Sample records for biological oxygen demand

  1. Biological oxygen demand optode analysis of coral reef-associated microbial communities exposed to algal exudates

    NARCIS (Netherlands)

    Gregg, A.K.; Hatay, M.; Haas, A.F.; Robinett, N.L.; Barott, K.; Vermeij, M.J.A.; Marhaver, K.; Thompson, F.; Meirelles, P.; Rohwer, F.


    Algae-derived dissolved organic matter has been hypothesized to induce mortality of reef building corals. One proposed killing mechanism is a zone of hypoxia created by rapidly growing microbes. To investigate this hypothesis, biological oxygen demand (BOD) optodes were used to quantify the change i

  2. Biological oxygen demand optode analysis of coral reef-associated microbial communities exposed to algal exudates

    Directory of Open Access Journals (Sweden)

    AK Gregg


    Full Text Available Algae-derived dissolved organic matter has been hypothesized to induce mortality of reef building corals. One proposed killing mechanism is a zone of hypoxia created by rapidly growing microbes. To investigate this hypothesis, biological oxygen demand (BOD optodes were used to quantify the change in oxygen concentrations of microbial communities following exposure to exudates generated by turf algae and crustose coralline algae (CCA. BOD optodes were embedded with microbial communities cultured from Montastraea annularis and Mussismilia hispida, and respiration was measured during exposure to turf and CCA exudates. The oxygen concentrations along the optodes were visualized with a low-cost Submersible Oxygen Optode Recorder (SOOpR system. With this system we observed that exposure to exudates derived from turf algae stimulated higher oxygen drawdown by the coral-associated bacteria than CCA exudates or seawater controls. Furthermore, in both turf and CCA exudate treatments, all microbial communities (coral-, algae-associated and pelagic contributed significantly to the observed oxygen drawdown. This suggests that the driving factor for elevated oxygen consumption rates is the source of exudates rather than the initially introduced microbial community. Our results demonstrate that exudates from turf algae may contribute to hypoxia-induced coral stress in two different coral genera as a result of increased biological oxygen demand of the local microbial community. Additionally, the SOOpR system developed here can be applied to measure the BOD of any culturable microbe or microbial community.

  3. Using gas flux to estimate biological and chemical sediment oxygen demand in oil sands-affected wetlands

    Energy Technology Data Exchange (ETDEWEB)

    Gardner Costa, J.; Slama, C.; Ciborowski, J. [Windsor Univ., ON (Canada)


    The constituents of oil sands process-affected (OSPM) wetlands include high salinity, conductivity and naphthenic acid concentrations. These constituents are expected to strain microbial communities and change methane and carbon dioxide flux rates as well as sediment oxygen consumption compared to fresher, reference wetland sites. Four OSPM and 4 reference wetlands were examined during the summers of 2009 and 2010 to determine if carbon loss in the form of sediment-associated microbial respiration differs between OSPM and reference wetlands. The study showed that OSPM wetlands release about 10 times less methane than reference wetlands. Sediment oxygen demand (SOD) was measured in 2009 and gas flux estimates of carbon dioxide were used to estimate biological sediment oxygen consumption (BSOC). Chemical sediment oxygen demand (CSOD) was estimated by subtracting BSOC from total SOD. SOD rates were found to be two times higher in OSPM wetlands than reference. CSOD was higher than biologically consumed oxygen for both wetland classes. Although microbial activity in OSPM wetlands may be lower, more oxygen is consumed in OSPM than in reference wetlands. The reclamation of boreal wetlands in the Alberta Athabasca region requires carbon accrual. Less microbial activity may promote carbon accumulation within OSPM wetlands. However, the wetland's sediment layer may have less organic input as a result of high chemical oxygen consumption because it limits benthos respiration.

  4. 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.


    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...

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


    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.

  6. Influence of biological oxygen demand degradation patterns on water-quality modeling for rivers running through urban areas. (United States)

    Fan, Chihhao; Wang, Wei-Shen


    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.

  7. Sediment oxygen demand in eastern Kansas streams, 2014 and 2015 (United States)

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


    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.

  8. Methods for assessing biochemical oxygen demand (BOD): a review. (United States)

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


    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.

  9. 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


    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.

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

    Directory of Open Access Journals (Sweden)

    Tri Joko


    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.

  11. Optimization of the determination of chemical oxygen demand in wastewaters. (United States)

    Silva, Alexandra M E Viana da; Silva, Ricardo J N Bettencourt da; Camões, M Filomena G F C


    Chemical oxygen demand (COD) is one of the most relevant chemical parameters for the management of wastewater treatment facilities including the control of the quality of an effluent. The adequacy of decisions based on COD values relies on the quality of the measurements. Cost effective management of the minor sources of uncertainty can be applied to the analytical procedure without affecting measurement quality. This work presents a detailed assessment of the determination of COD values in wastewaters, according to ISO6060:1989 standard, which can support reduction of both measurement uncertainty and cost of analysis. This assessment includes the definition of the measurement traceability chain and the validation of the measurement procedure supported on sound and objective criteria. Detailed models of the measurement performance, including uncertainty, developed from the Differential Approach, were successfully validated by proficiency tests. The assumption of the measurement function linearity of the uncertainty propagation law was tested through the comparison with the numerical Kragten method. The gathered information supported the definition of strategies for measurement uncertainty or cost reduction. The developed models are available as electronic supplementary material, in an MS-Excel file, to be updated with the user's data.

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


    Khaled Zaher Abdallah; Gina Hammam


    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...

  13. 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


    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.

  14. Watershed modeling of dissolved oxygen and biochemical oxygen demand using a hydrological simulation Fortran program. (United States)

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


    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.

  15. Simulation of Temperature, Nutrients, Biochemical Oxygen Demand, and Dissolved Oxygen in the Catawba River, South Carolina, 1996-97 (United States)

    Feaster, Toby D.; Conrads, Paul A.; Guimaraes, Wladmir B.; Sanders, Curtis L.; Bales, Jerad D.


    Time-series plots of dissolved-oxygen concentrations were determined for various simulated hydrologic and point-source loading conditions along a free-flowing section of the Catawba River from Lake Wylie Dam to the headwaters of Fishing Creek Reservoir in South Carolina. The U.S. Geological Survey one-dimensional dynamic-flow model, BRANCH, was used to simulate hydrodynamic data for the Branched Lagrangian Transport Model. Waterquality data were used to calibrate the Branched Lagrangian Transport Model and included concentrations of nutrients, chlorophyll a, and biochemical oxygen demand in water samples collected during two synoptic sampling surveys at 10 sites along the main stem of the Catawba River and at 3 tributaries; and continuous water temperature and dissolved-oxygen concentrations measured at 5 locations along the main stem of the Catawba River. A sensitivity analysis of the simulated dissolved-oxygen concentrations to model coefficients and data inputs indicated that the simulated dissolved-oxygen concentrations were most sensitive to watertemperature boundary data due to the effect of temperature on reaction kinetics and the solubility of dissolved oxygen. Of the model coefficients, the simulated dissolved-oxygen concentration was most sensitive to the biological oxidation rate of nitrite to nitrate. To demonstrate the utility of the Branched Lagrangian Transport Model for the Catawba River, the model was used to simulate several water-quality scenarios to evaluate the effect on the 24-hour mean dissolved-oxygen concentrations at selected sites for August 24, 1996, as simulated during the model calibration period of August 23 27, 1996. The first scenario included three loading conditions of the major effluent discharges along the main stem of the Catawba River (1) current load (as sampled in August 1996); (2) no load (all point-source loads were removed from the main stem of the Catawba River; loads from the main tributaries were not removed); and (3

  16. Southern Ocean biological impacts on global ocean oxygen (United States)

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


    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.

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

    NARCIS (Netherlands)

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


    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


    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...

  19. Determination of Biochemical Oxygen Demand of Area Waters: A Bioassay Procedure for Environmental Monitoring (United States)

    Riehl, Matthew


    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,…

  20. The effect of mayfly (Hexagenia spp.) burrowing activity on sediment oxygen demand in western Lake Erie (United States)

    Edwards, William J.; Soster, Frederick M.; Matisoff, Gerald; Schloesser, Donald W.


    Previous studies support the hypothesis that large numbers of infaunal burrow-irrigating organisms in the western basin of Lake Erie may increase significantly the sediment oxygen demand, thus enhancing the rate of hypolimnetic oxygen depletion. We conducted laboratory experiments to quantify burrow oxygen dynamics and increased oxygen demand resulting from burrow irrigation using two different year classes of Hexagenia spp. nymphs from western Lake Erie during summer, 2006. Using oxygen microelectrodes and hot film anemometry, we simultaneously determined oxygen concentrations and burrow water flow velocities. Burrow oxygen depletion rates ranged from 21.7 mg/nymph/mo for 15 mm nymphs at 23 °C to 240.7 mg/nymph/mo for 23 mm nymphs at 13 °C. Sealed microcosm experiments demonstrated that mayflies increase the rate of oxygen depletion by 2-5 times that of controls, depending on size of nymph and water temperature, with colder waters having greater impact. At natural population densities, nymph pumping activity increased total sediment oxygen demand 0.3-2.5 times compared to sediments with no mayflies and accounted for 22-71% of the total sediment oxygen demand. Extrapolating laboratory results to the natural system suggest that Hexagenia spp. populations may exert a significant control on oxygen depletion during intermittent stratification. This finding may help explain some of the fluctuations in Hexagenia spp. population densities in western Lake Erie and suggests that mayflies, by causing their own population collapse irrespective of other environmental conditions, may need longer term averages when used as a bio-indicator of the success of pollution-abatement programs in western Lake Erie and possibly throughout the Great Lakes.

  1. 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


    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.

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

  3. A New Approach for On-Demand Generation of Various Oxygen Tensions for In Vitro Hypoxia Models.

    Directory of Open Access Journals (Sweden)

    Chunyan Li

    Full Text Available The development of in vitro disease models closely mimicking the functions of human disease has captured increasing attention in recent years. Oxygen tensions and gradients play essential roles in modulating biological systems in both physiologic and pathologic events. Thus, controlling oxygen tension is critical for mimicking physiologically relevant in vivo environments for cell, tissue and organ research. We present a new approach for on-demand generation of various oxygen tensions for in vitro hypoxia models. Proof-of-concept prototypes have been developed for conventional cell culture microplate by immobilizing a novel oxygen-consuming biomaterial on the 3D-printed insert. For the first time, rapid (~3.8 minutes to reach 0.5% O2 from 20.9% O2 and precisely controlled oxygen tensions/gradients (2.68 mmHg per 50 μm distance were generated by exposing the biocompatible biomaterial to the different depth of cell culture media. In addition, changing the position of 3D-printed inserts with immobilized biomaterials relative to the cultured cells resulted in controllable and rapid changes in oxygen tensions (<130 seconds. Compared to the current technologies, our approach allows enhanced spatiotemporal resolution and accuracy of the oxygen tensions. Additionally, it does not interfere with the testing environment while maintaining ease of use. The elegance of oxygen tension manipulation introduced by our new approach will drastically improve control and lower the technological barrier of entry for hypoxia studies. Since the biomaterials can be immobilized in any devices, including microfluidic devices and 3D-printed tissues or organs, it will serve as the basis for a new generation of experimental models previously impossible or very difficult to implement.

  4. Formulations for aircraft and airfield deicing and anti-icing: aquatic toxicity and biochemical oxygen demand (United States)

    Ferguson, Lee; Corsi, Steven R.; Geis, Steven W.; Anderson, Graham; Joback, Kevin; Gold, Harris; Mericas, Dean; Cancilla, Devon A.


    The Airport Cooperative Research Program (ACRP) has sponsored research on environmental characteristics of aircraft and pavement deicers and anti-icers focusing primarily on biochemical oxygen demand (BOD) and aquatic toxicity of formulated products and individual chemical components of formulations. This report presents a background of issues leading to this research, objectives of this document, and a description of the efforts and findings of this research.

  5. Non-steady response of BOD biosensor for the determination of biochemical oxygen demand in wastewater. (United States)

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


    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.

  6. Explorations on Temperature, Oxygen, Nutrients and Habitat Demands of Fish Species Found in River Coruh

    Directory of Open Access Journals (Sweden)

    Bilal Akbulut


    Full Text Available For the protection of our natural resources, fish species being economic and ecological richness of the natural in the basin of the Çoruh to know their request is extremely a vital important issue. In this study, temperature and oxygen demand, food and habitat of 18 fish species in six families found in river Çoruh assessed and discussed with the literature and database. Limiting the impact of water temperature on the reproductive, growth and nutrition emphasized. The fish species in the basin spawn at temperatures between 14-30°C according to database. Three species belonging to a family feed with animal food floating in the water. The species belonging to the other families more feed mixed with plant and animal foods diet in the floor or near the ground. Importance of their environmental demands has clarified for conservation and sustainable use of these fish species inhabiting in Çoruh River.

  7. Sediment Oxygen Demand in Cochin backwaters, a tropical estuarine system in the south-west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Abhilash, K.R.; Raveendran, T.V.; LimnaMol, V.P.; Deepak, M.P.

    Eutrophication has often been one of the major problems encountered in estuaries and coastal waters. The oxic/anoxic status of an estuary can be effectively determined by measurement of the Sediment Oxygen Demand (SOD). An attempt is made...

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

    Energy Technology Data Exchange (ETDEWEB)

    Hadder, G.R.


    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.

  9. Sedimentary microbial oxygen demand for laminar flow over a sediment bed of finite length. (United States)

    Higashino, Makoto; Stefan, Heinz G


    Dead organic material accumulated on the bed of a lake, reservoir or wetland often provides the substrate for substantial microbial activity as well as chemical processes that withdraw dissolved oxygen (DO) from the water column. A model to estimate the actual DO profile and the "sedimentary oxygen demand (SOD)" must specify the rate of microbial or chemical activity in the sediment as well as the diffusive supply of DO from the water column through the diffusive boundary layer into the sediment. Most previous experimental and field studies have considered this problem with the assumptions that the diffusive boundary layer is (a) turbulent and (b) fully developed. These assumptions require that (a) the flow velocity above the sediment bed is fast enough to produce turbulent mixing in the boundary layer, and (b) the sediment bed is long. In this paper a model for laminar flow and SOD over a sediment bed of finite length is presented and the results are compared with those for turbulent flow. Laminar flow near a sediment bed is encountered in quiescent water bodies such as lakes, reservoirs, river backwaters, wetlands and ponds under calm wind conditions. The diffusive oxygen transfer through the laminar diffusive boundary layer above the sediment surface can restrict the microbial or chemical oxygen uptake inside the sediment significantly. The developing laminar diffusive boundary layer above the sediment/water interface is modeled based on the analogy with heat transfer, and DO uptake inside the sediment is modeled by Michaelis-Menten microbial growth kinetics. The model predicts that the rate of SOD at the beginning of the reactive sediment bed is solely dependent on microbial density in the sediment regardless of flow velocity and type. The rate of SOD, and the DO penetration depth into the sediment decrease in stream-wise direction over the length of the sediment bed, as the diffusive boundary layer above the sediment/water interface thickens. With increasing

  10. Demonstration study of biofilm reactor based rapid biochemical oxygen demand determination of surface water

    Directory of Open Access Journals (Sweden)

    Changyu Liu


    Full Text Available Application investigations of rapid biochemical oxygen demand (BOD online analyzer for surface water in Wuxi, China were carried out since 2013. The analyzer adopted a novel working principle, that is, the oxygen concentration of the sample to be tested was regarded as a reference, and the oxygen consumption by the biofilm reactor (BFR was calculated according to the difference between the reference and sample effluent from BFR. The BFR was fabricated via a cultivation process using naturally occurring microbial seeds from in site surface water. This analytical principle was first presented and clearly clarified, and the impact of microbial endogenous respiration to the measured values was also proposed and analyzed. The improved analyzers were equipped in three application sites with significant differences in BOD concentration, for the purpose of evaluating the feasibility and applicability of the proposed method. This study revealed that the online analyzer could continually operate over 30 days without human intervention and additional chemical reagent consumption. The obtained rapid BOD trend line showed that this analyzer could track the fluctuation of the biodegradable organic compound level timely and accurately. The innovative analytical method, as well as the outstanding adaptation and well accuracy rating, provided the highlights for wide applications in the future.

  11. Analysis of nitrogenous and algal oxygen demand in effluent from a system of aerated lagoons followed by polishing pond. (United States)

    Khorsandi, Hassan; Alizadeh, Rahimeh; Tosinejad, Horiyeh; Porghaffar, Hadi


    In this descriptive-analytical study, nitrogenous and algal oxygen demand were assessed for effluent from a system of facultative partially mixed lagoons followed by the polishing pond using 120 grab samples over 1 year. Filtered and non-filtered samples of polishing pond effluent were tested in the presence and absence of a nitrification inhibitor. Effective factors, including 5-day biochemical and chemical oxygen demand (BOD and COD), total suspended solids (TSS), dissolved oxygen, chlorophyll A, and temperature, were measured using standard methods for water and wastewater tests. The results were analyzed using repeated measures analysis of variance with SPSS version 16. Findings show that the annual mean of the total 5-day BOD in the effluent from the polishing pond consisted of 44.92% as the algal carbonaceous biochemical oxygen demand (CBOD), 43.61% as the nitrogenous biochemical oxygen demand (NBOD), and 11.47% as the soluble CBOD. According to this study, the annual mean ratios of algal COD and 5-day algal CBOD to TSS were 0.8 and 0.37, respectively. As the results demonstrate, undertaking quality evaluation of the final effluent from the lagoons without considering nitrogenous and algal oxygen demand would undermine effluent quality assessment and interpretation of the performance of the wastewater treatment plant.

  12. 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. (United States)

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


    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.

  13. 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


    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.

  14. A modified method for estimation of chemical oxygen demand for samples having high suspended solids. (United States)

    Yadvika; Yadav, Asheesh Kumar; Sreekrishnan, T R; Satya, Santosh; Kohli, Sangeeta


    Determination of chemical oxygen demand (COD) of samples having high suspended solids concentration such as cattle dung slurry with open reflux method of APHA-AWWA-WPCF did not give consistent results. This study presents a modification of the open reflux method (APHA-AWWA-WPCF) to make it suitable for samples with high percentage of suspended solids. The new method is based on a different technique of sample preparation, modified quantities of reagents and higher reflux time as compared to the existing open reflux method. For samples having solids contents of 14.0 g/l or higher, the modified method was found to give higher value of COD with much higher consistency and accuracy as compared to the existing open reflux method.

  15. 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


    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.

  16. Total, chemical, and biological oxygen consumption of the sediments in the Ziya River watershed, China. (United States)

    Rong, Nan; Shan, Baoqing


    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.

  17. Oxygen demand of aircraft and airfield pavement deicers and alternative freezing point depressants (United States)

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


    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.

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

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


    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.

  19. Peroxone mineralization of chemical oxygen demand for direct potable water reuse: Kinetics and process control. (United States)

    Wu, Tingting; Englehardt, James D


    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.

  20. Protozoan biomass relation to nutrient and chemical oxygen demand removal in activated sludge mixed liquor. (United States)

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


    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.

  1. Sediment oxygen demand in the Tualatin River basin, Oregon, 1992-96 (United States)

    Rounds, Stewart; Doyle, M.C.


    Sediment oxygen demand (SOD) rates were measured by U.S. Geological Survey (USGS) personnel at 20 stream sites in the Tualatin River Basin from 1992 through 1996 as part of an investigation into the sources and sinks of dissolved oxygen in the Tualatin River. During the low-flow summer periods of 1992 through 1994, 97 measurements were collected at 9 sites on the main stem of the river between river miles (RMs) 5.5 and 43.2. During the low-flow summer periods of 1995 and 1996, 28 measurements of SOD were collected at 11 sites on 8 tributaries of the Tualatin River. All SOD rates were measured with in-situ benthic chambers designed to monitor the loss of dissolved oxygen in a known volume of water circulating above a known area of minimally disturbed stream sediment. For main-stem Tualatin River sites, the observed SOD rate ranged from 0.6 to 4.4 grams of oxygen per square meter per day (g/m 2 d) with a median of 2.3 g/m 2 d. In the tributaries, the measured SOD rate ranged from 0.2 to 10.9 with a median of 3.6 g/m 2 d. These rates are in the range of those reported for other sites in Oregon and across the United States. Most of the variation in the measured SOD rates was likely due to heterogeneities in the bed sediment. Statistical comparisons show that the rates measured at the tributary sites are significantly larger than those measured in the main stem. Within the main stem, the rates measured at sites in the meander reach of the river were not significantly different from those measured in the reservoir reach. Similarly, no difference was found when the sites affected by the cycle of phytoplankton bloom and die-off were compared to those unaffected by phytoplankton. Only one site on the main stem, RM 5.5, was found to have an SOD rate that was significantly higher than that found at the other main-stem sites. Algal detritus may contribute to the elevated rate at that site, but other factors such as the rate of sediment accumulation could also account for the

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

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


    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.

  3. 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)



    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.

  4. A portable photoelectrochemical probe for rapid determination of chemical oxygen demand in wastewaters. (United States)

    Zhang, Shanqing; Li, Lihong; Zhao, Huijun


    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.

  5. Electrochemical treatment of rice grain-based distillery effluent: chemical oxygen demand and colour removal. (United States)

    Prajapati, Abhinesh Kumar; Chaudhari, Parmesh Kumar


    The electrochemical (EC) treatment of rice grain-based distillery wastewater was carried out in a 1.5 dm3 electrolytic batch reactor using aluminium plate electrodes. With the four-plate configurations, a current density (j) of 89.3 A/m2 and pH 8 was found to be optimal, obtaining a maximum chemical oxygen demand (COD) and colour removal of 93% and 87%, respectively. The chemical dissolution of aluminium was strongly influenced by initial pH (pHi). At higher pHi (pH 9.5) anode consumption decreased while energy consumption increased. At the optimal current density 89.3 A/m2, the aluminium electrode consumption was 16.855 g/dm3 wastewater and energy consumption was 31.4 Wh/dm3 achieving a maximum COD removal of 87%. The settling and filterability characteristics ofelectrochemically treated sludge were also analysed at different pH. It was noted that treated slurry at pHi 9.5 gave best settling characteristic, which decreased with increase in pH. EC-treated effluent at pHi 8 had provided best filterability. Characteristics of scum and residues are also analysed at different pH.

  6. Removal of chemical oxygen demand from textile wastewater using a natural coagulant

    Energy Technology Data Exchange (ETDEWEB)

    Ramavandi, Bahman [Bushehr University of Medical Sciences, Bushehr (Iran, Islamic Republic of); Farjadfard, Sima [Islamic Azad University, Tehran (Iran, Islamic Republic of)


    A biomaterial was successfully synthesized from Plantago ovata by using an FeCl{sub 3}-induced crude extract (FCE). The potential of FCE to act as a natural coagulant was tested for the pretreatment of real textile wastewater. Tests were performed to evaluate the effects of FCE quantity, salt concentration, and wastewater pH on chemical oxygen demand (COD) reduction during a coagulation/flocculation process. Experimental results indicated that the wastewater could be effectively treated by using a coagulation/flocculation process, where the BOD{sub 5}/COD ratio of the effluent was improved to 0.48. A low coagulant dose, 1.5mg/L, achieved a high COD removal percentage, 89%, at operational conditions of neutral pH and room temperature. The experimental data revealed that the maximum COD removal occurred at water pH<8. Increasing the salt promoted the COD removal. The settling and filterability characteristics of the sludge were also studied. Scanning electron microscopy and energy dispersive spectroscopy studies were conducted to determine the sludge structure and composition, respectively. Overall, FCE as an eco-friendly biomaterial was revealed to be a very efficient coagulant and a promising option for the removal of COD from wastewaters.

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

    Directory of Open Access Journals (Sweden)

    Jihyun Kwak


    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.

  8. Development and characterization of microbial biosensors for evaluating low biochemical oxygen demand in rivers. (United States)

    Chee, Gab-Joo


    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.

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

    Institute of Scientific and Technical Information of China (English)



    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.

  10. 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


    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.

  11. 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


    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.

  12. Chemometrics-assisted spectrophotometry method for the determination of chemical oxygen demand in pulping effluent. (United States)

    Chen, Honglei; Chen, Yuancai; Zhan, Huaiyu; Fu, Shiyu


    A new method has been developed for the determination of chemical oxygen demand (COD) in pulping effluent using chemometrics-assisted spectrophotometry. Two calibration models were established by inducing UV-visible spectroscopy (model 1) and derivative spectroscopy (model 2), combined with the chemometrics software Smica-P. Correlation coefficients of the two models are 0.9954 (model 1) and 0.9963 (model 2) when COD of samples is in the range of 0 to 405 mg/L. Sensitivities of the two models are 0.0061 (model 1) and 0.0056 (model 2) and method detection limits are 2.02-2.45 mg/L (model 1) and 2.13-2.51 mg/L (model 2). Validation experiment showed that the average standard deviation of model 2 was 1.11 and that of model 1 was 1.54. Similarly, average relative error of model 2 (4.25%) was lower than model 1 (5.00%), which indicated that the predictability of model 2 was better than that of model 1. Chemometrics-assisted spectrophotometry method did not need chemical reagents and digestion which were required in the conventional methods, and the testing time of the new method was significantly shorter than the conventional ones. The proposed method can be used to measure COD in pulping effluent as an environmentally friendly approach with satisfactory results.

  13. Determination of Sediment Oxygen Demand in the Ziya River Watershed, China: Based on Laboratory Core Incubation and Microelectrode Measurements. (United States)

    Rong, Nan; Shan, Baoqing; Wang, Chao


    A study coupling sedimentcore incubation and microelectrode measurement was performed to explore the sediment oxygen demand (SOD) at 16 stations in the Ziya River Watershed, a severely polluted and anoxic river system in the north of China. Total oxygen flux values in the range 0.19-1.41 g/(m²·d) with an average of 0.62 g/(m²·d) were obtained by core incubations, and diffusive oxygen flux values in the range 0.15-1.38 g/(m²·d) with an average of 0.51 g/(m²·d) were determined by microelectrodes. Total oxygen flux obviously correlated with diffusive oxygen flux (R² = 0.842). The microelectrode method produced smaller results than the incubation method in 15 of 16 sites, and the diffusive oxygen flux was smaller than the total oxygen flux. Although the two sets of SOD values had significant difference accepted by the two methods via the Wilcoxon signed-rank test (p Watershed when the dissolved oxygen (DO) recovered in the overlying water.

  14. On-Demand Targeting: Investigating Biology with Proximity-Directed Chemistry. (United States)

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


    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.

  15. Enhanced response of microbial fuel cell using sulfonated poly ether ether ketone membrane as a biochemical oxygen demand sensor. (United States)

    Ayyaru, Sivasankaran; Dharmalingam, Sangeetha


    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.

  16. Stackable Miniature Fuel Cells with On-Demand Fuel and Oxygen Supply


    Hur, Janet


    This dissertation summarizes our progress towards miniature fuel cells that could replace and outperform small batteries to meet various power demands. With increasing need of power being critical for portable electronics, the demand for better batteries continues to grow. Lithium-ion batteries dominate the market at the moment, but the current capacities on the order of 200 Wh/kg are approaching their inherent limits. Many researchers have being pursuing alternative power sources, forming a ...

  17. Characterization of water quality and simulation of temperature, nutrients, biochemical oxygen demand, and dissolved oxygen in the Wateree River, South Carolina, 1996-98 (United States)

    Feaster, Toby D.; Conrads, Paul A.


    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

  18. 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: [Xavier University of Louisiana, Department of Chemistry, 1 Drexel Drive, New Orleans, LA 70125 (United States)


    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)

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

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


    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.

  20. 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:


    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.

  1. 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)


    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

  2. Quantum dots assisted photocatalysis for the chemiluminometric determination of chemical oxygen demand using a single interface flow system

    Energy Technology Data Exchange (ETDEWEB)

    Silvestre, Cristina I.C.; Frigerio, Christian [Requimte, Department of Chemistry, Faculty of Pharmacy, Porto University, Rua Anibal Cunha 164, 4099-030, Porto (Portugal); Santos, Joao L.M., E-mail: [Requimte, Department of Chemistry, Faculty of Pharmacy, Porto University, Rua Anibal Cunha 164, 4099-030, Porto (Portugal); Lima, Jose L.F.C. [Requimte, Department of Chemistry, Faculty of Pharmacy, Porto University, Rua Anibal Cunha 164, 4099-030, Porto (Portugal)


    Highlights: {yields} A novel flow method for the determination of chemical oxygen demand is proposed. {yields} CdTe nanocrystals are irradiated with UV light to generate strong oxidizing species. {yields} Reactive species promote a fast catalytic degradation of organic matter. {yields} Luminol is used as a chemiluminescence probe for indirect COD assessment. {yields} A single interface flow system was implemented to automate the assays. - Abstract: A novel flow method for the determination of chemical oxygen demand (COD) is proposed in this work. It relies on the combination of a fully automated single interface flow system, an on-line UV photocatalytic unit and quantum dot (QD) nanotechnology. The developed approach takes advantage of CdTe nanocrystals capacity to generate strong oxidizing species upon irradiation with UV light, which fostered a fast catalytic degradation of the organic compounds. Luminol was used as a chemiluminescence (CL) probe for indirect COD assessment, since it is easily oxidized by the QD generated species yielding a strong CL emission that is quenched in the presence of the organic matter. The proposed methodology allowed the determination of COD concentrations between 1 and 35 mg L{sup -1}, with good precision (R.S.D. < 1.1%, n = 3) and a sampling frequency of about 33 h{sup -1}. The procedure was applied to the determination of COD in wastewater certified reference materials and the obtained results showed an excellent agreement with the certified values.

  3. Luminescence spectroscopy of singlet oxygen enables monitoring of oxygen consumption in biological systems consisting of fatty acids. (United States)

    Gollmer, Anita; Regensburger, Johannes; Maisch, Tim; Bäumler, Wolfgang


    The interaction of singlet oxygen ((1)O2) generated in a photosensitized process with well-known reference photosensitizers Perinaphthenone (PN) and TMPyP is investigated in a model system consisting of fatty acids and the respective exogenous photosensitizer (PS) in solution by direct detection of the luminescence photons of (1)O2 at 1270 nm. Such a model system is a first approach to mimic the complex environment of (1)O2 in a biological cell which consists mainly of water, proteins, sugars and lipids. Firstly, the important issue of oxygen consumption is evaluated which has to be considered during luminescence detection of (1)O2. It is known that the luminescence signal of (1)O2 is dependent on the oxygen concentration of the environment. Cellular components such as lipids represent oxygen consumers due to peroxidation of their unsaturated double bonds. Secondly, the experimental conditions for this model system regarding oxygen consumption are optimized to estimate the rates and rate constants of the coupled system. Thirdly, the triplet decay of the PS can provide more precise information about the actual oxygen concentration close to the PS and can be used, therefore, as a more precise method to determine the oxygen concentration in more complex systems such as a biological cell. The aim is to get a better understanding of photosensitized reactions of (1)O2 with cellular components to further improve methodologies, in particular at a cellular level using luminescence spectroscopy. In conclusion, luminescence detection might be a helpful tool to monitor precisely and promptly changes in oxygen concentration in a complex environment.

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

    Directory of Open Access Journals (Sweden)

    Pierre Asselin, MS


    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.

  5. Chromium (VI) biosorption and removal of chemical oxygen demand by Spirulina platensis from wastewater-supplemented culture medium. (United States)

    Magro, Clinei D; Deon, Maitê C; De Rossi, Andreia; Reinehr, Christian O; Hemkemeier, Marcelo; Colla, Luciane M


    The inappropriate discharge of wastewater containing high concentrations of toxic metals is a serious threat to the environment. Given that the microalga Spirulina platensis has demonstrated a capacity for chromium VI (Cr (VI) biosorption, we assessed the ideal concentration of chromium-containing wastewater required for maximum removal of Cr (VI) and chemical oxygen demand (COD) from the environment by using this microalga. The Paracas and Leb-52 strains of S. platensis, with initial wastewater concentrations of 0%, 12.5%, 25%, and 50%, were cultured in Zarrouk medium diluted to 50% under controlled air, temperature, and lighting conditions. The cultures were maintained for 28 days, and pH, biomass growth, COD, and Cr (VI) were assessed. The wastewater concentration influenced microalgal growth, especially at high concentrations. Removal of 82.19% COD and 60.92% Cr (VI) was obtained, but the COD removal was greater than the Cr (VI) removal in both strains of S. platensis.

  6. Efficiency of some soil bacteria for chemical oxygen demand reduction of synthetic chlorsulfuron solutions under agiated culture conditions. (United States)

    Erguven, G O; Yildirim, N


    This study searches the efficiency of certain soil bacteria on chemical oxygen demand (COD) reduction of synthetic chlorsulfuron solutions under agitated culture conditions. It also aims to determine the turbidity of liquid culture medium with chlorsulfuron during bacterial incubation for 120 hours. As a result the highest and lowest COD removal efficiency of bacteria was determined for Bacillus simplex as 94% and for Micrococcus luteus as 70%, respectively at the end of the 96th hour. It was found that COD removal efficiency showed certain differences depend on the bacterial species. It was also observed that B. simplex had the highest COD removal efficiency and it was a suitable bacterium species for bioremediation of a chlorsulfuron contaminated soils.

  7. Converting Chemical Oxygen Demand (COD) of Cellulosic Ethanol Fermentation Wastewater into Microbial Lipid by Oleaginous Yeast Trichosporon cutaneum. (United States)

    Wang, Juan; Hu, Mingshan; Zhang, Huizhan; Bao, Jie


    Cellulosic ethanol fermentation wastewater is the stillage stream of distillation column of cellulosic ethanol fermentation broth with high chemical oxygen demand (COD). The COD is required to reduce before the wastewater is released or recycled. Without any pretreatment nor external nutrients, the cellulosic ethanol fermentation wastewater bioconversion by Trichosporon cutaneum ACCC 20271 was carried out for the first time. The major components of the wastewater including glucose, xylose, acetic acid, ethanol, and partial of phenolic compounds could be utilized by T. cutaneum ACCC 20271. In a 3-L bioreactor, 2.16 g/L of microbial lipid accumulated with 55.05% of COD reduced after a 5-day culture of T. cutaneum ACCC 20271 in the wastewater. The fatty acid composition of the derived microbial lipid was similar with vegetable oil, in which it could be used as biodiesel production feedstock. This study will both solve the environmental problem and offer low-cost lipid feedstock for biodiesel production.

  8. 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


    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.

  9. 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:; Wojnowska-Baryla, Irena


    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.

  10. The effects of graded changes in oxygen and carbon dioxide tension on coronary blood velocity independent of myocardial energy demand. (United States)

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


    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.

  11. 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


    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.

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

    CERN Document Server

    Cockell, C S; Raven, J A


    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. Development of biological oxygen demand biosensor for monitoring the fermentation industry effluent. (United States)

    Verma, Neelam; Singh, Ashish Kumar


    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 time was optimized by immobilizing different concentrations of cell biomass on CA membrane. Once the response time was optimized, it was used for determination of BOD of fermentation industry effluent. For analysis of fermentation industry effluent, the response time was observed 7 minutes with detection limit 1 mg/L. Good linear range with GGA standard solution was observed, R (2) 0.99 with relative standard deviation (RSD) <%. The observed BOD value by biosensor showed a good comparison with the conventional method for the determination of BOD.

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


    Neelam Verma; Ashish Kumar Singh


    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...

  15. The Quantum Biology of Reactive Oxygen Species Partitioning Impacts Cellular Bioenergetics (United States)

    Usselman, Robert J.; Chavarriaga, Cristina; Castello, Pablo R.; Procopio, Maria; Ritz, Thorsten; Dratz, Edward A.; Singel, David J.; Martino, Carlos F.


    Quantum biology is the study of quantum effects on biochemical mechanisms and biological function. We show that the biological production of reactive oxygen species (ROS) in live cells can be influenced by coherent electron spin dynamics, providing a new example of quantum biology in cellular regulation. ROS partitioning appears to be mediated during the activation of molecular oxygen (O2) by reduced flavoenzymes, forming spin-correlated radical pairs (RPs). We find that oscillating magnetic fields at Zeeman resonance alter relative yields of cellular superoxide (O2•-) and hydrogen peroxide (H2O2) ROS products, indicating coherent singlet-triplet mixing at the point of ROS formation. Furthermore, the orientation-dependence of magnetic stimulation, which leads to specific changes in ROS levels, increases either mitochondrial respiration and glycolysis rates. Our results reveal quantum effects in live cell cultures that bridge atomic and cellular levels by connecting ROS partitioning to cellular bioenergetics.

  16. Achieving low effluent NO3-N and TN concentrations in low influent chemical oxygen demand (COD) to total Kjeldahl nitrogen (TKN) ratio without using external carbon source (United States)

    Cao, Jiashun; Oleyiblo, Oloche James; Xue, Zhaoxia; Otache, Y. Martins; Feng, Qian


    Two mathematical models were used to optimize the performance of a full-scale biological nutrient removal (BNR) activated treatment plant, a plug-flow bioreactors operated in a 3-stage phoredox process configuration, anaerobic anoxic oxic (A2/O). The ASM2d implemented on the platform of WEST2011 software and the BioWin activated sludge/anaerobic digestion (AS/AD) models were used in this study with the aim of consistently achieving the designed effluent criteria at a low operational cost. Four ASM2d parameters (the reduction factor for denitrification , the maximum growth rate of heterotrophs (µH), the rate constant for stored polyphosphates in PAOs ( q pp), and the hydrolysis rate constant ( k h)) were adjusted. Whereas three BioWin parameters (aerobic decay rate ( b H), heterotrophic dissolved oxygen (DO) half saturation ( K OA), and Y P/acetic) were adjusted. Calibration of the two models was successful; both models have average relative deviations (ARD) less than 10% for all the output variables. Low effluent concentrations of nitrate nitrogen (N-NO3), total nitrogen (TN), and total phosphorus (TP) were achieved in a full-scale BNR treatment plant having low influent chemical oxygen demand (COD) to total Kjeldahl nitrogen (TKN) ratio (COD/TKN). The effluent total nitrogen and nitrate nitrogen concentrations were improved by 50% and energy consumption was reduced by approximately 25%, which was accomplished by converting the two-pass aerobic compartment of the plug-flow bioreactor to anoxic reactors and being operated in an alternating mode. Findings in this work are helpful in improving the operation of wastewater treatment plant while eliminating the cost of external carbon source and reducing energy consumption.

  17. 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


    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.

  18. A miniature photoelectrochemical sensor based on organic electrochemical transistor for sensitive determination of chemical oxygen demand in wastewaters. (United States)

    Liao, Jianjun; Lin, Shiwei; Zeng, Min; Yang, Yue


    A three-electrode configuration is often required in the conventional photoelectrochemical measurements. Nevertheless, one common drawback is the reference electrode and the counter electrode used in the measurements, which has been proved to be an impediment for the miniaturization. In this study, a simple, cost-effective and miniature photoelectrochemical sensor based on high sensitive organic electrochemical transistor (OECT) is developed and used for the determination of chemical oxygen demand (COD) in wastewaters. The devices show detection limit down to 0.01 mg/L COD, which is two orders of magnitude better than that of the conventional photoelectrochemical method. The excellent sensing performance can be contributed to the novel sensing mechanism of OECT devices. That is, the devices are sensitive to the potential changes induced by the photoelectrochemical reaction on TiO2 nanotube arrays gate electrodes. Real sample analyses are also carried out. The results demonstrate that the measured COD values using the OECT devices and the standard dichromate methods are in a good agreement. Since the proposed sensor is constructed on a miniature transistor, it is expected that the device shows a promising application on the integrated COD monitoring platform.

  19. Myocardial oxygen supply/demand ratio in aortic stenosis: hemodynamic and echocardiographic evaluation of patients with and without angina pectoris. (United States)

    Nadell, R; DePace, N L; Ren, J F; Hakki, A H; Iskandrian, A S; Morganroth, J


    Angina pectoris is a common symptom in patients with aortic stenosis without coronary artery disease. To investigate the correlates of angina pectoris, echocardiographic and hemodynamic data from 44 patients with aortic stenosis and no coronary artery disease (mean age 56 +/- 10 years) were analyzed. Twenty-three patients had no angina pectoris and 21 patients had angina pectoris. The ratio of the diastolic pressure-time index (area between the aortic and left ventricular pressure curves during diastole) to the systolic pressure-time index (area under the left ventricular pressure curve during systole), an index of the oxygen supply/demand ratio, was not different in patients with or without angina pectoris. There were no differences between patients with and without angina pectoris in echocardiographically determined wall thickness, chamber size, systolic and diastolic wall stress and left ventricular mass; in electrocardiographically defined voltage; and in hemodynamically defined aortic valve area, transaortic gradient and stroke work index. Thus, echocardiographic and hemodynamic measurements at rest are not significantly different in the presence or absence of angina pectoris in patients with aortic stenosis. Dynamic data appear to be essential for evaluation of the mechanisms of angina pectoris in patients with aortic stenosis.

  20. Removal of chemical oxygen demand and dissolved nutrients by a sunken lawn infiltration system during intermittent storm events. (United States)

    Hou, Lizhu; Yang, Huan; Li, Ming


    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.

  1. A sensitive ferricyanide-mediated biochemical oxygen demand assay for analysis of wastewater treatment plant influents and treated effluents. (United States)

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


    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.

  2. Semi-specific Microbacterium phyllosphaerae-based microbial sensor for biochemical oxygen demand measurements in dairy wastewater. (United States)

    Kibena, Elo; Raud, Merlin; Jõgi, Eerik; Kikas, Timo


    Although the long incubation time of biochemical oxygen demand (BOD7) measurements has been addressed by the use of microbial biosensors, the resulting sensor-BOD values gained from the measurements with specific industrial wastewaters still underestimates the BOD value of such samples. This research aims to provide fast and more accurate BOD measurements in the dairy wastewater samples. Unlike municipal wastewater, wastewater from the dairy industry contains many substrates that are not easily accessible to a majority of microorganisms. Therefore, a bacterial culture, Microbacterium phyllosphaerae, isolated from dairy wastewater was used to construct a semi-specific microbial biosensor. A universal microbial biosensor based on Pseudomonas fluorescens, which has a wide substrate spectrum but is nonspecific to dairy wastewater, was used as a comparison. BOD biosensors were calibrated with OECD synthetic wastewater, and experiments with different synthetic and actual wastewater samples were carried out. Results show that the semi-specific M. phyllosphaerae-based microbial biosensor is more sensitive towards wastewaters that contain milk derivates and butter whey than the P. fluorescens-based biosensor. Although the M. phyllosphaerae biosensor underestimates the BOD7 value of actual dairy wastewaters by 25-32%, this bacterial culture is more suitable for BOD monitoring in dairy wastewater than P. fluorescens, which underestimated the same samples by 46-61%.

  3. Chemistry and biology of reactive oxygen species in signaling or stress responses. (United States)

    Dickinson, Bryan C; Chang, Christopher J


    Reactive oxygen species (ROS) are a family of molecules that are continuously generated, transformed and consumed in all living organisms as a consequence of aerobic life. The traditional view of these reactive oxygen metabolites is one of oxidative stress and damage that leads to decline of tissue and organ systems in aging and disease. However, emerging data show that ROS produced in certain situations can also contribute to physiology and increased fitness. This Perspective provides a focused discussion on what factors lead ROS molecules to become signal and/or stress agents, highlighting how increasing knowledge of the underlying chemistry of ROS can lead to advances in understanding their disparate contributions to biology. An important facet of this emerging area at the chemistry-biology interface is the development of new tools to study these small molecules and their reactivity in complex biological systems.

  4. 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


    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.

  5. The effect of chamber mixing velocity on bias in measurement of sediment oxygen demand rates in the Tualatin River basin, Oregon (United States)

    Doyle, Micelis C.; Rounds, Stewart


    Three sediment oxygen demand (SOD) measurement chambers were deployed in the Tualatin River near Tigard, Oregon, at river mile 10 in August 2000. SOD rates were calculated for three different circulation velocities during each chamber deployment. The SOD rate at each velocity was calculated from a graph of dissolved oxygen concentration versus elapsed time. An acoustic doppler current profiler (ADCP) was used to measure stream discharge and near-bottom water velocities in the Tualatin at river mile 10 and at two upstream locations. Measured river and chamber velocities were similar, indicating that results from the chambers were representative of instream effects.

  6. 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


    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

  7. Replacement of chemical oxygen demand (COD) with total organic carbon (TOC) for monitoring wastewater treatment performance to minimize disposal of toxic analytical waste. (United States)

    Dubber, Donata; Gray, Nicholas F


    Chemical oxygen demand (COD) is widely used for wastewater monitoring, design, modeling and plant operational analysis. However this method results in the production of hazardous wastes including mercury and hexavalent chromium. The study examined the replacement of COD with total organic carbon (TOC) for general performance monitoring by comparing their relationship with influent and effluent samples from 11 wastewater treatment plants. Biochemical oxygen demand (BOD5) was also included in the comparison as a control. The results show significant linear relationships between TOC, COD and BOD5 in settled (influent) domestic and municipal wastewaters, but only between COD and TOC in treated effluents. The study concludes that TOC can be reliably used for the generic replacement of both COD (COD=49.2+3.00*TOC) and BOD5 (BOD5=23.7+1.68*TOC) in influent wastewaters but only for COD (COD=7.25+2.99*TOC) in final effluents.

  8. Effect of spent cotton stalks on color removal and chemical oxygen demand lowering in olive oil mill wastewater by white rot fungi. (United States)

    Kahraman, S; Yeşilada, O


    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.

  9. Mechanism and stereoselectivity of biologically important oxygenation reactions of the 7-dehydrocholesterol radical. (United States)

    Rajeev, Ramanan; Sunoj, Raghavan B


    The mechanism of free radical oxygenation of 7-dehydrocholesterol (7-DHC), one of the biologically important sterols, is investigated by using density functional theory. The energetic origin of the product distribution and the stereoelectronic factors involved in various mechanistic pathways are delineated. The addition of triplet molecular oxygen to two types of conjugatively stabilized radicals, generated by the removal of the reactive allylic hydrogens from C9 or C14 positions, respectively denoted as H9 and H14 pathways, is studied. The distortion-interaction analysis of the C-O bond formation transition states suggests that the energetic preference toward the α prochiral face stems from reduced skeletal distortions of the cholesterol backbone as compared to that in the corresponding β prochiral face. This insight derived through a detailed quantitative analysis of the stereocontrolling transition states suggests that the commonly found interpretations solely based on steric interactions between the incoming oxygen and the protruding angular methyl groups (C10, C13 methyls) in the β face calls for adequate refinement. The relative energies of the transition states for molecular oxygen addition to C9, C5, and C14 (where spin densities are higher) and the ensuing products thereof are in agreement with the experimentally reported distribution of oxygenated 7-DHCs.

  10. Reverse engineering of oxygen transport in the lung: adaptation to changing demands and resources through space-filling networks.

    Directory of Open Access Journals (Sweden)

    Chen Hou

    Full Text Available The space-filling fractal network in the human lung creates a remarkable distribution system for gas exchange. Landmark studies have illuminated how the fractal network guarantees minimum energy dissipation, slows air down with minimum hardware, maximizes the gas- exchange surface area, and creates respiratory flexibility between rest and exercise. In this paper, we investigate how the fractal architecture affects oxygen transport and exchange under varying physiological conditions, with respect to performance metrics not previously studied.We present a renormalization treatment of the diffusion-reaction equation which describes how oxygen concentrations drop in the airways as oxygen crosses the alveolar membrane system. The treatment predicts oxygen currents across the lung at different levels of exercise which agree with measured values within a few percent. The results exhibit wide-ranging adaptation to changing process parameters, including maximum oxygen uptake rate at minimum alveolar membrane permeability, the ability to rapidly switch from a low oxygen uptake rate at rest to high rates at exercise, and the ability to maintain a constant oxygen uptake rate in the event of a change in permeability or surface area. We show that alternative, less than space-filling architectures perform sub-optimally and that optimal performance of the space-filling architecture results from a competition between underexploration and overexploration of the surface by oxygen molecules.

  11. Reverse engineering of oxygen transport in the lung: adaptation to changing demands and resources through space-filling networks. (United States)

    Hou, Chen; Gheorghiu, Stefan; Huxley, Virginia H; Pfeifer, Peter


    The space-filling fractal network in the human lung creates a remarkable distribution system for gas exchange. Landmark studies have illuminated how the fractal network guarantees minimum energy dissipation, slows air down with minimum hardware, maximizes the gas- exchange surface area, and creates respiratory flexibility between rest and exercise. In this paper, we investigate how the fractal architecture affects oxygen transport and exchange under varying physiological conditions, with respect to performance metrics not previously studied.We present a renormalization treatment of the diffusion-reaction equation which describes how oxygen concentrations drop in the airways as oxygen crosses the alveolar membrane system. The treatment predicts oxygen currents across the lung at different levels of exercise which agree with measured values within a few percent. The results exhibit wide-ranging adaptation to changing process parameters, including maximum oxygen uptake rate at minimum alveolar membrane permeability, the ability to rapidly switch from a low oxygen uptake rate at rest to high rates at exercise, and the ability to maintain a constant oxygen uptake rate in the event of a change in permeability or surface area. We show that alternative, less than space-filling architectures perform sub-optimally and that optimal performance of the space-filling architecture results from a competition between underexploration and overexploration of the surface by oxygen molecules.

  12. 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.

  13. The role of biology in planetary evolution: cyanobacterial primary production in low-oxygen Proterozoic oceans. (United States)

    Hamilton, Trinity L; Bryant, Donald A; Macalady, Jennifer L


    Understanding the role of biology in planetary evolution remains an outstanding challenge to geobiologists. Progress towards unravelling this puzzle for Earth is hindered by the scarcity of well-preserved rocks from the Archean (4.0 to 2.5 Gyr ago) and Proterozoic (2.5 to 0.5 Gyr ago) Eons. In addition, the microscopic life that dominated Earth's biota for most of its history left a poor fossil record, consisting primarily of lithified microbial mats, rare microbial body fossils and membrane-derived hydrocarbon molecules that are still challenging to interpret. However, it is clear from the sulfur isotope record and other geochemical proxies that the production of oxygen or oxidizing power radically changed Earth's surface and atmosphere during the Proterozoic Eon, pushing it away from the more reducing conditions prevalent during the Archean. In addition to ancient rocks, our reconstruction of Earth's redox evolution is informed by our knowledge of biogeochemical cycles catalysed by extant biota. The emergence of oxygenic photosynthesis in ancient cyanobacteria represents one of the most impressive microbial innovations in Earth's history, and oxygenic photosynthesis is the largest source of O2 in the atmosphere today. Thus the study of microbial metabolisms and evolution provides an important link between extant biota and the clues from the geologic record. Here, we consider the physiology of cyanobacteria (the only microorganisms capable of oxygenic photosynthesis), their co-occurrence with anoxygenic phototrophs in a variety of environments and their persistence in low-oxygen environments, including in water columns as well as mats, throughout much of Earth's history. We examine insights gained from both the rock record and cyanobacteria presently living in early Earth analogue ecosystems and synthesize current knowledge of these ancient microbial mediators in planetary redox evolution. Our analysis supports the hypothesis that anoxygenic photosynthesis

  14. The role of biology in planetary evolution: cyanobacterial primary production in low‐oxygen Proterozoic oceans (United States)

    Bryant, Donald A.; Macalady, Jennifer L.


    Summary Understanding the role of biology in planetary evolution remains an outstanding challenge to geobiologists. Progress towards unravelling this puzzle for Earth is hindered by the scarcity of well‐preserved rocks from the Archean (4.0 to 2.5 Gyr ago) and Proterozoic (2.5 to 0.5 Gyr ago) Eons. In addition, the microscopic life that dominated Earth's biota for most of its history left a poor fossil record, consisting primarily of lithified microbial mats, rare microbial body fossils and membrane‐derived hydrocarbon molecules that are still challenging to interpret. However, it is clear from the sulfur isotope record and other geochemical proxies that the production of oxygen or oxidizing power radically changed Earth's surface and atmosphere during the Proterozoic Eon, pushing it away from the more reducing conditions prevalent during the Archean. In addition to ancient rocks, our reconstruction of Earth's redox evolution is informed by our knowledge of biogeochemical cycles catalysed by extant biota. The emergence of oxygenic photosynthesis in ancient cyanobacteria represents one of the most impressive microbial innovations in Earth's history, and oxygenic photosynthesis is the largest source of O 2 in the atmosphere today. Thus the study of microbial metabolisms and evolution provides an important link between extant biota and the clues from the geologic record. Here, we consider the physiology of cyanobacteria (the only microorganisms capable of oxygenic photosynthesis), their co‐occurrence with anoxygenic phototrophs in a variety of environments and their persistence in low‐oxygen environments, including in water columns as well as mats, throughout much of Earth's history. We examine insights gained from both the rock record and cyanobacteria presently living in early Earth analogue ecosystems and synthesize current knowledge of these ancient microbial mediators in planetary redox evolution. Our analysis supports the hypothesis that anoxygenic

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

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


    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. Investigating the role that the Southern Ocean biological pump plays in determining global ocean oxygen concentrations and deoxygenation


    Keller, David; Oschlies, Andreas


    Global ocean circulation connects marine biogeochemical cycles through the long-range transport of nutrients and oxygen with the Southern Ocean (SO) acting as a water mass crossroads. The biological pump in the SO has been shown to play an important role in these dynamics and the amount of export production is known to have a large impact on remote deep ocean nutrients and dissolved inorganic carbon. However, the role that the SO biological pump plays in determining ocean oxygen concentration...

  17. The Role of Reactive Oxygen Species (ROS in the Biological Activities of Metallic Nanoparticles

    Directory of Open Access Journals (Sweden)

    Ahmed Abdal Dayem


    Full Text Available Nanoparticles (NPs possess unique physical and chemical properties that make them appropriate for various applications. The structural alteration of metallic NPs leads to different biological functions, specifically resulting in different potentials for the generation of reactive oxygen species (ROS. The amount of ROS produced by metallic NPs correlates with particle size, shape, surface area, and chemistry. ROS possess multiple functions in cellular biology, with ROS generation a key factor in metallic NP-induced toxicity, as well as modulation of cellular signaling involved in cell death, proliferation, and differentiation. In this review, we briefly explained NP classes and their biomedical applications and describe the sources and roles of ROS in NP-related biological functions in vitro and in vivo. Furthermore, we also described the roles of metal NP-induced ROS generation in stem cell biology. Although the roles of ROS in metallic NP-related biological functions requires further investigation, modulation and characterization of metallic NP-induced ROS production are promising in the application of metallic NPs in the areas of regenerative medicine and medical devices.

  18. Blood Oxygen Conservation in Diving Sea Lions: How Low Does Oxygen Really Go? (United States)


    Does Oxygen Really Go? Paul J. Ponganis Center for Marine Biotechnology and Biomedicine Scripps Institution of Oceanography 8655 Discovery Way...demands of exercise for energy conservation at depth. Journal of Experimental Biology 202: 2739-2748.

  19. 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


    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.

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

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


    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.

  1. Biological and physiological role of reactive oxygen species--the good, the bad and the ugly. (United States)

    Zuo, L; Zhou, T; Pannell, B K; Ziegler, A C; Best, T M


    Reactive oxygen species (ROS) are chemically reactive molecules that are naturally produced within biological systems. Research has focused extensively on revealing the multi-faceted and complex roles that ROS play in living tissues. In regard to the good side of ROS, this article explores the effects of ROS on signalling, immune response and other physiological responses. To review the potentially bad side of ROS, we explain the consequences of high concentrations of molecules that lead to the disruption of redox homeostasis, which induces oxidative stress damaging intracellular components. The ugly effects of ROS can be observed in devastating cardiac, pulmonary, neurodegenerative and other disorders. Furthermore, this article covers the regulatory enzymes that mitigate the effects of ROS. Glutathione peroxidase, superoxide dismutase and catalase are discussed in particular detail. The current understanding of ROS is incomplete, and it is imperative that future research be performed to understand the implications of ROS in various therapeutic interventions.

  2. Characterization of a novel micro-pressure swirl reactor for removal of chemical oxygen demand and total nitrogen from domestic wastewater at low temperature. (United States)

    Ren, Qingkai; Yu, Yang; Zhu, Suiyi; Bian, Dejun; Huo, Mingxin; Zhou, Dandan; Huo, Hongliang


     A novel micro-pressure swirl reactor (MPSR) was designed and applied to treat domestic wastewater at low temperature by acclimating microbial biomass with steadily decreasing temperature from 15 to 3 °C. Chemical oxygen demand (COD) was constantly removed by 85% and maintained below 50 mg L(-1) in the effluent during the process. When the air flow was controlled at 0.2 m(3) h(-1), a swirl circulation was formed in the reactor, which created a dissolved oxygen (DO) gradient with a low DO zone in the center and a high DO zone in the periphery for denitrification and nitrification. 81% of total nitrogen was removed by this reactor, in which ammonium was reduced by over 90%. However, denitrification was less effective because of the presence of low levels of oxygen. The progressively decreasing temperature favored acclimation of psychrophilic bacteria in the reactor, which replaced mesophilic bacteria in the process of treatment.

  3. Occurrence, pathways and implications of biological production of reactive oxygen species in natural waters (United States)

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


    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.

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

    Itoh, Shinobu


    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. 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


    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.

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

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


    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.

  7. 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


    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.

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

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


    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.

  9. Interconnection of reactive oxygen species chemistry across the interfaces of atmospheric, environmental, and biological processes. (United States)

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


    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

  10. Extracorporeal blood oxygenation and ozonation: clinical and biological implications of ozone therapy. (United States)

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


    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

  11. Development of A Novel Methode for COD (Chemical Oxygen Demand Measurement based onPhotoelectrochemical Cell: Characterization of TiO2/ITO Film Working Electrode

    Directory of Open Access Journals (Sweden)

    Y.K. Krisnandi


    Full Text Available Nanosize TiO2 film,immobilized on an ITO (Indium Tin Oxide glass, was successfully fabricated. The film was prepared by a dip coatingtechnique in a hydrothermal sol-gel system and subjected to a heat treatment at 100°C up to 450°C. Characterization ofthe film by XRD, AFM, BET methods revealed the occurrence of anatase form and 9.64 nm in crystallite size; havingthree dimensional profile and roughness with height of typically 9.8 nm; and surface area of 58.21 m2/g. The film thenwas employed as a working electrode in a photo electrochemical system (PES. This PES generated a photocurrent thatproportional to the organic chemical concentration in the water sample. Integration of the photocurrent versus timegives a charge (Q that represent the event of complete mineralization of organic chemical in the TiO2 surface and canbe correlated to the Chemical Oxygen Demand (COD of measured water. This system has a potential to be developedfor a novel COD sensor.

  12. Assessment of a modified and optimised method for determining chemical oxygen demand of solid substrates and solutions with high suspended solid content. (United States)

    Raposo, F; de la Rubia, M A; Borja, R; Alaiz, M


    A modified approach to determine the chemical oxygen demand (COD) of solid substrates based on the DIN 38414-S9 standard method is proposed. The adapted procedure is assessed and compared with standard methods widely used for water and wastewater such as the American Public Health Association-American Water Works Association-Water Pollution Control Federation (APHA-AWWA-WPCF) standard methods 5220 B-open reflux (SM-OR) and 5220 D-closed reflux colorimetric (SM-CR). Solutions with high suspended concentration of solids, as well as digestates from an anaerobic reactor, were used during the comparative test. For solid substrates, the COD recovery was about 100% when the proposed method was used. For solutions with solid content higher than 20 g TS L(-1), the recovery was only completed when the proposed method was used, showing that the methods traditionally employed are not very appropriate for samples with the described characteristics. For instance, percentages of COD recovery in the ranges of 77.3-87.1% and 89.4-94.1% were achieved when the SM-OR and SM-CR methods were used, respectively.

  13. Chemical oxygen demand, total organic carbon and colour reduction in slaughterhouse wastewater by unmodified and iron-modified clinoptilolite-rich tuff. (United States)

    Torres-Pérez, J; Solache-Ríos, M; Martínez-Miranda, V


    In this study, reduction of chemical oxygen demand (COD), colour, and total organic carbon in effluents from a slaughterhouse in central Mexico was performed using clinoptilolite-rich tuff. The experimental parameters considered were initial concentration of the adsorbate, pH, adsorbent dosage, and contact time. Surface morphology of the materials was tested by using scanning electron microscopy. Specific surface area was analysed by using Brunauer-Emmett-Teller (BET) and phase composition was analysed by using X-ray diffraction. The experimental adsorption data were fitted to the first- and pseudo-second-order kinetic models. The highest COD removal was observed in slightly acidic pH conditions. The maximum reduction efficiency of COD was accomplished with unmodified clinoptilolite-rich tuff at a contact time of 1440 min. In these conditions, the adsorbent was efficient for treating wastewater from a slaughterhouse. Moreover, after several regeneration cycles with Fenton reagent or hydrogen peroxide, the regenerated zeolite with H2O2 (3%) showed the best reduction efficiencies.

  14. Simultaneous efficient removal of high-strength ammonia nitrogen and chemical oxygen demand from landfill leachate by using an extremely high ammonia nitrogen-resistant strain. (United States)

    Yu, Dahai; Yang, Jiyu; Fang, Xuexun; Ren, Hejun


    Bioaugmentation is a promising technology for pollutant elimination from stressed environments, and it would provide an efficient way to solve challenges in traditional biotreatment of wastewater with high strength of ammonia nitrogen (NH4(+)-N). A high NH4(+)-N-resistant bacteria strain, identified as Bacillus cereus (Jlu BC), was domesticated and isolated from the bacteria consortium in landfill leachate. Jlu BC could survive in 100 g/L NH4(+)-N environment, which indicated its extremely high NH4(+)-N tolerance than the stains found before. Jlu BC was employed in the bioaugmented system to remove high strength of NH4(+)-N from landfill leachate, and to increase the removal efficiency, response surface methodology (RSM) was used for optimizing bioaugmentation degradation conditions. At the optimum condition (initial pH 7.33, 4.14 days, initial chemical oxygen demand [COD] concentration [18,000 mg/L], 3.5 mL inoculated domesticated bacteria strain, 0.3 mg/mL phosphorus supplement, 30 °C, and 170 rpm), 94.74 ± 3.8% removal rate of NH4(+)-N was obtained, and the experiment data corresponded well with the predicted removal rate of the RSM models (95.50%). Furthermore, COD removal rate of 81.94 ± 1.4% was obtained simultaneously. The results presented are promising, and the screened strain would be of great practical importance in mature landfill leachate and other NH4(+)-N enrichment wastewater pollution control.

  15. The Role of Oxygen Radicals in Biology and Medicine 7-11 February 1983, Ventura, California, (United States)


    Center, Durham, NC 27710 Oxygen tolerant organisms usually contain superoxide dismutase (SOD). Lactobacillus plantarum was an apparent exception. We...prevented from accumulating Mn(II) by a phosphate deficiency, L. plantarum becomes oxygen intolerant and very sensitive to the lethality of

  16. 海水化学需氧量烘箱加热测定方法的研究%Determination of seawater chemical oxygen demand by oven heating

    Institute of Scientific and Technical Information of China (English)

    沈加正; 侯沙沙; 刘鹰; 罗荣强


    A method for the determination of seawater chemical oxygen demand (COD), using oven instead of electric furnace to heat samples, was proposed. In this study, standard samples were heated under different conditions of temperature and time to obtain optimum heating conditions. The concentration range of the method was then assessed under the optimum operation conditions. In the end the method was applied to analyze seawater samples in comparison with the electric furnace method. All these results showed a good accuracy and precision of the oven heating method with less time and energy consumed, expecially when a large number of samples were ana- lyzed simultaneously.%在海水化学需氧量(COD)测定中,利用烘箱代替海洋监测规范中的电炉对样品进行加热;探讨了烘箱加热测定法所需的加热条件及其测定范围,并通过实际水样测定了解此法的精确度和准确度。结果表明,烘箱加热测定法具有与海洋监测规范方法同等水平的精确度和准确度,并且在大批量样品测定中具有省时、省电、省力的优点,具有较好的应用价值。

  17. 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,


    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.

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

    Schmidt, Susan; Winter, Josef; Gallert, Claudia


    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.

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

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


    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.

  20. InfoBiology by printed arrays of microorganism colonies for timed and on-demand release of messages. (United States)

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


    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.

  1. 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.


    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

  2. Metabolic scaling theory in plant biology and the three oxygen paradoxa of aerobic life. (United States)

    Kutschera, Ulrich; Niklas, Karl J


    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".

  3. [Impact of biologically important anions on reactive oxygen species formation in water under the effect of non-ionizing physical agents]. (United States)

    Gudkov, S V; Ivanov, V E; Karp, O É; Chernikov, A V; Belosludtsev, K N; Bobylev, A G; Astashev, M E; Gapeev, A B; Bruskov, V I


    The influence of biologically relevant anions (succinate, acetate, citrate, chloride, bicarbonate, hydroorthophosphate, dihydroorthophosphate, nitrite, nitrate) on the formation of hydrogen peroxide and hydroxyl radicals in water was studied under the effect of non-ionizing radiation: heat, laser light with a wavelength of 632.8 nm, corresponding to the maximum absorption of molecular oxygen, and electromagnetic radiation of extremely high frequencies. It has been established that various anions may both inhibit the formation of reactive oxygen species and increase it. Bicarbonate and sulfate anions included in the biological fluids' and medicinal mineral waters have significant, but opposite effects on reactive oxygen species production. Different molecular mechanisms of reactive oxygen species formation are considered under the action of the investigated physical factors involving these anions, which may influence the biological processes by signal-regulatory manner and provide a healing effect in physical therapy.

  4. 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


    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.

  5. The emerging role of reactive oxygen and nitrogen species in redox biology and some implications for plasma applications to medicine and biology (United States)

    Graves, David B.


    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.

  6. Energy Demand

    NARCIS (Netherlands)

    Stehfest, E. et al.


    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

  7. The role of biology in planetary evolution: cyanobacterial primary production in low‐oxygen Proterozoic oceans


    Hamilton, Trinity L.; Donald A Bryant; Macalady, Jennifer L.


    Summary Understanding the role of biology in planetary evolution remains an outstanding challenge to geobiologists. Progress towards unravelling this puzzle for Earth is hindered by the scarcity of well‐preserved rocks from the Archean (4.0 to 2.5 Gyr ago) and Proterozoic (2.5 to 0.5 Gyr ago) Eons. In addition, the microscopic life that dominated Earth's biota for most of its history left a poor fossil record, consisting primarily of lithified microbial mats, rare microbial body fossils and m...

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

    Celi, P; Sullivan, M; Evans, D


    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.

  9. Oxygen bomb combustion of biological samples for inductively coupled plasma optical emission spectrometry (United States)

    Souza, Gilberto B.; Carrilho, Elma Neide V. M.; Oliveira, Camila V.; Nogueira, Ana Rita A.; Nóbrega, Joaquim A.


    A rapid sample preparation method is proposed for decomposition of milk powder, corn bran, bovine and fish tissues, containing certified contents of the analytes. The procedure involves sample combustion in a commercial stainless steel oxygen bomb operating at 25 bar. Most of the samples were decomposed within 5 min. Diluted nitric acid or water-soluble tertiary amines 10% v/v were used as absorption solutions. Calcium, Cu, K, Mg, Na, P, S and Zn were recovered with the bomb washings and determined by inductively coupled plasma optical emission spectrometry (ICP-OES). Ethanol mixed with paraffin was used as a combustion aid to allow complete combustion. A cooling step prior releasing of the bomb valve was employed to increase the efficiency of sample combustion. Iodine was also determined in milk samples spiked with potassium iodide to evaluate the volatilization and collection of iodine in amine CFA-C medium and the feasibility of its determination by ICP-OES with axial view configuration. Most of the element recoveries in the samples were between 91 and 105% and the certified and found contents exhibited a fair agreement at a 95% confidence level.

  10. Mitochondrial Flash: Integrative Reactive Oxygen Species and pH Signals in Cell and Organelle Biology (United States)

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


    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

  11. 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


    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.

  12. 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


    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

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

    DEFF Research Database (Denmark)

    Glud, Ronnie; Rysgaard, Søren; Turner, Gavin


    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...

  14. Dissolved Oxygen Dynamics in Coastal Pacific Northwest Rivers: Biological Controls and Management Options (United States)

    Sobota, D. J.; Foster, E.; Michie, R.; Waltz, D.


    In Oregon's Central Coast Range (OCR), dissolved O2 concentrations in at least 10% of stream length frequently dip below state standards set to ensure survival and reproduction of native salmonids. We examined O2 dynamics on 12 OCR rivers during times of the year when standards had been violated. Continuous dissolved O2 data were collected 15 minutes apart over a 24-hour period during spring (May - June) or fall (September - November) 2008 on each river. We modeled O2 dynamics for each river with parameters describing O2 exchange with the atmosphere, production of O2 from gross primary production (GPP), and consumption of O2 by ecosystem respiration (ER) fit to observed data. Average nighttime atmospheric O2 exchange and ER were estimated by regressing interval changes in dissolved O2 concentrations between measurements with corresponding O2 saturation deficits. GPP for each daytime sampling interval was calculated as the difference between O2 saturation deficit and the sum of temperature-corrected reaeration and ecosystem respiration. All regression models developed for estimating night-time reaeration and ER were highly significant (pmetabolism (NDM; net O2 flux controlled by biological processes) ranged from -11.64 to 3.75 mg O2 L-1 d-1 across all rivers and seasons. Increased aquatic productivity resulting from adjacent and upstream human activities likely altered dissolved O2 dynamics in these rivers. Through scenario analysis, we found that at one river (Alsea), GPP and ER would need to be reduced by 85 and 73%, respectively, to meet the state standard (95% saturation). Our modeling approach can be connected with management actions across a variety of spatial and temporal scales, ranging from local, riparian-scale manipulations of shading and organic matter input to watershed and regional nutrient and temperature management.

  15. Synthesis and Spectroscopic and Biological Activities of Zn(II Porphyrin with Oxygen Donors

    Directory of Open Access Journals (Sweden)

    Gauri Devi Bajju


    Full Text Available Results of investigation of the physicochemical properties of zinc complexes containing substituted phenols as axial ligand having general formula [X-Zn-t(p-CH3 PP] [where X = different phenolates as axial ligand] in impurity-free organic solvent are presented. The four-coordinated zinc porphyrin accepts one axial ligand in 1 : 1 molar ratio to form five-coordinated complex, which is purified by column chromatography and characterized by physicochemical, biological evaluation and TGA/DTA studies. Absorption spectra show two principal effects: a red shift for phenols bearing substituted electron releasing groups (−CH3, −NH2 and blue shift for phenols bearing electron withdrawing groups (−NO2, −Cl relative to Zn-t(p-CH3 PP, respectively. 1H NMR spectra show that the protons of the phenol ring axially attached to the central metal ion are merged with the protons of the porphyrin ring. Fluorescence spectra show two fluorescence peaks in the red region with emission ranging from 550 nm to 700 nm. IR spectra confirm the appearance of Zn-NPor and Zn-O vibrational frequencies, respectively. According to the thermal studies, the complexes have a higher thermal stability and the decomposition temperature of these complexes depends on the axial ligation. The respective complexes of X-ZnII-t(p-CH3 PP were found to possess higher antifungal activity (up to 90% and higher in vitro cytotoxicity against human cancer cells lines.

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

    Energy Technology Data Exchange (ETDEWEB)

    Youssef, E.A.; Chowdhury, M.B.I.; Nakhla, G.; Charpentier, P. [Western Ontario University, London, ON (Canada). Dept. of Biochemical and Chemical Engineering


    Hydrogen produced from biomass is considered to be an excellent alternative to the use of fossil fuels. Gasification and partial oxidation of glucose was performed in the presence of different metallic nickel (Ni) loadings on different catalyst supports in supercritical water at three temperature levels. For comparison, some experiments were conducted using high loading commercial catalyst Ni on silica-alumina. Hydrogen peroxide was used as a source of oxygen in the partial oxidation experiments. Oxygen to carbon stoichiometric ratios of 0.5 to 0.9 were examined to increase the hydrogen production via carbon monoxide production. The paper described the experimental and methods as well as results and discussion. Results showed that in the absence of catalyst, the optimum stoichiometric ratio was 0.8 of the amount of oxygen required for complete oxidation of glucose. It was concluded that enhancing hydrogen yield and selectivity from glucose by obtaining the desired catalytic property and the optimum process conditions and parameters would be an invaluable addition to the supercritical water oxidation technology. 24 refs., 2 tabs., 5 figs.

  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


    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. 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. (United States)

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


    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.

  19. Bioeconomic Analysis of Pesticide Demand


    Moffitt, L. Joe; Farnsworth, Richard L.


    The ability of insects to develop resistance to specific pesticides affects pesticide demand. However, the affect of resistance on demand cannot be observed or measured. This analysis substitutes an expression for the unobserved resistance variable in a pesticide demand model and then illustrates the model's potential by estimating demand for DDT. To arrive at the expression characterizing the unobserved resistance variable a biological resistance model is constructed then incorporated into t...

  20. Maternal and neonatal evaluation of derivated reactive oxygen metabolites (d-ROMs) and biological antioxidant potential in the horse. (United States)

    Sgorbini, M; Bonelli, F; Marmorini, P; Biagi, G; Corazza, M; Pasquini, A


    The aim of the present work was to evaluate derivated reactive oxygen metabolites (d-ROMs) and biological antioxidant potential (BAP) in mares and foals to study perinatal oxidative status. A total of 60 animals were included in the present study. Maternal and foal venous blood samples were collected immediately after delivery along with a sample drawn from one of the umbilical arteries, and plasma samples were evaluated for lactatemia, d-ROMs, and BAP. The t test for unpaired data was applied between mares versus umbilical artery blood versus foals, both for d-ROMs and BAP. The Pearson test with two-tailed P value and a confidence interval of 95% was performed between d-ROMs and BAP and between d-ROMs and lactatemia, both for mares and foals. Finally, the t test for unpaired data was performed between fillies and colts. The t test showed differences between mares versus their own foals versus umbilical artery blood but not foals versus. umbilical artery blood, both for d-ROMs and BAP. A positive correlation was found both in mares and foals between BAP and d-ROMs and in mares between lactatemia and d-ROM. No differences in gender were found in BAP concentration. Our data are in line to previous studies performed in women and cattle.

  1. Demand forecasting


    Gregor, Belčec


    Companies operate in an increasingly challenging environment that requires them to continuously improve all areas of the business process. Demand forecasting is one area in manufacturing companies where we can hope to gain great advantages. Improvements in forecasting can result in cost savings throughout the supply chain, improve the reliability of information and the quality of the service for our customers. In the company Danfoss Trata, d. o. o. we did not have a system for demand forecast...

  2. Tyrosyl radicals in dehaloperoxidase: how nature deals with evolving an oxygen-binding globin to a biologically relevant peroxidase. (United States)

    Dumarieh, Rania; D'Antonio, Jennifer; Deliz-Liang, Alexandria; Smirnova, Tatyana; Svistunenko, Dimitri A; Ghiladi, Reza A


    Dehaloperoxidase (DHP) from Amphitrite ornata, having been shown to catalyze the hydrogen peroxide-dependent oxidation of trihalophenols to dihaloquinones, is the first oxygen binding globin that possesses a biologically relevant peroxidase activity. The catalytically competent species in DHP appears to be Compound ES, a reactive intermediate that contains both a ferryl heme and a tyrosyl radical. By simulating the EPR spectra of DHP activated by H2O2, Thompson et al. (Thompson, M. K., Franzen, S., Ghiladi, R. A., Reeder, B. J., and Svistunenko, D. A. (2010) J. Am. Chem. Soc. 132, 17501-17510) proposed that two different radicals, depending on the pH, are formed, one located on either Tyr-34 or Tyr-28 and the other on Tyr-38. To provide additional support for these simulation-based assignments and to deduce the role(s) that tyrosyl radicals play in DHP, stopped-flow UV-visible and rapid-freeze-quench EPR spectroscopic methods were employed to study radical formation in DHP when three tyrosine residues, Tyr-28, Tyr-34, and Tyr-38, were replaced either individually or in combination with phenylalanines. The results indicate that radicals form on all three tyrosines in DHP. Evidence for the formation of DHP Compound I in several tyrosine mutants was obtained. Variants that formed Compound I showed an increase in the catalytic rate for substrate oxidation but also an increase in heme bleaching, suggesting that the tyrosines are necessary for protecting the enzyme from oxidizing itself. This protective role of tyrosines is likely an evolutionary adaptation allowing DHP to avoid self-inflicted damage in the oxidative environment.

  3. Demanding Satisfaction (United States)

    Oguntoyinbo, Lekan


    It was the kind of crisis most universities dread. In November 2006, a group of minority student leaders at Indiana University-Purdue University Indianapolis (IUPUI) threatened to sue the university if administrators did not heed demands that included providing more funding for multicultural student groups. This article discusses how this threat…

  4. 复杂水体中五日生化需氧量测定的硝化抑制%Inhibition to Nitriifcstion in Determination of Biochemical Oxygen Demand After Five Days in Complex Water

    Institute of Scientific and Technical Information of China (English)

    吴丽娟; 胡晓乐; 陆喜红


    Nitration reaction was inhibited by allyl thiourea. Biochemical oxygen demand after five days is oxygen amount consumed by the decomposition of organic pollutants in biochemistry process. Nitration reaction caused the estimated value significantly increased and even caused chemical oxygen demand more than biochemical oxygen demand. Through adding 0.1% allyl thiourea into dilution water, the method made B/C value of water sample come back to the normal value between 0.2 and 0.7. The results of the blank sample and the standard sample met the requirement of the national standard method. This method was effectively eliminating interference, simple operation, and reducing the risk of the test to select dilution ratio. It has no significant effects on water without interference, and also can simplify the determining procedure of large batches of compositional complicated water samples.%利用丙烯基硫脲对有机污染物硝化过程进行抑制。五日生化需氧量反映的是有机污染物生物氧化过程中碳化阶段的耗氧量,而硝化阶段会导致测定结果显著偏高。未知水样基体复杂,很难判断是否存在会引起硝化作用的硝化细菌,往往导致测定结果偏高甚至出现生化需氧量大于化学需氧量(即B/C值大于1)的不合理现象。向每升稀释水中加入0.1%的丙烯基硫脲硝化抑制剂,对基体复杂样品进行稀释后测定,使得样品的B/C值回到理论正常值(0.2~0.7)的范围内,对空白样品和标准样品的实验结果均满足国标方法的质控保证及要求。生化需氧量测定时间长而难以进行复测,该方法有效地排除了干扰,操作简便,降低了生化需氧量测定过程中稀释倍数选择不合适的风险,减小了工作量,提高了准确度。该方法对正常水样的测定结果不产生显著影响,适用于大批量复杂水体样品的测定。

  5. 通气程度对颅脑损伤患者脑氧供需平衡的影响%Effect of hyperventilation on cerebral oxygen supply-demand balance in patients with traumatic brain injury

    Institute of Scientific and Technical Information of China (English)

    程明华; 许映娜


    BACKGROUND: Inadequate hyperventilation may trigger cerebrovascular contraction and lead to lowered cerebral perfusion and oxygen supply-demand imbalance.OBJECTIVE: To investigate the influence of hyperventilation on oxygen saturation in the internal jugular vein, difference in oxygen and lactic acid contents between the cerebral arteries and veins in patients with serious traumatic brain injury.DESIGN: Case analysis.SETTING: Department of Anesthesiology, First Hospital Affiliated to Shantou University.PARTICIPANTS: Sixteen patients who received emergency operations in the First Hospital Affiliated to Shantou University between January and July 2002.METHODS: Patients with traumatic brain injury underwent operation under general anesthesia, and the PaCO2 was maintained at 30 mm Hg for 15 minutes by regulating the respiration rate, followed by decrease to 25 mm Hg, maintained for 15 minutes before restoration to 30 mm Hg for 15 minutes. The fractional concentration of inspired oxygen was adjusted to maintain blood PaO2 at around 100-150 mm Hg, and the blood sample was collected from the artery and internal jugular vein 15 minutes after adjustment of PaCO2 for blood gas analysis. The PaO2 was then increased to 200-250 mm Hg by increasing the fractional concentration of inspired oxygen, and the PaCO2 was adjusted from 30 to 25 and then back to 30 mm Hg in the described manner, and the oxygen saturation in the internal jugular vein, difference in oxygen and lactic acid contents between the arteries and the veins were measured.MAIN OUTCOME MEASURES: Influence of blood PaO2 and PaCO2 on oxygen saturation in the internal jugular vein, difference in oxygen and lactic acid contents between the arteries and the veins.RESULTS: Sixteen patients met the diagnostic criteria and completed data collection. The arterial PaCO2 decreased from 30 to 25 mm Hg when arterial blood oxygen pressure increased from 100-150 to 200-250 mm Hg, which leads to obvious decrease of oxygen saturation

  6. 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 (United States)

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


    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.

  7. 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....

  8. Biologic

    CERN Document Server

    Kauffman, L H


    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.

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

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


    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.

  10. Automatic flow injection based methodologies for determination of scavenging capacity against biologically relevant reactive species of oxygen and nitrogen. (United States)

    Magalhães, Luís M; Lúcio, Marlene; Segundo, Marcela A; Reis, Salette; Lima, José L F C


    Redox reactions are the heart of numerous biochemical pathways found in cellular chemistry, generating reactive oxygen species (ROS) and reactive nitrogen species (RNS), that includes superoxide anion radical (O2-), hydrogen peroxide (H2O2), hydroxyl radical (HO), singlet oxygen ((1)O2), hypochlorite anion (OCl-), peroxynitrite anion (ONOO-) and nitric oxide radical (NO). The measurement of scavenging capacity against these reactive species presents new challenges, which can be met by flow injection analysis (FIA). In the present review several methods based on FIA and also on its predecessors computer-controlled techniques (sequential injection analysis, multisyringe flow injection analysis, multicommutated and multipumping flow systems) are critically discussed. The selectivity and applicability of the methodology, the generation and detection of the target reactive species, the benefits and limitations of automation when compared to batch methods are some of the issues addressed.

  11. Study on visible spectrophotometer and chemical oxygen demand detection system%可见分光光度计及化学需氧量检测系统的研究

    Institute of Scientific and Technical Information of China (English)


    阐述了可见分光光度计在化学需氧量(COD)检测方向的研究方案,给出了可见分光光度计光路和电路两部分的研究方法。仪器光路采用了对称切尔尼特纳分光结构,并采用全息平面衍射闪耀光栅作为分光元件,使得检测光在光谱能量和光谱分辨率上都得到了提高。电路方面采用高速度高精度对数放大器 log114,使得电路检测精度和响应速度得到了提高。通过对COD标准液的标定测量,并与 HACH-DR61000紫外可见分光光度计进行对比,证明仪器在COD检测方面的系统性能和准确性稳定可靠。%This article expounds the research of the spectrophotometer used in determined the chemical oxygen demand (COD),discusses the research method of the optical system and electronic system.Optical system using symmetrical Czerny Turner system,and use the holographic plane diffraction grating as light splitting element,which improves the spectral energy and spectral resolution.Electronic systems using the high speed high accuracy logarithmic amplifier log114,improves the detecting precision and response speed.Use the COD standard solution calibration Instrument, Compared with HACH-DR6000,that proved the COD detection system’s performance and accuracy are stable and reliable.

  12. Low Pressure Radio-Frequency Oxygen Plasma Induced Oxidation of Titanium – Surface Characteristics and Biological Effects


    Wan-Yu Tseng; Sheng-Hao Hsu; Chieh-Hsiun Huang; Yu-Chieh Tu; Shao-Chin Tseng; Hsuen-Li Chen; Min-Huey Chen; Wei-Fang Su; Li-Deh Lin


    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: untre...

  13. Biologically inspired highly durable iron phthalocyanine catalysts for oxygen reduction reaction in polymer electrolyte membrane fuel cells. (United States)

    Li, Wenmu; Yu, Aiping; Higgins, Drew C; Llanos, Bernard G; Chen, Zhongwei


    In the present work, we have designed and synthesized a new highly durable iron phtalocyanine based nonprecious oxygen reduction reaction (ORR) catalyst (Fe-SPc) for polymer electrolyte membrane fuel cells (PEMFCs). The Fe-SPc, with a novel structure inspired by that of naturally occurring oxygen activation catalysts, is prepared by a nonpyrolyzing method, allowing adequate control of the atomic structure and surface properties of the material. Significantly improved ORR stability of the Fe-SPc is observed compared with the commercial Fe-Pc catalysts. The Fe-SPc has similar activity to that of the commercial Fe-Pc initially, while the Fe-SPc displays 4.6 times higher current density than that of the commercial Fe-Pc after 10 sweep potential cycles, and a current density that is 7.4 times higher after 100 cycles. This has been attributed to the incorporation of electron-donating functional groups, along with a high degree of steric hindrance maintaining active site isolation. Nonprecious Fe-SPc is promising as a potential alternative ORR electrocatalyst for PEMFCs.

  14. 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

  15. Hydroxyl radical generation caused by the reaction of singlet oxygen with a spin trap, DMPO, increases significantly in the presence of biological reductants. (United States)

    Nishizawa, Chiho; Takeshita, Keizo; Ueda, Jun-ichi; Mizuno, Michiko; Suzuki, Kazuo T; Ozawa, Toshihiko


    Photosensitizers newly developed for photodynamic therapy of cancer need to be assessed using accurate methods of measuring reactive oxygen species (ROS). Little is known about the characteristics of the reaction of singlet oxygen (1O2) with spin traps, although this knowledge is necessary in electron spin resonance (ESR)/spin trapping. In the present study, we examined the effect of various reductants usually present in biological samples on the reaction of 1O2 with 5,5-dimethyl-1-pyrroline-N-oxide (DMPO). The ESR signal of the hydroxyl radical (*OH) adduct of DMPO (DMPO-OH) resulting from 1O2-dependent generation of *OH strengthened remarkably in the presence of reduced glutathione (GSH), 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid (Trolox), ascorbic acid, NADPH, etc. A similar increase was observed in the photosensitization of uroporphyrin (UP), rose bengal (RB) or methylene blue (MB). Use of 5-(diethoxyphosphoryl)-5-methyl-1-pyrroline-N-oxide (DEPMPO) as a spin trap significantly lessened the production of its *OH adduct (DEPMPO-OH) in the presence of the reductants. The addition of DMPO to the DEPMPO-spin trapping system remarkably increased the signal intensity of DEPMPO-OH. DMPO-mediated generation of *OH was also confirmed utilizing the hydroxylation of salicylic acid (SA). These results suggest that biological reductants enhance the ESR signal of DMPO-OH produced by DMPO-mediated generation of *OH from 1O2, and that spin trap-mediated *OH generation hardly occurs with DEPMPO.

  16. 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


    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

  17. 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


    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.

  18. 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



    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 an...

  19. Improved operating efficiency due to the use of pure oxygen in biological treatment plants for industrial effluents; Mejora de la eficiencia en la operacion de plantas depuradoras biologicas de efluentes industriales mediante la utilizacion de oxigeno puro

    Energy Technology Data Exchange (ETDEWEB)

    Cabeza, R.; Bargallo, J.; Crespi, M.


    The use of pure oxygen in biological waste water treatment plants offers a number of advantages due to its physicochemical properties in relation to Henry's Law Flick's Law. Pure oxygen is employed in addition to, or instead of, the existing oxygenation system for treating waste in plants in industrial sectors such as foods, chemicals, paper-making, textiles and others. Its main application is in heavy load treatments and when there are problems of space for siting or enlarging the plant, as it combines well with membrane bioreactor (MBR) and sequence batch reactor (SBR) treatments, as has been shown in several plants in operation. (Author) 4 refs.

  20. Integration of pharmacokinetic and NRF2 system biology models to describe reactive oxygen species production and subsequent glutathione depletion in liver microfluidic biochips after flutamide exposure. (United States)

    Leclerc, Eric; Hamon, Jeremy; Legendre, Audrey; Bois, Frederic Y


    We present a systems biology analysis of rat primary hepatocytes response after exposure to 10 μM and 100 μM flutamide in liver microfluidic biochips. We coupled an in vitro pharmacokinetic (PK) model of flutamide to a system biology model of its reactive oxygen species (ROS) production and scavenging by the Nrf2 regulated glutathione production. The PK model was calibrated using data on flutamide kinetics, hydroxyflutamide and glutathione conjugates formation in microfluidic conditions. The parameters of Nrf2-related gene activities and the subsequent glutathione depletion were calibrated using microarray data from our microfluidic experiments and literature information. Following a 10 μM flutamide exposure, the model predicted a recovery time to baseline levels of glutathione (GSH) and ROS in agreement with our experimental observations. At 100 μM, the model predicted that metabolism saturation led to an important accumulation of flutamide in cells, a high ROS production and complete GSH depletion. The high levels of ROS predicted were consistent with the necrotic switch observed by transcriptomics, and the high cell mortality we had experimentally observed. The model predicted a transition between recoverable GSH depletion and deep GSH depletion at about 12.5 μM of flutamide (single perfusion exposure). Our work shows that in vitro biochip experiments can provide supporting information for complex in silico modeling including data from extra cellular and intra cellular levels. We believe that this approach can be an efficient strategy for a global integrated methodology in predictive toxicology.


    Directory of Open Access Journals (Sweden)

    A. B. Sarwade


    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.

  2. 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.

  3. Oxygen therapy reduces postoperative tachycardia

    DEFF Research Database (Denmark)

    Stausholm, K; Kehlet, H; Rosenberg, J


    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....

  4. Across-slope relations between the biological populations, the euphotic zone and the oxygen minimum layer off the coast of Oman during the southwest monsoon (August, 1994) (United States)

    Herring, P. J.; Fasham, M. J. R.; Weeks, A. R.; Hemmings, J. C. P.; Roe, H. S. J.; Pugh, P. R.; Holley, S.; Crisp, N. A.; Angel, M. V.


    An area some 120×70 km off the eastern coast of Oman (containing the UK JGOFS Arabesque station) was intensively studied over a 17 day period in August 1994, with the objective of determining the relationships between the biological populations, the oxygen minimum layer and the dynamic hydrography of the euphotic zone. The outer margin of the area was delimited by a rectangle of 15 full depth CTD casts and the hydrography was further defined by two Seasoar surveys within the box. Midwater trawls were used to sample the populations at three stations, oceanic, slope and shelf edge respectively. Day and night samples of macroplankton and micronekton were taken at each station to determine the extent of diel vertical migration and the effect of the hypoxic region on these migrations. Concurrent ADCP data were used to follow the migrations and spatial changes in real time. Despite the limited area studied the patterns of upwelling and their temporal and spatial changes were complex. Coastal upwelling was observed directly only at the southwestern edge of the area during both Seasoar surveys. Persian Gulf Water was a consistent but spatially discrete feature of the region at depths of 200-300 m. Arabian Sea Surface Water was present at the eastern margin of the first survey. Between these two water masses was a large area with small horizontal gradients and variable silicate and chlorophyll levels. Satellite data suggest that this water may have been advected as a filament from a more northerly coastal source. Very marked changes took place in the hydrography and in the phytoplankton composition and abundance at the reference station at 19°N 59°E over the 16 day period between visits. The highest biomass of plankton and micronekton (expressed as wet volume or as carbon) occurred in the upper 100 m, closely correlated with the relatively high oxygen levels at these depths. Gelatinous animals predominated in these layers, with additional swarms of swimming crabs. Quite

  5. Activation of biologically relevant levels of reactive oxygen species by Au/g-C3N4 hybrid nanozyme for bacteria killing and wound disinfection. (United States)

    Wang, Zhenzhen; Dong, Kai; Liu, Zhen; Zhang, Yan; Chen, Zhaowei; Sun, Hanjun; Ren, Jinsong; Qu, Xiaogang


    As common reactive oxygen species, H2O2 is widely used for bacterial inactivation and wound disinfection. However, the concentrations used are always higher than physiological levels, which frequently result in potential toxicity to healthy tissue and even delay wound healing. Here we report highly efficient nanozyme hybrids that are capable of activating biologically relevant concentrations of H2O2 for defending bacterial infections. The integration of AuNPs with ultrathin graphitic carbon nitride (g-C3N4) provides excellent peroxidase-activity, which can catalyze the decomposition of H2O2 to OH radicals much more efficiently, allowing the use of bio-safety levels of H2O2 for the first time. Furthermore, our system not only exhibits striking bactericidal performance against both DR Gram-negative and DR Gram-positive bacteria, but also shows high efficiency in breaking down the existing DR-biofilms and prevented formation of new biofilms in vitro. More importantly, in vivo experiments indicate that our system could significantly prevent bacterial infections and accelerate the healing rate of wounds.

  6. Neutrophil bactericidal activity against Staphylococcus aureus adherent on biological surfaces. Surface-bound extracellular matrix proteins activate intracellular killing by oxygen-dependent and -independent mechanisms. (United States)

    Hermann, M; Jaconi, M E; Dahlgren, C; Waldvogel, F A; Stendahl, O; Lew, D P


    The activation patterns of surface adherent neutrophils are modulated via interaction of extracellular matrix proteins with neutrophil integrins. To evaluate neutrophil bactericidal activity, Staphylococcus aureus adherent to biological surfaces were incubated with neutrophils and serum, and the survival of surface bacteria was determined. When compared to albumin-coated surfaces, the bactericidal activity of neutrophils adherent to purified human extracellular matrix was markedly enhanced (mean survival: 34.2% +/- 9.0% of albumin, P less than 0.0001) despite similar efficient ingestion of extracellular bacteria. Enhancement of killing was observed when surfaces were coated with purified constituents of extracellular matrix, i.e., fibronectin, fibrinogen, laminin, vitronectin, or type IV collagen. In addition to matrix proteins, the tetrapeptide RGDS (the sequence recognized by integrins) crosslinked to surface bound albumin was also active (survival: 74.5% +/- 5.5% of albumin, P less than 0.02), and fibronectin-increased killing was inhibited by soluble RGDS. Chemiluminescence measurements and experiments with CGD neutrophils revealed that both oxygen-dependent and -independent bactericidal mechanisms are involved. In conclusion, matrix proteins enhance intracellular bactericidal activity of adherent neutrophils, presumably by integrin recognition of RGDS-containing ligands. These results indicate a role for extracellular matrix proteins in the enhancement of the host defense against pyogenic infections.

  7. Oxygen Therapy (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 ...

  8. Physical demands during folk dancing. (United States)

    Wigaeus, E; Kilbom, A


    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.

  9. 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


    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

  10. 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


    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.

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

    Kim, Chang-Gyun; Lee, Jin-Seok


    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

  12. Innovation and Demand

    DEFF Research Database (Denmark)

    Andersen, Esben Sloth


    the demand-side of markets in the simplest possible way. This strategy has allowed a gradual increase in the sophistication of supply-side aspects of economic evolution, but the one-sided focus on supply is facing diminishing returns. Therefore, demand-side aspects of economic evolution have in recent years...... received increased attention. The present paper argues that the new emphasis on demand-side factors is quite crucial for a deepened understanding of economic evolution. The major reasons are the following: First, demand represents the core force of selection that gives direction to the evolutionary process....... 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....

  13. Ethanol Demand in United States Gasoline Production

    Energy Technology Data Exchange (ETDEWEB)

    Hadder, G.R.


    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.


    Directory of Open Access Journals (Sweden)

    Alexander Yu. Sulimov


    Full Text Available The article is devoted to technique «Perfect demand illusion», which allows to strengthen the competitive advantageof retailers. Also in the paper spells out the golden rules of visual merchandising.The definition of the method «Demand illusion», formulated the conditions of its functioning, and is determined by the mainhypothesis of the existence of this method.Furthermore, given the definition of the «Perfect demand illusion», and describes its additional conditions. Also spells out the advantages of the «Perfect demandillusion», before the «Demand illusion».

  15. Causality in demand

    DEFF Research Database (Denmark)

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


    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...... 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...... 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...

  16. Using oxygen at home (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 ...

  17. Household fuel demand analysis

    Energy Technology Data Exchange (ETDEWEB)

    Cohn, S.; Hirst, E.; Jackson, J.


    This study develops econometric models of residential demands for electricity, natural gas, and petroleum products. Fuel demands per household are estimated as functions of fuel prices, per capita income, heating degree days, and mean July temperature. Cross-sectional models are developed using a large data base containing observations for each state and year from 1951 through 1974. Long-run own-price elasticities for all three fuels are greater than unity with natural gas showing the greatest sensitivity to own-price changes. Cross-price elasticities are all less than unity except for the elasticity of demand for oil with respect to the price of gas (which is even larger than the own-price elasticity of demand for oil). The models show considerable stabiity with respect to own-price elasticities but much instability with respect to the cross-price and income elasticities.

  18. Intelligent energy demand forecasting

    CERN Document Server

    Hong, Wei-Chiang


    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.

  19. Domestic Demand Will Work

    Institute of Scientific and Technical Information of China (English)


    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.

  20. Impact of Energy Demands (United States)

    Cambel, Ali B.


    The types of pollutants associated with the process of power production are identified. A nine-point proposal is presented on the ways the increase in power demands might be achieved with the minimum threat to the environment. (PR)

  1. The viability of biological treatment at Ibi wastewater treatment station; Viabilidad del tratamiento biologico de aguas residuales

    Energy Technology Data Exchange (ETDEWEB)

    Flor Garcia, M.V.; Morenilla Martinez, J.J.; Ruiz Zapata, R.


    In this study, we have proved the viability of biological treatment of leaving waters from Ibi Wastewater Treatment Station, where water is subject to the action of coagulant agents, following a physical and chemical process. the experience was based on wastewater treatment by using activated sludge, at experimental scale in a pilot plant. During the experiments, we controlled the main parameters which indicate treatment success; namely, Suspended Solids (SS), pH, Biochemical Oxygen Demand (BOD) and Chemical Oxygen Demand (COD), in addition to other substances such as nutrients and toxicants, and inhibitors of bio metabolism. (Author) 6 refs.

  2. Oxygenated Derivatives of Hydrocarbons (United States)

    For the book entitled “Insect Hydrocarbons: Biology, Biochemistry and Chemical Ecology”, this chapter presents a comprehensive review of the occurrence, structure and function of oxygenated derivatives of hydrocarbons. The book chapter focuses on the occurrence, structural identification and functi...

  3. [Apneic oxygenation]. (United States)

    Alekseev, A V; Vyzhigina, M A; Parshin, V D; Fedorov, D S


    Recent technological advances in thoracic and tracheal surgery make the anaesthesiologist use different respiratory techniques during the operation. Apneic oxygenation is a one of alternative techniques. This method is relatively easy in use, does not require special expensive equipment and is the only possible technique in several clinical situations when other respiratory methods are undesirable or cannot be used. However there is no enough information about apneic oxygenation in Russian. This article reviews publications about apneic oxygenation. The review deals with experiments on diffusion respiration in animals, physiological changes during apneic oxygenation in man and defines clinical cases when apneic oxygenation can be used.

  4. Advanced Oxygen Systems for Aircraft (Systemes d’Oxygene Avances) (United States)


    son acheminement vers le convertisseur embarque, ainsi que la plus grande fiabilite de 1’OBOGS compare aux systemes ä oxygene liquide traditionnels...Standardisation Coordination Committee. Minimum Physiological Requirements for Aircrew Demand Breathing Systems. Air Standard 61/101/6A, Washington DC ...Washington DC 1981. 5. Ernsting J, and Stewart WK, Introduction to Oxygen Deprivation at Reduced Barometric Pressure in: Gilles JA, Ed., A Textbook of

  5. Education on Demand

    DEFF Research Database (Denmark)

    Boysen, Lis; Hende, Merete


    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 temat......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...

  6. Demand Modelling in Telecommunications

    Directory of Open Access Journals (Sweden)

    M. Chvalina


    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. 

  7. Travel Demand Modeling

    Energy Technology Data Exchange (ETDEWEB)

    Southworth, Frank [ORNL; Garrow, Dr. Laurie [Georgia Institute of Technology


    This chapter describes the principal types of both passenger and freight demand models in use today, providing a brief history of model development supported by references to a number of popular texts on the subject, and directing the reader to papers covering some of the more recent technical developments in the area. Over the past half century a variety of methods have been used to estimate and forecast travel demands, drawing concepts from economic/utility maximization theory, transportation system optimization and spatial interaction theory, using and often combining solution techniques as varied as Box-Jenkins methods, non-linear multivariate regression, non-linear mathematical programming, and agent-based microsimulation.

  8. Biological effects of short-term, high-concentration exposure to methyl isocyanate. IV. Influence on the oxygen-binding properties of guinea pig blood.


    Maginniss, L A; Szewczak, J M; Troup, C M


    Whole blood oxygen equilibrium curves (O2 ECs), blood buffer lines, and several hematologic properties were determined for adult guinea pigs exposed to 700 ppm methyl isocyanate (MIC) for 15 min. MIC inhalation effected a significant reduction of blood O2 affinity; the half-saturation pressure (P50) at 38 degrees C increased from the control (untreated) level of 22.8 +/- 0.1 mm Hg to values ranging from 28.5 to 43.7 mm Hg for experimental animals. MIC exposure had no apparent influence on O2 ...

  9. 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:


    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.

  10. Oil supply and demand

    Energy Technology Data Exchange (ETDEWEB)

    Rech, O


    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)


    Directory of Open Access Journals (Sweden)



    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.

  12. Neutrophil bactericidal activity against Staphylococcus aureus adherent on biological surfaces. Surface-bound extracellular matrix proteins activate intracellular killing by oxygen-dependent and -independent mechanisms.


    Hermann, M.; Jaconi, M E; Dahlgren, C; Waldvogel, F A; Stendahl, O; Lew, D P


    The activation patterns of surface adherent neutrophils are modulated via interaction of extracellular matrix proteins with neutrophil integrins. To evaluate neutrophil bactericidal activity, Staphylococcus aureus adherent to biological surfaces were incubated with neutrophils and serum, and the survival of surface bacteria was determined. When compared to albumin-coated surfaces, the bactericidal activity of neutrophils adherent to purified human extracellular matrix was markedly enhanced (m...

  13. Demonstrate a Low Biochemical Oxygen Demand Aircraft Deicing Fluid (United States)


    standard deviation of 0.007. For comparison, density of previously tested epoxy and bismaleimide ( BMI ) composites was 1.52 g/cm3 and 1.54 g/cm3...standard deviation of 4.22. Average fiber content for previously tested epoxy and BMI composite materials was 70.1% and 65.0%, respectively. EPA Environmental Protection Agency EPCRA Emergency Planning and Community Right-To-Know Act ESTCP Environmental Security Technology

  14. Demonstrate a Low Biochemical Oxygen Demand Aircraft Deicing Fluid (United States)


    and hazardous proprietary additive materials such as corrosion inhibitors . Specifically, the test objectives were as follows: 1. Illustrate...concentrations of deicing fluids are known to cause acute aquatic toxicological effects, due mainly to additives (e.g., to improve corrosion inhibition... coats the aircraft surface in a smooth and consistent manner with no foam. Fluid has good wetting characteristics and exhibits no pitting

  15. Demand surge following earthquakes (United States)

    Olsen, Anna H.


    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.

  16. Migration and Tourism Demand

    Directory of Open Access Journals (Sweden)

    Nuno Carlos LEITÃO


    Full Text Available This study considers the relationship between immigration and Portuguese tourism demand for the period 1995-2008, using a dynamic panel data approach. The findings indicate that Portuguese tourism increased significantly during the period in accordance with the values expected for a developed country. The regression results show that income, shock of immigration, population, and geographical distance between Portugal and countries of origin are the main determinants of Portuguese tourism.

  17. Market Expects Demand Increase

    Institute of Scientific and Technical Information of China (English)


    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.

  18. 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)


    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.

  19. Appreciating Oxygen (United States)

    Weiss, Hilton M.


    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…

  20. Biological phosphorus removal inhibition by roxarsone in batch culture systems. (United States)

    Guo, Qingfeng; Liu, Li; Hu, Zhenhu; Chen, Guowei


    Roxarsone has been extensively used in the feed of animals, which is usually excreted unchanged in the manure and eventually enter into animal wastewater, challenging the biological phosphorus removal processes. Knowledge of its inhibition effect is key for guiding treatment of roxarsone-contaminated wastewater, and is unfortunately keeping unclear. We study the inhibition of roxarsone on biological phosphorus removal processes for roxarsone-contaminated wastewater treatment, in terms of the removal and rates of chemical oxygen demand (COD), phosphate. Results showed that presence of roxarsone considerably limited the COD removals, especially at roxarsone concentration exceeding 40 mg L(-1). Additionally, roxarsone inhibited both phosphorus release and uptake processes, consistent with the phosphate profiles during the biological phosphorus removal processes; whereas, roxarsone is more toxic to phosphorus uptake process, than release function. The results indicated that it is roxarsone itself, rather than the inorganic arsenics, inhibit biological phosphorus removal processes within both aerobic and anaerobic roxarsone-contaminated wastewater treatment.

  1. Effects of indirect actions and oxygen on relative biological effectiveness: estimate of DSB induction and conversion induced by gamma rays and helium ions. (United States)

    Tsai, Ju-Ying; Chen, Fang-Hsin; Hsieh, Tsung-Yu; Hsiao, Ya-Yun


    Clustered DNA damage other than double-strand breaks (DSBs) can be detrimental to cells and can lead to mutagenesis or cell death. In addition to DSBs induced by ionizing radiation, misrepair of non-DSB clustered damage contributes extra DSBs converted from DNA misrepair via pathways for base excision repair and nucleotide excision repair. This study aimed to quantify the relative biological effectiveness (RBE) when DSB induction and conversion from non-DSB clustered damage misrepair were used as biological endpoints. The results showed that both linear energy transfer (LET) and indirect action had a strong impact on the yields for DSB induction and conversion. RBE values for DSB induction and maximum DSB conversion of helium ions (LET = 120 keV/μm) to (60)Co gamma rays were 3.0 and 3.2, respectively. These RBE values increased to 5.8 and 5.6 in the absence of interference of indirect action initiated by addition of 2-M dimethylsulfoxide. DSB conversion was ∼1-4% of the total non-DSB damage due to gamma rays, which was lower than the 10% estimate by experimental measurement. Five to twenty percent of total non-DSB damage due to helium ions was converted into DSBs. Hence, it may be possible to increase the yields of DSBs in cancerous cells through DNA repair pathways, ultimately enhancing cell killing.

  2. 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. (United States)

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


    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.

  3. Exploring the kinetic and thermodynamic aspects of four-electron electrochemical reactions: electrocatalysis of oxygen evolution by metal oxides and biological systems. (United States)

    Wang, Vincent C-C


    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.

  4. Meeting increased demand. (United States)

    Blair, Andrew


    New Zealand is a little country with a little economy but with a population that's rapidly aging. New Zealand's population is only 4.3 million people. It's GDP is only $US58.6 billion (2002). New Zealand's expenditure on health as a percentage of GDP is not out of line with that of other countries. As a nation we have been increasing expenditure on health over recent years. In 1990 we spent 7% of GDP on health. In 1995 that increased to 7.65% and is now 8.3%. However, in per capita terms our expenditure on health does not compare so well with like countries. The size of New Zealand's economy is restricting what our country spends on health. Health is already the second highest demand on the New Zealand tax dollar. The tolerance of New Zealanders would be challenged if a Government attempted to increase taxes further to meet the growing demands for expenditure on health, but at the same time the population's expectations are increasing. This is the challenging situation we face today. What lies ahead? Like all industrialized countries New Zealand is facing an aging population. The population below age 40 is decreasing, but it is increasing significantly over that age. 16% of the population is currently aged over 60. By 2051 this proportion will almost double to just over 31%. Coupled with the aging population is increased awareness and expectations, as access to options for treatment and technology becomes readily accessible to the population through such media as the internet. The extent of the impact of the aging population can be clearly represented by focusing on one specialty such as orthopaedics. The New Zealand Orthopaecic Association undertook a study in July 2003 which concluded (among other things) that as a result of the projected aging of the population, over the next 50 years: Musculo-skeletal operations will increase by over 30%. The number of hip replacements will nearly double. The incidence of osteoporosis will increase by a massive 201%. The number

  5. Road infrastructure and demand induction

    DEFF Research Database (Denmark)

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


    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...

  6. 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.


    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).

  7. 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. (United States)

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


    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.

  8. Evolution of Oxygenic Photosynthesis (United States)

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


    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.

  9. Oxygen Therapy (United States)

    ... oxygen at very high altitudes (like in the mountains or in an airplane) even if you do ... Med Vol 171. P1-P2, 2005 ATS Patient Education Series © 2016 American Thoracic Society www. thoracic. org ...

  10. Animating the Ethical Demand

    DEFF Research Database (Denmark)

    Vistisen, Peter; Jensen, Thessa; Poulsen, Søren Bolvig


    This paper addresses the challenge of attaining ethical user stances during the design process of products and services and proposes animation-based sketching as a design method, which supports elaborating and examining different ethical stances towards the user. The discussion is qualified...... dispositions, as well as create an incentive for ethical conduct in development and innovation processes. The ethical fulcrum evolves around Løgstrup’s Ethical Demand and his notion of spontaneous life manifestations. From this, three ethical stances are developed; apathy, sympathy and empathy. By exploring...... both apathetic and sympathetic views, the ethical reflections are more nuanced as a result of actually seeing the user experience simulated through different user dispositions. Exploring the three ethical stances by visualising real use cases with the technologies simulated as already being implemented...

  11. Rewarding yet demanding

    DEFF Research Database (Denmark)

    Bjørkedal, S T B; Torsting, A M B; Møller, T


    AIM: The purpose of this study, by exploring client perspectives, was to achieve a better understanding of how people with schizophrenia experience an occupational therapy intervention designed to enable them to carry out meaningful occupations in the early phases of recovery. METHOD: A qualitative......, as demanding. Participants valued engaging in real-life occupations while anchoring new strategies but also the occupational therapist's role in dealing with failure. Participants felt the intervention assisted in their recovery process and enabled them to engage in meaningful occupations. CONCLUSION......: The study provided unique insight into how participants experienced a client-centred partnership with an occupational therapist in the early phases of recovery. The intervention was feasible and supported the participants' recovery process....

  12. Physical demands in worklife. (United States)

    Astrand, I


    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.

  13. Imaging oxygen metabolism with hyperpolarized magnetic resonance

    DEFF Research Database (Denmark)

    Schroeder, Marie; Laustsen, Christoffer


    Every tissue in the body critically depends on meeting its energetic demands with sufficient oxygen supply. Oxygen supply/demand imbalances underlie the diseases that inflict the greatest socioeconomic burden globally. The purpose of this review is to examine how hyperpolarized contrast media, used...... in combination with MR data acquisition methods, may advance our ability to assess oxygen metabolism non-invasively and thus improve management of clinical disease. We first introduce the concept of hyperpolarization and how hyperpolarized contrast media have been practically implemented to achieve translational...... and clinical research. We will then analyze how incorporating hyperpolarized contrast media could enable realization of unmet technical needs in clinical practice. We will focus on imaging cardiac and renal oxygen metabolism, as both organs have unique physiological demands to satisfy their requirements...

  14. Participatory Demand-supply Systems

    NARCIS (Netherlands)

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


    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

  15. 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)



    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

  16. Do large predatory fish track ocean oxygenation? (United States)

    Dahl, Tais W; Hammarlund, Emma U


    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.

  17. Reverse osmosis and nanofiltration of biologically treated leachate. (United States)

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


    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.

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


    Gürtekin, Engin; ŞEKERDAĞ, Nusret


    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.

  19. Information Demand Pattern for Teams

    Directory of Open Access Journals (Sweden)

    Dirk Stamer


    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.

  20. Physiological demands of a simulated BMX competition. (United States)

    Louis, J; Billaut, F; Bernad, T; Vettoretti, F; Hausswirth, C; Brisswalter, J


    The aim of this study was to investigate the physiological demands of Supercross BMX in elite athletes. Firstly athletes underwent an incremental cycling test to determine maximal oxygen uptake (VO2max) and power at ventilatory thresholds. In a second phase, athletes performed alone a simulated competition, consisting of 6 cycling races separated by 30 min of passive recovery on an actual BMX track. Oxygen uptake, blood lactate, anion gap and base excess (BE) were measured. Results indicated that a simulated BMX performed by elite athletes induces a high solicitation of both aerobic (mean peak VO2 (VO2peak): 94.3±1.2% VO2max) and anaerobic glycolysis (mean blood lactate: 14.5±4. 5 mmol x L(-1) during every race. Furthermore, the repetition of the 6 cycling races separated by 30 min of recovery led to a significant impairment of the acid-base balance from the third to the sixth race (mean decrease in BE: -18.8±7.5%, pBMX performance. These results suggest that both oxygen-dependent and -independent fuel substrate pathways are important determinants of BMX performance.

  1. 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


    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.

  2. An integrated communications demand model (United States)

    Doubleday, C. F.


    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.

  3. North American oil demand outlook

    Energy Technology Data Exchange (ETDEWEB)

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


    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)

  4. Removal Factor Analysis of Chemical Oxygen Demand by Bipolar Pulsed Discharge in Dye Waste Water with Plasma Treatment%双极性脉冲放电等离子体处理染料废水时化学需氧量去除效果相关因素分析

    Institute of Scientific and Technical Information of China (English)

    张若兵; 马文长; 张弦


    在双极性脉冲放电等离子体用于染料废水的降解过程中,废水化学需氧量(chemicaloxygendemand,COD)的变化是在更深层次上反映该技术对有机污染物的降解能力的重要指标。为此,重点研究了在气液固三相混合体双极性脉冲放电条件下典型染料废水COD的去除规律,测试了不同电压、气体流量、初始浓度等条件下染料废水COD的变化。实验结果表明:当负载电压较高时,染料废水的COD值会先升高然后不断降低;而负载电压较低时,COD值会在一定程度内缓慢上升;气体流量越高,COD的去除效果越好;废水初始浓度增加,COD的去除率略有下降;初始电导率增加,COD的去除率降低;对具有不同官能团的染料废水进行放电处理发现,双极性脉冲放电对于各种结构的染料均有良好的处理效果。%The removal rule of chemical oxygen demand (COD) in the typical dye solution was investigated using a packed bed reactor by bipolar pulsed discharge in the air-water-solid mixture, and the value of COD in different conditions such as different voltages, air flow rates and initial concentrations was measured. Experimental results prove that the COD value of dye waste water will increase first and then decrease constantly at a high load voltage, while the COD value increase slowly to a certain extent at a low load voltage. The removal effect of COD is better when the air flow rate is higher and is worse when the initial concentration and conductivity of the dye waste water increase. It is found that the degradation effect on dyes with different functional groups is remarkable after the bipolar pulsed discharge treatment.

  5. Assessment of Constructed Wetland Biological Integrity Using Aquatic Macroinvertebrates

    Directory of Open Access Journals (Sweden)

    C. Galbrand


    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.

  6. Passive migration barriers using slow release oxygen compounds

    Energy Technology Data Exchange (ETDEWEB)

    Norris, R.D. [Eckenfelder, Inc., Nashville, TN (United States); Johnson, J. [GRAM, Inc., Albuquerque, NM (United States); Odencrantz, J. [TRI-S Environmental Corp., Newport Beach, CA (United States)] [and others


    This paper describes passive barriers for controlling downgradient plume migration in contaminated aquifers. Numerous field studies using migration barriers to control benzene, toluene, ethylbenzene, and xylene (BTEX) plumes are briefly summarized. The barriers consist of a patented oxygen release compound placed in a row of wells transecting a BTEX plume. Oxygen is slowly released to the saturated zone, thus enhancing natural biodegradation. Migration is controlled by matching the oxygen release rate to the flux and oxygen demand of the dissolved contaminants.

  7. Demand Response in Smart Grids

    DEFF Research Database (Denmark)

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


    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 i...




  9. Technical Workers in Great Demand

    Institute of Scientific and Technical Information of China (English)


    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

  10. Job demands-resources model

    NARCIS (Netherlands)

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


    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. 七氟醚-瑞芬太尼麻醉对缺血型烟雾病脑血管重建术患者脑氧供需平衡的影响%Effects of sevoflurane-remifentanil anesthesia on the balance between cerebral oxygen supply and demand during cerebral revascularization for ischemic moyamoya disease

    Institute of Scientific and Technical Information of China (English)

    梁发; 崔伟华; 何颖; 焦希平; 王嵘; 张东; 韩如泉


    目的 评价七氟醚-瑞芬太尼麻醉对缺血型烟雾病脑血管重建术患者脑氧供需平衡的影响.方法 择期行颞浅动脉-大脑中动脉分支吻合术的缺血型烟雾病患者40例,性别不限,年龄19~ 59岁,BMI 19~ 25 kg/m2,ASA分级Ⅰ或Ⅱ级,Suzuki分期≥3.采用随机数字表法,将患者随机分为2组(n=20):异丙酚-瑞芬太尼组(PR组)和七氟醚-瑞芬太尼组(SR组).麻醉诱导:靶控输注异丙酚,血浆靶浓度5 μg/ml,静脉注射芬太尼3 μg/kg和罗库溴铵0.6 mg/kg.气管插管后行机械通气,麻醉维持:SR组吸入七氟醚(呼气末浓度1.0% ~ 1.7%),PR组TCI异丙酚,血浆靶浓度3~4 μg/ml,2组均TCI瑞芬太尼,血浆靶浓度3.5 ng/ml,维持BIS值40 ~ 60,间断静脉注射罗库溴铵0.3 mg/kg.分别于麻醉诱导前(T0)、血管阻断前10 min (T1)、血管阻断后10 min (T2)、血管吻合-开放后10 min (T3)时记录局部脑氧饱和度(rSO2).结果 与T0时比较,PR组T3时术侧rSO2升高,SR组T1-3时术侧和非术侧rSO2升高(P<0.05或0.01);与PR组比较,SR组T1时术侧rSO2升高(P<0.05),非术侧rSO2差异无统计学意义(P>0.05).结论 对于缺血型烟雾病脑血管重建术患者,七氟醚复合瑞芬太尼麻醉可维持良好的脑氧供需平衡状态,且与异丙酚复合瑞芬太尼麻醉的效果相似.%Objective To evaluate the effects of sevoflurane-remifentanil anesthesia on the balance between cerebral oxygen supply and demand during cerebral revascularization for ischemic moyamoya disease by monitoring regional cerebral O2 saturation (rSO2) with near infrared spectroscopy.Methods Forty patients of both sexes aged 19-59 yr with a body mass index of 19-25 kg/m2 undergoing superficial temporal artery-middle cerebral artery anastomosis were randomly allocated into 2 groups (n =20 each):propofol-remifentanil group (group PR) and sevoflurane-remifentanil group (group SR).Radial artery was cannulated for direct BP monitoring and blood sampling

  12. Reversible Oxygenation of Oxygen Transport Proteins. (United States)

    Drain, C. M.; Corden, Barry B.


    Describes a lecture demonstration which illustrates changes in the visible spectra of oxygen transport proteins upon reversible oxygen binding. Provides a comparison of the physical characteristics of oxygen storage and transport proteins. Reviews essentials for preparation of the materials. (ML)

  13. Are demand forecasting techniques applicable to libraries?



    Examines the nature and limitations of demand forecasting, discuses plausible methods of forecasting demand for information, suggests some useful hints for demand forecasting and concludes by emphasizing unified approach to demand forecasting.

  14. Hyperbaric Oxygen Therapy (United States)

    ... before your first hyperbaric oxygen therapy session. During hyperbaric oxygen therapy Hyperbaric oxygen therapy typically is performed ... and the therapy unit throughout your treatment. After hyperbaric oxygen therapy You may feel somewhat tired or ...

  15. Demand, Energy, and Power Factor (United States)


    demand, but first, let’s talk some more about why electrical demand charges occur. Electric Load Leveling: 5 ** show flip chart of daily utility load (see...and cost savings for energy are available as a result of lowering demand. 3 ’~ show flip chart of block structure (see copy at end of script) Shown... flip chart (see copy at end of script) This is a graphical representation of real, apparent and reactive power in3 an AC circuit. Real power is the power

  16. Voltage Controlled Dynamic Demand Response

    DEFF Research Database (Denmark)

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


    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...... 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...... by Danish electricity distribution company SEAS-NVE....

  17. Hydrophobic organic chemicals (HOCs) removal from biologically treated landfill leachate by powder-activated carbon (PAC), granular-activated carbon (GAC) and biomimetic fat cell (BFC). (United States)

    Liyan, Song; Youcai, Zhao; Weimin, Sun; Ziyang, Lou


    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 (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.

  18. Saving Electricity and Demand Response (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.

  19. Temperature Effect on Energy Demand

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Young Duk [Korea Energy Economics Institute, Euiwang (Korea)


    We provide various estimates of temperature effect for accommodating seasonality in energy demand, particularly natural gas demand. We exploit temperature response and monthly temperature distribution to estimate the temperature effect on natural gas demand. Both local and global smoothed temperature responses are estimated from empirical relationship between hourly temperature and hourly energy consumption data during the sample period (1990 - 1996). Monthly temperature distribution estimates are obtained by kernel density estimation from temperature dispersion within a month. We integrate temperature response and monthly temperature density over all the temperatures in the sample period to estimate temperature effect on energy demand. Then, estimates of temperature effect are compared between global and local smoothing methods. (author). 15 refs., 14 figs., 2 tabs.

  20. 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.


    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.

  1. The metabolic demands of kayaking: a review. (United States)

    Michael, Jacob S; Rooney, Kieron B; Smith, Richard


    Flat water kayaking is characterised by exceptional demands on upper body performance.When examining the oxygen consumption, it is notable that although a high value is attainable, they are not quite as high as other sporting events such as road cycling, rowing or running where lower body is dominant.Elite kayakers demonstrate superior aerobic and anaerobic quantities and have reported maximal oxygen consumptions of around 58 ml·kg(-1)·min(-1) (4.7 L·min(-1)) and lactate values of around 12 mM during laboratory and on water testing.

  2. 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


    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.

  3. Workload demand in police officers during mountain bike patrols. (United States)

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


    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.

  4. Energy supply and demand in California (United States)

    Griffith, E. D.


    The author expresses his views on future energy demand on the west coast of the United States and how that energy demand translates into demand for major fuels. He identifies the major uncertainties in determining what future demands may be. The major supply options that are available to meet projected demands and the policy implications that flow from these options are discussed.

  5. International Oil Supplies and Demands

    Energy Technology Data Exchange (ETDEWEB)


    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.

  6. International Oil Supplies and Demands

    Energy Technology Data Exchange (ETDEWEB)


    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. Consumer demand and quality assurance

    DEFF Research Database (Denmark)

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


    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......, 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....

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

    Seibel, Brad A.


    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.

  9. Credit demand in Mozambican manufacturing

    DEFF Research Database (Denmark)

    Byiers, Bruce; Rand, John; Tarp, Finn


    manager education and business association membership are associated with whether a firm is credit constrained or not. Using our preferred measure of credit constraint suggests that around 43 per cent of the firms surveyed are constrained, and these enterprises would almost triple their debt burden......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...

  10. Demand inducement as cheap talk. (United States)

    Calcott, P


    The doctor-patient interaction is analysed in a game of cheap talk. Causes and consequences of imperfect agency are examined. One form of imperfect agency, supplier-induced demand, is a feature of neologism proof equilibria with some parameter values but not with others. The model is used to evaluate two tests that have been used to test for the existence of supplier-induced demand. The analysis suggests that the two tests, which compare the medical utilization of informed and uninformed consumers, are not valid.

  11. Rapid hydrogen and oxygen atom transfer by a high-valent nickel-oxygen species

    NARCIS (Netherlands)

    Corona, Teresa; Draksharapu, Apparao; Padamati, Sandeep K; Gamba, Ilaria; Martin-Diaconescu, Vlad; Acuña-Parés, Ferran; Browne, Wesley R; Company, Anna


    Terminal high-valent metal-oxygen species are key reaction intermediates in the catalytic cycle of both enzymes (e.g., oxygenases) and synthetic oxidation catalysts. While tremendous efforts have been directed towards the characterization of the biologically relevant terminal manganese-oxygen and ir

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

    DEFF Research Database (Denmark)

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


    conditions. However, this fails to take into account that oxygen solubility declines with decreasing atmospheric pressure, which may be of importance at high altitudes. 2. Based on samples of macroinvertebrate benthos and in situ measurements of respiratory oxygen demand of macroinvertebrates in small...

  13. 46 CFR 169.689 - Demand loads. (United States)


    ... Electrical Electrical Installations on Vessels of 100 Gross Tons and Over § 169.689 Demand loads. Demand loads must meet § 111.60-7 of this chapter except that smaller demand loads for motor feeders...

  14. Optical detection of singlet oxygen from single cells

    DEFF Research Database (Denmark)

    Snyder, John; Skovsen, Esben; Lambert, John D. C.;


    The lowest excited electronic state of molecular oxygen, singlet molecular oxygen, O2(a 1g), is a reactive species involved in many chemical and biological processes. To better understand the roles played by singlet oxygen in biological systems, particularly at the sub-cellular level, optical too...... for mechanistic studies of intra- and inter-cellular signaling and events that ultimately lead to photo-induced cell death....

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

    Directory of Open Access Journals (Sweden)

    Carrasquero-Ferrer Sedolfo José


    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.

  16. Market demands to Danish pork

    DEFF Research Database (Denmark)

    Bredahl, Lone


    . The study focuses on the development on the most important markets for Danish pork. The countries are Denmark, Japan, UK, Germany, Italy, France, USA, Russia and South Korea. The primary purpose is to identify market demands of importance to the Danish pork sector in order to maintain and strengthen its...

  17. Physical Demands Study - Focus Groups (United States)


    and the rounds in the boxes weigh 35 lb, which is lighter than equipment handled in the other physically demanding job tasks already identified...and standards. Ergonomics . 53: 858-871. 40 Appendix A: Questionnaires Completed by Volunteers prior to each Focus Group Interview 1 2 3 4a 4b 5

  18. The Cognitive Demands of Writing

    NARCIS (Netherlands)

    Torrance, Mark; Jeffery, Gaynor


    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

  19. Cotton Demand Dropping in China

    Institute of Scientific and Technical Information of China (English)


    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.

  20. 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)


    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.

  1. The moral demands of affluence

    DEFF Research Database (Denmark)

    Sønderholm, Jørn


    In 2004, Garrett Cullity made a significant contribution to the literature on what the world’s relatively affluent owe to the world’s relatively poor through the publishing of The Moral Demands of Affluence. In this discussion note, I draw attention to a logical problem in Cullity’s master argument...

  2. Managed care demands flexibility, creativity. (United States)


    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.

  3. Employer Demands from Business Graduates (United States)

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


    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,…

  4. Demand as Frequency Controlled Reserve

    DEFF Research Database (Denmark)

    Xu, Zhao; Østergaard, Jacob; Togeby, Mikael


    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...

  5. Demand Controlled Ventilation and Classroom Ventilation

    Energy Technology Data Exchange (ETDEWEB)

    Fisk, William J. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Mendell, Mark J. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Davies, Molly [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Eliseeva, Ekaterina [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Faulkner, David [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Hong, Tienzen [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Sullivan, Douglas P. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)


    This document summarizes a research effort on demand controlled ventilation and classroom ventilation. The research on demand controlled ventilation included field studies and building energy modeling.

  6. Demand as frequency controlled reserve

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Z.; Togeby, M.; OEstergaard, J.


    Using demand as frequency controlled reserve (DFR) is an emerging technology which allow demand to participate actively in maintaining the system operation without reducing the energy service delivered to the customer and without need of user interaction. The basic premise is that traditional frequency controlled reserves from power plants and interconnections with neighbouring systems can be costly, slow and not fulfil the need for future power grids with a high share of wind power and fewer central power plants, and an intention to perform flexible operation such as is landing. Electricity demands, on the other hand, have advantages as frequency reserve including fast activation speed, smooth linear activation, low expected costs, and well-dispersed in the distribution grid. The main challenge of DFR is new methods for monitoring the available capacity. This project has investigated the technology of using electricity demands for providing frequency reserve to power systems. Within the project the potential and economy of DFR compatible loads in Denmark has been investigated, control logic has been designed, power system impact has been investigated, potential business models has been evaluated and an implementation strategy has been suggested. The tasks and goals of the project have been successfully accomplished based on which the conclusion and future recommendation are made. This project has developed the DFR technology that enables electricity demands to autonomously disconnect or reconnect to the grid in response to system frequency variations. The developed DFR technology is proved to be a promising technology from several perspectives. Technically, using DFR is feasible to provide reserves and enhance power system frequency control, while fulfilling technical requirements such as linear activation (or reconnection) according to frequency (or time). Environmentally, the DFR technology is pollution free in contrast to traditional reserves from generation

  7. Aspects of food hygiene and demands on irradiation of food

    Energy Technology Data Exchange (ETDEWEB)

    Janetschke, P.; Voigtlaender, K.H.; Streuer, H.J.


    Legislation of food irradiation in the GDR has been entailing a number of topical demands on food research and monitoring. International literature has been evaluated for aspects of food hygiene in the context of irradiation, with the view to ensure proper preservation and hygiene of foodstuff. Dose-dependent induced radioactivity, formation of toxic substances as well as the impact of radiation on biological valence and on sensorial food conditions are discussed, with particular reference to microbicidal action of ionizidng radiation. Conclusions are drawn in the context of food hygiene, with general demands on irradiation of foodstuff.

  8. How plasma induced oxidation, oxygenation, and de-oxygenation influences viability of skin cells (United States)

    Oh, Jun-Seok; Strudwick, Xanthe; Short, Robert D.; Ogawa, Kotaro; Hatta, Akimitsu; Furuta, Hiroshi; Gaur, Nishtha; Hong, Sung-Ha; Cowin, Allison J.; Fukuhara, Hideo; Inoue, Keiji; Ito, Masafumi; Charles, Christine; Boswell, Roderick W.; Bradley, James W.; Graves, David B.; Szili, Endre J.


    The effect of oxidation, oxygenation, and de-oxygenation arising from He gas jet and He plasma jet treatments on the viability of skin cells cultured in vitro has been investigated. He gas jet treatment de-oxygenated cell culture medium in a process referred to as "sparging." He plasma jet treatments oxidized, as well as oxygenated or de-oxygenated cell culture medium depending on the dissolved oxygen concentration at the time of treatment. He gas and plasma jets were shown to have beneficial or deleterious effects on skin cells depending on the concentration of dissolved oxygen and other oxidative molecules at the time of treatment. Different combinations of treatments with He gas and plasma jets can be used to modulate the concentrations of dissolved oxygen and other oxidative molecules to influence cell viability. This study highlights the importance of a priori knowledge of the concentration of dissolved oxygen at the time of plasma jet treatment, given the potential for significant impact on the biological or medical outcome. Monitoring and controlling the dynamic changes in dissolved oxygen is essential in order to develop effective strategies for the use of cold atmospheric plasma jets in biology and medicine.

  9. 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


    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).

  10. Simultaneous Monitoring of Vascular Oxygenation and Tissue Oxygen Tension of Breast Tumors Under Hyperbaric Oxygen Exposure (United States)


    biological tissue, and allow for detection of specific light-absorbing chromophores in human in vivo, such as oxygenated and deoxygenated hemoglobin...spectra from tumor tissue. Briefly, continuous wave (CW) light from a 20 W tungsten-halogen light source (HL-2000HP, ocean optics, FL) is coupled...spectrometer (USB2000, Ocean optics, FL). The broadband light diffuse spectrometer provides reflectance spectra from 400 to 900 nm. According to

  11. Metabolic Demands of Heavy Metal Drumming

    Directory of Open Access Journals (Sweden)

    Bryan Romero


    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

  12. Demand chain management - The evolution

    Directory of Open Access Journals (Sweden)

    D Ericsson


    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

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

    Directory of Open Access Journals (Sweden)

    Harun Akif Kabuk


    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.

  14. DataBase on Demand (United States)

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


    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.

  15. DataBase on demand

    CERN Document Server

    Aparicio, Ruben Gaspar; Coterillo Coz, I


    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.

  16. 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...... general public’ or ‘the troops’. The other lab has many diffuse ‘side-activities’ with bio-hackers, government and policy groups, but partly seems to engage in order to stay ahead of policy-makers and protect their core activity, which they find to be ‘basic research’. The paper finally argues...

  17. Energy demand modeling for Uzbekistan

    Directory of Open Access Journals (Sweden)

    Bobur Khodjaev


    Full Text Available The paper is devoted to energy demand forecasting in Uzbekistan. Studies show that in spite of the abundant reserves of hydrocarbons, low energy efficiency can have an adverse impact on energy security in Uzbekistan in the future. Oil and gas are the main primary energy source and they ensure energy security of Uzbekistan. Energy demand forecasting is essential in order to develop an effective energy policy. Such forecast can be useful to plan oil and gas production volumes, to identify priorities for the industrial modernization and to create favorable conditions for sustainable economic development in the future. Author proposes model based on translog function for developing medium-and long-term development programs in energy sector and the modernization and technological re-equipment of industry.

  18. Disruptive innovation: the demand side. (United States)

    Havighurst, Clark C


    The notion of disruptive innovation provides a welcome framework for considering the prospects for low-cost alternatives in American medicine. Such innovations as have been seen, however, are largely the result of demand by patients paying their own bills because they have high-deductible coverage or are uninsured. Many other cost-saving innovations are discouraged by financing systems that are themselves largely immune to competition from disruptive innovators.

  19. Demand controlled ventilation; Behovsstyrt ventilasjon

    Energy Technology Data Exchange (ETDEWEB)

    Soerensen, Henning Holm


    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)

  20. Fish demand and supply projections


    Sverdrup-Jensen, S.


    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...

  1. 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......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...

  2. Clinical review: Oxygen as a signaling molecule



    Molecular oxygen is obviously essential for conserving energy in a form useable for aerobic life; however, its utilization comes at a cost - the production of reactive oxygen species (ROS). ROS can be highly damaging to a range of biological macromolecules, and in the past the overproduction of these short-lived molecules in a variety of disease states was thought to be exclusively toxic to cells and tissues such as the lung. Recent basic research, however, has indicated that ROS production -...

  3. Artificial oxygen transport protein (United States)

    Dutton, P. Leslie


    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.

  4. Study on Customer Demands for Product Innovation

    Institute of Scientific and Technical Information of China (English)

    XIONG Zhiyong; YANG Mingzhong; LI Yibing; LI Jun


    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.

  5. Preliminary Study of Greywater Treatment through Rotating Biological Contactor

    Directory of Open Access Journals (Sweden)

    Ashfaq Ahmed Pathan


    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.

  6. Oxygen supply in aquatic ectotherms: partial pressure and solubility together explain biodiversity and size patterns. (United States)

    Verberk, Wilco C E P; Bilton, David T; Calosi, Piero; Spicer, John I


    Aquatic ectotherms face the continuous challenge of capturing sufficient oxygen from their environment as the diffusion rate of oxygen in water is 3 x 10(5) times lower than in air. Despite the recognized importance of oxygen in shaping aquatic communities, consensus on what drives environmental oxygen availability is lacking. Physiologists emphasize oxygen partial pressure, while ecologists emphasize oxygen solubility, traditionally expressing oxygen in terms of concentrations. To resolve the question of whether partial pressure or solubility limits oxygen supply in nature, we return to first principles and derive an index of oxygen supply from Fick's classic first law of diffusion. This oxygen supply index (OSI) incorporates both partial pressure and solubility. Our OSI successfully explains published patterns in body size and species across environmental clines linked to differences in oxygen partial pressure (altitude, organic pollution) or oxygen solubility (temperature and salinity). Moreover, the OSI was more accurately and consistently related to these ecological patterns than other measures of oxygen (oxygen saturation, dissolved oxygen concentration, biochemical oxygen demand concentrations) and similarly outperformed temperature and altitude, which covaried with these environmental clines. Intriguingly, by incorporating gas diffusion rates, it becomes clear that actually more oxygen is available to an organism in warmer habitats where lower oxygen concentrations would suggest the reverse. Under our model, the observed reductions in aerobic performance in warmer habitats do not arise from lower oxygen concentrations, but instead through organismal oxygen demand exceeding supply. This reappraisal of how organismal thermal physiology and oxygen demands together shape aerobic performance in aquatic ectotherms and the new insight of how these components change with temperature have broad implications for predicting the responses of aquatic communities to

  7. Oxygen sensing and signaling. (United States)

    van Dongen, Joost T; Licausi, Francesco


    Oxygen is an indispensable substrate for many biochemical reactions in plants, including energy metabolism (respiration). Despite its importance, plants lack an active transport mechanism to distribute oxygen to all cells. Therefore, steep oxygen gradients occur within most plant tissues, which can be exacerbated by environmental perturbations that further reduce oxygen availability. Plants possess various responses to cope with spatial and temporal variations in oxygen availability, many of which involve metabolic adaptations to deal with energy crises induced by low oxygen. Responses are induced gradually when oxygen concentrations decrease and are rapidly reversed upon reoxygenation. A direct effect of the oxygen level can be observed in the stability, and thus activity, of various transcription factors that control the expression of hypoxia-induced genes. Additional signaling pathways are activated by the impact of oxygen deficiency on mitochondrial and chloroplast functioning. Here, we describe the molecular components of the oxygen-sensing pathway.

  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)


    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. Oxygen-enhanced combustion

    CERN Document Server

    Baukal, Charles E


    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

  10. Oxygen - A Four Billion Year History

    DEFF Research Database (Denmark)

    Canfield, Donald Eugene

    guides readers through the various lines of scientific evidence, considers some of the wrong turns and dead ends along the way, and highlights the scientists and researchers who have made key discoveries in the field. Showing how Earth's atmosphere developed over time, Oxygen takes readers...... 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...

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

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


    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. All biology is computational biology (United States)


    Here, I argue that computational thinking and techniques are so central to the quest of understanding life that today all biology is computational biology. Computational biology brings order into our understanding of life, it makes biological concepts rigorous and testable, and it provides a reference map that holds together individual insights. The next modern synthesis in biology will be driven by mathematical, statistical, and computational methods being absorbed into mainstream biological training, turning biology into a quantitative science. PMID:28278152

  13. Modeling impact of storage zones on stream dissolved oxygen (United States)

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


    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.

  14. Preparation and analysis of zirconia oxygen sensors

    Institute of Scientific and Technical Information of China (English)

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


    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.

  15. Boron PLA for oxygen sensing & hypoxia imaging

    Directory of Open Access Journals (Sweden)

    Cassandra L. Fraser


    Full Text Available Oxygen is essential for many forms of life and its depletion in the body and the environment can lead to deleterious effects. Low oxygen conditions, even anoxia, are associated with eutrophication of lakes and rivers, wherein an over abundance of nutrients often caused by pollution result in excessive plant growth and decay, threatening water quality, ecosystem balance, and aquatic life. In the body, low oxygen conditions or hypoxia may be generalized, as can occur at high altitude or during strenuous exercise, or localized in particular tissues, when there is a mismatch between oxygen supply and demand. Hypoxia is present in many important diseases as well. Low oxygen levels in tumors are often associated with biochemical changes, increased invasiveness, cancer progression, and resistance to radiation and chemotherapies. Vascular blockage in strokes, heart attacks, and peripheral artery disease, which is common in diabetes, are other situations where oxygen levels can drop precipitously and cause great damage to affected tissues. Clearly, innovative sensing technologies that provide new insight into these many oxygen dependent processes can impact global society in significant ways.

  16. 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


    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)

  17. Comet assay with gill cells of Mytilus galloprovincialis end point tools for biomonitoring of water antibiotic contamination: Biological treatment is a reliable process for detoxification. (United States)

    Mustapha, Nadia; Zouiten, Amina; Dridi, Dorra; Tahrani, Leyla; Zouiten, Dorra; Mosrati, Ridha; Cherif, Ameur; Chekir-Ghedira, Leila; Mansour, Hedi Ben


    This article investigates the ability of Pseudomonas peli to treat industrial pharmaceuticals wastewater (PW). Liquid chromatography-mass spectrometry (MS)/MS analysis revealed the presence, in this PW, of a variety of antibiotics such as sulfathiazole, sulfamoxole, norfloxacine, cloxacilline, doxycycline, and cefquinome.P. peli was very effective to be grown in PW and inducts a remarkable increase in chemical oxygen demand and biochemical oxygen demand (140.31 and 148.51%, respectively). On the other hand, genotoxicity of the studied effluent, before and after 24 h of shaking incubation with P. peli, was evaluated in vivo in the Mediterranean wild mussels Mytilus galloprovincialis using comet assay for quantification of DNA fragmentation. Results show that PW exhibited a statistically significant (pcomet assay genotoxicity end points are useful tools to biomonitor the physicochemical and biological quality of water. Also, it could be concluded that P. peli can treat and detoxify the studied PW.

  18. Living with the extreme demand

    Directory of Open Access Journals (Sweden)

    Teppo Eskelinen


    Full Text Available 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 (postindustrial 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 one's possessions, and elaborate the conception of needs prevalent in both Singer's theory and the theories of many of his critics. My argument is that we have to recognise a category of needs called 'social necessities' that are neither luxuries nor basic needs. This leads to two main conclusions: first, the space for ethical deliberation on whether to donate to life-saving purposes is socially conditioned; and second, ethical strategies of redistribution ought to be accompanied with institutional changes, which also concern the conditions in wealthy countries.

  19. Positional demands of professional rugby. (United States)

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


    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. Demand Response Valuation Frameworks Paper

    Energy Technology Data Exchange (ETDEWEB)

    Heffner, Grayson


    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.

  1. Estimating Aggregate Demand in Egypt

    Directory of Open Access Journals (Sweden)

    Noha EMARA


    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.

  2. Prospects for European labour demand. (United States)

    Lindley, R M


    The impact of economic and technological trends upon the level and structure of labor demand is examined, exploring the methods used to model the labor market and making special reference to demography and technology. Evidence on recent and prospective changes in labor demand is reviewed for France, Germany, Italy, the Netherlands, and the UK. The models used to explore future employment scenarios usually fail to incorporate the linkages required to fully analyze the various demographic-economic interactions. Further, this is not generally viewed as a limitation, given the time frame of most employment projections and their preoccupation with changes in the structure of labor demand. Medium-term multisectoral models tend to pay more attention to both demographic and technical change, but the treatment of both aspects is limited. The projections provide a framework for considering how both socioeconomic behavior and policy might change to achieve different outcomes. The greater a model's behavioral content, as expressed in its relationships between different variables, the greater the insight obtainable from simulation exercises. The 1st half of the 1970s was characterized by a reduction in German employment, representing the severest of European reactions to the oil crisis. The 2nd half of the decade recorded rapid growth in Italy and the Netherlands. The 1980s started with marked declines in Germany and the UK. Overall, the net gains of the 1970s were lost in the recession following the 2nd oil crisis. In none of the 5 countries studied does any realistic prospect emerge of achieving full employment before 2000. The most optimistic outcome is that unemployment will decline only slowly, it at all. The growth of both new forms and areas of employment will not compensate sufficiently for the loss of jobs elsewhere and the growth of labor supply. The industrial sector will continue to experience change in favor of the service sector but at a slower rate than during

  3. Driving demand for broadband networks and services

    CERN Document Server

    Katz, Raul L


    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 ...

  4. Demands Set Upon Modern Cartographic Visualization

    Directory of Open Access Journals (Sweden)

    Stanislav Frangeš


    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.

  5. Global nitrogen fertilizer supply and demand outlook

    Institute of Scientific and Technical Information of China (English)

    Michel; Prud'homme


    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.

  6. Biological hydrogen photoproduction

    Energy Technology Data Exchange (ETDEWEB)

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


    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.

  7. Chahla Chafiq, Demande au Miroir


    Guilyardi, Catherine


    Le regard est omniprésent dans le premier roman en français de Chahla Chafiq, écrivain et sociologue iranienne exilée en France depuis 1983, reconnue pour ses travaux sur l’islamisme. Le personnage central de Demande au miroir, Guita Salim, regarde la vie de sa fenêtre. « Entre la fenêtre et le voir, il y a toujours un écart », écrit Forough Farrokhzâd, poétesse persane qui illumina les années 1950-1960, dont la poésie traverse ce roman. Adolescente, dans une ruelle de Téhéran, la jeune héroï...



    Irina CHIRITA; Ioana ZAHEU


    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...

  9. Study on Customer Demands for Product Innovation

    Institute of Scientific and Technical Information of China (English)

    XIONG Zhiyong; YANG Mingzhong; LI Yibing; LI Jun


    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.

  10. Cache County Water Demand/Supply Model


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


    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...

  11. Demand side management of electric car charging

    DEFF Research Database (Denmark)

    Finn, P.; Fitzpatrick, C.; Connolly, David


    in terms of distributed energy storage and flexible load. This paper examines how optimising the charging cycles of an electriccar using DSM (DemandSideManagement) based on a number of criteria could be used to achieve financial savings, increased demand on renewable energy, reduce demand on thermal...... generation plant, and reduce peak load demand. The results demonstrate that significant gains can be achieved using currently available market data which highlights the point that DSM can be implemented without any further technological advents....

  12. Development of a model for activated sludge aeration systems: linking air supply, distribution, and demand. (United States)

    Schraa, Oliver; Rieger, Leiv; Alex, Jens


    During the design of a water resource recovery facility, it is becoming industry practice to use simulation software to assist with process design. Aeration is one of the key components of the activated sludge process, and is one of the most important aspects of modelling wastewater treatment systems. However, aeration systems are typically not modelled in detail in most wastewater treatment process modelling studies. A comprehensive dynamic aeration system model has been developed that captures both air supply and demand. The model includes sub-models for blowers, pipes, fittings, and valves. An extended diffuser model predicts both oxygen transfer efficiency within an aeration basin and pressure drop across the diffusers. The aeration system model allows engineers to analyse aeration systems as a whole to determine biological air requirements, blower performance, air distribution, control valve impacts, controller design and tuning, and energy costs. This enables engineers to trouble-shoot the entire aeration system including process, equipment and controls. It also allows much more realistic design of these highly complex systems.

  13. Oxygen transport membrane

    DEFF Research Database (Denmark)


    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....

  14. Hyperbaric oxygen therapy (United States)

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

  15. Home Oxygen Therapy (United States)

    ... Teenagers Living With Lung Disease Articles written by Respiratory Experts Home Oxygen Therapy More and more people are using oxygen therapy ... April 12, 2012 Revised: © 2017 American Association for Respiratory Care

  16. Biogeochemistry: Oxygen burrowed away

    NARCIS (Netherlands)

    Meysman, F.J.R.


    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.

  17. Oxygen evolution reaction catalysis (United States)

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


    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.

  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. EDITORIAL: Photonic materials on demand Photonic materials on demand (United States)

    Zheludev, Nikolay; Padilla, Willie J.; Brener, Igal


    As David Payne famously said, 'we never have a photonic material that we want...'. This has changed with the proliferation of nanotechnology. Metamaterials—artificial media structured on a sub-wavelength scale—offer a radical paradigm for the engineering of optical properties. Some remarkable advances have been possible with metamaterials. These include, for instance, negative-index media that refract light in the opposite direction from that of conventional materials, chiral materials that rotate the polarization state of light hundreds of thousands of times more strongly than natural optical crystals, and structured thin films with remarkably strong dispersion that can slow light in much the same way as resonant atomic systems with electromagnetically induced transparency. The research agenda is now shifting towards achieving tunable and switchable functionalities with metamaterials [1] where the goal is, paraphrasing Dave Payne, 'to have on demand the photonic material that we want'. The papers in this Journal of Optics special issue explore and review the different approaches to both switching and tuning of metamaterial properties through exploiting effects such as phase conjugation, intense photo-excitation and photoconductivity, the use of electro-optical effects in conductive oxides, the exploitation global quantum coherency and resonantly coupled classical resonator and quantum structures, hybridization with gain media and the manipulation with shapes and constitution of the complex metamolecules and metamaterial reliefs by design, or using MEMS actuation. References [1] Zheludev N I and Kivshar Y 2012 From metamaterials to metadevices Nature Mater.11 917

  20. Removal of stigmasterol from Kraft mill effluent by aerobic biological treatment with steroidal metabolite detection. (United States)

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


    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.

  1. Combined technology for clomazone herbicide wastewater treatment: three-dimensional packed-bed electrochemical oxidation and biological contact degradation. (United States)

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


    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.

  2. 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


    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

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

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


    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.

  4. The oxygen minimum zone in the Arabian Sea during 1995

    Digital Repository Service at National Institute of Oceanography (India)

    Morrison, J.M.; Codispoti, L.A.; Smith, S.L.; Wishner, K.; Flagg, C.; Gardner, W.D.; Gaurin, S.; Naqvi, S.W.A.; Manghnani, V.; Prosperie, L.; Gundersen, J.S.

    showed string relationships to the oxygen profiles, especially in locations where the OMZ was pronounced, but the biological responses to the OMZ varied with type of organism. ADCP acoustic backscatter measurements show diel vertical migration of plankton...

  5. Three-dimensional three-phase model for simulation of hydrodynamics, oxygen mass transfer, carbon oxidation, nitrification and denitrification in an oxidation ditch. (United States)

    Lei, Li; Ni, Jinren


    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.

  6. Stability of Money Demand Function in Pakistan

    Directory of Open Access Journals (Sweden)

    Haroon Sarwar


    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.

  7. Demands of immigration among Chinese immigrant nurses. (United States)

    Ma, Amy X; Griffin, Mary T Quinn; Capitulo, Katie L; Fitzpatrick, Joyce J


    The purpose of this study was to identify the demands of immigration among Chinese nurses that have immigrated to the USA. The relationship between the demands of immigration and length of stay in the USA was investigated also. A descriptive correlational study design was used. A convenience sample of 128 nurses was recruited. A self-administered survey was conducted using the demands of immigration scale developed by Aroian, along with a demographic questionnaire. The results showed Chinese immigrant nurses have high demands of immigration. There were significant negative relationships between the demands of immigration and length of stay in the USA. Immigration demands decreased as length of stay increased but remained high even for those who had been in the USA for > 5 years. This information is vital to health-care agencies designing and implementing adaptation programmes targeting these demands to facilitate Chinese nurses' adaptation process.

  8. Development of a model to determine oxygen consumption when crawling. (United States)

    Pollard, J P; Heberger, J R; Dempsey, P G

    During a mine disaster or emergency, underground air can quickly become contaminated. In these circumstances, all underground mine workers are taught to don breathable air supply units at the first sign of an emergency. However, no contemporary oxygen consumption data is available for the purposes of designing breathing air supply equipment specifically for mine escape. Further, it would be useful to quantify the oxygen requirements of breathing air supply users for various escape scenarios. To address this need, 14 participants crawled a distance of 305 m each while their breath-by-breath oxygen consumption measurements were taken. Using these data, linear regression models were developed to determine peak and average oxygen consumption rates as well as total oxygen consumption. These models can be used by manufacturers of breathing air supply equipment to aid in the design of devices that would be capable of producing sufficient on-demand oxygen to allow miners to perform self-escape.

  9. Phosphate oxygen isotope ratios as a tracer for sources and cycling of phosphate in North San Francisco Bay, California (United States)

    McLaughlin, Karen; Kendall, Carol; Silva, Steven R.; Young, Megan; Paytan, Adina


    A seasonal analysis assesing variations in the oxygen isotopic composition of dissolved inorganic phosphate (DIP) was conducted in the San Francisco Bay estuarine system, California. Isotopic fractionation of oxygen in DIP (exchange of oxygen between phosphate and environmental water) at surface water temperatures occurs only as a result of enzyme-mediated, biological reactions. Accordingly, if phospate demand is low relative to input and phosphate is not heavily cycled in the ecosystem, the oxygen isotopic composition of DIP (δ18Op) will reflect the isotopic composition of the source of phosphate to the system. Such is the case for the North San Francisco Bay, an anthropogenically impacted estuary with high surface water phosphate concentrations. Variability in the δ18Op in the bay is primarily controlled by mixing of water masses with different δ18Op signatures. The δ18Op values range from 11.4‰ at the Sacramento River to 20.1‰ at the Golden Gate. Deviations from the two-component mixing model for the North Bay reflect additional, local sources of phosphate to the estuary that vary seasonally. Most notably, deviations from the mixing model occur at the confluence of a major river into the bay during periods of high river discharge and near wastewater treatment outlets. These data suggest that δ18Op can be an effective tool for identifying P point sources and understanding phosphate dynamics in estuarine systems.

  10. Females become infertile as the stored sperm's oxygen radicals increase



    International audience; AbstractPredicting infertility is central to reproductive biology, medicine and evolutionary biology. In-vitro studies suggest that oxidative sperm damage causes infertility. Oxidative sperm damage can be reduced via two fundamental pathways: the removal of oxygen radicals by antioxidants, or the interference with cell metabolism to reduce the formation of oxygen radicals. Oxidative damage protection of spermatozoa should evolve frequently, especially during female spe...

  11. Balancing the generation and elimination of reactive oxygen species (United States)

    Rodriguez, Rusty; Redman, Regina


    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.

  12. BATMAN: MOS Spectroscopy on Demand (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.


    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.

  13. Measurement of oxygen transfer from air into organic solvents

    DEFF Research Database (Denmark)

    Ramesh, Hemalata; Mayr, Torsten; Hobisch, Mathias;


    For the first time, we demonstrate on-line oxygen measurements in non-aqueous media using a novel optical sensor. The sensor was used to measure oxygen concentration in various organic solvents including toluene, THF, isooctane, DMF, heptane and hexane (which have all been shown suitable for several biological...

  14. Benthic biological effects of seasonal hypoxia in a eutrophic estuary predate rapid coastal development (United States)

    Bishop, Melanie J.; Powers, Sean P.; Porter, Hugh J.; Peterson, Charles H.


    Nutrient and organic loading associated with escalating human activities increases biological oxygen demand from microbial decomposition. In the Neuse River estuary, North Carolina, recurrent nuisance algal blooms, bottom-water hypoxic events, and fish kills during summers of the 1990s suggest that uncapped nutrient loading may have increased the frequency, duration, and/or spatial scope of important biological effects of hypoxia during summer, when persistent water column stratification can occur and microbial metabolism is greatest. We test the hypothesis that the severity of benthic biological effects of hypoxia in this estuary has increased over a 30-year period of dramatic human population growth in eastern North Carolina by comparing survival over summer of the benthic bivalve Macoma spp. between historical (1968-1970) and recent (1997-1998) years. Macoma is a demonstrated indicator of oxygen availability, the benthic biomass dominant in the Neuse and other temperate estuaries and the major prey link to higher trophic levels. All three historical summers exhibited patterns of collapse in Macoma populations indistinguishable from the recent summer of severe hypoxia (1997) but distinct from the modest changes documented during the mildly hypoxic summer of 1998. The only Macoma to survive any severely hypoxic summer were those in shallows where oxygen could be renewed by surface mixing. Thus, the biological effects of hypoxia observed in the Neuse River estuary in the late 1990s appear no more severe than 30 years before. Historic rates of organic loading to the Neuse River estuary may have been sufficient to induce widespread and intense hypoxia beneath the surface mixed layer, implying that even if algal blooms are diminished through nutrient reductions, the severity of biological effects of bottom-water hypoxia may not change detectably.

  15. [Oxygen in the field hospitals: current experience in the military health service]. (United States)

    Rouvier, B; Dupeyron, C; Carpentier, J P; Evrard, P


    A fifty per cent oxygen ratio locks quite sufficient for putting at sleep war wounded patient. After the present time, every french field surgical structures are equipped with oxygen extractors. Furthermore, those teams have at heir disposal for several years, oxygen generators, working with sodium chlorate candels. Those one can fill oxygen cylinders (3.5 l at 90 or 150 bars), providing pure oxygen, which will ever be essential under exceptional conditions. During war period, the supply difficulties demand to have at disposal two different production capabilities for oxygen administration.

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

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


    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.

  17. Biological decolourisation of pulp mill effluent using white rot fungus Trametes versicolor. (United States)

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


    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.

  18. Cyanobacterial diazotrophy and Earth's delayed oxygenation

    Directory of Open Access Journals (Sweden)

    Stephanie L Olson


    Full Text Available The redox landscape of Earth’s ocean-atmosphere system has changed dramatically throughout Earth history. Although Earth’s protracted oxygenation is undoubtedly the consequence of cyanobacterial oxygenic photosynthesis, the relationship between biological O2 production and Earth’s redox evolution remains poorly understood. Existing models for Earth’s oxygenation cannot adequately explain the nearly 2.5 billion year delay between the origin of oxygenic photosynthesis and the oxygenation of the deep ocean, in large part owing to major deficiencies in our understanding of the coevolution of O2 and Earth’s key biogeochemical cycles (e.g., the N cycle. For example, although possible links between O2 and N scarcity have been previously explored, the consequences of N2 limitation for net biological O2 production have not been examined thoroughly. Here, we revisit the prevailing view that N2 fixation has always been able to keep pace with P supply and discuss the possibility that bioavailable N, rather than P, limited export production for extended periods of Earth’s history. Based on the observation that diazotrophy occurs at the expense of oxygenesis in the modern ocean, we suggest that an N-limited biosphere may be inherently less oxygenic than a P-limited biosphere—and that cyanobacterial diazotrophy was a primary control on the timing and tempo of Earth’s oxygenation by modulating net biogenic O2 fluxes. We further hypothesize that negative feedbacks inhibit the transition between N and P limitation, with the implication that the pervasive accumulation of O2 in Earth’s ocean-atmosphere system may not have been an inevitable consequence of oxygenic photosynthesis by marine cyanobacteria.

  19. 42 CFR 414.226 - Oxygen and oxygen equipment. (United States)


    ... 42 Public Health 3 2010-10-01 2010-10-01 false Oxygen and oxygen equipment. 414.226 Section 414... Equipment and Prosthetic and Orthotic Devices § 414.226 Oxygen and oxygen equipment. (a) Payment rules—(1) Oxygen equipment. Payment for rental of oxygen equipment is made based on a monthly fee schedule...

  20. Biological computation

    CERN Document Server

    Lamm, Ehud


    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

  1. A hyperbaric oxygen chamber for animal experimental purposes. (United States)

    Djasim, U M; Spiegelberg, L; Wolvius, E B; van der Wal, K G H


    Facilities for hyperbaric oxygen therapy that are suitable for animal experimental research are scarce. In this paper, the authors introduce a hyperbaric oxygen chamber that was developed specifically for animal experimental purposes. The hyperbaric oxygen chamber was designed to meet a number of criteria regarding safety and ease of use. The hyperbaric oxygen chamber conforms to 97/23/EC (Pressure Equipment Directive), Conformity Assessment Module G Product Group 1. It provides easy access, and can be run in manual mode, semi-automatic mode and full-automatic mode. Sensors for pressure level, oxygen level, temperature, humidity and carbon dioxide level allow full control. This state-of-the-art hyperbaric oxygen chamber for animal experimental purposes permits the investigation of the biological mechanisms through which hyperbaric oxygen therapy acts at a fundamental level.

  2. Demand forecast model based on CRM (United States)

    Cai, Yuancui; Chen, Lichao


    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.

  3. Food safety information and food demand

    DEFF Research Database (Denmark)

    Smed, Sinne; Jensen, Jørgen Dejgård


    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...

  4. Electricity Demand and Energy Consumption Management System

    CERN Document Server

    Sarmiento, Juan Ojeda


    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. 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.

  6. Integrated turbomachine oxygen plant (United States)

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


    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.

  7. Modelling Demand for Broad Money in Australia


    Abbas Valadkhani


    The existence of a stable demand for money is very important for the conduct of monetary policy. It is argued that previous work on the demand for money in Australia has not been very satisfactory in a number of ways. This paper examines the long- and short-run determinants of the demand for broad money employing the Johansen cointegration technique and a short-run dynamic model. Using quarterly data for the period 1976:3-2002:2, this paper finds, inter alia, that the demand for broad money i...

  8. Income distribution trends and future food demand. (United States)

    Cirera, Xavier; Masset, Edoardo


    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.

  9. Solid state oxygen sensor (United States)

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


    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.

  10. Measuring tissue oxygenation (United States)

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


    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.

  11. Coping with cyclic oxygen availability: evolutionary aspects. (United States)

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


    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.

  12. [Biological weapons]. (United States)

    Kerwat, K; Becker, S; Wulf, H; Densow, D


    Biological weapons are weapons of mass destruction that use pathogens (bacteria, viruses) or the toxins produced by them to target living organisms or to contaminate non-living substances. In the past, biological warfare has been repeatedly used. Anthrax, plague and smallpox are regarded as the most dangerous biological weapons by various institutions. Nowadays it seems quite unlikely that biological warfare will be employed in any military campaigns. However, the possibility remains that biological weapons may be used in acts of bioterrorism. In addition all diseases caused by biological weapons may also occur naturally or as a result of a laboratory accident. Risk assessment with regard to biological danger often proves to be difficult. In this context, an early identification of a potentially dangerous situation through experts is essential to limit the degree of damage.

  13. Drivers of U.S. mineral demand (United States)

    Sznopek, John L.


    Introduction: The word 'demand' has different meanings for different people. To some, it means their 'wants and needs,' to others it is what they consume. Yet, when considering economics, demand refers to the specific amounts of goods or services that individuals will purchase at various prices. Demand is measured over a given time period. It is determined by a number of factors including income, tastes, and the price of complementary and substitute goods. In this paper, the term consumption is used fairly synonymously with the term demand. Most mineral commodities, like iron ore, copper, zinc, and gravel, are intermediate goods, which means that they are used in the production of other goods, called final goods. Demand for intermediate goods is called derived demand because such demand is derived from the demand for final goods. When demand increases for a commodity, generally the price rises. With everything else held constant, this increases the profits for those who provide this commodity. Normally, this would increase profits of existing producers and attract new producers to the market. When demand for a commodity decreases, generally the price falls. Normally, this would cause profits to fall and, as a consequence, the least efficient firms may be forced from the industry. Demand changes for specific materials as final goods or production techniques are reengineered while maintaining or improving product performance, for example, the use of aluminum in the place of copper in long distance electrical transmission lines or plastic replacing steel in automobile bumpers. Substitution contributes to efficient material usage by utilizing cheaper or technically superior materials. In this way, it may also alleviate materials scarcity. If a material becomes relatively scarce (and thus more expensive), a more abundant (and less expensive) material generally replaces it (Wagner and others, 2003, p. 91).

  14. Systems biology: experimental design. (United States)

    Kreutz, Clemens; Timmer, Jens


    Experimental design has a long tradition in statistics, engineering and life sciences, dating back to the beginning of the last century when optimal designs for industrial and agricultural trials were considered. In cell biology, the use of mathematical modeling approaches raises new demands on experimental planning. A maximum informative investigation of the dynamic behavior of cellular systems is achieved by an optimal combination of stimulations and observations over time. In this minireview, the existing approaches concerning this optimization for parameter estimation and model discrimination are summarized. Furthermore, the relevant classical aspects of experimental design, such as randomization, replication and confounding, are reviewed.

  15. Combining supramolecular chemistry with biology. (United States)

    Uhlenheuer, Dana A; Petkau, Katja; Brunsveld, Luc


    Supramolecular chemistry has primarily found its inspiration in biological molecules, such as proteins and lipids, and their interactions. Currently the supramolecular assembly of designed compounds can be controlled to great extent. This provides the opportunity to combine these synthetic supramolecular elements with biomolecules for the study of biological phenomena. This tutorial review focuses on the possibilities of the marriage of synthetic supramolecular architectures and biological systems. It highlights that synthetic supramolecular elements are for example ideal platforms for the recognition and modulation of proteins and cells. The unique features of synthetic supramolecular systems with control over size, shape, valency, and interaction strength allow the generation of structures fitting the demands to approach the biological problems at hand. Supramolecular chemistry has come full circle, studying the biology and its molecules which initially inspired its conception.

  16. Oxygen transfer in a pressurized airlift bioreactor. (United States)

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


    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.

  17. A field pilot-scale study of biological treatment of heavy oil-produced water by biological filter with airlift aeration and hydrolytic acidification system. (United States)

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


    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.

  18. Disaggregation of the demand for hospital care

    NARCIS (Netherlands)

    E.K.A. van Doorslaer (Eddy); R.C.J.A. van Vliet (René)


    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

  19. Teaching Aggregate Demand and Supply Models (United States)

    Wells, Graeme


    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…

  20. Intermittent demand : Linking forecasting to inventory obsolescence

    NARCIS (Netherlands)

    Teunter, Ruud H.; Syntetos, Aris A.; Babai, M. Zied


    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

  1. Modelling energy demand of Croatian industry sector

    DEFF Research Database (Denmark)

    Medić, Zlatko Bačelić; Pukšec, Tomislav; Mathiesen, Brian Vad


    Industry represents one of the most interesting sectors when analysing Croatian final energy demand. Croatian industry represents 20% of nation's GDP and employs 25% of total labour force making it a significant subject for the economy. Today, with around 60 PJ of final energy demand...

  2. Cost and Demand Characteristics of Telecom Networks

    DEFF Research Database (Denmark)

    Falch, Morten


    The Chapter presents the general characteristics of the cost and demand profiles for telecommunication services and identifies the barriers towards a free competitive market for telecommunication services related to these characteristics.......The Chapter presents the general characteristics of the cost and demand profiles for telecommunication services and identifies the barriers towards a free competitive market for telecommunication services related to these characteristics....

  3. Demand flexibility from residential heat pump

    DEFF Research Database (Denmark)

    Bhattarai, Bishnu Prasad; Bak-Jensen, Birgitte; Pillai, Jayakrishnan Radhakrishna


    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...

  4. 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.


    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

  5. Information management - Assessing the demand for information (United States)

    Rogers, William H.


    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.

  6. Simple utility functions with Giffen demand

    DEFF Research Database (Denmark)

    Sørensen, Peter Norman


    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...


    Department of Labor, Washington, DC.


  8. Lighting Systems Control for Demand Response

    NARCIS (Netherlands)

    Husen, S.A.; Pandharipande, A.; Tolhuizen, L.M.G.; Wang, Y.; Zhao, M.


    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

  9. The Demand for Rental Homes in Denmark

    DEFF Research Database (Denmark)

    Skak, Morten


    development, and gives some indications of the future demand for rental housing in Denmark. The results indicate a future stagnant rental demand kept up by an increasing share of persons of old age and young persons undergoing education, and thus a rising homeownership rate. It is believed that the structural...

  10. A Novel Technique to Enhance Demand Responsiveness

    DEFF Research Database (Denmark)

    Farashbashi-Astaneh, Seyed-Mostafa; Bhattarai, Bishnu Prasad; Bak-Jensen, Birgitte


    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...

  11. Energy infrastructure: Mapping future electricity demand (United States)

    Janetos, Anthony C.


    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.

  12. Oxygen therapy - infants (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. ...

  13. Proterozoic atmospheric oxygen

    DEFF Research Database (Denmark)

    Canfield, Donald Eugene


    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 histor...

  14. Highest Oxygen Bar

    Institute of Scientific and Technical Information of China (English)


    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.

  15. Extracorporeal membrane oxygenation circuitry. (United States)

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


    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.

  16. Demanded competences in the agricultural engineering sector in Spain (United States)

    Perdigones, A.; García, J. L.; Benavente, R. M.; Tarquis, A. M.


    (engineering, economy, biological competences). These differences suggest it might be a good idea to increase the amount of time devoted to the skills demanded by the enterprises. The software packages most commonly used by practising engineers were Microsoft Office / Excel (used by 79% of respondents) and CAD (56%), as well as budgeting (27%), statistical (21%), engineering (15%) and GIS (13%) programs. As a result of this survey our university department opened an additional computer suite in order to provide students practical experience in the use of the demanded competences. The results of this survey underline the importance of competence training in this and perhaps other fields of engineering.

  17. Communication technologies for demand side management

    Energy Technology Data Exchange (ETDEWEB)

    Uuspaeae, P. [VTT Energy, Espoo (Finland)


    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

  18. Uranium 2009 resources, production and demand

    CERN Document Server

    Organisation for Economic Cooperation and Development. Paris


    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...

  19. Sulfide removal by moderate oxygenation of anaerobic sludge environments

    Energy Technology Data Exchange (ETDEWEB)

    Van der Zee, F.P.; Villaverde, S.; Polanco, F. [Valladolid Univ., Valladolid (Spain). Dept. of Chemical Engineering; Garcia, P.A.


    Treating wastewater through anaerobic bioreactors results in the formation of hydrogen sulfide. The sulfide can be removed from the biogas by introducing air directly into the anaerobic bioreactor system. This study presents the results of batch experiments that provided a better insight into the fate of sulfur compounds and oxygen during microaerobic sulfide oxidation in granular sludge. It was shown that sulfide could be removed rapidly upon introduction of low amounts of oxygen to the sulfide-amended batch vials with granular sludge treating vinasse. Initially, the sulfide was oxidized to elemental sulfur, thiosulfate and polysulfide. Significant production of sulfate did not occur. The introduction of oxygen, however, could result in the growth of aerobic organic-chemical oxygen demand-oxidizing bacteria that compete with sulfide oxidation for oxygen. 6 refs., 1 tab., 1 fig.

  20. 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)


    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)

  1. Coordination of Energy Efficiency and Demand Response

    Energy Technology Data Exchange (ETDEWEB)

    Goldman, Charles; Reid, Michael; Levy, Roger; Silverstein, Alison


    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

  2. Next-generation biology

    DEFF Research Database (Denmark)

    Rodrigues da Fonseca, Rute Andreia; Albrechtsen, Anders; Themudo, Gonçalo Espregueira;


    we present an overview of the current sequencing technologies and the methods used in typical high-throughput data analysis pipelines. Subsequently, we contextualize high-throughput DNA sequencing technologies within their applications in non-model organism biology. We include tips regarding managing......As sequencing technologies become more affordable, it is now realistic to propose studying the evolutionary history of virtually any organism on a genomic scale. However, when dealing with non-model organisms it is not always easy to choose the best approach given a specific biological question......, a limited budget, and challenging sample material. Furthermore, although recent advances in technology offer unprecedented opportunities for research in non-model organisms, they also demand unprecedented awareness from the researcher regarding the assumptions and limitations of each method. In this review...

  3. Engineered Hybrid Nanoparticles for On-Demand Diagnostics and Therapeutics. (United States)

    Nguyen, Kim Truc; Zhao, Yanli


    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



    Marsh, John M.


    Three methods of calculating the derived elasticity of demand for Choice slaughter beef are used: (a) a traditional marketing margin approach, (b) a modified marketing margin approach, and (c) an econometric, inverse demand model approach. The first method is more restrictive than the second but both tend to overestimate beef price flexibility and revenue changes. The econometric model, though an incomplete demand system, yields demand elasticities that are more consistent with marketing flex...

  5. Demand System Analysis of the South Korean Beef Market with the Free Trade Demand Model


    Lee, Young-Jae; Kennedy, P. Lynn


    In this study a demand system analysis for beef in South Korea is constructed. A free trade demand system was used in which the economic welfare of market participants are maximized. Recognizing implicit discrimination about non-locally sourced beef products, this study deduces market demand equations with respect to consumer preference in order to identify the marginal effect of change consumer preference has on market demand.

  6. Structure Biology of Membrane Bound Enzymes

    Energy Technology Data Exchange (ETDEWEB)

    Fu, Dax [Johns Hopkins Univ., Baltimore, MD (United States). School of Medicine. Dept. of Physiology


    The overall goal of the proposed research is to understand the membrane-associated active processes catalyzed by an alkane $\\square$-hydroxylase (AlkB) from eubacterium Pseudomonase oleovorans. AlkB performs oxygenation of unactivated hydrocarbons found in crude oils. The enzymatic reaction involves energy-demanding steps in the membrane with the uses of structurally unknown metal active sites featuring a diiron [FeFe] center. At present, a critical barrier to understanding the membrane-associated reaction mechanism is the lack of structural information. The structural biology efforts have been challenged by technical difficulties commonly encountered in crystallization and structural determination of membrane proteins. The specific aims of the current budget cycle are to crystalize AlkB and initiate X-ray analysis to set the stage for structural determination. The long-term goals of our structural biology efforts are to provide an atomic description of AlkB structure, and to uncover the mechanisms of selective modification of hydrocarbons. The structural information will help elucidating how the unactivated C-H bonds of saturated hydrocarbons are oxidized to initiate biodegradation and biotransformation processes. The knowledge gained will be fundamental to biotechnological applications to biofuel transformation of non-edible oil feedstock. Renewable biodiesel is a promising energy carry that can be used to reduce fossil fuel dependency. The proposed research capitalizes on prior BES-supported efforts on over-expression and purification of AlkB to explore the inner workings of a bioenergy-relevant membrane-bound enzyme.

  7. Demand for human allograft tissue in Canada. (United States)

    Lakey, Jonathan R T; Mirbolooki, Mohammadreza; Rogers, Christina; Mohr, Jim


    There is relatively little known about the demand for allograft tissues in Canada. The Canadian Council for Donation and Transplantation (CCDT) is a national advisory body that undertook a comprehensive "market survey" to estimate surgical demand for human allograft tissues in Canada. The report "Demand for Human Allograft Tissue in Canada" reflects survey results sent to 5 prominent User Groups. User Groups were identified as orthopaedic surgeons; neurosurgeons; corneal transplant surgeons; plastic surgeons, specifically those at Canadian Burn Units; and cardiac surgeons (adult and paediatric surgery). The demand for allograft grafts was determined and then extrapolated across the total User Group and then increases in allograft tissue use over the next 1-2 years across User Groups were predicted. The overall response rate for the survey was 21.4%. It varied from a low of 19.6% for the orthopaedic survey to a high of 40.5% for the corneal survey. The estimated current demand for allograft tissue in Canada ranges from a low of 34,442 grafts per year to a high of 62,098 grafts per year. The predicted increase in use of allograft tissue over the next 1-2 year period would suggest that annual demand could rise to somewhere in the range of 42,589-72,210 grafts. The highest rated preferences (98% and 94%) were for accredited and Canadian tissue banks, respectively. This study represents a key step in addressing the paucity of information concerning the demand for allograft tissue in Canada.

  8. Oxygen foreshock of Mars (United States)

    Yamauchi, M.; Lundin, R.; Frahm, R. A.; Sauvaud, J.-A.; Holmström, M.; Barabash, S.


    Mars Express (MEX) has operated for more than 10 years in the environment of Mars, providing solar wind ion observations from the Analyzer of Space Plasmas and Energetic Atoms experiment's Ion Mass Analyser (IMA). On 21 September 2008, MEX/IMA detected foreshock-like discrete distributions of oxygen ions at around 1 keV in the solar wind attached to the bow shock and this distribution was observed continuously up to more than 2000 km from the bow shock. Foreshock-like protons are also observed but at a shifted location from the oxygen by about 1000 km, at a slightly higher energy, and flowing in a slightly different direction than the oxygen ions. Both protons and oxygen ions are flowing anti-sunward at different angles with respect to the solar wind direction. This is the first time that a substantial amount of planetary oxygen is observed upstream of the bow shock. Although rare, this is not the only IMA observation of foreshock-like oxygen: oxygen ions are sometimes observed for a short period of time (<5 min) inside the foreshock region. These observations suggest a new escape channel for planetary ions through the acceleration in the bow shock-magnetosheath region.

  9. Photo-oxidation: Major sink of oxygen in the ocean surface layer

    NARCIS (Netherlands)

    Gieskes, W.W.C.; Laane, R.W.P.M.; Ruardij, P.


    Evidence is presented that the oxygen demand associated with photochemical processes in the surface layer of oceans and seas worldwide is of the same order of magnitude as the amount of oxygen released by photosynthesis of the world's marine phytoplankton. Both estimates are of necessity quite rough

  10. Photo-oxidation : Major sink of oxygen in the ocean surface layer

    NARCIS (Netherlands)

    Gieskes, W. W. C.; Laane, R. W. P. M.; Ruardij, P.


    Evidence is presented that the oxygen demand associated with photochemical processes in the surface layer of oceans and seas worldwide is of the same order of magnitude as the amount of oxygen released by photosynthesis of the world's marine phytoplankton. Both estimates are of necessity quite rough

  11. Probabilistic Quantification of Potentially Flexible Residential Demand

    DEFF Research Database (Denmark)

    Kouzelis, Konstantinos; Mendaza, Iker Diaz de Cerio; Bak-Jensen, Birgitte


    The balancing of power systems with high penetration of renewable energy is a serious challenge to be faced in the near future. One of the possible solutions, recently capturing a lot of attention, is demand response. Demand response can only be achieved by power consumers holding loads which allow...... them to modify their normal power consumption pattern, namely flexible consumers. However flexibility, despite being constantly mentioned, is usually not properly defined and even rarer quantified. This manuscript introduces a methodology to identify and quantify potentially flexible demand...

  12. The demand for dairy products in Malawi


    Akaichi, Faiçal; Revoredo-Giha, Cesar


    In this paper a multi-stage almost ideal demand system with censoring was estimated to assess Malawians’ demand for six dairy products (viz. fresh milk, powdered milk, margarine and butter, chambiko, yogurt and cheese). We found that the consumption of dairy products depended on whether the household was rural or urban, the region of the country (viz. North, Centre, South) and the household poverty status. The results also show that the demand for fresh and powdered milk, butter and margari...

  13. Is synthetic biology mechanical biology? (United States)

    Holm, Sune


    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.

  14. Oxygen cycling in the northern Benguela Upwelling System: Modelling oxygen sources and sinks (United States)

    Schmidt, Martin; Eggert, Anja


    This paper elucidates the oxygen dynamics in the northern Benguela Upwelling System by means of process oriented, numerical modelling. Owing to the complex physical-biological interaction in this system, a coupled hydrodynamic-biogeochemical model is required to grasp the various aspects of the oxygen dynamics. We used high-resolution atmospheric fields derived from observations to force our model, available since 1999. The model results represent a 15 years, consistent data set of realistic hydrographic and ecosystem variables, including oxygen distribution patterns. After a concise description of the main aspects of the model, we use the model data to analyse the components contributing to the oxygen dynamics, namely, the ocean circulation, the exchange between ocean and atmosphere as well as the local biogeochemical oxygen cycling in the system. We thoroughly validate the model with available field observations and remote sensing data. The strengths of coastal upwelling, which controls the nutrient supply to the euphotic zone, as well as the poleward undercurrent that carries oxygen and nutrients to the shelf in the northern Benguela Upwelling System are well reproduced in the model. Among the biological oxygen sinks, mineralisation in the sediment, respiration of zooplankton and nitrification in the water column are important. We also found that vertical migration of zooplankton in response to the oxygen conditions provides a regulating feedback, which may prevent a complete deoxygenation of suboxic waters. As long as oxygen or nitrate are available in the bottom waters, the activities of chemolithoautotrophic sulphur bacteria on the sediment surface keep the redoxcline within the sediment and prevent the release of hydrogen sulphide into the water column. By horizontal integration of the simulated ocean-atmosphere oxygen flux, it can be shown that the Kunene upwelling cell between 16 ° S and 18 ° S is a boundary between the equatorial ocean, characterise by

  15. Serendipitous Findings While Researching Oxygen Free Radicals


    Floyd, Robert A.


    This review is based on the honor of receiving the Discovery Award from the Society of Free Radical Biology and Medicine. The review is reflective and presents our thinking which led to experiments that yielded novel observations. Critical questioning of our understanding of oxygen free radicals in biomedical problems led us to use and develop more direct and extremely sensitive methods. This included nitrone free radical spin-trapping and HPLC-electrochemical detection. This technology led t...

  16. Physiological roles of mitochondrial reactive oxygen species


    Sena, Laura A.; Chandel, Navdeep S.


    Historically, mitochondrial reactive oxygen species (mROS) were thought to exclusively cause cellular damage and lack a physiological function. Accumulation of ROS and oxidative damage have been linked to multiple pathologies, including neurodegenerative diseases, diabetes, cancer, and premature aging. Thus, mROS were originally envisioned as a necessary evil of oxidative metabolism, a product of an imperfect system. Yet few biological systems possess such flagrant imperfections, thanks to th...

  17. Models of reactive oxygen species in cancer


    Lu, Weiqin; Ogasawara, Marcia A.; Huang, Peng


    Increased generation of reactive oxygen species (ROS) has been observed in cancer, degenerative diseases, and other pathological conditions. ROS can stimulate cell proliferation, promote genetic instability, and induce adaptive responses that enable cancer cells to maintain their malignant phenotypes. However, when cellular redox balance is severely disturbed, high levels of ROS may cause various damages leading to cell death. The studies of ROS effects on biological systems, their underlying...

  18. Computational biology

    DEFF Research Database (Denmark)

    Hartmann, Lars Røeboe; Jones, Neil; Simonsen, Jakob Grue


    Computation via biological devices has been the subject of close scrutiny since von Neumann’s early work some 60 years ago. In spite of the many relevant works in this field, the notion of programming biological devices seems to be, at best, ill-defined. While many devices are claimed or proved t...

  19. Optic nerve oxygen tension

    DEFF Research Database (Denmark)

    la Cour, M; Kiilgaard, Jens Folke; Eysteinsson, T


    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. High Selectivity Oxygen Delignification

    Energy Technology Data Exchange (ETDEWEB)

    Lucian A. Lucia


    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.

  1. On-Demand Special Use Airspace Project (United States)

    National Aeronautics and Space Administration — We design and develop a Decision Support Tool (DST) that supports On-Demand Special Use Airspace (SUA) scheduling and flight plan optimization around SUA between...

  2. On-Demand Special Use Airspace Project (United States)

    National Aeronautics and Space Administration — We design and develope a Decision Support Tool (DST) that supports On-Demand Special Use Airspace (SUA) scheduling and flight plan optimization around SUA between...

  3. Minimum Energy Demand Locomotion on Space Station

    Directory of Open Access Journals (Sweden)

    Wing Kwong Chung


    Full Text Available The energy of a space station is a precious resource, and the minimization of energy consumption of a space manipulator is crucial to maintain its normal functionalities. This paper first presents novel gaits for space manipulators by equipping a new gripping mechanism. With the use of wheels locomotion, lower energy demand gaits can be achieved. With the use of the proposed gaits, we further develop a global path planning algorithm for space manipulators which can plan a moving path on a space station with a minimum total energy demand. Different from existing approaches, we emphasize both the use of the proposed low energy demand gaits and the gaits composition during the path planning process. To evaluate the performance of the proposed gaits and path planning algorithm, numerous simulations are performed. Results show that the energy demand of both the proposed gaits and the resultant moving path is also minimum.

  4. Demand Response and Energy Storage Integration Study

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Ookie [Dept. of Energy (DOE), Washington DC (United States). Office of Energy Efficiency and Renewable Energy; Cheung, Kerry [Dept. of Energy (DOE), Washington DC (United States). Office of Electricity Delivery and Energy Reliability; Olsen, Daniel J. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Matson, Nance [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Sohn, Michael D. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Rose, Cody M. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Dudley, Junqiao Han [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Goli, Sasank [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Kiliccote, Sila [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Cappers, Peter [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); MacDonald, Jason [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Denholm, Paul [National Renewable Energy Lab. (NREL), Golden, CO (United States); Hummon, Marissa [National Renewable Energy Lab. (NREL), Golden, CO (United States); Jorgenson, Jennie [National Renewable Energy Lab. (NREL), Golden, CO (United States); Palchak, David [National Renewable Energy Lab. (NREL), Golden, CO (United States); Starke, Michael [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Alkadi, Nasr [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Bhatnagar, Dhruv [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Currier, Aileen [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Hernandez, Jaci [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Kirby, Brendan [Consultant; O' Malley, Mark [Univ. College, Dublin (Ireland)


    Demand response and energy storage resources present potentially important sources of bulk power system services that can aid in integrating variable renewable generation. While renewable integration studies have evaluated many of the challenges associated with deploying large amounts of variable wind and solar generation technologies, integration analyses have not yet fully incorporated demand response and energy storage resources. This report represents an initial effort in analyzing the potential integration value of demand response and energy storage, focusing on the western United States. It evaluates two major aspects of increased deployment of demand response and energy storage: (1) Their operational value in providing bulk power system services and (2) Market and regulatory issues, including potential barriers to deployment.

  5. Hawaiian Electric Company Demand Response Roadmap Project

    Energy Technology Data Exchange (ETDEWEB)

    Levy, Roger [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Kiliccote, Sila [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)


    The objective of this project was to develop a “roadmap” to guide the Hawaiian Electric Company (HECO) demand response (DR) planning and implementation in support of the Hawaii Clean Energy Initiative (HCEI) 70% clean energy goal by 2030.

  6. Future United States Domestic Water Demand (United States)

    U.S. Environmental Protection Agency — Population projections, estimated per capita consumption rate, and estimated total annual water demand to 2100 for four future projections based off the IPCC SRES...

  7. Demand Uncertainty: Exporting Delays and Exporting Failures

    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 the resolution of uncertainty found in models with heterogeneity...... to forecast unknown demands in untested destinations. The option to forecast demands causes firms to delay exporting in order to gather more information about foreign demand. Third, since uncertainty is resolved after entry, many firms enter a destination and then exit after learning that they cannot profit....... This prediction reconciles the high rate of exit seen in the first years of exporting. Finally, when faced with multiple destinations to which they can export, many firms will choose to sequentially export in order to slowly learn more about its chances for success in untested markets....

  8. Demand Response With Micro-CHP Systems

    NARCIS (Netherlands)

    Houwing, M.; Negenborn, R.R.; De Schutter, B.


    With the increasing application of distributed energy resources and novel information technologies in the electricity infrastructure, innovative possibilities to incorporate the demand side more actively in power system operation are enabled. A promising, controllable, residential distributed genera

  9. Response of benthic foraminifera to phytodetritus in the eastern Arabian Sea under low oxygen conditions (United States)

    Enge, Annekatrin; Wukovits, Julia; Wanek, Wolfgang; Watzka, Margarete; Witte, Ursula; Hunter, William; Heinz, Petra


    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

  10. Climate policy implications for agricultural water demand

    Energy Technology Data Exchange (ETDEWEB)

    Chaturvedi, Vaibhav [Joint Global Change Research Inst., College Park, MD (United States); Hejazi, Mohamad I. [Joint Global Change Research Inst., College Park, MD (United States); Edmonds, James A. [Joint Global Change Research Inst., College Park, MD (United States); Clarke, Leon E. [Joint Global Change Research Inst., College Park, MD (United States); Kyle, G. Page [Joint Global Change Research Inst., College Park, MD (United States); Davies, Evan [Univ. of Alberta, Edmonton, AB (Canada); Wise, Marshall A. [Joint Global Change Research Inst., College Park, MD (United States); Calvin, Katherine V. [Joint Global Change Research Inst., College Park, MD (United States)


    Energy, water and land are scarce resources, critical to humans. Developments in each affect the availability and cost of the others, and consequently human prosperity. Measures to limit greenhouse gas concentrations will inevitably exact dramatic changes on energy and land systems and in turn alter the character, magnitude and geographic distribution of human claims on water resources. We employ the Global Change Assessment Model (GCAM), an integrated assessment model to explore the interactions of energy, land and water systems in the context of alternative policies to limit climate change to three alternative levels: 2.5 Wm-2 (445 ppm CO2-e), 3.5 Wm-2 (535 ppm CO2-e) and 4.5 Wm-2 (645 ppm CO2-e). We explore the effects of two alternative land-use emissions mitigation policy options—one which taxes terrestrial carbon emissions equally with fossil fuel and industrial emissions, and an alternative which only taxes fossil fuel and industrial emissions but places no penalty on land-use change emissions. We find that increasing populations and economic growth could be anticipated to almost triple demand for water for agricultural systems across the century even in the absence of climate policy. In general policies to mitigate climate change increase agricultural demands for water still further, though the largest changes occur in the second half of the century, under both policy regimes. The two policies examined profoundly affected both the sources and magnitudes of the increase in irrigation water demands. The largest increases in agricultural irrigation water demand occurred in scenarios where only fossil fuel emissions were priced (but not land-use change emission) and were primarily driven by rapid expansion in bioenergy production. In these scenarios water demands were large relative to present-day total available water, calling into question whether it would be physically possible to produce the associated biomass energy. We explored the potential of improved

  11. Biological Denitrification of High Nitrate Processing Wastewaters from Explosives Production Plant. (United States)

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


    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.

  12. Application of integrated ozone biological aerated filters and membrane filtration in water reuse of textile effluents. (United States)

    He, Yaozhong; Wang, Xiaojun; Xu, Jinling; Yan, Jinli; Ge, Qilong; Gu, Xiaoyang; Jian, Lei


    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.

  13. De-oxygenation

    Digital Repository Service at National Institute of Oceanography (India)

    Naqvi, S.W.A; Kortzinger, A

    of fixed nitrogen that keeps the atmospheric nitrogen content constant over geological time scales. An important aspect of redox chemistry of nitrogen is the production of nitrous oxide (N2O), a potent greenhouse gas both as an intermediate during... denitrification and as a byproduct during the 30 oxidation of ammonium to nitrate (nitrification). Denitrification is confined to low-oxygen waters, but even during nitrification, the yield of N2O is greatly enhanced as the waters get depleted with oxygen...

  14. Currency substitution, portfolio diversification, and money demand


    Freitas, Miguel Lebre de; Veiga, Francisco José


    We extend the Thomas (1985) dynamic optimising model of money demand and currency substitution to the case in which the individual has restricted or no access to foreign currency denominated bonds. In this case Currency Substitution decisions and Asset Substitution decisions are not separable. The results obtained suggest that the significance of an expected exchange rate depreciation term in the demand for domestic money provides a valid test for the presence of currency subst...

  15. Eliciting Demand Information through Cheap Talk

    DEFF Research Database (Denmark)

    Frisell, Lars; Lagerlöf, Johan N. M.


    A uniform pricing rule may enable the communication of demand information from buyer to seller in situations where this would not have been possible if the seller could price discriminate. Importantly, such a rule can benefit both buyer and seller.......A uniform pricing rule may enable the communication of demand information from buyer to seller in situations where this would not have been possible if the seller could price discriminate. Importantly, such a rule can benefit both buyer and seller....

  16. Water Demand Under Alternative Price Structures


    Sheila Olmstead; W. Michael Hanemann; Robert N. Stavins


    We estimate the price elasticity of water demand with household-level data, structurally modeling the piecewise-linear budget constraints imposed by increasing-block pricing. We develop a mathematical expression for the unconditional price elasticity of demand under increasing-block prices and compare conditional and unconditional elasticities analytically and empirically. We test the hypothesis that price elasticity may depend on price structure, beyond technical differences in elasticity co...

  17. Surveys and forecasting industrial property demand



    The aim of this paper is to increase the knowledge about industrial land and floor space forecasting. From the rare research on this subject it is known that the knowledge about factors that influence demand and techniques that model demand is not available in abundance. However, different kinds of models are used extensively in practice. This paper focuses the difference between of stated and revealed preferences. In planning practices stated preferences are often used to forecast land and f...

  18. Biological Oceanography (United States)

    Dyhrman, Sonya


    The ocean is arguably the largest habitat on the planet, and it houses an astounding array of life, from microbes to whales. As a testament to this diversity and its importance, the discipline of biological oceanography spans studies of all levels of biological organization, from that of single genes, to organisms, to their population dynamics. Biological oceanography also includes studies on how organisms interact with, and contribute to, essential global processes. Students of biological oceanography are often as comfortable looking at satellite images as they are electron micrographs. This diversity of perspective begins the textbook Biological Oceanography, with cover graphics including a Coastal Zone Color Scanner image representing chlorophyll concentration, an electron micrograph of a dinoflagellate, and a photograph of a copepod. These images instantly capture the reader's attention and illustrate some of the different scales on which budding oceanographers are required to think. Having taught a core graduate course in biological oceanography for many years, Charlie Miller has used his lecture notes as the genesis for this book. The text covers the subject of biological oceanography in a manner that is targeted to introductory graduate students, but it would also be appropriate for advanced undergraduates.

  19. Quantum Biology

    Directory of Open Access Journals (Sweden)

    Alessandro Sergi


    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.

  20. Foldit Biology (United States)


    Report 8/1/2013-7/31/2015 4. TITLE AND SUBTITLE Sa. CONTRACT NUMBER Foldit Biology NOOO 14-13-C-0221 Sb. GRANT NUMBER N/A Sc. PROGRAM ELEMENT...Include area code) Unclassified Unclassified Unclassified (206) 616-2660 Zoran Popović Foldit Biology (Task 1, 2, 3, 4) Final Report...Period Covered by the Report August 1, 2013 – July 31, 2015 Date of Report: July 31, 2015 Project Title: Foldit Biology Contract Number: N00014-13

  1. Smart interface materials integrated with microfluidics for on-demand local capture and release of cells. (United States)

    Gurkan, Umut Atakan; Tasoglu, Savas; Akkaynak, Derya; Avci, Oguzhan; Unluisler, Sebnem; Canikyan, Serli; Maccallum, Noah; Demirci, Utkan


    Stimuli responsive, smart interface materials are integrated with microfluidic technologies creating new functions for a broad range of biological and clinical applications by controlling the material and cell interactions. Local capture and on-demand local release of cells are demonstrated with spatial and temporal control in a microfluidic system.

  2. Regulation of kidney function and metabolism: a question of supply and demand. (United States)

    Blantz, Roland C; Deng, Aihua; Miracle, Cynthia M; Thomson, Scott C


    Kidney blood flow and glomerular filtration rate (GFR) are maintained relatively constant by hormonal influences and by efficient autoregulation. However, the kidney remains at risk for ischemia and acute kidney injury. Increases in kidney blood flow cause parallel increments in GFR, thereby dictating tubular reabsorption and increased oxygen/metabolic demands. Coordination between kidney blood flow and GFR with tubular reabsorption is maintained by the tubuloglomerular feedback (TGF) system whereby delivery of NaCl to the macula densa varies inversely with nephron GFR. Metabolic products, ATP and adenosine, are the mediators of TGF via afferent arteriolar vasoconstriction, and nitric oxide; COX-2 products and angiotensin II are modulators of acute TGF responses and temporal adaptation of TGF. Oxygen requirements and metabolic efficiency of Na transport in the kidney are significant variables that are regulated by both mediators and modulators of TGF. These metabolic and hormonal substances efficiently regulate both kidney supply and demand.


    Directory of Open Access Journals (Sweden)

    R. C. Contrera


    Full Text Available Abstract In some operational circumstances a fast evaluation of landfill leachate anaerobic treatability is necessary, and neither Biochemical Methane Potential nor BOD/COD ratio are fast enough. Looking for a fast indicator, this work evaluated the anaerobic treatability of landfill leachate from São Carlos-SP (Brazil in a pilot scale Anaerobic Sequence Batch Biofilm Reactor (AnSBBR. The experiment was conducted at ambient temperature in the landfill area. After the acclimation, at a second stage of operation, the AnSBBR presented efficiency above 70%, in terms of COD removal, utilizing landfill leachate without water dilution, with an inlet COD of about 11,000 mg.L-1, a TVA/COD ratio of approximately 0.6 and reaction time equal to 7 days. To evaluate the landfill leachate biodegradability variation over time, temporal profiles of concentration were performed in the AnSBBR. The landfill leachate anaerobic biodegradability was verified to have a direct and strong relationship to the TVA/COD ratio. For a TVA/CODTotal ratio lower than 0.20, the biodegradability was considered low, for ratios between 0.20 and 0.40 it was considered medium, and above 0.40 it was considered high.

  4. Penentuan Kadar COD (Chemical Oxygen Demand) Pada Limbah Cair Pabrik Kelapa Sawit, Pabrik Karet Dan Domestik




    Telah dilakukan penentuan kadar COD pada limbah cair pabrik kelapa sawit, industri karet, dan domestik dengan metode titrimetri. Dari hasil analisa COD diperoleh kadar limbah kelapa sawit sebesar 206,33mg/l, limbah industri karet sebesar 31,74 mg/l, dan limbah domestik sebesar 162,68 mg/l. dimana menurut Standart baku mutu yang telah ditetapkan oleh Menteri Lingkungan Hidup Nomor: Kep-51/MENLH/10/1995, kadar maksimum COD dalam air limbah industri kelapa sawit sebesar 350 mg/l, dalam indust...



    Contrera,R. C.; K. C. da Cruz Silva; G. H. Ribeiro Silva; D. M. Morita; Zaiat,M.; V. Schalch


    Abstract In some operational circumstances a fast evaluation of landfill leachate anaerobic treatability is necessary, and neither Biochemical Methane Potential nor BOD/COD ratio are fast enough. Looking for a fast indicator, this work evaluated the anaerobic treatability of landfill leachate from São Carlos-SP (Brazil) in a pilot scale Anaerobic Sequence Batch Biofilm Reactor (AnSBBR). The experiment was conducted at ambient temperature in the landfill area. After the acclimation, at a ...

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

    Energy Technology Data Exchange (ETDEWEB)

    Hadder, G.R.


    The Energy Policy Act of 1992 (the Act) outlined a national energy strategy that called for reducing the nation's dependency on petroleum imports. The Act directed the Secretary of Energy to establish a program to promote and expand the use of renewable fuels. The Office of Transportation Technologies (OTT) within the U.S. Department of Energy (DOE) has evaluated a wide range of potential fuels and has concluded that cellulosic ethanol is one of the most promising near-term prospects. Ethanol is widely recognized as a clean fuel that helps reduce emissions of toxic air pollutants. Furthermore, cellulosic ethanol produces less greenhouse gas emissions than gasoline or any of the other alternative transportation fuels being considered by DOE.

  7. Refrigerated Warehouse Demand Response Strategy Guide

    Energy Technology Data Exchange (ETDEWEB)

    Scott, Doug [VaCom Technologies, San Luis Obispo, CA (United States); Castillo, Rafael [VaCom Technologies, San Luis Obispo, CA (United States); Larson, Kyle [VaCom Technologies, San Luis Obispo, CA (United States); Dobbs, Brian [VaCom Technologies, San Luis Obispo, CA (United States); Olsen, Daniel [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)


    This guide summarizes demand response measures that can be implemented in refrigerated warehouses. In an appendix, it also addresses related energy efficiency opportunities. Reducing overall grid demand during peak periods and energy consumption has benefits for facility operators, grid operators, utility companies, and society. State wide demand response potential for the refrigerated warehouse sector in California is estimated to be over 22.1 Megawatts. Two categories of demand response strategies are described in this guide: load shifting and load shedding. Load shifting can be accomplished via pre-cooling, capacity limiting, and battery charger load management. Load shedding can be achieved by lighting reduction, demand defrost and defrost termination, infiltration reduction, and shutting down miscellaneous equipment. Estimation of the costs and benefits of demand response participation yields simple payback periods of 2-4 years. To improve demand response performance, it’s suggested to install air curtains and another form of infiltration barrier, such as a rollup door, for the passageways. Further modifications to increase efficiency of the refrigeration unit are also analyzed. A larger condenser can maintain the minimum saturated condensing temperature (SCT) for more hours of the day. Lowering the SCT reduces the compressor lift, which results in an overall increase in refrigeration system capacity and energy efficiency. Another way of saving energy in refrigerated warehouses is eliminating the use of under-floor resistance heaters. A more energy efficient alternative to resistance heaters is to utilize the heat that is being rejected from the condenser through a heat exchanger. These energy efficiency measures improve efficiency either by reducing the required electric energy input for the refrigeration system, by helping to curtail the refrigeration load on the system, or by reducing both the load and required energy input.

  8. Wireless Mesh Network Routing Under Uncertain Demands (United States)

    Wellons, Jonathan; Dai, Liang; Chang, Bin; Xue, Yuan

    Traffic routing plays a critical role in determining the performance of a wireless mesh network. Recent research results usually fall into two ends of the spectrum. On one end are the heuristic routing algorithms, which are highly adaptive to the dynamic environments of wireless networks yet lack the analytical properties of how well the network performs globally. On the other end are the optimal routing algorithms that are derived from the optimization problem formulation of mesh network routing. They can usually claim analytical properties such as resource use optimality and throughput fairness. However, traffic demand is usually implicitly assumed as static and known a priori in these problem formulations. In contrast, recent studies of wireless network traces show that the traffic demand, even being aggregated at access points, is highly dynamic and hard to estimate. Thus, to apply the optimization-based routing solution in practice, one must take into account the dynamic and uncertain nature of wireless traffic demand. There are two basic approaches to address the traffic uncertainty in optimal mesh network routing (1) predictive routing that infers the traffic demand with maximum possibility based in its history and optimizes the routing strategy based on the predicted traffic demand and (2) oblivious routing that considers all the possible traffic demands and selects the routing strategy where the worst-case network performance could be optimized. This chapter provides an overview of the optimal routing strategies for wireless mesh networks with a focus on the above two strategies that explicitly consider the traffic uncertainty. It also identifies the key factors that affect the performance of each routing strategy and provides guidelines towards the strategy selection in mesh network routing under uncertain traffic demands.

  9. Comparative study on the treatment of raw and biologically treated textile effluents through submerged nanofiltration. (United States)

    Chen, Qing; Yang, Ying; Zhou, Mengsi; Liu, Meihong; Yu, Sanchuan; Gao, Congjie


    Raw and biologically treated textile effluents were submerged filtrated using lab-fabricated hollow fiber nanofiltration membrane with a molecular weight cut-off of about 650 g/mol. Permeate flux, chemical oxygen demand (COD) reduction, color removal, membrane fouling, and cleaning were investigated and compared by varying the trans-membrane pressure (TMP) and volume concentrating factor (VCF). It was found that both raw and biologically treated textile effluents could be efficiently treated through submerged nanofiltration. The increase of TMP resulted in a decline in water permeability, COD reduction, color removal, and flux recovery ratio, while the increase of VCF resulted in both increased COD reduction and color removal. Under the TMP of 0.4 bar and VCF of 5.0, fluxes of 1.96 and 2.59 l/m(2)h, COD reductions of 95.7 and 94.2%, color removals of 99.0, and 97.3% and flux recovery ratios of 91.1 and 92.9% could be obtained in filtration of raw and biologically treated effluents, respectively. After filtration, the COD and color contents of the raw effluent declined sharply from 1780 to 325 mg/l and 1.200 to 0.060 Abs/cm, respectively, while for the biologically treated effluent, they decreased from 780 to 180 mg/l and 0.370 to 0.045 Abs/cm, respectively.

  10. Rainwater harvesting systems for low demanding applications. (United States)

    Sanches Fernandes, Luís F; Terêncio, Daniela P S; Pacheco, Fernando A L


    A rainwater harvesting system (RHS) was designed for a waste treatment facility located near the town of Mirandela (northern Portugal), to be used in the washing of vehicles and other equipment, the cleaning of outside concrete or asphalt floors, and the watering of green areas. Water tank volumes representing 100% efficiency (Vr) were calculated by the Ripple method with different results depending on two consumption scenarios adopted for irrigation. The RHS design was based on a precipitation record spanning a rather long period (3 decades). The calculated storage capacities fulfilled the water demand even when prolonged droughts occurred during that timeframe. However, because the drought events have been rather scarce the Vr values were considered oversized and replaced by optimal volumes. Notwithstanding the new volumes were solely half of the original Vr values, the projected RHS efficiency remained very high (around 90%) while the probability of system failure (efficiencyrainwater harvesting, where water availability (Vw) largely exceeds water demand (Cw), that is to say where demand fractions (Cw/Vw) are very low. Based on the results of a literature review covering an ample geographic distribution and describing a very large number of demand fraction scenarios, a Cw/Vw=0.8 was defined as the threshold to generally distinguish the low from the high demanding RHS applications.


    Institute of Scientific and Technical Information of China (English)

    Minghui XU; Xiangtong QI; Gang YU; Hanqin ZHANG; Chengxiu GAO


    This paper addresses the problem of handling the uncertainty of demand in aone-supplier-one-retailer supply chain system. Demand variation often makes the real productiondifferent from what is originally planned, causing a deviation cost from the production plan. Assumethe market demand is sensitive to the retail price in a nonlinear form, we show how to effectivelyhandle the demand uncertainty in a supply chain, both for the case of centralized-decision-makingsystem and the case of decentralized-decision-making system with perfect coordination.

  12. Quantifying consumption rates of dissolved oxygen along bed forms (United States)

    Boano, Fulvio; De Falco, Natalie; Arnon, Shai


    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.

  13. Reactive Oxygen Species in Vascular Formation and Development



    Reactive oxygen species (ROS) are derived from the metabolism of oxygen and are traditionally viewed as toxic byproducts that cause damage to biomolecules. It is now becoming widely acknowledged that ROS are key modulators in a variety of biological processes and pathological states. ROS mediate key signaling transduction pathways by reversible oxidation of certain signaling components and are involved in the signaling of growth factors, G-protein-coupled receptors, Notch, and Wnt and its dow...

  14. Co-evolution of Eukaryotes and Ocean and Atmosphere Oxygenation in the Neoproterozoic and Paleozoic Eras (United States)

    Lenton, T. M.; Daines, S. J.; Mills, B.; Boyle, R. A.


    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

  15. A single-stage biological process for municipal sewage treatment in tourist areas. (United States)

    Di Iaconi, C; De Sanctis, M; Lopez, A


    This pilot scale study aims to test the effectiveness of an innovative compact biological system (SBBGR - Sequencing Batch Biofilter Granular Reactor) for treating municipal wastewater in tourist areas characterised by intense seasonal water demand and wastewater discharge. The results obtained after a long term operation of 463 days have shown that the proposed system is able to assure average removal efficiencies higher than 90% for COD (chemical oxygen demand), total suspended solids and TKN (total Kjeldahl nitrogen) independently of the influent concentration values and organic loading, which ranged from 0.2 to 5.1 kgCOD/m(3)biofilter.d Furthermore, the plant showed a high degree of operation flexibility and stability in response to the organic load variations occurring in tourist areas. In fact, no significant deterioration in the plant's effluent quality was observed even during a sudden several-fold increase in organic loading. High nitrogen removal efficiencies (80%, on average) were also achieved thanks to the establishment of simultaneous nitrification-denitrification process favoured by the plant's high biomass concentration and operating conditions. Finally, the system was characterized by an excess sludge production much lower (60-80% lower) than that of conventional biological systems operating without a primary clarifier. An acceptable level of stabilization of excess sludge was also obtained so that a further stabilization process was no longer required.

  16. Does unilateral transtibial amputation lead to greater metabolic demand during walking?

    Directory of Open Access Journals (Sweden)

    Elizabeth Russell Esposito, PhD


    Full Text Available Previous literature reports greater metabolic demand of walking following transtibial amputation. However, most research focuses on relatively older, less active, and often dysvascular amputees. Servicemembers with traumatic amputation are typically young, fit, and highly active before and often following surgical amputation of their lower limb. This study compared the metabolic demand of walking in young, active individuals with traumatic unilateral transtibial amputation (TTA and nondisabled controls. Heart rate (HR, rate of oxygen consumption, and rating of perceived exertion (RPE were calculated as subjects walked at a self-selected velocity and at five standardized velocities based on leg length. The TTA group completed a Prosthetics Evaluation Questionnaire. Oxygen consumption (p = 0.89, net oxygen consumption (p = 0.32, and RPE (p = 0.14 did not differ between groups. Compared with controls, HR was greater in the TTA group and increased to a greater extent with velocity (p < 0.001. Overall, the TTA group rated their walking abilities as high (mean: 93% out of 100%. This is the first study to report equivalent metabolic demand between persons with amputation and controls walking at the same velocity. These results may reflect the physical fitness of the young servicemembers with traumatic amputations and may serve to guide outcome expectations in the future.

  17. International Oil Supplies and Demands. Volume 1

    Energy Technology Data Exchange (ETDEWEB)


    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.

  18. International Oil Supplies and Demands. Volume 2

    Energy Technology Data Exchange (ETDEWEB)


    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.

  19. Demand response in a market environment

    DEFF Research Database (Denmark)

    Larsen, Emil Mahler

    This thesis addresses the design, deployment and benefits of demand response in a market environment. Demand response is consumption that can be controlled by an external stimulus in the power system. Flexible consumption is a useful tool for absorbing volatile power from renewable sources like...... and sometimes not, that will lead to power system failure. The type of demand response investigated is consumption controlled by indirect means, like an electricity price. Initially, algorithms responding to real-time electricity prices are researched and benchmarked according to comfort and cost. After...... this simulation, real power system data from the Danish island of Bornholm is introduced and methods to quantify an aggregated load is developed. These methods can be used for real-time operation and to support investment decisions. More specifically, they can be used to forecast the response to electricity...

  20. Uranium 2011 resources, production and demand

    CERN Document Server

    Organisation for Economic Cooperation and Development. Paris


    In the wake of the Fukushima Daiichi nuclear power plant accident, questions are being raised about the future of the uranium market, including as regards the number of reactors expected to be built in the coming years, the amount of uranium required to meet forward demand, the adequacy of identified uranium resources to meet that demand and the ability of the sector to meet reactor requirements in a challenging investment climate. This 24th edition of the “Red Book”, a recognised world reference on uranium jointly prepared by the OECD Nuclear Energy Agency and the International Atomic Energy Agency, provides analyses and information from 42 producing and consuming countries in order to address these and other questions. It offers a comprehensive review of world uranium supply and demand as well as data on global uranium exploration, resources, production and reactor-related requirements. It also provides substantive new information on established uranium production centres around the world and in countri...

  1. Wireless Demand Response Controls for HVAC Systems

    Energy Technology Data Exchange (ETDEWEB)

    Federspiel, Clifford


    The objectives of this scoping study were to develop and test control software and wireless hardware that could enable closed-loop, zone-temperature-based demand response in buildings that have either pneumatic controls or legacy digital controls that cannot be used as part of a demand response automation system. We designed a SOAP client that is compatible with the Demand Response Automation Server (DRAS) being used by the IOUs in California for their CPP program, design the DR control software, investigated the use of cellular routers for connecting to the DRAS, and tested the wireless DR system with an emulator running a calibrated model of a working building. The results show that the wireless DR system can shed approximately 1.5 Watts per design CFM on the design day in a hot, inland climate in California while keeping temperatures within the limits of ASHRAE Standard 55: Thermal Environmental Conditions for Human Occupancy.

  2. Reliability Demands in FTTH Access Networks

    DEFF Research Database (Denmark)

    Pedersen, Jens Myrup; Knudsen, Thomas Phillip; Madsen, Ole Brun


    In this paper reliability and bandwidth demands of existing, new and expected classes of applications running over Fiber To The Home (FTTH) networks to private users and small enterprises are analysed and discussed. Certain applications such as home security and telemedicine are likely to require...... high levels of reliability in the sense that the demands for network availability are high; even short times without connectivity are unacceptable. To satisfy these demands, physical redundancy in the networks is needed. It seems to be the case that - at least in the short term - most reliability......-critical applications do not require much bandwidth. This implies that redundancy do not need to be by fiber, but can be ensured by e.g. coax, copper or wireless solutions. However, implementing these solutions need careful planning to ensure the physical redundancy. In the long term, it is more likely that physical...

  3. Reliability Demands in FTTH Access Networks

    DEFF Research Database (Denmark)

    Pedersen, Jens Myrup; Knudsen, Thomas Phillip; Madsen, Ole Brun


    In this paper reliability and bandwidth demands of existing, new and expected classes of applications running over Fiber To The Home (FTTH) networks to private users and small enterprises are analyzed and discussed. Certain applications such as home security and telemedicine are likely to require...... high levels of reliability in the sense that the demands for network availability are high; even short times without connectivity are unacceptable. To satisfy these demands, physical redundancy in the networks is needed. It seems to be the case that - at least in the short term - most reliability......-critical applications do not require much bandwidth. This implies that redundancy do not need to be by fiber, but can be ensured by e.g. coax, copper or wireless solutions. However, implementing these solutions need careful planning to ensure the physical redundancy. In the long term, it is more likely that physical...

  4. Comparison of on Demand Routing Protocols

    Directory of Open Access Journals (Sweden)

    Bharat Bhushan


    Full Text Available A routing protocol is used to facilitate communication in ad hoc network. The primary goal of such a routing protocol is to provide an efficient and reliable path between a pair of nodes. The routing protocols for ad hoc network can be categorized into three categories: table driven, on demand and hybrid routing. The table driven and hybrid routing strategies require periodic exchange of hello messages between nodes of the ad hoc network and thus have high processing and bandwidth requirements. On the other hand on demand routing strategy creates routes when required and hence is very much suitable for ad hoc network. This paper therefore examines the performance of three on demand routing protocols at application layer using QualNet-5.01 simulator.

  5. Uranium 2014 resources, production and demand

    CERN Document Server

    Organisation for Economic Cooperation and Development. Paris


    Published every other year, Uranium Resources, Production, and Demand, or the "Red Book" as it is commonly known, is jointly prepared by the OECD Nuclear Energy Agency and the International Atomic Energy Agency. It is the recognised world reference on uranium and is based on official information received from 43 countries. It presents the results of a thorough review of world uranium supplies and demand and provides a statistical profile of the world uranium industry in the areas of exploration, resource estimates, production and reactor-related requirements. It provides substantial new information from all major uranium production centres in Africa, Australia, Central Asia, Eastern Europe and North America. Long-term projections of nuclear generating capacity and reactor-related uranium requirements are provided as well as a discussion of long-term uranium supply and demand issues. This edition focuses on recent price and production increases that could signal major changes in the industry.

  6. Uranium 2007 resources, production and demand

    CERN Document Server

    Organisation for Economic Cooperation and Development. Paris


    Based on official information received from 40 countries, Uranium 2007 provides a comprehensive review of world uranium supply and demand as of 1st January 2007, as well as data on global uranium exploration, resources, production and reactor-related requirements. It provides substantive new information from major uranium production centres in Africa, Australia, Central Asia, Eastern Europe and North America. Projections of nuclear generating capacity and reactor-related uranium requirements through 2030 are also featured, along with an analysis of long-term uranium supply and demand issues. It finds that with rising demand and declining inventories, uranium prices have increased dramatically in recent years. As a result, the uranium industry is undergoing a significant revival, bringing to an end a period of over 20 years of underinvestment.

  7. Uranium 2005 Resources, Production and Demand

    CERN Document Server

    Organisation for Economic Cooperation and Development. Paris. Nuclear Energy Agency


    Published every other year, Uranium Resources, Production, and Demand, or the "Red Book" as it is commonly known, is jointly prepared by the OECD Nuclear Energy Agency and the International Atomic Energy Agency. It is the recognised world reference on uranium and is based on official information received from 43 countries. This 21st edition presents the results of a thorough review of world uranium supplies and demand as of 1st January 2005 and provides a statistical profile of the world uranium industry in the areas of exploration, resource estimates, production and reactor-related requirements. It provides substantial new information from all major uranium production centres in Africa, Australia, Central Asia, Eastern Europe and North America. Projections of nuclear generating capacity and reactor-related uranium requirements through 2025 are provided as well as a discussion of long-term uranium supply and demand issues. This edition focuses on recent price and production increases that could signal major c...

  8. A quantification of the physiological demands of the army emergency responder in the Australian army. (United States)

    Tofari, Paul J; Laing Treloar, Alison K; Silk, Aaron J


    The Australian Defence Force is reviewing the physical demands of all employment categories in the Australian Army to establish valid and legally defensible assessments. The current assessments, performed in physical training attire, are not specific to job demands. Moreover, the fitness standards decrease based on age and are lower for females, and as job requirements are constant, these assessments are counterintuitive. With regard to the Army Emergency Responder employment category, tasks of physical demand in the present study were selected through consultation with subject-matter experts. Participants consisted of 10 qualified Army Emergency Responder soldiers and three noncareer firefighters under instruction. Real-life firefighting scenarios were witnessed by researchers and helped form task simulations allowing measurement of heart rate and oxygen consumption. Peak oxygen consumption ranged from 21.8 ± 3.8 to 40.0 ± 3.4 mL kg(-1) min(-1) during cutting activities and a search and rescue task, respectively, representing values similar to or higher than the current entry standards. Manual handling tasks were also assessed, with the heaviest measured being two soldiers lifting a 37.7-kg Utility Trunk to 150 cm. The findings provide a quantitative assessment of the physiological demands of Army Emergency Responders, and highlight the need for change in current fitness assessments.

  9. Oxygen ion conductors

    Directory of Open Access Journals (Sweden)

    Stephen J Skinner


    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.

  10. Neurological oxygen toxicity. (United States)

    Farmery, Scott; Sykes, Oliver


    SCUBA diving has several risks associated with it from breathing air under pressure--nitrogen narcosis, barotrauma and decompression sickness (the bends). Trimix SCUBA diving involves regulating mixtures of nitrogen, oxygen and helium in an attempt to overcome the risks of narcosis and decompression sickness during deep dives, but introduces other potential hazards such as hypoxia and oxygen toxicity convulsions. This study reports on a seizure during the ascent phase, its potential causes and management and discusses the hazards posed to the diver and his rescuer by an emergency ascent to the surface.


    Energy Technology Data Exchange (ETDEWEB)

    Fisk, William J.; Mendell, Mark J.; Davies, Molly; Eliseeva, Ekaterina; Faulkner, David; Hong, Tienzen; Sullivan, Douglas P.


    This document summarizes a research effort on demand controlled ventilation and classroom ventilation. The research on demand controlled ventilation included field studies and building energy modeling. Major findings included: ? The single-location carbon dioxide sensors widely used for demand controlled ventilation frequently have large errors and will fail to effectively control ventilation rates (VRs).? Multi-location carbon dioxide measurement systems with more expensive sensors connected to multi-location sampling systems may measure carbon dioxide more accurately.? Currently-available optical people counting systems work well much of the time but have large counting errors in some situations. ? In meeting rooms, measurements of carbon dioxide at return-air grilles appear to be a better choice than wall-mounted sensors.? In California, demand controlled ventilation in general office spaces is projected to save significant energy and be cost effective only if typical VRs without demand controlled ventilation are very high relative to VRs in codes. Based on the research, several recommendations were developed for demand controlled ventilation specifications in the California Title 24 Building Energy Efficiency Standards.The research on classroom ventilation collected data over two years on California elementary school classrooms to investigate associations between VRs and student illness absence (IA). Major findings included: ? Median classroom VRs in all studied climate zones were below the California guideline, and 40percent lower in portable than permanent buildings.? Overall, one additional L/s per person of VR was associated with 1.6percent less IA. ? Increasing average VRs in California K-12 classrooms from the current average to the required level is estimated to decrease IA by 3.4percent, increasing State attendance-based funding to school districts by $33M, with $6.2 M in increased energy costs. Further VR increases would provide additional benefits

  12. Accuracy analysis of TDRSS demand forecasts (United States)

    Stern, Daniel C.; Levine, Allen J.; Pitt, Karl J.


    This paper reviews Space Network (SN) demand forecasting experience over the past 16 years and describes methods used in the forecasts. The paper focuses on the Single Access (SA) service, the most sought-after resource in the Space Network. Of the ten years of actual demand data available, only the last five years (1989 to 1993) were considered predictive due to the extensive impact of the Challenger accident of 1986. NASA's Space Network provides tracking and communications services to user spacecraft such as the Shuttle and the Hubble Space Telescope. Forecasting the customer requirements is essential to planning network resources and to establishing service commitments to future customers. The lead time to procure Tracking and Data Relay Satellites (TDRS's) requires demand forecasts ten years in the future a planning horizon beyond the funding commitments for missions to be supported. The long range forecasts are shown to have had a bias toward underestimation in the 1991 -1992 period. The trend of underestimation can be expected to be replaced by overestimation for a number of years starting with 1998. At that time demand from new missions slated for launch will be larger than the demand from ongoing missions, making the potential for delay the dominant factor. If the new missions appear as scheduled, the forecasts are likely to be moderately underestimated. The SN commitment to meet the negotiated customer's requirements calls for conservatism in the forecasting. Modification of the forecasting procedure to account for a delay bias is, therefore, not advised. Fine tuning the mission model to more accurately reflect the current actual demand is recommended as it may marginally improve the first year forecasting.

  13. A Theoretic Model of Transport Logistics Demand

    Directory of Open Access Journals (Sweden)

    Natalija Jolić


    Full Text Available Concerning transport logistics as relation between transportand integrated approaches to logistics, some transport and logisticsspecialists consider the tenn tautological. However,transport is one of the components of logistics, along with inventories,resources, warehousing, infonnation and goods handling.Transport logistics considers wider commercial and operationalframeworks within which the flow of goods is plannedand managed. The demand for transport logistics services canbe valorised as highly qualitative, differentiated and derived.While researching transport phenomenon the implementationof models is inevitable and demand models highly desirable. Asa contribution to transport modelling this paper improves decisionmaking and planning in the transport logistics field.

  14. Entry Regulation under Asymmetric Information about Demand

    Directory of Open Access Journals (Sweden)

    Paula Sarmento


    Full Text Available We investigate how an incumbent firm can use the regulatory policy about entry and the informational advantage to protect his market position. This question is studied through the construction of a signalling game where we assume that the regulator has less information about demand than the firms. We conclude that there is a pooling equilibrium and partially separating equilibria in which entry is deterred and, if demand is high, there will be insufficient entry. The final effect on welfare depends on the tradeoff between short-run benefits (lower price and long-run losses (weaker competition.

  15. The demand for electricity in Israel

    Energy Technology Data Exchange (ETDEWEB)

    Beenstock, M. [Department of Economics, Hebrew University of Jerusalem, Mount Scopus, 91905 Jerusalem (Israel); Goldin, E.; Nabot, D. [EG Consulting, Hameasef 11, Jerusalem (Israel)


    Quarterly data for Israel are used to compare and contrast three dynamic econometric methodologies for estimating the demand for electricity by households and industrial companies. These are the Dynamic Regression Model and two approaches to cointegration (OLS and Maximum Likelihood). Since we find evidence of seasonal unit roots in the data we also test for seasonal cointegration. We find that the scale elasticities are similar in all three approaches but the OLS price elasticities are considerably lower. Moreover, OLS suggests non-cointegration. The paper concludes by stochastically simulating the DRMs to calculate upside-risk in electricity demand. (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

  16. Demand Response as a System Reliability Resource

    Energy Technology Data Exchange (ETDEWEB)

    Eto, Joseph H. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Environmental Energy Technologies Division; Lewis, Nancy Jo [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Environmental Energy Technologies Division; Watson, David [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Environmental Energy Technologies Division; Kiliccote, Sila [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Environmental Energy Technologies Division; Auslander, David [Univ. of California, Berkeley, CA (United States); Paprotny, Igor [Univ. of California, Berkeley, CA (United States); Makarov, Yuri [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)


    The Demand Response as a System Reliability Resource project consists of six technical tasks: • Task 2.1. Test Plan and Conduct Tests: Contingency Reserves Demand Response (DR) Demonstration—a pioneering demonstration of how existing utility load-management assets can provide an important electricity system reliability resource known as contingency reserve. • Task 2.2. Participation in Electric Power Research Institute (EPRI) IntelliGrid—technical assistance to the EPRI IntelliGrid team in developing use cases and other high-level requirements for the architecture. • Task 2.3. Research, Development, and Demonstration (RD&D) Planning for Demand Response Technology Development—technical support to the Public Interest Energy Research (PIER) Program on five topics: Sub-task 1. PIER Smart Grid RD&D Planning Document; Sub-task 2. System Dynamics of Programmable Controllable Thermostats; Sub-task 3. California Independent System Operator (California ISO) DR Use Cases; Sub-task 4. California ISO Telemetry Requirements; and Sub-task 5. Design of a Building Load Data Storage Platform. • Task 2.4. Time Value of Demand Response—research that will enable California ISO to take better account of the speed of the resources that it deploys to ensure compliance with reliability rules for frequency control. • Task 2.5. System Integration and Market Research: Southern California Edison (SCE)—research and technical support for efforts led by SCE to conduct demand response pilot demonstrations to provide a contingency reserve service (known as non-spinning reserve) through a targeted sub-population of aggregated residential and small commercial customers enrolled in SCE’s traditional air conditioning (AC) load cycling program, the Summer Discount Plan. • Task 2.6. Demonstrate Demand Response Technologies: Pacific Gas and Electric (PG&E)—research and technical support for efforts led by PG&E to conduct a demand response pilot demonstration to provide non

  17. Owning, letting and demanding second homes

    DEFF Research Database (Denmark)

    Bloze, Gintautas; Skak, Morten

    An increasing number of households consume housing beyond the primary home as owners of a second home. Economic studies of second homeownership are still very scarce, and the present empirical study fills this gap to some extent. It is based on Danish survey data combined with administrative...... register data and presents estimations of the probability of owning a second home, the decision to let the second home and the number of let weeks per year. Also income elasticities for primary and second housing demand are estimated. We find a conventional monotonic increase in demand elasticities...

  18. Biological preconcentrator (United States)

    Manginell, Ronald P.; Bunker, Bruce C.; Huber, Dale L.


    A biological preconcentrator comprises a stimulus-responsive active film on a stimulus-producing microfabricated platform. The active film can comprise a thermally switchable polymer film that can be used to selectively absorb and desorb proteins from a protein mixture. The biological microfabricated platform can comprise a thin membrane suspended on a substrate with an integral resistive heater and/or thermoelectric cooler for thermal switching of the active polymer film disposed on the membrane. The active polymer film can comprise hydrogel-like polymers, such as poly(ethylene oxide) or poly(n-isopropylacrylamide), that are tethered to the membrane. The biological preconcentrator can be fabricated with semiconductor materials and technologies.

  19. Towards integrated operation of membrane bioreactors: effects of aeration on biological and filtration performance. (United States)

    Dalmau, M; Monclús, H; Gabarrón, S; Rodriguez-Roda, I; Comas, J


    Two experimental studies evaluated the effect of aerobic and membrane aeration changes on sludge properties, biological nutrient removal and filtration processes in a pilot plant membrane bioreactor. The optimal operating conditions were found at an aerobic dissolved oxygen set-point (DO) of 0.5 mg O2 L(-1) and a membrane specific aeration demand (SADm) of 1 m h(-1), where membrane aeration can be used for nitrification. Under these conditions, a total flow reduction of 42% was achieved (75% energy reduction) without compromising nutrient removal efficiencies, maintaining sludge characteristics and controlled filtration. Below these optimal operating conditions, the nutrient removal efficiency was reduced, increasing 20% for soluble microbial products, 14% for capillarity suction time and reducing a 15% for filterability. Below this DO set-point, fouling increased with a transmembrane pressure 75% higher. SADm below 1 m h(-1) doubled the values of transmembrane pressure, without recovery after achieving the initial conditions.

  20. Two-photon absorbing porphyrins for oxygen microscopy (Conference Presentation) (United States)

    Esipova, Tatiana V.; Vinogradov, Sergei A.


    The ability to quantify oxygen in vivo in 3D with high spatial and temporal resolution is invaluable for many areas of the biomedical science, including ophthalmology, neuroscience, cancer and stem biology. An optical method based on oxygen-dependent quenching of phosphorescence is being developed, that allows quantitative minimally invasive real-time imaging of partial pressure of oxygen (pO2) in tissue. In the past, dendritically protected phosphorescent oxygen probes with controllable quenching parameters and defined bio-distributions have been developed. More recently our probe strategy has extended to encompass two-photon excitable oxygen probes, which brought about first demonstrations of two-photon phosphorescence lifetime microscopy (2PLM) of oxygen in vivo, providing new valuable information for neuroscience and stem cell biology. However, current two-photon oxygen probes suffer from a number of limitations, such as low brightness and high cost of synthesis, which dramatically reduce imaging performance and limit usability of the method. Here we present an approach to new bright phosphorescent chromophores with internally enhanced two-photon absorption cross-sections, which pave a way to novel proves for 2PLM. In addition to substantial increase in performance, the new probes can be synthesized by much more efficient methods, thereby greatly reducing the cost of the synthesis and making the technique accessible to a broader range of researchers across different fields.

  1. Indications for a changing electricity demand pattern : The temperature dependence of electricity demand in the Netherlands

    NARCIS (Netherlands)

    Hekkenberg, M.; Benders, R. M. J.; Moll, H. C.; Uiterkamp, A. J. M. Schoot


    This study assesses the electricity demand pattern in the relatively temperate climate of the Netherlands (latitude 52 degrees 30'N). Daily electricity demand and average temperature during the period from 1970 until 2007 are investigated for possible trends in the temperature dependence of electric

  2. Demanding Dynamics - Demand articulation of intermediary organisations in emerging pharmaceutical innovations

    NARCIS (Netherlands)

    Boon, W.P.C.


    User involvement in emerging technological fields is carried by so-called demand articulation processes. These demand articulation processes are interactive learning processes in which stakeholders try to address what they perceive as important characteristics of, and to unravel preferences for an e

  3. Benzoylation of Ergosterol through Nucleophilic Acyl Substitution and Subsequent Formation of Ergosterol Benzoate Endoperoxide by Reaction with Singlet Oxygen Generated by Photosensitization (United States)

    Roslaniec, Mary C.; Sanford, Elizabeth M.


    Reactive oxygen species such as singlet oxygen have been a major focus of research in medicine. The effect of singlet oxygen on sterols within biological membranes is becoming increasingly more important. Ergosterol, a vitamin D precursor, is one such sterol. The benzoylation of ergosterol and subsequent reaction with singlet oxygen to form an…

  4. Oxygen effects in radiation biology and radiation chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Powers, E.L.; Held, K.D.


    The question of the influence of O/sub 2/ on the radiation sensitivity of organisms, cells and biomolecules is reviewed. Evidence is presented to show that there are two mechanisms that govern the manner in which O/sub 2/ acts in cells. It is also suggested that these may in addition be other mechanisms but no evidence is presented to support this. (ACR)

  5. Optic nerve oxygen tension

    DEFF Research Database (Denmark)

    Kiilgaard, Jens Folke; Pedersen, D B; Eysteinsson, T


    The authors have previously reported that carbonic anhydrase inhibitors such as acetazolamide and dorzolamide raise optic nerve oxygen tension (ONPO(2)) in pigs. The purpose of the present study was to investigate whether timolol, which belongs to another group of glaucoma drugs called beta block...

  6. Aircraft Oxygen Generation (United States)


    aircraft use some form of on-board oxygen generation provided by one of two corporations that dominate this market . A review of safety incident data...manufacture of synthetic resins (e.g., Bakelite), and for 161 making dyestuffs, flavorings, perfumes , and other chemicals. Some are used as

  7. Hybrid Oxygen System (United States)


    otherwise in any manner construed, as licensing the holder or any other person or corporation ; or as conveying any rights or permission to manufacture, use...12 Modest Activity 2 12 24 Comnat ane G’s Average 5 32 64 Peak Activity (NATO) 10 50 Instantaneous Peak Flow N/A 150-20W_ Published oxygen flow rates

  8. Redesigning photosynthesis to sustainably meet global food and bioenergy demand. (United States)

    Ort, Donald R; Merchant, Sabeeha S; Alric, Jean; Barkan, Alice; Blankenship, Robert E; Bock, Ralph; Croce, Roberta; Hanson, Maureen R; Hibberd, Julian M; Long, Stephen P; Moore, Thomas A; Moroney, James; Niyogi, Krishna K; Parry, Martin A J; Peralta-Yahya, Pamela P; Prince, Roger C; Redding, Kevin E; Spalding, Martin H; van Wijk, Klaas J; Vermaas, Wim F J; von Caemmerer, Susanne; Weber, Andreas P M; Yeates, Todd O; Yuan, Joshua S; Zhu, Xin Guang


    The world's crop productivity is stagnating whereas population growth, rising affluence, and mandates for biofuels put increasing demands on agriculture. Meanwhile, demand for increasing cropland competes with equally crucial global sustainability and environmental protection needs. Addressing this looming agricultural crisis will be one of our greatest scientific challenges in the coming decades, and success will require substantial improvements at many levels. We assert that increasing the efficiency and productivity of photosynthesis in crop plants will be essential if this grand challenge is to be met. Here, we explore an array of prospective redesigns of plant systems at various scales, all aimed at increasing crop yields through improved photosynthetic efficiency and performance. Prospects range from straightforward alterations, already supported by preliminary evidence of feasibility, to substantial redesigns that are currently only conceptual, but that may be enabled by new developments in synthetic biology. Although some proposed redesigns are certain to face obstacles that will require alternate routes, the efforts should lead to new discoveries and technical advances with important impacts on the global problem of crop productivity and bioenergy production.

  9. Oxygen Extraction from Minerals (United States)

    Muscatello, Tony


    Oxygen, whether used as part of rocket bipropellant or for astronaut life support, is a key consumable for space exploration and commercialization. In Situ Resource Utilization (ISRU) has been proposed many times as a method for making space exploration more cost effective and sustainable. On planetary and asteroid surfaces the presence of minerals in the regolith that contain oxygen is very common, making them a potential oxygen resource. The majority of research and development for oxygen extraction from minerals has been for lunar regolith although this work would generally be applicable to regolith at other locations in space. This presentation will briefly survey the major methods investigated for oxygen extraction from regolith with a focus on the current status of those methods and possible future development pathways. The major oxygen production methods are (1) extraction from lunar ilmenite (FeTiO3) with either hydrogen or carbon monoxide, (2) carbothermal reduction of iron oxides and silicates with methane, and (3) molten regolith electrolysis (MRE) of silicates. Methods (1) and (2) have also been investigated in a two-step process using CO reduction and carbon deposition followed by carbothermal reduction. All three processes have byproducts that could also be used as resources. Hydrogen or carbon monoxide reduction produce iron metal in small amounts that could potentially be used as construction material. Carbothermal reduction also makes iron metal along with silicon metal and a glass with possible applications. MRE produces iron, silicon, aluminum, titanium, and glass, with higher silicon yields than carbothermal reduction. On Mars and possibly on some moons and asteroids, water is present in the form of mineral hydrates, hydroxyl (-OH) groups on minerals, andor water adsorbed on mineral surfaces. Heating of the minerals can liberate the water which can be electrolyzed to provide a source of oxygen as well. The chemistry of these processes, some key



    Levedahl, J. William; Reed, Albert J.; Clark, J. Stephen


    Two aggregation schemes for food demand systems are tested for consistency with the Generalized Composite Commodity Theorem (GCCT). One scheme is based on the standard CES classification of food expenditures. The second scheme is based on the Food Guide Pyramid. Evidence is found that both schemes are consistent with the GCCT.

  11. The Demand for Rental Homes in Denmark

    DEFF Research Database (Denmark)

    Skak, Morten

    For a number of years, homeownership rates have been increasing with increasing GDP per capita in most European countries, but not in Denmark after 2000. How has increased real incomes kept demand for rental housing up in Denmark? The present paper takes a closer look at the Danish development...

  12. Delivering Training for Highly Demanding Information Systems (United States)

    Norton, Andrew Lawrence; Coulson-Thomas, Yvette May; Coulson-Thomas, Colin Joseph; Ashurst, Colin


    Purpose: There is a lack of research covering the training requirements of organisations implementing highly demanding information systems (HDISs). The aim of this paper is to help in the understanding of appropriate training requirements for such systems. Design/methodology/approach: This research investigates the training delivery within a…

  13. Chinese Demand Boosts Luxury Brand Profits

    Institute of Scientific and Technical Information of China (English)


    The world’s biggest luxury brands have their eyes set on the Chinese consumer - a strategy that is reaping profits. In the next few months,the British fashion house Burberry will expand its retail space in China to capitalize on strong Chinese consumer demand for luxury products.Already,sales in China have contributed 4 percent to the

  14. Market design for rapid demand response

    DEFF Research Database (Denmark)

    Nielsen, Kurt; Tamirat, Tseganesh Wubale

    the nature of the demand response system and reveals that a simple markup contract between the Aggregator and the TSO is sufficiently flexible and little distorting. The simulation also provide a the less intuitive result, that the auction motivates the TSO to o er a high markup contract to the Aggregator...

  15. Modelling global container freight transport demand

    NARCIS (Netherlands)

    Tavasszy, L.A.; Ivanova, O.; Halim, R.A.


    The objective of this chapter is to discuss methods and techniques for a quantitative and descriptive analysis of future container transport demand at a global level. Information on future container transport flows is useful for various purposes. It is instrumental for the assessment of returns of i

  16. Job Demand in the Cosmetology Industry. (United States)

    Rudner, Lawrence M.; Deutermann, William V., Jr.

    In order to determine job demand in the cosmetology industry, a survey was made of a nationally representative stratified random sample of 1,454 beauty salons, barber shops, and unisex salons in July 1991. Salon owners were asked about 1990 and their plans for the future. Survey results were supplemented with information about the industry…

  17. China's rising hydropower demand challenges water sector

    NARCIS (Netherlands)

    Liu, J.; Zhao, D.; Gerbens-Leenes, P.W.; Guan, D.


    Demand for hydropower is increasing, yet the water footprints (WFs) of reservoirs and hydropower, and their contributions to water scarcity, are poorly understood. Here, we calculate reservoir WFs (freshwater that evaporates from reservoirs) and hydropower WFs (the WF of hydroelectricity) in China b

  18. Multicultural Schools and New Demands on Leadership (United States)

    Andersen, Fred Carlo


    The purpose of this study is to explore the Norwegian Government's expectations pertaining to new demands on leadership expressed in policy documents with regard to a multicultural society. Data from seven government's white papers were thematically analyzed with regard to knowledge, skills and attitudes. The study is framed within a theoretical…

  19. Demand management implementation in Southeast Asia

    Energy Technology Data Exchange (ETDEWEB)

    Tanaboriboon, Y.


    The need to apply transportation system management, to developing countries is urgent. Attempts to alleviate severe traffic congestion in their metropolises have so far failed to provide adequate solutions. The countries are faced with many difficulties because of the lack of sufficient financial resources together with their complex internal administrative and political problems. They are incapable of providing sufficient road space to cope with the escalating demand in private automobiles. This has led to excessive delays in urban traveling, environmental pollution problems, decline of road-based public transit services and deterioration of the quality of life in these metropolises. Demand management, in use for decades in the Western world, has also been recognized in Singapore`s famous area licensing scheme (ALS) making other Southeast Asian Metropolises aware of its advantages as an alternative in solving their chaotic traffic problems. However, realization is far different from implementation and still many metropolises are not able to apply the technique. Singapore and Thailand, two leaders among many other Southeast Asian regions in economics, tourism, trade and industry handle their problems far differently, especially the traffic congestion problem. While a number of demand management schemes have been implemented successfully in Singapore since 1975, Bangkok is still struggling to implement such measures to alleviate severe traffic congestion problems. This article intends to high light the successful practices and unsuccessful attempts of demand management techniques applied in Singapore and Bangkok.

  20. Demand for money and shortages in Ethiopia

    NARCIS (Netherlands)

    Sterken, E.


    The paper discusses the long-run monetary conditions in Ethiopia in the last three decades. These decades can be characterized by large political changes, leading to shocks on income and population growth, and two serious periods of drought. Both affected inflation and real demand for M-1 through sh

  1. 2007:Coal Supply & Demand to Balance

    Institute of Scientific and Technical Information of China (English)

    Chun Yi


    @@ The National Development and Reform Commission of China (NDRC)released on August 27 a report on the first-half operation and the second-half expectation of the coal industry.The coal industry is predicted to have a consecutive balance of supply and demand this year with a less strained supply in the second half.

  2. Education and the Demand for Emancipation (United States)

    Skarpenes, Ove


    This paper puts forward the hypothesis that in recent decades, pupils of schools in the western world have been given a new form of individuality. This construction has been nourished by both the demand for emancipation as it was expressed in the critical sociology of education (and pedagogy) and by the neoliberal turn in education policy. It…

  3. Estimating Reduced Consumption for Dynamic Demand Response

    Energy Technology Data Exchange (ETDEWEB)

    Chelmis, Charalampos [Univ. of Southern California, Los Angeles, CA (United States); Aman, Saima [Univ. of Southern California, Los Angeles, CA (United States); Saeed, Muhammad Rizwan [Univ. of Southern California, Los Angeles, CA (United States); Frincu, Marc [Univ. of Southern California, Los Angeles, CA (United States); Prasanna, Viktor K. [Univ. of Southern California, Los Angeles, CA (United States)


    Growing demand is straining our existing electricity generation facilities and requires active participation of the utility and the consumers to achieve energy sustainability. One of the most effective and widely used ways to achieve this goal in the smart grid is demand response (DR), whereby consumers reduce their electricity consumption in response to a request sent from the utility whenever it anticipates a peak in demand. To successfully plan and implement demand response, the utility requires reliable estimate of reduced consumption during DR. This also helps in optimal selection of consumers and curtailment strategies during DR. While much work has been done on predicting normal consumption, reduced consumption prediction is an open problem that is under-studied. In this paper, we introduce and formalize the problem of reduced consumption prediction, and discuss the challenges associated with it. We also describe computational methods that use historical DR data as well as pre-DR conditions to make such predictions. Our experiments are conducted in the real-world setting of a university campus microgrid, and our preliminary results set the foundation for more detailed modeling.

  4. UK money demand 1873-2001

    DEFF Research Database (Denmark)

    Nielsen, Heino Bohn


    This paper performs a multivariate cointegration analysis of UK money demand 1873-2001, and illustrates how a long-run time series analysis may be conducted on a data set characterized by turbulent episodes and institutional changes. We suggest accounting for the effects of the two world wars...

  5. Future demands for an Industrialized Architecture?

    DEFF Research Database (Denmark)

    Beim, Anne


    When speaking about the future demands for industrialized architecture – or how to translate industrialized processes into tectonic sustainable design strategies in architecture – several questions come to mind. First of all, why is the building industry in comparison to the production industry...

  6. Demand Side Management for Multiple Devices

    NARCIS (Netherlands)

    Molderink, Albert; Bakker, Vincent; Smit, Gerard J.M.


    Steering a heterogeneous set of devices in a Smart Grid using cost functions: Demand Side Management (DSM) is an important element in smart grids. DSM is already in operation for large consumers, but thorough research is required into DSM on a building level within the distribution grid.


    Directory of Open Access Journals (Sweden)

    Edmilson Santos Cruz


    Full Text Available This study aimed at analyzing the international pulp market, taking into account themain exporting countries and importing regions, with the objective of estimating, for each market, theown-price and cross-price elasticity in relation to the demand of the pulp, differentiated for country oforigin. The model considers that imports are differentiated by origin; therefore they are not perfect substitutes. The demand from Europe, North America and the Rest of the World for the pulp from theUnited States,Canada, Sweden, Finland, Portugal and Brazil was inelastic. The Asian demand for thissome pulp was elastic. Europe and the Rest of the World showed negative cross-price elasticity, i. e.,and the imported pulp from other countries are complementary products. North America and Asiashowed positive crow-price elasticity, i. e., they consider the pulp produced in other countries assubstitute products. The net effect of the variation on the price of pulp in a country h, over the amountof pulp that goes to the region i depends on the matching of values related to the elasticity ofsubstitution and the price elasticity of the total demand.

  8. The World Demand for Catfish Pangasius

    DEFF Research Database (Denmark)

    Nguyen, Thong Tien; Roth, Eva; Nielsen, Max


    . Direct elasticity including own- and cross- price elasticity and income elasticity are calculated to show how consumers from different markets of the world prefer for the Pangasius catfish. We found that catfish products have big room of market demand, indicated by absolute values of own price...

  9. Monopoly price discrimination with constant elasticity demand


    Aguirre Pérez, Iñaki; Cowan, Simon George


    This paper presents new results on the welfare e¤ects of third-degree price discrimination under constant elasticity demand. We show that when both the share of the strong market under uniform pricing and the elasticity di¤erence between markets are high enough,then price discrimination not only can increase social welfare but also consumer surplus.

  10. Assessing Demand for Graduate and Professional Programs. (United States)

    Syverson, Peter D.


    Graduate education is entering an era of market segmentation, varying student demand, and changing requirements from employers, meaning graduate students will assess graduate opportunities differently and institutions will assess programs differently. The traditional view of graduate study as preparation for a research or teaching career and…

  11. Egalitarianism Policy and Effective Demand under Globalization

    Directory of Open Access Journals (Sweden)

    Taro ABE


    Full Text Available Abstract. The study examines egalitarianism policies in terms of the relationship between labor and capital and extends the model developed by the economist Bowles. We introduce the demand factor to the Bowles model (2012, which discussed the effectiveness of the income and asset redistribution policies in a global economy. The improvement of productivity and the decrease in the ratio of monitoring labor through asset-based redistribution increase the real wage rate because of its lure for foreign capital. At this point in the Bowles model, the labor supply increases and then employment increases. In contrast, in our model, with the addition of the demand factor, the improvement of productivity increases employment, but the decrease in monitoring labor does not always increase employment as both demand and supply increase. This means that asset-based redistribution in a global economy is not always effective.Keywords. Egalitarianism, Redistribution, Effective demand, Globalization.JEL. E12, F60, J80, J88.

  12. Sequentiality versus simultaneity: Interrelated factor demand

    NARCIS (Netherlands)

    Asphjell, M.K.; Letterie, W.A.; Nilsen, O.A.; Pfann, G.A.


    Firms may adjust capital and labor sequentially or simultaneously. In this paper, we develop a structural model of interrelated factor demand subject to nonconvex adjustment costs and estimated by simulated method of moments. Based on Norwegian manufacturing industry plant-level data, parameter esti

  13. Performance of digester decant system with biological filter followed by constructed wetland and solar reactor in the treatment of domestic sewage

    Directory of Open Access Journals (Sweden)

    Delfran Batista dos Santos


    Full Text Available This study aimed to analyze the performance of digester decant system with biological filter followed by constructed wetland and solar reactor in the treatment of domestic sewage from Milagres rural community in Apodi-RN. The treatment system was monitored for the period of October and November 2010, 48 days after planting Pennisetum purpureum Schumach. Samples of domestic sewage were collected at different stages of treatment, in four replications on time, to determine physicochemical and microbiological characteristics about the system performance. The results indicated significant removal of turbidity, biochemical oxygen demand, chemical oxygen demand, total solids, suspended solids, phosphorus and oil and grease using the set digester decant with biological filter, followed by constructed wetland and solar reactor; the association of average solar radiation of 28.73 MJ m-2 d-1, effluent depth of 0.10 m on reactor and time of sun exposure of 12 hours provided removal of fecal coliform up to 99.99% of domestic sewage in Apodi, RN, the treated effluent met microbiological standard of the Brazilian guidelines for agricultural use with restrictions.

  14. Biology Notes. (United States)

    School Science Review, 1981


    Outlines a variety of laboratory procedures, techniques, and materials including construction of a survey frame for field biology, a simple tidal system, isolation and applications of plant protoplasts, tropisms, teaching lung structure, and a key to statistical methods for biologists. (DS)

  15. (Biological dosimetry)

    Energy Technology Data Exchange (ETDEWEB)

    Preston, R.J.


    The traveler attended the 1st International Conference on Biological Dosimetry in Madrid, Spain. This conference was organized to provide information to a general audience of biologists, physicists, radiotherapists, industrial hygiene personnel and individuals from related fields on the current ability of cytogenetic analysis to provide estimates of radiation dose in cases of occupational or environmental exposure. There is a growing interest in Spain in biological dosimetry because of the increased use of radiation sources for medical and occupational uses, and with this the anticipated and actual increase in numbers of overexposure. The traveler delivered the introductory lecture on Biological Dosimetry: Mechanistic Concepts'' that was intended to provide a framework by which the more applied lectures could be interpreted in a mechanistic way. A second component of the trip was to provide advice with regard to several recent cases of overexposure that had been or were being assessed by the Radiopathology and Radiotherapy Department of the Hospital General Gregorio Maranon'' in Madrid. The traveler had provided information on several of these, and had analyzed cells from some exposed or purportedly exposed individuals. The members of the biological dosimetry group were referred to individuals at REACTS at Oak Ridge Associated Universities for advice on follow-up treatment.

  16. Marine Biology (United States)

    Dewees, Christopher M.; Hooper, Jon K.


    A variety of informational material for a course in marine biology or oceanology at the secondary level is presented. Among the topics discussed are: food webs and pyramids, planktonic blooms, marine life, plankton nets, food chains, phytoplankton, zooplankton, larval plankton and filter feeders. (BT)

  17. Scaffolded biology. (United States)

    Minelli, Alessandro


    Descriptions and interpretations of the natural world are dominated by dichotomies such as organism vs. environment, nature vs. nurture, genetic vs. epigenetic, but in the last couple of decades strong dissatisfaction with those partitions has been repeatedly voiced and a number of alternative perspectives have been suggested, from perspectives such as Dawkins' extended phenotype, Turner's extended organism, Oyama's Developmental Systems Theory and Odling-Smee's niche construction theory. Last in time is the description of biological phenomena in terms of hybrids between an organism (scaffolded system) and a living or non-living scaffold, forming unit systems to study processes such as reproduction and development. As scaffold, eventually, we can define any resource used by the biological system, especially in development and reproduction, without incorporating it as happens in the case of resources fueling metabolism. Addressing biological systems as functionally scaffolded systems may help pointing to functional relationships that can impart temporal marking to the developmental process and thus explain its irreversibility; revisiting the boundary between development and metabolism and also regeneration phenomena, by suggesting a conceptual framework within which to investigate phenomena of regular hypermorphic regeneration such as characteristic of deer antlers; fixing a periodization of development in terms of the times at which a scaffolding relationship begins or is terminated; and promoting plant galls to legitimate study objects of developmental biology.

  18. Biology Notes. (United States)

    School Science Review, 1984


    Presents information on the teaching of nutrition (including new information relating to many current O-level syllabi) and part 16 of a reading list for A- and S-level biology. Also includes a note on using earthworms as a source of material for teaching meiosis. (JN)

  19. Modelling and forecasting Turkish residential electricity demand

    Energy Technology Data Exchange (ETDEWEB)

    Dilaver, Zafer, E-mail: [Surrey Energy Economics Centre (SEEC), Department of Economics, University of Surrey, Guildford, GU2 7XH United Kingdom (United Kingdom); The Republic of Turkey Prime Ministry, PK 06573, Ankara (Turkey); Hunt, Lester C [Surrey Energy Economics Centre (SEEC), Department of Economics, University of Surrey, Guildford, GU2 7XH United Kingdom (United Kingdom)


    This research investigates the relationship between Turkish residential electricity consumption, household total final consumption expenditure and residential electricity prices by applying the structural time series model to annual data over the period from 1960 to 2008. Household total final consumption expenditure, real energy prices and an underlying energy demand trend are found to be important drivers of Turkish residential electricity demand with the estimated short run and the long run total final consumption expenditure elasticities being 0.38 and 1.57, respectively, and the estimated short run and long run price elasticities being -0.09 and -0.38, respectively. Moreover, the estimated underlying energy demand trend, (which, as far as is known, has not been investigated before for the Turkish residential sector) should be of some benefit to Turkish decision makers in terms of energy planning. It provides information about the impact of past policies, the influence of technical progress, the impacts of changes in consumer behaviour and the effects of changes in economic structure. Furthermore, based on the estimated equation, and different forecast assumptions, it is predicted that Turkish residential electricity demand will be somewhere between 48 and 80 TWh by 2020 compared to 40 TWh in 2008. - Research Highlights: > Estimated short run and long run expenditure elasticities of 0.38 and 1.57, respectively. > Estimated short run and long run price elasticities of -0.09 and -0.38, respectively. > Estimated UEDT has increasing (i.e. energy using) and decreasing (i.e. energy saving) periods. > Predicted Turkish residential electricity demand between 48 and 80 TWh in 2020.

  20. Stochastic model of forecasting spare parts demand

    Directory of Open Access Journals (Sweden)

    Ivan S. Milojević


    Full Text Available If demand is known for the whole planning period (complete information, then this type of demand or a supply system is deterministic. In the simplest cases, the demand per time unit is constant. If demand levels change over time following a precisely determined and pre-known principle, this type of demand is also classified as deterministic. This quality of demand is very rare. In most cases demand is the product of a process, for example TMS maintenance, whose progression cannot be predicted due to a number of factors influencing the process and causing random demand changes. In this case, a supply system must function according to the complete information and with a certain degree of uncertainty. In cases when demand may be defined by some of the laws of the probability theory, we are talking about stochastic demand and a stochastic supply system. Demand can be described by mathematical expectation, mathematical expectation and standard deviation, probability distribution or as a random process. However, there is usually a need for the most complex description, i.e. the complex random process because both intensity of demand and the probability distribution change during the observed intervals. The level of temporal (dynamic series is traditionally considered as a complex phenomenon consisting of four components: - basic tendency of phenomenon development - cyclical impact (long-term, 'ancient' - seasonal effects - random fluctuations. The basic tendency of phenomenon development means a long-term evolution of phenomena. A function that expresses the trajectory of changes of the basic tendency of a phenomenon development in the form of the equation is called a trend. Often, the trend involves time regression; i.e. the coefficients of the proposed functions are often determined by the least squares method. To roughly determine the coefficients of the proposed function, the sum of three and three-point methods are also used. After checking the