate, DS had different contribution towards COD. The corresponding COD did not show a linear relationship under the conditions of the same kind of flotation reagent with different concentrations. Overall, xaughogenate made the greatest contribution to the COD, while that of diethyldithioearbamate was the minimum contribution in five kinds of flotation reagents. Foaming agents with different sources had greater differences contribution on COD. The foaming agent 2~ named GY2# had made greater contribution of COD than that of ZZ2~ and SD2#. The more contents of the multi

  6. Future butanes supply/demand

    International Nuclear Information System (INIS)

    This paper graphically depicts, through in-depth supply/demand analysis, how environmental regulations can be both bad and good for an industry. In the case of n-butane, the Environmental Protection Agency (EPA) summertime gasoline volatility regulations are a culprit - threatening to ultimately destroy refinery demand for the product as a gasoline blendstock. Waiting in the wings are environmental regulations that should eventually prove to be n-butane's savior. The regulations referred to here are the Clean Air Act (CAA) of 1990's mandate for motor fuel oxygenates. The negative impact of gasoline volatility regulations on U.S. n-butane demand and the positive impact that should come from the use of n-butane as a MTBE precursor are covered. Many variables exist which make studying the effects of these environmental regulations very difficult. Over the past three years RPC Group has conducted numerous studies on n-butane supply/demand, as impacted by both EPA gasoline volatility and fuel oxygenate regulations

  7. Effect of startup circuit exercise on derivatives reactive oxygen metabolites, biological antioxidant potential levels and physical fitness of adolescents boys with intellectual disabilities

    Science.gov (United States)

    Kim, Chang-Gyun; Lee, Jin-Seok

    2016-01-01

    The purpose of this study was to examine the effect of starup circuit exercise program on derivatives reactive oxygen metabolite (d-ROM) and biological antioxidant potential (BAP) levels and physical fitness of adolescents with intellectual disabilities, and to sugesst exercise programs to promote the health and physical development of such adolescents. Twelve students with intellectual disabilities were divided into two groups; circuit exercise group (CE group: n=6; age, 14.83±0.98 years; height, 163.83±5.78 cm; body mass, 67.08±3.32 kg; %Fat, 25.68±2.42), control group (CON group: n=6; age: 15.00±0.63 years; height, 162.33±4.41 cm; body mass, 67.50±3.62 kg; %Fat, 26.96±2.06). The CE group performed the CE program 4 times a week over a 12-week period. The CON group maintained their activities of daily living. The following were measured before and after intervention: physical fitness by before and after the completion of the training programm, and were measured and blood samples were assessed. The results of the study indicate that the 12-week CE program increased significantly physical fitness (P<0.05). Furthermore, This study proved that the CE program improved physical fitness, and reduced the d-ROM levels, and increased the BAP levels of the adolescents with intellectual disabilities. Therefore, it may enhance the health and physical development of adolescents boys with intellectual disabilities. PMID:27807529

  8. Responses of hematological parameters, beta-endorphin, cortisol, reactive oxygen metabolites, and biological antioxidant potential in horses participating in a traditional tournament.

    Science.gov (United States)

    Pazzola, M; Pira, E; Sedda, G; Vacca, G M; Cocco, R; Sechi, S; Bonelli, P; Nicolussi, P

    2015-04-01

    Several concerns have been raised over the health of animals used in equestrian games that have their origins in historical or religious events and are currently held in many countries. This study investigated physiological stress response and health status of horses participating in the Sartiglia, a historical horse tournament held in the city of Oristano, Italy, which is principally based on the attempts of masked horsemen at a gallop to run a sword through a hole in a suspended silver star. Blood samples were collected from 21 horses the day before the tournament (D0), during the tournament (D1), and the day after the tournament (D2). Samples were analyzed for complete blood count and biochemical, hormonal, and oxidative stress assays. Data were analyzed using the mixed effect model with sampling session as one of the fixed effects. On the whole, blood parameters evidenced an optimal health status of horses at D0. Significant dehydration and increase of circulating glucose, enzymes, cortisol, and β-endorphin were registered at D1 (P < 0.001) with a complete recovery of physiological values just at D2. The reactive oxygen metabolites (d-ROM), from which the prooxidant activity can be evaluated, showed an increase from D0 to D1 and D2. Concentration of biological antioxidant potential, which measured the antioxidant capacity, was characterized by the maximum level registered during the tournament and counteracted the simultaneous increase of d-ROM. It can be hypothesized that the tournament played an important role in causing high levels of oxidant markers not only because of the physical exercise represented by the gallop but also because the emotional stressors. In conclusion, the tournament caused significant changes of most parameters, which rapidly recovered to baseline values within the day after. These data will certainly be useful for a future implementation of tests in equine medicine and for the improvements of knowledge of changes of blood parameters

  9. Endothelin-2/Vasoactive Intestinal Contractor: Regulation of Expression via Reactive Oxygen Species Induced by CoCl22, and Biological Activities Including Neurite Outgrowth in PC12 Cells

    Directory of Open Access Journals (Sweden)

    Eiichi Kotake-Nara

    2006-01-01

    Full Text Available This paper reviews the local hormone endothelin-2 (ET-2, or vasoactive intestinal contractor (VIC, a member of the vasoconstrictor ET peptide family, where ET-2 is the human orthologous peptide of the murine VIC. While ET-2/VIC gene expression has been observed in some normal tissues, ET-2 recently has been reported to act as a tumor marker and as a hypoxia-induced autocrine survival factor in tumor cells. A recently published study reported that the hypoxic mimetic agent CoCl2 at 200 µM increased expression of the ET-2/VIC gene, decreased expression of the ET-1 gene, and induced intracellular reactive oxygen species (ROS increase and neurite outgrowth in neuronal model PC12 cells. The ROS was generated by addition of CoCl2 to the culture medium, and the CoCl2-induced effects were completely inhibited by the antioxidant N-acetyl cysteine. Furthermore, interleukin-6 (IL-6 gene expression was up-regulated upon the differentiation induced by CoCl2. These results suggest that expression of ET-2/VIC and ET-1 mediated by CoCl2-induced ROS may be associated with neuronal differentiation through the regulation of IL-6 expression. CoCl2 acts as a pro-oxidant, as do Fe(II, III and Cu(II. However, some biological activities have been reported for CoCl2 that have not been observed for other metal salts such as FeCl3, CuSO4, and NiCl2. The characteristic actions of CoCl2 may be associated with the differentiation of PC12 cells. Further elucidation of the mechanism of neurite outgrowth and regulation of ET-2/VIC expression by CoCl2 may lead to the development of treatments for neuronal disorders.

  10. The synergistic effects of dissolved oxygen and pH on N2O production in biological domestic wastewater treatment under nitrifying conditions.

    Science.gov (United States)

    Li, Pengzhang; Wang, Shuying; Peng, Yongzhen; Liu, Yue; He, Janzhong

    2015-01-01

    Nitrous oxide (N2O) is a potent greenhouse gas, which is produced during nitrifying and denitrifying processes. Some factors and mechanisms affecting N2O emission have been reported in previous literature, but wastewater biological nitrification is accompanied by a dynamic process of dissolved oxygen (DO) consumption and pH reduction, it is more meaningful to study the synergistic effects between DO and pH on N2O production. In this study, the synergistic effects between DO and pH on N2O production were investigated with real domestic wastewater. The results showed that high DO levels and a high pH could improve the oxidation ratio of NH4+-N and the production ratio of NO2--N, while effectively reducing the accumulation ratio of N2O. The NH4+-N was a prerequisite for nitrifier denitrification; when NH4+-N was oxidized completely, there would be no N2O production and an even higher concentration of NO2- The pH factor is shown to directly affect N2O emission, although free ammonia and free nitrous acid which changed with pH had no correlation with N2O emission. There were two reasons: (1) pH can influence the flow direction of electrons afforded by NH2OH oxidation; at high pH, electrons were mainly used for combining H+ and O2 (O2+4H++4e-=2H2O), the accumulation of NO2- cannot be a result of denitrification, and a higher DO can get more electrons to prefer NO2- and (2) NH4+ was the prerequisite for NH2OH oxidation, since NH2OH oxidation process was the way to provide electrons for nitrifier denitrification. PMID:25619120

  11. Effect of Cu(2+)-complexation on the scavenging ability of chrysin towards photogenerated singlet molecular oxygen (O2((1)Δg)). Possible biological implications.

    Science.gov (United States)

    Muñoz, Vanesa A; Ferrari, Gabriela V; Montaña, M Paulina; Miskoski, Sandra; García, Norman A

    2016-09-01

    Visible-light irradiation of aqueous-ethanolic solutions of Riboflavin (Rf) in the individual presence of the flavone chrysin (Chr) and its complex with Cu(2+) ([Chr2Cu]; 2:1 L:M) generates singlet molecular oxygen O2((1)Δg), that concomitantly interact with both flavone derivatives. Overall (kt) and reactive (kr) rate constants in the order of 10(7)M(-1)s(-1) were determined for the process. Metal chelation greatly enhances the scavenging ability of [Chr2Cu] towards O2((1)Δg) through a mechanism dominated, in >80%, by the physical component. In this way, practically all O2((1)Δg) is deactivated by the complex without significant loss of the quencher. The isolated flavone quenches O2((1)Δg) in a prevailing reactive fashion. The very low value exhibited by [Chr2Cu] for the kr/kt ratio constitutes a positive quality for antioxidative protectors in biological media, where elevated local concentration and high reactivity of significant molecules make them initial targets for O2((1)Δg) aggression. Finally, two interesting properties in the field of free radicals scavenging by [Chr2Cu] must be mentioned. In first place metal chelation itself, in the obvious sense of free metal ion withdrawal from the oxidizable medium, prevents the initiation of a free radical-mediated oxidation processes through mechanisms of Fenton or lipid peroxidation. In addition, the incorporation of Cu adds to [Chr2Cu] the ability of a free radical scavenger, already described for similar Cu-chelate compounds. This collection of beneficial properties positions the complex as a remarkably promising bioprotector towards ROS-mediated oxidation. A quantification of the efficiency on the initial anti-oxidative effect exerted by Chr and [Chr2Cu] towards tryptophan was carried out. The amino acid is an archetypal molecular model, commonly employed to monitor oxidative degradation of proteinaceous media. It was efficiently photoprotected against O2((1)Δg)-mediated photooxidation by [Chr2Cu]. PMID

  12. Modelación numérica de la hidrodinámica, del oxígeno disuelto y la demanda bioquímica de oxígeno en sistemas con vegetación Numerical modeling of hydrodynamics, dissolved oxygen and biochemical oxygen demand in systems with vegetation

    Directory of Open Access Journals (Sweden)

    Ricardo González-López

    2011-08-01

    Full Text Available El presente trabajo trata sobre la implementación de un modelo numérico para simular la hidrodinámica y el transporte de contaminantes en sistemas donde existe vegetación, tanto sumergida como emergente. Dicho modelo se basa en las ecuaciones de aguas someras para el cálculo de las velocidades del flujo, haciendo énfasis en la evaluación del esfuerzo cortante de arrastre de las plantas y en la turbulencia; así como en la ecuación de advección-difusión-reacción para la simulación del transporte de sustancias disueltas. En este trabajo se presenta el cálculo del transporte de la Demanda Bioquímica de Oxígeno y del Oxígeno Disuelto. El objetivo principal es reproducir las funciones de filtrado de contaminación y reaereación que cumplen las plantas en cuerpos de agua, como los humedales. En los resultados obtenidos del campo de velocidades se aprecia el cambio de comportamiento por la restricción al flujo que impone la vegetación. Las concentraciones de DBO y OD varían debido al tiempo de residencia y a la reaereación producida por el intercambio atmosférico y la respiración de las plantas. Se concluye que el modelo representa de manera óptima el comportamiento del transporte de sustancias disueltas en flujos con presencia de vegetación y que se puede aplicar a la gran variedad de ecosistemas, siendo capaz de predecir la ruta y destino de la contaminación.This work deals with the implementation of a numerical model to simulate hydrodynamics and transport of pollutants in flows where submerged vegetation is present. The model is based on the Shallow-Water Equations to calculate the mean velocities, emphasizing calculations of the shear stress produced by both the vegetation and turbulence. The Advection-Diffusion-Reaction Equation is used to calculate the transport of the Biochemical Oxygen Demand and the Dissolved Oxygen. The main objective is to simulate the transport of these substances and the pollution filtering and

  13. Supplemental Oxygen

    Science.gov (United States)

    ... Disease Lookup > COPD > Diagnosing and Treating COPD Supplemental Oxygen Sometimes with chronic obstructive pulmonary disease (COPD), lung ... in people with severe lung disease Three Ways Oxygen Therapy Is Supplied Compressed oxygen gas and liquid ...

  14. Oxygen transfer in marsh-pond-marsh constructed wetlands treating swine wastewater.

    Science.gov (United States)

    Ro, Kyoung S; Hunt, Patrick G; Johnson, Melvin H; Matheny, Terry A; Forbes, Dean; Reddy, Gudigopuram B

    2010-01-01

    Oxygen transfer efficiencies of various components of the marsh-pond-marsh (M-P-M) and marsh-floating bed-marsh (M-FB-M) wetlands treating swine wastewater were determined by performing oxygen mass balance around the wetlands. Biological oxygen demand (BOD) and total nitrogen (TN) loading and escaping rates from each wetland were used to calculate carbonaceous and nitrogenous oxygen demands. Ammonia emissions were measured using a wind tunnel. Oxygen transfer efficiencies of the aerated ponds were estimated by conducting the ASCE standard oxygen transfer test in a tank using the same aeration device. Covering pond water surface with the floating bed slightly decreased oxygen transfer efficiency. The diffused membrane aeration (26.7 kg O2 ha-1 d-1) of M-P-M was surprisingly not as effective as plant aeration in the marsh (38.9 to 42.0 kg O2 ha-1 d-1). This unusually low oxygen transfer efficiency of the diffused aeration was attributed to its low submergence depth of 0.8 m compared to typical depth of 4.5 m. The wetlands consisting entirely of marsh removed similar amounts of C and N without investing additional equipment and energy costs of aerating ponds in the middle of wetlands. PMID:20390880

  15. Biological Denitrification of High Nitrate Processing Wastewaters from Explosives Production Plant

    OpenAIRE

    Cyplik, Paweł; Marecik, Roman; Piotrowska-Cyplik, Agnieszka; Olejnik, Anna; Drożdżyńska, Agnieszka; Chrzanowski, Łukasz

    2011-01-01

    Wastewater samples originating from an explosives production plant (3,000 mg N l−1 nitrate, 4.8 mg l−1 nitroglycerin, 1.9 mg l−1 nitroglycol and 1,200 mg l−1 chemical oxygen demand) were subjected to biological purification. An attempt to completely remove nitrate and to decrease the chemical oxygen demand was carried out under anaerobic conditions. A soil isolated microbial consortium capable of biodegrading various organic compounds and reduce nitrate to atmospheric nitrogen under anaerobic...

  16. Physical demands during folk dancing.

    Science.gov (United States)

    Wigaeus, E; Kilbom, A

    1980-01-01

    This investigation was undertaken to evaluate the aerobic demands during one of the most popular and demanding Swedish folk dances the "hambo". Six men and six women, ranging in age from 22 to 32, participated. Their physical work capacity was investigated on a bicycle ergometer and a treadmill, using two to three submaximal and one maximal loads. All subjects were moderately well-trained and their average maximal oxygen uptake on the treadmill were 2.5 and 3.7 l/min (42.8 and 53.2 ml/kg . min-1) for women and men, respectively. When dancing the "hambo" the heart rate was telemetered, and the Douglas bag technique was used for measurements of pulmonary ventilation and oxygen uptake. The physical demand during "hambo" dancing was high in all subjects. Oxygen uptake was 38.5 and 37.3 ml/kg . min-1 and heart rate 179 and 172 in women and men, respectively. Women used 90% and men 70% of their maximal aerobic power obtained on the treadmill. The pulmonary ventilation and respiratory quotient of the female subjects were lower when dancing as compared to running, possibly because of voluntary restriction of the movements of the thoracic cage. Some popular Scandinavian folk dances are performed at a speed and with an activity pattern resembling the "hambo", while others are performed at a slower pace. The exercise intensity used in "hambo" is more than sufficient to induce training effects in the average individual provided that the dancing is performed at the frequency and for length of time usually recommended for physical training. For older or less fit people dances with a slow pace can be used for training purposes.

  17. The Kinked Demand Curve When Demand Shifts.

    Science.gov (United States)

    Frasco, Gregg P.

    1993-01-01

    Reviews recent research into the theory of the kinked demand curve in economics. Applies this theory to economic concepts such as marginal cost and price flexibility. Discusses the implications for corporations and government policymakers. (CFR)

  18. Clinical review : use of venous oxygen saturations as a goal - a yet unfinished puzzle

    NARCIS (Netherlands)

    van Beest, Paul; Wietasch, Gotz; Scheeren, Thomas; Spronk, Peter; Kuiper, Michael

    2011-01-01

    Shock is defined as global tissue hypoxia secondary to an imbalance between systemic oxygen delivery and oxygen demand. Venous oxygen saturations represent this relationship between oxygen delivery and oxygen demand and can therefore be used as an additional parameter to detect an impaired cardiores

  19. DECOLORIZATION AND BIOLOGICAL DEGRADATION OF AZO DYE REACTIVE RED2 BY ANAEROBIC/AEROBIC SEQUENTIAL PROCESS

    Directory of Open Access Journals (Sweden)

    A. Naimabadi ، H. Movahedian Attar ، A. Shahsavani

    2009-04-01

    Full Text Available This study investigates the anaerobic treatability of reactive Red2 in an anaerobic/aerobic sequential process. Laboratory scale anaerobic baffled reactor and fixed activated sludge reactor were operated at different organic loadings and hydraulic retention times. The effects of shock dye concentration on the chemical oxygen demand and color removal efficiencies were investigated in the anaerobic baffled reactor. The effect of hydraulic retention time on the color and chemical oxygen demand removal efficiencies were also investigated in the aerobic reactor. The studies were carried out in continuous mode and the effluent of the anaerobic baffled reactor was used as feed for the fixed activated sludge reactor. Chemical oxygen demand removal efficiency of 54.5% was obtained at HRT =1 day in the anaerobic reactor. The average color removal was 89.5%. Chemical oxygen demand removal efficiency of 69% was obtained at HRT =7 h in the aerobic fixed activated sludge reactor. A slight decrease of the color was also observed in the aerobic reactor. This investigation has shown that successful treatment of a highly colored wastewater is possible in the anaerobic baffled reactor. Also the results showed that, anaerobic biological system has higher efficiency in dye removal than fixed activated sludge system, while aerobic system has higher efficiency in chemical oxygen demand removal comparing with the anaerobic baffled reactor.

  20. Using oxygen at home

    Science.gov (United States)

    Oxygen - home use; COPD - home oxygen; Chronic obstructive airways disease - home oxygen; Chronic obstructive lung disease - home oxygen; Chronic bronchitis - home oxygen; Emphysema - home oxygen; Chronic respiratory ...

  1. Stable Isotope Analyses of Phosphate Oxygen From Micro-samples of Biological Apatite: A new Routine Procedure for Silverphosphate Micro-precipitation and the Removal of Organic Contamination

    Science.gov (United States)

    Wiedemann-Bidlack, F. B.; Colman, A. S.; Fogel, M. L.

    2003-12-01

    Oxygen isotope analyses in bone and teeth of living and fossil animals are widely used for testing hypotheses about variability of diet and habitat. For the analysis of environmental or dietary changes in the past, tooth enamel has become the preferred study material, because its mineral content is higher than bone and dentine, and the relatively large size of the carbonato-apatite crystals of enamel make it more stable against post mortem diagenetic alteration than dentine or bone. Intra-tooth sampling of dental enamel is increasingly used for the investigation of seasonal climate variability, taking advantage of both the high correlation between an animal's drinking water and the δ 18O in its mineralized tissues and the incremental growth pattern of tooth enamel. The different oxygen-containing ions of bioapatite (phosphate, carbonate, and hydroxyl group) incorporate into the mineral lattice at different rates during enamel mineralization, and differ in their susceptibility against post mortem diagenetic alteration. In addition, it is difficult to account for the different reaction chemistries of phosphate, carbonate, and hydroxyl group using isotope analysis techniques that include all oxygen contained in the enamel (e.g., laser ablation). These problems can be addressed analyzing phosphate oxygen only. However, two major factors limit the potential of δ 18O analyses in dental enamel: A) the starting sample size for isotope analyzes often precludes the use of small teeth or the intra-tooth sampling of a given tooth; B) Small amounts of biogenic organic material in tooth enamel (less than 1% by wt) can reduce the precision and lead to anomalous analytical results in δ 18O measurements on Ag3PO4 produced from tooth enamel. A new procedure was developed for the pre-treatment and δ 18O analysis of phosphate from small samples (500 μ g) of tooth enamel containing organic matter. Ag3PO{4} was precipitated quantitatively for analysis of δ 18Ophosphate using a

  2. Oxygen analyzer

    Science.gov (United States)

    Benner, William H.

    1986-01-01

    An oxygen analyzer which identifies and classifies microgram quantities of oxygen in ambient particulate matter and for quantitating organic oxygen in solvent extracts of ambient particulate matter. A sample is pyrolyzed in oxygen-free nitrogen gas (N.sub.2), and the resulting oxygen quantitatively converted to carbon monoxide (CO) by contact with hot granular carbon (C). Two analysis modes are made possible: (1) rapid determination of total pyrolyzable oxygen obtained by decomposing the sample at 1135.degree. C., or (2) temperature-programmed oxygen thermal analysis obtained by heating the sample from room temperature to 1135.degree. C. as a function of time. The analyzer basically comprises a pyrolysis tube containing a bed of granular carbon under N.sub.2, ovens used to heat the carbon and/or decompose the sample, and a non-dispersive infrared CO detector coupled to a mini-computer to quantitate oxygen in the decomposition products and control oven heating.

  3. Managing Demands for Social Engagement

    DEFF Research Database (Denmark)

    Glerup, Cecilie

    In recent years numerous calls have been made to enhance the social responsibility of biotechnology from both social scientists (e.g. Nowotny et. al. 2001) and political institutions (e.g. Royal Society 2004; U.S. Congress 2003; EEA 2002). The demands vary in form and content: From state incentives...... pressure on the biotech research organizations that find themselves in a jumble of demands to engage themselves with society. Mccarthy and Kelty, for instance, quote a nano-technologist for saying that he is afraid of “too much responsibility” (2010: 407). Based on a laboratory ethnography, this paper...... explores how two research organizations in the field of synthetic biology strategically manoeuvre among the many discourses on scientific responsibility. One of the labs defines itself through user-inspired science and focuses on the development of ‘products’ that benefit abstract stakeholders such as ‘the...

  4. Ethanol Demand in United States Gasoline Production

    Energy Technology Data Exchange (ETDEWEB)

    Hadder, G.R.

    1998-11-24

    The Oak Ridge National Laboratory (OWL) Refinery Yield Model (RYM) has been used to estimate the demand for ethanol in U.S. gasoline production in year 2010. Study cases examine ethanol demand with variations in world oil price, cost of competing oxygenate, ethanol value, and gasoline specifications. For combined-regions outside California summer ethanol demand is dominated by conventional gasoline (CG) because the premised share of reformulated gasoline (RFG) production is relatively low and because CG offers greater flexibility for blending high vapor pressure components like ethanol. Vapor pressure advantages disappear for winter CG, but total ethanol used in winter RFG remains low because of the low RFG production share. In California, relatively less ethanol is used in CG because the RFG production share is very high. During the winter in California, there is a significant increase in use of ethanol in RFG, as ethanol displaces lower-vapor-pressure ethers. Estimated U.S. ethanol demand is a function of the refiner value of ethanol. For example, ethanol demand for reference conditions in year 2010 is 2 billion gallons per year (BGY) at a refiner value of $1.00 per gallon (1996 dollars), and 9 BGY at a refiner value of $0.60 per gallon. Ethanol demand could be increased with higher oil prices, or by changes in gasoline specifications for oxygen content, sulfur content, emissions of volatile organic compounds (VOCS), and octane numbers.

  5. Electricity demand in Kazakhstan

    International Nuclear Information System (INIS)

    Properties of electricity demand in transition economies have not been sufficiently well researched mostly due to data limitations. However, information on the properties of electricity demand is necessary for policy makers to evaluate effects of price changes on different consumers and obtain demand forecasts for capacity planning. This study estimates Kazakhstan's aggregate demand for electricity as well as electricity demand in the industrial, service, and residential sectors using regional data. Firstly, our results show that price elasticity of demand in all sectors is low. This fact suggests that there is considerable room for price increases necessary to finance generation and distribution system upgrading. Secondly, we find that income elasticity of demand in the aggregate and all sectoral models is less than unity. Of the three sectors, electricity demand in the residential sector has the lowest income elasticity. This result indicates that policy initiatives to secure affordability of electricity consumption to lower income residential consumers may be required. Finally, our forecast shows that electricity demand may grow at either 3% or 5% per year depending on rates of economic growth and government policy regarding price increases and promotion of efficiency. We find that planned supply increases would be sufficient to cover growing demand only if real electricity prices start to increase toward long-run cost-recovery levels and policy measures are implemented to maintain the current high growth of electricity efficiency

  6. Law of Demand

    OpenAIRE

    Michael Jerison; John K.-H. Quah

    2006-01-01

    We formulate several laws of individual and market demand and describe their relationship to neoclassical demand theory. The laws have implications for comparative statics and stability of competitive equilibrium. We survey results that offer interpretable sufficient conditions for the laws to hold and we refer to related empirical evidence. The laws for market demand are more likely to be satisfied if commodities are more substitutable. Certain kinds of heterogeneity across individuals make ...

  7. Stochastic Volatility Demand Systems

    OpenAIRE

    Apostolos Serletis; Maksim Isakin

    2014-01-01

    We address the estimation of stochastic volatility demand systems. In particular, we relax the homoscedasticity assumption and instead assume that the covariance matrix of the errors of demand systems is time-varying. Since most economic and fiÂ…nancial time series are nonlinear, we achieve superior modeling using parametric nonlinear demand systems in which the unconditional variance is constant but the conditional variance, like the conditional mean, is also a random variable depending on c...

  8. ELASTICITY OF PARTY DEMAND

    OpenAIRE

    Yaskova L.V.

    2012-01-01

    On basis of sociological researches political parties as social organizations in Russia (on the example of regional branches of Lipetsk region political parties) on the entry into force of the law «About political parties» 2001 till the present moment are analyzed. It is underlined the change of volume of party space actors during various elective periods, characterized by elasticity of party demand. The factors defining elasticity of party demand are concluded. The estimation of party demand...

  9. Demand and Supply Surfaces

    OpenAIRE

    Ruiz Estrada, M.A.

    2008-01-01

    This paper shows a new optical visualization of demand and supply based on the application of surfaces. The objective of initiating the demand and supply surfaces is to propose the application of multi-dimensional graphs among academics, economists and policy makers in the study of microeconomics and macroeconomics analyses in the short and long term. To create the demand and supply surfaces, this research suggests applying “the Infinity Cartesian space (I-Cartesian space)” (Ruiz 2006). In ap...

  10. Divers of Passenger Demand

    OpenAIRE

    Wittmer, Andreas

    2011-01-01

    -Overview drivers of passenger demand -Driver 1: Economic growth in developing countries -Driver 2: International business travel in developed countries -Driver 3: International leisure travel in developed countries

  11. Causality in demand

    DEFF Research Database (Denmark)

    Nielsen, Max; Jensen, Frank; Setälä, Jari;

    2011-01-01

    to fish demand. On the German market for farmed trout and substitutes, it is found that supply sources, i.e. aquaculture and fishery, are not the only determinant of causality. Storing, tightness of management and aggregation level of integrated markets might also be important. The methodological......This article focuses on causality in demand. A methodology where causality is imposed and tested within an empirical co-integrated demand model, not prespecified, is suggested. The methodology allows different causality of different products within the same demand system. The methodology is applied...... implication is that more explicit focus on causality in demand analyses provides improved information. The results suggest that frozen trout forms part of a large European whitefish market, where prices of fresh trout are formed on a relatively separate market. Redfish is a substitute on both markets. The...

  12. Morphology impact on oxygen sensing ability of Ru(dpp){sub 3}Cl{sub 2} containing biocompatible polymers

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Susan Y.; Harrison, Benjamin S., E-mail: bharriso@wakehealth.edu

    2015-08-01

    Especially for tissue engineering applications, the diffusion of oxygen is a critical factor affecting spatial distribution and migration of cells. The cellular oxygen demand also fluctuates depending on tissue type and growth phase. Sensors that determine dissolved oxygen levels under biological conditions provide critical metabolic information about the growing cells as well as the state of the tissue culture within the tissue scaffold. This work focused on the effect of the scaffold morphology on the oxygen sensing response time. It was found that electrospun scaffolds had a faster oxygen-sensing response time than their bulk film counterparts. Tris-(4,7-diphenyl-1,10-phenanthroline) ruthenium (II) dichloride doped electrospun fiber mats of polycaprolactone (PCL) were found to be the most responsive to the presence of oxygen, followed by polyethylene (PEO) glycol mats. Systems containing poly vinyl alcohol were found to be the least responsive. This would suggest that, out of all the polymers tested, PCL and PEO are the most suitable biomaterials for oxygen-sensing applications. - Highlights: • Ru(DPP){sub 3}Cl{sub 2} was blended into common biocompatible polymers such as PEO, PCL, and PVA. • Oxygen sensing was more responsive when polymers were electrospun compared to bulk. • Electrospun PEO and PCL with Ru(dpp){sub 3}Cl{sub 2} showed similar oxygen sensing responses. • PVA showed a slight improvement in oxygen sensing rate when electrospun.

  13. Asian oil demand

    International Nuclear Information System (INIS)

    This conference presentation examined global oil market development and the role of Asian demand. It discussed plateau change versus cyclical movement in the global oil market; supply and demand issues of OPEC and non-OPEC oil; if high oil prices reduce demand; and the Asian oil picture in the global context. Asian oil demand has accounted for about 50 per cent of the global incremental oil market growth. The presentation provided data charts in graphical format on global and Asia-Pacific incremental oil demand from 1990-2005; Asia oil demand growth for selected nations; real GDP growth in selected Asian countries; and, Asia-Pacific oil production and net import requirements. It also included charts in petroleum product demand for Asia-Pacific, China, India, Japan, and South Korea. Other data charts included key indicators for China's petroleum sector; China crude production and net oil import requirements; China's imports and the share of the Middle East; China's oil exports and imports; China's crude imports by source for 2004; China's imports of main oil products for 2004; India's refining capacity; India's product balance for net-imports and net-exports; and India's trade pattern of oil products. tabs., figs

  14. Domestic Demand Will Work

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    China can invigorate its economy by expanding domestic demand and boosting consumption chinese bankers are preparing to set up finance companies that provide consumer loans in major cities like Beijing and Shanghai.

  15. Intelligent energy demand forecasting

    CERN Document Server

    Hong, Wei-Chiang

    2013-01-01

    This book offers approaches and methods to calculate optimal electric energy allocation, using evolutionary algorithms and intelligent analytical tools to improve the accuracy of demand forecasting. Focuses on improving the drawbacks of existing algorithms.

  16. A universal algorithm for genome-wide in silicio identification of biologically significant gene promoter putative cis-regulatory-elements; identification of new elements for reactive oxygen species and sucrose signaling in Arabidopsis.

    Science.gov (United States)

    Geisler, Matt; Kleczkowski, Leszek A; Karpinski, Stanislaw

    2006-02-01

    Short motifs of many cis-regulatory elements (CREs) can be found in the promoters of most Arabidopsis genes, and this raises the question of how their presence can confer specific regulation. We developed a universal algorithm to test the biological significance of CREs by first identifying every Arabidopsis gene with a CRE and then statistically correlating the presence or absence of the element with the gene expression profile on multiple DNA microarrays. This algorithm was successfully verified for previously characterized abscisic acid, ethylene, sucrose and drought responsive CREs in Arabidopsis, showing that the presence of these elements indeed correlates with treatment-specific gene induction. Later, we used standard motif sampling methods to identify 128 putative motifs induced by excess light, reactive oxygen species and sucrose. Our algorithm was able to filter 20 out of 128 novel CREs which significantly correlated with gene induction by either heat, reactive oxygen species and/or sucrose. The position, orientation and sequence specificity of CREs was tested in silicio by analyzing the expression of genes with naturally occurring sequence variations. In three novel CREs the forward orientation correlated with sucrose induction and the reverse orientation with sucrose suppression. The functionality of the predicted novel CREs was experimentally confirmed using Arabidopsis cell-suspension cultures transformed with short promoter fragments or artificial promoters fused with the GUS reporter gene. Our genome-wide analysis opens up new possibilities for in silicio verification of the biological significance of newly discovered CREs, and allows for subsequent selection of such CREs for experimental studies.

  17. Appreciating Oxygen

    Science.gov (United States)

    Weiss, Hilton M.

    2008-01-01

    Photosynthetic flora and microfauna utilize light from the sun to convert carbon dioxide and water into carbohydrates and oxygen. While these carbohydrates and their derivative hydrocarbons are generally considered to be fuels, it is the thermodynamically energetic oxygen molecule that traps, stores, and provides almost all of the energy that…

  18. Demand for public safety

    OpenAIRE

    Pradhan, Menno; Ravallion, Martin

    1999-01-01

    In public safety of less concern to poor people? What about people in poor areas? How is demand for public safety affected by income inequality? Is there a self-correcting mechanism whereby higher crime increases demand for public safety? The authors study subjective assessments of public safety using a comprehensive socioeconomic survey of living standards in Brazil. They find public safety to be a normal good at the household level. Marginal income effects are higher for the poor, so inequa...

  19. Food Demand in Slovenia

    OpenAIRE

    Regorsek, Darja; Erjavec, Emil

    2007-01-01

    The objective of this research is to analyse food consumption patterns in Slovenia for households segmented by quartile income levels and for whole Slovenian population. Food items are divided into seven commodity groups. Cross-sectional household data from Household Budget Survey 2001 were used. We apply the linearly approximated Almost Ideal Demand System (LA/AIDS). Empirical results show positive expenditure elasticities being close to one where in general demands for dairy products and fo...

  20. Maximum power demand cost

    International Nuclear Information System (INIS)

    The charging for a service is a supplier's remuneration for the expenses incurred in providing it. There are currently two charges for electricity: consumption and maximum demand. While no problem arises about the former, the issue is more complicated for the latter and the analysis in this article tends to show that the annual charge for maximum demand arbitrarily discriminates among consumer groups, to the disadvantage of some

  1. Exploring the kinetic and thermodynamic aspects of four-electron electrochemical reactions: electrocatalysis of oxygen evolution by metal oxides and biological systems.

    Science.gov (United States)

    Wang, Vincent C-C

    2016-08-10

    Finding fundamental and general mechanisms for electrochemical reactions, such as the oxygen evolution reaction (OER) from water and reduction of CO2, plays vital roles in developing the desired electrocatalysts for facilitating solar fuel production. Recently, density functional theory (DFT) calculations have shown that there is a universal scaling relation of adsorption energy between key intermediate species, HO(ad) and HOO(ad), on the surface of metal oxides as OER electrocatalysts. In this paper, a kinetic and thermodynamic model for the four-electron electrochemical reaction based on previous OER mechanisms proposed by DFT calculations is developed to further investigate the electrocatalytic properties over a wide range of metal oxides and photosystem II. The OER activity of metal oxides (i.e. electrocatalytic current) calculated from the DFT-calculated equilibrium potentials with kinetic properties, such as the rate constants for interfacial electron transfer and catalytic turnover, can lead to a volcano-shaped trend that agrees with the results observed in experiments. In addition, the kinetic aspects of the impact on the electrocatalysts are evaluated. Finally, comparing the results of metal oxides and photosystem II, and fitting experimental voltammograms give further insights into kinetic and thermodynamic roles. Here, the general guidelines for designing OER electrocatalysts with unified kinetic and thermodynamic properties are presented. PMID:27460039

  2. A prospective, randomized clinical study evaluating the effect of transdermal continuous oxygen therapy on biological processes and foot ulcer healing in persons with diabetes mellitus.

    Science.gov (United States)

    Driver, Vickie R; Yao, Min; Kantarci, Alpdogan; Gu, Guosheng; Park, Nanjin; Hasturk, Hatice

    2013-11-01

    Hypoxia is a major factor in delayed wound healing. The aim of this prospective, randomized, clinical trial was to compare outcomes of treatment in persons with chronic diabetic foot ulcers (DFUs) randomly assigned to transdermal continuous oxygen therapy (TCOT) for 4 weeks as an adjunct to standard care (debridement, offloading, and moisture). Nine patients (age 58.6±7.1, range 38-73 years) received TCOT (treatment group) and eight patients (age 59.9±12.6, range 35-76 years) received standard care alone (control group). Most patients (12) were male, and all had a Wagner I or II foot ulcer for an average of 14 (control group) or 20 months (treatment group). Weekly wound measurements and wound tissue biopsies were obtained and wound fluid collected. Levels of pro-inflammatory cytokines and proteases in wound fluid samples were analyzed using Luminex-based multiplex assays. Tissue-resident macrophages were quantified by immunohistochemistry. At week 4, average wound size reduction was 87% (range 55.7% to 100%) in the treatment group compared to 46% (15% to 99%) in the control group (P <0.05). Changes in cytokine levels (IL-6, IL-8) and proteinases (MMP-1,-2,-9, TIMP-1) at weeks 2 to 4 in wound fluid correlated with clinical findings. CD68+ macrophage counts showed statistically significant reduction in response to TCOT compared to the control group (P <0.01). The results of this study show that TCOT may facilitate healing of DFUs by reversing the inflammatory process through reduction in pro-inflammatory cytokines and tissue-degrading proteases. Additional research to elucidate the effects of this treatment on complete healing and increase understanding about the role of wound fluid analysis is needed.

  3. Lesson on Demand. Lesson Plan.

    Science.gov (United States)

    Weaver, Sue

    This lesson plan helps students understand the role consumer demand plays in the market system, i.e., how interactions in the marketplace help determine pricing. Students will participate in an activity that demonstrates the concepts of demand, demand schedule, demand curve, and the law of demand. The lesson plan provides student objectives;…

  4. Evolution of Oxygenic Photosynthesis

    Science.gov (United States)

    Fischer, Woodward W.; Hemp, James; Johnson, Jena E.

    2016-06-01

    The origin of oxygenic photosynthesis was the most important metabolic innovation in Earth history. It allowed life to generate energy and reducing power directly from sunlight and water, freeing it from the limited resources of geochemically derived reductants. This greatly increased global primary productivity and restructured ecosystems. The release of O2 as an end product of water oxidation led to the rise of oxygen, which dramatically altered the redox state of Earth's atmosphere and oceans and permanently changed all major biogeochemical cycles. Furthermore, the biological availability of O2 allowed for the evolution of aerobic respiration and novel biosynthetic pathways, facilitating much of the richness we associate with modern biology, including complex multicellularity. Here we critically review and synthesize information from the geological and biological records for the origin and evolution of oxygenic photosynthesis. Data from both of these archives illustrate that this metabolism first appeared in early Paleoproterozoic time and, despite its biogeochemical prominence, is a relatively late invention in the context of our planet's history.

  5. Treatment test of supernatant from sewage sludge by irradiation of high energy electron beams under supersaturation with oxygen

    Energy Technology Data Exchange (ETDEWEB)

    Hosono, Masakazu; Arai, Hidehiko (Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment); Aizawa, Masaki; Shimooka, Toshio; Yamamoto, Ichiro; Shimizu, Ken; Sugiyama, Masashi.

    1993-02-01

    Supernatant comes from dewaterization of sewage sludge, and contains biologically nondegradable organics. Therefore, it is hard to be treated by conventional activated sludge method. The development of a new technology is required to decrease the chemical oxygen demand (COD) effectively below 30 mg/l. Irradiation of high energy electron beams can convert nondegradable organics in water into substances which are biodegradable. However, sufficient dissolved oxygen in water is needed to induce oxidation effectively. In the present study, the treatment of supernatant was studied using an apparatus which can be irradiated by high intensity electron beams in flow system under supersaturation with oxygen by pressurization up to 3 atms. The dependence of oxygen concentration on the reduction in absorbance at 230 nm of azo dye (Acid Red 265) aqueous solution was examined, and it was clarified that sufficient oxygen was supplied in the solution up to about 14 kGy under 3 atms of oxygen. Radiation treatment of supernatant which came from the leather works was carried out using the above apparatus. However, as this supernatant contained high concentration of nitrite, the nitrite was removed by limited aeration activated sludge method. By this pretreatment, COD was reduced from 200 mg/l to 53 mg/l. Then, the biodegradability of supernatant irradiated under supersaturation with oxygen was examined. The final COD of the supernatant was reduced below 30 mg/l by the combined method of irradiation of 7 kGy and biological treatment. (author).

  6. Hospital demand for physicians.

    Science.gov (United States)

    Morrisey, M A; Jensen, G A

    1990-01-01

    This article develops a derived demand for physicians that is general enough to encompass physician control, simple profit maximization and hospital utility maximization models of the hospital. The analysis focuses on three special aspects of physician affiliations: the price of adding a physician to the staff is unobserved; the physician holds appointments at multiple hospitals, and physicians are not homogeneous. Using 1983 American Hospital Association data, a system of specialty-specific demand equations is estimated. The results are consistent with the model and suggest that physicians should be concerned about reduced access to hospitals, particularly as the stock of hospitals declines. PMID:10104050

  7. Demand Modelling in Telecommunications

    Directory of Open Access Journals (Sweden)

    M. Chvalina

    2009-01-01

    Full Text Available This article analyses the existing possibilities for using Standard Statistical Methods and Artificial Intelligence Methods for a short-term forecast and simulation of demand in the field of telecommunications. The most widespread methods are based on Time Series Analysis. Nowadays, approaches based on Artificial Intelligence Methods, including Neural Networks, are booming. Separate approaches will be used in the study of Demand Modelling in Telecommunications, and the results of these models will be compared with actual guaranteed values. Then we will examine the quality of Neural Network models. 

  8. Biochemical oxygen demand in Malta Lake, Poznan, Poland

    OpenAIRE

    Mustapha, Kehinde

    2010-01-01

    Lots of research was done by different departments in Poznan region for many years which have been put together in this project. The departments that carried out the tests on Malta Lake were Laboratory tests of water, wastewater and air pollution in Poznan, Department of Environmental Protection Office of City Hall, Water and Soil Testing Laboratory of Voivodeship Sanitary and Epidemiological Station in Poznan. The aim of this work was to analyse the environmental condition of Malta Lake,...

  9. Considerações práticas sobre o teste de demanda química de oxigênio (DQO aplicado a análise de efluentes anaeróbios Practical aspects of the chemical oxygen demand (COD test applied to the analysis of anaerobic effluents

    Directory of Open Access Journals (Sweden)

    Sérgio F. de Aquino

    2006-12-01

    Full Text Available Este artigo apresenta resultados de testes laboratoriais que investigaram a influência dos íons cloreto, amonium, ferro e sulfeto no teste de demanda química de oxigênio (DQO, bem como valores dos coeficientes de conversão da matéria orgânica específica (proteínas, carboidratos e lipídeos determinados empiricamente. O artigo apresenta, ainda, resultados da comparação dos métodos colorimétrico e titulométrico de determinação da DQO e faz uma discussão crítica do uso do teste de DQO como parâmetro de monitoramento da eficiência de sistemas de tratamento anaeróbio.This paper presents practical results on the influence of chloride, amonium, sulphide and iron on the chemical oxygen demand (COD test, as well as experimental values of stoichiometric coefficients to convert the specific organic matter (protein, carbohydrate and lipid into COD. The paper also presents results that compare the titrimetric and colorimetric methods used to measure the COD and makes a critical analysis of the use of COD test as a tool to monitor the efficiency of anaerobic treatment systems.

  10. Carbon removal and nitrification in a rotating biological contractor under different steady-state conditions

    Energy Technology Data Exchange (ETDEWEB)

    Lowhorn, R.W. (Ben Cor Construction Co., Chattanooga, TN); Bustamante, R.B.; Bonner, W.P.

    1980-01-01

    The stage-by-stage degradation of soluble organics was monitored during waste water treatment. The effects of process parameters on nitration of waste water were determined. The rotating biological contactor, applying the fixed film prinicple, was used in this study. Parameters affecting nitrifying bacteria are: dissolved oxygen, temperature, pH, ammonia, nitrite, mean-cell retention time, organic matter, alkalinity, and rotational speed. It was shown that an increase in chemical oxygen demand can occur in the stages following heterotrophic activity in an RBC unit as a result of inadequate buffering capacity in waste water. (DMC)

  11. Innovative value-added chain. The short innovative way to the market of biological natural gas. How supply and demand increasingly get in touch; Innovative Wertschoepfungskette. Der kurze innovative Weg zum Bioerdgas-Markt. Wie Angebot und Nachfrage besser zusammenfinden

    Energy Technology Data Exchange (ETDEWEB)

    Schuermann, Vera; Kern, Helmut [Arcanum Energy Management GmbH / Arcanum Energy Systems GmbH und Co. KG, Unna (Germany)

    2011-07-01

    With the business concept ''Biogas Pool fuer Stadtwerke'' the business company Arcanum Energy Systems GmbH and Co. KG contributes an innovative and unique input to the market development of the biogas feed in. The ''Biogas Pool fuer Stadtwerke'' enables the municipal energy suppliers a long term secured acquisition of biogas, without self-investing into the raw biogas production. The investment for the biogas production is done by the farmers, who develop on this way a permanent and secure business field as ''energy hosts''. Every Biogas plant will be supplemented with a concentration plant by the Biogas Pool. Communal public services participate proportionately according to their ordered quantities. Pool solutions are already realized successfully on three different places of location in Northern Germany. Furthermore, BiomethaneCenter (BioerdgasZentrale) by Arcanum Energy accomplishes supply and demand on bio methane market without involving intercalated chandlers e.g. conglomerates. Producers of biogas and gas consumers, e.g. communal public services are directly contracting by a nationwide network. The network determines nationwide availabilities and quantity demanded. (orig.)

  12. Oil supply and demand

    Energy Technology Data Exchange (ETDEWEB)

    Rech, O

    2004-07-01

    World oil demand, driven by economic development in China, posted the highest growth rate in 20 years. In a context of geopolitical uncertainty, prices are soaring, encouraged by low inventory and the low availability of residual production capacity. Will 2004 bring a change in the oil market paradigm? (author)

  13. Education on Demand

    DEFF Research Database (Denmark)

    Boysen, Lis; Hende, Merete

    2015-01-01

    Dette notat beskriver nogle af resultaterne fra programmet "Education on Demand' i projektet Det erhvervsrettede Uddannelseslaboratorium. Programmet har haft fokus på udfordringer og forandringsbehov i uddannelsesinstitutioner og -systemet. Herunder har det beskæftiget sig særligt med de to...

  14. Oil supply and demand

    Energy Technology Data Exchange (ETDEWEB)

    Babusiaux, D

    2004-07-01

    Following the military intervention in Iraq, it is taking longer than expected for Iraqi exports to make a comeback on the market. Demand is sustained by economic growth in China and in the United States. OPEC is modulating production to prevent inventory build-up. Prices have stayed high despite increased production by non-OPEC countries, especially Russia. (author)

  15. Oil supply and demand

    International Nuclear Information System (INIS)

    The year 2004 saw a change in the oil market paradigm that was confirmed in 2005. Despite a calmer geopolitical context, prices continued to rise vigorously. Driven by world demand, they remain high as a result of the saturation of production and refining capacity. The market is still seeking its new equilibrium. (author)

  16. Oil supply and demand

    Energy Technology Data Exchange (ETDEWEB)

    Rech, O

    2006-07-01

    The year 2004 saw a change in the oil market paradigm that was confirmed in 2005. Despite a calmer geopolitical context, prices continued to rise vigorously. Driven by world demand, they remain high as a result of the saturation of production and refining capacity. The market is still seeking its new equilibrium. (author)

  17. Oil supply and demand

    International Nuclear Information System (INIS)

    Following the military intervention in Iraq, it is taking longer than expected for Iraqi exports to make a comeback on the market. Demand is sustained by economic growth in China and in the United States. OPEC is modulating production to prevent inventory build-up. Prices have stayed high despite increased production by non-OPEC countries, especially Russia. (author)

  18. Oil supply and demand

    International Nuclear Information System (INIS)

    World oil demand, driven by economic development in China, posted the highest growth rate in 20 years. In a context of geopolitical uncertainty, prices are soaring, encouraged by low inventory and the low availability of residual production capacity. Will 2004 bring a change in the oil market paradigm? (author)

  19. The demand for euros

    NARCIS (Netherlands)

    Arnold, I.J.M.; Roelands, S.

    2010-01-01

    This paper investigates the demand for euros using panel data for 10 euro area countries covering the period from 1999 to 2008. Monetary aggregates are constructed to ensure that money is a national concept by excluding deposits owned by non-residents and including external deposits owned by residen

  20. Textbook Factor Demand Curves.

    Science.gov (United States)

    Davis, Joe C.

    1994-01-01

    Maintains that teachers and textbook graphics follow the same basic pattern in illustrating changes in demand curves when product prices increase. Asserts that the use of computer graphics will enable teachers to be more precise in their graphic presentation of price elasticity. (CFR)

  1. DEMAND AND PRICES

    Directory of Open Access Journals (Sweden)

    VĂDUVA MARIA

    2014-08-01

    Full Text Available Studying the consumer’s behavior by the ordinal approach of utility with the help of indifference curves allows us to deduce the two “movement laws of demand” in this chapter: the demand for a “normal” good is decreasing function of its price and an increasing function of income. We will use the elasticity concept to measure the intensity of the relation that is established between the demand, on the one hand, and prices or income, on the other hand: elasticity – price, direct and crossed, and elasticity – income. We can classify the goods in many categories, depending on the values that this elasticity takes. The demand elasticity can be determined depending on price and income. It reflects the proportion in which the demand for different products changes with the modification of the consumers’ income, the other factors remaining constant. The elasticity compared to the income is a demonstration of legality from the consumer’s sphere, which determines a certain hierarchy of the needs of each population category in a certain level of income. The movement of prices orients both the options and decisions of producers, namely the most useful productions and the most efficient investments, as well as the consumers’ options and decisions on the most advantageous buying of goods and services that they need. The prices appear as a “signal system” coordinating and making coherence the economic agents’ decisions – producers, consumers and population.

  2. Electricity demand in Tunisia

    International Nuclear Information System (INIS)

    This paper examines the global electricity demand in Tunisia as a function of gross domestic product in constant price, the degree of urbanization, the average annual temperature, and the real electricity price per Kwh. This demand will be examined employing annual data over a period spanning almost thirty one years from 1976 to 2006. A long run relationship between the variables under consideration is determined using the Vector Autoregressive Regression. The empirical results suggest that the electricity demand in Tunisia is sensitive to its past value, any changes in gross domestic product and electricity price. The electricity price effects have a negative impact on long-run electricity consumption. However, the gross domestic product and the past value of electricity consumption have a positive effect. Moreover, the causality test reveals a unidirectional relationship between price and electricity consumption. Our empirical findings are effective to policy makers to maintain the electricity consumption in Tunisia by using the appropriate strategy. - Highlights: ► This paper examined the electricity demand in Tunisia in the long-run. ► The empirical analysis revealed that in the long-run the electricity demand is affected by changes in its past value, GDP in constant price and real electricity price. ► There is a unidirectional relationship between price and electricity consumption, that is to say, that the electricity price causes the consumption. ► Those results suggest that a pricing policy can be an effective instrument to rationalize the electricity consumption in Tunisia in the long-run.

  3. Oxygen Regulates Tissue Nitrite Metabolism

    OpenAIRE

    Curtis, Erin; Hsu, Lewis L.; Noguchi, Audrey C.; Geary, Lisa; Shiva, Sruti

    2012-01-01

    Aims: Once dismissed as an inert byproduct of nitric oxide (NO) auto-oxidation, nitrite (NO2-) is now accepted as an endocrine reservoir of NO that elicits biological responses in major organs. While it is known that tissue nitrite is derived from NO oxidation and the diet, little is known about how nitrite is metabolized by tissue, particularly at intermediate oxygen tensions. We investigated the rates and mechanisms of tissue nitrite metabolism over a range of oxygen concentrations. Results...

  4. Demand surge following earthquakes

    Science.gov (United States)

    Olsen, Anna H.

    2012-01-01

    Demand surge is understood to be a socio-economic phenomenon where repair costs for the same damage are higher after large- versus small-scale natural disasters. It has reportedly increased monetary losses by 20 to 50%. In previous work, a model for the increased costs of reconstruction labor and materials was developed for hurricanes in the Southeast United States. The model showed that labor cost increases, rather than the material component, drove the total repair cost increases, and this finding could be extended to earthquakes. A study of past large-scale disasters suggested that there may be additional explanations for demand surge. Two such explanations specific to earthquakes are the exclusion of insurance coverage for earthquake damage and possible concurrent causation of damage from an earthquake followed by fire or tsunami. Additional research into these aspects might provide a better explanation for increased monetary losses after large- vs. small-scale earthquakes.

  5. Innovation and Demand

    DEFF Research Database (Denmark)

    Andersen, Esben Sloth

    2007-01-01

    Economic evolution is an immensely complex phenomenon, so there is an obvious need of simplifying the way we handle this phenomenon. Since Nelson and Winter's pioneering formalisation of the Schumpeterian vision of innovation-driven evolution, the major simplification has been obtained by modelli....... Second, firms' innovative activities relate, directly or indirectly, to the structure of expected and actual demand. Third, the demand side represents the most obvious way of turning to the much-needed analysis of macro-evolutionary change of the economic system.......Economic evolution is an immensely complex phenomenon, so there is an obvious need of simplifying the way we handle this phenomenon. Since Nelson and Winter's pioneering formalisation of the Schumpeterian vision of innovation-driven evolution, the major simplification has been obtained by modelling...

  6. Scientific Demand for CAMEA

    OpenAIRE

    Freeman, Paul

    2014-01-01

    To document the enthusiasm for the CAMEA spectrometer, we provide in this document: i) Letters of support from leading scientists representing several of the fields of science that will be enabled by CAMEA. ii) A list of scientists who wished to be listed as supporters of CAMEA, because they are keen to see CAMEA built. iii) Statistics from a survey to identify the need for CAMEA, and the demand for each of the advanced measurement capabilities CAMEA will enable.

  7. Demand scenarios, worldwide

    Energy Technology Data Exchange (ETDEWEB)

    Schaefer, A. [Massachusetts Inst. of Technology, Center for Technology, Policy and Industrial Development and the MIT Joint Program on the Science and Policy of Global Change, Cambridge, MA (United States)

    1996-11-01

    Existing methods are inadequate for developing aggregate (regional and global) and long-term (several decades) passenger transport demand scenarios, since they are mainly based on simple extensions of current patterns rather than causal relationships that account for the competition among transport modes (aircraft, automobiles, buses and trains) to provide transport services. The demand scenario presented in this paper is based on two empirically proven invariances of human behavior. First, transport accounts for 10 to 15 percent of household total expenditures for those owning an automobile, and around 5 percent for non-motorized households on average (travel money budget). Second, the mean time spent traveling is approximately one hour per capita per day (travel time budget). These two budgets constraints determine the dynamics of the scenario: rising income increases per capita expenditure on travel which, in turn, increase demand for mobility. Limited travel time constraints travelers to shift to faster transport systems. The scenario is initiated with the first integrated historical data set on traffic volume in 11 world regions and the globe from 1960 to 1990 for all major modes of motorized transport. World average per capita traffic volume, which was 1,800 kilometers in 1960 and 4,2090 in 1990, is estimated to rise to 7,900 kilometers in 2020 - given a modest average increase in Gross World Product of 1.9% per year. Higher economic growth rates in Asian regions result in an increase in regional per capita traffic volume up to a factor of 5.3 from 1990 levels. Modal splits continue shifting to more flexible and faster modes of transport. At one point, passenger cars can no longer satisfy the increasing demand for speed (i.e. rising mobility within a fixed time budget). In North America it is estimated that the absolute traffic volume of automobiles will gradually decline starting in the 2010s. (author) 13 figs., 6 tabs., 35 refs.

  8. Demographics in demand systems

    OpenAIRE

    Blow, Laura

    2003-01-01

    Household composition can be expected to affect the allocation of household expenditure among goods, at the very least because of economies of scale as household size increases and because different people have different needs (adults versus children, for example). Specifying demographic effects correctly in demand analysis is important both in order to estimate correct price and expenditure elasticities and for the purpose of making household welfare comparisons. A common way of including de...

  9. Ontario demand response scenarios

    International Nuclear Information System (INIS)

    Strategies for demand management in Ontario were examined via 2 scenarios for a commercial/institutional building with a normal summertime peak load of 300 kW between 14:00 and 18:00 during a period of high electricity demand and high electricity prices. The first scenario involved the deployment of a 150 kW on-site generator fuelled by either diesel or natural gas. The second scenario involved curtailing load by 60 kW during the same periods. Costs and benefits of both scenarios were evaluated for 3 groups: consumers, system operators and society. Benefits included electricity cost savings, deferred transmission capacity development, lower system prices for electricity, as well as environmental changes, economic development, and a greater sense of corporate social responsibility. It was noted that while significant benefits were observed for all 3 groups, they were not substantial enough to encourage action, as the savings arising from deferred generation capacity development do not accrue to individual players. The largest potential benefit was identified as lower prices, spread across all users of electricity in Ontario. It was recommended that representative bodies cooperate so that the system-wide benefits can be reaped. It was noted that if 10 municipal utilities were able to have 250 commercial or institutional customers engaged in distributed response, then a total peak demand reduction of 375 MW could be achieved, representing more than 25 per cent of Ontario's target for energy conservation. It was concluded that demand response often involves the investment of capital and new on-site procedures, which may affect reactions to various incentives. 78 refs., 10 tabs., 5 figs

  10. Market Expects Demand Increase

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    In the recent releasing Textile Industry Invigorating Plan,"givingattention to both domestlc and overseas markets"is put into a keyposition.Under a series policies,such as increasing the tax rebaterate for textile and garment exports,and granting loan for SME,thefurther development of this industry is expectative.Otherwise,weshould know that it costs time for demand driving.This need ourpatients.The only questionis how much time we have to wait.

  11. Adjusting supply to demand

    OpenAIRE

    Trindade, Armando Rocha

    2005-01-01

    Este artigo, publicado na revista da EADTU (European Association of Distance Teaching Universities), em 1993, dá continuidade ao trabalho de A.Rocha Trindade, intitulado The Demand Side of the Distance Education Market, publicado no número anterior. Ambos os artigos contribuíram para o debate, então em curso, sobre Opening the Distance Learning Market in Europe.

  12. Cardiac oxygen supply is compromised during the night in hypertensive patients

    OpenAIRE

    Westerhof, B E; Lieshout, van, J.J.; Parati, G.; Montfrans, van, G.A.; Guelen, I.; Spaan, J.A.E.; Westerhof, N.; Karemaker, J. M.; W J W Bos

    2011-01-01

    The enhanced heart rate and blood pressure soon after awaking increases cardiac oxygen demand, and has been associated with the high incidence of acute myocardial infarction in the morning. The behavior of cardiac oxygen supply is unknown. We hypothesized that oxygen supply decreases in the morning and to that purpose investigated cardiac oxygen demand and oxygen supply at night and after awaking. We compared hypertensive to normotensive subjects and furthermore assessed whether pressures mea...

  13. Reverse osmosis and nanofiltration of biologically treated leachate.

    Science.gov (United States)

    Kuusik, Aare; Pachel, Karin; Kuusik, Argo; Loigu, Enn; Tang, Walter Z

    2014-01-01

    Experiments of nano-filtration (NF) and reverse osmosis (RO) were conducted to remove most pollutants from the biological treated leachate. For example, the purified permeate after reverse osmosis treatment with spiral membranes reached effluent water quality as follows: COD of 57 mg O2/l, BOD7 of 35 mg O2/l, and suspended solid of 1 mg/l which satisfies the discharge standards in Estonia. For both RO and NF, conductivity can be reduced by 91% from 6.06 to 0.371 mS/cm by RO and 99% from 200 to 1 mS/cm by NF. To test the service life of the RO spiral membranes, the process was able to reduce chemical oxygen demand (COD) and biological oxygen demand (BOD) of biologically treated leachate by 97.9% and 93.2% even after 328 and 586 hours, respectively. However, only 39.0% and 21.7% reductions of Ptot and Ntot were achieved. As a result, neither RO (spiral membranes process) nor NF was able to reduce the total nitrogen (TN) to the required discharge limit of 15 mg/l.

  14. Do large predatory fish track ocean oxygenation?

    Science.gov (United States)

    Dahl, Tais W; Hammarlund, Emma U

    2011-01-01

    The Devonian appearance of 1-10 meter long armored fish (placoderms) coincides with geochemical evidence recording a transition into fully oxygenated oceans.1 A comparison of extant fish shows that the large individuals are less tolerant to hypoxia than their smaller cousins. This leads us to hypothesize that Early Paleozoic O(2) saturation levels were too low to support >1 meter size marine, predatory fish. According to a simple model, both oxygen uptake and oxygen demand scale positively with size, but the demand exceeds supply for the largest fish with an active, predatory life style. Therefore, the largest individuals may lead us to a lower limit on oceanic O(2) concentrations. Our presented model suggests 2-10 meter long predators require >30-50% PAL while smaller fish would survive at oxygen pressure acted as an evolutionary barrier for fish to grow much above ∼1 meter before the Devonian oxygenation.

  15. Biological fluidized-bed treatment of groundwater from a manufactured gas plant site

    International Nuclear Information System (INIS)

    Bench- and pilot-scale biological treatability studies were performed as part of a comprehensive study for developing an on-site treatment system for contaminated groundwater at a former manufactured gas plant site. The bench-scale work, which included evaluations of activated sludge and fluidized-bed biological processes, indicated that a carbon-based fluidized-bed process was most appropriate. The process was then demonstrated on a pilot level at the site. The bench and pilot studies demonstrated significant reductions of chemical oxygen demand (COD), and all target organics including polycyclic aromatic hydrocarbons (PAHs) and volatile organic compounds (VOCs)

  16. Oxygen diffusion and oxygen effect in tumor tissue

    International Nuclear Information System (INIS)

    The diffusion of oxygen in tumor cords of bronchus carcinoma of the lung have been studied with refined computer methods for solving the diffusion equation in axis symmetric tumor structures. In this tumor configuration we may find three different regions consisting of euoxic cells, hypoxic tumor cells and necrotic parts. In the case of oxygen supply from a capillary inside a cylinder of tumor tissue with radius 200 μm or in a tumor cord of radius 300 μm with oxygen supply by capillaries outside, we get a relation of well oxygenated cells to hypoxic cells approximately as 1:8 or as 1:1.1 respectively. Of course most of the tumor cords observed in histological slices have smaller diameters, so that an average of approximately 20% hypoxic cells can be assumed. Based on the work of Ardenne, the diffusion of oxygen and glucose in a tumor of type DS-carcinosarcom has been investigated in both intact tumor and tumor treated with ionizing radiation. We can show that a strong reoxygenation effect takes place in that the well supplied regions may increase in some tumor configurations up to a factor of four by volume. The biological consequences of the oxygen pressure determined in tumor cells are discussed in detail. The investigation of oxygen diffusion in the intercapillary tumor region should give a quantitative physical basis for considering the oxygen effect with the aim to explain the advantages of neutron therapy against conventional radiotherapy. (orig./MG)

  17. Production and Consumption of Reactive Oxygen Species by Fullerenes

    Science.gov (United States)

    Reactive oxygen species (ROS) are one of the most important intermediates in chemical, photochemical, and biological processes. To understand the environmental exposure and toxicity of fullerenes better, the production and consumption of ROS (singlet oxygen, superoxide, hydrogen ...

  18. Comparison of airline passenger oxygen systems.

    Science.gov (United States)

    Byrne, N J

    1995-08-01

    The principal sources of oxygen for inflight passenger use, scheduled and unscheduled, are examined. Present practices of assessment of the passenger's "fitness to fly" are described. Three partner airlines, British Airways, U.S. Air, and Qantas, catering for more than 8000 oxygen requests annually, are compared. Analysis of customer use suggests that medical oxygen requests are frequently not clinically justified. The growth in demand, for both scheduled and unscheduled use of an expensive resource, supports the need for a "recommended best practice" among carriers. Passengers with respiratory disorders who will most benefit from inflight oxygen are vulnerable either to hypoxia or asthma. PMID:7487813

  19. The Denitrifying Biological Phosphorus Removal Performance in Anaerobic/Anoxic Sequencing Batch Reactor: The Effect of Carbon Source

    OpenAIRE

    Gürtekin, Engin; Nusret ŞEKERDAĞ

    2015-01-01

    In this study, the effect of carbon source on denitrifying biological phosphorus removal performance in acetate and glucose fed two anaerobic/anoxic sequencinq batch reactor (SBR) was investigated. Glucose and acetate were used as the substrates. In acetate and glucose fed reactors, the COD (Chemical Oxygen Demand) removal efficiencies were 91,90% and PO4-P removal efficiencies were 87,51% respectively. These results shows that the phosphorus removal efficiency is lower in glucose fed reactor.

  20. Road infrastructure and demand induction

    DEFF Research Database (Denmark)

    Nielsen, Thomas Alexander Sick; Hovgesen, Henrik Harder; Lahrmann, Harry

    2006-01-01

    a long screenline is used to measure the development in aggregate demand in selected corridors. The paper analyses demand induction by establishing time series of aggregate demand that is compared with the national traffic index. Significant trend breaks in the association between aggregate demand...... in the corridors and the national index, following the opening of motorways or bridges, indicates demand induction by infrastructure expansion in a number of instances. Lack of significant trend breaks following opening year is found in peripheral areas where major population centres are missing. This indicates...... the necessity of some latent demand within suitable travel range for new infrastructure elements to produce significant amounts of induced demand. Estimates of demand induction as a percentage of the realised demand five years after opening are between 10% and 67% for new motorway sections depending...

  1. Aggregate Demand and Supply

    OpenAIRE

    Farmer, Roger E.A.

    2007-01-01

    This paper is part of a broader project that provides a microfoundation to the General Theory of J.M. Keynes. I call this project 'old Keynesian economics' to distinguish it from new-Keynesian economics, a theory that is based on the idea that to make sense of Keynes we must assume that prices are sticky. I describe a multi-good model in which I interpret the definitions of aggregate demand and supply found in the General Theory through the lens of a search theory of the labor market. I argue...

  2. Pulmonary hematological parameters, energetic flight demands and their correlation with oxygen diffusion capacity in the lungs Parámetros hematológicos pulmonares, demandas energéticas del vuelo y su correlación la capacidad de difusión de oxígeno en los pulmones

    Directory of Open Access Journals (Sweden)

    M CANALS

    2007-09-01

    Full Text Available Hematological parameters of birds and mammals seem to respond to environmental requirements, such as hypoxia at high altitude and the energetic demands of locomotion and flight. In this work we hypothesize that lung capillary hematocrit and red blood size may be influenced by the energetic requirements of flight. Also, we propose that hematological parameters should vary together with the morphological parameters that determine oxygen diffusion capacity. We analyzed the red blood cell size and the local characteristics of the pulmonary capillary hematocrit correlating these with the pulmonary factors that determines the oxygen diffusion capacity. We deal with seven species, non-flying and flying birds and mammals, with different energetic requirements. The capillary hematocrit was not different in each taxon, but the red blood cell size was smaller in flying mammals and birds than non-flying ones. Correlation of erythrocyte size with the diffusing characteristics of the lungs produced a non-phylogenetic clustering with a group constituting by the bats Tadarida brasiliensis y Myotis chiloensis, and the bird Z. auriculata; revealing similar functional response in unrelated species. Finally, in mammals, a negative correlation between the red blood cell size and the mass-specific oxygen diffusion capacity was obtained. These results suggest that the direction of the hematological and pulmonary adjustments is governed mainly by the requirements of flight independent of phylogenetic origin of the species studiedLos parámetros hematológicos y pulmonares parecen responder a las exigencias ambientales como la hipoxia y la alta altitud y a los requerimientos energéticos de la locomoción. En este trabajo sometemos a prueba la hipótesis que el hematocrito del capilar pulmonar y el tamaño del glóbulo rojo pueden ser influidos por los requerimientos energéticos del vuelo. También proponemos que los parámetros hematológicos varían en conjunto con

  3. The supply and demand for pollution control: Evidence from wastewater treatment

    Science.gov (United States)

    McConnell, V.D.; Schwarz, G.E.

    1992-01-01

    This paper analyzes the determination of pollution control from wastewater treatment plants as an economic decision facing local or regional regulators. Pollution control is measured by plant design effluent concentration levels and is fully endogenous in a supply- and-demand model of treatment choice. On the supply side, plant costs are a function of the design treatment level of the plant, and on the demand side, treatment level is a function of both the costs of control and the regional or regulatory preferences for control. We find evidence that the economic model of effluent choice by local regulators has a good deal of explanatory power. We find evidence that wastewater treatment plant removal of biological oxygen demand (BOD) is sensitive to many local factors including the size of the treatment plant, the flow rate of the receiving water, the population density of the surrounding area, regional growth, state sensitivity to environmental issues, state income, and the extent to which the damages from pollution fall on other states. We find strong evidence that regulators are sensitive to capital costs in determining the design level of BOD effluent reduction at a plant. Thus, proposed reductions in federal subsidies for wastewater treatment plant construction are likely to have significant adverse effects on water quality. ?? 1992.

  4. Assessment of Constructed Wetland Biological Integrity Using Aquatic Macroinvertebrates

    Directory of Open Access Journals (Sweden)

    C. Galbrand

    2007-01-01

    Full Text Available A surface flow constructed wetland consisting of seven cells was used to treat the leachates from a decommissioned landfill. Wetland monitoring was performed by evaluating the treatment efficiency of the landfill leachate and the wetland biological integrity of the wetland. The water quality samples were analyzed for iron, manganese, phosphorus (orthophosphate, pH, dissolved oxygen (DO, nitrogen (ammonia, nitrate, nitrite and TKN, chemical oxygen demand (COD, total suspended solids (TSS and total dissolved solids (TDS. Aquatic macroinvertebrates were examined using Average Score per Taxon (ASPT via the Biological Monitoring Working Party (BMWP biotic index, the Ephemeroptera, Trichoptera, Sphaeriidae and Odonata (ETSD biotic index, abundance of mayflies and trophic structure. Reductions of 49.66, 66.66, 1.91, 46.37 and 8.33% were obtained for manganese, orthophosphate, TSS, TDS and COD, respectively. The nitrite, dissolved oxygen and iron concentrations were not in accordance with the water quality guidelines for aquatic life. ASPT, ETSD, percent abundance of mayflies and trophic structure represented moderate to moderately-poor water quality in comparison to a high quality reference site. Iron had most adverse effect on the biological system of the wetland.

  5. Biological nutrient removal by internal circulation upflow sludge blanket reactor after landfill leachate pretreatment.

    Science.gov (United States)

    Abood, Alkhafaji R; Bao, Jianguo; Abudi, Zaidun N

    2013-10-01

    The removal of biological nutrient from mature landfill leachate with a high nitrogen load by an internal circulation upflow sludge blanket (ICUSB) reactor was studied. The reactor is a set of anaerobic-anoxic-aerobic (A2/O) bioreactors, developed on the basis of an expended granular sludge blanket (EGSB), granular sequencing batch reactor (GSBR) and intermittent cycle extended aeration system (ICEAS). Leachate was subjected to stripping by agitation process and poly ferric sulfate coagulation as a pretreatment process, in order to reduce both ammonia toxicity to microorganisms and the organic contents. The reactor was operated under three different operating systems, consisting of recycling sludge with air (A2/O), recycling sludge without air (low oxygen) and a combination of both (A2/O and low oxygen). The lowest effluent nutrient levels were realised by the combined system of A2/O and low oxygen, which resulted in effluent of chemical oxygen demand (COD), NH3-N and biological oxygen demand (BOD5) concentrations of 98.20, 13.50 and 22.50 mg/L. The optimal operating conditions for the efficient removal of biological nutrient using the ICUSB reactor were examined to evaluate the influence of the parameters on its performance. The results showed that average removal efficiencies of COD and NH3-N of 96.49% and 99.39%, respectively were achieved under the condition of a hydraulic retention time of 12 hr, including 4 hr of pumping air into the reactor, with dissolved oxygen at an rate of 4 mg/L and an upflow velocity 2 m/hr. These combined processes were successfully employed and effectively decreased pollutant loading. PMID:24494501

  6. Supplement and Consumption of Dissolved Oxygen and Their Seasonal Variations in Shrimp Pond

    Institute of Scientific and Technical Information of China (English)

    孙耀; 张淑芳; 陈聚法; 宋云利

    2001-01-01

    On the basis of the research of DO budget or kinetics in shrimp pond, the main influence process of DO and its seasonal variations are quantitatively described through redividing the budget process and modifying the quantitative method of the process. The percentages of oxygen demand of various processes in the total oxygen demand are different in shrimp cultivation seasons. It is showed that the dissolved oxygen demand of mini-organisms is the major affected factor of DO in this environment and approximately accounts for 64.1~74.1% of the total oxygen demand. In the early period of shrimp culture, the dissolved oxygen demand of allotrophic bacteria degrading organic matters is much lower than that of phytoplankton respiration. But in the midterrn and later period, it is about 50% of the total oxygen demand because of the higher water temperature and more serious self-pollution. The dissolved oxygen demand of sediment is lower and just 19.1~28.8%, while the percentage of shrimp oxygen demand is lower. The effect of phytoplankton on DO in shrimp culturing water has dualism. One is the oxygen producing process of photosynthesis and the other is the oxygen consumption process of respiration. It is estimated that the dissolved oxygen demand of phytoplankton respiration is approximately one-fifth of the oxygen produced by photosynthesis under normal illumination conditions. The dissolved oxygen demand of al lotrophic bacteria degrading organic matters and the total oxygen demand of sediment increase 4 times and 1.7 times respectively from the early period to the midterm and later period.Obviously, the DO of culturing water can be also greatly improved by controlling the selfpollution of organic matters during shrimp culture.

  7. Physical demands in worklife.

    Science.gov (United States)

    Astrand, I

    1988-01-01

    Industrial occupations which are physically strenuous in the traditional sense of the word have decreased in number. They have partly been replaced by "light," repetitive, monotonous work tasks performed in a sitting position. The number of heavy work tasks within the service sector has increased. Specialization has been intensified. The individual's capacity for strenuous work is still of importance to successful work performance. Many studies show that an optional choice of work pace in physically demanding occupational work results in an adaptation of pace or intensity until the worker is utilizing 40-50% of her or his capacity. When the work rate is constrained, the relative strain of the individual varies inversely with the physical work capacity. The frequency of musculoskeletal disorders has concurrently increased with the implementation of industrial mechanization. New, wise, ergonomic moves are needed to stop this development.

  8. Water demand and supply

    International Nuclear Information System (INIS)

    Major international conferences have dealt with the growing concern over the ever increasing use of limited fresh water resources on the planet, including the United Nations Water Conference held in Mar del Plata (1977), the Dublin Conference (1992) and the UN Conference on Environment and Development held in Rio de Janeiro (1992). In April 1997, the UN Commission on Sustainable Development was presented with a report on a Comprehensive Assessment of the Freshwater Resources of the World, in which all UN agencies concerned with water participated. Matching the ever growing demands with the limited supply of a finite resource has led to tremendous stress on natural fresh water. This starts with low water stress, when about 10% of the available fresh water is being used. Use of more than 40% of the available water indicates serious scarcity, and usually increasing dependence on desalination and overexploitation of aquifers. On the basis of population increase projections for the year 2025, and extrapolating current trends, as much as two-thirds of the world's population may be living in moderate or high water stress situations. With increasing water stress and scarcity, drastic changes in the way water business is being done will have to be introduced, particularly in low income countries. Agricultural practices, in particular, have to be introduced that reduce losses. Improved strategies have to make use of rigorously enforced demand management, better resource management, waste water reuse to the extent possible, and finally desalination of sea water and brackish groundwaters. Some of the current water intensive patterns of development may even have to be abandoned. (author)

  9. Participatory Demand-supply Systems

    NARCIS (Netherlands)

    Rezaee, S.A.; Oey, M.A.; Nevejan, C.I.M.; Brazier, F.M.

    2015-01-01

    Introducing the notion of Participatory Demand-Supply (PDS) systems as socio-technical systems, this paper focuses on a new approach to coordinating demand and supply in dynamic environments. A participatory approach to demand and supply provides a new frame of reference for system design, for which

  10. Monitoring oxygenation.

    Science.gov (United States)

    Severinghaus, John W

    2011-06-01

    Cyanosis was used for a century after dentists began pulling teeth under 100% N(2)O in 1844 because brief (2 min) severe hypoxia is harmless. Deaths came with curare and potent anesthetic respiratory arrest. Leland Clark's invention of a polarographic blood oxygen tension electrode (1954) was introduced for transcutaneous PO2 monitoring to adjust PEEP and CPAP PO2 to prevent premature infant blindness from excess O2 (1972). Oximetry for warning military aviators was tried after WW II but not used for routine monitoring until Takuo Aoyagi (1973) discovered an equation to measure SaO2 by the ratio of ratios of red and IR light transmitted through tissue as it changed with arterial pulses. Pulse oximetry (1982) depended on simultaneous technology improvements of light emitting red and IR diodes, tiny cheap solid state sensors and micro-chip computers. Continuous monitoring of airway anesthetic concentration and oxygen also became very common after 1980. Death from anesthesia fell 10 fold between 1985 and 2000 as pulse oximetry became universally used, but no proof of a causative relationship to pulse oximetry exists. It is now assumed that all anesthesiologist became much more aware of the dangers of prolonged hypoxia, perhaps by using the pulse oximeters. PMID:21717228

  11. Biological treatment of wine of distilleries

    International Nuclear Information System (INIS)

    The potential of the yeast Candida tropicalis and Candida guillermondii was evaluated and an isolated partnership of microorganisms of waters of the Medellin River, conformed by two bacteria and one leavening, to degrade the content of organic matter present in wine produced by the factory of Licores and Alcoholes de Antioquia (FLA) in aerobic process with biomass production. For each one of the microorganisms in study this capacity of removal in units of chemical demand of oxygen was quantified (CDO); in addition, parameters were analyzed such as yield of the biomass in relation to the removed CDO and to total reducing sugars (TRS) consumed, time of fermentation and speed of growth different dilutions from wine. Also the possible inhibition was analyzed that the present phenolic compounds in this wine can cause in the biological process of degradation

  12. Simultaneous high-resolution pH and spectrophotometric recordings of oxygen binding in blood microvolumes.

    Science.gov (United States)

    Oellermann, Michael; Pörtner, Hans-O; Mark, Felix C

    2014-05-01

    Oxygen equilibrium curves have been widely used to understand oxygen transport in numerous organisms. A major challenge has been to monitor oxygen binding characteristics and concomitant pH changes as they occur in vivo, in limited sample volumes. Here we report a technique allowing highly resolved and simultaneous monitoring of pH and blood pigment saturation in minute blood volumes. We equipped a gas diffusion chamber with a broad-range fibre-optic spectrophotometer and a micro-pH optode and recorded changes of pigment oxygenation along oxygen partial pressure (PO2) and pH gradients to test the setup. Oxygen binding parameters derived from measurements in only 15 μl of haemolymph from the cephalopod Octopus vulgaris showed low instrumental error (0.93%) and good agreement with published data. Broad-range spectra, each resolving 2048 data points, provided detailed insight into the complex absorbance characteristics of diverse blood types. After consideration of photobleaching and intrinsic fluorescence, pH optodes yielded accurate recordings and resolved a sigmoidal shift of 0.03 pH units in response to changing PO2 from 0 to 21 kPa. Highly resolved continuous recordings along pH gradients conformed to stepwise measurements at low rates of pH changes. In this study we showed that a diffusion chamber upgraded with a broad-range spectrophotometer and an optical pH sensor accurately characterizes oxygen binding with minimal sample consumption and manipulation. We conclude that the modified diffusion chamber is highly suitable for experimental biologists who demand high flexibility, detailed insight into oxygen binding as well as experimental and biological accuracy combined in a single setup. PMID:24436387

  13. Agility in adversity: Vaccines on Demand.

    Science.gov (United States)

    De Groot, Anne S; Moise, Leonard; Olive, David; Einck, Leo; Martin, William

    2016-09-01

    Is the US ready for a biological attack using Ebola virus or Anthrax? Will vaccine developers be able to produce a Zika virus vaccine, before the epidemic spreads around the world? A recent report by The Blue Ribbon Study Panel on Biodefense argues that the US is not ready for these challenges, however, technologies and capabilities that could address these deficiencies are within reach. Vaccine technologies have advanced and readiness has improved in recent years, due to advances in sequencing technology and computational power making the 'vaccines on demand' concept a reality. Building a robust strategy to design effective biodefense vaccines from genome sequences harvested by real-time biosurveillance will benefit from technologies that are being brought to bear on the cancer cure 'moonshot'. When combined with flexible vaccine production platforms, vaccines on demand will relegate expensive and, in some cases, insufficiently effective vaccine stockpiles to the dust heap of history. PMID:27389971

  14. Agility in adversity: Vaccines on Demand.

    Science.gov (United States)

    De Groot, Anne S; Moise, Leonard; Olive, David; Einck, Leo; Martin, William

    2016-09-01

    Is the US ready for a biological attack using Ebola virus or Anthrax? Will vaccine developers be able to produce a Zika virus vaccine, before the epidemic spreads around the world? A recent report by The Blue Ribbon Study Panel on Biodefense argues that the US is not ready for these challenges, however, technologies and capabilities that could address these deficiencies are within reach. Vaccine technologies have advanced and readiness has improved in recent years, due to advances in sequencing technology and computational power making the 'vaccines on demand' concept a reality. Building a robust strategy to design effective biodefense vaccines from genome sequences harvested by real-time biosurveillance will benefit from technologies that are being brought to bear on the cancer cure 'moonshot'. When combined with flexible vaccine production platforms, vaccines on demand will relegate expensive and, in some cases, insufficiently effective vaccine stockpiles to the dust heap of history.

  15. 14 CFR 25.1445 - Equipment standards for the oxygen distributing system.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Equipment standards for the oxygen... Miscellaneous Equipment § 25.1445 Equipment standards for the oxygen distributing system. (a) When oxygen is... crew on duty. (b) Portable walk-around oxygen units of the continuous flow, diluter-demand,...

  16. Information Demand Pattern for Teams

    Directory of Open Access Journals (Sweden)

    Dirk Stamer

    2016-04-01

    Full Text Available Modern organizations face the challenge of having to manage an increasing amount of information. The resulting information overload leads more and more to problems in decision making with potentially negative economic consequences. Decision-makers and knowledge intensive workers are especially affected. To address this problem, information demand patterns were proposed which capture organizational knowledge about the information demand of single roles. This work extends the concept of information demand patterns from single roles to teams. Using the knowledge intensive field of project management, the paper shows how to apply the concept of information demand patterns for a whole team. The contributions of this work are (1 the methodical approach to develop information demand patterns for teams, (2 an actual information demand pattern for a steering committee in the context of project management, (3 reflections on the differences between role patterns and team patterns.

  17. Metonymy and Cross Section Demand

    OpenAIRE

    Evstigneev, Igor V.; Hildenbrand, Werner; Jerison, Michael

    1996-01-01

    Cross section consumer expenditure data are frequently used to make conclusions about consumer demand behavior. Such conclusions, however, can only be justified under certain assumptions, which are often left unstated in the empirical demand literature. An assumption of this type, the metonymy hypothesis, was stated rigorously and then exploited by Hardle, Hildenbrand and Jerison when analyzing the monotonicity property of aggregate demand functions. The purpose of the present paper is to exa...

  18. Participatory Demand-supply Systems

    OpenAIRE

    Rezaee, S.A.; Oey, M.A.; Nevejan, C.I.M.; Brazier, F.M.

    2015-01-01

    Introducing the notion of Participatory Demand-Supply (PDS) systems as socio-technical systems, this paper focuses on a new approach to coordinating demand and supply in dynamic environments. A participatory approach to demand and supply provides a new frame of reference for system design, for which the engagement of all stakeholders plays an important role, as does distributed ICT. This approach has been applied to an industrial case to explore new opportunities enabled by distributed ICT fo...

  19. OXYGEN-18 + OXYGEN-18 Reactions.

    Science.gov (United States)

    Yuan, Ren-Feng

    Cross sections for the ^{18 }O + ^{18}O reactions (fusion, inelastic excitation and transfer reactions) have been determined in the range 6.73 <=q E_{c.m}<=q 13.24 MeV by measuring the low-lying gamma-ray transitions in the residual nuclei with a high resolution Ge detector. A statistical model calculation of the populations of the residual nuclear states was employed in deducing cross sections from the measured gamma -yields. gamma-ray angular distributions were determined at E_{lab} = 20.0 MeV. The total fusion cross sections were compared with an IWBC calculation employing a parameter set obtained from fitting elastic scattering data. The interaction barrier shape has been obtained by means of the BKN inversion procedure and compared with the barriers for other oxygen isotopes. The inelastic scattering cross section and the two-neutron transfer reaction cross section are reproduced well by the DWBA approach.

  20. An integrated communications demand model

    Science.gov (United States)

    Doubleday, C. F.

    1980-11-01

    A computer model of communications demand is being developed to permit dynamic simulations of the long-term evolution of demand for communications media in the U.K. to be made under alternative assumptions about social, economic and technological trends in British Telecom's business environment. The context and objectives of the project and the potential uses of the model are reviewed, and four key concepts in the demand for communications media, around which the model is being structured are discussed: (1) the generation of communications demand; (2) substitution between media; (3) technological convergence; and (4) competition. Two outline perspectives on the model itself are given.

  1. North American oil demand outlook

    Energy Technology Data Exchange (ETDEWEB)

    Stewart, M.B. [National Economic Research Associates, White Plains, NY (United States)

    1995-11-01

    An understanding of the relationship of economic growth and potential petroleum product demand is needed to forecast the potential for North American oil demand growth as well as knowledge of world supply and price. The bullish expectations for economic growth in the US and Canada auger well for North American refiners and marketeers. The growth in world economic output forecast, however, means a larger oil demand and an increase in OPEC`s pricing power. Such price increases could depress North American oil demand growth. (author)

  2. North American oil demand outlook

    International Nuclear Information System (INIS)

    An understanding of the relationship of economic growth and potential petroleum product demand is needed to forecast the potential for North American oil demand growth as well as knowledge of world supply and price. The bullish expectations for economic growth in the US and Canada auger well for North American refiners and marketeers. The growth in world economic output forecast, however, means a larger oil demand and an increase in OPEC's pricing power. Such price increases could depress North American oil demand growth. (author)

  3. Global energy demand outlook

    International Nuclear Information System (INIS)

    Perhaps the most compelling issue the world will face in the next century is the quality of life of the increasing populations of the poorer regions of the world. Energy is the key to generating wealth and protecting the environment. Today, most of the energy generated comes from fossil fuels and there should be enough for an increase in consumption over the next half century. However, this is likely to be impacted by the Kyoto Protocol on carbon dioxide emissions. Various authoritative studies lead to a global energy demand projection of between 850 to 1070 EJ per year in the mid-21st century, which is nearly three times as much as the world uses today. The studies further indicate that, unless there is a major thrust by governments to create incentives and/or to levy heavy taxes, the use of fossil fuels will continue to increase and there will be a major increase in carbon dioxide emissions globally. Most of the increase will come from the newly industrializing countries which do not have the technology or financial resources to install non-carbon energy sources such as nuclear power, and the new renewable energy technologies. The real issue for the nuclear industry is investment cost. Developing countries, in particular will have difficulty in raising capital for energy projects with a high installed cost and will have difficulties in raising large blocks of capital. A reduction in investment costs of the order of 50% with a short construction schedule is in order if nuclear power is to compete and contribute significantly to energy supply and the reduction of carbon dioxide emissions. Current nuclear power plants and methods are simply not suited to the production of plants that will compete in this situation. Mass production designs are needed to get the benefits of cost reduction. Water cooled reactors are well demonstrated and positioned to achieve the cost reduction necessary but only via some radical thinking on the part of the designers. The reactors of

  4. Are macroinvertebrates in high altitude streams affected by oxygen deficiency?

    DEFF Research Database (Denmark)

    Jacobsen, Dean; Rostgaard, S.; Vásconez, J. J.

    2003-01-01

    1. The solubility of oxygen in water increases with decreasing temperature. This has led to a general perception of cold, high mountain streams as more oxygen rich than warmer lowland streams, and that macroinvertebrates inhabiting high altitude streams have had no need to adapt to critical oxygen...... streams from sea level to 4000 m a.s.l. in Ecuador, we determined predicted oxygen availability, oxygen demand and macroinvertebrate assemblage structure along this wide altitudinal gradient. 3. We show that the predicted oxygen availability at 4000 m a.s.l. is only one fifth of that at sea level, whereas...... relatively few groups normally regarded as oxygen-sensitive. Nevertheless, high altitude assemblages react more strongly to lowering of oxygen saturation, and are thus more sensitive to organic pollution. 5. Oxygen deficiency has been overlooked completely in studies of the altitudinal distribution...

  5. Portable, On-Demand Biomolecular Manufacturing.

    Science.gov (United States)

    Pardee, Keith; Slomovic, Shimyn; Nguyen, Peter Q; Lee, Jeong Wook; Donghia, Nina; Burrill, Devin; Ferrante, Tom; McSorley, Fern R; Furuta, Yoshikazu; Vernet, Andyna; Lewandowski, Michael; Boddy, Christopher N; Joshi, Neel S; Collins, James J

    2016-09-22

    Synthetic biology uses living cells as molecular foundries for the biosynthesis of drugs, therapeutic proteins, and other commodities. However, the need for specialized equipment and refrigeration for production and distribution poses a challenge for the delivery of these technologies to the field and to low-resource areas. Here, we present a portable platform that provides the means for on-site, on-demand manufacturing of therapeutics and biomolecules. This flexible system is based on reaction pellets composed of freeze-dried, cell-free transcription and translation machinery, which can be easily hydrated and utilized for biosynthesis through the addition of DNA encoding the desired output. We demonstrate this approach with the manufacture and functional validation of antimicrobial peptides and vaccines and present combinatorial methods for the production of antibody conjugates and small molecules. This synthetic biology platform resolves important practical limitations in the production and distribution of therapeutics and molecular tools, both to the developed and developing world. PMID:27662092

  6. Carbon and nitrogen uptake of calcareous benthic foraminifera along a depth-related oxygen gradient in the OMZ of the Arabian Sea

    Directory of Open Access Journals (Sweden)

    Annekatrin Julie Enge

    2016-02-01

    Full Text Available Foraminifera are an important faunal element of the benthos in oxygen-depleted settings such as Oxygen Minimum Zones (OMZs where they can play a relevant role in the processing of phytodetritus. We investigated the uptake of phytodetritus (labeled with 13C and 15N by cal-careous foraminifera in the 0-1 cm sediment horizon under different oxygen concentrations within the OMZ in the eastern Arabian Sea. The in situ tracer experiments were carried out along a depth transect on the Indian margin over a period of 4 to 10 days. The uptake of phy-todetrital carbon within 4 days by all investigated species shows that phytodetritus is a rele-vant food source for foraminifera in OMZ sediments. The decrease of total carbon uptake from 540 to 1100 m suggests a higher demand for carbon by species in the low-oxygen core region of the OMZ or less food competition with macrofauna. Especially Uvigerinids showed high uptake of phytodetrital carbon at the lowest oxygenated site. Variation in the ratio of phytodetrital carbon to nitrogen between species and sites indicates that foraminiferal carbon and nitrogen use can be decoupled and different nutritional demands are found between spe-cies. Lower ratio of phytodetrital carbon and nitrogen at 540 m could hint for greater demand or storage of food-based nitrogen, ingestion or hosting of bacteria under almost anoxic condi-tions. Shifts in the foraminiferal assemblage structure (controlled by oxygen or food availabil-ity and in the presence of other benthic organisms account for observed changes in the pro-cessing of phytodetritus in the different OMZ habitats. Foraminifera dominate the short-term processing of phytodetritus in the OMZ core but are less important in the lower OMZ bounda-ry region of the Indian margin as biological interactions and species distribution of foraminif-era change with depth and oxygen levels.

  7. Demand Response in Smart Grids

    DEFF Research Database (Denmark)

    Hansen, Jacob; Knudsen, Jesper Viese; Annaswamy, Anuradha M.

    2014-01-01

    In recent decades, moves toward higher integration of Renewable Energy Resources have called for fundamental changes in both the planning and operation of the overall power grid. One such change is the incorporation of Demand Response (DR), the process by which consumers can adjust their demand...

  8. On constant elasticities of demand

    OpenAIRE

    Andrés Vázquez

    1998-01-01

    While the Slutsky matrix and duality theory have been used to establish that constant elasticity demand functions imply unitary income elasticities, zero cross price elasticities and own price elasticities equal to minus one, this note shows that these results can also be straightforwardly derived from the simple assumption that demand functions satisfy the budget constraint with strict equality.

  9. CAREER GUIDE FOR DEMAND OCCUPATIONS.

    Science.gov (United States)

    LEE, E.R.; WELCH, JOHN L.

    THIS PUBLICATION UPDATES THE "CAREER GUIDE FOR DEMAND OCCUPATIONS" PUBLISHED IN 1959 AND PROVIDES COUNSELORS WITH INFORMATION ABOUT OCCUPATIONS IN DEMAND IN MANY AREAS WHICH REQUIRE PREEMPLOYMENT TRAINING. IT PRESENTS, IN COLUMN FORM, THE EDUCATION AND OTHER TRAINING USUALLY REQUIRED BY EMPLOYERS, HIGH SCHOOL SUBJECTS OF PARTICULAR PERTINENCE TO…

  10. Job demands-resources model

    NARCIS (Netherlands)

    A.B. Bakker (Arnold); E. Demerouti (Eva)

    2013-01-01

    markdownabstract* The question of what causes job stress and what motivates people has received a lot of research attention during the past five decades. In this paper, we discuss Job Demands-Resources (JD-R) theory, which represents an extension of the Job Demands-Resources model (Bakker & Demerout

  11. Technical Workers in Great Demand

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The Labor and Social Security Ministry conducted a survey on 81 labor markets across China in the second quarter of this year, the results of which showed that the demand for technical workers, especially those of middle and senior titles, far outnumbers the supply.The survey shows that the demand/supply

  12. Learning to face stochastic demand

    OpenAIRE

    Flåm, Sjur Didrik; Sandsmark, Maria

    2000-01-01

    We consider repeated interaction among several producers of a homogenous, divisible good, traded at a common market. Demand is uncertain, and its law is unknown. We explore an adaptive scheme leading such producers over time, to face correct demand data. Extensions include non-cooperative games in which strategic interaction is felt via exactly two real parameters.

  13. Uranium resources, demand and production

    International Nuclear Information System (INIS)

    Estimations of the demand and production of principal uranium resource categories are presented. The estimations based on data analysis made by a joint 'NEA/IAEA Working Party on Uranium Resources' and the corresponding results are published by the OECD (Organization for Economic Co-operation and Development) in the 'Uranium Resources, Production and Demand' Known as 'Red Book'. (M.C.K.)

  14. Credit demand in Mozambican manufacturing

    DEFF Research Database (Denmark)

    Byiers, Bruce; Rand, John; Tarp, Finn;

    2010-01-01

    This paper uses two industrial firm surveys to identify the key determinants of credit demand in Mozambican manufacturing. We construct five different measures of being credit constrained and estimate desired debt demand. Besides firm size and ownership structure, we find evidence that general...

  15. Demand-Supply Gap Analysis

    OpenAIRE

    Aized H. Mir; Abidi, Sohail; Amer Z. Durrani

    2007-01-01

    An essential part of the Pakistan Infrastructure Implementation Capacity Assessment (PIICA) was an assessment of available resources and the demand generated for these resources by the proposed infrastructure projects. A demand-supply gap analysis for Human Resources (HR), major construction materials and equipment keeping in view the Medium Term Development Framework (MTDF) for up to 2010...

  16. The jumbo squid, Dosidicus gigas (Ommastrephidae), living in oxygen minimum zones II: Blood-oxygen binding

    Science.gov (United States)

    Seibel, Brad A.

    2013-10-01

    Dosidicus gigas is a large, metabolically active squid that migrates across a strong oxygen and temperature gradient in the Eastern Pacific. Here we analyze the oxygen-binding properties of the squid's respiratory protein (hemocyanin, Hc) that facilitate such activity. A high Hc-oxygen affinity, strong temperature dependence, and pronounced pH sensitivity (P50=0.009T2.03, pH 7.4; Bohr coefficient=ΔlogP50/ΔpH=-1.55+0.034T) of oxygen binding facilitate night-time foraging in the upper water column, and support suppressed oxygen demand in hypoxic waters at greater depths. Expanding hypoxia may act to alter the species habitable depth range. This analysis supports the contention that ocean acidification could limit oxygen carrying capacity in squids at warmer temperature leading to reduced activity levels or altered distribution.

  17. Oxygen - A Four Billion Year History

    DEFF Research Database (Denmark)

    Canfield, Donald Eugene

    The air we breathe is twenty-one percent oxygen, an amount higher than on any other known world. While we may take our air for granted, Earth was not always an oxygenated planet. How did it become this way? Oxygen is the most current account of the history of atmospheric oxygen on Earth. Donald...... Canfield--one of the world's leading authorities on geochemistry, earth history, and the early oceans--covers this vast history, emphasizing its relationship to the evolution of life and the evolving chemistry of the Earth. With an accessible and colorful first-person narrative, he draws from a variety...... of fields, including geology, paleontology, geochemistry, biochemistry, animal physiology, and microbiology, to explain why our oxygenated Earth became the ideal place for life. Describing which processes, both biological and geological, act to control oxygen levels in the atmosphere, Canfield traces...

  18. The metabolic demands of endosymbiotic chemoautotrophic metabolism on host physiological capacities

    OpenAIRE

    J. J. Childress; Peter R. Girguis

    2011-01-01

    While chemoautotrophic endosymbioses of hydrothermal vents and other reducing environments have been well studied, little attention has been paid to the magnitude of the metabolic demands placed upon the host by symbiont metabolism and the adaptations necessary to meet such demands. Here we make the first attempt at such an evaluation, and show that moderate to high rates of chemoautotrophic or methanotrophic metabolism impose oxygen uptake and proton equivalent elimination demands upon the h...

  19. Biological Threats

    Science.gov (United States)

    ... Workplace Plans School Emergency Plans Main Content Biological Threats Biological agents are organisms or toxins that can ... for Disease Control and Prevention . Before a Biological Threat Unlike an explosion, a biological attack may or ...

  20. Monitoring of Biological Nitrogen Removal in Tannery Wastewater Using a Sequencing Batch Reactor

    Directory of Open Access Journals (Sweden)

    Carrasquero-Ferrer Sedolfo José

    2014-04-01

    Full Text Available The objective of this research was to relate the biological nitrogen removal in tannery wastewater with profiles of pH, alkalinity and redox potential (ORP using a sequencing batch reactor (SBR with a working volume of 2 L. The reactor worked under two operational sequences: anoxic-aerobic-anoxic (Ax/Ae/Ax and aerobic-anoxic (Ae/Ax, which were combined with two cell retention times (CRT (15 and 25 days, with an operation cycle time (OCT of 11 hours. The profiles were performed by measuring each 15 minutes the following parameters: pH, dissolved oxygen (DO, ORP, and each hour the parameters: total alkalinity, total chemical oxygen demand (DQOT, soluble chemical oxygen demand (DQOS, total Kjeldahl nitrogen (TKN, nitrite (NO2-, nitrate (NO3- and ammonia nitrogen (N-NH4+. Alkalinity and ORP profile were excellent indicators of the processes of biological nitrogen removal. However, pH could not be used as a control parameter, due to the buffering capacity of tannery wastewater. Finally, this research work showed that alkalinity and ORP values can be used as on-line control parameters to monitor the evolution of the nitrogen removal in tannery wastewater (nitrification and denitrification processes.

  1. Home Oxygen Therapy

    Science.gov (United States)

    ... Oxygen Therapy Font: Aerosol Delivery Oxygen Resources Immunizations Pollution Nutrition Exercise Coming Of Age Older Adults Allergy ... oxygen is so cold it can hurt your skin. Keep a fire extinguisher close by, and let ...

  2. Demand as Frequency Controlled Reserve

    DEFF Research Database (Denmark)

    Xu, Zhao; Togeby, Mikael; Østergaard, Jacob

    This report summaries the research outcomes of the project ‘Demand as Frequency Controlled Reserve (DFR)’, which has received the support from Energinet.dk’s PSO program, Grant no. 2005-2-6380. The objective of this project is to investigate the technology of using electricity demands for providing...... frequency reserve to power systems. The project consists of five work packages, including: Background and perspective Dynamical simulation of chosen concepts Monitoring demand as frequency controlled reserve Strategy and practical implementation Conclusion and evaluation Within the project, the frequency...

  3. Saving Electricity and Demand Response

    Science.gov (United States)

    Yamaguchi, Nobuyuki

    A lot of people lost their lives in the tremendous earthquake in Tohoku region on March 11. A large capacity of electric power plants in TEPCO area was also damaged and large scale power shortage in this summer is predicted. In this situation, electricity customers are making great effort to save electricity to avoid planned outage. Customers take actions not only by their selves but also by some customers' cooperative movements. All actions taken actually are based on responses to request form the government or voluntary decision. On the other hand, demand response based on a financial stimulus is not observed as an actual behavior. Saving electricity by this demand response only discussed in the newspapers. In this commentary, the events regarding electricity-saving measure after this disaster are described and the discussions on demand response, especially a raise in power rate, are put into shapes in the context of this electricity supply-demand gap.

  4. Voltage Controlled Dynamic Demand Response

    DEFF Research Database (Denmark)

    Bhattarai, Bishnu Prasad; Bak-Jensen, Birgitte; Mahat, Pukar;

    2013-01-01

    central or dispersed generations might not be sufficient for future scenario. One of the effective methods to cope with this scenario is to enable demand response. This paper proposes a dynamic voltage regulation based demand response technique to be applied in low voltage (LV) distribution feeders......Future power system is expected to be characterized by increased penetration of intermittent sources. Random and rapid fluctuations in demands together with intermittency in generation impose new challenges for power balancing in the existing system. Conventional techniques of balancing by large....... An adaptive dynamic model has been developed to determine composite voltage dependency of an aggregated load on feeder level. Following the demand dispatch or control signal, optimum voltage setting at the LV substation is determined based on the voltage dependency of the load. Furthermore, a new technique...

  5. Television Advertising and Soda Demand

    OpenAIRE

    Rigoberto A. Lopez; Liu, Yizao; Zhu, Chen

    2012-01-01

    This study examines the effects of television advertising on consumer demand for carbonated soft drinks using a random coefficients logit model (BLP) with household and advertising data from seven U.S. cities over a three year period. We find that advertising decreases the price elasticity of demand, indicating that advertising plays predominantly a persuasive, therefore anti-competitive role in this market. Further results show that brand spillover effects are significant and that measuring ...

  6. The Strong Law of Demand

    OpenAIRE

    Brown, Donald J.; Caterina Calsamiglia

    2003-01-01

    We show that a demand function is derived from maximizing a quasilinear utility function subject to a budget constraint if and only if the demand function is cyclically monotone. On finite data sets consisting of pairs of market prices and consumption vectors, this result is equivalent to a solution of the Afriat inequalities where all the marginal utilities of income are equal. We explore the implications of these results for maximization of a random quasilinear utility function subject to a...

  7. Consumer preferences and demand systems

    OpenAIRE

    Barnett, William A.; Serletis, Apostolos

    2008-01-01

    This paper is an up-to-date survey of the state-of-the-art in consumer demand modelling. We review and evaluate advances in a number of related areas, including different approaches to empirical demand analysis, such as the differential approach, the locally �flexible functional forms approach, the semi-nonparametric approach, and a nonparametric approach. We also address estimation issues, including sampling theoretic and Bayesian estimation methods, and discuss the limitations of the curren...

  8. Demand Response Spinning Reserve Demonstration

    Energy Technology Data Exchange (ETDEWEB)

    Eto, Joseph H.; Nelson-Hoffman, Janine; Torres, Carlos; Hirth,Scott; Yinger, Bob; Kueck, John; Kirby, Brendan; Bernier, Clark; Wright,Roger; Barat, A.; Watson, David S.

    2007-05-01

    The Demand Response Spinning Reserve project is a pioneeringdemonstration of how existing utility load-management assets can providean important electricity system reliability resource known as spinningreserve. Using aggregated demand-side resources to provide spinningreserve will give grid operators at the California Independent SystemOperator (CAISO) and Southern California Edison (SCE) a powerful, newtool to improve system reliability, prevent rolling blackouts, and lowersystem operating costs.

  9. Information Demand Pattern for Teams

    OpenAIRE

    Dirk Stamer; Kurt Sandkuhl; Veronika Zeiner

    2016-01-01

    Modern organizations face the challenge of having to manage an increasing amount of information. The resulting information overload leads more and more to problems in decision making with potentially negative economic consequences. Decision-makers and knowledge intensive workers are especially affected. To address this problem, information demand patterns were proposed which capture organizational knowledge about the information demand of single roles. This work extends the concept of informa...

  10. Living with the extreme demand

    OpenAIRE

    Teppo Eskelinen

    2013-01-01

    Most of the ethical literature on extreme poverty suggests, that some, if not most, of the incomes of the residents of rich countries ought to be donated to the global poor. Yet complying with this ethical demand becomes increasingly more difficult as the changes in lifestyle in the (post)industrial north demand ever more consumption in order to obtain the necessities for survival in such societies. In this article, I will discuss Peter Singer's famous arguments for the ethical duty to donate...

  11. Personalized Demand Responsive Transit Systems

    OpenAIRE

    Yim, Y. B.; Khattak, Asad J.

    2000-01-01

    An aging population in the US, low-density urban sprawl and the accessibility needs of certain groups (particularly disabled and aged) increasingly point to more flexible demand-responsive transit systems in the future. This paper describes the important aspects of a consumer-oriented Personalized Demand Responsive Transit (PDRT) service. The system will provide services to the traveling public for journeys to work and for journeys to other destinations. A PDRT that responds to the travelers'...

  12. Optimal supply against fluctuating demand

    OpenAIRE

    Nobuyuki Sakai; Hisanori Kudoh

    2005-01-01

    Sornette et al. claimed that the optimal supply does not agree with the average demand, by analyzing a bakery model where a daily demand fluctuates with a uniform distribution. In this note, we extend the model to general probability distributions, and obtain the formula of the optimal supply for Gaussian distribution, which is more realistic. Our result is useful in a real market to earn the largest income on average.

  13. Optimal Supply against Fluctuating Demand

    OpenAIRE

    SAKAI, Nobuyuki; Kudo, Hisanori

    2006-01-01

    Contrary to the common sense in economy, the optimal supply does not always agree with the average demand. This was pointed out by Sornette et al. (1999), who analyzed a bakery model where a daily demand fluctuates with a uniform distribution. In this note, we extend the model to general probability distributions, and obtain the formula of the optimal supply for Gaussian distribution, which is more realistic. Our result is useful in a real market to earn the largest income on average.

  14. Determination of Biological Treatability Processes of Textile Wastewater and Implementation of a Fuzzy Logic Model

    Directory of Open Access Journals (Sweden)

    Harun Akif Kabuk

    2015-01-01

    Full Text Available This study investigated the biological treatability of textile wastewater. For this purpose, a membrane bioreactor (MBR was utilized for biological treatment after the ozonation process. Due to the refractory organic contents of textile wastewater that has a low biodegradability capacity, ozonation was implemented as an advanced oxidation process prior to the MBR system to increase the biodegradability of the wastewater. Textile wastewater, oxidized by ozonation, was fed to the MBR at different hydraulic retention times (HRT. During the process, color, chemical oxygen demand (COD, and biochemical oxygen demand (BOD removal efficiencies were monitored for 24-hour, 12-hour, 6-hour, and 3-hour retention times. Under these conditions, 94% color, 65% COD, and 55% BOD removal efficiencies were obtained in the MBR system. The experimental outputs were modeled with multiple linear regressions (MLR and fuzzy logic. MLR results suggested that color removal is more related to COD removal relative to BOD removal. A surface map of this issue was prepared with a fuzzy logic model. Furthermore, fuzzy logic was employed to the whole modeling of the biological system treatment. Determination coefficients for COD, BOD, and color removal efficiencies were 0.96, 0.97, and 0.92, respectively.

  15. An update on the MTBE supply and demand picture

    International Nuclear Information System (INIS)

    The initial Clean Air Act to establish emissions standards for automobiles and light-duty trucks was passed in 1966. It was modified in 1970 and again in 1977. In 1990 it was amended to present a 20 year plan to achieve cleaner air through fuel composition and vehicle design. This paper discusses the supply and demand within the US of methyl tertiary butyl ether as an oxygenated fuel additive to gasoline to help control the ozone pollution problem

  16. Workload demand in police officers during mountain bike patrols.

    Science.gov (United States)

    Takken, T; Ribbink, A; Heneweer, H; Moolenaar, H; Wittink, H

    2009-02-01

    To the authors' knowledge this is the first paper that has used the training impulse (TRIMP) 'methodology' to calculate workload demand. It is believed that this is a promising method to calculate workload in a range of professions in order to understand the relationship between work demands and aerobic fitness. The aim of this study was to assess workload demand in police officers from the Utrecht police department in the Netherlands, during patrol by mountain bike. Maximum oxygen intake, maximum heart rate (HRmax), ventilatory threshold (VT)1 and VT2 were determined with a maximal exercise test on a bicycle ergometer. Heart rates were registered throughout three shifts in 20 subjects using a heart rate monitor. Exercise intensity was divided into three phases: phase I (between 40% of HRmax and VT1); phase II (between VT and the respiratory compensation point (RCP)); and phase III (>RCP). The total TRIMP score was obtained by summating the results of the three phases. Average daily workload demands of 355 TRIMPs per day and 1777 TRIMPs per week were measured. Workload demand approached and in some cases exceeded the upper limit of 2000 TRIMPs per week threshold level for physiological stress demands in professional male cyclists.

  17. Artificial oxygen transport protein

    Science.gov (United States)

    Dutton, P. Leslie

    2014-09-30

    This invention provides heme-containing peptides capable of binding molecular oxygen at room temperature. These compounds may be useful in the absorption of molecular oxygen from molecular oxygen-containing atmospheres. Also included in the invention are methods for treating an oxygen transport deficiency in a mammal.

  18. Preliminary Study of Greywater Treatment through Rotating Biological Contactor

    Directory of Open Access Journals (Sweden)

    Ashfaq Ahmed Pathan

    2011-07-01

    Full Text Available The characteristics of the greywater vary from country to country and it depends upon the cultural and social behavior of the respective country. There was a considerable need to characterize and recycle the greywater. In this regard greywater was separated from the black water and analyzed for various physiochemical parameters. Among various greywater recycling treatment technologies, RBC (Rotating Biological Contactor is more effective treatment technique in reducing COD (Chemical Oxygen Demand and organic matters from the greywater. But this technology was not applied and tested in Pakistan. There was extensive need to investigate the RBC technology for greywater recycling at small scale before applying at mass scale. To treat the greywater, a single-stage RBC simulator was designed and developed at laboratory scale. An electric motor equipped with gear box to control the rotations of the disks was mounted on the tank. The simulator was run at the rate of 1.7 rpm. The disc area of the RBC was immersed about 40% in the greywater. Water samples were collected at each HRT (Hydraulic Retention Time and analyzed for the parameters such as pH, conductivity, TDS (Total Dissolved Solids, salinity, BOD5 (Biochemical Oxygen Demand, COD and suspended solids by using standard methods. The results are encouraging with percentage removal of BOD5 and COD being 53 and 60% respectively.

  19. Oxygen-enhanced combustion

    CERN Document Server

    Baukal, Charles E

    2013-01-01

    Combustion technology has traditionally been dominated by air/fuel combustion. However, two developments have increased the significance of oxygen-enhanced combustion-new technologies that produce oxygen less expensively and the increased importance of environmental regulations. Advantages of oxygen-enhanced combustion include less pollutant emissions as well as increased energy efficiency and productivity. Oxygen-Enhanced Combustion, Second Edition compiles information about using oxygen to enhance industrial heating and melting processes. It integrates fundamental principles, applications, a

  20. Consumer demand and quality assurance

    DEFF Research Database (Denmark)

    Grunert, Klaus G; Wognum, Nel; Trienekens, Jacques;

    2011-01-01

    Consumers differ in their demands, and this mau have implications for the type of supply chain governance that is most suitable for serving them. We present a segmentation of pork consumers in the EU based on their food-related lifestyles and demand for different pork products. We then present an......, and that these implications are different for fresh meat and processed meat. The paper closes with a call for more collaboration between chain researchers and consumer researchers.......Consumers differ in their demands, and this mau have implications for the type of supply chain governance that is most suitable for serving them. We present a segmentation of pork consumers in the EU based on their food-related lifestyles and demand for different pork products. We then present...... an inventory of pork chain governance and quality management systems, also resulting from a pan-European study, and attempt to match types of chains to consumer segments, arguing that the type of quality demanded by the consumers has implications especially for the quality management system governing the chain...

  1. [The story of oxygen (2)].

    Science.gov (United States)

    Marini, F; Radin, S; Tenchini, P

    1985-04-01

    The authors, in this second part of the oxygen story, resolutely cross the borders of the biophysical field, and face the origins and becoming of life, the stages of which are synthesized in "casket" terms, unusual for surgeons: "protobionts", "procariots", "cyanobacteria", "chlorophyll", "caroteonides", "fermentation", "anaerobic glycolysis", "eucariots", "respiratory chain", "mitocondria". This is not an unconventional biological exercise, but the effort to give clinics a more legible ground, a sort of common denominator of the most different pathologies, and, among these ones, at the first place, just those of the specialistic branch, also less frequenter of biology, that is, surgery. This common denominator, the oxygen radicals represent the emerging apex of, like the peak of an iceberg, in fact, can be only investigated through an exasperated "philogenetic" recovering. Such process of "archaeology" seems to be the only suitable to supply us the cipher-key of the ambiguous, shifty character of oxygen, and entrust us with a cultural patrimony being unique as it is spendable in an immediate clinical future. PMID:4017137

  2. International Oil Supplies and Demands

    Energy Technology Data Exchange (ETDEWEB)

    1991-09-01

    The eleventh Energy Modeling Forum (EMF) working group met four times over the 1989--90 period to compare alternative perspectives on international oil supplies and demands through 2010 and to discuss how alternative supply and demand trends influence the world's dependence upon Middle Eastern oil. Proprietors of eleven economic models of the world oil market used their respective models to simulate a dozen scenarios using standardized assumptions. From its inception, the study was not designed to focus on the short-run impacts of disruptions on oil markets. Nor did the working group attempt to provide a forecast or just a single view of the likely future path for oil prices. The model results guided the group's thinking about many important longer-run market relationships and helped to identify differences of opinion about future oil supplies, demands, and dependence.

  3. Fundamental Travel Demand Model Example

    Science.gov (United States)

    Hanssen, Joel

    2010-01-01

    Instances of transportation models are abundant and detailed "how to" instruction is available in the form of transportation software help documentation. The purpose of this paper is to look at the fundamental inputs required to build a transportation model by developing an example passenger travel demand model. The example model reduces the scale to a manageable size for the purpose of illustrating the data collection and analysis required before the first step of the model begins. This aspect of the model development would not reasonably be discussed in software help documentation (it is assumed the model developer comes prepared). Recommendations are derived from the example passenger travel demand model to suggest future work regarding the data collection and analysis required for a freight travel demand model.

  4. International Oil Supplies and Demands

    International Nuclear Information System (INIS)

    The eleventh Energy Modeling Forum (EMF) working group met four times over the 1989--90 period to compare alternative perspectives on international oil supplies and demands through 2010 and to discuss how alternative supply and demand trends influence the world's dependence upon Middle Eastern oil. Proprietors of eleven economic models of the world oil market used their respective models to simulate a dozen scenarios using standardized assumptions. From its inception, the study was not designed to focus on the short-run impacts of disruptions on oil markets. Nor did the working group attempt to provide a forecast or just a single view of the likely future path for oil prices. The model results guided the group's thinking about many important longer-run market relationships and helped to identify differences of opinion about future oil supplies, demands, and dependence

  5. International Oil Supplies and Demands

    International Nuclear Information System (INIS)

    The eleventh Energy Modeling Forum (EMF) working group met four times over the 1989--1990 period to compare alternative perspectives on international oil supplies and demands through 2010 and to discuss how alternative supply and demand trends influence the world's dependence upon Middle Eastern oil. Proprietors of eleven economic models of the world oil market used their respective models to simulate a dozen scenarios using standardized assumptions. From its inception, the study was not designed to focus on the short-run impacts of disruptions on oil markets. Nor did the working group attempt to provide a forecast or just a single view of the likely future path for oil prices. The model results guided the group's thinking about many important longer-run market relationships and helped to identify differences of opinion about future oil supplies, demands, and dependence

  6. International Oil Supplies and Demands

    Energy Technology Data Exchange (ETDEWEB)

    1992-04-01

    The eleventh Energy Modeling Forum (EMF) working group met four times over the 1989--1990 period to compare alternative perspectives on international oil supplies and demands through 2010 and to discuss how alternative supply and demand trends influence the world's dependence upon Middle Eastern oil. Proprietors of eleven economic models of the world oil market used their respective models to simulate a dozen scenarios using standardized assumptions. From its inception, the study was not designed to focus on the short-run impacts of disruptions on oil markets. Nor did the working group attempt to provide a forecast or just a single view of the likely future path for oil prices. The model results guided the group's thinking about many important longer-run market relationships and helped to identify differences of opinion about future oil supplies, demands, and dependence.

  7. Ferritin Protein Nanocages Use Ion Channels, Catalytic Sites, and Nucleation Channels To Manage Iron/Oxygen Chemistry: A review for: Current Opinion In Chemical Biology/Bioinorganic Chemistry: Iron Biochemistry

    OpenAIRE

    Theil, Elizabeth C.

    2011-01-01

    The ferritin superfamily is composed of ancient, nanocage proteins with an internal cavity, 60% of total volume, that reversibly synthesize solid minerals of hydrated ferric oxide; the minerals are iron concentrates for cell nutrition as well as antioxidants due to ferrous and oxygen consumption during mineralization. The cages have multiple iron entry/exit channels, oxidoreductase enzyme sites, and, in eukaryotes, Fe(III)O nucleation channels with clustered exits that extend protein activity...

  8. Oxygen nitrogen and ozone: application in wastewater treatment and environment protection

    Energy Technology Data Exchange (ETDEWEB)

    Pinto, Julio A.G. [Oxigenio do Brasil, Sao Paulo, SP (Brazil)

    1993-12-31

    Oxygen`s versatility as an oxidant and as a combustion atmosphere provides clean solutions to different industries. Oxygen also finds excellent application for the regeneration of eutrophic surface waters where high biochemical oxygen demand loading demands extra available oxygen for life support. When even stronger oxidizing properties are needed, ozone may act as a supplement. Nitrogen, on the other hand, has excellent cooling capacity, resulting in practical application in solvent recapture, enabling processes to meet emission standards while allowing solvent recycle for reuse. 7 figs., 1 tab.

  9. Dissolved oxygen in the Tualatin River, Oregon, during winter flow conditions, 1991 and 1992

    Science.gov (United States)

    Kelly, V.J.

    1996-01-01

    Throughout the winter period, November through April, wastewater treatment plants in the Tualatin River Basin discharge from 10,000 to 15,000 pounds per day of biochemical oxygen demand to the river. These loads often increase substantially during storms when streamflow is high. During the early winter season, when streamflow is frequently less than the average winter flow, the treatment plants discharge about 2,000 pounds per day of ammonia. This study focused on the capacity of the Tualatin River to assimilat oxygen-demanding loads under winter streamflow conditions during the 1992 water year, with an emphasis on peak-flow conditions in the river, and winter-base-flow conditions during November 1992. Concentrations of dissolved oxygen throughout the main stem of the river during the winter remained generally high relative to the State standard for Oregon of 6 milligrams per liter. The most important factors controlling oxygen consumption during winter-low-flow conditions were carbonaceous biochemical oxygen demand and input of oxygen-depleted waters from tributaries. During peak-flow conditions, reduced travel time and increased dilution associated with the increased streamflow minimized the effect of increased oxygen-demanding loads. During the base-flow period in November 1992, concentrations of dissolved oxygen were consistently below 6 milligrams per liter. A hydrodynamic water-quality model was used to identify the processes depleting dissolved oxygen, including sediment oxygen demand, nitrification, and carbonaceous biochemical oxygen demand. Sediment oxygen demand was the most significant factor; nitrification was also important. Hypothetical scenarios were posed to evaluate the effect of different wastewater treatment plant loads during winter-base-flow conditions. Streamflow and temperature were significant factors governing concentrations of dissolved oxygen in the main-stem river.

  10. Pay for load demand - electricity pricing with load demand component

    International Nuclear Information System (INIS)

    This publication is part of a project called Direct and Indirect Load Control in Buildings. Peak load problems have attracted considerable attention in Sweden during last three winters, caused by a significant decrease in available reserve power, which is a consequence of political decisions and liberalisation of the electricity market. A possible way to lower peak loads, avoiding electricity shortages and reducing electricity costs both for users and utilities, is to make customers experience the price difference during peak load periods and, in this way, become more aware of their energy consumption pattern and load demand. As of January 1st 2001, one of the Swedish energy utilities - Sollentuna Energi - operating in the Stockholm area, introduced a new electricity tariff with differentiated grid fees based on a mean value of the peak load every month. This tariff was introduced for all residential customers in the service area. The objective of this study is to investigate the extent to which a Load Demand Component, included in electricity pricing, can influence energy use and load demand in residential buildings. What are the benefits and disadvantages for customers and utilities? This paper investigates the impact of the new tariff on the utility and different types of typical residential customers, making comparisons with previous tariff. Keywords Load demand, electricity pricing, tariff, residential customers, energy behaviour

  11. Comparative quantification of oxygen release by wetland plants: electrode technique and oxygen consumption model.

    Science.gov (United States)

    Wu, Haiming; Liu, Jufeng; Zhang, Jian; Li, Cong; Fan, Jinlin; Xu, Xiaoli

    2014-01-01

    Understanding oxygen release by plants is important to the design of constructed wetlands for wastewater treatment. Lab-scale systems planted with Phragmites australis were studied to evaluate the amount of oxygen release by plants using electrode techniques and oxygen consumption model. Oxygen release rate (0.14 g O2/m(2)/day) measured using electrode techniques was much lower than that (3.94-25.20 gO2/m(2)/day) calculated using the oxygen consumption model. The results revealed that oxygen release by plants was significantly influenced by the oxygen demand for the degradation of pollutants, and the oxygen release rate increased with the rising of the concentration of degradable materials in the solution. The summary of the methods in qualifying oxygen release by wetland plants demonstrated that variations existed among different measuring methods and even in the same measuring approach. The results would be helpful for understanding the contribution of plants in constructed wetlands toward actual wastewater treatment.

  12. Asymmetric Information and Consumer Demand

    OpenAIRE

    Ismagilova G. N.; Danilina E. I.; Gafurov I. R.; Ismagilov R. I.; Safiullin L. N.

    2014-01-01

    In the paper study the peculiarities of the formation the consumer demand for durable goods, the so-called «experience goods» in markets with asymmetric information. In the known literature sources studying of the demand is based on the assumption that at the moment of the purchase of goods and services people know exactly what price they are willing to pay for them and what utility they are going to obtain using those goods and services. Consider the signal model in which the initial price a...

  13. Demand as Frequency Controlled Reserve

    DEFF Research Database (Denmark)

    Xu, Zhao; Østergaard, Jacob; Togeby, Mikael

    2011-01-01

    Relying on generation side alone is deemed insufficient to fulfill the system balancing needs for future Danish power system, where a 50% wind penetration is outlined by the government for year 2025. This paper investigates using the electricity demand as frequency controlled reserve (DFR) as a new...... balancing measure, which has a high potential and can provide many advantages. Firstly, the background of the research is reviewed, including conventional power system reserves and the electricity demand side potentials. Subsequently, the control logics and corresponding design considerations for the DFR...

  14. Oxygen chemisorption cryogenic refrigerator

    Science.gov (United States)

    Jones, Jack A. (Inventor)

    1987-01-01

    The present invention relates to a chemisorption compressor cryogenic refrigerator which employs oxygen to provide cooling at 60 to 100 K. The invention includes dual vessels containing an oxygen absorbent material, alternately heated and cooled to provide a continuous flow of high pressure oxygen, multiple heat exchangers for precooling the oxygen, a Joule-Thomson expansion valve system for expanding the oxygen to partially liquefy it and a liquid oxygen pressure vessel. The primary novelty is that, while it was believed that once oxygen combined with an element or compound the reaction could not reverse to release gaseous oxygen, in this case oxygen will indeed react in a reversible fashion with certain materials and will do so at temperatures and pressures which make it practical for incorporation into a cryogenic refrigeration system.

  15. Preparation and analysis of zirconia oxygen sensors

    Institute of Scientific and Technical Information of China (English)

    LUO Zhi-an; XIAO Jian-zhong; XIA Feng

    2006-01-01

    Thimble zirconia oxygen sensors were prepared with yttria stabilized zirconia(YSZ). The surfaces of the electrode,electrolyte and their interface were observed by scanning electron microscope(SEM). The sensor was examined with engine bench test to evaluate the essential performance. The results show that the oxygen sensor has good performance,which can meet the demand of practical applications. Chemical equilibrium theory was introduced to explain electromotive force of the sensors and the influence of temperature on the signals. The educed theoretical model of electromotive force agrees well with testing results.

  16. Biological hydrogen photoproduction

    Energy Technology Data Exchange (ETDEWEB)

    Nemoto, Y. [Univ. of Miami, FL (United States)

    1995-09-01

    Following are the major accomplishments of the 6th year`s study of biological hydrogen photoproduction which were supported by DOE/NREL. (1) We have been characterizing a biological hydrogen production system using synchronously growing aerobically nitrogen-fixing unicellular cyanobacterium, Synechococcus sp. Miami BG 043511. So far it was necessary to irradiate the cells to produce hydrogen. Under darkness they did not produce hydrogen. However, we found that, if the cells are incubated with oxygen, they produce hydrogen under the dark. Under 80% argon + 20% oxygen condition, the hydrogen production activity under the dark was about one third of that under the light + argon condition. (2) Also it was necessary so far to incubate the cells under argon atmosphere to produce hydrogen in this system. Argon treatment is very expensive and should be avoided in an actual hydrogen production system. We found that, if the cells are incubated at a high cell density and in a container with minimum headspace, it is not necessary to use argon for the hydrogen production. (3) Calcium ion was found to play an important role in the mechanisms of protection of nitrogenase from external oxygen. This will be a clue to understand the reason why the hydrogen production is so resistant to oxygen in this strain. (4) In this strain, sulfide can be used as electron donor for the hydrogen production. This result shows that waste water can be used for the hydrogen production system using this strain.

  17. Modeling impact of storage zones on stream dissolved oxygen

    Science.gov (United States)

    Chapra, S.C.; Runkel, R.L.

    1999-01-01

    The Streeter-Phelps dissolved oxygen model is modified to incorporate storage zones. A dimensionless number reflecting enhanced decomposition caused by the increased residence time of the biochemical oxygen demand in the storage zone parameterizes the impact. This result provides a partial explanation for the high decomposition rates observed in shallow streams. An application suggests that the storage zone increases the critical oxygen deficit and moves it closer to the point source. It also indicates that the storage zone should have lower oxygen concentration than the main channel. An analysis of a dimensionless enhancement factor indicates that the biochemical oxygen demand decomposition in small streams could be up to two to three times more than anticipated based on the standard Streeter-Phelps model without storage zones. For larger rivers, enhancements of up to 1.5 could occur.The Streeter-Phelps dissolved oxygen model is modified to incorporate storage zones. A dimensionless number reflecting enhanced decomposition caused by the increased residence time of the biochemical oxygen demand in the storage zone parameterizes the impact. This result provides a partial explanation for the high decomposition rates observed in shallow streams. An application suggests that the storage zone increases the critical oxygen deficit and moves it closer to the point source. It also indicates that the storage zone should have lower oxygen concentration than the main channel. An analysis of a dimensionless enhancement factor indicates that the biochemical oxygen demand decomposition in small streams could be up to two to three times more than anticipated based on the standard Streeter-Phelps model without storage zones. For larger rivers, enhancements of up to 1.5 could occur.

  18. The moral demands of affluence

    DEFF Research Database (Denmark)

    Sønderholm, Jørn

    2015-01-01

    in favor of the view that affluent individuals are justified in spending monetary resources on themselves at a level that lies well above what Peter Singer finds justified. The proposition I defend is that the premises leading to Cullity’s conclusion about the moderate, and not extremely demanding, nature...

  19. Faculty Demand in Higher Education

    Science.gov (United States)

    Rosenthal, Danielle

    2007-01-01

    The objective of this study is to identify the factors that shift the demand curve for faculty at not-for-profit private institutions. It is unique in that to the author's knowledge no other study has directly addressed the question of how the positive correlation between average faculty salaries and faculty-student ratios can be reconciled with…

  20. The Cognitive Demands of Writing

    NARCIS (Netherlands)

    Torrance, Mark; Jeffery, Gaynor

    1999-01-01

    Writing is a complex activity that places demands on cognitive resources. This volume presents original theory and research exploring the ways in which the sub-components of the writing process (generating and organizing content, producing grammatical sentences, etc.) differ in their cognitive deman

  1. Projecting Electricity Demand in 2050

    Energy Technology Data Exchange (ETDEWEB)

    Hostick, Donna J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Belzer, David B. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Hadley, Stanton W. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Markel, Tony [National Renewable Energy Lab. (NREL), Golden, CO (United States); Marnay, Chris [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Kintner-Meyer, Michael C. W. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2014-07-01

    This paper describes the development of end-use electricity projections and load curves that were developed for the Renewable Electricity (RE) Futures Study (hereafter RE Futures), which explored the prospect of higher percentages (30% - 90%) of total electricity generation that could be supplied by renewable sources in the United States. As input to RE Futures, two projections of electricity demand were produced representing reasonable upper and lower bounds of electricity demand out to 2050. The electric sector models used in RE Futures required underlying load profiles, so RE Futures also produced load profile data in two formats: 8760 hourly data for the year 2050 for the GridView model, and in 2-year increments for 17 time slices as input to the Regional Energy Deployment System (ReEDS) model. The process for developing demand projections and load profiles involved three steps: discussion regarding the scenario approach and general assumptions, literature reviews to determine readily available data, and development of the demand curves and load profiles.

  2. Rejection sampling in demand systems

    OpenAIRE

    Ley, Eduardo; Mark F.J. Steel

    1992-01-01

    We illustrate the method of rejection sampling in a Bayesian application of a new approach toı estimating Demand Systems. This approach, suggested by Varian (1990), is based on a generalization of Afriat's (1967) efficiency index. Rejection sampling is applied to the prior-to-posterior mapping enabling us to obtain posterior results in a nonstandard model.

  3. Cotton Demand Dropping in China

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    The ICAC claimed, global cotton market outlook is bleak in the 2012/2013 annual. Global cotton production is estimated at 25.9 million tons and cotton usage is estimated at 23.4 million tons. Cotton supply will exceed demand; the excess volume will reach 2.4 million tons.

  4. Managed care demands flexibility, creativity.

    Science.gov (United States)

    1996-05-01

    The definition of hospice care is changing as home care providers come under managed care regulations. Hospice care for AIDS patients is demanding, requiring extra time from home care providers. The managed care cost-cutting measures require creativitity and patience. The Visiting Nurses and Hospice of San Francisco (VNH) has held seminars to help providers adapt to managed care.

  5. Employer Demands from Business Graduates

    Science.gov (United States)

    McMurray, Stephen; Dutton, Matthew; McQuaid, Ronald; Richard, Alec

    2016-01-01

    Purpose: The purpose of this paper is to report on research carried out with employers to determine demand for business and management skills in the Scottish workforce. Design/methodology/approach: The research used a questionnaire in which employers were interviewed (either telephone or face to face), completed themselves and returned by e-mail,…

  6. Cocurrent biological nitrification and denitrification in wastewater treatment

    Energy Technology Data Exchange (ETDEWEB)

    Spector, M.

    1998-11-01

    Repetitive conditioning of recycle activated sludge (RAS) under strict anaerobic conditions gradually changes the products of ammonia oxidation from nitrite and nitrate to nitrous oxide (N{sub 2}O) and nitrogen (N{sub 2}). Nitrite inhibits oxygen respiration of anaerobically conditioned sludge; biochemical oxygen demand (BOD) is then oxidized by nitrite, which is reduce to N{sub 2}O and N{sub 2}. When anaerobic RAS conditioning is initially imposed on a nitrifying system, Nitrobacter species continue to oxidize nitrite to nitrate and thus reduce the nitrite available to oxidize BOD. However, Nitrobacter in the mixed liquor gradually tend to wash out because the sole source of Nictrobacter energy, the oxidation of nitrite to nitrate, is diminished to the extent that nitrite is reduced. Incorporation of an RAS conditioning zone to the activate-sludge process results in evolution of a nonfilamentous biomass, which affects both cocurrent biological nitrification and denitrification (CBND) and biological phosphorus removal (BPR). The initial feed zone may be either aerobic or anaerobic. A final anoxic denitrification zone is desirable for removal of residual nitrite plus nitrate (NO{sub x}) from aeration effluent. Nitrous oxide, the main reaction product of CBND, promotes both global warming and destruction of the stratospheric ozone layer.

  7. Metabolic Demands of Heavy Metal Drumming

    Directory of Open Access Journals (Sweden)

    Bryan Romero

    2016-07-01

    Full Text Available Background: The drum set involves dynamic movement of all four limbs. Motor control studies have been done on drum set playing, yet not much is known about the physiological responses to this activity. Even less is known about heavy metal drumming. Aims: The purpose of this study was to determine metabolic responses and demands of heavy metal drumming. Methods: Five semi-professional male drummers (mean ± SD age = 27.4 ± 2.6 y, height = 177.2 ± 3.8 cm, body mass = 85.1 ± 17.8 kg performed four prescribed and four self-selected heavy metal songs. Oxygen consumption (VO2, minute ventilation (VE and respiratory exchange ratio (RER were measured using a metabolic cart.  Heart rate (HR was measured using a heart rate monitor. VO2max was determined using a graded cycle ergometer test. Results: The results indicated a metabolic cost of 6.3 ± 1.4 METs and heart rate of 145.1 ± 15.7 beats·min-1 (75.4 ± 8.3% of age-predicted HRmax. VO2 peak values reached approximately 90% of the drummer’s VO2max when performing at the fastest speeds. According to these results, heavy metal drumming may be considered vigorous intensity activity (≥ 6.0 METs. The relative VO2max of 40.2 ± 9.5 mL·kg·min-1 leads to an aerobic fitness classification of “average” for adult males. Conclusions: The metabolic demands required during heavy metal drumming meet the American College of Sports Medicine guidelines for the development of health related fitness. Keywords: Drum set, Exercise physiology, VO2, Music

  8. Process development for the simultaneous biological nitrogen and phosphorus elimination with high process stability. Final report/Summary report; Verfahrensentwicklung zur simultanen biologischen Stickstoff- und Phosphor-Elimination mit hoher Prozessstabilitaet. Endbericht/Zusammenfassender Bericht

    Energy Technology Data Exchange (ETDEWEB)

    Bartl, J. [Suedhessische Gas und Wasser AG, Darmstadt (Germany); Hillenbrand, T.; Boehm, E.; Corley, M. [Fraunhofer-Institut fuer Systemtechnik und Innovationsforschung (ISI), Karlsruhe (Germany); Memmen, K.; Wolf, P. [Kassel Univ. (Gesamthochschule) (Germany). Fachgebiet Siedlungswasserwirtschaft; Fischer, K.; Motz, U. [Stuttgart Univ. (Germany). Inst. fuer Siedlungswasserbau, Wasserguete- und Abfallwirtschaft; Schoen, G. [Freiburg Univ. (Germany). Inst. fuer Biologie 2

    1996-12-01

    The operation of a waste water treatment plant in Darmstadt, Germany, has been investigated (biochemical oxygen demand, chemical oxygen demand, nitrgen elimination, phosphorus elimination, sewage sludge) and optimized. (SR)

  9. The alchemy of demand response: turning demand into supply

    Energy Technology Data Exchange (ETDEWEB)

    Rochlin, Cliff

    2009-11-15

    Paying customers to refrain from purchasing products they want seems to run counter to the normal operation of markets. Demand response should be interpreted not as a supply-side resource but as a secondary market that attempts to correct the misallocation of electricity among electric users caused by regulated average rate tariffs. In a world with costless metering, the DR solution results in inefficiency as measured by deadweight losses. (author)

  10. Addressing Energy Demand through Demand Response. International Experiences and Practices

    Energy Technology Data Exchange (ETDEWEB)

    Shen, Bo [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Ghatikar, Girish [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Ni, Chun Chun [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Dudley, Junqiao [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Martin, Phil [Enernoc, Inc., Boston, MA (United States); Wikler, Greg

    2012-06-01

    Demand response (DR) is a load management tool which provides a cost-effective alternative to traditional supply-side solutions to address the growing demand during times of peak electrical load. According to the US Department of Energy (DOE), demand response reflects “changes in electric usage by end-use customers from their normal consumption patterns in response to changes in the price of electricity over time, or to incentive payments designed to induce lower electricity use at times of high wholesale market prices or when system reliability is jeopardized.” 1 The California Energy Commission (CEC) defines DR as “a reduction in customers’ electricity consumption over a given time interval relative to what would otherwise occur in response to a price signal, other financial incentives, or a reliability signal.” 2 This latter definition is perhaps most reflective of how DR is understood and implemented today in countries such as the US, Canada, and Australia where DR is primarily a dispatchable resource responding to signals from utilities, grid operators, and/or load aggregators (or DR providers).

  11. Biogeochemistry: Oxygen burrowed away

    NARCIS (Netherlands)

    Meysman, F.J.R.

    2014-01-01

    Multicellular animals probably evolved at the seafloor after a rise in oceanic oxygen levels. Biogeochemical model simulations suggest that as these animals started to rework the seafloor, they triggered a negative feedback that reduced global oxygen.

  12. Oxygen transport membrane

    DEFF Research Database (Denmark)

    2015-01-01

    The present invention relates to a novel composite oxygen transport membrane as well as its preparation and uses thereof.......The present invention relates to a novel composite oxygen transport membrane as well as its preparation and uses thereof....

  13. Hyperbaric oxygen therapy

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/article/002375.htm Hyperbaric oxygen therapy To use the sharing features on this page, please enable JavaScript. Hyperbaric oxygen therapy uses a special pressure chamber to increase ...

  14. Oxygen evolution reaction catalysis

    Energy Technology Data Exchange (ETDEWEB)

    Haber, Joel A.; Jin, Jian; Xiang, Chengxiang; Gregoire, John M.; Jones, Ryan J.; Guevarra, Dan W.; Shinde, Aniketa A.

    2016-09-06

    An Oxygen Evolution Reaction (OER) catalyst includes a metal oxide that includes oxygen, cerium, and one or more second metals. In some instances, the cerium is 10 to 80 molar % of the metals in the metal oxide and/or the catalyst includes two or more second metals. The OER catalyst can be included in or on an electrode. The electrode can be arranged in an oxygen evolution system such that the Oxygen Evolution Reaction occurs at the electrode.

  15. Demand chain management - The evolution

    Directory of Open Access Journals (Sweden)

    D Ericsson

    2011-06-01

    Full Text Available The concepts of Supply Chain Management (SCM and Demand Chain Management (DCM are among the new and debated topics concerning logistics in the literature. The question considered in this paper is: “Are these concepts needed or will they just add to the confusion?” Lasting business concepts have always evolved in close interaction between business and academia. Different approaches start out in business and they are then, more or less si- multaneously, aligned, integrated, systemised and structured in academia. In this way a terminology (or language is provided that helps in further diffusion of the concepts. There is a lack of consensus on the definition of the concept of SCM. This may be one of the major reasons for the difficulty in advancing the science and measuring the results of implementation in business. Relationships in SCM span from rather loose coalitions to highly structured virtual network integrations. DCM is a highly organised chain in which the key is mutual interdependence and partnership. The purpose is to create a distinctive competence for the chain as a whole that helps to identify and satisfy customer needs and wishes. The classical research concerning vertical marketing systems is very helpful in systemising the rather unstructured discussions in current SCM research. The trend lies in increasing competition between channels rather than between companies, which in turn leads to the creation of channels with a high degree of partnership and mutual interdependence between members. These types of channels are known as organised vertical marketing systems in the classic marketing channel research. The behaviour in these types of channels, as well as the formal and informal structures, roles in the network, power and dependence relations, etc. are well covered topics in the literature. The concept of vertical marketing systems lies behind the definition of demand chains and demand chain management proposed in this paper. A

  16. The Influence of the Biological Pump on Marine Redox Conditions During Earth History

    Science.gov (United States)

    Meyer, K. M.; Ridgwell, A.; Payne, J.

    2015-12-01

    Evidence for bottom-water anoxia on the continental shelves waned over the course of the Phanerozoic, which may be influenced by secular changes in the biological pump that led to weaker positive feedbacks within the oceans. The biological pump describes the transfer of carbon from the atmosphere to the deep ocean, which creates vertical gradients in nutrients and oxygen, both important influences in the structure of marine ecosystems. We used the cGENIE Earth system model to quantitatively test the hypothesis that reductions in the efficiency of the nutrient recycling loop of the biological pump during the past 550 Ma reduced the extent of anoxia on the shelves and acted as an important control on marine animal ecosystems. When the modeled remineralization depth is shallow relative to the modern ocean, anoxia tends to be more widespread at continental shelf depths. As the modeled remineralization depth increases toward modern conditions, anoxia is less prevalent and occurs at depths below the continental shelves. Reduced marine productivity in the closed system configuration of cGENIE cannot produce the frequent bottom-water anoxia conditions envisioned for the Paleozoic. We hypothesize that evidence for greater animal abundance and metabolic demand during the Phanerozoic was driven by progressive oxygenation of shelf environments related to changes in the biological pump rather than greater food availability. In general, these model simulations suggest changes in the depth distribution of organic carbon remineralization may have controlled observed shifts in ocean chemistry, biogeochemical cycling, and ecosystem structure during the Phanerozoic.

  17. An evaluation of physical and biogeochemical processes regulating the oxygen minimum zone in the water column of the Bay of Bengal

    Digital Repository Service at National Institute of Oceanography (India)

    Sarma, V.V.S.S.

    of the biological processes. The inconsistency observed among oxygen consumption rates derived based on the present oxygen budget, carbon regeneration rate, and oxygen consumption rates computed based on electron transport system technique could be due to inadequate...

  18. DataBase on Demand

    Science.gov (United States)

    Gaspar Aparicio, R.; Gomez, D.; Coterillo Coz, I.; Wojcik, D.

    2012-12-01

    At CERN a number of key database applications are running on user-managed MySQL database services. The database on demand project was born out of an idea to provide the CERN user community with an environment to develop and run database services outside of the actual centralised Oracle based database services. The Database on Demand (DBoD) empowers the user to perform certain actions that had been traditionally done by database administrators, DBA's, providing an enterprise platform for database applications. It also allows the CERN user community to run different database engines, e.g. presently open community version of MySQL and single instance Oracle database server. This article describes a technology approach to face this challenge, a service level agreement, the SLA that the project provides, and an evolution of possible scenarios.

  19. DataBase on Demand

    International Nuclear Information System (INIS)

    At CERN a number of key database applications are running on user-managed MySQL database services. The database on demand project was born out of an idea to provide the CERN user community with an environment to develop and run database services outside of the actual centralised Oracle based database services. The Database on Demand (DBoD) empowers the user to perform certain actions that had been traditionally done by database administrators, DBA's, providing an enterprise platform for database applications. It also allows the CERN user community to run different database engines, e.g. presently open community version of MySQL and single instance Oracle database server. This article describes a technology approach to face this challenge, a service level agreement, the SLA that the project provides, and an evolution of possible scenarios.

  20. DataBase on demand

    CERN Document Server

    Aparicio, Ruben Gaspar; Coterillo Coz, I

    2012-01-01

    At CERN a number of key database applications are running on user-managed MySQL database services. The database on demand project was born out of an idea to provide the CERN user community with an environment to develop and run database services outside of the actual centralised Oracle based database services. The Database on Demand (DBoD) empowers the user to perform certain actions that had been traditionally done by database administrators, DBA's, providing an enterprise platform for database applications. It also allows the CERN user community to run different database engines, e.g. presently open community version of MySQL and single instance Oracle database server. This article describes a technology approach to face this challenge, a service level agreement, the SLA that the project provides, and an evolution of possible scenarios.

  1. Demands from the school inclusion

    OpenAIRE

    Selma Norberto Matos; Eniceia Gonçalves Mendes

    2014-01-01

    From the implementation of public policies on school inclusion, mainly those directed to the target audience of special education, the number of students with special educational needs in common classes has increased. This fact has helped to compose the picture in schools where the limitations and contradictions of the Brazilian educational system have appeared. Educational actors and authors are challenged to build knowledge able of responding to demands of daily school, concerning living an...

  2. Optimal Advertising with Stochastic Demand

    OpenAIRE

    George E. Monahan

    1983-01-01

    A stochastic, sequential model is developed to determine optimal advertising expenditures as a function of product maturity and past advertising. Random demand for the product depends upon an aggregate measure of current and past advertising called "goodwill," and the position of the product in its life cycle measured by sales-to-date. Conditions on the parameters of the model are established that insure that it is optimal to advertise less as the product matures. Additional characteristics o...

  3. Uranium resources, production and demand

    International Nuclear Information System (INIS)

    Nuclear power-generating capacity will continue to expand, albeit at a slower pace than during the past fifteen years. This expansion must be matched by an adequately increasing supply of uranium. This report compares uranium supply and demand data in free market countries with the nuclear industry's natural uranium requirements up to the year 2000. It also reviews the status of uranium exploration, resources and production in 46 countries

  4. Demand controlled ventilation; Behovsstyrt ventilasjon

    Energy Technology Data Exchange (ETDEWEB)

    Soerensen, Henning Holm

    2006-07-01

    The terms CAV and VAV have been known terms for many years in the ventilation business. The terms are also included in building regulations, but the time is now right to focus on demand controlled ventilation (DCV). The new building regulations and the accompanying energy framework underline the need for a more nuanced thinking when it comes to controlling ventilation systems. Descriptions and further details of the ventilation systems are provided (ml)

  5. Alcohol demand and risk preference.

    Science.gov (United States)

    Dave, Dhaval; Saffer, Henry

    2008-12-01

    Both economists and psychologists have studied the concept of risk preference. Economists categorize individuals as more or less risk-tolerant based on the marginal utility of income. Psychologists categorize individuals' propensity towards risk based on harm avoidance, novelty seeking and reward dependence traits. The two concepts of risk are related, although the instruments used for empirical measurement are quite different. Psychologists have found risk preference to be an important determinant of alcohol consumption; however economists have not included risk preference in studies of alcohol demand. This is the first study to examine the effect of risk preference on alcohol consumption in the context of a demand function. The specifications employ multiple waves from the Panel Study of Income Dynamics (PSID) and the Health and Retirement Study (HRS), which permit the estimation of age-specific models based on nationally representative samples. Both of these data sets include a unique and consistent survey instrument designed to directly measure risk preference in accordance with the economist's definition. This study estimates the direct impact of risk preference on alcohol demand and also explores how risk preference affects the price elasticity of demand. The empirical results indicate that risk preference has a significant negative effect on alcohol consumption, with the prevalence and consumption among risk-tolerant individuals being 6-8% higher. Furthermore, the tax elasticity is similar across both risk-averse and risk-tolerant individuals. This suggests that tax policies are as equally effective in deterring alcohol consumption among those who have a higher versus a lower propensity for alcohol use. PMID:19956353

  6. Family physicians: supply and demand.

    OpenAIRE

    Bowman, M A

    1989-01-01

    The nation's supply of family physicians as estimated by the Graduate Medical Education National Advisory Committee appears fairly accurate. At the same time, the demands for family physicians appear to be strong, partially because case-management systems recognize the cost-effectiveness and appropriate training of family physicians for their needs. The largest factor inhibiting the supply of such physicians appears to be the relatively lower income of family practice compared to other specia...

  7. Demand and Supply Chain Management

    OpenAIRE

    Jack A.A. van der Veenl:; Robben, Henry S.J.

    1999-01-01

    In dit artikel wordt ingegaan op de recente ontwikkelingen met be-trekking tot de managementactiviteiten gericht op de keten die begint bij het winnen van grondstoffen en via toeleveranciers, fabrikanten en de (detail)handel loopt naar de eindgebruikers. De moderne denkbeelden op dit terrein worden samengevat met de term Demand & Supply Chain Management (DSCM); het management van de keten die onafhankelijke klanten en leveranciers verbindt als ware het een enkele en-titeit met het doel om waa...

  8. Fish demand and supply projections

    OpenAIRE

    Sverdrup-Jensen, S.

    1997-01-01

    It has been predicted that the global demand for fish for human consumption will increase by more than 50% over the next 15 years. The FAO has projected that the increase in supply will originate primarily from marine fisheries, aquaculture and to a lesser extent from inland fisheries, but with a commensurate price increase. However, there are constraints to increased production in both marine and inland fisheries, such as overfishing, overexploitation limited potential increase and environme...

  9. Endogenous Timing with Demand Uncertainty

    OpenAIRE

    Fei Shi

    2008-01-01

    This paper develops an endogenous timing model for a quantity-setting duopoly with imperfect information on market demand and costly market research. If the market research cost K is too high, market research never plays a role. For intermediate values of K, and independently of production costs, there are two SPNE with endogenous leadership. If K is low, SPNE with endogenous leadership appear if the production costs of the leader are low enough relative to market conditions (e.g. large expec...

  10. Removal of stigmasterol from Kraft mill effluent by aerobic biological treatment with steroidal metabolite detection.

    Science.gov (United States)

    Chamorro, Soledad; Vergara, Juan P; Jarpa, Mayra; Hernandez, Victor; Becerra, Jose; Vidal, Gladys

    2016-10-14

    Stigmasterol is a phytosterol contained in Kraft mill effluent that is able to increase over 100% after aerobic biological treatment. This compound can act as an endocrine disrupter as its structure is similar to that of cholesterol. The aim of this study was to evaluate the removal of stigmasterol from Kraft mill effluents treated by a moving bed biofilm reactor (MBBR) with steroidal metabolite detection. The MBBR was operated for 145 days, with a hydraulic retention time of 2 days. Stigmasterol and steroidal metabolites were detected by gas chromatography with a flame ionization detector during MBBR operation. The results show that the MBBR removed 87.4% of biological oxygen demand (BOD5), 61.5% of chemical oxygen demand (COD), 24.5% of phenol and 31.5% of lignin, expressed in average values. The MBBR system successfully removed 100% of the stigmasterol contained in the influent (33 µg L(-1)) after 5 weeks of operation. In that case, the organic load rate was 0.343 kg COD m(-3) d(-1). Furthermore, different steroidal compounds (e.g., testosterone propionate, stigmast-4-en-3-one, 5α-pregnan-12-one-20α-hydroxy, 5α-pregnane-3,11,20-trione and 3α-hydroxy-5α-androstane-11,17-dione were detected in the Kraft mill effluent as potential products of phytosterol biotransformation. PMID:27399163

  11. Demands from the school inclusion

    Directory of Open Access Journals (Sweden)

    Selma Norberto Matos

    2014-04-01

    Full Text Available From the implementation of public policies on school inclusion, mainly those directed to the target audience of special education, the number of students with special educational needs in common classes has increased. This fact has helped to compose the picture in schools where the limitations and contradictions of the Brazilian educational system have appeared. Educational actors and authors are challenged to build knowledge able of responding to demands of daily school, concerning living and learning in diversity. Whereas this inclusive process is new in the schools, the study aimed to analyze the demands of teachers from the school inclusion. The research was qualitative and exploratory, and six teachers, their students with special educational needs and three professionals in the Nucleus of Inclusive Education from the Municipal Department of Education took in it. Technique of participant observation, field diary, semi-structured interview and questionnaire were used for data collection, while analysis of content was used for discussion of the data. The results indicate that there are achievements and contradictions in the reality of schools that themselves propose inclusive; advances and limitations resulting from the municipal politics; that the model of performance of the group of special education, in the context analyzed, may be revised or expanded; and that the teachers has demands with regard to public policy, training, and the psychologist.

  12. Effect of Flow Rate and Disc Area Increment on the Efficiency of Rotating Biological Contactor for Treating Greywater

    Directory of Open Access Journals (Sweden)

    Ashfaq Ahmed Pathan

    2015-04-01

    Full Text Available The performance of greywater treatment through RBC (Rotating Biological Contactor is related to many factors including rotational speed of disc, surface area of the media, thickness of biological film; quality and flow rate of influent. The plastic media provides surface for biological slime. The slime is rotated alternatively into the settled wastewater and then into atmosphere to provide aerobic conditions for the microorganisms. In this study the performance of RBC is investigated at different flow rates and disk areas of media by introducing additional discs on the shaft of RBC. Initially efficiency of the RBC was observed on six flow rates at the disc area of 9.78m2. Furthermore optimized three flow rates were used to augment the disk area. The efficiency of RBC system was improved significantly at disk area of 11.76m2 and flow rate of 20 L/h. Under these conditions the removal of BOD5 (Biochemical Oxygen Demand COD (Chemical Oxygen Demand and TSS (Total Suspended Solid was observed 83, 57 and 90% respectively

  13. Combined technology for clomazone herbicide wastewater treatment: three-dimensional packed-bed electrochemical oxidation and biological contact degradation.

    Science.gov (United States)

    Feng, Yujie; Liu, Junfeng; Zhu, Limin; Wei, Jinzhi

    2013-01-01

    The clomazone herbicide wastewater was treated using a combined technology composed of electrochemical catalytic oxidation and biological contact degradation. A new type of electrochemical reactor was fabricated and a Ti/SnO2 electrode was chosen as the anode in electrochemical-oxidation reactor and stainless steel as the cathode. Ceramic rings loaded with SnO2 were used as three-dimensional electrodes forming a packed bed. The operation parameters that might influence the degradation of organic contaminants in the clomazone wastewater were optimized. When the cell voltage was set at 30 V and the volume of particle electrodes was designed as two-thirds of the volume of the total reactor bed, the chemical oxygen demand (COD) removal rate could reach 82% after 120 min electrolysis, and the ratio of biochemical oxygen demand (BOD)/COD of wastewater increased from 0.12 to 0.38. After 12 h degradation with biological contact oxidation, the total COD removal rate of the combined technology reached 95%, and effluent COD was below 120 mg/L. The results demonstrated that this electrocatalytic oxidation method can be used as a pretreatment for refractory organic wastewater before biological treatment.

  14. Effect of flow rate and disc area increment on the efficiency of rotating biological contactor for treating greywater

    International Nuclear Information System (INIS)

    The performance of greywater treatment through RBC (Rotating Biological Contactor) is related to many factors including rotational speed of disc, surface area of the media, thickness of biological film; quality and flow rate of influent. The plastic media provides surface for biological slime. The slime is rotated alternatively into the settled wastewater and then into atmosphere to provide aerobic conditions for the microorganisms. In this study the performance of RBC is investigated at different flow rates and disk areas of media by introducing additional discs on the shaft of RBC. Initially efficiency of the RBC was observed on six flow rates at the disc area of 9.78m/sup 2/. Furthermore optimized three flow rates were used to augment the disk area. The efficiency of RBC system was improved significantly at disk area of 11.76m/sup 2/ and flow rate of 20 L/h. Under these conditions the removal of BOD5 (Biochemical Oxygen Demand) COD (Chemical Oxygen Demand) and TSS (Total Suspended Solid) was observed 83, 57 and 90% respectively. (author)

  15. Biological computation

    CERN Document Server

    Lamm, Ehud

    2011-01-01

    Introduction and Biological BackgroundBiological ComputationThe Influence of Biology on Mathematics-Historical ExamplesBiological IntroductionModels and Simulations Cellular Automata Biological BackgroundThe Game of Life General Definition of Cellular Automata One-Dimensional AutomataExamples of Cellular AutomataComparison with a Continuous Mathematical Model Computational UniversalitySelf-Replication Pseudo Code Evolutionary ComputationEvolutionary Biology and Evolutionary ComputationGenetic AlgorithmsExample ApplicationsAnalysis of the Behavior of Genetic AlgorithmsLamarckian Evolution Genet

  16. Summertime in situ monitoring of oxygen depletion in Amursky Bay (Japan/East Sea)

    Science.gov (United States)

    Tishchenko, Petr; Tishchenko, Pavel; Lobanov, Vyacheslav; Sergeev, Alexander; Semkin, Pavel; Zvalinsky, Vladimir

    2016-04-01

    For more than three months in 2011, in situ monitoring of temperature (T), salinity (S) and dissolved oxygen concentrations (DO) was carried out using a Water Quality Monitor (WQM) station deployed on the seafloor of Amursky Bay (Japan/East Sea). During this period, hypoxia in the bottom waters persisted for 93 days. In the summers of 2012 and 2013, the spatial distribution of DO was measured during ship surveys. Using these time series of DO, the biological oxygen demand (BOD) and ventilation rates in bottom waters were estimated from May 10 to August 7. The seasonal change in the dominant direction of the wind, which occurs twice a year (spring and autumn), was an important natural factor in development and termination of seasonal hypoxia in the bay. Dominant southern winds in the summer induced downwelling circulation on the northwestern part of the Japan/East Sea shelf. Under this circulation, hypoxia developed in the bottom waters of Amursky Bay. In autumn, dominant northern winds induced upwelling, causing the advection of cold, oxygenated seawater into the bay, ending the period of hypoxia. Short-term fluctuations in wind direction in the summertime influenced spatial and vertical distribution of T, S and DO. At the end of the summer, the oscillation of the downwelling/upwelling circulations revealed complicated temporal-space distributions of hydrological parameters in Amursky Bay.

  17. Balancing the generation and elimination of reactive oxygen species

    Science.gov (United States)

    Rodriguez, Rusty; Redman, Regina

    2005-01-01

    Fossil records suggest that bacteria developed the ability to photosynthesize ≈3,500 million years ago (mya), initiating a very slow accumulation of atmospheric oxygen (1). Recent geochemical models suggest that atmospheric oxygen did not accumulate to levels conducive for aerobic life until 500–1,000 mya (2, 3). The oxygenation of Earth's atmosphere resulted in the emergence of aerobic organisms followed by a great diversification of biological species and the eventual evolution of humans.

  18. Estimating oxygen needs for childhood pneumonia in developing country health systems: a new model for expecting the unexpected.

    Directory of Open Access Journals (Sweden)

    Beverly D Bradley

    Full Text Available BACKGROUND: Planning for the reliable and cost-effective supply of a health service commodity such as medical oxygen requires an understanding of the dynamic need or 'demand' for the commodity over time. In developing country health systems, however, collecting longitudinal clinical data for forecasting purposes is very difficult. Furthermore, approaches to estimating demand for supplies based on annual averages can underestimate demand some of the time by missing temporal variability. METHODS: A discrete event simulation model was developed to estimate variable demand for a health service commodity using the important example of medical oxygen for childhood pneumonia. The model is based on five key factors affecting oxygen demand: annual pneumonia admission rate, hypoxaemia prevalence, degree of seasonality, treatment duration, and oxygen flow rate. These parameters were varied over a wide range of values to generate simulation results for different settings. Total oxygen volume, peak patient load, and hours spent above average-based demand estimates were computed for both low and high seasons. FINDINGS: Oxygen demand estimates based on annual average values of demand factors can often severely underestimate actual demand. For scenarios with high hypoxaemia prevalence and degree of seasonality, demand can exceed average levels up to 68% of the time. Even for typical scenarios, demand may exceed three times the average level for several hours per day. Peak patient load is sensitive to hypoxaemia prevalence, whereas time spent at such peak loads is strongly influenced by degree of seasonality. CONCLUSION: A theoretical study is presented whereby a simulation approach to estimating oxygen demand is used to better capture temporal variability compared to standard average-based approaches. This approach provides better grounds for health service planning, including decision-making around technologies for oxygen delivery. Beyond oxygen, this approach

  19. Demand uncertainty in skill-based competition

    OpenAIRE

    Artinger, Sabrina

    2013-01-01

    How does demand uncertainty affect entry into skill-based competition? I investigate this question in a market entry experiment with skill-based payoffs by systematically varying two key elements of the market environment: demand risk and expected market size. Results show that people's reactions to demand risk depend on the market size: in small markets people enter more when demand is risky, in large markets they enter less when demand is risky. This leads to substantial inefficiencies in b...

  20. Hourly Electricity Demand in Italian Market

    OpenAIRE

    Simona Bigerna; Bollino, Carlo Andrea

    2013-01-01

    In the existing literature only recently there has been attention to consumer demand for electricity in organized markets. In this paper we assume a theoretical model of demand behavior and we estimate a complete system for hourly electricity demand. We use individual demand bid data in the Italian Power Exchange (IPEX). The novel contribution of this paper is twofold. Firstly we construct a theory based behavioral model of hourly electricity demand for agents acting in the Italian market; se...

  1. Study on Customer Demands for Product Innovation

    Institute of Scientific and Technical Information of China (English)

    XIONG Zhiyong; YANG Mingzhong; LI Yibing; LI Jun

    2006-01-01

    In order to improve the satisfaction degree of customers' individual demands for products and reduce the risk of the product innovation, the characteristics of customer demands for product innovation are analyzed, and the type and content of customer demands are discussed. Then the framework of customer demands acquisition for product innovation is established. Finally, the prototype system of customer demands information acquisition and product customization for product innovation which takes mobile phone as the example is developed successfully.

  2. Three-dimensional three-phase model for simulation of hydrodynamics, oxygen mass transfer, carbon oxidation, nitrification and denitrification in an oxidation ditch.

    Science.gov (United States)

    Lei, Li; Ni, Jinren

    2014-04-15

    A three-dimensional three-phase fluid model, supplemented by laboratory data, was developed to simulate the hydrodynamics, oxygen mass transfer, carbon oxidation, nitrification and denitrification processes in an oxidation ditch. The model provided detailed phase information on the liquid flow field, gas hold-up distribution and sludge sedimentation. The three-phase model described water-gas, water-sludge and gas-sludge interactions. Activated sludge was taken to be in a pseudo-solid phase, comprising an initially separated solid phase that was transported and later underwent biological reactions with the surrounding liquidmedia. Floc parameters were modified to improve the sludge viscosity, sludge density, oxygen mass transfer rate, and carbon substrate uptake due to adsorption onto the activated sludge. The validation test results were in very satisfactory agreement with laboratory data on the behavior of activated sludge in an oxidation ditch. By coupling species transport and biological process models, reasonable predictions are made of: (1) the biochemical kinetics of dissolved oxygen, chemical oxygen demand (COD) and nitrogen variation, and (2) the physical kinematics of sludge sedimentation.

  3. Study of regenerative medicine in China: demands and clinical translation

    OpenAIRE

    Fu, Xiao-Bing

    2012-01-01

    The repair and regeneration of tissue is a well-discussed topic. Over the past 20 years, with the development of genetics, auxology, stem cell biology, and tissue engineering, tissue repair and regeneration have rapidly developed as emerging "Regenerative Medicine". Regenerative medicine has significant market demand in China. Based on national statistics, injury and poisoning patients rank third in afflictions in city hospitals (accounting for 9.13%) and rank second in afflictions in county ...

  4. Oxygen uptake during modern dance class, rehearsal, and performance.

    Science.gov (United States)

    Wyon, Matthew A; Abt, Grant; Redding, Emma; Head, Andrew; Sharp, N Craig C

    2004-08-01

    The aim of the present study was to examine whether the workload, expressed in oxygen uptake and heart rate, during dance class and rehearsal prepared the dancer for performance. Previous research on the demands of class and performance has been affected by equipment limitations and could only provide limited insight into the physiological demands placed on the dancer. The present study noted that dance performance had significantly greater mean oxygen uptake and heart rate than noted in both class and rehearsal (p Dance performance placed a greater demand on the aerobic and anaerobic glycolytic energy systems than seen during class and rehearsal, which placed a greater emphasis on the adenosine triphosphate-creatine phosphate system. Practical implications suggest the need to supplement training within dance companies to overcome this deficit in training demand. PMID:15320648

  5. Comparison on decolorization of palm oil mill effluent by biological, chemical and physical methods

    Directory of Open Access Journals (Sweden)

    Chantaphaso, S.

    2001-11-01

    Full Text Available Decolorization of palm oil mill effluent pretreated by enzyme from Aspergillus niger ATCC 6275 was investigated. The culture filtrate after separation of suspended solids was used for decolorization by biological, chemical and physical methods. Results indicated that the chemical method (using coagulant was more effective than the biological method (using commercial peroxidase, two strains of white-rot fungi Phanerochaete chrysosporium and Coriolus versicolor and physical method (using activated carbon, pararubber seed and sand filter. Studies on the effect of coagulant concentrations on decolorization revealed that using the combination of 10 ml/l polyferric sulphate and 10 g/l calcium oxide gave the highest color removal of 84.5% and organic matter (in term of chemical oxygen demand, COD removal of 86.5%.

  6. Biological decolourisation of pulp mill effluent using white rot fungus Trametes versicolor.

    Science.gov (United States)

    Srinivasan, S V; Murthy, D V S; Swaminathan, T

    2012-07-01

    The conventional biological treatment methods employed in the pulp and paper industries are not effective in reducing the colour and chemical oxygen demand (COD). The white-rot fungi are reported to have the ability to biodegrade the lignin and its derivatives. This paper is focused on the biological treatment of pulp mill effluent from a bagasse-based pulp and paper industry using fungal treatment. Experiments were conducted using the white rot fungus, Trametes versicolor in shake flasks operated in batch mode with different carbon sources. The decolourisation efficiencies of 82.5% and 80.3% were obtained in the presence of 15 g/L and 5 g/L of glucose and sucrose concentrations respectively with a considerable COD reduction. The possibility of reusing the grown fungus was examined for repeated treatment studies.

  7. How Does Oxygen Therapy Work?

    Science.gov (United States)

    ... page from the NHLBI on Twitter. How Does Oxygen Therapy Work? Oxygen therapy provides you with extra ... be delivered to your lungs in several ways. Oxygen Therapy Systems Oxygen is supplied in three forms: ...

  8. LPG world supply and demand

    International Nuclear Information System (INIS)

    Over the course of this decade, the global LPG market has moved from being tight, where supply barely exceeded non-price sensitive demand, to the current market situation where supply growth has outstripped demand growth to such an extent that current fundamentals suggest that considerable length will prevail in the market over the near term. As is the case for many other energy commodity markets, the LPG industry has experienced a considerable transformation over the last five years with many new LPG supply projects coming on-stream and demand growth in many developing markets slowing in response to higher energy prices. The near term challenge for LPG producers will be securing outlets for output as the market becomes increasingly oversupplied. With expanding LPG supply and a worldwide tightness in the naphtha market, it is expected that petrochemical consumers will favor relatively low priced LPG over naphtha and the resulting increase in LPG cracking rates will go some way to reducing the expected supply surplus. However, the timing of several new LPG supply projects and the start-up of LPG-based petrochemical plants in the Middle-East are expected to impact global LPG trade and pricing over the next few years. Thus, at this point in time, the global LPG market has a high degree of uncertainty with questions remaining over the impact of high energy (and LPG) prices on traditional and developing market demand, the timing of new supply projects and the combined effect of these two factors on international LPG prices. World LPG production has been rising in nearly every region of the world over the last few years and totaled about 229 million tons in 2007, which is some 30 million tons per year higher than in 2000. The exception is North America which accounts for the largest share of global LPG supply at about 24% but production there has remained relatively flat in recent years. Strong LPG production growth in the Middle-East which contributed to about 19% of

  9. Uranium, resources, production and demand

    International Nuclear Information System (INIS)

    The thirteenth edition of the report looks at recent developments and their impact on the short term (i.e. to the year 2005) and presents a longer term (to 2030) analysis of supply possibilities in the context of a range of requirement scenarios. It presents results of a 1989 review of uranium supply and demand in the World Outside Centrally Planned Economies Areas. It contains updated information on uranium exploration activities, resources and production for over 40 countries including a few CPEs, covering the period 1987 and 1988

  10. Growing energy demand - environmental impact

    International Nuclear Information System (INIS)

    Scientists can bring information, insights, and analytical skills to bear on matters of public concern. Often they can help the public and its representatives to understand the likely causes of events (such as natural and technological disasters) and to estimate the possible effects of projected policies. Often they can testify to what is not possible. Even so, scientists can seldom bring definitive answers to matters of public debate. Some issues are too complex to fit within the current scope of science, or there may be little reliable information available, or the values involved may lie outside of science. Scientists and technologists strive to find an answer to the growing energy demand

  11. The Demand for Economic Goods

    OpenAIRE

    Claudia Mungiu-Pupăzan

    2009-01-01

    Satisfying the most needs of the consumer is done/achieved with economic assets. Each good has substitutes: using other goods where the original cost of using asset increases. The needs are desires. If needs are analyzed carefully, it is found to have various emergencies. People buy more or less a good since the price they have to pay reduced or increased. The concept of needs projects the concept of demand in the application that links quantities that are purchased by the sacrifices made to ...

  12. Credit, Money, and Aggregate Demand

    OpenAIRE

    Bernanke, Ben S.; Alan S. Blinder

    1988-01-01

    Standard models of aggregate demand treat money and credit asymmetrically; money is given a special status, while loans, bonds, and other debt instruments are lumped together in a "bond market" and suppressed by Walras' Law. This makes bank liabilities central to the monetary transmission mechanism, while giving no role to bank assets. We show how to modify a textbook IS-UI model so as to permit a more balanced treatment. As in Tobin (1969) and Brunner-Meltzer (1972), the key assumption is th...

  13. Biological treatment of the liquid effluents of a paper industry

    International Nuclear Information System (INIS)

    The objective of this paper is to determine the effect of the microorganisms Candida utilis and Candida tropicalis in the reduction of the chemical oxygen demand (COD) of the liquid effluents of a producing factory of paper kraft type, by means of fermentations made to pH of 5 and a 30 centigrade degrees during 6 days. The biological processing is preceded by a physicochemical process of directed acidulation to reduce pH of the effluent (liquor black) from its initial value, of approximately 13, to 5, in order to it is adapted for the growth of yeast. In this process, which forms precipitated, that is necessary to eliminate by centrifugation and filtration to facilitate the growth of the microorganisms, with is obtained one first removal of the COD of the order of 70 %. With the biological processing obtains for both yeasts a percentage of removal of 45 -50% of the COD surplus. The total removal of the COD, that is to say, obtained with the pre-cure and the fermentation it is of the order of 84% for the yeast. Additionally the possibility studied of implementing some complementary procedures to the biological processing, with a view to obtaining greater growth of yeast in the black liquor and thus obtaining additional reductions in the OCD of the same one

  14. Investigating Comparative Advantages of Advance Demand Information in Presence of Heterogeneous Demand

    DEFF Research Database (Denmark)

    Du, Bisheng; Larsen, Christian

    The paper studies aspects of advance demand information and heterogeneous demand in a mathematical model of an inventory system. The concept advance demand information is that customers ahead in time of actual demand place their orders. The concept heterogeneous demand refers to that there are di...

  15. Ambient oxygen promotes tumorigenesis.

    Directory of Open Access Journals (Sweden)

    Ho Joong Sung

    Full Text Available Oxygen serves as an essential factor for oxidative stress, and it has been shown to be a mutagen in bacteria. While it is well established that ambient oxygen can also cause genomic instability in cultured mammalian cells, its effect on de novo tumorigenesis at the organismal level is unclear. Herein, by decreasing ambient oxygen exposure, we report a ∼50% increase in the median tumor-free survival time of p53-/- mice. In the thymus, reducing oxygen exposure decreased the levels of oxidative DNA damage and RAG recombinase, both of which are known to promote lymphomagenesis in p53-/- mice. Oxygen is further shown to be associated with genomic instability in two additional cancer models involving the APC tumor suppressor gene and chemical carcinogenesis. Together, these observations represent the first report directly testing the effect of ambient oxygen on de novo tumorigenesis and provide important physiologic evidence demonstrating its critical role in increasing genomic instability in vivo.

  16. Integrated turbomachine oxygen plant

    Science.gov (United States)

    Anand, Ashok Kumar; DePuy, Richard Anthony; Muthaiah, Veerappan

    2014-06-17

    An integrated turbomachine oxygen plant includes a turbomachine and an air separation unit. One or more compressor pathways flow compressed air from a compressor through one or more of a combustor and a turbine expander to cool the combustor and/or the turbine expander. An air separation unit is operably connected to the one or more compressor pathways and is configured to separate the compressed air into oxygen and oxygen-depleted air. A method of air separation in an integrated turbomachine oxygen plant includes compressing a flow of air in a compressor of a turbomachine. The compressed flow of air is flowed through one or more of a combustor and a turbine expander of the turbomachine to cool the combustor and/or the turbine expander. The compressed flow of air is directed to an air separation unit and is separated into oxygen and oxygen-depleted air.

  17. Estimating Aggregate Demand in Egypt

    Directory of Open Access Journals (Sweden)

    Noha EMARA

    2016-03-01

    Full Text Available Abstract. This econometric study seeks to determine the most important factors of aggregate demand in Egypt so as to provide insight into how this developing nation can grow economically in the coming years. The Ordinary Least Squares estimation method was used in order to estimate nominal GDP for the time period 1975 to 2009. Based on the results the real interest rate, the inflation rate, the growth rate of government expenditure, and the growth rate of the money supply are the most statistically and economically significant factors of the growth rate of nominal GDP for the coming year. A one percent change in the growth rate of the previous year government expenditure is predicted to cause the growth rate of the current year nominal GDP to increase by 54%.The role of government expenditures on public sector wage expansion is discussed in this study as to shed light on this factor’s significant influence on income inequality post-1975 in Egypt, which will continue to impact nominal GDP and social conditions for the developing nation in the coming years.Keywords. GDP, Aggregate Demand, Egypt.JEL. E25, O40, Q11.

  18. Demand Response Valuation Frameworks Paper

    Energy Technology Data Exchange (ETDEWEB)

    Heffner, Grayson

    2009-02-01

    While there is general agreement that demand response (DR) is a valued component in a utility resource plan, there is a lack of consensus regarding how to value DR. Establishing the value of DR is a prerequisite to determining how much and what types of DR should be implemented, to which customers DR should be targeted, and a key determinant that drives the development of economically viable DR consumer technology. Most approaches for quantifying the value of DR focus on changes in utility system revenue requirements based on resource plans with and without DR. This ''utility centric'' approach does not assign any value to DR impacts that lower energy and capacity prices, improve reliability, lower system and network operating costs, produce better air quality, and provide improved customer choice and control. Proper valuation of these benefits requires a different basis for monetization. The review concludes that no single methodology today adequately captures the wide range of benefits and value potentially attributed to DR. To provide a more comprehensive valuation approach, current methods such as the Standard Practice Method (SPM) will most likely have to be supplemented with one or more alternative benefit-valuation approaches. This report provides an updated perspective on the DR valuation framework. It includes an introduction and four chapters that address the key elements of demand response valuation, a comprehensive literature review, and specific research recommendations.

  19. Positional demands of professional rugby.

    Science.gov (United States)

    Lindsay, Angus; Draper, Nick; Lewis, John; Gieseg, Steven P; Gill, Nicholas

    2015-01-01

    Rugby union is a physically intense intermittent sport coupled with high force collisions. Each position within a team has specific requirements which are typically based on speed, size and skill. The aim of this study was to investigate the contemporary demands of each position and whether they can explain changes in psychophysiological stress. Urine and saliva samples were collected before and after five selected Super 15 rugby games from 37 players. Total neopterin (NP), cortisol and immunoglobulin A were analysed by SCX-high performance liquid chromatography and enzyme linked immunosorbent assay. Global positioning system software provided distance data, while live video analysis provided impact data. All contemporary demands were analysed as events per minute of game time. Forwards were involved in more total impacts, tackles and rucks compared to backs (p cortisol and sIgA. The results indicate distance covered and number of impacts per minute of game time is position-dependent whereas changes in psychophysiological stress are independent. This information can be used to adapt training and recovery interventions to better prepare each position based on the physical requirements of the game.

  20. Atomic Oxygen Effects

    Science.gov (United States)

    Miller, Sharon K. R.

    2014-01-01

    Atomic oxygen, which is the most predominant species in low Earth orbit, is highly reactive and can break chemical bonds on the surface of a wide variety of materials leading to volatilization or surface oxidation which can result in failure of spacecraft materials and components. This presentation will give an overview of how atomic oxygen reacts with spacecraft materials, results of space exposure testing of a variety of materials, and examples of failures caused by atomic oxygen.

  1. Measuring tissue oxygenation

    Science.gov (United States)

    Soyemi, Olusola O. (Inventor); Soller, Babs R. (Inventor); Yang, Ye (Inventor)

    2009-01-01

    Methods and systems for calculating tissue oxygenation, e.g., oxygen saturation, in a target tissue are disclosed. In some embodiments, the methods include: (a) directing incident radiation to a target tissue and determining reflectance spectra of the target tissue by measuring intensities of reflected radiation from the target tissue at a plurality of radiation wavelengths; (b) correcting the measured intensities of the reflectance spectra to reduce contributions thereto from skin and fat layers through which the incident radiation propagates; (c) determining oxygen saturation in the target tissue based on the corrected reflectance spectra; and (d) outputting the determined value of oxygen saturation.

  2. Solid state oxygen sensor

    Science.gov (United States)

    Garzon, F.H.; Brosha, E.L.

    1997-12-09

    A potentiometric oxygen sensor is formed having a logarithmic response to a differential oxygen concentration while operating as a Nernstian-type sensor. Very thin films of mixed conducting oxide materials form electrode services while permitting diffusional oxygen access to the interface between the zirconia electrolyte and the electrode. Diffusion of oxygen through the mixed oxide is not rate-limiting. Metal electrodes are not used so that morphological changes in the electrode structure do not occur during extended operation at elevated temperatures. 6 figs.

  3. Coping with cyclic oxygen availability: evolutionary aspects.

    Science.gov (United States)

    Flück, Martin; Webster, Keith A; Graham, Jeffrey; Giomi, Folco; Gerlach, Frank; Schmitz, Anke

    2007-10-01

    Both the gradual rise in atmospheric oxygen over the Proterozoic Eon as well as episodic fluctuations in oxygen over several million-year time spans during the Phanerozoic Era, have arguably exerted strong selective forces on cellular and organismic respiratory specialization and evolution. The rise in atmospheric oxygen, some 2 billion years after the origin of life, dramatically altered cell biology and set the stage for the appearance of multicelluar life forms in the Vendian (Ediacaran) Period of the Neoproterozoic Era. Over much of the Paleozoic, the level of oxygen in the atmosphere was near the present atmospheric level (21%). In the Late Paleozoic, however, there were extended times during which the level of atmospheric oxygen was either markedly lower or markedly higher than 21%. That these Paleozoic shifts in atmospheric oxygen affected the biota is suggested by the correlations between: (1) Reduced oxygen and the occurrences of extinctions, a lowered biodiversity and shifts in phyletic succession, and (2) During hyperoxia, the corresponding occurrence of phenomena such as arthropod gigantism, the origin of insect flight, and the evolution of vertebrate terrestriality. Basic similarities in features of adaptation to hyopoxia, manifest in living organisms at levels ranging from genetic and cellular to physiological and behavioral, suggest the common and early origin of a suite of adaptive mechanisms responsive to fluctuations in ambient oxygen. Comparative integrative approaches addressing the molecular bases of phenotypic adjustments to cyclic oxygen fluctuation provide broad insight into the incremental steps leading to the early evolution of homeostatic respiratory mechanisms and to the specialization of organismic respiratory function.

  4. Supply and demand for endocannabinoids

    OpenAIRE

    Bradley E Alger; Kim, Jimok

    2011-01-01

    The endocannabinoid system consists of G-protein coupled cannabinoid receptors that can be activated by cannabis-derived drugs and small lipids called endocannabinoids, plus associated biochemical machinery (precursors, synthetic and degradative enzymes, transporters). The endocannabinoid system in the brain primarily influences neuronal synaptic communication, and affects biological – functions including eating, anxiety, learning and memory, growth and development – via an array of actions t...

  5. Driving demand for broadband networks and services

    CERN Document Server

    Katz, Raul L

    2014-01-01

    This book examines the reasons why various groups around the world choose not to adopt broadband services and evaluates strategies to stimulate the demand that will lead to increased broadband use. It introduces readers to the benefits of higher adoption rates while examining the progress that developed and emerging countries have made in stimulating broadband demand. By relying on concepts such as a supply and demand gap, broadband price elasticity, and demand promotion, this book explains differences between the fixed and mobile broadband demand gap, introducing the notions of substitution and complementarity between both platforms. Building on these concepts, ‘Driving Demand for Broadband Networks and Services’ offers a set of best practices and recommendations aimed at promoting broadband demand.  The broadband demand gap is defined as individuals and households that could buy a broadband subscription because they live in areas served by telecommunications carriers but do not do so because of either ...

  6. Global nitrogen fertilizer supply and demand outlook

    Institute of Scientific and Technical Information of China (English)

    Michel; Prud'homme

    2005-01-01

    This paper presents a brief overview of the world nitrogen fertilizer demand, high-lights trends in the global and regional developments of production capacity and provides a medium-term perspective of the global nitrogen supply/demand balance.

  7. Demands Set Upon Modern Cartographic Visualization

    Directory of Open Access Journals (Sweden)

    Stanislav Frangeš

    2007-05-01

    Full Text Available Scientific cartography has the task to develop and research new methods of cartographic visualization. General demands are set upon modern cartographic visualization, which encompasses digital cartography and computer graphics: legibility, clearness, accuracy, plainness and aesthetics. In this paper, it is explained in detail what demands should be met in order to satisfy the general demands set. In order to satisfy the demand of legibility, one should respect conditions of minimal sizes, appropriate graphical density and better differentiation of known features. Demand of clearness needs to be met by fulfilling conditions of simplicity, contrasting quality and layer arrangement of cartographic representation. Accuracy, as the demand on cartographic visualization, can be divided into positioning accuracy and accuracy signs. For fulfilling the demand of plainness, the conditions of symbolism, traditionalism and hierarchic organization should be met. Demand of aesthetics will be met if the conditions of beauty and harmony are fulfilled.

  8. Milestones and challenges in oxygen steelmaking

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-09-15

    While oxygen converter steelmaking and the electric arc furnace are converging in steelmaking technologies, developments in BOS, product quality demands and available charge materials will ensure the BOS will be present for at least another 50 years. This paper reviews the history, developments and 10 milestones of the oxygen steelmaking processes with a special focus on conventional autothermic converters, high speed converters with a blowing rate up to 5 m{sup 3}n/t min (Normal m{sup 3} of O{sub 2} per metric tonne of steel per minute) and allothermic converters with coal addition, post-combustion and the possibility to increase the scrap rate up to 50%. Related operating results are introduced. A new process route which is based on hot metal and chromium ore is outlined. The cost advantage for the production of 304 stainless steel grade is higher than $100 US/ton. The synthesis of electric arc furnace (EAF) and oxygen converter steelmaking, a comparison of decarburization rates, refining combustion burners for optimized oxygen management in an EAF and an example for a large advanced EAF are outlined. Possibilities of flexible steelmaking and the growth and outlook of worldwide oxygen steelmaking are described. Abridged from a paper by Ernst Fritz Senior Expert, Steelmaking and Walter Gebert, Vice President, Plant Integration, Steelmaking Environmental Technologies, Siemens Voest-Alpine Industrieanlagenbau GmbH & Co (VAI), Linz, Austria. 10 figs., 2 tabs.

  9. THE ACCOUNTANT INFORMATION. DEMAND AND OFFER

    OpenAIRE

    Irina CHIRITA; Ioana ZAHEU

    2008-01-01

    The present paper is trying to correlate what Demand and Offer mean, from the economical point of view, which in the end tends towards the demand and offer of the accountant information. The objective of the demand and offer of accountant information is to promo te an efficient financial communication, objective that might be reached through the confrontation of the informational offer with the user’s demand. The information given by the enterprises are the basis of numerous economical and po...

  10. Food demand for quality in Egypt

    OpenAIRE

    Soliman, Ibrahim

    2012-01-01

    The study objective was the estimation of the food demand for quality of perishable food commodity groups. The magnitude of the estimated elasticity of demand for food quality would indicate to the incentives the market provides to the market stages, to supply food quality,. The cross section data of the household budget survey of Egypt in 2009 were used to estimate per capita income-consumption function. The income elasticity of food demand for quality was derived from the food demand for ex...

  11. Aggregate Demand Model for Theatre in Lithuania

    OpenAIRE

    Rusnė Kregždaitė

    2014-01-01

    The aim of this article is to analyse aggregate demand for theatre which is the demand for the whole theatre sector described by the box office performance. In reference to foreign authors’ models a demand model for theatre in Lithuania was created which allows to analyse the relations between theatre demand and social or economical structure. The econometric models with time series model expression were used. Proposed methods could be applied to the analysis of the other sectors of cultural ...

  12. DOES GENERIC ADVERTISING WRAP DEMAND CURVATURE?

    OpenAIRE

    Weaver, Robert D.; Chin, Ming-Chin

    2002-01-01

    This paper reconsiders the impacts of generic advertising on commodity prices that may be induced through demand effects. Rather than considering a simple demand shift, we consider the possibility that advertising leads to a change in the curvature of the demand curve. In this case, generic advertising is shown to affect both the level of market prices as well as their volatility. Based on parametric tests, we find that the demand elasticity appears to be affected by the intensity of generic ...

  13. Price elasticity of demand: An overlooked concept

    International Nuclear Information System (INIS)

    An all-too-common mistake in analyzing the uranium market is to assume that demand for uranium is driven only by the design and operational parameters of nuclear power plants. Because it is generally accepted that demand for uranium is inelastic, not much attention has been given to how prices can indirectly affect demand. The purpose of this paper is to highlight the factors that are most sensitive to uranium prices, and to show how they alter uranium demand

  14. Study on Customer Demands for Product Innovation

    Institute of Scientific and Technical Information of China (English)

    XIONG Zhiyong; YANG Mingzhong; LI Yibing; LI Jun

    2006-01-01

    In order to improve the satisfaction degree of customers' individual demands on products and reduce the risk of the product innovation, the characteristics of customer demands for product innovation are analyzed, and their type and content are discussed. Then the framework of customer demands acquisition for product innovation is established. Finally, the prototype system of customer demands information acquisition and product customization for product innovation which takes mobile phone as the example is developed successfully.

  15. Income distribution trends and future food demand

    OpenAIRE

    Cirera,Xavier; Masset, Edoardo

    2010-01-01

    This paper surveys the theoretical literature on the relationship between income distribution and food demand, and identifies main gaps of current food modelling techniques that affect the accuracy of food demand projections. At the heart of the relationship between income distribution and food demand is Engel's law. Engel's law establishes that as income increases, households' demand for food increases less than proportionally. A consequence of this law is that the particular shape of the di...

  16. Endogenous Money Supply and Money Demand

    OpenAIRE

    Woon Gyu Choi; Seonghwan Oh

    2000-01-01

    This paper explores the behavior of money demand by explicitly accounting for the money supply endogeneity arising from endogenous monetary policy and financial innovations. Our theoretical analysis indicates that money supply factors matter in the money demand function when the money supply partially responds to money demand. Our empirical results with U.S. data provide strong evidence for the relevance of the policy stance to the demand for MI under a regime in which monetary policy is subs...

  17. Cache County Water Demand/Supply Model

    OpenAIRE

    Hughes, Trevor C.; Norby, Gregory J.; Thyagarajan, Laxman

    1996-01-01

    This report descibes a municipal water demand forecasting model for use in areas of mixed rural and urban housing types. A series of residential demand functions were derived which forecast water demand based on the ype and density of housing and season. Micro sampling techniques were used to correlate water use data and explanatory variable data for low, medium, and high density housing. The demand functions were...

  18. Treatment of waste metalworking fluid by a hybrid ozone-biological process.

    Science.gov (United States)

    Jagadevan, Sheeja; Graham, Nigel J; Thompson, Ian P

    2013-01-15

    In metal machining processes, the regulation of heat generation and lubrication at the contact point are achieved by application of a fluid referred to as metalworking fluid (MWF). MWFs inevitably become operationally exhausted with age and intensive use, which leads to compromised properties, thereby necessitating their safe disposal. Disposal of this waste through a biological route is an increasingly attractive option, since it is effective with relatively low energy demands. However, successful biological treatment is challenging since MWFs are chemically complex, and include biocides specifically to retard microbial deterioration whilst the fluids are operational. In this study remediation of the recalcitrant component of a semi-synthetic MWF by a novel hybrid ozone-bacteriological treatment, was investigated. The hybrid treatment proved to be effective and reduced the chemical oxygen demand by 72% (26.9% and 44.9% reduction after ozonation and biological oxidation respectively). Furthermore, a near-complete degradation of three non-biodegradable compounds (viz. benzotriazole, monoethanolamine, triethanolamine), commonly added as biocides and corrosion inhibitors in MWF formulations, under ozonation was observed. PMID:23274939

  19. Detecting pipe bursts by monitoring water demand

    NARCIS (Netherlands)

    Bakker, M.; Vreeburg, J.H.G.; Van der Roer, M.; Sperber, V.

    2012-01-01

    An algorithm which compares measured and predicted water demands to detect pipe bursts was developed and tested on three data sets of water demand and reported pipe bursts of three years. The algorithm proved to be able to detect bursts where the water loss exceeds 30% of the average water demand in

  20. The Law of Demand and Risk Aversion

    OpenAIRE

    John Quah

    2002-01-01

    This note proposes a necessary and sufficient condition on a preference to guarantee that the demand function it generates satisfies the law of demand. It shows that the law of demand may be succinctly characterized by differences in an agent's level of risk aversion when she is confronted with different lotteries composed of commodity bundles.

  1. Impact of fresh grapefruit quality on demand

    OpenAIRE

    Brown, Mark G.; Lee, Jonq-Ying

    1998-01-01

    This study incorporates quality into the Rotterdam demand system based on utility theory. Quality was modeled through its impact on marginal utility via perceived prices, following theoretical work by Basemann and Barten, among others. Results show that the price elasticity of fresh grapefruit demand is near unitary at the retail level and juice content has had relatively large impacts on fresh grapefruit demand.

  2. Oil prices: demand and supply. Lesson plan

    OpenAIRE

    anonymous

    2005-01-01

    Upon completion of this lesson, students will be able to list the determinants of demand and supply, recognize which factors will cause demand curves or supply curves to shift, determine equilibrium using a demand/supply graph, and show the effects on price and quantity when equilibrium changes.

  3. Relative biological effectiveness (RBE) and oxygen enhancement ratio (OER) of neutron beams produced by 50 Mev deuterons and 34, 45, 65, 75 MeV protons in Vicia faba

    International Nuclear Information System (INIS)

    Variation of neutron RBE and OER, as a function of energy, was determined for differrent neutron beams produced at the cyclotron ''Cyclone'' of Louvain-la-Neuve. The biological system was growth inhibition in Vicia faba bean roots. RBE of neutron beams produced by bombarding a beryllium target by 34, 45, 65 and 75 MeV proton (2 cm thick polythene additional filter) was found equal to 1.15 +- 0.13, 1.02 +- 0.10, 0.85 +- 0.08 and 0.83 +- 0.09, for absorbed doses of 0.39 Gy, 0.44 Gy, 0.53 Gy and 0.54 Gy respectively. These doses correspond to 50 % growth inhibition. Neutrons produced by 50 MeV deuterons on beryllium are taken as reference. For the same beams, OER value are equal to 1.55 +- 0.13, 1.38 +- 0.12, 1.29 +- 0.12 and 1.41 +- 0.11 respectively. OER is equal to 1.60 +- 0.15 for neutrons produced by 50 MeV deuterons (P = 0.05)

  4. Oxygen therapy - infants

    Science.gov (United States)

    ... may not work well and may die. Your baby may not grow properly. Many of the developing organs, including the brain and heart, may be injured. Too much oxygen can also cause injury. Breathing too much oxygen can damage the lung. ...

  5. Proterozoic atmospheric oxygen

    DEFF Research Database (Denmark)

    Canfield, Donald Eugene

    2014-01-01

    This article is concerned with the evolution of atmospheric oxygen concentrations through the Proterozoic Eon. In particular, this article will seek to place the history of atmospheric oxygenation through the Proterozoic Eon in the context of the evolving physical environment including the history...

  6. Extracorporeal membrane oxygenation circuitry.

    Science.gov (United States)

    Lequier, Laurance; Horton, Stephen B; McMullan, D Michael; Bartlett, Robert H

    2013-06-01

    The extracorporeal membrane oxygenation circuit is made of a number of components that have been customized to provide adequate tissue oxygen delivery in patients with severe cardiac and/or respiratory failure for a prolonged period of time (days to weeks). A standard extracorporeal membrane oxygenation circuit consists of a mechanical blood pump, gas-exchange device, and a heat exchanger all connected together with circuit tubing. Extracorporeal membrane oxygenation circuits can vary from simple to complex and may include a variety of blood flow and pressure monitors, continuous oxyhemoglobin saturation monitors, circuit access sites, and a bridge connecting the venous access and arterial infusion limbs of the circuit. Significant technical advancements have been made in the equipment available for short- and long-term extracorporeal membrane oxygenation applications. Contemporary extracorporeal membrane oxygenation circuits have greater biocompatibility and allow for more prolonged cardiopulmonary support time while minimizing the procedure-related complications of bleeding, thrombosis, and other physiologic derangements, which were so common with the early application of extracorporeal membrane oxygenation. Modern era extracorporeal membrane oxygenation circuitry and components are simpler, safer, more compact, and can be used across a wide variety of patient sizes from neonates to adults. PMID:23735989

  7. Highest Oxygen Bar

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    The world’s highest altitude Lhalu Wetland in Tibet is rebounding from past environmental damage In Lhasa, where the oxygen content is just 60 percent of that of the plain area, a place known as the "natural oxygen bar"is highly prized by residents.

  8. Traveling with Portable Oxygen

    Science.gov (United States)

    ... that is right for you depends on your travel plans, your health requirements, and your personal preferences. Compressed Oxygen Compressed ... notice before your ight if you plan to travel with oxygen. For this ... to review procedures and complete all necessary paperwork required by ...

  9. Oxygen transfer in a pressurized airlift bioreactor.

    Science.gov (United States)

    Campani, Gilson; Ribeiro, Marcelo Perencin Arruda; Horta, Antônio Carlos Luperni; Giordano, Roberto Campos; Badino, Alberto Colli; Zangirolami, Teresa Cristina

    2015-08-01

    Airlift bioreactors (ALBs) offer advantages over conventional systems, such as simplicity of construction, reduced risk of contamination, and efficient gas-liquid dispersion with low power consumption. ALBs are usually operated under atmospheric pressure. However, in bioprocesses with high oxygen demand, such as high cell density cultures, oxygen limitation may occur even when operating with high superficial gas velocity and air enriched with oxygen. One way of overcoming this drawback is to pressurize the reactor. In this configuration, it is important to assess the influence of bioreactor internal pressure on the gas hold-up, volumetric oxygen transfer coefficient (k(L)a), and volumetric oxygen transfer rate (OTR). Experiments were carried out in a concentric-tube airlift bioreactor with a 5 dm(3) working volume, equipped with a system for automatic monitoring and control of the pressure, temperature, and inlet gas flow rate. The results showed that, in disagreement with previous published results for bubble column and external loop airlift reactors, overpressure did not significantly affect k(L)a within the studied ranges of pressure (0.1-0.4 MPa) and superficial gas velocity in the riser (0.032-0.065 m s(-1)). Nevertheless, a positive effect on OTR was observed: it increased up to 5.4 times, surpassing by 2.3 times the oxygen transfer in a 4 dm(3) stirred tank reactor operated under standard cultivation conditions. These results contribute to the development of non-conventional reactors, especially pneumatic bioreactors operated using novel strategies for oxygen control.

  10. Oxygen enrichment incineration

    International Nuclear Information System (INIS)

    Oxygen enriched combustion technology has recently been used in waste incineration. To apply the oxygen enrichment on alpha-bearing waste incineration, which is being developed, a state-of-an-art review has been performed. The use of oxygen or oxygen-enriched air instead of air in incineration would result in increase of combustion efficiency and capacity, and reduction of off-gas product. Especially, the off-gas could be reduced below a quarter, which might reduce off-gas treatment facilities, and also increase an efficiency of off-gas treatment. However, the use of oxygen might also lead to local overheating and high nitrogen oxides (NOx) formation. To overcome these problems, an application of low NOx oxy-fuel burner and recycling of a part of off-gas to combustion chamber have been suggested

  11. Oxygen enrichment incineration

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jeong Guk; Yang, Hee Chul; Park, Geun Il; Kim, Joon Hyung

    2000-10-01

    Oxygen enriched combustion technology has recently been used in waste incineration. To apply the oxygen enrichment on alpha-bearing waste incineration, which is being developed, a state-of-an-art review has been performed. The use of oxygen or oxygen-enriched air instead of air in incineration would result in increase of combustion efficiency and capacity, and reduction of off-gas product. Especially, the off-gas could be reduced below a quarter, which might reduce off-gas treatment facilities, and also increase an efficiency of off-gas treatment. However, the use of oxygen might also lead to local overheating and high nitrogen oxides (NOx) formation. To overcome these problems, an application of low NOx oxy-fuel burner and recycling of a part of off-gas to combustion chamber have been suggested.

  12. A field pilot-scale study of biological treatment of heavy oil-produced water by biological filter with airlift aeration and hydrolytic acidification system.

    Science.gov (United States)

    Zhang, Min; Wang, Junming; Zhang, Zhongzhi; Song, Zhaozheng; Zhang, Zhenjia; Zhang, Beiyu; Zhang, Guangqing; Wu, Wei-Min

    2016-03-01

    Heavy oil-produced water (HOPW) is a by-product during heavy oil exploitation and can cause serious environmental pollution if discharged without adequate treatment. Commercial biochemical treatment units are important parts of HOPW treatment processes, but many are not in stable operation because of the toxic and refractory substances, salt, present. Therefore, pilot-scale experiments were conducted to evaluate the performance of hydrolytic acidification-biological filter with airlift aeration (HA-BFAA), a novel HOPW treatment system. Four strains isolated from oily sludge were used for bioaugmentation to enhance the biodegradation of organic pollutants. The isolated bacteria were evaluated using 3-day biochemical oxygen demand, oil, dodecyl benzene sulfonic acid, and chemical oxygen demand (COD) removals as evaluation indices. Bioaugmentation enhanced the COD removal by 43.5 mg/L under a volume load of 0.249 kg COD/m(3) day and hydraulic retention time of 33.6 h. The effluent COD was 70.9 mg/L and the corresponding COD removal was 75.0 %. The optimum volumetric air-to-water ratio was below 10. The removal ratios of the total extractable organic pollutants, alkanes, and poly-aromatic hydrocarbons were 71.1, 94.4, and 94.0 %, respectively. Results demonstrated that HA-BFAA was an excellent HOPW treatment system.

  13. Water column biogeochemistry of oxygen minimum zones in the eastern tropical North Atlantic and eastern tropical South Pacific Oceans

    DEFF Research Database (Denmark)

    Löscher, Carolin

    2016-01-01

    intensification of tropical oxygen minimum zones (OMZs), which are connected to the most productive upwelling systems in the ocean. There are numerous feedbacks among oxygen concentrations, nutrient cycling and biological productivity; however, existing knowledge is insufficient to understand physical, chemical...

  14. Deciphering the Interconnections between Nutrient Supply, Demand, and Limitation

    Science.gov (United States)

    Covino, T. P.; Heffernan, J. B.; Bernhardt, E. S.

    2015-12-01

    Studies of stream nutrient dynamics have often focused on the influence of a single potentially limiting nutrient; however, it has become increasingly evident that ecosystems are constrained by the supply of numerous limiting resources. These resources may vary seasonally as a function of temperature, sunlight, and input of carbon and nutrients from upstream or terrestrial sources. We used multiple approaches, including plateau and TASCC nutrient additions, as well as analysis of diel nitrate dynamics as three different and complementary measures of nutrient demand/limitation in New Hope Creek, a third order stream in the Duke Forest of North Carolina over the course of one year. Nitrate-N concentrations were relatively high during the winter, spring, and summer months ranging from 105 - 518 and averaging 383 µg/L between January - August. During this time frame there was low demand for and limited uptake of added nitrate during plateau or TASCC additions (i.e., addition of N did not stimulate increased N uptake) although there was processing of background N evident from diel N and oxygen analyses. During autumn litterfall ecosystem respiration increased strongly and nitrate-N concentrations dropped precipitously, ranging from 9 - 34 and averaging 23 µg/L between September - December. During this period of low in-stream nitrate-N, demand for and uptake of added nitrate was high with maximum uptake rates of 560 µg/m2/min. This highlights the importance of understanding the relationship between nutrient supply and demand and the need to determine multiple resource controls over system processing. We also suggest that nutrient addition experiments need to be interpreted within the context of the supply and demand of multiple potentially limiting resources and the that the temporal dynamics of these relationships should be considered.

  15. Optimum air-demand ratio for maximum aeration efficiency in high-head gated circular conduits.

    Science.gov (United States)

    Ozkan, Fahri; Tuna, M Cihat; Baylar, Ahmet; Ozturk, Mualla

    2014-01-01

    Oxygen is an important component of water quality and its ability to sustain life. Water aeration is the process of introducing air into a body of water to increase its oxygen saturation. Water aeration can be accomplished in a variety of ways, for instance, closed-conduit aeration. High-speed flow in a closed conduit involves air-water mixture flow. The air flow results from the subatmospheric pressure downstream of the gate. The air entrained by the high-speed flow is supplied by the air vent. The air entrained into the flow in the form of a large number of bubbles accelerates oxygen transfer and hence also increases aeration efficiency. In the present work, the optimum air-demand ratio for maximum aeration efficiency in high-head gated circular conduits was studied experimentally. Results showed that aeration efficiency increased with the air-demand ratio to a certain point and then aeration efficiency did not change with a further increase of the air-demand ratio. Thus, there was an optimum value for the air-demand ratio, depending on the Froude number, which provides maximum aeration efficiency. Furthermore, a design formula for aeration efficiency was presented relating aeration efficiency to the air-demand ratio and Froude number.

  16. Optimum air-demand ratio for maximum aeration efficiency in high-head gated circular conduits.

    Science.gov (United States)

    Ozkan, Fahri; Tuna, M Cihat; Baylar, Ahmet; Ozturk, Mualla

    2014-01-01

    Oxygen is an important component of water quality and its ability to sustain life. Water aeration is the process of introducing air into a body of water to increase its oxygen saturation. Water aeration can be accomplished in a variety of ways, for instance, closed-conduit aeration. High-speed flow in a closed conduit involves air-water mixture flow. The air flow results from the subatmospheric pressure downstream of the gate. The air entrained by the high-speed flow is supplied by the air vent. The air entrained into the flow in the form of a large number of bubbles accelerates oxygen transfer and hence also increases aeration efficiency. In the present work, the optimum air-demand ratio for maximum aeration efficiency in high-head gated circular conduits was studied experimentally. Results showed that aeration efficiency increased with the air-demand ratio to a certain point and then aeration efficiency did not change with a further increase of the air-demand ratio. Thus, there was an optimum value for the air-demand ratio, depending on the Froude number, which provides maximum aeration efficiency. Furthermore, a design formula for aeration efficiency was presented relating aeration efficiency to the air-demand ratio and Froude number. PMID:25225935

  17. Is synthetic biology mechanical biology?

    Science.gov (United States)

    Holm, Sune

    2015-12-01

    A widespread and influential characterization of synthetic biology emphasizes that synthetic biology is the application of engineering principles to living systems. Furthermore, there is a strong tendency to express the engineering approach to organisms in terms of what seems to be an ontological claim: organisms are machines. In the paper I investigate the ontological and heuristic significance of the machine analogy in synthetic biology. I argue that the use of the machine analogy and the aim of producing rationally designed organisms does not necessarily imply a commitment to mechanical biology. The ideal of applying engineering principles to biology is best understood as expressing recognition of the machine-unlikeness of natural organisms and the limits of human cognition. The paper suggests an interpretation of the identification of organisms with machines in synthetic biology according to which it expresses a strategy for representing, understanding, and constructing living systems that are more machine-like than natural organisms.

  18. Oxygen starvation analysis during air feeding faults in PEMFC

    Energy Technology Data Exchange (ETDEWEB)

    Gerard, Mathias [Commissariat a l' Energie Atomique (CEA), DRT/LITEN, 17, rue des Martyrs -38000 Grenoble (France); University of Franche-Comte, FEMTO-ST ENISYS/FCLAB Laboratory, rue Thierry Mieg, bat. F -90010 Belfort (France); Poirot-Crouvezier, Jean-Philippe [Commissariat a l' Energie Atomique (CEA), DRT/LITEN, 17, rue des Martyrs -38000 Grenoble (France); Hissel, Daniel; Pera, Marie-Cecile [University of Franche-Comte, FEMTO-ST ENISYS/FCLAB Laboratory, rue Thierry Mieg, bat. F -90010 Belfort (France)

    2010-11-15

    A new analysis of performance degradation during oxygen starvation of PEMFC (Proton Exchange Membrane Fuel Cell) is proposed in this paper. Oxygen starvation happens for several reasons like compressor delay, fault during peak power demand or water management issues. The consequences on fuel cell performance degradation are not still well understood. This paper proposes a complete study with experimental tests and modeling. Impacts on performance were investigated under oxygen starvation and effects on the local conditions in the MEA (Membrane Electrode Assembly) were measured and modeled. In particular, current density measurements during oxygen starvation have been made with a specific bi-cell stack. Voltage oscillations were also found. Durability test have been realized on a PEMFC stack. Samples from the degraded MEA were analyzed by TEM (Transmission Electron Microscopy). Degradation mechanisms are proposed and the local conditions during oxygen starvation are identified. (author)

  19. Outcome measures for palliative oxygen therapy: relevance and practical utility.

    Science.gov (United States)

    Antoniu, Sabina; Mihaltan, Florin

    2014-06-01

    Dyspnea is a common symptom in many advanced malignant and non-malignant diseases and often is refractory to the usual therapies. In such circumstances palliative care approaches are necessary and among them palliative care oxygen therapy can be applied although currently its effectiveness is rather uncertain. Palliative oxygen therapy can be given on either continuous basis or on demand. Often the continuous palliative oxygen therapy is seen as long-term oxygen therapy although their aims are rather different. Palliative oxygen therapy was evaluated in populations with mixed underlying diseases, with outcome measures not only the most appropriate for the setting and therefore these limitations might have influenced the overall perceived therapeutic benefit. Therefore an evaluation of this method in subsets defined based on the etiology and pathogenic mechanisms and with appropriate outcome measures would help to better define the criteria for its indication and would increase its acceptability.

  20. Biology Notes.

    Science.gov (United States)

    School Science Review, 1982

    1982-01-01

    Presents procedures, exercises, demonstrations, and information on a variety of biology topics including labeling systems, biological indicators of stream pollution, growth of lichens, reproductive capacity of bulbous buttercups, a straw balance to measure transpiration, interaction of fungi, osmosis, and nitrogen fixation and crop production. (DC)

  1. Crucial market demands and company competencies

    DEFF Research Database (Denmark)

    Jensen, Bjarne; Stacey, Julia

    1999-01-01

    More and more, it is acknowledged that a company's success depends on it being capable of complying with the market's demands and wishes. It is, however, not always obvious, how the individual company will be able to meet the market's demands. A recent MAPP study has investigated this topic...... and identified a number of central market demands, which Danish food companies are faced with. Moreover, the study has identified which competencies are required to meet these demands and have also looked at howsuccessful companies structure some of these competencies. The study takes its point of departure...... in a literature review of MAPP's research. Results show that there are 27 central market demands, retail and consumer demands that Danish companies ought to be able to live up to. The study has also identified which competencies food companies must possess to be able to meet market's demands. Results from three...

  2. Stability of Money Demand Function in Pakistan

    Directory of Open Access Journals (Sweden)

    Haroon Sarwar

    2013-09-01

    Full Text Available The role, which money demand function plays in monetary policy formulation has attracted a lot of research studies to analyze this macroeconomic phenomenon. In the wake of current global and local economic and political upheavals, it is imperative to revisit the stability of money demand function. The study used the time series data and applied latest econometric techniques to find out the long run and short run money demand relationship. Moreover, all the three official monetary aggregates were used for finding out the most stable monetary demand relationship, which could provide correct signals for monetary policy formulation. The study found that broader monetary aggregate (M2 was the proper aggregate, which provided stable money demand function for Pakistan. The real GDP was positively related to the demand for real balances, while opportunity cost of money was negatively related. The study found that the role of financial innovation, in explaining the demand for money warrants attention in formulating monetary policy.

  3. Demand Discipline of Air Transportation for Passengers

    Directory of Open Access Journals (Sweden)

    Yunqian Qu

    2013-05-01

    Full Text Available The Yangtze River Delta (YRD region in China is taken for an example to research demand discipline of air transportation for passengers in this paper. The discipline includes three parts: demand generation, distribution and flow. First of all, the key factors influencing demand generation are got with information entropy. A threshold is set to choose more important factors and weights of these factors are calculated at the same time. Contribution rate of a factor is definedto analyze the difference of the factors for different city. By comparing demand distribution with airports’ throughput, we can analyze the demand flow. There are some conclusions. The factors have different contribution rate to different city for demand generation. Aircraft movement is the most important factor influencing demand flow. It provides more accurate basis for market positioning and developing, airport layout in a multi-airport system.

  4. Photosynthetic hydrogen and oxygen production - Kinetic studies

    Science.gov (United States)

    Greenbaum, E.

    1982-01-01

    The simultaneous photoproduction of hydrogen and oxygen was measured in a study of the steady-state turnover times of two biological systems, by driving them into the steady state with repetitive, single-turnover flash illumination. The systems were: (1) in vitro, isolated chloroplasts, ferredoxin and hydrogenase; and (2) the anaerobically-adapted green alga Chlamydomonas reinhardtii. It is found that the turnover times for production of both oxygen and hydrogen in photosynthetic water splitting are in milliseconds, and either equal to, or less than, the turnover time for carbon dioxide reduction in intact algal cells. There is therefore mutual compatibility between hydrogen and oxygen turnover times, and partial compatibility with the excitation rate of the photosynthetic reaction centers under solar irradiation conditions.

  5. Treatment and decolorization of biologically treated Palm Oil Mill Effluent (POME) using banana peel as novel biosorbent.

    Science.gov (United States)

    Mohammed, Rafie Rushdy; Chong, Mei Fong

    2014-01-01

    Palm Oil Mill Effluent (POME) treatment has always been a topic of research in Malaysia. This effluent that is extremely rich in organic content needs to be properly treated to minimize environmental hazards before it is released into watercourses. The main aim of this work is to evaluate the potential of applying natural, chemically and thermally modified banana peel as sorbent for the treatment of biologically treated POME. Characteristics of these sorbents were analyzed with BET surface area and SEM. Batch adsorption studies were carried out to remove color, total suspended solids (TSS), chemical oxygen demand (COD), tannin and lignin, and biological oxygen demand (BOD) onto natural banana peel (NBP), methylated banana peel (MBP), and banana peel activated carbon (BPAC) respectively. The variables of pH, adsorbent dosage, and contact time were investigated in this study. Maximum percentage removal of color, TSS, COD, BOD, and tannin and lignin (95.96%, 100%, 100%, 97.41%, and 76.74% respectively) on BPAC were obtained at optimized pH of 2, contact time of 30 h and adsorbent dosage of 30 g/100 ml. The isotherm data were well described by the Redlich-Peterson isotherm model with correlation coefficient of more than 0.99. Kinetic of adsorption was examined by Langergren pseudo first order, pseudo second order, and second order. The pseudo second order was identified to be the governing mechanism with high correlation coefficient of more than 0.99. PMID:24321284

  6. A novel hybrid nano zerovalent iron initiated oxidation--biological degradation approach for remediation of recalcitrant waste metalworking fluids.

    Science.gov (United States)

    Jagadevan, Sheeja; Jayamurthy, Manickam; Dobson, Peter; Thompson, Ian P

    2012-05-01

    Disposal of operationally exhausted metal working fluids (MWF) through a biological route is an attractive option, since it is effective with relatively low energy demands. However, it is enormously challenging since these fluids are chemically complex, including the addition of toxic biocides which are added specifically to retard bio-deterioration whilst the fluids are operational. Nano-sized elemental iron represents a new generation of environmental remediation technologies. Laboratory scale batch studies were performed to test the degradation ability of a semi-synthetic metalworking fluid (MWF) wastewater (which was found to be resistant to initial bacterial treatment in specifically established bioreactors) by employing a novel hybrid approach. The approach was to combine the synergistic effects of nano zerovalent iron (nZVI) induced oxidation, followed by biodegradation, specifically for the remediation of recalcitrant components of MWF effluent. Addition of nZVI particles to oxygenated wastewater resulted in oxidation of organic contaminants present. Our studies confirmed 78% reduction in chemical oxygen demand (COD) by nZVI oxidation at pH 3.0 and 67% reduction in neutral pH (7.5), and 85% concurrent reduction in toxicity. Importantly, this low toxicity made the nZVI treated effluent more amenable for a second stage biological oxidation step. An overall COD reduction of 95.5% was achieved by the novel combined treatment described, demonstrating that nZVI oxidation can be exploited for enhancing the biodegradability of a recalcitrant wastewater in treatment processes. PMID:22365368

  7. World uranium supply and demand

    International Nuclear Information System (INIS)

    The role of nuclear energy is under increasing scrutiny and uncertainty. None the less, there will be an increasing need for expansion of uranium supply to fuel committed reactors. Longer-term demand projections are very uncertain. Improved knowledge of the extent of world resources and their availability and economics is needed to support planning for reactor development, especially for breeder reactors, and for fuel-cycle development, especially enrichment, and reprocessing and recycle of uranium and plutonium. Efforts to date to estimate world uranium resources have been very useful but have largely reflected the state of available knowledge for the lower cost resources in regions that have received considerable exploration efforts. The IUREP evaluation of world resources provides an initial speculative estimate of world resources, including areas not previously appraised. Projections of long-range supply from the estimated resources suggest that the high-growth nuclear cases using once-through cycle may not be supportable for very long. However, additional effort is needed to appraise and report more completely and consistently on world resources, the production levels attainable from these resources, and the economic and price characteristics of such production. (author)

  8. Oil supply, demand and price

    International Nuclear Information System (INIS)

    To date the new millennium has seen a new twist in the history of oil. At the time of the last counter-shock, the IFP chairman declared. 'Our hero is no longer that of a Shakespearean drama of sound and fury. He has become just one of the players on a trivial theatre stage'. Peace lasted fifteen years, during which the barrel price fluctuated gently. But the oil price chronicle has become passionate once again and tragedy is stepping back in. Yet, this crisis is reminiscent of previous ones, those of the seventies and also of the 1910's, and its outcome could be surprisingly muted. Owing to inertia in production and consumption, the oil system is not responsive in the short run to sudden price variations, and the price rebound could go further as the economic situation improves; in the long term, however, innovation plays a primary role in both supply and demand functions, which have proven very flexible for 150 years, so a new period of balance could start by the twenties. (author)

  9. BATMAN: MOS Spectroscopy on Demand

    Science.gov (United States)

    Molinari, E.; Zamkotsian, F.; Moschetti, M.; Spano, P.; Boschin, W.; Cosentino, R.; Ghedina, A.; González, M.; Pérez, H.; Lanzoni, P.; Ramarijaona, H.; Riva, M.; Zerbi, F.; Nicastro, L.; Valenziano, L.; Di Marcantonio, P.; Coretti, I.; Cirami, R.

    2016-10-01

    Multi-Object Spectrographs (MOS) are the major instruments for studying primary galaxies and remote and faint objects. Current object selection systems are limited and/or difficult to implement in next generation MOS for space and ground-based telescopes. A promising solution is the use of MOEMS devices such as micromirror arrays, which allow the remote control of the multi-slit configuration in real time. TNG is hosting a novelty project for real-time, on-demand MOS masks based on MOEMS programmable slits. We are developing a 2048×1080 Digital-Micromirror-Device-based (DMD) MOS instrument to be mounted on the Galileo telescope, called BATMAN. It is a two-arm instrument designed for providing in parallel imaging and spectroscopic capabilities. With a field of view of 6.8×3.6 arcmin and a plate scale of 0.2 arcsec per micromirror, this astronomical setup can be used to investigate the formation and evolution of galaxies. The wavelength range is in the visible and the spectral resolution is R=560 for a 1 arcsec object, and the two arms will have 2k × 4k CCD detectors. ROBIN, a BATMAN demonstrator, has been designed, realized and integrated. We plan to have BATMAN first light by mid-2016.

  10. Hydrophobic organic chemicals (HOCs) removal from biologically treated landfill leachate by powder-activated carbon (PAC), granular-activated carbon (GAC) and biomimetic fat cell (BFC).

    Science.gov (United States)

    Liyan, Song; Youcai, Zhao; Weimin, Sun; Ziyang, Lou

    2009-04-30

    Biological pretreatment efficiently remove organic matter from landfill leachate, but further removal of refractory hydrophobic organic chemicals (HOCs) is hard even with advanced treatment. In this work, three-stage-aged refuse bioreactor (ARB) efficiently removed chemical oxygen demand (COD) and biochemical oxygen demand (BOD) of fresh leachate produced in Shanghai laogang landfill, from 8603 to 451 mg L(-1) and 1368 to 30 mg L(-1), respectively. In downstream treatment, 3 g L(-1) powder-activated carbon (PAC), granular-activated carbon (GAC) and biomimetic fat cell (BFC) removed 89.2, 73.4 and 81.1% HOCs, but only 24.6, 19.1 and 8.9% COD, respectively. Through the specific HOCs accumulation characteristics of BFC, about 11.2% HOCs with low molecular weight (BFC. It was also found that the biologically treated leachate effluent exhibited a wide molecular weight distribution (34-514,646 Da). These constitutes are derived from both autochthonous and allochthonous matters as well as biological activities.

  11. Supply and demand for endocannabinoids

    Science.gov (United States)

    Alger, Bradley E.; Kim, Jimok

    2011-01-01

    The endocannabinoid system consists of G-protein coupled cannabinoid receptors that can be activated by cannabis-derived drugs and small lipids called endocannabinoids, plus associated biochemical machinery (precursors, synthetic and degradative enzymes, transporters). The endocannabinoid system in the brain primarily influences neuronal synaptic communication, and affects biological – functions including eating, anxiety, learning and memory, growth and development – via an array of actions throughout the nervous system. While many aspects of synaptic regulation by endocannabinoids are becoming clear, details of the subcellular organization and regulation of the endocannabinoid system are less well understood. This review focuses on recent investigations that illuminate fundamental issues of endocannabinoid storage, release, and functional roles. PMID:21507493

  12. Quantum Biology

    Directory of Open Access Journals (Sweden)

    Alessandro Sergi

    2009-06-01

    Full Text Available A critical assessment of the recent developmentsof molecular biology is presented.The thesis that they do not lead to a conceptualunderstanding of life and biological systems is defended.Maturana and Varela's concept of autopoiesis is briefly sketchedand its logical circularity avoided by postulatingthe existence of underlying living processes,entailing amplification from the microscopic to the macroscopic scale,with increasing complexity in the passage from one scale to the other.Following such a line of thought, the currently accepted model of condensed matter, which is based on electrostatics and short-ranged forces,is criticized. It is suggested that the correct interpretationof quantum dispersion forces (van der Waals, hydrogen bonding, and so onas quantum coherence effects hints at the necessity of includinglong-ranged forces (or mechanisms for them incondensed matter theories of biological processes.Some quantum effects in biology are reviewedand quantum mechanics is acknowledged as conceptually important to biology since withoutit most (if not all of the biological structuresand signalling processes would not even exist. Moreover, it is suggested that long-rangequantum coherent dynamics, including electron polarization,may be invoked to explain signal amplificationprocess in biological systems in general.

  13. Emerging food demand behaviors in Malaysia: Incorporating quality effects in demand analyses

    OpenAIRE

    Tey, (John) Yeong-Sheng; SHAMSUDIN Mad Nasir; Mohamed, Zainalabidin; Abdullah, Amin Mahir; Radam, Alias

    2008-01-01

    In this study, the focus is on analyzing food demand behaviors in Malaysia. To be more specific, this study intends to estimate demand elasticities for twelve food categories with incorporation of food quality effects in the demand analyses. This study analyses the data from the Household Expenditure Survey 2004/2005 by Linear Approximate Almost Ideal Demand System (LA/AIDS) and unit value function. The estimated expenditure elasticities indicate that there will be growing demand for all the ...

  14. One-legged endurance training: leg blood flow and oxygen extraction during cycling exercise

    DEFF Research Database (Denmark)

    Rud, B; Foss, O; Krustrup, Peter;

    2012-01-01

    Aim: As a consequence of enhanced local vascular conductance, perfusion of muscles increases with exercise intensity to suffice the oxygen demand. However, when maximal oxygen uptake (VO(2) max) and cardiac output are approached, the increase in conductance is blunted. Endurance training increases...

  15. High Selectivity Oxygen Delignification

    Energy Technology Data Exchange (ETDEWEB)

    Lucian A. Lucia

    2005-11-15

    Project Objective: The objectives of this project are as follows: (1) Examine the physical and chemical characteristics of a partner mill pre- and post-oxygen delignified pulp and compare them to lab generated oxygen delignified pulps; (2) Apply the chemical selectivity enhancement system to the partner pre-oxygen delignified pulps under mill conditions (with and without any predetermined amounts of carryover) to determine how efficiently viscosity is preserved, how well selectivity is enhanced, if strength is improved, measure any yield differences and/or bleachability differences; and (3) Initiate a mill scale oxygen delignification run using the selectivity enhancement agent, collect the mill data, analyze it, and propose any future plans for implementation.

  16. Living with Oxygen Therapy

    Science.gov (United States)

    ... transportation carrier (for example, the airline or bus company). If you need oxygen while traveling, plan in ... NEXT >> Updated: February 24, 2012 Twitter Facebook YouTube Google+ SITE INDEX ACCESSIBILITY PRIVACY STATEMENT FOIA OIG CONTACT ...

  17. Optic nerve oxygenation

    DEFF Research Database (Denmark)

    Stefánsson, Einar; Pedersen, Daniella Bach; Jensen, Peter Koch;

    2005-01-01

    at similar levels of perfusion pressure. The levels of perfusion pressure that lead to optic nerve hypoxia in the laboratory correspond remarkably well to the levels that increase the risk of glaucomatous optic nerve atrophy in human glaucoma patients. The risk for progressive optic nerve atrophy in human......The oxygen tension of the optic nerve is regulated by the intraocular pressure and systemic blood pressure, the resistance in the blood vessels and oxygen consumption of the tissue. The oxygen tension is autoregulated and moderate changes in intraocular pressure or blood pressure do not affect...... glaucoma patients is six times higher at a perfusion pressure of 30 mmHg, which corresponds to a level where the optic nerve is hypoxic in experimental animals, as compared to perfusion pressure levels above 50 mmHg where the optic nerve is normoxic. Medical intervention can affect optic nerve oxygen...

  18. Determining the Source of Water Vapor in a Cerium Oxide Electrochemical Oxygen Separator to Achieve Aviator Grade Oxygen

    Science.gov (United States)

    Graf, John; Taylor, Dale; Martinez, James

    2014-01-01

    More than a metric ton of water is transported to the International Space Station (ISS) each year to provide breathing oxygen for the astronauts. Water is a safe and compact form of stored oxygen. The water is electrolyzed on ISS and ambient pressure oxygen is delivered to the cabin. A much smaller amount of oxygen is used each year in spacesuits to conduct Extra Vehicular Activities (EVAs). Space suits need high pressure (>1000 psia) high purity oxygen (must meet Aviator Breathing Oxygen "ABO" specifications, >99.5% O2). The water / water electrolysis system cannot directly provide high pressure, high purity oxygen, so oxygen for EVAs is transported to ISS in high pressure gas tanks. The tanks are relatively large and heavy, and the majority of the system launch weight is for the tanks and not the oxygen. Extracting high purity oxygen from cabin air and mechanically compressing the oxygen might enable on-board production of EVA grade oxygen using the existing water / water electrolysis system. This capability might also benefit human spaceflight missions, where oxygen for EVAs could be stored in the form of water, and converted into high pressure oxygen on-demand. Cerium oxide solid electrolyte-based ion transport membranes have been shown to separate oxygen from air, and a supported monolithic wafer form of the CeO2 electrolyte membrane has been shown to deliver oxygen at pressures greater than 300 psia. These supported monolithic wafers can withstand high pressure differentials even though the membrane is very thin, because the ion transport membrane is supported on both sides (Fig 1). The monolithic supported wafers have six distinct layers, each with matched coefficients of thermal expansion. The wafers are assembled into a cell stack which allows easy air flow across the wafers, uniform current distribution, and uniform current density (Fig 2). The oxygen separation is reported to be "infinitely selective" to oxygen [1] with reported purity of 99.99% [2

  19. Optic nerve oxygen tension

    DEFF Research Database (Denmark)

    la Cour, M; Kiilgaard, Jens Folke; Eysteinsson, T;

    2000-01-01

    To investigate the influence of acute changes in intraocular pressure on the oxygen tension in the vicinity of the optic nerve head under control conditions and after intravenous administration of 500 mg of the carbonic anhydrase inhibitor dorzolamide.......To investigate the influence of acute changes in intraocular pressure on the oxygen tension in the vicinity of the optic nerve head under control conditions and after intravenous administration of 500 mg of the carbonic anhydrase inhibitor dorzolamide....

  20. Practical procedures: oxygen therapy.

    Science.gov (United States)

    Olive, Sandra

    Knowing when to start patients on oxygen therapy can save lives, but ongoing assessment and evaluation must be carried out to ensure the treatment is safe and effective. This article outlines when oxygen therapy should be used and the procedures to follow. It also describes the delivery methods applicable to different patient groups, along with the appropriate target saturation ranges, and details relevant nurse competencies.

  1. Preparation of atomic oxygen resistant polymeric materials

    Science.gov (United States)

    Tortorelli, Victor J.; Hergenrother, P. M.; Connell, J. W.

    1991-01-01

    Polyphenyl quinoxalines (PPQs) are an important family of high performance polymers that offer good chemical and thermal stability coupled with excellent mechanical properties. These aromatic heterocyclic polymers are potentially useful as films, coatings, adhesives, and composite materials that demand stability in harsh environments. Our approach was to prepare PPQs with pendent siloxane groups using the appropriate chemistry and then evaluate these polymers before and after exposure to simulated atomic oxygen. Either monomer, the bis(o-diamine)s or the bis(alpha-diketone)s can be synthesized with a hydroxy group to which the siloxane chain will be attached. Several novel materials were prepared.

  2. Rapid oxygenation of Earths atmosphere 2.33 billion years ago

    OpenAIRE

    Luo, Genming; Ono, Shuhei; Beukes, Nicolas J.; Wang, David T.; Xie, Shucheng; Summons, Roger E.

    2016-01-01

    Molecular oxygen (O[subscript 2]) is, and has been, a primary driver of biological evolution and shapes the contemporary landscape of Earth’s biogeochemical cycles. Although “whiffs” of oxygen have been documented in the Archean atmosphere, substantial O2 did not accumulate irreversibly until the Early Paleoproterozoic, during what has been termed the Great Oxygenation Event (GOE). The timing of the GOE and the rate at which this oxygenation took place have been poorly constrained until now. ...

  3. Quantum Biology

    CERN Document Server

    Sergi, Alessandro

    2009-01-01

    A critical assessment of the recent developments of molecular biology is presented. The thesis that they do not lead to a conceptual understanding of life and biological systems is defended. Maturana and Varela's concept of autopoiesis is briefly sketched and its logical circularity avoided by postulating the existence of underlying {\\it living processes}, entailing amplification from the microscopic to the macroscopic scale, with increasing complexity in the passage from one scale to the other. Following such a line of thought, the currently accepted model of condensed matter, which is based on electrostatics and short-ranged forces, is criticized. It is suggested that the correct interpretation of quantum dispersion forces (van der Waals, hydrogen bonding, and so on) as quantum coherence effects hints at the necessity of including long-ranged forces (or mechanisms for them) in condensed matter theories of biological processes. Some quantum effects in biology are reviewed and quantum mechanics is acknowledge...

  4. Electricity Demand and Energy Consumption Management System

    CERN Document Server

    Sarmiento, Juan Ojeda

    2008-01-01

    This project describes the electricity demand and energy consumption management system and its application to the Smelter Plant of Southern Peru. It is composted of an hourly demand-forecasting module and of a simulation component for a plant electrical system. The first module was done using dynamic neural networks, with backpropagation training algorithm; it is used to predict the electric power demanded every hour, with an error percentage below of 1%. This information allows management the peak demand before this happen, distributing the raise of electric load to other hours or improving those equipments that increase the demand. The simulation module is based in advanced estimation techniques, such as: parametric estimation, neural network modeling, statistic regression and previously developed models, which simulates the electric behavior of the smelter plant. These modules allow the proper planning because it allows knowing the behavior of the hourly demand and the consumption patterns of the plant, in...

  5. Supply and demand assert their roles

    International Nuclear Information System (INIS)

    The last 12 months have been a period when the most fundamental of economic factors, supply and demand, took control of the global upstream market. Supply affected the market in terms of equipment and manpower, or more precisely, the growing lack thereof. Demand made its presence felt strongly as regards growth of oil consumption. Indeed, the pace of world oil demand growth is accelerating. According to the International Energy Agency (IEA), demand rose 1.9% in 1994. In 1995, the pace got faster, rising 2.2%. Last year, the rate of increase jumped again, with global oil demand growing 2.4% to 72.0 million bopd. IEA predicts that 1997's growth rate will go higher, to 2.5%, resulting in demand of 73.8 million bopd. Data are presented on drilling activities for gas and oil wells, oil/gas condensate production, and gas and oil reserves

  6. Demand forecast model based on CRM

    Science.gov (United States)

    Cai, Yuancui; Chen, Lichao

    2006-11-01

    With interiorizing day by day management thought that regarding customer as the centre, forecasting customer demand becomes more and more important. In the demand forecast of customer relationship management, the traditional forecast methods have very great limitation because much uncertainty of the demand, these all require new modeling to meet the demands of development. In this paper, the notion is that forecasting the demand according to characteristics of the potential customer, then modeling by it. The model first depicts customer adopting uniform multiple indexes. Secondly, the model acquires characteristic customers on the basis of data warehouse and the technology of data mining. The last, there get the most similar characteristic customer by their comparing and forecast the demands of new customer by the most similar characteristic customer.

  7. Food safety information and food demand

    DEFF Research Database (Denmark)

    Smed, Sinne; Jensen, Jørgen Dejgård

    2005-01-01

    Purpose – The purpose of this paper is to analyze how news about food-related health risks affects consumers’ demands for safe food products. Design/methodology/approach – By identifying structural breaks in an econometrically estimated demand model, news with permanent impact on demand...... induces a permanent increase in the demand for pasteurized eggs, while more moderate negative news influences demand temporarily and to a lesser extent. There is, however, considerable variation in the response to food safety news across socio-demographic groups of consumers. Research limitations....../implications – The study has focused on the demand for raw eggs. Responses to food safety news may differ across foods. Furthermore, the study abstracts from possible cross-effects of safety news concerning other foods. Practical implications – The findings may be utilized for optimization of the timing and targeting...

  8. Biological Denitrification of High Nitrate Processing Wastewaters from Explosives Production Plant.

    Science.gov (United States)

    Cyplik, Paweł; Marecik, Roman; Piotrowska-Cyplik, Agnieszka; Olejnik, Anna; Drożdżyńska, Agnieszka; Chrzanowski, Lukasz

    2012-05-01

    Wastewater samples originating from an explosives production plant (3,000 mg N l(-1) nitrate, 4.8 mg l(-1) nitroglycerin, 1.9 mg l(-1) nitroglycol and 1,200 mg l(-1) chemical oxygen demand) were subjected to biological purification. An attempt to completely remove nitrate and to decrease the chemical oxygen demand was carried out under anaerobic conditions. A soil isolated microbial consortium capable of biodegrading various organic compounds and reduce nitrate to atmospheric nitrogen under anaerobic conditions was used. Complete removal of nitrates with simultaneous elimination of nitroglycerin and ethylene glycol dinitrate (nitroglycol) was achieved as a result of the conducted research. Specific nitrate reduction rate was estimated at 12.3 mg N g(-1) VSS h(-1). Toxicity of wastewater samples during the denitrification process was studied by measuring the activity of dehydrogenases in the activated sludge. Mutagenicity was determined by employing the Ames test. The maximum mutagenic activity did not exceed 0.5. The obtained results suggest that the studied wastewater samples did not exhibit mutagenic properties. PMID:22593607

  9. Application of integrated ozone biological aerated filters and membrane filtration in water reuse of textile effluents.

    Science.gov (United States)

    He, Yaozhong; Wang, Xiaojun; Xu, Jinling; Yan, Jinli; Ge, Qilong; Gu, Xiaoyang; Jian, Lei

    2013-04-01

    A combined process including integrated ozone-BAFs (ozone biological aerated filters) and membrane filtration was first applied for recycling textile effluents in a cotton textile mill with capacity of 5000 m(3)/d. Influent COD (chemical oxygen demand) in the range of 82-120 mg/L, BOD5 (5-day biochemical oxygen demand) of 12.6-23.1 mg/L, suspended solids (SSs) of 38-52 mg/L and color of 32-64° were observed during operation. Outflows with COD≤45 mg/L, BOD5≤7.6 mg/L, SS≤15 mg/L, color≤8° were obtained after being decontaminated by ozone-BAF with ozone dosage of 20-25 mg/L. Besides, the average removal rates of PVA (polyvinyl alcohol) and UV254 were 100% and 73.4% respectively. Permeate water produced by RO (reverse osmosis) could be reused in dyeing and finishing processes, while the RO concentrates could be discharged directly under local regulations with COD≤100 mg/L, BOD5≤21 mg/L, SS≤52 mg/L, color≤32°. Results showed that the combined process could guarantee water reuse with high quality, and solve the problem of RO concentrate disposal.

  10. Demand response-enabled residential thermostat controls.

    OpenAIRE

    Chen, Xue; Jang, Jaehwi; David M. Auslander; Peffer, Therese; Arens, Edward A.

    2008-01-01

    A number of Demand Response (DR) technologies work by responding to variable electricity pricing, but have not yet been applied to control residential HVAC systems. An autonomous thermostat system, the Demand Response Electrical Appliance Manager (DREAM), provides possibilities to improve price-based demand responsiveness in residences. Built on low-cost, low-power wireless technology, the system uses a disaggregated set of energy- and environmental sensors. Control strategies are im...

  11. Demand Discipline of Air Transportation for Passengers

    OpenAIRE

    Yunqian Qu; Jinfu Zhu

    2013-01-01

    The Yangtze River Delta (YRD) region in China is taken for an example to research demand discipline of air transportation for passengers in this paper. The discipline includes three parts: demand generation, distribution and flow. First of all, the key factors influencing demand generation are got with information entropy. A threshold is set to choose more important factors and weights of these factors are calculated at the same time. Contribution rate of a factor is definedto analyze the dif...

  12. Comprehensive areal model of residential heating demands

    Energy Technology Data Exchange (ETDEWEB)

    Tessmer, R.G. Jr.

    1978-01-01

    Data sources and methodology for modeling annual residential heating demands are described. A small areal basis is chosen, census tract or minor civil division, to permit estimation of demand densities and economic evaluation of community district heating systems. The demand model is specified for the entire nation in order to provide general applicability and to permit validation with other published fuel consumption estimates for 1970.

  13. ESTIMATION OF POTATO DEMAND ELASTICITIES IN BANGLADESH

    OpenAIRE

    Huq, A. S. M. Anwarul; ALAM, SHAMSUL; Sabur, S. A.

    2004-01-01

    The study estimated potato demand elasticities in Bangladesh by using AIDS model with corrected Stone price index. The income elasticity of demand for potato was 0.632. The compensated and uncompensated own price elasticities indicated that all food items were price inelastic. The estimated own price elasticity indicated that if the potato price fell by 10 per cent, demand for potato would increase by 8.82 percent. The estimates of cross price elasticities indicated that the substitution effe...

  14. Measuring the price responsiveness of gasoline demand

    OpenAIRE

    Blundell, Richard; Horowitz, Joel L.; Parey, Matthias

    2009-01-01

    This paper develops a new method for estimating the demand function for gasoline and the deadweight loss due to an increase in the gasoline tax. The method is also applicable to other goods. The method uses shape restrictions derived from economic theory to improve the precision of a nonparametric estimate of the demand function. Using data from the U.S. National Household Travel Survey, we show that the restrictions are consistent with the data on gasoline demand and remove the anomalous beh...

  15. Cointegration and the Demand for Gasoline

    OpenAIRE

    Rao, B. Bhaskara; Rao, Gyaneshwar

    2008-01-01

    Since the early 1970s there has been a worldwide upsurge in the price of energy and in particular of gasoline. Therefore, demand functions for energy and its components like gasoline have received much attention. However, since confidence in the estimated demand functions is important for use in policy and forecasting, following Amarawickrama and Hunt (2008), this paper estimates the demand for gasoline is estimated with 6 alternative time series techniques with data from Fiji. Estimates w...

  16. Demand analyses of rice in Malaysia

    OpenAIRE

    Tey, (John) Yeong-Sheng; SHAMSUDIN Mad Nasir; Mohamed, Zainalabidin; Abdullah, Amin Mahir; Radam, Alias

    2008-01-01

    As a typical developing Asian county, the growth in per capita income generally brings to diversification in Malaysians food basket. The most significant observation is the falling in per capita consumption of rice with continuous growth of demand for wheat based products. The objective of this study is to estimate the demand elasticities of rice in Malaysia, focusing whether rice is an inferior good. By using data from Household Expenditure Survey 2004/2005, this study obtains demand elastic...

  17. Reduce Demand Rather than Increase Supply

    OpenAIRE

    Shoup, Donald C.

    2006-01-01

    The logic behind off-street parking requirements is simple: development increases the demand for parking, so cities require enough off-street spaces to satisfy this new demand. Off-street parking requirements thus ensure that cars will not spill over onto the neighborhood streets. This logic suggests another potential reform within the existing system of off-street parking requirements: if developers reduce parking demand, cities should allow them to provide fewer parking spaces; that is, cit...

  18. Forecasting Daily Demand in Cash Supply Chains

    OpenAIRE

    Michael Wagner

    2010-01-01

    Problem statement: Previous studies focused on explaining the long run determinants of currency demand offering limited insight into the short-run determinants and co-variability of daily demand in cash supply chains. Approach: This study contrasted competing techniques of forecasting daily demand in cash supply chains in order to determine the overall performance and the potential of joint forecasting for integrated planning. A joint forecasting approach was compared with...

  19. Evolution of ARMA Demand in Supply Chains

    OpenAIRE

    Xiaolong Zhang

    2004-01-01

    This paper shows that an ARMA demand generates an ARMA order history when ordering decisions are made based on an order-up-to policy. The order history preserves the autoregressive structure of the demand and transforms its moving average structure according to a simple algorithm. We apply this ARMA-in-ARMA-out property to examine the evolution of the demand signal in supply chains. Its practical implications are discussed in the context of quantifying the bullwhip effect, coordinating foreca...

  20. Evolution, atmospheric oxygen, and complex disease.

    Science.gov (United States)

    Koch, Lauren Gerard; Britton, Steven L

    2007-08-20

    If evolution is an accurate statement of our biology, then disease must be tightly associated with its patterns. We considered selection for more optimal capacity for energy transfer as the most general pattern of evolution. From this, we propose that the etiology of complex disease is linked tightly to the evolutionary transition to cellular complexity that was afforded by the steep thermodynamic gradient of an oxygen atmosphere. In accord with this thesis, clinical studies reveal a strong statistical link between low aerobic capacity and all-cause mortality. In addition, large-scale unbiased network analyses demonstrate the pivotal role of oxygen metabolism in cellular function. The demonstration that multiple disease risks segregated during two-way artificial selection for low and high aerobic capacity in rats provides a remote test of these possible connections between evolution, oxygen metabolism, and complex disease. Even more broadly, an atmosphere with oxygen may be uniquely essential for development of complex life anywhere because oxygen is stable as a diatomic gas, is easily transported, and has a high electronegativity for participation in energy transfer via redox reactions. PMID:17473218

  1. Response of benthic foraminifera to phytodetritus in the eastern Arabian Sea under low oxygen conditions

    Science.gov (United States)

    Enge, Annekatrin; Wukovits, Julia; Wanek, Wolfgang; Watzka, Margarete; Witte, Ursula; Hunter, William; Heinz, Petra

    2016-04-01

    At water depths between 100 and 1500 m a permanent Oxygen Minimum Zone (OMZ) impinges on the sea floor in the eastern Arabian Sea, exposing benthic organisms to anoxic to suboxic conditions. The flux of organic matter to the sea floor is relatively high at these depths but displays seasonal variation. Deposition of relatively fresh phytodetrital material (phytoplankton remains) can occur within a short period of time after monsoon periods. Several organism groups including foraminifera are involved to different extent in the processing of phytodetritus in the OMZs of the northern Arabian Sea. A series of in situ feeding experiments were performed to study the short-term processing (nutritional demands of foraminifera at different oxygen concentrations on the continental margin in the eastern Arabian Sea. For the experiments, a single pulse of isotopically labeled phytodetritus was added to the sediment along a depth transect (540-1100 m) on the Indian Margin, covering the OMZ core and the lower OMZ boundary region. Uptake of phytodetritus within 4 days shows the relevance of phytodetritus as food source for foraminifera. Lower content of phytodetrital carbon recorded in foraminifera from more oxygenated depths shows greater food uptake by foraminifera in the OMZ core than in the OMZ boundary region. The foraminiferal assemblage living under almost anoxic conditions in the OMZ core is dominated by species typically found in eutroph environments (such as Uvigerinids) that are adapted to high flux of organic matter. The elevated carbon uptake can also result from missing food competition by macrofauna or from greater energy demand in foraminifera to sustain metabolic processes under hypoxic stress. Variable levels and ratios of phytodetrital carbon and nitrogen indicate specific nutritional demands and storage of food-derived nitrogen in some foraminifera species under near anoxia where the mean phytodetrital nitrogen content in foraminifera was elevated. In summary

  2. Income distribution trends and future food demand.

    Science.gov (United States)

    Cirera, Xavier; Masset, Edoardo

    2010-09-27

    This paper surveys the theoretical literature on the relationship between income distribution and food demand, and identifies main gaps of current food modelling techniques that affect the accuracy of food demand projections. At the heart of the relationship between income distribution and food demand is Engel's law. Engel's law establishes that as income increases, households' demand for food increases less than proportionally. A consequence of this law is that the particular shape of the distribution of income across individuals and countries affects the rate of growth of food demand. Our review of the literature suggests that existing models of food demand fail to incorporate the required Engel flexibility when (i) aggregating different food budget shares among households; and (ii) changing budget shares as income grows. We perform simple simulations to predict growth in food demand under alternative income distribution scenarios taking into account nonlinearity of food demand. Results suggest that (i) distributional effects are to be expected from changes in between-countries inequality, rather than within-country inequality; and (ii) simulations of an optimistic and a pessimistic scenario of income inequality suggest that world food demand in 2050 would be 2.7 per cent higher and 5.4 per cent lower than distributional-neutral growth, respectively.

  3. China's Grain Demand and Supply: Trade Implications

    OpenAIRE

    Wu, Harry X.; Christopher Findlay

    1997-01-01

    This study reviews research on China's grain demand and supply. The purpose is to comment on the outlook for China's trade in grain and grain-based food, but also to identify the sensitivities of the projections of China's grain demand to key parameters. The paper will therefore 1) review a set of projections of grain demand and trade, 2) examine studies of major factors considered to affect grain demand in China, 3) comment on some trade and production policy issues based on a new projection...

  4. Introduction: Biological Constraints on Learning

    OpenAIRE

    Burgos, José E

    2015-01-01

    This special section stemmed from a symposium on biological constraints on learning that was organized for the XVII Biennial Meeting of the International Society for Comparative Psychology in Bogotá, Colombia, September 2014.  The symposium sought to revisit the topic of biological constraints on learning.  Such is the aim of this special section as well, guided by the conviction that the topic demands further study.  Some of the most important researchers in the area were invited to contribu...

  5. Oxygen safety margins set thermal limits in an insect model system.

    Science.gov (United States)

    Boardman, Leigh; Terblanche, John S

    2015-06-01

    A mismatch between oxygen availability and metabolic demand may constrain thermal tolerance. While considerable support for this idea has been found in marine organisms, results from insects are equivocal and raise the possibility that mode of gas exchange, oxygen safety margins and the physico-chemical properties of the gas medium influence heat tolerance estimates. Here, we examined critical thermal maximum (CTmax) and aerobic scope under altered oxygen supply and in two life stages that varied in metabolic demand in Bombyx mori (Lepidoptera: Bombycidae). We also systematically examined the influence of changes in gas properties on CTmax. Larvae have a lower oxygen safety margin (higher critical oxygen partial pressure at which metabolism is suppressed relative to metabolic demand) and significantly higher CTmax under normoxia than pupae (53°C vs 50°C). Larvae, but not pupae, were oxygen limited with hypoxia (2.5 kPa) decreasing CTmax significantly from 53 to 51°C. Humidifying hypoxic air relieved the oxygen limitation effect on CTmax in larvae, whereas variation in other gas properties did not affect CTmax. Our data suggest that oxygen safety margins set thermal limits in air-breathing invertebrates and the magnitude of this effect potentially reconciles differences in oxygen limitation effects on thermal tolerance found among diverse taxa to date. PMID:26041031

  6. Dissolved-oxygen regimen of the Willamette River, Oregon, under conditions of basinwide secondary treatment

    Science.gov (United States)

    Hines, Walter G.; McKenzie, S.W.; Rickert, D.A.; Rinella, F.A.

    1977-01-01

    For nearly half a century the Willamette River in Oregon experienced severe dissolved-oxygen problems related to large loads of organically rich waste waters from industries and municipalities. Since the mid-1950 's dissolved oxygen quality has gradually improved owing to low-flow augmentation, the achievement of basinwide secondary treatment, and the use of other waste-management practices. As a result, summer dissolved-oxygen levels have increased, salmon runs have returned, and the overall effort is widely regarded as a singular water-quality success. To document the improved dissolved-oxygen regimen, the U.S. Geological Survey conducted intensive studies of the Willamette during the summer low-flow seasons of 1973 and 1974. During each summer the mean daily dissolved-oxygen levels were found to be higher than 5 milligrams per liter throughout the river. Because of the basinwide secondary treatment, carbonaceous deoxygenation rates were low. In addition, almost half of the biochemical oxygen demand entering the Willamette was from diffuse (nonpoint) sources rather than outfalls. These results indicated that point-source biochemical oxygen demand was no longer the primary cause of dissolved-oxygen depletion. Instead, the major causes of deoxygenation were nitrification in a shallow ' surface active ' reach below Salem and an anomalous oxygen demand (believed to be primarily of benthal origin) in Portland Harbor. (Woodard-USGS)

  7. Co-evolution of eukaryotes and ocean oxygenation in the Neoproterozoic era

    Science.gov (United States)

    Lenton, Timothy M.; Boyle, Richard A.; Poulton, Simon W.; Shields-Zhou, Graham A.; Butterfield, Nicholas J.

    2014-04-01

    The Neoproterozoic era (about 1,000 to 542 million years ago) was a time of turbulent environmental change. Large fluctuations in the carbon cycle were associated with at least two severe -- possible Snowball Earth -- glaciations. There were also massive changes in the redox state of the oceans, culminating in the oxygenation of much of the deep oceans. Amid this environmental change, increasingly complex life forms evolved. The traditional view is that a rise in atmospheric oxygen concentrations led to the oxygenation of the ocean, thus triggering the evolution of animals. We argue instead that the evolution of increasingly complex eukaryotes, including the first animals, could have oxygenated the ocean without requiring an increase in atmospheric oxygen. We propose that large eukaryotic particles sank quickly through the water column and reduced the consumption of oxygen in the surface waters. Combined with the advent of benthic filter feeding, this shifted oxygen demand away from the surface to greater depths and into sediments, allowing oxygen to reach deeper waters. The decline in bottom-water anoxia would hinder the release of phosphorus from sediments, potentially triggering a potent positive feedback: phosphorus removal from the ocean reduced global productivity and ocean-wide oxygen demand, resulting in oxygenation of the deep ocean. That, in turn, would have further reinforced eukaryote evolution, phosphorus removal and ocean oxygenation.

  8. Ethanol demand in Brazil: Regional approach

    International Nuclear Information System (INIS)

    Successive studies attempting to clarify national aspects of ethanol demand have assisted policy makers and producers in defining strategies, but little information is available on the dynamic of regional ethanol markets. This study aims to analyze the characteristics of ethanol demand at the regional level taking into account the peculiarities of the developed center-south and the developing north-northeast regions. Regional ethanol demand is evaluated based on a set of market variables that include ethanol price, consumer's income, vehicle stock and prices of substitute fuels; i.e., gasoline and natural gas. A panel cointegration analysis with monthly observations from January 2003 to April 2010 is employed to estimate the long-run demand elasticity. The results reveal that the demand for ethanol in Brazil differs between regions. While in the center-south region the price elasticity for both ethanol and alternative fuels is high, consumption in the north-northeast is more sensitive to changes in the stock of the ethanol-powered fleet and income. These, among other evidences, suggest that the pattern of ethanol demand in the center-south region most closely resembles that in developed nations, while the pattern of demand in the north-northeast most closely resembles that in developing nations. - Research highlights: → Article consists of a first insight on regional demand for ethanol in Brazil. → It proposes a model with multiple fuels, i.e., hydrous ethanol, gasohol and natural gas. → Results evidence that figures for regional demand for ethanol differ amongst regions and with values reported for national demand. → Elasticities for the center-south keep similarities to patterns for fuel demand in developed nations while coefficients for the north-northeast are aligned to patterns on developing countries.

  9. Engineered Hybrid Nanoparticles for On-Demand Diagnostics and Therapeutics.

    Science.gov (United States)

    Nguyen, Kim Truc; Zhao, Yanli

    2015-12-15

    Together with the simultaneous development of nanomaterials and molecular biology, the bionano interface brings about various applications of hybrid nanoparticles in nanomedicine. The hybrid nanoparticles not only present properties of the individual components but also show synergistic effects for specialized applications. Thus, the development of advanced hybrid nanoparticles for targeted and on-demand diagnostics and therapeutics of diseases has rapidly become a hot research topic in nanomedicine. The research focus is to fabricate novel classes of programmable hybrid nanoparticles that are precisely engineered to maximize drug concentrations in diseased cells, leading to enhanced efficacy and reduced side effects of chemotherapy for the disease treatment. In particular, the hybrid nanoparticle platforms can simultaneously target diseased cells, enable the location to be imaged by optical methods, and release therapeutic drugs to the diseased cells by command. This Account specially discusses the rational fabrication of integrated hybrid nanoparticles and their applications in diagnostics and therapeutics. For diagnostics applications, hybrid nanoparticles can be utilized as imaging agents that enable detailed visualization at the molecular level. By the use of suitable targeting ligands incorporated on the nanoparticles, targeted optical imaging may be feasible with improved performance. Novel imaging techniques such as multiphoton excitation and photoacoustic imaging using near-infrared light have been developed using the intrinsic properties of particular nanoparticles. The use of longer-wavelength excitation sources allows deeper penetration into the human body for disease diagnostics and at the same time reduces the adverse effects on normal tissues. Furthermore, multimodal imaging techniques have been achieved by combining several types of components in nanoparticles, offering higher accuracy and better spatial views, with the aim of detecting life

  10. Engineered Hybrid Nanoparticles for On-Demand Diagnostics and Therapeutics.

    Science.gov (United States)

    Nguyen, Kim Truc; Zhao, Yanli

    2015-12-15

    Together with the simultaneous development of nanomaterials and molecular biology, the bionano interface brings about various applications of hybrid nanoparticles in nanomedicine. The hybrid nanoparticles not only present properties of the individual components but also show synergistic effects for specialized applications. Thus, the development of advanced hybrid nanoparticles for targeted and on-demand diagnostics and therapeutics of diseases has rapidly become a hot research topic in nanomedicine. The research focus is to fabricate novel classes of programmable hybrid nanoparticles that are precisely engineered to maximize drug concentrations in diseased cells, leading to enhanced efficacy and reduced side effects of chemotherapy for the disease treatment. In particular, the hybrid nanoparticle platforms can simultaneously target diseased cells, enable the location to be imaged by optical methods, and release therapeutic drugs to the diseased cells by command. This Account specially discusses the rational fabrication of integrated hybrid nanoparticles and their applications in diagnostics and therapeutics. For diagnostics applications, hybrid nanoparticles can be utilized as imaging agents that enable detailed visualization at the molecular level. By the use of suitable targeting ligands incorporated on the nanoparticles, targeted optical imaging may be feasible with improved performance. Novel imaging techniques such as multiphoton excitation and photoacoustic imaging using near-infrared light have been developed using the intrinsic properties of particular nanoparticles. The use of longer-wavelength excitation sources allows deeper penetration into the human body for disease diagnostics and at the same time reduces the adverse effects on normal tissues. Furthermore, multimodal imaging techniques have been achieved by combining several types of components in nanoparticles, offering higher accuracy and better spatial views, with the aim of detecting life

  11. Job demands, health perception and sickness absence

    NARCIS (Netherlands)

    Roelen, C.A.; Koopmans, P.C.; de Graaf, J.H.; van Zandbergen, J.W.; Groothoff, J.W.

    2007-01-01

    Background Investigation of the relations between job demands, health and sickness absence is required to design a strategy for the prevention of absence and disability. Aim To study the relationships between (physical and psychological) job demands, health perception and sickness absence. Methods P

  12. Information management - Assessing the demand for information

    Science.gov (United States)

    Rogers, William H.

    1991-01-01

    Information demand is defined in terms of both information content (what information) and form (when, how, and where it is needed). Providing the information richness required for flight crews to be informed without overwhelming their information processing capabilities will require a great deal of automated intelligence. It is seen that the essence of this intelligence is comprehending and capturing the demand for information.

  13. Simple utility functions with Giffen demand

    DEFF Research Database (Denmark)

    Sørensen, Peter Norman

    2007-01-01

    Simple utility functions with the Giffen property are presented: locally, the demand curve for a good is upward sloping. The utility functions represent continuous, monotone, convex preferences......Simple utility functions with the Giffen property are presented: locally, the demand curve for a good is upward sloping. The utility functions represent continuous, monotone, convex preferences...

  14. Intermittent demand : Linking forecasting to inventory obsolescence

    NARCIS (Netherlands)

    Teunter, Ruud H.; Syntetos, Aris A.; Babai, M. Zied

    2011-01-01

    The standard method to forecast intermittent demand is that by Croston. This method is available in ERP-type solutions such as SAP and specialised forecasting software packages (e.g. Forecast Pro), and often applied in practice. It uses exponential smoothing to separately update the estimated demand

  15. The demand for currency in Malta

    OpenAIRE

    Grech, Aaron George

    2014-01-01

    This article studies the demand for one particular component of the money stock, currency, in Malta in the light of the existing theoretical and empirical framework. In particular, it argues that the commonly applied analytical framework needs to be tweaked slightly for it to better explain the reasons underpinning the relatively high currency demand in Malta compared with other euro area countries.

  16. Technology in the Differential Input Demand Model

    OpenAIRE

    Brown, Mark G.; Lee, Jonq-Ying

    2003-01-01

    This study considers incorporating changes in technology in the differential input demand system through effects on output and input marginal products. The effects of technology on input demand are related to Slutsky coefficients and input shares of marginal cost. Technology effects on marginal-product changes are viewed as price changes, and restrictions on technology are considered.

  17. A Novel Technique to Enhance Demand Responsiveness

    DEFF Research Database (Denmark)

    Farashbashi-Astaneh, Seyed-Mostafa; Bhattarai, Bishnu Prasad; Bak-Jensen, Birgitte;

    2015-01-01

    In this study, a new pricing approach is proposed to increase demand responsiveness. The proposed approach considers two well-known demand side management techniques, namely peak shaving and valley filling. This is done by incentivising consumers by magnifying price difference between peak and off...

  18. Lighting Systems Control for Demand Response

    NARCIS (Netherlands)

    Husen, S.A.; Pandharipande, A.; Tolhuizen, L.M.G.; Wang, Y.; Zhao, M.

    2012-01-01

    Lighting is a major part of energy consumption in buildings. Lighting systems will thus be one of the important component systems of a smart grid for dynamic load management services like demand response.In the scenario considered in this paper, under a demand response request, lighting systems in a

  19. Energy infrastructure: Mapping future electricity demand

    Science.gov (United States)

    Janetos, Anthony C.

    2016-08-01

    Electricity distribution system planners rely on estimations of future energy demand to build adequate supply, but these are complicated to achieve. An approach that combines spatially resolved projections of population movement and climate change offers a method for building better demand maps to mid-century.

  20. Teaching Aggregate Demand and Supply Models

    Science.gov (United States)

    Wells, Graeme

    2010-01-01

    The author analyzes the inflation-targeting model that underlies recent textbook expositions of the aggregate demand-aggregate supply approach used in introductory courses in macroeconomics. He shows how numerical simulations of a model with inflation inertia can be used as a tool to help students understand adjustments in response to demand and…

  1. Teaching Aggregate Demand and Supply Models

    OpenAIRE

    Wells, Graeme

    2007-01-01

    This note analyses the inflation-targeting model that underlies recent textbook expositions of the Aggregate Demand-Aggregate Supply approach used in introductory courses in macroeconomics. The paper shows how numerical simulations of a model with inflation inertia can be used as a tool to help students understand adjustments in response to demand and supply shocks of various kinds.

  2. Disaggregation of the demand for hospital care

    NARCIS (Netherlands)

    E.K.A. van Doorslaer (Eddy); R.C.J.A. van Vliet (René)

    1988-01-01

    textabstractIn this article we want to confront some of the results of the theoretical literature on aggregation with the empirical consequences of aggregation in the context of the analysis of demand for hospital care. There has been an evolution in the estimation of hospital demand functions from

  3. Biological Oceanography

    Science.gov (United States)

    Abbott, M. R.

    1984-01-01

    Within the framework of global biogeochemical cycles and ocean productivity, there are two areas that will be of particular interest to biological oceanography in the 1990s. The first is the mapping in space time of the biomass and productivity of phytoplankton in the world ocean. The second area is the coupling of biological and physical processes as it affects the distribution and growth rate of phytoplankton biomass. Certainly other areas will be of interest to biological oceanographers, but these two areas are amenable to observations from satellites. Temporal and spatial variability is a regular feature of marine ecosystems. The temporal and spatial variability of phytoplankton biomass and productivity which is ubiquitous at all time and space scales in the ocean must be characterized. Remote sensing from satellites addresses these problems with global observations of mesocale (2 to 20 days, 10 to 200 km) features over a long period of time.

  4. Uranium 2009 resources, production and demand

    CERN Document Server

    Organisation for Economic Cooperation and Development. Paris

    2010-01-01

    With several countries currently building nuclear power plants and planning the construction of more to meet long-term increases in electricity demand, uranium resources, production and demand remain topics of notable interest. In response to the projected growth in demand for uranium and declining inventories, the uranium industry – the first critical link in the fuel supply chain for nuclear reactors – is boosting production and developing plans for further increases in the near future. Strong market conditions will, however, be necessary to trigger the investments required to meet projected demand. The "Red Book", jointly prepared by the OECD Nuclear Energy Agency and the International Atomic Energy Agency, is a recognised world reference on uranium. It is based on information compiled in 40 countries, including those that are major producers and consumers of uranium. This 23rd edition provides a comprehensive review of world uranium supply and demand as of 1 January 2009, as well as data on global ur...

  5. Communication technologies for demand side management

    Energy Technology Data Exchange (ETDEWEB)

    Uuspaeae, P. [VTT Energy, Espoo (Finland)

    1998-08-01

    The scope of this research is data communications for electric utilities, specifically for the purposes of Demand Side Management (DSM). Demand Side Management has the objective to change the customer`s end use of energy in a manner that benefits both the customer and the utility. For example, peak demand may be reduced, and the peak demand may be relocated to off peak periods. Thus additional investments in generation and network may be avoided. A number of Demand Side Management functions can be implemented if a communication system is available between the Electric Utility and the Customer. The total communication capacity that is needed, will depend on several factors, such as the functions that are chosen for DSM, and on the number and type of customers. Some functions may be handled with one-way communications, while some other functions need to have two-way communication

  6. Demand flexibility from residential heat pump

    DEFF Research Database (Denmark)

    Bhattarai, Bishnu Prasad; Bak-Jensen, Birgitte; Pillai, Jayakrishnan Radhakrishna;

    2014-01-01

    Demand response (DR) is considered as a potentially effective tool to compensate generation intermittency imposed by renewable sources. Further, DR can instigate to offer optimum asset utilization and to avoid or delay the need for new infrastructure investment. Being a sizable load together...... with high thermal time constant, heat pumps (HP) can offer a great deal of flexibility in the future intelligent grids especially to compensate fluctuating generation. However, the HP flexibility is highly dependent on thermal demand profile, namely hot water and space heating demand. This paper proposes...... price based scheduling followed by a demand dispatch based central control and a local voltage based adaptive control, to realize HP demand flexibility. Two-step control architecture, namely local primary control encompassed by the central coordinative control, is proposed to implement...

  7. Competition with supply and demand functions

    International Nuclear Information System (INIS)

    If economic agents have to determine in advance their supply or demand in reaction to different market prices we may assume that their strategic instruments are supply or demand functions. The best examples for such markets are the spot markets for electricity in England and Wales, in Chile, in New Zealand, in Scandinavia and perhaps elsewhere. A further example is computerized trading in stock markets, financial markets, or commodity exchanges. The functional form of equilibria is explicitly determined in this paper. Under a certain condition, equilibria exist for every finite spread of (stochastic) autonomous demand, i.e. demand from small, non-strategically acting consumers. Contrary to competition with supply functions alone, however, there is no tendency for market prices to converge to 0 if the spread of autonomous demand increases infinitely. Lower bounds of market prices can be computed instead

  8. Dissolved-oxygen regime of the Jordan River, Salt Lake County, Utah

    Science.gov (United States)

    Stephens, D.W.

    1984-01-01

    Concentrations of dissolved oxygen in the Jordan River in Salt Lake County decrease considerably as the river flows northward. Mean concentrations of dissolved oxygen decreased from 8.1 milligrams per liter at the Jordan Narrows to 4.7 milligrams per liter at 500 North Street during April 1981 to September 1982. Coincident with the decrease, the biochemical-oxygen demand increased from 5 to 7 milligrams per liter. About 50 percent of the dissolved-oxygen concentrations and 90 percent of the 5-day biochemical-oxygen demand measured downstream from 1700 South Street exceeded the State intended-use standards. An estimated 6. million pounds of oxygen-demanding substances as measured by 5-day biochemical-oxygen demand were discharged to the Jordan River during 1981 from point sources downstream from 9000 South Street. Seven wastewater-treatment plants contributed 77 percent of this load, nonstorm base flows contributed 22 percent, and storm flows less than 1 percent. The Surplus Canal diversion at 2100 South Street removed about 70 percent of this load, and travel time of about 1 day also decreased the actual effects of the load on the river. Reaeration rates during September and October were quite high (average K2 at 20 degrees Celsius was about 12 per day) between the Jordan Narrows and 9000 South Street, but they decreased to 2.4 per day in the reach from 1330 South to 1800 North Streets. (USGS)

  9. Hyperbaric oxygen and radiotherapy

    International Nuclear Information System (INIS)

    Background: Hyperbaric oxygen (HBO) therapy is the inhalation of 100% oxygen at a pressure of at least 1.5 atmospheres absolute (150 kPa). It uses oxygen as a drug by dissolving it in the plasma and delivering it to the tissues independent of hemoglobin. For a variety of organ systems, HBO is known to promote new vessel growth into areas with reduced oxygen tension due to poor vascularity, and therewith promotes wound healing and recovery of radiation-injured tissue. Furthermore, tumors may be sensitized to irradiation by raising intratumoral oxygen tensions. Methods: A network of hyperbaric facilities exists in Europe, and a number of clinical studies are ongoing. The intergovernmental framework COST B14 action 'Hyperbaric Oxygen Therapy' started in 1999. The main goal of the Working Group Oncology is preparation and actual implementation of prospective study protocols in the field of HBO and radiation oncology in Europe. Results: In this paper a short overview on HBO is given and the following randomized clinical studies are presented: (a) reirradiation of recurrent squamous cell carcinoma of the head and neck after HBO sensitization; (b) role of HBO in enhancing radiosensitivity on glioblastoma multiforme; (c) osseointegration in irradiated patients; adjunctive HBO to prevent implant failures; (d) the role of HBO in the treatment of late irradiation sequelae in the pelvic region. The two radiosensitization protocols (a, b) allow a time interval between HBO and subsequent irradiation of 10-20 min. Conclusion: Recruitment of centers and patients is being strongly encouraged, detailed information is given on www.oxynet.org. (orig.)

  10. Hyperbaric oxygen and radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Mayer, R. [Medical Univ. of Graz (Austria). Dept. of Radiation; Hamilton-Farrell, M.R. [Whipps Cross Hospital, Leytonstone, London (United Kingdom). Hyperbaric Unit; Kleij, A.J. van der [Academic Medical Center, Amsterdam (NL). Dept. of Surgery] [and others

    2005-02-01

    Background: Hyperbaric oxygen (HBO) therapy is the inhalation of 100% oxygen at a pressure of at least 1.5 atmospheres absolute (150 kPa). It uses oxygen as a drug by dissolving it in the plasma and delivering it to the tissues independent of hemoglobin. For a variety of organ systems, HBO is known to promote new vessel growth into areas with reduced oxygen tension due to poor vascularity, and therewith promotes wound healing and recovery of radiation-injured tissue. Furthermore, tumors may be sensitized to irradiation by raising intratumoral oxygen tensions. Methods: A network of hyperbaric facilities exists in Europe, and a number of clinical studies are ongoing. The intergovernmental framework COST B14 action 'Hyperbaric Oxygen Therapy' started in 1999. The main goal of the Working Group Oncology is preparation and actual implementation of prospective study protocols in the field of HBO and radiation oncology in Europe. Results: In this paper a short overview on HBO is given and the following randomized clinical studies are presented: (a) reirradiation of recurrent squamous cell carcinoma of the head and neck after HBO sensitization; (b) role of HBO in enhancing radiosensitivity on glioblastoma multiforme; (c) osseointegration in irradiated patients; adjunctive HBO to prevent implant failures; (d) the role of HBO in the treatment of late irradiation sequelae in the pelvic region. The two radiosensitization protocols (a, b) allow a time interval between HBO and subsequent irradiation of 10-20 min. Conclusion: Recruitment of centers and patients is being strongly encouraged, detailed information is given on www.oxynet.org. (orig.)

  11. Strategies for Demand Response in Commercial Buildings

    Energy Technology Data Exchange (ETDEWEB)

    Watson, David S.; Kiliccote, Sila; Motegi, Naoya; Piette, Mary Ann

    2006-06-20

    This paper describes strategies that can be used in commercial buildings to temporarily reduce electric load in response to electric grid emergencies in which supplies are limited or in response to high prices that would be incurred if these strategies were not employed. The demand response strategies discussed herein are based on the results of three years of automated demand response field tests in which 28 commercial facilities with an occupied area totaling over 11 million ft{sup 2} were tested. Although the demand response events in the field tests were initiated remotely and performed automatically, the strategies used could also be initiated by on-site building operators and performed manually, if desired. While energy efficiency measures can be used during normal building operations, demand response measures are transient; they are employed to produce a temporary reduction in demand. Demand response strategies achieve reductions in electric demand by temporarily reducing the level of service in facilities. Heating ventilating and air conditioning (HVAC) and lighting are the systems most commonly adjusted for demand response in commercial buildings. The goal of demand response strategies is to meet the electric shed savings targets while minimizing any negative impacts on the occupants of the buildings or the processes that they perform. Occupant complaints were minimal in the field tests. In some cases, ''reductions'' in service level actually improved occupant comfort or productivity. In other cases, permanent improvements in efficiency were discovered through the planning and implementation of ''temporary'' demand response strategies. The DR strategies that are available to a given facility are based on factors such as the type of HVAC, lighting and energy management and control systems (EMCS) installed at the site.

  12. Coordination of Energy Efficiency and Demand Response

    Energy Technology Data Exchange (ETDEWEB)

    Goldman, Charles; Reid, Michael; Levy, Roger; Silverstein, Alison

    2010-01-29

    This paper reviews the relationship between energy efficiency and demand response and discusses approaches and barriers to coordinating energy efficiency and demand response. The paper is intended to support the 10 implementation goals of the National Action Plan for Energy Efficiency's Vision to achieve all cost-effective energy efficiency by 2025. Improving energy efficiency in our homes, businesses, schools, governments, and industries - which consume more than 70 percent of the nation's natural gas and electricity - is one of the most constructive, cost-effective ways to address the challenges of high energy prices, energy security and independence, air pollution, and global climate change. While energy efficiency is an increasingly prominent component of efforts to supply affordable, reliable, secure, and clean electric power, demand response is becoming a valuable tool in utility and regional resource plans. The Federal Energy Regulatory Commission (FERC) estimated the contribution from existing U.S. demand response resources at about 41,000 megawatts (MW), about 5.8 percent of 2008 summer peak demand (FERC, 2008). Moreover, FERC recently estimated nationwide achievable demand response potential at 138,000 MW (14 percent of peak demand) by 2019 (FERC, 2009).2 A recent Electric Power Research Institute study estimates that 'the combination of demand response and energy efficiency programs has the potential to reduce non-coincident summer peak demand by 157 GW' by 2030, or 14-20 percent below projected levels (EPRI, 2009a). This paper supports the Action Plan's effort to coordinate energy efficiency and demand response programs to maximize value to customers. For information on the full suite of policy and programmatic options for removing barriers to energy efficiency, see the Vision for 2025 and the various other Action Plan papers and guides available at www.epa.gov/eeactionplan.

  13. Brain magnetic resonance imaging with contrast dependent on blood oxygenation

    Energy Technology Data Exchange (ETDEWEB)

    Ogawa, S.; Lee, T.M.; Kay, A.R.; Tank, D.W. (AT and T Bell Laboratories, Murray Hill, NJ (United States))

    1990-12-01

    Paramagnetic deoxyhemoglobin in venous blood is a naturally occurring contrast agent for magnetic resonance imaging (MRI). By accentuating the effects of this agent through the use of gradient-echo techniques in high yields, the authors demonstrate in vivo images of brain microvasculature with image contrast reflecting the blood oxygen level. This blood oxygenation level-dependent (BOLD) contrast follows blood oxygen changes induced by anesthetics, by insulin-induced hypoglycemia, and by inhaled gas mixtures that alter metabolic demand or blood flow. The results suggest that BOLD contrast can be used to provide in vivo real-time maps of blood oxygenation in the brain under normal physiological conditions. BOLD contrast adds an additional feature to magnetic resonance imaging and complement other techniques that are attempting to provide position emission tomography-like measurements related to regional neural activity.

  14. Quantifying consumption rates of dissolved oxygen along bed forms

    Science.gov (United States)

    Boano, Fulvio; De Falco, Natalie; Arnon, Shai

    2016-04-01

    Streambed interfaces represent hotspots for nutrient transformations because they host different microbial species, and the evaluation of these reaction rates is important to assess the fate of nutrients in riverine environments. In this work we analyze a series of flume experiments on oxygen demand in dune-shaped hyporheic sediments under losing and gaining flow conditions. We employ a new modeling code to quantify oxygen consumption rates from observed vertical profiles of oxygen concentration. The code accounts for transport by molecular diffusion and water advection, and automatically determines the reaction rates that provide the best fit between observed and modeled concentration values. The results show that reaction rates are not uniformly distributed across the streambed, in agreement with the expected behavior predicted by hyporheic exchange theory. Oxygen consumption was found to be highly influenced by the presence of gaining or losing flow conditions, which controlled the delivery of labile DOC to streambed microorganisms.

  15. Brain magnetic resonance imaging with contrast dependent on blood oxygenation

    International Nuclear Information System (INIS)

    Paramagnetic deoxyhemoglobin in venous blood is a naturally occurring contrast agent for magnetic resonance imaging (MRI). By accentuating the effects of this agent through the use of gradient-echo techniques in high yields, the authors demonstrate in vivo images of brain microvasculature with image contrast reflecting the blood oxygen level. This blood oxygenation level-dependent (BOLD) contrast follows blood oxygen changes induced by anesthetics, by insulin-induced hypoglycemia, and by inhaled gas mixtures that alter metabolic demand or blood flow. The results suggest that BOLD contrast can be used to provide in vivo real-time maps of blood oxygenation in the brain under normal physiological conditions. BOLD contrast adds an additional feature to magnetic resonance imaging and complement other techniques that are attempting to provide position emission tomography-like measurements related to regional neural activity

  16. Co-evolution of Eukaryotes and Ocean and Atmosphere Oxygenation in the Neoproterozoic and Paleozoic Eras

    Science.gov (United States)

    Lenton, T. M.; Daines, S. J.; Mills, B.; Boyle, R. A.

    2014-12-01

    The nature, timing and cause(s) of the Earth's second oxygenation event are widely debated. It has been argued that there was a single pronounced rise in atmospheric oxygen toward present levels in the Late Neoproterozoic, which in turn triggered the evolution of animals. Here we suggest a more complex co-evolutionary scenario, with fluctuations in ocean and atmosphere oxygenation in the Late Neoproterozoic and Early Paleozoic caused partly by the evolution of animals, followed by a pronounced rise of atmospheric oxygen to present levels later in the Paleozoic caused by the rise of land plants. Current geochemical evidence suggests some parts of the deep oceans became oxygenated during the Ediacaran, but there was subsequent de-oxygenation of the ocean during the Cambrian that may have persisted into the Ordovician. Only later in the Paleozoic is there evidence for widespread oxygenation of the deep ocean, together with charcoal indicating atmospheric oxygen had approached present levels. The limited Neoproterozoic oxygenation of the ocean could be explained by the evolution of filter-feeding sponges removing oxygen demand from the water column and encouraging a shift from cyanobacteria to faster-sinking eukaryotic algae, which transferred oxygen demand to greater depths and into sediments. The resulting oxygenation of shelf bottom waters would have increased phosphorus removal from the ocean thus lowering global productivity and oxygen demand in a positive feedback loop encouraging ocean oxygenation [1]. The subsequent Cambrian de-oxygenation of the ocean could be explained by the evolution of bioturbating animals oxygenating the sediments and thus lowering the C/P burial ratio of organic matter, reducing organic carbon burial and lowering atmospheric oxygen [2]. The later rise of land plants, selectively weathering phosphorus from continental rocks and producing recalcitrant high C/P biomass, increased organic carbon burial and atmospheric oxygen, finally

  17. Oxygen ion conductors

    Directory of Open Access Journals (Sweden)

    Stephen J Skinner

    2003-03-01

    A very interesting subgroup of this class of materials are the oxides that display oxygen ion conductivity. As well as the intrinsic interest in these materials, there has been a continued drive for their development because of the promise of important technological devices such as the solid oxide fuel cell (SOFC, oxygen separation membranes, and membranes for the conversion of methane to syngas1. All of these devices offer the potential of enormous commercial and ecological benefits provided suitable high performance materials can be developed. In this article we will review the materials currently under development for application in such devices with particular reference to some of the newly discovered oxide ion conductors.

  18. The chemical and biological evolution of mature fine tailings in oil sands end-pit lakes

    International Nuclear Information System (INIS)

    This presentation described an innovative bench-scale technique to characterize oil sand tailings and their impact on sediment oxygen demand (SOD) for future end-pit lake model behaviour. SOD is a dominant contributor to oxygen depletion in wetlands. The function and sustainability of a wetland ecosystem depends on the biochemical processes occurring at the sediment-water interface. The biochemical reactions associated with natural sediment can change with the addition of oil sands processed material (OSPM), which can affect SOD and ecosystem viability. It is important to establishing the biotic and abiotic controls of SOD. In order to evaluate the effectiveness of current wetland reclamation designs, it is important to establish the biotic and abiotic controls of SOD. The REDOX chemistry of fresh tailings sediment (MFT) was measured in this laboratory microcosm to determine the chemical and biological influences, and to study the role of developing microbial communities as new mature fine tailings (MFT) age. The study evaluated the changes in the main chemical, physical and biological populations of the MFT in both aerobic and anaerobic microcosms. A combination of microelectrode arrays and DNA profiling at the tailings water interface was used in the study.

  19. Household Demand for Food in Switzerland. A Quadratic Almost Ideal Demand System

    OpenAIRE

    Awudu Abdulai

    2002-01-01

    In this paper we estimate a complete demand system for Switzerland, with emphasis on food demand, using a recent household expenditure survey. The Quadratic Almost Ideal Demand System (QUAIDS) is employed in the analysis of six food commodity and a non-food groups. The quadratic terms in the QUAIDS were found to be empirically important in describing household budget behaviour in Switzerland. For most food commodity groups, demand is inelastic, with elasticities ranging between -0.64 and -1.0...

  20. Outlook for World Fertilizer Demand, Supply, and Supply/Demand Balance

    OpenAIRE

    HEFFER, Patrick; Prud'Homme, Michel

    2008-01-01

    The outlook is driven by impressive economic growth in Asia, increasing demand for biofuel, and a tight grain market. As a result of tight supply/demand conditions, prices for almost all agricultural commodities are unusually high. The need to boost agricultural production worldwide is stimulating fertilizer consumption in Asia and the Americas, driving global demand to new record levels. For the production of most nutrients 2007 was a record year, as buoyant demand stretched the industry&apo...