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Sample records for factors controlling anaerobic

  1. Factors controlling pathogen destruction during anaerobic digestion of biowastes

    International Nuclear Information System (INIS)

    Smith, S.R.; Lang, N.L.; Cheung, K.H.M.; Spanoudaki, K.

    2005-01-01

    Anaerobic digestion is the principal method of stabilising biosolids from urban wastewater treatment in the UK, and it also has application for the treatment of other types of biowaste. Increasing awareness of the potential risks to human and animal health from environmental sources of pathogens has focused attention on the efficacy of waste treatment processes at destroying pathogenic microorganisms in biowastes recycled to agricultural land. The degree of disinfection achieved by a particular anaerobic digester is influenced by a variety of interacting operational variables and conditions, which can often deviate from the ideal. Experimental investigations demonstrate that Escherichia coli and Salmonella spp. are not damaged by mesophilic temperatures, whereas rapid inactivation occurs by thermophilic digestion. A hydraulic, biokinetic and thermodynamic model of pathogen inactivation during anaerobic digestion showed that a 2 log 10 reduction in E. coli (the minimum removal required for agricultural use of conventionally treated biosolids) is likely to challenge most conventional mesophilic digesters, unless strict maintenance and management practices are adopted to minimise dead zones and by-pass flow. Efficient mixing and organic matter stabilisation are the main factors controlling the rate of inactivation under mesophilic conditions and not a direct effect of temperature per se on pathogenic organisms

  2. Membrane controlled anaerobic digestion

    Science.gov (United States)

    Omstead, D. R.

    In response to general shortages of energy, examination of the anaerboic digestion process as a potential source of a combustible, methane-rich fuel has intensified in recent years. It has been suggested that orgaic intermediates (such as fatty acids), produced during digestion, might also be recovered for use as chemical feedstocks. This investigation has been concerned with combining ultrafiltration separation techniques with anaerobic digestion for the development of a process in which the total production of acetic acid (the most valuable intermediate in anaerobic digestion) and methane are optimized. Enrichment cultures, able to utilize glucose as a sole carbon source, were adapted from sewage digesting cultures using conventional techniques. An ultrafiltration system was constructed and coupled to an anaerobic digester culture vessel which contained the glucose enrichment. The membrane controlled anaerobic digester appears to show promise as a means of producing high rates of both methane gas and acetic acid.

  3. Monitoring and control of anaerobic reactors

    DEFF Research Database (Denmark)

    Pind, Peter Frode; Angelidaki, Irini; Ahring, Birgitte Kiær

    2003-01-01

    The current status in monitoring and control of anaerobic reactors is reviewed. The influence of reactor design and waste composition on the possible monitoring and control schemes is examined. After defining the overall control structure, and possible control objectives, the possible process mea...... control approaches that have been used are comprehensively described. These include simple and adaptive controllers, as well as more recent developments such as fuzzy controllers, knowledge-based controllers and controllers based on neural networks....

  4. Monitoring and control of anaerobic reactors

    DEFF Research Database (Denmark)

    Pind, Peter Frode; Angelidaki, Irini; Ahring, Birgitte Kiær

    2003-01-01

    The current status in monitoring and control of anaerobic reactors is reviewed. The influence of reactor design and waste composition on the possible monitoring and control schemes is examined. After defining the overall control structure, and possible control objectives, the possible process...

  5. RISK FACTORS IN NEONATAL ANAEROBIC INFECTIONS

    Directory of Open Access Journals (Sweden)

    M. S. Tabib

    2008-06-01

    Full Text Available Anaerobic bacteria are well known causes of sepsis in adults but there are few studies regarding their role in neonatal sepsis. In an attempt to define the incidence of neonatal anaerobic infections a prospective study was performed during one year period. A total number of 400 neonates under sepsis study were entered this investigation. Anaerobic as well as aerobic cultures were sent. The patients were subjected to comparison in two groups: anaerobic culture positive and anaerobic culture negative and this comparison were analyzed statistically. There were 7 neonates with positive anaerobic culture and 35 neonates with positive aerobic culture. A significant statistical relationship was found between anaerobic infections and abdominal distention and pneumonia. It is recommended for those neonates with abdominal distention and pneumonia refractory to antibiotic treatment to be started on antibiotics with anaerobic coverage.

  6. Anaerobic Digestion. Student Manual. Biological Treatment Process Control.

    Science.gov (United States)

    Carnegie, John W., Ed.

    This student manual contains the textual material for a four-lesson unit on anaerobic digestion control. Areas addressed include: (1) anaerobic sludge digestion (considering the nature of raw sludge, purposes of anaerobic digestion, the results of digestion, types of equipment, and other topics); (2) digester process control (considering feeding…

  7. Instrumentation and Control in Anaerobic Digestion

    DEFF Research Database (Denmark)

    Anaerobic digestion is a multistep process, and is most applied to solids destruction and wastewater treatment for energy production. Despite wide application, and long-term industrial proof of application, some industries are still reluctant to apply this technology. One of the classical reasons...... benchmark. There has therefore been, overall, a quantum advance in application and sophistication of instrumentation and control in anaerobic digestion, and it is an effective option for improved process loading rate and conversion efficiency....... are still a limitation, but this is being partly addressed by the increased complexity of digestion processes. Methods for control benchmarking have also been improved, as there is now an industry standard model (the IWA ADM1), and this is being applied in an improved whole wastewater treatment plant...

  8. A fuzzy logic approach to control anaerobic digestion

    NARCIS (Netherlands)

    Domnanovich, A.M.; Strik, D.P.B.T.B.; Pfeiffer, B.; Karlovits, M.; Zani, L.; Braun, R.; Holubar, P.

    2003-01-01

    One of the goals of the EU-Project AMONCO (Advanced Prediction, Monitoring and Controlling of Anaerobic Digestion Process Behaviour towards Biogas Usage in Fuel Cells) is to create a control tool for the anaerobic digestion process, which predicts the volumetric organic loading rate (Bv) for the

  9. Factors Involved in Sludge Granulation under Anaerobic Conditions

    Directory of Open Access Journals (Sweden)

    Jalal Shayegan

    2011-03-01

    Full Text Available This paper investigates the effects of factors involved in sludge anaerobic granulation. Granulated sludge formation is the main parameter contributing to the success of UASB reactors. Anaerobic granulation leads to reduced reactor size, space requirement, and investment costs. Operation costs are also greatly reduced due to lack of aeration. An important parameter affecting process performance is the size of sludge granules; the factors involved in granule size will be investigated. Some of the important parameters of anaerobic sludge granulation are: existence of growth cores as inert particles or granulated sludge, process operational conditions (Sludge Loading Rate and Organic Loading Rate, Loading rate increase and …, and environment conditions (nutrients, temperature, pH, combination and ….

  10. Factors involved in anaerobic growth of Saccharomyces cerevisiae.

    Science.gov (United States)

    Ishtar Snoek, I S; Yde Steensma, H

    2007-01-01

    Life in the absence of molecular oxygen requires several adaptations. Traditionally, the switch from respiratory metabolism to fermentation has attracted much attention in Saccharomyces cerevisiae, as this is the basis for the use of this yeast in the production of alcohol and in baking. It has also been clear that under anaerobic conditions the yeast is not able to synthesize sterols and unsaturated fatty acids and that for anaerobic growth these have to be added to the media. More recently it has been found that many more factors play a role. Several other biosynthetic reactions also require molecular oxygen and the yeast must have alternatives for these. In addition, the composition of the cell wall and cell membrane show major differences when aerobic and anaerobic cells are compared. All these changes are reflected by the observation that the transcription of more than 500 genes changes significantly between aerobically and anaerobically growing cultures. In this review we will give an overview of the factors that play a role in the survival in the absence of molecular oxygen. Copyright (c) 2007 John Wiley & Sons, Ltd.

  11. Anaerobic Digestion. Instructor's Guide. Biological Treatment Process Control.

    Science.gov (United States)

    Carnegie, John W., Ed.

    This instructor's guide contains materials needed to teach a four-lesson unit on anaerobic digestion control. These materials include: (1) unit overview; (2) lesson plans; (3) lecture outlines; (4) student worksheets for each lesson (with answers); and (5) two copies of a final quiz (with and without answers). Lesson 1 is a review of the theory of…

  12. Instrumentation, control, and automation for submerged anaerobic membrane bioreactors

    OpenAIRE

    Robles Martínez, Ángel; Durán Pinzón, Freddy; Ruano García, María Victoria; Ribes Bertomeu, José; Rosado Muñoz, Alfredo; SECO TORRECILLAS, AURORA; FERRER, J.

    2015-01-01

    A submerged anaerobic membrane bioreactor (AnMBR) demonstration plant with two commercial hollow-fibre ultrafiltration systems (PURON® , Koch Membrane Systems, PUR-PSH31) was designed and operated for urban wastewater treatment. An instrumentation, control, and automation (ICA) system was designed and implemented for proper process performance. Several single-input-single-output (SISO) feedback control loops based on conventional on off and PID algorithms were implemented to control the follo...

  13. Anaerobic granular sludge and biofilm reactors

    DEFF Research Database (Denmark)

    Skiadas, Ioannis V.; Gavala, Hariklia N.; Schmidt, Jens Ejbye

    2003-01-01

    -rate anaerobic treatment systems based on anaerobic granular sludge and biofilm are described in this chapter. Emphasis is given to a) the Up-flow Anaerobic Sludge Blanket (UASB) systems, b) the main characteristics of the anaerobic granular sludge, and c) the factors that control the granulation process...

  14. Techniques for controlling variability in gram staining of obligate anaerobes.

    Science.gov (United States)

    Johnson, M J; Thatcher, E; Cox, M E

    1995-01-01

    Identification of anaerobes recovered from clinical samples is complicated by the fact that certain gram-positive anaerobes routinely stain gram negative; Peptostreptococcus asaccharolyticus, Eubacterium plautii, Clostridium ramosum, Clostridium symbiosum, and Clostridium clostridiiforme are among the nonconformists with regard to conventional Gram-staining procedures. Accurate Gram staining of American Type Culture Collection strains of these anaerobic bacteria is possible by implementing fixing and staining techniques within a gloveless anaerobic chamber. Under anaerobic conditions, gram-positive staining occurred in all test organisms with "quick" fixing techniques with both absolute methanol and formalin. The results support the hypothesis that, when anaerobic bacteria are exposed to oxygen, a breakdown of the physical integrity of the cell wall occurs, introducing Gram stain variability in gram-positive anaerobes. PMID:7538512

  15. Control of calcium carbonate precipitation in anaerobic reactors

    NARCIS (Netherlands)

    Langerak, van E.P.A.

    1998-01-01

    Anaerobic treatment of waste waters with a high calcium content may lead to excessive precipitation of calcium carbonate. So far, no proper methods were available to predict or reduce the extent of precipitation in an anaerobic treatment system. Moreover, it also was not clear to what

  16. Instrumentation and control of anaerobic digestion processes : A review and some research challenges

    NARCIS (Netherlands)

    Jimenez, J.; Latrille, E.; Harmand, J.; Robles, A.; Ferrer, J.; Gaida, D.; Wolf, C.; Mairet, F.; Bernard, O.; Alcaraz-Gonzalez, V.; Mendez-Acosta, H.; Zitomer, D.; Totzke, D.; Spanjers, H.; Jacobi, F.; Guwy, A.; Dinsdale, R.; Premier, G.; Mazhegrane, S.; Ruiz-Filippi, G.; Seco, A.; Ribeiro, T.; Pauss, A.; Steyer, J.P.

    2015-01-01

    To enhance energy production from methane or resource recovery from digestate, anaerobic digestion processes require advanced instrumentation and control tools. Over the years, research on these topics has evolved and followed the main fields of application of anaerobic digestion processes: from

  17. Key geochemical factors regulating Mn(IV)-catalyzed anaerobic nitrification in coastal marine sediments

    Science.gov (United States)

    Lin, Hui; Taillefert, Martial

    2014-05-01

    The reduction of Mn(IV) oxides coupled to the anaerobic oxidation of NH4+ has been proposed for more than a decade to contribute to the fixed nitrogen pool in marine sediments, yet the existence of this process is still under debate. In this study, surface sediments from an intertidal salt marsh were incubated with MnO2 in the presence of elevated concentrations of NH4+ to test the hypothesis that the reduction of Mn(IV) oxides catalyzes anaerobic NH4+ oxidation to NO2- or NO3-. Geochemical factors such as the ratio of Mn(IV) to NH4+, the type of Mn(IV) oxides (amorphous or colloidal MnO2), and the redox potential of the sediment significantly affect the activity of anaerobic nitrification. Incubations show that the net production of NO3- is stimulated under anaerobic conditions with external addition of colloidal but not amorphous MnO2 and is facilitated by the presence of high concentrations of NH4+. Mass balance calculations demonstrate that anaerobic NH4+ oxidation contributes to the net consumption of NH4+, providing another piece of evidence for the occurrence of Mn(IV)-catalyzed anaerobic nitrification in coastal marine sediments. Finally, anaerobic nitrification is stimulated by the amendment of small concentrations of NO3- or the absence of sulfate reduction, suggesting that moderately reducing conditions favor anaerobic NH4+ oxidation. Overall, these findings suggest that Mn(IV)-catalyzed anaerobic nitrification in suboxic sediments with high N/Mn concentration ratios and highly reactive manganese oxides may be an important source of NO2- and NO3- for subsequent marine nitrogen loss via denitrification or anammox.

  18. Use of artificial neuronal networks for prediction of the control parameters in the process of anaerobic digestion with thermal pretreatment.

    Science.gov (United States)

    Flores-Asis, Rita; Méndez-Contreras, Juan M; Juárez-Martínez, Ulises; Alvarado-Lassman, Alejandro; Villanueva-Vásquez, Daniel; Aguilar-Lasserre, Alberto A

    2018-04-19

    This article focuses on the analysis of the behavior patterns of the variables involved in the anaerobic digestion process. The objective is to predict the impact factor and the behavior pattern of the variables, i.e., temperature, pH, volatile solids (VS), total solids, volumetric load, and hydraulic residence time, considering that these are the control variables for the conservation of the different groups of anaerobic microorganisms. To conduct the research, samples of physicochemical sludge were taken from a water treatment plant in a poultry processing factory, and, then, the substrate was characterized, and a thermal pretreatment was used to accelerate the hydrolysis process. The anaerobic digestion process was analyzed in order to obtain experimental data of the control variables and observe their impact on the production of biogas. The results showed that the thermal pre-hydrolysis applied at 90°C for 90 min accelerated the hydrolysis phase, allowing a significant 52% increase in the volume of methane produced. An artificial neural network was developed, and it was trained with the database obtained by monitoring the anaerobic digestion process. The results obtained from the artificial neural network showed that there is an adjustment between the real values and the prediction of validation based on 60 samples with a 96.4% coefficient of determination, and it was observed that the variables with the major impact on the process were the loading rate and VS, with impact factors of 36% and 23%, respectively.

  19. Anaerobic biodegradability of macropollutants

    DEFF Research Database (Denmark)

    Angelidaki, Irini

    2002-01-01

    A variety of test procedures for determination of anaerobic biodegradability has been reported. This paper reviews the methods developed for determination of anaerobic biodegradability of macro-pollutants. Anaerobic biodegradability of micro-pollutants is not included. Furthermore, factors...

  20. Controls on Methanogenesis in Organic-Rich Anaerobic Environments

    Science.gov (United States)

    Wilson, R.; Tfaily, M.; Chanton, J.; Rich, V. I.; Saleska, S. R.; Holmes, B.; Langford, L.; Hanson, P. J.; Bridgham, S. D.; Hopple, A.; Keller, J.; Cory, A.; Kostka, J. E.

    2017-12-01

    Peatlands contain an amount of C equal to half the CO2 in the atmosphere. That C is stored as organic C (OC) in peat deposits which form when plant productivity exceeds heterotrophic respiration. This balance has been attributed to cold, anaerobic, low pH conditions which slow microbial respiration rates, high aromatic content which may inhibit microbial decomposition, and recalcitrance of OC under terminal electron-acceptor (TEA) depleted conditions. Peat has been described as a potential C bomb which could release Gt of C into the atmosphere if rising global temperatures shifted this balance in favor of increased microbial respiration. At the Spruce and Peatlands Responses Under Changing Environments (SPRUCE) experimental site in Minnesota, U.S.A., peat up to 2 m deep was heated (+2.25°C to +9°C above ambient) both in situ and in laboratory incubations to test the response of microbial respiration to increasing temperatures. Our results demonstrated (1) that temperature did not influence CO2 or CH4 production rates in deep anaerobic peat, (2) that microbial decomposition was dominated by dissolved OC rather than the solid phase peat, and (3) that microbial decomposition in surface peat may become more methanogenic with warming. This shift towards higher CH4 production relative to CO2 has significant climate change implications since CH4 is a much stronger greenhouse gas than CO2. Under TEA-poor, anaerobic conditions, such as peat deposits, thermodynamic principles dictate that cellulose, the dominant OC form in Sphagnum peat, should be mineralized into equimolar CO2 and CH­4. However, deviations from this predicted ratio abound. The literature of rumen, a system similar to peat in many ways, revealed a potential mechanism for sustaining elevated CO2 production without accumulating inhibitory H2. Using FTICRMS, we found ubiquitous hydrogenation of unsaturated OC which could be acting as TEAs in peat deposits. This mechanism has the further advantages of

  1. Anaerobic granular sludge : characterization, and factors affecting its functioning

    NARCIS (Netherlands)

    Alphenaar, P.A.

    1994-01-01

    Many UASB reactors are designed in such a fashion that the presence of granular sludge is necessary for a proper purification process. For achieving an optimum wastewater purification with such reactors, knowledge of the factors that determine the growth, retention and disintegration of

  2. GM(1,N) method for the prediction of anaerobic digestion system and sensitivity analysis of influential factors.

    Science.gov (United States)

    Ren, Jingzheng

    2018-01-01

    Anaerobic digestion process has been recognized as a promising way for waste treatment and energy recovery in a sustainable way. Modelling of anaerobic digestion system is significantly important for effectively and accurately controlling, adjusting, and predicting the system for higher methane yield. The GM(1,N) approach which does not need the mechanism or a large number of samples was employed to model the anaerobic digestion system to predict methane yield. In order to illustrate the proposed model, an illustrative case about anaerobic digestion of municipal solid waste for methane yield was studied, and the results demonstrate that GM(1,N) model can effectively simulate anaerobic digestion system at the cases of poor information with less computational expense. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. A fuzzy-logic-based controller for methane production in anaerobic fixed-film reactors.

    Science.gov (United States)

    Robles, A; Latrille, E; Ruano, M V; Steyer, J P

    2017-01-01

    The main objective of this work was to develop a controller for biogas production in continuous anaerobic fixed-bed reactors, which used effluent total volatile fatty acids (VFA) concentration as control input in order to prevent process acidification at closed loop. To this aim, a fuzzy-logic-based control system was developed, tuned and validated in an anaerobic fixed-bed reactor at pilot scale that treated industrial winery wastewater. The proposed controller varied the flow rate of wastewater entering the system as a function of the gaseous outflow rate of methane and VFA concentration. Simulation results show that the proposed controller is capable to achieve great process stability even when operating at high VFA concentrations. Pilot results showed the potential of this control approach to maintain the process working properly under similar conditions to the ones expected at full-scale plants.

  4. Tenax extraction for exploring rate-limiting factors in methyl-β-cyclodextrin enhanced anaerobic biodegradation of PAHs under denitrifying conditions in a red paddy soil

    International Nuclear Information System (INIS)

    Sun, Mingming; Ye, Mao; Hu, Feng; Li, Huixin; Teng, Ying; Luo, Yongming; Jiang, Xin; Kengara, Fredrick Orori

    2014-01-01

    Highlights: • Enhanced anaerobic bioremediation of a red paddy soil polluted with PAHs. • 1% (w/w) methyl-β-cyclodextrin (MCD) and 20 mM nitrate addition acted as solubility-enhancing agent and electron acceptor respectively. • Tenax extraction and a first-three-compartment modeling were applicable to explore the rate-limiting factors in the biodegradation. • Lack of PAH-degraders hindered biodegradation in control and MCD addition treatments. • Inadequate bioaccessible PAHs was vital rate-limiting factor in nitrate addition treatments. -- Abstract: The effectiveness of anaerobic bioremediation systems for PAH-contaminated soil may be constrained by low contaminants bioaccessibility due to limited aqueous solubility and lack of suitable electron acceptors. Information on what is the rate-limiting factor in bioremediation process is of vital importance in the decision in what measures can be taken to assist the biodegradation efficacy. In the present study, four different microcosms were set to study the effect of methyl-β-cyclodextrin (MCD) and nitrate addition (N) on PAHs biodegradation under anaerobic conditions in a red paddy soil. Meanwhile, sequential Tenax extraction combined with a first-three-compartment model was employed to evaluate the rate-limiting factors in MCD enhanced anaerobic biodegradation of PAHs. Microcosms with both 1% (w/w) MCD and 20 mM N addition produced maximum biodegradation of total PAHs of up to 61.7%. It appears rate-limiting factors vary with microcosms: low activity of degrading microorganisms is the vital rate-limiting factor for control and MCD addition treatments (CK and M treatments); and lack of bioaccessible PAHs is the main rate-limiting factor for nitrate addition treatments (N and MN treatments). These results have practical implications for site risk assessment and cleanup strategies

  5. Monitoring the anaerobic treatment of waste waters; Control en la depuracion anaerobia de aguas residuales

    Energy Technology Data Exchange (ETDEWEB)

    Leon de Mora, C.; Molina Cantero, F.J.; Romero Galey, F.J.; Gomez Banderas, J.M. [Dpto. Tecnologia Electronica. Esc. Univ. Politec. Sevilla, Sevilla, (Spain)

    1997-04-01

    This article describes the results obtained in developing a system for monitoring sewage treatment. The system, supported by a PC, includes a fuzzy logic control algorithm for monitoring the anaerobic treatment of waste waters on the basis of data from sensors attached to an industrial robot (PLC). Its most outstanding features is that it is also capable of evaluating new monitoring strategies using parameters not originally included. (Author) 6 refs.

  6. Anaerobes and Bacterial Vaginosis in Pregnancy: Virulence Factors Contributing to Vaginal Colonisation

    Directory of Open Access Journals (Sweden)

    Charlene W. J. Africa

    2014-07-01

    Full Text Available The aetiology and pathogenesis of bacterial vaginosis (BV is unclear but it appears to be associated with factors that disrupt the normal acidity of the vagina thus altering the equilibrium between the normal vaginal microbiota. BV has serious implications for female morbidity, including reports of pelvic inflammatory disease, adverse pregnancy outcomes, increased susceptibility to sexually transmitted infections and infertility. This paper reviewed new available information regarding possible factors contributing to the establishment of the BV vaginal biofilm, examined the proposed role of anaerobic microbial species recently detected by new culture-independent methods and discusses developments related to the effects of BV on human pregnancy. The literature search included Pubmed (NLM, LISTA (EBSCO, and Web of Science. Because of the complexity and diversity of population groups, diagnosis and methodology used, no meta-analysis was performed. Several anaerobic microbial species previously missed in the laboratory diagnosis of BV have been revealed while taking cognisance of newly proposed theories of infection, thereby improving our understanding and knowledge of the complex aetiology and pathogenesis of BV and its perceived role in adverse pregnancy outcomes.

  7. Methane conversion efficiency as a simple control parameter for an anaerobic digester at high loading rates.

    Science.gov (United States)

    Charles, W; Carnaje, N P; Cord-Ruwisch, R

    2011-01-01

    The anaerobic digestion process is globally applied to the treatment of highly concentrated wastes such as industrial and rural effluents, and sewage sludge. However, it is known to be relatively unstable. When loaded with high concentrations of organic material, unwanted volatile fatty acids (VFA) are often produced rather than methane (CH4) gas which can lead to digester acidification and failure. This study investigated digester behaviour under high loading rates, testing the usefulness of stoichiometric methane conversion efficiency as a digester control parameter at high loading rates. Our results show that, in general, the CH4 production rate was proportional to the feed rate (loading rate). However, at very high loading rates, the CH4 production rate was not proportional to the increase in the feeding rate. Consequently, VFA accumulated and the H2 partial pressure increased. The proportionality of the loading rate and gas production rate is stoichiometrically expressed as the conversion efficiency. We found that conversion efficiency was a useful indicator as an early warning of digester imbalance. The digester remained stable at conversion efficiencies above 75%. Dropping below 70% signified the onset of digester failure. As loading rate and methane production data are readily available on-line in most anaerobic digestion plants, the conversion efficiency can be monitored on-line and used as an efficient control technique to maintain safe operation of anaerobic digesters at high loading rates.

  8. Power factor controllers

    International Nuclear Information System (INIS)

    1982-01-01

    The power factor controller (PFC) is a solid state electronic device that reduces excessive energy waste in ac induction motors. The significance of the PFC lies in the fact that nearly a billion induction motors are used daily. The PFC is applicable to both single phase and three phase induction motors. Since it is connected to the power lines of the motor and requires no modification to the motor itself, it may be applied to existing motors as well as to new installations

  9. Power Factor Controller

    Science.gov (United States)

    1997-01-01

    Frank Nola invented the Power Factor Controller (PFC) at Marshall Space Flight Center more than a decade ago. Nola came up with a way to curb power wastage in AC induction motors. The PFC matches voltage with the motor's actual need by continuously sensing shifts between voltage and current. When it senses a light load it cuts the voltage to the minimum needed. Potential energy savings range from 8 to 65 percent.

  10. Effects of physico-chemical factors on the viscosity evolution of anaerobic granular sludge

    NARCIS (Netherlands)

    Pevere, A.; Guibaud, G.; Goin, E.; Hullebusch, van E.D.; Lens, P.N.L.

    2009-01-01

    The rheological properties of anaerobic granular Sludge samples from four full-scale and one lab-scale anaerobic bioreactors were characterized by determining their "limit viscosity" values. These values were deducted from the evolution of the apparent viscosity of granular sludge samples (20 mL) at

  11. New approach to control the methanogenic reactor of a two-phase anaerobic digestion system

    Energy Technology Data Exchange (ETDEWEB)

    Sachs, J. von; Meyer, U.; Rys, P.; Feitkenhauer, H. [ETH Zurich (Switzerland). Laboratorium fuer Technische Chemie

    2003-03-01

    A new control strategy for the methanogenic reactor of a two-phase anaerobic digestion system has been developed and successfully tested on the laboratory scale. The control strategy serves the purpose to detect inhibitory effects and to achieve good conversion. The concept is based on the idea that volatile fatty acids (VFA) can be measured in the influent of the methanogenic reactor by means of titration. Thus, information on the output (methane production) and input of the methanogenic reactor is available, and a (carbon) mass balance can be obtained. The control algorithm comprises a proportional/integral structure with the ratio of (a) the methane production rate measured online and (b) a maximum methane production rate expected (derived from the stoichiometry) as a control variable. The manipulated variable is the volumetric feed rate. Results are shown for an experiment with VFA (feed) concentration ramps and for experiments with sodium chloride as inhibitor. (author)

  12. A pH-based control of ammonia in biogas during anaerobic digestion of artificial pig manure and maize silage

    NARCIS (Netherlands)

    Strik, D.P.B.T.B.; Domnanovich, A.M.; Braun, R.; Holubar, P.

    2006-01-01

    The purposes of this study were to prove that ammonia can be present in biogas from anaerobic digestion and to control this ammonia by reducing the reactor pH. Ammonia containing biogas was produced for a period of more than 100 days, with a maximum of 332 ppm. Especially during periods of high free

  13. Effect of anaerobic soil disinfestation and mustard seed meal for control of charcoal rot in California strawberries

    Science.gov (United States)

    Anaerobic soil disinfestation (ASD) and mustard seed meal (MSM) appear to be promising non-fumigant alternatives for soilborne disease control. However studies of their effect on charcoal rot caused by Macrophomina phaseolina in California strawberry are limited. ASD with rice bran 20 t ha-1 (ASD-RB...

  14. A novel process for synthesis of spherical nanocellulose by controlled hydrolysis of microcrystalline cellulose using anaerobic microbial consortium.

    Science.gov (United States)

    Satyamurthy, P; Vigneshwaran, N

    2013-01-10

    Degradation of cellulose by anaerobic microbial consortium is brought about either by an exocellular process or by secretion of extracellular enzymes. In this work, a novel route for synthesis of nanocellulose is described where in an anaerobic microbial consortium enriched for cellulase producers is used for hydrolysis. Microcrystalline cellulose derived from cotton fibers was subjected to controlled hydrolysis by the anaerobic microbial consortium and the resultant nanocellulose was purified by differential centrifugation technique. The nanocellulose had a bimodal size distribution (43±13 and 119±9 nm) as revealed by atomic force microscopy. A maximum nanocellulose yield of 12.3% was achieved in a span of 7 days. While the conventional process of nanocellulose preparation using 63.5% (w/w) sulfuric acid resulted in the formation of whisker shaped nanocellulose with surface modified by sulfation, controlled hydrolysis by anaerobic microbial consortium yielded spherical nanocellulose also referred to as nano crystalline cellulose (NCC) without any surface modification as evidenced from Fourier transform infrared spectroscopy. Also, it scores over chemo-mechanical production of nanofibrillated cellulose by consuming less energy due to enzyme (cellulase) assisted catalysis. This implies the scope for use of microbial prepared nanocellulose in drug delivery and bio-medical applications requiring bio-compatibility. Copyright © 2012 Elsevier Inc. All rights reserved.

  15. Yolo County's Accelerated Anaerobic and Aerobic Composting (Full-Scale Controlled Landfill Bioreactor) Project

    Science.gov (United States)

    Yazdani, R.; Kieffer, J.; Akau, H.; Augenstein, D.

    2002-12-01

    Sanitary landfilling is the dominant method of solid waste disposal in the United States, accounting for about 217 million tons of waste annually (U.S. EPA, 1997) and has more than doubled since 1960. In spite of increasing rates of reuse and recycling, population and economic growth will continue to render landfilling as an important and necessary component of solid waste management. Yolo County Department of Planning and Public Works, Division of Integrated Waste Management is demonstrating a new landfill technology called Bioreactor Landfill to better manage solid waste. In a Bioreactor Landfill, controlled quantities of liquid (leachate, groundwater, gray-water, etc.) are added and recirculated to increase the moisture content of the waste and improve waste decomposition. As demonstrated in a small-scale demonstration project at the Yolo County Central Landfill in 1995, this process significantly increases the biodegradation rate of waste and thus decreases the waste stabilization and composting time (5 to 10 years) relative to what would occur within a conventional landfill (30 to 50 years or more). When waste decomposes anaerobically (in absence of oxygen), it produces landfill gas (biogas). Biogas is primarily a mixture of methane, a potent greenhouse gas, carbon dioxide, and small amounts of Volatile Organic Compounds (VOC's) which can be recovered for electricity or other uses. Other benefits of a bioreactor landfill composting operation include increased landfill waste settlement which increases in landfill capacity and life, improved leachate chemistry, possible reduction of landfill post-closure management time, opportunity to explore decomposed waste for landfill mining, and abatement of greenhouse gases through highly efficient methane capture over a much shorter period of time than is typical of waste management through conventional landfilling. This project also investigates the aerobic decomposition of waste of 13,000 tons of waste (2.5 acre) for

  16. Optimal control of hydrogen production in a continuous anaerobic fermentation bioreactor

    Energy Technology Data Exchange (ETDEWEB)

    Aceves-Lara, Cesar-Arturo [INRA, UMR792, Ingenierie des Systemes Biologiques et des Procedes, Toulouse (France); CNRS, UMR5504, Toulouse, France 135 Avenue de Rangueil, Toulouse Cedex F-31077 (France); INRA, UR050, Laboratoire de Biotechnologie de l' Environnement, Avenue des Etangs, Narbonne F-11100 (France); Latrille, Eric; Steyer, Jean-Philippe [INRA, UR050, Laboratoire de Biotechnologie de l' Environnement, Avenue des Etangs, Narbonne F-11100 (France)

    2010-10-15

    This paper addresses the problem of optimization of hydrogen production in continuous anaerobic digesters using a model predictive control (MPC) strategy. The process is described by a dynamic nonlinear model. The influent concentration of molasses together with the effluent substrate and product concentrations of acetate, propionate, butyrate and biomass were estimated by an asymptotic online observer from measurements of gas composition in H{sub 2} and CO{sub 2} and gas flow rate. The observer was tested experimentally before to apply MPC online. The combined strategy (MPC and observer) was used in order to optimize a bioreactor of 2 L. The hydrogen production was increased by 75% up to 8.27mL{sub H{sub 2}} L{sup -1}min{sup -1}, using the influent flow rate as the main control variable while keeping the conversion of the influent concentration higher than 95% and maintaining the temperature at 37 C and pH at 5.5. (author)

  17. Anaerobic degradation of inedible crop residues produced in a Controlled Ecological Life Support System

    Science.gov (United States)

    Schwingel, W. R.; Sager, J. C.

    1996-01-01

    An anaerobic reactor seeded with organisms from an anaerobic lagoon was used to study the degradation of inedible crop residues from potato and wheat crops grown in a closed environment. Conversion of this biomass into other products was also evaluated. Degradation of wheat volatile solids was about 25% where that of potato was about 50%. The main product of the anaerobic fermentation of both crops was acetic acid with smaller quantities of propionate and butyrate produced. Nitrate, known to be high in concentration in inedible potato and wheat biomass grown hydroponically, was converted to ammonia in the anaerobic reactor. Both volatile fatty acid and ammonia production may have implications in a crop production system.

  18. Improved power factor controller

    Science.gov (United States)

    Nola, F. J.

    1980-01-01

    Power dissipation is ac induction motor is reduced by circuit that lowers applied voltage when motor is idling or only lightly loaded. Timing voltages in phase with motor current are sensed a cross gate-controlled semiconductor whitch with motor, rather than across high-power resistor, as in earlier version.

  19. Three phase power factor controller

    Science.gov (United States)

    Nola, F. J. (Inventor)

    1984-01-01

    A power control circuit for a three phase induction motor is described. Power factors for the three phases are summed to provide a control signal, and this control signal is particularly filtered and then employed to control the duty cycle of each phase of input power to the motor.

  20. Optimization and control of a novel upflow anaerobic solid-state (UASS) reactor

    Energy Technology Data Exchange (ETDEWEB)

    Mumme, J.; Linke, B. [Leibniz Inst. for Agricultural Engineering, Potsdam (Germany); Tolle, R. [Humboldt Univ., Berlin (Germany). Dept. of Biosystems Technology

    2010-07-01

    Optimization and control strategies for a newly developed upflow anaerobic solid-state (UASS) reactor equipped with liquor recirculation were investigated. The UASS reactor converts solid biomass into biogas while the particulate organic matter (POM) ascends in the form of a solid-state bed (SSB) driven by the adherence of self-produced micro gas bubbles. Performance data and technical characteristics were obtained from a technical scale semi-automatic 400 L UASS reactor that operated for 117 days with maize silage under thermophilic conditions at 55 degrees C. The process liquor was continuously recirculated through separate methanogenic reactors in order to prevent an accumulation of volatile fatty acids. Emphasis was placed on determining the gas and metabolite production. The volatile solids (VS) loading rate was fixed at 5 g per litre per day. The methane production rate of the UASS reactor stabilized between 1.5 and 2.0 L per litre per day. The average volatile solids (VS) methane yield of the maize silage was 380 L per kg. The liquor exchange was found to play an important role in the performance and stability of the digestion process. Although low exchange rates can cause process failure by acidification, high exchange rates have the risk of clogging inside the SSB. It was concluded that the UASS reactor is a viable solution for the digestion of various organic matter.

  1. Comparative study on factors affecting anaerobic digestion of agricultural vegetal residues

    Directory of Open Access Journals (Sweden)

    Cioabla Adrian

    2012-06-01

    Full Text Available Abstract Background Presently, different studies are conducted related to the topic of biomass potential to generate through anaerobic fermentation process alternative fuels supposed to support the existing fossil fuel resources, which are more and more needed, in quantity, but also in quality of so called green energy. The present study focuses on depicting an optional way of capitalizing agricultural biomass residues using anaerobic fermentation in order to obtain biogas with satisfactory characteristics.. The research is based on wheat bran and a mix of damaged ground grains substrates for biogas production. Results The information and conclusions delivered offer results covering the general characteristics of biomass used , the process parameters with direct impact over the biogas production (temperature regime, pH values and the daily biogas production for each batch relative to the used material. Conclusions All conclusions are based on processing of monitoring process results , with accent on temperature and pH influence on the daily biogas production for the two batches. The main conclusion underlines the fact that the mixture batch produces a larger quantity of biogas, using approximately the same process conditions and input, in comparison to alone analyzed probes, indicating thus a higher potential for the biogas production than the wheat bran substrate. Adrian Eugen Cioabla, Ioana Ionel, Gabriela-Alina Dumitrel and Francisc Popescu contributed equally to this work

  2. Start-up of intensive anaerobic wastewater methanization processes: impact of hydrodynamic conditions and of control strategy of organic load increase on biofilm formation and activity

    International Nuclear Information System (INIS)

    Cresson, Romain

    2006-01-01

    This research thesis aims at being a contribution to the understanding of mechanisms of anaerobic film development and maturation, in order to obtain a better control of their formation and this to decrease the duration of the bioreactor start-up phase. More precisely, the author analysed the impact of hydrodynamic parameters and of load rise strategy on biofilm characteristics (thickness, density, biodiversity) and on its activity (anaerobic breathing, decontamination kinetics) during its development. Thus, after a recall of the anaerobic digestion principle, the author presents processes, methods and techniques used during this research, reports and discusses the obtained results

  3. Control of hydrogen sulphide in full-scale anaerobic digesters using ...

    African Journals Online (AJOL)

    scale anaerobic digesters (ADs) at a largescale municipal wastewater treatment plant (WWTP). Iron (III) ('ferric') chloride was applied at a range of 24–105 mg FeCl3/L with and without alkali solution using different strategies. Introduction points ...

  4. Control of hydrogen sulphide in full-scale anaerobic digesters using ...

    African Journals Online (AJOL)

    2018-04-02

    Apr 2, 2018 ... requirements present the weakest point of anaerobic digestion, which is crucially important in the renewable energy field. Additionally, design capacity of the biogas desulfurization unit is usually based on the biogas production rate and may be underestimated in H2S removal capacity terms in wastewater.

  5. The control of H2S in biogas using iron ores as in situ desulfurizers during anaerobic digestion process.

    Science.gov (United States)

    Zhou, Qiying; Jiang, Xia; Li, Xi; Jiang, Wenju

    2016-09-01

    In this study, five kinds of iron ores, limonite, hematite, manganese ore, magnetite and lava rock, were used as the in situ desulfurizers in the anaerobic digestion reactors to investigate their effects on controlling H2S in biogas. The results show that the addition of the five iron ores could significantly control the content of H2S in biogas, with the best performance for limonite. As limonite dosages increase (10-60 g/L), the contents of H2S in biogas were evidently decreased in the digesters with different initial sulfate concentrations (0-1000 mg/L). After the anaerobic digestion, the removed sulfur was mostly deposited on the surface of limonite. A possible mechanism of H2S control in biogas by limonite was proposed preliminarily, including adsorption, FeS precipitation, and Fe (III) oxidation. The results demonstrated that limonite was a promising in situ desulfurizer for controlling H2S in biogas with low cost and high efficiency.

  6. Importance and controls of anaerobic ammonium oxidation influenced by riverbed geology

    OpenAIRE

    Lansdown, K.; McKew, B. A.; Whitby, C.; Heppell, C. M.; Dumbrell, A. J.; Binley, Andrew Mark; Olde, L.; Trimmer, Mark

    2016-01-01

    Rivers are an important global sink for excess bioavailable nitrogen: they convert approximately 40% of terrestrial N-runoff per year (~47 Tg) to biologically unavailable N2 gas and return it to the atmosphere.1 Currently, riverine N2 production is conceptualised and modelled as denitrification.2-4 The contribution of anaerobic ammonium oxidation (or anammox), an alternate pathway of N2 production important in marine environments, is not well understood.5,6 Here we use in situ and laboratory ...

  7. In situ demonstration of anaerobic BTEX biodegradation through controlled-release experiments

    International Nuclear Information System (INIS)

    Reinhard, M.; Hopkins, G.D.; Orwin, E.; Shang, S.; Lebron, C.A.

    1995-01-01

    Anaerobic biodegradation of the aromatic hydrocarbons benzene, toluene, ethylbenzene, m-xylene and o-xylene (BTEX) was studied in situ within the anaerobic zone of a weathered gasoline spill site. Slug tests were conducted in which approximately 1,000 L of treated anaerobic groundwater was injected into a test zone through a multiport injection well. The injectate contained bromide as the conservative tracer, nitrate or sulfate as the electron acceptor, and trace concentrations of BTEX compounds. Following injection, water was withdraw and analyzed for bromide, nitrate, sulfate, and BTEX. Under denitrification conditions, transformation was complete within 8 days for toluene, ethylbenzene, and m-xylene and within 75 days for o-xylene. Benzene removal was not observed within the time span and the conditions of the experiment. With sulfate as the predominant electron acceptor under sulfidogenic conditions, toluene, and m- and o-xylene were transformed and completely removed over a period of 40 to 50 days. Ethylbenzene removal began to accelerate after 30 days. Benzene removal was slow but appeared to be significant

  8. Biogas-pH automation control strategy for optimizing organic loading rate of anaerobic membrane bioreactor treating high COD wastewater.

    Science.gov (United States)

    Yu, Dawei; Liu, Jibao; Sui, Qianwen; Wei, Yuansong

    2016-03-01

    Control of organic loading rate (OLR) is essential for anaerobic digestion treating high COD wastewater, which would cause operation failure by overload or less efficiency by underload. A novel biogas-pH automation control strategy using the combined gas-liquor phase monitoring was developed for an anaerobic membrane bioreactor (AnMBR) treating high COD (27.53 g·L(-1)) starch wastewater. The biogas-pH strategy was proceeded with threshold between biogas production rate >98 Nml·h(-1) preventing overload and pH>7.4 preventing underload, which were determined by methane production kinetics and pH titration of methanogenesis slurry, respectively. The OLR and the effluent COD were doubled as 11.81 kgCOD·kgVSS(-1)·d(-1) and halved as 253.4 mg·L(-1), respectively, comparing with a constant OLR control strategy. Meanwhile COD removal rate, biogas yield and methane concentration were synchronously improved to 99.1%, 312 Nml·gCODin(-1) and 74%, respectively. Using the biogas-pH strategy, AnMBR formed a "pH self-regulation ternary buffer system" which seizes carbon dioxide and hence provides sufficient buffering capacity. Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. Trace metal speciation and bioavailability in anaerobic digestion: A review.

    Science.gov (United States)

    Thanh, Pham Minh; Ketheesan, Balachandran; Yan, Zhou; Stuckey, David

    2016-01-01

    Trace metals are essential for the growth of anaerobic microorganisms, however, in practice they are often added to anaerobic digesters in excessive amounts, which can lead to inhibition. The concept of bioavailability of metals in anaerobic digestion has been poorly understood in the past, and a lack of deep understanding of the relationship between trace metal speciation and bioavailability can result in ineffective metal dosing strategies for anaerobic digesters. Sequential extraction schemes are useful for fractionating trace metals into their different forms, and metal sulfides can serve as a store and source for trace metals during anaerobic digestion, while natural/synthetic chelating agents (soluble microbial products-SMPs, extracellular polysaccharides-EPS, and EDTA/NTA) are capable of controlling trace metal bioavailability. Nevertheless, more work is needed to: investigate the speciation and bioavailability of Ca, Mg, Mn, W, and Se; compare the bioavailability of different forms of trace metals e.g. carbonates, sulfides, phosphates to different anaerobic trophic groups; determine what factors influence metal sulfide dissolution; investigate whether chelating agents can increase trace metal bioavailability; develop and adapt specialized analytical techniques, and; determine how trace metal dynamics change in an anaerobic membrane bioreactor (AnMBR). Copyright © 2015 Elsevier Inc. All rights reserved.

  10. Clinical characteristics associated with mortality of patients with anaerobic bacteremia.

    Science.gov (United States)

    Umemura, Takumi; Hamada, Yukihiro; Yamagishi, Yuka; Suematsu, Hiroyuki; Mikamo, Hiroshige

    2016-06-01

    The presence of anaerobes in the blood stream is known to be associated with a higher rate of mortality. However, few prognostic risk factor analyses examining whether a patient's background characteristics are associated with the prognosis have been reported. We performed a retrospective case-controlled study to assess the prognostic factors associated with death from anaerobic bacteremia. Seventy-four patients with anaerobic bacteremia were treated between January 2005 and December 2014 at Aichi Medical University Hospital. The clinical information included drug susceptibility was used for analysis of prognostic factors for 30-day mortality. Multivariate logistic analyses revealed an association between the 30-day mortality rate and malignancy (OR: 3.64, 95% CI: 1.08-12.31) and clindamycin resistance (OR: 7.93, 95% CI: 2.33-27.94). The result of Kaplan-Meier analysis of mortality showed that the 30-day survival rate was 83% in clindamycin susceptible and 38.1% in clindamycin resistant anaerobes causing bacteremia. The result of log-rank test also showed that susceptibility to clindamycin affected mortality (P anaerobic bacteremia with a higher risk of 30-day mortality. The results of this study are important for the early and appropriate management of patients with anaerobic bacteremia. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. Inhibition of Anaerobic Biological Treatment: A Review

    Science.gov (United States)

    Hou, Li; Ji, Dandan; Zang, Lihua

    2018-01-01

    Anaerobic digestion is a method for treating living and industrial wastewater by anaerobic degradation of organic compounds, which can produce biogas (carbon dioxide and methane mixture) and microbial biomass. And biogas as a renewable resource, can replace the use of ore fuel. In the process of anaerobic digestion, the problems of low methane yield and unstable reaction process are often encountered, which limits the widespread use of this technology. Various inhibitors are the main limiting factors for anaerobic digestion. In this paper, the main factors limiting anaerobic digestion are reviewed, and the latest research progress is introduced.

  12. Importance and controls of anaerobic ammonium oxidation influenced by riverbed geology

    Science.gov (United States)

    Lansdown, K.; McKew, B. A.; Whitby, C.; Heppell, C. M.; Dumbrell, A. J.; Binley, A.; Olde, L.; Trimmer, M.

    2016-05-01

    Rivers are an important global sink for excess bioavailable nitrogen: they convert approximately 40% of terrestrial N runoff per year (~47 Tg) to biologically unavailable N2 gas and return it to the atmosphere. At present, riverine N2 production is conceptualized and modelled as denitrification. Anaerobic ammonium oxidation, known as anammox, is an alternative pathway of N2 production important in marine environments, but its contribution to riverine N2 production is not well understood. Here we use in situ and laboratory measurements of anammox activity using 15N tracers and molecular analyses of microbial communities to evaluate anammox in clay-, sand- and chalk-dominated river beds in the Hampshire Avon catchment, UK during summer 2013. Abundance of the hzo gene, which encodes an enzyme central to anammox metabolism, varied across the contrasting geologies. Anammox rates were similar across geologies but contributed different proportions of N2 production because of variation in denitrification rates. In spite of requiring anoxic conditions, anammox, most likely coupled to partial nitrification, contributed up to 58% of in situ N2 production in oxic, permeable riverbeds. In contrast, denitrification dominated in low-permeability clay-bed rivers, where anammox contributes roughly 7% to the production of N2 gas. We conclude that anammox can represent an important nitrogen loss pathway in permeable river sediments.

  13. Economic viability of anaerobic digestion

    Energy Technology Data Exchange (ETDEWEB)

    Wellinger, A. [INFOENERGIE, Ettenhausen (Switzerland)

    1996-01-01

    The industrial application of anaerobic digestion is a relatively new, yet proven waste treatment technology. Anaerobic digestion reduces and upgrades organic waste, and is a good way to control air pollution as it reduces methane and nitrous gas emissions. For environmental and energy considerations, anaerobic digestion is a nearly perfect waste treatment process. However, its economic viability is still in question. A number of parameters - type of waste (solid or liquid), digester system, facility size, product quality and end use, environmental requirements, cost of alternative treatments (including labor), and interest rates - define the investment and operating costs of an anaerobic digestion facility. Therefore, identical facilities that treat the same amount and type of waste may, depending on location, legislation, and end product characteristics, reveal radically different costs. A good approach for evaluating the economics of anaerobic digestion is to compare it to treatment techniques such as aeration or conventional sewage treatment (for industrial wastewater), or composting and incineration (for solid organic waste). For example, the cost (per ton of waste) of in-vessel composting with biofilters is somewhat higher than that of anaerobic digestion, but the investment costs 1 1/2 to 2 times more than either composting or anaerobic digestion. Two distinct advantages of anaerobic digestion are: (1) it requires less land than either composting or incinerating, which translates into lower costs and milder environmental and community impacts (especially in densely populated areas); and (2) it produces net energy, which can be used to operate the facility or sold to nearby industries.

  14. Enhanced simulations of CH4 and CO2 production in permafrost-affected soils address soil moisture controls on anaerobic decomposition

    Science.gov (United States)

    Graham, D. E.; Zheng, J.; Moon, J. W.; Painter, S. L.; Thornton, P. E.; Gu, B.; Wullschleger, S. D.

    2017-12-01

    Rapid warming of Arctic ecosystems exposes soil organic carbon (SOC) to accelerated microbial decomposition, leading to increased emissions of carbon dioxide (CO2) and methane (CH4) that have a positive feedback on global warming. The magnitude, timing, and form of carbon release will depend not only on changes in temperature, but also on biogeochemical and hydrological properties of soils. In this synthesis study, we assessed the decomposability of thawed organic carbon from active layer soils and permafrost from the Barrow Environmental Observatory across different microtopographic positions under anoxic conditions. The main objectives of this study were to (i) examine environmental conditions and soil properties that control anaerobic carbon decomposition and carbon release (as both CO2 and CH4); (ii) develop a common set of parameters to simulate anaerobic CO2 and CH4 production; and (iii) evaluate uncertainties generated from representations of pH and temperature effects in the current model framework. A newly developed anaerobic carbon decomposition framework simulated incubation experiment results across a range of soil water contents. Anaerobic CO2 and CH4 production have different temperature and pH sensitivities, which are not well represented in current biogeochemical models. Distinct dynamics of CH4 production at -2° C suggest methanogen biomass and growth rate limit activity in these near-frozen soils, compared to warmer temperatures. Anaerobic CO2 production is well constrained by the model using data-informed labile carbon pool and fermentation rate initialization to accurately simulate its temperature sensitivity. On the other hand, CH4 production is controlled by water content, methanogenesis biomass, and the presence of alternative electron acceptors, producing a high temperature sensitivity with large uncertainties for methanogenesis. This set of environmental constraints to methanogenesis is likely to undergo drastic changes due to permafrost

  15. Assessment of ex-vitro anaerobic digestion kinetics of crop residues through first order exponential models: effect of lag phase period and curve factor

    International Nuclear Information System (INIS)

    Sahito, A.R.; Brohi, K.M.

    2013-01-01

    Kinetic studies of AD (Anaerobic Digestion) process are useful to predict the performance of digesters and design appropriate digesters and also helpful in understanding inhibitory mechanisms of biodegradation. The aim of this study was to assess the anaerobic kinetics of crop residues digestion with buffalo dung. Seven crop residues namely, bagasse, banana plant waste, canola straw, cotton stalks, rice straw, sugarcane trash and wheat straw were selected from the field and were analyzed on MC (Moisture Contents), TS (Total Solids) and VS (Volatile Solids) with standard methods. In present study, three first order exponential models namely exponential model, exponential lag phase model and exponential curve factor model were used to assess the kinetics of the AD process of crop residues and the effect of lag phase and curve factor was analyzed based on statistical hypothesis testing and on information theory. Assessment of kinetics of the AD of crop residues and buffalo dung follows the first order kinetics. Out of the three models, the simple exponential model was the poorest model, while the first order exponential curve factor model is the best fit model. In addition to statistical hypothesis testing, the exponential curve factor model has least value of AIC (Akaike's Information Criterion) and can generate methane production data more accurately. Furthermore, there is an inverse linear relationship between the lag phase period and the curve factor. (author)

  16. Neural-fuzzy control system application for monitoring process response and control of anaerobic hybrid reactor in wastewater treatment and biogas production.

    Science.gov (United States)

    Waewsak, Chaiwat; Nopharatana, Annop; Chaiprasert, Pawinee

    2010-01-01

    Based on the developed neural-fuzzy control system for anaerobic hybrid reactor (AHR) in wastewater treatment and biogas production, the neural network with backpropagation algorithm for prediction of the variables pH, alkalinity (Alk) and total volatile acids (TVA) at present day time t was used as input data for the fuzzy logic to calculate the influent feed flow rate that was applied to control and monitor the process response at different operations in the initial, overload influent feeding and the recovery phases. In all three phases, this neural-fuzzy control system showed great potential to control AHR in high stability and performance and quick response. Although in the overloading operation phase II with two fold calculating influent flow rate together with a two fold organic loading rate (OLR), this control system had rapid response and was sensitive to the intended overload. When the influent feeding rate was followed by the calculation of control system in the initial operation phase I and the recovery operation phase III, it was found that the neural-fuzzy control system application was capable of controlling the AHR in a good manner with the pH close to 7, TVA/Alk 80% with biogas and methane yields at 0.45 and 0.30 m3/kg COD removed.

  17. Three-Phase Power Factor Controller

    Science.gov (United States)

    Nola, F. J.

    1982-01-01

    Three-Phase Power-Factor Controller develops a control signal for each motor winding. As motor loading decreases, rms value of applied voltage is decreased by feedback-control circuit. Power consumption is therefore lower than in unregulated operation. Controller employs phase detector for each of three phases of delta-connected induction motor. Phase-difference sum is basis for control.

  18. Temperature and solids retention time control microbial population dynamics and volatile fatty acid production in replicated anaerobic digesters

    Science.gov (United States)

    Vanwonterghem, Inka; Jensen, Paul D.; Rabaey, Korneel; Tyson, Gene W.

    2015-02-01

    Anaerobic digestion is a widely used technology for waste stabilization and generation of biogas, and has recently emerged as a potentially important process for the production of high value volatile fatty acids (VFAs) and alcohols. Here, three reactors were seeded with inoculum from a stably performing methanogenic digester, and selective operating conditions (37°C and 55°C 12 day and 4 day solids retention time) were applied to restrict methanogenesis while maintaining hydrolysis and fermentation. Replicated experiments performed at each set of operating conditions led to reproducible VFA production profiles which could be correlated with specific changes in microbial community composition. The mesophilic reactor at short solids retention time showed accumulation of propionate and acetate (42 +/- 2% and 15 +/- 6% of CODhydrolyzed, respectively), and dominance of Fibrobacter and Bacteroidales. Acetate accumulation (>50% of CODhydrolyzed) was also observed in the thermophilic reactors, which were dominated by Clostridium. Under all tested conditions, there was a shift from acetoclastic to hydrogenotrophic methanogenesis, and a reduction in methane production by >50% of CODhydrolyzed. Our results demonstrate that shortening the SRT and increasing the temperature are effective strategies for driving microbial communities towards controlled production of high levels of specific volatile fatty acids.

  19. Power-Factor Controller With Regenerative Braking

    Science.gov (United States)

    Nola, F. J.

    1982-01-01

    Modified power-factor motor-control circuit operates motor as a phase-controlled generator when load attempts to turn at higher than synchronous speed. An induction motor is required to act at times as a brake. Circuit modification allows power-factor controller to save energy in motoring mode and convert automatically to an induction-generator controller in generating, or braking, mode.

  20. Failure Detector for Power-Factor Controller

    Science.gov (United States)

    Nola, F. J.

    1982-01-01

    New protective circuits have been developed for power-factor ac motor controllers. Circuits prevent direct current and consequent motor heating that would normally result from failure of solid-state switch in controller. Single-phase power-factor controller with short detector compensates for short-circuit failure in either direction by applying full power to motor. Controller with open detector compensates for open-circuit failure in either direction by turning off power to motor.

  1. Accumulation of Pesticides in Anaerobic Clayey Till-Controls and Implications for Groundwater

    DEFF Research Database (Denmark)

    Jorgensen, Peter R.; Spliid, Niels H.

    2016-01-01

    of the phenoxy acids and triazines was much closer in sand-filled fractures and thin sand layers/lamina in the clay, suggesting that the migration of the same compounds along these textural preferential flow paths into the underlying aquifer was less different. Despite that a greater mass had originally been...... spilled of 2,4-D and MCPA having similar mobility as the accumulated MCPP and dichlorprop, these compounds were not accumulated in the zone of maximum concentrations. It is suggested that the controls, which initially allowed for the observed separate accumulation of MCPP and dichlorprop as a zone...

  2. Increased anaerobic metabolism is a distinctive signature in a colorectal cancer cellular model of resistance to antiepidermal growth factor receptor antibody.

    Science.gov (United States)

    Monteleone, Francesca; Rosa, Roberta; Vitale, Monica; D'Ambrosio, Chiara; Succoio, Mariangela; Formisano, Luigi; Nappi, Lucia; Romano, Maria Fiammetta; Scaloni, Andrea; Tortora, Giampaolo; Bianco, Roberto; Zambrano, Nicola

    2013-03-01

    Cetuximab is a chimeric antibody approved for the treatment of metastatic colorectal cancer that selectively targets epidermal growth factor receptor (EGFR) signaling. Treatment efficacy with this drug is often impaired by acquired resistance and poor information has been accumulated on the mechanisms underlying such a phenomenon. By taking advantage of a syngenic cellular system of sensitivity and acquired resistance to anti-EGFR therapy in the colorectal carcinoma GEO cell line, we profiled protein expression differences between Cetuximab-sensitive and -resistant cells. Combined 2D DIGE and MS analyses revealed a main proteomic signature resulting from selective deregulation of various metabolic enzymes, including glucose-6-phosphate dehydrogenase, transketolase, lactate dehydrogenase B, and pyruvate dehydrogenase E1, which was also confirmed by Western blotting experiments. Lactate dehydrogenase B downregulation has been already related to an increased anaerobic utilization of glucose by tumor cells; accordingly, we verified that Cetuximab-resistant cells have a significantly higher production of lactate. Resistant cells also showed decreased nicotinamide adenine dinucleotide phosphate (NADPH) levels. Observed protein deregulations were not related to functional alterations of the hypoxia-inducible factor 1-associated pathways. Our data demonstrate that increased anaerobic metabolism is a prominent feature observed in the GEO syngenic model of acquired resistance to anti-EGFR therapy in colorectal cancer. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Microbial Anaerobic Digestion (Bio-Digesters as an Approach to the Decontamination of Animal Wastes in Pollution Control and the Generation of Renewable Energy

    Directory of Open Access Journals (Sweden)

    Golden Makaka

    2013-09-01

    Full Text Available With an ever increasing population rate; a vast array of biomass wastes rich in organic and inorganic nutrients as well as pathogenic microorganisms will result from the diversified human, industrial and agricultural activities. Anaerobic digestion is applauded as one of the best ways to properly handle and manage these wastes. Animal wastes have been recognized as suitable substrates for anaerobic digestion process, a natural biological process in which complex organic materials are broken down into simpler molecules in the absence of oxygen by the concerted activities of four sets of metabolically linked microorganisms. This process occurs in an airtight chamber (biodigester via four stages represented by hydrolytic, acidogenic, acetogenic and methanogenic microorganisms. The microbial population and structure can be identified by the combined use of culture-based, microscopic and molecular techniques. Overall, the process is affected by bio-digester design, operational factors and manure characteristics. The purpose of anaerobic digestion is the production of a renewable energy source (biogas and an odor free nutrient-rich fertilizer. Conversely, if animal wastes are accidentally found in the environment, it can cause a drastic chain of environmental and public health complications.

  4. Microbial anaerobic digestion (bio-digesters) as an approach to the decontamination of animal wastes in pollution control and the generation of renewable energy.

    Science.gov (United States)

    Manyi-Loh, Christy E; Mamphweli, Sampson N; Meyer, Edson L; Okoh, Anthony I; Makaka, Golden; Simon, Michael

    2013-09-17

    With an ever increasing population rate; a vast array of biomass wastes rich in organic and inorganic nutrients as well as pathogenic microorganisms will result from the diversified human, industrial and agricultural activities. Anaerobic digestion is applauded as one of the best ways to properly handle and manage these wastes. Animal wastes have been recognized as suitable substrates for anaerobic digestion process, a natural biological process in which complex organic materials are broken down into simpler molecules in the absence of oxygen by the concerted activities of four sets of metabolically linked microorganisms. This process occurs in an airtight chamber (biodigester) via four stages represented by hydrolytic, acidogenic, acetogenic and methanogenic microorganisms. The microbial population and structure can be identified by the combined use of culture-based, microscopic and molecular techniques. Overall, the process is affected by bio-digester design, operational factors and manure characteristics. The purpose of anaerobic digestion is the production of a renewable energy source (biogas) and an odor free nutrient-rich fertilizer. Conversely, if animal wastes are accidentally found in the environment, it can cause a drastic chain of environmental and public health complications.

  5. Microbial Anaerobic Digestion (Bio-Digesters) as an Approach to the Decontamination of Animal Wastes in Pollution Control and the Generation of Renewable Energy

    Science.gov (United States)

    Manyi-Loh, Christy E.; Mamphweli, Sampson N.; Meyer, Edson L.; Okoh, Anthony I.; Makaka, Golden; Simon, Michael

    2013-01-01

    With an ever increasing population rate; a vast array of biomass wastes rich in organic and inorganic nutrients as well as pathogenic microorganisms will result from the diversified human, industrial and agricultural activities. Anaerobic digestion is applauded as one of the best ways to properly handle and manage these wastes. Animal wastes have been recognized as suitable substrates for anaerobic digestion process, a natural biological process in which complex organic materials are broken down into simpler molecules in the absence of oxygen by the concerted activities of four sets of metabolically linked microorganisms. This process occurs in an airtight chamber (biodigester) via four stages represented by hydrolytic, acidogenic, acetogenic and methanogenic microorganisms. The microbial population and structure can be identified by the combined use of culture-based, microscopic and molecular techniques. Overall, the process is affected by bio-digester design, operational factors and manure characteristics. The purpose of anaerobic digestion is the production of a renewable energy source (biogas) and an odor free nutrient-rich fertilizer. Conversely, if animal wastes are accidentally found in the environment, it can cause a drastic chain of environmental and public health complications. PMID:24048207

  6. Enhancing dissolved oxygen control using an on-line hybrid fuzzy-neural soft-sensing model-based control system in an anaerobic/anoxic/oxic process.

    Science.gov (United States)

    Huang, Mingzhi; Wan, Jinquan; Hu, Kang; Ma, Yongwen; Wang, Yan

    2013-12-01

    An on-line hybrid fuzzy-neural soft-sensing model-based control system was developed to optimize dissolved oxygen concentration in a bench-scale anaerobic/anoxic/oxic (A(2)/O) process. In order to improve the performance of the control system, a self-adapted fuzzy c-means clustering algorithm and adaptive network-based fuzzy inference system (ANFIS) models were employed. The proposed control system permits the on-line implementation of every operating strategy of the experimental system. A set of experiments involving variable hydraulic retention time (HRT), influent pH (pH), dissolved oxygen in the aerobic reactor (DO), and mixed-liquid return ratio (r) was carried out. Using the proposed system, the amount of COD in the effluent stabilized at the set-point and below. The improvement was achieved with optimum dissolved oxygen concentration because the performance of the treatment process was optimized using operating rules implemented in real time. The system allows various expert operational approaches to be deployed with the goal of minimizing organic substances in the outlet while using the minimum amount of energy.

  7. Anaerobic Thermophiles

    Directory of Open Access Journals (Sweden)

    Francesco Canganella

    2014-02-01

    Full Text Available The term “extremophile” was introduced to describe any organism capable of living and growing under extreme conditions. With the further development of studies on microbial ecology and taxonomy, a variety of “extreme” environments have been found and an increasing number of extremophiles are being described. Extremophiles have also been investigated as far as regarding the search for life on other planets and even evaluating the hypothesis that life on Earth originally came from space. The first extreme environments to be largely investigated were those characterized by elevated temperatures. The naturally “hot environments” on Earth range from solar heated surface soils and water with temperatures up to 65 °C, subterranean sites such as oil reserves and terrestrial geothermal with temperatures ranging from slightly above ambient to above 100 °C, to submarine hydrothermal systems with temperatures exceeding 300 °C. There are also human-made environments with elevated temperatures such as compost piles, slag heaps, industrial processes and water heaters. Thermophilic anaerobic microorganisms have been known for a long time, but scientists have often resisted the belief that some organisms do not only survive at high temperatures, but actually thrive under those hot conditions. They are perhaps one of the most interesting varieties of extremophilic organisms. These microorganisms can thrive at temperatures over 50 °C and, based on their optimal temperature, anaerobic thermophiles can be subdivided into three main groups: thermophiles with an optimal temperature between 50 °C and 64 °C and a maximum at 70 °C, extreme thermophiles with an optimal temperature between 65 °C and 80 °C, and finally hyperthermophiles with an optimal temperature above 80 °C and a maximum above 90 °C. The finding of novel extremely thermophilic and hyperthermophilic anaerobic bacteria in recent years, and the fact that a large fraction of them belong

  8. Guidance Document on Anaerobic Digester Foaming Prevention and Control Methods (WERF Report INFR1SG10a)

    Science.gov (United States)

    The development of this anaerobic digester (AD) foaming guidance document is based on the need for a specific detailed methodology that water resource recovery facilities (WRRF) personnel can follow and implement to manage or mitigate AD foam incidents. This guidance manual is th...

  9. The content of trace element iron is a key factor for competition between anaerobic ammonium oxidation and methane-dependent denitrification processes.

    Science.gov (United States)

    Lu, Yong-Ze; Fu, Liang; Li, Na; Ding, Jing; Bai, Ya-Nan; Samaras, Petros; Zeng, Raymond Jianxiong

    2018-05-01

    Coupling of anaerobic ammonium oxidation (Anammox) with denitrifying anaerobic methane oxidation (DAMO) is a sustainable pathway for nitrogen removal and reducing methane emissions from wastewater treatment processes. However, studies on the competitive relation between Anammox bacteria and DAMO bacteria are limited. Here, we investigated the effects of variations in the contents of trace element iron on Anammox and DAMO microorganisms. The short-term results indicated that optimal concentrations of iron, which obviously stimulated the activity of Amammox bacteria, DAMO bacteria and DAMO archaea, were 80, 20, and 80 μM, respectively. The activity of Amammox bacteria increased more significant than DAMO bacteria with increasing contents of trace element iron. After long-term incubation with high content of trace element iron of 160 μM in the medium, Candidatus Brocadia (Amammox bacteria) outcompeted Candidatus Methylomirabilis oxyfera (DAMO bacteria), and ANME-2d (DAMO archaea) remarkably increased in number and dominated the co-culture systems (64.5%). Meanwhile, with further addition of iron, the removal rate of ammonium and nitrate increased by 13.6 and 9.2 times, respectively, when compared with that noted in the control. As far as we know, this study is the first to explore the important role of trace element iron contents in the competition between Anammox bacteria and DAMO bacteria and further enrichment of DAMO archaea by regulating the contents of trace element iron. Copyright © 2018 Elsevier Ltd. All rights reserved.

  10. Phase Detector for Power-Factor Controller

    Science.gov (United States)

    Nola, F. J.

    1984-01-01

    Positive feedback assures reliable switching. Three Phase Power Factor Controller includes three phase detectors, each produces rectangular waves of duration approximately equal to lag time between line voltage and motor current.

  11. Survival of Antibiotic Resistant Bacteria and Horizontal Gene Transfer Control Antibiotic Resistance Gene Content in Anaerobic Digesters

    OpenAIRE

    Miller, Jennifer H.; Novak, John T.; Knocke, William R.; Pruden, Amy

    2016-01-01

    Understanding fate of antibiotic resistant bacteria (ARB) versus their antibiotic resistance genes (ARGs) during wastewater sludge treatment is critical in order to reduce the spread of antibiotic resistance through process optimization. Here, we spiked high concentrations of tetracycline-resistant bacteria, isolated from mesophilic (Iso M1-1- a Pseudomonas sp.) and thermophilic (Iso T10- a Bacillus sp.) anaerobic digested sludge, into batch digesters and monitored their fate by plate counts ...

  12. Human factors challenges for advanced process control

    International Nuclear Information System (INIS)

    Stubler, W.F.; O'Hara, J..M.

    1996-01-01

    New human-system interface technologies provide opportunities for improving operator and plant performance. However, if these technologies are not properly implemented, they may introduce new challenges to performance and safety. This paper reports the results from a survey of human factors considerations that arise in the implementation of advanced human-system interface technologies in process control and other complex systems. General trends were identified for several areas based on a review of technical literature and a combination of interviews and site visits with process control organizations. Human factors considerations are discussed for two of these areas, automation and controls

  13. Commercialization of the power factor controller

    Science.gov (United States)

    1981-01-01

    The purpose of the Motor Power Controller, also known as the Power Factor Controller, is to improve power factor and reduce power dissipation in induction motors operating below full load. These purposes were studied and tested in detail. The Motor Power Controller is capable of raising power factors from 0.2 to 0.8 and results in energy savings. It was found that many motors, in their present operating applications, are classified as unstable. The electronic nature of the controller vs. the electrical nature of the motor, compound this problem due to the differences in response time of the two devices. Many tests were successfully completed, the most indicating greater savings than anticipated. Also, there was an effect on efficiency which was not included in the calculations.

  14. Anaerobic Digestion: Process

    DEFF Research Database (Denmark)

    Angelidaki, Irini; Batstone, Damien J.

    2011-01-01

    Organic waste may degrade anaerobically in nature as well as in engineered systems. The latter is called anaerobic digestion or biogasification. Anaerobic digestion produces two main outputs: An energy-rich gas called biogas and an effluent. The effluent, which may be a solid as well as liquid...... with very little dry matter may also be called a digest. The digest should not be termed compost unless it specifically has been composted in an aerated step. This chapter describes the basic processes of anaerobic digestion. Chapter 9.5 describes the anaerobic treatment technologies, and Chapter 9.......6 addresses the mass balances and environmental aspects of anaerobic digestion....

  15. Anaerobic granular sludge and biofilm reactors

    DEFF Research Database (Denmark)

    Skiadas, Ioannis V.; Gavala, Hariklia N.; Schmidt, Jens Ejbye

    2003-01-01

    The long retention time of the active biomass in the high-rate anaerobic digesters is the key factor for the successful application of the high rate anaerobic wastewater treatment. The long solids retention time is achieved due to the specific reactor configuration and it is enhanced by the immob......The long retention time of the active biomass in the high-rate anaerobic digesters is the key factor for the successful application of the high rate anaerobic wastewater treatment. The long solids retention time is achieved due to the specific reactor configuration and it is enhanced...... by the immobilization of the biomass, which forms static biofilms, particle-supported biofilms, or granules depending on the reactor's operational conditions. The advantages of the high-rate anaerobic digestion over the conventional aerobic wastewater treatment methods has created a clear trend for the change...

  16. Cell cycle control factors and skeletal development

    Directory of Open Access Journals (Sweden)

    Toru Ogasawara

    2013-05-01

    Full Text Available In the oral and maxillofacial region, conditions such as delayed bone healing after tooth extraction, bone fracture, trauma-induced bone or cartilage defects, and tumors or birth defects are common, and it is necessary to identify the molecular mechanisms that control skeletogenesis or the differentiation of cells, in order to establish new treatment strategies for these conditions. Multiple studies have been conducted to investigate the involvement of factors that may be crucial for skeletogenesis or the differentiation of cells, including transcription factors, growth factors and cell cycle factors. Several genetically engineered mouse models of cell cycle factors have been generated in research seeking to identify cell cycle factor(s involved in the differentiation of cells, carcinogenesis, etc. Many groups have also reported the importance of cell cycle factors in the differentiation of osteoblasts, osteoclasts, chondrocytes and other cell types. Herein, we review the phenotypes of the genetically engineered mouse models of cell cycle factors with a particular focus on the size, body weight and skeletal abnormalities of the mice, and we discuss the potential of cell cycle factors as targets of clinical applications.

  17. Anaerobic Treatment of Methanolic Wastes

    NARCIS (Netherlands)

    Lettinga, G.; Geest, van der A.Th.; Hobma, S.W.; Laan, van der J.B.R.

    1979-01-01

    Although it is well known that methanol can be fermented directly by a specific species of methane bacteria, viz. Methanosarcina barkeri, until now little information was available about the effect of important environmental factors on the anaerobic fermentation of methanol. As methanol can be the

  18. Livestock Anaerobic Digester Database

    Science.gov (United States)

    The Anaerobic Digester Database provides basic information about anaerobic digesters on livestock farms in the United States, organized in Excel spreadsheets. It includes projects that are under construction, operating, or shut down.

  19. Anaerobic benzene degradation by bacteria.

    Science.gov (United States)

    Vogt, Carsten; Kleinsteuber, Sabine; Richnow, Hans-Hermann

    2011-11-01

    Benzene is a widespread and toxic contaminant. The fate of benzene in contaminated aquifers seems to be primarily controlled by the abundance of oxygen: benzene is aerobically degraded at high rates by ubiquitous microorganisms, and the oxygen-dependent pathways for its breakdown were elucidated more than 50 years ago. In contrast, benzene was thought to be persistent under anoxic conditions until 25 years ago. Nevertheless, within the last 15 years, several benzene-degrading cultures have been enriched under varying electron acceptor conditions in laboratories around the world, and organisms involved in anaerobic benzene degradation have been identified, indicating that anaerobic benzene degradation is a relevant environmental process. However, only a few benzene degraders have been isolated in pure culture so far, and they all use nitrate as an electron acceptor. In some highly enriched strictly anaerobic cultures, benzene has been described to be mineralized cooperatively by two or more different organisms. Despite great efforts, the biochemical mechanism by which the aromatic ring of benzene is activated in the absence of oxygen is still not fully elucidated; methylation, hydroxylation and carboxylation are discussed as likely reactions. This review summarizes the current knowledge about the 'key players' of anaerobic benzene degradation under different electron acceptor conditions and the possible pathway(s) of anaerobic benzene degradation. © 2011 The Authors; Journal compilation © 2011 Society for Applied Microbiology and Blackwell Publishing Ltd.

  20. Anaerobic benzene degradation by bacteria

    Science.gov (United States)

    Vogt, Carsten; Kleinsteuber, Sabine; Richnow, Hans‐Hermann

    2011-01-01

    Summary Benzene is a widespread and toxic contaminant. The fate of benzene in contaminated aquifers seems to be primarily controlled by the abundance of oxygen: benzene is aerobically degraded at high rates by ubiquitous microorganisms, and the oxygen‐dependent pathways for its breakdown were elucidated more than 50 years ago. In contrast, benzene was thought to be persistent under anoxic conditions until 25 years ago. Nevertheless, within the last 15 years, several benzene‐degrading cultures have been enriched under varying electron acceptor conditions in laboratories around the world, and organisms involved in anaerobic benzene degradation have been identified, indicating that anaerobic benzene degradation is a relevant environmental process. However, only a few benzene degraders have been isolated in pure culture so far, and they all use nitrate as an electron acceptor. In some highly enriched strictly anaerobic cultures, benzene has been described to be mineralized cooperatively by two or more different organisms. Despite great efforts, the biochemical mechanism by which the aromatic ring of benzene is activated in the absence of oxygen is still not fully elucidated; methylation, hydroxylation and carboxylation are discussed as likely reactions. This review summarizes the current knowledge about the ‘key players’ of anaerobic benzene degradation under different electron acceptor conditions and the possible pathway(s) of anaerobic benzene degradation. PMID:21450012

  1. Power Factor Controller Avoids False Turnoff

    Science.gov (United States)

    Nola, F. J.

    1983-01-01

    Single-phase power-factor controller includes special inhibiting circuit to avoid false turnoff. If thyristor trigger signal occurs during flow of current from preceding half cycle, inhibiting signal delays application of trigger pulse until beginning of next current half cycle.

  2. Power-Factor Controllers: How Safe?

    Science.gov (United States)

    Long, K.; Christian, W.; Kovacik, J.; Grazyk, T.

    1985-01-01

    Potential safety problems with power-factor controllers (PFC's) evaluated. Based on study of PFCs in use with appliances, report recommends measures to prevent consumers from misapplying these energy saving devices. Device used on such appliances as refrigerators, sewing machines, pumps, hair dryers, and food processors. When misused, they fail to save energy and may cause damage.

  3. Survival of Antibiotic Resistant Bacteria and Horizontal Gene Transfer Control Antibiotic Resistance Gene Content in Anaerobic Digesters

    Science.gov (United States)

    Miller, Jennifer H.; Novak, John T.; Knocke, William R.; Pruden, Amy

    2016-01-01

    Understanding fate of antibiotic resistant bacteria (ARB) vs. their antibiotic resistance genes (ARGs) during wastewater sludge treatment is critical in order to reduce the spread of antibiotic resistance through process optimization. Here, we spiked high concentrations of tetracycline-resistant bacteria, isolated from mesophilic (Iso M1-1—a Pseudomonas sp.) and thermophilic (Iso T10—a Bacillus sp.) anaerobic digested sludge, into batch digesters and monitored their fate by plate counts and quantitative polymerase chain reaction (QPCR) of their corresponding tetracycline ARGs. In batch studies, spiked ARB plate counts returned to baseline (thermophilic) or 1-log above baseline (mesophilic) while levels of the ARG present in the spiked isolate [tet(G)] remained high in mesophilic batch reactors. To compare results under semi-continuous flow conditions with natural influent variation, tet(O), tet(W), and sul1 ARGs, along with the intI1 integrase gene, were monitored over a 9-month period in the raw feed sludge and effluent sludge of lab-scale thermophilic and mesophilic anaerobic digesters. sul1 and intI1 in mesophilic and thermophilic digesters correlated positively (Spearman rho = 0.457–0.829, P digested sludge or thermophilic digested sludge (Spearman rho = 0.130–0.486, P = 0.075–0.612). However, in the thermophilic digester, the tet(O) and tet(W) ratios remained consistently low over the entire monitoring period. We conclude that the influent sludge microbial composition can influence the ARG content of a digester, apparently as a result of differential survival or death of ARBs or horizontal gene transfer of genes between raw sludge ARBs and the digester microbial community. Notably, mesophilic digestion was more susceptible to ARG intrusion than thermophilic digestion, which may be attributed to a higher rate of ARB survival and/or horizontal gene transfer between raw sludge bacteria and the digester microbial community. PMID:27014196

  4. Neurotrophic factor control of adult SVZ neurogenesis.

    Science.gov (United States)

    Bath, Kevin G; Lee, Francis S

    2010-04-01

    Neurogenesis is the process by which cells divide, migrate, and subsequently differentiate into a neuronal phenotype. Significant rates of neurogenesis persist into adulthood in two brain regions, the subgranular zone (SGZ) of the dentate gyrus and the subventricular zone (SVZ) of the lateral ventricles. Cells of the SVZ divide and migrate via the rostral migratory stream (RMS) to the olfactory bulb (OB) where they differentiate into granule and periglomerular cells. With the discovery of large-scale neurogenesis in the adult brain, there have been significant efforts to identify the mechanisms that control this process as well as the role of these cells in neuronal functioning. Neurotrophic factors are a family of molecules that serve critical roles in the survival and differentiation of neurons during development, as well as contribute to continued plasticity throughout life. Several members of the neurotrophin family have been implicated in the control of adult postnatal SVZ neurogenesis. In this review we will address what is currently known regarding neurotrophic factor-dependent control of SVZ neurogenesis and place these findings in the context of what is known regarding other growth factors.

  5. Covering Materials for Anaerobic Digesters Producing Biogas

    International Nuclear Information System (INIS)

    Itodo, I. N.; Philips, T. K.

    2002-01-01

    The suitability of foam, concrete and clay soil as covering material on anaerobic digesters producing biogas was investigated using four batch-type digesters of 20 litres volume. The methane yield from the digesters was of the order: foam >control> concrete > clay soil. The digester covered with foam had the highest methane yield, best temperature control and most favourable pH conditions. It is most suitable as cover material on anaerobic digesters

  6. Survival of Antibiotic Resistant Bacteria and Horizontal Gene Transfer Control Antibiotic Resistance Gene Content in Anaerobic Digesters.

    Science.gov (United States)

    Miller, Jennifer H; Novak, John T; Knocke, William R; Pruden, Amy

    2016-01-01

    Understanding fate of antibiotic resistant bacteria (ARB) vs. their antibiotic resistance genes (ARGs) during wastewater sludge treatment is critical in order to reduce the spread of antibiotic resistance through process optimization. Here, we spiked high concentrations of tetracycline-resistant bacteria, isolated from mesophilic (Iso M1-1-a Pseudomonas sp.) and thermophilic (Iso T10-a Bacillus sp.) anaerobic digested sludge, into batch digesters and monitored their fate by plate counts and quantitative polymerase chain reaction (QPCR) of their corresponding tetracycline ARGs. In batch studies, spiked ARB plate counts returned to baseline (thermophilic) or 1-log above baseline (mesophilic) while levels of the ARG present in the spiked isolate [tet(G)] remained high in mesophilic batch reactors. To compare results under semi-continuous flow conditions with natural influent variation, tet(O), tet(W), and sul1 ARGs, along with the intI1 integrase gene, were monitored over a 9-month period in the raw feed sludge and effluent sludge of lab-scale thermophilic and mesophilic anaerobic digesters. sul1 and intI1 in mesophilic and thermophilic digesters correlated positively (Spearman rho = 0.457-0.829, P < 0.05) with the raw feed sludge. There was no correlation in tet(O) or tet(W) ratios in raw sludge and mesophilic digested sludge or thermophilic digested sludge (Spearman rho = 0.130-0.486, P = 0.075-0.612). However, in the thermophilic digester, the tet(O) and tet(W) ratios remained consistently low over the entire monitoring period. We conclude that the influent sludge microbial composition can influence the ARG content of a digester, apparently as a result of differential survival or death of ARBs or horizontal gene transfer of genes between raw sludge ARBs and the digester microbial community. Notably, mesophilic digestion was more susceptible to ARG intrusion than thermophilic digestion, which may be attributed to a higher rate of ARB survival and/or horizontal gene

  7. Survival of antibiotic resistant bacteria and horizontal gene transfer control antibiotic resistance gene content in anaerobic digesters

    Directory of Open Access Journals (Sweden)

    Jennifer Hafer Miller

    2016-03-01

    Full Text Available Understanding fate of antibiotic resistant bacteria (ARB versus their antibiotic resistance genes (ARGs during wastewater sludge treatment is critical in order to reduce the spread of antibiotic resistance through process optimization. Here, we spiked high concentrations of tetracycline-resistant bacteria, isolated from mesophilic (Iso M1-1- a Pseudomonas sp. and thermophilic (Iso T10- a Bacillus sp. anaerobic digested sludge, into batch digesters and monitored their fate by plate counts and quantitative polymerase chain reaction (QPCR of their corresponding tetracycline ARGs. In batch studies, spiked ARB plate counts returned to baseline (thermophilic or 1-log above baseline (mesophilic while levels of the ARG present in the spiked isolate (tet(G remained high in mesophilic batch reactors. To compare results under semi-continuous flow conditions with natural influent variation, tet(O, tet(W, and sul1 ARGs, along with the intI1 integrase gene, were monitored over a 9-month period in the raw feed sludge and effluent sludge of lab-scale thermophilic and mesophilic anaerobic digesters. sul1 and intI1 in mesophilic and thermophilic digesters correlated positively (Spearman rho = 0.457 to 0.829, P<0.05 with the raw feed sludge. There was no correlation in tet(O or tet(W ratios in raw sludge and mesophilic digested sludge or thermophilic digested sludge (Spearman rho = 0.130 to 0.486, P = 0.075 to 0.612. However, in the thermophilic digester, the tet(O and tet(W ratios remained consistently low over the entire monitoring period. We conclude that the influent sludge microbial composition can influence the ARG content of a digester, apparently as a result of differential survival or death of ARBs or horizontal gene transfer of genes between raw sludge ARBs and the digester microbial community. Notably, mesophilic digestion was more susceptible to ARG intrusion than thermophilic digestion, which may be attributed to a higher rate of ARB survival and

  8. Anaerobe Reinigung von Abwasser

    OpenAIRE

    Sternad, W.; Mohr, M.; Spork, C.; Troesch, W.; Trick, I.; Krischke, W.

    2007-01-01

    WO 2007076953 A1 UPAB: 20070822 NOVELTY - The municipal wastewater purification comprises anaerobic biological purification of the wastewater by using a biomass (15-100 g/l) from psychrophilic microorganisms, concentrating the sludge by separating the wastewater and feeding back the sludge into the anaerobic biological purification. The psychrophilic microorganisms exhibit an optimum temperature of less than 25degreesC. The anaerobic purification takes place as single- or two-step methanizati...

  9. Safety factor profile control in a tokamak

    CERN Document Server

    Bribiesca Argomedo, Federico; Prieur, Christophe

    2014-01-01

    Control of the Safety Factor Profile in a Tokamak uses Lyapunov techniques to address a challenging problem for which even the simplest physically relevant models are represented by nonlinear, time-dependent, partial differential equations (PDEs). This is because of the  spatiotemporal dynamics of transport phenomena (magnetic flux, heat, densities, etc.) in the anisotropic plasma medium. Robustness considerations are ubiquitous in the analysis and control design since direct measurements on the magnetic flux are impossible (its estimation relies on virtual sensors) and large uncertainties remain in the coupling between the plasma particles and the radio-frequency waves (distributed inputs). The Brief begins with a presentation of the reference dynamical model and continues by developing a Lyapunov function for the discretized system (in a polytopic linear-parameter-varying formulation). The limitations of this finite-dimensional approach motivate new developments in the infinite-dimensional framework. The t...

  10. Factors Controlling Liquid Particulate Matter in Amazonia

    Science.gov (United States)

    Bateman, A. P.; Gong, Z.; de Sá, S. S.; Wernis, R. A.; Yee, L.; Isaacman-VanWertz, G. A.; Goldstein, A. H.; Castillo, P.; Sedlacek, A. J., III; Palm, B. B.; Campuzano-Jost, P.; Day, D. A.; Hu, W.; Jimenez, J. L.; Alexander, L.; Manzi, A. O.; Souza, R. A. F. D.; Artaxo, P.; Martin, S. T.

    2015-12-01

    The hygroscopic response of particulate matter (PM) during GoAmazon 2014/5 was investigated through the use of particle rebound (or lack thereof) during impaction. The hygroscopic response was measured online and in real-time using a custom designed impaction apparatus. The impaction apparatus was calibrated with respect to particle viscosity indicating a liquid state (viscosity hygroscopic response and phase state of the PM under investigation was determined. The hygroscopic response curves were categorized according to the rebound fraction at high RH (80 - 98%) bounded by two extremes. 1) Time periods that resemble pure SOM generated under controlled chamber conditions, where no particle rebound is observed above 80% RH. 2) Time periods that a large fraction (10 - 40%) of particles rebound at RH values >95%, an indication of hydrophobic particles. The role of anthropogenic and biogenic factors in controlling the hygroscopic response of PM in Amazonia is investigated through meteorological conditions and particle chemical composition.

  11. Anaerobic Soil Disinfestation (ASD) Combined with Soil Solarization for Root-Knot Nematode Control in Vegetable and Ornamental Crops in Florida

    Science.gov (United States)

    Anaerobic soil disinfestation (ASD) combined with soil solarization continues to be evaluated for management of plant-parasitic nematodes in vegetable and ornamental crops in Florida. ASD combines organic amendments and soil saturation to stimulate microbial activity and create anaerobic conditions...

  12. The Azoarcus anaerobius 1,3-Dihydroxybenzene (Resorcinol) Anaerobic Degradation Pathway Is Controlled by the Coordinated Activity of Two Enhancer-Binding Proteins.

    Science.gov (United States)

    Pacheco-Sánchez, Daniel; Molina-Fuentes, Águeda; Marín, Patricia; Medina-Bellver, Javier-I; González-López, Óscar; Marqués, Silvia

    2017-05-01

    The anaerobic resorcinol degradation pathway in Azoarcus anaerobius is unique in that it uses an oxidative rather than a reductive strategy to overcome the aromatic ring stability in degradation of this compound, in a process that is dependent on nitrate respiration. We show that the pathway is organized in five transcriptional units, three of which are inducible by the presence of the substrate. Three σ 54 -dependent promoters located upstream from the three operons coding for the main pathway enzymes were identified, which shared a similar structure with conserved upstream activating sequences (UASs) located at 103 to 111 bp from the transcription start site. Expression of the pathway is controlled by the bacterial enhancer-binding proteins (bEBPs) RedR1 and RedR2, two homologous regulators that, despite their high sequence identity (97%), have nonredundant functions: RedR2, the master regulator which also controls RedR1 expression, is itself able to promote transcription from two of the promoters, while RedR1 activity is strictly dependent on the presence of RedR2. The two regulators were shown to interact with each other, suggesting that the natural mode of activation is by forming heterodimers, which become active in the presence of the substrate after its metabolization to hydroxybenzoquinone through the pathway enzymes. The model structure of the N-terminal domain of the proteins is composed of tandem GAF and PAS motifs; the possible mechanisms controlling the activity of the regulators are discussed. IMPORTANCE Azoarcus anaerobius is a strict anaerobe that is able to use 1,3-dihydroxybenzene as the sole carbon source in a process that is dependent on nitrate respiration. We have shown that expression of the pathway is controlled by two regulators of almost identical sequences: the bEBPs RedR1 and RedR2, which share 97% identity. These regulators control three promoters with similar structure. Despite their sequence identity, the two bEBPs are not redundant

  13. Anaerobic sludge granulation

    NARCIS (Netherlands)

    Hulshoff Pol, L.W.; Castro Lopes, de S.I.; Lettinga, G.; Lens, P.N.L.

    2004-01-01

    This paper reviews different theories on anaerobic sludge granulation in UASB-reactors that have been proposed during the past two decades
    This paper reviews different theories on anaerobic sludge granulation in UASB-reactors that have been proposed during the past two decades. The initial

  14. Colon cancer controls versus population controls in case-control studies of occupational risk factors

    DEFF Research Database (Denmark)

    Kaerlev, Linda; Lynge, Elsebeth; Sabroe, Svend

    2004-01-01

    are interchangeable with the experience for population controls. Patient controls may even be preferable from population controls under certain conditions. In this study we examine if colon cancer patients can serve as surrogates for proper population controls in case-control studies of occupational risk factors....... METHODS: The study was conducted from 1995 to 1997. Incident colon cancer controls (N = 428) aged 35-69 years with a histological verified diagnosis and population controls (N = 583) were selected. Altogether 254 (59%) of the colon cancer controls and 320 (55%) of the population controls were interviewed...... to pesticides among colon cancer controls. CONCLUSIONS: Use of colon cancer controls may provide valid exposure estimates in studies of many occupational risk factors for cancer, but not for studies on exposure related to farming....

  15. Factors controlling contrail cirrus optical depth

    Directory of Open Access Journals (Sweden)

    B. Kärcher

    2009-08-01

    Full Text Available Aircraft contrails develop into contrail cirrus by depositional growth and sedimentation of ice particles and horizontal spreading due to wind shear. Factors controlling this development include temperature, ice supersaturation, thickness of ice-supersaturated layers, and vertical gradients in the horizontal wind field. An analytical microphysical cloud model is presented and validated that captures these processes. Many individual contrail cirrus are simulated that develop differently owing to the variability in the controlling factors, resulting in large samples of cloud properties that are statistically analyzed. Contrail cirrus development is studied over the first four hours past formation, similar to the ages of line-shaped contrails that were tracked in satellite imagery on regional scales. On these time scales, contrail cirrus optical depth and microphysical variables exhibit a marked variability, expressed in terms of broad and skewed probability distribution functions. Simulated mean optical depths at a wavelength of 0.55 μm range from 0.05-0.5 and a substantial fraction 20-50% of contrail cirrus stay subvisible (optical depth <0.02, depending on meteorological conditions.

    A detailed analysis based on an observational case study over the continental USA suggests that previous satellite measurements of line-shaped persistent contrails have missed about 89%, 50%, and 11% of contrails with optical depths 0-0.05, 0.05-0.1, and 0.1-0.2, respectively, amounting to 65% of contrail coverage of all optical depths. When comparing observations with simulations and when estimating the contrail cirrus climate impact, not only mean values but also the variability in optical depth and microphysical properties need to be considered.

  16. [Relationship between balance control and psychological factors].

    Science.gov (United States)

    Grub, Elisabeth Johanna; Wydra, Georg; Köllner, Volker

    2015-03-01

    The goal of the study was to capture the relationship between motor balance and psychological factors, using sport-motoric tests as well as subjective self-evaluations. The balance control of 118 patients of a psychosomatic rehabilitation clinic was examined at the beginning and end of rehabilitation using various motor tests. Additionally, psychological variables including self-esteem (MSWS), degree of anxiety (BAI) and depressive symptoms (BDI) were assessed. To examine subjective self-evaluation a numerical analog scale and a questionnaire with open questions were used. Content analysis was performed on the questionnaire. In the area of physical self-esteem, especially sportiness, low to moderate correlations were found between self-esteem and balance. No significant relationship was found between anxiety or depressive symptoms and balance. In the open questions most patients described a distinct connection between emotional distress and balance. The participation in the tests was often a topic in their therapy. The expected relationship between psychological factors and motor balance could be only partially confirmed. A question is raised as to whether this relationship appears merely in situations of acute stress, as detected in the patients answers to the open questions. Addressing the study in psychotherapie an indication that balance tasks are well suited for the subjective experience and discussion of psychosomatic relationships. © Georg Thieme Verlag KG Stuttgart · New York.

  17. Cholera Toxin Production Induced upon Anaerobic Respiration is Suppressed by Glucose Fermentation in Vibrio cholerae.

    Science.gov (United States)

    Oh, Young Taek; Lee, Kang-Mu; Bari, Wasimul; Kim, Hwa Young; Kim, Hye Jin; Yoon, Sang Sun

    2016-03-01

    The causative agent of pandemic cholera, Vibrio cholerae, infects the anaerobic environment of the human intestine. Production of cholera toxin (CT), a major virulence factor of V. cholerae, is highly induced during anaerobic respiration with trimethylamine N-oxide (TMAO) as an alternative electron acceptor. However, the molecular mechanism of TMAO-stimulated CT production is not fully understood. Herein, we reveal that CT production during anaerobic TMAO respiration is affected by glucose fermentation. When the seventh pandemic V. cholerae O1 strain N16961 was grown with TMAO and additional glucose, CT production was markedly reduced. Furthermore, an N16961 Δcrp mutant, devoid of cyclic AMP receptor protein (CRP), was defective in CT production during growth by anaerobic TMAO respiration, further suggesting a role of glucose metabolism in regulating TMAO-mediated CT production. TMAO reductase activity was noticeably decreased when grown together with glucose or by mutation of the crp gene. A CRP binding region was identified in the promoter region of the torD gene, which encodes a structural subunit of the TMAO reductase. Gel shift assays further confirmed the binding of purified CRP to the torD promoter sequence. Together, our results suggest that the bacterial ability to respire using TMAO is controlled by CRP, whose activity is dependent on glucose availability. Our results reveal a novel mechanism for the regulation of major virulence factor production by V. cholerae under anaerobic growth conditions.

  18. Anaerobic sequencing batch reactor in pilot scale for treatment of tofu industry wastewater

    Science.gov (United States)

    Rahayu, Suparni Setyowati; Purwanto, Budiyono

    2015-12-01

    The small industry of tofu production process releases the waste water without being processed first, and the wastewater is directly discharged into water. In this study, Anaerobic Sequencing Batch Reactor in Pilot Scale for Treatment of Tofu Industry was developed through an anaerobic process to produce biogas as one kind of environmentally friendly renewable energy which can be developed into the countryside. The purpose of this study was to examine the fundamental characteristics of organic matter elimination of industrial wastewater with small tofu effective method and utilize anaerobic active sludge with Anaerobic Sequencing Bath Reactor (ASBR) to get rural biogas as an energy source. The first factor is the amount of the active sludge concentration which functions as the decomposers of organic matter and controlling selectivity allowance to degrade organic matter. The second factor is that HRT is the average period required substrate to react with the bacteria in the Anaerobic Sequencing Bath Reactor (ASBR).The results of processing the waste of tofu production industry using ASBR reactor with active sludge additions as starter generates cumulative volume of 5814.4 mL at HRT 5 days so that in this study it is obtained the conversion 0.16 L of CH4/g COD and produce biogas containing of CH4: 81.23% and CO2: 16.12%. The wastewater treatment of tofu production using ASBR reactor is able to produce renewable energy that has economic value as well as environmentally friendly by nature.

  19. Model-based automatic tuning of a filtration control system for submerged anaerobic membrane bioreactors (AnMBR)

    OpenAIRE

    Robles Martínez, Ángel; Ruano García, María Victoria; Ribes Bertomeu, José; SECO TORRECILLAS, AURORA; FERRER, J.

    2014-01-01

    This paper describes a model-based method to optimise filtration in submerged AnMBRs. The method is applied to an advanced knowledge-based control system and considers three statistical methods: (1) sensitivity analysis (Morris screening method) to identify an input subset for the advanced controller; (2) Monte Carlo method (trajectory-based random sampling) to find suitable initial values for the control inputs; and (3) optimisation algorithm (performing as a supervisory controller) to re-ca...

  20. Early-warning process/control for anaerobic digestion and biological nitrogen transformation processes: Batch, semi-continuous, and/or chemostat experiments. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Hickey, R. [Science Applications International Corp., McLean, VA (United States)

    1992-09-01

    The objective of this project was to develop and test an early-warning/process control model for anaerobic sludge digestion (AD). The approach was to use batch and semi-continuously fed systems and to assemble system parameter data on a real-time basis. Specific goals were to produce a real-time early warning control model and computer code, tested for internal and external validity; to determine the minimum rate of data collection for maximum lag time to predict failure with a prescribed accuracy and confidence in the prediction; and to determine and characterize any trends in the real-time data collected in response to particular perturbations to feedstock quality. Trends in the response of trace gases carbon monoxide and hydrogen in batch experiments, were found to depend on toxicant type. For example, these trace gases respond differently for organic substances vs. heavy metals. In both batch and semi-continuously feed experiments, increased organic loading lead to proportionate increases in gas production rates as well as increases in CO and H{sub 2} concentration. An analysis of variance of gas parameters confirmed that CO was the most sensitive indicator variable by virtue of its relatively larger variance compared to the others. The other parameters evaluated including gas production, methane production, hydrogen, carbon monoxide, carbon dioxide and methane concentration. In addition, a relationship was hypothesized between gaseous CO concentration and acetate concentrations in the digester. The data from semicontinuous feed experiments were supportive.

  1. Anaerobic Digestion and its Applications

    Science.gov (United States)

    Anaerobic digestion is a natural biological process. The initials "AD" may refer to the process of anaerobic digestion, or the built systems of anaerobic digesters. While there are many kinds of digesters, the biology is basically the same for all. Anaerobic digesters are built...

  2. Anaerobic critical velocity in four swimming techniques.

    Science.gov (United States)

    Neiva, H P; Fernandes, R J; Vilas-Boas, J P

    2011-03-01

    The aim of this study was to assess critical velocity in order to control and evaluate anaerobic swimming training. 51 highly trained male swimmers performed maximal 15, 25, 37.5 and 50 m in the 4 swimming techniques to determine critical velocity from the distance-time relationship. Anaerobic critical velocity was compared with 100 m swimming performance and corresponding partials. Complementarily, 9 swimmers performed a 6×50 m (4 min interval) training series at front crawl individual anaerobic critical velocity, capillary blood lactate concentrations being assessed after each repetition. The mean±SD values of anaerobic critical velocity and its relationship with the 100 m event were: 1.61±0.07 (r=0.60, p=0.037), 1.53±0.05 (r=0.81, p=0.015), 1.33±0.05 (r=0.83, p=0.002), and 1.75±0.05 (r=0.74, p=0.001), for butterfly, backstroke, breaststroke and front crawl, respectively. However, differences between anaerobic critical velocity and performance were observed (with exception of the second half of the 100 m swimming events in breaststroke and butterfly). Lactate concentration values at the end of the series were 14.52±1.06 mmol.l (-1), which suggests that it was indeed an anaerobic training set. In this sense, anaerobic critical velocity can be used to prescribe anaerobic training intensities. © Georg Thieme Verlag KG Stuttgart · New York.

  3. Upflow anaerobic sludge blanket reactor--a review.

    Science.gov (United States)

    Bal, A S; Dhagat, N N

    2001-04-01

    means that a sudden increase in the easily degradable organics will result in increased acid production with subsequent accumulation of acids. This inhibits the methanogenesis step. Acclimatization of the microorganisms to a substrate has been reported to take more than five weeks. Sufficiently acclimated bacteria have shown greater stability towards stress-inducing events such as hydraulic overloads, fluctuations in temperature, fluctuations in volatile acid and ammonia concentrations etc. Several environmental factors can affect anaerobic digestion, by altering the parameters such as specific growth rate, decay rate, gas production, substrate utilization, start-up and response to changes in input. It has long been recognized that an anaerobic process is in many ways ideal for wastewater treatment and has following merits: A high degree of waste stabilization A low production of excess A low nutrient requirements No oxygen requirement Production of methane gas Anaerobic microorganisms, especially methanogens have a slow growth rate. At lower HRTs, the possibility of washout of biomass is more prominent. This makes it difficult to maintain the effective number of useful microorganisms in the system. To maintain the population of anaerobes, large reactor volumes or higher HRTs are required. This may ultimately provide longer SRTs upto 20 days for high rate systems. Thus, provision of larger reactor volumes or higher HRTs ultimately lead to higher capital cost. Among notable disadvantages, it has low synthesis/reaction rate hence long start up periods and difficulty in recovery from upset conditions. Special attention is, therefore, warranted towards, controlling the factors that affect process adversely; important among them being environmental factors such as temperature, pH and concentration of toxic substances. The conventional anaerobic treatment process consists of a reactor containing waste and biological solids (bacteria) responsible for the digestion process

  4. Anaerobic Digestion Foaming Causes

    OpenAIRE

    Ganidi, Nafsika

    2008-01-01

    Anaerobic digestion foaming has been encountered in several sewage treatment plants in the UK. Foaming has raised major concerns for the water utilities due to significant impacts on process efficiency and operational costs. Several foaming causes have been suggested over the past few years by researchers. However, the supporting experimental information is limited and in some cases site specific. The present report aimed to provide a better understanding of the anaerobic di...

  5. Anaerobic microsites have an unaccounted role in soil carbon stabilization.

    Science.gov (United States)

    Keiluweit, Marco; Wanzek, Tom; Kleber, Markus; Nico, Peter; Fendorf, Scott

    2017-11-24

    Soils represent the largest carbon reservoir within terrestrial ecosystems. The mechanisms controlling the amount of carbon stored and its feedback to the climate system, however, remain poorly resolved. Global carbon models assume that carbon cycling in upland soils is entirely driven by aerobic respiration; the impact of anaerobic microsites prevalent even within well-drained soils is missed within this conception. Here, we show that anaerobic microsites are important regulators of soil carbon persistence, shifting microbial metabolism to less efficient anaerobic respiration, and selectively protecting otherwise bioavailable, reduced organic compounds such as lipids and waxes from decomposition. Further, shifting from anaerobic to aerobic conditions leads to a 10-fold increase in volume-specific mineralization rate, illustrating the sensitivity of anaerobically protected carbon to disturbance. The vulnerability of anaerobically protected carbon to future climate or land use change thus constitutes a yet unrecognized soil carbon-climate feedback that should be incorporated into terrestrial ecosystem models.

  6. Techno-economic assessment of anaerobic digestion systems for agri-food wastes

    Energy Technology Data Exchange (ETDEWEB)

    Lau, A.; Baldwin, S.; Wang, M. [British Colombia Univ., Vancouver, BC (Canada)

    2010-07-01

    Activities in British Columbia's Fraser Valley generate an estimated 3 million tones of agriculture and food wastes annually, of which 85 per cent are readily available for anaerobic digestion. The potential for energy generation from biogas through anaerobic digestion is approximately 30 MW. On-farm manure-based systems represent the most likely scenario for the development of anaerobic digestion in British Columbia in the near future. Off-farm food processing wastes may be an alternative option to large centralized industrial complexes. Odour control, pathogen reduction, improved water quality, reduced greenhouse gas emissions and reduced landfill usage are among the environmental benefits of anaerobic digestion. The economical benefits include power and heat generation, biogas upgrading, and further processing of the residues to produce compost or animal bedding. This paper described a newly developed anaerobic digestion (AD) calculator that helps users regarding their investment decision in AD facilities. The calculator classifies various technology options into several major types of AD systems. It also constructs kinetic and economic models for these systems and provides a fair estimation on biogas yield, digester volume, capital cost and annual income. The calculator takes into consideration factors such as the degradability of wastes with different compositions and different operating parameters.

  7. Enhanced biogas yield from energy crops with rumen anaerobic fungi

    Czech Academy of Sciences Publication Activity Database

    Procházka, J.; Mrázek, Jakub; Štrosová, Lenka; Fliegerová, Kateřina; Zábranská, J.; Dohányos, M.

    2012-01-01

    Roč. 12, č. 3 (2012), s. 343-351 ISSN 1618-0240 R&D Projects: GA ČR GPP503/10/P394; GA MZe QI92A286 Institutional support: RVO:67985904 Keywords : Anaerobic digestion * Anaerobic fungi * Biogas yield Subject RIV: EI - Biotechnology ; Bionics Impact factor: 1.633, year: 2012

  8. Influence of temperature on the performance of anaerobic treatment ...

    African Journals Online (AJOL)

    2018-04-02

    Apr 2, 2018 ... ABSTRACT. Anaerobic sewage treatment systems, especially upflow anaerobic sludge blanket (UASB) reactors, have found wide application over the past decades, particularly in regions with a warm climate. A low sewage temperature is generally considered as a factor contributing to poor performance, ...

  9. Performance of an innovative multi-stage anaerobic reactor during ...

    African Journals Online (AJOL)

    Start-up of an anaerobic reactor is a relatively delicate process and depends on various factors such as wastewater composition, available inoculum, operating conditions and reactor configuration. Accordingly, systematized operational procedures are important, mainly during the start-up of an anaerobic reactor.

  10. Factors controlling micropropagation of Myrica esculenta buch ...

    African Journals Online (AJOL)

    Various factors such as browning, season, media type and plant growth regulators influence the micropropagation of female trees of Myrica esculenta. These factors have successfully been addressed after addition of some media additives, collection of the explant at right season, standardizing the media type and use of ...

  11. Anaerobic Treatment of Cane Sugar Effluent from Muhoroni Sugar ...

    African Journals Online (AJOL)

    It was therefore concluded that anaerobic treatment, particularly with pH control and seeding shows potential in first stage management of sugar mill wastewater. Keywords: cane sugar mill effluent, anaerobic treatment, batch reactor, waste stabilization ponds. Journal of Civil Engineering Research and Practice Vol.

  12. Power factor control system for ac induction motors

    Science.gov (United States)

    Nola, F. J. (Inventor)

    1981-01-01

    A power control circuit for an induction motor is disclosed in which a servo loop is used to control power input by controlling the power factor of motor operation. The power factor is measured by summing the voltage and current derived square wave signals.

  13. Digital Single-Phase Power-Factor Controller

    Science.gov (United States)

    Dabney, R. W.

    1983-01-01

    Digital circuit has faster response to load changes. Digital power-factor controller senses changing motor-load torques by sampling open-circuit voltage across gate-controlled silicon switch. Circuit responds more rapidly to hanging loads than analog power-factor controllers because no low-pass filter is in feedback loop.

  14. Proceedings of the 10. world congress on anaerobic digestion 2004 : anaerobic bioconversion, answer for sustainability

    International Nuclear Information System (INIS)

    2004-01-01

    This conference reviewed the broad scope of anaerobic process-related activities taking place globally and confirmed the possibilities of using anaerobic processes to add value to industrial wastewaters, municipal solid wastes and organic wastes while minimizing pollution and greenhouse gases. It focused on biomolecular tools, instrumentation of anaerobic digestion processes, anaerobic bioremediation of chlorinated organics, and thermophilic and mesophilic digestion. Several papers focused on the feasibility of using waste products to produce hydrogen and methane for electricity generation. The sessions of the conference were entitled acidogenesis; microbial ecology; process control; sulfur content; technical development; domestic wastewater; agricultural waste; organic municipal solid wastes; instrumentation; molecular biology; sludges; agricultural feedstock; bioremediation; industrial wastewater; hydrogen production; pretreatments; sustainability; and integrated systems. The conference featured 387 posters and 192 oral presentations, of which 111 have been indexed separately for inclusion in this database. refs., tabs., figs

  15. Environmental impacts of anaerobic digestion and the use of anaerobic residues as soil amendment

    Energy Technology Data Exchange (ETDEWEB)

    Mosey, F.E. [VFA Services Ltd., Herts (United Kingdom)

    1996-01-01

    This paper defines the environmental role of anaerobic digestion within the overall objective of recovering energy from renewable biomass resources. Examples and opportunities for incorporating anaerobic digestion into biomass-to-energy schemes are discussed, together with environmental aspects of anaerobic digestion plants. These include visual, public amenity, pathogens and public health, odor control, and gaseous emissions. Digestate disposal and the benefits of restrictions on recycling organic wastes and biomass residues back to the land are discussed, particularly as they relate to American and European codes of practice and environmental legislation. The paper concludes that anaerobic digestion, if performed in purpose-designed reactors that efficiently recover and use biogas, is an environmentally benign process that can enhance energy recovery and aid the beneficial land use of plant residues in many biomass-to-energy schemes.

  16. Factors influencing the profitability of optimizing control systems

    International Nuclear Information System (INIS)

    Broussaud, A.; Guyot, O.

    1999-01-01

    Optimizing control systems supplement conventional Distributed Control Systems and Programmable Logic Controllers. They continuously implement set points, which aim at maximizing the profitability of plant operation. They are becoming an integral part of modern mineral processing plants. This trend is justified by economic considerations, optimizing control being among the most cost-effective methods of improving metallurgical plant performance. The paper successively analyzes three sets of factors, which influence the profitability of optimizing control systems, and provides guidelines for analyzing the potential value of an optimizing control system at a given operation: external factors, such as economic factors and factors related to plant feed; features of the optimizing control system; and subsequent maintenance of the optimizing control system. It is shown that pay back times for optimization control projects are typically measured in days. The OCS software used by the authors for their applications is described briefly. (author)

  17. Factors influencing the profitability of optimizing control systems

    Energy Technology Data Exchange (ETDEWEB)

    Broussaud, A.; Guyot, O. [Svedala Cisa, Orleans Cedex 2 (France)

    1999-07-01

    Optimizing control systems supplement conventional Distributed Control Systems and Programmable Logic Controllers. They continuously implement set points, which aim at maximizing the profitability of plant operation. They are becoming an integral part of modern mineral processing plants. This trend is justified by economic considerations, optimizing control being among the most cost-effective methods of improving metallurgical plant performance. The paper successively analyzes three sets of factors, which influence the profitability of optimizing control systems, and provides guidelines for analyzing the potential value of an optimizing control system at a given operation: external factors, such as economic factors and factors related to plant feed; features of the optimizing control system; and subsequent maintenance of the optimizing control system. It is shown that pay back times for optimization control projects are typically measured in days. The OCS software used by the authors for their applications is described briefly. (author)

  18. Anaerobic Digestion Performance in the Energy Recovery of Kiwi Residues

    Science.gov (United States)

    Martins, Ramiro; Boaventura, Rui; Paulista, Larissa

    2017-12-01

    World production and trade of fruits generate losses in the harvest, post-harvest, handling, distribution and consumption phases, corresponding to 6.8% of total production. These residues present high potential as a substrate for the anaerobic digestion process and biogas generation. Thus, the energy valuation of the agro-industrial residues of kiwi production was evaluated by anaerobic digestion, aiming at optimizing the biogas production and its quality. Ten assays were carried out in a batch reactor (500 mL) under mesophilic conditions and varying a number of operational factors: different substrate/inoculum ratios; four distinct values for C: N ratio; inoculum from different digesters; and inoculum collected at different times of the year. The following parameters were used to control and monitor the process: pH, alkalinity, volatile fatty acids (VFA), volatile solids (VS) and chemical oxygen demand (COD). Among the tests performed, the best result obtained for the biogas production corresponded to the use of 2 g of substrate and 98 mL of inoculum of the anaerobic digester of the Wastewater Treatment Plant (WWTP) of Bragança, with addition of 150 mg of bicarbonate leading to a production of 1628 L biogas.kg-1 VS (57% methane). In relation to the biogas quality, the best result was obtained with 20 g of substrate and 380 mL of inoculum from the anaerobic digester sludge of WWTP of Ave (with addition 600 mg of sodium bicarbonate), presenting a value of 85% of CH4, with a production of 464 L biogas.kg-1 VS.

  19. Human Factors in Air Traffic Control

    Science.gov (United States)

    1982-04-01

    knowlodg of the world from our experience, undverstanding, end acquisition of’ information. These divisions do not fit practical considerations nuatly...Clearly in air tra.ffic control the coan-troller relies liavily on long term memory for hei general knowlodge of the principles, methods and techniques of...air traffic control and for his specific knowledge about the way those prinoiples are translated into practice in a partioalar air space under his own

  20. Factors controlling superelastic damping capacity of SMAs

    Czech Academy of Sciences Publication Activity Database

    Heller, Luděk; Šittner, Petr; Pilch, Jan; Landa, Michal

    2009-01-01

    Roč. 18, 5-6 (2009), 603-611 ISSN 1059-9495 Institutional research plan: CEZ:AV0Z10100520; CEZ:AV0Z20760514 Keywords : shape memory alloys * superelastic damping * thermomechanical testing Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 0.592, year: 2009

  1. Hydrologic factors controlling groundwater salinity in northwestern

    Indian Academy of Sciences (India)

    The aim of this article is to assess the main factors influencing salinity of groundwater in the coastal area between El Dabaa and Sidi Barani, Egypt. The types and ages of the main aquifers in this area are the fractured limestone of Middle Miocene, the calcareous sandstone of Pliocene and the Oolitic Limestone of ...

  2. Wastewater Treatment Anaerobic Digester Foaming Prevention and Control Methods - Literature Review and Survey - Full-Scale Studies (WERF Report INFR1SG10)

    Science.gov (United States)

    This project addresses the issue of anaerobic digester (AD) foaming in different water resource recovery facilities (WRRFs). This two-volume report is a compilation of an AD foaming literature review, a plant survey, and findings from full-scale studies. The literature review hel...

  3. Control circuit maintains unity power factor of reactive load

    Science.gov (United States)

    Kramer, M.; Martinage, L. H.

    1966-01-01

    Circuit including feedback control elements automatically corrects the power factor of a reactive load. It maintains power supply efficiency where negative load reactance changes and varies by providing corrective error signals to the control windings of a power supply transformer.

  4. Anaerobic and aerobic acetylene hydratase

    Indian Academy of Sciences (India)

    Administrator

    Acetaldehyde is the first metabolite produced during acetylene degradation by bacteria either aerobically or anaerobically. Conversion of acetylene into acetaldehyde, ethanol, acetate, and biomass occurs in anaerobic cultures of Palobacter acetylinicus or aerobically with Mycobacterium lacticola, Nocardia rhodochrous, ...

  5. HUMAN FACTORS GUIDANCE FOR CONTROL ROOM EVALUATION

    International Nuclear Information System (INIS)

    OHARA, J.; BROWN, W.; STUBLER, W.; HIGGINS, J.; WACHTEL, J.; PERSENSKY, J.J.

    2000-01-01

    The Human-System Interface Design Review Guideline (NUREG-0700, Revision 1) was developed by the US Nuclear Regulatory Commission (NRC) to provide human factors guidance as a basis for the review of advanced human-system interface technologies. The guidance consists of three components: design review procedures, human factors engineering guidelines, and a software application to provide design review support called the ''Design Review Guideline.'' Since it was published in June 1996, Rev. 1 to NUREG-0700 has been used successfully by NRC staff, contractors and nuclear industry organizations, as well as by interested organizations outside the nuclear industry. The NRC has committed to the periodic update and improvement of the guidance to ensure that it remains a state-of-the-art design evaluation tool in the face of emerging and rapidly changing technology. This paper addresses the current research to update of NUREG-0700 based on the substantial work that has taken place since the publication of Revision 1

  6. Hydrologic factors controlling groundwater salinity in northwestern ...

    Indian Academy of Sciences (India)

    From the comprehensive survey of groundwater conditions in the study area, it has been noticed that the ground- water widely ranges in salinity between 1000 and about 15000 mg/l. This great variation in salinity is mainly attributed to the dominant hydrologic conditions controlling the groundwater occurrence and recharge.

  7. Soft-Starting Power-Factor Motor Controller

    Science.gov (United States)

    Nola, F. J.

    1983-01-01

    Three-phase power-factor controller with soft start is based on earlier version that does not control starting transients. Additional components serve to turn off "run" command signal and substitute gradual startup command signal during preset startup interval. Improved controller reduces large current surge that usually accompanies starting. Controller applies power smoothly, without causing motor vibrations.

  8. Human factors methods for nuclear control room design. Volume I. Human factors enhancement of existing nuclear control rooms. Final report

    International Nuclear Information System (INIS)

    Seminara, J.L.; Seidenstein, S.; Eckert, S.K.; Smith, D.L.

    1979-11-01

    Human factors engineering is an interdisciplinary specialty concerned with influencing the design of equipment systems, facilities, and operational environments to promote safe, efficient, and reliable operator performance. Human factors approaches were applied in the design of representative nuclear power plant control panels. First, methods for upgrading existing operational control panels were examined. Then, based on detailed human factors analyses of operator information and control requirements, designs of reactor, feedwater, and turbine-generator control panels were developed to improve the operator-control board interface, thereby reducing the potential for operator errors. In addition to examining present-generation concepts, human factors aspects of advanced systems and of hybrid combinations of advanced and conventional designs were investigated. Special attention was given to warning system designs. Also, a survey was conducted among control board designers to (1) develop an overview of design practices in the industry, and (2) establish appropriate measures leading to a more systematic concern for human factors in control board design

  9. Inhibition experiments on anaerobic methane oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Alperin, M.J.; Reeburgh, W.S.

    1985-10-01

    Anaerobic methane oxidation is a general process important in controlling fluxes of methane from anoxic marine sediments. The responsible organism has not been isolated, and little is known about the electron acceptors and substrates involved in the process. Laboratory evidence indicates that sulfate reducers and methanogens are able to oxidize small quantities of methane. Field evidence suggests anaerobic methane oxidation may be linked to sulfate reduction. Experiments with specific inhibitors for sulfate reduction (molybdate), methanogenesis (2-bromoethanesulfonic acid), and acetate utilization (fluoroacetate) were performed on marine sediments from the zone of methane oxidation to determine whether sulfate-reducing bacteria or methanogenic bacteria are responsible for methane oxidation. The inhibition experiment results suggest that methane oxidation in anoxic marine sediments is not directly mediated by sulfate-reducing bacteria or methanogenic bacteria. Our results are consistent with two possibilities: anaerobic methane oxidation may be mediated by an unknown organism or a consortium involving an unknown methane oxidizer and sulfate-reducing bacteria.

  10. Multivariate monitoring of anaerobic co-digestion

    DEFF Research Database (Denmark)

    Madsen, Michael; Holm-Nielsen, Jens Bo

    Anaerobic digestion processes for production of renewable energy in the form of biogas, and in the future hydrogen, are becoming increasingly important worldwide. Sustainable solutions for renewable energy production systems are given high political priority, amongst other things due to global...... warming and environmental concerns. Anaerobic digestion applied in agriculture can simultaneously convert heterogeneous biomasses and wastes from the primary agricultural sector and from the bio processing industries, for instance food processing, pharma, and biofuel production, into valuable organic...... fertiliser and renewable energy. Meanwhile, in order for the biogas sector to become a significant player in the energy supply chain, the anaerobic digestion process has to be controlled to a greater extent than what is implemented as state-of-the-art today. Through application of the philosophy behind...

  11. Anaerobic prefermentation and primary sedimentation of wastewater ...

    African Journals Online (AJOL)

    2006-09-01

    Sep 1, 2006 ... EASTMAN J A and FERGUSON J F (1981) Solubilisation of particu- late organic carbon during the acid phase of anaerobic digestion. J. Water Pollut. Control Fed. 53 352-366. GONCALVES RF, CHARLIER AC and SAMMUT F (1994) Primary fermentation of soluble and particulate organic matter for waste-.

  12. ANAEROBIC BIOLOGICAL TREATMENT OF PRODUCED WATER

    Energy Technology Data Exchange (ETDEWEB)

    John R. Gallagher

    2001-07-31

    reactor. Batch tests were conducted to examine naphthenic acid biodegradability under several conditions. The conditions used were seed from the anaerobic reactor, wetland sediments under aerobic and anaerobic conditions, and a sterile control. The naphthenic acid was from a commercial source isolated from Gulf Coast petroleum as was dosed at 2 mg/mL. The incubations were for 30 days at 30 C. The results showed that the naphthenic acids were not biodegraded under anaerobic conditions, but were degraded under aerobic conditions. Despite poor performance of the anaerobic reactor, it remains likely that anaerobic treatment of acetate, toluene, and, potentially, other produced-water components is feasible.

  13. ANAEROBIC BIOLOGICAL TREATMENT OF PRODUCED WATER; TOPICAL

    International Nuclear Information System (INIS)

    John R. Gallagher

    2001-01-01

    reactor. Batch tests were conducted to examine naphthenic acid biodegradability under several conditions. The conditions used were seed from the anaerobic reactor, wetland sediments under aerobic and anaerobic conditions, and a sterile control. The naphthenic acid was from a commercial source isolated from Gulf Coast petroleum as was dosed at 2 mg/mL. The incubations were for 30 days at 30 C. The results showed that the naphthenic acids were not biodegraded under anaerobic conditions, but were degraded under aerobic conditions. Despite poor performance of the anaerobic reactor, it remains likely that anaerobic treatment of acetate, toluene, and, potentially, other produced-water components is feasible

  14. Anaerobic biotransformation of estrogens

    International Nuclear Information System (INIS)

    Czajka, Cynthia P.; Londry, Kathleen L.

    2006-01-01

    Estrogens are important environmental contaminants that disrupt endocrine systems and feminize male fish. We investigated the potential for anaerobic biodegradation of the estrogens 17-α-ethynylestradiol (EE2) and 17-β-estradiol (E2) in order to understand their fate in aquatic and terrestrial environments. Cultures were established using lake water and sediment under methanogenic, sulfate-, iron-, and nitrate-reducing conditions. Anaerobic degradation of EE2 (added at 5 mg/L) was not observed in multiple trials over long incubation periods (over three years). E2 (added at 5 mg/L) was transformed to estrone (E1) under all four anaerobic conditions (99-176 μg L -1 day -1 ), but the extent of conversion was different for each electron acceptor. The oxidation of E2 to E1 was not inhibited by E1. Under some conditions, reversible inter-conversion of E2 and E1 was observed, and the final steady state concentration of E2 depended on the electron-accepting condition but was independent of the total amount of estrogens added. In addition, racemization occurred and E1 was also transformed to 17-α-estradiol under all but nitrate-reducing conditions. Although E2 could be readily transformed to E1 and in many cases 17-α-estradiol under anaerobic conditions, the complete degradation of estrogens under these conditions was minimal, suggesting that they would accumulate in anoxic environments

  15. Anaerobic biotransformation of estrogens

    Energy Technology Data Exchange (ETDEWEB)

    Czajka, Cynthia P. [Department of Microbiology, University of Manitoba, Winnipeg, MB, R3T 2N2 (Canada); Londry, Kathleen L. [Department of Microbiology, University of Manitoba, Winnipeg, MB, R3T 2N2 (Canada)]. E-mail: londryk@cc.umanitoba.ca

    2006-08-31

    Estrogens are important environmental contaminants that disrupt endocrine systems and feminize male fish. We investigated the potential for anaerobic biodegradation of the estrogens 17-{alpha}-ethynylestradiol (EE2) and 17-{beta}-estradiol (E2) in order to understand their fate in aquatic and terrestrial environments. Cultures were established using lake water and sediment under methanogenic, sulfate-, iron-, and nitrate-reducing conditions. Anaerobic degradation of EE2 (added at 5 mg/L) was not observed in multiple trials over long incubation periods (over three years). E2 (added at 5 mg/L) was transformed to estrone (E1) under all four anaerobic conditions (99-176 {mu}g L{sup -1} day{sup -1}), but the extent of conversion was different for each electron acceptor. The oxidation of E2 to E1 was not inhibited by E1. Under some conditions, reversible inter-conversion of E2 and E1 was observed, and the final steady state concentration of E2 depended on the electron-accepting condition but was independent of the total amount of estrogens added. In addition, racemization occurred and E1 was also transformed to 17-{alpha}-estradiol under all but nitrate-reducing conditions. Although E2 could be readily transformed to E1 and in many cases 17-{alpha}-estradiol under anaerobic conditions, the complete degradation of estrogens under these conditions was minimal, suggesting that they would accumulate in anoxic environments.

  16. The anaerobic digestion process

    Energy Technology Data Exchange (ETDEWEB)

    Rivard, C.J. [National Renewable Energy Lab., Golden, CO (United States); Boone, D.R. [Oregon Graduate Inst., Portland, OR (United States)

    1996-01-01

    The microbial process of converting organic matter into methane and carbon dioxide is so complex that anaerobic digesters have long been treated as {open_quotes}black boxes.{close_quotes} Research into this process during the past few decades has gradually unraveled this complexity, but many questions remain. The major biochemical reactions for forming methane by methanogens are largely understood, and evolutionary studies indicate that these microbes are as different from bacteria as they are from plants and animals. In anaerobic digesters, methanogens are at the terminus of a metabolic web, in which the reactions of myriads of other microbes produce a very limited range of compounds - mainly acetate, hydrogen, and formate - on which the methanogens grow and from which they form methane. {open_quotes}Interspecies hydrogen-transfer{close_quotes} and {open_quotes}interspecies formate-transfer{close_quotes} are major mechanisms by which methanogens obtain their substrates and by which volatile fatty acids are degraded. Present understanding of these reactions and other complex interactions among the bacteria involved in anaerobic digestion is only now to the point where anaerobic digesters need no longer be treated as black boxes.

  17. Anaerobic Fungi and Their Potential for Biogas Production

    Czech Academy of Sciences Publication Activity Database

    Dollhofer, V.; Podmirseg, S.M.; Callaghan, T. M.; Griffith, G.W.; Fliegerová, Kateřina

    2015-01-01

    Roč. 151, č. 1 (2015), s. 41-61 ISSN 0724-6145 Institutional support: RVO:67985904 Keywords : anaerobic fungi * Neocallimastigomycota * phylogeny Subject RIV: EE - Microbiology, Virology Impact factor: 1.911, year: 2015

  18. Anaerobic biodegradability essays from brewery wastewater using granular and flocculent sludges

    OpenAIRE

    C J Collazos Chávez; M C Díaz Báez

    2003-01-01

    At the beginning of nineties the colombian beer industry begun the application of anaerobic technology for the treatment of their wastewater efluents throught different regions of the country. These treatment plants have not been working appropriately due to different factors, and are creating concern among the industrial sector and the water pollution control agencies. This work constitutes the second phase of a research project designed to establish a selection and improvement criteria of t...

  19. Application of a fuzzy logic control system for continuous anaerobic digestion of low buffered, acidic energy crops as mono-substrate.

    Science.gov (United States)

    Scherer, P; Lehmann, K; Schmidt, O; Demirel, B

    2009-02-15

    A fuzzy logic control (FLC) system was developed at the Hamburg University of Applied Sciences (HAW Hamburg) for operation of biogas reactors running on energy crops. Three commercially available measuring parameters, namely pH, the methane (CH4) content, and the specific gas production rate (spec. GPR = m(3)/kg VS/day) were included. The objective was to avoid stabilization of pH with use of buffering supplements, like lime or manure. The developed FLC system can cover most of all applications, such as a careful start-up process and a gentle recovery strategy after a severe reactor failure, also enabling a process with a high organic loading rate (OLR) and a low hydraulic retention time (HRT), that is, a high throughput anaerobic digestion process with a stable pH and CH4 content. A precondition for a high load process was the concept of interval feeding, for example, with 8 h of interval. The FLC system was proved to be reliable during the long term fermentation studies over 3 years in one-stage, completely stirred tank reactors (CSTR) with acidic beet silage as mono-input (pH 3.3-3.4). During fermentation of the fodder beet silage (FBS), a stable HRT of 6.0 days with an OLR of up to 15 kg VS/m(3)/day and a volumetric GPR of 9 m(3)/m(3)/day could be reached. The FLC enabled an automatic recovery of the digester after two induced severe reactor failures. In another attempt to prove the feasibility of the FLC, substrate FBS was changed to sugar beet silage (SBS), which had a substantially lower buffering capacity than that of the FBS. With SBS, the FLC accomplished a stable fermentation at a pH level between 6.5 and 6.6, and a volatile fatty acid level (VFA) below 500 mg/L, but the FLC had to interact and to change the substrate dosage permanently. In a further experiment, the reactor temperature was increased from 41 to 50 degrees C. Concomitantly, the specific GPR, pH and CH4 dropped down. Finally, the FLC automatically enabled a complete recovery in 16 days.

  20. Anaerobic biological treatment

    International Nuclear Information System (INIS)

    Speece, R.E.

    1990-01-01

    The Enso-Fenox process has been very successfully used to remove chlorinated phenolic compounds from pulp bleaching effluents. It is a two-stage anaerobic/aerobic process consisting of a nonmethanogenic anaerobic fluidized bed followed by a trickling filter. Studies have been conducted on reductive dechlorination of chlorinated aromatic compounds under anaerobic conditions with chlorinated phenols as the sole carbon and energy source. Approximately 40% of the added chlorophenols was converted to CH 4 and CO 2 . Substrate loading rates were 20 mg/L/d at hydraulic detention times of 2-4 days with 90% substrate conversion efficiency. Reductive dechlorination of mono, di-, tri-, and pentachlorophenols has been demonstrated in anaerobic sewage sludge. The following constituents were tested in the laboratory at their approximate concentrations in coal conversion wastewater (CCWW) and were anaerobically degraded in serum bottles: 1,000 mg/L phenol; 500 mg/L resorcinol; 1,000 mg/L benzoic acid; 500 mg/L p-cresol; 200 mg/L pyridine; 2,000 mg/L benzoic acid; 250 mg/L 40 methylcatechol; 500 mg/L 4-ethylpyridine; and 2,000 mg/L hexanoic acid. A petrochemical may initially exhibit toxicity to an unacclimated population of methane-fermenting bacteria, but with acclimation the toxicity may be greatly reduced or disappear. In addition, the microorganisms may develop the capacity to actually degrade compounds which showed initial toxicity. Since biomass digestion requires a complete consortium of bacteria, it is relevant to study the effect of a given process as well as to individual steps within the process. A toxicant can inhibit the rate-limiting step and/or change the step that is rate-limiting. Both manifestations of toxicity can severely affect the overall process

  1. Risk factors for caries - control and prevention

    Directory of Open Access Journals (Sweden)

    Melida Hasanagić

    2008-08-01

    Full Text Available Objectives. To investigate a prevalence of caries, filled permanentand extracted permanent teeth, as well as caries risk factors inschool children aged 7, 9 and 11.Methods. The survey included 800 children (296 children aged7; 254 children aged 9 and 250 children aged 11 from the MostarMunicipality, 400 of them living in both rural and urban areas.A dental mirror and standard light of dental chair were used forexamination. The DMF index (Dental Caries, Missing Teeth andFilled Teeth was determined, as well as failure in keeping teethhygiene, sugar intake with food, and incidence of oral cavity infection.Results. The dental state of permanent teeth in children aged 7and 9 has shown significant difference between the children fromrural and urban areas (p < 0,001. Out of 2,698 and 2,790 permanentteeth in children aged 11 from rural and urban areas, 1,086(40,25 % and 884 (31.68 % had caries, respectively (p < 0.01.The difference between these groups of children has been foundin relation to the index of oral hygiene too (p < 0.05.Conclusion. An identification of risk groups for getting caries wasvery important and could help health and social structures to maintaintheir programs in order to improve oral health.

  2. Underlying Factors for Practicality of the Production Control Systems

    DEFF Research Database (Denmark)

    Arica, Emrah; Strandhagen, Jan Ola; Hvolby, Hans-Henrik

    2012-01-01

    This paper gives indications to important factors that must be considered for effectiveness of the production control systems under uncertainty. Five key factors have been identified by the literature study. Production schedule generation and execution approach under uncertainty, information...... and communication technology, coordination and feedback, human factors and decision making, and measurement are the identified factors to be taken into account. Industrial interviews with three case companies, that are participating to the research program called The Norwegian Manufacturing Future (SFI NORMAN...

  3. Risk factors associated with lipomyelomeningocele: a case-control study.

    Science.gov (United States)

    Esmaeili, Arash; Hanaei, Sara; Fadakar, Kaveh; Dadkhah, Sahar; Arjipour, Mahdi; Habibi, Zohreh; Nejat, Farideh; El Khashab, Mostafa

    2013-01-01

    In general, it seems that both genetic and environmental factors play important roles in the induction of neural tube defects. Lipomyelomeningocele (LipoMMC) is a rather common type of closed neural tube defect, but only limited studies have investigated the potential risk factors of this anomaly. Therefore, the purpose of this case-control study was to investigate the risk factors involved in LipoMMC formation. Various risk factors were evaluated in 35 children between 1 month and 10 years of age with LipoMMC in a hospital-based case-control study. The 2 control arms consisted of 35 children with myelomeningocele (MMC group) and 35 children with congenital anomalies other than central nervous system problems (control group). All groups were matched for age and visited the same hospital. A structured questionnaire was used for the collection of all data, including the mothers' weight and height during pregnancy, education, reproductive history, previous abortions, and socioeconomic status, as well as the parents' consanguinity and family history of the same anomalies. Univariate analysis of the children with LipoMMC compared to the control group showed that the use of periconceptional folic acid supplementation was significantly lower in the MMC and LipoMMC groups compared to the control group. In addition, comparison of the MMC and control groups revealed statistically significant differences regarding the use of folic acid and maternal obesity. In multivariate analysis, use of folic acid in the periconceptional period and during the first trimester was an independent risk factor for LipoMMC and MMC. Furthermore, maternal obesity was a significantly positive risk factor for MMC. The probable risk factors for LipoMMC were investigated in this case-control study. Consumption of folic acid in the periconceptional period and during the first trimester is an independent protective factor against LipoMMC. It seems that larger studies are needed to examine other possible

  4. Early anaerobic metabolisms

    DEFF Research Database (Denmark)

    Canfield, Donald Eugene; Rosing, Minik T; Bjerrum, Christian

    2006-01-01

    probably driven by the cycling of H2 and Fe2+ through primary production conducted by anoxygenic phototrophs. Interesting and dynamic ecosystems would have also been driven by the microbial cycling of sulphur and nitrogen species, but their activity levels were probably not so great. Despite the diversity......Before the advent of oxygenic photosynthesis, the biosphere was driven by anaerobic metabolisms. We catalogue and quantify the source strengths of the most probable electron donors and electron acceptors that would have been available to fuel early-Earth ecosystems. The most active ecosystems were...... of potential early ecosystems, rates of primary production in the early-Earth anaerobic biosphere were probably well below those rates observed in the marine environment. We shift our attention to the Earth environment at 3.8Gyr ago, where the earliest marine sediments are preserved. We calculate, consistent...

  5. Inhibition of microbial metabolism in anaerobic lagoons by selected sulfonamides, tetracyclines, lincomycin, and tylosin tartrate

    Science.gov (United States)

    Loftin, Keith A.; Henny, Cynthia; Adams, Craig D.; Surampali, Rao; Mormile, Melanie R.

    2005-01-01

    Antibiotics are used to maintain healthy livestock and to promote weight gain in concentrated animal feed operations. Antibiotics rarely are metabolized completely by livestock and, thus, are often present in livestock waste and in waste-treatment lagoons. The introduction of antibiotics into anaerobic lagoons commonly used for swine waste treatment has the potential for negative impacts on lagoon performance, which relies on a consortium of microbes ranging from fermentative microorganisms to methanogens. To address this concern, the effects of eight common veterinary antibiotics on anaerobic activity were studied. Anaerobic microcosms, prepared from freshly collected lagoon slurries, were amended with individual antibiotics at 10 mg/L for the initial screening study and at 1, 5, and 25 mg/L for the dose-response study. Monitored metabolic indicators included hydrogen, methane, and volatile fatty acid concentrations as well as chemical oxygen demand. The selected antibiotics significantly inhibited methane production relative to unamended controls, thus indicating that antibiotics at concentrations commonly found in swine lagoons can negatively impact anaerobic metabolism. Additionally, historical antibiotic usage seems to be a potential factor in affecting methane production. Specifically, less inhibition of methane production was noted in samples taken from the lagoon with a history of multiple-antibiotic use.

  6. Anaerobic biodegradability essays from brewery wastewater using granular and flocculent sludges

    Directory of Open Access Journals (Sweden)

    C J Collazos Chávez

    2003-01-01

    Full Text Available At the beginning of nineties the colombian beer industry begun the application of anaerobic technology for the treatment of their wastewater efluents throught different regions of the country. These treatment plants have not been working appropriately due to different factors, and are creating concern among the industrial sector and the water pollution control agencies. This work constitutes the second phase of a research project designed to establish a selection and improvement criteria of the sludges used in the systems. It also looks to analyze other associated factors such as: waste, characteristics, operation conditions and design parameters. The investigation was conducted in two phases using granular and floculent sludges. This method was used for determining the anaerobic biodegradability of wastewater from two industrial plants.

  7. Early anaerobic metabolisms

    Science.gov (United States)

    Canfield, Don E; Rosing, Minik T; Bjerrum, Christian

    2006-01-01

    Before the advent of oxygenic photosynthesis, the biosphere was driven by anaerobic metabolisms. We catalogue and quantify the source strengths of the most probable electron donors and electron acceptors that would have been available to fuel early-Earth ecosystems. The most active ecosystems were probably driven by the cycling of H2 and Fe2+ through primary production conducted by anoxygenic phototrophs. Interesting and dynamic ecosystems would have also been driven by the microbial cycling of sulphur and nitrogen species, but their activity levels were probably not so great. Despite the diversity of potential early ecosystems, rates of primary production in the early-Earth anaerobic biosphere were probably well below those rates observed in the marine environment. We shift our attention to the Earth environment at 3.8 Gyr ago, where the earliest marine sediments are preserved. We calculate, consistent with the carbon isotope record and other considerations of the carbon cycle, that marine rates of primary production at this time were probably an order of magnitude (or more) less than today. We conclude that the flux of reduced species to the Earth surface at this time may have been sufficient to drive anaerobic ecosystems of sufficient activity to be consistent with the carbon isotope record. Conversely, an ecosystem based on oxygenic photosynthesis was also possible with complete removal of the oxygen by reaction with reduced species from the mantle. PMID:17008221

  8. Revisiting factors controlling methane emissions from high-Arctic tundra

    DEFF Research Database (Denmark)

    Mastepanov, Mikhail; Sigsgaard, Charlotte; Tagesson, Torbern

    2013-01-01

    controlling methane emission, i.e. temperature and water table position. Late in the growing season CH4 emissions were found to be very similar between the study years (except the extremely dry 2010) despite large differences in climatic factors (temperature and water table). Late-season bursts of CH4...... short-term control factors (temperature and water table). Our findings suggest the importance of multiyear studies with a continued focus on shoulder seasons in Arctic ecosystems....

  9. Control to goal of cardiometabolic risk factors among Nigerians ...

    African Journals Online (AJOL)

    2011-07-12

    Jul 12, 2011 ... Background: Cardiovascular risk factors contribute to morbidity and mortality among diabetic patients. National and ... Objective: To evaluate the status of control to goals of cardiometabolic risk factors among the diabetic patients attending .... Males were older and taller while females had higher mean.

  10. Control of Risk Factors For Nephropathy Among Nigerian Outpatients

    African Journals Online (AJOL)

    Zamzar

    control of risk factors for nephropathy in a Nigerian teaching hospital. Methods: Between April and July 2005, 160 type 2 diabetic outpatients were assessed for control of average fasting blood glucose and blood pressure over 3 visits, and current use of ACE inhibitors. All patients were over 30 years of age and had been ...

  11. Evaluation of factors affecting adherence to asthma controller ...

    African Journals Online (AJOL)

    Evaluation of factors affecting adherence to asthma controller therapy in chest clinics in a sub-Saharan African setting: a cross-sectional study. ... Background: Adherence to controller therapy in asthma is a major concern during the management of the disease. Objective: To determine the adherence rate and identify the ...

  12. PMBLDC motor drive with power factor correction controller

    DEFF Research Database (Denmark)

    George, G.J.; Ramachandran, Rakesh; Arun, N.

    2012-01-01

    This paper presents a boost converter configuration, control scheme and design of single phase power factor controller for permanent magnet brushless DC motor (PMBLDCM) drive. PMBLDC motors are the latest choice of researchers, due to the high efficiency, silent operation, compact size, high...

  13. New perspectives in anaerobic digestion

    DEFF Research Database (Denmark)

    van Lier, J.B.; Tilche, A.; Ahring, Birgitte Kiær

    2001-01-01

    The IWA specialised group on anaerobic digestion (AD) is one of the oldest working groups of the former IAWQ organisation. Despite the fact that anaerobic technology dates back more than 100 years, the technology is still under development, adapting novel treatment systems to the modern...... requirements. In fact, most advances were achieved during the last three decades, when high-rate reactor systems were developed and a profound insight was obtained in the microbiology of the anaerobic communities. This insight led to a better understanding of anaerobic treatment and, subsequently, to a broader...

  14. New perspectives in anaerobic digestion

    DEFF Research Database (Denmark)

    van Lier, J.B.; Tilche, A.; Ahring, Birgitte Kiær

    2001-01-01

    The IWA specialised group on anaerobic digestion (AD) is one of the oldest working groups of the former IAWQ organisation. Despite the fact that anaerobic technology dates back more than 100 years, the technology is still under development, adapting novel treatment systems to the modern requireme......The IWA specialised group on anaerobic digestion (AD) is one of the oldest working groups of the former IAWQ organisation. Despite the fact that anaerobic technology dates back more than 100 years, the technology is still under development, adapting novel treatment systems to the modern...

  15. Human factors survey of advanced instrumentation and controls

    International Nuclear Information System (INIS)

    Carter, R.J.

    1989-01-01

    A survey oriented towards identifying the human factors issues in regard to the use of advanced instrumentation and controls (I ampersand C) in the nuclear industry was conducted. A number of United States (US) and Canadian nuclear vendors and utilities were participants in the survey. Human factors items, subsumed under the categories of computer-generated displays (CGD), controls, organizational support, training, and related topics, were discussed. The survey found the industry to be concerned about the human factors issues related to the implementation of advanced I ampersand C. Fifteen potential human factors problems were identified. They include: the need for an advanced I ampersand C guideline equivalent to NUREG-0700; a role change in the control room from operator to supervisor; information overload; adequacy of existing training technology for advanced I ampersand C; and operator acceptance and trust. 11 refs., 1 tab

  16. Human factors evaluation of the engineering test reactor control room

    International Nuclear Information System (INIS)

    Banks, W.W.; Boone, M.P.

    1981-03-01

    The Reactor and Process Control Rooms at the Engineering Test Reactor were evaluated by a team of human factors engineers using available human factors design criteria. During the evaluation, ETR, equipment and facilities were compared with MIL-STD-1472-B, Human Engineering design Criteria for Military Systems. The focus of recommendations centered on: (a) displays and controls; placing displays and controls in functional groups; (b) establishing a consistent color coding (in compliance with a standard if possible); (c) systematizing annunciator alarms and reducing their number; (d) organizing equipment in functional groups; and (e) modifying labeling and lines of demarcation

  17. Taking account of human factors in control-room design

    International Nuclear Information System (INIS)

    Dien, Y.; Montmayeul, R.

    1995-07-01

    Since the Three Mile Island accident two ways for improving the Human-Machine Interface have mainly been followed: the development of computerized operator aids in existing control-rooms and the design of advanced control-rooms. Insufficient attention paid to human factors in the design of operator aids has generally led to these aids being neglected or unused by their potential users. While for the design of advanced control-rooms efforts have been made for dealing with human factors in more extensive way. Based upon this experience, a general method for taking account of human factors in a control-room design has been devised and is described in this paper. (author)

  18. Anaerobic Digestion Modeling: from One to Several Bacterial Populations

    Directory of Open Access Journals (Sweden)

    Iván D. Ramírez-Rivas

    2013-11-01

    Full Text Available Anaerobic digestion systems are complex processes that unfortunately often suffer from instability causing digester failure. In order to be able to design, optimizing and operate efficiently anaerobic digestion systems, appropriate control strategies need to be designed. Such strategies require, in general, the development of mathematical models. The anaerobic digestion process comprises a complex network of sequential and parallel reactions of biochemical and physicochemical nature. Usually, such reactions contain a particular step, the so called rate-limiting step which, being the slowest, limits the reaction rate of the overall process. The first attempts for modeling anaerobic digestion led to models describing only the limiting step. However, over a wide range of operating conditions, the limiting step is not always the same. It may depend on wastewater characteristics, hydraulic loading, temperature, etc. It is apparent that the "limiting step hypothesis" leads to simple and readily usable models. Such models, however, do not describe very well the digester behavior, especially under transient operating conditions. This work reviews the current state-of-the-art in anaerobic digestion modeling. We give a brief description of the key anaerobic digestion models that have been developed so far for describing biomass growth systems, including the International Water Association’s Anaerobic Digestion Model 1 (ADM1 and we identify the areas that require further research endeavors.

  19. Conditions of the Anaerobic Digestion of Biomass

    OpenAIRE

    N. Boontian

    2014-01-01

    Biological conversion of biomass to methane has received increasing attention in recent years. Grasses have been explored for their potential anaerobic digestion to methane. In this review, extensive literature data have been tabulated and classified. The influences of several parameters on the potential of these feedstocks to produce methane are presented. Lignocellulosic biomass represents a mostly unused source for biogas and ethanol production. Many factors, including...

  20. Anaerobic sludge digestion with a biocatalytic additive

    Energy Technology Data Exchange (ETDEWEB)

    Ghosh, S.; Henry, M.P.; Fedde, P.A.

    1982-01-01

    The objective of this research was to evaluate the effects of a lactobacillus additive an anaerobic sludge digestion under normal, variable, and overload operating conditions. The additive was a whey fermentation product of an acid-tolerant strain of Lactobacillus acidophilus fortified with CaCO/sub 3/, (NH/sub 4/)/sub 2/HPO/sub 4/, ferrous lactate, and lactic acid. The lactobacillus additive is multifunctional in nature and provides growth factors, metabolic intermediates, and enzymes needed for substrate degradation and cellular synthesis. The experimental work consisted of several pairs of parallel mesophilic (35/sup 0/C) digestion runs (control and test) conducted in five experimental phases. Baseline runs without the additive showed that the two experimental digesters had the same methane content, gas production rate (GPR), and ethane yield. The effect of the additive was to increase methane yield and GPR by about 5% (which was statistically significant) during digester operation at a loading rate (LR) of 3.2 kg VS/m/sup 3/-day and a hydraulic retention time (HRT) of 14 days. Data collected from the various experimental phases showed that the biochemical additive increased methane yield, gas production rate, and VS reduction, and decreased volatile acids accumulation. In addition, it enhanced digester buffer capacity and improved the fertilizer value and dewatering characteristics of the digested residue.

  1. Motor power factor controller with a reduced voltage starter

    Science.gov (United States)

    Nola, Frank J. (Inventor)

    1983-01-01

    A power factor type motor controller in which the conventional power factor constant voltage command signal is replaced during a starting interval with a graduated control voltage. The present invention adds to the three-phase system of pending application Ser. No. 199,765, filed Oct. 23, 1980, means for modifying the operation of the system for a motor start-up interval of 5 to 30 seconds. The modification is that of providing via ramp generator 174 an initial ramp-like signal which replaces a constant power factor signal supplied by potentiometer 70. The ramp-like signal is applied to terminal 40 where it is summed with an operating power factor signal from phase detectors 32, 34, and 36 to thereby obtain a control signal for ultimately controlling SCR devices 12, 14, and 16 to effect a gradual turn-on of motor 10. The significant difference of the present invention over prior art is that the SCR devices are turned on at an advancing rate with time responsive to the combination signal described rather than simply a function of a ramp-like signal alone. The added signal, the operating power factor signal, enables the production of a control signal which effectively eliminates a prior problem with many motor starting circuits, which is that of accompanying motor instabilities.

  2. Risk Factors for Eating Disorders among Male Adolescent Athletes

    OpenAIRE

    PUSTIV?EK, Suzana; HAD?I?, Vedran; DERVI?EVI?, Edvin

    2014-01-01

    Objective Eating disorders (ED) are an important and increasing problem in adolescents. The objective of this study was to examine the risk factors and the prevalence of risk for ED among male adolescent elite athletes and nonathletic controls. Differences between male athletes competing in aerobic, anaerobic and aerobic-anaerobic sports were examined as well. Methods This was a cross-sectional epidemiological study. A cross-sectional questionnaire survey and anthropometric measurements were ...

  3. Characterization of Spartina alterniflora as feedstock for anaerobic digestion

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Shiguan; Zheng, Zheng; Meng, Zhuo [State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210093 (China); Li, Jihong [State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210093 (China); Renewable Energy School, North China Electric Power University, Beijing 102206 (China)

    2009-04-15

    Smooth cordgrass (Spartina alterniflora), a saltmarsh plant with high production, was characterized for its potential for use as feedstock for anaerobic digestion processes. The anaerobic digestibility and biogas yield of S. alterniflora were evaluated by anaerobic batch digestion experiments performed at 35 {+-} 1 C at initial volatile solids (VS) of 6%. The nutrient content analysis indicated that S. alterniflora contained the required nutrition for anaerobic microorganisms, but its high C/N of 58.8, high K and Na contents of 8.1, 22.7 g kg{sup -1}, respectively, may be disadvantageous to its anaerobic digestion. The cumulative biogas yield was determined to be 358 L kg{sup -1} VS and the biodegradation efficiency was 45% after 60 days of digestion. The methane content of biogas increased from 53% on day 3 to around 62% after 13 days of digestion. The changes of volatile fatty acids (VFAs) indicated that the acidification of S. alterniflora was propionate-type fermentation with proportion of acetate and propionate ranging from 54.8% to 98.4%, and the hydrolysis of lignocellulose was the rate-limiting step for its anaerobic digestion. The analysis of cations suggested that K{sup +} and Mg{sup 2+}, with the maximum concentration of 1.35 and 0.43 g L{sup -1} in fermentation liquor, respectively, could be inhibitory to the anaerobic digestion of S. alterniflora. It is concluded that S. alterniflora can be transformed into clean energy by anaerobic digestion and the high contents of K, Na, Ca and Mg may be the inhibitory factors when S. alterniflora is digested by continuous or semi-continuous anaerobic process. (author)

  4. Characterization of Spartina alterniflora as feedstock for anaerobic digestion

    International Nuclear Information System (INIS)

    Yang, Shiguan; Zheng, Zheng; Meng, Zhuo; Li, Jihong

    2009-01-01

    Smooth cordgrass (Spartina alterniflora), a saltmarsh plant with high production, was characterized for its potential for use as feedstock for anaerobic digestion processes. The anaerobic digestibility and biogas yield of S. alterniflora were evaluated by anaerobic batch digestion experiments performed at 35 ± 1 C at initial volatile solids (VS) of 6%. The nutrient content analysis indicated that S. alterniflora contained the required nutrition for anaerobic microorganisms, but its high C/N of 58.8, high K and Na contents of 8.1, 22.7 g kg -1 , respectively, may be disadvantageous to its anaerobic digestion. The cumulative biogas yield was determined to be 358 L kg -1 VS and the biodegradation efficiency was 45% after 60 days of digestion. The methane content of biogas increased from 53% on day 3 to around 62% after 13 days of digestion. The changes of volatile fatty acids (VFAs) indicated that the acidification of S. alterniflora was propionate-type fermentation with proportion of acetate and propionate ranging from 54.8% to 98.4%, and the hydrolysis of lignocellulose was the rate-limiting step for its anaerobic digestion. The analysis of cations suggested that K + and Mg 2+ , with the maximum concentration of 1.35 and 0.43 g L -1 in fermentation liquor, respectively, could be inhibitory to the anaerobic digestion of S. alterniflora. It is concluded that S. alterniflora can be transformed into clean energy by anaerobic digestion and the high contents of K, Na, Ca and Mg may be the inhibitory factors when S. alterniflora is digested by continuous or semi-continuous anaerobic process. (author)

  5. Simplifying the audit of risk factor recording and control

    DEFF Research Database (Denmark)

    Zhao, Min; Cooney, Marie Therese; Klipstein-Grobusch, Kerstin

    2016-01-01

    BACKGROUND: To simplify the assessment of the recording and control of coronary heart disease risk factors in different countries and regions. DESIGN: The SUrvey of Risk Factors (SURF) is an international clinical audit. METHODS: Data on consecutive patients with established coronary heart disease......% in Europe and 36% in the Middle East. Variations in medications were noted, with lower use of statins in Asia. CONCLUSIONS: SURF proved to be practical in daily practice. Results indicated poor control of risk factors with substantial variation between countries, calling for development and implementation...... from countries in Europe, Asia and the Middle East were collected on a one-page collection sheet or electronically during routine clinic visits. Information on demographics, diagnostic category, risk factors, physical and laboratory measurements, and medications were included and key variables...

  6. Human Factors Engineering Aspects of Modifications in Control Room Modernization

    Energy Technology Data Exchange (ETDEWEB)

    Hugo, Jacques [Idaho National Lab. (INL), Idaho Falls, ID (United States); Clefton, Gordon [Idaho National Lab. (INL), Idaho Falls, ID (United States); Joe, Jeffrey [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2017-06-01

    This report describes the basic aspects of control room modernization projects in the U.S. nuclear industry and the need for supplementary guidance on the integration of human factors considerations into the licensing and regulatory aspects of digital upgrades. The report pays specific attention to the integration of principles described in NUREG-0711 (Human Factors Engineering Program Review Model) and how supplementary guidance can help to raise general awareness in the industry regarding the complexities of control room modernization projects created by many interdependent regulations, standards and guidelines. The report also describes how human factors engineering principles and methods provided by various resources and international standards can help in navigating through the process of licensing digital upgrades. In particular, the integration of human factors engineering guidance and requirements into the process of licensing digital upgrades can help reduce uncertainty related to development of technical bases for digital upgrades that will avoid the introduction of new failure modes.

  7. New perspectives in anaerobic digestion.

    NARCIS (Netherlands)

    Lier, van J.B.; Tilche, A.; Ahring, B.K.; Macarie, H.; Moletta, R.; Dohanyos, M.; Hulshoff Pol, L.W.; Lens, P.N.L.; Verstraete, W.

    2001-01-01

    The IWA specialised group on anaerobic digestion (AD) is one of the oldest working groups of the former IAWQ organisation. Despite the fact that anaerobic technology dates back more than 100 years, the technology is still under development, adapting novel treatment systems to the modern

  8. Anaerobic digestion of piggery waste

    NARCIS (Netherlands)

    Velsen, van A.F.M.

    1981-01-01

    Anaerobic digestion is a biological process by which organic matter is converted to methane and carbon dioxide by microbes in the absence of air (oxygen). In nature, anaerobic conversions occur at all places where organic material accumulates and the supply of oxygen is deficient, e.g. in marshes

  9. Risk factors for gonorrhoea: case-control study.

    OpenAIRE

    Bjekić, M; Vlajinac, H; Sipetić, S; Marinković, J

    1997-01-01

    OBJECTIVE: To define risk factors for gonococcal infection. METHODS: A case-control study comparing 200 gonorrhoea cases with 400 patients with non-gonococcal genitourinary infections and 400 patients with various skin diseases, all of them attending City Department for Skin and Venereal Diseases In Belgrade (Yugoslavia) from October 1993 to December 1994. RESULTS: According to multivariate logistic regression analysis the following factors were significantly related to gonorrhoea in men: edu...

  10. HIGH-RATE ANAEROBIC TREATMENT OF ALCOHOLIC WASTEWATERS

    Directory of Open Access Journals (Sweden)

    Florencio L.

    1997-01-01

    Full Text Available Modern high-rate anaerobic wastewater treatment processes are rapidly becoming popular for industrial wastewater treatment. However, until recently stable process conditions could not be guaranteed for alcoholic wastewaters containing higher concentrations of methanol. Although methanol can be directly converted into methane by methanogens, under specific conditions it can also be converted into acetate and butyrate by acetogens. The accumulation of volatile fatty acids can lead to reactor instability in a weakly buffered reactor. Since this process was insufficiently understood, the application of high-rate anaerobic reactors was highly questionable. This research investigated the environmental factors that are of importance in the predominance of methylotrophic methanogens over acetogens in a natural mixed culture during anaerobic wastewater treatment in upflow anaerobic sludge bed reactors. Technological and microbiological aspects were investigated. Additionally, the route by which methanol is converted into methane is also presented

  11. Three-phase power factor controller with induced EMF sensing

    Science.gov (United States)

    Nola, F. J. (Inventor)

    1984-01-01

    A power factor controller for an ac induction motor is provided which is of the type comprising thyristor switches connected in series with the motor, phase detectors for sensing the motor current and voltage and providing an output proportional to the phase difference between the motor voltage and current, and a control circuit, responsive to the output of the phase detector and to a power factor command signal, for controlling switching of the thyristor. The invention involves sensing the induced emf produced by the motor during the time interval when the thyristor is off and for producing a corresponding feedback signal for controlling switching of the thyristor. The sensed emf is also used to enhance soft starting of the motor.

  12. Active Power Factor Correction Using a Sliding Mode Controller

    Directory of Open Access Journals (Sweden)

    Korhan KAYIŞLI

    2008-03-01

    Full Text Available In this paper, a sliding mode controller is designed for active shaping of the input current in the boost converter. Robustness of the designed controller is tested with variable output voltage references, different loads and network voltage variations. For the simulations, MATLAB/Simulink programme is used. From simulation results, the same phase was provided between input current and input voltage and nearly unity power factor was obtained.

  13. Neurotrophic Factor Control of Satiety and Body Weight

    Science.gov (United States)

    Xu, Baoji; Xie, Xiangyang

    2016-01-01

    Energy balance, the relationship between energy intake and expenditure, is regulated by a complex interplay of hormones, brain circuits and peripheral tissues. Leptin is an adipocyte-derived cytokine that suppresses appetite and increases energy expenditure. Ironically, obese individuals have high levels of plasma leptin and are resistant to leptin treatment. Neurotrophic factors, particularly ciliary neurotrophic factor (CNTF) and brain-derived neurotrophic factor (BDNF), are also important for the control of body weight. CNTF can overcome leptin resistance to reduce body weight, although CNTF and leptin activate similar signalling cascades. Mutations in the gene for BDNF lead to insatiable appetite and severe obesity. PMID:27052383

  14. Anaerobic survival of Pseudomonas aeruginosa by pyruvate fermentation requires an Usp-type stress protein

    DEFF Research Database (Denmark)

    Schreiber, K; Boes, N; Escbach, M

    2006-01-01

    activity was detected in the deeper layers of a P. aeruginosa biofilm using a PPA3309-gfp (green fluorescent protein gene) fusion and confocal laser-scanning microscopy. This is the first description of an Anr-dependent, anaerobically induced, and functional Usp-like protein in bacteria....... the induced synthesis of three enzymes involved in arginine fermentation, ArcA, ArcB, and ArcC, and the outer membrane protein OprL. Moreover, formation of two proteins of unknown function, PA3309 and PA4352, increased by factors of 72- and 22-fold, respectively. Both belong to the group of universal stress...... proteins (Usp). Long-term survival of a PA3309 knockout mutant by pyruvate fermentation was found drastically reduced. The oxygen-sensing regulator Anr controls expression of the PPA3309-lacZ reporter gene fusion after a shift to anaerobic conditions and further pyruvate fermentation. PA3309 expression...

  15. Potential risk factors for diabetic neuropathy: a case control study

    Directory of Open Access Journals (Sweden)

    Nooraei Mahdi

    2005-12-01

    Full Text Available Abstract Background Diabetes mellitus type II afflicts at least 2 million people in Iran. Neuropathy is one of the most common complications of diabetes and lowers the patient's quality of life. Since neuropathy often leads to ulceration and amputation, we have tried to elucidate the factors that can affect its progression. Methods In this case-control study, 110 diabetic patients were selected from the Shariati Hospital diabetes clinic. Michigan Neuropathic Diabetic Scoring (MNDS was used to differentiate cases from controls. The diagnosis of neuropathy was confirmed by nerve conduction studies (nerve conduction velocity and electromyography. The multiple factors compared between the two groups included consumption of angiotensin converting enzyme inhibitors (ACEI, blood pressure, serum lipid level, sex, smoking, method of diabetes control and its quality. Results Statistically significant relationships were found between neuropathy and age, gender, quality of diabetes control and duration of disease (P values in the order: 0.04, 0.04, Conclusion In this study, hyperglycemia was the only modifiable risk factor for diabetic neuropathy. Glycemic control reduces the incidence of neuropathy, slows its progression and improves the diabetic patient's quality of life. More attention must be paid to elderly male diabetic patients with poor diabetes control with regard to regular foot examinations and more practical education.

  16. Perinatal mortality and associated risk factors: a case control study ...

    African Journals Online (AJOL)

    BACKGROUND: Perinatal mortality is reported to be five times higher in developing than in developed nations. Little is known about the commonly associated risk factors for perinatal mortality in Southern Nations National Regional State of Ethiopia. METHODS: A case control study for perinatal mortality was conducted in ...

  17. Control to goal of cardiometabolic risk factors among Nigerians ...

    African Journals Online (AJOL)

    Background: Cardiovascular risk factors contribute to morbidity and mortality among diabetic patients. National and international guidelines on management of diabetes therefore emphasize control to goals of blood glucose, blood pressure, dyslipidemia, and obesity so as to minimize the development of complications and ...

  18. Factors affecting sustainable animal trypanosomosis control in parts ...

    African Journals Online (AJOL)

    This study examined the factors affecting sustainable trypanosomiasis control in parts of Kaduna State within the sub-humid savannah ecological zone of Nigeria. Focus group discussions were ... More awareness and preference for pour-on and aerial spraying were higher than the use of traps, target or screens. Rearing of ...

  19. Power-Factor Controller With Fast Load Response

    Science.gov (United States)

    Nola, F. J.

    1984-01-01

    Sudden changes in induced emf sensed. In refinement of soft starting three phase power-factor controller, additional components enable circuit to respond quickly to sudden increase in motor load. Rapid-load-response addition senses induced motor emf to detect sudden load increase and generates command signal to increase applied power in response.

  20. Patient related factors for optimal blood pressure control in patients ...

    African Journals Online (AJOL)

    Background: Patient related factors hindering optimal blood pressure (BP) control in patients with hypertension are unclear. Objectives: To investigate the barriers to optimal hypertension management. Methods: A survey on the awareness and management of hypertension was conducted in 556 patients (365 males, mean ...

  1. Anaerobic fungal populations

    International Nuclear Information System (INIS)

    Brookman, J.L.; Nicholson, M.J.

    2005-01-01

    The development of molecular techniques has greatly broadened our view of microbial diversity and enabled a more complete detection and description of microbial communities. The application of these techniques provides a simple means of following community changes, for example, Ishii et al. described transient and more stable inhabitants in another dynamic microbial system, compost. Our present knowledge of anaerobic gut fungal population diversity within the gastrointestinal tract is based upon isolation, cultivation and observations in vivo. It is likely that there are many species yet to be described, some of which may be non-culturable. We have observed a distinct difference in the ease of cultivation between the different genera, for example, Caecomyes isolates are especially difficult to isolate and maintain in vitro, a feature that is likely to result in the under representation of this genera in culture-based enumerations. The anaerobic gut fungi are the only known obligately anaerobic fungi. For the majority of their life cycles, they are found tightly associated with solid digesta in the rumen and/or hindgut. They produce potent fibrolytic enzymes and grow invasively on and into the plant material they are digesting making them important contributors to fibre digestion. This close association with intestinal digesta has made it difficult to accurately determine the amount of fungal biomass present in the rumen, with Orpin suggesting 8% contribution to the total microbial biomass, whereas Rezaeian et al. more recently gave a value of approximately 20%. It is clear that the rumen microbial complement is affected by dietary changes, and that the fungi are more important in digestion in the rumens of animals fed with high-fibre diets. It seems likely that the gut fungi play an important role within the rumen as primary colonizers of plant fibre, and so we are particularly interested in being able to measure the appearance and diversity of fungi on the plant

  2. Control of VOCs from printing press air emissions by anaerobic bioscrubber: Performance and microbial community of an on-site pilot unit.

    Science.gov (United States)

    Bravo, D; Ferrero, P; Penya-Roja, J M; Álvarez-Hornos, F J; Gabaldón, C

    2017-07-15

    A novel process consisted of an anaerobic bioscrubber was studied at the field scale for the removal of volatile organic compounds (VOCs) emitted from a printing press facility. The pilot unit worked under high fluctuating waste gas emissions containing ethanol, ethyl acetate, and 1-ethoxy-2-propanol as main pollutants, with airflows ranging between 184 and 1253 m 3  h -1 and an average concentration of 1126 ± 470 mg-C Nm -3 . Three scrubber configurations (cross-flow and vertical-flow packings and spray tower) were tested, and cross-flow packing was found to be the best one. For this packing, daily average values of VOC removal efficiency ranged between 83% and 93% for liquid to air volume ratios between 3.5·10 -3 and 9.1·10 -3 . Biomass growth was prevented by periodical chemical cleaning; the average pressure drop was 165 Pa m -1 . Rapid initiation of anaerobic degradation was achieved by using granular sludge from a brewery wastewater treatment plant. Despite the intermittent and fluctuating organic load, the expanded granular sludge bed reactor showed an excellent level of performance, reaching removal efficiencies of 93 ± 5% at 25.1 ± 3.2 °C, with biogas methane content of 94 ± 3% in volume. Volatile fatty acid concentration was as low as 200 mg acetic acid L -1 by treating daily average organic loads up to 3.0 kg COD h -1 , equivalent to 24 kg COD m -3 bed d -1 . The denaturing gradient gel electrophoresis (DGGE) results revealed the initial shift of the domains Archaea and Bacteria associated with the limitation of the carbon source to a few organic solvents. The Archaea domain was more sensitive, resulting in a drop of the Shannon index from 1.07 to 0.41 in the first 123 days. Among Archaea, the predominance of Methanosaeta persisted throughout the experimental period. The increase in the proportion of Methanospirillum and Methanobacterium sp. was linked to the spontaneous variations of operating temperature and load, respectively

  3. Isolation and Cultivation of Anaerobes

    DEFF Research Database (Denmark)

    Aragao Börner, Rosa

    2016-01-01

    Anaerobic microorganisms play important roles in different biotechnological processes. Their complex metabolism and special cultivation requirements have led to less isolated representatives in comparison to their aerobic counterparts.In view of that, the isolation and cultivation of anaerobic...... microorganisms is still a promising venture, and conventional methodologies as well as considerations and modifications are presented here. An insight into new methodologies and devices as well as a discussion on future perspectives for the cultivation of anaerobes may open the prospects of the exploitation...... of these microorganisms as a source for biotechnology....

  4. Risk factors for syphilis in women: case-control study

    Directory of Open Access Journals (Sweden)

    Vilma Costa de Macêdo

    2017-08-01

    Full Text Available ABSTRACT OBJECTIVE To determine the sociodemographic, behavioral, and health care factors related to the occurrence of syphilis in women treated at public maternity hospitals. METHODS This is a case-control study (239 cases and 322 controls with women admitted to seven maternity hospitals in the municipality of Recife, Brazil, from July 2013 to July 2014. Eligible women were recruited after the result of the VDRL (Venereal Disease Research Laboratory under any titration. The selection of cases and controls was based on the result of the serology for syphilis using ELISA (enzyme-linked immunosorbent assay. The independent variables were grouped into: sociodemographic, behavioral, clinical and obstetric history, and health care in prenatal care and maternity hospital. Information was obtained by interview, during hospitalization, with the application of a questionnaire. Odds ratios and 95% confidence intervals were estimated using logistic regression to identify the predicting factors of the variable to be explained. RESULTS The logistic regression analysis identified as determinant factors for gestational syphilis: education level of incomplete basic education or illiterate (OR = 2.02, lack of access to telephone (OR = 2.4, catholic religion (OR = 1.70 , four or more pregnancies (OR = 2.2, three or more sexual partners in the last year (OR = 3.1, use of illicit drugs before the age of 18 (OR = 3.0, and use of illicit drugs by the current partner (OR = 1.7. Only one to three prenatal appointments (OR = 3.5 and a previous history of sexually transmitted infection (OR = 9.7 were also identified as determinant factors. CONCLUSIONS Sociodemographic, behavioral, and health care factors are associated with the occurrence of syphilis in women and should be taken into account in the elaboration of universal strategies aimed at the prevention and control of syphilis, but with a focus on situations of greater vulnerability.

  5. REPRODUCTIVE FACTORS AND COLORECTAL CANCER RISK. Case - control study.

    Directory of Open Access Journals (Sweden)

    Adriana Ruseva

    2015-02-01

    Full Text Available Colorectal cancer is one of the most common cancers worldwide. The role of the female sex hormones in the etiology of the disease is very intriguing. Reproductive factors are surrogate measure of lifetime exposition to the sex hormones. Purpose: Our aim is to investigate the association between the reproductive factors and colorectal carcinoma risk. Materials and methods: We include 234 Bulgarian women in our study – 117 cases with colorectal cancer and the same number of healthy controls. Cases are divided into three groups according to the localization of the tumor. We conduct case-control study, using questionnaires about reproductive factors. We use the following statistical methods – descriptive, variational analysis, binary logistic regression. Results: We observed that only the age at menopause is associated with colorectal cancer risk, and this factor has strongest protective effect in the proximal colon (95% CI - 0,051-0,781, OR – 0,200, p – 0,021. Conclusion: Analyzing our data we observed that among Bulgarian women the only reproductive factor that show association with the risk of colorectal cancer is the age at menopause.

  6. Factores de necesidad asociados al uso adecuado del control prenatal

    Directory of Open Access Journals (Sweden)

    Clarybel Miranda Mellado

    2016-07-01

    Full Text Available Introducción: Por las implicaciones sociales de la mortalidad y morbilidad materna es importante determinar los factores de necesidad que influyen en el uso adecuado del control prenatal en gestantes de Sincelejo. Materiales y Métodos: Estudio analítico de corte transversal, que incluyó 730 gestantes, seleccionadas mediante muestreo aleatorio por conglomerados, de las comunas de la ciudad. La información fue recolectada por medio de una encuesta sociodemográfica, una ficha de uso de control prenatal y un Cuestionario para evaluar los factores de necesidad  propuestos por el Modelo de Promoción de la Salud de Nola Pender. Las gestantes fueron contactadas en sus domicilios y diligenciaron los instrumentos. Los datos fueron analizados aplicando estadística descriptiva e inferencial para determinar las asociaciones entre variables. Resultados: El 97,7% (713 de las gestantes asistía al control prenatal, con una mediana de 4 controles prenatales. Un 2,3% (17 no lo habían iniciado al momento de la encuesta y 24,4% (178 hizo uso inadecuado. El 80,7% (589 de las gestantes califican su estado de salud como bueno o muy bueno, 94,8% (692 percibieron beneficios del control prenatal. Se encontró asociación significativa entre la percepción de beneficios y el uso adecuado de control prenatal [OR=5,5 (IC 95%: 2,8 - 10,8]. Discusión y Conclusiones: La percepción que las mujeres tienen sobre los buenos resultados que reporta la asistencia al control prenatal, es el principal factor que puede explicar la adherencia al control y el cumplimiento regular de las consultas. Cómo citar este artículo: Miranda C, Castillo IY. Factores de necesidad asociados al uso adecuado del control prenatal. Rev Cuid. 2016; 7(2: 1345-51. http://dx.doi.org/10.15649/cuidarte.v7i2.340

  7. Effect of alkaline pretreatment on anaerobic digestion of solid wastes

    International Nuclear Information System (INIS)

    Lopez Torres, M.; Espinosa Llorens, Ma. del C.

    2008-01-01

    The introduction of the anaerobic digestion for the treatment of the organic fraction of municipal solid waste (OFMSW) is currently of special interest. The main difficulty in the treatment of this waste fraction is its biotransformation, due to the complexity of organic material. Therefore, the first step must be its physical, chemical and biological pretreatment for breaking complex molecules into simple monomers, to increase solubilization of organic material and improve the efficiency of the anaerobic treatment in the second step. This paper describes chemical pretreatment based on lime addition (Ca(OH) 2 ), in order to enhance chemical oxygen demand (COD) solubilization, followed by anaerobic digestion of the OFMSW. Laboratory-scale experiments were carried out in completely mixed reactors, 1 L capacity. Optimal conditions for COD solubilization in the first step of pretreatment were 62.0 mEq Ca(OH) 2 /L for 6.0 h. Under these conditions, 11.5% of the COD was solubilized. The anaerobic digestion efficiency of the OFMSW, with and without pretreatment, was evaluated. The highest methane yield under anaerobic digestion of the pretreated waste was 0.15 m 3 CH 4 /kg volatile solids (VS), 172.0% of the control. Under that condition the soluble COD and VS removal were 93.0% and 94.0%, respectively. The results have shown that chemical pretreatment with lime, followed by anaerobic digestion, provides the best results for stabilizing the OFMSW

  8. Human factors in aviation: Terminal control area boundary conflicts

    Science.gov (United States)

    Monan, William P.

    1989-01-01

    Air-to-air conflicts in the vicinity of Terminal Control Area (TCA) boundaries were studied to obtain a better understanding of the causal dynamics of these events with particular focus on human factor issues. The study dataset consisted of 381 Instrument Flight Rules/Visual Flight Rules (IFR/VFR) traffic conflicts in airspace layers above TCA ceiling and below TCA floors; 213 reports of incursions in TCA terminal airspace by VFR aircraft, of which 123 resulted in conflicts; and an additional set of reports describing problems with Air Traffic Control (ATC) services in and around TCAs. Results and conclusions are detailed.

  9. Implementing Livestock Anaerobic Digestion Projects

    Science.gov (United States)

    Page provides information to help make an informed decision about installing an anaerobic digester. Is it a good match for a farm’s organic waste, project financing, development guidelines and permit requirements?

  10. The human factors specialist in nuclear control centre design

    International Nuclear Information System (INIS)

    Wilson, R.B.; Beattie, J.D.

    The main focus at Ontario Hydro for man-machine interface design is in the design of control centres. Because the control of a nuclear generating unit is highly centralized there is an increasing need for effective information display and control layout. Control panel design innovations such as the use of CRT displays and the extended use of computerized control in the Darlington station have made it possible for Ontario Hydro to continue to have one first operator for each generating unit. The human factors specialist involved in control panel design must deal with people who know much more about the specific systems being controlled, and must become a generalist in all these systems as well. Designers have to use conceptual techniques such as task analysis, systems design, panel mock-ups, anthropometric data, and personal judgement based on experience as they design panels. They must find a balance between becoming locked into existing technology and methods, slavishly following the latest technological trends, and forgetting that real people will be using what they design

  11. Factors Controlling Nanoparticle Pharmacokinetics: An Integrated Analysis and Perspective

    DEFF Research Database (Denmark)

    Moghimi, Seyed Moien; Hunter, A.C.; Andresen, T.L.

    2012-01-01

    of interrelated core and interfacial physicochemical and biological factors. Pertinent to realizing therapeutic goals, definitive maps that establish the interdependency of nanoparticle size, shape, and surface characteristics in relation to interfacial forces, biodistribution, controlled drug release, excretion...... are already on the market and many are in late-phase clinical trials. With concomitant advances in extensive computational knowledge of the genomics and epigenomics of interindividual variations in drug responses, the boundaries toward development of personalized nanomedicines can be pushed further....

  12. Factors controlling marine fouling in some Alexandria Harbours, Egypt

    Directory of Open Access Journals (Sweden)

    SH.E. RAMADAN

    2006-12-01

    Full Text Available The present work aims to relate the settlement of marine fouling organisms in three different harbours in Alexandria city which present a wide range of ecological/environmental variations. Theses are the Abu Qir, Eastern and El-Dekheila harbours. Monthly samples of marine fouling were collected from the three harbours by using white roughened polystyrene test panels (12.5x12.5 cm, as well as physicochemical, chemical and other biological data. Results were treated with multivariate statistical analysis (PCA. At the Abu Qir harbour, it was found that water temperature and salinity are the most important environmental factors controlling the temporal distribution of total fouling density, whereas water temperature and chlorophyll a are the most significant environmental factors controlling the total biomass. At the Eastern harbour it was demonstrated that ammonia and phosphate are the most significant environmental factors controlling the temporal distribution and total biomass of fouling organisms. Concerning El-Dekheila harbour, the total density and total biomass of fouling organisms were inversely correlated with the total zooplankton.

  13. Final Report: Molecular mechanisms and kinetics of microbial anaerobic nitrate-dependent U(IV) and Fe(II) oxidation

    Energy Technology Data Exchange (ETDEWEB)

    O' Day, Peggy A. [Univ. of California, Merced, CA (United States); Asta, Maria P. [Univ. of California, Merced, CA (United States); Kanematsu, Masakazu [Univ. of California, Merced, CA (United States); Beller, Harry [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Zhou, Peng [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Steefel, Carl [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2015-02-27

    In this project, we combined molecular genetic, spectroscopic, and microscopic techniques with kinetic and reactive transport studies to describe and quantify biotic and abiotic mechanisms underlying anaerobic, nitrate-dependent U(IV) and Fe(II) oxidation, which influences the long-term efficacy of in situ reductive immobilization of uranium at DOE sites. In these studies, Thiobacillus denitrificans, an autotrophic bacterium that catalyzes anaerobic U(IV) and Fe(II) oxidation, was used to examine coupled oxidation-reduction processes under either biotic (enzymatic) or abiotic conditions in batch and column experiments with biogenically produced UIVO2(s). Synthesis and quantitative analysis of coupled chemical and transport processes were done with the reactive transport modeling code Crunchflow. Research focused on identifying the primary redox proteins that catalyze metal oxidation, environmental factors that influence protein expression, and molecular-scale geochemical factors that control the rates of biotic and abiotic oxidation.

  14. IMPACTS OF IRON, NUTRIENTS, AND MINERAL FINES ON ANAEROBIC BIODEGRADATION OF CANOLA OIL IN FRESHWATER SEDIMENTS

    Science.gov (United States)

    Factors affecting anaerobic biodegradation kinetics of canola oil in freshwater sediments were investigated. An optimum dose of ferric hydroxide (10.5 g Fe(III)·kg-1 sediment) was found to stimulate anaerobic biodegradation of canola oil (18.6 g oil kg-1). ...

  15. Colon cancer controls versus population controls in case-control studies of occupational risk factors

    DEFF Research Database (Denmark)

    Kaerlev, Linda; Lynge, Elsebeth; Sabroe, Svend

    2004-01-01

    . METHODS: The study was conducted from 1995 to 1997. Incident colon cancer controls (N = 428) aged 35-69 years with a histological verified diagnosis and population controls (N = 583) were selected. Altogether 254 (59%) of the colon cancer controls and 320 (55%) of the population controls were interviewed...... about occupational, medical and life style conditions. RESULTS: No statistical significant difference for educational level, medical history or smoking status was seen between the two control groups. There was evidence of a higher alcohol intake, less frequent work as a farmer and less exposure......BACKGROUND: Since updated population registers do not exist in many countries it is often difficult to sample valid population controls from the study base to a case-control study. Use of patient controls is an alternative option if the exposure experience under study for these patients...

  16. Anaerobic digestion of cellulosic wastes

    International Nuclear Information System (INIS)

    Donaldson, T.L.; Lee, D.D.

    1984-01-01

    Anaerobic digestion is a potentially attractive technology for volume reduction of cellulosic wastes. A substantial fraction of the waste is converted to off-gas and a relatively small volume of biologically stabilized sludge is produced. Process development work is underway using a 75-L digester to verify rates and conversions obtained at the bench scale, to develop start-up and operating procedures, and to generate effluent for characterization and disposal studies. Three runs using batch and batch-fed conditions have been made lasting 36, 90, and over 200 days. Solids solubilization and gas production rates and total solids destruction have met or exceeded the target values of 0.6 g cellulose per L of reactor per day, 0.5 L off-gas per L of reactor per day, and 80% destruction of solids, respectively. Successful start-up procedures have been developed, and preliminary effluent characterization and disposal studies have been done. A simple dynamic process model has been constructed to aid in further process development and for use in process monitoring and control of a large-scale digester. 7 references, 5 figures, 1 table

  17. Anaerobic digestion of cellulosic wastes

    International Nuclear Information System (INIS)

    Lee, D.D.; Donaldson, T.L.

    1985-01-01

    Anaerobic digestion is a potentially attractive technology for volume reduction of low-level radioactive cellulosic wastes. A substantial fraction of the waste is converted to off-gas and a relatively small volume of biologically stabilized sludge is produced. Process development work has been completed using a 75-L digester to verify rates and conversions obtained at the bench scale. Start-up and operating procedures have been developed, and effluent was generated for characterization and disposal studies. Three runs using batch and fed-batch conditions were made lasting 36, 90, and 423 d. Solids solubilization rates and gas production rates averaged approximately 1.8 g cellulose per L of reactor per d and 1.2 L of off-gas per L reactor per d. Greater than 80% destruction of the volatile suspended solids was obtained. A simple dynamic process model was constructed to aid in process design and for use in process monitoring and control of a large-scale digester

  18. Gelatin Methacrylate Microspheres for Growth Factor Controlled Release

    Science.gov (United States)

    Nguyen, Anh H.; McKinney, Jay; Miller, Tobias; Bongiorno, Tom; McDevitt, Todd C.

    2014-01-01

    Gelatin has been commonly used as a delivery vehicle for various biomolecules for tissue engineering and regenerative medicine applications due to its simple fabrication methods, inherent electrostatic binding properties, and proteolytic degradability. Compared to traditional chemical cross-linking methods, such as the use of glutaraldehyde (GA), methacrylate modification of gelatin offers an alternative method to better control the extent of hydrogel cross-linking. Here we examined the physical properties and growth factor delivery of gelatin methacrylate (GMA) microparticles formulated with a wide range of different cross-linking densities (15–90%). Less methacrylated MPs had decreased elastic moduli and larger mesh sizes compared to GA MPs, with increasing methacrylation correlating to greater moduli and smaller mesh sizes. As expected, an inverse correlation between microparticle cross-linking density and degradation was observed, with the lowest cross-linked GMA MPs degrading at the fastest rate, comparable to GA MPs. Interestingly, GMA MPs at lower cross-linking densities could be loaded with up to a 10-fold higher relative amount of growth factor over conventional GA cross-linked MPs, despite an order of magnitude greater gelatin content of GA MPs. Moreover, a reduced GMA cross-linking density resulted in more complete release of bone morphogenic protein 4 (BMP4) and basic fibroblast growth factor (bFGF) and accelerated release rate with collagenase treatment. These studies demonstrate that GMA MPs provide a more flexible platform for growth factor delivery by enhancing the relative binding capacity and permitting proteolytic degradation tunability, thereby offering a more potent controlled release system for growth factor delivery. PMID:25463489

  19. Horse manure as feedstock for anaerobic digestion.

    Science.gov (United States)

    Hadin, Sa; Eriksson, Ola

    2016-10-01

    Horse keeping is of great economic, social and environmental benefit for society, but causes environmental impacts throughout the whole chain from feed production to manure treatment. According to national statistics, the number of horses in Sweden is continually increasing and is currently approximately 360,000. This in turn leads to increasing amounts of horse manure that have to be managed and treated. Current practices could cause local and global environmental impacts due to poor performance or lack of proper management. Horse manure with its content of nutrients and organic material can however contribute to fertilisation of arable land and recovery of renewable energy following anaerobic digestion. At present anaerobic digestion of horse manure is not a common treatment. In this paper the potential for producing biogas and biofertiliser from horse manure is analysed based on a thorough literature review in combination with mathematical modelling and simulations. Anaerobic digestion was chosen as it has a high degree of resource conservation, both in terms of energy (biogas) and nutrients (digestate). Important factors regarding manure characteristics and operating factors in the biogas plant are identified. Two crucial factors are the type and amount of bedding material used, which has strong implications for feedstock characteristics, and the type of digestion method applied (dry or wet process). Straw and waste paper are identified as the best materials in an energy point of view. While the specific methane yield decreases with a high amount of bedding, the bedding material still makes a positive contribution to the energy balance. Thermophilic digestion increases the methane generation rate and yield, compared with mesophilic digestion, but the total effect is negligible. Copyright © 2016. Published by Elsevier Ltd.

  20. Key players and team play: anaerobic microbial communities in hydrocarbon-contaminated aquifers.

    Science.gov (United States)

    Kleinsteuber, Sabine; Schleinitz, Kathleen M; Vogt, Carsten

    2012-05-01

    Biodegradation of anthropogenic pollutants in shallow aquifers is an important microbial ecosystem service which is mainly brought about by indigenous anaerobic microorganisms. For the management of contaminated sites, risk assessment and control of natural attenuation, the assessment of in situ biodegradation and the underlying microbial processes is essential. The development of novel molecular methods, "omics" approaches, and high-throughput techniques has revealed new insight into complex microbial communities and their functions in anoxic environmental systems. This review summarizes recent advances in the application of molecular methods to study anaerobic microbial communities in contaminated terrestrial subsurface ecosystems. We focus on current approaches to analyze composition, dynamics, and functional diversity of subsurface communities, to link identity to activity and metabolic function, and to identify the ecophysiological role of not yet cultured microbes and syntrophic consortia. We discuss recent molecular surveys of contaminated sites from an ecological viewpoint regarding degrader ecotypes, abiotic factors shaping anaerobic communities, and biotic interactions underpinning the importance of microbial cooperation for microbial ecosystem services such as contaminant degradation.

  1. Risk Factors For Ectopic Pregnancy : A Case Control Study

    Directory of Open Access Journals (Sweden)

    Deshmukh J.S

    1999-01-01

    Full Text Available Research question: Which are the risk factors for ectopic pregnancy . Objective: To study the strength of association between hypothesised risk factors and ectopic pregnancy. Study design: Unmatched case- control study. Setting: Government Medical College, Hospital, Nagpur. Participants: 133 cases of ectopic pregnancy and equal number of controls (non pregnant women admitted to study hospital. Study variables : Pelvic inflammatory diseases, sexually transmitted diseases, IUD use at conception , past use of IUD, prior ectopic pregnancy, OC pills use at the time of conception, past use of OC pills, induced abortion, spontaneous abortion, infertility and pelvic and abdominal surgery. Statistical analysis: Odds ratios & their 95% CI, Pearson’s chi square test, unconditional logistic regression analysis and population attributable risk proportion. Results : Use of IUD at conception, prior ectopic pregnancy , pelvic inflammatory disease, sexually transmitted diseases, infertility, OC pills use at the time of conception, past use of IUD and induced abortion were found to be significantly associated with ectopic pregnancy. Conclusion: Identification of these risk factors for etopic pregnancy shall help in early detection and appropriate management in an individual case and it may help in devising a comprehensive preventive strategy for ectopic pregnancy

  2. Lipid-activated transcription factors control bile acid glucuronidation.

    Science.gov (United States)

    Barbier, Olivier; Trottier, Jocelyn; Kaeding, Jenny; Caron, Patrick; Verreault, Mélanie

    2009-06-01

    Bile acids subserve important physiological functions in the control of cholesterol homeostasis. Indeed, hepatic bile acid synthesis and biliary excretion constitute the main route for cholesterol removal from the human body. On the other hand, bile acids serve as natural detergents for the intestinal absorption of dietary cholesterol. However, due to their detergent properties, bile acids are inherently cytotoxic, and their cellular level may be tightly controlled to avoid pathological situations such as cholestasis. Recent investigations have illustrated the crucial roles that a series of ligand-activated transcription factors has in the control of hepatic bile acids synthesis, transport and metabolism. Thus, the lipid-activated nuclear receptors, farnesoid X-receptor (FXR), liver X-receptor (LXR), pregnane X-receptor (PXR) and peroxisome proliferator-activated receptor alpha (PPAR alpha), modulate the expression and activity of genes controlling bile acid homeostasis in the liver. Several members of the UDP-glucuronosyltransferase (UGT) enzymes family are among the bile acid metabolizing enzymes regulated by these receptors. UGTs catalyze glucuronidation, a major phase II metabolic reaction, which converts hydrophobic bile acids into polar and urinary excretable metabolites. This article summarizes our recent observations on the regulation of bile acid conjugating UGTs upon pharmacological activation of lipid-activated receptors, with a particular interest for the role of PPAR alpha and LXRalpha in controlling human UGT1A3 expression.

  3. Comparison of atherogenic risk factors among poorly controlled and well-controlled adolescent phenylketonuria patients.

    Science.gov (United States)

    Gündüz, Mehmet; Çakar, Sevim; Kuyum, Pınar; Makay, Balahan; Arslan, Nur

    2016-06-01

    Previous studies investigating the known risk factors of atherosclerosis in phenylketonuria patients have shown conflicting results. The primary aim of our study was to investigate the serum atherogenic markers in adolescent classical phenylketonuria patients and compare these parameters with healthy peers. The secondary aim was to compare these atherogenic markers in well-controlled and poorly controlled patients. A total of 59 patients (median age: 12.6 years, range: 11-17 years) and 44 healthy controls (median age: 12.0 years, range: 11-15 years) were enrolled in our study. Phenylketonuria patients were divided into two groups: well-controlled (serum phenylalanine levels below 360 µmol/L; 24 patients) and poorly controlled patients (serum phenylalanine levels higher than 360 µmol/L). The mean high-density lipoprotein cholesterol levels of well-controlled patients (1.0±0.2 mmol/L) were significantly lower compared with poorly controlled patients and controls (1.1±0.2 mmol/L, p=0.011 and 1.4±0.2 mmol/L, pphenylketonuria patients. In particular, these changes were more prominent in well-controlled patients. We conclude that phenylketonuria patients might be at risk for atherosclerosis, and therefore screening for atherosclerotic risk factors should be included in the phenylketonuria therapy and follow-up in addition to other parameters.

  4. Renewable Energy Production from DoD Installation Solid Wastes by Anaerobic Digestion

    Science.gov (United States)

    2016-06-01

    OPTIMAL-CONTROL OF BIOREACTORS - APPLICATION TO ANAEROBIC DEGRADATION." Journal of Biotechnology 22(1-2): 89-105. Sanders, W.T.M, van Bergen, D...BIOREACTORS - APPLICATION TO ANAEROBIC DEGRADATION." Journal of Biotechnology 22(1-2): 89-105. Sanders, W.T.M, van Bergen, D., et al. (1996

  5. Aerobic and anaerobic exercise capacity in children with juvenile idiopathic arthritis

    NARCIS (Netherlands)

    van Brussel, M.; Lelieveld, O. T. H. M.; van der Net, J.; Engelbert, R. H. H.; Helders, P. J. M.; Takken, T.

    2007-01-01

    To compare the aerobic and anaerobic exercise capacity of children with juvenile idiopathic arthritis (JIA) with healthy controls, to determine if there were differences based on disease onset type, and to examine the relationship between aerobic and anaerobic exercise capacity in children with JIA.

  6. Aerobic and anaerobic exercise capacity in children with juvenile idiopathic arthritis

    NARCIS (Netherlands)

    van Brussel, Marco; Lelieveld, O T H M; van der Net, J; Engelbert, R H H; Helders, P J M; Takken, T

    2007-01-01

    Objective. To compare the aerobic and anaerobic exercise capacity of children with juvenile idiopathic arthritis (JIA) with healthy controls, to determine if there were differences based on disease onset type, and to examine the relationship between aerobic and anaerobic exercise capacity in

  7. Speciation modeling of ammonia and other major solutes in anaerobic digesters

    Science.gov (United States)

    Anaerobic digestion of high-nitrogen wastes can be inhibited by high concentrations of un-ionized ammonia, NH**3 (aq). Understanding the toxicity of NH**3 (aq) to anaerobic digestion requires an understanding of the mechanisms controlling its concentration. Previous work on ammonia toxicity in an...

  8. Can oral anaerobic bacteria cause adverse pregnancy outcomes?

    Science.gov (United States)

    Andonova, I; Iliev, V; Živković, N; Sušič, E; Bego, I; Kotevska, V

    2015-01-01

    Maternal periodontal infection has been recognized as a risk factor for premature and low birthweight infants. It is suspected that pathogens causing periodontal disease may translocate to the amniotic cavity and so contribute to triggering an adverse pregnancy outcome. The aim of this study was to evaluate whether the presence of specific periodontal pathogens may influence the incidence of preterm labor and premature birth. This study was designed as a hospital-based case-control study. A total of 70 pregnant women, aged 18-40 with single live pregnancy were recruited from the Departement of Gynecolgy and Obstetrics at a General hospital in Sibenik, Croatia, between March 2013 to March 2014. The case group: 30 pregnant women who were hospitalised with signs of premature labor. 40 patients with normal pregnancy post-delivery up to 48 hrs, who had given birth at term, and the baby had a weight of more than 2500 gr. These women had undergone microbiological examination at the time of recruitment, microbial samples, paper point subgingival swabs were obtained in both groups and processed by anaerobic culturing. Standard procedures were used for culture and identification of bacteria. Information was collected on demographics, health behaviors, and obstetric and systemic diseases that may have influence the premature delivery. The levels of periodontal pathogens tended to be higher in the premature (case group) labor compared to the term deliveries (control group). Levels of Porphyromonas gingivalis, Fuscobacterium nucleatum, Actinomyces actinomycetecomitans were statistically significantly higher in premature births as compared to term deliveries, adjusting for baseline levels. The joint effects of red and orange microbial clusters were significantly higher in the premature group compared to the term group. The study shows a significant association betwen periodontal anaerobic infection and adverse pregnancy outcome. High levels of periodontal pathogens during

  9. Differential interactions between Notch and ID factors control neurogenesis by modulating Hes factor autoregulation.

    Science.gov (United States)

    Boareto, Marcelo; Iber, Dagmar; Taylor, Verdon

    2017-10-01

    During embryonic and adult neurogenesis, neural stem cells (NSCs) generate the correct number and types of neurons in a temporospatial fashion. Control of NSC activity and fate is crucial for brain formation and homeostasis. Neurogenesis in the embryonic and adult brain differ considerably, but Notch signaling and inhibitor of DNA-binding (ID) factors are pivotal in both. Notch and ID factors regulate NSC maintenance; however, it has been difficult to evaluate how these pathways potentially interact. Here, we combined mathematical modeling with analysis of single-cell transcriptomic data to elucidate unforeseen interactions between the Notch and ID factor pathways. During brain development, Notch signaling dominates and directly regulates Id4 expression, preventing other ID factors from inducing NSC quiescence. Conversely, during adult neurogenesis, Notch signaling and Id2/3 regulate neurogenesis in a complementary manner and ID factors can induce NSC maintenance and quiescence in the absence of Notch. Our analyses unveil key molecular interactions underlying NSC maintenance and mechanistic differences between embryonic and adult neurogenesis. Similar Notch and ID factor interactions may be crucial in other stem cell systems. © 2017. Published by The Company of Biologists Ltd.

  10. Biological Stability of Drinking Water: Controlling Factors, Methods, and Challenges.

    Science.gov (United States)

    Prest, Emmanuelle I; Hammes, Frederik; van Loosdrecht, Mark C M; Vrouwenvelder, Johannes S

    2016-01-01

    Biological stability of drinking water refers to the concept of providing consumers with drinking water of same microbial quality at the tap as produced at the water treatment facility. However, uncontrolled growth of bacteria can occur during distribution in water mains and premise plumbing, and can lead to hygienic (e.g., development of opportunistic pathogens), aesthetic (e.g., deterioration of taste, odor, color) or operational (e.g., fouling or biocorrosion of pipes) problems. Drinking water contains diverse microorganisms competing for limited available nutrients for growth. Bacterial growth and interactions are regulated by factors, such as (i) type and concentration of available organic and inorganic nutrients, (ii) type and concentration of residual disinfectant, (iii) presence of predators, such as protozoa and invertebrates, (iv) environmental conditions, such as water temperature, and (v) spatial location of microorganisms (bulk water, sediment, or biofilm). Water treatment and distribution conditions in water mains and premise plumbing affect each of these factors and shape bacterial community characteristics (abundance, composition, viability) in distribution systems. Improved understanding of bacterial interactions in distribution systems and of environmental conditions impact is needed for better control of bacterial communities during drinking water production and distribution. This article reviews (i) existing knowledge on biological stability controlling factors and (ii) how these factors are affected by drinking water production and distribution conditions. In addition, (iii) the concept of biological stability is discussed in light of experience with well-established and new analytical methods, enabling high throughput analysis and in-depth characterization of bacterial communities in drinking water. We discussed, how knowledge gained from novel techniques will improve design and monitoring of water treatment and distribution systems in order

  11. Biological stability of drinking water: controlling factors, methods and challenges

    Directory of Open Access Journals (Sweden)

    Emmanuelle ePrest

    2016-02-01

    Full Text Available Biological stability of drinking water refers to the concept of providing consumers with drinking water of same microbial quality at the tap as produced at the water treatment facility. However, uncontrolled growth of bacteria can occur during distribution in water mains and premise plumbing, and can lead to hygienic (e.g. development of opportunistic pathogens, aesthetic (e.g. deterioration of taste, odour, colour or operational (e.g. fouling or biocorrosion of pipes problems. Drinking water contains diverse microorganisms competing for limited available nutrients for growth. Bacterial growth and interactions are regulated by factors such as (i type and concentration of available organic and inorganic nutrients, (ii type and concentration of residual disinfectant, (iii presence of predators such as protozoa and invertebrates, (iv environmental conditions such as water temperature, and (v spatial location of microorganisms (bulk water, sediment or biofilm. Water treatment and distribution conditions in water mains and premise plumbing affect each of these factors and shape bacterial community characteristics (abundance, composition, viability in distribution systems. Improved understanding of bacterial interactions in distribution systems and of environmental conditions impact is needed for better control of bacterial communities during drinking water production and distribution. This article reviews (i existing knowledge on biological stability controlling factors and (ii how these factors are affected by drinking water production and distribution conditions. In addition, (iii the concept of biological stability is discussed in light of experience with well-established and new analytical methods, enabling high throughput analysis and in-depth characterization of bacterial communities in drinking water. We discuss how knowledge gained from novel techniques will improve design and monitoring of water treatment and distribution systems in order to

  12. Biological Stability of Drinking Water: Controlling Factors, Methods, and Challenges

    KAUST Repository

    Prest, Emmanuelle I.

    2016-02-01

    Biological stability of drinking water refers to the concept of providing consumers with drinking water of same microbial quality at the tap as produced at the water treatment facility. However, uncontrolled growth of bacteria can occur during distribution in water mains and premise plumbing, and can lead to hygienic (e.g., development of opportunistic pathogens), aesthetic (e.g., deterioration of taste, odor, color) or operational (e.g., fouling or biocorrosion of pipes) problems. Drinking water contains diverse microorganisms competing for limited available nutrients for growth. Bacterial growth and interactions are regulated by factors, such as (i) type and concentration of available organic and inorganic nutrients, (ii) type and concentration of residual disinfectant, (iii) presence of predators, such as protozoa and invertebrates, (iv) environmental conditions, such as water temperature, and (v) spatial location of microorganisms (bulk water, sediment, or biofilm). Water treatment and distribution conditions in water mains and premise plumbing affect each of these factors and shape bacterial community characteristics (abundance, composition, viability) in distribution systems. Improved understanding of bacterial interactions in distribution systems and of environmental conditions impact is needed for better control of bacterial communities during drinking water production and distribution. This article reviews (i) existing knowledge on biological stability controlling factors and (ii) how these factors are affected by drinking water production and distribution conditions. In addition, (iii) the concept of biological stability is discussed in light of experience with well-established and new analytical methods, enabling high throughput analysis and in-depth characterization of bacterial communities in drinking water. We discussed, how knowledge gained from novel techniques will improve design and monitoring of water treatment and distribution systems in order

  13. Biological Stability of Drinking Water: Controlling Factors, Methods, and Challenges

    Science.gov (United States)

    Prest, Emmanuelle I.; Hammes, Frederik; van Loosdrecht, Mark C. M.; Vrouwenvelder, Johannes S.

    2016-01-01

    Biological stability of drinking water refers to the concept of providing consumers with drinking water of same microbial quality at the tap as produced at the water treatment facility. However, uncontrolled growth of bacteria can occur during distribution in water mains and premise plumbing, and can lead to hygienic (e.g., development of opportunistic pathogens), aesthetic (e.g., deterioration of taste, odor, color) or operational (e.g., fouling or biocorrosion of pipes) problems. Drinking water contains diverse microorganisms competing for limited available nutrients for growth. Bacterial growth and interactions are regulated by factors, such as (i) type and concentration of available organic and inorganic nutrients, (ii) type and concentration of residual disinfectant, (iii) presence of predators, such as protozoa and invertebrates, (iv) environmental conditions, such as water temperature, and (v) spatial location of microorganisms (bulk water, sediment, or biofilm). Water treatment and distribution conditions in water mains and premise plumbing affect each of these factors and shape bacterial community characteristics (abundance, composition, viability) in distribution systems. Improved understanding of bacterial interactions in distribution systems and of environmental conditions impact is needed for better control of bacterial communities during drinking water production and distribution. This article reviews (i) existing knowledge on biological stability controlling factors and (ii) how these factors are affected by drinking water production and distribution conditions. In addition, (iii) the concept of biological stability is discussed in light of experience with well-established and new analytical methods, enabling high throughput analysis and in-depth characterization of bacterial communities in drinking water. We discussed, how knowledge gained from novel techniques will improve design and monitoring of water treatment and distribution systems in order

  14. Anaerobic bacteria colonizing the lower airways in lung cancer patients

    Directory of Open Access Journals (Sweden)

    Anna Malm

    2011-07-01

    Full Text Available Anaerobes comprise most of the endogenous oropharyngeal microflora, and can cause infections of airways in lung cancer patients who are at high risk for respiratory tract infections. The aim of this study was to determine the frequency and species diversity of anaerobes in specimens from the lower airways of lung cancer patients. Sensitivity of the isolates to conventional antimicrobial agents used in anaerobe therapy was assessed. Respiratory secretions obtained by bronchoscopy from 30 lung cancer patients were cultured onto Wilkins- -Chalgren agar in anaerobic conditions at 37°C for 72–96 hours. The isolates were identified using microtest Api 20A. The minimal inhibitory concentrations for penicillin G, amoxicillin/clavulanate, piperacillin/tazobactam, cefoxitin, imipenem, clindamycin, and metronidazole were determined by E-test. A total of 47 isolates of anaerobic bacteria were detected in 22 (73.3% specimens. More than one species of anaerobe was found in 16 (53.3% samples. The most frequently isolated were Actinomyces spp. and Peptostreptococcus spp., followed by Eubacterium lentum, Veillonella parvula, Prevotella spp., Bacteroides spp., Lactobacillus jensenii. Among antibiotics used in the study amoxicillin/clavulanate and imipenem were the most active in vitro (0% and 2% resistant strains, respectively. The highest resistance rate was found for penicillin G and metronidazole (36% and 38% resistant strains, respectively. The results obtained confirm the need to conduct analyses of anaerobic microflora colonizing the lower respiratory tract in patients with lung cancer to monitor potential etiologic factors of airways infections, as well as to propose efficient, empirical therapy. (Folia Histochemica et Cytobiologica 2011; Vol. 49, No. 2, pp. 263–266

  15. Physical factors controlling the ductility of bulk metallic glasses

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Y. [Central South University, China; Liu, Chain T [ORNL; Zhang, Z. [University of Tennessee, Knoxville (UTK); Keppens, V. [University of Tennessee, Knoxville (UTK)

    2008-01-01

    In order to identify key physical factor controlling the deformation and fracture behavior of bulk metallic glasses (BMGs), we compiled and analyzed the elastic moduli and compressive ductility for BMGs. In addition, new modulus data were generated in the critical ranges in order to facilitate the analysis. We have found that the intrinsic ductility of BMGs can be correlated with the bulk-to-shear modulus ratio B/G according to Pugh's [Philos. Mag. 45, 823 (1954) ] rule. In some individual BMG systems, for example, Fe based, the relationship seems to be very clear. The physical meaning of this correlation is discussed in terms of atomic bonding and connectivity.

  16. Human factors in remote control engineering development activities

    International Nuclear Information System (INIS)

    Clarke, M.M.; Hamel, W.R.; Draper, J.V.

    1983-01-01

    Human factors engineering, which is an integral part of the advanced remote control development activities at the Oak Ridge National Laboratory, is described. First, work at the Remote Systems Development Facility (RSDF) has shown that operators can perform a wide variety of tasks, some of which were not specifically designed for remote systems, with a dextrous electronic force-reflecting servomanipulator and good television remote viewing capabilities. Second, the data collected during mock-up remote maintenance experiments at the RSDF have been analyzed to provide guidelines for the design of human interfaces with an integrated advanced remote maintenance system currently under development. Guidelines have been provided for task allocation between operators, remote viewing systems, and operator controls. 6 references, 5 figures, 2 tables

  17. Understanding disease control: influence of epidemiological and economic factors.

    Directory of Open Access Journals (Sweden)

    Katarzyna Oleś

    Full Text Available We present a model of disease transmission on a regular and small world network and compare different control options. Comparison is based on a total cost of epidemic, including cost of palliative treatment of ill individuals and preventive cost aimed at vaccination or culling of susceptible individuals. Disease is characterized by pre-symptomatic phase, which makes detection and control difficult. Three general strategies emerge: global preventive treatment, local treatment within a neighborhood of certain size and only palliative treatment with no prevention. While the choice between the strategies depends on a relative cost of palliative and preventive treatment, the details of the local strategy and, in particular, the size of the optimal treatment neighborhood depend on the epidemiological factors. The required extent of prevention is proportional to the size of the infection neighborhood, but depends on time till detection and time till treatment in a non-nonlinear (power law. The optimal size of control neighborhood is also highly sensitive to the relative cost, particularly for inefficient detection and control application. These results have important consequences for design of prevention strategies aiming at emerging diseases for which parameters are not nessecerly known in advance.

  18. Anaerobic xylose fermentation by Spathaspora passalidarum

    DEFF Research Database (Denmark)

    Hou, Xiaoru

    2012-01-01

    A cost-effective conversion of lignocellulosic biomass into bioethanol requires that the xylose released from the hemicellulose fraction (20–40% of biomass) can be fermented. Baker’s yeast, Saccharomyces cerevisiae, efficiently ferments glucose but it lacks the ability to ferment xylose. Xylose-fermenting...... yeast such as Pichia stipitis requires accurately controlled microaerophilic conditions during the xylose fermentation, rendering the process technically difficult and expensive. In this study, it is demonstrated that under anaerobic conditions Spathaspora passalidarum showed high ethanol production...

  19. Stringent factor and proteolysis control of sigma factor RpoS expression in Vibrio cholerae.

    Science.gov (United States)

    Wurm, Philipp; Tutz, Sarah; Mutsam, Beatrice; Vorkapic, Dina; Heyne, Barbara; Grabner, Claudia; Kleewein, Katharina; Halscheidt, Anja; Schild, Stefan; Reidl, Joachim

    2017-04-01

    Vibrio cholerae can colonize the gastrointestinal track of humans and cause the disease cholera. During colonization, the alternative sigma factor, RpoS, controls a process known as "mucosal escape response," defining a specific spatial and temporal response and effecting chemotaxis and motility. In this report, the expression and proteolytic control of RpoS in V. cholerae was characterized. To date, aspects of proteolysis control, the involved components, and proteolysis regulation have not been addressed for RpoS in V. cholerae. Similar to Escherichia coli, we find that the RpoS protein is subjected to regulated intracellular proteolysis, which is mediated by homologues of the proteolysis-targeting factor RssB and the protease complex ClpXP. As demonstrated, RpoS expression transiently peaks after cells are shifted from rich to minimal growth medium. This peak level is dependent on (p)ppGpp-activated rpoS transcription and controlled RpoS proteolysis. The RpoS peak level also correlates with induction of a chemotaxis gene, encoding a methyl-accepting chemotaxis protein, earlier identified to belong to the mucosal escape response pathway. These results suggest that the RpoS expression peak is linked to (p)ppGpp alarmone increase, leading to enhanced motility and chemotaxis, and possibly contributing to the mucosal escape response. Copyright © 2017 Elsevier GmbH. All rights reserved.

  20. Factors controlling phosphorus release from sediments in coastal archipelago areas.

    Science.gov (United States)

    Puttonen, Irma; Kohonen, Tuula; Mattila, Johanna

    2016-07-15

    In coastal archipelago areas of the northern Baltic Sea, significantly higher phosphate concentrations (6.0±4.5μmol/l, mean±SD) were measured in water samples close to the sediment surface compared with those from 1m above the seafloor (1.6±2.0μmol/l). The results indicated notable phosphate release from sediments under the bottom water oxygen concentrations of up to 250μmol/l, especially in areas that had experienced recent temporal fluctuation between oxic and hypoxic/anoxic conditions. No single factor alone was found to control the elevated PO4-P concentrations in the near-bottom water. In addition to the oxygen in the water, the contents of potentially mobile phosphorus fractions, grain-size, the organic content at the sediment surface, and the water depth were all important factors controlling the internal loading of phosphorus. The complexity of this process needs to be accounted for in assessments of the internal loading of phosphorus and in potential mitigation plans. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. Control of Dual-Opposed Stirling Convertors with Active Power Factor Correction Controllers

    Science.gov (United States)

    Regan, Timothy F.; Lewandowski, Edward J.; Schreiber, Jeffrey G.

    2007-01-01

    When using recently-developed active power factor correction (APFC) controllers in power systems comprised of dual-opposed free-piston Stirling convertors, a variety of configurations of the convertors and controller(s) can be considered, with configuration ultimately selected based on benefits of efficiency, reliability, and robust operation. The configuration must not only achieve stable control of the two convertors, but also synchronize and regulate motion of the pistons to minimize net dynamic forces. The NASA Glenn Research Center (GRC) System Dynamic Model (SDM) was used to study ten configurations of dual-opposed convertor systems. These configurations considered one controller with the alternators connected in series or in parallel, and two controllers with the alternators not connected (isolated). For the configurations where the alternators were not connected, several different approaches were evaluated to synchronize the two convertors. In addition, two thermodynamic configurations were considered: two convertors with isolated working spaces and convertors with a shared expansion space. Of the ten configurations studied, stable operating modes were found for four. Three of those four had a common expansion space. One stable configuration was found for the dual-opposed convertors with separate working spaces. That configuration required isochronous control of both convertors, and two APFC controllers were used to accomplish this. A frequency/phase control loop was necessary to allow each APFC controller to synchronize its associated convertor with a common frequency.

  2. Anaerobic digestion of solid material

    DEFF Research Database (Denmark)

    Vavilin, V.A.; Lokshina, L.Y.; Flotats, X.

    2007-01-01

    A new multidimensional (3 and 2D) anaerobic digestion model for cylindrical reactor with non-uniform influent concentration distributions was developed to study the way in which mixing intensity affects the efficiency of continuous-flow anaerobic digestion. Batch experiments reported and simulated....... In the system, the threshold methanogenic biomass concentration existed because of inhibition by high VFA concentration. High methanogenic biomass concentration is required for efficient anaerobic digestion of MSW in order to avoid possible inhibition due to high VFA build-up. Thus, CSTR configuration might...... have unstable dynamics at high organic loading as shown in earlier experiments carried out by Stroot et al. (2001). A gradual increase of organic loading during the start up of a completely mixed digester causing an accumulation of methanogenic biomass is a solution to prevent a probable digester...

  3. Characteristics of residues from thermally treated anaerobic sludges

    International Nuclear Information System (INIS)

    Friedman, A.A.; Smith, J.E.; De Santis, J.; Ptak, T.; Ganley, R.C.

    1988-01-01

    Sludge management and disposal are probably the most difficult and expensive operations involved in wastewater treatment today. To minimize final disposal costs many waste treatment facilities practice some form of anaerobic digestion and dewatering to reduce the volume and offensiveness of their by-product sludges. One potential alternative for reducing sludge volumes consists of high temperature, partial oxidation of these previously digested sludges (PDS) and subsequent anaerobic biological conversion of resulting soluble organics to methane. This paper describes solids destruction, residue characteristics and biodegradability factors that should be considered in the design of liquid thermal treatment processes for the management of anaerobic sludges. To date only very limited information is available concerning the suitability of thermally treated PDS to serve as a substrate for the generation of methane. The primary objective of this research was to determine the feasibility of producing methane efficiently from the residual VSS in anaerobically digested sludges. Secondary goals were to establish the ''best'' conditions for thermal treatment for solubilizing PDS, to observe the effect of the soluble products on methanogenesis and to evaluate process sidestreams for dewaterability and anaerobic biodegradability

  4. Controllability analysis of transcriptional regulatory networks reveals circular control patterns among transcription factors

    DEFF Research Database (Denmark)

    Österlund, Tobias; Bordel, Sergio; Nielsen, Jens

    2015-01-01

    we analyze the topology and organization of nine transcriptional regulatory networks for E. coli, yeast, mouse and human, and we evaluate how the structure of these networks influences two of their key properties, namely controllability and stability. We calculate the controllability for each network......Transcriptional regulation is the most committed type of regulation in living cells where transcription factors (TFs) control the expression of their target genes and TF expression is controlled by other TFs forming complex transcriptional regulatory networks that can be highly interconnected. Here...... as a measure of the organization and interconnectivity of the network. We find that the number of driver nodes n(D) needed to control the whole network is 64% of the TFs in the E. coli transcriptional regulatory network in contrast to only 17% for the yeast network, 4% for the mouse network and 8...

  5. Special properties of polycentric anaerobic fungus Anaeromyces mucronatus

    Czech Academy of Sciences Publication Activity Database

    Fliegerová, Kateřina; Pažoutová, Sylvie; Mrázek, Jakub; Kopečný, Jan

    2002-01-01

    Roč. 71, - (2002), s. 441-444 ISSN 0001-7213 R&D Projects: GA AV ČR KSK5020115; GA ČR GA523/96/0103; GA AV ČR KSK5052113 Keywords : rumen * fungi * anaerobic Subject RIV: ED - Physiology Impact factor: 0.370, year: 2002

  6. Characterization of chitinases of polycentric anaerobic rumen fungi

    Czech Academy of Sciences Publication Activity Database

    Novotná, Zuzana; Fliegerová, Kateřina; Šimůnek, Jiří

    2008-01-01

    Roč. 53, č. 3 (2008), s. 241-245 ISSN 0015-5632 Institutional research plan: CEZ:AV0Z50450515 Keywords : endochitinase * anaerobic * rumen fungi Subject RIV: EE - Microbiology, Virology Impact factor: 1.172, year: 2008

  7. Analysis of fatty acid composition of anaerobic rumen fungi

    Czech Academy of Sciences Publication Activity Database

    Koppová, Ingrid; Novotná, Zuzana; Štrosová, Lenka; Fliegerová, Kateřina

    2008-01-01

    Roč. 53, č. 3 (2008), s. 217-220 ISSN 0015-5632 R&D Projects: GA ČR GA523/05/2555 Institutional research plan: CEZ:AV0Z50450515 Keywords : fatty acid * rumen * anaerobic fungi Subject RIV: EE - Microbiology, Virology Impact factor: 1.172, year: 2008

  8. Oxygen sensitivity of various anaerobic bacteria.

    Science.gov (United States)

    Loesche, W J

    1969-11-01

    Anaerobes differ in their sensitivity to oxygen, as two patterns were recognizable in the organisms included in this study. Strict anaerobes were species incapable of agar surface growth at pO(2) levels greater than 0.5%. Species that were found to be strict anaerobes were Treponema macrodentium, Treponema denticola, Treponema oralis n. sp., Clostridium haemolyticum, Selenomonas ruminatium, Butyrivibrio fibrisolvens, Succinivibrio dextrinosolvens, and Lachnospira multiparus. Moderate anaerobes would include those species capable of growth in the presence of oxygen levels as high as 2 to 8%. The moderate anaerobes could be exposed to room atmosphere for 60 to 90 min without appreciable loss of viability. Species considered as moderate anaerobes were Bacteroides fragilis, B. melaninogenicus, B. oralis, Fusobacteria nucleatum, Clostridium novyi type A, and Peptostreptococcus elsdenii. The recognition of at least two general types of anaerobes would seem to have practical import in regard to the primary isolation of anaerobes from source material.

  9. Instrumentation in anaerobic treatment - research and practice

    NARCIS (Netherlands)

    Spanjers, H.; Lier, van J.B.

    2006-01-01

    High rate anaerobic treatment reactors are able to uncouple solids and liquid retention time, resulting in high biomass concentrations. Principal advantages of anaerobic treatment include: energy efficiency, low biomass yield, low nutrient requirement and high volumetric organic loadings. In order

  10. Anaerobic bacterial meningitis in adults.

    Science.gov (United States)

    Lee, Jun-Jun; Lien, Chia-Yi; Chien, Chun-Chih; Huang, Chi-Ren; Tsai, Nai-Wen; Chang, Chiung-Chih; Lu, Cheng-Hsien; Chang, Wen-Neng

    2018-01-22

    Anaerobic infection is a very uncommon condition in adult bacterial meningitis (ABM), and its clinical characteristics have yet to be clarified. We enrolled 540 patients with culture-proven bacterial meningitis during a study period of 30 years (1986-2015), of whom 13 (2.4%) had anaerobic infections. These 13 patients were eight men and five women, aged 22-77 years. Among them, 53.8% (7/13) had a postneurosurgical state as the preceding event, and 79.6% (10/13) had underlying medical conditions including diabetes mellitus, malignancy, liver cirrhosis, cerebral infarct and alcoholism. Nosocomial and mixed infections were found in 15.5% (2/13) and 46.1% (6/13) of the patients, respectively. A total of 14 anaerobic strains were isolated from cerebrospinal fluid specimens, including nine Gram-negative (G(-)) strains: Fusobacterium nucleatum (3), Prevotella species (3) and Bacteroides fragilis (3), and five Gram-positive (G(+)) strains: Propionibacterium acnes (3) and Peptostreptococcus micros (also known as Parvimonas micra) (2). All of the implicated G(+) anaerobic bacteria were susceptible to penicillin, and no multiple drug-resistant strains were found among the implicated G(-) anaerobic bacteria. Despite treatment, 30.8% (4/13) of the patients died. Of the nine survivors, 22.2% (2/9) had a full recovery, while the other 77.8% (7/9) had varying degrees of neurological deficits. Compared with the good outcome group (n = 6, modified Rankin scale (mRS) scores: 0-2), the poor outcome group (n = 7, mRS scores ≧3) had higher incidence of seizure. These results may offer a preliminary view of the clinical characteristics of anaerobic ABM. Copyright © 2018 Elsevier Ltd. All rights reserved.

  11. Arsenic, Anaerobes, and Astrobiology

    Science.gov (United States)

    Stolz, J. F.; Oremland, R. S.; Switzer Blum, J.; Hoeft, S. E.; Baesman, S. M.; Bennett, S.; Miller, L. G.; Kulp, T. R.; Saltikov, C.

    2013-12-01

    Arsenic is an element best known for its highly poisonous nature, so it is not something one would associate with being a well-spring for life. Yet discoveries made over the past two decades have delineated that not only are some microbes resistant to arsenic, but that this element's primary redox states can be exploited to conserve energy and support prokaryotic growth ('arsenotrophy') in the absence of oxygen. Hence, arsenite [As(III)] can serve as an electron donor for chemo- or photo-autotrophy while arsenate [As(V)] will serve as an electron acceptor for chemo-heterotrophs and chemo-autotrophs. The phylogenetic diversity of these microbes is broad, encompassing many individual species from diverse taxonomic groups in the Domain Bacteria, with fewer representatives in the Domain Archaea. Speculation with regard to the evolutionary origins of the key functional genes in anaerobic arsenic transformations (arrA and arxA) and aerobic oxidation (aioB) has led to a disputation as to which gene and function is the most ancient and whether arsenic metabolism extended back into the Archaean. Regardless of its origin, robust arsenic metabolism has been documented in extreme environments that are rich in their arsenic content, such as hot springs and especially hypersaline soda lakes associated with volcanic regions. Searles Lake, CA is an extreme, salt-saturated end member where vigorous arsenic metabolism occurs, but there is no detectable sulfate-reduction or methanogenesis. The latter processes are too weak bio-energetically to survive as compared with arsenotrophy, and are also highly sensitive to the abundance of borate ions present in these locales. These observations have implications with respect to the search for microbial life elsewhere in the Solar System where volcanic-like processes have been operative. Hence, because of the likelihood of encountering dense brines in the regolith of Mars (formed by evapo-concentration) or beneath the ice layers of Europa

  12. Anaerobic bioprocessing of organic wastes.

    Science.gov (United States)

    Verstraete, W; de Beer, D; Pena, M; Lettinga, G; Lens, P

    1996-05-01

    Anaerobic digestion of dissolved, suspended and solid organics has rapidly evolved in the last decades but nevertheless still faces several scientific unknowns. In this review, some fundamentals of bacterial conversions and adhesion are addressed initially. It is argued in the light of ΔG-values of reactions, and in view of the minimum energy quantum per mol, that anaerobic syntrophs must have special survival strategies in order to support their existence: redistributing the available energy between the partners, reduced end-product fermentation reactions and special cell-to-cell physiological interactions. In terms of kinetics, it appears that both reaction rates and residual substrate thresholds are strongly related to minimum ΔG-values. These new fundamental insights open perspectives for efficient design and operation of anaerobic bioprocesses. Subsequently, an overview is given of the current anaerobic biotechnology. For treating wastewaters, a novel and high performance new system has been introduced during the last decade; the upflow anaerobic sludge blanket system (UASB). This reactor concept requires anaerobic consortia to grow in a dense and eco-physiologically well-organized way. The microbial principles of such granular sludge growth are presented. Using a thermodynamic approach, the formation of different types of aggregates is explained. The application of this bioprocess in worldwide wastewater treatment is indicated. Due to the long retention times of the active biomass, the UASB is also suitable for the development of bacterial consortia capable of degrading xenobiotics. Operating granular sludge reactors at high upflow velocities (5-6 m/h) in expanded granular sludge bed (EGSB) systems enlarges the application field to very low strength wastewaters (chemical oxygen demand system to the thermophilic configuration, as the latter permits higher conversion rates and easier sanitation. Integration of ultrafiltration in anaerobic slurry digestion

  13. Molecular genetic studies on obligate anaerobic bacteria

    International Nuclear Information System (INIS)

    Woods, D.R.

    1982-01-01

    Molecular genetic studies on obligate anaerobic bacteria have lagged behind similar studies in aerobes. However, the current interest in biotechnology, the involvement of anaerobes in disease and the emergence of antibioticresistant strains have focused attention on the genetics of anaerobes. This article reviews molecular genetic studies in Bacteroides spp., Clostridium spp. and methanogens. Certain genetic systems in some anaerobes differ from those in aerobes and illustrate the genetic diversity among bacteria

  14. Anaerobic Co-Digestion of the Microalgae Scenedesmus Sp.

    Energy Technology Data Exchange (ETDEWEB)

    Ramos-Suarez, J. L.; Carreras, N.

    2011-06-07

    Microalgae biomass has been widely studied for biogas production over the last years and results show that anaerobic digestion is often limited by the low C/N ratio of this type of biomass. Therefore, codigestion with substrates of high C/N ratio is necessary. The objectives of this study are to set up an experimental method that ease reproducibility and control of anaerobic digestion processes in laboratory conditions and to determine the biodegradability and biogas production potential of the co-digestion process of microalgae Scenedesmus sp. and energy crop Opuntia ficus indica (L.) Miller. Results obtained showed that higher C/N ratios are preferred in order to maximize methane production. Highest methane yield obtained was 0.252m3CH4/Kg VS and degradability expressed as percentage COD reduced is around 30% for the ideal mixture found, made up of 75% O. ficus-indica and 25% Scenedesmus sp. in VS basis. A laboratory setup using MicroOxymax respirometer, after its adaptation to work under anaerobic conditions, can be used for the monitoring of anaerobic digestion processes. Scenedesmus sp. as sole substrate for anaerobic digestion does not give good results due to low C/N ratio. However, when codigesting it with O. ficus-indica methane production is satisfactory. Best mixture was made up of 75% O. ficus-indica and 25% Scenedesmus sp. in VS basis. (Author)

  15. Multiphase modeling of settling and suspension in anaerobic digester

    International Nuclear Information System (INIS)

    Yu, Liang; Ma, Jingwei; Frear, Craig; Zhao, Quanbao; Dillon, Robert; Li, Xiujin; Chen, Shulin

    2013-01-01

    Highlights: • Develop biowaste fluid dynamics for collision, aggregation and breakup of clusters. • Explore the mechanisms of settling and suspension in anaerobic digester. • Biowaste particles tended to have fluid properties. • Aided with CFD simulation, the scale-up effect was reduced. - Abstract: Effective suspension and settling are critical for controlling biomass retention in a bioreactor. In this paper, a multi-fluid model with kinetic theory of granular flow (KTGF) was established to describe these phenomena in the biowaste particles flow in anaerobic digesters. Solid retention time (SRT) was added as a parameter into anaerobic digestion No.1 (ADM1) model to evaluate its effect on the biogas productivity. The model was experimentally validated in a liquid–gas–solid column reactor with gas and solid volume fraction and granular temperature as the major variables. The wastewater residence time distribution was also determined through modeling and measurement to evaluate the mixing pattern in the pilot column reactor. The effect of restitution coefficient on flow behavior of biowaste particles, particles settling and suspension were predicted. Settling and suspension processes of anaerobic digesters were simulated for lab and pilot-scale reactors with comparisons made for reactor configuration and geometry model, respectively. This study demonstrated that the multi-fluid model with KTGF could provide better understanding of impact of suspension and settling upon retaining biomass particles in the anaerobic digesters

  16. Anaerobic Benzene Oxidation via Phenol in Geobacter metallireducens

    Science.gov (United States)

    Tremblay, Pier-Luc; Chaurasia, Akhilesh Kumar; Smith, Jessica A.; Bain, Timothy S.; Lovley, Derek R.

    2013-01-01

    Anaerobic activation of benzene is expected to represent a novel biochemistry of environmental significance. Therefore, benzene metabolism was investigated in Geobacter metallireducens, the only genetically tractable organism known to anaerobically degrade benzene. Trace amounts (benzene to carbon dioxide with the reduction of Fe(III). Phenol was not detected in cell-free controls or in Fe(II)- and benzene-containing cultures of Geobacter sulfurreducens, a Geobacter species that cannot metabolize benzene. The phenol produced in G. metallireducens cultures was labeled with 18O during growth in H218O, as expected for anaerobic conversion of benzene to phenol. Analysis of whole-genome gene expression patterns indicated that genes for phenol metabolism were upregulated during growth on benzene but that genes for benzoate or toluene metabolism were not, further suggesting that phenol was an intermediate in benzene metabolism. Deletion of the genes for PpsA or PpcB, subunits of two enzymes specifically required for the metabolism of phenol, removed the capacity for benzene metabolism. These results demonstrate that benzene hydroxylation to phenol is an alternative to carboxylation for anaerobic benzene activation and suggest that this may be an important metabolic route for benzene removal in petroleum-contaminated groundwaters, in which Geobacter species are considered to play an important role in anaerobic benzene degradation. PMID:24096430

  17. Viscosity evolution of anaerobic granular sludge

    NARCIS (Netherlands)

    Pevere, A.; Guibaud, G.; Hullebusch, van E.D.; Lens, P.N.L.; Baudu, M.

    2006-01-01

    The evolution of the apparent viscosity at steady shear rate of sieved anaerobic granular sludge (20¿315 ¿m diameter) sampled from different full-scale anaerobic reactors was recorded using rotation tests. The ¿limit viscosity¿ of sieved anaerobic granular sludge was determined from the apparent

  18. Kinetics and modeling of anaerobic digestion process

    DEFF Research Database (Denmark)

    Gavala, Hariklia N.; Angelidaki, Irini; Ahring, Birgitte Kiær

    2003-01-01

    Anaerobic digestion modeling started in the early 1970s when the need for design and efficient operation of anaerobic systems became evident. At that time not only was the knowledge about the complex process of anaerobic digestion inadequate but also there were computational limitations. Thus...

  19. 21 CFR 866.2120 - Anaerobic chamber.

    Science.gov (United States)

    2010-04-01

    ... and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Microbiology Devices § 866.2120 Anaerobic chamber. (a) Identification. An anaerobic chamber is a device intended for medical purposes to maintain an anaerobic (oxygen...

  20. Anaerobic N mineralization in paddy soils in relation to inundation management, physicochemical soil fractions, mineralogy and soil properties

    Science.gov (United States)

    Sleutel, Steven; Kader, Mohammed Abdul; Ara Begum, Shamim; De Neve, Stefaan

    2013-04-01

    Anaerobic N mineralization measured from (saturated) repacked soil cores from 25 paddy fields in Bangladesh and was previously found to negatively related to soil N content on a relative basis. This suggests that other factors like soil organic matter (SOM) quality or abiotic factors instead control the anaerobic N mineralization process. We therefore assessed different physical and chemical fractions of SOM, management factors and various soil properties as predictors for the net anaerobic N mineralization. 1° First, we assessed routinely analyzed soil parameters (soil N and soil organic carbon, texture, pH, oxalate- and pyrophosphate-extractable Fe, Al, and Mn, fixed-NH4 content). We found no significant influences of neither soil mineralogy nor the annual length of inundation on soil N mineralization. The anaerobic N mineralization correlated positively with Na-pyrophosphate-extractable Fe and negatively with pH (both at Presistant OM fraction, followed by extraction of mineral bound OM with 10%HF thereby isolating the HF-resistant OM. None of the physicochemical SOM fractions were found useful predictors anaerobic N mineralization. The linkage between these chemical soil N fractions and N supplying processes actually occurring in the soil thus appears to be weak. Regardless, we hypothesize that variation in strength of N-mineral and N-OM linkages is likely to explain variation in bio-availability of organic N and proneness to mineralization. Yet, in order to separate kinetically different soil N fractions we then postulated that an alternative approach would be required, which instead isolates soil N fractions on the basis of bonding strength. In this respect bonding strength should be seen as opposite of proneness to dissolution of released N into water, the habitat of soil microorganisms mediating soil N mineralization. We hypothesize that soil N extracted by water at increasing temperatures would reflect such N fractions with increasing bonding strength, in

  1. Risk factors for syphilis in women: case-control study.

    Science.gov (United States)

    Macêdo, Vilma Costa de; Lira, Pedro Israel Cabral de; Frias, Paulo Germano de; Romaguera, Luciana Maria Delgado; Caires, Silvana de Fátima Ferreira; Ximenes, Ricardo Arraes de Alencar

    2017-08-17

    To determine the sociodemographic, behavioral, and health care factors related to the occurrence of syphilis in women treated at public maternity hospitals. This is a case-control study (239 cases and 322 controls) with women admitted to seven maternity hospitals in the municipality of Recife, Brazil, from July 2013 to July 2014. Eligible women were recruited after the result of the VDRL (Venereal Disease Research Laboratory) under any titration. The selection of cases and controls was based on the result of the serology for syphilis using ELISA (enzyme-linked immunosorbent assay). The independent variables were grouped into: sociodemographic, behavioral, clinical and obstetric history, and health care in prenatal care and maternity hospital. Information was obtained by interview, during hospitalization, with the application of a questionnaire. Odds ratios and 95% confidence intervals were estimated using logistic regression to identify the predicting factors of the variable to be explained. The logistic regression analysis identified as determinant factors for gestational syphilis: education level of incomplete basic education or illiterate (OR = 2.02), lack of access to telephone (OR = 2.4), catholic religion (OR = 1.70 ), four or more pregnancies (OR = 2.2), three or more sexual partners in the last year (OR = 3.1), use of illicit drugs before the age of 18 (OR = 3.0), and use of illicit drugs by the current partner (OR = 1.7). Only one to three prenatal appointments (OR = 3.5) and a previous history of sexually transmitted infection (OR = 9.7) were also identified as determinant factors. Sociodemographic, behavioral, and health care factors are associated with the occurrence of syphilis in women and should be taken into account in the elaboration of universal strategies aimed at the prevention and control of syphilis, but with a focus on situations of greater vulnerability. Determinar os fatores sociodemográficos, comportamentais e de assistência à sa

  2. Revisiting factors controlling methane emissions from high-Arctic tundra

    DEFF Research Database (Denmark)

    Mastepanov, M.; Sigsgaard, C.; Tagesson, T.

    2013-01-01

    The northern latitudes are experiencing disproportionate warming relative to the mid-latitudes, and there is growing concern about feedbacks between this warming and methane production and release from high-latitude soils. Studies of methane emissions carried out in the Arctic, particularly those....... The measurements show clear seasonal dynamics in methane emission. The start of the growing season and the increase in CH4 fluxes were strongly related to the date of snowmelt. Within each particular growing season, CH4 fluxes were highly correlated with the soil temperature (R-2 > 0.75), which is probably...... controlling methane emission, i.e. temperature and water table position. Late in the growing season CH4 emissions were found to be very similar between the study years (except the extremely dry 2010) despite large differences in climatic factors (temperature and water table). Late-season bursts of CH4...

  3. Ets transcription factor GABP controls T cell homeostasis and immunity.

    Science.gov (United States)

    Luo, Chong T; Osmanbeyoglu, Hatice U; Do, Mytrang H; Bivona, Michael R; Toure, Ahmed; Kang, Davina; Xie, Yuchen; Leslie, Christina S; Li, Ming O

    2017-10-20

    Peripheral T cells are maintained in the absence of vigorous stimuli, and respond to antigenic stimulation by initiating cell cycle progression and functional differentiation. Here we show that depletion of the Ets family transcription factor GA-binding protein (GABP) in T cells impairs T-cell homeostasis. In addition, GABP is critically required for antigen-stimulated T-cell responses in vitro and in vivo. Transcriptome and genome-wide GABP-binding site analyses identify GABP direct targets encoding proteins involved in cellular redox balance and DNA replication, including the Mcm replicative helicases. These findings show that GABP has a nonredundant role in the control of T-cell homeostasis and immunity.

  4. Phase detector for three-phase power factor controller

    Science.gov (United States)

    Nola, F. J. (Inventor)

    1984-01-01

    A phase detector for the three phase power factor controller (PFC) is described. The phase detector for each phase includes an operational amplifier which senses the current phase angle for that phase by sensing the voltage across the phase thyristor. Common mode rejection is achieved by providing positive feedback between the input and output of the voltage sensing operational amplifier. this feedback preferably comprises a resistor connected between the output and input of the operational amplifier. The novelty of the invention resides in providing positive feedback such that switching of the operational amplifier is synchronized with switching of the voltage across the thyristor. The invention provides a solution to problems associated with high common mode voltage and enables use of lower cost components than would be required by other approaches.

  5. Allometric Scaling of Wingate Anaerobic Power Test Scores in Women

    Science.gov (United States)

    Hetzler, Ronald K.; Stickley, Christopher D.; Kimura, Iris F.

    2011-01-01

    In this study, we developed allometric exponents for scaling Wingate anaerobic test (WAnT) power data that are reflective in controlling for body mass (BM) and lean body mass (LBM) and established a normative WAnT data set for college-age women. One hundred women completed a standard WAnT. Allometric exponents and percentile ranks for peak (PP)…

  6. Anaerobic oxidation of methane in coastal sediment from Guishan ...

    Indian Academy of Sciences (India)

    Pearl River Estuary),. South China Sea, were ... profiles of the pore-water support the existence of anaerobic oxidation of methane (AOM), which is mainly controlled by the ...... area; Environmental Microbiology 4 296–305. Niewöhner C, Hensen C, ...

  7. Transcription factor PIF4 controls the thermosensory activation of flowering

    KAUST Repository

    Kumar, S. Vinod

    2012-03-21

    Plant growth and development are strongly affected by small differences in temperature. Current climate change has already altered global plant phenology and distribution, and projected increases in temperature pose a significant challenge to agriculture. Despite the important role of temperature on plant development, the underlying pathways are unknown. It has previously been shown that thermal acceleration of flowering is dependent on the florigen, FLOWERING LOCUS T (FT). How this occurs is, however, not understood, because the major pathway known to upregulate FT, the photoperiod pathway, is not required for thermal acceleration of flowering. Here we demonstrate a direct mechanism by which increasing temperature causes the bHLH transcription factor PHYTOCHROME INTERACTING FACTOR4 (PIF4) to activate FT. Our findings provide a new understanding of how plants control their timing of reproduction in response to temperature. Flowering time is an important trait in crops as well as affecting the life cycles of pollinator species. A molecular understanding of how temperature affects flowering will be important for mitigating the effects of climate change. © 2012 Macmillan Publishers Limited. All rights reserved.

  8. Perspectives of Anaerobic Soil Disinfestation

    NARCIS (Netherlands)

    Lamers, J.G.; Runia, W.T.; Molendijk, L.P.G.; Bleeker, P.O.

    2010-01-01

    Biological soil disinfestation is an environmentally friendly method to disinfest soil. From now on we refer to it as anaerobic soil disinfestation (ASD). With ASD a green manure crop (40 t/ha) is homogeneously incorporated into the topsoil (0-30 cm) after which the field is lightly compacted and

  9. Deciphering factors controlling groundwater arsenic spatial variability in Bangladesh

    Science.gov (United States)

    Tan, Z.; Yang, Q.; Zheng, C.; Zheng, Y.

    2017-12-01

    Elevated concentrations of geogenic arsenic in groundwater have been found in many countries to exceed 10 μg/L, the WHO's guideline value for drinking water. A common yet unexplained characteristic of groundwater arsenic spatial distribution is the extensive variability at various spatial scales. This study investigates factors influencing the spatial variability of groundwater arsenic in Bangladesh to improve the accuracy of models predicting arsenic exceedance rate spatially. A novel boosted regression tree method is used to establish a weak-learning ensemble model, which is compared to a linear model using a conventional stepwise logistic regression method. The boosted regression tree models offer the advantage of parametric interaction when big datasets are analyzed in comparison to the logistic regression. The point data set (n=3,538) of groundwater hydrochemistry with 19 parameters was obtained by the British Geological Survey in 2001. The spatial data sets of geological parameters (n=13) were from the Consortium for Spatial Information, Technical University of Denmark, University of East Anglia and the FAO, while the soil parameters (n=42) were from the Harmonized World Soil Database. The aforementioned parameters were regressed to categorical groundwater arsenic concentrations below or above three thresholds: 5 μg/L, 10 μg/L and 50 μg/L to identify respective controlling factors. Boosted regression tree method outperformed logistic regression methods in all three threshold levels in terms of accuracy, specificity and sensitivity, resulting in an improvement of spatial distribution map of probability of groundwater arsenic exceeding all three thresholds when compared to disjunctive-kriging interpolated spatial arsenic map using the same groundwater arsenic dataset. Boosted regression tree models also show that the most important controlling factors of groundwater arsenic distribution include groundwater iron content and well depth for all three

  10. Power factor improvement in three-phase networks with unbalanced inductive loads using the Roederstein ESTAmat RPR power factor controller

    Science.gov (United States)

    Diniş, C. M.; Cunţan, C. D.; Rob, R. O. S.; Popa, G. N.

    2018-01-01

    The paper presents the analysis of a power factor with capacitors banks, without series coils, used for improving power factor for a three-phase and single-phase inductive loads. In the experimental measurements, to improve the power factor, the Roederstein ESTAmat RPR power factor controller can command up to twelve capacitors banks, while experimenting using only six capacitors banks. Six delta capacitors banks with approximately equal reactive powers were used for experimentation. The experimental measurements were carried out with a three-phase power quality analyser which worked in three cases: a case without a controller with all capacitors banks permanently parallel connected with network, and two other cases with power factor controller (one with setting power factor at 0.92 and the other one at 1). When performing experiments with the power factor controller, a current transformer was used to measure the current on one phase (at a more charged or less loaded phase).

  11. Factors Controlling Nitrogen Fluxes in Groundwater in Agricultural Areas

    Science.gov (United States)

    Liao, L.; Green, C. T.; Bekins, B. A.; Bohlke, J. K.

    2010-12-01

    Predictions of effects of land use changes on water quality require identification of the relative importance of geochemical and hydrologic factors. To understand the factors controlling the transport of nitrogen in groundwater, vertical fluxes of water and solutes were estimated for 13 aquifers in agricultural areas located in California, Iowa, Maryland, Minnesota, Mississippi, Nebraska, North Carolina, Texas, and Wisconsin. The aquifers are overlain by unsaturated zones with thicknesses ranging from 2.5 to 100 m. Precipitation ranges from 19 to 132 cm/yr and irrigation ranges from 0 to 120 cm/yr. Main crop types include corn, soybeans, forage, wheat, and cotton. A 1-dimensional mathematical model was developed to estimate vertical N transport in response to N inputs on the land surface from chemical fertilizer, manure and atmospheric deposition. Simulated vertical profiles of O2, NO3-, N2 from denitrification, Cl- and atmospheric age tracers were matched to observations by adjusting parameters for recharge rate, unsaturated zone travel time, N leaching ratio (defined as leaching fraction of N reaching water table of N input at land surface), Cl- leaching ratio, O2 reduction rate and denitrification rate. Results indicated that vertical NO3 fluxes below the water table were affected by both geochemical and physical factors. High vertical NO3 fluxes below the water table are associated with high N input at the land surface. Values of Cl- leaching ratios were less than 1 (0.42 to 1) likely as a result of runoff and exported harvested crops. N leaching ratios were lower (0.1 to 0.6), consistent with additional N losses such as denitrification and volatilization. The sites with high leaching ratios for both N and Cl tended to be those with high recharge rates and low ET loss, defined as the fraction of applied water lost to ET. Modeled zero-order denitrification rates in the saturated zone varied within an order of magnitude with a maximum rate of 1.6 mg

  12. Redundancy of anaerobic digestion microbiomes during disturbances by the antibiotic monensin.

    Science.gov (United States)

    Spirito, Catherine M; Daly, Sarah E; Werner, Jeffrey J; Angenent, Largus T

    2018-03-02

    The antibiotic monensin is fed to dairy cows to increase milk production efficiency. A fraction of this monensin is excreted into the cow manure. Previous studies have found that cow manure containing monensin can negatively impact the performance of anaerobic digesters, especially upon first introduction. Few studies have examined whether the anaerobic digester microbiome can adapt to monensin during the operating time. Here, we conducted a long-term, time-series study of four lab-scale anaerobic digesters fed with cow manure. We examined changes in both the microbiome composition and function of the anaerobic digesters when subjected to the dairy antibiotic monensin. In our digesters, monensin was not rapidly degraded at anaerobic conditions. The two anaerobic digesters that were subjected to manure from monensin feed-dosed cows exhibited relatively small changes in microbiome composition and function due to relatively low monensin concentrations. At higher concentrations of monensin, which we dosed directly to control manure (from dairy cows without monensin), we observed major changes in the microbiome composition and function of two anaerobic digesters. Rapid introduction of monensin to one of these anaerobic digesters led to the impairment of methane production. Conversely, more gradual addition of the same concentrations of monensin to the other anaerobic digester led to the adaptation of the anaerobic digester microbiome to the relatively high monensin concentration. A member of the candidate OP11 (Microgenomates) phylum arose in this anaerobic digester and appeared to be redundant with certain Bacteroidetes phylum members, which had previously been dominating. IMPORTANCE Monensin is a common antibiotic given to dairy cows in the United States and is partly excreted with dairy manure. An improved understanding of how monensin affects the anaerobic digester microbiome composition and function is important to prevent process failure for farm-based anaerobic

  13. Directed influence on anaerobic energy supply systems of qualified free style wrestlers

    Directory of Open Access Journals (Sweden)

    M.G. Sybil

    2015-07-01

    Full Text Available Purpose: to experimentally prove effectiveness of directed influence on anaerobic energy supply systems of free style wrestlers, considering individual characteristics of their bio energetic. Material: in this article the data of laboratory bicycle stress test «Vita maxima» and results of special control testing have been presented. 40 sportsmen participated in the experiment. Results: individual characteristics of dominating type of anaerobic energy supply have been determined. Statistically confident difference between development of lactate and a-lactate anaerobic energetic components were found. By the data of bio-chemical indicators’ changes the authors observed increase of adenosine triphosphate (glycolytic or creatine-phosphate in some, weaker developed mechanisms of anaerobic re-synthesis. Ways of influence on anaerobic energy supply systems, considering individual characteristics of dominating of different components (lactate or a-lactate have been found. Conclusions: it is recommended to take in consideration individual dominating type of energy supply.

  14. Anaerobic metabolism of pentachloronitrobenzene (PCNB) in soils

    International Nuclear Information System (INIS)

    Murthy, N.B.K.

    1980-01-01

    A manifold assembly system was used to study the metabolism of 14 C labelled PCNB in flooded and moist anaerobic soils. Soil respiration was generally enhanced by PCNB. More CO 2 was produced in moist anaerobic than in flooded anaerobic soil. Flooding reduced the volatilization of pesticide. The extractable radioactivity from the soil was same (70%) in the treatments. Nevertheless, differences were observed in distribution of PCNB and its degradation products. Pentachloroaniline (PCA) was the principal degradation product. Pentachlorothioanisole (PCTA) was more abundant in moist anaerobic than in flooded anaerobic soil. Pentachlorophenol (PCP) was formed from PCNB in anaerobic soil. Degradation of PCA, PCTA and PCP were further studied in soil and a possible pathway for anaerobic degradation of PCNB was proposed. (author)

  15. Determining anaerobic capacity in sporting activities.

    Science.gov (United States)

    Noordhof, Dionne A; Skiba, Philip F; de Koning, Jos J

    2013-09-01

    Anaerobic capacity/anaerobically attributable power is an important parameter for athletic performance, not only for short high-intensity activities but also for breakaway efforts and end spurts during endurance events. Unlike aerobic capacity, anaerobic capacity cannot be easily quantified. The 3 most commonly used methodologies to quantify anaerobic capacity are the maximal accumulated oxygen deficit method, the critical power concept, and the gross efficiency method. This review describes these methods, evaluates if they result in similar estimates of anaerobic capacity, and highlights how anaerobic capacity is used during sporting activities. All 3 methods have their own strengths and weaknesses and result in more or less similar estimates of anaerobic capacity but cannot be used interchangeably. The method of choice depends on the research question or practical goal.

  16. Anaerobic digestion of wastewater generated from the hydrothermal liquefaction of Spirulina: Toxicity assessment and minimization

    International Nuclear Information System (INIS)

    Zheng, Mingxia; Schideman, Lance C.; Tommaso, Giovana; Chen, Wan-Ting; Zhou, Yan; Nair, Ken; Qian, Wanyi; Zhang, Yuanhui; Wang, Kaijun

    2017-01-01

    Highlights: • Nutrient reuse and energy recovery of HTL-WW are realized. • Anaerobic digestion of HTL-WW is vital to the sustainability of algal biocrude. • An anaerobic toxicity assay was conducted to evaluate HTL-WW toxicity. • The presence of adsorbents and biofilms effectively minimized inhibition. • A portion of the toxic compounds could be removed after anaerobic digestion. - Abstract: Previous studies demonstrate anaerobic digestion of hydrothermal liquefaction wastewater (HTL-WW) is significant to the sustainability of algal biofuel development for nutrient reuse and residual energy recovery. HTL-WW contains substantial amounts of residual energy but is toxic to anaerobes. With 6% HTL-WW converted from cyanobacteria (e.g. Spirulina), anaerobes were 50% inhibited. In this study, zeolite, granular activated carbon (GAC), and polyurethane matrices (PM) were used during a two-round anaerobic batch test with HTL-WW, and in the presence of each material, the total methane yields were 136 mL/g COD, 169 mL/g COD, and 168 mL/g COD, respectively, being 11%, 37% and 36% higher than the control. GAC was considered promising due to its highest methane yield of 124 mL/g COD at the second feeding, indicating a good recovery of adsorption capacity. The observed low methane production rates indicated the necessity for anaerobic process optimization. The physicochemical analysis of the digestates demonstrated that most of the compounds identified in the HTL-WW were degraded.

  17. Anaerobic degradation of nonylphenol in sludge.

    Science.gov (United States)

    Chang, B V; Chiang, F; Yuan, S Y

    2005-06-01

    We investigated the effects of various factors on the anaerobic degradation of nonylphenol (NP) in sludge. NP (5 mg/l) anaerobic degradation rate constants were 0.029 1/day for sewage sludge and 0.019l/day for petrochemical sludge, and half-lives were 23.9 days and 36.5 days respectively. The optimal pH for NP degradation in sludge was 7 and the degradation rate was enhanced when the temperature was increased. The addition of yeast extract (5 mg/l) or surfactants such as brij 30 or brij 35 (55 or 91 microM) also enhanced the NP degradation rate. The addition of aluminum sulfate (200 mg/l) inhibited the NP degradation rate within 84 days of incubation. The high-to-low order of degradation rates was: sulfate-reducing conditions>methanogenic conditions>nitrate-reducing conditions. Sulfate-reducing bacteria, methanogen, and eubacteria are involved in the degradation of NP, sulfate-reducing bacteria being a major component of sludge.

  18. Risk Factors Of Low Birth Weight; Case-Control Study

    Directory of Open Access Journals (Sweden)

    Özgür Önal

    2017-06-01

    Full Text Available Low birth weight (LBW (defined as a birth weight of less than 2500 grams is associated with fetal and neonatal morbidity and mortality, impaired cognitive development, and the advent of chronic diseases in later life. The global incidence of LBW is around 15,5%. The aim of this study was to identify risk factors for low birthweight in the centre of Denizli province. A case-control study was carried out and mothers of 295 newborns with birthweight between 1500-2499 g (cases and 302 newborns with birthweight between 2500-4000 g (controls were analyzed. The questionnare was applied to women using face to face technics between July,2009 and June,2010 . The questionnare included birth weight and birth lenght of newborn, the date of last pregnacy and type of last delivery, profile of mother, anthropometric measures, life styles, habits, addictions, sociodemographic and socioeconomic characteristics of mother and father of newborn. Analysis included frequency and percent distributions, means, standart deviations. In group comparisions for categorical variable, chi square test and odds ratio (OR was used. Logistic regression model was performed for some selected risk factors. P<0.05 was considered statistically significant. Statistical Package for Social Sciences (SPSS program, Version 10 was used for data entry and analysis. When backward logistic regression model was performed for some selected factors in relation to low birth weight, there was a positive relationship between multiple pregnancy [OR(95%CI 18.50 (8.54, 40.39], BMI lower than 20 kg/m2 of mother before pregnancy andemployment status [OR(95%CI 1.98 (1.23, 3.19], weight gain of 7 kg and under during pregnanacy [OR(95%CI 2.49 (1.56, 3.96], a history of giving birth to low birth weight infant [OR(95%CI 3.44 (1.69, 7.02], first- degree and second- degree relative’s histories of giving birth to low birth weight infant [OR(95%CI 4.28 (2.61, 6.94], X- ray exposure in the three months before and

  19. The Expression of BAFF Is Controlled by IRF Transcription Factors.

    Science.gov (United States)

    Sjöstrand, Maria; Johansson, Alina; Aqrawi, Lara; Olsson, Tomas; Wahren-Herlenius, Marie; Espinosa, Alexander

    2016-01-01

    Patients with systemic lupus erythematosus (SLE) and primary Sjögren's syndrome (pSS) are typically characterized by the presence of autoantibodies and an IFN-signature. The strength of the IFN-signature positively correlates with disease severity, suggesting that type I IFNs are active players in these diseases. BAFF is a cytokine critical for development and proper selection of B cells, and the targeting of BAFF has emerged as a successful treatment strategy of SLE. Previous reports have suggested that BAFF expression is directly induced by type I IFNs, but the precise mechanism for this remains unknown. In this article, we demonstrate that BAFF is a bona fide ISG and that IFN regulatory factors (IRFs) control the expression of BAFF. We identify IRF1 and IRF2 as positive regulators of BAFF transcription and IRF4 and IRF8 as potent repressors; in addition, we have mapped the precise binding site for these factors in the BAFF promoter. IFN-β injections induced BAFF expression mainly in neutrophils and monocytes, and BAFF expression in neutrophils from pSS patients strongly correlated with the strength of the IFN-signature. In summary, we show that BAFF expression is directly induced by type I IFNs via IRF1 and IRF2, whereas IRF4 and IRF8 are negative regulators of BAFF expression. These data suggest that type I IFN blockade in SLE and pSS patients will lead to downregulation of BAFF and a consequential reduction of autoreactive B cell clones and autoantibodies. Copyright © 2015 by The American Association of Immunologists, Inc.

  20. Design of automatic power factor control system | Yanev | Botswana ...

    African Journals Online (AJOL)

    Maintenance of the proper power factor is a very important matter for the industry and for the economy of any country. A study of the power factor values for a number of industrial plants in Botswana shows that they operate at power-factors lower than the optimal values. If a plant power factor is different from its optimal value, ...

  1. 75 FR 5536 - Pipeline Safety: Control Room Management/Human Factors, Correction

    Science.gov (United States)

    2010-02-03

    ...: Control Room Management/Human Factors, Correction AGENCY: Pipeline and Hazardous Materials Safety... 63310) entitled ``Pipeline Safety: Control Room Management/Human Factors.'' This final rule contained... DEPARTMENT OF TRANSPORTATION Pipeline and Hazardous Materials Safety Administration 49 CFR Parts...

  2. A modified oxic-settling-anaerobic activated sludge process using gravity thickening for excess sludge reduction

    Science.gov (United States)

    Wang, Jun; Li, Shi-Yu; Jiang, Feng; Wu, Ke; Liu, Guang-Li; Lu, Hui; Chen, Guang-Hao

    2015-01-01

    Oxic-settling-anaerobic process (OSA) was known as a cost-effective way to reduce the excess sludge production with simple upgrade of conventional activated sludge process (CAS). A low oxidation-reduction potential (ORP) level was the key factor to sludge decay and lysis in the sludge holding tank of the OSA process. However, the ORP control with nitrogen purge or chemical dosing in the OSA process would induce extra expense and complicate the operation. Hence, in this study, a sludge holding tank using gravity thickening was applied to OSA process to reduce the excess sludge production without any ORP control. Results showed that the modified OSA process not only reduced the excess sludge production effectively but also improved the sludge settleability without affected the treatment capacity. The reduction of the excess sludge production in the modified OSA process resulted from interactions among lots of factors. The key element of the process was the gravity thickening sludge holding tank. PMID:26350761

  3. Hydroponic system for the treatment of anaerobic liquid.

    Science.gov (United States)

    Krishnasamy, K; Nair, J; Bäuml, B

    2012-01-01

    The effluent from anaerobic digestion process has high concentrations of nutrients, particularly nitrogen, essential for plant growth but is not suitable for direct disposal or application due to high chemical oxygen demand (COD), low dissolved oxygen (DO), odour issues and is potentially phytotoxic. This research explored the optimum conditions of anaerobic effluent for application and dilutions of the effluent required to obtain better plant growth. A small-scale hydroponic system was constructed in a glasshouse to test different concentrations of anaerobic effluent against a commercial hydroponic medium as the control for the growth of silverbeet. It was found that the survival of silverbeet was negatively affected at 50% concentration due to low DO and NH(4) toxicity. The concentration of 20% anaerobic liquid was found to be the most efficient with highest foliage yield and plant growth. The hydroponic system with 20% concentrated effluent had better utilisation of nutrients for plant growth and a COD reduction of 95% was achieved during the 50-day growth period. This preliminary evaluation revealed that the growth and development of silverbeet was significantly lower in anaerobic effluent compared with a commercial hydroponic plant growth solution. The nutrient quality of anaerobic effluent could be highly variable with the process and the waste material used and dilution may depend on the nutrient content of the effluent. It is recommended that, a pre-treatment of the effluent to increase DO and reduce ammonium content is required before plant application, and simple dilution by itself is not suitable for optimum plant growth in a hydroponic system.

  4. Implementation of online volatile fatty acids sensor for control and optimization of anaerobic process for low cost biogas production from manure. Project report

    Energy Technology Data Exchange (ETDEWEB)

    Boe, K.; Angelidaki, I.

    2010-10-15

    Proper monitoring and control can improve process stability and enhance process performance for better economy of the biogas plants. Volatile fatty acid (VFA) is the most widely recognized as a direct, relevant measure of stability. Classic on-line measurement of individual VFA is based on filtration, which suffers from fouling when applied with manure slurries. A VFA sensor developed at DTU Environment, based on headspace chromatography technique could avoid the problems from particulate matters. In this work, the sensor had been implemented for online monitoring of the lab-scale and the pilot-scale manure digester. The industrial prototype of the VFA sensor and sample acquisition system has been constructed and implemented at a pilot scale biogas plant, located at Lundtofte, DTU. The VFA sensor has shown very satisfying results in terms of sensitivity and reliability for monitoring the biogas process. Moreover, the online VFA and biogas registration data were used as process indicators for automatic control of the biogas reactor. The results from control experiments confirmed that the combination of biogas production, total VFA concentration and propionate concentration could effectively reflect the dynamic state of the process which was very crucial for automatic control. Due to the standardized analyzing condition (pH<2, temperature>70 deg. C), the sensor responses were not affected by the manure composition (TS, VS or the addition of extra organics), which made these results representative for implementing in the full-scale biogas plant where some industrial organic wastes were added to increase the biogas production. During the project period, the sensor design and construction had been modified and tested several times to improve the robustness. However, the implementation of the sensor in full-scale biogas plant would need some further development such as improvement of mechanical design and further up-scaling depending on the dry solid content in the

  5. Effects of aerobic and anaerobic exercise on spatial learning ability in hypothyroid rats: a pilot study.

    Science.gov (United States)

    Park, Sung-Hyun; Song, MinYoung

    2016-12-01

    [Purpose] This pilot study analyzed the degradation of spatial learning ability caused by hypothyroidism using aerobic and anaerobic exercise. [Subjects and Methods] The experiments were performed on 11, four-week-old male Sprague-Dawley rats. Hypothyroidism-induced rats receiving propylthiouracil (PTU) treatment were divided into aerobic exercise, anaerobic exercise, and control groups. Each group performed exercise and rest for four weeks. Changes in lethargy, memory deterioration, and thyroid function were measured in each group by blood analysis and open field and Morris water maze tests. [Results] After four weeks, blood analysis revealed that the thyroid hormone levels had returned to normal in the aerobic exercise, anaerobic exercise, and control groups, whereas the open field and Morris water maze tests showed that the aerobic and anaerobic exercise groups had faster recovery compared to that of the control group. In addition, comparison of aerobic and anaerobic groups showed that the anaerobic exercise group had faster recovery compared to that of the aerobic group. [Conclusion] The findings of this study suggest that exercise helped to improve lethargy and deteriorated spatial learning ability caused by hypothyroidism and to recover function in rats. Anaerobic exercise was more beneficial than aerobic exercise in alleviating symptoms.

  6. Factors controlling crystallization of miserite glass-ceramic.

    Science.gov (United States)

    Muhammed, Fenik K; Moorehead, Robert; van Noort, Richard; Pollington, Sarah

    2015-12-01

    The purpose of this study was to investigate a range of variables affecting the synthesis of a miserite glass-ceramic (GC). Miserite glass was synthesized by the melt quench technique. The crystallization kinetics of the glass were determined using Differential Thermal Analysis (DTA). The glasses were ground with dry ball-milling and then sieved to different particle sizes prior to sintering. These particle sizes were submitted to heat treatment regimes in a high temperature furnace to form the GC. The crystal phases of the GC were analyzed by X-ray diffraction (XRD). Scanning electron microscopy (SEM) was used to examine the microstructure of the cerammed glass. XRD analysis confirmed that the predominant crystalline phase of the GC was miserite along with a minor crystalline phase of cristobalite only when the particle size is <20 μm and the heat treatment at 1000°C was carried out for 4h and slowly cooled at the furnace rate. For larger particle sizes and faster cooling rates, a pseudowollastonite crystalline phase was produced. Short sintering times produced either a pseudowollastonite or xonotolite crystalline phase. The current study has shown that particle size and heat treatment schedules are major factors in controlling the synthesis of miserite GC. Copyright © 2015 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  7. The Effect of Concurrent Aerobic and Anaerobic Exercise on Stress, Anxiety, Depressive Symptoms, and Blood Pressure in Renal Transplant Female Patients: A Randomized Control Trial

    Directory of Open Access Journals (Sweden)

    Elham Shakoor

    2016-10-01

    Full Text Available Background: Prevalence of stress, anxiety, depressive symptoms, and high blood pressure are known to be important issues among renal transplant patients. Objective: The main purpose of this study was to evaluate the effect of selected exercises on blood pressure, stress, anxiety, depressive symptoms, and blood pressure among renal transplant patients. Method: Thirty two women patients (aged, 20-50 years with 2 to 3 years post renal transplantation history were voluntarily and objectively recruited. Participants were randomly divided into two groups, exercise (n=16 and control (n=16. The exercise group performed 10 weeks of exercise 3 days per week, and for 60-90 minutes per session. The control group involved no exercise. The DASS21 questionnaire was used to collect psychological data, and blood pressure was measured before and after 10 weeks of exercise. Data analysis was conducted using dependent and independent t-tests. Results: Concurrent exercise significantly reduced anxiety, stress, depressive symptoms, and systolic blood pressure in the exercise group only (p=0.000. Conclusion: Ten weeks of low-intensity exercise can be an effective measure to improve the stress, anxiety, depressive symptoms, and blood pressure in renal transplant patients. Our results suggest that a regular pattern of selected exercises can be effective on stress, anxiety, depressive symptoms, and blood pressure and may be beneficial for renal transplant patients. Keywords: Selected exercise, Stress, Anxiety, Depressive symptoms, Renal transplant

  8. Leveraging rural energy investment for parasitic disease control: schistosome ova inactivation and energy co-benefits of anaerobic digesters in rural China.

    Directory of Open Access Journals (Sweden)

    Justin Remais

    Full Text Available Cooking and heating remain the most energy intensive activities among the world's poor, and thus improved access to clean energies for these tasks has been highlighted as a key requirement of attaining the major objectives of the UN Millennium Development Goals. A move towards clean energy technologies such as biogas systems (which produce methane from human and animal waste has the potential to provide immediate benefits for the control of neglected tropical diseases. Here, an assessment of the parasitic disease and energy benefits of biogas systems in Sichuan Province, China, is presented, highlighting how the public health sector can leverage the proliferation of rural energy projects for infectious disease control.First, the effectiveness of biogas systems at inactivating and removing ova of the human parasite Schistosoma japonicum is experimentally evaluated. Second, the impact of biogas infrastructure on energy use and environmental quality as reported by surveyed village populations is assessed, as is the community acceptance of the technology. No viable eggs were recovered in the effluent collected weekly from biogas systems for two months following seeding with infected stool. Less than 1% of ova were recovered viable from a series of nylon bags seeded with ova, a 2-log removal attributable to biochemical inactivation. More than 90% of Ascaris lumbricoides ova (used as a proxy for S. japonicum ova counted at the influent of two biogas systems were removed in the systems when adjusted for system residence time, an approximate 1-log removal attributable to sedimentation. Combined, these inactivation/removal processes underscore the promise of biogas infrastructure for reducing parasite contamination resulting from nightsoil use. When interviewed an average of 4 years after construction, villagers attributed large changes in fuel usage to the installation of biogas systems. Household coal usage decreased by 68%, wood by 74%, and crop waste

  9. [Start-up of a thermophilic anaerobic sludge digester].

    Science.gov (United States)

    Wu, Jing; Zhao, Peng-Juan; Tian, Lei; Shi, Lin; Shi, Han-Chang; Jiang, Yan

    2011-02-01

    Anaerobic digestion is one of the most widely-used technologies of the sludge reduction and stabilization, in which thermophilic digestion has advantage of fast stabilization. But it is lack of operation experience in China. Thus start-up of a thermophilic anaerobic sludge digester treating excess activated sludge was investigated. The digester was an internal circulation anaerobic sludge digester. It belongs to upflow reactor and its hydrodynamic conditions can be controlled by backflow biogas. A multistep strategy was applied to the start-up to enhance anaerobic bacteria to adapt the changes of temperature, reactor and treated sludge, including: to feed the digester with easily-degraded glucose to enhance bacteria reproduce at the first beginning with COD organic loading of 2.4 kg/(m3 x d); to accelerate the internal circulation; to control pH within a optimal range; to gradually increase excess sludge flow rate as well as to initiate pydrohydrolysis to enhance hydrolysis. The start-up took 63 days and when it finished, the VSS organic loading reached 1.60 kg/(m3 x d), the average VSS biogas rate was 0.51 L/g, i. e. 15.3 m3/m3 sludge (96% water content), VSS and SS removals were 60.8% and 45.8%. This shows that the strategy is valid.

  10. Modeling Nitrous Oxide emissions and identifying emission controlling factors for a spruce forest ecosystem on drained organic soil

    Science.gov (United States)

    He, Hongxing; Kasimir, Åsa; Jansson, Per-Erik; Svensson, Magnus; Meyer, Astrid; Klemedtsson, Leif

    2015-04-01

    High Nitrous Oxide (N2O) emission has been identified in hemiboreal forests on drained organic soils. However, the controlling factors regulating the emissions have been unclear. To examine the importance of different factors on the N2O emission in a spruce forest on drained organic soil, a process-based model, CoupModel, was calibrated by the generalized likelihood uncertainty estimation (GLUE) method. The calibrated model reproduced most of the high resolution data (total net radiation, soil temperature, groundwater level, net ecosystem exchange, etc.) very well, as well as accumulated measured N2O emissions, but showed difficulties to capture all the measured emission peaks. Parameter uncertainties could be reduced by combining selected criteria with the measurement data. The model showed the N2O emissions during the summer to be controlled mainly by the competition between plants and microbes while during the winter season snow melt periods are important. The simulated N budget shows >100 kg N ha-1 yr-1 to be in circulation between soil and plants and back again. Each year the peat mineralization adds about 60 kg N ha-1 and atmospheric deposition 12 kg N ha-1. Most of the mineralized litter and peat N is directly taken up by the plants but only a part accumulates in the plant biomass. As long as no timber is harvested the main N loss from the system is through nitrate leaching (30 kg N ha-1 yr-1) and gas emissions (20 kg N ha-1 yr-1), 55% as NO, 27% as N2O and 18% as N2. Regarding N2O gas emissions, our modeling indicates denitrification to be the most responsible process, of the size 6 kg N ha-1 yr-1, which could be compared to 0.04 kg N ha-1 yr-1 from nitrification. Our modelling also reveal 88% of the N2O mainly to be produced by denitrification in the capillary fringe (c.a. 40-60 cm below soil surface) of the anaerobic zone using nitrate produced in the upper more aerobic layers. We conclude N2O production/emission to be controlled mainly by the complex

  11. Perspectives for anaerobic digestion

    DEFF Research Database (Denmark)

    Ahring, Birgitte Kiær

    2003-01-01

    The modern society generates large amounts of waste that represent a tremendous threat to the environment and human and animal health. To prevent and control this, a range of different waste treatment and disposal methods are used. The choice of method must always be based on maximum safety...

  12. Perspectives for anaerobic digestion

    DEFF Research Database (Denmark)

    Ahring, Birgitte Kiær

    2003-01-01

    The modern society generates large amounts of waste that represent a tremendous threat to the environment and human and animal health. To prevent and control this, a range of different waste treatment and disposal methods are used. The choice of method must always be based on maximum safety...... as well as future perspectives will be discussed...

  13. Synergistic effect of co-digestion to enhance anaerobic degradation of catering waste and orange peel for biogas production.

    Science.gov (United States)

    Anjum, Muzammil; Khalid, Azeem; Qadeer, Samia; Miandad, Rashid

    2017-09-01

    Catering waste and orange peel were co-digested using an anaerobic digestion process. Orange peel is difficult to degrade anaerobically due to the presence of antimicrobial agents such as limonene. The present study aimed to examine the feasibility of anaerobic co-digestion of catering waste with orange peel to provide the optimum nutrient balance with reduced inhibitory effects of orange peel. Batch experiments were conducted using catering waste as a potential substrate mixed in varying ratios (20-50%) with orange peel. Similar ratios were followed using green vegetable waste as co-substrate. The results showed that the highest organic matter degradation (49%) was achieved with co-digestion of catering waste and orange peel at a 50% mixing ratio (CF4). Similarly, the soluble chemical oxygen demand (sCOD) was increased by 51% and reached its maximum value (9040 mg l -1 ) due to conversion of organic matter from insoluble to soluble form. Biogas production was increased by 1.5 times in CF4 where accumulative biogas was 89.61 m 3 t -1 substrate compared with 57.35 m 3 t -1 substrate in the control after 80 days. The main reason behind the improved biogas production and degradation is the dilution of inhibitory factors (limonene), with subsequent provision of balanced nutrients in the co-digestion system. The tCOD of the final digestate was decreased by 79.9% in CF4, which was quite high as compared with 68.3% for the control. Overall, this study revealed that orange peel waste is a highly feasible co-substrate for anaerobic digestion with catering waste for enhanced biogas production.

  14. What factors control the size of an eruption?

    Science.gov (United States)

    Gudmundsson, Agust

    2017-04-01

    pressure so as to drive out magma for a much longer time during an eruption than is otherwise possible. As a consequence a much higher proportion of the magma in the chamber is driven or squeezed out during an eruption associated with caldera or graben subsidence than is possible during an ordinary poroelastic chamber behaviour. It follows that the volume of eruptive materials may approach the total volume of the chamber resulting in a large eruption. Here a large eruption is thus the consequence—not the cause—of the subsidence of the caldera/graben block. Thus, once the factors controlling large-scale subsidence of a caldera/graben block are established during a particular unrest/rifting episode, primarily using geodetic and seismic data, the probability of a large eruption can be assessed and used for reliable forecasting. Gudmundsson, A., 2015. Collapse-driven large eruptions. Journal of Volcanology and Geothermal Research, 304, 1-10. Gudmundsson, A., 2016. The mechanics of large volcanic eruptions. Earth-Science Reviews, 163, 72-93.

  15. Anaerobic fermentation of beef cattle manure. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Hashimoto, A.G.; Chen, Y.R.; Varel, V.H.

    1981-01-01

    The research to convert livestock manure and crop residues into methane and a high protein feed ingredient by thermophilic anaerobic fermentation are summarized. The major biological and operational factors involved in methanogenesis were discussed, and a kinetic model that describes the fermentation process was presented. Substrate biodegradability, fermentation temperature, and influent substrate concentration were shown to have significant effects on CH/sub 4/ production rate. The kinetic model predicted methane production rates of existing pilot and full-scale fermentation systems to within 15%. The highest methane production rate achieved by the fermenter was 4.7 L CH/sub 4//L fermenter day. This is the highest rate reported in the literature and about 4 times higher than other pilot or full-scale systems fermenting livestock manures. Assessment of the energy requirements for anaerobic fermentation systems showed that the major energy requirement for a thermophilic system was for maintaining the fermenter temperature. The next major energy consumption was due to the mixing of the influent slurry and fermenter liquor. An approach to optimizing anaerobic fermenter designs by selecting design criteria that maximize the net energy production per unit cost was presented. Based on the results, we believe that the economics of anaerobic fermentation is sufficiently favorable for farm-scale demonstration of this technology.

  16. Identification of anaerobic microorganisms for converting kitchen waste to biogas

    International Nuclear Information System (INIS)

    Amirhossein Malakahmad; Shahrom Mohd Zain; Noor Ezlin Ahmad Basri; Shamsul Rahman Mohamed Kutty; Mohd Hasnain Isa

    2010-01-01

    Anaerobic digestion process is one of the alternative methods to convert organic waste into methane gas which is a fuel and energy source. Activities of various kinds of microorganisms are the main factor for anaerobic digestion which produces methane gas. Therefore, in this study a modified Anaerobic Baffled Reactor (ABR) with working volume of 50 liters was designed to identify the microorganisms through biogas production. The mixture of 75% kitchen waste and 25% sewage sludge was used as substrate. Observations on microorganisms in the ABR showed that there exists a small amount of protozoa (5%) and fungi (2%) in the system, but almost 93% of the microorganism population consists of bacteria. It is definitely clear that bacteria are responsible for anaerobic biodegradation of kitchen waste. Results show that in the acidification zone of the ABR (front compartments of reactor) fast growing bacteria capable of growth at high substrate levels and reduced pH was dominant. A shift to slower growing scavenging bacteria that grow better at higher pH was occurring towards the end of the reactor. Due to the ability of activity in acetate environment the percentages of Methanococcus, Methanosarcina and Methanotrix were higher than other kinds of methane former in the system. (Author)

  17. Application of dynamic membranes in anaerobic membranes in anaerobic membrane bioreactor systems

    NARCIS (Netherlands)

    Erşahin, M.E.

    2015-01-01

    Anaerobic membrane bioreactors (AnMBRs) physically ensure biomass retention by the application of a membrane filtration process. With growing application experiences from aerobic membrane bioreactors (MBRs), the combination of membrane and anaerobic processes has received much attention and become

  18. Potential for anaerobic conversion of xenobiotics

    DEFF Research Database (Denmark)

    Mogensen, Anders Skibsted; Dolfing, J.; Haagensen, Frank

    2003-01-01

    This review covers the latest research on the anaerobic biodegradation of aromatic xenobiotic compounds, with emphasis on surfactants, polycyclic aromatic hydrocarbons, phthalate esters, polychlorinated biphenyls, halogenated phenols, and pesticides. The versatility of anaerobic reactor systems...... regarding the treatment of xenobiotics is shown with the focus on the UASB reactor, but the applicability of other reactor designs for treatment of hazardous waste is also included. Bioaugmentation has proved to be a viable technique to enhance a specific activity in anaerobic reactors and recent research...

  19. Understanding and Predicting Foam in Anaerobic Digester

    OpenAIRE

    I. R. Kanu; T. J. Aspray; A. J. Adeloye

    2015-01-01

    As a result of the ambiguity and complexity surrounding anaerobic digester foaming, efforts have been made by various researchers to understand the process of anaerobic digester foaming so as to proffer a solution that can be universally applied rather than site specific. All attempts ranging from experimental analysis to comparative review of other process has not fully explained the conditions and process of foaming in anaerobic digester. Studying the current available ...

  20. Detection of anaerobic odontogenic infections by fluorine-18 fluoromisonidazole

    International Nuclear Information System (INIS)

    Liu Renshyan; Chu Leeshing; Yen Sanhui; Chang Chenpei; Chou Kuoliang; Wu Liangchi; Chang Chiwei; Lui Muntain; Chen Kuangy; Yeh Shinhwa

    1996-01-01

    Odontogenic infections are a potential risk for patients who receive cervicofacial radiotherapy and should be treated before irradiation. Anaerobic microbial infections are the most common causes. This study assessed the value of the hypoxic imaging agent fluorine-18 fluoromisonidazole (FMISO) in detecting anaerobic odontogenic infections. Positron emission tomography (PET) imaging was performed at 2 h after injection of 370 MBq (10 mCi) of FMISO in 26 nasopharyngeal carcinoma patients and six controls with healthy teeth. Tomograms were interpreted visually to identify hypoxic foci in the jaw. All patients received thorough dental examinations as a pre-radiotherapy work-up. Fifty-one sites of periodonititis, 15 periodontal abscesses, 14 sites of dental caries with root canal infection, 23 sites of dental caries without root canal infection, and seven necrotic pulps were found by dental examination. Anaerobic pathogens were isolated from 12 patients. Increased uptake of FMISO was found at 45 out of 51 sites of periodontitis, all 15 sites of periodontal abscess, all 14 sites of dental caries with root canal infection, all seven sites of necrotic pulp and 15 sites of dental carries without obvious evidence of active root canal infection. No abnormal uptake was seen in the healthy teeth of patients or in the six controls. The diagnostic sensitivity, specificity, positive and negative predictive values, and accuracy of FMISO PET scan in detecting odontogenic infections were 93%, 97%, 84%, 99% and 96%, respectively. 18 F-fluoride ion bone scan done in three patients showed that 18 F-fluoride ion plays no role in the demonstration of anaerobic odontogenic infection. FMISO PET scan is a sensitive method for the detection of anaerobic odontogenic infections, and may play a complementary role in the evaluation of the dental condition of patients with head and neck tumours prior to radiation therapy. (orig.)

  1. Detection of anaerobic odontogenic infections by fluorine-18 fluoromisonidazole

    Energy Technology Data Exchange (ETDEWEB)

    Liu Renshyan [National PET/Cyclotron Center and Dept. of Nuclear Medicine, Taipei Veterans General Hospital, National Yang-Ming Univ. Medical School, Taipei (Taiwan, Province of China); Chu Leeshing [National PET/Cyclotron Center and Dept. of Nuclear Medicine, Taipei Veterans General Hospital, National Yang-Ming Univ. Medical School, Taipei (Taiwan, Province of China)]|[National Defense Medical Center, Taipei (Taiwan); Yen Sanhui [National PET/Cyclotron Center and Dept. of Nuclear Medicine, Taipei Veterans General Hospital, National Yang-Ming Univ. Medical School, Taipei (Taiwan, Province of China)]|[National Defense Medical Center, Taipei (Taiwan); Chang Chenpei [National PET/Cyclotron Center and Dept. of Nuclear Medicine, Taipei Veterans General Hospital, National Yang-Ming Univ. Medical School, Taipei (Taiwan, Province of China); Chou Kuoliang [National PET/Cyclotron Center and Dept. of Nuclear Medicine, Taipei Veterans General Hospital, National Yang-Ming Univ. Medical School, Taipei (Taiwan, Province of China); Wu Liangchi [National PET/Cyclotron Center and Dept. of Nuclear Medicine, Taipei Veterans General Hospital, National Yang-Ming Univ. Medical School, Taipei (Taiwan, Province of China); Chang Chiwei [National PET/Cyclotron Center and Dept. of Nuclear Medicine, Taipei Veterans General Hospital, National Yang-Ming Univ. Medical School, Taipei (Taiwan, Province of China); Lui Muntain [Dept. of Dentistry, Taipei Veterans General Hospital (Taiwan, Province of China); Chen Kuangy [National PET/Cyclotron Center and Dept. of Nuclear Medicine, Taipei Veterans General Hospital, National Yang-Ming Univ. Medical School, Taipei (Taiwan, Province of China)]|[National Defense Medical Center, Taipei (Taiwan); Yeh Shinhwa [National PET/Cyclotron Center and Dept. of Nuclear Medicine, Taipei Veterans General Hospital, National Yang-Ming Univ. Medical School, Taipei (Taiwan, Province of China)

    1996-10-01

    Odontogenic infections are a potential risk for patients who receive cervicofacial radiotherapy and should be treated before irradiation. Anaerobic microbial infections are the most common causes. This study assessed the value of the hypoxic imaging agent fluorine-18 fluoromisonidazole (FMISO) in detecting anaerobic odontogenic infections. Positron emission tomography (PET) imaging was performed at 2 h after injection of 370 MBq (10 mCi) of FMISO in 26 nasopharyngeal carcinoma patients and six controls with healthy teeth. Tomograms were interpreted visually to identify hypoxic foci in the jaw. All patients received thorough dental examinations as a pre-radiotherapy work-up. Fifty-one sites of periodonititis, 15 periodontal abscesses, 14 sites of dental caries with root canal infection, 23 sites of dental caries without root canal infection, and seven necrotic pulps were found by dental examination. Anaerobic pathogens were isolated from 12 patients. Increased uptake of FMISO was found at 45 out of 51 sites of periodontitis, all 15 sites of periodontal abscess, all 14 sites of dental caries with root canal infection, all seven sites of necrotic pulp and 15 sites of dental carries without obvious evidence of active root canal infection. No abnormal uptake was seen in the healthy teeth of patients or in the six controls. The diagnostic sensitivity, specificity, positive and negative predictive values, and accuracy of FMISO PET scan in detecting odontogenic infections were 93%, 97%, 84%, 99% and 96%, respectively. {sup 18}F-fluoride ion bone scan done in three patients showed that {sup 18}F-fluoride ion plays no role in the demonstration of anaerobic odontogenic infection. FMISO PET scan is a sensitive method for the detection of anaerobic odontogenic infections, and may play a complementary role in the evaluation of the dental condition of patients with head and neck tumours prior to radiation therapy. (orig.)

  2. Physiologically anaerobic microorganisms of the deep subsurface

    Energy Technology Data Exchange (ETDEWEB)

    Stevens, S.E. Jr.; Chung, K.T.

    1991-06-01

    This study seeks to determine numbers, diversity, and morphology of anaerobic microorganisms in 15 samples of subsurface material from the Idaho National Engineering Laboratory, in 18 samples from the Hanford Reservation and in 1 rock sample from the Nevada Test Site; set up long term experiments on the chemical activities of anaerobic microorganisms based on these same samples; work to improve methods for the micro-scale determination of in situ anaerobic microbial activity;and to begin to isolate anaerobes from these samples into axenic culture with identification of the axenic isolates.

  3. Investigating the effective factors on management internal controls applying

    Directory of Open Access Journals (Sweden)

    Ahmad Ahmadkhani

    2012-08-01

    Full Text Available Information technology plays an important role on increasing internal control in many organizations. In this paper, we present an empirical study to measure the impact of information technology, hiring high quality skilled management team, using high quality standards and increasing employees' awareness on managing internal control. The survey uses a questionnaire based on Likert scale and distributes among the people who work in either administration or financial sectors of governmental agencies in province of Zanjan, Iran. The results of the study indicate that the implementation of information technology positively influences management team to control their system, more effectively, using more skilled and specialized managers positively influences management internal control, an organization with suitable standard positively influences management internal control and increasing employees' awareness positively influences management internal control.

  4. Biogas plasticization coupled anaerobic digestion: continuous flow anaerobic pump test results.

    Science.gov (United States)

    Schimel, Keith A; Boone, David R

    2010-03-01

    In this investigation, the Anaerobic Pump (TAP) and a conventional continuous flow stirred tank reactor (CFSTR) were tested side by side to compare performance. TAP integrates anaerobic digestion (AD) with biogas plasticization-disruption cycle to improve mass conversion to methane. Both prototypes were fed a "real world" 50:50 mixture of waste-activated sludge (WAS) and primary sludge and operated at room temperature (20 degrees Celsius). The quantitative results from three steady states show TAP peaked at 97% conversion of the particulate COD in a system hydraulic residence time (HRT) of only 6 days. It achieved a methane production of 0.32 STP cubic meter CH(4) per kilogram COD fed and specific methane yield of 0.78 m(3) CH(4) per cubic meter per day. This was more than three times the CFSTR specific methane yield (0.22 m(3) CH(4) per cubic meter per day) and more than double the CFSTR methane production (0.15 m(3) CH(4) per kilogram COD fed). A comparative kinetics analysis showed the TAP peak substrate COD removal rate (R (o)) was 2.24 kg COD per cubic meter per day, more than three times the CFSTR substrate removal rate of 0.67 kg COD per cubic meter per day. The three important factors contributing to the superior TAP performance were (1) effective solids capture (96%) with (2) mass recycle and (3) stage II plasticization-disruption during active AD. The Anaerobic Pump (TAP) is a high rate, high efficiency-low temperature microbial energy engine that could be used to improve renewable energy yields from classic AD waste substrates like refuse-derived fuels, treatment plant sludges, food wastes, livestock residues, green wastes and crop residuals.

  5. Factors controlling floc settling velocity along a longitudinal estuarine transect

    Science.gov (United States)

    Manning, A.J.; Schoellhamer, D.H.

    2013-01-01

    A 147 km longitudinal transect of flocculated cohesive sediment properties in San Francisco Bay (SFB) was conducted on June 17th, 2008. Our aim was to determine the factors that control floc settling velocity along the longitudinal axis of the estuary. The INSSEV-LF video system was used to measure floc diameters and settling velocities at 30 stations at a distance of 0.7 m above the estuary bed. Floc sizes (D) ranged from 22 μm to 639 μm and settling velocities (Ws) ranged between 0.04 mm·s− 1 and 15.8 mm·s− 1 during the longitudinal transect. Nearbed turbulent shear stresses throughout the transect duration were within the 0.2–0.5 Pa range which typically stimulates flocculation growth. The individual D–Ws–floc density plots suggest the suspended sediments encountered throughout SFB were composed of both muddy cohesive sediment and mixed sediments flocs. Mass-weighted population mean settling velocity (Wsmass) ranged from 0.5 mm·s− 1 to 10 mm·s− 1. The macrofloc and microfloc (demarcation at 160 μm) sub-populations demonstrated parameterised settling velocities which spanned nearly double the range of the sample mean settling velocities (Wsmean). The macroflocs tended to dominate the suspended mass (up to 77% of the ambient suspended solid concentration; SSC) from San Pablo Bay to Carquinez Strait (the vicinity of the turbidity maximum zone). Microfloc mass was particularly significant (typically 60–100% of the SSC) in the northern section of South Bay and most of Central Bay. The transect took eleven hours to complete and was not fully synoptic. During slack tide, larger and faster settling flocs deposited, accounting for most of the longitudinal variability. The best single predictor of settling velocity was water velocity 39 min prior to sampling, not suspended-sediment concentration or salinity. Resuspension and settling lags are likely responsible for the lagged response of settling velocity to water velocity. The distribution of

  6. Animal and industrial waste anaerobic digestion: USA status report

    Energy Technology Data Exchange (ETDEWEB)

    Lusk, P.D. [Resource Development Associates, Washington, DC (United States)

    1996-01-01

    Pollutants from unmanaged animal and bio-based industrial wastes can degrade the environment, and methane emitted from decomposing wastes may contribute to global climate change. One waste management system prevents pollution and converts a disposal problem into a new profit center. Case studies of operating systems indicate that the anaerobic digestion of animal and industrial wastes is a commercially available bioconversion technology with considerable potential for providing profitable coproducts, including a cost-effective renewable fuel. Growth and concentration of the livestock industry create opportunities to properly dispose of the large quantities of manures generated at dairy, swine, and poultry farms. Beyond the farm, extension of the anaerobic digestion process to recover methane has considerable potential for certain classified industries - with a waste stream characterization similar to livestock manures. More than 35 example industries have been identified, and include processors of chemicals, fiber, food, meat, milk, and pharmaceuticals. Some of these industries already recover methane for energy. This status report examines some current opportunities for recovering methane from the anaerobic digestion of animal and industrial wastes in the US. Case studies of operating digesters, including project and maintenance histories, and the operator`s {open_quotes}lessons learned,{close_quotes} are included as a reality check. Factors necessary for successful projects, as well as a list of reasons explaining why some anaerobic digestion projects fail, are provided. The role of management is key; not only must digesters be well engineered and built with high-quality components, they must also be sited at facilities willing to incorporate the uncertainties of a new technology. Anaerobic digestion can provide monetary benefits and mitigate possible pollution problems, thereby sustaining development while maintaining environmental quality.

  7. Monitoring and control of anaerobic reactors

    DEFF Research Database (Denmark)

    Pind, Peter Frode; Angelidaki, Irini; Ahring, Birgitte Kiær

    2003-01-01

    measurements are reviewed in detail. In the sequel, possible manipulated variables, such as the hydraulic retention time, the organic loading rate, the sludge retention time, temperature, pH and alkalinity are evaluated with respect to the two main reactor types: high-rate and low-rate. Finally, the different...

  8. Effects of type of tapering on anaerobic capacity in young basketball players

    Directory of Open Access Journals (Sweden)

    Hugo Augusto Alvares da Silva Lira

    2017-11-01

    Full Text Available The aim of this study was to analyze the effect of the type of tapering on anaerobic capacity in male young basketball players. This was an experimental research with 12 weeks, developed with 47 basketball players, randomly divided into three groups: linear tapering (LG, tapering by step (SG and control group (CG. All groups participated of the same planning training until the last three weeks of periodization (the tapering phase. Only the CG did not perform tapering. Anaerobic Running Speed Test was carried in the last week of each mesocycle to assess the anaerobic capacity. The findings revealed that anaerobic capacity attenuated from the competitive to tapering phase in LG (p= .01 and SG (p= .01, which was not verified for the CG (p= .29. Significant difference of anaerobic capacity was found between LG and CG (p= .01, SG and CG (p= .01 and between LG and SG (p= .04 in the tapering phase. It was concluded that the tapering strategies were efficient to maximize anaerobic capacity in young basketball players, although linear tapering strategy has been revealed the best strategy for improvement the anaerobic capacity.

  9. Reflexivity as a control factor of personal coping behavior

    OpenAIRE

    BEKHTER A.A.

    2014-01-01

    The article deals with the issue of coping behavior control. The author defines the criteria, levels and aspects of reflexivity within the framework of personal coping behavior. In conclusion the author describes the key facets of coping behavior control and how reflexivity affects them.

  10. Factors associated with blood pressure control in predialysis chronic ...

    African Journals Online (AJOL)

    Poor BP control was associated with middle age, proteinuric CKD, and prescription of 3 or more BP medication. Conclusion: BP control in predialysis CKD patients still needs to be optimized. Special attention should be given to middle‑aged patients who have proteinuric CKD and those on multiple BP drugs without optimal ...

  11. Chiling slows anaerobic metabolism to improve anoxia tolerance of insects

    Czech Academy of Sciences Publication Activity Database

    Boardman, L.; Sorensen, J. G.; Košťál, Vladimír; Šimek, Petr; Terblanche, J. S.

    2016-01-01

    Roč. 12, č. 12 (2016), č. článku 176. ISSN 1573-3882 R&D Projects: GA ČR GA13-18509S Institutional support: RVO:60077344 Keywords : anoxia * anaerobism * cold tolerance Subject RIV: ED - Physiology Impact factor: 3.692, year: 2016 http://link.springer.com/article/10.1007/s11306-016-1119-1

  12. Similar PAH fate in anaerobic digesters inoculated with three microbial communities accumulating either volatile fatty acids or methane.

    Directory of Open Access Journals (Sweden)

    Florence Braun

    Full Text Available Urban sludge produced on wastewater treatment plants are often contaminated by organic pollutants such as polycyclic aromatic hydrocarbons (PAH. Their removal under methanogenic conditions was already reported, but the factors influencing this removal remain unclear. Here, we determined the influence of microbial communities on PAH removal under controlled physico-chemical conditions. Twelve mesophilic anaerobic digesters were inoculated with three microbial communities extracted from ecosystems with contrasting pollution histories: a PAH contaminated soil, a PCB contaminated sediment and a low contaminated anaerobic sludge. These anaerobic digesters were operated during 100 days in continuous mode. A sterilised activated sludge, spiked with 13 PAH at concentrations usually encountered in full-scale wastewater treatment plants, was used as substrate. The dry matter and volatile solid degradation, the biogas production rate and composition, the volatile fatty acids (VFA production and the PAH removals were monitored. Bacterial and archaeal communities were compared in abundance (qPCR, in community structure (SSCP fingerprinting and in dominant microbial species (454-pyrosequencing. The bioreactors inoculated with the community extracted from low contaminated anaerobic sludge showed the greater methane production. The PAH removals ranged from 10% to 30%, respectively, for high and low molecular weight PAH, whatever the inoculums tested, and were highly correlated with the dry matter and volatile solid removals. The microbial community structure and diversity differed with the inoculum source; this difference was maintained after the 100 days of digestion. However, the PAH removal was not correlated to these diverse structures and diversities. We hence obtained three functional stable consortia with two contrasted metabolic activities, and three different pictures of microbial diversity, but similar PAH and matter removals. These results confirm

  13. Cold water recovery reduces anaerobic performance.

    Science.gov (United States)

    Crowe, M J; O'Connor, D; Rudd, D

    2007-12-01

    This study investigated the effects of cold water immersion on recovery from anaerobic cycling. Seventeen (13 male, 4 female) active subjects underwent a crossover, randomised design involving two testing sessions 2 - 6 d apart. Testing involved two 30-s maximal cycling efforts separated by a one-hour recovery period of 10-min cycling warm-down followed by either passive rest or 15-min cold water immersion (13 - 14 degrees C) with passive rest. Peak power, total work and postexercise blood lactate were significantly reduced following cold water immersion compared to the first exercise test and the control condition. These variables did not differ significantly between the control tests. Peak exercise heart rate was significantly lower after cold water immersion compared to the control. Time to peak power, rating of perceived exertion, and blood pH were not affected by cold water immersion compared to the control. Core temperature rose significantly (0.3 degrees C) during ice bath immersion but a similar increase also occurred in the control condition. Therefore, cold water immersion caused a significant decrease in sprint cycling performance with one-hour recovery between tests.

  14. ANAEROBIC BIODEGRADATION OF A BIODEGRADABLE MATERIAL UNDER ANAEROBIC - THERMOPHILIC DIGESTION

    Directory of Open Access Journals (Sweden)

    RICARDO CAMACHO-MUÑOZ

    2014-12-01

    Full Text Available This paper dertermined the anaerobic biodegradation of a polymer obtained by extrusion process of native cassava starch, polylactic acid and polycaprolactone. Initially a thermophilic - methanogenic inoculum was prepared from urban solid waste. The gas final methane concentration and medium’s pH reached values of 59,6% and 7,89 respectively. The assay assembly was carried out according ASTM D5511 standard. The biodegradation percent of used materials after 15 day of digestion were: 77,49%, 61,27%, 0,31% for cellulose, sample and polyethylene respectively. Due cellulose showed biodegradation levels higher than 70% it’s deduced that the inoculum conditions were appropriate. A biodegradation level of 61,27%, 59,35% of methane concentration in sample’s evolved gas and a medium’s finale pH of 7,71 in sample’s vessels, reveal the extruded polymer´s capacity to be anaerobically degraded under thermophilic- high solid concentration conditions.

  15. Processing anaerobic sludge for extended storage as anaerobic digester inoculum.

    Science.gov (United States)

    Li, Jiajia; Zicari, Steven M; Cui, Zongjun; Zhang, Ruihong

    2014-08-01

    Thermophilic anaerobic sludge was processed to reduce the volume and moisture content in order to reduce costs for storing and transporting the sludge as microbial inoculum for anaerobic digester startup. The moisture content of the sludge was reduced from 98.7% to 82.0% via centrifugation and further to 71.5% via vacuum evaporation. The processed sludge was stored for 2 and 4 months and compared with the fresh sludge for the biogas and methane production using food waste and non-fat dry milk as substrates. It was found that fresh unprocessed sludge had the highest methane yield and the yields of both unprocessed and processed sludges decreased during storage by 1-34%, however processed sludges seemed to regain some activity after 4 months of storage as compared to samples stored for only 2 months. Maximum methane production rates obtained from modified Gompertz model application also increased between the 2-month and 4-month processed samples. Copyright © 2014. Published by Elsevier Ltd.

  16. Potential application of anaerobic extremophiles for hydrogen production

    Science.gov (United States)

    Pikuta, Elena V.; Hoover, Richard B.

    2004-11-01

    In processes of the substrate fermentation most anaerobes produce molecular hydrogen as a waste end product, which often controls the culture growth as an inhibitor. Usually in nature the hydrogen is easily removed from an ecosystem, due to its physical features, and an immediate consumption by the secondary anaerobes that sometimes behave as competitors for electron donors; a classical example of this kind of substrate competition in anaerobic microbial communities is the interaction between methanogens and sulfate- or sulfur-reducers. Previously, on the mixed cultures of anaerobes at neutral pH, it was demonstrated that bacterial hydrogen production could provide a good alternative energy source. At neutral pH the original cultures could easily contaminated by methanogens, and the most unpleasant side effect of these conditions is the development of pathogenic bacteria. In both cases the rate of hydrogen production was dramatically decreased since some part of the hydrogen was transformed to methane, and furthermore, the cultivation with pathogenic contaminants on an industrial scale would create an unsafe situation. In our laboratory the experiments with obligately alkaliphilic bacteria producing hydrogen as an end metabolic product were performed at different conditions. The mesophilic, haloalkaliphilic and obligately anaerobic bacterium Spirochaeta americana ASpG1T was studied and various cultivation regimes were compared for the most effective hydrogen production. In a highly mineralized media with pH 9.5-10.0 not many known methanogens are capable of growth, and the probability of developing pathogenic contaminants is theoretically is close to zero (in medicine carbonate- saturated solutions are applied as antiseptics). Therefore the cultivation of alkaliphilic hydrogen producing bacteria could be considered as a safe and economical process for large-scale industrial bio-hydrogen production in the future. Here we present and discuss the experimental data

  17. CubeSat Form Factor Thermal Control Louvers

    Data.gov (United States)

    National Aeronautics and Space Administration — As small spacecraft become a part of NASA’s repertoire of missions, one reoccurring theme is an increased need for thermal control as power budgets increase and...

  18. CubeSat Form Factor Thermal Control Louvers Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Thermal control of small spacecraft, including CubeSats, is a challenge for the next era of NASA spaceflight. Science objectives and components will still require...

  19. Human factors considerations in the design and evaluation of flight deck displays and controls

    Science.gov (United States)

    2013-11-01

    The objective of this effort is to have a single source document for human factors regulatory and guidance material for flight deck displays and controls, in the interest of improving aviation safety. This document identifies guidance on human factor...

  20. Factors influencing the control strategy of hybrid drive of urban public transport buses

    International Nuclear Information System (INIS)

    Barta, Dalibor; Mruzek, Martin

    2015-01-01

    The efficiency of each drives is dependent on many factors. Hybrid drives and specially the drives of urban public transport may be affected by other factors given by transport infrastructure or operational conditions. These factors condition the suitable configuration of the individual elements of hybrid drive and the establishment of good control strategy of such drive. The study of influencing factors of the control strategy is the aim of this paper. (full text)

  1. Method for anaerobic fermentation and biogas production

    DEFF Research Database (Denmark)

    2013-01-01

    The present invention relates to a method for biomass processing, anaerobic fermentation of the processed biomass, and the production biogas. In particular, the invention relates to a system and method for generating biogas from anaerobic fermentation of processed organic material that comprises...

  2. Anaerobic exercise - Induced changes in serum mineral ...

    African Journals Online (AJOL)

    Anaerobic exercise, a non 02 – dependent energy metabolism leads to transient metabolic changes, which are corrected gradually by homestatic mechanism. We investigated in eight male subjects, the effects of anaerobic exercise after a day sedentary activity on serum mineral concentration. There was significant ...

  3. Integrated anaerobic and aerobic treatment of sewage

    NARCIS (Netherlands)

    Wang, K.

    1994-01-01

    This thesis describes results of investigations dealing with sequential concept of anaerobic-aerobic treatment of municipal wastewater. The main purposes of the study were 1) to develop a proper anaerobic hydrolytic pretreatment unit, consisting of a Hydrolysis Upflow Sludge Bed (HUSB-)

  4. Anaerobic induction in B. cereus ATCC 14579

    NARCIS (Netherlands)

    Voort, van der M.; Abee, Tjakko

    2008-01-01

    A comparative transcriptome approach was used to assess genes involved in metabolism and pathogenesis that are specifically activated during anaerobic growth of the spore-forming food-borne human pathogen Bacillus cereus ATCC 14579. Growth under anaerobic conditions in Brain Heart Infusion broth

  5. Risk factors for measles among adults in Tianjin, China: Who should be controls in a case-control study?

    Science.gov (United States)

    Wagner, Abram L; Boulton, Matthew L; Gillespie, Brenda W; Zhang, Ying; Ding, Yaxing; Carlson, Bradley F; Luo, Xiaoyan; Montgomery, JoLynn P; Wang, Xiexiu

    2017-01-01

    Control groups in previous case-control studies of vaccine-preventable diseases have included people immune to disease. This study examines risk factors for measles acquisition among adults 20 to 49 years of age in Tianjin, China, and compares findings using measles IgG antibody-negative controls to all controls, both IgG-negative and IgG-positive. Measles cases were sampled from a disease registry, and controls were enrolled from community registries in Tianjin, China, 2011-2015. Through a best subsets selection procedure, we compared which variables were selected at different model sizes when using IgG-negative controls or all controls. We entered risk factors for measles in two separate logistic regression models: one with measles IgG-negative controls and the other with all controls. The study included 384 measles cases and 1,596 community controls (194 IgG-negative). Visiting a hospital was an important risk factor. For specialty hospitals, the odds ratio (OR) was 4.53 (95% confidence interval (CI): 1.28, 16.03) using IgG-negative controls, and OR = 5.27 (95% CI: 2.73, 10.18) using all controls. Variables, such as age or length of time in Tianjin, were differentially selected depending on the control group. Individuals living in Tianjin ≤3 years had 2.87 (95% CI: 1.46, 5.66) times greater odds of measles case status compared to all controls, but this relationship was not apparent for IgG-negative controls. We recommend that case-control studies examining risk factors for infectious diseases, particularly in the context of transmission dynamics, consider antibody-negative controls as the gold standard.

  6. Anaerobic biological treatment of in-situ retort water

    Energy Technology Data Exchange (ETDEWEB)

    Ossio, E.; Fox, P.

    1980-03-01

    Anaerobic fermentation was successfully used in a laboratory-scale batch digester to remove soluble organics from retort water. Required pretreatment includes reduction of ammonia levels to 360 mg-N/l, pH adjustment to 7.0, sulfide control, and the addition of the nutrients, calcium, magnesium, and phoshorus. If the prescribed pretreatment is used, BOD/sub 5/ and COD removal efficiencies of 89 to 90% and 65 to 70% are achieved, respectively.

  7. Factors determining the use of botanical insect pest control methods ...

    African Journals Online (AJOL)

    A farm survey was conducted in three representative administrative districts of the Lake Victoria Basin (LVB), Kenya to document farmers' indigenous knowledge and the factors that influence the use of botanicals instead of synthetic insecticides in insect pest management. A total of 65 farm households were randomly ...

  8. Investigation and control of factors influencing resistance upset butt welding.

    NARCIS (Netherlands)

    Kerstens, N.F.H.

    2010-01-01

    The purpose of this work is to investigate the factors influencing the resistance upset butt welding process to obtain an understanding of the metal behaviour and welding process characteristics, so that new automotive steels can be welded with reduced development time and fewer failures in

  9. Heart Disease Risk Factors You Can't Control

    Science.gov (United States)

    ... white and African-American women. 5 African-American women: Are more likely than other groups to have heart disease risk factors like high blood pressure, obesity, and diabetes 6,7 May be less likely than others to receive preventive treatment including medicines to lower blood pressure and advice ...

  10. Control of cellulose biosynthesis by overexpression of a transcription factor

    Science.gov (United States)

    Han, Kyung-Hwan; Ko, Jae-Heung; Kim, Won-Chan; Kim; , Joo-Yeol

    2017-05-16

    The invention relates to the over-expression of a transcription factor selected from the group consisting of MYB46, HAM1, HAM2, MYB112, WRKY11, ERF6, and any combination thereof in a plant, which can modulate and thereby modulating the cellulose content of the plant.

  11. Molecular Factors Controlling Photosynthetic Light Harvesting by Carotenoids

    Czech Academy of Sciences Publication Activity Database

    Polívka, Tomáš; Frank, H.A.

    2010-01-01

    Roč. 43, č. 8 (2010), s. 1125-1134 ISSN 0001-4842 Institutional research plan: CEZ:AV0Z50510513 Keywords : carotenoids * energy transfer * photosynthesis * light-harvesting Subject RIV: BO - Biophysics Impact factor: 21.840, year: 2010

  12. Controlled growth factor release from synthetic extracellular matrices

    Science.gov (United States)

    Lee, Kuen Yong; Peters, Martin C.; Anderson, Kenneth W.; Mooney, David J.

    2000-12-01

    Polymeric matrices can be used to grow new tissues and organs, and the delivery of growth factors from these matrices is one method to regenerate tissues. A problem with engineering tissues that exist in a mechanically dynamic environment, such as bone, muscle and blood vessels, is that most drug delivery systems have been designed to operate under static conditions. We thought that polymeric matrices, which release growth factors in response to mechanical signals, might provide a new approach to guide tissue formation in mechanically stressed environments. Critical design features for this type of system include the ability to undergo repeated deformation, and a reversible binding of the protein growth factors to polymeric matrices to allow for responses to repeated stimuli. Here we report a model delivery system that can respond to mechanical signalling and upregulate the release of a growth factor to promote blood vessel formation. This approach may find a number of applications, including regeneration and engineering of new tissues and more general drug-delivery applications.

  13. The effects of operational and environmental variations on anaerobic wastewater treatment systems: a review

    Energy Technology Data Exchange (ETDEWEB)

    Leitao, R.C. [Embrapa Agroindustria Tropical (Brazilian Agricultural Research Corporation, Inst. of Tropical Agroindustry), Fortaleza (Brazil); Haandel, A.C. van [Federal University of Campina Grande (Brazil); Zeeman, G.; Lettinga, G. [Wageningen Univ. (Netherlands)

    2006-06-15

    With the aim of improving knowledge about the stability and reliability of anaerobic wastewater treatment systems, several researchers have studied the effects of operational or environmental variations on the performance of such reactors. In general, anaerobic reactors are affected by changes in external factors, but the severity of the effect is dependent upon the type, magnitude, duration and frequency of the imposed changes. The typical responses include a decrease in performance, accumulation of volatile fatty acids, drop in pH and alkalinity, change in biogas production and composition, and sludge washout. This review summarises the causes, types and effects of operational and environmental variation on anaerobic wastewater treatment systems. However, there still remain some unclear technical and scientific aspects that are necessary for the improvement of the stability and reliability of anaerobic processes. (author)

  14. DEVELOPMENT OF IMPROVED ANAEROBIC GROWTH OF BACILLUS MOJAVENSIS STRAIN JF-2 FOR THE PURPOSE OF IMPROVED ANAEROBIC BIOSURFACTANT PRODUCTION FOR ENHANCED OIL RECOVERY

    Energy Technology Data Exchange (ETDEWEB)

    M.J. McInerney; M. Folmsbee; D. Nagle

    2004-05-31

    Our work focuses on the use of microorganisms to recover petroleum hydrocarbons that remain entrapped after current recovery technologies reach their economic limit. Capillary forces between the hydrocarbon and aqueous phases are largely responsible for trapping the hydrocarbons in the pores of the rock and large reductions in the interfacial tension between the hydrocarbon and aqueous phases are needed for hydrocarbon mobilization (1-3, 10, 11). Microorganisms produce a variety of biosurfactants (4), several of which generate the ultra low interfacial tensions needed for hydrocarbon mobilization (4, 5, 8). In particular, the lipopeptide biosurfactant produced by Bacillus mojavensis strain JF-2 reduces the interfacial tension between hydrocarbon and aqueous phases to very low levels (<0.016 mN/m) (8) (9). B. mojavensis JF-2 grows under the environmental conditions found in many oil reservoirs, i. e., anaerobic, NaCl concentrations up to 80 g l{sup -1}, and temperatures up to 45 C (6, 7), making it ideally suited for in situ applications. However, anaerobic growth of B. mojavensis JF-2 was inconsistent and difficult to replicate, which limited its use for in situ applications. Our initial studies revealed that enzymatic digests, such as Proteose Peptone, were required for anaerobic growth of Bacillus mojavensis JF-2. Subsequent purification of the growth-enhancing factor in Proteose Peptone resulted in the identification of the growth-enhancing factor as DNA or deoxyribonucleosides. The addition of salmon sperm DNA, herring sperm DNA, E. coli DNA or synthetic DNA (single or double stranded) to Medium E all supported anaerobic growth of JF-2. Further, we found that JF-2 required all four deoxyribonucleosides (deoxyadeonosine, deoxyguanosine, deoxycytidine and thymidine) for growth under strict anaerobic conditions. The requirement for the deoxyribonucleosides did not occur under aerobic growth conditions. DNA was not used as a sole energy source; sucrose was required

  15. Population prevalence and control of cardiovascular risk factors: What electronic medical records tell us

    Directory of Open Access Journals (Sweden)

    Arantxa Catalán-Ramos

    2014-01-01

    Conclusions: Hypertension was the most prevalent cardiovascular risk factor in the Catalan population attended at primary care centers. About two thirds of individuals with hypertension or DM2 were adequately controlled; hypercholesterolemia control was particularly low.

  16. Transcription factor control of growth rate dependent genes in Saccharomyces cerevisiae: A three factor design

    DEFF Research Database (Denmark)

    Fazio, Alessandro; Jewett, Michael Christopher; Daran-Lapujade, Pascale

    2008-01-01

    transcription factor target sets, transcription factors that coordinate balanced growth were also identified. Our analysis shows that FhII, Rap1, and Sfp1, regulating protein biosynthesis, have significantly enriched target sets for genes up-regulated with increasing growth rate. Cell cycle regulators...

  17. Odor from anaerobic digestion of swine slurry: influence of pH, temperature and organic loading

    Directory of Open Access Journals (Sweden)

    Gerardo Ortiz

    2014-12-01

    Full Text Available Farm slurry management from storage and/or treatment is the main source of odors from swine production, which are determined by factors such as operational variations (organic loading, cleaning of facilities and animal diet (pH or environmental conditions (temperature. The aim of this study was to evaluate the influence of pH, temperature and organic loading on odor generation during anaerobic digestion of swine slurry. The methodology employed batch experimental units under controlled pH (6.0, 6.5, 7.0 and 8.0 and temperature (20, 35 and 55 °C conditions. Additionally, an Upflow Anaerobic Sludge Blanket (UASB system was operated under two Organic Loading Rate (OLR conditions as Chemical Oxygen Demand (COD (Phase I: 0.4 g L-1 d-1 of COD, Phase II: 1.1 g L-1 d-1 of COD. Odor (batch and UASB reactor was evaluated by detection and recognition threshold as Dilution Threshold (D-T. Acidic conditions (pH 6.0 and thermophilic temperatures (55 °C increased odors (1,358 D-T and acidified the system (Intermediate/Total Alkalinity ratio (IT/TA: 0.85 in batch experiments. Increasing OLR on UASB reactor reduced odors from 6.3 to 9.6 D-T d-1 due to an increase in the production of biogas (0.4 to 0.6 g g-1 COD removed of biogas.

  18. Recurrence of fecal coliforms and Salmonella species in biosolids following thermophilic anaerobic digestion.

    Science.gov (United States)

    Iranpour, Reza; Cox, Huub H J

    2006-09-01

    The U.S. Environmental Protection Agency (U.S. EPA) Part 503 Biosolids Rule requires the fecal coliform (indicator) or Salmonella species (pathogen) density requirements for Class A biosolids to be met at the last point of plant control (truck-loading facility and/or farm for land application). The three Southern Californian wastewater treatment plants in this study produced biosolids by thermophilic anaerobic digestion and all met the Class A limits for both fecal coliforms and Salmonella sp. in the digester outflow biosolids. At two plants, however, a recurrence of fecal coliforms was observed in postdigestion biosolids, which caused exceedance of the Class A limit for fecal coliforms at the truck-loading facility and farm for land application. Comparison of observations at the three plants and further laboratory tests indicated that the recurrence of fecal coliforms can possibly be related to the following combination of factors: (1) incomplete destruction of fecal coliforms during thermophilic anaerobic digestion, (2) contamination of Class A biosolids with fecal coliforms from external sources during postdigestion, (3) a large drop of the postdigestion biosolids temperature to below the maximum for fecal coliform growth, (4) an unknown effect of biosolids dewatering in centrifuges. At Hyperion Treatment Plant (City of Los Angeles, California), fecal coliform recurrence could be prevented by the following: (1) complete conversion to thermophilic operation to exclude contamination by mesophilically digested biosolids and (2) insulation and electrical heat-tracing of postdigestion train for maintaining a high biosolids temperature in postdigestion.

  19. Active transport, substrate specificity, and methylation of Hg(II) in anaerobic bacteria

    Science.gov (United States)

    Schaefer, Jeffra K.; Rocks, Sara S.; Zheng, Wang; Liang, Liyuan; Gu, Baohua; Morel, François M. M.

    2011-01-01

    The formation of methylmercury (MeHg), which is biomagnified in aquatic food chains and poses a risk to human health, is effected by some iron- and sulfate-reducing bacteria (FeRB and SRB) in anaerobic environments. However, very little is known regarding the mechanism of uptake of inorganic Hg by these organisms, in part because of the inherent difficulty in measuring the intracellular Hg concentration. By using the FeRB Geobacter sulfurreducens and the SRB Desulfovibrio desulfuricans ND132 as model organisms, we demonstrate that Hg(II) uptake occurs by active transport. We also establish that Hg(II) uptake by G. sulfurreducens is highly dependent on the characteristics of the thiols that bind Hg(II) in the external medium, with some thiols promoting uptake and methylation and others inhibiting both. The Hg(II) uptake system of D. desulfuricans has a higher affinity than that of G. sulfurreducens and promotes Hg methylation in the presence of stronger complexing thiols. We observed a tight coupling between Hg methylation and MeHg export from the cell, suggesting that these two processes may serve to avoid the build up and toxicity of cellular Hg. Our results bring up the question of whether cellular Hg uptake is specific for Hg(II) or accidental, occurring via some essential metal importer. Our data also point at Hg(II) complexation by thiols as an important factor controlling Hg methylation in anaerobic environments. PMID:21555571

  20. Design of a T Factor Based RBFNC for a Flight Control System

    OpenAIRE

    Mohanty, C. S.; Khuntia, P. S.; Mitra, D.

    2014-01-01

    This paper presents the design of modified radial basic function neural controller (MRBFNC) for the pitch control of an aircraft to obtain the desired pitch angel as required by the pilot while maneuvering an aircraft. In this design, the parameters of radial basis function neural controller (RBFNC) are optimized by implementing a feedback mechanism which is controlled by a tuning factor “α” (T factor). For a given input, the response of the RBFN controller is tuned by using T factor for bet...

  1. Hypertension control and other cardiovascular risk factors among ...

    African Journals Online (AJOL)

    Their age, sex weight, height, blood pressure, fasting capillary blood glucose, lipid and renal profiles, hypertension and diabetes therapy were ascertained. Results: Hypertension prevalence was 54.7%. Treatment and control rates of hypertension were 81.7% and 34% respectively. Hypertensive patients were older, more ...

  2. Factors Influencing Prevention and Control of Malaria among ...

    African Journals Online (AJOL)

    AJRH Managing Editor

    transmitted from person to person by the bite of anopheles ... strategies include diagnosis and treatment of clinical cases and the promotion of ..... Employment status. 120. 61.76 .00. Income earning status. 120. 53.94 .00. Socio-cultural conditions and malaria prevention and control practices. Age. 120. 16.79 .00. Education.

  3. Factors influencing community participation in control and related ...

    African Journals Online (AJOL)

    Multivariate analysis was done using binary logistic regression to control for confounders and effect modification. Qualitative data was transcribed, coded and analyzed thematically. Results: religion and levels of income were significantly (P =0.04 and P=0.026 respectively) associated with participation in the research and ...

  4. Resource Form Factor and Installation of GFA Controllers

    Energy Technology Data Exchange (ETDEWEB)

    DeSteese, John G.; Hammerstrom, Donald J.

    2009-11-15

    The focus of this task is to optimize the form and placement of a controller comprising the Grid Friendly™ appliance (GFA) controller, power supply and power relay (and/or a solid-state power electronic switch) that would command a domestic water heater to shed its load in response to stress on the electric power grid. The GFA controller would disconnect the water heater from its supply circuit whenever it senses a low voltage signal or other indicators of system stress communicated via the electric power distribution system. Power would be reconnected to the appliance when the GFA controller senses the absence of these signals. This project has also considered more frequent cycling of this controller’s relay switch to perform demand-side frequency regulation. The principal criteria considered in this optimization are reliability, cost and life expectancy of the GFA components. The alternative embodiments of the GFA equipment under consideration are: Option 1- installation inside the insulation space of the water heater between the tank and jacket Option 2 containment in a separate nearby electrical enclosure Option 3 - as a modification or adjunct to the distribution panel housing and/or the breaker that protects the water heater supply circuit.

  5. Laboratory Preparation of Simulated Sludge for Anaerobic Digestion Experimentation

    Directory of Open Access Journals (Sweden)

    Mahmood K. H. Al-mashhadani

    2015-06-01

    Full Text Available Health and environmental factors as well as operational difficulties are major challenges facing the development of an anaerobic digestion process. Some of these problems relate to the use of sludge collected from primary and secondary clarifier units in wastewater treatment plants for laboratory purposes. The present study addresses the preparation of sludge for laboratory purposes by using a mixture that consists of the digested sludge, which is less pathogenic, compared to the collected sludge from the primary or secondary clarifier, and food wastes. The sludge has been tested experimentally for 19 and 32 days under mesophilic conditions. The results show a steady methane production rate from the anaerobic digester which used sludge with a rate of 1.5 l/day and concentration around 60%, with comparatively low H2S gas content (10 ppm. The methane produced from the digester that used only digested sludge decreases during the experimental period.

  6. Influence of two high-intensity intermittent training programmes on anaerobic capacity in humans

    Directory of Open Access Journals (Sweden)

    K Buśko

    2011-03-01

    Full Text Available The aim of this work was to determine the influence of a maximal effort training programme with variation of the pedalling rate on the anaerobic capacity, post-exercise maximal concentration of lactic acid (LA and acid-alkali balance changes in the capillary blood. Identification of the dependence between the lactic acid concentration and the anaerobic capacity produced in the Wingate test was also the goal. The hypothesis that cycloergometer training consisting of maximal efforts with a load equal to 10% of body weight (BW will elicit bigger changes of measured values in comparison to training with a load of 5% BW was verified. Twenty non-athletes, students of UPE took part in the study. They were divided into 2 groups. The first group (M10; n=9 performed maximal efforts with a load equal to 10% of body weight (BW. The second group (M5; n=11 performed maximal efforts with a load of 5% BW. Control measurements of anaerobic capacity (Wingate test were taken every Monday: before the test (0, during 4 weeks of training (1-4 and for 2 weeks after the test (5-6. Blood for the determination of lactic acid concentration and acid-alkali balance was taken from the fingertip before performing the Wingate test – in the 5th, 7th, 9th and 30th resting minute. Changes of maximal power (Pmax were not statistically significant in either group. Significant differences were found between the two groups after the second week of rest. For mean power (Pm the most important changes were noted in the first week from training (M10 – 6.5%; M5 – 11.0% No significant differences were found between groups. Average values of the individual LA concentration peak (the highest LA concentration occurring after the Wingate test for each individual changed significantly in group M10 from 15.233±2.367 mmol/l in the measurement made before training to 12.340±2.353 mmol/l in the measurement taken 2 weeks after training. Group M5 is characterised by a change of this factor

  7. Strong antimicrobial activity of xanthohumol and other derivatives from hops (Humulus lupulus L.) on gut anaerobic bacteria

    Czech Academy of Sciences Publication Activity Database

    Čermák, P.; Olšovská, J.; Mikyška, A.; Dušek, M.; Kadlečková, Z.; Vaníček, J.; Nyč, O.; Sigler, Karel; Bostíková, V.; Bostík, P.

    2017-01-01

    Roč. 125, č. 11 (2017), s. 1033-1038 ISSN 0903-4641 Institutional support: RVO:61388971 Keywords : Xanthohumol * gut * anaerobic bacteria Subject RIV: EE - Microbiology, Virology OBOR OECD: Microbiology Impact factor: 1.795, year: 2016

  8. Factors Controlling Methane in Arctic Lakes of Southwest Greenland

    Science.gov (United States)

    2016-01-01

    We surveyed 15 lakes during the growing season of 2014 in Arctic lakes of southwest Greenland to determine which factors influence methane concentrations in these systems. Methane averaged 2.5 μmol L-1 in lakes, but varied a great deal across the landscape with lakes on older landscapes farther from the ice sheet margin having some of the highest values of methane reported in lakes in the northern hemisphere (125 μmol L-1). The most important factors influencing methane in Greenland lakes included ionic composition (SO4, Na, Cl) and chlorophyll a in the water column. DOC concentrations were also related to methane, but the short length of the study likely underestimated the influence and timing of DOC on methane concentrations in the region. Atmospheric methane concentrations are increasing globally, with freshwater ecosystems in northern latitudes continuing to serve as potentially large sources in the future. Much less is known about how freshwater lakes in Greenland fit in the global methane budget compared to other, more well-studied areas of the Arctic, hence our work provides essential data for a more complete view of this rapidly changing region. PMID:27454863

  9. A case of MRSA controlled: predisposing factors and immune stimulation.

    Science.gov (United States)

    Lamson, Davis W; Sadlon, Angela E

    2010-07-01

    Most treatments for methicillin-resistant Staphylococcus aureus (MRSA) focus on agents to eliminate the bacterium. Since MRSA infection is not universal, susceptibility factors are possible. Immune resistance could be lowered in such individuals; therefore, locating immune-inhibiting or immune-enhancing factors might decrease susceptibility. Such seemed to be the case in a 48-year-old female who presented with recurring MRSA despite multiple rounds of a variety of antibiotics. When the patient encountered an intensely stressful situation an outbreak of MRSA occurred. The patient had additional underlying health issues that suppressed her immune system and made her more susceptible to stress. Gluten allergy and hypothyroidism were discovered and alleviated but did not end the MRSA outbreaks. Implementation of a popular treatment from the 1930s, intravenous dilute hydrochloric acid (for immune stimulation), prevented most MRSA outbreaks when administered frequently. This case provides anecdotal support for the proposition that immune enhancement is a viable approach to forestall or clear recurring MRSA.

  10. Factors Controlling the Pharmacokinetics, Biodistribution and Intratumoral Penetration of Nanoparticles

    Science.gov (United States)

    Ernsting, Mark J.; Murakami, Mami; Roy, Aniruddha; Li, Shyh-Dar

    2014-01-01

    Nanoparticle drug delivery to the tumor is impacted by multiple factors: nanoparticles must evade clearance by renal filtration and the reticuloendothelial system, extravasate through the enlarged endothelial gaps in tumors, penetrate through dense stroma in the tumor microenvironment to reach the tumor cells, remain in the tumor tissue for a prolonged period of time, and finally release the active agent to induce pharmacological effect. The physicochemical properties of nanoparticles such as size, shape, surface charge, surface chemistry (PEGylation, ligand conjugation) and composition affect the pharmacokinetics, biodistribution, intratumoral penetration and tumor bioavailability. On the other hand, tumor biology (blood flow, perfusion, permeability, interstitial fluid pressure and stroma content) and patient characteristics (age, gender, tumor type, tumor location, body composition and prior treatments) also have impact on drug delivery by nanoparticles. It is now believed that both nanoparticles and the tumor microenvironment have to be optimized or adjusted for optimal delivery. This review provides a comprehensive summary of how these nanoparticle and biological factors impact nanoparticle delivery to tumors, with discussion on how the tumor microenvironment can be adjusted and how patients can be stratified by imaging methods to receive the maximal benefit of nanomedicine. Perspectives and future directions are also provided. PMID:24075927

  11. Idiopathic epistaxis and meteorological factors: case-control study.

    Science.gov (United States)

    Jelavic, B; Majstorovic, Z; Kordić, M; Leventić, M; Grgić, M V; Baudoin, T

    2015-01-01

    The aim of this study was to determine the relationship between the occurrence of idiopathic epistaxis and daily values of air pressure, temperature, and humidity. We also investigated whether biometeorological forecasts should be addressed to persons with a history of nosebleed diathesis. We analyzed consecutive idiopathic epistaxis events over a 3-year period. Patients were included if they had been in the municipality of Mostar, Bosnia and Herzegovina at least 24 hours before the epistaxis occurrence. The monthly variation in epistaxis events was determined. Epistaxis days (Days "0", 0 = day with epistaxis occurrence) and selected nonepistaxis days (Days "-1", -1 = each first single day without epistaxis prior to Day 0) were compared according to daily values of mean, minimum, and maximum temperature; diurnal temperature range; minimum and maximum atmospheric pressure; diurnal pressure range; and mean relative humidity. The greatest and smallest percentage of epistaxis events occurred in the months of March and August, respectively. There were no significant differences between Days 0 and Days -1 with respect to the examined meteorological factors. In this region with a Mediterranean climate, we found a seasonal variation with an incidence peak during the spring transition months, but we did not identify any meteorological trigger factors for epistaxis. Thus, there is no need for biometeorological forecasts to be addressed to persons with a history of nosebleed diathesis.

  12. Risk factors for Creutzfeldt-Jakob disease: a reanalysis of case-control studies.

    NARCIS (Netherlands)

    D.P.W.M. Wientjens (Dorothee); Z. Davanipour; K. Kondo; W.B. Matthews; R.G. Will (Robert); C.M. van Duijn (Cornelia); A. Hofman (Albert)

    1996-01-01

    textabstractTo review the evidence for risk factors of Creutzfeldt-Jakob disease (CJD), we pooled and reanalyzed the raw data of three case-control studies. The pooled data set comprised 178 patients and 333 control subjects. The strength of association between CJD and putative risk factors was

  13. Human Factors Analysis of Pipeline Monitoring and Control Operations: Final Technical Report

    Science.gov (United States)

    2008-11-26

    The purpose of the Human Factors Analysis of Pipeline Monitoring and Control Operations project was to develop procedures that could be used by liquid pipeline operators to assess and manage the human factors risks in their control rooms that may adv...

  14. Tobacco control policy development in the European Union: do political factors matter?

    NARCIS (Netherlands)

    Bosdriesz, Jizzo R.; Willemsen, Marc C.; Stronks, Karien; Kunst, Anton E.

    2015-01-01

    There has been much variation between European countries in the development of tobacco control policy. Not much is known about the factors that shape this variation. This study aimed to assess the role of political factors in tobacco control policy development. We used data from 11 European

  15. 76 FR 35130 - Pipeline Safety: Control Room Management/Human Factors

    Science.gov (United States)

    2011-06-16

    ... benefit of this rulemaking action is an expedited implementation deadline of the CRM rule that realizes... the Control Room Management/Human Factors regulations in order to realize the safety benefits sooner... FR 5536). By this amendment to the Control Room Management/Human Factors (CRM) rule, an operator must...

  16. Produksi biogas dari pencerna anaerob serasah dan eceng gondok (Eichhornia crassipes dengan sumber inokulum kotoran sapi dan kotoran ayam

    Directory of Open Access Journals (Sweden)

    REVOLUSI PRAJANINGRAT SAKTIYUDHA

    2014-11-01

    Full Text Available Saktiyudha RP. 2014. Biogas production from anaerobic digesters of leaf litter and water hyacinth (Eichhornia crassipes with a source of inoculum cattle and chicken manures. Bioteknologi 11: 23-27. Biogas is a renewable alternative energy source also has the added value, which is in the processing of waste biomass is environmentally friendly. This study aims to examine the production of biogas in anaerobic reform process based on a mixture of biomass litter substrate and water hyacinth (Eichhornia crassipes Mart. Solms using inoculum source of cattle manure and chicken manure. Litter biomass and water hyacinth biomass were as a substrate (80% in the anaerobic digester with inoculum source of cattle manure or chicken manure (20% through the fermentation process. Factorial experiment with four replications performed using a completely randomized design (CRD with two factors. The first factor in the form of variations in the substrate, the substrate control with 100 % litter, litter substrate variation and water hyacinth (75%:25%, and a mixture of litter and water hyacinth (50%:50% . The second factor were a variation of the source of inoculum, ie cattle manure and chicken manure. Parameter measurements performed at weeks 0th, 2nd, 4th, 6th. Parameters observed were volume of biogas, CH4 concentration, temperature, pH, COD, BOD, TS and VS. Data were analyzed by ANOVA followed by DMRT at 5 % level test. Highest production of biogas in the sixth week (862.5 ml was showed by the treatment of 75 % litter and 25 % water hyacinth with inoculum source of cattle manure. Removal efficiency of COD; BOD; TS and VS on that treatment were amounted to 76.12 %, 32.88 %, 66.53 % and 63.74 %.

  17. Patient factors and glycaemic control--associations and explanatory power

    DEFF Research Database (Denmark)

    Rogvi, S; Tapager, I; Almdal, T P

    2012-01-01

    . The electronic patient record provided information about HbA(1c), medication, body mass index, and duration of diabetes. Data were analysed using multiple linear regression models with stepwise addition of covariates. RESULTS: The response rate was 54% (n = 1081). Good glycaemic control was significantly...... of care and diabetes distress accounted for 14% of the total variance in HbA(1c) levels (P = 0.0134), but the variance explained was higher for respondents treated with medications other than insulin. CONCLUSIONS: Our study emphasizes the complex relationships between patient activation, distress...

  18. Rate Controlling Factors in a Bunsen Burner Flame

    Science.gov (United States)

    Andrade-Gamboa, Julio; Corso, Hugo L.; Gennari, Fabiana C.

    2003-05-01

    Combustion and flames have been extensively investigated during past decades due to their industrial importance. The associated phenomena are both physical and chemical in nature, and the rigorous mathematical description is beyond the undergraduate teaching level. While thermodynamic calculations of temperature of a Bunsen burner flame can be made at the college level, there are not accessible chemical kinetic descriptions that can be used for instruction. In this paper we present a simple model that accounts for mass transfer, energy transfer, and kinetics of chemical reaction. From such a description, different controlling regimes can be deduced and tested with experimental data.

  19. Batch anaerobic methanogenesis of phenolic coal conversion waste water

    Energy Technology Data Exchange (ETDEWEB)

    Fedorak, P.M.; Hrudey, S.E.

    1985-01-01

    The amenability to anaerobic treatment of a phenolic wastewater from a coal conversion pilot plant was investigated in batch experiments using the Hungate serum bottle technique, using cultures containing unmodified wastewater, wastewater extracted with ether, and pre-reduced, reconstituted wastewater. Data are given on the composition of the wastewater and the concentrations of various phenolic compounds present. Wastewater concentrations of 2, 4 and 6% (vol/vol) increased methane production compared with control cultures, but higher concentrations of the wastewater were inhibitory. Further experiments indicated that the inhibitory components were ether-extractable, but were not any of the major phenolic compounds present in the original wastewater. There was also evidence to confirm that m-cresol was amenable to anaerobic degradation.

  20. Design considerations and operational performance of Anaerobic Digester: A Review

    Directory of Open Access Journals (Sweden)

    Muzaffar Ahmad Mir

    2016-04-01

    Full Text Available Due to the decline in fossil fuel reservoirs, the researchers emphasized more on the production of biogas from organic waste. Producing the renewable energy from biodegradable waste helps to overcome the energy crisis and solid waste management, done by anaerobic digestion. Anaerobic digestion is controlled breakdown of organic matter into methane gas (60%, carbon dioxide (40%, trace components along with digested used as soil conditioner. However there is vast dearth of literature regarding the design considerations. The batch digestion system yields a cost-effective and economically viable means for conversion of the food waste to useful energy. It is therefore recommended that such process can be increasingly employed in order to get and simultaneously protect the environment .This paper aims to draw key analysis and concern about the design considerations, analysis of gas production, substrates and inoculums utilization, uses and impacts of biogas.

  1. Microbial electrochemical monitoring of volatile fatty acids during anaerobic digestion

    DEFF Research Database (Denmark)

    Jin, Xiangdan; Angelidaki, Irini; Zhang, Yifeng

    2016-01-01

    Volatile fatty acid (VFA) concentration is known as an important indicator to control and optimize anaerobic digestion (AD) process. In this study, an innovative VFA biosensor was developed based on the principle of a microbial desalination cell. The correlation between current densities and VFA...... concentrations was firstly evaluated with synthetic digestate. Two linear relationships were observed between current densities and VFA levels from 1 to 30 mM (0.04 to 8.50 mA/m2, R2=0.97) and then from 30 to 200 mM (8.50 to 10.80 mA/m2, R2=0.95). The detection range was much broader than that of other existing...... and reliable measurement of VFA levels during AD and other anaerobic processes....

  2. Special Issue on “Microbial Ecology of Anaerobic Digestion”

    Directory of Open Access Journals (Sweden)

    Sabine Kleinsteuber

    2014-06-01

    Full Text Available Anaerobic digestion (AD is an efficient and sustainable way of using organic carbon from residual biomass and organic waste for the production of renewable energy, while simultaneously recycling nutrients and cleaning up waste streams. The process relies on complex microbial communities comprised of diverse functional guilds; these communities have manifold metabolic pathways and interactions. In contrast to the conventional view of an anaerobic digester as a black box, advanced microbiological methods have paved the way for understanding and even controlling complex microbial networks. Nowadays, microbial resource management is crucial for technological progress in AD, and offers new perspectives concerning sustainable waste management, renewable energy production, resource efficiency, and advanced bio-refineries; these perspectives lead to novel applications of AD processes that go beyond biogas as the main product. [...

  3. An Experimental Protocol to Model Recovery of Anaerobic Work Capacity

    Directory of Open Access Journals (Sweden)

    Vijay Sarthy M. Sreedhara

    2018-02-01

    Full Text Available Models of fatigue are based on physiological parameters such as Critical Power (CP and Anaerobic Work Capacity (AWC. CP is a theoretical threshold value that a human can generate for an indefinite amount of time and AWC represents a finite expendable amount of anaerobic energy at intensities above CP. There is an increasing interest in developing mathematical models of energy expenditure and recovery for athletic training and human performance. The objective of this research is to propose and validate a model for recovery of AWC during a post exertion recovery interval of cycling. A cycling ergometer study is proposed which involves a VO2max ramp test to determine gas exchange threshold, a 3-min all-out intensity test to determine CP and AWC, and exertion-recovery interval tests to understand recovery of AWC. The results will be used to build a human in the loop control system to optimize cycling performance.

  4. Dynamics of the anaerobic process: Effects of volatile fatty acids

    DEFF Research Database (Denmark)

    Pind, Peter Frode; Angelidaki, Irini; Ahring, Birgitte Kiær

    2003-01-01

    A complex and fast dynamic response of the anaerobic biogas system was observed when the system was subjected to pulses of volatile fatty acids (VFAs). It was shown that a pulse of specific VFAs into a well-functioning continuous stirred tank reactor (CSTR) system operating on cow manure affected...... or inhibition was shown for the degradation of all VFAs tested. Based on the results, it was concluded that measurements of all specific VFAs are important for control purposes and increase and decrease in a specific VFA should always be evaluated in close relationship to the conversion of other VFAs...... and the history of the reactor process. It should be pointed out that the observed dynamics of VFA responses were based on hourly measurements, meaning that the response duration was much lower than the hydraulic retention time, which exceeds several days in anaerobic CSTR systems....

  5. EFFECT OF MUSIC ON ANAEROBIC EXERCISE PERFORMANCE

    Science.gov (United States)

    2013-01-01

    For years, mostly the effects of music on cardiorespiratory exercise performance have been studied, but a few studies have examined the effect of music on anaerobic exercise. The purpose of this study was to assess the effect of listening to music and its rhythm on anaerobic exercise: on power output, heart rate and the concentration of blood lactate. 28 male subjects were required to visit the laboratory on 6 occasions, each separated by 48 hours. Firstly, each subject performed the Running-based Anaerobic Sprint Test (RAST) under 3 conditions on separate days: while listening to “slow rhythm music”, “fast rhythm music” or “no music”. 48 hours after the subjects completed RAST under 3 conditions, Wingate Anaerobic Power (WAN) tests were performed under 3 music conditions. The order of the 3 conditions (slow music, fast music and no music) was selected randomly to prevent an order effect. Results showed no significant differences between 3 conditions in anaerobic power assessments, heart rate or blood lactate (p > 0.05). On the basis of these results it can be said that music cannot improve anaerobic performance. The type of music had no impact on power outputs during RAST and WAN exercise. As a conclusion, listening to music and its rhythm cannot enhance anaerobic performance and cannot change the physiological response to supramaximal exercise. PMID:24744463

  6. EFFECT OF MUSIC ON ANAEROBIC EXERCISE PERFORMANCE

    Directory of Open Access Journals (Sweden)

    Tülin Atan

    2013-01-01

    Full Text Available For years, mostly the effects of music on cardiorespiratory exercise performance have been studied, but a few studies have examined the effect of music on anaerobic exercise. The purpose of this study was to assess the effect of listening to music and its rhythm on anaerobic exercise: on power output, heart rate and the concentration of blood lactate. 28 male subjects were required to visit the laboratory on 6 occasions, each separated by 48 hours. Firstly, each subject performed the Running-based Anaerobic Sprint Test (RAST under 3 conditions on separate days: while listening to “slow rhythm music”, “fast rhythm music” or “no music”. 48 hours after the subjects completed RAST under 3 conditions, Wingate Anaerobic Power (WAN tests were performed under 3 music conditions. The order of the 3 conditions (slow music, fast music and no music was selected randomly to prevent an order effect. Results showed no significant differences between 3 conditions in anaerobic power assessments, heart rate or blood lactate (p>0.05. On the basis of these results it can be said that music cannot improve anaerobic performance. The type of music had no impact on power outputs during RAST and WAN exercise. As a conclusion, listening to music and its rhythm cannot enhance anaerobic performance and cannot change the physiological response to supramaximal exercise.

  7. Molecular ecology of anaerobic reactor systems

    DEFF Research Database (Denmark)

    Hofman-Bang, H. Jacob Peider; Zheng, D.; Westermann, Peter

    2003-01-01

    Anaerobic reactor systems are essential for the treatment of solid and liquid wastes and constitute a core facility in many waste treatment plants. Although much is known about the basic metabolism in different types of anaerobic reactors, little is known about the microbes responsible for these ......Anaerobic reactor systems are essential for the treatment of solid and liquid wastes and constitute a core facility in many waste treatment plants. Although much is known about the basic metabolism in different types of anaerobic reactors, little is known about the microbes responsible...... and malfunctions of anaerobic digesters occasionally experienced, leading to sub-optimal methane production and wastewater treatment. Using a variety of molecular techniques, we are able to determine which microorganisms are active, where they are active, and when they are active, but we still need to determine...... to the abundance of each microbe in anaerobic reactor systems by rRNA probing. This chapter focuses on various molecular techniques employed and problems encountered when elucidating the microbial ecology of anaerobic reactor systems. Methods such as quantitative dot blot/fluorescence in-situ probing using various...

  8. Tunable signal processing through modular control of transcription factor translocation.

    Science.gov (United States)

    Hao, Nan; Budnik, Bogdan A; Gunawardena, Jeremy; O'Shea, Erin K

    2013-01-25

    Signaling pathways can induce different dynamics of transcription factor (TF) activation. We explored how TFs process signaling inputs to generate diverse dynamic responses. The budding yeast general stress-responsive TF Msn2 acted as a tunable signal processor that could track, filter, or integrate signals in an input-dependent manner. This tunable signal processing appears to originate from dual regulation of both nuclear import and export by phosphorylation, as mutants with one form of regulation sustained only one signal-processing function. Versatile signal processing by Msn2 is crucial for generating distinct dynamic responses to different natural stresses. Our findings reveal how complex signal-processing functions are integrated into a single molecule and provide a guide for the design of TFs with "programmable" signal-processing functions.

  9. [Development of mobile monitor for risk factor control on chronic disease].

    Science.gov (United States)

    Yao, Danhua; Zhu, Chaoyang; Bao, Jiali

    2013-11-01

    In order to improve the control rate of risk factors of chronic disease, it is developed a status control method of risk factor and its mobile monitor. The monitor uses 32 bit RISC microprocessor of S3C2410X as a controller based on ARM920T core, and MC35i cellular engine GSM/GPRS supported by SIEMENS as the communication unit. The proving tests show that the physical activity, diet, smoking and alcohol of the controlled people can be controlled using the status control method, and the monitor plays a key role in the method. The conclusion is that status control method and mobile monitor can become an alternation method and technology for the risk factor control of chronic disease.

  10. A case-control study of risk factors for sporadic campylobacter infections in Denmark

    DEFF Research Database (Denmark)

    Neimann, J.; Engberg, J.; Molbak, K.

    2003-01-01

    as risk factors in one of the two models only. Finally, foreign travel was found to be a significant risk factor (OR 2(.)5). Seasonal and regional interaction was observed for several risk factors and the time elapsed from interviewing of cases to interviewing of controls seemed to influence the effect...

  11. Optimization of up-flow anaerobic sludge blanket reactor for ...

    African Journals Online (AJOL)

    Optimization of up-flow anaerobic sludge blanket reactor for treatment of composite fermentation and distillation wastewater. ... Keywords: Composite wastewater, up-flow anaerobic sludge blanket (UASB), anaerobic biological treatment, biogas, granulated anaerobic sludge, industrial wastewater. African Journal of ...

  12. A simple anaerobic system for onsite treatment of domestic wastewater

    African Journals Online (AJOL)

    Among several anaerobic treatment processes, high rate anaerobic digesters receive great attention due to its high loading capacity and chemical oxygen demand removal rate. Up-flow anaerobic sludge blanket reactor (UASB) is getting wide acceptance among several anaerobic processes. However, its application is still ...

  13. Factors controlling sulfur gas exchange in Sphagnum-dominated wetlands

    Science.gov (United States)

    Demello, William Zamboni; Hines, Mark E.; Bayley, Suzanne E.

    1992-01-01

    Atmosphere-peatland exchange of reduced sulfur gases was determined seasonally in fen in NH, and in an artificially-acidified fen at the Experimental Lakes Area (ELA) in Canada. Dimethyl sulfide (DMS) dominated gas fluxes at rates as high as 400 nmol/m(sup -2)hr(sup -1). DMS fluxes measured using enclosures were much higher than those calculated using a stagnant-film model, suggesting that Sphagnum regulated efflux. Temperature controlled diel and seasonal variability in DMS emissions. Use of differing enclosure techniques indicated that vegetated peatlands consume atmospheric carbonyl sulfide. Sulfate amendments caused DMS and methane thiol concentrations in near-surface pore waters to increase rapidly, but fluxes of these gases to the atmosphere were not affected. However, emission data from sites experiencing large differences in rates of sulfate deposition from the atmosphere suggested that chronic elevated sulfate inputs enhance DMS emissions from northern wetlands.

  14. Block factorization of step response model predictive control problems

    DEFF Research Database (Denmark)

    Kufoalor, D. K.M.; Frison, Gianluca; Imsland, L.

    2017-01-01

    implemented in the HPMPC framework, and the performance is evaluated through simulation studies. The results confirm that a computationally fast controller is achieved, compared to the traditional step response MPC scheme that relies on an explicit prediction formulation. Moreover, the tailored condensing......By introducing a stage-wise prediction formulation that enables the use of highly efficient quadratic programming (QP) solution methods, this paper expands the computational toolbox for solving step response MPC problems. We propose a novel MPC scheme that is able to incorporate step response data...... algorithm exhibits superior performance and produces solution times comparable to that achieved when using a condensing scheme for an equivalent (but much smaller) state-space model derived from first-principles. Implementation aspects necessary for high performance on embedded platforms are discussed...

  15. Factors controlling the regional distribution of vanadium in ground water

    Science.gov (United States)

    Wright, Michael T.; Belitz, Kenneth

    2010-01-01

    Although the ingestion of vanadium (V) in drinking water may have possible adverse health effects, there have been relatively few studies of V in groundwater. Given the importance of groundwater as a source of drinking water in many areas of the world, this study examines the potential sources and geochemical processes that control the distribution of V in groundwater on a regional scale. Potential sources of V to groundwater include dissolution of V rich rocks, and waste streams from industrial processes. Geochemical processes such as adsorption/desorption, precipitation/dissolution, and chemical transformations control V concentrations in groundwater. Based on thermodynamic data and laboratory studies, V concentrations are expected to be highest in samples collected from oxic and alkaline groundwater. However, the extent to which thermodynamic data and laboratory results apply to the actual distribution of V in groundwater is not well understood. More than 8400 groundwater samples collected in California were used in this study. Of these samples, high (> or = 50 μg/L) and moderate (25 to 49 μg/L) V concentrations were most frequently detected in regions where both source rock and favorable geochemical conditions occurred. The distribution of V concentrations in groundwater samples suggests that significant sources of V are mafic and andesitic rock. Anthropogenic activities do not appear to be a significant contributor of V to groundwater in this study. High V concentrations in groundwater samples analyzed in this study were almost always associated with oxic and alkaline groundwater conditions, which is consistent with predictions based on thermodynamic data.

  16. ISOLATION OF OBLIGATELY ANAEROBIC PSYCHROPHILIC BACTERIA.

    Science.gov (United States)

    SINCLAIR, N A; STOKES, J L

    1964-03-01

    Sinclair, N. A. (Washington State University, Pullman), and J. L. Stokes. Isolation of obligately anaerobic psychrophilic bacteria. J. Bacteriol. 87:562-565. 1964.-A total of 11 strains of strictly anaerobic psychrophilic bacteria have been isolated from soil, mud, and sewage. The organisms grow well at 0 C in liquid and on solid media, and grow only in the complete absence of oxygen. On the basis of shape, sporulation, flagellation, and strictly anaerobic growth, all of the organisms were classified as strains of Clostridium. Some of the biochemical properties of the strains and the effect of temperature on growth are described.

  17. Intraspecific variation in aerobic and anaerobic locomotion

    DEFF Research Database (Denmark)

    Svendsen, Jon Christian; Tirsgård, Bjørn; Cordero, Gerardo A.

    2015-01-01

    Intraspecific variation and trade-off in aerobic and anaerobic traits remain poorly understood in aquatic locomotion. Using gilthead sea bream (Sparus aurata) and Trinidadian guppy (Poecilia reticulata), both axial swimmers, this study tested four hypotheses: (1) gait transition from steady...... to unsteady (i.e., burst-assisted) swimming is associated with anaerobic metabolism evidenced as excess post exercise oxygen consumption (EPOC); (2) variation in swimming performance (critical swimming speed; U crit) correlates with metabolic scope (MS) or anaerobic capacity (i.e., maximum EPOC); (3...

  18. Anaerobic degradation of linear alkylbenzene sulfonate

    DEFF Research Database (Denmark)

    Mogensen, Anders Skibsted; Haagensen, Frank; Ahring, Birgitte Kiær

    2003-01-01

    Linear alkylbenzene sulfonate (LAS) found in wastewater is removed in the wastewater treatment facilities by sorption and aerobic biodegradation. The anaerobic digestion of sewage sludge has not been shown to contribute to the removal. The concentration of LAS based on dry matter typically...... increases during anaerobic stabilization due to transformation of easily degradable organic matter. Hence, LAS is regarded as resistant to biodegradation under anaerobic conditions. We present data from a lab-scale semi-continuously stirred tank reactor (CSTR) spiked with linear dodecylbenzene sulfonate (C...

  19. Single-cell analysis of growth and cell division of the anaerobe Desulfovibrio vulgaris Hildenborough

    Directory of Open Access Journals (Sweden)

    Anouchka eFievet

    2015-12-01

    Full Text Available Recent years have seen significant progress in understanding basic bacterial cell cycle properties such as cell growth and cell division. While characterization and regulation of bacterial cell cycle is quite well documented in the case of fast growing aerobic model organisms, no data has been so far reported for anaerobic bacteria. This lack of information in anaerobic microorganisms can mainly be explained by the absence of molecular and cellular tools such as single cell microscopy and fluorescent probes usable for anaerobes and essential to study cellular events and/or subcellular localization of the actors involved in cell cycle.In this study, single-cell microscopy has been adapted to study for the first time, in real time, the cell cycle of a bacterial anaerobe, Desulfovibrio vulgaris Hildenborough (DvH. This single-cell analysis provides mechanistic insights into the cell division cycle of DvH, which seems to be governed by the recently discussed so-called incremental model that generates remarkably homogeneous cell sizes. Furthermore, cell division was reversibly blocked during oxygen exposure. This may constitute a strategy for anaerobic cells to cope with transient exposure to oxygen that they may encounter in their natural environment, thereby contributing to their aerotolerance. This study lays the foundation for the first molecular, single-cell assay that will address factors that cannot otherwise be resolved in bulk assays and that will allow visualization of a wide range of molecular mechanisms within living anaerobic cells.

  20. Physiological testing of basketball players: toward a standard evaluation of anaerobic fitness.

    Science.gov (United States)

    Delextrat, Anne; Cohen, Daniel

    2008-07-01

    The aim of this study was to examine whether the changes in the rules of the game instituted in 2000 have modified the physiological factors of success in basketball. The performances of 8 elite male players and 8 average-level players were compared in order to identify which components of fitness among agility, speed, anaerobic power, anaerobic capacity, and upper body strength were key determinants of performance in modern basketball. Each subject performed 7 tests, including vertical jump (VJ), 20-m sprint, agility T test, suicide sprint, 30-second Wingate anaerobic test (WAnT), isokinetic testing of the knee extensors, and 1 repetition maximum (1RM) bench press test. The statistical difference in the anaerobic performances was assessed by Student's t test. The main results showed that, compared to average-level players, elite-level players achieved significantly better performances in the agility T test (+6.2%), VJ test (+8.8%), peak torques developed by knee extensors (+20.2%), and 1RM bench press (+18.6%, p 0.05). These results emphasized the importance of anaerobic power in modern basketball, whereas anaerobic capacity does not seem to be a key aspect to consider. In this context, coaches are advised to avoid using exercises lasting >/=30 seconds in their physical fitness programs, but instead to focus on short and intense tests such as VJ, agility T test, and sprints over very short distances (5 or 10 m).

  1. Stress hormone epinephrine (adrenaline) and norepinephrine (noradrenaline) effects on the anaerobic bacteria.

    Science.gov (United States)

    Boyanova, Lyudmila

    2017-04-01

    Microbial endocrinology is a relatively new research area that already encompasses the anaerobes. Stress hormones, epinephrine and norepinephrine, can affect the growth of anaerobic bacteria such as Fusobacterium nucleatum, Prevotella spp., Porhyromonas spp., Tanerella forsythia and Propionibacterium acnes and can increase virulence gene expression, iron acquisition and many virulence factors of some anaerobic species such as Clostridium perfringens, Porphyromonas gingivalis and Brachyspira pilosicoli. Epinephrine and norepinephrine effects can lead to a growth increase or decrease, or no effect on the growth of the anaerobes. The effects are species-specific and perhaps strain-specific. Discrepancies in the results of some studies can be due to the different methods and media used, catecholamine concentrations, measurement techniques and the low number of strains tested. Biological effects of the stress hormones on the anaerobes may range from halitosis and a worsening of periodontal diseases to tissue damages and atherosclerotic plaque ruptures. Optimizations of the research methods and a detailed assessment of the catecholamine effects in conditions mimicking those in affected organs and tissues, as well as the effects on the quorum sensing and virulence of the anaerobes and the full spectrum of biological consequences of the effects are interesting topics for further evaluation. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Accelerated anaerobic hydrolysis rates under a combination of intermittent aeration and anaerobic conditions

    DEFF Research Database (Denmark)

    Jensen, T. R.; Lastra Milone, T.; Petersen, G.

    2017-01-01

    Anaerobic hydrolysis in activated return sludge was investigated in laboratory scale experiments to find if intermittent aeration would accelerate anaerobic hydrolysis rates compared to anaerobic hydrolysis rates under strict anaerobic conditions. The intermittent reactors were set up in a 240 h...... for calculating hydrolysis rates based on soluble COD were compared. Two-way ANOVA with the Bonferroni post-test was performed in order to register any significant difference between reactors with intermittent aeration and strictly anaerobic conditions respectively. The experiment demonstrated a statistically...... significant difference in favor of the reactors with intermittent aeration showing a tendency towards accelerated anaerobic hydrolysis rates due to application of intermittent aeration. The conclusion of the work is thus that intermittent aeration applied in the activated return sludge process (ARP) can...

  3. Crustacean biodiversity as an important factor for mosquito larval control.

    Science.gov (United States)

    Kroeger, Iris; Duquesne, Sabine; Liess, Matthias

    2013-12-01

    Newly established ponds, which are highly dynamic systems with changing levels of biological interactions among species, are common larval mosquito habitats. We investigated the impact of crustacean abundance and taxa diversity on mosquito oviposition and larval development. The effects of the biological larvicide Bacillus thuringiensis israelensis (Bti) on mosquito larvae were monitored according to fluctuations in crustacean communities. Populations of the mosquito Culex pipiens colonized artificial ponds that contained crustacean communities at different time points of colonization by crustaceans: 1) 'no colonization' (no crustaceans), 2) 'simultaneous colonization' by crustaceans and mosquitoes, and 3) 'head-start colonization' by crustaceans (preceding colonization by mosquitoes). All types of ponds were treated with three concentrations of Bti (10, 100, or 1,000 µg/liter). Colonization of all ponds by Cx. pipiens (in terms of oviposition, larval abundance, and larval development) decreased significantly with increasing diversity of crustacean taxa. The total abundance of crustaceans had a minor effect on colonization by Cx. pipiens. The presence of crustaceans increased the sensitivity of Cx. pipiens larvae to Bti treatment by a factor of 10 and delayed the time of recolonization. This effect of Bti was relevant in the short term. In the long term, the presence of Cx. pipiens was determined by crustacean biodiversity. © 2013 The Society for Vector Ecology.

  4. Strain Specific Factors Control Effector Gene Silencing in Phytophthora sojae.

    Directory of Open Access Journals (Sweden)

    Sirjana Devi Shrestha

    Full Text Available The Phytophthora sojae avirulence gene Avr3a encodes an effector that is capable of triggering immunity on soybean plants carrying the resistance gene Rps3a. P. sojae strains that express Avr3a are avirulent to Rps3a plants, while strains that do not are virulent. To study the inheritance of Avr3a expression and virulence towards Rps3a, genetic crosses and self-fertilizations were performed. A cross between P. sojae strains ACR10 X P7076 causes transgenerational gene silencing of Avr3a allele, and this effect is meiotically stable up to the F5 generation. However, test-crosses of F1 progeny (ACR10 X P7076 with strain P6497 result in the release of silencing of Avr3a. Expression of Avr3a in the progeny is variable and correlates with the phenotypic penetrance of the avirulence trait. The F1 progeny from a direct cross of P6497 X ACR10 segregate for inheritance for Avr3a expression, a result that could not be explained by parental imprinting or heterozygosity. Analysis of small RNA arising from the Avr3a gene sequence in the parental strains and hybrid progeny suggests that the presence of small RNA is necessary but not sufficient for gene silencing. Overall, we conclude that inheritance of the Avr3a gene silenced phenotype relies on factors that are variable among P. sojae strains.

  5. Anaerobic microflora under Class I and Class II composite and amalgam restorations.

    Science.gov (United States)

    Splieth, Christian; Bernhardt, Olaf; Heinrich, Annegret; Bernhardt, Hannelore; Meyer, Georg

    2003-01-01

    The microflora around and beneath restorations is an important factor of restoration failure. The aim of this pilot study was to determine and compare the microbial spectrum under composite and amalgam restorations with special attention to the anaerobic flora. Ten composite and five amalgam restorations scheduled for replacement were clinically evaluated for marginal gaps, fractures, and secondary caries. After their removal and caries diagnosis, a dentin sample just below the restoration was taken under sterile conditions, stored in a prereduced transport medium for anaerobic bacteria, and immediately transferred to a laboratory for microbial diagnosis. The clinical parameters showing mostly moderate marginal imperfections and the ratios of aerobic to anaerobic flora were comparable for composite and amalgam restorations (11.4%:88.6% and 15.4%:84.5%, respectively). The microbial variety under composite restorations was much greater compared to amalgam, and it was similar to that of infected root canals including anaerobic gram-negative rods, such as Fusobacterium species or Porphyromonas species. Beneath amalgam, the microbial flora was similar to the one found in carious dentin and plaque, with anaerobic and facultatively anaerobic gram-positive rods dominating. Quantitatively, there were up to eight times more microorganisms under composite restorations. The number of bacterial strains correlated with the caries activity and the filling material, the number of anaerobic rods correlated highly with caries activity and localization. In a linear regression, caries activity and the filling material had statistically significant influence on the bacterial load. Although caries activity and location had the greatest influence on the microbial flora under the restorations, the kind of restoration material seemed to have an additional effect on the composition of the microflora. This pilot study indicates that inadequate composite restorations may promote the growth of

  6. Deep sequencing-based analysis of the anaerobic stimulon in Neisseria gonorrhoeae

    Directory of Open Access Journals (Sweden)

    Clark Virginia L

    2011-01-01

    Full Text Available Abstract Background Maintenance of an anaerobic denitrification system in the obligate human pathogen, Neisseria gonorrhoeae, suggests that an anaerobic lifestyle may be important during the course of infection. Furthermore, mounting evidence suggests that reduction of host-produced nitric oxide has several immunomodulary effects on the host. However, at this point there have been no studies analyzing the complete gonococcal transcriptome response to anaerobiosis. Here we performed deep sequencing to compare the gonococcal transcriptomes of aerobically and anaerobically grown cells. Using the information derived from this sequencing, we discuss the implications of the robust transcriptional response to anaerobic growth. Results We determined that 198 chromosomal genes were differentially expressed (~10% of the genome in response to anaerobic conditions. We also observed a large induction of genes encoded within the cryptic plasmid, pJD1. Validation of RNA-seq data using translational-lacZ fusions or RT-PCR demonstrated the RNA-seq results to be very reproducible. Surprisingly, many genes of prophage origin were induced anaerobically, as well as several transcriptional regulators previously unknown to be involved in anaerobic growth. We also confirmed expression and regulation of a small RNA, likely a functional equivalent of fnrS in the Enterobacteriaceae family. We also determined that many genes found to be responsive to anaerobiosis have also been shown to be responsive to iron and/or oxidative stress. Conclusions Gonococci will be subject to many forms of environmental stress, including oxygen-limitation, during the course of infection. Here we determined that the anaerobic stimulon in gonococci was larger than previous studies would suggest. Many new targets for future research have been uncovered, and the results derived from this study may have helped to elucidate factors or mechanisms of virulence that may have otherwise been overlooked.

  7. AN ASSESSMENT OF FACTORS AFFECTING MATERIAL STOCK CONTROL PRACTICE ON SELECTED CONSTRUCTION SITES IN NIGERIA

    OpenAIRE

    Adafin, Johnson Kayode; Ayodele, Elijah Olusegun; Daramola, Olufemi

    2011-01-01

    This research examines the stock control methods utilized by construction firms on construction sites with a view to assessing the factors affecting material stock control practice by construction firms as well as determining the impact of factors affecting material stock control on building project performance. Data were collected with the aid of well-structured questionnaire administered on a number of construction professionals and technicians in some randomly selected building constructio...

  8. Research progress on influencing factors of hospital infection and prevention and control measures

    OpenAIRE

    He Wenlong; Meng Lingbo; Wang Yaogang

    2015-01-01

    Hospital infections are associated with the emergence of hospitals. As the understanding of hospital infections deepen and prevention and control measures improve, hospital infections have become manageable. In recent years, affected by the increase in invasive treatment technology, antimicrobial abuse, and other factors, the control of hospital infection has encountered new problems. This paper reviews the influencing factors of hospital infections and their prevention and control measures.

  9. Evaluation of a microwave-heating anaerobic digester treating municipal secondary sludge.

    Science.gov (United States)

    Jang, Joo-Hyun; Ahn, Johng-Hwa

    2013-01-01

    This work experimentally determined the effect of microwave irradiation on the anaerobic digestion of municipal secondary sludge in semi-continuous mesophilic digesters at hydraulic retention times (HRT) of 15, 10 and 5 days when microwaves were used as a heating source. A microwave-heating anaerobic digester (MHAD) was compared with a water-heating reactor (control). Biogas production increased in both digesters as the HRT decreased except for the control with a HRT of 5 days. Improvement in removal efficiency of volatile solid and biogas production of the MHAD relative to the control increased as the HRT decreased. The results show that the MHAD was more effective than the control in increasing mesophilic anaerobic biodegradability and biogas production treating secondary sludge.

  10. Factors controlling the engraftment of transplanted dog bone marrow cells

    International Nuclear Information System (INIS)

    Vriesendorp, H.M.; Klapwyk, W.M.; Heidt, P.J.; Hogeweg, B.; Zurcher, C.; Bekkum, D.W. van

    1982-01-01

    The LD50 of total body irradiation (TBI) for the bone marrow (BM) syndrome and the gastrointestinal (GI) syndrme was determined in dogs as 3.7 Gy, and 8.5 Gy respectively. Five Gy TBI was adequate conditioning for BM cells of littermate donors identical for the major histocompatibility comples (MHC). The maximum tolerated TBI (about 7.5 Gy) caused more side effects than 5.0 Gy TBI and was insufficient for engraftment of realistic numbers of BM cells of MHC mismatched donors. In autologous and MHC matched transplants, the rateof hemopoietic recovery correlated with the number of BM cells given. Approximtely 2 x 10 7 autologous and 1 x 10 8 MHC identical BM cells.kg -1 were needed for radiation protection. Platelet recovery was significantly more rapid in allogeneic combinations in comparison to autologous transplants. Low numbers of autologous cryopreserved bone marrow cells were as effective as fresh bone marrow cells in rescuing animals after lethal TBI. Other factors that influence BM cell engraftment were confirmed (prior sensitization of the recipient, donor selection) or identified (purification of BM cells on density gradient and selective gastrointestinal decontamination of the recipient). Consistent engraftment of gradient separated, MHC identical, BM cells was found after conditioning with two fractions of 6.0 Gy TBI, separated by 72 h. One MHC haplotype mismatched marrow did engraft after two TBI fractions of 6.0 Gy. Engraftment no longer occurred with gradient purified bone marrow cells from this type of donor. Late effects of TBI were early greying in all animals, and secondary uterine inertia in female dogs after 7.5 GY TBI. Fertility in males or females was not changed by radiation. An increase of pancreas fibrosis was noted in dogs receiving fractions of 6.0 Gy TBI. (author)

  11. Abiotic and Microbiotic Factors Controlling Biofilm Formation by Thermophilic Sporeformers

    Science.gov (United States)

    Zhao, Yu; Caspers, Martien P. M.; Metselaar, Karin I.; de Boer, Paulo; Roeselers, Guus; Moezelaar, Roy; Nierop Groot, Masja; Montijn, Roy C.; Abee, Tjakko

    2013-01-01

    One of the major concerns in the production of dairy concentrates is the risk of contamination by heat-resistant spores from thermophilic bacteria. In order to acquire more insight in the composition of microbial communities occurring in the dairy concentrate industry, a bar-coded 16S amplicon sequencing analysis was carried out on milk, final products, and fouling samples taken from dairy concentrate production lines. The analysis of these samples revealed the presence of DNA from a broad range of bacterial taxa, including a majority of mesophiles and a minority of (thermophilic) spore-forming bacteria. Enrichments of fouling samples at 55°C showed the accumulation of predominantly Brevibacillus and Bacillus, whereas enrichments at 65°C led to the accumulation of Anoxybacillus and Geobacillus species. Bacterial population analysis of biofilms grown using fouling samples as an inoculum indicated that both Anoxybacillus and Geobacillus preferentially form biofilms on surfaces at air-liquid interfaces rather than on submerged surfaces. Three of the most potent biofilm-forming strains isolated from the dairy factory industrial samples, including Geobacillus thermoglucosidans, Geobacillus stearothermophilus, and Anoxybacillus flavithermus, have been characterized in detail with respect to their growth conditions and spore resistance. Strikingly, Geobacillus thermoglucosidans, which forms the most thermostable spores of these three species, is not able to grow in dairy intermediates as a pure culture but appears to be dependent for growth on other spoilage organisms present, probably as a result of their proteolytic activity. These results underscore the importance of abiotic and microbiotic factors in niche colonization in dairy factories, where the presence of thermophilic sporeformers can affect the quality of end products. PMID:23851093

  12. ERAD-dependent control of the Wnt secretory factor Evi.

    Science.gov (United States)

    Glaeser, Kathrin; Urban, Manuela; Fenech, Emma; Voloshanenko, Oksana; Kranz, Dominique; Lari, Federica; Christianson, John C; Boutros, Michael

    2018-02-15

    Active regulation of protein abundance is an essential strategy to modulate cellular signaling pathways. Within the Wnt signaling cascade, regulated degradation of β-catenin by the ubiquitin-proteasome system (UPS) affects the outcome of canonical Wnt signaling. Here, we found that abundance of the Wnt cargo receptor Evi (Wls/GPR177), which is required for Wnt protein secretion, is also regulated by the UPS through endoplasmic reticulum (ER)-associated degradation (ERAD). In the absence of Wnt ligands, Evi is ubiquitinated and targeted for ERAD in a VCP-dependent manner. Ubiquitination of Evi involves the E2-conjugating enzyme UBE2J2 and the E3-ligase CGRRF1. Furthermore, we show that a triaging complex of Porcn and VCP determines whether Evi enters the secretory or the ERAD pathway. In this way, ERAD-dependent control of Evi availability impacts the scale of Wnt protein secretion by adjusting the amount of Evi to meet the requirement of Wnt protein export. As Wnt and Evi protein levels are often dysregulated in cancer, targeting regulatory ERAD components might be a useful approach for therapeutic interventions. © 2018 The Authors. Published under the terms of the CC BY 4.0 license.

  13. Carbohydrate as a factor controlling leaf development in cocoa

    Energy Technology Data Exchange (ETDEWEB)

    Machado, R.C.R.

    1986-01-01

    Cocoa shows growth periodicity of the shoot apex where periods of active new leaf development (flushing) alternate with periods of dormancy (Interflush). This thesis presents the results of an investigation into the characteristics of leaf growth, and the production and translocation of photosynthate/carbohydrate between source and sink leaves aimed to investigate the possible role of plant carbohydrate status in the control of the intermittent leaf production. The photosynthetic capacity of mature leaves did not increase during the phase of major increase in carbohydrate consumption by developing leaves but rather decreased slightly. Translocation of assimilated /sup 14/carbon from mature leaves was however significantly increased during phase of rapid expansion of the new leaves. Compensatory changes in the /sup 14/carbon-export from a single remaining source leaf after defoliation showed that mature leaves normally operate much below both their maximum photosynthate loading capacity and export potential. Partial removal of developing leaves within one flush resulted in increased /sup 14/C-photosynthate import into the remaining leaf showing that a developing leaf has a greater import and unloading potential than that utilized during its development in one normal flush.

  14. Research on Open-Closed-Loop Iterative Learning Control with Variable Forgetting Factor of Mobile Robots

    Directory of Open Access Journals (Sweden)

    Hongbin Wang

    2016-01-01

    Full Text Available We propose an iterative learning control algorithm (ILC that is developed using a variable forgetting factor to control a mobile robot. The proposed algorithm can be categorized as an open-closed-loop iterative learning control, which produces control instructions by using both previous and current data. However, introducing a variable forgetting factor can weaken the former control output and its variance in the control law while strengthening the robustness of the iterative learning control. If it is applied to the mobile robot, this will reduce position errors in robot trajectory tracking control effectively. In this work, we show that the proposed algorithm guarantees tracking error bound convergence to a small neighborhood of the origin under the condition of state disturbances, output measurement noises, and fluctuation of system dynamics. By using simulation, we demonstrate that the controller is effective in realizing the prefect tracking.

  15. Antibiotics with anaerobic ammonium oxidation in urban wastewater treatment

    Science.gov (United States)

    Zhou, Ruipeng; Yang, Yuanming

    2017-05-01

    Biofilter process is based on biological oxidation process on the introduction of fast water filter design ideas generated by an integrated filtration, adsorption and biological role of aerobic wastewater treatment process various purification processes. By engineering example, we show that the process is an ideal sewage and industrial wastewater treatment process of low concentration. Anaerobic ammonia oxidation process because of its advantage of the high efficiency and low consumption, wastewater biological denitrification field has broad application prospects. The process in practical wastewater treatment at home and abroad has become a hot spot. In this paper, anammox bacteria habitats and species diversity, and anaerobic ammonium oxidation process in the form of diversity, and one and split the process operating conditions are compared, focusing on a review of the anammox process technology various types of wastewater laboratory research and engineering applications, including general water quality and pressure filtrate sludge digestion, landfill leachate, aquaculture wastewater, monosodium glutamate wastewater, wastewater, sewage, fecal sewage, waste water salinity wastewater characteristics, research progress and application of the obstacles. Finally, we summarize the anaerobic ammonium oxidation process potential problems during the processing of the actual waste water, and proposed future research focus on in-depth study of water quality anammox obstacle factor and its regulatory policy, and vigorously develop on this basis, and combined process optimization.

  16. The anaerobic corrosion of carbon steel in concrete

    International Nuclear Information System (INIS)

    Naish, C.C.; Balkwill, P.H.; O'Brien, T.M.; Taylor, K.J.; Marsh, G.P.

    1990-11-01

    The report describes the work of a two year programme investigating the anaerobic corrosion of carbon steel embedded in a range of candidate repository cements and concretes at laboratory temperatures. The factors investigated in the study were the rate of the anaerobic corrosion reaction, the effect of hydrogen overpressure on the reaction rate and the form of the corrosion product. Both electrochemical and sample weight loss corrosion rate measurements were used. The cements and concretes used were prepared both with and without small additions of chloride (2% by weight of mix water). The results indicate that the corrosion rate is low, < 1 μm/year, the effect of hydrogen overpressure is not significant over the range of pressures investigated, 1-100 atmospheres, and that the corrosion product is dependent on the cement used to cast the samples. Magnetite was identified in the case of blast furnace slag replacement cements but for pulverised fuel ash and ordinary Portland cements no corrosion product was evident either from X-ray diffraction or laser Raman measurements. Further work is presently underway to investigate the effects of elevated temperatures and chloride levels on the anaerobic corrosion reaction and the rate of hydrogen gas production. (author)

  17. Psychosocial and Psychiatric Factors Associated with Adolescent Suicide: A Case-Control Psychological Autopsy Study

    Science.gov (United States)

    Portzky, Gwendolyn; Audenaert, Kurt; van Heeringen, Kees

    2009-01-01

    This study aimed at the investigation of psychosocial and psychiatric risk factors of adolescent suicide by means of a case-control psychological autopsy study. Relatives and other informants of 19 suicide victims and 19 matched psychiatric controls were interviewed by means of a semi-structured interview schedule. Psychiatric controls included…

  18. Control of the tokamak safety factor profile with time-varying constraints using MPC

    NARCIS (Netherlands)

    Maljaars, E.; Felici, F.; M.R. de Baar,; van Dongen, J.; Hogeweij, G. M. D.; P. J. M. Geelen,; Steinbuch, M.

    2015-01-01

    A controller is designed for the tokamak safety factor profile that takes real-time-varying operational and physics limits into account. This so-called model predictive controller (MPC) employs a prediction model in order to compute optimal control inputs that satisfy the given limits. The use of

  19. Anaerobic degradation of benzene by enriched consortia with humic acids as terminal electron acceptors

    Energy Technology Data Exchange (ETDEWEB)

    Cervantes, Francisco J., E-mail: fjcervantes@ipicyt.edu.mx [Division de Ciencias Ambientales, Instituto Potosino de Investigacion Cientifica y Tecnologica (IPICyT), Camino a la Presa San Jose 2055, Col. Lomas 4a. Seccion, San Luis Potosi, SLP, 78216 Mexico (Mexico); Mancilla, Ana Rosa; Toro, E. Emilia Rios-del [Division de Ciencias Ambientales, Instituto Potosino de Investigacion Cientifica y Tecnologica (IPICyT), Camino a la Presa San Jose 2055, Col. Lomas 4a. Seccion, San Luis Potosi, SLP, 78216 Mexico (Mexico); Alpuche-Solis, Angel G.; Montoya-Lorenzana, Lilia [Division de Biologia Molecular, Instituto Potosino de Investigacion Cientifica y Tecnologica (IPICyT), Camino a la Presa San Jose 2055, Col. Lomas 4a. Seccion, San Luis Potosi, SLP, 78216 Mexico (Mexico)

    2011-11-15

    Highlights: {yields} Enriched consortia were able to couple the anaerobic degradation of benzene to the reduction of humic acids. {yields} Electron-equivalents derived from anaerobic benzene oxidation were highly recovered as reduced humic acids. {yields} Several species from classes {beta}-, {delta}- and {gamma}-Proteobacteria were enriched during the anaerobic degradation of benzene. - Abstract: The anaerobic degradation of benzene coupled to the reduction of humic acids (HA) was demonstrated in two enriched consortia. Both inocula were able to oxidize benzene under strict anaerobic conditions when the humic model compound, anthraquinone-2,6-disulfonate (AQDS), was supplied as terminal electron acceptor. An enrichment culture originated from a contaminated soil was also able to oxidize benzene linked to the reduction of highly purified soil humic acids (HPSHA). In HPSHA-amended cultures, 9.3 {mu}M of benzene were degraded, which corresponds to 279 {+-} 27 micro-electron equivalents ({mu}Eq) L{sup -1}, linked to the reduction of 619 {+-} 81 {mu}Eq L{sup -1} of HPSHA. Neither anaerobic benzene oxidation nor reduction of HPSHA occurred in sterilized controls. Anaerobic benzene oxidation did not occur in soil incubations lacking HPSHA. Furthermore, negligible reduction of HPSHA occurred in the absence of benzene. The enrichment culture derived from this soil was dominated by two {gamma}-Proteobacteria phylotypes. A benzene-degrading AQDS-reducing enrichment originated from a sediment sample showed the prevalence of different species from classes {beta}-, {delta}- and {gamma}-Proteobacteria. The present study provides clear quantitative demonstration of anaerobic degradation of benzene coupled to the reduction of HA.

  20. Anaerobic degradation of benzene by enriched consortia with humic acids as terminal electron acceptors

    International Nuclear Information System (INIS)

    Cervantes, Francisco J.; Mancilla, Ana Rosa; Toro, E. Emilia Rios-del; Alpuche-Solis, Angel G.; Montoya-Lorenzana, Lilia

    2011-01-01

    Highlights: → Enriched consortia were able to couple the anaerobic degradation of benzene to the reduction of humic acids. → Electron-equivalents derived from anaerobic benzene oxidation were highly recovered as reduced humic acids. → Several species from classes β-, δ- and γ-Proteobacteria were enriched during the anaerobic degradation of benzene. - Abstract: The anaerobic degradation of benzene coupled to the reduction of humic acids (HA) was demonstrated in two enriched consortia. Both inocula were able to oxidize benzene under strict anaerobic conditions when the humic model compound, anthraquinone-2,6-disulfonate (AQDS), was supplied as terminal electron acceptor. An enrichment culture originated from a contaminated soil was also able to oxidize benzene linked to the reduction of highly purified soil humic acids (HPSHA). In HPSHA-amended cultures, 9.3 μM of benzene were degraded, which corresponds to 279 ± 27 micro-electron equivalents (μEq) L -1 , linked to the reduction of 619 ± 81 μEq L -1 of HPSHA. Neither anaerobic benzene oxidation nor reduction of HPSHA occurred in sterilized controls. Anaerobic benzene oxidation did not occur in soil incubations lacking HPSHA. Furthermore, negligible reduction of HPSHA occurred in the absence of benzene. The enrichment culture derived from this soil was dominated by two γ-Proteobacteria phylotypes. A benzene-degrading AQDS-reducing enrichment originated from a sediment sample showed the prevalence of different species from classes β-, δ- and γ-Proteobacteria. The present study provides clear quantitative demonstration of anaerobic degradation of benzene coupled to the reduction of HA.

  1. Anaerobe Tolerance to Oxygen and the Potentials of Anaerobic and Aerobic Cocultures for Wastewater Treatment

    Directory of Open Access Journals (Sweden)

    M.T. Kato

    1997-12-01

    Full Text Available The anaerobic treatment processes are considered to be well-established methods for the elimination of easily biodegradable organic matter from wastewaters. Some difficulties concerning certain wastewaters are related to the possible presence of dissolved oxygen. The common belief is that anaerobes are oxygen intolerant. Therefore, the common practice is to use sequencing anaerobic and aerobic steps in separate tanks. Enhanced treatment by polishing off the residual biodegradable oxygen demand from effluents of anaerobic reactors, or the biodegradation of recalcitrant wastewater pollutants, usually requires sequenced anaerobic and aerobic bacteria activities. However, the combined activity of both bacteria can also be obtained in a single reactor. Previous experiments with either pure or mixed cultures showed that anaerobes can tolerate oxygen to a certain extent. The oxygen toxicity to methanogens in anaerobic sludges was quantified in batch experiments, as well as in anaerobic reactors. The results showed that methanogens have a high tolerance to oxygen. In practice, it was confirmed that dissolved oxygen does not constitute any detrimental effect on reactor treatment performance. This means that the coexistence of anaerobic and aerobic bacteria in one single reactor is feasible and increases the potentials of new applications in wastewater treatment

  2. Proportional-Integral-Derivative (PID) Control of Secreted Factors for Blood Stem Cell Culture.

    Science.gov (United States)

    Caldwell, Julia; Wang, Weijia; Zandstra, Peter W

    2015-01-01

    Clinical use of umbilical cord blood has typically been limited by the need to expand hematopoietic stem and progenitor cells (HSPC) ex vivo. This expansion is challenging due to the accumulation of secreted signaling factors in the culture that have a negative regulatory effect on HSPC output. Strategies for global regulation of these factors through dilution have been developed, but do not accommodate the dynamic nature or inherent variability of hematopoietic cell culture. We have developed a mathematical model to simulate the impact of feedback control on in vitro hematopoiesis, and used it to design a proportional-integral-derivative (PID) control algorithm. This algorithm was implemented with a fed-batch bioreactor to regulate the concentrations of secreted factors. Controlling the concentration of a key target factor, TGF-β1, through dilution limited the negative effect it had on HSPCs, and allowed global control of other similarly-produced inhibitory endogenous factors. The PID control algorithm effectively maintained the target soluble factor at the target concentration. We show that feedback controlled dilution is predicted to be a more cost effective dilution strategy compared to other open-loop strategies, and can enhance HSPC expansion in short term culture. This study demonstrates the utility of secreted factor process control strategies to optimize stem cell culture systems, and motivates the development of multi-analyte protein sensors to automate the manufacturing of cell therapies.

  3. Proportional-Integral-Derivative (PID) Control of Secreted Factors for Blood Stem Cell Culture

    Science.gov (United States)

    Caldwell, Julia; Wang, Weijia; Zandstra, Peter W.

    2015-01-01

    Clinical use of umbilical cord blood has typically been limited by the need to expand hematopoietic stem and progenitor cells (HSPC) ex vivo. This expansion is challenging due to the accumulation of secreted signaling factors in the culture that have a negative regulatory effect on HSPC output. Strategies for global regulation of these factors through dilution have been developed, but do not accommodate the dynamic nature or inherent variability of hematopoietic cell culture. We have developed a mathematical model to simulate the impact of feedback control on in vitro hematopoiesis, and used it to design a proportional-integral-derivative (PID) control algorithm. This algorithm was implemented with a fed-batch bioreactor to regulate the concentrations of secreted factors. Controlling the concentration of a key target factor, TGF-β1, through dilution limited the negative effect it had on HSPCs, and allowed global control of other similarly-produced inhibitory endogenous factors. The PID control algorithm effectively maintained the target soluble factor at the target concentration. We show that feedback controlled dilution is predicted to be a more cost effective dilution strategy compared to other open-loop strategies, and can enhance HSPC expansion in short term culture. This study demonstrates the utility of secreted factor process control strategies to optimize stem cell culture systems, and motivates the development of multi-analyte protein sensors to automate the manufacturing of cell therapies. PMID:26348930

  4. Exocellular electron transfer in anaerobic microbial communities

    NARCIS (Netherlands)

    Stams, A.J.M.; Bok, de F.A.M.; Plugge, C.M.; Eekert, van M.H.A.; Dolfing, J.; Schraa, G.

    2006-01-01

    Exocellular electron transfer plays an important role in anaerobic microbial communities that degrade organic matter. Interspecies hydrogen transfer between microorganisms is the driving force for complete biodegradation in methanogenic environments. Many organic compounds are degraded by obligatory

  5. Anaerobic Toxicity of Cationic Silver Nanoparticles

    Data.gov (United States)

    U.S. Environmental Protection Agency — Toxicity data for the impact of nano-silver on anaerobic degradation. This dataset is associated with the following publication: Gitipour, A., S. Thiel, K. Scheckel,...

  6. Solar pond for heating anaerobic digesters

    International Nuclear Information System (INIS)

    Song Kehui; Li Shensheng

    1991-10-01

    A theoretical analysis and numerical results calculated for solar pond heating anaerobic digesters in Beijing area in China are presented. The effect of temperature rise is evident and rather steady. 3 refs, 1 fig., 1 tab

  7. Anaerobic microbial associations degrading aminoaromatic acids

    NARCIS (Netherlands)

    Kotova, I.; Savelieva, O.; Dyakonova, A.T.; Sklyar, V.; Kalyushnyi, S.V.; Stams, A.J.M.; Netrusov, A.

    2005-01-01

    Anaerobic microbial associations have been isolated that degrade aminoaromatic acids to methane and carbon dioxide at high rates. Significant differences between the morphological, cytological, and physiological traits of cultures isolated from samples of adapted and unadapted sludge are shown. The

  8. Biogas plasticization coupled anaerobic digestion: the anaerobic pump stoichiometry.

    Science.gov (United States)

    Schimel, Keith A

    2014-02-01

    This paper presents the stoichiometry section of a bioenergetics investigation into the biogas plasticization of wastewater sludge using the Anaerobic Pump (TAP). Three residue samples, an input substrate and two residual products, were collected from two side by side operated AD systems, a conventional continuous flow and stirred reactor, and TAP, and submitted for elemental and calorimetric analyses. The elemental compositions of the residues were fitted to a heterotrophic metabolism model [1] for both systems. To facilitate balanced stoichiometric models, a simple "cell" correction computation separates measured residual composites into "real" residual composition and cell growth (C5H7NO2) components. The elemental data and model results show that the TAP stage II residual composition (C1H0.065O0.0027N0.036) was nearly devoid of hydrogen and oxygen, leaving only fixed carbon and cells grown as the composition of the remaining mass. This quantitative evidence supports prior measurements of very high methane yields from TAP stage II reactor during steady-state experiments [2]. All performance parameters derived from the stoichiometric model(s) showed good agreement with measured steady-state averaged values. These findings are strong evidence that plasticization-disruption (TAP) cycle is the mechanism responsible for the observed increases in methane yield. The accuracy achieved by the stoichiometry models qualifies them for thermodynamic analysis to obtain potentials and bioconversion efficiencies. How applied pressure causes matrix conformation changes triggered by a functional consequence (plasticization and disruption) is this study's essential focus.

  9. Significance of dissolved methane in effluents of anaerobically ...

    Science.gov (United States)

    The need for energy efficient Domestic Wastewater (DWW) treatment is increasing annually with population growth and expanding global energy demand. Anaerobic treatment of low strength DWW produces methane which can be used to as an energy product. Temperature sensitivity, low removal efficiencies (Chemical Oxygen Demand (COD), Suspended Solids (SS), and Nutrients), alkalinity demand, and potential greenhouse gas (GHG) emissions have limited its application to warmer climates. Although well designed anaerobic Membrane Bioreactors (AnMBRs) are able to effectively treat DWW at psychrophilic temperatures (10–30 °C), lower temperatures increase methane solubility leading to increased energy losses in the form of dissolved methane in the effluent. Estimates of dissolved methane losses are typically based on concentrations calculated using Henry's Law but advection limitations can lead to supersaturation of methane between 1.34 and 6.9 times equilibrium concentrations and 11–100% of generated methane being lost in the effluent. In well mixed systems such as AnMBRs which use biogas sparging to control membrane fouling, actual concentrations approach equilibrium values. Non-porous membranes have been used to recover up to 92.6% of dissolved methane and well suited for degassing effluents of Upflow Anaerobic Sludge Blanket (UASB) reactors which have considerable solids and organic contents and can cause pore wetting and clogging in microporous membrane modules. Micro

  10. Ammonia recovery from anaerobically digested cattle manure by steam stripping.

    Science.gov (United States)

    Zeng, L; Mangan, C; Li, X

    2006-01-01

    Ammonia recovery from anaerobically digested cattle manure effluents through steam stripping was studied at a stripping tower temperature of 98-99 degrees C and a steam-water ratio approximately 56-72 g/L. The digested manure effluents were first treated by microfiltration and then the permeate was used as feed in steam stripping. The stripping performance was evaluated under different feed pH values, ammonia concentrations and temperatures. The increase of the initial feed pH does not significantly improve ammonia stripping efficiency due to the fact that the stripped effluent pH is increased during steam stripping. This suggests that steam stripping of anaerobically digested manure effluents for ammonia recovery may not need pre-raised pH. In contrast, the pH value of the synthetic ammonia wastewater containing NH4Cl dramatically decreases after steam stripping. Increasing the feed temperature slightly improves ammonia stripping efficiency, but reduces the concentration of the recovered ammonia in the condensate due to an increased condensate volume at a higher feed temperature. Therefore, the feed temperature should be controlled at an optimum point that can compromise the condensate ammonia concentration and the ammonia stripping efficiency. Experimental results indicate that recovery of ammonia from anaerobically digested cattle manure effluents as NH4OH is technically feasible.

  11. EFFECT OF MUSIC ON ANAEROBIC EXERCISE PERFORMANCE

    OpenAIRE

    Atan, T.

    2013-01-01

    For years, mostly the effects of music on cardiorespiratory exercise performance have been studied, but a few studies have examined the effect of music on anaerobic exercise. The purpose of this study was to assess the effect of listening to music and its rhythm on anaerobic exercise: on power output, heart rate and the concentration of blood lactate. 28 male subjects were required to visit the laboratory on 6 occasions, each separated by 48 hours. Firstly, each subject performed the Running-...

  12. Discussion on verification criterion and method of human factors engineering for nuclear power plant controller

    International Nuclear Information System (INIS)

    Yang Hualong; Liu Yanzi; Jia Ming; Huang Weijun

    2014-01-01

    In order to prevent or reduce human error and ensure the safe operation of nuclear power plants, control device should be verified from the perspective of human factors engineering (HFE). The domestic and international human factors engineering guidelines about nuclear power plant controller were considered, the verification criterion and method of human factors engineering for nuclear power plant controller were discussed and the application examples were provided for reference in this paper. The results show that the appropriate verification criterion and method should be selected to ensure the objectivity and accuracy of the conclusion. (authors)

  13. Analysis on nuclear power plant control room system design and improvement based on human factor engineering

    International Nuclear Information System (INIS)

    Gao Feng; Liu Yanzi; Sun Yongbin

    2014-01-01

    The design of nuclear power plant control room system is a process of improvement with the implementation of human factor engineering theory and guidance. The method of implementation human factor engineering principles into the nuclear power plant control room system design and improvement was discussed in this paper. It is recommended that comprehensive address should be done from control room system function, human machine interface, digital procedure, control room layout and environment design based on the human factor engineering theory and experience. The main issues which should be paid more attention during the control room system design and improvement also were addressed in this paper, and then advices and notices for the design and improvement of the nuclear power plant control room system were afforded. (authors)

  14. SLEEP DEPRIVATION INDUCED ANXIETY AND ANAEROBIC PERFORMANCE

    Directory of Open Access Journals (Sweden)

    Selma Arzu Vardar

    2007-12-01

    Full Text Available The aim of this study was to investigate the effects of sleep deprivation induced anxiety on anaerobic performance. Thirteen volunteer male physical education students completed the Turkish version of State Anxiety Inventory and performed Wingate anaerobic test for three times: (1 following a full-night of habitual sleep (baseline measurements, (2 following 30 hours of sleep deprivation, and (3 following partial-night sleep deprivation. Baseline measurements were performed the day before total sleep deprivation. Measurements following partial sleep deprivation were made 2 weeks later than total sleep deprivation measurements. State anxiety was measured prior to each Wingate test. The mean state anxiety following total sleep deprivation was higher than the baseline measurement (44.9 ± 12.9 vs. 27.6 ± 4.2, respectively, p = 0.02 whereas anaerobic performance parameters remained unchanged. Neither anaerobic parameters nor state anxiety levels were affected by one night partial sleep deprivation. Our results suggest that 30 hours continuous wakefulness may increase anxiety level without impairing anaerobic performance, whereas one night of partial sleep deprivation was ineffective on both state anxiety and anaerobic performance

  15. A Year in the Life: Annual Patterns of CO2 and CH4 from a Northern Finland Peatland, Including Anaerobic Methane Oxidation and Summer Ebullition Rates

    Science.gov (United States)

    Miller, K.; Lipson, D.; Biasi, C.; Dorodnikov, M.; Männistö, M.; Lai, C. T.

    2014-12-01

    The major ecological controls on methane (CH4) and carbon dioxide (CO2) fluxes in northern wetland systems are well known, yet estimates of source/sink magnitudes are often incongruous with measured rates. This mismatch persists because holistic flux datasets are rare, preventing 'whole picture' determinations of flux controls. To combat this, we measured net CO2 and CH4 fluxes from September 2012-2013 within a peatland in northern Lapland, Finland. In addition, we performed in situ manipulations and in vitro soil incubations to quantify anaerobic methane oxidation and methanogenic rates as they related to alternative electron acceptor availability. Average annual fluxes varied substantially between different depressions within the wetland, a pattern that persisted through all seasons. Season was a strong predictor of both CO2 and CH4 flux rates, yet CH4 rates were not related to melt-season 10cm or 30cm soil temperatures, and only poorly predicted with air temperatures. We found evidence for both autumnal and spring thaw CH4 bursts, collectively accounting for 26% of annual CH4 flux, although the autumnal burst was more than 5 fold larger than the spring burst. CH4 ebullition measured throughout the growing season augmented the CH4 source load by a factor of 1.5, and was linked with fine-scale spatial heterogeneity within the wetland. Surprisingly, CH4 flux rates were insensitive to Fe(III) and humic acid soil amendments, both of which amplified CO2 fluxes. Using in vitro incubations, we determined anaerobic methane oxidation and methanogenesis rates. Measured anaerobic oxidation rates showed potential consumption of between 6-39% of the methane produced, contributing approximately 1% of total carbon dioxide flux. Treatments of nitrate, sulfate and ferric iron showed that nitrate suppressed methanogenesis, but were not associated with anaerobic oxidation rates.

  16. Prevalence of asthma, level of control and factors associated with asthma control in Thai elementary school students in Bangkok.

    Science.gov (United States)

    Wanlapakorn, Nasamon; Sritippayawan, Suchada; Deerojanawong, Jitladda

    2014-12-01

    Little is known about the level of asthma control in Thai elementary school students living in the inner city of Bangkok. Our study aimed to evaluate the prevalence of asthma, level of asthma control and factors associated with asthma control in Thai students. We conducted a cross-sectional descriptive study in students aged between 6-12 years at 3 public schools and 3 private schools in Bangkok. The parent-completed questionnaire used to assess the prevalence of asthma and asthma symptoms was translated from the Phase I ISAAC (The International Study of Asthma and Allergies in Childhood) questionnaire. Univariate analysis was used to identify possible risk factors related to partly and uncontrolled asthma. A population of 1,428 students was recruited by screening questionnaires (66.1% of response rate). The mean age was 9.5 years. Prevalence of physician-diagnosed asthma was 9% and the most common asthma symptom was night cough (23.8%). The level of asthma control was assessed in students with current asthma and classified as controlled (46.7%), partly controlled (43.3%) and uncontrolled (10%). Around 27% of students with current asthma in this study use controller medications. Factors associated with asthma control were analyzed but none approached significance. The prevalence of asthma in elementary school students living in Bangkok has decreased since the previous survey and the use of controller medications has increased. Asthma management strategies should focus on encouraging awareness among physicians and parents about the importance of using controller medications to achieve better control of asthma.

  17. Visual control as a key factor in a production process of a company from automotive branch

    Directory of Open Access Journals (Sweden)

    Stanisław Borkowski

    2013-04-01

    Full Text Available This article presents a theoretical basis for one type of control in enterprises – visual control. It presents the meaning of visual control in the Toyota Production System and BOST researches as a tool of measure, among other things, the importance of visual control in production companies. The level of importance of visual control usage as one of the production process elements in the analysed company was indicated. The usage of visual control is a main factor in a production process of the analyzed company, the factor which provides continuous help to employees to check whether the process differs from the standard. The characteristic progression of production process elements was indicated and the SW factor (the use of visual control took the third place, PE factor (interruption of production when it detects a problem of quality turned out to be the most important one, while the least important was the EU factor (granting power of attorney down. The main tools for this evaluation: an innovative BOST survey - Toyota's management principles in questions, in particular, the Pareto-Lorenz diagram, radar graph and series of importance as graphical interpretation tools, were used to present the importance of each factor in relation to individual assessments.

  18. Anaerobic digestion of cellulosic wastes: laboratory tests

    International Nuclear Information System (INIS)

    Lee, D.D.; Donaldson, T.L.

    1984-11-01

    Anaerobic digestion is a potentially attractive technology for volume reduction of cellulosic wastes. A substantial fraction of the waste is converted to off-gas and a relatively small volume of biologically stabilized sludge is produced. Process development work is underway using a 75-L digester to verify rates and conversions obtained at the bench scale, to develop start-up and operating procedures, and to generate effluent for characterization and disposal studies. Three runs using batch and batch-fed conditions have been made lasting 36, 90, and over 200 days. Solids solubilization and gas production rates and total solids destruction have met or exceeded the target values of 0.6 g cellulose per L of reactor per day, 0.5 L off-gas per L of reactor per day, and 80% destruction of solids, respectively. Successful start-up procedures have been developed, and preliminary effluent characterization and disposal studies have been done. A simple dynamic process model has been constructed to aid in further process development and for use in process monitoring and control of a large-scale digester. 10 references, 17 figures, 4 tables

  19. Modeling and Control of DC/DC Boost Converter using K-Factor Control for MPPT of Solar PV System

    DEFF Research Database (Denmark)

    Vangari, Adithya; Haribabu, Divyanagalakshmi; Sakamuri, Jayachandra N.

    2015-01-01

    is presented. Design of the passive elements of the boost converter as per the system specifications is also illustrated. The performance of the proposed K factor control method is verified with the simulations for MPPT on solar PV system at different atmospheric conditions. A new circuit based model for solar......This paper is focused on the design of a controller for the DC/DC boost converter using K factor control, which is based on modified PI control method, for maximum power point tracking (MPPT) of solar PV system. A mathematical model for boost converter based on small signal averaging approach...... PV array, which includes the effect of solar insolation and temperature on PV array output, for the application in power system transient simulations, is also presented. The performance of the PV array model is verified with simulations at different atmospheric conditions. A 160W PV module from BP...

  20. Integrated application of human factors to a power plant control room information system

    International Nuclear Information System (INIS)

    Fish, H.C. Jr.; Gutierrez, R.

    1988-01-01

    The human factors plan was developed as a methodology to apply human factors from the conceptual design of the EPIC system to the functional verification conducted at the plant. An integral part of the Human Factors Plan was the Functional Verification Plan. Developed in parallel, this second plan and its resultant programs verified functional appropriateness of the SPDS display, NSSS displays, EOP displays, man-machine interfaces (MMI), and workstation designs. The functional verification process was performed at the hardware/software developer's factory and at the JAFNPP, following installation of the EPIC system. Because the EPIC system replaces existing control room equipment, it is important that human factors be applied in a systematic manner consistent with other control room displays and controls. To ensure that this goal was met, a human factors plan was developed

  1. Anaerobic soil disinfestation and Brassica seed meal amendment alter soil microbiology and system resistance

    Science.gov (United States)

    Brassica seed meal amendments and anaerobic soil disinfestation control a spectrum of soil-borne plant pathogens via a diversity of mechanisms. Transformations in microbial community structure and function in certain instances were determinants of disease control and enhanced plant performance. Fo...

  2. Risk factors for candidemia in cancer patients: a case-control study.

    OpenAIRE

    Karabinis, A; Hill, C; Leclercq, B; Tancrède, C; Baume, D; Andremont, A

    1988-01-01

    Risk factors for candidemia were analyzed in a case-control study of 30 cancer patients with candidemia and 58 controls. In a univariate analysis, previous surgery, neutropenia, central catheterization, chemotherapy, specific antibiotic treatments, and peripheral cultures positive for Candida spp. were associated with a significantly increased risk of candidemia. In a multivariate logistic model, the significant risk factors for candidemia were positive peripheral cultures for Candida spp. (P...

  3. Verification and validation of human factors issues in control room design and upgrades

    International Nuclear Information System (INIS)

    Green, M.; Collier, S.

    1999-12-01

    Systems, facilities and equipment are periodically updated during a power plant's lifetime. This has human factors implications, especially if the central control room is involved. Human factors work may therefore be required. There is an extensive literature on human factors itself, but not so much on how it is verified and validated. Therefore, HRP and the Swedish Nuclear Power Inspectorate commissioned a study. The objective was to review the literature and establish a knowledge base on verification and validation (V and V) of human factors issues. The report first discusses verification and validation as applied to human factors work. It describes a design process and the typical human factors topics involved. It then presents a generic method for V and V of human factors. This is built on a review of standards, guidelines and other references given in an annotated bibliography. The method is illustrated by application to some human factors topics

  4. Verification and validation of human factors issues in control room design and upgrades

    Energy Technology Data Exchange (ETDEWEB)

    Green, M.; Collier, S. [Inst. for Energiteknikk, Halden (Norway). OECD Halden Reactor Project

    1999-12-01

    Systems, facilities and equipment are periodically updated during a power plant's lifetime. This has human factors implications, especially if the central control room is involved. Human factors work may therefore be required. There is an extensive literature on human factors itself, but not so much on how it is verified and validated. Therefore, HRP and the Swedish Nuclear Power Inspectorate commissioned a study. The objective was to review the literature and establish a knowledge base on verification and validation (V and V) of human factors issues. The report first discusses verification and validation as applied to human factors work. It describes a design process and the typical human factors topics involved. It then presents a generic method for V and V of human factors. This is built on a review of standards, guidelines and other references given in an annotated bibliography. The method is illustrated by application to some human factors topics.

  5. Incidence of anaerobic bacteria in patients with suspected pneumonia in surgical Intensive Care Unit.

    Science.gov (United States)

    Clavier, T; Gouin, P; Frebourg, N; Rey, N; Royon, V; Bergis, A; Hobeika, S; Dureuil, B; Veber, B

    2014-10-01

    Few studies have investigated the incidence of pulmonary anaerobes in a specific population in surgical Intensive Care Unit (ICU). The objective of this work was to determine the incidence of anaerobes in surgical ICU patients with suspected pneumonia. This was a prospective observational, single-center study. Analysis was based on data collected over 30 months from the surgical ICU of a tertiary care hospital (Rouen University Hospital), including data on risk factors for anaerobes in the lungs. Patients with suspected pneumonia (community-acquired or nosocomial) were included. Bacteriological sampling was performed by protected distal bronchial sampling (PDBS) with minilavage under bronchoscopy. Aerobic and anaerobic cultures were performed for each sample. Clinicians were only aware of aerobic results. Univariate and multivariate statistical analysis compared groups with and without anaerobes. A total of 134 samples were obtained from 117 patients. Surgery was performed on 74 patients (63.2%), within 24 hours of admission. Fifty-four patients (46.2%) had a chest trauma and 20 patients (17.1%) were admitted for a digestive pathology. Average age was 53.6±20.9 years and sex ratio was 5.9 (100 men/17 women). Average SAPS II was 41.6±15.1, median length of ICU stay was 23 days (25th percentile=13, 75th percentile=33), and median duration of mechanical ventilation was 21 days (25th percentile=11, 75th percentile=28). Mortality rate in ICU was 14.5%. After sampling, diagnosis of pneumonia was confirmed in 70 cases (52.2%). Anaerobe cultures were positive in 11 samples taken from 11 different patients (overall incidence 8.2%). Aerobic bacteria were also involved in 9 patients (81.8%). In univariate analysis, enteral feeding (P=0.02) and absence of catecholamines at time of sampling (P=0.003) were significantly associated with the presence of anaerobes in PDBS. Enteral nutrition was also found to be a risk factor in multivariate analysis (OR=11.8, 95% CI [1.36 to 102

  6. The place of human-factors in the work of the Atomic Energy Control Board

    International Nuclear Information System (INIS)

    Barkow, B.

    1982-01-01

    The AECB do not effectively regulate human factors in nuclear power plants since they have no staff trained to do so. Two new positions are recommended and their activities are outlined. Special problems are identified in the certification of personnel, management information control, and in accommodating human factors to AECB style

  7. Dynamic increase and decrease of photonic crystal nanocavity Q factors for optical pulse control.

    Science.gov (United States)

    Upham, Jeremy; Tanaka, Yoshinori; Asano, Takashi; Noda, Susumu

    2008-12-22

    We introduce recent advances in dynamic control over the Q factor of a photonic crystal nanocavity system. By carefully timing a rapid increase of the Q factor from 3800 to 22,000, we succeed in capturing a 4ps signal pulse within the nanocavity with a photon lifetime of 18ps. By performing an additional transition of the Q factor within the photon lifetime, the held light is once again ejected from of the system on demand.

  8. Ranking Malaria Risk Factors to Guide Malaria Control Efforts in African Highlands

    OpenAIRE

    Protopopoff, Natacha; Van Bortel, Wim; Speybroeck, Niko; Van Geertruyden, Jean-Pierre; Baza, Dismas; D'Alessandro, Umberto; Coosemans, Marc

    2009-01-01

    Introduction: Malaria is re-emerging in most of the African highlands exposing the non immune population to deadly epidemics. A better understanding of the factors impacting transmission in the highlands is crucial to improve well targeted malaria control strategies. Methods and Findings: A conceptual model of potential malaria risk factors in the highlands was built based on the available literature. Furthermore, the relative importance of these factors on malaria can be estimated through...

  9. Modeling de novo granulation of anaerobic sludge.

    Science.gov (United States)

    Doloman, Anna; Varghese, Honey; Miller, Charles D; Flann, Nicholas S

    2017-07-17

    A unique combination of mechanical, physiochemical and biological forces influences granulation during processes of anaerobic digestion. Understanding this process requires a systems biology approach due to the need to consider not just single-cell metabolic processes, but also the multicellular organization and development of the granule. In this computational experiment, we address the role that physiochemical and biological processes play in granulation and provide a literature-validated working model of anaerobic granule de novo formation. The agent-based model developed in a cDynoMiCs simulation environment successfully demonstrated a de novo granulation in a glucose fed system, with the average specific methanogenic activity of 1.11 ml C H 4 /g biomass and formation of a 0.5 mm mature granule in 33 days. The simulated granules exhibit experimental observations of radial stratification: a central dead core surrounded by methanogens then encased in acidogens. Practical application of the granulation model was assessed on the anaerobic digestion of low-strength wastewater by measuring the changes in methane yield as experimental configuration parameters were systematically searched. In the model, the emergence of multicellular organization of anaerobic granules from randomly mixed population of methanogens and acidogens was observed and validated. The model of anaerobic de novo granulation can be used to predict the morphology of the anaerobic granules in a alternative substrates of interest and to estimate methane potential of the resulting microbial consortia. The study demonstrates a successful integration of a systems biology approach to model multicellular systems with the engineering of an efficient anaerobic digestion system.

  10. Decentralised treatment of concentrated sewage at low temperature in a two-step anaerobic system: two upflow-hybrid septic tanks

    NARCIS (Netherlands)

    Elmitwally, T.A.; Sayed, S.; Groendijk, L.; Lier, van J.B.; Zeeman, G.; Lettinga, G.

    2003-01-01

    The decentralised treatment of concentrated sewage (about 3,600 mgCOD/1) at low temperature was investigated in a two-step anaerobic system: two-anaerobic hybrid (AH) septic tanks (each 0.575 m(3)). The two reactors were placed in a temperature controlled-room and the HRT was 2.5 days for each

  11. A Survey of Sludge Granulation Theories Under Anaerobic Conditions

    Directory of Open Access Journals (Sweden)

    Jalal Shayegan

    2011-01-01

    Full Text Available This paper surveys the different theories developed on anaerobic sludge granulation. The theories are generally categorized as physical, microbial, and thermodynamic approaches. In the physical approach to the granulation process, granulation is described by such physical conditions of the reactor as upflow velocity of gas and liquid streams, suspended solids in the effluent flow, and excess sludge removal. Microbial theories are based on the properties of specific organisms and on granule properties (granule structure and its microbiology. The thermodynamic approach studies such factors as hydrophobia, electrophoretic mobility, effective energy in granule adhesion process, and effect of proton transferring activities on bacterial membrane surfaces.

  12. Anaerobic digestion in the treatment of waste and wastewater effluent; Digestion anaerobia en el tratamiento de efluentes y lodos residuales

    Energy Technology Data Exchange (ETDEWEB)

    Baraza, X.; Galimary, F.; Torres, R.

    2003-07-01

    Anaerobic digestion is one of the processes most commonly employed at the present time in treating effluent and wastewater containing a large proportion of organic matter. This article describes the process involved and its applications in the environmental engineering field. It also discusses the physical, chemical and biological factors influencing anaerobic digestion and which therefore have a bearing on whether to implements this process and how it is actually applied from a technological point of view. (Author) 125 refs.

  13. FAST CP: protocol of a randomised controlled trial of the efficacy of a 12-week combined Functional Anaerobic and Strength Training programme on muscle properties and mechanical gait deficiencies in adolescents and young adults with spastic-type cerebral palsy

    Science.gov (United States)

    Gillett, Jarred G; Lichtwark, Glen A; Boyd, Roslyn N; Barber, Lee A

    2015-01-01

    Introduction Individuals with cerebral palsy (CP) have muscles that are smaller, weaker and more resistant to stretch compared to typically developing people. Progressive resistance training leads to increases in muscle size and strength. In CP, the benefits of resistance training alone may not transfer to improve other activities such as walking; however, the transfer of strength improvements to improved mobility may be enhanced by performing training that involves specific functional tasks or motor skills. This study aims to determine the efficacy of combined functional anaerobic and strength training in (1) influencing muscle strength, structure and function and (2) to determine if any changes in muscle strength and structure following training impact on walking ability and gross motor functional capacity and performance in the short (following 3 months of training) and medium terms (a further 3 months post-training). Methods and analysis 40 adolescents and young adults with CP will be recruited to undertake a 12-week training programme. The training programme will consist of 3×75 min sessions per week, made up of 5 lower limb resistance exercises and 2–3 functional anaerobic exercises per session. The calf muscles will be specifically targeted, as they are the most commonly impacted muscles in CP and are a key muscle group involved in walking. If, as we believe, muscle properties change following combined strength and functional training, there may be long-term benefits of this type of training in slowing the deterioration of muscle function in people with spastic-type CP. Ethics and dissemination Ethical approval has been obtained from the ethics committees at The University of Queensland (2014000066) and Children's Health Queensland (HREC/15/QRCH/30). The findings will be disseminated by publications in peer-reviewed journals, conferences and local research organisations’ media. Trial registration number Australian and New Zealand Clinical Trials

  14. FAST CP: protocol of a randomised controlled trial of the efficacy of a 12-week combined Functional Anaerobic and Strength Training programme on muscle properties and mechanical gait deficiencies in adolescents and young adults with spastic-type cerebral palsy.

    Science.gov (United States)

    Gillett, Jarred G; Lichtwark, Glen A; Boyd, Roslyn N; Barber, Lee A

    2015-06-26

    Individuals with cerebral palsy (CP) have muscles that are smaller, weaker and more resistant to stretch compared to typically developing people. Progressive resistance training leads to increases in muscle size and strength. In CP, the benefits of resistance training alone may not transfer to improve other activities such as walking; however, the transfer of strength improvements to improved mobility may be enhanced by performing training that involves specific functional tasks or motor skills. This study aims to determine the efficacy of combined functional anaerobic and strength training in (1) influencing muscle strength, structure and function and (2) to determine if any changes in muscle strength and structure following training impact on walking ability and gross motor functional capacity and performance in the short (following 3 months of training) and medium terms (a further 3 months post-training). 40 adolescents and young adults with CP will be recruited to undertake a 12-week training programme. The training programme will consist of 3 × 75 min sessions per week, made up of 5 lower limb resistance exercises and 2-3 functional anaerobic exercises per session. The calf muscles will be specifically targeted, as they are the most commonly impacted muscles in CP and are a key muscle group involved in walking. If, as we believe, muscle properties change following combined strength and functional training, there may be long-term benefits of this type of training in slowing the deterioration of muscle function in people with spastic-type CP. Ethical approval has been obtained from the ethics committees at The University of Queensland (2014000066) and Children's Health Queensland (HREC/15/QRCH/30). The findings will be disseminated by publications in peer-reviewed journals, conferences and local research organisations' media. Australian and New Zealand Clinical Trials Registry (ACTRN12614001217695). Published by the BMJ Publishing Group Limited. For permission

  15. Potential for energy conservation in the food and beverage industries through anaerobic digestion of wastes to methane

    Energy Technology Data Exchange (ETDEWEB)

    1983-01-01

    The Canadian food and beverage industry is the fourth largest consumer of energy among manufacturers. An area of energy use which has received little attention in the past is that of waste treatment. Conventional aerobic treatment systems tend to be energy-intensive, unlike new high-rate anaerobic processes which often have better balances because they produce recoverable methane that can be used for fuel. For these reasons, anaerobic systems may be attractive to food and beverage industries seeking an economical means of waste treatment. A number of factors will determine whether anaerobic treatment is a feasible option for a given plant. Chief among these are waste strength, waste temperature, waste flow rate, consistent production of waste, and need for and cost of treatment. This study attempted to determine for what proportion of Canadian food and beverage companies anaerobic treatment is likely to be a feasible option in the near to middle term. It was found that the general plant effluents of several industries appear in many cases to be economically treatable by anaerobic processes, and practical considerations involved in methane end-use were briefly considered. A number of barriers to the application of anaerobic technology were revealed, including high capital costs, the dilution of high strength effluents, misconception about anaerobic processes, ignorance of the state of the art and the ambiguities in regulations and standards concerning biogas. 108 refs., 22 figs., 45 tabs.

  16. The design and operation of the THORP central control room: a human factors perspective

    International Nuclear Information System (INIS)

    Reed, Julie.

    1996-01-01

    The new Thermal Oxide Reprocessing Plant (THORP) at British Nuclear Fuels (BNFL) Sellafield Site is now operational. This paper describes the Central Control Room (CCR), focusing on the control system components. Throughout the design, commissioning and operation of THORP, human factors played an important part. (author)

  17. A case-control study of risk factors for male infertility in Southern ...

    African Journals Online (AJOL)

    Aim: The purpose of this study was to evaluate the association between selected potential socio-demographic and behavioural risk factors and infertility in Nigeria males. Methods: The study consisted of cases and controls. The cases were 150 males with proven male infertility, while the controls were 150 fertile males with ...

  18. Medical and environmental risk factors for sporadic frontotemporal dementia: a retrospective case-control study

    NARCIS (Netherlands)

    S.M. Rosso (Sonia); E.J. Landweer; M. Houterman; C.M. van Duijn (Cornelia); J.C. van Swieten (John); L. Donker Kaat (Laura)

    2003-01-01

    textabstractA retrospective case-control study was carried out on 80 patients with sporadic frontotemporal dementia and 124 age, sex, and surrogate informant matched controls with respect to various medical and environmental risk factors. Head trauma was associated with an odds ratio of 3.3 (95%

  19. IMPROVING CONTROL ROOM DESIGN AND OPERATIONS BASED ON HUMAN FACTORS ANALYSES OR HOW MUCH HUMAN FACTORS UPGRADE IS ENOUGH ?

    Energy Technology Data Exchange (ETDEWEB)

    HIGGINS,J.C.; OHARA,J.M.; ALMEIDA,P.

    2002-09-19

    THE JOSE CABRERA NUCLEAR POWER PLANT IS A ONE LOOP WESTINGHOUSE PRESSURIZED WATER REACTOR. IN THE CONTROL ROOM, THE DISPLAYS AND CONTROLS USED BY OPERATORS FOR THE EMERGENCY OPERATING PROCEDURES ARE DISTRIBUTED ON FRONT AND BACK PANELS. THIS CONFIGURATION CONTRIBUTED TO RISK IN THE PROBABILISTIC SAFETY ASSESSMENT WHERE IMPORTANT OPERATOR ACTIONS ARE REQUIRED. THIS STUDY WAS UNDERTAKEN TO EVALUATE THE IMPACT OF THE DESIGN ON CREW PERFORMANCE AND PLANT SAFETY AND TO DEVELOP DESIGN IMPROVEMENTS.FIVE POTENTIAL EFFECTS WERE IDENTIFIED. THEN NUREG-0711 [1], PROGRAMMATIC, HUMAN FACTORS, ANALYSES WERE CONDUCTED TO SYSTEMATICALLY EVALUATE THE CR-LA YOUT TO DETERMINE IF THERE WAS EVIDENCE OF THE POTENTIAL EFFECTS. THESE ANALYSES INCLUDED OPERATING EXPERIENCE REVIEW, PSA REVIEW, TASK ANALYSES, AND WALKTHROUGH SIMULATIONS. BASED ON THE RESULTS OF THESE ANALYSES, A VARIETY OF CONTROL ROOM MODIFICATIONS WERE IDENTIFIED. FROM THE ALTERNATIVES, A SELECTION WAS MADE THAT PROVIDED A REASONABLEBALANCE BE TWEEN PERFORMANCE, RISK AND ECONOMICS, AND MODIFICATIONS WERE MADE TO THE PLANT.

  20. Ultrasonic and Thermal Pretreatments on Anaerobic Digestion of Petrochemical Sludge: Dewaterability and Degradation of PAHs

    Science.gov (United States)

    Zhou, Jun; Xu, Weizhong; Wong, Jonathan W. C.; Yong, Xiaoyu; Yan, Binghua; Zhang, Xueying; Jia, Honghua

    2015-01-01

    Effects of different pretreatment methods on sludge dewaterability and polycyclic aromatic hydrocarbons (PAHs) degradation during petrochemical sludge anaerobic digestion were studied. Results showed that the total biogas production volume in the thermal pretreatment system was 4 and 5 times higher than that in the ultrasound pretreatment and in the control system, and the corresponding volatile solid removal efficiencies reached 28%, 15%, and 8%. Phenanthrene, paranaphthalene, fluoranthene, benzofluoranthene, and benzopyrene removal rates reached 43.3%, 55.5%, 30.6%, 42.9%, and 41.7%, respectively, in the thermal pretreatment system, which were much higher than those in the ultrasound pretreatment and in the control system. Moreover, capillary suction time (CST) of sludge increased after pretreatment, and then reduced after 20 days of anaerobic digestion, indicating that sludge dewaterability was greatly improved after anaerobic digestion. The decrease of protein and polysaccharide in the sludge could improve sludge dewaterability during petrochemical sludge anaerobic digestion. This study suggested that thermal pretreatment might be a promising enhancement method for petrochemical sludge solubilization, thus contributing to degradation of the PAHs, biogas production, and improvement of dewaterability during petrochemical sludge anaerobic digestion. PMID:26327510

  1. Factor structure, reliability, and validity of the Levenson's Locus of Control Scale in Iranian infertile people.

    Science.gov (United States)

    Maroufizadeh, Saman; Omani Samani, Reza; Amini, Payam; Navid, Behnaz

    2016-09-01

    This study examined psychometric properties of the Levenson's Locus of Control Scale among Iranian infertile patients. In all, 312 infertile patients completed the Levenson's Locus of Control Scale and Hospital Anxiety and Depression Scale. The confirmatory factor analysis indicated that the original three-factor model of Levenson's Locus of Control Scale was adequate ( χ 2 / df = 2.139; goodness-of-fit index = 0.88; root mean square error of approximation = 0.061; and standardized root mean square residual = 0.076). The Cronbach's alpha of the subscales ranged from 0.56 to 0.67. The Levenson's Locus of Control Scale subscales significantly correlated with anxiety and depression, showing an acceptable convergent validity. In conclusion, the Levenson's Locus of Control Scale has adequate reliability and validity and can be used to measure locus of control orientation in Iranian infertile patients.

  2. Factors associated with glycemic control in people with diabetes at the Family Health Strategy in Pernambuco

    Directory of Open Access Journals (Sweden)

    Rodrigo Fonseca Lima

    Full Text Available Abstract OBJECTIVE Identifying factors associated with glycemic control in people with type 2 Diabetes Mellitus (DM registered in the Family Health Strategy (FHS in Pernambuco, Brazil. METHOD Associations between glycemic control (glycosylated hemoglobin A lower or equal to 7% presented by people with DM and variables related to sociodemographic conditions, lifestyle, characteristics of diabetes, treatment and follow-up of patients by health services were investigated by multiple regression. RESULTS More than 65% of the participants presented inadequate glycemic control, especially those with lower age, longer illness duration, more annual contacts with FHS and complex therapeutic regimen. People with DM without referrals to specialists presented greater glycemic control. Associations with education level and obesity did not remain significant in the multivariate model. CONCLUSION The evolution of diabetes hinders adequate control, however, attention to younger people with DM and referrals to specialists are factors that can improve glycemic control.

  3. Leachate properties as indicators of methane production process in MSW anaerobic digestion bioreactor landfill

    Science.gov (United States)

    Zeng, Yunmin; Wang, Li'ao; Xu, Tengtun; Li, Jiaxiang; Song, Xue; Hu, Chaochao

    2018-03-01

    In this paper, bioreactor was used to simulate the municipal solid waste (MSW) biodegradation process of landfill, tracing and testing trash methanogenic process and characteristics of leachate during anaerobic digestion, exploring the relationship between the two processes, aiming to screen out the indicators that can predict the methane production process of anaerobic digestion, which provides the support for real-time adjustment of technological parameters of MSW anaerobic digestion system and ensures the efficient operation of bioreactor landfill. The results showed that MSW digestion gas production rate constant is 0.0259 1/d, biogas production potential is 61.93 L/kg. The concentration of TN in leachate continued to increase, showing the trend of nitrogen accumulation. "Ammonia poisoning" was an important factor inhibiting waste anaerobic digestion gas production. In the anaerobic digestion system, although pH values of leachate can indicate methane production process to some degree, there are obvious lagging behind, so it cannot be used as indicator alone. The TOC/TN value of leachate has a certain indication on the stability of the methane production system. When TOC/TN value was larger than12, anaerobic digestion system was stable along with normal production of biogas. However, when TOC/TN value was lower than 12, the digestive system is unstable and the gas production is small. In the process of anaerobic digestion, the synthesis and transformation of valeric acid is more active. HAc/HVa changed greatly and had obvious inflection points, from which methane production period can be predicted.

  4. Human factors design review guidelines for advanced nuclear control room technologies

    International Nuclear Information System (INIS)

    O'Hara, J.; Brown, W.; Granda, T.; Baker, C.

    1991-01-01

    Advanced control rooms (ACRs) for future nuclear power plants are being designed utilizing computer-based technologies. The US Nuclear Regulatory Commission reviews the human engineering aspects of such control rooms to ensure that they are designed to good human factors engineering principles and that operator performance and reliability are appropriately supported in order to protect public health and safety. This paper describes the rationale, general approach, and initial development of an NRC Advanced Control Room Design Review Guideline. 20 refs., 1 fig

  5. Survey of control-room design practices with respect to human factors engineering

    International Nuclear Information System (INIS)

    Seminara, J.L.; Parsons, S.O.

    1980-01-01

    Human factors engineering is an interdisciplinary speciality concerned with influencing the design of equipment systems, facilities, and operational environments to promote safe, efficient, and reliable operator performance. This emphasis has been applied to most military and space systems in the past 30 y. A review of five nuclear power-plant control rooms, reported in the November-December 1977 issue of Nuclear Safety, revealed that human factors principles of design have generally not been incorporated in present-generation control rooms. This article summarizes the findings of a survey of 20 control-board designers from a mix of nuclear steam-supply system and architect-engineering firms. The interviews with these designers probed design methods currently used in developing control rooms. From these data it was concluded that there is currently no consistent, formal, uniform concern for the human factors aspects of control-room design on the part of the design organizations, the utilities, or the Nuclear Regulatory Commission. Although all the parties involved are concerned with human factors issues, this responsibility is not focused, and human factors yardsticks, or design standards, specific to power plants have not been evolved and applied in the development and verification of control-room designs from the standpoint of the man-machine interface

  6. [Isolation, Identification and Characteristic Analysis of an Oil-producing Chlorella sp. Tolerant to High-strength Anaerobic Digestion Effluent].

    Science.gov (United States)

    Yang, Chuang; Wang, Wen-guo; Ma, Dan-wei; Tang, Xiao-yu; Hu, Qi-chun

    2015-07-01

    A Chlorella strain tolerant to high-strength anaerobic digestion effluent was isolated from the anaerobic digestion effluent with a long-term exposure to air. The strain was identified as a Chlorella by morphological and molecular biological methods, and named Chlorella sp. BWY-1, The anaerobic digestion effluent used in this study was from a biogas plant with the raw materials of swine wastewater after solid-liquid separation. The Chlorella regularis (FACHB-729) was used as the control strain. The comparative study showed that Chlorella sp, BWY-Ihad relatively higher growth rate, biomass accumulation capacity and pollutants removal rate in BG11. and different concentrations of anaerobic digestion effluent. Chlorella sp. BWY-1 had the highest growth rate and biomass productivity (324.40 mg.L-1) in BG11, but its lipid productivity and lipid content increased with the increase of anaerobic digestion effluent concentration, In undiluted anaerobic digestion effluent, the lipid productivity and lipid content of Chlorella sp. BWY-1 were up to 44. 43% and 108. 70 mg.L-1, respectively. Those results showed that the isolated algal strain bad some potential applications in livestock wastewater treatment and bioenergy production, it could be combined with a solid-liquid separation, anaerobic fermentation and other techniques for processing livestock wastewater and producing biodiesel.

  7. Factor V Leiden, factor V Cambridge, factor II GA20210, and methylenetetrahydrofolate reductase in cerebral venous and sinus thrombosis: A case-control study.

    Science.gov (United States)

    Saadatnia, Mohammad; Salehi, Mansour; Movahedian, Ahmad; Shariat, Seyed Ziaeddin Samsam; Salari, Mehri; Tajmirriahi, Marzieh; Asadimobarakeh, Elham; Salehi, Rasoul; Amini, Gilda; Ebrahimi, Homa; Kheradmand, Ehsan

    2015-06-01

    Factor V G1691A (FV Leiden), FII GA20210, and methylenetetrahydrofolate reductase (MTHFR) C677T mutations are the most common genetic risk factors for thromboembolism in the Western countries. However, there is rare data in Iran about cerebral venous and sinus thrombosis (CVST) patients. The aim of this study was to evaluate the frequency of common genetic thrombophilic factors in CVST patients. Forty consequently CVST patients from two University Hospital in Isfahan University of Medical Sciences aged more than 15 years from January 2009 to January 2011 were recruited. In parallel, 51 healthy subjects with the same age and race from similar population selected as controls. FV Leiden, FII GA20210, MTHFR C677T, and FV Cambridge gene mutations by polymerase chain reaction technique were evaluated in case and control groups. FV Leiden, FII GA20210, and FV Cambridge gene mutations had very low prevalence in both case (5%, 2%, 0%) and control (2.5%, 0%, 0%) and were not found any significant difference between groups. MTHFR C677T mutations was in 22 (55%) of patients in case group and 18 (35.5%) of control group (P = 0.09). This study showed that the prevalence of FV Leiden, FII GA20210, and FV Cambridge were low. Laboratory investigations of these mutations as a routine test for all patients with CVST may not be cost benefit.

  8. Applying human factors to the design of control centre and workstation of a nuclear reactor

    International Nuclear Information System (INIS)

    Santos, Isaac J.A. Luquetti dos; Carvalho, Paulo V.R.; Goncalves, Gabriel de L.; Souza, Tamara D.M.F.; Falcao, Mariana A.

    2013-01-01

    Human factors is a body of scientific factors about human characteristics, covering biomedical, psychological and psychosocial considerations, including principles and applications in the personnel selection areas, training, job performance aid tools and human performance evaluation. Control Centre is a combination of control rooms, control suites and local control stations which are functionally related and all on the same site. Digital control room includes an arrangement of systems, equipment such as computers and communication terminals and workstations at which control and monitoring functions are conducted by operators. Inadequate integration between control room and operators reduces safety, increases the operation complexity, complicates operator training and increases the likelihood of human errors occurrence. The objective of this paper is to present a specific approach for the conceptual and basic design of the control centre and workstation of a nuclear reactor used to produce radioisotope. The approach is based on human factors standards, guidelines and the participation of a multidisciplinary team in the conceptual and basic phases of the design. Using the information gathered from standards and from the multidisciplinary team, an initial sketch 3D of the control centre and workstation are being developed. (author)

  9. Comparative study of mutational factors in high background and control areas

    International Nuclear Information System (INIS)

    Tao Zufan; Li Hong; Zha Yongru

    1985-01-01

    The results of further study of the socioeconomic environmental factors concerning with mutations in the high background radiation area and the control area are presented in this paper. The factors studied can be divided into two categories: (1) those which have been confirmed to be related to mutations, including occupations involved with poisonous and noxious substances, application of pesticides, smoking, alcohol drinking, and exposure to medical X-ray, etc; (2) those which may not necessarily relate to mutations, such as socioeconomic states etc. Case-control study has been used. 'Case' and 'control' were selected from the inhabitants in the high background and control areas respectively by means of two-stage sampling method, and matched by sex and age. The data were collected by interview. There were 459 pairs available for analysis. The results of studied factors of category 1 show that no significant difference was found between two areas except that the frequency of medical X-ray exposure of the people in the control area was a little higher than that in the high background area. For the factors of category 2, the results show that the economic condition and educational level of the control group were better than those of the high background group. Besides, the papulation of high background area was more steady than that of control area

  10. Human factors engineering applied to Control Centre Design of a research nuclear reactor

    Energy Technology Data Exchange (ETDEWEB)

    Farias, Larissa P. de; Santos, Isaac J.A. Luquetti dos; Carvalho, Paulo V.R., E-mail: larissapfarias@ymail.com [Instituto de Engenharia Nuclear (DENN/SEESC/IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil). Lab, de Usabilidade e Confiabilidade Humana; Monteiro, Beany G. [Universidade Federal do Rio Janeiro (UFRJ), Rio Janeiro, RJ (Brazil). Departamento de Desenho Industrial

    2017-07-01

    The Human Factors Engineering (HFE) program is an essential aspect for the design of nuclear installations. The overall aim of the HFE program is the improvement of the operational reliability and safety of plant operation. The HFE program main purpose is to ensure that human factor practices are incorporated into the plant design, emphasizing man-machine interface issues and design improvement of the nuclear reactor Control Centre. The Control Centre of nuclear reactor is a combination of control rooms, control suites and local control stations, which are functionally connected and located on the reactor site. The objective of this paper is to present a design approach for the Control Centre of a nuclear reactor used to produce radioisotopes and for nuclear research, including human factor issues. The design approach is based on participatory design principles, using human factor standards, ergonomic guidelines, and the participation of a multidisciplinary team during all design phases. Using the information gathered, an initial sketch 3D of the Control Centre was developed. (author)

  11. Human factors engineering applied to Control Centre Design of a research nuclear reactor

    International Nuclear Information System (INIS)

    Farias, Larissa P. de; Santos, Isaac J.A. Luquetti dos; Carvalho, Paulo V.R.; Monteiro, Beany G.

    2017-01-01

    The Human Factors Engineering (HFE) program is an essential aspect for the design of nuclear installations. The overall aim of the HFE program is the improvement of the operational reliability and safety of plant operation. The HFE program main purpose is to ensure that human factor practices are incorporated into the plant design, emphasizing man-machine interface issues and design improvement of the nuclear reactor Control Centre. The Control Centre of nuclear reactor is a combination of control rooms, control suites and local control stations, which are functionally connected and located on the reactor site. The objective of this paper is to present a design approach for the Control Centre of a nuclear reactor used to produce radioisotopes and for nuclear research, including human factor issues. The design approach is based on participatory design principles, using human factor standards, ergonomic guidelines, and the participation of a multidisciplinary team during all design phases. Using the information gathered, an initial sketch 3D of the Control Centre was developed. (author)

  12. Frecuencia de control prenatal inadecuado y de factores asociados a su ocurrencia: Frequency of inadequate prenatal care and associated factors

    Directory of Open Access Journals (Sweden)

    Claudia Arispe

    2011-10-01

    Full Text Available Objetivo: Determinar la frecuencia de pacientes con control prenatal (CPN inadecuado y los factores asociados a dicho evento. Material y métodos: Se realizó un estudio descriptivo transversal donde se entrevistó a puérperas en el Hospital Nacional Cayetano Heredia entre agosto 2010 y enero 2011, y se revisó la historia clínica y carnet materno perinatal (CLAP. Se definió CPN inadecuado al incumplimiento del número mínimo y cronograma de visitas propuesto por el Ministerio de Salud. Se compararon factores epidemiológicos, maternos y socioeconómicos entre grupos de gestantes con CPN adecuado e inadecuado.Resultados: Se incluyeron 384 puérperas, 66,05% recibieron 6 ó más controles prenatales y sólo 7,36% tuvo CPN adecuado. Ciento cuarenta y cinco puérperas tuvieron su primer CPN antes de las 12 semanas. Los factores que se presentaron con mayor frecuencia en el grupo de CPN inadecuado fueron paridad mayor a 2 (p=0,02 y no planificación de la gestación (p=0,003. Conclusiones: El porcentaje de CPN inadecuado fue elevado. El CPN inadecuado se asoció con paridad mayor a 2 y gestación no planificada. (Rev Med Hered 2011;22:169-175.

  13. Anti tumour necrosis factor as risk factor for free perforations in Crohn's disease? A case-control study.

    Science.gov (United States)

    Eshuis, E J; Griffioen, G H M J; Stokkers, P C F; Ubbink, D T; Bemelman, W A

    2012-05-01

    Although the occurrence of intestinal perforation in Crohn's disease (CD) is rare, clinical observation has led to the question whether anti tumour necrosis factor (TNF) treatment is a risk factor for free perforation. The aim of this study was to investigate the possible relation between anti-TNF treatment and occurrence of free perforation, defined as intestinal perforations leading to emergency surgery. In this case-control study, all emergency operation reports from the period 1999-2009 of patients diagnosed with CD were checked for the presence of free perforation. These cases were compared with a sixfold larger control group derived from our CD patient database. Cases and controls were matched for age, gender, Montreal classification and surgical stage to ensure equal disease severity. Cases and controls were then compared regarding previous or current exposure to anti-TNF treatment. Thirteen patients underwent emergency surgery for spontaneous free perforation. Eight (62%) had been treated with anti-TNF within 5 months before the perforation. In the 78 matched controls, 29 (37%) had been or were still treated with anti-TNF. The odds for a free perforation adjusted for known confounders in two separate regression analyses were significantly higher in anti-TNF treated CD patients, albeit with a large confidence interval (OR 4.1, 95% CI: 1.1-16.0; and OR 23.0, 95% CI 2.2-238.5). This study showed a higher occurrence of free perforations in CD patients with anti-TNF therapy compared with those without anti-TNF therapy. Patients with CD and anti-TNF treatment showing acute abdominal pain must be suspected of this complication. © 2011 The Authors. Colorectal Disease © 2011 The Association of Coloproctology of Great Britain and Ireland.

  14. Biochemistry and physiology of anaerobic bacteria

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-05-18

    We welcome you to The Power of Anaerobes. This conference serves two purposes. One is to celebrate the life of Harry D. Peck, Jr.,who was born May 18, 1927 and would have celebrated his 73rd birthday at this conference. He died November 20, 1998. The second is to gather investigators to exchange views within the realm of anaerobic microbiology, an area in which tremendous progress has been seen during recent years. It is sufficient to mention discoveries of a new form of life (the archaea), hyper or extreme thermophiles, thermophilic alkaliphiles and anaerobic fungi. With these discoveries has come a new realization about physiological and metabolic properties of microorganisms, and this in turn has demonstrated their importance for the development, maintenance and sustenance of life on Earth.

  15. Physiologically anaerobic microorganisms of the deep subsurface

    Energy Technology Data Exchange (ETDEWEB)

    Stevens, S.E. Jr.; Chung, K.T.

    1992-06-01

    A variety of different media were used to isolate facultatively (FAB) and obligately anaerobic bacteria (OAB). These bacteria were isolated from core subsamples obtained from boreholes at the Idaho National Engineering Lab. (INEL) or at the Hanford Lab. (Yakima). Core material was sampled at various depths to 600 feet below the surface. All core samples with culturable bacteria contained at least FAB making thisthe most common physiological type of anaerobic bacteria present in the deep subsurface at these two sites. INEL core samples are characterized by isolates of both FAB and OAB. No isolates of acetogenic, methanogenic, or sulfate reducing bacteria were obtained. Yakima core samples are characterized by a marked predominance of FAB in comparison to OAB. In addition, isolates of acetogenic, methanogenic, and sulfate reducing bacteria were obtained. The Yakima site has the potential for complete anaerobic mineralization of organic compounds whereas this potential appears to be lacking at INEL.

  16. An integrative perspective of the anaerobic threshold.

    Science.gov (United States)

    Sales, Marcelo Magalhães; Sousa, Caio Victor; da Silva Aguiar, Samuel; Knechtle, Beat; Nikolaidis, Pantelis Theodoros; Alves, Polissandro Mortoza; Simões, Herbert Gustavo

    2017-12-14

    The concept of anaerobic threshold (AT) was introduced during the nineteen sixties. Since then, several methods to identify the anaerobic threshold (AT) have been studied and suggested as novel 'thresholds' based upon the variable used for its detection (i.e. lactate threshold, ventilatory threshold, glucose threshold). These different techniques have brought some confusion about how we should name this parameter, for instance, anaerobic threshold or the physiological measure used (i.e. lactate, ventilation). On the other hand, the modernization of scientific methods and apparatus to detect AT, as well as the body of literature formed in the past decades, could provide a more cohesive understanding over the AT and the multiple physiological systems involved. Thus, the purpose of this review was to provide an integrative perspective of the methods to determine AT. Copyright © 2017 Elsevier Inc. All rights reserved.

  17. Glucose metabolism in anaerobic rice seedlings

    International Nuclear Information System (INIS)

    Mayne, R.G.; Kende, Hans

    1986-01-01

    More than 80% of the radioactivity from (U- 14 C)glucose metabolised by anaerobic rice seedlings or by excised roots or coleoptiles was recovered as ethanol plus CO 2 ; less than 5% was recovered as water-soluble acidic components. Rates of 14 CO 2 formation from (U- 14 C)glucose were similar in roots and coleoptiles in both N 2 and air atmospheres. More 14 C0 2 was formed from (U- 14 C)glucose than could be accounted for by ethanolic fermentation, and the specific yields of 14 CO 2 from (6- 14 C)glucose and (1- 14 C)glucose gave unusually high C-6/C-1 ratios (1.7) in the anaerobic coleoptile. The results may indicate that appreciable pentan synthesis occurs in the anaerobic coleoptile. (author)

  18. A Mathematical Model for Dynamic Simulation of Anaerobic Digestion of Complex Substrates

    DEFF Research Database (Denmark)

    Angelidaki, Irini; Ellegaard, L.; Ahring, Birgitte Kiær

    1993-01-01

    A mathematical model for anaerobic degradation of complex organic material, such as manure, has been developed. The model includes an enzymatic hydrolytic step and four bacterial steps and involves 12 chemical compounds. The model focuses on ammonia inhibition and includes a detailed description...... of pH and temperature characteristics in order to accurately simulate free ammonia concentration. Free ammonia and acetate constitute the primary modulating factors in the model. The model has been applied for the simulation of digestion of cattle manure in continuously stirred tank reactors (CSTRs......), and results compare favorably with experimental data. 0 1993 John Wiley & Sons, Inc. Key words: anaerobic digestion ammonia inhibition manure mathematical model....

  19. Social support in depression: structural and functional factors, perceived control and help-seeking.

    Science.gov (United States)

    Kleinberg, A; Aluoja, A; Vasar, V

    2013-12-01

    Aims. This study examined the associations of social support, loneliness and locus of control with depression and help-seeking in persons with major depression. Methods. Twelve-month help-seeking for emotional problems was assessed in a cross-sectional 2006 Estonian Health Survey. Non-institutionalized individuals aged 18-84 years (n = 6105) were interviewed. A major depressive episode was assessed using the Mini-International Neuropsychiatric Interview. Factors describing social support, social and emotional loneliness and locus of control were assessed, and their associations with depression were analysed. The associations with reported help-seeking behaviour among people identified as having a major depressive episode (n = 343) were explored. Results. Low frequency of contacts with one's friends and parents, emotional loneliness, external locus of control and emotional dissatisfaction with couple relations were significant factors predicting depression in the multivariate model. External locus of control was associated with help-seeking in the depressed sample. Interactions of emotional loneliness, locus of control and frequency of contacts with parents significantly predicted help-seeking in the depressed sample. Conclusions. Depression is associated with structural and functional factors of social support and locus of control. Help-seeking of depressed persons depends on locus of control, interactions of emotional loneliness, locus of control and contacts with the parental family.

  20. Anaerobic oxidation of methane in grassland soils used for cattle husbandry

    Czech Academy of Sciences Publication Activity Database

    Bannert, A.; Bogen, C.; Esperschütz, J.; Koubová, Anna; Buegger, F.; Fischer, D.; Radl, V.; Fuss, R.; Chroňáková, Alica; Elhottová, Dana; Šimek, Miloslav; Schloter, M.

    2012-01-01

    Roč. 9, č. 10 (2012), s. 3891-3899 ISSN 1726-4170 R&D Projects: GA ČR GA526/09/1570 Institutional support: RVO:60077344 Keywords : anaerobic oxidation of methane * grassland soils * cattle husbandry Subject RIV: EH - Ecology, Behaviour Impact factor: 3.754, year: 2012

  1. An anaerobic field injection experiment in a landfill leachate plume (Grindsted, Denmark)

    DEFF Research Database (Denmark)

    Albrechtsen, Hans-Jørgen; Bjerg, Poul Løgstrup; Ludvigsen, L.

    1999-01-01

    Redox conditions may be environmental factors which affect the fate of the xenobiotic organic compounds. Therefore the redox conditions were characterized in an anaerobic, leachate-contaminated aquifer 15–60 m downgradient from the Grindsted Landfill, Denmark, where an field injection experiment ...

  2. Anaerobic digestion and digestate use: accounting of greenhouse gases and global warming contribution

    DEFF Research Database (Denmark)

    Møller, Jacob; Boldrin, Alessio; Christensen, Thomas Højlund

    2009-01-01

    Anaerobic digestion (AD) of source-separated municipal solid waste (MSW) and use of the digestate is presented from a global warming (GW) point of view by providing ranges of greenhouse gas (GHG) emissions that are useful for calculation of global warming factors (GWFs), i.e. the contribution to GW...

  3. Temperature regulates deterministic processes and the succession of microbial interactions in anaerobic digestion process

    Czech Academy of Sciences Publication Activity Database

    Lin, Qiang; De Vrieze, J.; Li, Ch.; Li, J.; Li, J.; Yao, M.; Heděnec, Petr; Li, H.; Li, T.; Rui, J.; Frouz, Jan; Li, X.

    2017-01-01

    Roč. 123, October (2017), s. 134-143 ISSN 0043-1354 Institutional support: RVO:60077344 Keywords : anaerobic digestion * deterministic process * microbial interactions * modularity * temperature gradient Subject RIV: DJ - Water Pollution ; Quality OBOR OECD: Water resources Impact factor: 6.942, year: 2016

  4. Combination of anaerobic effluent and lignocellulosic bacterial consortium to reduce vermicomposting time

    Science.gov (United States)

    Utilization of solid bio-fertilizers is an alternative to avoid chemical degradation of soil. Anaerobic biodigestor effluents/digestates have been used effectively as fertilizers. However, they may have several risk factors such as the presence of pathogens and heavy metals. Vermicomposting could he...

  5. Differentiation of anaerobic polycentric fungi by rDNA PCR-RFLP

    Czech Academy of Sciences Publication Activity Database

    Fliegerová, Kateřina; Mrázek, Jakub; Voigt, K.

    2006-01-01

    Roč. 51, č. 4 (2006), s. 273-277 ISSN 0015-5632 R&D Projects: GA ČR GA523/05/2555 Institutional research plan: CEZ:AV0Z50450515 Keywords : anaerobic polycentric fungi Subject RIV: EE - Microbiology, Virology Impact factor: 0.963, year: 2006

  6. Effect of temperature on methane production from field-scale anaerobic digesters treating dairy manure

    Science.gov (United States)

    Temperature is a critical factor affecting anaerobic digestion because it influences both system heating requirements and methane production. Temperatures of 35-37°C are typically suggested for manure digestion, yet in temperate climate digesters, require a considerable amount of additional heat en...

  7. Metabolic interactions between methanogenic consortia and anaerobic respiring bacteria

    DEFF Research Database (Denmark)

    Stams, A.J.; Oude Elferink, S.J.; Westermann, Peter

    2003-01-01

    Most types of anaerobic respiration are able to outcompete methanogenic consortia for common substrates if the respective electron acceptors are present in sufficient amounts. Furthermore, several products or intermediate compounds formed by anaerobic respiring bacteria are toxic to methanogenic...

  8. Characterization and Optimization of Dual Anaerobic/Aerobic Biofilm Process

    National Research Council Canada - National Science Library

    Togna, A

    1997-01-01

    The purpose of this Phase I STTR effort was to develop and characterize a dual anaerobic/aerobic biofilm process that promotes anaerobic reductive dehalogenation and aerobic cometabolic biodegradation...

  9. A simple anaerobic system for onsite treatment of domestic wastewater

    African Journals Online (AJOL)

    user

    UASB), carbon footprint. INTRODUCTION. Domestic wastewater refers to the wastewater from toilet, bathroom and kitchen of household. Anaerobic treatment of organic material proceeds in the absence of oxygen and the presence of anaerobic ...

  10. The effect of tannic compounds on anaerobic wastewater treatment

    NARCIS (Netherlands)

    Field, J.A.

    1989-01-01

    Anaerobic wastewater treatment is an alternative to the conventional aerobic treatment processes for the removal of easily biodegradable organic matter in medium to high strength industrial wastestreams. Anaerobic treatment has several advantages, however one important disadvantage is the

  11. Metabolic interactions between methanogenic consortia and anaerobic respiring bacteria

    DEFF Research Database (Denmark)

    Stams, A.J.; Oude Elferink, S.J.; Westermann, Peter

    2003-01-01

    Most types of anaerobic respiration are able to outcompete methanogenic consortia for common substrates if the respective electron acceptors are present in sufficient amounts. Furthermore, several products or intermediate compounds formed by anaerobic respiring bacteria are toxic to methanogenic ...

  12. The influence of thrombotic risk factors when oral contraceptives are prescribed. A control-only study.

    Science.gov (United States)

    Lidegaard, O

    1997-03-01

    The aim of this study was to assess preferential prescribing of OC according to different thrombotic risk factors. The control group in an ongoing Danish case-control study on stroke and OCs collected in 1994 and 1995 underwent a control-only analysis concerning the occurrence of thrombotic risk factors among users of different types of OC. Specific attention was given to differences between OCs with second and third generation progestagens. The association between specific risk factors and the pill types was assessed crude and after multivariate analysis with confounder control for age and other risk factors, in order to identify risk factors, which after these corrections still had a significant confounding influence on the prescribing of OC. Users of OCs with third generation progestagens had a significantly higher proportion of familial thrombotic disposition (23.1%) than users of OCs with second generation progestagens (7.1%) (p = 0.01). After correction for age and other risk factors this difference was still highly significant (p = 0.002). Among users of third generation pills the proportion of short time users (correction for age and other risk factors (p < 0.001). Smoking, years of schooling, migraine, and body mass index did not differ significantly between the two pill groups. In Denmark, women with familial thrombotic disposition are four times more likely being prescribed OCs with third versus second generation progestagens compared with women without such a disposition. At the same time users of OCs with third generation progestagens include significantly more short time users than users of OCs with second generation progestagens. For thrombotic diseases where familial disposition or duration of use of OCs play a role for the pill-associated risk, these differences may significantly influence the thrombotic risk measures in case-control studies and non-randomized cohort studies unless confounder control is conducted for this selection.

  13. Job strain (demands and control model) as a predictor of cardiovascular risk factors among petrochemical personnel

    Science.gov (United States)

    Habibi, Ehsanollah; Poorabdian, Siamak; Shakerian, Mahnaz

    2015-01-01

    Background: One of the practical models for the assessment of stressful working conditions due to job strain is job demand and control model, which explains how physical and psychological adverse consequences, including cardiovascular risk factors can be established due to high work demands (the amount of workload, in addition to time limitations to complete that work) and low control of the worker on his/her work (lack of decision making) in the workplace. The aim of this study was to investigate how certain cardiovascular risk factors (including body mass index [BMI], heart rate, blood pressure, cholesterol and smoking) and the job demand and job control are related to each other. Materials and Methods: This prospective cohort study was conducted on 500 workers of the petrochemical industry in south of Iran, 2009. The study population was selected using simple random statistical method. They completed job demand and control questionnaire. The cardiovascular risk factors data was extracted from the workers hygiene profiles. Chi-square (χ2) test and hypothesis test (η) were used to assess the possible relationship between different quantified variables, individual demographic and cardiovascular risk factors. Results: The results of this study revealed that a significant relationship can be found between job demand control model and cardiovascular risk factors. Chi-square test result for the heart rate showed the highest (χ2 = 145.078) relationship, the corresponding results for smoking and BMI were χ2 = 85.652 and χ2 = 30.941, respectively. Subsequently, hypothesis testing results for cholesterol and hypertension was 0.469 and 0.684, respectively. Discussion: Job strain is likely to be associated with an increased risk of cardiovascular risk factors among male staff in a petrochemical company in Iran. The parameters illustrated in the Job demands and control model can act as acceptable predictors for the probability of job stress occurrence followed by showing

  14. Expression profile of host restriction factors in HIV-1 elite controllers.

    Science.gov (United States)

    Abdel-Mohsen, Mohamed; Raposo, Rui André Saraiva; Deng, Xutao; Li, Manqing; Liegler, Teri; Sinclair, Elizabeth; Salama, Mohamed S; Ghanem, Hussam El-Din A; Hoh, Rebecca; Wong, Joseph K; David, Michael; Nixon, Douglas F; Deeks, Steven G; Pillai, Satish K

    2013-10-16

    Several host-encoded antiviral factors suppress HIV-1 replication in a cell-autonomous fashion in vitro. The relevance of these defenses to the control of HIV-1 in vivo remains to be elucidated. We hypothesized that cellular restriction of HIV-1 replication plays a significant role in the observed suppression of HIV-1 in "elite controllers", individuals who maintain undetectable levels of viremia in the absence of antiretroviral therapy (ART). We comprehensively compared the expression levels of 34 host restriction factors and cellular activation levels in CD4+ T cells and sorted T cell subsets between elite controllers, HIV-1-infected (untreated) non-controllers, ART-suppressed, and uninfected individuals. Expression of schlafen 11, a codon usage-based inhibitor of HIV-1 protein synthesis, was significantly elevated in CD4+ T cells from elite controllers as compared to both non-controllers (p = 0.048) and ART-suppressed individuals (p = 0.024), with this effect most apparent in central memory CD4+ T cells. Schlafen 11 expression levels were comparable between controllers and uninfected individuals. Cumulative restriction factor expression was positively correlated with CD4+ T cell activation (r² = 0.597, p < 0.0001), viral load (r² = 0.34, p = 0.015), and expression of ISG15 (r² = 0.73, p < 0.0001), a marker of interferon exposure. APOBEC3C, APOBEC3D, CTR9, TRIM26, and TRIM32 were elevated in elite controllers with respect to ART-suppressed individuals, while levels were comparable to uninfected individuals and non-controllers. Host restriction factor expression typically scales with cellular activation levels. However, the elevated mRNA and protein expression of schlafen 11, despite low activation and viral load, violates the global pattern and may be a signature characteristic of HIV-1 elite control.

  15. Biotransformation of RDX and HMX by Anaerobic Granular Sludge with Enriched Sulfate and Nitrate.

    Science.gov (United States)

    An, Chunjiang; Shi, Yarong; He, Yanling; Huang, Guohe; Liu, Yonghong; Yang, Shucheng

    2017-05-01

      RDX and HMX are widely used energetic materials and they are recognized as environmental contaminants at numerous locations. The present study investigated the biotransformation of RDX and HMX by anaerobic granular sludge under sulfate- and nitrate-enriched conditions. The results showed that RDX and HMX could be transformed by anaerobic granular sludge when nitrate was present. However, the biotransformation of RDX and HMX was negatively influenced, especially with high nitrate concentrations. Sulfate-enriched conditions were more favorable for the removal of ammunition compounds by anaerobic granular sludge than nitrate-enriched conditions. The removal of RDX and HMX under both nitrate- and sulfate-enriched conditions was facilitated by the use of glucose as additional substrate. This knowledge may help identify factors required for rapid removal of RDX and HMX in high-rate bioreactors. These results can also be applied to devise an appropriate and practical biological treatment strategy for explosive contaminated wastewater.

  16. Tobacco control policy development in the European Union: do political factors matter?

    Science.gov (United States)

    Bosdriesz, Jizzo R; Willemsen, Marc C; Stronks, Karien; Kunst, Anton E

    2015-04-01

    There has been much variation between European countries in the development of tobacco control policy. Not much is known about the factors that shape this variation. This study aimed to assess the role of political factors in tobacco control policy development. We used data from 11 European countries from 1996 to 2010. Multilevel regression modelling was used to investigate associations between the Tobacco Control Scale (TCS) and indicators of left-wing government and government effectiveness (policy formulation, implementation and enforcement), with control for confounders. An association was found between left-wing government and TCS over the period 1996-2003, but not over the whole period. The association between government effectiveness and TCS was significant and negative over the whole period, but positive between 2001 and 2005. Residual analysis showed that TCS scores from 2002 onwards were higher than expected based on the political factors. Associations varied among the five subscales of the TCS. The results suggest that, on the whole, national political factors have had only a minor influence on the large variations in tobacco control policy development in Europe over the last 15 years. However, there are indications that left-wing governments were important for early adoption of tobacco control policy, and high government effectiveness was important in the phase of adopting innovative policies. However, since 2002, with the advent of international treaties, the influence of national politics has diminished. © The Author 2014. Published by Oxford University Press on behalf of the European Public Health Association. All rights reserved.

  17. A possible methodological approach to setting up control level of radiation factors

    International Nuclear Information System (INIS)

    Devyatajkin, E.V.; Abramov, Yu.V.

    1986-01-01

    The mathematical formalization of the concept of control levels (CL) which enables one to obtain CL numerical values of controllable parameters required for rapid control purposes is described. The initial data for the assessment of environmental radioactivity are the controllable parameter values that is practical characteristic of controllable radiation factor showing technically measurable or calculation value. The controllable parameters can be divided into two classes depending on the degree of radiation effect on a man: possessing additivity properties (dosimetric class) and non-possessing (radiation class, which comprises the results of control of medium alteration dynamics, equipment operation safety, completeness of protection measures performance). The CL calculation formulas with account for requirements of radiation safety standards (RSS-76) are presented

  18. A comparative study of leachate quality and biogas generation in simulated anaerobic and hybrid bioreactors

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Qiyong; Tian, Ying; Wang, Shen; Ko, Jae Hac, E-mail: jaehacko@pkusz.edu.cn

    2015-07-15

    Highlights: • Temporary aeration shortened the initial acid inhibition phase for methanogens. • COD decreased faster in the hybrid bioreactor than that in the anaerobic control. • Methane generations from hybrid bioreactors were 133.4 L/kg{sub vs} and 113.2 L/kg{sub vs}. • MSW settlement increased with increasing the frequency of intermittent aeration. - Abstract: Research has been conducted to compare leachate characterization and biogas generation in simulated anaerobic and hybrid bioreactor landfills with typical Chinese municipal solid waste (MSW). Three laboratory-scale reactors, an anaerobic (A1) and two hybrid bioreactors (C1 and C2), were constructed and operated for about 10 months. The hybrid bioreactors were operated in an aerobic–anaerobic mode with different aeration frequencies by providing air into the upper layer of waste. Results showed that the temporary aeration into the upper layer aided methane generation by shortening the initial acidogenic phase because of volatile fatty acids (VFAs) reduction and pH increase. Chemical oxygen demand (COD) decreased faster in the hybrid bioreactors, but the concentrations of ammonia–nitrogen in the hybrid bioreactors were greater than those in the anaerobic control. Methanogenic conditions were established within 75 d and 60 d in C1 and C2, respectively. However, high aeration frequency led to the consumption of organic matters by aerobic degradation and resulted in reducing accumulative methane volume. The temporary aeration enhanced waste settlement and the settlement increased with increasing the frequency of aeration. Methane production was inhibited in the anaerobic control; however, the total methane generations from hybrid bioreactors were 133.4 L/kg{sub vs} and 113.2 L/kg{sub vs}. As for MSW with high content of food waste, leachate recirculation right after aeration stopped was not recommended due to VFA inhibition for methanogens.

  19. Human factors engineering control-room-design review/audit report: Palo Verde Nuclear Generating Station, Arizona Public Service Company

    International Nuclear Information System (INIS)

    Savage, J.W.; Lappa, D.A.

    1981-01-01

    A human factors engineering design review of the Palo Verde control room simulator was performed at the site on September 15 through September 17, 1981. Observed human factors design discrepancies were given priority ratings. This report summarizes the team's observations of the control room design and layout and of the control room operators' interface with the control room environment. A list of the human factors strengths observed in the Palo Verde control room simulator is given

  20. Molecular ecology of anaerobic reactor systems

    DEFF Research Database (Denmark)

    Hofman-Bang, H. Jacob Peider; Zheng, D.; Westermann, Peter

    2003-01-01

    for these processes. Only a few percent of Bacteria and Archaea have so far been isolated, and almost nothing is known about the dynamics and interactions between these and other microorganisms. This lack of knowledge is most clearly exemplified by the sometimes unpredictable and unexplainable failures...... to the abundance of each microbe in anaerobic reactor systems by rRNA probing. This chapter focuses on various molecular techniques employed and problems encountered when elucidating the microbial ecology of anaerobic reactor systems. Methods such as quantitative dot blot/fluorescence in-situ probing using various...

  1. Anaerobic digestion of cider apple residues

    Energy Technology Data Exchange (ETDEWEB)

    Contreras Lopez, A. (E.T.S.I.I., U.N.E.D., Madrid (Spain). Dept. Quimica Applicada a la Ingenieria); Lopez Bobo, R. (E.T.S. Ingeneiros Industriales, Asturias (Spain). Dept. de Energia)

    1992-12-01

    Apple residue from the cider industry is used here for anaerobic fermentation. The effect of retention time and volatile solids concentration on the production of biogas and methane was investigated by using continuously mixed anaerobic fermentors with a working volume of 1 1. The maximum proportions of biogas and methane obtained were 430 1 biogas/kg per day (12 days' retention time and 3% of volatile solids) and 281 1 of methane per day (a retention time of 30 days and 2% of volatile solids), respectively. (author)

  2. Anaerobic bacteria, the colon and colitis.

    Science.gov (United States)

    Roediger, W E

    1980-02-01

    Anaerobic bacteria constitute more than 90% of the bacteria in the colon. An anaerobic environment is needed to maintain their growth and the production of short-chain fatty acids by these bacteria from carbohydrates. Short-chain fatty acids are rapidly absorbed and essential for metabolic as well as functional welfare of the colonic mucosa. The importance of these acids in water absorption and in the patogenesis of colitis is discussed in relation to the concept of "energy deficiency diseases" of the colonic mucosa.

  3. Methane from Syngas by Anaerobic Digestion

    OpenAIRE

    Shah, Sanjay; Bergland, Wenche Hennie; Bakke, Rune

    2017-01-01

    Anaerobic digestion (AD) is a prominent green technology used for methane production from organic waste. Previous studies have shown that the amount of CH4 produced during anaerobic digestion can be increased by adding inorganic electron donors such as H2 and CO, both which can be produced as syngas from wood. Syngas inflow is implemented in the ADM1 model and simulations are carried out with different syngas additions to a well-documented case of wastewater treatment plant sludge AD. Three d...

  4. Renewable methane from anaerobic digestion of biomass

    International Nuclear Information System (INIS)

    Chynoweth, D.P.; Owens, J.M.

    2001-01-01

    Production of methane via anaerobic digestion of energy crops and organic wastes would benefit society by providing a clean fuel from renewable feedstocks. This would replace fossil fuel-derived energy and reduce environmental impacts including global warming and acid rain. Although biomass energy is more costly than fossil fuel-derived energy, trends to limit carbon dioxide and other emissions through emission regulations, carbon taxes, and subsidies of biomass energy would make it cost competitive. Methane derived from anaerobic digestion is competitive in efficiencies and costs to other biomass energy forms including heat, synthesis gases, and ethanol. (author)

  5. Anaerobic digestion of industrial activated aerobic sludge

    International Nuclear Information System (INIS)

    Goodloe, J.G.; Roberts, R.S.

    1990-04-01

    The Tennessee Eastman Company manufactures a variety of organic chemicals, plastics and fibers at their Kingsport Tennessee Facility. The wastewater generated during the manufacture of these compounds is currently treated using an activated sludge process. The objective of the project is to evaluate the economic potential of an anaerobic digestion process to convert industrial sludge at the Tennessee Eastman Company into biogas. The evaluation will require collection and analysis of experimental data on the anaerobic digestion of industrial sludge obtained from Kingsport. Although the experiments will be conducted using Tennessee Eastman sludge, these results should be also generally applicable to similar industrial sludge

  6. Evaluation of induction motor performance using an electronic power factor controller

    Science.gov (United States)

    1978-01-01

    The concept of reducing the losses in an induction motor by electronically controlling the time interval between the zero crossing of the applied voltage and the zero crossing of the armature current was evaluated. The effect on power losses and power factor of reducing the applied sinusoidal voltages below the rated value was investigated experimentally. The reduction in power losses was measured using an electronic controller designed and built at MSFC. Modifications to the MSFC controller are described as well as a manually controlled electronic device which does not require that the motor be wye connected and the neutral available. Possible energy savings are examined.

  7. In vitro activity of mecillinam against anaerobic bacteria.

    OpenAIRE

    Steinkraus, G E; McCarthy, L R

    1980-01-01

    A microtiter broth dilution method was employed to determine the in vitro activity of mecillinam against 201 recent clinical isolates of anaerobic bacteria. Both the anerobic gram-positive and anaerobic gram-negative bacilli displayed a wide range of minimal inhibitory concentrations of mecillinam; most strains were resistant to the antibiotic. The anaerobic cocci exhibited a narrower range of minimal inhibitory concentrations than were observed with other anaerobes, but also exhibited mecill...

  8. Size-dependent antibacterial activities of silver nanoparticles against oral anaerobic pathogenic bacteria.

    Science.gov (United States)

    Lu, Zhong; Rong, Kaifeng; Li, Ju; Yang, Hao; Chen, Rong

    2013-06-01

    Dental caries and periodontal disease are widespread diseases for which microorganism infections have been identified as the main etiology. Silver nanoparticles (Ag Nps) were considered as potential control oral bacteria infection agent due to its excellent antimicrobial activity and non acute toxic effects on human cells. In this work, stable Ag Nps with different sizes (~5, 15 and 55 nm mean values) were synthesized by using a simple reduction method or hydrothermal method. The Nps were characterized by powder X-ray diffraction, transmission electron microscopy and UV-vis absorption spectroscopy. The antibacterial activities were evaluated by colony counting assay and growth inhibition curve method, and corresponding minimum inhibitory concentration (MIC) against five anaerobic oral pathogenic bacteria and aerobic bacteria E. coli were determined. The results showed that Ag Nps had apparent antibacterial effects against the anaerobic oral pathogenic bacteria and aerobic bacteria. The MIC values of 5-nm Ag against anaerobic oral pathogenic bacteria A. actinomycetemcomitans, F. nuceatum, S. mitis, S. mutans and S. sanguis were 25, 25, 25, 50 and 50 μg/mL, respectively. The aerobic bacteria were more susceptible to Ag NPs than the anaerobic oral pathogenic bacteria. In the mean time, Ag NPs displayed an obvious size-dependent antibacterial activity against the anaerobic bacteria. The 5-nm Ag presents the highest antibacterial activity. The results of this work indicated a potential application of Ag Nps in the inhibition of oral microorganism infections.

  9. The Effect of Anaerobic and Aerobic Fish Sludge Supernatant on Hydroponic Lettuce

    Directory of Open Access Journals (Sweden)

    Simon Goddek

    2016-06-01

    Full Text Available The mobilization of nutrients from fish sludge (i.e., feces and uneaten feed plays a key role in optimizing the resource utilization and thus in improving the sustainability of aquaponic systems. While several studies have documented the aerobic and anaerobic digestion performance of aquaculture sludge, the impact of the digestate on plant growth has yet to be understood. The present study examines the impact of either an aerobic or an anaerobic digestion effluent on lettuce plant growth, by enriching a mixture of aquaculture and tap water with supernatants from both aerobic and anaerobic batch reactors. The lettuce plants grown in the hydroponic system supplied with supernatant from an anaerobic reactor had significantly better performance with respect to weight gain than both, those in the system where supernatant from the aerobic reactor was added, as well as the control system. It can be hypothesized that this effect was caused by the presence of NH4+ as well as dissolved organic matter, plant growth promoting rhizobacteria and fungi, and humic acid, which are predominantly present in anaerobic effluents. This study should therefore be of value to researchers and practitioners wishing to further develop sludge remineralization in aquaponic systems.

  10. Effect of tapering on anaerobic power and capacity of tae-kwon-do athletes

    Directory of Open Access Journals (Sweden)

    Leonardo de Sousa Fortes

    2017-05-01

    Full Text Available DOI: http://dx.doi.org/10.5007/1980-0037.2017v19n2p224   The aim of the study was to analyze the effect of a tapering period on anaerobic power and capacity of tae-kwon-do athletes. Thirty-one male tae-kwon-do participants of the Brazilian Championship were selected in a non-probabilistic way. Subjects were randomly divided into two groups, namely: experimental group (EG, n = 15 and control group (CG, n = 17. Both groups followed the same training protocol up to the tapering stage. CG was submitted to training loads contained in the last two weeks of the macrocycle. Only EG was submitted to tapering. Tapering had 2 weeks duration, adopting the linear tapering method. Taekwondo Anaerobic Test was performed by athletes before the start of the season, which was named as pre-intervention, and the last week of each mesocycle [Prep I, Prep II and Tapering (only EG]. Group vs. time effect interaction (p < 0.01 was identified for alactic anaerobic power, with an increase only in EG in tapering (p = 0.01. A significant group vs. time interaction (p <0.01 was revealed to fatigue index, improved anaerobic capacity being checked in EG only after the tapering period (p = 0.01. It was concluded that two weeks of linear type tapering optimized the anaerobic power and capacity of male tae-kwon-do athletes.

  11. Anaerobic digestion of buffalo dung: simulation of process kinetics

    International Nuclear Information System (INIS)

    Sahito, A.R.

    2015-01-01

    Assessment of kinetic of AD (Anaerobic Digestion) is a beneficial practice to forecast the performance of the process. It is helpful in the design of AD vessels, substrate feeding and digestate exit systems. The aim of this work was to assess the kinetics of anaerobically digested buffalo dung at different quantities of water added. It comprises the assessment of the specific methane production on the basis of VS (Volatile Solids) added in each reactor by using three first order models, i.e. the modified Gompertz model, the Cone model and the Exponential Curve Factor model. The analysis was tested by using the three statistical parameters, i.e. the coefficient of multiple determinations, the standard deviation of residuals and the Akaike's Information Criteria. The result reveals that the Exponential Curve Factor model was the best model that described the experimental data well. Moreover, there was not a direct or indirect relation between the kinetic coefficients of the AD process with the varying total or volatile solid content. (author)

  12. Rationale and design of INTERSTROKE: a global case-control study of risk factors for stroke

    DEFF Research Database (Denmark)

    O'Donnell, M; Serpault, Damien Xavier; Diener, C

    2010-01-01

    Stroke is a major global health problem. It is the third leading cause of death and the leading cause of adult disability. INTERHEART, a global case-control study of acute myocardial infarction in 52 countries (29,972 participants), identified nine modifiable risk factors that accounted for >90......% of population-attributable risk. However, traditional risk factors (e.g. hypertension, cholesterol) appear to exert contrasting risks for stroke compared with coronary heart disease, and the etiology of stroke is far more heterogeneous. In addition, our knowledge of risk factors for stroke in low...... years). A questionnaire (cases and controls) is used to acquire information on known and proposed risk factors for stroke. Cardiovascular (e.g. blood pressure) and anthropometric (e.g. waist-to-hip ratio) measurements are obtained at the time of interview. Nonfasting blood samples and random urine...

  13. The Development of Human Factor Guidelines for Unmanned Aircraft System Control Stations

    Science.gov (United States)

    Hobbs, Alan

    2014-01-01

    Despite being referred to as unmanned some of the major challenges confronting unmanned aircraft systems (UAS) relate to human factors. NASA is conducting research to address the human factors relevant to UAS access to non-segregated airspace. This work covers the issues of pilot performance, interaction with ATC, and control station design. A major outcome of this research will be recommendations for human factors design guidelines for UAS control stations to support routine beyond-line-of-sight operations in the US national airspace system (NAS). To be effective, guidelines must be relevant to a wide range of systems, must not be overly prescriptive, and must not impose premature standardization on evolving technologies. In developing guidelines, we recognize that existing regulatory and guidance material may already provide adequate coverage of certain issues. In other cases suitable guidelines may be found in existing military or industry human factors standards. In cases where appropriate existing standards cannot be identified, original guidelines will be proposed.

  14. Risk factors for femicide in abusive relationships: results from a multisite case control study.

    Science.gov (United States)

    Campbell, Jacquelyn C; Webster, Daniel; Koziol-McLain, Jane; Block, Carolyn; Campbell, Doris; Curry, Mary Ann; Gary, Faye; Glass, Nancy; McFarlane, Judith; Sachs, Carolyn; Sharps, Phyllis; Ulrich, Yvonne; Wilt, Susan A; Manganello, Jennifer; Xu, Xiao; Schollenberger, Janet; Frye, Victoria; Laughon, Kathryn

    2003-07-01

    This 11-city study sought to identify risk factors for femicide in abusive relationships. Proxies of 220 intimate partner femicide victims identified from police or medical examiner records were interviewed, along with 343 abused control women. Preincident risk factors associated in multivariate analyses with increased risk of intimate partner femicide included perpetrator's access to a gun and previous threat with a weapon, perpetrator's stepchild in the home, and estrangement, especially from a controlling partner. Never living together and prior domestic violence arrest were associated with lowered risks. Significant incident factors included the victim having left for another partner and the perpetrator's use of a gun. Other significant bivariate-level risks included stalking, forced sex, and abuse during pregnancy. There are identifiable risk factors for intimate partner femicides.

  15. Evidence from intrinsic activity that asymmetry of the human brain is controlled by multiple factors.

    Science.gov (United States)

    Liu, Hesheng; Stufflebeam, Steven M; Sepulcre, Jorge; Hedden, Trey; Buckner, Randy L

    2009-12-01

    Cerebral lateralization is a fundamental property of the human brain and a marker of successful development. Here we provide evidence that multiple mechanisms control asymmetry for distinct brain systems. Using intrinsic activity to measure asymmetry in 300 adults, we mapped the most strongly lateralized brain regions. Both men and women showed strong asymmetries with a significant, but small, group difference. Factor analysis on the asymmetric regions revealed 4 separate factors that each accounted for significant variation across subjects. The factors were associated with brain systems involved in vision, internal thought (the default network), attention, and language. An independent sample of right- and left-handed individuals showed that hand dominance affects brain asymmetry but differentially across the 4 factors supporting their independence. These findings show the feasibility of measuring brain asymmetry using intrinsic activity fluctuations and suggest that multiple genetic or environmental mechanisms control cerebral lateralization.

  16. Optimization of up-flow anaerobic sludge blanket reactor for ...

    African Journals Online (AJOL)

    aghomotsegin

    2013-06-05

    Jun 5, 2013 ... grown in the bottom part of UASB reactor were more compact and tense than those that occurred in the ... anaerobic sludge blanket (UASB), anaerobic biological treatment, biogas, granulated anaerobic sludge, industrial wastewater. INTRODUCTION ... structure of filaments of methanogenic bacteria,.

  17. The developments of anaerobic baffled reactor for wastewater ...

    African Journals Online (AJOL)

    STORAGESEVER

    2010-03-15

    Mar 15, 2010 ... Key words: Anaerobic baffled reactor, anaerobic process, reactor development, performance, solids retention, full-scale. INTRODUCTION. With the ... erobic reactors for the treatment of wastewater. As one of the high-rate anaerobic reactors, the ABR was extensively used in treating wastewater. The ABR ...

  18. The IWA Anaerobic Digestion Model No 1 (ADM1)

    NARCIS (Netherlands)

    Batstone, D.J.; Keller, J.; Angelidaki, I.; Kalyuzhnyi, S.V.; Pavalostathis, S.G.; Rozzi, A.; Sanders, W.T.M.; Siegrist, H.; Vavilin, V.A.

    2002-01-01

    The IWA Anaerobic Digestion Modelling Task Group was established in 1997 at the 8th World Congress on Anaerobic Digestion (Sendai, Japan) with the goal of developing a generalised anaerobic digestion model. The structured model includes multiple steps describing biochemical as well as

  19. The IWA Anaerobic digestion model no 1. (ADM1)

    DEFF Research Database (Denmark)

    Batstone, Damien J.; Keller, J.; Angelidaki, Irini

    2002-01-01

    The IWA Anaerobic Digestion Modelling Task Group was established in 1997 at the 8th World Congress on Anaerobic Digestion (Sendai, Japan) with the goal of developing a generalised anaerobic digestion model. The structured model includes multiple steps describing biochemical as well...

  20. Effects of mixing on methane production during thermophilic anaerobic digestion of manure

    DEFF Research Database (Denmark)

    Kaparaju, Prasad Laxmi-Narasimha; Buendia, Inmaculada M.; Ellegaard, Lars

    2008-01-01

    The effect of mixing on anaerobic digestion of manure was evaluated in lab-scale and pilot-scale experiments at 55 °C. The effect of continuous (control), minimal (mixing for 10 min prior to extraction/feeding) and intermittent mixing (withholding mixing for 2 h prior to extraction...... (10 min mixing before feeding) was advantageous compared to vigorous mixing (110 times per minute). On the other hand, under low substrate to inoculum ratio (10/90), gentle mixing was the best. The study thus indicated that mixing schemes and intensities have some effect on anaerobic digestion...

  1. Anaerobic digestion of onion residuals using a mesophilic Anaerobic Phased Solids Digester

    International Nuclear Information System (INIS)

    Romano, Rowena T.; Zhang, Ruihong

    2011-01-01

    The anaerobic digestion of onion residual from an onion processing plant was studied under batch-fed and continuously-fed mesophilic (35 ± 2 o C) conditions in an Anaerobic Phased Solids (APS) Digester. The batch digestion tests were performed at an initial loading of 2.8 gVS L -1 and retention time of 14 days. The biogas and methane yields, and volatile solids reduction from the onion residual were determined to be 0.69 ± 0.06 L gVS -1 , 0.38 ± 0.05 L CH 4 gVS -1 , and 64 ± 17%, respectively. Continuous digestion tests were carried out at organic loading rates (OLRs) of 0.5-2.0 gVS L -1 d -1 . Hydrated lime (Ca(OH) 2 ) was added to the APS-Digester along with the onion residual at 16 mg Ca(OH) 2 gVS -1 to control the pH of the biogasification reactor above 7.0. At steady state the average biogas yields were 0.51, 0.56, and 0.62 L gVS -1 for the OLRs of 0.5, 1.0, and 2.0 gVS L -1 d -1 respectively. The methane yields at steady state were 0.29, 0.32, and 0.31 L CH 4 gVS -1 for the OLRs of 0.5, 1.0, and 2.0 gVS L -1 d -1 respectively. The study shows that the digestion of onion residual required proper alkalinity and pH control, which was possible through the use of caustic chemicals. However, such chemicals will begin to have an inhibitory effect on the microbial population at high loading rates, and therefore alternative operational parameters are needed. -- Highlights: → An APS-Digester was used to study biogas production from onion solid residues. → Biogas and methane yields from onion solids were determined. → Study showed substantial findings for treating onion solid residues.

  2. Control to goal of cardiometabolic risk factors among Nigerians living with type 2 diabetes mellitus.

    Science.gov (United States)

    Okafor, C I; Ofoegbu, E N

    2012-01-01

    Cardiovascular risk factors contribute to morbidity and mortality among diabetic patients. National and international guidelines on management of diabetes therefore emphasize control to goals of blood glucose, blood pressure, dyslipidemia, and obesity so as to minimize the development of complications and enhance the patients' quality of life. To evaluate the status of control to goals of cardiometabolic risk factors among the diabetic patients attending the Diabetes clinic of University of Nigeria Teaching Hospital, Enugu. A survey of 233 type 2 diabetic patients recruited from the Diabetes clinic of our hospital was carried out. Standard procedures as described in the WHO STEP instrument were used to determine the waist circumference, weight, height, and systolic and diastolic blood pressure. Fasting blood glucose and lipid profiles were also assessed. Therapeutic goals used to define risk or poor control were values adopted by expert groups such as American diabetes association (ADA), National cholesterol education program (NCEP), American association of clinical endocrinologist (AACE) and International diabetes federation (IDF). There were 98 males and 135 females with mean (SD) duration of diabetes mellitus (DM) of 6.7 (6.3) years. Suboptimal glycemic, blood pressure control and dyslipidemia were observed in 65.7%, 51.9%, 97.1% of the subjects respectively while 60.1% of the subjects were found to be overweight/obese. Comparing the mean indices of risk factors with the recommended therapeutic goals, status of control was optimal for HDL-cholesterol, waist circumference and triglycerides. All the other risk factors were suboptimal. Control to goals of cardiovascular risk factors is poor among the patients. There is the need to identify and tackle the possible contributing factors so as to reduce the morbidity and mortality in these patients.

  3. Application of fuzzy synthetic assessment to assess human factors design level on reactor control panel

    International Nuclear Information System (INIS)

    Peng Xuecheng

    1999-01-01

    Reactor control panel design level on human factors must be considered by designer. The author evaluated the human factor design level of arrangement and combinations including the switch buttons, meter dials and indication lamps on Minjiang Reactor and High-Flux Engineer Test Reactor (HFETR) critical device by application of fuzzy synthetic assessment method in mathematics. From the assessment results, the advantages and shortcomings are fount, and some modification suggestions have also been proposed

  4. An Overview of the Application of Human Factors Guidance to Control Room Design

    International Nuclear Information System (INIS)

    Yondola, Paul R.; Karlewicz, George T.

    2002-01-01

    A new power plant design has the goal of making major improvements in cost and ease of operation over previous designs. Improvements in the way information is organized and presented to control room operators based on established Human Factors Engineering (HFE) criteria is key to achieving these goals. An overview of the process and methods being employed in an ongoing design effort will be discussed, including the ways in which current Human Factors guidance is being applied in a unique operating environment

  5. Potential Effect of Opium Consumption on Controlling Diabetes and Some Cardiovascular Risk Factors in Diabetic Patients

    OpenAIRE

    Rahimi, Najmeh; Gozashti, Mohamad Hossain; Najafipour, Hamid; Shokoohi, Mostafa; Marefati, Hamid

    2014-01-01

    Background Due to this belief that opium may have beneficial effects on diabetes or cardiovascular risk factors, the present study aimed to assess the potential and possible effects of opium consumption on diabetes control and some cardiovascular risk factors in diabetic patients. Methods This study enrolled 374 diabetic subjects from diabetes care centers in Kerman, Iran, including opium user group (n = 179) and a non-opium user group (n = 195). The data were collected through a questionnair...

  6. Risk factors for noma disease: a 6-year, prospective, matched case-control study in Niger

    OpenAIRE

    Baratti, Denise; Gayet-Ageron, Angèle; Hugonnet, Stéphane; Francois, Patrice; Pittet Cuenod, Brigitte Maud; Huyghe, Antoine; Bornand, Jacques-Etienne; Gervaix, Alain; Montandon, Denys; Schrenzel, Jacques; Mombelli, Andrea; Pittet, Didier

    2013-01-01

    Background: Noma is a poorly studied disease that leads to severe facial tissue destruction in children in developing countries, but the cause remains unknown. We aimed to identify the epidemiological and microbiological risk factors associated with noma disease. Methods: We did a prospective, matched, case-control study in Niger between Aug 1, 2001, and Oct 31, 2006, in children younger than 12 years to assess risk factors for acute noma. All acute noma cases were included and four contro...

  7. Evidence from intrinsic activity that asymmetry of the human brain is controlled by multiple factors

    OpenAIRE

    Liu, Hesheng; Stufflebeam, Steven M.; Sepulcre, Jorge; Hedden, Trey; Buckner, Randy L.

    2009-01-01

    Cerebral lateralization is a fundamental property of the human brain and a marker of successful development. Here we provide evidence that multiple mechanisms control asymmetry for distinct brain systems. Using intrinsic activity to measure asymmetry in 300 adults, we mapped the most strongly lateralized brain regions. Both men and women showed strong asymmetries with a significant, but small, group difference. Factor analysis on the asymmetric regions revealed 4 separate factors that each ac...

  8. A Survey on Some of the Effective Factors in Premature Birth: A Case-Control Study

    OpenAIRE

    Nader Esmailnasab; Hossein Amirian; Batoul Eskandai; Mina Zarei

    2015-01-01

    Background and objectives : Preterm birth (birth that occurs before the 37th week of pregnancy) is the major factor affecting a child's health and survival. Compared with term infants, these infants are at higher risk of mortality and incidence of health problems. The aim of this study was to identify risk factors associated with preterm birth. Material and Methods : A case-control study was conducted in Hamadan Fatemieh hospital, Iran, between 23rd October 2011 and 21st June 2012. Convenie...

  9. Correlation between microbial community and granule conductivity in anaerobic bioreactors for brewery wastewater treatment

    DEFF Research Database (Denmark)

    Shrestha, Pravin; Malvankar, Nikhil S.; Werner, Jeffrey

    2014-01-01

    Prior investigation of an upflow anaerobic sludge blanket (UASB) reactor treating brewery wastes suggested that direct interspecies electron transfer (DIET) significantly contributed to interspecies electron transfer to methanogens. To investigate DIET in granules further, the electrical conducti......Prior investigation of an upflow anaerobic sludge blanket (UASB) reactor treating brewery wastes suggested that direct interspecies electron transfer (DIET) significantly contributed to interspecies electron transfer to methanogens. To investigate DIET in granules further, the electrical...... conductivity and bacterial community composition of granules in fourteen samples from four different UASB reactors treating brewery wastes were investigated. All of the UASB granules were electrically conductive whereas control granules from ANAMMOX (ANaerobic AMMonium OXidation) reactors and microbial...... granules from an aerobic bioreactor designed for phosphate removal were not. There was a moderate correlation (r = 0.67) between the abundance of Geobacter species in the UASB granules and granule conductivity, suggesting that Geobacter contributed to granule conductivity. These results, coupled...

  10. Evaluation of the aerobic and anaerobic biodegradability of the antibiotic norfloxacin.

    Science.gov (United States)

    de Souza Santos, Lucilaine Valéria; Teixeira, Danusa Campos; Jacob, Raquel Sampaio; Amaral, Míriam Cristina Santos do; Lange, Liséte Celina

    2014-01-01

    The purpose of studying the biodegradability of pharmaceutical compounds is to evaluate their behaviors in relation to the treatment processes generally used in domestic and industrial wastewater treatment plants. The antibiotic norfloxacin was found to be a recalcitrant compound. The studies conducted showed norfloxacin removal rates of 12% and 18% when biomasses from treatments with activated sludge and anaerobic biodigesters, respectively, were used without acclimatization. This suggests that anaerobic digestion shows better performance for norfloxacin removal. Ecotoxicological tests, using the luminescent marine bacteria Aliivibrio fischeri as the test organism, show that anaerobic digestion could eliminate the toxicity of the antibiotic norfloxacin, even though total degradation of the drug was not observed. The release of norfloxacin during cell lysis suggests the importance of controlling this phenomenon in biological treatment systems that handle wastewater contaminated with norfloxacin, thus preventing the return of this drug to the environment.

  11. The role of hormones and growth factors in the cellular proliferation control in mammals

    International Nuclear Information System (INIS)

    Armelin, H.A.

    1978-01-01

    A review is done about fibroblast proliferation, its control by classic hormones and hormonal growth factors, showing their main implications and the stage of this research at present. The control exerted on fibronlast proliferation by hormonal growth factors and classic hormones is demonstrated. The existence of basic mechanisms valid for all types of cells is suggested. Experiences are carried out with the aim of finding growth mutants useful in the elucidation of the biochemical mechanisms involved in growth regulation. Radiactive precursors and autoradiographic techniques are used in the research. (M.A.) [pt

  12. Risk factors for femicide-suicide in abusive relationships: results from a multisite case control study.

    Science.gov (United States)

    Koziol-McLain, Jane; Webster, Daniel; McFarlane, Judith; Block, Carolyn Rebecca; Ulrich, Yvonne; Glass, Nancy; Campbell, Jacquelyn C

    2006-02-01

    The killing of women by men who then take their own lives (femicide-suicide) is the most common form of homicide-suicide. This study identified femicide-suicide risk factors in an 11-city case-control study of femicide in the United States. Perpetrator, victim, relationship, and incident characteristics were analyzed for femicide-suicide cases (n = 67) and controls (n = 356, women living in the community with nonfatal physical abuse) using logistic regression modeling. Two risk factors emerged that were unique to femicide-suicides cases compared to overall femicide risk analyses: prior perpetrator suicide threats and victims having ever been married to the perpetrator.

  13. 3D microwave cavity with magnetic flux control and enhanced quality factor

    Energy Technology Data Exchange (ETDEWEB)

    Reshitnyk, Yarema [The University of Queensland, School of Mathematics and Physics, St Lucia (Australia); Jerger, Markus [The University of Queensland, ARC Centre of Excellence for Engineered Quantum Systems, 4072 (Australia); Fedorov, Arkady [The University of Queensland, School of Mathematics and Physics, St Lucia (Australia); The University of Queensland, ARC Centre of Excellence for Engineered Quantum Systems, 4072 (Australia)

    2016-12-15

    Three-dimensional (3D) microwave cavities have been extensively used for coupling and interacting with superconducting quantum bits (qubits), providing a versatile platform for quantum control experiments and for realizing hybrid quantum systems. While having high quality factors (>10{sup 6}) superconducting cavities do not permit magnetic field control of qubits. In contrast, cavities made of normal metals are transparent to magnetic fields, but experience lower quality factors (∝10{sup 4}). We have created a hybrid cavity which is primarily composed of aluminium but also contains a small copper insert reaching the internal quality factor of ≅10{sup 5}, an order of magnitude improvement over all previously tested normal metal cavities. In order to demonstrate precise magnetic control, we performed spectroscopy of three superconducting qubits, where individual control of each qubit's frequency was exerted with small external wire coils. An improvement in quality factor and magnetic field control makes this 3D hybrid cavity an attractive new element for circuit quantum electrodynamics experiments. (orig.)

  14. Dehalogenation of chlorinated ethenes and immobilization of nickel in anaerobic sediment columns under sulfidogenic conditions

    NARCIS (Netherlands)

    Drzyzga, O; EL Mamouni, R; Agathos, SN; Gottschal, JC

    2002-01-01

    A sediment column study was carried out to demonstrate the bioremediation of chloroethene- and nickel-contaminated sediment in a single anaerobic step under sulfate-reducing conditions. Four columns (one untreated control column and three experimental columns) with sediment from a chloroethene- and

  15. Exercise- and Hypoxia-Induced Anaerobic Metabolism and Recovery: A Student Laboratory Exercise Using Teleost Fish

    Science.gov (United States)

    Rees, B. B.; Boily, P.; Williamson, L. A. C.

    2009-01-01

    Anaerobic metabolism is recruited in vertebrates under conditions of intense exercise or lowered environmental oxygen availability (hypoxia), typically resulting in the accumulation of lactate in blood and tissues. Lactate will be cleared over time after the reoxygenation of tissues, eventually returning to control levels. Here, we present a…

  16. Pilot plant study of the effects of quebracho and wattle on anaerobic digestion

    Energy Technology Data Exchange (ETDEWEB)

    Eye, J.D.; Ficker, C.F.

    1982-01-01

    Quebracho and wattle tannin adversely affected the operational control required for the systems as well as CH4 production. The anaerobic organisms however degraded the tannins and the characteristic red color was effectively removed from the supernatant (liquid phase of digested sludge) during digestion.

  17. Fe(II) oxidation kinetics and Fe hydroxyphosphate precipitation upon aeration of anaerobic (ground)water

    NARCIS (Netherlands)

    van der Grift, B.|info:eu-repo/dai/nl/373433484; Griffioen, J.|info:eu-repo/dai/nl/091129265; Behrends, T.|info:eu-repo/dai/nl/30484358X; Wassen, M.J.|info:eu-repo/dai/nl/07165710X; Schot, P.P.|info:eu-repo/dai/nl/08071563X; Osté, Leonard

    2015-01-01

    Exfiltration of anaerobic Fe-rich groundwater into surface water plays an important role in controlling the transport of phosphate (P) from agricultural areas to the sea. Previous laboratory and field studies showed that Fe(II) oxidation upon aeration leads to effective immobilization of dissolved P

  18. Anaerobic Digestion II. Sludge Treatment and Disposal Course #166. Instructor's Guide [and] Student Workbook.

    Science.gov (United States)

    Arasmith, E. E.

    This lesson is the second of a two-part series on anaerobic digestion. Topics discussed include classification of digester by function, roof design, and temperature range, mixing systems, gas system components, operational control basics, and general safety considerations. The lesson includes an instructor's guide and student workbook. The…

  19. Anaerobic soil disinfestation reduces survival and infectivity of Phytophthora nicotianae chlamydospores in pepper

    Science.gov (United States)

    Phytophthora nicotianae is the principal causal agent of root and crown rot disease of pepper plants in Extremadura (western Spain), a spring-summer crop in this region. Preplant soil treatment by anaerobic soil disinfestation (ASD) may effectively control plant pathogens in many crop production sys...

  20. Response of anaerobic carbon cycling to water table manipulation in an Alaskan rich fen

    Science.gov (United States)

    E.S. Kane; M.R. Chivers; M.S. Turetsky; C.C. Treat; D.G. Petersen; M. Waldrop; J.W. Harden; A.D. McGuire

    2013-01-01

    To test the effects of altered hydrology on organic soil decomposition, we investigated CO2 and CH4 production potential of rich-fen peat (mean surface pH = 6.3) collected from a field water table manipulation experiment including control, raised and lowered water table treatments. Mean anaerobic CO2...