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Sample records for chilled ammonia process

  1. Chilled Ammonia Process for CO2 Capture

    DEFF Research Database (Denmark)

    Darde, Victor Camille Alfred; Thomsen, Kaj; Well, Willy J.M. van

    2010-01-01

    The chilled ammonia process absorbs the CO2 at low temperature (2–10°C). The heat of absorption of carbon dioxide by ammonia is significantly lower than for amines. In addition, degradation problems can be avoided and a high carbon dioxide capacity is achieved. Hence, this process shows good...

  2. Chilled ammonia process for CO2 capture

    DEFF Research Database (Denmark)

    Darde, Victor Camille Alfred; Thomsen, Kaj; van Well, Willy J. M

    2009-01-01

    The chilled ammonia process absorbs the CO2 at low temperature (2-10 degrees C). The heat of absorption of carbon dioxide by ammonia is significantly lower than for amines. In addition, degradation problems can be avoided and a high carbon dioxide capacity is achieved. Hence, this process shows...

  3. Alternative Layouts for the Carbon Capture with the Chilled Ammonia Process

    DEFF Research Database (Denmark)

    Valenti, Gianluca; Bonalumi, Davide; Fosbøl, Philip Loldrup

    2013-01-01

    Many alternatives are being investigated for the carbon capture, but none appears to have been proved as the choice for full-scale applications. This work considers the Chilled Ammonia Process for coal-fired Ultra Super Critical power plants. Three layouts are simulated with Aspen Plus...

  4. A low-energy chilled ammonia process exploiting controlled solid formation for post-combustion CO2 capture.

    Science.gov (United States)

    Sutter, Daniel; Gazzani, Matteo; Mazzotti, Marco

    2016-10-20

    A new ammonia-based process for CO2 capture from flue gas has been developed, which utilizes the formation of solid ammonium bicarbonate to increase the CO2 concentration in the regeneration section of the process. Precipitation, separation, and dissolution of the solid phase are realized in a dedicated process section, while the packed absorption and desorption columns remain free of solids. Additionally, the CO2 wash section applies solid formation to enable a reduction of the wash water consumption. A rigorous performance assessment employing the SPECCA index (Specific Primary Energy Consumption for CO2 Avoided) has been implemented to allow for a comparison of the overall energy penalty between the new process and a standard ammonia-based capture process without solid formation. A thorough understanding of the relevant solid-solid-liquid-vapor phase equilibria and an accurate modeling of them have enabled the synthesis of the process, and have inspired the development of the optimization algorithm used to screen a wide range of operating conditions in equilibrium-based process simulations. Under the assumptions on which the analysis is based, the new process with controlled solid formation achieved a SPECCA of 2.43 MJ kgCO2(-1), corresponding to a reduction of 17% compared to the process without solid formation (with a SPECCA of 2.93 MJ kgCO2(-1)). Ways forward to confirm this significant improvement, and to increase the accuracy of the optimization are also discussed.

  5. Process simulation of CO2 capture with aqueous ammonia using the Extended UNIQUAC model

    DEFF Research Database (Denmark)

    Darde, Victor Camille Alfred; Maribo-Mogensen, Bjørn; van Well, Willy J.M.

    2012-01-01

    The use of aqueous ammonia is a promising option to capture carbon dioxide from power plants thanks to the potential low heat requirement during the carbon dioxide desorption compared to monoethanolamine (MEA) based process. The patented Chilled Ammonia Process developed by Alstom absorbs carbon...... of the process is necessary.In this work, the performance of the carbon dioxide capture process using aqueous ammonia has been analyzed by process simulation. The Extended UNIQUAC thermodynamic model available for the CO2–NH3–H2O system has been implemented in the commercial simulator Aspen Plus®1 by using...... to be in the same range as the values reported recently for advanced amine processes. Assuming that cold cooling water is available, the electricity consumption remains limited. Hence the Chilled Ammonia Process is a promising option for post combustion carbon dioxide capture....

  6. GENERAL ALGORITHMIC SCHEMA OF THE PROCESS OF THE CHILL AUXILIARIES PROJECTION

    Directory of Open Access Journals (Sweden)

    A. N. Chichko

    2006-01-01

    Full Text Available The general algorithmic diagram of systematization of the existing approaches to the process of projection is offered and the foundation of computer system of the chill mold arming construction is laid.

  7. Quality and safety of fish curry processed by sous vide cook chilled and hot filled technology process during refrigerated storage.

    Science.gov (United States)

    Shakila, R Jeya; Raj, B Edwin; Felix, N

    2012-06-01

    Fish curry, a traditional Indian dish was prepared from farmed fish Cobia (Rachycentron canadum), packaged by two different cook-chill processes namely, sous vide cook chilled and hot filled technology and held at 2 °C. Biochemical composition revealed that fish curry contained 5% protein and 6% fat. Omega-3 fatty acids, eicosapentaenoic acid (EPA) retained 55.44% while docosahexaenoic acid (DHA) retained 29% during cook-chilling process. The major fatty acids in fish curry were C18:2, C12:0, C16:0 and C18:1. Shelf-life of sous vide cook chilled and hot filled technology processed fish curry were 8 and 12 weeks, respectively. Total bacterial counts were detected after 4 weeks and 12 weeks in sous vide cook chilled and hot filled technology processes, respectively. Total staphylococci were detected in sous vide cook chilled and hot filled technology processed cobia fish curry after 4 and 12 weeks, respectively. Total bacilli, anaerobic sulfite reducing clostridia, Salmonella, and lactic acid bacteria were absent. Hot filled technology process was more efficient and could be applied for chilled fish curry preservation for 12 weeks without any safety problems.

  8. Chloroplast RNA-Binding Protein RBD1 Promotes Chilling Tolerance through 23S rRNA Processing in Arabidopsis

    Science.gov (United States)

    Yang, Leiyun; Yang, Fen; Wang, Yi; Zhu, Jian-Kang; Hua, Jian

    2016-01-01

    Plants have varying abilities to tolerate chilling (low but not freezing temperatures), and it is largely unknown how plants such as Arabidopsis thaliana achieve chilling tolerance. Here, we describe a genome-wide screen for genes important for chilling tolerance by their putative knockout mutants in Arabidopsis thaliana. Out of 11,000 T-DNA insertion mutant lines representing half of the genome, 54 lines associated with disruption of 49 genes had a drastic chilling sensitive phenotype. Sixteen of these genes encode proteins with chloroplast localization, suggesting a critical role of chloroplast function in chilling tolerance. Study of one of these proteins RBD1 with an RNA binding domain further reveals the importance of chloroplast translation in chilling tolerance. RBD1 is expressed in the green tissues and is localized in the chloroplast nucleoid. It binds directly to 23S rRNA and the binding is stronger under chilling than at normal growth temperatures. The rbd1 mutants are defective in generating mature 23S rRNAs and deficient in chloroplast protein synthesis especially under chilling conditions. Together, our study identifies RBD1 as a regulator of 23S rRNA processing and reveals the importance of chloroplast function especially protein translation in chilling tolerance. PMID:27138552

  9. Ammonia measurement with a pH electrode in the ammonia/urea-SCR process

    Science.gov (United States)

    Kröcher, Oliver; Elsener, Martin

    2007-03-01

    The selective catalytic reduction of nitrogen oxides with ammonia (ammonia SCR) and urea (urea SCR), respectively, is a widespread process to clean flue and diesel exhaust gases due to its simplicity and efficiency. The main challenge of the process is to minimize the ammonia emissions downstream of the SCR catalyst. We found that ammonia emissions of >10 ppm can reliably be detected with a simple pH electrode in the presence of CO2, SOx, NOx, and moderately weak organic acids. 10-20 ppm of ammonia in the exhaust gas are sufficient to neutralize the acids and to increase the pH value from 3 to 6. On this basis a continuous measuring method for ammonia was developed, which was used to control the dosage of urea in the SCR process. While keeping the ammonia emissions after the SCR catalyst at 5-30 ppm an average NOx removal efficiency (DeNOx) of >95% were achieved at a diesel test rig. The method can also be applied for exhaust gases with higher acid contents, if a basic pre-filter is added adsorbing the acidic exhaust components. Compared to water as absorption solution, more precise ammonia measurements are possible, if a 0.1 M NH4Cl absorption solution is applied, whose pH value is changing as a Nernst function of the ammonia concentration.

  10. Ammonia Process by Pressure Swing Adsorption

    Energy Technology Data Exchange (ETDEWEB)

    Dr Felix Jegede

    2010-12-27

    The overall objective of the project is to design, develop and demonstrate a technically feasible and commercially viable system to produce ammonia along with recovery of the products by adsorption separation methods and significantly decrease the energy requirement in ammonia production. This is achieved through a significantly more efficient ammonia psa recovery system. The new ammonia recovery system receives the reactor effluents and achieves complete ammonia recovery, (which completely eliminates the energy intensive refrigeration and condensation system currently used in ammonia production). It also recovers the unused reactants and recycles them back to the reactor, free of potential reactor contaminants, and without the need for re-compression and re-heat of recycle stream thereby further saving more energy. The result is a significantly lower energy consumption, along with capital cost savings.

  11. Optimization of biomethanation focusing on high ammonia loaded processes

    DEFF Research Database (Denmark)

    Wang, Han

    , could theoretically mitigate the ammonia inhibition problem (Angelidaki et al., 1999). Therefore, the effect of co-digestion of cattle manure with lipids (i.e. glycerol trioleate (GTO)) under high ammonia levels (5 g NH4+-N·L-1) in anaerobic continuous stirred tank (CSTR) reactors (RGTO) was assessed...... and subsequently been converted together with carbon dioxide to methane by hydrogenotrophic methanogens, could potentially be more tolerant to ammonia toxicity. Therefore, the effect of different ammonia levels on this hydrogen assisted biogas upgrading process under different hydrogen partial pressure (0, 0.25, 0.......5 and 1 atm) in anaerobic reactors at both mesophilic and thermophilic temperature was evaluated. When the initial hydrogen partial pressure was 0.5 atm, the methane yield at high ammonia load (7 g NH4+-N L-1) was 41.0% and 22.3% lower than at low ammonia load (1 g NH4+-N L-1) in mesophilic...

  12. Evaluation of Disinfectants Used in Pre-Chilling water Tanks of Poultry Processing Plants

    Directory of Open Access Journals (Sweden)

    BHL Guastalli

    Full Text Available ABSTRACT In poultry processing plants, disinfectants are often added to pre-chilling water tanks to reduce microbial contamination. The present study aimed at evaluating the effect of five disinfectants (acidified sodium chlorite, alkyl dimethyl benzyl ammonium chloride, chlorine dioxide, peracetic acid, and sodium hypochlorite on the populations of food quality indicator microorganisms and on Salmonella Enteritidis (SE in the presence and absence of organic matter. The results showed that chlorine dioxide and sodium hypochlorite did not reduce microbial carcass counts. On the other hand, acidified sodium chlorite, alkyl dimethyl benzyl ammonium chloride and peracetic acid reduced total and fecal coliform counts. Peracetic acid reduced the number of psychrotrophic microorganisms. All products were effective in reducing SE counts only in the absence of organic matter. Acidified sodium chlorite, alkyl dimethyl benzyl ammonium chloride and peracetic acid could be candidates for the replacement of sodium hypochlorite (commonly used in Brazil in pre-chilling tanks.

  13. Removal of ammonia solutions used in catalytic wet oxidation processes.

    Science.gov (United States)

    Hung, Chang Mao; Lou, Jie Chung; Lin, Chia Hua

    2003-08-01

    Ammonia (NH(3)) is an important product used in the chemical industry, and is common place in industrial wastewater. Industrial wastewater containing ammonia is generally either toxic or has concentrations or temperatures such that direct biological treatment is unfeasible. This investigation used aqueous solutions containing more of ammonia for catalytic liquid-phase oxidation in a trickle-bed reactor (TBR) based on Cu/La/Ce composite catalysts, prepared by co-precipitation of Cu(NO(3))(2), La(NO(3))(2), and Ce(NO(3))(3) at 7:2:1 molar concentrations. The experimental results indicated that the ammonia conversion of the wet oxidation in the presence of the Cu/La/Ce composite catalysts was determined by the Cu/La/Ce catalyst. Minimal ammonia was removed from the solution by the wet oxidation in the absence of any catalyst, while approximately 91% ammonia removal was achieved by wet oxidation over the Cu/La/Ce catalyst at 230 degrees C with oxygen partial pressure of 2.0 MPa. Furthermore, the effluent streams were conducted at a liquid hourly space velocity of under 9 h(-1) in the wet catalytic processes, and a reaction pathway was found linking the oxidizing ammonia to nitric oxide, nitrogen and water. The solution contained by-products, including nitrates and nitrites. Nitrite selectivity was minimized and ammonia removal maximized when the feed ammonia solution had a pH of around 12.0.

  14. Experimental investigation on chill-down process of cryogenic flow line

    Science.gov (United States)

    Jin, Lingxue; Park, Changgi; Cho, Hyokjin; Lee, Cheonkyu; Jeong, Sangkwon

    2016-10-01

    This paper describes the cryogenic chill-down experiments that are conducted on a 12.7 mm outer diameter, 1.25 mm wall thickness and 7 m long stainless steel horizontal pipe with liquid nitrogen (LN2). The pipe is vacuum insulated during the experiment to minimize the heat leak from room temperature and to enable one to numerically simulate the process easily. The temperature and the pressure profiles of the chill-down line are obtained at the location which is 5.5 m in a distance from the pipe inlet. The mass flux range is approximately from 19 kg/m2 s to 49 kg/m2 s, which corresponds to the Reynolds numbers range from 1469 to 5240. The transient histories of temperature, pressure and mass flow rate during the line chill-down process are monitored, and the heat transfer coefficient and the heat flux are computed by an inverse problem solving method. The amplitude of the pressure oscillation and the oscillating period become larger and longer at higher pressure conditions. In the low mass flux conditions, the critical heat flux in horizontal pipes is not sensitive to mass flux, and is higher than that in vertical pipes. Kutateladze's correlation with the constant coefficient, B = 0.029 , well matches the experimental data in the current work. In nucleate flow boiling regime, heat transfer coefficient, h , is proportional to (q″)n , and n is equal to 0.7.

  15. Deammoniation and ammoniation processes with ammonia complexes

    Directory of Open Access Journals (Sweden)

    Pim Donkers

    2016-12-01

    Full Text Available For selecting the most suitable ammoniate as a heat storage material we have reviewed all the available literature since 1860. This data reveal that we can order the dissociation temperature and the enthalpy of reaction of di erent ammoniates. We show that all data can be represented by a single master curve. This curve shows that ammoniates belonging to the alkali metal periodic group have the lowest energy pro ammonia molecule, whereas transition metals (3d have the highest energy pro ammonia molecule. These trends can be used to select the most suitable ammoniates under certain working conditions.

  16. Process model for ammonia volatilization from anaerobic swine lagoons incorporating varying wind speeds and biogas bubbling

    Science.gov (United States)

    Ammonia volatilization from treatment lagoons varies widely with the total ammonia concentration, pH, temperature, suspended solids, atmospheric ammonia concentration above the water surface, and wind speed. Ammonia emissions were estimated with a process-based mechanistic model integrating ammonia ...

  17. PRETREATMENT AND FRACTIONATION OF CORN STOVER BY AMMONIA RECYCLE PERCOLATION PROCESS. (R831645)

    Science.gov (United States)

    Corn stover was pretreated with aqueous ammonia in a flow-through column reactor,a process termed as Ammonia Recycle Percolation (ARP). The aqueous ammonia causesswelling and efficient delignification of biomass at high temperatures. The ARPprocess solubilizes abou...

  18. The importance of the ammonia purification process in ammonia-water absorption systems

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez-Seara, Jose [Area de Maquinas y Motores Termicos, Escuela Tecnica Superior de Ingenieros Industriales, Universidad de Vigo, Campus Lagoas-Marcosende No. 9, 36200 Vigo (Spain)]. E-mail: jseara@uvigo.es; Sieres, Jaime [Area de Maquinas y Motores Termicos, Escuela Tecnica Superior de Ingenieros Industriales, Universidad de Vigo, Campus Lagoas-Marcosende No. 9, 36200 Vigo (Spain)

    2006-08-15

    Practical experience in working with ammonia-water absorption systems shows that the ammonia purification process is a crucial issue in order to obtain an efficient and reliable system. In this paper, the detrimental effects of the residual water content in the vapour refrigerant are described and quantified based on the system design variables that determine the effectiveness of the purification process. The study has been performed considering a single stage system with a distillation column with complete condensation. The ammonia purification effectiveness of the column is analysed in terms of the efficiencies in the stripping and rectifying sections and the reflux ratio. By varying the efficiencies from 0 to 1, systems with neither the rectifying nor stripping section, with either the rectifying or stripping section, or with both sections can be considered. The impact of the ammonia purification process on the absorption system performance is studied based on the column efficiencies and reflux ratio; and its effects on refrigerant concentration, system COP, system pressures and main system mass flow rates and concentrations are analysed. When the highest efficiency rectifying sections are used a combination of generation temperature and reflux ratio which leads to optimum COP values is found. The analysis covers different operating conditions with air and water cooled systems from refrigeration to air conditioning applications by changing the evaporation temperature. The importance of rectification in each kind of application is evaluated.

  19. Modeling and Analysis of Chill and Fill Processes for the EDU Tank

    Science.gov (United States)

    Hedayat, A.; Cartagena, W.; Majumdar, A. K.; Leclair, A. C.

    2015-01-01

    NASA's future missions may require long-term storage and transfer of cryogenic propellants. The Engineering Development Unit (EDU), a NASA in-house effort supported by both Marshall Space Flight Center (MSFC) and Glenn Research Center (GRC), is a Cryogenic Fluid Management (CFM) test article that primarily serves as a manufacturing pathfinder and a risk reduction task for a future CFM payload. The EDU test article, comprises a flight like tank, internal components, insulation, and attachment struts. The EDU is designed to perform integrated passive thermal control performance testing with liquid hydrogen in a space-like vacuum environment. A series of tests, with liquid hydrogen as a testing fluid, was conducted at Test Stand 300 at MSFC during summer of 2014. The objective of this effort was to develop a thermal/fluid model for evaluating the thermodynamic behavior of the EDU tank during the chill and fill processes. Generalized Fluid System Simulation Program (GFSSP), an MSFC in-house general-purpose computer program for flow network analysis, was utilized to model and simulate the chill and fill portion of the testing. The model contained the liquid hydrogen supply source, feed system, EDU tank, and vent system. The modeling description and comparison of model predictions with the test data will be presented in the final paper.

  20. The chilling of carcasses.

    Science.gov (United States)

    Savell, J W; Mueller, S L; Baird, B E

    2005-07-01

    Biochemical processes and structural changes that occur in muscle during the first 24h postmortem play a great role in the ultimate quality and palatability of meat and are influenced by the chilling processes that carcasses are subjected to after slaughter. For beef and lamb, employing chilling parameters that minimize cold shortening is of greatest importance and can be best addressed by ensuring that muscle temperatures are not below 10°C before pH reaches 6.2. For pork, because of the impact of high muscle temperatures and low pH on the development of pale, soft, and exudative (PSE) pork, a more rapid chilling process is needed to reduce PSE with the recommended internal muscle temperature of 10°C at 12h and 2-4°C at 24h. Spray chilling, a system whereby chilled water is applied to carcasses during the early part of postmortem cooling, is used to control carcass shrinkage and to improve chilling rates through evaporative cooling. Delayed chilling can be used to reduce or prevent the negative effects of cold shortening; however, production constraints in high-volume facilities and food safety concerns make this method less useful in commercial settings. Electrical stimulation and alternative carcass suspension programs offer processors the opportunity to negate most or all of the effects of cold shortening while still using traditional chilling systems. Rapid or blast chilling can be an effective method to reduce the incidence of PSE in pork but extreme chilling systems may cause quality problems because of the differential between the cold temperatures on the outside of the carcass compared to the warm muscle temperatures within the carcass (i.e., muscles that are darker in color externally and lighter in color internally).

  1. Engineering Tests of Experimental Ammonia Process Printer-Developer

    Science.gov (United States)

    1950-07-06

    up for an experimental am:tmoa process printer- developer to meet the military characteristics. Thlis machine was Krocurod under development contract ...over the top of the can. A small light on the front panel of the mucl -ine indicates when the level of the ammonia in the storage tank is such that

  2. A comparative kinetic study of SNCR process using ammonia

    Energy Technology Data Exchange (ETDEWEB)

    Javed, M. Tayyeb; Ahmed, Z.; Ibrahim, M. Asim; Irfan, N.

    2008-07-01

    The paper presents comparative kinetic modelling of nitrogen oxides (NOx) removal from flue gases by selective non-catalytic reduction process using ammonia as reducing agent. The computer code SENKIN is used in this study with the three published chemical kinetic mechanisms; Zanoelo, Kilpinen and Skreiberg. Kinetic modeling was performed for an isothermal plug flow reactor at atmospheric pressure so as to compare it with the experimental results. A 500 ppm NOx background in the flue gas is considered and kept constant throughout the investigation. The ammonia performance was modeled in the range of 750 to 1250{sup o}C using the molar ratios NH{sub 3}/NOx from 0.25 to 3.0 and residence times up to 1.5 seconds. The modeling using all the mechanisms exhibits and confirms a temperature window of NOx reduction with ammonia. It was observed that 80% of NOx reduction efficiency could be achieved if the flue gas is given 300 msec to react with ammonia, while it is passing through a section within a temperature range of 910 to 1060{sup o}C (Kilpinen mechanism) or within a temperature range of 925 to 1030{sup o}C (Zanoelo mechanism) or within a temperature range of 890 to 1090{sup o}C (Skreiberg mechanism). 20 refs., 6 figs.

  3. The Role of Left Hemispheric Structures for Emotional Processing as a Monitor of Bodily Reaction and Felt Chill – a Case-Control Functional Imaging Study

    Science.gov (United States)

    Grunkina, Viktoria; Holtz, Katharina; Klepzig, Kai; Neubert, Jörg; Horn, Ulrike; Domin, Martin; Hamm, Alfons O.; Lotze, Martin

    2017-01-01

    Background: The particular function of the left anterior human insula on emotional arousal has been illustrated with several case studies. Only after left hemispheric insula lesions, patients lose their pleasure in habits such as listening to joyful music. In functional magnetic resonance imaging studies (fMRI) activation in the left anterior insula has been associated with both processing of emotional valence and arousal. Tight interactions with different areas of the prefrontal cortex are involved in bodily response monitoring and cognitive appraisal of a given stimulus. Therefore, a large left hemispheric lesion including the left insula should impair the bodily response of chill experience (objective chill response) but leave the cognitive aspects of chill processing (subjective chill response) unaffected. Methods: We investigated a patient (MC) with a complete left hemispheric media cerebral artery stroke, testing fMRI representation of pleasant (music) and unpleasant (harsh sounds) chill response. Results: Although chill response to both pleasant and unpleasant rated sounds was confirmed verbally at passages also rated as chilling by healthy participants, skin conductance response was almost absent in MC. For a healthy control (HC) objective and subjective chill response was positively associated. Bilateral prefrontal fMRI-response to chill stimuli was sustained in MC whereas insula activation restricted to the right hemisphere. Diffusion imaging together with lesion maps revealed that left lateral tracts were completely damaged but medial prefrontal structures were intact. Conclusion: With this case study we demonstrate how bodily response and cognitive appraisal are differentially participating in the internal monitor of chill response. PMID:28111546

  4. Chilling Tendency and Chill of Cast Iron

    Institute of Scientific and Technical Information of China (English)

    E. Fra(s); M. Górny; W. Kapturkiewicz; H. López

    2008-01-01

    An analytical expression is presented for the susceptibility of liquid cast iron to solidify according tothe Fe-C-X metastable system (also known as the chilling tendency of cast iron, CT). The analysis incorpo-rates the nucleation and growth processes associated with the eutectic transformation. The CT is related tothe physicochemical state of the liquid, the eutectic cells in the flake graphite, and the number of nodules innodular cast iron. In particular, the CT can be related to the critical wall thickness, Scr, or the chill width, Wcr,in wedge shaped castings. Finally, this work serves as a guide for understanding the effect of technical fac-tors such as the melt chemistry, the spheroidizing and inoculation practice, and the holding time and tam-perature on the resultant CT and chill of the cast iron. Theoretical calculations of Scr and Wcr compare wellwith experimental data for flake graphite and nodular cast iron.

  5. Chilling tolerant U.S. processing cucumber (Cucumis sativus L.): three advanced backcross and ten inbred backcross lines

    Science.gov (United States)

    Environmental stresses such as chilling temperatures can reduce seed germination rate, seeding emergence rate, flower and fruit development, marketable yield, and postharvest fruit storage longevity in cucumber (Cucumis sativus L.). Chilling temperatures occur in unpredictable patterns, making it d...

  6. STUDY OF CYLPEBS CHILLING

    Directory of Open Access Journals (Sweden)

    E. I. Marukovich

    2016-01-01

    Full Text Available Methods of increasing the shock resistance of cast-iron grinding bodies are researched. The models of heat transfer in the process of casting and shock-abrasive wear are presented. Tooling to produce experimental samples of milling bodies chilling(gravity die casting is manufactured, samples of cylpebs are produced.

  7. Sustainable Ammonia Synthesis – Exploring the scientific challenges associated with discovering alternative, sustainable processes for ammonia production

    Energy Technology Data Exchange (ETDEWEB)

    Nørskov, Jens [Stanford Univ., CA (United States); ; SLAC National Accelerator Lab., Menlo Park, CA (United States); Chen, Jingguang [Columbia Univ., New York, NY (United States); Brookhaven National Lab. (BNL), Upton, NY (United States); Miranda, Raul [Dept. of Energy (DOE), Washington DC (United States). Office of Science; Fitzsimmons, Tim [Dept. of Energy (DOE), Washington DC (United States). Office of Science; Stack, Robert [Dept. of Energy (DOE), Washington DC (United States). Office of Science

    2016-02-18

    Ammonia (NH3) is essential to all life on our planet. Until about 100 years ago, NH3 produced by reduction of dinitrogen (N2) in air came almost exclusively from bacteria containing the enzyme nitrogenase.. DOE convened a roundtable of experts on February 18, 2016. Participants in the Roundtable discussions concluded that the scientific basis for sustainable processes for ammonia synthesis is currently lacking, and it needs to be enhanced substantially before it can form the foundation for alternative processes. The Roundtable Panel identified an overarching grand challenge and several additional scientific grand challenges and research opportunities: -Discovery of active, selective, scalable, long-lived catalysts for sustainable ammonia synthesis. -Development of relatively low pressure (<10 atm) and relatively low temperature (<200 C) thermal processes. -Integration of knowledge from nature (enzyme catalysis), molecular/homogeneous and heterogeneous catalysis. -Development of electrochemical and photochemical routes for N2 reduction based on proton and electron transfer -Development of biochemical routes to N2 reduction -Development of chemical looping (solar thermochemical) approaches -Identification of descriptors of catalytic activity using a combination of theory and experiments -Characterization of surface adsorbates and catalyst structures (chemical, physical and electronic) under conditions relevant to ammonia synthesis.

  8. Improved process model for ammonia volatilization from anaerobic swine lagoons under varying wind speeds and gas bubbling

    Science.gov (United States)

    Ammonia volatilization from treatment lagoons varies widely with the lagoon water total ammonia concentration, pH, temperature, suspended solids, atmospheric ammonia concentration above the water surface, and wind speed. Ammonia emissions were estimated with a process-based mechanistic model using a...

  9. Modeling and analysis of chill and fill processes for the cryogenic storage and transfer engineering development unit tank

    Science.gov (United States)

    Hedayat, A.; Cartagena, W.; Majumdar, A. K.; LeClair, A. C.

    2016-03-01

    NASA's future missions may require long-term storage and transfer of cryogenic propellants. The Engineering Development Unit (EDU), a NASA in-house effort supported by both Marshall Space Flight Center (MSFC) and Glenn Research Center, is a cryogenic fluid management (CFM) test article that primarily serves as a manufacturing pathfinder and a risk reduction task for a future CFM payload. The EDU test article comprises a flight-like tank, internal components, insulation, and attachment struts. The EDU is designed to perform integrated passive thermal control performance testing with liquid hydrogen (LH2) in a test-like vacuum environment. A series of tests, with LH2 as a testing fluid, was conducted at Test Stand 300 at MSFC during the summer of 2014. The objective of this effort was to develop a thermal/fluid model for evaluating the thermodynamic behavior of the EDU tank during the chill and fill processes. The Generalized Fluid System Simulation Program, an MSFC in-house general-purpose computer program for flow network analysis, was utilized to model and simulate the chill and fill portion of the testing. The model contained the LH2 supply source, feed system, EDU tank, and vent system. The test setup, modeling description, and comparison of model predictions with the test data are presented.

  10. Process for synthesis of ammonia borane for bulk hydrogen storage

    Science.gov (United States)

    Autrey, S Thomas [West Richland, WA; Heldebrant, David J [Richland, WA; Linehan, John C [Richland, WA; Karkamkar, Abhijeet J [Richland, WA; Zheng, Feng [Richland, WA

    2011-03-01

    The present invention discloses new methods for synthesizing ammonia borane (NH.sub.3BH.sub.3, or AB). Ammonium borohydride (NH.sub.4BH.sub.4) is formed from the reaction of borohydride salts and ammonium salts in liquid ammonia. Ammonium borohydride is decomposed in an ether-based solvent that yields AB at a near quantitative yield. The AB product shows promise as a chemical hydrogen storage material for fuel cell powered applications.

  11. Control of ammonia air pollution through the management of thermal processes in cowsheds.

    Science.gov (United States)

    Bleizgys, Rolandas; Bagdoniene, Indre

    2016-10-15

    Experimental researches performed in manufacturing cowsheds have demonstrated a variation of ammonia concentration and the factors influencing this most during different periods of the year. The process of ammonia evaporation from manure is influenced by many varying and interrelated factors with temperature and the intensity of air ventilation being the most critical ones. The influence of these factors on the process of ammonia evaporation was established by laboratory researches. An increase in temperature results in an exponential increase in ammonia emission, whereas the dependence of the emission on the air velocity is best expressed by a second degree polynomial. The results obtained may be used as a forecast of the ammonia emissions from cowsheds during different periods of the year. Intensive ventilation is required for the removal of excess moisture from the housing, and this limits the possibilities to reduce ammonia emissions by controlling the intensity of ventilation. A reduction in the amount of ventilation is only recommended if the air quality indices meet the requirements applied to the housing. Better opportunities to reduce ammonia emissions are provided through management of the thermal processes in a cowshed. If the average annual air temperature (11.3°C) is reduced by one degree in a cubicle housing cowshed, the ammonia emissions will decrease by 10%.

  12. CHEMICAL PROCESSING OF PURE AMMONIA AND AMMONIA-WATER ICES INDUCED BY HEAVY IONS

    Energy Technology Data Exchange (ETDEWEB)

    Bordalo, V.; Da Silveira, E. F. [Departamento de Fisica/Laboratorio do Acelerador Van de Graaff, Pontificia Universidade Catolica do Rio de Janeiro, Rua Marques de S. Vicente 225, 22451-900 Rio de Janeiro, RJ (Brazil); Lv, X. Y.; Domaracka, A.; Rothard, H.; Boduch, P. [Centre de Recherche sur les Ions, les Materiaux et la Photonique (CEA/CNRS/ENSICAEN/Universite de Caen-Basse Normandie), CIMAP-CIRIL-GANIL, Boulevard Henri Becquerel, BP 5133, F-14070 Caen Cedex 05 (France); Seperuelo Duarte, E., E-mail: vbordalo@fis.puc-rio.br [Grupo de Fisica e Astronomia, Instituto Federal do Rio de Janeiro, Rua Lucio Tavares 1045, 26530-060 Nilopolis, RJ (Brazil)

    2013-09-10

    Cosmic rays are possibly the main agents to prevent the freeze-out of molecules onto grain surfaces in cold dense clouds. Ammonia (NH{sub 3}) is one of the most abundant molecules present in dust ice mantles, with a concentration of up to 15% relative to water (H{sub 2}O). FTIR spectroscopy is used to monitor pure NH{sub 3} and NH{sub 3}-H{sub 2}O ice samples as they are irradiated with Ni and Zn ion beams (500-600 MeV) at GANIL/France. New species, such as hydrazine (N{sub 2}H{sub 4}), diazene (N{sub 2}H{sub 2} isomers), molecular hydrogen (H{sub 2}), and nitrogen (N{sub 2}) were identified after irradiation of pure NH{sub 3} ices. Nitrous oxide (N{sub 2}O), nitrogen oxide (NO), nitrogen dioxide (NO{sub 2}), and hydroxylamine (NH{sub 2}OH) are some of the products of the NH{sub 3}-H{sub 2}O ice radiolysis. The spectral band at 6.85 {mu}m was observed after irradiation of both types of ice. Besides the likely contribution of ammonium (NH{sub 4}{sup +}) and amino (NH{sub 2}) radicals, data suggest a small contribution of NH{sub 2}OH to this band profile after high fluences of irradiation of NH{sub 3}-H{sub 2}O ices. The spectral shift of the NH{sub 3} ''umbrella'' mode (9.3 {mu}m) band is parameterized as a function of NH{sub 3}/H{sub 2}O ratio in amorphous ices. Ammonia and water destruction cross-sections are obtained, as well as the rate of NH{sub 3}-H{sub 2}O (1:10) ice compaction, measured by the OH dangling bond destruction cross-section. Ammonia destruction is enhanced in the presence of H{sub 2}O in the ice and a power law relationship between stopping power and NH{sub 3} destruction cross-section is verified. Such results may provide relevant information for the evolution of molecular species in dense molecular clouds.

  13. Carbon Capture by a Continuous, Regenerative Ammonia-Based Scrubbing Process

    Energy Technology Data Exchange (ETDEWEB)

    Resnik, K.P.; Yeh, J.T.; Pennline, H.W.

    2006-10-01

    Overview: To develop a knowledge/data base to determine whether an ammonia-based scrubbing process is a viable regenerable-capture technique that can simultaneously remove carbon dioxide, sulfur dioxide, nitric oxides, and trace pollutants from flue gas.

  14. Nitrogen removal from sludge dewatering effluent through anaerobic ammonia oxidation process

    Institute of Scientific and Technical Information of China (English)

    ZHANG Shao-hui; ZHENG Ping; HUA Yu-mei

    2005-01-01

    Anaerobic ammonia oxidation(Anammox) process is a novel and promising wastewater nitrogen removal process. The feasibility of transition of Anammox from denitrification and the performance of lab-scale Anammox biofilm reactor were investigated with sludge dewatering effluent. The results showed that Anammox process could be successfully started up after cultivation of denitrification biofilm and using it as inoculum. The transition of Anammox from denitrification was accomplished within 85 d. Anammox process was found suitable to remove ammonia from sludge dewatering effluent. The effluent ammonia concentration was detected to be 23.11 mgN/L at HRT of 28 h when influent ammonia concentration was fed 245 mgN/L, which was less than that for the national discharge standard Ⅱ (25 mgN/L) of 243.25 mg NH4+ -N/L and 288.31 mg NO2- -N/L.

  15. The kinetics of process dependent ammonia inhibition of methanogenesis from acetic acid.

    Science.gov (United States)

    Wilson, Christopher Allen; Novak, John; Takacs, Imre; Wett, Bernhard; Murthy, Sudhir

    2012-12-01

    Advanced anaerobic digestion processes aimed at improving the methanization of sewage sludge may be potentially impaired by the production of inhibitory compounds (e.g. free ammonia). The result of methanogenic inhibition is relatively high effluent concentrations of acetic acid and other soluble organics, as well as reduced methane yields. An extreme example of such an advanced process is the thermal hydrolytic pretreatment of sludge prior to high solids digestion (THD). Compared to a conventional mesophilic anaerobic digestion process (MAD), THD operates in a state of constant inhibition driven by high free ammonia concentrations, and elevated pH values. As such, previous investigations of the kinetics of methanogenesis from acetic acid under uninhibited conditions do not necessarily apply well to the modeling of extreme processes such as THD. By conducting batch ammonia toxicity assays using biomass from THD and MAD reactors, we compared the response of these communities over a broad range of ammonia inhibition. For both processes, increased inhibitor concentrations resulted in a reduction of biomass growth rate (r(max) = μ(max)∙X) and a resulting decrease in the substrate half saturation coefficient (K(S)). These two parameters exhibited a high degree of correlation, suggesting that for a constant transport limited system, the K(S) was mostly a linear function of the growth rate. After correcting for reactor pH and temperature, we found that the THD and MAD biomass were both able to perform methanogenesis from acetate at high free ammonia concentrations (equivalent to 3-5 g/L total ammonia nitrogen), albeit at less than 30% of their respective maximum rates. The reduction in methane production was slightly less pronounced for the THD biomass than for MAD, suggesting that the long term exposure to ammonia had selected for a methanogenic pathway less dependent on those organisms most sensitive to ammonia inhibition (i.e. aceticlastic methanogens).

  16. Effect of high pressure processing on textural and microbiological quality of pink perch (Nemipterus japonicus) sausage during chilled storage

    Science.gov (United States)

    Kunnath, Sarika; Panda, Satyen Kumar; Jaganath, Bindu; Gudipati, Venkateshwarlu

    2015-10-01

    The non-thermal high pressure (HP) processing was studied on fish sausage to enhance the quality during chilled storage. Pink perch (Nemipterus japonicus) sausages, packed in poly amide casing under vacuum were subjected to 400, 500 and 600 MPa pressures (dwell time: 10 min and ramp rate: 300 MPa/min) and compared with heat-set samples for physico-chemical and microbial quality parameters. Pressurized samples formed softer and glossier gels with a slight reduction in water-holding capacity. HP made the texture of sausage softer, cohesive and less chewy and gummier than heat-treated ones. Folding test seen higher acceptance values in samples treated at 500 and 600 MPa, during storage. Maximum log reduction in microbial count was observed in 600 MPa immediately, and significant difference in cooked and pressurized sausages was seen only up to 7th day. This revealed the potential application of HP in replacing conventional heat treatment for sausages preparation with enhanced shelf-life.

  17. Present on the process and device of ammonia recovery by ammonia distillation%蒸氨法氨回收工艺及装置简介

    Institute of Scientific and Technical Information of China (English)

    李爱仙

    2011-01-01

    Glyphosate by IDAN method in alkali solution reaction produces a lot of gas containing ammonia in pesticide factory. The ammonia gas can be recycled by medium-pressure ammonia stripping process. The characteristics of low-pressure de-sorption ammonia stripping process and medium-pressure ammonia stripping process are introduced. The medium-pressure ammonia stripping process, products quality, consumption indicators, process indicators and major equipments are elaborated, and the production costs and earnings are analyzed.%农药厂IDAN法草甘磷在碱解反应中产生大量的含氨气体,采用中压蒸氨工艺回收氨.介绍了低压解吸蒸氨工艺和中压蒸氨工艺各自的特点,阐述了中压蒸氨工艺流程、产品质量、消耗指标、工艺指标、主要设备,介绍了生产成本、收益情况,并进行了分析.

  18. Consumer acceptance of high pressure processed beef-based chilled ready meals: the mediating role of food-related lifestyle factors.

    Science.gov (United States)

    Sorenson, Douglas; Henchion, Maeve; Marcos, Begonya; Ward, Paddy; Mullen, Anne Maria; Allen, Paul

    2011-01-01

    The aim of this research was to investigate the effects of high pressure processing (HPP) on consumer acceptance for chilled ready meals manufactured using a low-value beef cut. Three hundred consumers evaluated chilled ready meals subjected to 4 pressure treatments and a non-treated control monadically on a 9-point scale for liking for beef tenderness and juiciness, overall flavour, overall liking, and purchase intent. Data were also collected on consumers' food consumption patterns, their attitudes towards food by means of the reduced food-related lifestyle (FRL) instrument, and socio-demographics. The results indicated that a pressure treatment of 200 MPa was acceptable to most consumers. K-means cluster analysis identified 4 consumer groups with similar preferences, and the optimal pressure treatments acceptable to specific consumer groups were identified for those firms that would wish to target attitudinally differentiated consumer segments.

  19. CO2 capture using aqueous ammonia: kinetic study and process simulation

    DEFF Research Database (Denmark)

    Darde, Victor Camille Alfred; van Well, Willy J.M.; Stenby, Erling Halfdan

    2011-01-01

    Carbon dioxide capture using aqueous ammonia is a post-combustion technology that has shown a good potential. Therefore this process is studied by measuring the rate of absorption of carbon dioxide by aqueous ammonia and by performing process simulation. The rate of absorption of carbon dioxide...... to 0.6. The results were compared with those found for 30 wt% mono-ethanolamine (MEA) solutions.The capture process was simulated successfully using the simulator Aspen Plus coupled with the extended UNIQUAC thermodynamic model available for the NH3–CO2–H2O system. For this purpose, a user model...

  20. Chilled storage of foods - principles

    Science.gov (United States)

    Chilled storage is the most common method for preserving perishable foods. The consumers’ increasing demand for convenient, minimally processed foods has caused food manufacturers to increase production of refrigerated foods worldwide. This book chapter reviews the development of using low tempera...

  1. Ammonia removal from leachate by photochemical process using H2O2

    Directory of Open Access Journals (Sweden)

    Giovani Archanjo Brota

    2010-08-01

    Full Text Available In this work, it was studied the optimization of the photochemical process using H2O2/UV in order to reduce the concentration of ammonia in leachate. It was used landfills leachate previously treated in the development of studies. A photochemical reactor with the capacity of 1.7 liters equipped with refrigeration system and recirculation of leachate was employed in the research. The influence of temperature, the light bulb power, the concentration of H2O2 and treatment time were tested during the study. A removal of 97% of ammonia was observed at 90 min.

  2. Ammonia removal in the carbon contactor of a hybrid membrane process.

    Science.gov (United States)

    Stoquart, Céline; Servais, Pierre; Barbeau, Benoit

    2014-12-15

    The hybrid membrane process (HMP) coupling powdered activated carbon (PAC) and low-pressure membrane filtration is emerging as a promising new option to remove dissolved contaminants from drinking water. Yet, defining optimal HMP operating conditions has not been confirmed. In this study, ammonia removal occurring in the PAC contactor of an HMP was simulated at lab-scale. Kinetics were monitored using three PAC concentrations (1-5-10 g L(-1)), three PAC ages (0-10-60 days), two temperatures (7-22 °C), in ambient influent condition (100 μg N-NH4 L(-1)) as well as with a simulated peak pollution scenario (1000 μg N-NH4L(-1)). The following conclusions were drawn: i) Using a colonized PAC in the HMP is essential to reach complete ammonia removal, ii) an older PAC offers a higher resilience to temperature decrease as well as lower operating costs; ii) PAC concentration inside the HMP reactor is not a key operating parameter as under the conditions tested, PAC colonization was not limited by the available surface; iii) ammonia flux limited biomass growth and iv) hydraulic retention time was a critical parameter. In the case of a peak pollution, the process was most probably phosphate-limited but a mixed adsorption/nitrification still allowed reaching a 50% ammonia removal. Finally, a kinetic model based on these experiments is proposed to predict ammonia removal occurring in the PAC reactor of the HMP. The model determines the relative importance of the adsorption and biological oxidation of ammonia on colonized PAC, and demonstrates the combined role of nitrification and residual adsorption capacity of colonized PAC.

  3. Chilled beam application guidebook

    CERN Document Server

    Butler, David; Gräslund, Jonas; Hogeling, Jaap; Lund Kristiansen, Erik; Reinikanen, Mika; Svensson, Gunnar

    2007-01-01

    Chilled beam systems are primarily used for cooling and ventilation in spaces, which appreciate good indoor environmental quality and individual space control. Active chilled beams are connected to the ventilation ductwork, high temperature cold water, and when desired, low temperature hot water system. Primary air supply induces room air to be recirculated through the heat exchanger of the chilled beam. In order to cool or heat the room either cold or warm water is cycled through the heat exchanger.

  4. Short-and long-term effects of ammonia and nitrite on the anammox process

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez, I.; Campos, J. L.; Mosquera-Corral, A.; Mendez, R.

    2009-07-01

    Auto trophic anaerobic ammonium oxidation (Anammox) process is a feasible alternative to treat industrial wastewater with high ammonia concentration but low content of organic matter. In this process ammonium and nitrite are used by Planctomycete-type bacteria under anoxic conditions to generate nitrogen gas. Both substrates can exert inhibitory effects on the process, causing the decrease of the specific activity of the biomass and the loss of the performance and stability of reactors. (Author)

  5. Study of an ammonia-based wet scrubbing process in a continuous flow system

    Energy Technology Data Exchange (ETDEWEB)

    Resnik, Kevin P.; Pennline, Henry W.

    2013-03-01

    A continuous gas and liquid flow, regenerative scrubbing process for CO{sub 2} capture was demonstrated at the bench-scale level. An aqueous ammonia-based solution captures CO{sub 2} from simulated flue gas in an absorber and releases a nearly pure stream of CO{sub 2} in the regenerator. After the regeneration, the solution of ammonium compounds is recycled to the absorber. The design of a continuous flow unit was based on earlier exploratory results from a semi-batch reactor, where a CO{sub 2} and N{sub 2} simulated flue gas mixture flowed through a well-mixed batch of ammonia-based solution. During the semi-batch tests, the solution was cycled between absorption and regeneration steps to measure the carrying capacity of the solution at various initial ammonia concentrations and temperatures. Consequentially, a series of tests were conducted on the continuous unit to observe the effect of various parameters on CO{sub 2} removal efficiency and regenerator effectiveness within the flow system. The parameters that were studied included absorber temperature, regenerator temperature, initial NH{sub 3} concentration, simulated flue gas flow rate, liquid solvent inventory in the flow system, and height of the packed-bed absorber. From this testing and subsequent testing, ammonia losses from both the absorption and regeneration steps were quantified, and attempts were made to maintain steady state during operations. Implications of experimental results with respect to process design are discussed.

  6. 冰鲜鸭加工车间的菌相变化分析%Microflora changes of chilled duck at processing plants

    Institute of Scientific and Technical Information of China (English)

    王华伟; 刘芳; 王道营; 诸永志; 徐幸莲; 徐为民

    2013-01-01

    应用传统微生物培养和聚合酶链反应-变性梯度凝胶电泳(PCR-DGGE)技术,综合分析冰鲜鸭加工中主要工序点的菌相变化.同时对车间环境包括车间空气、工人手面、案板、胴体表面以及预冷水进行污染调查,并通过PCR-DGGE研究车间环境菌种的多样性.结果表明:影响冰鲜鸭产品微生物污染状况的主要来源为净膛间,主要菌种有Aeromonas veronii、Macrococcus caseolyticus、Acinetobacter lwoffii、Shewanella baltica、Enhydrobacter aerosaccus、Rothia mucilaginosa以及Staphylococcus 属;直接来源为二阶预冷水,主要菌种为Aeromonas veronii、Enhydrobacter aerosaccus、Pseudomonas fluorescens、Shewanella baltica 和Acinetobacter lwoffii,与产品菌种组成相同.前区与后区的隔离对降低后区微生物污染起到关键作用,净膛工序和预冷工序是影响产品微生物指标的关键.%Assisted with traditional microbial culture and polymerase chain reaction-denaturing gradient gel electrophoresis ( PCR-DGGE) technology,the microflora changes of chilled duck at major processing steps were detected. The microbiological contamination of air, workers' hands, table, carcass surface and pre-chilling water was assayed with conventional culture method and the diversity of microbes was analyzed with PCR-DGGE technology. Taken together.it showed that the main contamination source of the product was eviscerating plant,with the major strains being Aeromonas veronii,Macrococcus caseolyticus,Acinetobacter lwoffii,Shewanella baltica, Enhydrobacter aerosaccus ,Rothia mucilaginosa and Staphylococcus, and the direct contamination source was the second stage pre-chilling water,with the major strains being Aeromonas veronii,Enhydrobacter aerosaccus,Pseudomonas fluorescens,Shewanella baltica and Acinetobacter Iwqffii, which were identical with the strain composition of the products. The separation of products between front area and back area had a critical effect on

  7. A process-based model for ammonia emission from urine patches, GAG (Generation of Ammonia from Grazing): description and sensitivity analysis

    Science.gov (United States)

    Móring, Andrea; Vieno, Massimo; Doherty, Ruth M.; Laubach, Johannes; Taghizadeh-Toosi, Arezoo; Sutton, Mark A.

    2016-03-01

    In this paper a new process-based, weather-driven model for ammonia (NH3) emission from a urine patch has been developed and its sensitivity to various factors assessed. The GAG model (Generation of Ammonia from Grazing) is capable of simulating the TAN (total ammoniacal nitrogen) and the water content of the soil under a urine patch and also soil pH dynamics. The model tests suggest that ammonia volatilization from a urine patch can be affected by the possible restart of urea hydrolysis after a rain event as well as CO2 emission from the soil. The vital role of temperature in NH3 exchange is supported by our model results; however, the GAG model provides only a modest overall temperature dependence in total NH3 emission compared with the literature. This, according to our findings, can be explained by the higher sensitivity to temperature close to urine application than in the later stages and may depend on interactions with other nitrogen cycling processes. In addition, we found that wind speed and relative humidity are also significant influencing factors. Considering that all the input parameters can be obtained for larger scales, GAG is potentially suitable for field and regional scale application, serving as a tool for further investigation of the effects of climate change on ammonia emissions and deposition.

  8. A process-based model for ammonia emission from urine patches, GAG (Generation of Ammonia from Grazing): description, validation and sensitivity analysis

    DEFF Research Database (Denmark)

    Móring, A; Vieno, M.; Doherty, R M;

    2015-01-01

    In this paper a new process-based, weather-driven model for ammonia (NH3) emission from a urine patch has been developed and its sensitivity to various factors assessed. This model, the GAG model (Generation of Ammonia from Grazing) was developed as a part of a suite of weather-driven NH3 exchange...... models, as a necessary basis for assessing the effects of climate change on NH3 related atmospheric processes. GAG is capable of simulating the TAN (Total Ammoniacal Nitrogen) content, pH and the water content of the soil under a urine patch. To calculate the TAN budget, GAG takes into account urea...... hydrolysis as a TAN input and NH3 volatilization as a loss. In the water budget, in addition to the water content of urine, precipitation and evaporation are also considered. In the pH module we assumed that the main regulating processes are the dissociation and dissolution equilibria related to the two...

  9. An innovative bioelectrochemical-anaerobic digestion-coupled system for in-situ ammonia recovery and biogas enhancement: process performance and microbial ecology

    OpenAIRE

    Zhang, Yifeng; Angelidaki, Irini

    2014-01-01

    Ammonia (NH4+/NH3) inhibition during anaerobic digestion process is one of the most frequent problems existing in biogas plants, resulting in unstable process and reduced biogas production. In this study, we developed a novel hybrid system, consisted of a submersed microbial resource recovery cell (SMRC) and a continuous stirred tank reactor (CSTR), to prevent ammonia toxicity during anaerobic digestion by in-situ ammonia recovery and electricity production. In batch experiment, the ammonia c...

  10. Putative paternal factors controlling chilling tolerance in Korean market-type cucumber (Cucumis sativus L.)

    Science.gov (United States)

    Chilling temperatures (Cucumis sativus L.) plants during winter and early spring growing seasons. Inheritance to chilling in U.S. processing cucumber is controlled by cytoplasmic (maternally) and nuclear factors. To understand inherit...

  11. Novel Regenerated Solvent Extraction Processes for the Recovery of Carboxylic Acids or Ammonia from Aqueous Solutions Part II. Recovery of Ammonia from Sour Waters

    Energy Technology Data Exchange (ETDEWEB)

    Poole, L.J.; King, C.J.

    1990-03-01

    Two novel regenerated solvent extraction processes are examined. The first process has the potential to reduce the energy costs inherent in the recovery of low-volatility carboxylic acids from dilute aqueous solutions. The second process has the potential for reducing the energy costs required for separate recovery of ammonia and acid gases (e.g. CO{sub 2} and H{sub 2}S) from industrial sour waters. The recovery of carboxylic acids from dilute aqueous solution can be achieved by extraction with tertiary amines. An approach for regeneration and product recovery from such extracts is to back-extract the carboxylic acid with a water-soluble, volatile tertiary amine, such as trimethylamine. The resulting trimethylammonium carboxylate solution can be concentrated and thermally decomposed, yielding the product acid and the volatile amine for recycle. Experimental work was performed with lactic acid, SUCCiOlC acid, and fumaric acid. Equilibrium data show near-stoichiometric recovery of the carboxylic acids from an organic solution of Alamine 336 into aqueous solutions of trimethylamine. For fumaric and succinic acids, partial evaporation of the aqueous back extract decomposes the carboxylate and yields the acid product in crystalline form. The decomposition of aqueous solutions of trimethylammonium lactates was not carried out to completion, due to the high water solubility of lactic acid and the tendency of the acid to self-associate. The separate recovery of ammonia and acid gases from sour waters can be achieved by combining steam-stripping of the acid gases with simultaneous removal of ammonia by extraction with a liquid cation exchanger. The use of di-2,4,4-trimethylpentyl phosphinic acid as the liquid cation exchanger is explored in this work. Batch extraction experiments were carried out to measure the equilibrium distribution ratio of ammonia between an aqueous buffer solution and an organic solution of the phosphinic acid (0.2N) in Norpar 12. The concentration

  12. Effects of Different Concentrations of Ammonia Nitrogen on N2O Emission in the Process of Partial Nitrification

    Institute of Scientific and Technical Information of China (English)

    TIAN; Lin; KONG; Qiang; ZHANG; Jian; MIAO; Ming-sheng

    2012-01-01

    [Objective] The study aimed to discuss the effects of different concentrations of ammonia nitrogen on N2O emission in the process of partial nitrification. [Method] By using a sequencing batch biofilm reactor (SBBR) under intermittent aeration, the influences of various concentrations of influent ammonia nitrogen on nitrous oxide (N2O) emission from partial nitrification were analyzed. [Result] When the concentration of influent ammonia nitrogen varied from 200 to 400 mg/L, the changing trends of DO and ORP value were consistent during the process of partial nitrification, and the concentration ratio of NO-2-N to NH+4-N in effluent water reached 1∶1, with lower NO-3-N level. In addition, ammonia nitrogen concentration in the influent had significant effects on N2O emission in the process of partial nitrification, that is, the higher the ammonia nitrogen concentration, the more the N2O emission. When ammonia nitrogen concentration was 400 mg/L, N2O emission was up to about 37 mg. [Conclusion] N2O emission in the process of partial nitrification might be related to the concentrations of NH+4 and NO-2.

  13. Effects of Different Concentrations of Ammonia Nitrogen on N_2O Emission in the Process of Partial Nitrification

    Institute of Scientific and Technical Information of China (English)

    TIAN; Lin; KONG; Qiang; ZHANG; Jian; MIAO; Ming-sheng

    2012-01-01

    [Objective] The study aimed to discuss the effects of different concentrations of ammonia nitrogen on N2O emission in the process of partial nitrification. [Method] By using a sequencing batch biofilm reactor (SBBR) under intermittent aeration, the influences of various concentrations of influent ammonia nitrogen on nitrous oxide (N2O) emission from partial nitrification were analyzed. [Result] When the concentration of influent ammonia nitrogen varied from 200 to 400 mg/L, the changing trends of DO and ORP value were consistent during the process of partial nitrification, and the concentration ratio of NO-2-N to NH+4-N in effluent water reached 1∶1, with lower NO-3-N level. In addition, ammonia nitrogen concentration in the influent had significant effects on N2O emission in the process of partial nitrification, that is, the higher the ammonia nitrogen concentration, the more the N2O emission. When ammonia nitrogen concentration was 400 mg/L, N2O emission was up to about 37 mg. [Conclusion] N2O emission in the process of partial nitrification might be related to the concentrations of NH+4 and NO-2.

  14. A low energy aqueous ammonia CO2 capture process

    DEFF Research Database (Denmark)

    Gaspar, Jozsef; Waseem Arshad, Muhammad; Blaker, Eirik Ask

    2014-01-01

    with existing aqueous ammonia CO2 capture processes. Moreover, the thermal reactor can operate at 1 bar and 86 °C, therefore the NH3 regeneration temperature is reduced by approximately 50 qC. The integration of low- and mid- temperature waste heat becomes possible which can greatly improve the economics...... based CO2 capture with a thermal decomposition reactor. The overall energy penalty is reduced at the expense of introducing a solid handling section which consists of a saturation reactor, a crystallizer and a belt filter. The feasibility of the present approach is demonstrated by simulation. Flow...

  15. The Full-Scale Implementation of an Innovative Biological Ammonia Treatment Process

    Science.gov (United States)

    Across the United States, high levels of ammonia in drinking water sources can be found, including small communities like Palo, Iowa (approximate population of 1,026). Although ammonia in water does not pose a direct health concern, ammonia nitrification can cause a number of iss...

  16. Influence of dielectric constant of polymerization medium on processability and ammonia gas sensing properties of polyaniline

    Indian Academy of Sciences (India)

    Partha Pratim Sengupta; Pradip Kar; Basudam Adhikari

    2011-04-01

    Polyaniline (PANI) was synthesized by the oxidation of aniline hydrochloride in the presence of ammonium persulphate and hydrochloric acid. The polymerization reaction was carried out in several batches in different solvent media by changing the volume ratio of ,-dimethyl formamide (DMF) and water as binary solvent mixture. The dielectric constant of the polymerizationmedium for each batch reaction was determined by measuring the capacitance with change in frequency. The UV spectra of the synthesized polyaniline solutions helped us to optimize the ratio of the binary solvent to get sufficient polymer growth and processability. Thin film of processable polyaniline was then deposited on glass slides coated with polyvinyl alcohol (PVA) crosslinked with maleic anhydride (MA). FTIR and XRD studies of the coated film were also done. AFM studies further helped in the morphological study of the film deposited. Finally, conductivity and ammonia gas-sensing property of the polyaniline film were also studied.

  17. Chilling injury in mangoes

    NARCIS (Netherlands)

    Arafat, L.A.E.T.

    2005-01-01

    At present, the value and production quantity of mango fruits are increasing worldwide. Many studies emphasize how chilling injury phenomena affect the quality of tropical fruits, such as mango, during postharvest handling, transport, and storage. Since mango is one of the most favored and popular f

  18. ChillFish

    DEFF Research Database (Denmark)

    Sonne, Tobias; Jensen, Mads Møller

    2016-01-01

    Breathing exercises can help children with ADHD control their stress level, but it can be hard for a child to sustain attention throughout such an exercise. In this paper, we present ChillFish, a breath-controlled biofeedback game designed in collaboration with ADHD professionals to investigate...

  19. Ammonia-based feedforward and feedback aeration control in activated sludge processes.

    Science.gov (United States)

    Rieger, Leiv; Jones, Richard M; Dold, Peter L; Bott, Charles B

    2014-01-01

    Aeration control at wastewater treatment plants based on ammonia as the controlled variable is applied for one of two reasons: (1) to reduce aeration costs, or (2) to reduce peaks in effluent ammonia. Aeration limitation has proven to result in significant energy savings, may reduce external carbon addition, and can improve denitrification and biological phosphorus (bio-P) performance. Ammonia control for limiting aeration has been based mainly on feedback control to constrain complete nitrification by maintaining approximately one to two milligrams of nitrogen per liter of ammonia in the effluent. Increased attention has been given to feedforward ammonia control, where aeration control is based on monitoring influent ammonia load. Typically, the intent is to anticipate the impact of sudden load changes, and thereby reduce effluent ammonia peaks. This paper evaluates the fundamentals of ammonia control with a primary focus on feedforward control concepts. A case study discussion is presented that reviews different ammonia-based control approaches. In most instances, feedback control meets the objectives for both aeration limitation and containment of effluent ammonia peaks. Feedforward control, applied specifically for switching aeration on or off in swing zones, can be beneficial when the plant encounters particularly unusual influent disturbances.

  20. Identification of chilling and heat requirements of cherry trees—a statistical approach

    Science.gov (United States)

    Luedeling, Eike; Kunz, Achim; Blanke, Michael M.

    2013-09-01

    Most trees from temperate climates require the accumulation of winter chill and subsequent heat during their dormant phase to resume growth and initiate flowering in the following spring. Global warming could reduce chill and hence hamper the cultivation of high-chill species such as cherries. Yet determining chilling and heat requirements requires large-scale controlled-forcing experiments, and estimates are thus often unavailable. Where long-term phenology datasets exist, partial least squares (PLS) regression can be used as an alternative, to determine climatic requirements statistically. Bloom dates of cherry cv. `Schneiders späte Knorpelkirsche' trees in Klein-Altendorf, Germany, from 24 growing seasons were correlated with 11-day running means of daily mean temperature. Based on the output of the PLS regression, five candidate chilling periods ranging in length from 17 to 102 days, and one forcing phase of 66 days were delineated. Among three common chill models used to quantify chill, the Dynamic Model showed the lowest variation in chill, indicating that it may be more accurate than the Utah and Chilling Hours Models. Based on the longest candidate chilling phase with the earliest starting date, cv. `Schneiders späte Knorpelkirsche' cherries at Bonn exhibited a chilling requirement of 68.6 ± 5.7 chill portions (or 1,375 ± 178 chilling hours or 1,410 ± 238 Utah chill units) and a heat requirement of 3,473 ± 1,236 growing degree hours. Closer investigation of the distinct chilling phases detected by PLS regression could contribute to our understanding of dormancy processes and thus help fruit and nut growers identify suitable tree cultivars for a future in which static climatic conditions can no longer be assumed. All procedures used in this study were bundled in an R package (`chillR') and are provided as Supplementary materials. The procedure was also applied to leaf emergence dates of walnut (cv. `Payne') at Davis, California.

  1. Thio residue from thermal processing of cometary ices containing carbon disulfide and ammonia

    Science.gov (United States)

    Methikkalam, R. R. J.; Pavithraa, S.; Murali Babu, S. P.; Hill, H.; Raja Sekhar, B. N.; Pradeep, T.; Sivaraman, B.

    2016-08-01

    We have carried out experimental investigation on binary ice mixture containing carbon disulfide (CS2) and ammonia (NH3) ices formed at 10 K. Icy films were formed in various combinations to investigate the reactivity of CS2 and NH3 molecules on cometary nucleus. In the case of NH3 ices, deposition carried out at 10 K was found to contain NH3 homo-dimers that was found to reorient upon annealing to 40 K. Phase transition was found to take place as the 10 K ice was warmed to higher temperatures and the phase transition temperature was found to be 5 K higher for the mixed ice in comparison to the layered deposits. Thermal processing of the mixed deposition of CS2sbnd NH3 ice was found to leave thio residue, which could be ammonium dithiocarbamate that was even found to be present at 340 K.

  2. High efficient ammonia heat pump system for industrial process water using the ISEC concept. Part 1

    DEFF Research Database (Denmark)

    Rothuizen, Erasmus Damgaard; Madsen, C.; Elmegaard, Brian

    2014-01-01

    The purpose of the Isolated System Energy Charging (ISEC) is to provide a high-efficient ammonia heat pump system for hot water production. The ISEC concept uses two storage tanks for the water, one discharged and one charged. The charged tank is used for the industrial process while the discharged...... to investigate the performance of the ISEC system. The ISEC concept approaches the efficiency of a number of heat pumps in series and the COP of the system may reach 6.8, which is up to 25 % higher than a conventional heat pump heating water in one step....... tank, is charging. Charging is done by circulating the water in the tank through the condenser several times and thereby gradually heats the water. This result in a lower condensing temperature than if the water was heated in one step. A dynamic model of the system, implemented in Dymola, is used...

  3. Optimization on refreshment process in chilled meat hurdle preservative technology%冷却肉栅栏保鲜工艺优化

    Institute of Scientific and Technical Information of China (English)

    张根生; 姜艳; 张毅超; 姚烨

    2015-01-01

    目的:以新鲜猪肉为原料,开发一种能延长冷却肉货架期的保鲜工艺。方法根据栅栏因子理论选取3种栅栏因子,研究低温冷藏、紫外灭菌和天然保鲜液对冷却肉综合保鲜的影响。在单因素基础上,通过正交试验,以菌落总数和挥发性盐基氮(TVB-N)值为评价指标。结果紫外灭菌(20 W、90 s和30 cm)+天然保鲜液配方(ε-聚赖氨酸0.5%、茶多酚1.75%和植酸0.3%)能在4℃保存18 d。结论根据栅栏技术因子保鲜理论,采用多种栅栏因子的科学组合能有效将货架期从4 d延长至18 d。%ABSTRACT:Objective To develop a new technology for prolonging the shelf life of chilled meat using fresh pork as raw material.Methods According to the theory of barrier factors, 3 kinds of barrier factors were selected to study the effect of low temperature, UV-C, and natural fresh keeping agents on the preservation of chilled meat. Based on the single factor, the total numbers of colony and total volatile basic nitrogen (TVB-N) were evaluated by orthogonal test.Results After process of UV-contamination control (20 W, 90 s, 30 cm)+natural preservation fluid formulations (ε-polylysine 0.5%, tea polyphenol 1.75% and phytic acid 0.3%) + vacuum packaging, products could maintain refresh under refrigerated (4℃ ) for 18 d without corruption or deterioration.Conclusion Based on the theory of the technology factor of the fence, the combination of a va-riety of fence factor can effectively extend the shelf life from 4 d to 18 d.

  4. Life cycle assessment of carbon capture and utilization from ammonia process in Mexico.

    Science.gov (United States)

    Morales Mora, M A; Vergara, C Pretelín; Leiva, M A; Martínez Delgadillo, S A; Rosa-Domínguez, E R

    2016-12-01

    Post-combustion CO2 capture (PCC) of flue gas from an ammonia plant (AP) and the environmental performance of the carbon capture utilization (CCU) technology for greenhouse gas (GHG) emissions to an enhanced oil recovery (EOR) system in Mexico was performed as case study. The process simulations (PS) and life cycle assessment (LCA) were used as supporting tools to quantify the CO2 capture and their environmental impacts, respectively. Two scenarios were considered: 1) the AP with its shift and CO2 removal unit and 2) Scenario 1 plus PCC of the flue gas from the AP primary reformer (AP-2CO2) and the global warming (GW) impact. Also, the GW of the whole of a CO2-EOR project, from these two streams of captured CO2, was evaluated. Results show that 372,426 tCO2/year can be PCC from the flue gas of the primary reformer and 480,000 tons/y of capacity from the AP. The energy requirement for solvent regeneration is estimated to be 2.8 MJ/kgCO2 or a GW impact of 0.22 kgCO2e/kgCO2 captured. GW performances are 297.6 kgCO2e emitted/barrel (bbl) for scenario one, and 106.5 kgCO2e emitted/bbl for the second. The net emissions, in scenario one, were 0.52 tCO2e/bbl and 0.33 tCO2e/bbl in scenario two. Based on PS, this study could be used to evaluate the potential of CO2 capture of 4080 t/d of 4 ammonia plants. The integration of PS-LCA to a PCC study allows the applicability as methodological framework for the development of a cluster of projects in which of CO2 could be recycled back to fuel, chemical, petrochemical products or for enhanced oil recovery (EOR). With AP-2CO2, "CO2 emission free" ammonia production could be achieved.

  5. Pretreatment of corn stover using low-moisture anhydrous ammonia (LMAA) process.

    Science.gov (United States)

    Yoo, Chang Geun; Nghiem, Nhuan P; Hicks, Kevin B; Kim, Tae Hyun

    2011-11-01

    A simple pretreatment method using anhydrous ammonia was developed to minimize water and ammonia inputs for cellulosic ethanol production, termed the low moisture anhydrous ammonia (LMAA) pretreatment. In this method, corn stover with 30-70% moisture was contacted with anhydrous ammonia in a reactor under nearly ambient conditions. After the ammoniation step, biomass was subjected to a simple pretreatment step at moderate temperatures (40-120°C) for 48-144 h. Pretreated biomass was saccharified and fermented without an additional washing step. With 3% glucan loading of LMAA-treated corn stover under best treatment conditions (0.1g-ammonia+1.0 g-water per g biomass, 80°C, and 84 h), simultaneous saccharification and cofermentation test resulted in 24.9 g/l (89% of theoretical ethanol yield based on glucan+xylan in corn stover).

  6. Quantum states for quantum processes: A toy model for ammonia inversion spectra

    Energy Technology Data Exchange (ETDEWEB)

    Arteca, Gustavo A. [Departement de Chimie et Biochimie and Biomolecular Sciences Programme, Laurentian University, Ramsey Lake Road, Sudbury, Ontario, Canada P3E 2C6 (Canada); Department of Physical Chemistry, Uppsala University, A ring ngstroemlaboratoriet, Box 259, S-751 05 Uppsala (Sweden); Tapia, O. [Department of Physical Chemistry, Uppsala University, A ring ngstroemlaboratoriet, Box 259, S-751 05 Uppsala (Sweden)

    2011-07-15

    Chemical transformations are viewed here as quantum processes modulated by external fields, that is, as shifts in reactant to product amplitudes within a quantum state represented by a linear (coherent) superposition of electronuclear basis functions; their electronic quantum numbers identify the ''chemical species.'' This basis set can be mapped from attractors built from a unique electronic configurational space that is invariant with respect to the nuclear geometry. In turn, the quantum numbers that label these basis functions and the semiclassical potentials for the electronic attractors may be used to derive reaction coordinates to monitor progress as a function of the applied field. A generalization of Feynman's three-state model for the ammonia inversion process illustrates the scheme; to enforce symmetry for the entire inversion process model and ensure invariance with respect to nuclear configurations, the three attractors and their basis functions are computed with a grid of fixed floating Gaussian functions. The external-field modulation of the effective inversion barrier is discussed within this conceptual approach. This analysis brings the descriptions of chemical processes near modern technologies that employ molecules to encode information by means of confinement and external fields.

  7. Differences detected in vivo between samples of aflatoxin-contaminated peanut meal, following decontamination by two ammonia-based processes

    NARCIS (Netherlands)

    Neal, G.E.; Judah, D.J.; Garthew, P.; Verma, A.; Latour, I.; Weir, L.; Coker, R.D.; Nagler, M.J.; Hoogenboom, L.A.P.

    2001-01-01

    A sample of peanut meal, highly contaminated with aflatoxins, has been subjected to decontamination by two commercial ammonia-based processes. The original contaminated and the two decontaminated meals were fed to rats for 90 days. No lesions associated with aflatoxin-induced hepatocarcinogenesis we

  8. [Climatic risk zoning for banana and litchi's chilling injury in South China].

    Science.gov (United States)

    Li, Na; Huo, Zhi-guo; He, Nan; Xiao, Jing-jing; Wen, Quan-pei

    2010-05-01

    Based on the 1951-2006 climatic observation data from 224 meteorological stations in South China (Guangdong Province, Guangxi Autonomous Region, and Fujian Province) and the historical information about the chilling injury losses of banana and litchi, the accumulated harmful chilling for the processes with minimum daily temperature zoning for banana and litchi's chilling injury were drawn, and the spatial variation of climatic risk for banana and litchi's chilling injury was commented. The results indicated that in the study area, climate warming might lead to the decrease of cold resistance of banana and litchi, which could increase the disaster risk of chilling injury. The geographical distribution of climatic risk probability for banana and litchi's chilling injury showed a zonal pattern. According to the integrated climatic risk index, the banana and litchi's chilling injury region was divided into three risk types, i.e., high risk, moderate risk, and low risk, which provided an important basis for the adjustment of agricultural production structure.

  9. Chemically deposited CdS by an ammonia-free process for solar cells window layers

    Energy Technology Data Exchange (ETDEWEB)

    Ochoa-Landin, R. [Centro de Investigacion y Estudios Avanzados del IPN, Unidad Queretaro, Apdo. Postal 1-798, 76001 Queretaro, Qro. (Mexico); Departamento de Fisica, Universidad de Sonora, Apdo. Postal 88, 83190 Hermosillo, Son. (Mexico); Sastre-Hernandez, J.; Vigil-Galan, O. [Escuela Superior de Fisica y Matematicas, Instituto Politecnico Nacional UP Adolfo Lopez Mateos, Edif. 9, 07738 Mexico, DF (Mexico); Ramirez-Bon, R. [Centro de Investigacion y Estudios Avanzados del IPN, Unidad Queretaro, Apdo. Postal 1-798, 76001 Queretaro, Qro. (Mexico)

    2010-02-15

    Chemically deposited CdS window layers were studied on two different transparent conductive substrates, namely indium tin oxide (ITO) and fluorine doped tin oxide (FTO), to determine the influence of their properties on CdS/CdTe solar cells performance. Three types of CdS films obtained from different chemical bath deposition (CBD) processes were studied. The three CBD processes employed sodium citrate as the complexing agent in partial or full substitution of ammonia. The CdS films were studied by X-ray diffraction, optical transmission spectroscopy and atomic force microscopy. CdS/CdTe devices were completed by depositing 3 {mu}m thick CdTe absorbent layers by means of the close-spaced vapor transport technique (CSVT). Evaporated Cu-Au was used as the back contact in all the solar cells. Dark and under illumination J-V characteristic and quantum efficiency measurements were done on the CdS/CdTe devices to determine their conversion efficiency and spectral response. The efficiency of the cells depended on the window layer and on the transparent contact with values between 5.7% and 8.7%. (author)

  10. Ammonia emissions from the composting of different organic wastes : dependency on process temperature

    OpenAIRE

    Pagans i Miró, Estel·la; Barrena Gómez, Raquel; Font Segura, Xavier; Sánchez Ferrer, Antoni

    2006-01-01

    Ammonia emissions were quantified for the laboratory-scale composting of three typical organic wastes with medium nitrogen content: organic fraction of municipal solid wastes, raw sludge and anaerobically digested sludge; and the composting of two wastes with high nitrogen content: animal by-products from slaughterhouses and partially hydrolysed hair from the leather industry. All the wastes were mixed with the proper amount of bulking agent. Ammonia emitted in the composting of the five wast...

  11. Biogenic amine formation and nitrite reactions in meat batter as affected by high-pressure processing and chilled storage.

    Science.gov (United States)

    Ruiz-Capillas, C; Aller-Guiote, P; Carballo, J; Colmenero, F Jiménez

    2006-12-27

    Changes in biogenic amine formation and nitrite depletion in meat batters as affected by pressure-temperature combinations (300 MPa/30 min/7, 20, and 40 degrees C), cooking process (70 degrees C/30 min), and storage (54 days/2 degrees C) were studied. Changes in residual nitrite concentration in raw meat batters were conditioned by the temperature and not by the pressure applied. Cooking process decreased (P batters. High-pressure processing conditions had no effect on the rate of residual nitrite loss throughout the storage. The application of high pressure decreased (P < 0.05) the concentration of some biogenic amines (tyramine, agmatine, and spermine). Irrespective of the high processing conditions, generally, throughout storage biogenic amine levels did not change or increased, although quantitatively this effect was not very important.

  12. Investigation of the degradation mechanism of catalytic wires during oxidation of ammonia process

    Science.gov (United States)

    Pura, Jarosław; Wieciński, Piotr; Kwaśniak, Piotr; Zwolińska, Marta; Garbacz, Halina; Zdunek, Joanna; Laskowski, Zbigniew; Gierej, Maciej

    2016-12-01

    The most common catalysts for the ammonia oxidation process are 80 μm diameter platinum-rhodium wires knitted or woven into the form of a gauze. In an aggressive environment and under extreme conditions (temperature 800-900 °C, intensive gas flow, high pressure) precious elements are drained from the surface of the wires. Part of this separated material quickly decomposes on the surface in the form of characteristic "cauliflower-shape protrusions". The rest of the platinum is captured by palladium-nickel catalytic-capture gauzes located beneath. In our investigation we focused on the effects of the degradation of gauzes from one industrial catalytic system. The aim of the study was to compare the degree and the mechanism of degradation of gauzes from a different part of the reactor. The study covered PtRh7 catalytic and PdNi5 catalytic-capture gauzes. X-ray computer microtomography investigation revealed that despite strong differences in morphology, each Pt-Rh wire has a similar specific surface area. This indicates that the oxidation process and morphological changes of the wires occur in a self-regulating balance, resulting in the value of the specific surface area of the catalyst. Microtomography analysis of Pd-Ni wires revealed strong redevelopment of the wires' surface, which is related to the platinum capture phenomenon. Scanning electron microscope observations also revealed the nanostructure in the cauliflower-shape protrusions and large grains in the wires' preserved cores. The high temperature in the reactor and the long-term nature of the process do not favor the occurrence of the nanostructure in this type of material. Further and detailed analysis of this phenomena will provide a better understanding of the precious metals etching and deposition processes during oxidation.

  13. Synthesis and photocatalytic performances of BiVO 4 by ammonia co-precipitation process

    Science.gov (United States)

    Yu, Jianqiang; Zhang, Yan; Kudo, Akihiko

    2009-02-01

    This paper reports the preparation and photocatalytic performance of Bismuth vanadate (BiVO 4) by a facile and inexpensive approach. An amorphous BiVO 4 was first prepared by a co-precipitation process from aqueous solutions of Bi(NO 3) 3 and NH 4VO 3 using ammonia. Followed by heating treatment at various temperatures, the amorphous phase converted to crystalline BiVO 4 with a structure between monoclinic and tetragonal scheelite. The crystallization of BiVO 4 occurred at about 523 K, while the nanocrystalline BiVO 4 were formed with a heat-treatment of lower than 673 K. However, when the heat-treatment was carried out at 773 K, the accumulation of nanocrystals to bulk particles was observed. The photocatalytic performances of the materials were investigated by O 2 evolution under visible-light, and MB decomposition under solar simulator. The results demonstrated that the crystalline structure is still the vital factor for the activities of both reactions. However, the crystallinity of BiVO 4 gives a major influence on the activity of O 2 evolution, whereas the surface area, plays an important role for photocatalytic MB decomposition.

  14. Ammonia removal in food waste anaerobic digestion using a side-stream stripping process.

    Science.gov (United States)

    Serna-Maza, A; Heaven, S; Banks, C J

    2014-01-01

    Three 35-L anaerobic digesters fed on source segregated food waste were coupled to side-stream ammonia stripping columns and operated semi-continuously over 300 days, with results in terms of performance and stability compared to those of a control digester without stripping. Biogas was used as the stripping medium, and the columns were operated under different conditions of temperature (55, 70, 85 °C), pH (unadjusted and pH 10), and RT (2-5 days). To reduce digester TAN concentrations to a useful level a high temperature (≥70 °C) and a pH of 10 were needed; under these conditions 48% of the TAN was removed over a 138-day period without any detrimental effects on digester performance. Other effects of the stripping process were an overall reduction in digestate organic nitrogen-containing fraction compared to the control and a recovery in the acetoclastic pathway when TAN concentration was 1770±20 mg kg(-1).

  15. Cod and rainbow trout as freeze-chilled meal elements

    DEFF Research Database (Denmark)

    Jensen, Louise Helene Søgaard; Nielsen, Jette; Jørgensen, Bo

    2010-01-01

    Meal elements' are elements of a meal, e.g. portions of pre-fried meat, sauces, frozen fish or pre-processed vegetables typically prepared industrially. The meal elements are distributed to professional satellite kitchens, where the staff can combine them into complete meals. Freeze...... and cod and rainbow trout seem potential candidates for freeze-chilled meal elements. (C) 2009 Society of Chemical Industry......-chilling is a process consisting of freezing and frozen storage followed by thawing and chilled storage. Combining the two would enable the manufacturer to produce large quantities of frozen meal elements to be released into the chill chain according to demand. We have studied the influence of freeze...

  16. A Zirconium Dioxide Ammonia Microsensor Integrated with a Readout Circuit Manufactured Using the 0.18 μm CMOS Process

    Directory of Open Access Journals (Sweden)

    Ming-Zhi Yang

    2013-03-01

    Full Text Available The study presents an ammonia microsensor integrated with a readout circuit on-a-chip fabricated using the commercial 0.18 μm complementary metal oxide semiconductor (CMOS process. The integrated sensor chip consists of a heater, an ammonia sensor and a readout circuit. The ammonia sensor is constructed by a sensitive film and the interdigitated electrodes. The sensitive film is zirconium dioxide that is coated on the interdigitated electrodes. The heater is used to provide a working temperature to the sensitive film. A post-process is employed to remove the sacrificial layer and to coat zirconium dioxide on the sensor. When the sensitive film adsorbs or desorbs ammonia gas, the sensor produces a change in resistance. The readout circuit converts the resistance variation of the sensor into the output voltage. The experiments show that the integrated ammonia sensor has a sensitivity of 4.1 mV/ppm.

  17. A zirconium dioxide ammonia microsensor integrated with a readout circuit manufactured using the 0.18 μm CMOS process.

    Science.gov (United States)

    Lin, Guan-Ming; Dai, Ching-Liang; Yang, Ming-Zhi

    2013-03-15

    The study presents an ammonia microsensor integrated with a readout circuit on-a-chip fabricated using the commercial 0.18 μm complementary metal oxide semiconductor (CMOS) process. The integrated sensor chip consists of a heater, an ammonia sensor and a readout circuit. The ammonia sensor is constructed by a sensitive film and the interdigitated electrodes. The sensitive film is zirconium dioxide that is coated on the interdigitated electrodes. The heater is used to provide a working temperature to the sensitive film. A post-process is employed to remove the sacrificial layer and to coat zirconium dioxide on the sensor. When the sensitive film adsorbs or desorbs ammonia gas, the sensor produces a change in resistance. The readout circuit converts the resistance variation of the sensor into the output voltage. The experiments show that the integrated ammonia sensor has a sensitivity of 4.1 mV/ppm.

  18. 5A Zirconium Dioxide Ammonia Microsensor Integrated with a Readout Circuit Manufactured Using the 0.18 μm CMOS Process

    Science.gov (United States)

    Lin, Guan-Ming; Dai, Ching-Liang; Yang, Ming-Zhi

    2013-01-01

    The study presents an ammonia microsensor integrated with a readout circuit on-a-chip fabricated using the commercial 0.18 μm complementary metal oxide semiconductor (CMOS) process. The integrated sensor chip consists of a heater, an ammonia sensor and a readout circuit. The ammonia sensor is constructed by a sensitive film and the interdigitated electrodes. The sensitive film is zirconium dioxide that is coated on the interdigitated electrodes. The heater is used to provide a working temperature to the sensitive film. A post-process is employed to remove the sacrificial layer and to coat zirconium dioxide on the sensor. When the sensitive film adsorbs or desorbs ammonia gas, the sensor produces a change in resistance. The readout circuit converts the resistance variation of the sensor into the output voltage. The experiments show that the integrated ammonia sensor has a sensitivity of 4.1 mV/ppm. PMID:23503294

  19. A process-based model for ammonia emission from urine patches, GAG (Generation of Ammonia from Grazing: description, validation and sensitivity analysis

    Directory of Open Access Journals (Sweden)

    A. Móring

    2015-07-01

    Full Text Available In this paper a new process-based, weather-driven model for ammonia (NH3 emission from a urine patch has been developed and its sensitivity to various factors assessed. This model, the GAG model (Generation of Ammonia from Grazing was developed as a part of a suite of weather-driven NH3 exchange models, as a necessary basis for assessing the effects of climate change on NH3 related atmospheric processes. GAG is capable of simulating the TAN (Total Ammoniacal Nitrogen content, pH and the water content of the soil under a urine patch. To calculate the TAN budget, GAG takes into account urea hydrolysis as a TAN input and NH3 volatilization as a loss. In the water budget, in addition to the water content of urine, precipitation and evaporation are also considered. In the pH module we assumed that the main regulating processes are the dissociation and dissolution equilibria related to the two products of urea hydrolysis: ammonium and bicarbonate. Finally, in the NH3 exchange flux calculation we adapted a canopy compensation point model that accounts for exchange with soil pores and stomata as well as deposition to the leaf surface. We validated our model against measurements, and carried out a sensitivity analysis. The validation showed that the simulated parameters (NH3 exchange flux, soil pH, TAN budget and water budget are well captured by the model (r > 0.5 for every parameter at p 3 emission. In addition, our results suggested that more sophisticated simulation of CO2 emission in the model could potentially improve the modelling of pH. The sensitivity analysis highlighted the vital role of temperature in NH3 exchange; however, presumably due to the TAN limitation, the GAG model currently provides only a modest overall temperature dependence in total NH3 emission compared with the values in the literature. Since all the input parameters can be obtained for study at larger scales, GAG is potentially suitable for larger scale application, such as

  20. Influence of Citric Acid on the Pink Color and Characteristics of Sous Vide Processed Chicken Breasts During Chill Storage.

    Science.gov (United States)

    Kim, Ji-Han; Hong, Go-Eun; Lim, Ki-Won; Park, Woojoon; Lee, Chi-Ho

    2015-01-01

    Chicken breast dipped with citric acid (CA) was treated by sous vide processing and stored in a refrigerated state for 0, 3, 6, 9, and 14 d. A non-dipped control group (CON) and three groups dipped in different concentrations of citric acid concentration were analyzed (0.5%, 0.5CIT; 2.0%, 2CIT and 5.0%, 5CIT; w/v). Cooking yield and moisture content increased due to the citric acid. While the redness of the juice and meat in all groups showed significant increase during storage, the redness of the citric acid groups was reduced compared to the control group (pacid reactive substances (TBARS) were generally lower in the citric acid-treated samples than in untreated ones, indicating extended shelf life of the cooked chicken breast dipped in citric acid solution. The shear force of the 2CIT and 5CIT groups was significantly lower (pcitric acid concentrations.

  1. Stable isotope composition of biogas allows early warning of complete process failure as a result of ammonia inhibition in anaerobic digesters.

    Science.gov (United States)

    Lv, Zuopeng; Hu, Meng; Harms, Hauke; Richnow, Hans Hermann; Liebetrau, Jan; Nikolausz, Marcell

    2014-09-01

    Four 15-L lab-scale continuous stirred tank reactors were operated under mesophilic conditions to investigate the effect of ammonia inhibition. Stable isotope fingerprinting of biogas was applied as a process monitoring tool. Ammonia inhibition was initiated by amendment of chicken manure to maize silage fed reactors. During the accumulation of ammonia, the concentration of volatile fatty acids increased while the biogas production and pH decreased. However, in one reactor, an inhibited steady state with stable gas production even at high ammonia levels was achieved, while the other reactor proceeded to complete process failure. A depletion of the δ(13)CH4 and δ(13)CO2 values preceded the process inhibition. Moreover, the stable isotope composition of biogas also forecasted the complete process failure earlier than other standard parameters. The stable isotope analyses of biogas have a potential for mechanistic insights in anaerobic processes, and may be used to pre-warn process failure under stress conditions.

  2. Modeling of simultaneous heat and mass transfer processes in ammonia-water absorption systems from general correlations

    Energy Technology Data Exchange (ETDEWEB)

    Sieres, Jaime; Fernandez-Seara, Jose [University of Vigo, Area de Maquinas y Motores Termicos, E.T.S. de Ingenieros Industriales, Vigo (Spain)

    2007-11-15

    This paper presents a general differential mathematical model to analyze the simultaneous heat and mass transfer processes that occur in different components of an ammonia-water absorption system: absorber, desorber, rectifier, distillation column, condenser and evaporator. Heat and mass transfer equations are considered, taking into account the heat and mass transfer resistances in the liquid and vapour phases. The model considers the different regions: vapour phase, liquid phase and an external heating or cooling medium. A finite difference numerical method has been considered to solve the resulting set of nonlinear differential equations and an iterative algorithm is proposed for its solution. A map of possible solutions of the mass transferred composition z is presented when varying the interface temperature, which enables to establish a robust implementation code. The analysis is focused on the processes presented in ammonia-water absorption systems. The model is applied to analyze the ammonia purification process in an adiabatic packed rectification column and the numerical results show good agreement with experimental data. (orig.)

  3. Fouling mitigation in membrane distillation processes during ammonia stripping from pig manure

    DEFF Research Database (Denmark)

    Zarebska, Agata; Amor, Angel Cid; Ciurkot, Klaudia

    2015-01-01

    . This study investigates preliminary fouling of polypropylene (PP) and polytetrafluoroethylene (PTFE) membranes. A model manure solution was used as feed. In addition cleaning efficiencies with deionized water, NaOH/citric acid, and Novadan agents were studied. Further microfiltration and ultrafiltration were...... additionally contained carboxylates, free fatty acids and lignin. Among the tested cleaning strategies, Novadan agents were the most successful in removing proteins and carbohydrates from the PTFE membrane while it only removed proteins from the PP membrane. Using microfiltration or ultrafiltration...... as a pretreatment prior to MD doubled the ammonia mass transfer coefficient for the PTFE membrane, while for the PP membrane, the ammonia mass transfer coefficient was increased 4-fold....

  4. HACCP在冷却牛肉生产中控制微生物的应用%Application of HACCP in control of microbial in processing chilled beef

    Institute of Scientific and Technical Information of China (English)

    徐晓霞; 张怀珠; 冯晓群

    2012-01-01

    According to the principles of hazard analysis and critical control points ( HACCP), ana- lyzing microorganism hazards in chilled beef procedure, identifying critical control points and critical lim- its, monitoring methods and corrective measures, and construct a normative HACCP system were the aims of this study, so as to eliminate, prevent and minimize microorganism hazards in chilled beef procedure ef- fectively, and ensure the quality of chilled beef.%根据危害分析与关键控制点系统原理,对冷却牛肉加工过程中主要环节可能存在的微生物危害进行分析,确立关键控制点、关键限值、监控方法及纠偏措施,构建规范的HACCP质量管理体系,从而有效消除、预防或最大限度地降低冷却牛肉生产过程中的微生物危害,确保产品质量。

  5. Ammonia - LCFA synergetic co-inhibition effect in manure-based continuous biomethanation process

    DEFF Research Database (Denmark)

    Wang, Han; Fotidis, Ioannis; Angelidaki, Irini

    2016-01-01

    uninhibited production, respectively. At the same time control reactor (RCTL), only fed with manure, reached 32.7% compared to the uninhibited basis production. Therefore, it seems that using lipids to counteract the ammonia effect in CSTR reactors creates an “ammonia–LCFA (long chain fatty acids) synergetic...

  6. Effect of free ammonia and free nitrous acid concentration on the anabolic and catabolic processes of an enriched Nitrosomonas culture.

    Science.gov (United States)

    Vadivelu, Vel M; Keller, Jurg; Yuan, Zhiguo

    2006-12-05

    The effects of free ammonia (FA; NH(3)) and free nitrous acid (FNA; HNO(2)) concentrations on the metabolisms of an enriched ammonia oxidizing bacteria (AOB) culture were investigated using a method allowing the decoupling of growth and energy generation processes. A lab-scale sequencing batch reactor (SBR) was operated for the enrichment of an AOB culture. Fluorescent in-situ hybridization (FISH) analysis showed that 82% of the bacterial population in the SBR bound to the NEU probe specifically designed for Nitrosomonas europaea. Batch tests were carried out to measure the oxygen and ammonium consumption rates by the culture at various FA and FNA levels, in the presence or absence of inorganic carbon (CO(2), HCO(3) (-), and CO(3) (2-)). It was revealed that FA of up to 16.0 mgNH(3)-N . L(-1), which was the highest concentration used in this study, did not have any inhibitory effect on either the catabolic or anabolic processes of the Nitrosomonas culture. In contrast, FNA inhibited both the growth and energy production capabilities of the Nitrosomonas culture. The inhibition on growth initiated at approximately 0.10 mgHNO(2)-N . L(-1), and the data suggested that the biosynthesis was completely stopped at an FNA concentration of 0.40 mgHNO(2)-N . L(-1). The inhibition on energy generation initiated at a slightly lower level but the Nitrosomonas culture was still oxidizing ammonia at half of the maximum rate at an FNA concentration of 0.50-0.63 mgHNO(2)-N . L(-1). The affinity constant of the Nitrosomonas culture with respect to ammonia was determined to be 0.36 mgNH(3)-N . L(-1), independent of the presence or absence of inorganic carbon.

  7. Implementation of flowsheet change to minimize hydrogen and ammonia generation during chemical processing of high level waste in the Defense Waste Processing Facility

    Energy Technology Data Exchange (ETDEWEB)

    Lambert, Dan P. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Woodham, Wesley H. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Williams, Matthew S. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Newell, J. David [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Luther, Michelle C. [Auburn Univ., AL (United States); Brandenburg, Clayton H. [Univ.of South Carolina, Columbia, SC (United States)

    2016-09-27

    Testing was completed to develop a chemical processing flowsheet for the Defense Waste Processing Facility (DWPF), designed to vitrify and stabilize high level radioactive waste. DWPF processing uses a reducing acid (formic acid) and an oxidizing acid (nitric acid) to rheologically thin the slurry and complete the necessary acid base and reduction reactions (primarily mercury and manganese). Formic acid reduces mercuric oxide to elemental mercury, allowing the mercury to be removed during the boiling phase of processing through steam stripping. In runs with active catalysts, formic acid can decompose to hydrogen and nitrate can be reduced to ammonia, both flammable gases, due to rhodium and ruthenium catalysis. Replacement of formic acid with glycolic acid eliminates the generation of rhodium- and ruthenium-catalyzed hydrogen and ammonia. In addition, mercury reduction is still effective with glycolic acid. Hydrogen, ammonia and mercury are discussed in the body of the report. Ten abbreviated tests were completed to develop the operating window for implementation of the flowsheet and determine the impact of changes in acid stoichiometry and the blend of nitric and glycolic acid as it impacts various processing variables over a wide processing region. Three full-length 4-L lab-scale simulations demonstrated the viability of the flowsheet under planned operating conditions. The flowsheet is planned for implementation in early 2017.

  8. Implementation of flowsheet change to minimize hydrogen and ammonia generation during chemical processing of high level waste in the defense waste processing facility

    Energy Technology Data Exchange (ETDEWEB)

    Lambert, Dan P. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Woodham, Wesley H. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Williams, Matthew S. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Newell, J. David [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Luther, Michelle C. [Auburn Univ., AL (United States); Brandenburg, Clayton H. [Univ.of South Carolina, Columbia, SC (United States)

    2016-09-27

    Testing was completed to develop a chemical processing flowsheet for the Defense Waste Processing Facility (DWPF), designed to vitrify and stabilize high level radioactive waste. DWPF processing uses a reducing acid (formic acid) and an oxidizing acid (nitric acid) to rheologically thin the slurry and complete the necessary acid base and reduction reactions (primarily mercury and manganese). Formic acid reduces mercuric oxide to elemental mercury, allowing the mercury to be removed during the boiling phase of processing through steam stripping. In runs with active catalysts, formic acid can decompose to hydrogen and nitrate can be reduced to ammonia, both flammable gases, due to rhodium and ruthenium catalysis. Replacement of formic acid with glycolic acid eliminates the generation of rhodium- and ruthenium-catalyzed hydrogen and ammonia. In addition, mercury reduction is still effective with glycolic acid. Hydrogen, ammonia and mercury are discussed in the body of the report. Ten abbreviated tests were completed to develop the operating window for implementation of the flowsheet and determine the impact of changes in acid stoichiometry and the blend of nitric and glycolic acid as it impacts various processing variables over a wide processing region. Three full-length 4-L lab-scale simulations demonstrated the viability of the flowsheet under planned operating conditions. The flowsheet is planned for implementation in early 2017.

  9. The Big Chills

    Science.gov (United States)

    Bond, G. C.; Dwyer, G. S.; Bauch, H. A.

    2002-12-01

    At the end of the last glacial, the Earth's climate system abruptly shifted into the Younger Dryas, a 1500-year long cold snap known in the popular media as the Big Chill. Following an abrupt warming ending the Younger Dryas about 11,600 years ago, the climate system has remained in an interglacial state, thought to have been relatively stable and devoid, with possibly one or two exceptions, of abrupt climate change. A growing amount of evidence suggests that this benign view of interglacial climate is incorrect. High resolution records of North Atlantic ice rafted sediment, now regarded as evidence of extreme multiyear sea ice drift, reveal abrupt shifts on centennial and millennial time scales. These have been traced from the end of the Younger Dryas to the present, revealing evidence of significant climate variability through all of the last two millennia. Correlatives of these events have been found in drift ice records from the Arctic's Laptev Sea, in the isotopic composition of North Grip ice, and in dissolved K from the GISP2 ice core, attesting to their regional extent and imprint in proxies of very different origins. Measurements of Mg/Ca ratios in planktic foraminifera over the last two millennia in the eastern North Atlantic demonstrate that increases in drifting multiyear sea ice were accompanied by abrupt decreases in sea surface temperatures, especially during the Little Ice Age. Estimated rates of temperature change are on the order of two degrees centigrade, more than thirty percent of the regional glacial to interglacial change, within a few decades. When compared at the same resolution, these interglacial variations are as abrupt as the last glacial's Dansgaard-Oeschger cycles. The interglacial abrupt changes are especially striking because they occurred within the core of the warm North Atlantic Current. The changes may have been triggered by variations in solar irradiance, but if so their large magnitude and regional extent requires amplifying

  10. Redox Signaling and CBF-Responsive Pathway are Involved in Salicylic Acid-Improved Photosynthesis and Growth under Chilling Stress in Watermelon

    Directory of Open Access Journals (Sweden)

    Fei Cheng

    2016-10-01

    Full Text Available Salicylic acid (SA plays an important role in plant response to abiotic stresses. This study investigated the potential role of SA in alleviating the adverse effects of chilling stress on photosynthesis and growth in watermelon (Citrullus lanatus. Chilling stress induced the simultaneous accumulation of free and conjugated SA in watermelon plants, and the chilling-induced SA production was attributed to the phenylalanine ammonia-lyase pathway. Applying SA at moderate concentrations induced chilling tolerance, whereas inhibition of SA biosynthesis by L-ɑ-aminooxy-β-phenylpropionic acid (AOPP increased the photooxidation of PS II under chilling stress in watermelon, resulting in reduced photosynthesis and growth. Chilling induced a transient increase in the ratios of reduced to oxidized glutathione and reduced ascorbate to dehydroascorbate. Then, the expression of antioxidant genes was upregulated, and the activities of antioxidant enzymes were enhanced. Furthermore, SA-induced chilling tolerance was associated with cellular glutathione and ascorbate homeostasis, which served as redox signals to regulate antioxidant metabolism under chilling stress. AOPP treatment stimulated the chilling-induced expression of cold-responsive genes, particularly via C-repeat binding factors CBF3 and CBF4. These results confirm the synergistic role of SA signaling and the CBF-dependent responsive pathway during chilling stress in watermelon.

  11. Redox Signaling and CBF-Responsive Pathway Are Involved in Salicylic Acid-Improved Photosynthesis and Growth under Chilling Stress in Watermelon

    Science.gov (United States)

    Cheng, Fei; Lu, Junyang; Gao, Min; Shi, Kai; Kong, Qiusheng; Huang, Yuan; Bie, Zhilong

    2016-01-01

    Salicylic acid (SA) plays an important role in plant response to abiotic stresses. This study investigated the potential role of SA in alleviating the adverse effects of chilling stress on photosynthesis and growth in watermelon (Citrullus lanatus). Chilling stress induced the simultaneous accumulation of free and conjugated SA in watermelon plants, and the chilling-induced SA production was attributed to the phenylalanine ammonia-lyase pathway. Applying SA at moderate concentrations induced chilling tolerance, whereas inhibition of SA biosynthesis by L-α-aminooxy-β-phenylpropionic acid (AOPP) increased the photooxidation of PS II under chilling stress in watermelon, resulting in reduced photosynthesis and growth. Chilling induced a transient increase in the ratios of reduced to oxidized glutathione and reduced ascorbate to dehydroascorbate. Then, the expression of antioxidant genes was upregulated, and the activities of antioxidant enzymes were enhanced. Furthermore, SA-induced chilling tolerance was associated with cellular glutathione and ascorbate homeostasis, which served as redox signals to regulate antioxidant metabolism under chilling stress. AOPP treatment stimulated the chilling-induced expression of cold-responsive genes, particularly via C-repeat binding factors CBF3 and CBF4. These results confirm the synergistic role of SA signaling and the CBF-dependent responsive pathway during chilling stress in watermelon. PMID:27777580

  12. A process-based model for ammonia emission from urine patches, GAG (Generation of Ammonia from Grazing): description and sensitivity analysis

    DEFF Research Database (Denmark)

    Móring, Andrea; Vieno, Massimo; M. Doherty, Ruth;

    2016-01-01

    content of the soil under a urine patch and also soil pH dynamics. The model tests suggest that ammonia volatilization from a urine patch can be affected by the possible restart of urea hydrolysis after a rain event as well as CO2 emission from the soil. The vital role of temperature in NH3 exchange...

  13. Anammox for ammonia removal from pig manure effluents: Effect of organic matter content on process performance

    DEFF Research Database (Denmark)

    Salces, Beatriz Molinuevo; García, M. C.; Karakashev, Dimitar Borisov

    2009-01-01

    oxidation) diluted with synthetic wastewater. High ammonium removal was achieved, up to 92.1 +/- 4.9% for diluted UASB-post-digested effluent (95 mg COD L-1) and up to 98.5 +/- 0.8% for diluted partially oxidized effluent (121 mg COD L-1). Mass balance clearly showed that an increase in organic loading...... improved ammonium removal at high organic matter concentration. Up to threshold organic load concentration of 142 mg COD L-1 of UASB-post-digested effluent and 242 mg COD L-1 of partially oxidized effluent, no effect of organic loading on ammonia removal was registered (ammonium removal was above 80...

  14. Modeling of ammonia absorption chillers integration in energy systems of process plants

    Energy Technology Data Exchange (ETDEWEB)

    Bruno, J.C.; Castells, F. [Universitat Rovira i Virgili, Tarragona (Spain). Dept. d' Enginyeria Quimica; Miquel, J. [Universitat Politecnica de Catalunya (Spain). Dept. de Mecanica de Fluids

    1999-12-01

    A mathematical programming approach is proposed to study the integration of absorption chillers in combined heat and power plants. The aim of this work is to determine the economic viability of the introduction of ammonia absorption chillers in energy systems instead of using the more conventional compression cycles. This procedure selects the best refrigeration alternative taking into account both absorption and compression cycles. To select the most suitable refrigeration cycle for a given refrigeration load, it is not only necessary to model the performance of each cycle, but also to take into account the interactions between the energy system and the considered cycles, optimizing the performance of the global plant. This approach has been implemented in the computer program XV, and tested in an energy plant in the petrochemical complex of Tarragona (Catalunya, Spain). The refrigeration demands to be met are at 0 and -20{sup o}C. The results highlighted the benefit obtained with the simultaneous presence of ammonia absorption cycles and a cogeneration based energy plant. (author)

  15. Ammonia mobility in chabazite: insight into the diffusion component of the NH3-SCR process.

    Science.gov (United States)

    O'Malley, Alexander J; Hitchcock, Iain; Sarwar, Misbah; Silverwood, Ian P; Hindocha, Sheena; Catlow, C Richard A; York, Andrew P E; Collier, P J

    2016-06-29

    The diffusion of ammonia in commercial NH3-SCR catalyst Cu-CHA was measured and compared with H-CHA using quasielastic neutron scattering (QENS) and molecular dynamics (MD) simulations to assess the effect of counterion presence on NH3 mobility in automotive emission control relevant zeolite catalysts. QENS experiments observed jump diffusion with a jump distance of 3 Å, giving similar self-diffusion coefficient measurements for both Cu- and H-CHA samples, in the range of ca. 5-10 × 10(-10) m(2) s(-1) over the measured temperature range. Self-diffusivities calculated by MD were within a factor of 6 of those measured experimentally at each temperature. The activation energies of diffusion were also similar for both studied systems: 3.7 and 4.4 kJ mol(-1) for the H- and Cu-chabazite respectively, suggesting that counterion presence has little impact on ammonia diffusivity on the timescale of the QENS experiment. An explanation is given by the MD simulations, which showed the strong coordination of NH3 with Cu(2+) counterions in the centre of the chabazite cage, shielding other molecules from interaction with the ion, and allowing for intercage diffusion through the 8-ring windows (consistent with the experimentally observed jump length) to carry on unhindered.

  16. Removal of ammonium chloride generated by ammonia slip from the SNCR process in municipal solid waste incinerators.

    Science.gov (United States)

    Hwang, In-Hee; Minoya, Hiroshi; Matsuto, Toshihiko; Matsuo, Takayuki; Matsumoto, Akihiro; Sameshima, Ryoji

    2009-03-01

    The selective non-catalytic reduction (SNCR) process is one of the methods used to reduce NO(x) to N(2) and H(2)O by injecting NH(3) or urea solution into a high-temperature furnace. Merits of this method include simple handling, low cost, and energy savings. However, a critical problem of the SNCR process is the generation of ammonia slip; in reactions with HCl in flue gas, ammonium chloride is generated and forms detached white plumes near the stack. Using a laboratory-scale experimental apparatus, we examined the possibility of NH(4)Cl collection and removal by a bag filter (BF). The molar NH(3)/HCl ratio of the compound collected at the filter was nearly one, regardless of gas temperature, retention time, and concentration, confirming the formation of NH(4)Cl. The NH(4)Cl generation ratio increased as reaction temperature decreased, indicating that the collection efficiency of NH(4)Cl should increase if the BF is operated at the lowest possible temperature while avoiding the critical point causing low-temperature corrosion (e.g., 150 degrees C). In addition, the use of activated carbon injection in the front of the BF and the dust layer on the BF are expected to capture slipped ammonia at the BF and reduce NH(4)Cl fume generation in the stack.

  17. Endogenous salicylic acid accumulation is required for chilling tolerance in cucumber (Cucumis sativus L.) seedlings.

    Science.gov (United States)

    Dong, Chun-Juan; Li, Liang; Shang, Qing-Mao; Liu, Xin-Yan; Zhang, Zhi-Gang

    2014-10-01

    Salicylic acid (SA) is an important plant hormone, and its exogenous application can induce tolerance to multiple environmental stresses in plants. In this study, we examine the potential involvement of endogenous SA in response to chilling in cucumber (Cucumis sativus L.) seedlings. A low temperature of 8 °C induces a moderate increase in endogenous SA levels. Chilling stimulates the enzymatic activities and the expression of genes for phenylalanine ammonia-lyase (PAL) and benzoic acid-2-hydroxylase rather than isochorismate synthase. This indicates that the PAL enzymatic pathway contributes to chilling-induced SA production. Cucumber seedlings pretreated with SA biosynthesis inhibitors accumulate less endogenous SA and suffer more from chilling damage. The expression of cold-responsive genes is also repressed by SA inhibitors. The reduction in stress tolerance and in gene expression can be restored by the exogenous application of SA, confirming the critical roles of SA in chilling responses in cucumber seedlings. Furthermore, the inhibition of SA biosynthesis under chilling stress results in a prolonged and enhanced hydrogen peroxide (H2O2) accumulation. The application of exogenous SA and the chemical scavenger of H2O2 reduces the excess H2O2 and alleviates chilling injury. In contrast, the protective effects of SA are negated by foliar spraying with high concentrations of H2O2 and an inhibitor of the antioxidant enzyme. These results suggest that endogenous SA is required in response to chilling stress in cucumber seedlings, by modulating the expression of cold-responsive genes and the precise induction of cellular H2O2 levels.

  18. Synthesis of D- and L-phenylalanine derivatives by phenylalanine ammonia lyases: a multienzymatic cascade process.

    Science.gov (United States)

    Parmeggiani, Fabio; Lovelock, Sarah L; Weise, Nicholas J; Ahmed, Syed T; Turner, Nicholas J

    2015-04-01

    The synthesis of substituted D-phenylalanines in high yield and excellent optical purity, starting from inexpensive cinnamic acids, has been achieved with a novel one-pot approach by coupling phenylalanine ammonia lyase (PAL) amination with a chemoenzymatic deracemization (based on stereoselective oxidation and nonselective reduction). A simple high-throughput solid-phase screening method has also been developed to identify PALs with higher rates of formation of non-natural D-phenylalanines. The best variants were exploited in the chemoenzymatic cascade, thus increasing the yield and ee value of the D-configured product. Furthermore, the system was extended to the preparation of those L-phenylalanines which are obtained with a low ee value using PAL amination.

  19. Distribution and rate of microbial processes in ammonia-loaded air filter biofilm

    DEFF Research Database (Denmark)

    Juhler, Susanne; Nielsen, Lars Peter; Schramm, Andreas;

    2009-01-01

    was investigated by microsensor analysis, fluorescence in situ hybridization, quantitative PCR, and batch incubation activity measurements. In situ aerobic activity showed a significant decrease through the filter, while the distribution of ammonia-oxidizing bacteria (AOB) was highly skewed toward the filter......The in situ activity and distribution of heterotrophic and nitrifying bacteria and their potential interactions were investigated in a full-scale, two-section, trickling filter designed for biological degradation of volatile organics and NH3 in ventilation air from pig farms. The filter biofilm...... with heterotrophic bacteria for O2 and inhibition by the protonated form of NO2-, HNO2. Product inhibition of AOB growth could explain why this type of filter tends to emit air with a rather constant NH3 concentration irrespective of variations in inlet concentration and airflow....

  20. Synthesis of d- and l-Phenylalanine Derivatives by Phenylalanine Ammonia Lyases: A Multienzymatic Cascade Process**

    Science.gov (United States)

    Parmeggiani, Fabio; Lovelock, Sarah L; Weise, Nicholas J; Ahmed, Syed T; Turner, Nicholas J

    2015-01-01

    The synthesis of substituted d-phenylalanines in high yield and excellent optical purity, starting from inexpensive cinnamic acids, has been achieved with a novel one-pot approach by coupling phenylalanine ammonia lyase (PAL) amination with a chemoenzymatic deracemization (based on stereoselective oxidation and nonselective reduction). A simple high-throughput solid-phase screening method has also been developed to identify PALs with higher rates of formation of non-natural d-phenylalanines. The best variants were exploited in the chemoenzymatic cascade, thus increasing the yield and ee value of the d-configured product. Furthermore, the system was extended to the preparation of those l-phenylalanines which are obtained with a low ee value using PAL amination. PMID:25728350

  1. Synthesis of d- and l-Phenylalanine Derivatives by Phenylalanine Ammonia Lyases: A Multienzymatic Cascade Process.

    Science.gov (United States)

    Parmeggiani, Fabio; Lovelock, Sarah L; Weise, Nicholas J; Ahmed, Syed T; Turner, Nicholas J

    2015-04-07

    The synthesis of substituted d-phenylalanines in high yield and excellent optical purity, starting from inexpensive cinnamic acids, has been achieved with a novel one-pot approach by coupling phenylalanine ammonia lyase (PAL) amination with a chemoenzymatic deracemization (based on stereoselective oxidation and nonselective reduction). A simple high-throughput solid-phase screening method has also been developed to identify PALs with higher rates of formation of non-natural d-phenylalanines. The best variants were exploited in the chemoenzymatic cascade, thus increasing the yield and ee value of the d-configured product. Furthermore, the system was extended to the preparation of those l-phenylalanines which are obtained with a low ee value using PAL amination.

  2. The Relationships between Rheological Properties and Structural Changes of Chilled Abalone Meat

    Institute of Scientific and Technical Information of China (English)

    GAO Xin; ZHANG Zhaohui; TANG Zhixu; TASHIRO Yuri; OGAWA Hiroo

    2003-01-01

    The quantitative correlation between theological properties and structural characteristic values of chilled abalone meat was studied. Structural changes were observed, and these values were enumerated using image processing and analysis technique. Structural changes in the myofibrils and collagen fibrils were the greatest in chilling for 24 h. After chilling for 48 h, similar structures of vertical and cross sections were observed. For chilling from 0h to 72h, the instantaneous modulus E0 of the both section meat decreases gradually with time, but no significant differences were observed after chilling for 48 h.The relaxation time and viscosity of both sections attained the same values for the same chilling time, but increased gradually with increasing chilling time. Meanwhile, a negative correlation between the structural characteristic values (Dm, Am,Rvm), and rheological properties (E1,τi,η1) clearly exists. Some logarithmic expressions have been obtained for these negative correlations. These results suggest that the difference in rheological properties between the cross and vertical sections was mainly due to the structural changes of myofibrils and collagen fibrils, and rheological properties are influenced quantitatively by the structural characteristic values for chilling from 0 h to 72 h.

  3. Research and Application of No Steam and Negative Pressure Ammonia Distillation Process%无蒸汽负压蒸氨工艺的研究与应用

    Institute of Scientific and Technical Information of China (English)

    祝仰勇; 宁述芹; 王贺红; 张顺贤; 叶冰

    2012-01-01

      By redesigning the negative pressure ammonia distillation process, transforming the ammonia distillation tower, increasing the stable vacuum system, selecting different device material, improving the process of adding alkali, adding tail gas recycling device and other reform measures, no steam and negative pressure ammonia distillation was achieved in No.6 and No.7 coke ovens, but also the consumption of coal gas was reduced. The quality of adding alkali negative pressure evaporation ammonia water achieved the requirements of atmospheric pressure ammonia distillation and realized the recovery of all tail gas.%  济钢通过重新设计6#、7#焦炉负压蒸氨工艺流程,改造蒸氨塔,增加稳定的真空系统,选择不同的设备材质,改进加碱工艺,增加尾气回收利用装置等改造措施,实现了无蒸汽负压蒸氨,同时降低了煤气消耗,加碱负压蒸氨废水水质达到了常压蒸氨的要求,尾气实现了全部回收。

  4. THE EFFECTS OF SPRAY-CHILLING ASSOCIATED TO CONVENTIONAL CHILLING ON MASS LOSS, BACTERIOLOGYCAL AND PHYSICO-CHEMICAL QUALITY OF BEEF CARCASS

    Directory of Open Access Journals (Sweden)

    Moacir Evandro Lage

    2006-10-01

    Full Text Available The purpose of this study was to verify the effect of conventional air chilling associated to intermittent spray-chilling treatment, on weight loss, physico-chemical and bacteriological quality of beef carcasses. Two plants of commercial beef slaughterhouse located in Goiânia and fiscalized by the Federal Inspection Service were used to develop the research. The spray-chilling treatment was accomplished in an intermittent way, commanded by acontrolled logical program, with cycles of 90 seconds, in intervals of 30 minutes, during the first 4 hours of the chilling process. Physico-chemical and bacteriological analysis were made in spray-chilled water and carcasses samples, according to recommendation of the effective legislation.The average values of carcasses weight loss of treatment group were lower to the ones verified for the control group,in both plants, A and B, (P < 0,001, showing a high economic potential. As a conclusion of physico-chemical and bacteriological analysis results of water and meat samples, it is clear that the technology of chilling beef carcasses inthe conventional system associated to spraying did not interfere in the quality of meat, and it can become an analysis object on part of official organs for sanitary regulation and fiscalization, for its definitive adoption. KEY WORDS: Spray-chilling, shrinkage, beef carcass.

  5. Effect of pelleting process variables on physical properties and sugar yields of ammonia fiber expansion pretreated corn stover.

    Science.gov (United States)

    Hoover, Amber N; Tumuluru, Jaya Shankar; Teymouri, Farzaneh; Moore, Janette; Gresham, Garold

    2014-07-01

    Pelletization process variables, including grind size (4, 6mm), die speed (40, 50, 60 Hz), and preheating (none, 70°C), were evaluated to understand their effect on pellet quality attributes and sugar yields of ammonia fiber expansion (AFEX) pretreated biomass. The bulk density of the pelletized AFEX corn stover was three to six times greater compared to untreated and AFEX-treated corn stover. Also, the durability of the pelletized AFEX corn stover was>97.5% for all pelletization conditions studied except for preheated pellets. Die speed had no effect on enzymatic hydrolysis sugar yields of pellets. Pellets produced with preheating or a larger grind size (6mm) had similar or lower sugar yields. Pellets generated with 4mm AFEX-treated corn stover, a 60Hz die speed, and no preheating resulted in pellets with similar or greater density, durability, and sugar yields compared to other pelletization conditions.

  6. Evaluating the impact of an ammonia-based post-combustion CO2 capture process on a steam power plant with different cooling water temperatures

    DEFF Research Database (Denmark)

    Linnenberg, Sebastian; Darde, Victor Camille Alfred; Oexmann, Jochen

    2012-01-01

    The use of aqueous ammonia is a promising option to capture carbon dioxide from the flue gas of coal-fired power plants. Compared to a capture process using monoethanolamine (MEA), the use of ammonia can reduce the heat requirement of the CO2 desorption significantly, although an additional effort...... is necessary to provide the cooling of the process. To allow for a fair evaluation of the integration of this CO2 capture process into a power plant process, an overall process evaluation is carried out. The use of detailed models of the power plant, of the compressor and of the CO2 capture process enables....... Additionally, two different process configurations of the capture plant, with either one single absorber or two absorbers connected in series where the first absorber captures the majority of the CO2 and the second limits the NH3 slip, are evaluated.The influence of the main process parameters (desorber...

  7. Analysis and improvement of ammonia stripping process by heat transfer oil%导热油蒸氨工艺分析与改进

    Institute of Scientific and Technical Information of China (English)

    张利杰

    2016-01-01

    The problems in ammonia stripping process by heat transfer oil is analyzed. After improve-ment, the efficiency of ammonia stripping is increased, the index of waste water is stabilized and maintenance costs of the equipment are lowered.%分析了导热油蒸氨工艺存在的问题,改进后提高了蒸氨效率,稳定了废水指标,降低了蒸氨系统的设备维修费用。

  8. The Technical Characteristics and Comparison of New Ammonia Synthesis Process%新型氨合成工艺技术的特点及比较

    Institute of Scientific and Technical Information of China (English)

    张占一

    2011-01-01

    The supply and demand of synthetic ammonia in domestic market is briefly overviewed in this paper,while several kinds of new ammonia synthesis process and flow is introduced in details,with the analysis and comparison of different technical characteristics and the prospect of the development trend of synthetic ammonia industry in our country.%分析了国内合成氨的市场供需概况;介绍了几种新型氨合成工艺技术、装置特点和工艺流程;以50万t/a合成氨生产装置为例,对比了KBR、托普索、卡萨利氨合成工艺的综合技术参数;展望了我国合成氨工艺技术的发展趋势。

  9. Membrane-Based Gas Traps for Ammonia, Freon-21, and Water Systems to Simplify Ground Processing

    Science.gov (United States)

    Ritchie, Stephen M. C.

    2003-01-01

    is when particles adhere to the hydrophobic membrane, promoting formation of a water layer about it that can blind the membrane for gas transport (Figure 1). This mechanism is the most probable cause for observed failures with the existing design. The objective of this project was to devise a strategy for choosing new membrane materials (database development and procedure), redesign of the gas trap to mitigate blinding effects, and to develop a design that can be used in ammonia and Freon-21 coolant loops.

  10. RESULTS OF INITIAL AMMONIA OXIDATION TESTING

    Energy Technology Data Exchange (ETDEWEB)

    Nash, C. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Fowley, M. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2016-12-30

    This memo presents an experimental survey of aqueous phase chemical processes to remove aqueous ammonia from waste process streams. Ammonia is generated in both the current Hanford waste flowsheet and in future waste processing. Much ammonia will be generated in the Low Activity Waste (LAW) melters.i Testing with simulants in glass melters at Catholic University has demonstrated the significant ammonia production.ii The primary reaction there is the reducing action of sugar on nitrate in the melter cold cap. Ammonia has been found to be a problem in secondary waste stabilization. Ammonia vapors are noxious and destruction of ammonia could reduce hazards to waste treatment process personnel. It is easily evolved especially when ammonia-bearing solutions are adjusted to high pH.

  11. Morphological and chemical study of the initial growth of CdS thin films deposited using an ammonia-free chemical process

    Energy Technology Data Exchange (ETDEWEB)

    Mazon-Montijo, D.A.; Sotelo-Lerma, M.; Quevedo-Lopez, M. [Centro de Investigacion en Polimeros y Materiales, Universidad de Sonora, Apdo. Postal 130, 83190 Hermosillo, Son. (Mexico); El-Bouanani, M. [Department of Materials Science and Engineering, University of North Texas, P.O. Box 305310 Denton, TX 76203-5310 (United States); Alshareef, H.N. [SEMATECH, 2706 Montopolis Drive, Austin, TX 78741 (United States); Espinoza-Beltran, F.J. [Centro de Investigacion y Estudios Avanzados del IPN, Unidad Queretaro, Apdo. Postal 1-798, 76001 Queretaro, Qro. (Mexico); Ramirez-Bon, R. [Centro de Investigacion y Estudios Avanzados del IPN, Unidad Queretaro, Apdo. Postal 1-798, 76001 Queretaro, Qro. (Mexico)], E-mail: rrbon@qro.cinvestav.mx

    2007-11-15

    We study the initial growth stages of CdS thin films deposited by an ammonia-free chemical bath deposition process. This ammonia-free process is more environmentally benign because it reduces potential ammonia release to the environment due to its high volatility. Instead of ammonia, sodium citrate was used as the complexing agent. We used atomic force microscopy (AFM), Rutherford backscattering (RBS) and X-ray photoelectron spectroscopy (XPS) to investigate the morphological and chemical modifications at the substrate surface during the first initial stages of the CdS deposition process. Additionally, X-ray diffraction (XRD) and optical transmission spectroscopy measurements were carried out to compliment the study. XPS results show that the first nucleation centers are composed by Cd(OH){sub 2} which agglomerate in patterns of bands, as demonstrated by AFM results. It is also observed that the conversion to CdS (by anionic exchange) of the first nucleus begins before the substrate surface is completely covered by a homogenous film.

  12. A Systematic Approach for Conceptual and Sustainable Process Design: Production of Methylamines From Methanol and Ammonia

    DEFF Research Database (Denmark)

    Mansouri, Seyed Soheil; Ismail, Muhammad Imran Bin; Almoor, Karim

    2012-01-01

    of the process flow sheet and preliminary calculations to the detailed process simulations, equipment sizing, costing, an economic evaluation, and sustainability of the designed process. At the end of task-9, the base case design is obtained, which is then further refined and improved with respect to heat...... integration and process optimization. In the final task-12, a sustainability and life cycle assessment (LCA) analysis are performed to assess the environmental impact of the process design. This is done through the following special software: SustainPro and LCASoft, which determine the key sustainability...... elsewhere. This information is then used as target for process improvement by heat integration and process optimization, thus increasing the annual profit and reducing the payback time. The environmental impact analysis identifies impact due to the release of chemicals. The environmental impact analysis...

  13. Abundance and diversity of ammonia-oxidizing archaea and bacteria on biological activated carbon in a pilot-scale drinking water treatment plant with different treatment processes.

    Science.gov (United States)

    Kasuga, Ikuro; Nakagaki, Hirotaka; Kurisu, Futoshi; Furumai, Hiroaki

    2010-01-01

    The effects of different placements of rapid sand filtration on nitrification performance of BAC treatment in a pilot-scale plant were evaluated. In this plant, rapid sand filtration was placed after ozonation-BAC treatment in Process (A), while it preceded ozonation-BAC treatment in Process (B). Analysis of amoA genes of ammonia-oxidizing archaea (AOA) and bacteria (AOB) combined with nitrification potential test was conducted. BAC from Process (A) demonstrated slightly higher nitrification potential at every sampling occasion. This might be due to higher abundances of AOB on BAC from Process (A) than those on BAC from Process (B). However, AOA rather than AOB could be predominant ammonia-oxidizers in BAC treatment regardless of the position of rapid sand filtration. The highest nitrification potential was observed for BAC from both processes in February when the highest abundances of AOA-amoA and AOB-amoA genes were detected. Since rapid sand filtration was placed after BAC treatment in Process (A), residual aluminum concentration in BAC influent was higher in Process (A). However, adverse effects of aluminum on nitrification activity were not observed. These results suggest that factors other than aluminum concentration in different treatment processes could possibly have some influence on abundances of ammonia-oxidizing microorganisms on BAC.

  14. Parameter Optimization on Experimental Study to Reduce Ammonia Escape in CO2 Absorption by Ammonia Scrubbing

    Institute of Scientific and Technical Information of China (English)

    Hao Leng; Jianmin Gao; Mingyue He; Min Xie; Qian Du; Rui Sun; Shaohua Wu

    2016-01-01

    In order to research ammonia escape in CO2 absorption by ammonia scrubbing, ammonia escape was studied in CO2 absorption process using the bubbling reactor in different conditions as gas flow rate, CO2 ratio, absorbent temperature and ammonia concentration and quantity of escaped ammonia was measured by chemical titration. The results indicated that, the amount of ammonia escape can be around 20% of original amount in 90 min and the escaped amount will increase with the rise of gas flow rate, absorbent temperature, concentration of ammonia while decrease as CO2 ratio goes up. Through the analysis of the law of ammonia escape, at the same time, combined with ammonia escape and the influence of the relationship between the CO2 absorption efficiency, reducing ammonia escape working condition parameter optimization is given.

  15. Optimization on processing of low-temperature drying of chilled meat by uniform design method%均匀设计法优化冷鲜肉低温干燥工艺

    Institute of Scientific and Technical Information of China (English)

    赵惠麟; 周林

    2014-01-01

    The low-temperature food drying equipment was running at 0-10℃ to simulate the win-ter climate. The chilled meat with little salt and without food additives was dried. Through single factor ex-periment and uniform design method, the optimal processing technology was optimized. The quality differ-ences of product processed by low-temperature drying, natural drying and hot air drying was compared and analyzed. The result showed that the optimal low-temperature drying technology of chilled meat was 60% humidity, dried 72h at 5℃. The quality of product reached the best state with neat appearance, fresh color, cured flavor, smooth taste and modest hardness and the moisture content was 60. 2%. The product processed by low-temperature drying technology had significant advantages compared with natural drying and hot air drying.%利用低温食品干燥机在0~10℃运行,全年模拟冬季气候,用于低盐化无添加风干冷鲜肉,采用单因素实验法和均匀设计法优化了冷鲜肉低温干燥的最佳工艺,并对比分析了低温干燥与自然晾晒及热风干燥两种干燥方式的产品品质差异。结果表明:冷鲜肉的最佳低温干燥工艺为:5℃、60%湿度、干燥72h;产品外观整齐、色泽鲜嫩、腊味浓郁,含水率为60.2%,口感爽滑软硬适中,产品品质达到最佳状态;低温干燥与自然晾晒及热风干燥两种干燥方式相比,低温干燥产品品质优势明显。

  16. Why do insects enter chill coma? Low temperature and high extracellular potassium compromises muscle function in Locusta migratoria

    DEFF Research Database (Denmark)

    Findsen, Anders; Pedersen, Thomas Holm; Nielsen, Ole Bækgaard

    Many insect species enter a comatose state when their body temperature is lowered to a critical limit (critical thermal minimum) but the physiological and cellular processes that underlie chill coma are still unresolved. Several studies have demonstrated that transition into chill-coma involves a...

  17. Low Energy Consumption Technique for Processing Rapeseed with Two—phase Extraction System without Ammonia

    Institute of Scientific and Technical Information of China (English)

    ShiMeiren; QinJinping; 等

    2000-01-01

    The mother liquid of methanol phase obtained from rapeseed two-phase extraction process can directly be reused in large amounts to process rapeseed again together with some fresh methanol phase,so long as it is treated with a litter of proper additives in advance.The ratio of the reused mother liquid may be more than 3/4 of the total amount of the methanol phase needed for processing rapeseed,so the energy consumption can be decreased tremendously.The meal obtained by use of the reused mother liquid keeps the quality as good as those obtained by use of totally fresh methanol phase with light color,weak taste,crispness,good palatability,high protein content,and a low level of glu-cosinolates much more less than that stipulated by the State for the fodder of grade A.

  18. Low Energy Consumption Technique for Processing Rapeseed with Two-phase Extraction System without Ammonia

    Institute of Scientific and Technical Information of China (English)

    Shi Meiren; Qin Jinping; SQian Renyuan

    2000-01-01

    the mother liquid of methanol phase obtained from rapeseed two-phase extraction process can directly be reused in large amounts to process rapeseed again together with some fresh methanol phase, so long as it is treated with a litter of proper additives in advance. The ratio of the reused mother liquid may be more than 3/ 4 of the total amount of the methanol phase needed for processing rapeseed, so the energy consumption can be decreased tremendously. The meal obtained by use of the reused mother liquid keeps the quality as good as those obtained by use of totally fresh methanol phase with light color, weak taste, crispness, good palatability, high protein content, and a low level of glucosinolates much more less than that stipulated by the State for the fodder of grade A.

  19. 冷却肉微生物腐败与冷链系统%Chilled meat microbial spoilage and chill chain system

    Institute of Scientific and Technical Information of China (English)

    金鑫; 周光宏; 徐幸莲

    2012-01-01

    冷却肉极易发生微生物腐败,温度是最关键的影响因素。冷链系统持续的低温能抑制微生物的生长繁殖,预防冷却肉腐败。本文简述了微生物代谢活动对冷却肉腐败的影响,重点将冷链系统分为加工冷链、运输冷链、销售冷链和家庭保藏四部分,分别从概念及存在的问题等方面加以阐述,并展望了其未来有待提高完善的地方。%Chilled meat highly prone to microbial spoilage,temperature seems to be the most important factor that influences the spoilage.Sustained low-temperature of chill chain can inhibit microbial growth and prevent chilled meat spoilage.The effect of microbial metabolism on chilled meat spoilage was briefly introduced.Attention was drawn to the chill chain system which divided into four parts of processing, transportation, retail and domestic storage,and separately discussed the concept and issues of each part. The advance of chilled meat were prosoected as well.

  20. Novel process of bio-chemical ammonia removal from air streams using a water reflux system and zeolite as filter media.

    Science.gov (United States)

    Vitzthum von Eckstaedt, Sebastian; Charles, Wipa; Ho, Goen; Cord-Ruwisch, Ralf

    2016-02-01

    A novel biofilter that removes ammonia from air streams and converts it to nitrogen gas has been developed and operated continuously for 300 days. The ammonia from the incoming up-flow air stream is first absorbed into water and the carrier material, zeolite. A continuous gravity reflux of condensed water from the exit of the biofilter provides moisture for nitrifying bacteria to develop and convert dissolved ammonia (ammonium) to nitrite/nitrate. The down-flow of the condensed water reflux washes down nitrite/nitrate preventing ammonium and nitrite/nitrate accumulation at the top region of the biofilter. The evaporation caused by the inflow air leads to the accumulation of nitrite to extremely high concentrations in the bottom of the biofilter. The high nitrite concentrations favour the spontaneous chemical oxidation of ammonium by nitrite to nitrogen (N2). Tests showed that this chemical reaction was catalysed by the zeolite filter medium and allowed it to take place at room temperature. This study shows that ammonia can be removed from air streams and converted to N2 in a fully aerated single step biofilter. The process also overcomes the problem of microorganism-inhibition and resulted in zero leachate production.

  1. A pilot plant study for CO{sub 2} capture by aqueous ammonia applied to blast furnace gas in iron and steel making process

    Energy Technology Data Exchange (ETDEWEB)

    Young Kim, J.; Han, K.; Dong Chun, H. [CO2 Project, Research Inst. of Industrial Science and Technology, Pohang (Korea, Republic of)

    2009-07-01

    This presentation reported on a study in which carbon dioxide (CO{sub 2}) was captured from a demonstration iron and steel plant using low concentration aqueous ammonia as the absorbent chemical. The pilot plant was designed to process 50 Nm{sup 3}/h of blast furnace gas (BFG). The feed gas contained more than 20 per cent CO{sub 2} at 35 to 60 degrees C. Test runs revealed that the absorption efficiency of CO{sub 2} exceeded 80 per cent with a CO{sub 2} purity of more than 90 per cent in the product stream. The process parameters are currently being studied along with the various salts needed to prevent salt precipitation. It was determined that the use of waste heat recovery technology in the iron and steel-making process can render ammonia-based CO{sub 2} capture technology more economically feasible for the reduction of CO{sub 2}.

  2. Incoporating Ammonia Synthesis for an Offshore Gas-to-Liquid Process

    OpenAIRE

    2016-01-01

    The world energy demand is increasing, and so is the demand for fertilizer to sustain an exponential population growth. Currently, with low oil prices, asso- ciated natural gas is flared off or re-injected into oil reservoirs for enhanced oil recovery (EOR). A gas-to-liquid process (GTL) for offshore applications aboard a foating production, storage, and offoading vessel (FPSO) incorpo- rating Fischer-Tropsch Synthesis (FTS) seeks to reform natural gas into more valuable liq...

  3. Biological Behavior of Anammox Process for Municipal Wastewater Treatment: Effect of Ammonia Removal and Other Parameters

    Directory of Open Access Journals (Sweden)

    *R. Nabizadeh

    2012-09-01

    Full Text Available Historically, nitrogen compound due to major environmental and public health problems have been considered. Anaerobic ammonium oxidation processes were proposed by many advantages such as; novelty, promising method and cost-effective. In this work, we used of anommax process for a wastewater with high C:N ratios and the main parameter likes pH; temperature, NO2/NH4 ratio and behavior of COD, ammonium and nitrite during operation time of 55 days were evaluated. High efficiency in nitrite and ammonium removal is observed at pH values between 7.5 to 8 and operation times between 9 to 23 days. Furthermorethe variation of the nitrite/ammonium ratio done dependence to pH, and a higher ratio was associated with higher pH values. And lower values of NO2/NH4 ratio have occurred with decrease of pH at third phase of anommax process. The average elimination efficiency of COD was occurred about 89.22%, but the removal efficiency of COD in anommax reactor was obtained about 49.5%. Furthermorethe removal efficiency of ammonium and nitrite were provided about 50% for each.

  4. Salicylic acid and methyl jasmonate improve chilling tolerance in cold-stored lemon fruit (Citrus limon).

    Science.gov (United States)

    Siboza, Xolani Irvin; Bertling, Isa; Odindo, Alfred Oduor

    2014-11-15

    Chilling injury (CI) is associated with the degradation of membrane integrity which can be aligned to phenolic oxidation activated by polyphenol oxidase (PPO) and peroxidase (POD), enzymes responsible for tissue browning. Phenylalanine ammonia-lyase (PAL) is a further enzyme prominent in the phenolic metabolism that is involved in acclimation against chilling stress. It was hypothesized that treatment with methyl jasmonate (MJ) and salicylic acid (SA) may enhance chilling tolerance in lemon fruit by increasing the synthesis of total phenolics and PAL by activating the key enzyme regulating the shikimic acid pathway whilst inhibiting the activity of POD and PPO. Lemon fruit were treated with 10μM MJ, 2mM SA or 10μM MJ plus 2mM SA, waxed, stored at -0.5, 2 or 4.5°C for up to 28 days plus 7 days at 23°C. Membrane integrity was studied by investigating membrane permeability and the degree of membrane lipid peroxidation in lemon flavedo following cold storage. The 10μM MJ plus 2mM SA treatment was most effective in enhancing chilling tolerance of lemon fruit, significantly reducing chilling-induced membrane permeability and membrane lipid peroxidation of lemon flavedo tissue. This treatment also increased total phenolics and PAL activity in such tissue while inhibiting POD activity, the latter possibly contributing to the delay of CI manifestation. PPO activity was found to be a poor biochemical marker of CI. Treatment with 10μM MJ plus 2mM SA resulted in an alteration of the phenolic metabolism, enhancing chilling tolerance, possibly through increased production of total phenolics and the activation of PAL and inhibition of POD.

  5. Enrichment of high ammonia tolerant methanogenic culture

    DEFF Research Database (Denmark)

    Fotidis, Ioannis; Karakashev, Dimitar Borisov; Proietti, Nicolas

    Ammonia is the major toxicant in full scale anaerobic digesters of animal wastes which are rich in proteins and/or urea, such as pig or poultry wastes. Ammonia inhibition decreases methane production rates, increases volatile fatty acids concentration and leads to economic losses for the biogas...... plants. The methods used today to counteract ammonia inhibition are slow and costexpensive. A new biological approach to avoid or counteract ammonia inhibition by using ammonia tolerant methanogens, could provide a sustainable solution for cost-effective digestion of abundant ammonia-rich wastes. The aim...... of the current study was to isolate and identify methanogenic cultures tolerant to high ammonia concentrations. A mixed methanogenic population was stepwise exposed to ammonia concentrations (1 to 9.26 g NH4+-N L-1) during an enrichment process with successive batch cultivations. The methanogenic population...

  6. High efficient ammonia heat pump system for industrial process water using the ISEC concept. Part 2

    DEFF Research Database (Denmark)

    Olesen, Martin F.; Madsen, Claus; Olsen, Lars

    2014-01-01

    The Isolated System Energy Charging (ISEC) concept allows for a high efficiency of a heat pump system for hot water production. The ISEC concept consists of two water storage tanks, one charged and one discharged. The charged tank is used for the industrial process, while the discharged tank...... modelling of the heat pump and tank system is performed (in continuation of Part I). The modelling is extended to include the system performance with different natural refrigerants and the influence of different types of compressors....... is charging. The charging of the tank is done by recirculating water through the condenser and thereby gradually heating the water. The modelling of the system is described in Part I [1]. In this part, Part II, an experimental test setup of the tank system is reported, the results are presented and further...

  7. Novel Regenerated Solvent Extraction Processes for the Recovery of Carboxylic Acids or Ammonia from Aqueous Solutions Part I. Regeneration of Amine-Carboxylic Acid Extracts

    Energy Technology Data Exchange (ETDEWEB)

    Poole, L.J.; King, C.J.

    1990-03-01

    Two novel regenerated solvent extraction processes are examined. The first process has the potential to reduce the energy costs inherent in the recovery of low-volatility carboxylic acids from dilute aqueous solutions. The second process has the potential for reducing the energy costs required for separate recovery of ammonia and acid gases (e.g. CO{sub 2} and H{sub 2}S) from industrial sour waters. The recovery of carboxylic acids from dilute aqueous solution can be achieved by extraction with tertiary amines. An approach for regeneration and product recovery from such extracts is to back-extract the carboxylic acid with a water-soluble, volatile tertiary amine, such as trimethylamine. The resulting trimethylammonium carboxylate solution can be concentrated and thermally decomposed, yielding the product acid and the volatile amine for recycle. Experimental work was performed with lactic acid, succinic acid, and fumaric acid. Equilibrium data show near-stoichiometric recovery of the carboxylic acids from an organic solution of Alamine 336 into aqueous solutions of trimethylamine. For fumaric and succinic acids, partial evaporation of the aqueous back extract decomposes the carboxylate and yields the acid product in crystalline form. The decomposition of aqueous solutions of trimethylammonium lactates was not carried out to completion, due to the high water solubility of lactic acid and the tendency of the acid to self-associate. The separate recovery of ammonia and acid gases from sour waters can be achieved by combining steam-stripping of the acid gases with simultaneous removal of ammonia by extraction with a liquid cation exchanger. The use of di-2,4,4-trimethylpentyl phosphinic acid as the liquid cation exchanger is explored in this work. Batch extraction experiments were carried out to measure the equilibrium distribution ratio of ammonia between an aqueous buffer solution and an organic solution of the phosphinic acid (0.2N) in Norpar 12. The concentration

  8. Manure-DNDC: a biogeochemical process model for quantifying greenhouse gas and ammonia emissions from livestock manure systems

    Science.gov (United States)

    From the point of view of biogeochemistry, manure is a complex of organic matter containing minor minerals. When manure is excreted by animals, it undergoes a series of reactions such as decomposition, hydrolysis, ammonia volatilization, nitrification, denitrification, and fermentation from which ca...

  9. Archaeal ammonia oxidation in volcanic grassland soils of Iceland. Effects of elevated temperature and N availability on processes and organisms

    NARCIS (Netherlands)

    Daebeler, A.

    2014-01-01

    Thaumarchaea are recognized today as the most abundant and ubiquitously dis­tributed archaeal organisms, especially in the oceans and soil. Their phylogenetic placement as a phylum, the capability of all cultivated Thaumarchaea to oxidize ammonia for energy conservation as well as many further aspec

  10. Ammonia as efficient fuel for SOFC

    Energy Technology Data Exchange (ETDEWEB)

    Fuerte, A.; Valenzuela, R.X.; Escudero, M.J. [CIEMAT, Departamento de Energia, Av. Complutense 22, 28040 Madrid (Spain); Daza, L. [CIEMAT, Departamento de Energia, Av. Complutense 22, 28040 Madrid (Spain); Instituto de Catalisis y Petroleoquimica (CSIC), C/Marie Curie 2, Campus Cantoblanco, 28049 Madrid (Spain)

    2009-07-01

    Ammonia is a possible candidate as the fuel for SOFCs. In this work, the influence on the performance of a tubular SOFC running on ammonia is studied. Analysis of open circuit voltages (OCVs) on the cell indicated the oxidation of ammonia within a SOFC is a two-stage process: decomposition of the inlet ammonia into nitrogen and hydrogen, followed by oxidation of hydrogen to water. For comparison, cell was also tested with hydrogen as the fuel and air as oxidant at different temperatures showing a similar behaviour. The performance of the cell tested under various conditions shows the high potential of ammonia as fuel for SOFCs. (author)

  11. 氨法制取纳米氧化锌的粒径控制研究%Particle size control of nano - sized zinc oxide by ammonia process

    Institute of Scientific and Technical Information of China (English)

    蔡建国; 蔡睿敏

    2009-01-01

    为有效控制氨法制取纳米氧化锌的粒径,在蒸氨前将浸出原液用一定量的纯净水稀释,可增加初期沉淀生成的晶核数,使沉淀粒径更加均匀和细化,同时发现蒸氨残液不可以作为浸出原液的稀释剂回用.蒸氨的加热方式对纳米氧化锌的粒径也有影响,选择蒸汽直接加热,当溶液含锌质量浓度小于0.3 g/L时,所制取的纳米氧化锌粒径满足GB/T 19589-2004纳米氧化锌的要求 .%In order to effectively control the particle size of nano - sized zinc oxide prepared by ammonia process,leaching stock solution was diluted with a certain amount of purified water before ammonia distillation process,which could increase the quantity of crystal nucleus generated by initial precipitation and make particle size of precipitate more uniform and refined.Meanwhile,it was found that distilled ammonia residual liquid could not be served as diluent of leaching stock solution for recycling.Also,heating method of ammonia distillation will affect the particle size of nano - sized zinc oxide.Particle size of prepared nano - sized zinc oxide can satisfy the requirements of GB/T 19589-2004,when direct steam heating was selected and mass concentration of zinc in the solution was less than 0.3 g/L.

  12. 焦化蒸氨工艺的模拟与优化%Process Simulation and Optimization of the Ammonia Distillation System

    Institute of Scientific and Technical Information of China (English)

    闪俊杰

    2011-01-01

    The software of chemical process simulation was introduced in brief, and the ammonia distillation process of the Tangshan Zhongrun Coal Chemical Co., Ltd. was simulated and optimized operation conditions were obtained. The simulation result showed that the ammonia concentration in the water from the column bottom increased with the increase of the steam quantity, while decreased with the increase of the water quantity. The economic steam consumption was 7t/h when the water feed was 60t/h. ff the steam consumption increased to 10t/h, the maximum handling capacity increased to 85t/h in order to maintain less than 100mg/L mass concentration of ammonia in water. In case the water feed was greater than 90t/h, the concentration of ammonia in water was more than 200mg/L.%简要介绍了化工流程模拟软件,并利用化工流程模拟软件对唐山中润煤化工有限公司的蒸氨工艺进行了模拟,找到最佳操作条件.模拟结果表明:塔底出水氨浓度随蒸汽量的增加而增大,随进水量的增加而降低,当进水量为60t/h时,最经济的蒸汽量为7t/h;当蒸汽量为10t/h时,在保证塔底出水氨质量浓度小于100mg/L的前提下,最大处理能力为85t/h;当进水量>90t/h后,塔底出水氨质量浓度增加到200mg/L以上.

  13. Microbiological evaluation of chicken carcasses in an immersion chilling system with water renewal at 8 and 16 hours.

    Science.gov (United States)

    Souza, L C T; Pereira, J G; Spina, T L B; Izidoro, T B; Oliveira, A C; Pinto, J P A N

    2012-05-01

    Since 2004, Brazil has been the leading exporter of chicken. Because of the importance of this sector in the Brazilian economy, food safety must be ensured by control and monitoring of the production stages susceptible to contamination, such as the chilling process. The goal of this study was to evaluate changes in microbial levels on chicken carcasses and in chilling water after immersion in a chilling system for 8 and 16 h during commercial processing. An objective of the study was to encourage discussion regarding the Brazilian Ministry of Agriculture Livestock and Food Supply regulation that requires chicken processors to completely empty, clean, and disinfect each tank of the chilling system after every 8-h shift. Before and after immersion chilling, carcasses were collected and analyzed for mesophilic bacteria, Enterobacteriaceae, coliforms, and Escherichia coli. Samples of water from the chilling system were also analyzed for residual free chlorine. The results do not support required emptying of the chiller tank after 8 h; these tanks could be emptied after 16 h. The results for all carcasses tested at the 8- and 16-h time points indicated no significant differences in the microbiological indicators evaluated. These data provide both technical and scientific support for discussing changes in federal law regarding the management of immersion chilling water systems used as part of the poultry processing line.

  14. Quantitative risk assessment for hazards that arise from non-proteolytic Clostridium botulinum in minimally processed chilled dairy-based foods.

    Science.gov (United States)

    Malakar, P K; Barker, G C; Peck, M W

    2011-04-01

    A modular process risk model has been constructed that describes the manufacture of dairy dessert products and hazards that arise from non-proteolytic Clostridium botulinum. The model describes batch manufacture and consumer storage of a family size generic dairy dessert but includes a realistic quantification that could apply to a specific food product. The dairy dessert sector is an expanding part of the UK market. The model includes modules that describe spore loads in raw materials, spore inactivation during thermal processing, volume partition and the population kinetics for non-proteolytic C. botulinum during sequential isothermal storage regimes. Where possible elements of uncertainty and variability are identified explicitly. The model is constructed as a belief network from published data and expert opinions. The model provides marginal probabilities, and associated sensitivities, for a range of endpoint measures centred on the toxicity of a single retail unit after an extended period of storage. The decimal reduction time for non-proteolytic C. botulinum spore populations at the highest (hold) temperature of the primary thermal process and the highest temperature experienced during poorly controlled (consumer) storage are dominant factors determining risks. Priorities for additional information to support risk assessments have been identified.

  15. Effects of high-pressure processing on Listeria monocytogenes , spoilage microflora and multiple compound quality indices in chilled cold-smoked salmon

    DEFF Research Database (Denmark)

    Lakshmanan, R.; Dalgaard, Paw

    2004-01-01

    ), 150, 200 and 250 MPa. Secondly, storage trials with the naturally contaminated product and HPP at 0.1 (control) and 200 MPa were realized. Shelf-life, microbial changes and chemical changes were determined and existing predictive models and multiple compound quality indices evaluated. HPP with 250 MPa...... did not inactivate L. monocytogenes but significant lag phases of 17 and 10 days were observed at ca 5 and 10degreesC, respectively. HPP with 200 MPa had a marked effect on both colour and texture of CSS.Conclusions: High-pressure processing was unable to prevent growth of L. monocytogenes or spoilage...... like CSS where consumers expect specific quality attributes....

  16. Understanding and application of catalyst in the process of ammonia synthesis%氨合成中催化剂的理解与应用

    Institute of Scientific and Technical Information of China (English)

    李红伟

    2013-01-01

      文章从催化剂的组成和作用、催化剂的还原原理、催化剂的使用三个方面探讨了自己对催化剂在氨合成中的作用与理解。%This article analyzes personal understanding and application of catalyst in the process of ammonia synthesis from three aspects :the composition and function of catalyst, the catalyst reduction principle, the use of catalyst.

  17. Abundance and diversity of ammonia-oxidizing archaea and bacteria on granular activated carbon and their fates during drinking water purification process.

    Science.gov (United States)

    Niu, Jia; Kasuga, Ikuro; Kurisu, Futoshi; Furumai, Hiroaki; Shigeeda, Takaaki; Takahashi, Kazuhiko

    2016-01-01

    Ammonia is a precursor to trichloramine, which causes an undesirable chlorinous odor. Granular activated carbon (GAC) filtration is used to biologically oxidize ammonia during drinking water purification; however, little information is available regarding the abundance and diversity of ammonia-oxidizing archaea (AOA) and bacteria (AOB) associated with GAC. In addition, their sources and fates in water purification process remain unknown. In this study, six GAC samples were collected from five full-scale drinking water purification plants in Tokyo during summer and winter, and the abundance and community structure of AOA and AOB associated with GAC were studied in these two seasons. In summer, archaeal and bacterial amoA genes on GACs were present at 3.7 × 10(5)-3.9 × 10(8) gene copies/g-dry and 4.5 × 10(6)-4.2 × 10(8) gene copies/g-dry, respectively. In winter, archaeal amoA genes remained at the same level, while bacterial amoA genes decreased significantly for all GACs. No differences were observed in the community diversity of AOA and AOB from summer to winter. Phylogenetic analysis revealed high AOA diversity in group I.1a and group I.1b in raw water. Terminal-restriction fragment length polymorphism analysis of processed water samples revealed that AOA diversity decreased dramatically to only two OTUs in group I.1a after ozonation, which were identical to those detected on GAC. It suggests that ozonation plays an important role in determining AOA diversity on GAC. Further study on the cell-specific activity of AOA and AOB is necessary to understand their contributions to in situ nitrification performance.

  18. Ammonia tolerant enriched methanogenic cultures as bioaugmentation inocula to alleviate ammonia inhibition in continuous anaerobic reactors

    DEFF Research Database (Denmark)

    Fotidis, Ioannis; Wang, Han; Angelidaki, Irini

    Ammonia is the most common inhibitor of anaerobic digestion (AD) process, resulting in suboptimal exploitation of the biogas potential of the feedstocks, causing significant economic losses to the biogas plants. Ammonia is mainly inhibiting the aceticlastic methanogens, while the hydrogenotrophic...... of ammonia-rich organic waste in full-scale continuous reactors.......Ammonia is the most common inhibitor of anaerobic digestion (AD) process, resulting in suboptimal exploitation of the biogas potential of the feedstocks, causing significant economic losses to the biogas plants. Ammonia is mainly inhibiting the aceticlastic methanogens, while the hydrogenotrophic...... methanogens are more robust to ammonia toxicity effect. It has been shown that bioaugmentation of a pure strain of a hydrogenotrophic methanogen (i.e. Methanoculleus bourgensis) in an ammonia inhibited continuous anaerobic reactor can improve methane production more than 30%. Nevertheless, cultivation...

  19. [Music-induced chills as a strong emotional experience].

    Science.gov (United States)

    Mori, Kazuma; Iwanaga, Makoto

    2014-12-01

    While enjoying music and other works of art, people sometimes experience "chills," a strong emotional response characterized by a sensation of goose bumps or shivers. Such experiences differ from having goose bumps as a defense response or from shivering in reaction to cold temperatures. The current paper presents the phenomenon of music-induced chills and reviews the chill-related emotional response, autonomic nervous system activity, and brain activity. It also reviews the musico-acoustic features, listening contexts, and individual differences that cause chills. Based on the review, we propose a hypothetical model regarding the evocation of music-induced chills. Furthermore, we investigate the strong emotional response associated with chills by exploring the relationship between music-related chills and non-music-related chills, and discuss future research directions.

  20. 76 FR 166 - Fresh and Chilled Atlantic Salmon From Norway

    Science.gov (United States)

    2011-01-03

    ... COMMISSION Fresh and Chilled Atlantic Salmon From Norway AGENCY: United States International Trade Commission... on fresh and chilled Atlantic salmon from Norway. SUMMARY: The Commission hereby gives notice that it... and chilled Atlantic salmon from Norway would be likely to lead to continuation or recurrence...

  1. The inheritance of chilling tolerance in tomato (Lycopersicon spp).

    NARCIS (Netherlands)

    Venema, J.H.; Linger, P.; Heusden, van A.W.; Hasselt, van P.R.; Bruggemann, W.

    2005-01-01

    During the past 25 years, chilling tolerance of the cultivated (chilling-sensitive) tomato Lycopersicon esculentum and its wild, chilling-tolerant relatives L. peruvianum and L. hirsutum (and, less intensively studied, L. chilense) has been the object of several investigations. The final aim of thes

  2. The inheritance of chilling tolerance in tomato (Lycopersicon spp.)

    NARCIS (Netherlands)

    Venema, JH; Linger, P; van Heusden, AW; van Hasselt, PR; Brueggemann, W

    2005-01-01

    During the past 25 years, chilling tolerance of the cultivated (chilling-sensitive) tomato Lycopersicon esculentum and its wild, chilling-tolerant relatives L. peruvianum and L. hirsutum (and, less intensively studied, L. chilense) has been the object of several investigations. The final aim of thes

  3. Directional distribution of chilling winds in Estonia

    Science.gov (United States)

    Saue, Triin

    2016-08-01

    Wind chill equivalent temperature (WCET) is used to define thermal discomfort in winter months. Directional distributions of winds, which are associated with uncomfortable weather, were composed of three climatologically different Estonian locations: Vilsandi, Kuusiku, and Jõhvi. Cases with wind chill equivalent temperature Estonia: W, SW, and NW bring warm air in winter from the North Atlantic, while winds from the East-European plain (NE, E, and SE) are associated with cold air. The eastern prevalence was stronger when a lower threshold was used. A directional approach may find several applications, such as building, agricultural, landscape, or settlement planning.

  4. Ammonia effect on hydrogenotrophic methanogens and syntrophic acetate oxidizing bacteria

    DEFF Research Database (Denmark)

    Wang, Han; Fotidis, Ioannis; Angelidaki, Irini

    2015-01-01

    Ammonia-rich substrates can cause inhibition on anaerobic digestion process. Syntrophic acetate oxidizing bacteria (SAOB) and hydrogenotrophic methanogens are important for the ammonia inhibitory mechanism on anaerobic digestion. The roles and interactions of SAOB and hydrogenotrophic methanogens...

  5. Study of the acceleration of ammonia generation process from poultry residues aiming at hydrogen production; Estudo do processo para a aceleracao da geracao de amonia a partir de residuos avicolas visando a producao de hidrogenio

    Energy Technology Data Exchange (ETDEWEB)

    Egute, Nayara dos Santos

    2010-07-01

    The hydrogen, utilized in fuel cells, can be produced from a variety of intermediate chemicals, between them, the ammonia. The ammonia gas as a raw material for the hydrogen production has been used due to its high energetic content, facility of decomposition, high availability, low prices, low storage pressure and its by-products are environmentally correct. One of the sources of ammonia is poultry and egg production systems. In these systems the ammonia is produced from the decomposition of uric acid present in the excreta of birds. The residue from the poultry-rearing farms is the broiler litter and from the egg production system is the excreta without any substrate. The characterization of these residues was performed using the Wavelength-Dispersive X-Ray Fluorescence (WDXRF), Elementary Analysis (CHN), Thermogravimetry and GC/MS - Gas chromatography/ Mass spectrometry. The studied factors which influence the ammonia volatilization were: nitrogen content, raising period, urease enzyme, temperature, pH and moisture content. The experiment results with poultry litter and excreta allow to conclude that the manipulation of the following parameters increased the ammonia emission: pH, nitrogen content, raising period, age of birds and excreta accumulation, urease enzyme and the temperature. The addition of different amounts of sand in the excreta and different volumes of water in the poultry litter inhibited the emission of ammonia. The variation of the quantity of material (broiler litter or excreta) and the volume of the flask used as incubator chamber showed no significant alterations to be chosen as a variable. The excreta was considered more appropriate than poultry litter for the objectives of this work due to the higher ammonia concentrations determined in this material. Due to the large amount of poultry litter and excreta from the production processes, the reuse of poultry residues to obtain ammonia is necessary to improve the quality of the local

  6. Study of the process for accelerating ammonia generation from poultry residues aiming its hydrogen production; Estudo do processo para a aceleracao da geracao de amonia a partir de residuos avicolas visando a producao de hidrogenio

    Energy Technology Data Exchange (ETDEWEB)

    Egute, Nayara dos Santos

    2010-07-01

    The hydrogen, utilized in fuel cells, can be produced from a variety of intermediate chemicals, between them, the ammonia. The ammonia gas as a raw material for the hydrogen production has been used due to its high energetic content, facility of decomposition, high availability, low prices, low storage pressure and its by-products are environmentally correct. One of the sources of ammonia is poultry and egg production systems. In these systems the ammonia is produced from the decomposition of uric acid present in the excreta of birds. The residue from the poultry-rearing farms is the broiler litter and from the egg production system is the excreta without any substrate. The characterization of these residues was performed using the wavelength-dispersive X-ray fluorescence (WDXRF), elementary analysis (CHN), thermogravimetry and GC/MS - gas chromatography/ mass spectrometry. The studied factors which influence the ammonia volatilization were: nitrogen content, raising period, urease enzyme, temperature, pH and moisture content. The experiment results with poultry litter and excreta allow to conclude that the manipulation of the following parameters increased the ammonia emission: pH, nitrogen content, raising period, age of birds and excreta accumulation, urease enzyme and the temperature. The addition of different amounts of sand in the excreta and different volumes of water in the poultry litter inhibited the emission of ammonia. The variation of the quantity of material (broiler litter or excreta) and the volume of the flask used as incubator chamber showed no significant alterations to be chosen as a variable. The excreta was considered more appropriate than poultry litter for the objectives of this work due to the higher ammonia concentrations determined in this material. Due to the large amount of poultry litter and excreta from the production processes, the reuse of poultry residues to obtain ammonia is necessary to improve the quality of the local

  7. Ammonia stripping, activated carbon adsorption and anaerobic biological oxidation as process combination for the treatment of oil shale wastewater.

    Science.gov (United States)

    Alexandre, Verônica M F; do Nascimento, Felipe V; Cammarota, Magali C

    2016-10-01

    Anaerobic biodegradability of oil shale wastewater was investigated after the following pretreatment sequence: ammonia stripping and activated carbon adsorption. Anaerobic biological treatment of oil shale wastewater is technically feasible after stripping at pH 11 for reducing the N-NH3 concentration, adsorption with 5 g/L of activated carbon in order to reduce recalcitrance and pH adjustment with CO2 so that the sulphate concentration in the medium remains low. After this pretreatment sequence, it was possible to submit the wastewater without dilution to an anaerobic treatment with 62.7% soluble chemical oxygen demand removal and specific methane production of 233.2 mL CH4STP/g CODremoved.

  8. Inhibiting Wet Oxidation of Ammonia

    Science.gov (United States)

    Onisko, D. B. L.

    1985-01-01

    Simple modification of wet-oxidation process for treating organicwaste reduces loss of fixed nitrogen, potentially valuable byproduct of process. Addition of sufficient sulfuric acid to maintain reaction pH below 3 greatly reduces oxidation of ammonia to free nitrogen. No equipment modification required.

  9. A demonstration of chill block melt spinning of metal

    Science.gov (United States)

    Pond, Robert B.

    1990-01-01

    One of the most exciting adventures in materials in recent times has been the discovery of amorphous metals and the pursuit of methods of manufacturing various alloys into various shapes which are amorphous. Some of these alloys possess electrical properties which are extremely beneficial, whereas others offer different benefits such as corrosion resistence and no solidification shrinkage anomalies. There are a number of techniques for producing such amorphous shapes, but one of the earliest systems used is referred to as chill block melt spinning. The object of this demonstration is to show the simplicity of the process. The equipment and procedures are described.

  10. On the accretion process in a high-mass star forming region - A multitransitional THz Herschel-HIFI study of ammonia toward G34.26+0.15

    CERN Document Server

    Hajigholi, M; Wirström, E S; Black, J H; Bergman, P; Olofsson, A O H; Olberg, M; Wyrowski, F; Coutens, A; Hjalmarson, Å; Menten, K M

    2016-01-01

    [Abridged] Our aim is to explore the gas dynamics and the accretion process in the early phase of high-mass star formation. The inward motion of molecular gas in the massive star forming region G34.26+0.15 is investigated by using high-resolution profiles of seven transitions of ammonia at THz frequencies observed with Herschel-HIFI. The shapes and intensities of these lines are interpreted in terms of radiative transfer models of a spherical, collapsing molecular envelope. An accelerated Lambda Iteration (ALI) method is used to compute the models. The seven ammonia lines show mixed absorption and emission with inverse P-Cygni-type profiles that suggest infall onto the central source. A trend toward absorption at increasingly higher velocities for higher excitation transitions is clearly seen in the line profiles. The $J = 3\\leftarrow2$ lines show only very weak emission, so these absorption profiles can be used directly to analyze the inward motion of the gas. This is the first time a multitransitional study...

  11. Cd{sub 1−x}Zn{sub x}S thin films with low Zn content obtained by an ammonia-free chemical bath deposition process

    Energy Technology Data Exchange (ETDEWEB)

    Carreón-Moncada, I. [Centro de Investigación y de Estudios Avanzados del IPN, Unidad Saltillo, Av. Industria Metalúrgica 1062, CP. 25900, Ramos Arizpe, Coah., México (Mexico); González, L.A., E-mail: luis.gonzalez@cinvestav.edu.mx [Centro de Investigación y de Estudios Avanzados del IPN, Unidad Saltillo, Av. Industria Metalúrgica 1062, CP. 25900, Ramos Arizpe, Coah., México (Mexico); Pech-Canul, M.I. [Centro de Investigación y de Estudios Avanzados del IPN, Unidad Saltillo, Av. Industria Metalúrgica 1062, CP. 25900, Ramos Arizpe, Coah., México (Mexico); Ramírez-Bon, R. [Centro de Investigación y de Estudios Avanzados del IPN, Unidad Querétaro, Apartado Postal 1-798, CP. 76001 Querétaro, Qro., México (Mexico)

    2013-12-02

    Cd{sub 1−x}Zn{sub x}S films with low Zn content were obtained on glass substrates by an ammonia-free chemical bath deposition process. Alkaline reaction solutions were prepared using cadmium chloride, zinc chloride, sodium citrate, thiourea and potassium hydroxide. As a result of varying the mixture ratio between Cd and Zn precursors, microstructural studies from X-ray diffraction reveal that the resulting films have hexagonal, wurzite type, crystalline structure with changes in the preferential growth orientation. Important changes on the surface morphology and thickness of the Cd{sub 1−x}Zn{sub x}S films were also observed as effects of adding Zn to the CdS lattice. Optical studies show that Cd{sub 1−x}Zn{sub x}S thin films with energy band gaps in the range from 2.48 to 2.65 eV were obtained. - Highlights: • Cd{sub 1−x}Zn{sub x}S layers were grown on glass by ammonia-free chemical bath deposition • Films with low Zn content were obtained using reaction solutions with pH11.5 • Zn addition produced changes on the orientation growth and morphology of the films • Cd{sub 1−x}Zn{sub x}S films have energy band gap values from 2.48 to 2.65 eV.

  12. Chilling-Mediated DNA Methylation Changes during Dormancy and Its Release Reveal the Importance of Epigenetic Regulation during Winter Dormancy in Apple (Malus x domestica Borkh.).

    Science.gov (United States)

    Kumar, Gulshan; Rattan, Usha Kumari; Singh, Anil Kumar

    2016-01-01

    Winter dormancy is a well known mechanism adopted by temperate plants, to mitigate the chilling temperature of winters. However, acquisition of sufficient chilling during winter dormancy ensures the normal phenological traits in subsequent growing period. Thus, low temperature appears to play crucial roles in growth and development of temperate plants. Apple, being an important temperate fruit crop, also requires sufficient chilling to release winter dormancy and normal phenological traits, which are often associated with yield and quality of fruits. DNA cytosine methylation is one of the important epigenetic modifications which remarkably affect the gene expression during various developmental and adaptive processes. In present study, methylation sensitive amplified polymorphism was employed to assess the changes in cytosine methylation during dormancy, active growth and fruit set in apple, under differential chilling conditions. Under high chill conditions, total methylation was decreased from 27.2% in dormant bud to 21.0% in fruit set stage, while no significant reduction was found under low chill conditions. Moreover, the demethylation was found to be decreased, while methylation increased from dormant bud to fruit set stage under low chill as compared to high chill conditions. In addition, RNA-Seq analysis showed high expression of DNA methyltransferases and histone methyltransferases during dormancy and fruit set, and low expression of DNA glcosylases during active growth under low chill conditions, which was in accordance with changes in methylation patterns. The RNA-Seq data of 47 genes associated with MSAP fragments involved in cellular metabolism, stress response, antioxidant system and transcriptional regulation showed correlation between methylation and their expression. Similarly, bisulfite sequencing and qRT-PCR analysis of selected genes also showed correlation between gene body methylation and gene expression. Moreover, significant association

  13. Chilling-Mediated DNA Methylation Changes during Dormancy and Its Release Reveal the Importance of Epigenetic Regulation during Winter Dormancy in Apple (Malus x domestica Borkh..

    Directory of Open Access Journals (Sweden)

    Gulshan Kumar

    Full Text Available Winter dormancy is a well known mechanism adopted by temperate plants, to mitigate the chilling temperature of winters. However, acquisition of sufficient chilling during winter dormancy ensures the normal phenological traits in subsequent growing period. Thus, low temperature appears to play crucial roles in growth and development of temperate plants. Apple, being an important temperate fruit crop, also requires sufficient chilling to release winter dormancy and normal phenological traits, which are often associated with yield and quality of fruits. DNA cytosine methylation is one of the important epigenetic modifications which remarkably affect the gene expression during various developmental and adaptive processes. In present study, methylation sensitive amplified polymorphism was employed to assess the changes in cytosine methylation during dormancy, active growth and fruit set in apple, under differential chilling conditions. Under high chill conditions, total methylation was decreased from 27.2% in dormant bud to 21.0% in fruit set stage, while no significant reduction was found under low chill conditions. Moreover, the demethylation was found to be decreased, while methylation increased from dormant bud to fruit set stage under low chill as compared to high chill conditions. In addition, RNA-Seq analysis showed high expression of DNA methyltransferases and histone methyltransferases during dormancy and fruit set, and low expression of DNA glcosylases during active growth under low chill conditions, which was in accordance with changes in methylation patterns. The RNA-Seq data of 47 genes associated with MSAP fragments involved in cellular metabolism, stress response, antioxidant system and transcriptional regulation showed correlation between methylation and their expression. Similarly, bisulfite sequencing and qRT-PCR analysis of selected genes also showed correlation between gene body methylation and gene expression. Moreover

  14. Chilling-Mediated DNA Methylation Changes during Dormancy and Its Release Reveal the Importance of Epigenetic Regulation during Winter Dormancy in Apple (Malus x domestica Borkh.)

    Science.gov (United States)

    Kumar, Gulshan; Rattan, Usha Kumari; Singh, Anil Kumar

    2016-01-01

    Winter dormancy is a well known mechanism adopted by temperate plants, to mitigate the chilling temperature of winters. However, acquisition of sufficient chilling during winter dormancy ensures the normal phenological traits in subsequent growing period. Thus, low temperature appears to play crucial roles in growth and development of temperate plants. Apple, being an important temperate fruit crop, also requires sufficient chilling to release winter dormancy and normal phenological traits, which are often associated with yield and quality of fruits. DNA cytosine methylation is one of the important epigenetic modifications which remarkably affect the gene expression during various developmental and adaptive processes. In present study, methylation sensitive amplified polymorphism was employed to assess the changes in cytosine methylation during dormancy, active growth and fruit set in apple, under differential chilling conditions. Under high chill conditions, total methylation was decreased from 27.2% in dormant bud to 21.0% in fruit set stage, while no significant reduction was found under low chill conditions. Moreover, the demethylation was found to be decreased, while methylation increased from dormant bud to fruit set stage under low chill as compared to high chill conditions. In addition, RNA-Seq analysis showed high expression of DNA methyltransferases and histone methyltransferases during dormancy and fruit set, and low expression of DNA glcosylases during active growth under low chill conditions, which was in accordance with changes in methylation patterns. The RNA-Seq data of 47 genes associated with MSAP fragments involved in cellular metabolism, stress response, antioxidant system and transcriptional regulation showed correlation between methylation and their expression. Similarly, bisulfite sequencing and qRT-PCR analysis of selected genes also showed correlation between gene body methylation and gene expression. Moreover, significant association

  15. Ammonia synthesis at low temperatures

    DEFF Research Database (Denmark)

    Rod, Thomas Holm; Logadottir, Ashildur; Nørskov, Jens Kehlet

    2000-01-01

    Density functional theory (DFT) calculations of reaction paths and energies for the industrial and the biological catalytic ammonia synthesis processes are compared. The industrial catalyst is modeled by a ruthenium surface, while the active part of the enzyme is modeled by a MoFe6S9 complex...... have been carried out to evaluate its feasibility. The calculations suggest that it might be possible to catalytically produce ammonia from molecular nitrogen at low temperatures and pressures, in particular if energy is fed into the process electrochemically. (C) 2000 American Institute of Physics....

  16. Transcriptome Analysis of Pepper (Capsicum annuum Revealed a Role of 24-epibrassinolide in Response to Chilling

    Directory of Open Access Journals (Sweden)

    Li Jie

    2016-08-01

    Full Text Available Brassinosteroids (BRs have positive effects on many processes during plant growth, development, and various abiotic stress responses. However, little information is available regarding the global gene expression of BRs in response to chilling stress in pepper. In this study, we used RNA sequencing to determine the molecular roles of 24-epibrassinolide (EBR during a chilling stress response. There were 39,829 transcripts, and, among them, 656 were differently-expressed genes (DEGs following EBR treatment (Chill+EBR compared with the control (Chill only, including 335 up-regulated and 321 down-regulated DEGs. We selected 20 genes out of the 656 DEGs for RT-qPCR analysis to confirm the RNA-Seq. Based on GO enrich and KEGG pathway analysis, we found that photosynthesis was significantly up-enriched in biological processes, accompanied by significant increases in the net photosynthetic rate (Pn, Fv/Fm and chlorophyll content. Furthermore, the results indicate that EBR enhanced endogenous levels of salicylic acid (SA and jasmonic acid (JA while suppressing the ethylene (ETH biosynthesis pathway, suggesting that BRs function via a synergistic cross-talk with SA, JA and ETH signaling pathways in response to chilling stress. In addition, EBR induced cellulose synthase-like protein and UDP-glycosyltransferase, suggesting a contribution to the formation of cell wall and hormone metabolism. EBR also triggered the calcium signaling transduction in cytoplasm, and activated the expression of cellular redox homeostasis related genes, such as GSTX1, PER72, and CAT2. This work, therefor, identified the specific genes showed different expression patterns in EBR-treated pepper and associated with the processes of hormone metabolism, redox, signaling, transcription and defense. Our study provides the first evidence of the potent roles of BRs, at the transcription level, to induce the tolerance to chilling stress in pepper as a function of the combination of the

  17. Argon purge gas cooled by chill box

    Science.gov (United States)

    Spiro, L. W.

    1966-01-01

    Cooling argon purge gas by routing it through a shop-fabricated chill box reduces charring of tungsten inert gas torch head components. The argon gas is in a cooled state as it enters the torch and prevents buildup of char caused by the high concentrations of heat in the weld area during welding operations.

  18. Guns on Campus: A Chilling Effect

    Science.gov (United States)

    Mash, Kenneth M.

    2013-01-01

    The author of this article observes that, while much has been written on the overall topic of safety with regard to allowing guns on college campuses, little has been said about how allowing the possession of deadly weapons can create a "chilling effect" on academic discussions. This article considers how some universities have…

  19. Ammonia Sensor Using Wavelength Modulation Spectroscopy

    KAUST Repository

    Farooq, Aamir

    2015-09-01

    An ammonia sensor can include a laser detector configured to provide stable sample readings. The sensor can implement a method including processing the recorded intensity of the laser beam to determine a first harmonic component and a second harmonic component and the amount of ammonia in the sample.

  20. Control of core index in gasification ammonia synthesis process%对造气、氨合成工段几项工艺指标控制的认识

    Institute of Scientific and Technical Information of China (English)

    郭文龙; 王杰

    2015-01-01

    This paper introduces control and regulation of core index in gasification ammonia synthesis process at small and medium size synthesis ammonia companies which using coal as raw material. It also introduces key factors in effecting process indexes.%简要介绍了以煤为原料的中小型合成氨厂的造气、氨合成工段几项工艺指标的控制、调节及影响工艺指标的关键因素.

  1. 基于Aspen Plus的稀氨水吹脱工艺流程模拟%Simulation for Stripping Process flow of Dilute Ammonia Liquor Based on Aspen Plus

    Institute of Scientific and Technical Information of China (English)

    任苏孟; 陈洁; 宣爱国; 李志刚

    2014-01-01

    为了降低合成氨工艺中稀氨水的排放浓度,使用Aspen Plus 软件对氨水吹脱过程进行模拟计算,在满足塔底氨含量小于0.5%的要求下,得出吹脱塔适宜的操作参数:进料空气流量为500 kg/h,进料氨水温度为60℃,理论塔板为6块,选用50 mm钢制矩鞍环填料,塔径为1.4 m。%In order to decrease the concentration of diluted ammonia water emissions in synthetic ammonia process , the ammonia water stripping process was simulated based on Aspen Plus software.Under satisfying the condition that ammonia content in the tower bottom was less than 0.5%, the suitable operation parameters were obtained for the air stripping tower .The feeding temperature of ammonia water was 60℃, number of theoretical tower plates was 6, the feeding air flow was 500 kg/h, and the diameter of the stripping tower was 1.4 m with φ50 steel INTX packing selected.

  2. Gas Exchange and Co-regulation of Photochemical and Nonphotochemical Quenching in Bean during Chilling at Ambient and Elevated Carbon Dioxide.

    Science.gov (United States)

    Melkonian, Jeffrey; Owens, Thomas G; Wolfe, David W

    2004-01-01

    The effects of elevated (700 micromol mol(-1)) and ambient (350 micromol mol(-1)) CO(2) on gas exchange parameters and chlorophyll fluorescence were measured on bean (Phaseolus vulgaris) during 24 h chilling treatments at 6.5 degrees C. Consistent with previous research on this cultivar, photosynthetic decline during chilling was not significantly affected by CO(2) while post-chilling recovery was more rapid at elevated compared to ambient CO(2). Our primary focus was whether there were also CO(2)-mediated differences in demand on nonphotochemical quenching (NPQ) processes during the chilling treatments. We found that photosystem II quantum yield and total NPQ were similar between the CO(2) treatments during chilling. In both CO(2) treatments, chilling caused a shift from total NPQ largely composed of q(E), the protective, rapidly responding component of NPQ, to total NPQ dominated by the more slowly relaxing q(I), related to both protective and damage processes. The switch from q(E) to q(I) during chilling was more pronounced in the elevated CO(2) plants. Using complementary plots of the quantum yields of photochemistry and NPQ we demonstrate that, despite CO(2) effects on the partitioning of NPQ into q(E) and q(I) during chilling, total NPQ was regulated at both CO(2) levels to maximize photochemical utilization of absorbed light energy and dissipate only that fraction of light energy that was in excess of the capacity of photosynthesis. Photodamage did occur during chilling but was repaired within 3 h recovery from chilling in both CO(2) treatments.

  3. Modelling of ammonia emissions from dairy cow houses

    OpenAIRE

    Monteny, G.J.

    2000-01-01

    Dairy cow husbandry contributes to environmental acidification through the emission of ammonia. In-depth knowledge on the processes and variable factors that play a role in the emission of ammonia from dairy cow houses benefits the production of emission data, the development of low emission housing systems, and evaluation of emission levels in a farming system approach. A mechanistic simulation model for the ammonia emission from dairy cow houses was developed to facilitate this.An ammonia p...

  4. Thermal sensitivity of excitation-contraction-coupling in a chill susceptible insect, Locusta migratoria

    DEFF Research Database (Denmark)

    Findsen, Anders; Pedersen, Thomas Holm; Overgaard, Johannes

    Many insect species enter a state of neuromuscular paralysis when their body temperature is lowered to a critical limit but the physiological and cellular processes underlying this chill coma are largely unknown. Previous studies on locusts show that muscle force production is highly depressed at...

  5. FORMATION OF WEAR-RESISTANT CHROMIUM CAST IRON CASTING INTO THE CHILL MOLD

    Directory of Open Access Journals (Sweden)

    E. I. Marukovich

    2013-01-01

    Full Text Available The analysis of thermal processes of formation of castings from wearproof chromic cast irons for replaceable details of centrifugal mills and crushers is carried out. Influence of protective and dividing coverings on intensity of heating of the chill mold is investigated.

  6. Simulation Study of Al-1Mn/Al-10Si Circular Clad Ingots Prepared by Direct Chill Casting

    Science.gov (United States)

    Wu, Li; Kang, Huijun; Chen, Zongning; Fu, Ying; Wang, Tongmin

    2016-02-01

    A modified direct chill casting process based on Novelis FusionTM Technology co-casting process was used recently to prepare Al-1Mn/Al-10Si circular clad ingots. In the current study, a comprehensive simulation model was developed to investigate the direct chill casting process for preparing the Al-1Mn/Al-10Si circular clad ingots, and a parametric study and experimental research of the direct chill casting process was conducted to explore potential success and failure casting conditions. The simulation results revealed the bonding mechanism of the Al-1Mn/Al-10Si interface in the direct chill casting process and identified the effect of certain parameters on casting performance. The results indicated that the effect of casting speed and Al-1Mn casting temperature on the variations of the minimum solid fraction of Al-1Mn at the interface is stronger than that of cooling water flow rate in inner mold, while Al-10Si casting temperature is the weakest of the four casting parameters. The corresponding experimental results verified that Al-1Mn/Al-10Si circular clad ingot with acceptable metallurgical bonding can be successfully prepared by direct chill casting process under the proper casting parameters. The thickness of diffusion zone is about 40 μm, and the fractured position in tensile test was located in the Al-1Mn alloy side which indicated the strength of the interfacial region is higher than that of Al-1Mn alloy.

  7. Higher Chilling-Tolerance of Grafted-Cucumber Seedling Leaves upon Exposure to Chilling Stress

    Institute of Scientific and Technical Information of China (English)

    LI Jian-yong; TIAN Hai-xia; LI Xin-guo; MENG Jing-jing; HE Qi-wei

    2008-01-01

    The roots of figleaf gourd (Cucurbita ficifolia, as rootstock) could improve the resistance of cucumber plants (Cucumis sativus L. cv. Jinyan 4, as scion) to low temperature. In this experiment, the root activity and photosynthetic activity of photosystems in the own-rooted and grafted-cucumber plants were studied at chilling temperature (4℃) under low irradiance (100 μmol m-2 s-1 PFD). Compared with dark adaptation seedlings, the chlorophyll a fluorescence transient curve and the oxidizable P700 (P700+) of both the own-rooted and grafted seedlings decreased, and PS2 and PSl of the own-rooted seedling leaves were more inhibited than that of grafted ones at the end of chilling stress. The reduced triphenyltetrazolium chloride (TTC), which was used to reflect the root activity, kept stable in grafted seedling roots at the end of chilling stress, while it decreased noticeably in the own-rooted seedling roots. These results implied that the root system activity of the grafted seedling roots was higher than that of the own-rooted ones. Superoxide dismutase (SOD) activity was higher in both the grafted seedling roots and leaves than that in own-rooted seedlings at both room temperature and chilling temperature. Upon exposure to chilling stress, the malondialdehyde (MDA) content, which reflects the degree of lipid peroxidation, increased markedly in the own-rooted seedling roots and leaves and kept stable in the grafted-cucumber seedlings.

  8. Study of Ammonia Emissions in a Ventilated Pig Pen

    DEFF Research Database (Denmark)

    Rong, Li

    Pig productions cause a wide emission of odors, such as ammonia (NH3), hydrogen sulfide (H2S), and methane (CH4). Ammonia is one of the most important emissions for evaluating the air quality either in animal buildings or atmospheric environment. In studies of ammonia emission from animal buildings...... solution temperatures. The results show that the diffusive ceiling ventilation system can provide a relative low velocity in the pig pen and decrease ammonia emissions from the pig pen, but this ventilation system causes high ammonia concentration distribution in the animal occupied zone. Further, our...... reported in literature, little effort has been made to investigate the accuracy of current Henry’s law constant for modeling ammonia mass transfer process and study ammonia emissions in a full scale pig pen from fluid dynamics by CFD simulations. This will be the main objectives of this study. The ammonia...

  9. An innovative bioelectrochemical-anaerobic digestion-coupled system for in-situ ammonia recovery and biogas enhancement: process performance and microbial ecology

    DEFF Research Database (Denmark)

    Zhang, Yifeng; Angelidaki, Irini

    (SMRC) and a continuous stirred tank reactor (CSTR), to prevent ammonia toxicity during anaerobic digestion by in-situ ammonia recovery and electricity production. In batch experiment, the ammonia concentration in the CSTR decreased from 6 to 0.7 g-N/L with an average recovery rate of 0.18 g......-N/L(CSTR)/d. Meanwhile, a maximum power density of 0.71±0.5 W/m2 was produced (10 Ω). Both current driven NH4+ migration and free NH3 diffusion were identified as the mechanisms responsible for the ammonia transportation. With an increase in initial ammonia concentration and a decrease in external resistance, the SMRC...

  10. Fracture analysis of chilled cast iron camshaft

    OpenAIRE

    Li Ping; Li Fengjun; Cai Anke

    2009-01-01

    The fracture of a camshaft made of chilled cast iron, installed in a home-made Fukang car, happened only after running over a distance of 6,200 km. The fractured camshaft was received to conduct a series of failure analyses using visual inspection, SEM observation of fracture section, microstructure analysis, chemical composition analysis and hardness examination and so on, while those of CKD camshaft made by Citro雗 Company in France was also simultaneously analyzed to compare the difference ...

  11. 非等压醇烷化工艺技术在合成氨厂的应用%Application of non-isobaric methanolizing-methanation process in ammonia plant

    Institute of Scientific and Technical Information of China (English)

    刘俊兰

    2012-01-01

    介绍了合成气净化的几种方法并进行了比较,重点介绍了非等压醇烷化工艺在合成氨厂的应用情况.采用非等压醇烷化工艺对氨合成的补充气进行精制,可以制得高纯度合成气,满足氨合成需要,同时副产甲醇.应用结果表明,该工艺能降低消耗,提高企业经济效益,是一种性价比较高的净化气精制工艺,适合用于合成技术改造.%Several processes for synthesis gas purification are presented and compared. The application of non-isobaric methanol-izing-methanation process in ammonia plant is described with emphasis. The refinement of supplemental gas in ammonia synthesis using the non-isobaric methanolizing-methanation technology can obtain high purity synthesis gas for the ammonia synthesis and co-produce methanol. The results of application indicate that the process is a high performance-price ratio technology which can reduce consump-tion, increase enterprise economic benefits and is suitable for ammonia synthesis technical transformation.

  12. Cook & Chill - Rapid Chilling of Food 'in situ'

    DEFF Research Database (Denmark)

    Paul, Joachim

    2003-01-01

    Rapid cooling of products is of increasing importance for food preservation and for industrial processes. Slurry ice (Binary Ice) is a two-phase cooling fluid consisting of suspended ice crystals in an aqueous solution or mixture. Latent energy contained in the fluid yields rapid cooling which is...

  13. 硫酸四氨合铜结晶过程的粒度控制技术%Particle Size Control Technology of Copper Sulfate-ammonia Complex Solution in Crystallization Process

    Institute of Scientific and Technical Information of China (English)

    张楠; 冯璐璐; 柳沛宏

    2014-01-01

    氨水和硫酸铜溶液反应形成铜氨溶液,之后与乙醇混合使硫酸四氨合铜以晶体形式析出,过滤、干燥制备硫酸四氨合铜晶体。考察不同操作条件对硫酸四氨合铜晶体粒度分布的影响。结果表明,析出过程中加入合适的表面活性剂对粒度分布有一定影响,混料时以铜氨溶液分散加入到乙醇中效果较好,适当增加乙醇用量和提高搅拌强度有利于得到小粒度产品。%Ammonia reacted with copper sulfate solution to form copper sulfate-ammonia complex solution, and then the solution mixed with ethanol to form copper sulfate-ammonia complex crystal. After filtration and desiccation, copper sulfate-ammonia complex crystal was prepared. The influence of different operation conditions on copper sulfate-ammonia complex crystal size distribution was investigated. The results showed that in the precipitation process, the addition of suitable surface active agent had a certain influence on the particle size distribution. And it had good effect when copper sulfate-ammonia solution dispersed into ethanol. Increase of ethanol amount and stirring strength would get fine grain products.

  14. Comparative Proteomic Analysis of Rice at Filling Stage under Chilling Stress

    Institute of Scientific and Technical Information of China (English)

    Ying Wang; Weitong Cui; Shihua Shen

    2012-01-01

    Using comparative proteomic analysis,we carried out an investigation aiming at a better understanding of the molecular mechanisms of chilling stress adaptation in rice (O.sativa L.ssp.indica cultivar 93-11) at early filling stage.The rice plants at early filling stage were exposed to 12℃ for 6 h,12 h,24 h,48 h.Analysis of the dynamic proteome profile of the uppermost internodes showed that 99 protein spots were differentially expressed during this process.Among them,45 protein spots were found to be up-regulated and 54 protein spots were down-regulated in responding to chilling stress.81 protein spots were successfully identified through MALDITOF MS and database searching.Those identified proteins were the products of 65 genes,and could be sorted into 8 functional categories.Among them,secondary metabolism related proteins such as S-adenosylmethionine synthetase were up-regulated.That lignification-related proteins were up-regulated by chilling stress indicated the uppermost internodes supporting ear would be enhanced to resist the chilling stress.

  15. 氨合成系统开车初期避免设备结冰损坏的方式比较%Comparison of Equipment Freezing Damage Avoidance Processes during Initial Start ̄up of Ammonia Synthesis System

    Institute of Scientific and Technical Information of China (English)

    李雁

    2015-01-01

    Author has introduced 3 processes for avoiding equipment freezing damage during initial start ̄up of ammonia synthesis system, i. e. manu ̄al pressure control process, ammonia injection process and gas once passage. Expatiated upon the ammonia injection process principles and made analysis and comparison on these three processes from the viewpoint of process, and gave out preliminary recommendations for selection of start ̄up processes.%介绍了氨合成系统开车初期避免设备结冰损坏的3种主要方式,即手动控制压力流程、注氨流程和气体一次性通过流程。着重阐述了注氨流程的原理,并从工艺的角度对3种流程进行了分析和比较,对开车方式的选择给出了初步建议。

  16. 纯碱生产蒸氨过程智能优化控制及其应用%Intelligent optimization control and its application in ammonia distillation process for soda manufacturing

    Institute of Scientific and Technical Information of China (English)

    杨马英; 金晓明; 施晓珍

    2014-01-01

    In order to improve the automatic level of steamed ammonia production,save energy and reduce consumption in soda manufacture,this paper proposes an intelligent coordinated optimization control strategy for the ammonia distillation process,based on predictive control of single ammonia distillation towers. Facing the operation of ammonia process with large time delay,time-varying,mult-ivariable coupling and parallel operation of distillation towers, the dynamic mathematical model of ammonia evaporation tower is established. Afterwards the two layer optimization control of single towers is cooperated with multi-tower intelligent coordination and optimization, the intelligent optimization control of ammonia process is thus realized. Simulation results and industrial application illustrate that the strategies achieve better control performance,reduce 0. 21 kg ammonia and 16 kg steam consumptions per ton of soda.%为了提高纯碱生产蒸氨过程的综合自动化水平、实现节能降耗,该文在单座蒸氨塔预测控制的基础上,提出了一种蒸氨过程智能协调优化控制策略。针对蒸氨过程大时滞、时变、多变量耦合等复杂特性和多座蒸氨塔并行作业的运行情况,建立了蒸氨塔动态数学模型,并将单塔两层优化控制与多塔智能协调优化相结合,实现了蒸氨过程的智能优化控制。仿真与工业应用结果表明,上述方法不仅能明显改善过程控制性能,而且能实现每吨纯碱降低氨耗0.21 kg、蒸汽消耗16 kg的节能降耗效果。

  17. Treatment of ammonia by catalytic wet oxidation process over platinum-rhodium bimetallic catalyst in a trickle-bed reactor: effect of pH.

    Science.gov (United States)

    Hung, Chang-Mao; Lin, Wei-Bang; Ho, Ching-Lin; Shen, Yun-Hwei; Hsia, Shao-Yi

    2010-08-01

    This work adopted aqueous solutions of ammonia for use in catalytic liquid-phase reduction in a trickle-bed reactor with a platinum-rhodium bimetallic catalyst, prepared by the co-precipitation of chloroplatinic acid (H2PtCl6) and rhodium nitrate [Rh(NO3)3]. The experimental results demonstrated that a minimal amount of ammonia was removed from the solution by wet oxidation in the absence of any catalyst, while approximately 97.0% of the ammonia was removed by wet oxidation over the platinum-rhodium bimetallic catalyst at 230 degrees C with an oxygen partial pressure of 2.0 MPa. The oxidation of ammonia has been studied as a function of pH, and the main reaction products were determined. A synergistic effect is manifest in the platinum-rhodium bimetallic structure, in which the material has the greatest capacity to reduce ammonia. The reaction pathway linked the oxidizing ammonia to nitric oxide, nitrogen, and water.

  18. Vaporization reduction characteristics of aqueous ammonia solutions by the addition of ethylene glycol, glycerol and glycine to the CO2 absorption process

    Institute of Scientific and Technical Information of China (English)

    Jong-Beom Seo; Soo-Bin Jeon; Je-Young Kim; Gang-Woo Lee; Jong-Hyeon Jung; Kwang-Joong Oh

    2012-01-01

    Aqueous ammonia(NH3)solution can be used as an alternative absorption for the control of CO2 emitted from flue gases due to its high absorption capacity,fast absorption rate and low corrosion problem.The emission of CO2 from iron and steel plants requires much attention,as they are higher than those emitted from power plants at a single point source.In the present work,low concentration ammonia liquor,9 wt.%,was used with various additives to obtain the kinetic properties using the blast furnace gas model.Although a solution with a high ammonia concentration enables high CO2 absorption efficiency,ammonium ions are lost as ammonia vapor,resulting in reduced CO2 absorption due to the lower concentration of the ammonia absorbent.To decrease the vaporization of ammonia,ethylene glycol,glycerol and glycine,which contain more than one hydroxyl radical,were chosen.The experiments were conducted at 313 K similar to the CO2 absorption conditions for the blast furnace gas model.

  19. Vaporization reduction characteristics of aqueous ammonia solutions by the addition of ethylene glycol, glycerol and glycine to the CO2 absorption process.

    Science.gov (United States)

    Seo, Jong-Beom; Jeon, Soo-Bin; Kim, Je-Young; Lee, Gang-Woo; Jung, Jong-Hyeon; Oh, Kwang-Joong

    2012-01-01

    Aqueous ammonia (NH3) solution can be used as an alternative absorption for the control of CO2 emitted from flue gases due to its high absorption capacity, fast absorption rate and low corrosion problem. The emission of CO2 from iron and steel plants requires much attention, as they are higher than those emitted from power plants at a single point source. In the present work, low concentration ammonia liquor, 9 wt.%, was used with various additives to obtain the kinetic properties using the blast furnace gas model. Although a solution with a high ammonia concentration enables high CO2 absorption efficiency, ammonium ions are lost as ammonia vapor, resulting in reduced CO2 absorption due to the lower concentration of the ammonia absorbent. To decrease the vaporization of ammonia, ethylene glycol, glycerol and glycine, which contain more than one hydroxyl radical, were chosen. The experiments were conducted at 313 K similar to the CO2 absorption conditions for the blast furnace gas model.

  20. Assessing Ammonia Treatment Options

    Science.gov (United States)

    This is the second of three articles to help water system operators understand ammonia and how to monitor and control its effects at the plant and in the distribution system. The first article (Opflow, April 2012) provided an overview of ammonia's chemistry, origins, and water sy...

  1. Method for forming ammonia

    Science.gov (United States)

    Kong, Peter C.; Pink, Robert J.; Zuck, Larry D.

    2008-08-19

    A method for forming ammonia is disclosed and which includes the steps of forming a plasma; providing a source of metal particles, and supplying the metal particles to the plasma to form metal nitride particles; and providing a substance, and reacting the metal nitride particles with the substance to produce ammonia, and an oxide byproduct.

  2. Catalyst for Ammonia Oxidation

    DEFF Research Database (Denmark)

    2015-01-01

    The present invention relates to a bimetallic catalyst for ammonia oxidation, a method for producing a bimetallic catalyst for ammonia oxidation and a method for tuning the catalytic activity of a transition metal. By depositing an overlayer of less catalytic active metal onto a more catalytic...

  3. Performance of a chill ATES system

    Energy Technology Data Exchange (ETDEWEB)

    Midkiff, K.C.; Song, Y.K.; Schaetzle, W.J. [Univ. of Alabama, Tuscaloosa, AL (United States)] [and others

    1989-03-01

    An aquifer air-conditioning system has been installed to cool the Student Recreation Center on the University of Alabama Campus. This research program encompasses the monitoring of the operation of the aquifer system and provision of emplacements to the system. The monitoring includes establishing the instrumentation, acquiring data, and analyzing the results. The instrumentation allows the measurement of water flow rates and corresponding temperatures, electrical energy input, aquifer temperatures at nineteen monitoring wells, and aquifer levels at six monitoring wells. Recent acquifer performance data indicate that 76% of the chill energy stored was recovered for the period Oct/86 - Sep/87 and 70% for the period Oct/87 - Sep/88. This is a substantial improvement over recoveries of 38% for the 1985 season and 55% for 1986. The overall coefficient of performance was 5.4 for Oct/86 - Sep/87 and 4.6 for Oct/87 - Sep/88. THe system has supplied 100% of the cooling with only about one-half of the energy input required by a conventional system. Some of the increased recovery of chilled water is a result of modifying the production well operation to reduce the regional flow of water toward the northwest. All warm water is withdrawn form the southeast wells, chilled, and injected in northwest wells. The cold water then withdrawn from the cold wells is used for air-conditioning but not reinjected into the aquifer. Additional flow control is provided by pumping (and discarding) water out of a southeast well, although the complete results of this new strategy are as yet unclear.

  4. Comparison of opened with closed refrigeration processes in Plant of Synthetic Ammonia Made by Coal%煤制合成氨装置中开放式与封闭式冷冻流程的比较

    Institute of Scientific and Technical Information of China (English)

    彭杰; 卢文新; 李雁; 肖晓愚

    2013-01-01

    介绍了煤制合成氨装置冷冻系统中开放式冷冻流程和封闭式冷冻流程的工艺特点;从液氨产品中氢气等惰气的含量、氨损失量、能耗等方面对比了2种流程的工艺参数和指标。结果表明:①在配置尿素的合成氨装置中,宜选择开放式冷冻流程,以降低尿素装置爆炸的风险;②若下游装置对氢含量无严格要求,则可考虑选用封闭式冷冻流程,以降低装置的费用和投资。%Author has introduced the process features for the opened refrigeration process and closed refrigeration process in refrigeration system of the plant of synthetic ammonia made by coal; has compared the process parameters and indexes for the 2 kinds of processes from aspects of inert gas content of hydrogen gas etc.in liquid ammonia product, ammonia loss quantity, energy consume etc.Result indicates that:(1) In arranging the synthetic ammo-nia plant of urea, it is suitable to select the opened refrigeration process, in order to decrease the risk for explosion of urea plant;(2) In case of no re-quirement on hydrogen content in the downstream plant, it is considered to select the closed refrigeration process , in order to decrease the fee and invest-ment of plant.

  5. Ammonia transformation in a biotrickling air filter

    DEFF Research Database (Denmark)

    Nielsen, Lars Peter; Nielsen, Marie Louise; Andersen, Mathias;

    2007-01-01

    measurements and model was obtained by using conventional substrate and inhibition kinetics of ammonium and nitrite oxidizing bacteria. Highest rates of ammonia removal were observed in the central section of the filter. Near the air outlet and water inlet the process was ammonia limited, while high nitrous...... acid concentrations almost excluded any biological activity near the air inlet and water outlet. Nitrous acid inhibition also stabilized pH at 6.5-7 all through the filter. Being sensitive to both ammonia and nitrous acid the nitrite oxidation process occurred mainly in the filter sections near the air...... outlet / water inlet, and only 8% of the nitrite was turned into nitrate. Water supply only exceeded evaporation by 20% but modelling indicated that additional watering would have limited effect on filter efficiency. The filter was also robust to varying loading, as a 4-fold increase in ammonia inlet...

  6. Incidence of chilling injury in fresh-cut 'Kent' mangoes

    Science.gov (United States)

    The preferred storage temperature for fresh-cut fruits in terms of visual quality retention is around 5 °C, which is considered to be a chilling temperature for chilling sensitive tropical fruits like mango (Mangifera indica L.). Changes in visual and compositional quality factors, aroma volatile pr...

  7. Chilling and heat requirements for flowering in temperate fruit trees.

    Science.gov (United States)

    Guo, Liang; Dai, Junhu; Ranjitkar, Sailesh; Yu, Haiying; Xu, Jianchu; Luedeling, Eike

    2014-08-01

    Climate change has affected the rates of chilling and heat accumulation, which are vital for flowering and production, in temperate fruit trees, but few studies have been conducted in the cold-winter climates of East Asia. To evaluate tree responses to variation in chill and heat accumulation rates, partial least squares regression was used to correlate first flowering dates of chestnut (Castanea mollissima Blume) and jujube (Zizyphus jujube Mill.) in Beijing, China, with daily chill and heat accumulation between 1963 and 2008. The Dynamic Model and the Growing Degree Hour Model were used to convert daily records of minimum and maximum temperature into horticulturally meaningful metrics. Regression analyses identified the chilling and forcing periods for chestnut and jujube. The forcing periods started when half the chilling requirements were fulfilled. Over the past 50 years, heat accumulation during tree dormancy increased significantly, while chill accumulation remained relatively stable for both species. Heat accumulation was the main driver of bloom timing, with effects of variation in chill accumulation negligible in Beijing’s cold-winter climate. It does not seem likely that reductions in chill will have a major effect on the studied species in Beijing in the near future. Such problems are much more likely for trees grown in locations that are substantially warmer than their native habitats, such as temperate species in the subtropics and tropics.

  8. Chilling and heat requirements for flowering in temperate fruit trees

    Science.gov (United States)

    Guo, Liang; Dai, Junhu; Ranjitkar, Sailesh; Yu, Haiying; Xu, Jianchu; Luedeling, Eike

    2014-08-01

    Climate change has affected the rates of chilling and heat accumulation, which are vital for flowering and production, in temperate fruit trees, but few studies have been conducted in the cold-winter climates of East Asia. To evaluate tree responses to variation in chill and heat accumulation rates, partial least squares regression was used to correlate first flowering dates of chestnut ( Castanea mollissima Blume) and jujube ( Zizyphus jujube Mill.) in Beijing, China, with daily chill and heat accumulation between 1963 and 2008. The Dynamic Model and the Growing Degree Hour Model were used to convert daily records of minimum and maximum temperature into horticulturally meaningful metrics. Regression analyses identified the chilling and forcing periods for chestnut and jujube. The forcing periods started when half the chilling requirements were fulfilled. Over the past 50 years, heat accumulation during tree dormancy increased significantly, while chill accumulation remained relatively stable for both species. Heat accumulation was the main driver of bloom timing, with effects of variation in chill accumulation negligible in Beijing's cold-winter climate. It does not seem likely that reductions in chill will have a major effect on the studied species in Beijing in the near future. Such problems are much more likely for trees grown in locations that are substantially warmer than their native habitats, such as temperate species in the subtropics and tropics.

  9. 77 FR 10772 - Fresh and Chilled Atlantic Salmon From Norway

    Science.gov (United States)

    2012-02-23

    ... COMMISSION Fresh and Chilled Atlantic Salmon From Norway Determination On the basis of the record \\1... countervailing duty order and antidumping duty order on fresh and chilled Atlantic salmon from Norway would not... from Norway: Investigation Nos. 701-TA-302 and 731-TA-454 (Third Review). Issued: February 17, 2012....

  10. Low-cost anodes for ammonia electrooxidation

    Science.gov (United States)

    Selverston, Steven M.

    This research focused on the development of low-cost electrodes for the electrochemical oxidation of ammonia to nitrogen, a reaction that has possible applications in hydrogen generation, direct ammonia fuel cells, water treatment, and sensors. Statistical design of experiments was used to help develop an efficient and scalable process for electrodeposition of platinum with a specific electrochemical surface area of over 25 m2 /g. Catalyst surface area and activity were evaluated using cyclic voltammetry, and the material microstructure and morphology were investigated using x-ray diffraction and scanning electron microscopy. The synthesized electrodes were found to be active toward the ammonia electrooxidation reaction, particularly when supporting electrolyte was added. However, supporting electrolyte was not required in order to oxidize the ammonia. As proof of concept, a homemade direct ammonia fuel cell employing a commercial anion exchange membrane was tested at room temperature with gravity-fed fuel and without supporting electrolyte. At room temperature, with passive reactant supply and using dissolved oxygen at the cathode, the cell produced about one quarter the power of a direct methanol fuel cell that used active transport of humidified oxygen and preheated (50 °C) methanol. With continued development of the membrane, cathode and membrane electrode assembly, the passive direct ammonia fuel cell using anion exchange membrane could have performance similar to the equivalent direct methanol fuel cell, and it could benefit from many advantages of ammonia over methanol such as lower cost, higher energy density, and reduced greenhouse gas emissions.

  11. WOOD COLOR CHANGES BY AMMONIA FUMING

    Directory of Open Access Journals (Sweden)

    Josip Miklečić,

    2012-06-01

    Full Text Available This paper studies the influence of ammonia gas on wood color changes in response to an increasing demand for dark colored wood specimens. The darker wood color in ammonia fuming is accomplished through chemical reactions between ammonia gas and wood compounds. We exposed oak, maple, spruce, and larch wood samples to ammonia gas for 16 days. During fuming, the color changes were studied using CIE L*a*b* parameters. After fuming, the changes in extractives content, tannin, and nitrogen content were analyzed. The chemical changes of wood and residues of wood extractives after fuming were analyzed by FTIR spectroscopy. Oak wood reacted intensively with ammonia gas in a very short time, and the darkening was prominent for all the investigated wood species. It was established that tannin had no major influence on color changes of maple and larch wood in the ammonia-fuming process. The FTIR spectra of fumed wood indicated involvement of carbonyl groups, and the FTIR spectra of wood extractives indicated involvement of carbonyl, aromatic, and alcohol groups in reaction with ammonia gas.

  12. Comparative evaluation of gum arabic coating and vacuum packaging on chilled storage characteristics of Indian mackerel (Rastrelliger kanagurta).

    Science.gov (United States)

    Binsi, P K; Nayak, Natasha; Sarkar, P C; Sahu, Upali; Ninan, George; Ravishankar, C N

    2016-04-01

    The effect of edible coating using gum arabic on biochemical, microbiological, textural and sensory characteristics of fresh gutted mackerel stored at 4 °C was investigated. The results were further compared against the samples packed under vacuum (VP) and conventional polyethylene pouches (CP). Coating with gum arabic (GC) markedly retarded lipid oxidation process in gutted mackerel compared to VP and CP samples. Moreover, VP and CP samples showed higher degree of textural deterioration compared to GC samples. Microbiologically, the shelf life of chilled gutted Indian mackerel was estimated to be 7-8, 17 and 19-20 days for CP, GC and VP samples, respectively. The sensory analysis scores confirmed the efficacy of gum coating in retarding the spoilage process during chilled storage. The current study identifies the potential of edible coating with gum arabic to improve the overall quality of Indian mackerel and extend its storage life during chilled storage.

  13. Ammonia transformations and abundance of ammonia oxidizers in a clay soil underlying a manure pond.

    Science.gov (United States)

    Sher, Yonatan; Baram, Shahar; Dahan, Ofer; Ronen, Zeev; Nejidat, Ali

    2012-07-01

    Unlined manure ponds are constructed on clay soil worldwide to manage farm waste. Seepage of ammonia-rich liquor into underlying soil layers contributes to groundwater contamination by nitrate. To identify the possible processes that lead to the production of nitrate from ammonia in this oxygen-limited environment, we studied the diversity and abundance of ammonia-transforming microorganisms under an unlined manure pond. The numbers of ammonia-oxidizing bacteria and anammox bacteria were most abundant in the top of the soil profile and decreased significantly with depth (0.5 m), correlating with soil pore-water ammonia concentrations and soil ammonia concentrations, respectively. On the other hand, the numbers of ammonia-oxidizing archaea were relatively constant throughout the soil profile (10(7) amoA copies per g(soil)). Nitrite-oxidizing bacteria were detected mainly in the top 0.2 m. The results suggest that nitrate accumulation in the vadose zone under the manure pond could be the result of complete aerobic nitrification (ammonia oxidation to nitrate) and could exist as a byproduct of anammox activity. While the majority of the nitrogen was removed within the 0.5-m soil section, possibly by combined anammox and heterotrophic denitrification, a fraction of the produced nitrate leached into the groundwater.

  14. Preparation of soil nutrient amendment using white mud produced in ammonia-soda process and its environmental assessment

    Institute of Scientific and Technical Information of China (English)

    SHI Lin; LUO Han-jin

    2009-01-01

    A novel method to prepare soil nutrient amendment by calcining a mixture of white mud and potassium feldspar and its environmental assessment were investigated. Under the optimal conditions of a blending mass ratio of 70-30 for white mud to potassium feldspar, a calcination temperature of 1 000 ℃, a calcination time of 1.5 h and spherulitic diameter of 2.0 cm, the calcined product, as a soil nutrient amendment, could be prepared with the following nutrient composition (mass fraction): K2O 4.16%, CaO 23.43%, MgO 5.04%, SiO_2 22.92%, SO_4~(2-) 3.71%, and Cl- 3.87% in 0.1 mol/L citric acid solution. The concentrations of heavy metals in the calcined product and the emission concentrations of harmful gases from a mixture of white mud and potassium feldspar during calcination process could qualify the National Standards without causing secondary environmental pollution.

  15. Innovative bioelectrochemical-anaerobic-digestion integrated system for ammonia recovery and bioenergy production from ammonia-rich residues

    OpenAIRE

    Zhang, Yifeng; Angelidaki, Irini

    2015-01-01

    Ammonia (NH4+/NH3) inhibition during anaerobic digestion process is one of the most frequent problems existing in biogas plants, resulting in unstable process and reduced biogas production. In this study, we developed a novel hybrid system, consisted of a submersed microbial resource recovery cell (SMRC) and a continuous stirred tank reactor (CSTR), to prevent ammonia toxicity during anaerobic digestion by in-situ ammonia recovery and electricity production (Figure 1). In batch experiment, th...

  16. Experimental characterization of the rectification process in ammonia-water absorption systems with a large-specific-area corrugated sheet structured packing

    Energy Technology Data Exchange (ETDEWEB)

    Sieres, Jaime; Fernandez-Seara, Jose; Uhia, Francisco J. [Area de Maquinas y Motores Termicos, E.T.S. de Ingenieros Industriales, Campus Lagoas-Marcosende No 9, 36310 Vigo, Pontevedra (Spain)

    2009-09-15

    In this paper, the mass transfer performance of a large-specific-area corrugated sheet structured packing for ammonia-water absorption refrigeration systems (AARS) is reported. An experimental facility was used to test the performance of the packing. Experimental results of the temperature, ammonia concentration and mass flow rate of the rectified vapour are presented and discussed for different operating conditions including reflux ratio values from 0.2 to 1. The volumetric vapour phase mass transfer coefficient is calculated from the measured data and compared with different correlations found in the literature. A new correlation is proposed which was fitted from the experimental data. Finally, a comparison is made between the actual packing height used in the experimental setup and the height required to obtain the same ammonia rectification in AARS with different packings previously tested by the authors. (author)

  17. The nitrate to ammonia and ceramic (NAC) process for the denitration and immobilization of low-level radioactive liquid waste (LLW)

    Science.gov (United States)

    Muguercia, Ivan

    Hazardous radioactive liquid waste is the legacy of more than 50 years of plutonium production associated with the United States' nuclear weapons program. It is estimated that more than 245,000 tons of nitrate wastes are stored at facilities such as the single-shell tanks (SST) at the Hanford Site in the state of Washington, and the Melton Valley storage tanks at Oak Ridge National Laboratory (ORNL) in Tennessee. In order to develop an innovative, new technology for the destruction and immobilization of nitrate-based radioactive liquid waste, the United State Department of Energy (DOE) initiated the research project which resulted in the technology known as the Nitrate to Ammonia and Ceramic (NAC) process. However, inasmuch as the nitrate anion is highly mobile and difficult to immobilize, especially in relatively porous cement-based grout which has been used to date as a method for the immobilization of liquid waste, it presents a major obstacle to environmental clean-up initiatives. Thus, in an effort to contribute to the existing body of knowledge and enhance the efficacy of the NAC process, this research involved the experimental measurement of the rheological and heat transfer behaviors of the NAC product slurry and the determination of the optimal operating parameters for the continuous NAC chemical reaction process. Test results indicate that the NAC product slurry exhibits a typical non-Newtonian flow behavior. Correlation equations for the slurry's rheological properties and heat transfer rate in a pipe flow have been developed; these should prove valuable in the design of a full-scale NAC processing plant. The 20-percent slurry exhibited a typical dilatant (shear thickening) behavior and was in the turbulent flow regime due to its lower viscosity. The 40-percent slurry exhibited a typical pseudoplastic (shear thinning) behavior and remained in the laminar flow regime throughout its experimental range. The reactions were found to be more efficient in the

  18. Reactor for removing ammonia

    Science.gov (United States)

    Luo, Weifang; Stewart, Kenneth D.

    2009-11-17

    Disclosed is a device for removing trace amounts of ammonia from a stream of gas, particularly hydrogen gas, prepared by a reformation apparatus. The apparatus is used to prevent PEM "poisoning" in a fuel cell receiving the incoming hydrogen stream.

  19. Sensory quality control in the chilled and frozen ready meal, soup and sauce sectors

    OpenAIRE

    Swainson, Mark; McWatt, Linda

    2010-01-01

    This chapter discusses the use of sensory evaluation in the assurance of product quality within the food production sectors of ready meals, soups and sauces. The chapter methodically reviews typical food processing stages, from recipe development through to end product supply, and considers how sensory assessment methods can be utilised to help assure the quality of the end products within these selected High Risk Chilled Food sectors.

  20. Design and Exploration of the Automation Control Transformation of Hazardous Ammonia Synthesis Process%氨合成危险工艺自动化控制改造的设计及探讨

    Institute of Scientific and Technical Information of China (English)

    吴建颖

    2014-01-01

    As technology advances, the role of automation control in chemical production is continuously enhanced, so the whole country started the automation control transformation of the ammonia synthesis process. In this paper, the transformation of ammonia synthesis section is discussed.%随着科技的日新月异,自动化控制在化工生产中的发挥的作用不断增强,全国上下展开了合成氨生产装置工艺自动化控制改造。本论文仅对氨合成工段的改造进行探讨。

  1. Impact of dry chilling on the genetic diversity of Escherichia coli on beef carcasses and on the survival of E. coli and E. coli O157.

    Science.gov (United States)

    Visvalingam, Jeyachchandran; Liu, Yang; Yang, Xianqin

    2017-03-06

    The objective of this study was to examine the effect of dry chilling on the genetic diversity of naturally occurring Escherichia coli on beef carcasses, and to examine whether two populations of E. coli recovered from carcasses during chilling and E. coli O157 differed in their response to desiccation. Isolates of E. coli were obtained from beef carcasses during a 67h dry chilling process and were genotyped using multiple-locus variable-number tandem-repeat analysis (MLVA). Ten E. coli genotypes found only at 0h (group A) and found more than once (group B), as well as five strains of E. coli O157 (group C) were inoculated on stainless steel coupons and their survival was examined after exposure to 75 and 100% relative humidity (RH) at 0 or 35°C for 67h. A total of 450 E. coli isolates were obtained, with 254, 49, 49, 51, 23, 20, and 4 from 0, 1, 2, 4, 6, 8 and 24h of chilling, respectively. No E. coli were recovered at 67h. MLVA of the isolates revealed 173 distinct genotypes. Genetic diversity of E. coli isolates, defined as ratio of the number of isolates to the number of genotypes, remained between 2.3 and 1.3 during the 24h of chilling. All strains inoculated on stainless steel coupons and exposed to 75% RH at 35°C were completely inactivated, irrespective of their groups. Inactivation of E. coli of the three groups was not significantly (P>0.05) different by exposure to 75% RH at 0°C. The findings indicate that the genetic diversity of E. coli on beef carcasses was not affected by dry chilling. In addition, inactivation of E. coli genotypes and E. coli O157 by desiccation on stainless steel simulating dry chilling conditions did not differ significantly (P>0.05). Thus, dry chilling may be used as an effective antimicrobial intervention for beef carcasses.

  2. Effect of high pressure treatment on microbiological quality of Indian white prawn (Fenneropenaeus indicus) during chilled storage.

    Science.gov (United States)

    Ginson, J; Panda, Satyen Kumar; Bindu, J; Kamalakanth, C K; Srinivasa Gopal, T K

    2015-04-01

    High pressure treatment of 250 MPa for 6 min at 25 °C was applied to headless Indian white prawn (Fenneropenaeus indicus) to evaluate changes in microbiological characteristics of the species during chilled storage. Changes in load of mesophilic bacteria, psychrotrophic bacteria, proteolytic bacteria, Enterobacteriaceae, Pseudomonas spp., H2S producing bacteria, lactic acid bacteria, Brochothrix thermosphacta and yeast & mold were estimated in pressurized and un-pressurized samples during chilled storage. All microbes were reduced significantly after high pressure treatment and there was significant difference in microbial quality of control and high pressure treated samples in the entire duration of chilled storage (p bacteria up to 6th and 9th day of storage, respectively in high pressure treated samples. In high pressure treated sample, no lag phase (λ) was observed for psychrotrophic bacteria, H2S producing bacteria, B. thermosphacta, Pseudomonas spp. and lactic acid bacteria; however, other bacteria showed a reduced lag phase during chilled storage. Kinetic parameter such as specific growth rate (μmax) in high pressure treated samples was significantly reduced in most of the bacterial groups except for psychrotrophic bacteria, Enterobacteriaceae and lactic acid bacteria. Mesophilic bacterial count of control samples crossed the marginal limit of acceptability on 12th day and unacceptable limit on 18th day of storage, whereas high pressure treated samples never breached the acceptability limit during entire duration of chilled storage. The present study indicated that application of high pressure processing can be used to improve microbial quality of Indian white prawn and extend the chilled storage life.

  3. CHANGES OF BACKSCATTERING PARAMETERS DURING CHILLING INJURY IN BANANAS

    Directory of Open Access Journals (Sweden)

    NORHASHILA HASHIM

    2014-06-01

    Full Text Available The change in backscattering parameters during the appearance of chilling injury in bananas was investigated. Bananas were stored at a chilling temperature for two days and the degrees of the chilling injuries that appeared were measured before, during and after storage using backscattering imaging and visual assessment. Laser lights at 660 nm and 785 nm wavelengths were shot consecutively onto the samples in a dark room and a camera was used to capture the backscattered lights that appeared on the samples. The captured images were analysed and the changes of intensity against pixel count were plotted into graphs. The plotted graph provides useful information of backscattering parameters such as inflection point (IP, slope after inflection point (SA, and full width at half maximum (FWHM and saturation radius (RSAT. Results of statistical analysis indicated that there were significant changes of these backscattering parameters as chilling injury developed.

  4. Ammonia emission time profiles based on manure transport data improve ammonia modelling across north western Europe

    Science.gov (United States)

    Hendriks, C.; Kranenburg, R.; Kuenen, J. J. P.; Van den Bril, B.; Verguts, V.; Schaap, M.

    2016-04-01

    Accurate modelling of mitigation measures for nitrogen deposition and secondary inorganic aerosol (SIA) episodes requires a detailed representation of emission patterns from agriculture. In this study the meteorological influence on the temporal variability of ammonia emissions from livestock housing and application of manure and fertilizer are included in the chemistry transport model LOTOS-EUROS. For manure application, manure transport data from Flanders (Belgium) were used as a proxy to derive the emission variability. Using improved ammonia emission variability strongly improves model performance for ammonia, mainly by a better representation of the spring maximum. The impact on model performance for SIA was negligible as explained by the limited, ammonia rich region in which the emission variability was updated. The contribution of Flemish agriculture to modelled annual mean ammonia and SIA concentrations in Flanders were quantified at respectively 7-8 and 1-2 μg/m3. A scenario study was performed to investigate the effects of reducing ammonia emissions from manure application during PM episodes by 75%, yielding a maximum reduction in modelled SIA levels of 1-3 μg/m3 during episodes. Year-to-year emission variability and a soil module to explicitly model the emission process from manure and fertilizer application are needed to further improve the modelling of the ammonia budget.

  5. 回收合成氨尾气副产液化天然气工艺技术%Process Technology of Producing Byproduct Liquefied Natural Gas from Recovery of Ammonia Tail Gas

    Institute of Scientific and Technical Information of China (English)

    王辉

    2015-01-01

    A description is given of the selection of process schemes liquefying and separating methane from ammonia vent gas and purge gas from ammonia tank to produce liquefied natural gas, and the economic benefit of the project is analyzed.After constructed and put into operation of the project,the annual sales revenue is 21.456 million yuan,and the annual new profit is 4.972 million yuan,which has significance to the transformation of traditional ammonia industry chain.%介绍了氨合成放空气和氨罐弛放气中甲烷液化分离制液化天然气的工艺方案选择,分析了该项目的经济效益。该项目建成投产后,年销售收入2145.60万元,每年可新增利润497.20万元,对改造传统的合成氨产业链具有重要意义。

  6. Oxydesulfurization of a Turkish hard lignite with ammonia solutions

    Energy Technology Data Exchange (ETDEWEB)

    Yaman, S.; Kuecuekbayrak, S. [Istanbul Technical Univ. (Turkey). Chemical and Metallurgical Engineering Faculty

    1996-09-01

    In this study the desulfurization of a high pyritic and high organic sulfur lignite taken from the Gediz area (western Turkey) was investigated by the oxydesulfurization method using ammonia solutions. The influence of such parameters as the concentration of ammonia solution, partial pressure of oxygen, temperature, and reaction time were studied. The ranges of these parameters were selected as 0--10 M concentration of ammonia solution, 0--1.5 MPa partial pressure of oxygen, 403--473 K temperature, and 10--60 min reaction time. It was concluded that the use of ammonia solution as an extraction solution increased the efficiency of the oxydesulfurization process.

  7. Industrialization of New Process to Electrolysis Zinc from Zinc Chloride and Ammonia Complex%氯化锌氨络合物制锌新工艺的工业化实践

    Institute of Scientific and Technical Information of China (English)

    邓良勋; 吴保庆

    2011-01-01

    用氯化铵与含氧化锌原料反应生成氯化锌氨络合物,净化后电解制取阴极锌.介绍了该流程的原理及工业试生产的有关情况.%The zinc chloride and ammonia complex was produced by reacting ammonium chloride with zinc oxide containing raw materials, after purification which was used to produce cathode zinc via electrolysis process.The principles of this process and industrialization pilot production were introduced in detail.

  8. Manufacture of a Polyaniline Nanofiber Ammonia Sensor Integrated with a Readout Circuit Using the CMOS-MEMS Technique

    Science.gov (United States)

    Liu, Mao-Chen; Dai, Ching-Liang; Chan, Chih-Hua; Wu, Chyan-Chyi

    2009-01-01

    This study presents the fabrication of a polyaniline nanofiber ammonia sensor integrated with a readout circuit on a chip using the commercial 0.35 μm complementary metal oxide semiconductor (CMOS) process and a post-process. The micro ammonia sensor consists of a sensing resistor and an ammonia sensing film. Polyaniline prepared by a chemical polymerization method was adopted as the ammonia sensing film. The fabrication of the ammonia sensor needs a post-process to etch the sacrificial layers and to expose the sensing resistor, and then the ammonia sensing film is coated on the sensing resistor. The ammonia sensor, which is of resistive type, changes its resistance when the sensing film adsorbs or desorbs ammonia gas. A readout circuit is employed to convert the resistance of the ammonia sensor into the voltage output. Experimental results show that the sensitivity of the ammonia sensor is about 0.88 mV/ppm at room temperature. PMID:22399944

  9. Manufacture of a Polyaniline Nanofiber Ammonia Sensor Integrated with a Readout Circuit Using the CMOS-MEMS Technique

    Directory of Open Access Journals (Sweden)

    Chyan-Chyi Wu

    2009-02-01

    Full Text Available This study presents the fabrication of a polyaniline nanofiber ammonia sensor integrated with a readout circuit on a chip using the commercial 0.35 mm complementary metal oxide semiconductor (CMOS process and a post-process. The micro ammonia sensor consists of a sensing resistor and an ammonia sensing film. Polyaniline prepared by a chemical polymerization method was adopted as the ammonia sensing film. The fabrication of the ammonia sensor needs a post-process to etch the sacrificial layers and to expose the sensing resistor, and then the ammonia sensing film is coated on the sensing resistor. The ammonia sensor, which is of resistive type, changes its resistance when the sensing film adsorbs or desorbs ammonia gas. A readout circuit is employed to convert the resistance of the ammonia sensor into the voltage output. Experimental results show that the sensitivity of the ammonia sensor is about 0.88 mV/ppm at room temperature

  10. An early response regulatory cluster induced by low temperature and hydrogen peroxide in seedlings of chilling-tolerant japonica rice

    Directory of Open Access Journals (Sweden)

    Jia Yulin

    2007-06-01

    Full Text Available Abstract Background Plants respond to low temperature through an intricately coordinated transcriptional network. The CBF/DREB-regulated network of genes has been shown to play a prominent role in freeze-tolerance of Arabidopsis through the process of cold acclimation (CA. Recent evidence also showed that the CBF/DREB regulon is not unique to CA but evolutionarily conserved between chilling-insensitive (temperate and chilling-sensitive (warm-season plants. In this study, the wide contrast in chilling sensitivity between indica and japonica rice was used as model to identify other regulatory clusters by integrative analysis of promoter architecture (ab initio and gene expression profiles. Results Transcriptome analysis in chilling tolerant japonica rice identified a subset of 121 'early response' genes that were upregulated during the initial 24 hours at 10°C. Among this group were four transcription factors including ROS-bZIP1 and another larger sub-group with a common feature of having as1/ocs-like elements in their promoters. Cold-induction of ROS-bZIP1 preceded the induction of as1/ocs-like element-containing genes and they were also induced by exogenous H2O2 at ambient temperature. Coordinated expression patterns and similar promoter architectures among the 'early response' genes suggest that they belong to a potential regulon (ROS-bZIP – as1/ocs regulatory module that responds to elevated levels of ROS during chilling stress. Cultivar-specific expression signatures of the candidate genes indicate a positive correlation between the activity of the putative regulon and genotypic variation in chilling tolerance. Conclusion A hypothetical model of an ROS-mediated regulon (ROS-bZIP – as1/ocs triggered by chilling stress was assembled in rice. Based on the current results, it appears that this regulon is independent of ABA and CBF/DREB, and that its activation has an important contribution in configuring the rapid responses of rice seedlings

  11. Sugar-driven prebiotic synthesis of ammonia from nitrite.

    Science.gov (United States)

    Weber, Arthur L

    2010-06-01

    Reaction of 3-5 carbon sugars, glycolaldehyde, and alpha-ketoaldehydes with nitrite under mild anaerobic aqueous conditions yielded ammonia, an essential substrate for the synthesis of nitrogen-containing molecules during abiogenesis. Under the same conditions, ammonia synthesis was not driven by formaldehyde, glyoxylate, 2-deoxyribose, and glucose, a result indicating that the reduction process requires an organic reductant containing either an accessible alpha-hydroxycarbonyl group or an alpha-dicarbonyl group. Small amounts of aqueous Fe(+3) catalyzed the sugar-driven synthesis of ammonia. The glyceraldehyde concentration dependence of ammonia synthesis, and control studies of ammonia's reaction with glyceraldehyde, indicated that ammonia formation is accompanied by incorporation of part of the synthesized ammonia into sugar-derived organic products. The ability of sugars to drive the synthesis of ammonia is considered important to abiogenesis because it provides a way to generate photochemically unstable ammonia at sites of sugar-based origin-of-life processes from nitrite, a plausible prebiotic nitrogen species.

  12. Treatment of Low-concentration Ammonia Nitrogen Wastewater by Catalytic Ozonation Process with Activated Carbon%活性炭催化臭氧氧化处理低浓度氨氮废水

    Institute of Scientific and Technical Information of China (English)

    尚会建; 周艳丽; 赵彦; 张高; 郑学明

    2012-01-01

    Low-concentration ammonia nitrogen wastewater was treated by catalytic ozonation process with activated carbon. The factors affecting the treatment effect were studied. The experimental results show that: Activated carbon has a significant catalytic effect on ozonation and can improve the utilization of ozone; Under the condition of high pH, OH- can improve the decomposition of ozone and the generation of o OH, which is in favor of ammonia nitrogen removal with strong oxidation property and fast reaction rate; The increasing of ozone flow can weaken the resistance in the gas-liquid mass-transfer process and increase the removal rate of ammonia nitrogen; Under the conditions of initial ammonia nitrogen mass concentration 35 mg/L, activated carbon dosage 10.0 g/L, ozone flow 30 mg/min, simulated wastewater pH 11.0 and reaction time 90 min, the removal rate of ammonia nitrogen can reach 97.6%, which' is much higher than those by activated carbon adsorption or ozonation.%采用活性炭催化臭氧氧化法处理低浓度氨氮废水,考察了模拟废水pH、活性炭加入量、臭氧流量等因素对处理效果的影响.实验结果表明:活性炭对臭氧有明显的催化作用,并可提高臭氧的利用率;在高pH条件下,OH-能促进臭氧分解生成·OH,·OH氧化性强且反应速率快,有利于氨氮的去除;增大臭氧流量可减小气液传质过程中的阻力,使氨氮去除率增加;在初始氨氮质量浓度为35 mg/L、活性炭加入量为10.0 g/L、臭氧流量为30 mg/min、模拟废水pH为11.0的条件下,反应90 min后,氨氮去除率可达97.6%,相对于单独活性炭吸附和臭氧氧化过程,氨氮去除率有了显著提高.

  13. Prevalence and Serogroup Diversity of Salmonella for Broiler Neck Skin, Whole Carcass Rinse, and Whole Carcass Enrichment Sampling Methodologies following Air or Immersion Chilling.

    Science.gov (United States)

    Bourassa, D V; Holmes, J M; Cason, J A; Cox, N A; Rigsby, L L; Buhr, R J

    2015-11-01

    The purpose of this study was to evaluate neck skin (NS), whole carcass rinse (WCR), and whole carcass enrichment (WCE) sampling procedures for Salmonella isolation and serogroup identification from the same broiler chicken carcass treated with air or immersion chilling. Commercially processed and eviscerated broiler carcasses were collected from a commercial processing plant, individually bagged, and transported to the pilot processing plant. In experiment 1, carcasses were air chilled to 4°C. In experiment 2, carcasses were immersion chilled with or without chlorine. After air chilling, Salmonella was detected on 78% of NS and 89% of WCE samples. Only one Salmonella serogroup was detected from each of 13 Salmonella-positive NS samples, and two serogroups were detected on 1 Salmonella-positive NS sample. Only one Salmonella serogroup was detected from each of 13 Salmonella-positive WCE samples, and two serogroups were detected from 3 Salmonella-positive WCE samples. After immersion chilling without chlorine, Salmonella was detected on 38% of NS, 45% of WCR, and 100% of WCE samples. Without chlorine, the 15 Salmonella-positive NS samples included 14 samples with one serogroup and 1 sample with two serogroups. Only one Salmonella serogroup was detected from WCR samples after immersion chilling. Of 40 Salmonella-positive WCE samples, 23 had a one, 14 had two, and 3 had three Salmonella serogroups. After immersion chilling with chlorine, Salmonella was detected on 35% of NS, 0% of WCR, and 90% of WCE samples. With chlorine, the 14 Salmonella-positive NS samples included 11 samples with one serogroup and 3 samples with two serogroups. No Salmonella serogroups were detected from WCR samples after immersion chilling with 20 mg/liter free chlorine. The 36 Salmonella-positive WCE samples included 21 samples with one serogroup and 15 samples with two serogroups. NS and WCE sampling methodologies yielded similar prevalence and serogroup diversity after air chilling. However

  14. [Visible/NIR analysis of fat, protein and water in chilled pork].

    Science.gov (United States)

    Liu, Kui-Wu; Cheng, Fang; Lin, Hong-Jian; Sun, Tong; Xu, Kai; Hu, Lei-Xiu; Ying, Yi-Bin; Xu, Hui-Rong

    2009-01-01

    Fat, protein and water were determined by visible and NIR transmittance spectroscopy in chilled pork. After preprocessed by multiplicative scatter correction (MSC), the quantitative analysis models were developed based on the original, first derivative and second derivative spectra by using partial least squares (PLS) at the temperatures of 0-4 degrees C and 20 degrees C, respectively. By comparing the correlation coefficient (r), RMSEC, and SEP, we found that the first derivative model was the best, and the performance for 0-4 degrees C was better than that for 20 degrees C. At 0-4 degrees C and 20 degrees C, the correlation coefficients were 0.950 and 0.924 for fat, 0.713 and 0.455 for protein and 0.944 and 0.914 for water respectively, SEP values were 2.41 and 2.95 for fat, 5.44 and 4.25 for protein, and 2.37 and 2.38 for water respectively. The results showed that the visible and NIR analysis could measure the fat and water contents in chilled pork well, but was bad for protein, and this was caused by processing line of chilled pork. What's more, the spectrum offset was found in the original spectra at about 770 nm to be about 10 nm.

  15. Ammonia emissions in Europe

    DEFF Research Database (Denmark)

    Jacobsen, Brian H.

    2012-01-01

    The NEC (National Emission Ceiling) directive has set targets for the 2010 ammonia emissions from a number of European countries. The target will be reached by most EU-countries and the total emission for EU-27 has been reduced by 22% from 1990 to 2007. Denmark is one of the countries with the la......The NEC (National Emission Ceiling) directive has set targets for the 2010 ammonia emissions from a number of European countries. The target will be reached by most EU-countries and the total emission for EU-27 has been reduced by 22% from 1990 to 2007. Denmark is one of the countries...

  16. Respiratory ammonia output and blood ammonia concentration during incremental exercise

    NARCIS (Netherlands)

    Ament, W; Huizenga, [No Value; Kort, E; van der Mark, TW; Grevink, RG; Verkerke, GJ

    1999-01-01

    The aim of this study was to investigate whether the increase of ammonia concentration and lactate concentration in blood was accompanied by an increased expiration of ammonia during graded exercise. Eleven healthy subjects performed an incremental cycle ergometer test. Blood ammonia, blood lactate

  17. Treatment of nickel-ammonia complex ion-containing ammonia nitrogen wastewater

    Institute of Scientific and Technical Information of China (English)

    MIN Xiao-bo; ZHOU Min; CHAI Li-yuan; WANG Yun-yan; SHU Yu-de

    2009-01-01

    Air stripping was adopted to treat nickel ammonia complex ion-containing wastewater in order to remove nickel and ammonia simultaneously in one technological process. The relationship among pH, the concentration of nickel ammonia complex ion and total ammonia concentration was analyzed theoretically. Influence of pH value, water temperature, airflow rate and time on air stripping was studied in detail by static experiment in laboratory. The results show that at pH 11, temperature of 60 ℃ and airflow rate of 0.12 m~3/h, NH_3 and Ni~(2+) concentrations remained in wastewater are less than 2 and 0.2 mg/L, respectively, after blowing for 75 min, which reaches the standard of the state discharge. When the tail gas is absorbed by 0.5 mol/L H_2SO_4 in order to avoid the secondary pollution, the absorption rate can achieve 70%.

  18. Ammonia tolerant enriched methanogenic cultures as bioaugmentation inocula to alleviate ammonia inhibition in continuous anaerobic reactors

    DEFF Research Database (Denmark)

    Fotidis, Ioannis; Wang, Han; Angelidaki, Irini

    tolerant methanogenic culture as potential bioaugmentation inoculum in a continuous stirred tank reactor (CSTR) operating under “inhibited steady-state”, triggered by high ammonia levels (5 g NH4+-N L-1). The results of the current study established for the first time that bioaugmentation of an enriched...... ammonia tolerant methanogen in a CSTR reactor could completely alleviate the ammonia inhibitory effect. Furthermore, it was found that bioaugmentation with the enriched culture resulted in 25% higher methane production compared to when the bioaugmentation was achieved with pure methanogenic strains....... The bioaugmentation was performed without pausing the continuous operation of the CSTR reactor and without excluding the ammonia-rich substrate from the feedstock. Thus, bioaugmentation with mixed methanogenic cultures could potentially support the development of an efficient and cost-effective biomethanation process...

  19. Dissociation and Mass Transfer Coefficients for Ammonia Volatilization Models

    Science.gov (United States)

    Process-based models are being used to predict ammonia emissions from manure sources, but their accuracy has not been fully evaluated for cattle manure. Laboratory trials were conducted to measure the dissociation and mass transfer coefficients for ammonia volatilization from media of buffered ammon...

  20. Start of the big chill for the LHC

    CERN Multimedia

    2007-01-01

    The cooling of Sector 7-8 of the LHC, the first to undergo the process, is under way to the 1.9 K necessary for superconductivity. During the night of 14 to 15 March, an important milestone was reached when the entire sector was cooled to 4.5 K, the temperature of liquid helium. The two graphs above show the progression of cooling in Sector 7-8. The first gives the status of the sector on Tuesday 6 March at 4:00 pm, the second on Wednesday 7 March at 10:00 am. Each square represents a magnet.It's the start of the big chill for the LHC. Since the middle of January, the teams from the Accelerator Cryogenics group have been working to cool down the first sector of the machine. Three kilometres of magnets between Point 7 (Ferney-Voltaire) and Point 8 (Prévessin) are to be cooled to 1.9 Kelvin (-271°C), colder than outer space. The first step in the process was to cool the sector to 80 K. Following mechanical and electrical integrity tests at this temperature, it was then further cooled to 20 K for additional e...

  1. Performance of personalized ventilation combined with chilled ceiling in an office room: inhaled air quality and contaminant distribution

    DEFF Research Database (Denmark)

    Lipczynska, Aleksandra; Kaczmarczyk, Jan; Melikov, Arsen Krikor

    2014-01-01

    In a simulated two persons’ office room inhaled air quality and contaminant distribution provided with personalized ventilation combined with chilled ceiling, mixing ventilation only, chilled ceiling with mixing ventilation and chilled ceiling with mixing and personalized ventilation was studied...

  2. Effect of Low Frequency Electromagnetic Field on Macrosegregation of Horizontal Direct Chill Casting Aluminum Alloys

    Institute of Scientific and Technical Information of China (English)

    Zhihao ZHAO; Jianzhong CUI; Jie DONG; Beijiang ZHANG

    2005-01-01

    The horizontal direct chill (HDC) casting process is a well-established production route for aluminum alloy ingot but the ingot may suffer from macrosegregation sometimes. In order to control the defect, a low frequency electromagnetic field has been applied in HDC casting process and the relevant influence has been studied. The results show that application of low frequency electromagnetic field can reduce macrosegregation in HDC casting process; and two main parameters of electromagnetic field density and frequency, have great influences on the solution distribution along the diameter of ingot. Moreover, the mechanisms of reduction of macrosegregation by electromagnetic field have been discussed.

  3. Online chilling effects in England and Wales

    Directory of Open Access Journals (Sweden)

    Judith Townend

    2014-04-01

    Full Text Available Open and free internet-based platforms are seen as an enabler of global free expression, releasing writers from commercial and space constraints. However, many are working without the assistance of an in-house lawyer, or other legal resources. This may lead to undue suppression of public interest material, with important implications for freedom of expression and the democratic function of media. Two online surveys among digital and online journalists in England and Wales in 2013 indicated that the majority of encounters with defamation and privacy law take place outside the courts, with few formally recorded legal actions. This was particularly evident in a sample of ‘hyperlocal’ and local community publishers. In light of the results, this paper calls for a reappraisal of overly simplistic judicial and media applications of the ‘chilling effect’ doctrine, in order to expose its subjectivities and complexities. Additionally, attention needs to be paid to global and cross-jurisdictional media-legal environments, in order to help develop better internet policy and legal frameworks for protecting legitimate expression.

  4. Fracture analysis of chilled cast iron camshaft

    Directory of Open Access Journals (Sweden)

    Li Ping

    2009-05-01

    Full Text Available The fracture of a camshaft made of chilled cast iron, installed in a home-made Fukang car, happened only after running over a distance of 6,200 km. The fractured camshaft was received to conduct a series of failure analyses using visual inspection, SEM observation of fracture section, microstructure analysis, chemical composition analysis and hardness examination and so on, while those of CKD camshaft made by Citro雗 Company in France was also simultaneously analyzed to compare the difference between them. The results showed that the fracture of the camshaft mainly results from white section in macrostructure and Ledeburite in microstructure; the crack in the fractured camshaft should be recognized to initiate at the boundary of coarser needle-like carbide and matrix, and then propagate through the transverse section. At the same time, the casting defects such as dendritic shrinkage, accumulated inclusion and initiated crack and abnormal external force might stimulate the fracture of camshaft as well. Based on failure analysis, some measures have been employed, and as a result, the fracture of home-made camshafts has been effectively prevented.

  5. Fracture analysis of chilled cast iron camshaft

    Institute of Scientific and Technical Information of China (English)

    Li Ping; Li Fengjun; Cai Anke; Wei Bokang

    2009-01-01

    The fracture of a camshaft made of chilled cast iron, installed in a home-made Fukang car, happened only after running over a distance of 6,200 km. The fractured camshaft was received to conduct a series of failure analyses using visual inspection, SEM observation of fracture section, microstructure analysis, chemical composition analysis and hardness examination and so on, while those of CKD camshaft made by Citroen Company in France was also simultaneously analyzed to compare the difference between them. The results showed that the fracture of the camshaft mainly results from white section in macrostructure and Ledeburite in microstructure; the crack in the fractured camshaft should be recognized to initiate at the boundary of coarser needle-like carbide and matrix, and then propagate through the transverse section. At the same time, the casting defects such as dendritic shrinkage, accumulated inclusion and initiated crack and abnormal external force might stimulate the fracture of camshaft as well. Based on failure analysis, some measures have been employed, and as a result, the fracture of home-made camshafts has been effectively prevented.

  6. Hydroaminomethylation in supercritical ammonia

    Energy Technology Data Exchange (ETDEWEB)

    Martin, A.; Kant, M. [Leibniz-Institute for Catalysis, Berlin (Germany); Klein, H.; Jackstell, R.; Beller, M. [Leibniz-Institute for Catalysis, Rostock (Germany)

    2006-07-01

    Thermodynamic measurements were carried in the reaction system of hydroaminomethylation of olefins. Mixtures of ammonia, olefins, co-solvents, syngas and products such as nonylamine used as model and water were studied. In dependence on the reaction conditions and the mixtures selected opalescence points in a region from 92-290 bar and 120-172 C were found. (orig.)

  7. 废水中氨氮的处理工艺技术方法探讨%Discussion on Ammonia-nitrogen-containing Wastewater Removal Process Technologics and Methods

    Institute of Scientific and Technical Information of China (English)

    王界智

    2012-01-01

    Several main ammonia-nitrogen removal technical processes were introduced in the paper.Biological treatment methods including UASB,A/O membrane bioreactor,IMO-SBR were summarized.Meanwhile electrochemical oxidation method and membrane treatment technology were also discussed in the paper.%文中对目前常用的几种废水脱氮技术方法进行了简单介绍,其中包括生物法的UASB工艺、A/O膜生物反应器法、IMO-SBR生物组合工艺,电化学氧化法及膜处理技术。

  8. Electron-induced ammonia adsorption on iron

    CERN Document Server

    Narkiewicz, U; Trybuchowicz, A; Arabczyk, W

    2003-01-01

    The adsorption of ammonia on an iron surface at ambient temperature has been investigated using Auger electron spectroscopy (AES). The effect of the electron beam on the process of the ammonia adsorption has been studied. The polycrystalline iron samples precovered with different amounts of oxygen (0.15-1 ML) or sulphur (1 ML) were used. The initial sticking coefficient of ammonia to oxygen precovered iron surface was estimated as s sub 0 approx 5x10 sup - sup 4 (independently on the oxygen coverage) for the adsorption experiments without the effect of the electron beam. The strong inhibiting effect of sulphur precoverage on the ammonia adsorption has been found (s sub 0 approx 6.5x10 sup - sup 6). The electron beam has favourable effect on the adsorption of ammonia, and this effect increases with the oxygen coverage (one monolayer of adsorbed nitrogen atoms at the saturation state and s sub 0 approx 1 for the iron surface precovered with one monolayer of oxygen). The proposed explanation is the favourable ef...

  9. Enantioselective, iridium-catalyzed monoallylation of ammonia.

    Science.gov (United States)

    Pouy, Mark J; Stanley, Levi M; Hartwig, John F

    2009-08-19

    Highly enantioselective, iridium-catalyzed monoallylations of ammonia are reported. These reactions occur with electron-neutral, -rich, and -poor cinnamyl carbonates, alkyl and trityloxy-substituted allylic carbonates, and dienyl carbonates in moderate to good yields and excellent enantioselectivities. This process is enabled by the use of an iridium catalyst that does not require a Lewis acid for activation and that is stable toward a large excess of ammonia. This selective formation of primary allylic amines allows for one-pot syntheses of heterodiallylamines and allylic amides that are not otherwise accessible via iridium-catalyzed allylic amination without the use of blocking groups and protective group manipulations.

  10. Transformation of ammonia i biological airfilters

    DEFF Research Database (Denmark)

    Nielsen, Lars Peter; Sørensen, Karen; Andersen, Mathias;

    2007-01-01

    Ammonia is a major compound in ventilation air from animal houses. In biological filters it is with varying efficiency transformed by physical, biological, and chemical processes and ends up as ammonium, nitrate, and nitrite dissolved in water and as dinitrogen, nitrous oxide and nitric oxide...... emitted to the air. To identify the key regulators of these transformations we have combined data from studies of microbiology and performance in 10 experimental and full scale filters of varying design, loading, and management. Inhibition by nitrite controlled ammonium oxidation and pH, while biological...... nitrite oxidation only appeared in locations with minimal ammonia and nitrite levels. Nitrous oxide emission depended on anoxic microsites, and nitric oxide production was associated with nitrite accumulation. Water and biomass management appear to be the important tools for optimization of ammonia...

  11. Synthesis of chemically-modified single-walled carbon nanotubes by counter-current ammonia gas injection into the induction thermal plasma process

    Science.gov (United States)

    Shahverdi, Ali

    Pristine single-walled carbon nanotubes (SWCNTs) are poorly dispersible and insoluble in many solvents and need to be chemically modified prior to their use in many applications. This work is focused on the investigation of the synthesis of chemically modified SWCNTs material through an in situ approach. The main objectives of the presented research are: 1) to explore the in situ chemical process during the synthesis of SWCNT and 2) to closely examine the effect of a reactive environment on SWCNTs. Effects of the catalyst type and content on the SWCNTs final product, synthesized by induction thermal plasma (ITP), were studied to replace toxic cobalt (Co) in the feedstock. In this regard, three different catalyst mixtures (i.e. Ni-Y2O3, Ni-Co-Y2O3, and Ni-Mo-Y2O3) were used. Experimental results showed that the catalyst type affects the quality of the SWCNT final product. Similar quality SWCNTs can be produced when the same amount of Co was replaced by Ni. Moreover, the results observed in this experimental work were further explained by thermodynamic calculation results. Thermogravimetry (TG) was used throughout the work to characterize the SWCNTs product. TG was firstly standardized by studying the effects of three main instrumental parameters (temperature ramp, TR, initial mass of the sample, IM, and gas flow rate, FR) on the Tonset and full-width half maximum (FWHM) obtained from TG and derivative TG graphs of carbon black, respectively. Therefore, a two-level factorial statistical design was performed. The statistical analysis showed that the effect of TR, IM, and to a lower extent, FR, is significant on FWHM and insignificant on Tonset. A methodology was then developed based upon the SWCNTs synthesis using the ITP system, through an in situ chemistry approach. Ammonia (NH3) was selected and counter-currently injected into the ITP reactor at three different flow rates and by four different nozzle designs. Numerical simulation indicated a better mixing of NH3 in

  12. Exogenous application of glycinebetaine increases chilling tolerance in tomato plants.

    Science.gov (United States)

    Park, Eung-Jun; Jeknic, Zoran; Chen, Tony H H

    2006-06-01

    Tomato (Lycopersicon esculentum Mill. cv. Moneymaker) plants are chilling sensitive, and do not naturally accumulate glycinebetaine (GB), a metabolite that functions as a stress protectant. We reported previously that exogenous GB application enhanced chilling tolerance in tomato. To understand its protective role better, we have further evaluated various parameters associated with improved tolerance. Although its effect was most pronounced in younger plants, this benefit was diminished 1 week after GB application. When administered by foliar spray, GB was readily taken up and translocated to various organs, with the highest levels being measured in meristematic tissues, including the shoot apices and flower buds. In leaves, the majority of endogenous GB was found in the cytosol; only 0.6-22.0% of the total leaf GB was localized in chloroplasts. Immediately after GB application, levels of H(2)O(2), catalase activity and expression of the catalase gene (CAT1) were all higher in GB-treated than in control plants. One day after exposure to chilling stress, the treated plants had significantly greater catalase activity and CAT1 expression, although their H(2)O(2) levels remained unchanged. During the following 2 d of this chilling treatment, GB-treated plants maintained lower H(2)O(2) levels but had higher catalase activity than the controls. These results suggest that, in addition to protecting macromolecules and membranes directly, GB-enhanced chilling tolerance may involve the induction of H(2)O(2)-mediated antioxidant mechanisms, e.g. enhanced catalase expression and catalase activity.

  13. Dynamic Model of an Ammonia Synthesis Reactor Based on Open Information

    OpenAIRE

    Jinasena, Asanthi; Lie, Bernt; Glemmestad, Bjørn

    2016-01-01

    Ammonia is a widely used chemical, hence the ammonia manufacturing process has become a standard case study in the scientific community. In the field of mathematical modeling of the dynamics of ammonia synthesis reactors, there is a lack of complete and well documented models. Therefore, the main aim of this work is to develop a complete and well documented mathematical model for observing the dynamic behavior of an industrial ammonia synthesis reactor system. The mode...

  14. 合成氨工艺参数优化技术开发及应用%Development and application of optimization technology of the process parameters on ammonia plant

    Institute of Scientific and Technical Information of China (English)

    张运陶; 付伟忠; 张明荣; 郑怀江

    2011-01-01

    A prediction equation of ammonia plant production was set up about the relationship between the response value (net value of ammonia) and the five variables selected from the main factors by stepwise regression. The selected variables in the equations were included left temperature of catalyst 3, left temperature of catalyst 4, CH,% of recycle gas, H/N(hydrogen-nitrogen ratio) and NH3% inlet. According to the calculated results and error distribution of the equation, samples were classified. On this basis, attempting to get information from the superior samples, process parameters of the classified samples were compared and analyzed by the computer graphics. To guide production test, the optimization process parameters scheme was established and validated by the simulation. Compared with the pre-test the results had shown that the average net value of ammonia increased from 13.86 to 14.54 and steam consumption and power consumption per ton of ammonia decreased by 15.9887m3, 15.8 kWh, respectively. It is energy saving and has an obvious benefit.%以氨净值为响应值,影响响应值的17个过程参数为变量,经逐步回归选入触媒温度左3,触媒温度左4,循环CH4%,H/N,NH3%(进口)5个过程参数建立预测方程,并根据该方程对响应值的拟合结果和误差分布对样本进行分类.在此基础上,采取图形显示技术和统计分析的方法对分类样本集的过程参数进行比对分析,由此获取优类信息制订优化的工艺参数方案,经仿真验证后用于指导合成氨装置的生产试验.试验结果与试验前的对照期比较,氨净值均值由13.86提高到14.54,吨氨气耗减少15.9887 m3,吨氨电耗减少15.8 kWh,节能效益十分明显

  15. Biofilter Treating Ammonia Gas Using Agricultural Residues Media

    Directory of Open Access Journals (Sweden)

    Thaniya Kaosol

    2012-01-01

    Full Text Available Problem statement: Agricultural residues such as manure and sugarcane bagasse are wastes from agro-industry which has low value and requires some sustainable waste management method. In this research, a mixture of manure fertilizer and sugarcane bagasse is used as a biofilter media for an ammonia gas removal application. The aim of this research is to study the ammonia gas removal efficiency of such media. Approach: The experiments were conducted in laboratory-scale biofilters. Two inlet ammonia gas concentrations were used which are 500 and 1,000 ppm. Three ratios of manure fertilizer and sugarcane bagasse were studied including 1:3, 1:5 and 1:7 by volume. All experiments were conducted for a period of 40 days. Two Empty Bed Retention Time (EBRT of these experiments were used which is 39s and 78s. The moisture content of the biofilter media was maintained at 45-60% by adding water. Results: The maximum ammonia gas removal efficiency at 89.93% is observed from the following conditions: 500 ppm of the inlet ammonia gas concentration, the manure fertilizer and sugarcane bagasse mixture ratio of 1:5 and the EBRT of 78s. The important factors of the ammonia gas removal in biofiltration process are the inlet ammonia gas concentration and the EBRT. Conclusion: The experimental results showed that the mixture of manure fertilizer and sugarcane bagasse is an effective biofilter media for ammonia gas removal applications. However, the biofilter is more effective at low inlet ammonia gas concentration, while the ratio of manure fertilizer and sugarcane bagasse has no significant effect on the ammonia gas removal efficiency. Therefore, using both residues as biofilter media for ammonia gas removal application is an alternative sustainable way to such manage argo-industry waste.

  16. A simple route to vertical array of quasi-1D ZnO nanofilms on FTO surfaces: 1D-crystal growth of nanoseeds under ammonia-assisted hydrolysis process

    Directory of Open Access Journals (Sweden)

    Abd Rahman Mohd Yusri

    2011-01-01

    Full Text Available Abstract A simple method for the synthesis of ZnO nanofilms composed of vertical array of quasi-1D ZnO nanostructures (quasi-NRs on the surface was demonstrated via a 1D crystal growth of the attached nanoseeds under a rapid hydrolysis process of zinc salts in the presence of ammonia at room temperature. In a typical procedure, by simply controlling the concentration of zinc acetate and ammonia in the reaction, a high density of vertically oriented nanorod-like morphology could be successfully obtained in a relatively short growth period (approximately 4 to 5 min and at a room-temperature process. The average diameter and the length of the nanostructures are approximately 30 and 110 nm, respectively. The as-prepared quasi-NRs products were pure ZnO phase in nature without the presence of any zinc complexes as confirmed by the XRD characterisation. Room-temperature optical absorption spectroscopy exhibits the presence of two separate excitonic characters inferring that the as-prepared ZnO quasi-NRs are high-crystallinity properties in nature. The mechanism of growth for the ZnO quasi-NRs will be proposed. Due to their simplicity, the method should become a potential alternative for a rapid and cost-effective preparation of high-quality ZnO quasi-NRs nanofilms for use in photovoltaic or photocatalytics applications. PACS: 81.07.Bc; 81.16.-c; 81.07.Gf.

  17. Evaluation of trigeneration system using microturbine, ammonia-water absorption chiller, and a heat recovery boiler

    Energy Technology Data Exchange (ETDEWEB)

    Preter, Felipe C.; Rocha, Marcelo S.; Simoes-Moreira, Jose Roberto [SISEA - Alternative Energy Systems Lab. Dept. of Mechanical Engineering. University of Sao Paulo (EP/USP), SP (Brazil)], e-mails: felipe.preter@poli.usp.br, msrocha@poli.usp.br, jrsimoes@usp.br; Andreos, Ronaldo [COMGAS - Companhia de Gas de Sao Paulo, SP (Brazil)], e-mail: randreos@comgas.com.br

    2010-07-01

    In this work, a CCHP or tri generation system has been projected, mounted, and tested in laboratory, combining a microturbine for power generation, a heat recovery boiler for hot water production, and an ammonia water absorption chiller for chilled water production. The project was motivated by the large practical applications of this kind of energy recovery system in commerce, and industry, and, in general, more than 85% of the energy source is used as power, hot water, and cold water. In the first part, the trigeneration system theoretical model is detailed, and in the second part, experimental results are presented for different operation conditions. (author)

  18. Excretory nitrogen metabolism and defence against ammonia toxicity in air-breathing fishes.

    Science.gov (United States)

    Chew, S F; Ip, Y K

    2014-03-01

    With the development of air-breathing capabilities, some fishes can emerge from water, make excursions onto land or even burrow into mud during droughts. Air-breathing fishes have modified gill morphology and morphometry and accessory breathing organs, which would tend to reduce branchial ammonia excretion. As ammonia is toxic, air-breathing fishes, especially amphibious ones, are equipped with various strategies to ameliorate ammonia toxicity during emersion or ammonia exposure. These strategies can be categorized into (1) enhancement of ammonia excretion and reduction of ammonia entry, (2) conversion of ammonia to a less toxic product for accumulation and subsequent excretion, (3) reduction of ammonia production and avoidance of ammonia accumulation and (4) tolerance of ammonia at cellular and tissue levels. Active ammonia excretion, operating in conjunction with lowering of ambient pH and reduction in branchial and cutaneous NH₃ permeability, is theoretically the most effective strategy to maintain low internal ammonia concentrations. NH₃ volatilization involves the alkalization of certain epithelial surfaces and requires mechanisms to prevent NH₃ back flux. Urea synthesis is an energy-intensive process and hence uncommon among air-breathing teleosts. Aestivating African lungfishes detoxify ammonia to urea and the accumulated urea is excreted following arousal. Reduction in ammonia production is achieved in some air-breathing fishes through suppression of amino acid catabolism and proteolysis, or through partial amino acid catabolism leading to alanine formation. Others can slow down ammonia accumulation through increased glutamine synthesis in the liver and muscle. Yet, some others develop high tolerance of ammonia at cellular and tissue levels, including tissues in the brain. In summary, the responses of air-breathing fishes to ameliorate ammonia toxicity are many and varied, determined by the behaviour of the species and the nature of the environment in

  19. Exogenous Melatonin Mitigates Photoinhibition by Accelerating Non-photochemical Quenching in Tomato Seedlings Exposed to Moderate Light during Chilling

    Science.gov (United States)

    Ding, Fei; Wang, Meiling; Liu, Bin; Zhang, Shuoxin

    2017-01-01

    Melatonin plays an important role in tolerance to multiple stresses in plants. Recent studies have shown that melatonin relieves photoinhibition in plants under cold stress; however, the mechanisms are not fully understood. Non-photochemical quenching (NPQ) is a key process thermally dissipating excess light energy that plants employ as a protective mechanism to prevent the over reduction of photosystem II. Here, we report the effects of exogenous melatonin on NPQ and mitigation of photoinhibition in tomato seedlings exposed to moderate light during chilling. In response to moderate light during chilling, the maximum quantum yield (Fv/Fm) and the effective photochemical efficiency (F′v/F′m) of PSII were both substantially reduced, showing severe photoinhibition in tomato seedlings, whereas exogenous application of melatonin effectively alleviated the photoinhibition. Further experiment showed that melatonin accelerated the induction of NPQ in response to moderate light and maintained higher level of NPQ upon longer exposure to light during chilling. Consistent with the increased NPQ was the elevated de-epoxidation state of xanthophyll pigments in melatonin-pretreated seedlings exposed to light during chilling. Enzyme activity assay showed that violaxanthin de-epoxidase (VDE), which catalyzes the de-epoxidation reaction in the xanthophyll cycle, was activated by light and the activity was further enhanced by application of melatonin. Further analysis revealed that melatonin induced the expression of VDE gene in tomato seedlings under moderate light and chilling conditions. Ascorbic acid is an essential cofactor of VDE and the level of it was found to be increased in melatonin-pretreated seedlings. Feeding tomato seedlings with dithiothreitol, an inhibitor of VDE, blocked the effects of melatonin on the de-epoxidation state of xanthophyll pigments and the induction of NPQ. Collectively, these results suggest that exogenous melatonin mitigates photoinhibition by

  20. Quality effect of freeze-chilling in cod and rainbow trout

    DEFF Research Database (Denmark)

    Jensen, Louise Helene Søgaard; Nielsen, Jette; Jørgensen, Bo;

    -chilling on the quality of raw fish portions as an example of a meal element. The thawing of frozen products during transport was mimicked by placing cardboard boxes with frozen, vacuum packaged portions of fish in a chilling facility and allowing them to thaw slowly. To mimic possible subsequent chill storage...

  1. Review of Options for Ammonia/Ammonium Management

    Energy Technology Data Exchange (ETDEWEB)

    Nash, C. A. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2016-05-06

    This report is a review of literature supporting practical ammonia/ammonium destruction processes. Melter research supporting Hanford Low Activity Waste (LAW) glass production has shown that significant amounts of ammonia will be in the melter offgas condensate. Further work with secondary waste forms indicates the potential need to remove the ammonia, perhaps by an oxidative process. This review finds likely practical chemical methods to oxidize ammonia in aqueous solution at moderate temperatures and atmospheric pressure, using easily obtained reagents. Leading candidates include nitrite oxidation to produce nitrogen gas, various peroxide oxidative processes, and air stripping. This work reviews many other processes and provides reasoning to not consider those processes further for this application.

  2. Alkaline Ammonia Electrolysis on Electrodeposited Platinum for Controllable Hydrogen Production.

    Science.gov (United States)

    Gwak, Jieun; Choun, Myounghoon; Lee, Jaeyoung

    2016-02-19

    Ammonia is beginning to attract a great deal of attention as an alternative energy source carrier, because clean hydrogen can be produced through electrolytic processes without the emission of COx . In this study, we deposited various shapes of Pt catalysts under potentiostatic mode; the electrocatalytic oxidation behavior of ammonia using these catalysts was studied in alkaline media. The electrodeposited Pt was characterized by both qualitative and quantitative analysis. To discover the optimal structure and the effect of ammonia concentration, the bulk pH value, reaction temperature, and applied current of ammonia oxidation were investigated using potential sweep and galvanostatic methods. Finally, ammonia electrolysis was conducted using a zero-gap cell, producing highly pure hydrogen with an energy efficiency over 80 %.

  3. Combustion driven ammonia generation strategies for passive ammonia SCR system

    Energy Technology Data Exchange (ETDEWEB)

    Toner, Joel G.; Narayanaswamy, Kushal; Szekely, Jr., Gerald A.; Najt, Paul M.

    2016-12-06

    A method for controlling ammonia generation in an exhaust gas feedstream output from an internal combustion engine equipped with an exhaust aftertreatment system including a first aftertreatment device includes executing an ammonia generation cycle to generate ammonia on the first aftertreatment device. A desired air-fuel ratio output from the engine and entering the exhaust aftertreatment system conducive for generating ammonia on the first aftertreatment device is determined. Operation of a selected combination of a plurality of cylinders of the engine is selectively altered to achieve the desired air-fuel ratio entering the exhaust aftertreatment system.

  4. Ammonia synthesis. Ammonia synthesis by N₂ and steam electrolysis in molten hydroxide suspensions of nanoscale Fe₂O₃.

    Science.gov (United States)

    Licht, Stuart; Cui, Baochen; Wang, Baohui; Li, Fang-Fang; Lau, Jason; Liu, Shuzhi

    2014-08-08

    The Haber-Bosch process to produce ammonia for fertilizer currently relies on carbon-intensive steam reforming of methane as a hydrogen source. We present an electrochemical pathway in which ammonia is produced by electrolysis of air and steam in a molten hydroxide suspension of nano-Fe2O3. At 200°C in an electrolyte with a molar ratio of 0.5 NaOH/0.5 KOH, ammonia is produced at 1.2 volts (V) under 2 milliamperes per centimeter squared (mA cm(-2)) of applied current at coulombic efficiency of 35% (35% of the applied current results in the six-electron conversion of N2 and water to ammonia, and excess H2 is cogenerated with the ammonia). At 250°C and 25 bar of steam pressure, the electrolysis voltage necessary for 2 mA cm(-2) current density decreased to 1.0 V.

  5. A global analysis of the comparability of winter chill models for fruit and nut trees.

    Science.gov (United States)

    Luedeling, Eike; Brown, Patrick H

    2011-05-01

    Many fruit and nut trees must fulfill a chilling requirement to break their winter dormancy and resume normal growth in spring. Several models exist for quantifying winter chill, and growers and researchers often tacitly assume that the choice of model is not important and estimates of species chilling requirements are valid across growing regions. To test this assumption, Safe Winter Chill (the amount of winter chill that is exceeded in 90% of years) was calculated for 5,078 weather stations around the world, using the Dynamic Model [in Chill Portions (CP)], the Chilling Hours (CH) Model and the Utah Model [Utah Chill Units (UCU)]. Distributions of the ratios between different winter chill metrics were mapped on a global scale. These ratios should be constant if the models were strictly proportional. Ratios between winter chill metrics varied substantially, with the CH/CP ratio ranging between 0 and 34, the UCU/CP ratio between -155 and +20 and the UCU/CH ratio between -10 and +5. The models are thus not proportional, and chilling requirements determined in a given location may not be valid elsewhere. The Utah Model produced negative winter chill totals in many Subtropical regions, where it does not seem to be useful. Mean annual temperature and daily temperature range influenced all winter chill ratios, but explained only between 12 and 27% of the variation. Data on chilling requirements should always be amended with information on the location and experimental conditions of the study in which they were determined, ideally including site-specific conversion factors between winter chill models. This would greatly facilitate the transfer of such information across growing regions, and help prepare growers for the impact of climate change.

  6. Selection and Execution for Process Scheme of Synthetic Ammonia Made by Coke-Oven Gas%焦炉煤气制合成氨工艺方案的选取和实施

    Institute of Scientific and Technical Information of China (English)

    文德国; 苏庆贺; 陈世通

    2014-01-01

    介绍了山东临沂恒昌化工科技有限公司焦炉煤气制合成氨装置的立项背景;确定了装置的工艺方案和主要设备;简述了装置节能降耗的主要措施。结果表明:该装置一次试车成功,吨氨电耗约1000 kW· h,制造成本约1500元/t,经济效益明显。%Author has introduced the project approval background for plant of synthetic ammonia made by coke-oven gas in the Shandong Linyi Hengchang Chemical Engineering Science and Technology Company Ltd .; has determined the process scheme and main equipment; has described the main measures about energy saving and consume lowering.Result indicates that the trial run of plant was succesful in one time, the electricity power per ton of ammonia is saved by 1 000 kW· h, fabrication cost is saved by 1 500 Yuan RMB per ton, the economic benefit is obvious.

  7. Ammonia emissions from seabird colonies

    Science.gov (United States)

    Blackall, Trevor D.; Wilson, Linda J.; Theobald, Mark R.; Milford, Celia; Nemitz, Eiko; Bull, Jennifer; Bacon, Philip J.; Hamer, Keith C.; Wanless, Sarah; Sutton, Mark A.

    2007-05-01

    Ammonia emissions were measured from two entire seabird colonies with contrasting species assemblages, to ascertain the ammonia volatilisation potentials among seabird species in relation to their nesting behaviour. Emissions were calculated from downwind plume measurements of ammonia concentration using both inverse dispersion and tracer ratio methods. Measured colony emissions ranged 1-90 kg NH3 hour-1, and equated to 16 and 36% volatilization of excreted nitrogen for colonies dominated by ground/burrow nesting and bare rock nesting birds, respectively. The results were applied in a bioenergetics model with a global seabird database. Seabird colonies are found to represent the largest point sources of ammonia globally (up to ~6 Gg NH3 colony-1 year-1). Moreover the largest emissions occur mainly in remote environments with otherwise low NH3 emissions. These ammonia ``hot spots'' explain significant perturbations of the nitrogen cycle in these regions and add ~20% to oceanic ammonia emissions south of latitude 45°S.

  8. OPTIMIZATION OF LIQUID NITROGEN WASH PROCESS IN LARGE-SCALED AMMONIA PLANT%大型合成氨装置液氮洗工艺流程的优化

    Institute of Scientific and Technical Information of China (English)

    任多胜

    2011-01-01

    Based upon the main scheme for gas refining process in present domestic large-scaled ammonia plant and in combination with the several issues considered importantly in the course of optimization of liquid nitrogen wash process for the enterprise the issue%根据目前国内大型合成氨装置中气体精制工艺的主要方案,结合本企业液氮洗工艺流程在优化过程中所着重考虑的几个问题,主要阐明了流程选择过程注意的问题。

  9. Ammonia nitrogen desorption from sanitary landfill leachate in filling towers

    OpenAIRE

    Leite,Valderi D.; Barros,Aldre J. M.; Lopes,Wilton S.; Sousa,José T. de

    2014-01-01

    Sanitary landfill leachates present high concentrations of carbonaceous and nitrogenous materials. The crucial point is that carbonaceous materials are of difficult biodegradation, what compromises the performance of biological treatment processes, while nitrogenous materials, such as ammonia nitrogen, probably preclude the use of biological treatments. Therefore, the aim of this work was to study the desorption process of ammonia nitrogen from sanitary landfill leachate in filling towers. De...

  10. Microencapsulation of Bifidobacterium animalis subsp. lactis and Lactobacillus acidophilus in cocoa butter using spray chilling technology.

    Science.gov (United States)

    Pedroso, D L; Dogenski, M; Thomazini, M; Heinemann, R J B; Favaro-Trindade, C S

    2013-01-01

    In the present study, the cells of Bifidobacterium animalis subsp. lactis (BI-01) and Lactobacillus acidophilus (LAC-04) were encapsulated in cocoa butter using spray-chilling technology. Survival assays were conducted to evaluate the resistance of the probiotics to the spray-chilling process, their resistance to the simulated gastric and intestinal fluids (SGF and SIF), and their stability during 90 days of storage. The viability of the cells was not affected by microencapsulation. The free and encapsulated cells of B. animalis subsp. lactis were resistant to both SGF and SIF. The micro-encapsulated cells of L. acidophilus were more resistant to SGF and SIF than the free cells; the viability of the encapsulated cells was enhanced by 67%, while the free cells reached the detection limit of the method (10(3) CFU/g). The encapsulated probiotics were unstable when they were stored at 20 °C. The population of encapsulated L. acidophilus decreased drastically when they were stored at 7 °C; only 20% of cells were viable after 90 days of storage. The percentage of viable cells of the encapsulated B. animalis subsp.lactis, however, was 72% after the same period of storage. Promising results were obtained when the microparticles were stored at -18 °C; the freeze granted 90 days of shelf life to the encapsulated cells. These results suggest that the spray-chilling process using cocoa butter as carrier protects L. acidophilus from gastrointestinal fluids. However, the viability of the cells during storage must be improved.

  11. Microencapsulation of Bifidobacterium animalis subsp. lactis and Lactobacillus acidophilus in cocoa butter using spray chilling technology

    Directory of Open Access Journals (Sweden)

    D.L. Pedroso

    2013-09-01

    Full Text Available In the present study, the cells of Bifidobacterium animalis subsp. lactis (BI-01 and Lactobacillus acidophilus (LAC-04 were encapsulated in cocoa butter using spray-chilling technology. Survival assays were conducted to evaluate the resistance of the probiotics to the spray-chilling process, their resistance to the simulated gastric and intestinal fluids (SGF and SIF, and their stability during 90 days of storage. The viability of the cells was not affected by microencapsulation. The free and encapsulated cells of B. animalis subsp. lactis were resistant to both SGF and SIF. The micro-encapsulated cells of L. acidophilus were more resistant to SGF and SIF than the free cells; the viability of the encapsulated cells was enhanced by 67%, while the free cells reached the detection limit of the method (10³ CFU/g. The encapsulated probiotics were unstable when they were stored at 20 °C. The population of encapsulated L. acidophilus decreased drastically when they were stored at 7 °C; only 20% of cells were viable after 90 days of storage. The percentage of viable cells of the encapsulated B. animalis subsp.lactis, however, was 72% after the same period of storage. Promising results were obtained when the microparticles were stored at -18 °C; the freeze granted 90 days of shelf life to the encapsulated cells. These results suggest that the spray-chilling process using cocoa butter as carrier protects L. acidophilus from gastrointestinal fluids. However, the viability of the cells during storage must be improved.

  12. Transcript profiling of Paoenia ostii during artificial chilling induced dormancy release identifies activation of GA pathway and carbohydrate metabolism.

    Directory of Open Access Journals (Sweden)

    Shupeng Gai

    Full Text Available Endo-dormant flower buds must pass through a period of chilling to reinitiate growth and subsequent flowering, which is a major obstacle to the forcing culture of tree peony in winter. Customized cDNA microarray (8×15 K element was used to investigate gene expression profiling in tree peony 'Feng Dan Bai' buds during 24 d chilling treatment at 0-4°C. According to the morphological changes after the whole plants were transferred to green house, endo-dormancy was released after 18 d chilling treatment, and prolonged chilling treatment increased bud break rate. Pearson correlation hierarchical clustering of sample groups was highly consistent with the dormancy transitions revealed by morphological changes. Totally 3,174 significantly differentially-expressed genes (P<0.05 were observed through endo-dormancy release process, of which the number of up-regulated (1,611 and that of down-regulated (1,563 was almost the same. Functional annotation of differentially-expressed genes revealed that cellular process, metabolic process, response to stimulus, regulation of biological process and development process were well-represented. Hierarchical clustering indicated that activation of genes involved in carbohydrate metabolism (Glycolysis, Citrate cycle and Pentose phosphate pathway, energy metabolism and cell growth. Based on the results of GO analysis, totally 51 probes presented in the microarray were associated with GA response and GA signaling pathway, and 22 of them were differently expressed. The expression profiles also revealed that the genes of GA biosynthesis, signaling and response involved in endo-dormancy release. We hypothesized that activation of GA pathway played a central role in the regulation of dormancy release in tree peony.

  13. Meaningful wind chill indicators derived from heat transfer principles.

    Science.gov (United States)

    Brauner, N; Shacham, M

    1995-08-01

    The wind chill index (WCI) and the more widely used wind chill equivalent temperature represent an attempt to combine several weather-related variables (temperature, wind velocity and solar radiation) into a single index which can indicate human comfort. Since its introduction in 1945, the WCI has been criticized mainly on the ground that the underlying model does not comply with modern heat transfer theory. In spite of that, the WCI, "calibrated" to human comfort, has proven to be successful in predicting discomfort and tolerance of man to the cold. Nevertheless, neither the WCI nor the wind chill equivalent temperature can be actually measured and, therefore, without the additional 'calibration' they are meaningless. In this study we have shown that the WCI represents the instantaneous rate of heat loss from bare skin at the moment of exposure to the cold, and as such, it correlates reasonably well with measurable variables that represent a feeling of cold. Two new wind chill indicators have been introduced: exposed skin temperature and maximum exposure time. These indicators yield more information than the WCI provides, are measurable, have physical meaning and are based on established heat transfer principles.

  14. Meaningful wind chill indicators derived from heat transfer principles

    Science.gov (United States)

    Brauner, Neima; Shacham, M.

    1995-03-01

    The wind chill index (WCI) and the more widely used wind chill equivalent temperature represent an attempt to combine several weather-related variables (temperature, wind velocity and solar radiation) into a single index which can indicate human comfort. Since its introduction in 1945, the WCI has been criticized mainly on the ground that the underlying model does not comply with modern heat transfer theory. In spite of that, the WCI, “calibrated” to human comfort, has proven to be successful in predicting discomfort and tolerance of man to the cold. Nevertheless, neither the WCI nor the wind chill equivalent temperature can be actually measured and, therefore, without the additional ‘calibration’ they are meaningless. In this study we have shown that the WCI represents the instantaneous rate of heat loss from bare skin at the moment of exposure to the cold, and as such, it correlates reasonably well with measurable variables that represent a feeling of cold. Two new wind chill indicators have been introduced: exposed skin temperature and maximum exposure time. These indicators yield more information than the WCI provides, are measurable, have physical meaning and are based on established heat transfer principles.

  15. Variation in fruit chilling injury among mango cultivars

    NARCIS (Netherlands)

    Phakawatmongkol, W.; Ketsa, S.; Doorn, van W.G.

    2004-01-01

    Mango(Mangifera indica L.) fruit of six cultivars ('Kaew', 'Rad', 'Okrong', 'Tongdum', 'Nam Dok Mai' and 'Nungklangwun') were stored at 4, 8 and 12degreesC (85-90% RH) and randomly sampled every 5 days. Chilling injury was manifested initially as a gray to brown discoloration of the peel, followed b

  16. Dynamics of Aerosol Condensational Removal in Ammonia Desulfurization Process%氨法脱硫烟气中气溶胶凝结脱除动力学

    Institute of Scientific and Technical Information of China (English)

    颜金培; 杨林军; 沈湘林

    2011-01-01

    针对氨法脱硫烟气中气溶胶的排放特性,建立氨法脱硫后细颗粒凝结长大脱除动力学模型,对细颗粒的凝结长大及脱除规律进行数值预测,并将其与实验结果进行比较。结果表明:细颗粒在过饱和蒸汽条件下迅速长大成液滴,在相同条件下,细颗粒初始数浓度越高,完成凝结长大的时间越短,液滴的最终粒径也越小;细颗粒脱除效率随停留时间增大迅速提高,在50~100ms内达到稳定,与理论计算值比,实验停留时间滞后,约在1.5s后脱除效率趋于稳定;脱硫后细颗粒凝结长大脱除效率与细颗粒物化性质有关,水洗涤时,当过饱和度高于1.4,细颗粒的脱除效率才随过饱和度的增大而迅速提高;氨法脱硫后,细颗粒可在较低的过饱和条件下凝结长大,因而脱除效率随过饱和度增大而提高。%A numerical model for the simulation of the aerosol condensational removal dynamics after ammonia desulfurization was proposed to predict the growth property of fine particles and removal efficiency. The simulation model was applicable for the aerosols discharge property of ammonia desulfurization. The results show that fine particles growth into droplets is very fast in a supersaturation vapor condition. Droplets complete growth time decrease and the final diameters of droplets are smaller at a higher initial particles number concentration. The removal efficiency of fine particles increases rapidly with the residence time, and achieves stability after 50-100 ms. Compared with the simulated values, experimental residence time appeares delate, which tend to stabilize at 1.5 s. Fine particles removal efficiency improved by condensational enlargement is dominated by the particles physicochemical characteristics after desulfurization. Removal efficiency increases with initial supersaturation degree rapidly only when the supersaturation degree higher than 1.4 with water

  17. Spray chilling of deer carcasses--effects on carcass weight, meat moisture content, purge and microbiological quality.

    Science.gov (United States)

    Wiklund, E; Kemp, R M; leRoux, G J; Li, Y; Wu, G

    2010-12-01

    Twenty red deer carcasses were included in the study. Two treatments were applied to the carcasses; control (air chilling) and spray chilling (n=10 for each treatment). Carcass weight and temperature change were registered during over-night chilling. Meat moisture content was measured in the shoulder, loin, flap and leg before and after the chilling treatments; purge, cooking loss and tenderness were measured in loin samples stored at -1.5 °C for 3 and 9 weeks. Microbiological status was assessed on swabs taken at the lumbar end of the loin before and after the chilling treatments. Spray chilling reduced carcass weight loss significantly; air chilled and spray chilled carcasses lost 1 kg and less than 0.01 kg, respectively. No effects of spray chilling on tenderness, purge and cooking loss were found. Bacterial levels were low in general even after 9 weeks of vacuum packaged chilled storage.

  18. Effects of low-frequency magnetic field on grain boundary segregation in horizontal direct chill casting of 2024 aluminum alloy

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Effects of low frequency electromagnetic field on grain boundary segregation in horizontal direct chill (HDC)casting process was investigated experimentally. The grain boundary segregation and microstructures of the ingots,which manufactured by conventional HDC casting and low frequency electromagnetic HDC casting were compared.Results show that low frequency electromagnetic field significantly refines the microstructures and reduces grain boundary segregation. Decreasing electromagnetic frequency or increasing electromagnetic intensity has great effects in reducing grain boundary segregation. Meanwhile, the governing mechanisms were discussed.

  19. Characteristics of Three Thioredoxin Genes and Their Role in Chilling Tolerance of Harvested Banana Fruit

    Science.gov (United States)

    Wu, Fuwang; Li, Qing; Yan, Huiling; Zhang, Dandan; Jiang, Guoxiang; Jiang, Yueming; Duan, Xuewu

    2016-01-01

    Thioredoxins (Trxs) are small proteins with a conserved redox active site WCGPC and are involved in a wide range of cellular redox processes. However, little information on the role of Trx in regulating low-temperature stress of harvested fruit is available. In this study, three full-length Trx cDNAs, designated MaTrx6, MaTrx9 and MaTrx12, were cloned from banana (Musa acuminata) fruit. Phylogenetic analysis and protein sequence alignments showed that MaTrx6 was grouped to h2 type with a typical active site of WCGPC, whereas MaTrx9 and MaTrx12 were assigned to atypical cys his-rich Trxs (ACHT) and h3 type with atypical active sites of GCAGC and WCSPC, respectively. Subcellular localization indicated that MaTrx6 and MaTrx12 were located in the plasma membrane and cytoplasm, respectively, whereas MaTrx9 showed a dual cytoplasmic and chloroplast localization. Application of ethylene induced chilling tolerance of harvested banana fruit, whereas 1-MCP, an inhibitor of ethylene perception, aggravated the development of chilling injury. RT-qPCR analysis showed that expression of MaTrx12 was up-regulated and down-regulated in ethylene- and 1-MCP-treated banana fruit at low temperature, respectively. Furthermore, heterologous expression of MaTrx12 in cytoplasmic Trx-deficient Saccharomyces cerevisiae strain increased the viability of the strain under H2O2. These results suggest that MaTrx12 plays an important role in the chilling tolerance of harvested banana fruit, possibly by regulating redox homeostasis. PMID:27618038

  20. Characteristics of Three Thioredoxin Genes and Their Role in Chilling Tolerance of Harvested Banana Fruit

    Directory of Open Access Journals (Sweden)

    Fuwang Wu

    2016-09-01

    Full Text Available Thioredoxins (Trxs are small proteins with a conserved redox active site WCGPC and are involved in a wide range of cellular redox processes. However, little information on the role of Trx in regulating low-temperature stress of harvested fruit is available. In this study, three full-length Trx cDNAs, designated MaTrx6, MaTrx9 and MaTrx12, were cloned from banana (Musa acuminata fruit. Phylogenetic analysis and protein sequence alignments showed that MaTrx6 was grouped to h2 type with a typical active site of WCGPC, whereas MaTrx9 and MaTrx12 were assigned to atypical cys his-rich Trxs (ACHT and h3 type with atypical active sites of GCAGC and WCSPC, respectively. Subcellular localization indicated that MaTrx6 and MaTrx12 were located in the plasma membrane and cytoplasm, respectively, whereas MaTrx9 showed a dual cytoplasmic and chloroplast localization. Application of ethylene induced chilling tolerance of harvested banana fruit, whereas 1-MCP, an inhibitor of ethylene perception, aggravated the development of chilling injury. RT-qPCR analysis showed that expression of MaTrx12 was up-regulated and down-regulated in ethylene- and 1-MCP-treated banana fruit at low temperature, respectively. Furthermore, heterologous expression of MaTrx12 in cytoplasmic Trx-deficient Saccharomyces cerevisiae strain increased the viability of the strain under H2O2. These results suggest that MaTrx12 plays an important role in the chilling tolerance of harvested banana fruit, possibly by regulating redox homeostasis.

  1. The combined effects of water level reduction and an increase in ammonia concentration on organic matter processing by key freshwater shredders in alluvial wetlands.

    Science.gov (United States)

    Dehedin, Arnaud; Maazouzi, Chafik; Puijalon, Sara; Marmonier, Pierre; Piscart, Christophe

    2013-03-01

    In a global change context, the intensity and the frequency of drastic low flow periods or drought events will most likely increase to a substantial extent over the coming decades, leading to a modification in the abiotic characteristics of wetlands. This change in environmental parameters may induce severe shifts in plant and animal communities and the functioning of ecosystems. In this study, we experimentally estimated the effect of drought and the accumulation of ammonia (NH3 ) on the feeding activities of three generalist macroinvertebrates (i.e. Gammarus pulex, Gammarus roeselii and Asellus aquaticus) on three types of organic matter: leaves of Berula erecta growing in submerged conditions, leaves of the same species growing in emerged conditions and dead leaves of Alnus glutinosa. We observed a modification in the biomechanical and stoichiometric characteristics of the plants as a result of the emersion of the aquatic plants. This shift produced a substantial decrease in organic matter recycling by invertebrates and in their associated physiological ability (i.e. the energy stores of the animals) to face conditions associated with environmental change. Moreover, the accumulation of NH3 amplified the negative effect of emersion. This snowball effect on invertebrates may profoundly modify the functioning of ecosystems, particularly in terms of organic matter production/degradation and carbon mineralization.

  2. Use of smart photochromic indicator for dynamic monitoring of the shelf life of chilled chicken based products.

    Science.gov (United States)

    Brizio, Ana Paula Dutra Resem; Prentice, Carlos

    2014-03-01

    This study evaluated the applicability of a photochromic time temperature indicator (TTI) to monitor the time-temperature history and shelf life of chilled boneless chicken breast. The results showed that the smart indicator showed good reproducibility during the discoloring process in all the conditions investigated. The response was not only visibly interpretable but also well adaptable to measurement using appropriate equipment. For an activation configuration of 4 s of ultraviolet light (UV) per label, the TTI's rate of discoloration was similar to the quality loss of the meat samples analyzed. Thus, the photochromic label (4 s UV/label) attached to the samples set out to be a dynamic shelf-life label, assuring consumers the final point of quality of chilled boneless chicken breast in an easy and precise form, providing a reliable tool to monitor the supply chain of this product.

  3. Development of a convenience and safety chilled sous vide fish dish: Diversification of aquacultural products.

    Science.gov (United States)

    Espinosa, M C; López, G; Díaz, P; Linares, M B; Garrido, M D

    2016-04-01

    The dynamic expansion of the ready-to-eat seabream sector in its adaptation to new lifestyles has led to the search for new presentation formats in seabream (Sparus aurata). Green sauce (olive oil, wine vinegar, garlic, fresh parsley, black pepper, basil and salt) and 60 ℃ of cooking temperature were chosen by the panellists for the sous vide cooking process. Seabream fillet and sauce were packaged in polypropylene trays, cooked, chilled and stored at 2 ℃. Microbiological (total viable counts,Enterobacteriaceae,lactic acid bacteria, anaerobic psychrotrophic, moulds and yeasts, Salmonella and Listeria monocytogenes), chemical (pH and TBARs) and sensory parameters were determined at 0, 7, 17, 34, 48 and 62 days. In the conditions used, the microbiological counts remained stable, and Salmonella and Listeria monocytogenes were absent. The acidic sauce had a positive effect on the pH of the product, and low TBARs were obtained throughout storage. The processing conditions used in the present study allowed a chilled ready-to-eat seabream product of consistently high quality up to 62 days of storage to be obtained, representing an expansion of the products offered by the aquacultural industry.

  4. Microbial growth on broiler carcasses stored at different temperatures after air- or water-chilling.

    Science.gov (United States)

    Tuncer, B; Sireli, U T

    2008-04-01

    Poultry meat has a high risk of contamination during its processing. Storage temperature, type of packaging, and types and numbers of psychrotrophic bacteria are the major factors determining the spoilage of poultry meat. Before packaging, poultry carcasses are chilled by air or water currents in commercial slaughterhouses. The packaging material and methods are other factors influencing the spoilage of poultry meat. Although unpackaged carcasses had lower production costs, they were found to contain high numbers of microorganisms. The unpackaged carcasses are often not recommended for food safety and public health risks. The present study examines the growth of some spoilage microorganisms on unpackaged carcasses and on broiler carcasses packaged in polyethylene bags or synthetic plates. The carcasses examined in this study were collected from the slaughterhouses of the Bolu region of Turkey. All carcasses were subjected to an air or water chilling process in the slaughterhouse and then stored at 0, 4, or 7 degrees C for 14 d. Samples were taken on d 0, 4, 8, 10, and 14 of storage and analyzed for total bacterial count, and for Pseudomonas spp., Enterobacteriaceae, yeasts, and molds. The carcasses packaged in synthetic plates or polyethylene bags and kept at 0 degrees C were microbiologically safer and had longer shelf life, so they are found to be the most reliable for consuming. The shelf life of broiler carcasses could be further increased by improving hygiene and sanitation procedures at the slaughterhouse.

  5. [Visualization of the chilling storage time for turbot flesh based on hyperspectral imaging technique].

    Science.gov (United States)

    Zhu, Feng-Le; Zhang, Hai-Liang; Shao, Yong-Ni; He, Yong

    2014-07-01

    This study proposed a new method using visible and near infrared (Vis/NIR) hyperspectral imaging for the detection and visualization of the chilling storage time for turbot flesh rapid and nondestructively. A total of 160 fish samples with 8 different storage days were collected for hyperspectral image scanning, and mean spectra were extracted from the region of interest (ROD inside each image. Partial least squares regression (PLSR) was applied as calibration method to correlate the spectral data and storage time for the 120 samples in calibration set. Then the PLSR model was used to predict the storage time for the 40 prediction samples, which achieved accurate results with determination coefficient (R2) of 0.966 2 and root mean square error of prediction (RMSEP) of 0.679 9 d. Finally, the storage time of each pixel in the hyperspectral images for all prediction samples was predicted and displayed in different colors for visualization based on pseudo-color images with the aid of an IDL program. The results indicated that hyperspectral imaging technique combined with chemometrics and image processing allows the determination and visualization of the chilling storage time for fish, displaying fish freshness status and distribution vividly and laying a foundation for the automatic processing of aquatic products.

  6. Characterisation of non-toxigenic Clostridium spp. strains, to use as surrogates for non-proteolytic Clostridium botulinum in chilled food challenge testing.

    Science.gov (United States)

    Parker, M D; Barrett, P I; Shepherd, J; Price, L J; Bull, S D

    2015-01-01

    Under many of the conditions studied, a two-strain cocktail of non-toxigenic Clostridium spp. was found to be suitable as a surrogate for non-proteolytic Clostridium botulinum, and has the potential for use in chilled food challenge tests measuring growth. Non-toxigenic surrogates could also be used in thermal process screening studies.

  7. Use of MBR Process in Wastewater Treatment of Synthetic Ammonia Industry%MBR 工艺在合成氨工业废水处理中的应用

    Institute of Scientific and Technical Information of China (English)

    魏维刚; 刘岚

    2015-01-01

    Membrane bioreactor (MBR) is a high efficient wastewater biological treatment process which combines wastewater biological treatment technology and membrane separation technology,and can treat high ammonia-nitrogen content wastewater generated by synthetic ammonia industry effectively.After putting into operation of the MBR systems,COD content of effluent is less than 70 mg/L,ammonia-nitrogen content is stabilized less than 25 mg/L,water yield of each of the 2 MBR systems is 150 m3 /h,reaching the design requirements.The actual operation for more than one year shows that the wastewater treatment system provides a reliable guarantee for energy conservation and emission reduction of the enterprise,but some problems have appeared during operation,effectively solving these problems is crucial to long-term and stable running of the wastewater treatment station.%膜生物反应器(MBR)是将污水的生物处理技术与膜分离技术相结合的高效废水生物处理工艺,可有效处理合成氨工业产生的高 NH3-N 含量的废水。MBR 投运后,出水 COD 含量<70 mg/L,NH3-N 含量可稳定在<25 mg/L,2套 MBR 系统的产水量均为150 m3/h,达到了设计要求。1年多的实际运行情况表明,该污水处理系统为企业的节能减排提供了可靠保障,但运行中也出现了一些问题,这些问题的有效解决对废水处理站的长期稳定运行至关重要。

  8. Growth of organic microspherules in sugar-ammonia reactions.

    Science.gov (United States)

    Weber, Arthur L

    2005-12-01

    Reaction of small sugars of less than four carbons with ammonia in water yielded organic microspherules generally less than ten microns in size. The time course of microspherule growth was examined for the D-erythrose-ammonia reaction that yielded microspherules attached to the glass walls of containers. Measurements were made of the elemental composition and infrared spectrum of the microspherule material. These viscose semi-solid microspherules are viewed as possible containers for prebiotic catalytic processes relevant to the origin of life.

  9. Chilling Tolerance Improving of Watermelon Seedling by Salicylic Acid Seed and Foliar Application

    Directory of Open Access Journals (Sweden)

    Mohammad SAYYARI

    2013-02-01

    Full Text Available Chilling temperatures lead to numerous physiological disturbances in the cells of chilling-sensitive plants and result in chilling injury and death of tropical and subtropical plants such as watermelon. In this study, the possibility of cold stress tolerance enhancing of watermelon seedling (Citrullus lanatus by exogenous application of Salicylic acid (SA was investigated. SA was applied through seed soaking or foliar spray at 0, 0.5, 1 and 1.5 mM concentration. After SA treatment, the seedlings were subjected to chilling 5 h/day at 4°C for 5 days. Statistical analysis showed significant effects of the application methods and SA concentrations on plant growth parameters, photosynthetic pigments, electrolyte leakage, proline and chilling injury index. SA application improved growth parameters and increased chlorophyll content of watermelon seedling subjected to chilling stress and provided significant protection against chilling stress compared to non-SA-treated seedlings. Although two SA application methods improved chilling stress tolerance, seed soaking method provided better protection compared to foliar spray method. SA ameliorated the injury caused by chilling stress via inhibiting proline accumulation and leaf electrolyte leakage. The highest cold tolerance was obtained with 0.5 mM SA application. Results indicate that SA could be used effectively to protect watermelon seedling from damaging effects of chilling stress at the early stages of growth.

  10. Submersible microbial desalination cell for simultaneous ammonia recovery and electricity production from anaerobic reactors containing high levels of ammonia.

    Science.gov (United States)

    Zhang, Yifeng; Angelidaki, Irini

    2015-02-01

    High ammonia concentration in anaerobic reactors can seriously inhibit the anaerobic digestion process. In this study, a submersible microbial desalination cell (SMDC) was developed as an innovative method to lower the ammonia level in a continuous stirred tank reactor (CSTR) by in situ ammonia recovery and electricity production. In batch experiment, the ammonia concentration in the CSTR decreased from 6 to 0.7 g-N/L during 30 days, resulting in an average recovery rate of 80 g-N/m(2)/d. Meanwhile, a maximum power density of 0.71±0.5 W/m(2) was generated at 2.85 A/m(2). Both current driven NH4(+) migration and free NH3 diffusion were identified as the mechanisms responsible for the ammonia transportation. With an increase in initial ammonia concentration and a decrease in external resistance, the SMDC performance was enhanced. In addition, the coexistence of other cations in CSTR or cathode had no negative effect on the ammonia transportation.

  11. Autotrophic ammonia oxidation at low pH through urea hydrolysis.

    Science.gov (United States)

    Burton, S A; Prosser, J I

    2001-07-01

    Ammonia oxidation in laboratory liquid batch cultures of autotrophic ammonia oxidizers rarely occurs at pH values less than 7, due to ionization of ammonia and the requirement for ammonium transport rather than diffusion of ammonia. Nevertheless, there is strong evidence for autotrophic nitrification in acid soils, which may be carried out by ammonia oxidizers capable of using urea as a source of ammonia. To determine the mechanism of urea-linked ammonia oxidation, a ureolytic autotrophic ammonia oxidizer, Nitrosospira sp. strain NPAV, was grown in liquid batch culture at a range of pH values with either ammonium or urea as the sole nitrogen source. Growth and nitrite production from ammonium did not occur at pH values below 7. Growth on urea occurred at pH values in the range 4 to 7.5 but ceased when urea hydrolysis was complete, even though ammonia, released during urea hydrolysis, remained in the medium. The results support a mechanism whereby urea enters the cells by diffusion and intracellular urea hydrolysis and ammonia oxidation occur independently of extracellular pH in the range 4 to 7.5. A proportion of the ammonia produced during this process diffuses from the cell and is not subsequently available for growth if the extracellular pH is less than 7. Ureolysis therefore provides a mechanism for nitrification in acid soils, but a proportion of the ammonium produced is likely to be released from the cell and may be used by other soil organisms.

  12. A new method for chill and shrinkage control in ladle treated ductile iron

    Institute of Scientific and Technical Information of China (English)

    Torbj(o)rn Skaland

    2006-01-01

    The paper is undertaken with the objective of describing a new method for treating ductile cast iron in a ladle process, where the main objective is to minimize formation of eutectic carbides and shrinkage porosity during solidification. The suppression of carbide formation is associated with the nucleating properties of the nodularizer and inoculant alloys. By nucleating properties it is understood the number and potency of nuclei formed by an alloy addition. The nodularizer and inoculant additions also influence ductile iron solidification shrinkage. Some alloys may give good protection against shrinkage while others tend to promote more shrinkage.The use of vanous rare earth elements is found to have a pronounced impact on these conditions. It has been discovered that the use of pure lanthanum as the primary rare earth source in the magnesium ferrosilicon nodularizer surprisingly further improves the performance of the ductile iron ladle treatment method compared to similar methods using cerium or mishmetal bearing nodularizers. The nucleating properties are substantially improved and the risk for carbides (chill) and shrinkage formation in the sandwich or tundish ladle treated ductile iron is then minimized.The paper describes this new ladle treatment concept in detail, and gives examples from successful testing of the new nodularizing technology and how it simultaneously affects and minimizes critical ductile iron chill and shrinkage tendencies.

  13. Action of Cryogenic chill on Mechanical properties of Nickel alloy Metal Matrix Composites

    Science.gov (United States)

    Kumar, B. K. Anil; Ananthaprasad, M. G.; GopalaKrishna, K.

    2016-09-01

    In the area of material science engineering, metallurgists may be at the forefront of new technologies, developing metals for new applications, or involved in the traditional manufacture. By doing so it is possible for metallurgist to apply their knowledge of metals to solve complex problems and looking for ways to improve the mechanical properties of the materials. Therefore, an investigation in the present research was made to fabricate and evaluate the microstructure and mechanical properties of composites developed using cryogenically cooled copper chills, consisting of nickel alloy matrix and garnet particles as the reinforcement. The reinforcement being added ranges from 3 to 12 wt.% in steps of 3%. A stir casting process was used to fabricate the nickel base matrix alloy fused with garnet reinforcement particle. The matrix alloy was melted in a casting furnace at around 1350°C, the garnet particulates which was preheated to 600°C, was introduced evenly into the molten metal alloy. An arrangement was made at one end of the mould by placing copper chill blocks of varying thickness brazed with MS hallow block in which liquid nitrogen was circulated for cryogenic effect. After solidification, the composite materials thus synthesized were examined for microstructural and mechanical properties as per ASTM standards.

  14. 氨法烟气脱硫过程中气溶胶颗粒生成特性%Properties of aerosol formation during wet ammonia-based desulfurization process

    Institute of Scientific and Technical Information of China (English)

    黄荣廷; 潘丹萍; 盛溢; 杨林军

    2015-01-01

    An ammonia-based wet flue gas desulfurization (WFGD) simulation was built to simulate separately the two different aerosol formation mechanisms in ammonia-based desulfurization process of the inhomogeneous reaction mechanism and the entrainment mechanism. The electrical low pressure impactor (ELPI, Dekati Ltd.) was employed for the online measurement of aerosol concentration in the outlet flue gas after the WFGD scrubber. The pollutant PM sampler was used for aerosol sampling in the flue gas. The samples gathered were then scanned and analyzed by the field emission scanning electron microscope (FESEM). The results showed that the inhomogeneous reaction of NH3 escaped from desulfurization slurry with the moisture and SO2 in the flue gas was the dominating one of the two aerosol formation mechanisms in the ammonia-based WFGD, which produced the majority of the aerosols emitted from the scrubber. It was found that the aerosols were consisted mainly of submicron particles if counted in respect of numerical concentration and micron ones in respect of mass concentration. The amount of aerosols produced was depended mainly on the desulfurization solution pH along with the flue gas temperature at the inlet of WFGD,etc. The entrainment mechanism was of the secondary importance in the aerosol formation in the ammonia-based WFGD. The production of the aerosols was mainly related to the desulfurization solution concentration, the empty tower gas velocity, and so forth.%利用自行搭建的模拟氨法烟气脱硫实验平台,针对氨法脱硫中脱硫浆液液滴夹带蒸发和非均相反应两种气溶胶生成途径,采用电称低压冲击器(ELPI)、PM2.5/10采样器、场发射扫描电子显微镜(FESEM)等手段对两种途径下生成的气溶胶浓度、粒度分布以及形貌特征进行了测试分析,实验考察了氨法脱硫工艺参数对两种途径下生成的气溶胶特性的影响。结果表明,氨法脱硫中形成的气溶胶颗粒

  15. Control of chilling tendency in grey cast iron reuse

    Directory of Open Access Journals (Sweden)

    Saliu Ojo Seidu

    2013-02-01

    Full Text Available In grey cast iron remelt and recycling, white iron can result in the cast product if careful control of the chilling tendency is not ensured. Many jobbing foundries are constrained in furnace types and available foundry additives that the operation always results in white irons. This study is towards ensuring grey iron is reproduced from cast iron scrap auto engine blocks, when using a diesel fired rotary furnace and a FeSi alloy for structural modification (inoculation. With varying addition rate of the FeSi alloy to the tapped molten metal, chill wedge tests were performed on two different wedge samples of type W (according to ASTM A367- wedge test with cooling modulus of 0.45 cm (W3½ and 0.54 cm (W4. The carbon equivalents for the test casts were within hypoeutectic range (3.85 wt. (% to 4.11 wt. (%. In the W4 wedge sample, at 2.0 wt. (% addition rate of the FeSi alloy, the relative clear chill was totally reduced to zero from 19.76%, while the relative mottled chill was brought down to 9.59% from 33.71%. The microstructure from the cast at this level of addition was free of carbidic phases; it shows randomly oriented graphite flakes evenly distributed in the iron matrix. Hardness assessment shows that increasing rate of FeSi addition results in decreasing hardness, with maximum effect at 2.0 wt. (% addition. With equivalent aspect ratio (cooling modulus in a target cast product, this addition rate for this FeSi alloy under this furnace condition will attain graphitized microstructure in the cast product.

  16. Control of chilling tendency in grey cast iron reuse

    Directory of Open Access Journals (Sweden)

    Saliu Ojo Seidu

    2012-01-01

    Full Text Available In grey cast iron remelt and recycling, white iron can result in the cast product if careful control of the chilling tendency is not ensured. Many jobbing foundries are constrained in furnace types and available foundry additives that the operation always results in white irons. This study is towards ensuring grey iron is reproduced from cast iron scrap auto engine blocks, when using a diesel fired rotary furnace and a FeSi alloy for structural modification (inoculation. With varying addition rate of the FeSi alloy to the tapped molten metal, chill wedge tests were performed on two different wedge samples of type W (according to ASTM A367- wedge test with cooling modulus of 0.45 cm (W3½ and 0.54 cm (W4. The carbon equivalents for the test casts were within hypoeutectic range (3.85 wt. (% to 4.11 wt. (%. In the W4 wedge sample, at 2.0 wt. (% addition rate of the FeSi alloy, the relative clear chill was totally reduced to zero from 19.76%, while the relative mottled chill was brought down to 9.59% from 33.71%. The microstructure from the cast at this level of addition was free of carbidic phases; it shows randomly oriented graphite flakes evenly distributed in the iron matrix. Hardness assessment shows that increasing rate of FeSi addition results in decreasing hardness, with maximum effect at 2.0 wt. (% addition. With equivalent aspect ratio (cooling modulus in a target cast product, this addition rate for this FeSi alloy under this furnace condition will attain graphitized microstructure in the cast product.

  17. Electrolytes and Electrodes for Electrochemical Synthesis of Ammonia

    DEFF Research Database (Denmark)

    Lapina, Alberto

    to evaluate their applicability to electrochemical synthesis of ammonia. First a number of potential electrolytes are investigated in the temperature range 25-400°C in order to find a proton conductor with a conductivity higher than 10-4 S/cm in dry atmosphere (pH2O ... effective energy storage solutions. Production of synthetic fuels (e.g. ammonia) is a promising possibility. Ammonia (NH3) can be an interesting energy carrier, thanks to its high energy density and the existence of well developed storage and transportation technologies. However the present-day production...... technology is based on the Haber-Bosch process, which is energy intensive and requires large-scale plants. One possible way to produce ammonia from sustainable electricity, nitrogen and hydrogen/water is using an electrochemical cell. This thesis studies a number of electrolytes and electrocatalysts...

  18. Two-Pipe Chilled Beam System for Both Cooling and Heating of Office Buildings

    DEFF Research Database (Denmark)

    Afshari, Alireza; Gordnorouzi, Rouzbeh; Hultmark, Göran;

    2013-01-01

    advantage of renewable energy. The results showed that the energy consumption was 3% less in the 2-pipe chilled beam system in comparison with the conventional 4-pipe system when moving cooled and heated water through the building, transferring the energy to where it is needed. Using free cooling (taking...... consumption and hence energy savings in the 2-pipe chilled beam system in comparison with the 4-pipe system. The 2-pipe chilled beam system used high temperature cooling and low temperature heating with a water temperature of 20°C to 23°C, available for free most of the year. The system can thus take......Simulations were performed to compare a conventional 4-pipe chilled beam system and a 2-pipe chilled beam system. The objective was to establish requirements, possibilities and limitations for a well-functioning 2-pipe chilled beam system for both cooling and heating of office buildings...

  19. Chill-inducing music enhances altruism in humans

    Directory of Open Access Journals (Sweden)

    Hajime eFukui

    2014-10-01

    Full Text Available Music is a universal feature of human cultures, and it has both fascinated and troubled many researchers. In this paper we show through the Dictator Game that an individual’s listening to preferred chill-inducing music may promote altruistic behavior that extends beyond the bounds of kin selection or reciprocal altruism. Participants were 22 undergraduate and postgraduate students who were divided into two groups, the In-group (IG and the Out-group (OG, and they acted as dictators. The dictators listened to their own preferred chill-inducing music, to music they disliked, or to silence, and then played the Dictator Game. In this hypothetical experiment, the dictators were given real money (which they did not keep and were asked to distribute it to the recipients, who were presented as stylized images of men and women displayed on a computer screen. The dictators played the Dictator Game both before and after listening to the music. Both male and female dictators gave more money after listening to their preferred music and less after listening to the music they disliked, whereas silence had no effect on the allocated amounts. The group to which the recipient belonged did not influence these trends. The results suggest that listening to preferred chill-inducing music promotes altruistic behavior.

  20. Chill-inducing music enhances altruism in humans.

    Science.gov (United States)

    Fukui, Hajime; Toyoshima, Kumiko

    2014-01-01

    Music is a universal feature of human cultures, and it has both fascinated and troubled many researchers. In this paper we show through the dictator game (DG) that an individual's listening to preferred "chill-inducing" music may promote altruistic behavior that extends beyond the bounds of kin selection or reciprocal altruism. Participants were 22 undergraduate and postgraduate students who were divided into two groups, the in-group and the out-group, and they acted as dictators. The dictators listened to their own preferred "chill-inducing" music, to music they disliked, or to silence, and then played the DG. In this hypothetical experiment, the dictators were given real money (which they did not keep) and were asked to distribute it to the recipients, who were presented as stylized images of men and women displayed on a computer screen. The dictators played the DG both before and after listening to the music. Both male and female dictators gave more money after listening to their preferred music and less after listening to the music they disliked, whereas silence had no effect on the allocated amounts. The group to which the recipient belonged did not influence these trends. The results suggest that listening to preferred "chill-inducing" music promotes altruistic behavior.

  1. A meta-analysis study of the effect of chilling on prevalence of Salmonella on pig carcasses.

    Science.gov (United States)

    Gonzales Barron, U; Bergin, D; Butler, F

    2008-07-01

    In the field of food safety, meta-analysis can be used to combine results of prevalence studies of pathogens at critical stages within the food processing chain so that policy makers can access reliable and concise information on the effectiveness of interventions for controlling and preventing foodborne illnesses in humans. The objective of this work was to demonstrate the applicability of a parametric approach of meta-analysis to the specific case of determining the overall effect of chilling on Salmonella prevalence on pig carcasses. A meta-analysis was performed on each of two parameters measuring effect size for binary outcomes (relative risk and risk difference). Both meta-analyses confirmed that the chilling operation has a significant beneficial effect (P pig carcasses. Because risk difference is a parameter sensitive to the differences across studies in carcass swab areas and Salmonella detection methods, its meta-analysis highly reflected this heterogeneity (P meta-analysis solution, which is deemed more suitable for compilations based on a small number of individual studies (n = 9). Because of the systematic approach of meta-analysis (i.e., individual studies are weighed according to precision) and its reliance for actual data, the output distribution of the relative risk effect size (approximately eN(-0.868,0.166)) merits consideration for inclusion in the chilling stage of quantitative risk assessments modeling the prevalence of this pathogen along the pork production chain.

  2. Effect of processing plant on pork quality

    NARCIS (Netherlands)

    Hambrecht, E.; Eissen, J.J.; Verstegen, M.W.A.

    2003-01-01

    The impact of processing plant on pork quality was studied by assessing pork quality in three commercial plants (A, B, Q. Plants differed in the layout of the races, stunning systems (A and B: electrical, C: CO2 stunning) and chilling systems (A: rapid chilling, B and C: conventional). Factors not r

  3. Manufacture of Catalyst Systems for Ammonia Conversion

    Institute of Scientific and Technical Information of China (English)

    GAKH S.V.; SAVENKOV D.A.

    2012-01-01

    Platinum catalyst gauzes have been in use since the moment of development of the process of catalyst oxidation of ammonia for production of nitric acid or hydrocyanic acid.Catalyst gauzes are usually made of platinum or its alloys with rhodium and palladium.These precious metals have remarkable properties that make them ideal catalysts for acceleration of the ammonia/oxygen reaction.In 2008,OJSC "SIC ‘Supermetal’" and Umicore AG&Co.KG launched a production line for Pt-alloy-based catalyst systems to be used for ammonia oxidation in the production of weak nitric acid.Catalyst systems consist of a pack of catalyst gauzes and a pack of catchment gauzes,which are made using flat-bed knitting machines and wire-cloth looms.Today,up-to-date catalyst systems MKSpreciseTM are being manufactured,the basic advantages of which are an individual structure of gauzes and composition of the material,which allows to define precisely the position of each gauze in the catalyst pack,a high activity of the catalyst pack,direct catching of platinum and rhodium in the catalyst system,and a reasonable combination of single- and multilayer types of gauzes.This makes it possible to vary the configuration of the catalyst and select an optimum composition of the system to ensure the maximum efficiency of the ammonia oxidation process.We also produce the catchment systems that allow to find the best decision from the economic point view for each individual case.

  4. Corrosion of an aluminum alloy chilled in flowing seawater and the effect of cathodic prevention

    OpenAIRE

    Yabuki, Akihiro; Yasunaga, David T.; Shibutani, Toshihiro; Shinkai, Koichi

    2007-01-01

    A new type of jet-in-slit testing apparatus for a specimen, chilled with a peltier element, was developed to investigate corrosion on the heat transfer surface of an aluminum alloy heat exchanger, in contact with a liquefaction gas at cryogenic temperature and in flowing seawater. The specimen can be chilled, even under flowing conditions, using this apparatus. Corrosion tests and polarization measurements of a specimen chilled by a peltier element were carried out in flowing seawater at vari...

  5. Chilling Tolerance Improving of Watermelon Seedling by Salicylic Acid Seed and Foliar Application

    OpenAIRE

    Mohammad SAYYARI; Fardin GHANBARI; Sajad FATAHI; Fatemeh BAVANDPOUR

    2013-01-01

    Chilling temperatures lead to numerous physiological disturbances in the cells of chilling-sensitive plants and result in chilling injury and death of tropical and subtropical plants such as watermelon. In this study, the possibility of cold stress tolerance enhancing of watermelon seedling (Citrullus lanatus) by exogenous application of Salicylic acid (SA) was investigated. SA was applied through seed soaking or foliar spray at 0, 0.5, 1 and 1.5 mM concentration. After SA treatment, the see...

  6. Submersible microbial desalination cell for simultaneous ammonia recovery and electricity production from anaerobic reactors containing high levels of ammonia

    DEFF Research Database (Denmark)

    Zhang, Yifeng; Angelidaki, Irini

    2015-01-01

    High ammonia concentration in anaerobic reactors can seriously inhibit the anaerobic digestion process. In this study, a submersible microbial desalination cell (SMDC) was developed as an innovative method to lower the ammonia level in a continuous stirred tank reactor (CSTR) by in situ ammonia...... recovery and electricity production. In batch experiment, the ammonia concentration in the CSTR decreased from 6 to 0.7g-N/L during 30days, resulting in an average recovery rate of 80g-N/m2/d. Meanwhile, a maximum power density of 0.71±0.5W/m2 was generated at 2.85A/m2. Both current driven NH4+ migration...

  7. Tenderness of Pork Muscles as Influenced by Chilling Rate and Altered Carcass Suspension

    DEFF Research Database (Denmark)

    Kirkegaard, Elin; Møller, Anders Juel

    1987-01-01

    Evaluation of tenderness improvements in porcine muscles (longissimus dorsi, semimembranosus, biceps femoris) in 72 carcasses by using combinations of three different chilling rates and two different suspennnsion methods....

  8. Changes of biogenic amines and quality indicators of grass carp (Ctenpharyngodon idellus) during chilled storage and effect on biogenic amines during thermal processing%草鱼冷藏过程鱼肉品质与生物胺的变化及热处理对生物胺的影响

    Institute of Scientific and Technical Information of China (English)

    张月美; 包玉龙; 罗永康; 王航

    2013-01-01

    We investigated the changes in biogenic amines and other quality indicators during chilled storage(4 ℃) and effect of thermal processing on biogenic amines (85 ℃,15 min) of grass carp (Ctenpharyngodon idellus) by observing the drip loss,sensory assessment,total volatile basic nitrogen(TVB-N),total viable counts and content of eight biogenic amines (tryptamine,2-phenylethyl-amine,putrescine,cadaverine,histamine,tyramine,spermidine and spermine).The correlation was analyzed between biogenic amines and quality indicators of grass carp.The resuhs showed that drip loss,TVB-N and total viable counts increased with storage time,which accorded with the changes of sensory scores.The preservation life of grass carp at 4 ℃ was 9 days.During the storage,putrescine and cadaverine changed most significantly that putrescine content reached (17.12 ± 4.40) mg·kg-1 and cadaverine content reached (237.47 ±3.96) mg·kg-1 at 15th day.Besides,cadaverine and putrescine had good correlation with drip loss,sensory assessment,TVB-N and total viable counts.After thermal processing,contents of putrescine,cadaverine,histamine and spermine decreased slightly,saying that thermal processing could not remove the biogenic amines of grass carp effectively.%文章研究了草鱼(Ctenpharyngodon idellus)冷藏过程鱼肉品质与生物胺的变化及热处理对生物胺的影响.将经过前处理的草鱼鱼片于4℃条件下贮藏,对其感官品质、挥发性盐基氮(TVB-N)、菌落总数、汁液流失率以及生物胺等指标进行测定,另外经过85℃、15 min的热处理后对草鱼鱼片的生物胺进行测定,探求其变化规律及草鱼的生物胺与其品质指标的相关性.结果表明,随着贮藏时间的延长,草鱼的汁液流失率、TVB-N、菌落总数均呈现明显的上升趋势,与感官分值的变化趋势相符,草鱼的感官接受极限为9d.草鱼鱼片在冷藏加工过程中变化最显著的生物胺是腐胺和尸胺,第15

  9. The role of glutamate dehydrogenase in mammalian ammonia metabolism.

    Science.gov (United States)

    Spanaki, Cleanthe; Plaitakis, Andreas

    2012-01-01

    Glutamate dehydrogenase (GDH) catalyzes the reversible inter-conversion of glutamate to α-ketoglutarate and ammonia. High levels of GDH activity is found in mammalian liver, kidney, brain, and pancreas. In the liver, GDH reaction appears to be close-to-equilibrium, providing the appropriate ratio of ammonia and amino acids for urea synthesis in periportal hepatocytes. In addition, GDH produces glutamate for glutamine synthesis in a small rim of pericentral hepatocytes. Hence, hepatic GDH can be either a source for ammonia or an ammonia scavenger. In the kidney, GDH function produces ammonia from glutamate to control acidosis. In the human, the presence of two differentially regulated isoforms (hGDH1 and hGDH2) suggests a complex role for GDH in ammonia homeostasis. Whereas hGDH1 is sensitive to GTP inhibition, hGDH2 has dissociated its function from GTP control. Furthermore, hGDH2 shows a lower optimal pH than hGDH1. The hGDH2 enzyme is selectively expressed in human astrocytes and Sertoli cells, probably facilitating metabolic recycling processes essential for their supportive role. Here, we report that hGDH2 is also expressed in the epithelial cells lining the convoluted tubules of the renal cortex. As hGDH2 functions more efficiently under acidotic conditions without the operation of the GTP energy switch, its presence in the kidney may increase the efficacy of the organ to maintain acid base equilibrium.

  10. Optimality in the zonation of ammonia detoxification in rodent liver.

    Science.gov (United States)

    Bartl, Martin; Pfaff, Michael; Ghallab, Ahmed; Driesch, Dominik; Henkel, Sebastian G; Hengstler, Jan G; Schuster, Stefan; Kaleta, Christoph; Gebhardt, Rolf; Zellmer, Sebastian; Li, Pu

    2015-11-01

    The rodent liver eliminates toxic ammonia. In mammals, three enzymes (or enzyme systems) are involved in this process: glutaminase, glutamine synthetase and the urea cycle enzymes, represented by carbamoyl phosphate synthetase. The distribution of these enzymes for optimal ammonia detoxification was determined by numerical optimization. This in silico approach predicted that the enzymes have to be zonated in order to achieve maximal removal of toxic ammonia and minimal changes in glutamine concentration. Using 13 compartments, representing hepatocytes, the following predictions were generated: glutamine synthetase is active only within a narrow pericentral zone. Glutaminase and carbamoyl phosphate synthetase are located in the periportal zone in a non-homogeneous distribution. This correlates well with the paradoxical observation that in a first step glutamine-bound ammonia is released (by glutaminase) although one of the functions of the liver is detoxification by ammonia fixation. The in silico approach correctly predicted the in vivo enzyme distributions also for non-physiological conditions (e.g. starvation) and during regeneration after tetrachloromethane (CCl4) intoxication. Metabolite concentrations of glutamine, ammonia and urea in each compartment, representing individual hepatocytes, were predicted. Finally, a sensitivity analysis showed a striking robustness of the results. These bioinformatics predictions were validated experimentally by immunohistochemistry and are supported by the literature. In summary, optimization approaches like the one applied can provide valuable explanations and high-quality predictions for in vivo enzyme and metabolite distributions in tissues and can reveal unknown metabolic functions.

  11. Ammonia removal from water: The comparison between using the wind speed and agitation method

    Directory of Open Access Journals (Sweden)

    Intamanee, J.

    2005-01-01

    Full Text Available Ammonia removal from skim latex is an essential step in skim block production process. In general, skim latex contains about 0.4% ammonia by weight of skim latex and needs to be reduced in order to minimize acid usage during rubber coagulation step. The method used to remove ammonia from skim latex in many concentrated rubber latex plants is ammonia volatilization by agitating skim latex using a large agitator in a mixing pool. In this research, a new method to remove ammonia from water by blowing wind over the water surface was investigated. The effects of agitation speed and wind speed on overall mass transfer coefficient and removal rate of ammonia were investigated in a pilot scale experiment. The result has shown that the overall mass transfer coefficient and the ammonia removal rate increase linearly with increasing Reynolds number of air and liquid. However, the ammonia removal rate by using wind speed was much higher than that given by agitation method. The wind speed method proposed in this study is then recommended for ammonia removal from skim latex. Possible ways for applying the wind speed method for skim latex production plant are also suggested. The relationship between the wind speed or Reynolds number and the mass transfer coefficient can also be used to design the system for ammonia removal from water byusing wind speed.

  12. Ammonia disinfection of corn grains intended for ethanol fermentation

    Directory of Open Access Journals (Sweden)

    Magdalena Broda

    2009-12-01

    Full Text Available Background. Bacterial contamination is an ongoing problem for commercial bioethanol plants. It concerns factories using grain and also other raw materials for ethanol fermentation. Bacteria compete with precious yeasts for sugar substrates and micronutrients, secrete lactic and acetic acids, which are toxic for yeast and this competition leads to significant decrease of bioethanol productivity. For this study, bacterial contamination of corn grain was examined. Then the grain was treated by ammonia solution to reduce microbial pollution and after that the microbiological purity of grain was tested one more time. Disinfected and non-disinfected corn grains were ground and fermentation process was performed. Microbiological purity of this process and ethanol yield was checked out. Material and methods. The grain was disinfected by ammonia solution for two weeks. Then the grain was milled and used as a raw material for the ethanol fermentation. The fermentation process was carried out in 500-ml Erlenmeyer flasks. Samples were withdrawn for analysis at 0, 24, 48, 72 hrs. The number of total viable bacteria, lactic acid bacteria, acetic acid bacteria, anaerobic bacteria and the quantity of yeasts and moulds were signified by plate method. Results. Ammonia solution effectively reduces bacterial contamination of corn grain. Mash from grain disinfected by ammonia contains less undesirable microorganisms than mash from crude grain. Moreover, ethanol yield from disinfected grain is at the highest level. Conclusions. The ammonia solution proved to be a good disinfection agent for grain used as a raw material for bioethanol fermentation process.

  13. Effects of ammonia on processing and secretion of precursor and mature lysosomal enzyme from macrophages of normal and pale ear mice: evidence for two distinct pathways

    OpenAIRE

    1985-01-01

    Lysosomal enzymes have been shown to be synthesized as microsomal precursors, which are processed to mature enzymes located in lysosomes. We examined the effect of ammonium chloride on the intracellular processing and secretion of two lysosomal enzymes, beta-glucuronidase and beta-galactosidase, in mouse macrophages. This lysosomotropic drug caused extensive secretion of both precursor and mature enzyme forms within a few hours, as documented by pulse radiolabeling and molecular weight analys...

  14. Global Seabird Ammonia Emissions

    Science.gov (United States)

    Riddick, S. N.; Blackall, T. D.; Dragosits, U.; Daunt, F. H.; Braban, C. F.; Tang, Y. S.; Trathan, P.; Wanless, S.; Sutton, M. A.

    2010-12-01

    Seabird colonies represent a major source of atmospheric ammonia (NH3) in remote coastal and marine systems in temperate, tropical and polar regions. Previous studies have shown that NH3 emissions from Scottish seabird colonies were substantial - of similar magnitude to the most intensive agricultural point source emissions. The UK data were used to model global seabird NH3 emissions and suggested that penguins are a major source of emissions on and around the Antarctic continent. The largest seabird colonies are in the order of millions of seabirds. Due to the isolation of these colonies from anthropogenic nitrogen sources, they may play a major role in the nitrogen cycle within these ecosystems. A global seabird database was constructed and used in conjunction with a species-specific seabird bioenergetics model to map the locations of NH3 emissions from seabird colonies. The accuracy of the modelled emissions was validated with field data of NH3 emissions measured at key seabird colonies in different climatic regions of the world: temperate (Isle of May, Scotland), tropical (Ascension Island) and polar (Signy Island, South Georgia). The field data indicated good agreement between modelled and measured NH3 emissions. The measured NH3 emissions also showed the variability of emission with climate. Climate dependence of seabird NH3 emissions may have further implications under a changing global climate. Seabird colonies represent NH3 emission ‘hotspots’, often far from anthropogenic sources, and are likely to be the major source of nitrogen input to these remote coastal ecosystems. The direct manuring by seabirds at colony locations may strongly influence species richness and biodiversity. The subsequent volatilisation and deposition of NH3 increases the spatial extent of seabird influence on nitrogen cycling in their local ecosystem. As many seabird populations are fluctuating due to changing food supply, climate change or anthropogenic pressures, these factors

  15. Tolerance response to in situ ammonia stress in a pilot-scale anaerobic digestion reactor for alleviating ammonia inhibition.

    Science.gov (United States)

    Gao, Shumei; Zhao, Mingxing; Chen, Yang; Yu, Meijuan; Ruan, Wenquan

    2015-12-01

    The anaerobic digestion (AD) of protein-rich substrates is generally inhibited by ammonia. In this study, ammonia-tolerant acclimation was exposed to a stepwise in situ ammonia stress during the continuous AD of solid residual kitchen waste by using a continuous stirred tank reactor with a 50 L active volume. The reactor worked well during the acclimation process, with an average daily biogas production of 58 L/d, an effluent soluble chemical oxygen demand of 7238 mg/L, a volatile fatty acid (VFA) content of 578 mg/L, and a VFA/alkalinity ratio of less than 0.4. Moreover, ammonia stress enhanced the activity of Coenzyme F420. The results of high-throughput 16S rDNA sequencing showed that ammonia stress increased the relative abundance of Firmicutes bacteria and hydrogenotrophic methanogens but decreased the abundance of acetotrophic methanogens. This microbial community shift was proposed to be an in situ response strategy for ammonia stress adaptation.

  16. MEASUREMENT OF AMMONIA RELEASE FROM SALTSTONE

    Energy Technology Data Exchange (ETDEWEB)

    Zamecnik, J; Alex Cozzi, A

    2009-01-15

    SRNL was requested by WSRC Waste Solidification Engineering to characterize the release of ammonia from saltstone curing at 95 C by performing experimental testing. These tests were performed with an MCU-type Tank 50H salt simulant containing 0, 50, and 200 mg/L ammonia. The testing program showed that above saltstone made from the 200 mg/L ammonia simulant, the vapor space ammonia concentration was about 2.7 mg/L vapor at 95 C. An upper 95% confidence value for this concentration was found to be 3.9 mg/L. Testing also showed that ammonia was chemically generated from curing saltstone at 95 C; the amount of ammonia generated was estimated to be equivalent to 121 mg/L additional ammonia in the salt solution feed. Even with chemical generation, the ammonia release from saltstone was found to be lower than its release from salt solution only with 200 mg/L ammonia.

  17. Influence of pH on the kinetics of short-cut nitrification process inhibited by high concentrate ammonia%pH对高浓度氨氮短程硝化抑制动力学的影响

    Institute of Scientific and Technical Information of China (English)

    遇光禄; 喻立军; 唐颖栋

    2013-01-01

    在移动床生物膜反应器(MBBR)实现稳定短程硝化的前提下,采用模拟废水进行批式实验,研究生物膜短程硝化过程的基质抑制动力学特性及pH的影响.基于Haldane模型建立短程硝化基质抑制动力学方程,确定不同pH条件下的动力学常数.结果表明,不同pH条件下,高浓度氨氮对短程硝化的抑制特性均符合Haldane模型.pH为7.0、8.0和9.0时的氨氮最大比降解速率(qmax)分别为9.906、16.234、14.742mg/(g·h),pH=8.0是获得高效的短程硝化效果的适宜运行条件.但半亚硝化的实现则需要在氨氮降解速率适当降低的条件下(pH=7.0)才能实现.%The substrate inhibition kinetic characteristics of short-cut nitrification under different pH conditions were evaluated when the aerobic moving-bed biofilm reactor achieved a stable nitrite accumulation rate.Batch test with simulate wastewater was conducted and the kinetic equations for the different pH was established based on Haldane model.The results showed that Haldane model was able to represent the inhibitions caused by high concentrate ammonia during short-cut nitrification process under different pH.The maximal specific degrading rate (qmax) for per gram volatile suspended solids was calculated by Haldane model,when the pH value was 7.0,8.0 and 9.0,the obtained qmax was 9.906,16.234 and 14.742mg/(g·h),respectively.The pH of 8.0 was appropriate condition for short-cut nitrification,but not for the half partial nitrification.Appropriately reducing the ammonia decomposition rate could be beneficial to half partial nitrification,and pH 7.0 was the suitable condition for half partial nitrification.

  18. Industrial heat pumps for high temperature process applications.:A numerical study of the ammonia-water hybrid absorption-compression heat pump

    OpenAIRE

    Jensen, Jonas Kjær; Elmegaard, Brian; Markussen, Wiebke Brix

    2016-01-01

    Industrielle processer forbruger ofte store mængder varme, mens der ofte dissiperes store mængder spildvarme til omgivelserne. Industriel varmeforsyning er typisk drevet af fossilt brændsel, enten olie eller naturgas. Varmeforbruget i industrielle processer er derfor ofte skyld i store udledninger af CO2 samt udledning af andre skadelige stof-fer. Da varmepumper kan opgradere lavtemperatur spildvarme til en højtemperatur varmekilde med kun en brøkdel af primær energi, kan varmepumper anvendes...

  19. Synthesis of ammonia directly from air and water at ambient temperature and pressure.

    Science.gov (United States)

    Lan, Rong; Irvine, John T S; Tao, Shanwen

    2013-01-01

    The N≡N bond (225 kcal mol⁻¹) in dinitrogen is one of the strongest bonds in chemistry therefore artificial synthesis of ammonia under mild conditions is a significant challenge. Based on current knowledge, only bacteria and some plants can synthesise ammonia from air and water at ambient temperature and pressure. Here, for the first time, we report artificial ammonia synthesis bypassing N₂ separation and H₂ production stages. A maximum ammonia production rate of 1.14 × 10⁻⁵ mol m⁻² s⁻¹ has been achieved when a voltage of 1.6 V was applied. Potentially this can provide an alternative route for the mass production of the basic chemical ammonia under mild conditions. Considering climate change and the depletion of fossil fuels used for synthesis of ammonia by conventional methods, this is a renewable and sustainable chemical synthesis process for future.

  20. Enrichment and Characterization of an Autotrophic Ammonia-Oxidizing Archaeon of Mesophilic Crenarchaeal Group I.1a from an Agricultural Soil

    NARCIS (Netherlands)

    Jung, M.Y.; Park, S.J.; Min, D.; Kim, J.S.; Rijpstra, W.I.C.; Sinninghe Damsté, J.S.; Kim, G.J.; Madsen, E.L.; Rhee, S.K.

    2011-01-01

    Soil nitrification is an important process for agricultural productivity and environmental pollution. Though one cultivated representative of ammonia-oxidizing Archaea from soil has been described, additional representatives warrant characterization. We describe an ammonia-oxidizing archaeon (strain

  1. 两段式冷却对牛肉食用品质的影响%Effect of two-stage chilling on eating quality of beef

    Institute of Scientific and Technical Information of China (English)

    高淑娟; 毛衍伟; 王秀江; 胡铁军; 罗欣

    2009-01-01

    The objective was to study the effect of two-stage chilling on eating quality of beef. Twenty crossbred cattle were selected (Yanbian cattle X Simmental cattle) to study the effect of two-stage chilling (TC -13--15℃ for 2 h, air velocity of 3 m/s, then changed into conventional chilling till 24 h) and conventional chilling (CC 0-4℃ for 24 h) on eating quality value of beef. The test results showed: Two-stage chilling increased the rate of the carcass temperature drop, decreased the rate of pH value drop, decreased evaporative loss of carcasses, helped to improve the color of beef, and increased shear stress, but had no significant effect on water holding capacity of beef, In the cattle slaughter process, the separate two-stage chilling treatment could decrease the tenderness of meat. With the increase of aging time, shear stress value would decrease. Electrical stimulation treatment should be combined with two-stage chilling to improve the eating quality of meat.%为探讨两段式冷却对牛肉食用品质的影响,以20头杂交牛胴体(延边牛×西门塔尔牛)按试验设计进行两段式冷却(温度-13~-15℃、时间2 h,风速3 m/s,随后转入常规冷却间至24 h)和常规冷却处理(温度0~4℃、时间24 h)相比较,研究不同处理对牛肉食用品质的影响.表明:两段式冷却处理加快胴体温度下降速率,减缓pH值下降速率,显著降低胴体冷却质量损失,使肉的色泽鲜红,提高肉的剪切力,对背最长肌的保水性无影响.可以认为在肉牛屠宰加工流程中,单独采用两段式冷却处理能降低肉的嫩度,但随时间的增加,剪切力值会有所降低,建议应用时结合电刺激处理来同时改善肉的食用品质.

  2. Chills in Different Sensory Domains: Frisson Elicited by Acoustical, Visual, Tactile and Gustatory Stimuli

    Science.gov (United States)

    Grewe, Oliver; Katzur, Bjorn; Kopiez, Reinhard; Altenmuller, Eckart

    2011-01-01

    "Chills" (frisson manifested as goose bumps or shivers) have been used in an increasing number of studies as indicators of emotions in response to music (e.g., Craig, 2005; Guhn, Hamm, & Zentner, 2007; McCrae, 2007; Panksepp, 1995; Sloboda, 1991). In this study we present evidence that chills can be induced through aural, visual, tactile, and…

  3. Chilling Tolerance and Physiological Parameters as Influenced by Grafting in Watermelon Seedlings

    Institute of Scientific and Technical Information of China (English)

    LIU Hui-ying; ZHU Zhu-jun; LU Guo-hua; QIAN Qiong-qiu

    2003-01-01

    The influences of different rootstocks on chilling tolerance and physiological parameters in wa-termelon seedlings have been studied. The results showed that grafting improved the chilling tolerance. Com-pared with own-rooted watermelon seedlings, the grafted watermelon seedlings had lower chilling injury index,lower electrolytic leakage (%), lower malondialdehyde (MDA) content, higher chlorophyll and proline con-tent, and higher activities of superoxide dismutase (SOD), ascorbate peroxidase (AsA-POD) and de-hydroascorbate reductase (DR) in the leaves under iow temperature stress. There was a considerable differenceof chilling tolerance among different grafted watermelon seedlings due to the difference of rootstock chillingtolerance. After low temperature treatment, the grafted seedling with higher chilling tolerance had lower elec-trolytic leakage ( %), lower MDA content, higher proline content and higher activities of SOD, AsA-POD andDR in the leaves compared with the grafted seedling with weaker chilling tolerance. From these, we could con-clude that chilling tolerance of watermelon seedlings may be related to higher antioxidative ability and mem-brane stability in the plants. The chilling tolerance of grafted seedling could be properly evaluated by compre-hensive physiological indexes but not a single physiological index.

  4. 9 CFR 327.21 - Inspection procedures for chilled fresh and frozen boneless manufacturing meat.

    Science.gov (United States)

    2010-01-01

    ... fresh and frozen boneless manufacturing meat. 327.21 Section 327.21 Animals and Animal Products FOOD... manufacturing of meat food products. As used in this section, the term “frozen” includes “chilled fresh,” and....21 Inspection procedures for chilled fresh and frozen boneless manufacturing meat. (a)...

  5. Regulation of photosynthesis and antioxidant metabolism in maize leaves at optimal and chilling temperatures : review

    NARCIS (Netherlands)

    Foyer, C.H.; VanAcker, H.; Gomez, L.D.; Harbinson, J.

    2002-01-01

    Maize (Zea mays L.) is a chilling (below 15 °C) sensitive plant that shows little capacity to acclimate to low growth temperatures. Maize leaves are extremely sensitive to chilling injury, which usually results in premature leaf senescence. Leaves exposed to temperatures below 10 °C in the light sho

  6. Feeding impairs chill coma recovery in the migratory locust (Locusta migratoria).

    Science.gov (United States)

    Andersen, Jonas Lembcke; Findsen, Anders; Overgaard, Johannes

    2013-10-01

    Low temperature causes loss of neuromuscular function in a wide range of insects, such that the animals enter a state known as chill coma. The ability to recover from chill coma (chill coma recovery time) is often a popular phenotype to characterise chill tolerance in insects. Chill coma in insects has been shown to be associated with a decrease in haemolymph volume and a marked increase in [K(+)], causing dissipation of K(+) equilibrium potential and resting membrane potential. High potassium diet (wheat) has also previously been shown to increase haemolymph [K(+)] in Locusta migratoria leading to sluggish behaviour. The present study combined these two independent stressors of ion and water homeostasis, in order to investigate the role of K(+)- and water-balance during recovery from chill coma, in the chill sensitive insect L. migratoria. We confirmed that cold shock elicits a fast increase in haemolymph [K(+)] which is likely caused by a water shift from the haemolymph to the muscles and other tissues. Recovery of haemolymph [K(+)] is however not only reliant on recovery of haemolymph volume, as the recovery of water and K(+) is decoupled. Chill coma recovery time, after 2h at -4 °C, differed significantly between fasted animals and those fed on high K(+) diet. This difference was not associated with an increased disturbance of haemolymph [K(+)] in the fed animals, instead it was associated with a slowed recovery of muscle [K(+)], muslce water, haemolymph [Na(+)] and K(+)equilibrium potential in the fed animals.

  7. Tomato chilling injury threshold defined by the volatile profiles of pink harvested tomato fruit

    Science.gov (United States)

    Fresh tomato fruit show visible symptoms of chilling injury (CI) when stored at temperatures lower than the reported chilling threshold of 12.5°C. However, their sensitivity has been reported to decrease as they ripen. Volatile profiles change during ripening and are affected by physiological change...

  8. Diversity of low chill peaches from Asia, Brasil, Europe and the USA

    Science.gov (United States)

    One hundred fifty-five peach (Prunus persica) cultivars, from Asia, Brazil, Europe, and the USA, were examined using eleven SSRs to study the genetic relationships among low chill as compared to high chill peach germplasm. Data was analyzed by NTSYSpc to form a similarity matrix using Nei and Li’s ...

  9. Chilling privation during dormancy period and carbohydrate mobilization in Japanese pear trees

    Directory of Open Access Journals (Sweden)

    Anderson Carlos Marafon

    2011-08-01

    Full Text Available The flower bud abortion is one of the main problems that limit commercial pear (Pyrus pyrifolia production in the southern region of Brazil. Insufficient chilling during the dormancy period is known as the main factor of this problem. One of the hypotheses to explain this problem is that the starch mobilization and carbohydrate fluxes to the buds are impeded when mild temperatures occurred during winter. This study compared the total soluble sugars (TSS and reducing sugars (RS concentrations, the cell wall acid invertase (CWAI - EC 3.2.1.26 and sucrose-phosphate synthase (SPS - EC 2.4.1.14 activities in wood of branches and floral buds of Japanese pear trees cv. Housui, grafted on Pyrus calleryana and submitted to chilling conditions during the dormancy period. Treatments were: (i natural conditions; (ii continuous artificial chilling; (iii alternating temperatures, and (iv total chilling privation. TSS and RS contents, as well as CWAI and SPS activities in tissues of branches that received insufficient chilling were lower than those that received sufficient chilling during winter. The starch concentration was superior in wood tissues of branches kept under chilling privation. The chilling privation disturbs carbohydrate mobilization in pear trees, reducing the sucrose synthesis capacity in wood tissues (source and sucrose importation by the floral buds (sink.

  10. A chemical additive to limit potential bacterial contamination in chill tanks

    Science.gov (United States)

    Broiler carcasses with different types and numbers of bacteria are commonly chilled together in an ice water bath which may lead to transfer of unwanted bacteria from carcass to carcass. Historically chill tanks have been chlorinated to help prevent cross contamination and recently other chemical a...

  11. Integrated Quality Assurance of Chilled Food Fish at Sea

    DEFF Research Database (Denmark)

    Frederiksen, Marco Thorup; Olsen, Karsten Bæk; Popescu, Valeriu

    1997-01-01

    The aim of the IQAS project is to improve the quality of fresh fish (white fish and flat fish) landed by the Community vessels significantly and to increase the proportion of the fish caught used for food purposes, as well as to improve the on-board working conditions. This will be achieved...... by specifying and developing safe, efficient, mechanized on-board handling systems enabling the catch to be sorted, gutted, bled, characterized for length and weight, prepared quickly and correctly for rapid chilling and to be stored in appropriate, labelled containers at 0°C until sold. A monitoring, measuring...

  12. Human Response to Personalized Ventilation Combined with Chilled Ceiling

    DEFF Research Database (Denmark)

    Lipczynska, Aleksandra; Kaczmarczyk, Jan; Marcol, Bartosz;

    2014-01-01

    Personalized ventilation (PV) improves inhaled air quality, because it provides fresh air to each workstation and directly to occupant’s breathing zone. Previous research was focused on combining PV with additional total volume air distribution, i.e. mixing ventilation or displacement ventilation...... temperature for chilled ceiling was 15,5/16,8°C at room air temperature of 26°C and 19,5/20,6°C at 28°C. During the experiment the subjects were performing typical office tasks at workstations with computers. Exposure included also increased activity level office work for a period of 25 min...

  13. Occurrence of Campylobacter jejuni and C. coli on broiler carcasses after chilling in southern Brazil

    Directory of Open Access Journals (Sweden)

    Gustavo Perdoncini

    2015-04-01

    Full Text Available Campylobacter jejuni and C. coli have been associated with gastrointestinal disorders in human beings, due mainly to the consumption of chicken meat. Despite control measures for reducing contamination by these bacteria, the detection of Campylobacter in carcasses after chilling remains high. A total of 105 carcasses were assessed by the horizontal detection method in five federally inspected slaughterhouses in southern Brazil in 2012 and in the first three months of 2013. Campylobacterwas isolated in 37.1% of the carcasses, of which 97.5% contained C. jejuni and 2.5% were infected by C. coli. The rate of positive carcasses across the slaughterhouses ranged from 0 to 71.4%. Determining the occurrence of Campylobacter among flocks is crucial for estimating the microbial load at specific points along the slaughtering process and for minimizing the risk of contamination of end products by Campylobacter.

  14. Study on ammonia slip detection in the harsh combustion environments using diode laser spectroscopy

    Science.gov (United States)

    You, Kun; Zhang, Yu-jun; Li, Hong-bin; He, Yin; Gao, Yan-wei; Wang, Li-ming; Liu, Wen-qing

    2016-10-01

    The emissions of NOX from Cement plant or Coal-fired power plant have serious pollution to the environment. In recent years, Selective Catalytic Reduction (SCR) is an effective means of reducing the emissions of NOX by injecting ammonia into the combustion flue gas, which ideally reacts with the NOX to produce harmless components (H2O and N2). The efficiency of SCR is determined by monitoring the ammonia slip of the flue exhaust outlet, excess ammonia injection can cause ammonia slip, which not only destroy the plant, but also increase the operating costs. In addition, ammonia is also pollution gases as NOX. The flue gas at the measurement point is high temperature, vibrate and high particle density processes in Cement plant primarily, such harsh conditions coupled with the highly reactive nature of ammonia, so it is difficult to reliable extractive low level analysis. The paper describes an in-situ Tunable Diode Laser analyzer for measuring ammonia slip in the combustion flue gas after SCR in Cement Plant or Coal-fired power plant. A correlation filtering algorithm is developed to select high-quality spectral absorption signal, which improve the accuracy of concentration inversion of analyzer. The paper also includes field test data on an actual Cement plant all day, and we compare the ammonia slip and NOX emissions of flue gas during actual production process, the results indicate that the measured values of the ammonia slip and NOX emissions present a good correlation and comply with the principle of SCR.

  15. Insights on the development, kinetics, and variation of photoinhibition using chlorophyll fluorescence imaging af a chilled, variegated leaf

    NARCIS (Netherlands)

    Hogewoning, S.W.; Harbinson, J.

    2007-01-01

    The effect of chilling on photosystem II (PSII) efficiency was studied in the variegated leaves of Calathea makoyana, in order to gain insight into the causes of chilling-induced photoinhibition. Additionally, a relationship was revealed between (chilling) stress and variation in photosynthesis. Chi

  16. AMMONIA-FREE NOx CONTROL SYSTEM

    Energy Technology Data Exchange (ETDEWEB)

    Song Wu; Zhen Fan; Andrew H. Seltzer; Richard G. Herman

    2006-06-01

    This report describes a novel NOx control system that has the potential to drastically reduce cost, and enhance performance, operation and safety of power plant NOx control. The new system optimizes the burner and the furnace to achieve very low NOx levels and to provide an adequate amount of CO, and uses the CO for reducing NO both in-furnace and over a downstream AFSCR (ammonia-free selective catalytic reduction) reactor. The AF-SCR combines the advantages of the highly successful SCR technology for power plants and the TWC (three-way catalytic converter) widely used on automobiles. Like the SCR, it works in oxidizing environment of combustion flue gas and uses only base metal catalysts. Like the TWC, the AF-SCR removes NO and excess CO simultaneously without using any external reagent, such as ammonia. This new process has been studied in a development program jointed funded by the US Department of Energy and Foster Wheeler. The report outlines the experimental catalyst work performed on a bench-scale reactor, including test procedure, operating conditions, and results of various catalyst formulations. Several candidate catalysts, prepared with readily available transition metal oxides and common substrate materials, have shown over 80-90% removal for both NO and CO in oxidizing gas mixtures and at elevated temperatures. A detailed combustion study of a 400 MWe coal-fired boiler, applying computational fluid dynamics techniques to model boiler and burner design, has been carried out to investigate ways to optimize the combustion process for the lowest NOx formation and optimum CO/NO ratios. Results of this boiler and burner optimization work are reported. The paper further discusses catalyst scale-up considerations and the conceptual design of a 400 MWe size AF-SCR reactor, as well as economics analysis indicating large cost savings of the ammonia-free NOx control process over the current SCR technology.

  17. An Inexpensive Radiosonde Chilled Mirror Sensor: An Old Technology With New Impact

    Science.gov (United States)

    Schmidlin, F. J.; Busalacchi, Antonio J. (Technical Monitor)

    1999-01-01

    The availability of an inexpensive chilled mirror dewpoint sensor has made improved atmospheric relative humidity measurements accessible. Comparisons between the chilled mirror sensor and routine radiosonde sensors have provided new information on the limitation and reliability of the routine measurements. The chilled mirror has observed detailed moisture profiles at cirrus cloud levels when cirrus was not visible, a feature that routine sensors fail to observe. Comparison measurements between the chilled mirror, the carbon resistive (hygristor) and, the capacitive sensors will be discussed. Measurements from three locations (Wallops Island; Andros Island, Bahamas; and Camborne, UK) will be highlighted. It is conceivable that the chilled mirror sensor, when its capability is fully understood, may be sufficiently reliable to serve as a reference.

  18. Influence of the ventilation system on thermal comfort of the chilled panel system in heating mode

    Energy Technology Data Exchange (ETDEWEB)

    Tian, Zhe; Ding, Yan; Wang, Shuo; Yin, Xinglei; Wang, Menglei [Tianjin University, Tianjin 300072 (China)

    2010-12-15

    In heating mode, fresh air is still essential for a chilled panel system in order to ensure the indoor air quality. In this paper, a chilled ceiling panel system was designed and built in a typical office room. The thermal environment and thermal comfort in the room were fully measured and evaluated by using the Fanger's PMV-PPD model and the standard of ISO 7730 respectively, when room was heated in two modes, one of which is the chilled panel heating mode and the other of which is the combined heating mode of chilled panel and supply air. The research results indicate that in the combined mode, ceiling ventilation improves the general thermal comfort and reduces the risk of local discomfort. Under the condition of same general thermal comfort, the heating supply upper limit of chilled panel can be increased by 12.3% because of air mixing effect caused by introduction of air ventilation. (author)

  19. Ammonia-Free NOx Control System

    Energy Technology Data Exchange (ETDEWEB)

    Song Wu; Zhen Fan; Andrew H. Seltzer; Richard G. Herman

    2005-03-31

    Research is being conducted under United States Department of Energy (DOE) Contract DE-FC26-03NT41865 to develop a new technology to achieve very low levels of NOx emissions from pulverized coal fired boiler systems by employing a novel system level integration between the PC combustion process and the catalytic NOx reduction with CO present in the combustion flue gas. The combustor design and operating conditions will be optimized to achieve atypical flue gas conditions. This approach will not only suppress NOx generation during combustion but also further reduce NOx over a downstream catalytic reactor that does not require addition of an external reductant, such as ammonia.

  20. Biological denitrification process based on the Fe(0)-carbon micro-electrolysis for simultaneous ammonia and nitrate removal from low organic carbon water under a microaerobic condition.

    Science.gov (United States)

    Deng, Shihai; Li, Desheng; Yang, Xue; Xing, Wei; Li, Jinlong; Zhang, Qi

    2016-11-01

    A combined process between micro-electrolysis and biological denitrification (MEBD) using iron scraps and an activated carbon-based micro-electrolysis carrier was developed for nitrogen removal under a microaerobic condition. The process provided NH4(+)-N and total nitrogen (TN) removal efficiencies of 92.6% and 95.3%, respectively, and TN removal rate of 0.373±0.11kgN/(m(3)d) at corresponding DO of 1.0±0.1mg/L and HRT of 3h, and the optimal pH of 7.6-8.4. High-throughput sequencing analysis verified that dominant classes belonged to β-, α-, and γ-Proteobacteria, and Nitrospira. The dominant genera Hydrogenophaga and Sphaerotilus significantly increased during the operation, covering 13.2% and 6.1% in biofilms attached to the carrier in the middle of the reactor, respectively. Autotrophic denitrification contributed to >80% of the TN removal. The developed MEBD achieved efficient simultaneous nitrification and autotrophic denitrification, presenting significant potential for application in practical low organic carbon water treatment.

  1. Seasonal variation in denitrification and dissimilatory nitrate reduction to ammonia process rates and corresponding key functional genes along an estuarine nitrate gradient

    Directory of Open Access Journals (Sweden)

    Cindy J Smith

    2015-06-01

    Full Text Available This research investigated spatial-temporal variation in benthic bacterial community structure, rates of denitrification and dissimilatory nitrate reduction to ammonium (DNRA processes and abundances of corresponding genes and transcripts at three sites – the estuary-head, mid-estuary and the estuary mouth along the nitrate gradient of the Colne estuary over an annual cycle. Denitrification rates declined down the estuary, while DNRA rates were higher at the estuary head and middle than the estuary mouth. In four out of the six two-monthly time-points, rates of DNRA were greater than denitrification at each site. Abundance of gene markers for nitrate-reduction (nitrate reductase narG and napA, denitrification (nitrite reductase nirS and DNRA (DNRA nitrite reductase nrfA declined along the estuary with significant relationships between denitrification and nirS abundance, and DNRA and nrfA abundance. Spatially, rates of denitrification, DNRA and corresponding functional gene abundances decreased along the estuary. However, temporal correlations between rate processes and functional gene and transcript abundances were not observed.

  2. Ammonia abatement by slurry acidification

    DEFF Research Database (Denmark)

    Petersen, Søren O.; Hutchings, Nicholas John; Hafner, Sasha

    2016-01-01

    Livestock production systems can be major sources of trace gases including ammonia (NH3), the greenhouse gases methane (CH4) and nitrous oxide (N2O), and odorous compounds such as hydrogen sulphide (H2S). Short-term campaigns have indicated that acidification of livestock slurry during in...... sections with 30-32 pigs with or without daily adjustment of slurry pH to below 6. Ammonia losses from reference sections with untreated slurry were between 9.5 and 12.4% of N excreted, and from sections with acidified slurry between 3.1 and 6.2%. Acidification reduced total emissions of NH3 by 66 and 71...

  3. Nitrocarburizing in ammonia-hydrocarbon gas mixtures

    DEFF Research Database (Denmark)

    Pedersen, Hanne; Christiansen, Thomas; Somers, Marcel A. J.

    2011-01-01

    The present work investigates the possibility of nitrocarburising in ammonia-acetylene-hydrogen and ammonia-propene-hydrogen gas mixtures, where unsaturated hydrocarbon gas is the carbon source during nitrocarburising. Consequently, nitrocarburising is carried out in a reducing atmosphere...

  4. Recovery of ammonia from swine manure using gas-permeable membranes: Effect of aeration

    Science.gov (United States)

    Gas-permeable membranes can recover ammonia from manure, reducing pollution whilst converting ammonia into ammonium salt fertilizer. The process involves manure pH control to increase ammonium (NH4) recovery rate that is normally carried out using an alkali. In this study a new strategy to avoid the...

  5. Effects of Aesthetic Chills on a Cardiac Signature of Emotionality.

    Directory of Open Access Journals (Sweden)

    Maria Sumpf

    Full Text Available Previous studies have shown that a cardiac signature of emotionality (referred to as EK, which can be computed from the standard 12 lead electrocardiogram, ECG, predicts inter-individual differences in the tendency to experience and express positive emotion. Here, we investigated whether EK values can be transiently modulated during stimulation with participant-selected music pieces and film scenes that elicit strongly positive emotion.The phenomenon of aesthetic chills, as indicated by measurable piloerection on the forearm, was used to accurately locate moments of peak emotional responses during stimulation. From 58 healthy participants, continuous EK values, heart rate, and respiratory frequency were recorded during stimulation with film scenes and music pieces, and were related to the aesthetic chills. EK values, as well as heart rate, increased significantly during moments of peak positive emotion accompanied by piloerection.These results are the first to provide evidence for an influence of momentary psychological state on a cardiac signature of emotional personality (as reflected in EK values. The possibility to modulate ECG amplitude signatures via stimulation with emotionally significant music pieces and film scenes opens up new perspectives for the use of emotional peak experiences in the therapy of disorders characterized by flattened emotionality, such as depression or schizoid personality disorder.

  6. Effects of Aesthetic Chills on a Cardiac Signature of Emotionality

    Science.gov (United States)

    Sumpf, Maria; Jentschke, Sebastian; Koelsch, Stefan

    2015-01-01

    Background Previous studies have shown that a cardiac signature of emotionality (referred to as EK, which can be computed from the standard 12 lead electrocardiogram, ECG), predicts inter-individual differences in the tendency to experience and express positive emotion. Here, we investigated whether EK values can be transiently modulated during stimulation with participant-selected music pieces and film scenes that elicit strongly positive emotion. Methodology/Principal Findings The phenomenon of aesthetic chills, as indicated by measurable piloerection on the forearm, was used to accurately locate moments of peak emotional responses during stimulation. From 58 healthy participants, continuous EK values, heart rate, and respiratory frequency were recorded during stimulation with film scenes and music pieces, and were related to the aesthetic chills. EK values, as well as heart rate, increased significantly during moments of peak positive emotion accompanied by piloerection. Conclusions/Significance These results are the first to provide evidence for an influence of momentary psychological state on a cardiac signature of emotional personality (as reflected in EK values). The possibility to modulate ECG amplitude signatures via stimulation with emotionally significant music pieces and film scenes opens up new perspectives for the use of emotional peak experiences in the therapy of disorders characterized by flattened emotionality, such as depression or schizoid personality disorder. PMID:26083383

  7. Habitat-associated phylogenetic community patterns of microbial ammonia oxidizers.

    Directory of Open Access Journals (Sweden)

    Antoni Fernàndez-Guerra

    Full Text Available Microorganisms mediating ammonia oxidation play a fundamental role in the connection between biological nitrogen fixation and anaerobic nitrogen losses. Bacteria and Archaea ammonia oxidizers (AOB and AOA, respectively have colonized similar habitats worldwide. Ammonia oxidation is the rate-limiting step in nitrification, and the ammonia monooxygenase (Amo is the key enzyme involved. The molecular ecology of this process has been extensively explored by surveying the gene of the subunit A of the Amo (amoA gene. In the present study, we explored the phylogenetic community ecology of AOB and AOA, analyzing 5776 amoA gene sequences from >300 isolation sources, and clustering habitats by environmental ontologies. As a whole, phylogenetic richness was larger in AOA than in AOB, and sediments contained the highest phylogenetic richness whereas marine plankton the lowest. We also observed that freshwater ammonia oxidizers were phylogenetically richer than their marine counterparts. AOA communities were more dissimilar to each other than those of AOB, and consistent monophyletic lineages were observed for sediments, soils, and marine plankton in AOA but not in AOB. The diversification patterns showed a more constant cladogenesis through time for AOB whereas AOA apparently experienced two fast diversification events separated by a long steady-state episode. The diversification rate (γ statistic for most of the habitats indicated γ(AOA > γ(AOB. Soil and sediment experienced earlier bursts of diversification whereas habitats usually eutrophic and rich in ammonium such as wastewater and sludge showed accelerated diversification rates towards the present. Overall, this work shows for the first time a global picture of the phylogenetic community structure of both AOB and AOA assemblages following the strictest analytical standards, and provides an ecological view on the differential evolutionary paths experienced by widespread ammonia

  8. Effect of low frequency electromagnetic field on microstructures and macrosegregation of horizontal direct chill casting aluminum alloy

    Institute of Scientific and Technical Information of China (English)

    赵志浩; 崔建忠; 董杰; 张海涛; 张北江

    2004-01-01

    The influences of low frequency electromagnetic field on cast surface, microstructures and macrosegregation in horizontal direct chill(HDC) casting process were investigated experimentally. The cast surfaces, microstructures and macrosegregation of the ingots manufactured by conventional HDC and low frequency electromagnetic HDC casting were compared. The results show that low frequency electromagnetic field significantly improves the surface quality, refines the microstructures and reduces macrosegregation. Further more, increasing electromagnetic intensity or decreasing frequency is beneficial to the improvement. In the range of ampere-turns and frequency employed in the experiments, the optimum ampere-turns is found to be 10 000 A · turn and the frequency to be 30 Hz.

  9. DETERMINATION OF AMMONIA IN EAR-LOBE CAPILLARY BLOOD IS AN ALTERNATIVE TO ARTERIAL BLOOD AMMONIA

    NARCIS (Netherlands)

    HUIZENGA, [No Value; GIPS, CH; CONN, HO; JANSEN, PLM

    1995-01-01

    Blood ammonia determination is a laboratory test to diagnose hepatic encephalopathy. Arterial blood is superior to peripheral venous blood ammonia because of ammonia metabolism in muscle. We have compared capillary with arterial whole blood ammonia as capillary sampling is an attractive alternative.

  10. Interannual variability of ammonia concentrations over the United States: sources and implications

    Science.gov (United States)

    Schiferl, Luke D.; Heald, Colette L.; Van Damme, Martin; Clarisse, Lieven; Clerbaux, Cathy; Coheur, Pierre-François; Nowak, John B.; Neuman, J. Andrew; Herndon, Scott C.; Roscioli, Joseph R.; Eilerman, Scott J.

    2016-09-01

    The variability of atmospheric ammonia (NH3), emitted largely from agricultural sources, is an important factor when considering how inorganic fine particulate matter (PM2.5) concentrations and nitrogen cycling are changing over the United States. This study combines new observations of ammonia concentration from the surface, aboard aircraft, and retrieved by satellite to both evaluate the simulation of ammonia in a chemical transport model (GEOS-Chem) and identify which processes control the variability of these concentrations over a 5-year period (2008-2012). We find that the model generally underrepresents the ammonia concentration near large source regions (by 26 % at surface sites) and fails to reproduce the extent of interannual variability observed at the surface during the summer (JJA). Variability in the base simulation surface ammonia concentration is dominated by meteorology (64 %) as compared to reductions in SO2 and NOx emissions imposed by regulation (32 %) over this period. Introduction of year-to-year varying ammonia emissions based on animal population, fertilizer application, and meteorologically driven volatilization does not substantially improve the model comparison with observed ammonia concentrations, and these ammonia emissions changes have little effect on the simulated ammonia concentration variability compared to those caused by the variability of meteorology and acid-precursor emissions. There is also little effect on the PM2.5 concentration due to ammonia emissions variability in the summer when gas-phase changes are favored, but variability in wintertime emissions, as well as in early spring and late fall, will have a larger impact on PM2.5 formation. This work highlights the need for continued improvement in both satellite-based and in situ ammonia measurements to better constrain the magnitude and impacts of spatial and temporal variability in ammonia concentrations.

  11. Energy retrofit study of an ammonia plant

    Energy Technology Data Exchange (ETDEWEB)

    Lababidi, H.M.S.; Alatiqi, I.M.; Nayfeh, L.J. [Kuwait University Safat (Kuwait). Dept. of Chemical Engineering

    2000-11-01

    Detailed energy integration study of the front-end of an existing ammonia plant has been performed, using recent advances in Pinch technology. Utility loads demanded by the existing process were found to be very close to the calculated minimum targets. This indicated that the selected ammonia plant is well integrated, and not much saving is expected through process-to-process energy integration. Alternatively, the retrofit study concentrated on better placement of available utilities. Two promising options have been investigated. The first one studied the flue gas temperature in the convection section of the primary reformer, and proposed new arrangements of the heating coils. Boiler feed water heating for high-pressure steam generation has been also considered as a possible source for reduction in energy consumption. Total benefit claimed amounted to 17.6% reduction in combustion fuel consumption. The overall results of this case study are promising. However, economical evaluation of the proposed modifications is essential. Additional possible reduction in energy consumption is also possible in energy and power integration of the back-end section. (author)

  12. IC/MBBR工艺处理高COD、高氨氮煤化工废水%IC/MBBR Process for Treatment of High COD and Ammonia Nitrogen Wastewater

    Institute of Scientific and Technical Information of China (English)

    魏谷

    2012-01-01

    采用IC/MBBR生化工艺处理煤化工生产废水.通过监测COD的去除效果和产气状况,分析了IC厌氧反应器启动及负荷期间的运行情况;通过监测VFA、ALK和pH值的变化趋势分析了IC厌氧反应器的酸化及恢复情况.MBBR反应器启动期间对氨氮的去除率高于COD;通过氮衡算,发现反应器中存在非传统的硝化/反硝化脱氮途径,这一现象在运行期间的氧利用估算中得到进一步证实.%IC/MBBR was used as bio-process to treat coal chemical wastewater. The operation status of IC anaerobic reactor during start-up and loading was analyzed by monitoring COD removal and gas production. The acidification and recovery of IC anaerobic reactor were also analyzed by monitoring VFA, ALK and pH. During MBBR start-up, the removal rate of NH3 - N was higher than that of COD. It was found by nitrogen balance calculation that a non-nitrification/denitrification pathway for nitrogen removal existed in the reactor. This phenomenon was verified by oxygen consumption estimation during the operation.

  13. Process characteristics of ammonia wastewater treatment by embedded immobilized nitrifying sludge%包埋固定化硝化污泥处理氨氮废水的过程特性

    Institute of Scientific and Technical Information of China (English)

    许晓毅; 张婷婷; 尤晓露; 吕晨培

    2016-01-01

    effective diffusion coefficient (De) of ammonia and oxygen in immobilized particles were calculated as 0.467×10-9m2/s and 0.279×10-9m2/s, respectively. SEM observation and the test of specific surface area showed that the specific surface area and the average pore diameter in the interior of the particles increased greatly during the stable stage compared with the fresh particles. Comprehensive comparison of three different systems including immobilized particles reactor, activated sludge reactor, and the mixing reactor with immobilized particles and activated sludge was carried out. The sludge reactor with adding immobilized particles could enhance the nitrification and nitrogen removal process significantly. Moreover, the simultaneous nitrification and denitrification also could be observed.

  14. Ammonia effect on hydrogenotrophic methanogens and syntrophic acetate-oxidizing bacteria.

    Science.gov (United States)

    Wang, Han; Fotidis, Ioannis A; Angelidaki, Irini

    2015-11-01

    Ammonia-rich substrates can cause inhibition on anaerobic digestion process. Syntrophic acetate-oxidizing bacteria (SAOB) and hydrogenotrophic methanogens are important for the ammonia inhibitory mechanism on anaerobic digestion. The roles and interactions of SAOB and hydrogenotrophic methanogens to ammonia inhibition effect are still unclear. The aim of the current study was to determine the ammonia toxicity levels of various pure strains of SAOB and hydrogenotrophic methanogens. Moreover, ammonia toxicity on the syntrophic-cultivated strains of SAOB and hydrogenotrophic methanogens was tested. Thus, four hydrogenotrophic methanogens (i.e. Methanoculleus bourgensis, Methanobacterium congolense, Methanoculleu thermophilus and Methanothermobacter thermautotrophicus), two SAOB (i.e. Tepidanaerobacter acetatoxydans and Thermacetogenium phaeum) and their syntrophic cultivation were assessed under 0.26, 3, 5 and 7 g NH4 (+)-N L(-1). The results showed that some hydrogenotrophic methanogens were equally, or in some cases, more tolerant to high ammonia levels compared to SAOB. Furthermore, a mesophilic hydrogenotrophic methanogen was more sensitive to ammonia toxicity compared to thermophilic methanogens tested in the study, which is contradicting to the general belief that thermophilic methanogens are more vulnerable to high ammonia loads compared to mesophilic. This unexpected finding underlines the fact that the complete knowledge of ammonia inhibition effect on hydrogenotrophic methanogens is still absent.

  15. Emergency membrane contactor based absorption system for ammonia leaks in water treatment plants

    Institute of Scientific and Technical Information of China (English)

    SHAO Jiahui; FANG Xuliang; HE Yiliang; JIN Qiang

    2008-01-01

    Because of the suspected health risks of trihalomethanes (THMs), more and more water treatment plants have replaced traditionalchlorine disinfection process with chloramines but often without the proper absorption system installed in the case of ammonia leaksin the storage room. A pilot plant membrane absorption system was developed and installed in a water treatment plant for this purpose.Experimentally determined contact angle, surface tension, and corrosion tests indicated that the sulfuric acid was the proper choice as the absorbent for leaking ammonia using polypropylene hollow fiber membrane contactor. Effects of several operating conditionson the mass transfer coefficient, ammonia absorption, and removal efficiency were examined, including the liquid concentration,liquid velocity, and feed gas concentration. Under the operation conditions investigated, the gas absorption efficiency over 99.9%was achieved. This indicated that the designed pilot plant membrane absorption system was effective to absorb the leaking ammonia in the model storage room. The removal rate of the ammonia in the model storage room was also experimentally and theoretically foundto be primarily determined by the ammonia suction flow rate from the ammonia storage room to the membrane contactor. The ammoniaremoval rate of 99.9% was expected to be achieved within 1.3 h at the ammonia gas flow rate of 500 m3/h. The success of the pilot plantmembrane absorption system developed in this study illustrated the potential of this technology for ammonia leaks in water treatmentplant, also paved the way towards a larger scale application.

  16. 46 CFR 154.1760 - Liquid ammonia.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Liquid ammonia. 154.1760 Section 154.1760 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES SAFETY STANDARDS FOR....1760 Liquid ammonia. The master shall ensure that no person sprays liquid ammonia into a cargo...

  17. 27 CFR 21.96 - Ammonia, aqueous.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Ammonia, aqueous. 21.96 Section 21.96 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT... Ammonia, aqueous. (a) Alkalinity. Strongly alkaline to litmus. (b) Ammonia content. 27 to 30 percent...

  18. Hydrogen production using ammonia borane

    Science.gov (United States)

    Hamilton, Charles W; Baker, R. Thomas; Semelsberger, Troy A; Shrestha, Roshan P

    2013-12-24

    Hydrogen ("H.sub.2") is produced when ammonia borane reacts with a catalyst complex of the formula L.sub.nM-X wherein M is a base metal such as iron, X is an anionic nitrogen- or phosphorus-based ligand or hydride, and L is a neutral ancillary ligand that is a neutral monodentate or polydentate ligand.

  19. Ammonia in power plant emission

    Science.gov (United States)

    Hammerich, Mads; Henningsen, J. O.; Olafsson, Ari

    1990-08-01

    Ammonia monitoring is needed in most schemes for denitrification of power plant emission. In the PALAMON system we use a 500 MHz tunable, single mode, single line, CO2 laser as light source for a low pressure, high temperature, photoacoustic cell. With this cell we can resolve the sR(5,O) line of the ammonia spectrum, and suppress the interfering C02(9R30) absorption line down to a lppm NH3 detection limit. The validity of the measured ammonia concentrations is strongly dependent on details of the sampling system and on the reliability of the calibration routines. In particular calibration with certified mixtures of NH3:N2 has proved insufficient due to the multiple and long time constants caused by adsorption of ammonia to different materials in the system. Presence of water vapor in the gas greatly reduces these time constants. Therefore a number of methods for simple production of moist calibration gases from macroscopic amounts of NH3 are applied. The calibrations are translated to response from an easily managable absorber in order to allow automated recalibration of the photoacoustic response. Data from a field test of the system, and calibration data will be presented.

  20. Ceramic Membranes for Ammonia Recovery

    Energy Technology Data Exchange (ETDEWEB)

    Camus, O.; Perera, S.; Crittenden, B. [Department of Chemical Engineering, University of Bath, Bath, BA2 7AY (United Kingdom); Van Delft, Y.C.; Meyer, D.F.; Pex, P.P.A.C. [ECN Solar Energy, Westerduinweg 3, P.O. Box 1, 1755 ZG Petten (Netherlands); Kumakiri, I.; Miachon, S.; Dalmon, J.A. [CNRS-Institut de Recherches sur la Catalyse 2, av. A. Einstein, 69626 Villeurbanne (France); Tennison, S. [MAST Carbon, Ltd., Henley Park, Guildford, Surrey, GU3 2AF (United Kingdom); Chanaud, P. [Pall-Exekia, BP1, Usine a Bazet (France); Groensmit, E. [Kemira GrowHow SA/NV, Avenue Einstein 11, B-1300 Wavre (Belgium); Nobel, W. [Continental Engineers BV, Rustenburg 114, 1506 AZ Zaandam (Netherlands)

    2008-12-15

    An extensive screening program has been performed to find a suitable membrane configuration and operating conditions for the effective recovery of ammonia from the syngas loop. All the experiments have been performed at steady state. MFI zeolite membranes in tubular and multi-channel fiber configurations have been tested along with tubular silica membranes. At 80C, a high ammonia permeance (2.1 x 10{sup -7} mol.m{sup -2}.s{sup -1}.Pa{sup -1}), and a selectivity of about 10 were found with the tubular zeolite membrane, whereas for the silica membrane an even higher ammonia permeance was measured (7.6 x 10{sup -7} mol.m{sup -2}.s{sup -1}.Pa{sup -1}) with a selectivity of about 7. For both silica and zeolite membranes, the selectivity was found to increase with increasing temperature up to 80C. This is a combined effect of weaker adsorption of ammonia and increased diffusion at higher temperature. The results have been modeled using both the well-mixed reactor and the log mean pressure difference approaches. To overcome their limitations in addressing changes in feed concentration along the membrane surface, a segmental model has been used to obtain suitable operating conditions and membrane areas required for an industrial application.

  1. Reducing ammonia emissions in Europe

    DEFF Research Database (Denmark)

    Jacobsen, Brian H.

    2011-01-01

    The NEC directive has set targets for the 2010 ammonia emissions from a number of European countries. The target will be reached by most EU-countries and the total emission for EU-27 has been reduced by 22% from 1990 to 2007. Denmark is one of the countries with the largest reductions since 1990...

  2. Forthcoming Oversupply for Synthetic Ammonia

    Institute of Scientific and Technical Information of China (English)

    Zhang Zhantong

    2007-01-01

    @@ Stable output increase The total capacity of synthetic ammonia in China is 52.0 million t/a today.There are around 540 producers mainly located in Shandong, Shanxi, Hebei,Henan, Jiangsu and Sichuan provinces.The cumulative capacity in Shandong province ranks the highest, accounting for 14.6% of the national total.

  3. Power cycles with ammonia-water mixtures as working fluid

    Energy Technology Data Exchange (ETDEWEB)

    Thorin, Eva

    2000-05-01

    It is of great interest to improve the efficiency of power generating processes, i.e. to convert more of the energy in the heat source to power. This is favorable from an environmental point of view and can also be an economic advantage. To use an ammonia-water mixture instead of water as working fluid is a possible way to improve the efficiency of steam turbine processes. This thesis includes studies of power cycles with ammonia-water mixtures as working fluid utilizing different kinds of heat sources for power and heat generation. The thermophysical properties of the mixture are also studied. They play an important role in the calculations of the process performance and for the design of its components, such as heat exchangers. The studies concern thermodynamic simulations of processes in applications suitable for Swedish conditions. Available correlations for the thermophysical properties are compared and their influence on simulations and heat exchanger area predictions is investigated. Measurements of ammonia-water mixture viscosities using a vibrating wire viscometer are also described. The studies performed show that power cycles with ammonia-water mixtures as the working fluid are well suited for utilization of waste heat from industry and from gas engines. The ammonia-water power cycles can give up to 32 % more power in the industrial waste heat application and up to 54 % more power in the gas engine bottoming cycle application compared to a conventional Rankine steam cycle. However, ammonia-water power cycles in small direct-fired biomass-fueled cogeneration plants do not show better performance than a conventional Rankine steam cycle. When different correlations for the thermodynamic properties are used in simulations of a simple ammonia-water power cycle the difference in efficiency is not larger than 4 %, corresponding to about 1.3 percentage points. The differences in saturation properties between the correlations are, however, considerable at high

  4. Counteracting ammonia inhibition in anaerobic digestion by removal with a hollow fiber membrane contactor.

    Science.gov (United States)

    Lauterböck, B; Ortner, M; Haider, R; Fuchs, W

    2012-10-01

    The aim of the current study was to investigate the feasibility of membrane contactors for continuous ammonia (NH₃-N) removal in an anaerobic digestion process and to counteract ammonia inhibition. Two laboratory anaerobic digesters were fed slaughterhouse wastes with ammonium (NH₄⁺) concentrations ranging from 6 to 7.4 g/L. One reactor was used as reference reactor without any ammonia removal. In the second reactor, a hollow fiber membrane contactor module was used for continuous ammonia removal. The hollow fiber membranes were directly submerged into the digestate of the anaerobic reactor. Sulfuric acid was circulated in the lumen as an adsorbent solution. Using this set up, the NH₄⁺-N concentration in the membrane reactor was significantly reduced. Moreover the extraction of ammonia lowered the pH by 0.2 units. In combination that led to a lowering of the free NH₃-N concentration by about 70%. Ammonia inhibition in the reference reactor was observed when the concentration exceeded 6 g/L NH₄⁺-N or 1-1.2 g/L NH₃-N. In contrast, in the membrane reactor the volatile fatty acid concentration, an indicator for process stability, was much lower and a higher gas yield and better degradation was observed. The chosen approach offers an appealing technology to remove ammonia directly from media having high concentrations of solids and it can help to improve process efficiency in anaerobic digestion of ammonia rich substrates.

  5. Transcriptional Response of the Archaeal Ammonia Oxidizer Nitrosopumilus maritimus to Low and Environmentally Relevant Ammonia Concentrations

    OpenAIRE

    Nakagawa, Tatsunori; Stahl, David A.

    2013-01-01

    The ability of chemoautotrophic ammonia-oxidizing archaea to compete for ammonia among marine microorganisms at low ambient concentrations has been in part attributed to their extremely high affinity for ammonia, but as yet there is no mechanistic understanding of supporting metabolism. We examined transcription of selected genes for anabolic functions (CO2 fixation, ammonia transport, and cell wall synthesis) and a central catabolic function (ammonia oxidation) in the thaumarchaeon Nitrosopu...

  6. Amine substitution into sulfuric acid – ammonia clusters

    Directory of Open Access Journals (Sweden)

    O. Kupiainen

    2011-11-01

    Full Text Available The substitution of ammonia by dimethylamine in sulfuric acid – ammonia – dimethylamine clusters was studied using a collision and evaporation dynamics model. Quantum chemical formation free energies were computed using B3LYP/CBSB7 for geometries and frequencies and RI-CC2/aug-cc-pV(T+dZ for electronic energies. We first demonstrate the good performance of our method by a comparison with an experimental study investigating base substitution in positively charged clusters, and then continue by simulating base exchange in neutral clusters, which cannot be measured directly. Collisions of a dimethylamine molecule with an ammonia containing positively charged cluster result in the instantaneous evaporation of an ammonia molecule, while the dimethylamine molecule remains in the cluster. According to our simulations, a similar base exchange can take place in neutral clusters, although the overall process is more complicated. Neutral sulfuric acid – ammonia clusters are significantly less stable than their positively charged counterparts, resulting in a competition between cluster evaporation and base exchange.

  7. AMMONIA INHIBITION IN THERMOPHILIC ANAEROBIC DIGESTION OF DAIRY CATTLE MANURE

    Directory of Open Access Journals (Sweden)

    S. Sutaryo

    2015-04-01

    Full Text Available This study investigated the effect of five different concentrations of total ammonia nitrogen (TANand free ammonia (FA on the methane yield and digester performance under thermophilic conditions(50°C. Five identical continuously fed digesters were used. The experiment was run for four timeshydraulic retention time (HRT. Data were statitically analysed using the data Analysis Tool Packavailable with the Microsoft Excel program. Different ammonia levels were obtained by pulsing urea toobtain the target level of TAN and FA, and to subsequently maintaining the concentration of ammonialevels by daily urea additions. The result showed a strong negative correlation between both TAN andFA concentrations and methane yield. The methane yield was reduced by 24, 30, 52 and 66% indigesters that had TAN levels of 2.9, 3.6, 4.4 and 5.1 g/L, respectively, corresponding to 0.7, 1.1,1.5 and1.8 g/L FA. Total volatile fatty acid and especially isovaleric and isobutyric acid concentrations wereelevated during ammonia inhibition. Concentration of TAN in the biogas digester exceeding 3 g/Lindicating that very often the full biogas potential is not achieved due to ammonia inhibition and thatlonger HRT should be used to compensate or a lower process temperature should be chosen.

  8. Ammonia modification of oxide-free Si(111) surfaces

    Science.gov (United States)

    Chopra, Tatiana Peixoto; Longo, Roberto C.; Cho, Kyeongjae; Chabal, Yves J.

    2016-08-01

    Amination of surfaces is useful in a variety of fields, ranging from device manufacturing to biological applications. Previous studies of ammonia reaction on silicon surfaces have concentrated on vapor phase rather than wet chemical processes, and mostly on clean Si surfaces. In this work, the interaction of liquid and vapor-phase ammonia is examined on three types of oxide-free surfaces - passivated by hydrogen, fluorine (1/3 monolayer) or chlorine - combining infrared absorption spectroscopy, X-ray photoelectron spectroscopy, and first-principles calculations. The resulting chemical composition highly depends on the starting surface; there is a stronger reaction on both F- and Cl-terminated than on the H-terminated Si surfaces, as evidenced by the formation of Si-NH2. Side reactions can also occur, such as solvent reaction with surfaces, formation of ammonium salt by-products (in the case of 0.2 M ammonia in dioxane solution), and nitridation of silicon (in the case of neat and gas-phase ammonia reactions for instance). Unexpectedly, there is formation of Si-H bonds on hydrogen-free Cl-terminated Si(111) surfaces in all cases, whether vapor phase of neat liquid ammonia is used. The first-principles modeling of this complex system suggests that step-edge surface defects may play a key role in enabling the reaction under certain circumstances, despite the endothermic nature for Si-H bond formation.

  9. Different cultivation methods to acclimatise ammonia-tolerant methanogenic consortia.

    Science.gov (United States)

    Tian, Hailin; Fotidis, Ioannis A; Mancini, Enrico; Angelidaki, Irini

    2017-02-11

    Bioaugmentation with ammonia tolerant-methanogenic consortia was proposed as a solution to overcome ammonia inhibition during anaerobic digestion process recently. However, appropriate technology to generate ammonia tolerant methanogenic consortia is still lacking. In this study, three basic reactors (i.e. batch, fed-batch and continuous stirred-tank reactors (CSTR)) operated at mesophilic (37°C) and thermophilic (55°C) conditions were assessed, based on methane production efficiency, incubation time, TAN/FAN (total ammonium nitrogen/free ammonia nitrogen) levels and maximum methanogenic activity. Overall, fed-batch cultivation was clearly the most efficient method compared to batch and CSTR. Specifically, by saving incubation time up to 150%, fed-batch reactors were acclimatised to nearly 2-fold higher FAN levels with a 37%-153% methanogenic activity improvement, compared to batch method. Meanwhile, CSTR reactors were inhibited at lower ammonia levels. Finally, specific methanogenic activity test showed that hydrogenotrophic methanogens were more active than aceticlastic methanogens in all FAN levels above 540mgNH3-NL(-1).

  10. A comparison of chilled DI water/ozone and CO{sub 2}-based supercritical fluids as replacements for photoresist-stripping solvents

    Energy Technology Data Exchange (ETDEWEB)

    Rubin, J.B.; Davenhall, L.B.; Barton, J.; Taylor, C.M.V. [Los Alamos National Lab., NM (United States). Chemical Science and Technology Div.; Tiefert, K. [Hewlett-Packard Co., Santa Clara, CA (United States)

    1998-12-31

    Part of the Hewlett Packard Components Group`s Product Stewardship program is the ongoing effort to investigate ways to eliminate or reduce as much as possible the use of chemical substances from manufacturing processes. Currently used techniques to remove hard-baked photoresists from semiconductor wafers require the use of inorganic chemicals or organic strippers and associated organic solvents. Environmental, health and safety, as well as cost considerations prompted the search for alternative, more environmentally-benign, and cost-effective solutions. Two promising, emerging technologies were selected for evaluation: the chilled DI water/ozone technique and supercritical fluids based on carbon dioxide (CO{sub 2}). Evaluating chilled DI water/ozone shows this process to be effective for positive photoresist removal, but may not be compatible with all metallization systems. Testing of a closed-loop CO{sub 2}-based supercritical CO{sub 2} Resist Remover, or SCORR, at Los Alamos, on behalf of Hewlett-packard, shows that this treatment process is effective in removing photoresists, and is fully compatible with commonly used metallization systems. In this paper, the authors present details on the testing programs conducted with both the chilled DI H{sub 2}O/ozone and SCORR treatment processes.

  11. Two types of peak emotional responses to music: The psychophysiology of chills and tears

    Science.gov (United States)

    Mori, Kazuma; Iwanaga, Makoto

    2017-01-01

    People sometimes experience a strong emotional response to artworks. Previous studies have demonstrated that the peak emotional experience of chills (goose bumps or shivers) when listening to music involves psychophysiological arousal and a rewarding effect. However, many aspects of peak emotion are still not understood. The current research takes a new perspective of peak emotional response of tears (weeping, lump in the throat). A psychophysiological experiment showed that self-reported chills increased electrodermal activity and subjective arousal whereas tears produced slow respiration during heartbeat acceleration, although both chills and tears induced pleasure and deep breathing. A song that induced chills was perceived as being both happy and sad whereas a song that induced tears was perceived as sad. A tear-eliciting song was perceived as calmer than a chill-eliciting song. These results show that tears involve pleasure from sadness and that they are psychophysiologically calming; thus, psychophysiological responses permit the distinction between chills and tears. Because tears may have a cathartic effect, the functional significance of chills and tears seems to be different. We believe that the distinction of two types of peak emotions is theoretically relevant and further study of tears would contribute to more understanding of human peak emotional response. PMID:28387335

  12. Effects of Short-Term Chilling Stress on the Photosystems and Chloroplast Ultrastructure in Sweet Pepper

    Institute of Scientific and Technical Information of China (English)

    LI Xin-guo; BI Yu-ping; ZHAO Shi-jie; MENG Qing-wei; HE Qi-wei; ZOU Qi

    2005-01-01

    By measuring chlorophyll fluorescence parameters, composition of fatty acids, active oxygen species and activities of some antioxidant enzymes, effects of chilling stress (4℃) in the low light (100 μmol m-2 s-1) on chilling-sensitive plants were studied. After 6 h chilling stress (4℃) in the low light, the maximal photochemical efficiency of PSⅡ (Fv/Fm) of sweet pepper leaves decreased by 35.6%, and the oxidizable P700 decreased by 60%. However, chilling stress in the dark had no effect on both of them. Unsaturation of fatty acids in thylakoid membrane was accelerated, which might be helpful to stabilize photosynthetic apparatus. Distortion and swelling of grana caused by chilling in the dark probably decreased activities of antioxidant enzymes, which resulted in the accumulation of active oxygen species. On the contrary,photooxidation might be related to the disintegration and unstacking of grana. Chilling stress induced photoinhibition of PSⅡ and PSⅠ, and active oxygen species might be one of the factors causing the decrease of the oxidizable P700. PSⅠseemed to be more sensitive to chilling stress in the low light than PSⅡ.

  13. Reduction of Chilling Injury and Ultrastructural Damage in Cherry Tomato Fruits After Hot Water Treatment

    Institute of Scientific and Technical Information of China (English)

    YANG Jing; FU Mao-run; ZHAO Yu-ying; MAO Lin-chun

    2009-01-01

    The effects of hot water treatment in alleviating chilling injury and reducing ultrastructural damage of mature-green cherry tomatoes (Lycopersicun esculentum cv. cerasiform Alef) were investigated. Mature-green cherry tomato fruits were treated in water at 40℃ or 45℃ for 5 rain or 15 rain, and then stored at 5℃ for 19 days followed by ripening at 20℃. Water treatment at 40℃ for 15 rain increased tolerance of cherry tomato fruits to chilling stress, indicating as low outbreak of skin lesion, high color a* value, and low electrolyte leakage. Treated fi'uits showed typical climacteric respiration and developed normal red color with chlorophyll degradation and lyeopene accumulation during ripening, while fruits without treatment failed to develop red color and suffered skin lesion. After 19 days of chilling, heated fruits showed the conversion of chloroplast to ehromoplast with the disappearance of thylakoids. Mitochondria and other cell organelles were not adversely affected in treated fruits. However, ultrastruetures in periearp cells in control fruits severely damaged with extensive disorganization of cytoplasm, swelled chloroplasts, distorted and unstacked thylakoids. Chloroplast was the first and most severely impacted organelle by chilling stress. Hot water treatment (40℃ for 15 min) before storage alleviated chilling injury in cherry tomato fruits. The results suggest that chilling injury is related with the damage of cell structure under chilling stress.

  14. Music chills: The eye pupil as a mirror to music's soul.

    Science.gov (United States)

    Laeng, Bruno; Eidet, Lise Mette; Sulutvedt, Unni; Panksepp, Jaak

    2016-08-01

    This study evaluated whether music-induced aesthetic "chill" responses, which typically correspond to peak emotional experiences, can be objectively monitored by degree of pupillary dilation. Participants listened to self-chosen songs versus control songs chosen by other participants. The experiment included an active condition where participants made key presses to indicate when experiencing chills and a passive condition (without key presses). Chills were reported more frequently for self-selected songs than control songs. Pupil diameter was concurrently measured by an eye-tracker while participants listened to each of the songs. Pupil size was larger within specific time-windows around the chill events, as monitored by key responses, than in comparison to pupil size observed during 'passive' song listening. In addition, there was a clear relationship between pupil diameter within the chills-related time-windows during both active and passive conditions, thus ruling out the possibility that chills-related pupil dilations were an artifact of making a manual response. These findings strongly suggest that music chills can be visible in the moment-to-moment changes in the size of pupillary responses and that a neuromodulatory role of the central norepinephrine system is thereby implicated in this phenomenon.

  15. A Zinc Oxide Nanorod Ammonia Microsensor Integrated with a Readout Circuit on-a-Chip

    Directory of Open Access Journals (Sweden)

    Chyan-Chyi Wu

    2011-11-01

    Full Text Available A zinc oxide nanorod ammonia microsensor integrated with a readout circuit on-a-chip fabricated using the commercial 0.35 mm complementary metal oxide semiconductor (CMOS process was investigated. The structure of the ammonia sensor is composed of a sensitive film and polysilicon electrodes. The ammonia sensor requires a post-process to etch the sacrificial layer, and to coat the sensitive film on the polysilicon electrodes. The sensitive film that is prepared by a hydrothermal method is made of zinc oxide. The sensor resistance changes when the sensitive film adsorbs or desorbs ammonia gas. The readout circuit is used to convert the sensor resistance into the voltage output. Experiments show that the ammonia sensor has a sensitivity of about 1.5 mV/ppm at room temperature.

  16. A zinc oxide nanorod ammonia microsensor integrated with a readout circuit on-a-chip.

    Science.gov (United States)

    Yang, Ming-Zhi; Dai, Ching-Liang; Wu, Chyan-Chyi

    2011-01-01

    A zinc oxide nanorod ammonia microsensor integrated with a readout circuit on-a-chip fabricated using the commercial 0.35 μm complementary metal oxide semiconductor (CMOS) process was investigated. The structure of the ammonia sensor is composed of a sensitive film and polysilicon electrodes. The ammonia sensor requires a post-process to etch the sacrificial layer, and to coat the sensitive film on the polysilicon electrodes. The sensitive film that is prepared by a hydrothermal method is made of zinc oxide. The sensor resistance changes when the sensitive film adsorbs or desorbs ammonia gas. The readout circuit is used to convert the sensor resistance into the voltage output. Experiments show that the ammonia sensor has a sensitivity of about 1.5 mV/ppm at room temperature.

  17. A Zinc Oxide Nanorod Ammonia Microsensor Integrated with a Readout Circuit on-a-Chip

    Science.gov (United States)

    Yang, Ming-Zhi; Dai, Ching-Liang; Wu, Chyan-Chyi

    2011-01-01

    A zinc oxide nanorod ammonia microsensor integrated with a readout circuit on-a-chip fabricated using the commercial 0.35 μm complementary metal oxide semiconductor (CMOS) process was investigated. The structure of the ammonia sensor is composed of a sensitive film and polysilicon electrodes. The ammonia sensor requires a post-process to etch the sacrificial layer, and to coat the sensitive film on the polysilicon electrodes. The sensitive film that is prepared by a hydrothermal method is made of zinc oxide. The sensor resistance changes when the sensitive film adsorbs or desorbs ammonia gas. The readout circuit is used to convert the sensor resistance into the voltage output. Experiments show that the ammonia sensor has a sensitivity of about 1.5 mV/ppm at room temperature. PMID:22247656

  18. Transcriptional response of the archaeal ammonia oxidizer Nitrosopumilus maritimus to low and environmentally relevant ammonia concentrations.

    Science.gov (United States)

    Nakagawa, Tatsunori; Stahl, David A

    2013-11-01

    The ability of chemoautotrophic ammonia-oxidizing archaea to compete for ammonia among marine microorganisms at low ambient concentrations has been in part attributed to their extremely high affinity for ammonia, but as yet there is no mechanistic understanding of supporting metabolism. We examined transcription of selected genes for anabolic functions (CO2 fixation, ammonia transport, and cell wall synthesis) and a central catabolic function (ammonia oxidation) in the thaumarchaeon Nitrosopumilus maritimus SCM1 growing at two ammonia concentrations, as measured by combined ammonia and ammonium, one well above the Km for ammonia oxidation (∼500 μM) and the other well below the Km (ammonia-replete to ammonia-limiting conditions. Transcript levels for ammonia oxidation, CO2 fixation, and one of the ammonia transport genes were approximately the same at high and low ammonia availability. Transcripts for all analyzed genes decreased with time in the complete absence of ammonia, but with various rates of decay. The new steady-state mRNA levels established are presumably more reflective of the natural physiological state of ammonia-oxidizing archaea and offer a reference for interpreting message abundance patterns in the natural environment.

  19. Efficiency of deodorant materials for ammonia reduction in indoor air

    DEFF Research Database (Denmark)

    Bivolarova, Mariya Petrova; Mizutani, Chiyomi; Melikov, Arsen Krikor;

    2014-01-01

    A comparative study about the removability of ammonia gas in the air by activated carbon fiber (ACF) felt chemically treated with acid and a cotton fabric processed with iron phthalocyanine with copper (Cu) was performed in small-scale experiments. The test rig consisted of a heated plate and its...... proved activated carbon fiber felt with acid to be highly efficient in removing ammonia gas. Air temperature did not have profound effect on ACF performance. However, efficiency of the carbon fiber felt decreased when relative humidity was raised from 20 to 80%....

  20. Effects of liquid ammonia treatment on the physical properties of knit fabric

    Science.gov (United States)

    Lee, I. Y.; Kim, S. D.; Hwang, C. S.; Kim, S. R.; Park, S. W.

    2016-07-01

    The cellulosic knit fabric must be treated by NaOH solution in silket process to modify dyeability, luster, physical property, etc. But the silket treated knit fabric has a stiff touch, and must be treated with much of silicone softener. But it has bad durability of laundry. And the silket process has a problem that must discharge a lot of alkaline wastewater. In case of woven fabrics, as an alternative to silket process, liquid ammonia process was developed and this process is eco-friendly because the used ammonia is recovered by 98%. But the knit fabrics are not applicable to the conventional liquid ammonia process because they have selvedge curling problem and are very sensitive to tension. Recently, Korea High Tech Textile Research Institute(Korea) and Lafer SPA(Italy) worked together to develop the new liquid ammonia process for knit fabrics. In the present study, the physical properties of knit fabric after the newly-developed liquid ammonia treatment were investigated. The basic physical properties of knit fabric were measured using the Kawabata evaluation system. In addition, the dyeability, dimensional stability, eco-friendliness were investigated. The results showed that liquid ammonia treatment gave improved physical properties, which can be attributed to fast and uniform swelling, to knit fabric and resulted in a dimensional stability. The knit fabric treated in liquid ammonia showed a darker colour and unique appearance. Above all, the knit fabric treated in liquid ammonia had softer touch and superior gloss than the knit fabric of silket process. The new liquid ammonia process for knit fabrics will become the highest quality standard for knits and will be considered the preferred finish also thanks to eco-friendliness.

  1. "On-off" thermoresponsive coating agent containing salicylic acid applied to maize seeds for chilling tolerance.

    Directory of Open Access Journals (Sweden)

    Yajing Guan

    Full Text Available Chilling stress is an important constraint for maize seed establishment in the field. In this study, a type of "on-off" thermoresponsive coating agent containing poly (N-isopropylacrylamide-co-butylmethacrylate (Abbr. P(NIPAm-co-BMA hydrogel was developed to improve the chilling tolerance of coated maize seed. The P(NIPAm-co-BMA hydrogel was synthesized by free-radical polymerization of N-isopropylacrylamide (NIPAm and butylmethacrylate (BMA. Salicylic acid (SA was loaded in the hydrogel as the chilling resistance agent. SA-loaded P(NIPAm-co-BMA was used for seed film-coating of two maize varieties, Huang C (HC, chilling-tolerant and Mo17 (chilling-sensitive, to investigate the coated seed germination and seedling growth status under chilling stress. The results showed that the hydrogel obtained a phase transition temperature near 12°C with a NIPAM to MBA weight ratio of 1: 0.1988 (w/w. The temperature of 12°C was considered the "on-off" temperature for chilling-resistant agent release; the SA was released from the hydrogel more rapidly at external temperatures below 12°C than above 12°C. In addition, when seedlings of both maize varieties suffered a short chilling stress (5°C, higher concentrations of SA-loaded hydrogel resulted in increased germination energy, germination percentage, germination index, root length, shoot height, dry weight of roots and shoots and protective enzyme activities and a decreased malondialdehyde content in coated maize seeds compared to single SA treatments. The majority of these physiological and biochemical parameters achieved significant levels compared with the control. Therefore, SA-loaded P(NIPAm-co-BMA, a nontoxic thermoresponsive hydrogel, can be used as an effective material for chilling tolerance in film-coated maize seeds.

  2. "On-off" thermoresponsive coating agent containing salicylic acid applied to maize seeds for chilling tolerance.

    Science.gov (United States)

    Guan, Yajing; Li, Zhan; He, Fei; Huang, Yutao; Song, Wenjian; Hu, Jin

    2015-01-01

    Chilling stress is an important constraint for maize seed establishment in the field. In this study, a type of "on-off" thermoresponsive coating agent containing poly (N-isopropylacrylamide-co-butylmethacrylate) (Abbr. P(NIPAm-co-BMA)) hydrogel was developed to improve the chilling tolerance of coated maize seed. The P(NIPAm-co-BMA) hydrogel was synthesized by free-radical polymerization of N-isopropylacrylamide (NIPAm) and butylmethacrylate (BMA). Salicylic acid (SA) was loaded in the hydrogel as the chilling resistance agent. SA-loaded P(NIPAm-co-BMA) was used for seed film-coating of two maize varieties, Huang C (HC, chilling-tolerant) and Mo17 (chilling-sensitive), to investigate the coated seed germination and seedling growth status under chilling stress. The results showed that the hydrogel obtained a phase transition temperature near 12°C with a NIPAM to MBA weight ratio of 1: 0.1988 (w/w). The temperature of 12°C was considered the "on-off" temperature for chilling-resistant agent release; the SA was released from the hydrogel more rapidly at external temperatures below 12°C than above 12°C. In addition, when seedlings of both maize varieties suffered a short chilling stress (5°C), higher concentrations of SA-loaded hydrogel resulted in increased germination energy, germination percentage, germination index, root length, shoot height, dry weight of roots and shoots and protective enzyme activities and a decreased malondialdehyde content in coated maize seeds compared to single SA treatments. The majority of these physiological and biochemical parameters achieved significant levels compared with the control. Therefore, SA-loaded P(NIPAm-co-BMA), a nontoxic thermoresponsive hydrogel, can be used as an effective material for chilling tolerance in film-coated maize seeds.

  3. Physiological and biochemical mechanisms of seed priming-induced chilling tolerance in rice cultivars

    Directory of Open Access Journals (Sweden)

    Saddam eHussain

    2016-02-01

    Full Text Available Rice belongs to tropical and subtropical environments and is extremely sensitive to chilling stress particularly during emergence and early stages of seedling development. Seed priming can be a good approach to enhance rice germination and stand establishment under chilling stress. The present study examined the role of different seed priming techniques viz., hydropriming, osmopriming, redox priming, chemical priming, and hormonal priming, in enhancing the chilling tolerance in rice. The most effective reagents and their pre-optimized concentrations based on preliminary experiments were used in this study. Two different rice cultivars were sown under chilling stress (18˚C and normal temperatures (28˚C in separate growth chambers. A non-primed control treatment was also maintained for comparison. Chilling stress caused erratic and delayed germination, poor seedling growth, reduced starch metabolism and lower respiration rate, while higher lipid peroxidation and hydrogen peroxide accumulation in rice seedlings of both cultivars. Nevertheless, all the seed priming treatments effectively alleviated the negative effects of chilling stress. In addition, seed priming treatments triggered the activities of superoxide dismutase, peroxidase, and catalase, and enhanced the accumulations of glutathione and free proline in rice seedlings, which suggests that these measures help prevent the rice seedlings from chilling induced oxidative stress. Chemical priming with selenium and hormonal priming with salicylic acid remained more effective treatments for both rice cultivars under chilling stress than all other priming treatments. The better performance and greater tolerance of primed rice seedlings was associated with enhanced starch metabolism, high respiration rate, lower lipid peroxidation, and strong antioxidative defense system under chilling stress.

  4. Seed priming improves chilling tolerance in chickpea by modulating germination metabolism, trehalose accumulation and carbon assimilation.

    Science.gov (United States)

    Farooq, Muhammad; Hussain, Mubshar; Nawaz, Ahmad; Lee, Dong-Jin; Alghamdi, Salem S; Siddique, Kadambot H M

    2017-02-01

    Chilling stress is one of the major abiotic stresses affecting chickpea productivity worldwide. This study evaluated the potential role of seed priming in improving resistance to chilling stress in chickpea (cv. Punjab, 2008). The priming treatments involved soaking seeds of chickpea cultivar Punjab 2008 in either water for 8 h (on-farm priming), aerated water (hydropriming) for 18 h, or CaCl2 solution (ψs -1.25 MPa; osmopriming) for 18 h. Primed and untreated seeds were grown either at 18/15 °C (control) or 13/10 °C (chilling stress). Chilling stress suppressed the growth of chickpea while seed priming mitigated the adverse effects of chilling stress by improving stand establishment, growth, water relations, photosynthesis, α-amylase activity, sugar metabolism, antioxidant enzyme activity, membrane stability, and leaf accumulation of proline, nitrogen, potassium and soluble phenolics. Seed priming also improved the performance of chickpea under optimal (control) conditions. The overall order of improvement in resistance to chilling by using seed priming was osmopriming > hydropriming > on-farm priming. Osmopriming improved seedling dry weight, specific leaf area, leaf CO2 net assimilation rate, maximal photochemical efficiency of PSII, α-amylase activity, trehalose content and leaf relative water content by 10, 22, 17, 20, 73, 48 and 7%, respectively, relative to the non-primed control under chilling stress. Under optimal temperature conditions, the corresponding values were 30, 32, 16, 10, 83, 75 and 5%, respectively. Sugar metabolism, especially trehalose content, was strongly linked with stand establishment, photosynthesis, antioxidant potential (under chilling stress) and plant biomass. Overall, seed priming improved chickpea performance under both optimal temperature conditions and chilling stress through better germination metabolism and the accumulation of trehalose, which protected from oxidative damage and helped to maintain carbon

  5. Application of HACCP in Production of Chilled Meat%HACCP体系在冷却肉生产中的应用

    Institute of Scientific and Technical Information of China (English)

    刘娟

    2012-01-01

    介绍了HACCP体系及其在肉制品中的应用现状,并阐述了HACCP质量管理体系在冷却肉生产加工过程中的应用.%This paper introduced the HACCP system and its application status in meat product, and then expounded the application of HACCP quality management system in the processing of chilled pork.

  6. Growth of ammonia-oxidizing archaea and bacteria in cattle manure compost under various temperatures and ammonia concentrations.

    Science.gov (United States)

    Oishi, Ryu; Tada, Chika; Asano, Ryoki; Yamamoto, Nozomi; Suyama, Yoshihisa; Nakai, Yutaka

    2012-05-01

    A recent study showed that ammonia-oxidizing bacteria (AOB) and ammonia-oxidizing archaea (AOA) coexist in the process of cattle manure composting. To investigate their physiological characteristics, liquid cultures seeded with fermenting cattle manure compost were incubated at various temperatures (37°C, 46°C, or 60°C) and ammonium concentrations (0.5, 1, 4, or 10 mM NH (4) (+) -N). The growth rates of the AOB and AOA were monitored using real-time polymerase chain reaction analysis targeting the bacterial and archaeal ammonia monooxygenase subunit A genes. AOB grew at 37°C and 4 or 10 mM NH (4) (+) -N, whereas AOA grew at 46°C and 10 mM NH (4) (+) -N. Incubation with allylthiourea indicated that the AOB and AOA grew by oxidizing ammonia. Denaturing gradient gel electrophoresis and subsequent sequencing analyses revealed that a bacterium related to Nitrosomonas halophila and an archaeon related to Candidatus Nitrososphaera gargensis were the predominant AOB and AOA, respectively, in the seed compost and in cultures after incubation. This is the first report to demonstrate that the predominant AOA in cattle manure compost can grow and can probably oxidize ammonia under moderately thermophilic conditions.

  7. Nitrate to ammonia ceramic (NAC) bench scale stabilization study

    Energy Technology Data Exchange (ETDEWEB)

    Caime, W.J.; Hoeffner, S.L. [RUST - Clemson Technical Center, Anderson, SC (United States)

    1995-10-01

    Department of Energy (DOE) sites such as the Hanford site, Idaho National Engineering Laboratory (INEL), Savannah River site, Oak Ridge National Laboratory (ORNL) have large quantities of sodium-nitrate based liquid wastes. A process to reduce the nitrates to ammonia has been developed at ORNL. This technology creates a sludge lower in nitrates. This report describes stabilization possibilities of the sludge.

  8. Analysis and Evaluation Indicator Selection of Chilling Tolerance of Different Cotton Genotypes

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    [Objectivc] This study aimed to investigate the chilling tolerance of seedlings of different cotton genotypes and screen appropriate indicators for assess- ing chilling tolerance, to establish reliable mathematical evaluation model for chilling tolerance of cotton, thus providing theoretical basis for breeding and promoting new chilling-tolerant cotton germplasms and large-scale evaluation of chilling tolerance of cotton varieties. [Method] Fifteen cotton varieties (lines) were used as experimental materials. The photosynthetic gas exchange parameters, chlorophyll fluorescence ki- netic parameters, chlorophyll content, relative soluble sugar content, malonaldehyde content, relative proiine content, relative conductivity and other 12 physiological indi- cators of seedling leaves under low temperature treatment (5 ℃, 12 h) and recovery treatment (25 ℃. 24 h) were determined; based on the chilling tolerance coefficient (CTC) of various individual indicators, the comprehensive evaluation of chilling toler- ance was conducled by using principal component analysis, hierarchical cluster anal- ysis and stepwise regression analysis. [Result] The results showed that the 12 indi- vidual physiological indicators could be classified into 7 independent comprehensive components by principal component analysis; 15 cotton varieties (lines) were clus- tered into three categories by using membership function method and hierarchical cluster analysis; the mathematical model for evaluating chilling tolerance of cotton seedlings was established: D =0.275 -0.244Fo1 +0.206Fv/Fm1+0.326g,%-0.056SS + 0.225MDA+O.O38REC (FF=0.995), and the evaluation accuracy of the equation was higher than 94.25%,0. Six identification indicators closely related to chilling tolerance were screened, including Fo,, Fv/Fm1, Seedling leaves of cotton varieties (lines) gs2, SS, MDA, and REC. [Conclusion] with high chilling tolerance are less dam- aged under low temperature stress, and are able to maintain

  9. Prediction of Pressure Drop in Chilled Water Piping System Using Theoretical and CFD Analysis

    Directory of Open Access Journals (Sweden)

    Shirish P. Patil

    2013-08-01

    Full Text Available In the present study, three dimensional models of chilled water piping system is created using design modeler of Ansys-13. Ansys-13 fluent is used to analyses flow through chilled water pipe for pressure drop prediction. Karman-Prandtl equation is used for defining velocity profile of turbulent flow with the help of user defined function. Result obtained from CFD analysis is compared with results of 3K, 2K, ISHARE and Carrier equivalent length methods. Statistical analysis of performance based relative error has been carried out and based on that optimum analytical method for pressure drop prediction in chilled water piping is suggested.

  10. Human response to individually controlled micro environment generated with localized chilled beam

    DEFF Research Database (Denmark)

    Uth, Simon C.; Nygaard, Linette; Bolashikov, Zhecho Dimitrov;

    2014-01-01

    Indoor environment in a single-office room created by a localised chilled beam with individual control of the primary air flow was studied. Response of 24 human subjects when exposed to the environment generated by the chilled beam was collected via questionnaires under a 2-hour exposure including...... and local thermal sensation reported by the subjects with the two systems. Both systems were equally acceptable. At 26°C the individual control of the localised chilled beam lead to higher acceptability of the work environment. At 28°C the acceptability decreased with the two systems. It was not acceptable...

  11. Life cycle engineering of a system to deliver self-chilled beverages.

    OpenAIRE

    Arena, Noemi

    2016-01-01

    The chill-on-demand system is a technology designed to provide cooled products on demand, thereby avoiding any requirement for chilled storage. It uses the cooling effect provided by the endothermic desorption of carbon dioxide previously adsorbed onto a bed of activated carbon contained in an inner component of the self-chilling product. This has the potential to be applied to any type of product that needs to be cold at the point of consumption. The principles of life cycle engineering have...

  12. Electrochemically driven extraction and recovery of ammonia from human urine.

    Science.gov (United States)

    Luther, Amanda K; Desloover, Joachim; Fennell, Donna E; Rabaey, Korneel

    2015-12-15

    Human urine contains high concentrations of nitrogen, contributing about 75% of the nitrogen in municipal wastewaters yet only 1% of the volume. Source separation of urine produces an ideal waste stream for nitrogen and phosphorus recovery, reducing downstream costs of nutrient treatment at wastewater treatment facilities. We examined the efficiency and feasibility of ammonia extraction and recovery from synthetic and undiluted human urine using an electrochemical cell (EC). EC processing of synthetic urine produced an ammonium flux of 384 ± 8 g N m(-2) d(-1) with a 61 ± 1% current efficiency at an energy input of 12 kWh kg(-1) N removed. EC processing of real urine displayed similar performance, with an average ammonium flux of 275 ± 5 g N m(-2) d(-1) sustained over 10 days with 55 ± 1% current efficiency for ammonia and at an energy input of 13 kWh kg(-1) N removed. With the incorporation of an ammonia stripping and absorption unit into the real urine system, 57 ± 0.5% of the total nitrogen was recovered as ammonium sulfate. A system configuration additionally incorporating stripping of the influent headspace increased total nitrogen recovery to 79% but led to reduced performance of the EC as the urine ammonium concentration decrease. Direct stripping of ammonia (NH3) from urine with no chemical addition achieved only 12% total nitrogen recovery at hydraulic retention times comparable with the EC systems. Our results demonstrate that ammonia can be extracted via electrochemical means at reasonable energy inputs of approximately 12 kWh kg(-1) N. Considering also that the hydrogen generated is worth 4.3 kWh kg(-1) N, the net electrical input for extraction becomes approximately 8 kWh kg(-1) N if the hydrogen can be used. Critical for further development will be the inclusion of a passive means for ammonia stripping to reduce additional energy inputs.

  13. Ammonia for hydrogen storage: challenges and opportunities

    DEFF Research Database (Denmark)

    Klerke, Asbjørn; Christensen, Claus H.; Nørskov, Jens Kehlet

    2008-01-01

    The possibility of using ammonia as a hydrogen carrier is discussed. Compared to other hydrogen storage materials, ammonia has the advantages of a high hydrogen density, a well-developed technology for synthesis and distribution, and easy catalytic decomposition. Compared to hydrocarbons...... and alcohols, it has the advantage that there is no CO2 emission at the end user. The drawbacks are mainly the toxicity of liquid ammonia and the problems related to trace amounts of ammonia in the hydrogen after decomposition. Storage of ammonia in metal ammine salts is discussed, and it is shown...... that this maintains the high volumetric hydrogen density while alleviating the problems of handling the ammonia. Some of the remaining challenges for research in ammonia as a hydrogen carrier are outlined....

  14. Bioaugmentation as a solution to increase methane production from an ammonia-rich substrate.

    Science.gov (United States)

    Fotidis, Ioannis A; Wang, Han; Fiedel, Nicolai R; Luo, Gang; Karakashev, Dimitar B; Angelidaki, Irini

    2014-07-01

    Ammonia-rich substrates inhibit the anaerobic digestion (AD) process and constitute the main reason for low energy recovery in full-scale reactors. It is estimated that many full-scale AD reactors are operating in ammonia induced "inhibited steady-state" with significant losses of the potential biogas production yield. To date there are not any reliable methods to alleviate the ammonia toxicity effect or to efficiently digest ammonia-rich waste. In the current study, bioaugmentation as a possible method to alleviate ammonia toxicity effect in a mesophilic continuously stirred-tank reactor (CSTR) operating under "inhibited steady state" was tested. A fast growing hydrogenotrophic methanogen (i.e., Methanoculleus bourgensis MS2(T)) was bioaugmented in the CSTR reactor at high ammonia levels (5 g NH4(+)-N L(-1)). A second CSTR reactor was used as control with no bioaugmentation. The results derived from this study clearly demonstrated a 31.3% increase in methane production yield in the CSTR reactor, at steady-state, after bioaugmentation. Additionally, high-throughput 16S rRNA gene sequencing analysis showed a 5-fold increase in relative abundance of Methanoculleus spp. after bioaugmentation. On the contrary to all methods used today to alleviate ammonia toxicity effect, the tested bioaugmentation process performed without interrupting the continuous operation of the reactor and without replacing the ammonia-rich feedstock.

  15. Nitrification resilience and community dynamics of ammonia-oxidizing bacteria with respect to ammonia loading shock in a nitrification reactor treating steel wastewater.

    Science.gov (United States)

    Cho, Kyungjin; Shin, Seung Gu; Lee, Joonyeob; Koo, Taewoan; Kim, Woong; Hwang, Seokhwan

    2016-08-01

    The aim of this study was to investigate the nitrification resilience pattern and examine the key ammonia-oxidizing bacteria (AOB) with respect to ammonia loading shocks (ALSs) in a nitrification bioreactor treating steel wastewater. The perturbation experiments were conducted in a 4-L bioreactor operated in continuous mode with a hydraulic retention time of 10 d. Three sequential ALSs were given to the bioreactor (120, 180 and 180 mg total ammonia nitrogen (TAN)/L. When the first shock was given, the nitrification process completely recovered after 14 d of further operation. However, the resilience duration was significantly reduced to ∼1 d after the second and third ALSs. In the bioreactor, Nitrosomonas aestuarii dominated the other AOB species, Nitrosomonas europaea and N. nitrosa, throughout the process. In addition, the population of N. aestuarii increased with ammonia utilization following each ALS; i.e., this species responded to acute ammonia overloadings by contributing to ammonia oxidation. This finding suggests that N. aestuarii could be exploited to achieve stable nitrification in industrial wastewaters that contain high concentrations of ammonia.

  16. Respiratory Response of Dormant Nectarine Floral Buds on Chilling Deficiency

    Institute of Scientific and Technical Information of China (English)

    TAN Yue; GAO Dong-sheng; LI Ling; CHEN Xiu-de; XU Ai-hong

    2010-01-01

    Changes in main biochemical respiratory pathways in dormant nectarine floral buds were studied with nectarine trees (Prunus persica.var,nectariana cv.Shuguang) in order to determine the function of respiration in dormancy release.Oxygen-electrode system and respiratory inhibitors were used to measure total respiratory rates and rates of respiratory pathways.Results showed that chilling deficiency blocked the transition of respiratory mode,and made buds stay in a state of high level pentose phosphate pathway (PPP) and low level tricarboxylic acid cycle (TCA).The decline of PPP and activation of TCA occurred synchronously with the release of dormancy.In addition,the inhibition of PPP stimulated a respiration increase related with TCA.It could be concluded that the function of PPP activation in dormancy release might be limited and PPP declination inducing TCA activation might be part of respiration mode transition mechanism during bud sprouting.

  17. Development of the aerobic spoilage flora of chilled rabbit meat.

    Science.gov (United States)

    Rodríguez-Calleja, José M; García-López, María-Luisa; Santos, Jesús A; Otero, Andrés

    2005-06-01

    Even though worldwide production of rabbit meat is over 1,000,000ton, little information is available on rabbit meat microbiology. This paper reports on the microflora developing on chill-stored rabbit carcasses. Four different lots of 24h post-mortem rabbit carcasses dressed and kept at 0°C in a medium-size abattoir were collected and evaluated for sensory, physicochemical and microbiological changes during aerobic storage at 3±1°C. Mean initial pH value (pH(24)), extract-release volume (ERV) and lactate content of Biceps femoris muscle, were 6.26±0.20, 13.50±3.50ml and 0.70±0.07%, respectively. As with other muscle foods kept chilled in air, pH increased and ERV and lactate decreased as storage progressed. Initial levels (logcfu/g) of aerobes (APC), psychrotrophic flora, Pseudomonas spp., Brochothrix thermosphacta, lactic acid bacteria, Enterobacteriaceae and yeasts were 4.76±0.31, 4.81±0.81, 3.39±1.12, 2.01±0.92, 2.76±0.51, 0.49±0.45 and 3.46±0.32, respectively. Pseudomonads, most of them fluorescent, and to a lesser extent B. thermosphacta and yeasts grew faster than the remaining microorganisms and became predominant at the end of the shelf life. Carcasses spoiled when mean APC, psychrotrophic and pseudomonads numbers were ca. 8logcfu/g, their mean shelf life being estimated at 6.8 days. A lot of DFD-like rabbit carcasses, with higher pH and lower ERV values but similar microbial loads to normal meat, developed a strong putrid odour after 4 days.

  18. Effect of modified atmosphere and temperature abuse on the growth from spores and cereulide production of Bacillus weihenstephanensis in a cooked chilled meat sausage

    DEFF Research Database (Denmark)

    Thorsen, Line; Budde, Birgitte Bjørn; Koch, Anette Granly;

    2009-01-01

    demonstrates that MAP can be used to inhibit growth of a psychrotolerant toxin producing Bacillus spp. during chill storage at 8 °C, and substantially reduce the risk of emetic food poisoning at abuse condition. Results are of relevance for improving safety of ready to eat processed chilled foods of extended...... and temperature abuse for 1.5 h daily at 20 °C during 1 week resulted in increased cell counts and variable cereulide production in the meat sausage. A pre-history at 8 °C for 1 week inMAP with OTR of 1.3 or 40ml/m2/24 h and 2% O2 resulted in cereulide concentrations of 0.816-1.353 µg/gmeat sausage, while a pre-history...

  19. Avocado by-products as inhibitors of color deterioration and lipid and protein oxidation in raw porcine patties subjected to chilled storage.

    Science.gov (United States)

    Rodríguez-Carpena, J G; Morcuende, D; Estévez, M

    2011-10-01

    Processing of avocados generates an important amount of by-products such as peels and seeds that are rich in bioactive substances with proven radical suppressing activities. The objective of this study was to evaluate the effectiveness of peel and seed extracts from two avocado varieties-'Hass' and 'Fuerte'-as inhibitors of lipid and protein oxidation and color deterioration of raw porcine patties during chilled storage (4 °C/15 days). Avocado extracts significantly (pHass' extracts. Patties treated with avocado extracts had significantly lower amounts of TBA-RS than control ones throughout the storage. 'Hass' avocado extracts significantly inhibited the formation of protein carbonyls in chilled patties at day 15. The present results highlight the potential usage of extracts from avocado by-products as ingredients for the production of muscle foods with enhanced quality traits.

  20. The chilled storage life and retail display performance of vacuum and carbon dioxide packed hot deboned beef striploins.

    Science.gov (United States)

    Bell, R G; Penney, N; Gilbert, K V; Moorhead, S M; Scott, S M

    1996-04-01

    Two cooling regimes that complied with the New Zealand meat hygiene requirement that hot deboned meat be chilled to +7 °C or less within 24 hr of leaving the slaughter floor were evaluated for the production of chilled table meats. Electrically stimulated hot deboned bull beef half striploins were either vacuum or carbon dioxide packed before being cooled in accordance with either Regime 1 (cool at +5 °C for 24 hr, transfer to chiller operating at -1.0 ± 0.5 °C) or Regime 2 (cool at +5 °C for 24 hr, hold at 5 °C for 6 days, transfer to chiller operating at -1.0 ± 0.5 °C). Striploins were removed from -1.0 °C storage 8, 28, 42, 56, 70, 84 and 98 days after slaughter and subjected to microbiological, tenderness, sensory and retail display performance evaluations. Both Regimes 1 and 2 produced meat of acceptable mean tenderness, 8 kgF (MIRINZ Tenderometer) in either vacuum or carbon dioxide packs within 28 and 8 days of slaughter, respectively. However, 70 days after slaughter the first signs of over-ageing became apparent. Steaks from Regimes 1 and 2 maintained acceptable visual appearance during retail display at 5 °C for 48 hr and 24 hr, respectively. After these times, the product was judged by the panel to be unacceptable because of its dull dark lean tissue and grey to green discoloration of the fat. Poor colour stability during retail display was mirrored by deterioration of sensory attributes, particularly aroma which is indicative of incipient spoilage. While carbon dioxide packaging in combination with Regime 1 offered an initial microbiological advantage over vacuum packaging, this advantage was not, however, carried over into retail display. Poor colour and sensory stability during retail display suggest that chilled table cuts derived from hot deboned bull beef are more suited to the Hotel-Restaurant-Institutional (HRI) trade than supermarket retailing. To serve the HRI, vacuum packed hot deboned bull beef primal cuts processed by Regime 1

  1. Ammonia Production, Excretion, Toxicity, and Defense in Fish: A Review

    OpenAIRE

    Yuen K Ip; Chew, Shit F.

    2010-01-01

    Many fishes are ammonotelic but some species can detoxify ammonia to glutamine or urea. Certain fish species can accumulate high levels of ammonia in the brain or defense against ammonia toxicity by enhancing the effectiveness of ammonia excretion through active NH 4 + transport, manipulation of ambient pH, or reduction in ammonia permeability through the branchial and cutaneous epithelia. Recent reports on ammonia toxicity in mammalian brain reveal the importance of permeation of ammonia thr...

  2. Investigating the Efficiency of Biological Filters for Ammonia Removal

    Directory of Open Access Journals (Sweden)

    S Motesaddi Zarandi, MR Massoudinejad, A Mazaheri Tehrani, H Pouri

    2013-09-01

    Full Text Available Backgrounds and Aims: Ammonia removal from air to prevent severe damage to the environment and living organisms is very important. Biofiltration is an efficient, easy, cost-effective, and environmentally friendly process for degradation of ammonia from waste air. The aim of this study is to investigate the efficiency of biological filtration using a compost and scallop bed for ammonia removal. Materials and Methods: According to the ammonia removal method a column with 14cm inner diameter and 45cm height made from transparent Plexiglas was used. The column was filled up to 25 cm with compost and scallop (with a scallop: compost ratio of 1:4. In this study, performance of the biofilter was studied under 10 different flow rates (1, 2, 3, 4, 5, 6, 7, 8, 9 and 10 lit/min and 5 different concentrations (0-20, 20-40, 40-60, 60-80 and 80-100 ppm at a temperature of 25 degrees Celsius. Results: The results of this study showed that efficiency is decreased when the flow rate or concentration is increased because the microbial population is reduced. The efficiency was reduced by 84.6-98.2 percent. Maximum efficiency occurred at a 0.19g/(m3.h loading rate. Efficiency was in 0-20 concentration intervals at a flow rate of 1 lit/min and at an Empty Bed Residence Time (EBRT of 240 seconds. Conclusion: The results show that a biofilter with a compost and scallop bed is efficient for ammonia removal from air. Results can be optimized in the design and operation of biological systems to be used in the industrial control of ammonia gas.

  3. Synthesis of hydrides by interaction of intermetallic compounds with ammonia

    Energy Technology Data Exchange (ETDEWEB)

    Tarasov, Boris P., E-mail: tarasov@icp.ac.ru [Institute of Problems of Chemical Physics of the Russian Academy of Sciences, Chernogolovka 142432 (Russian Federation); Fokin, Valentin N.; Fokina, Evelina E. [Institute of Problems of Chemical Physics of the Russian Academy of Sciences, Chernogolovka 142432 (Russian Federation); Yartys, Volodymyr A., E-mail: volodymyr.yartys@ife.no [Institute for Energy Technology, Kjeller NO 2027 (Norway); Department of Materials Science and Engineering, Norwegian University of Science and Technology, Trondheim NO 7491 (Norway)

    2015-10-05

    Highlights: • Interaction of the intermetallics A{sub 2}B, AB, AB{sub 2}, AB{sub 5} and A{sub 2}B{sub 17} with NH{sub 3} was studied. • The mechanism of interaction of the alloys with ammonia is temperature-dependent. • Hydrides, hydridonitrides, disproportionation products or metal–N–H compounds are formed. • NH{sub 4}Cl was used as an activator of the reaction between ammonia and intermetallics. • Interaction with ammonia results in the synthesis of the nanopowders. - Abstract: Interaction of intermetallic compounds with ammonia was studied as a processing route to synthesize hydrides and hydridonitrides of intermetallic compounds having various stoichiometries and types of crystal structures, including A{sub 2}B, AB, AB{sub 2}, AB{sub 5} and A{sub 2}B{sub 17} (A = Mg, Ti, Zr, Sc, Nd, Sm; B = transition metals, including Fe, Co, Ni, Ti and nontransition elements, Al and B). In presence of NH{sub 4}Cl used as an activator of the reaction between ammonia and intermetallic alloys, their interaction proceeds at rather mild P–T conditions, at temperatures 100–200 °C and at pressures of 0.6–0.8 MPa. The mechanism of interaction of the alloys with ammonia appears to be temperature-dependent and, following a rise of the interaction temperature, it leads to the formation of interstitial hydrides; interstitial hydridonitrides; disproportionation products (binary hydride; new intermetallic hydrides and binary nitrides) or new metal–nitrogen–hydrogen compounds like magnesium amide Mg(NH{sub 2}){sub 2}. The interaction results in the synthesis of the nanopowders where hydrogen and nitrogen atoms become incorporated into the crystal lattices of the intermetallic alloys. The nitrogenated materials have the smallest particle size, down to 40 nm, and a specific surface area close to 20 m{sup 2}/g.

  4. Application of PTFE membrane for ammonia removal in a membrane contactor.

    Science.gov (United States)

    Ahn, Y T; Hwang, Y H; Shin, H S

    2011-01-01

    The feasibility of a membrane contactor system for ammonia removal was studied. The mass transfer coefficient was used to quantitatively compare the effect of various operation conditions on ammonia removal efficiency. Effective removal of ammonia was possible with a Polytetrafluoroethylene (PTFE) membrane contactor system at all tested conditions. Among the various operation parameters, contact time and solution pH showed significant effect on the ammonia removal mechanism. The overall ammonia removal rate was not affected by influent suspended solution concentration unlike other pressure driven membrane filtration processes. Also the osmotic distillation phenomena which deteriorate the mass transfer efficiency can be minimized by preheating of influent wastewater. A membrane contactor system can be a possible alternative to treat high strength nitrogen wastewater by optimizing operation conditions such as stripping solution flow rate, influent wastewater temperature, and influent pH.

  5. Neutrino oscillation provides clues to dark matter and signals from the chilled universe

    CERN Multimedia

    2006-01-01

    The new verification that oscillations exists and neutrinos have mass though not detectible easy provides the first clue to extra dimensions, dark matter, hyperspace and chilled universe acting as a platform below it. (1/2 page)

  6. Effect of Lanthanun on micructure and properties of a chilled iron camshaft

    Directory of Open Access Journals (Sweden)

    He Binfeng

    2012-02-01

    Full Text Available Inoculation can reduce the chill depth of a chilled iron, and therefore influence the microstructure and properties of the iron. In this paper, the effect of rare earth Lanthanun (La on the microstructure and properties of a chilled iron camshaft was studied. The results show that the La addition efficiently enhances the mechanical properties, yet with the unfavorable effect of decreasing the chilled depth and hardness. Moreover, La promotes graphite concentration and results in large graphite size, as well as A-type graphite. It is also found that excessive La destroys the interconnection and directivity of ledeburite. According to the experimental results, the optimum adding content of La should be no more than 0.02wt.%.

  7. Aesthetic Chills: Knowledge-Acquisition, Meaning-Making, and Aesthetic Emotions.

    Science.gov (United States)

    Schoeller, Felix; Perlovsky, Leonid

    2016-01-01

    This article addresses the relation between aesthetic emotions, knowledge-acquisition, and meaning-making. We briefly review theoretical foundations and present experimental data related to aesthetic chills. These results suggest that aesthetic chills are inhibited by exposing the subject to an incoherent prime prior to the chill-eliciting stimulation and that a meaningful prime makes the aesthetic experience more pleasurable than a neutral or an incoherent one. Aesthetic chills induced by narrative structures seem to be related to the pinnacle of the story, to have a significant calming effect and subjects describe a strong empathy for the characters. We discuss the relation between meaning-making and aesthetic emotions at the psychological, physiological, narratological, and mathematical levels and propose a series of hypotheses to be tested in future research.

  8. Enhanced electrokinetic remediation of fluorine-contaminated soil by applying an ammonia continuous circulation system

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Shufa; Zhou, Ming; Zhang, Shuangyan [Henan University of Science and Technology, Luoyang (China)

    2016-02-15

    The objective of this research was to investigate the effects of ammonia continuous circulation enhanced electrokinetic remediation of fluorine contaminated soil and to analyze its influence on soil pH after remediation. An experimental study was carried out in self-made electrokinetic apparatus. The voltage gradient was set at 1.0V/cm and ammonia water with different concentrations was used as electrolyte which circulated in series. Comparative studies were made by using deionized water as electrolyte which circulated separately in one experiment and continuously in another. According to the experiment the continuous circulation of ammonia water increased the current value during the remediation process and maintained current through the soil cell stabler, which not only increased fluorine migration but also reduced energy consumption. Among the given ammonia concentrations (0, 0.01, 0.1 and 0.2mol/L) the removal rate increased with ammonia concentration. 0.2mol/L had the highest current (26.8mA), and the removal rate amounted up to 57.3%. By using ammonia circulation enhanced electrokinetic technology, the difference between pH values of cathode soil and anode soil became smaller. Ammonia continuous circulation enhanced electrokinetics can effectively remediate fluorine contaminated soil and the residual ammonia in the soil can also improve soil fertility.

  9. Reducing concentrations of ammonia to nontoxic levels prior to initiating whole-sediment bioassays

    Energy Technology Data Exchange (ETDEWEB)

    Barrows, E.S.; Pinza, M.R.; Word, J.O. [Battelle/Marine Sciences Lab., Sequim, WA (United States); Greges, M.

    1994-12-31

    Determining the suitability of dredged material for ocean disposal requires whole-sediment toxicity tests with marine organisms. In addition to potential contaminants in dredged sediment, factors including grain size, salinity, hydrogen sulfide and ammonia can contribute to observed toxicity, thereby confounding test results. The presence of ammonia, a non-persistent but toxic compound, is particularly interesting because in open-water dredge and disposal situations, ammonia may not be a contaminant of concern. Sediment porewater ammonia concentrations in bioassays can be reduced to nontoxic levels before exposing organisms to permit evaluation of sediment contaminants without the additional toxicity effects of ammonia. Ten-day acute toxicity tests were conducted on sediments with Ampelisca abdita, Rhepoxynius abronius, Eohaustorius estuarius, and Mysidopsis bahia. Two procedures were followed to reduce ammonia prior to test initiation. In one, sediments in test chambers stood for 7 to 1 2 days while natural, nitrogen-reducing processes took place. In the other, sediments were tested in modified, flow-through systems. Ammonia was monitored in sediment porewater during ``purging`` periods, at test initiation and termination, and in overlying water during testing. Results were compared to the measured dose response of each species to ammonia, as determined by water-only reference toxicant tests. The question remains whether other sediment characteristics are affected by these procedures.

  10. 火电厂氨法烟气脱硫装置运行参数检测与控制系统设计%Operation Parameters Detection and Control System Design for Ammonia-based Flue Gas Desulfurization Process of Thermal Power Plant

    Institute of Scientific and Technical Information of China (English)

    徐澎波; 何仁初; 赵立华

    2011-01-01

    大型氨法烟气脱硫(FGD)作为一项新的环保技术,其装置几乎涉及了所有的化工操作单元,对工艺及控制也提出了很高的要求.本文以国内首套某电厂2×300MW机组氨法烟气脱硫装置为例,设计了一套氨法烟气脱硫系统运行参数检测及控制系统,使得装置操作更加安全平稳,有效的降低了氨耗并且改善了副产品质量,在满足环保要求的同时使氨法脱硫装置能经济有效地运行.%Large scale ammonia-based FGD is a new environmental protection technology almost including all chemical engineering operation units. This type equipment is very strict on process and control system. In this paper, taking the first control project with 2×300MW units ammonia-based FGD in a domestic thermal power plant as an example, an operation parameters detection and control system is designed according to the FGD technical requirements. This control system can make the equipment run stably and reducing ammonia consumption greatly with improving by-product quality, and this ammonia-based FGD equipment can run economically and effectively base on the meeting the requirements of environmental protection.

  11. Chill-coma recovery time, age and sex determine lipid profiles in Ceratitis capitata tissues.

    Science.gov (United States)

    Pujol-Lereis, Luciana Mercedes; Fagali, Natalia Soledad; Rabossi, Alejandro; Catalá, Ángel; Quesada-Allué, Luis Alberto

    2016-04-01

    The remodeling of membrane composition by changes in phospholipid head groups and fatty acids (FA) degree of unsaturation has been associated with the maintenance of membrane homeostasis under stress conditions. Overall lipid levels and the composition of cuticle lipids also influence insect stress resistance and tissue protection. In a previous study, we demonstrated differences in survival, behavior and Cu/Zn superoxide dismutase gene expression between subgroups of Ceratitis capitata flies that had a reversible recovery from chill-coma and those that developed chilling-injury. Here, we analyzed lipid profiles from comparable subgroups of 15 and 30-day-old flies separated according to their recovery time after a chill-coma treatment. Neutral and polar lipid classes of chill-coma subgroups were separated by thin layer chromatography and quantified by densitometry. FA composition of polar lipids of chill-coma subgroups and non-stressed flies was evaluated using gas chromatography coupled to mass spectrometry. Higher amounts of neutral lipids such as triglycerides, diacylglycerol, wax esters, sterol esters and free esters were found in male flies that recovered faster from chill-coma compared to slower flies. A multivariate analysis revealed changes in patterns of storage and cuticle lipids among subgroups both in males and females. FA unsaturation increased after cold exposure, and was higher in thorax of slower subgroups compared to faster subgroups. The changes in neutral lipid patterns and FA composition depended on recovery time, sex, age and body-part, and were not specifically associated with the development of chilling-injury. An analysis of phospholipid classes showed that the phosphatidylcholine to lysophosphatidylcholine ratio (PC/LPC) was significantly higher, or showed a tendency, in subgroups that may have developed chilling-injury compared to those with a reversible recovery from coma.

  12. The effect of lethal doses of X-rays on chilled and thyroidectomized animals

    Energy Technology Data Exchange (ETDEWEB)

    Hempelmann, L.H.; Trujillo, T.T.; Knowlton, N.P. Jr.

    1949-04-19

    The chilling of animals has been shown to offer some protection from the lethal effects of radiation. An effort has been made to extend the study of the effects of chilling on the lethal effects of x radiation and to determine whether or not the lowering of the basal metabolic rate by thyroidectomy will give similar protection. Five experiments were carried out using mice and rats as the experimental animals.

  13. Optimization protocol for storage of goldfish (Carassius auratus) embryos in chilled state.

    Science.gov (United States)

    Shaluei, F; Imanpoor, M R; Shabani, A; Nasr-Esfahani, M H

    2014-04-01

    A series of five experiments were conducted to explore suitable conditions for storing of goldfish embryos in a chilled state. The factors studied were embryo stage, storage temperature, physiological saline solutions and goldfish artificial coelomic fluid (GFACF) medium, antibiotics (penicillin and streptomycin), antioxidants (vitamin E, vitamin C), buffer (Hepes, Tris) and BSA (bovine serum albumin). First, goldfish embryos at eight developmental stages were incubated in aerated and dechlorinated tap water at 0 °C for 24 h. Result shows that early developmental stages were most sensitive to chilling. Heartbeat-stage goldfish embryos were chilled at 0, 4 or 8 °C for up to 72 h in water, and chilled storage was possible only for up to 18, 24 and 48 h at 0, 4 and 8 °C, respectively, without a decrease in viability. Chilling of goldfish embryos at 8 °C in GFACF medium and Dettlaff's solution instead of water and other physiological saline solutions prolonged their viability (p < 0.01). Nevertheless, viability of chilled embryos in GFACF medium was slightly, but non-significantly, higher than in Dettlaff's solution. Supplementation of the GFACF medium with antibiotics, Hepes or BSA increased the viability of chilled embryos, but the tested vitamin E analogue Trolox, vitamin C or Tris concentration had no effect on embryo viability. The outcome of this series of experiments shows that heartbeat-stage goldfish embryos could be chilled for 60 h in GFACF supplemented with 25 mm Hepes, 100 U/ml penicillin, 10 μg/l streptomycin and 1 g/l BSA in such a way that embryonic development does not proceed, and viability is not lost.

  14. Effect of LaCI3 on the chilling tolerance of rice seedlings

    Institute of Scientific and Technical Information of China (English)

    LIMeiru; LIUHongxian; WANGYirou

    1997-01-01

    The rice variety Tesanai 2 is susceptible to chilling. Exposure of the seedlings grown at 28±1℃ and under a photo flux density(PFD) of 30 μmol/m2s to 1℃ and under a PFD of 150μmol/m2s for 2 d caused a physiological disorder called chilling injury which reduced the survival rate to 50%.

  15. Life cycle engineering of production, use and recovery of self-chilling beverage cans

    OpenAIRE

    Arena, N; P Sinclair; Lee., J; Clift, R.

    2016-01-01

    The chill-on-demand system is a new technology designed to provide cooled products on demand, thereby avoiding chilled storage. It uses the cooling effect provided by endothermic desorption of carbon dioxide previously adsorbed onto a bed of activated carbon and has the potential to be applied to any type of product that needs to be cold at the point of consumption. The principles of life cycle engineering have been utilized to evaluate the overall environmental performance of one possible ap...

  16. Conventional food preparation, cook and chill and sous-vide as optional methods for institutional kitchens. Perinteinen ruoanvalmistus, cook and chill ja sous-vide toimintavaihtoehdot suurkeittioessae

    Energy Technology Data Exchange (ETDEWEB)

    Paeivaerinta, T., Reisbacka, A., Salminen, M.

    1993-01-01

    The purpose of the study was to clarify the situation concerning the energy consumption, economics and the appropriateness of the three options when applied in institutional households. The options included in the study were conventional (preparation-cooking-serving), cook and chill and sous-vide (vacuum cooking-chilling). A further aim was to compare industrially produced products to self-made products. Each option was studied in connection with several devices embodying latest technology. The overall price for a portion was found to be cheapest when using the conventional preparation method. The cook and chill method was only slightly more expensive. The result of this study also support the understanding that when appropriately planned, cook and chill and sous-vide food preparation options make possible the rationalisation of kitchen work. The appropriateness of different food preparation methods depends on the versatility of the functions and programmes built into cooking devices. A combination oven is appropriate and conserves energy when cooking or heating up large quantities. Significant waste of water (126-146 1/h) is possible because of the structural solutions and modes of use of such an oven. A microwave oven saves energy when used to heat up ready-made portions. The amount of energy consumed by an air-cooled chilling cabinet in the cooling of food makes it more economical to use than a water-cooled model. The amount of electricity consumed by a refrigerator or an equivalent cold storage is 5-14 times less than that consumed by chilling devices

  17. A missense mutation in CHS1, a TIR-NB protein, induces chilling sensitivity in Arabidopsis.

    Science.gov (United States)

    Wang, Yuancong; Zhang, Yao; Wang, Zheng; Zhang, Xiaoyan; Yang, Shuhua

    2013-08-01

    Low temperature is an environmental factor that affects plant growth and development and plant-pathogen interactions. How temperature regulates plant defense responses is not well understood. In this study, we characterized chilling-sensitive mutant 1 (chs1), and functionally analyzed the role of the CHS1 gene in plant responses to chilling stress. The chs1 mutant displayed a chilling-sensitive phenotype, and also displayed defense-associated phenotypes, including extensive cell death, the accumulation of hydrogen peroxide and salicylic acid, and an increased expression of PR genes: these phenotypes indicated that the mutation in chs1 activates the defense responses under chilling stress. A map-based cloning analysis revealed that CHS1 encodes a TIR-NB-type protein. The chilling sensitivity of chs1 was fully rescued by pad4 and eds1, but not by ndr1. The overexpression of the TIR and NB domains can suppress the chs1-conferred phenotypes. Interestingly, the stability of the CHS1 protein was positively regulated by low temperatures independently of the 26S proteasome pathway. This study revealed the role of a TIR-NB-type gene in plant growth and cell death under chilling stress, and suggests that temperature modulates the stability of the TIR-NB protein in Arabidopsis.

  18. Use of the spray chilling method to deliver hydrophobic components: physical characterization of microparticles

    Directory of Open Access Journals (Sweden)

    Izabela Dutra Alvim

    2013-02-01

    Full Text Available Food industry has been developing products to meet the demands of increasing number of consumers who are concerned with their health and who seek food products that satisfy their needs. Therefore, the development of processed foods that contain functional components has become important for this industry. Microencapsulation can be used to reduce the effects of processing on functional components and preserve their bioactivity. The present study investigated the production of lipid microparticles containing phytosterols by spray chilling. The matrices comprised mixtures of stearic acid and hydrogenated vegetable fat, and the ratio of the matrix components to phytosterols was defined by an experimental design using the mean diameters of the microparticles as the response variable. The melting point of the matrices ranged from 44.5 and 53.4 ºC. The process yield was melting point dependent; the particles that exhibited lower melting point had greater losses than those with higher melting point. The microparticles' mean diameters ranged from 13.8 and 32.2 µm and were influenced by the amount of phytosterols and stearic acid. The microparticles exhibited spherical shape and typical polydispersity of atomized products. From a technological and practical (handling, yield, and agglomeration points of view, lipid microparticles with higher melting point proved promising as phytosterol carriers.

  19. Mediterranean Berries as Inhibitors of Lipid Oxidation in Porcine Burger Patties Subjected to Cooking and Chilled Storage

    Institute of Scientific and Technical Information of China (English)

    Rui Ganho; Mario Estvez; Mnica Armenteros; David Morcuende

    2013-01-01

    The efifciency of extracts from Arbutus unedo L. (AU), Crataegus monogyna L. (CM), Rosa canina L. (RC), and Rubus ulmifolius Schott. (RU) to inhibit lipid oxidation in raw, cooked and cooked and chilled (2°C/12 d) porcine burger patties, was investigated. The modiifcation of the fatty acid proifle during processing treatments (cooking and chilling), the quantitative measurements of thiobarbituric acid reactive substances (TBA-RS), and lipid-derived volatiles, were used as indicators of lipid oxidation. Polyunsaturated fatty acids (PUFA) gradually decreased during cooking and the subsequent storage of cooked burger patties with this decrease being signiifcantly greater (P<0.05) in control patties than in those with added berry extracts. In accordance, the control patties showed signiifcantly higher TBA-RS numbers and counts of lipid-derived volatiles in all treatments when compared to the berry-added counterparts (P<0.05). Results from the present work show, for the ifrst time, that extracts from A. unedo, C. monogyna, R. canina, and R. ulmifolius are promising antioxidants which could enhance the nutritional, safety and sensory properties of porcine burger patties.

  20. Ammonia emission from crop residues : quantification of ammonia volatilization based on crop residue properties

    NARCIS (Netherlands)

    Ruijter, de F.J.; Huijsmans, J.F.M.

    2012-01-01

    This paper gives an overview of available literature data on ammonia volatilization from crop residues. From these data, a relation is derived for the ammonia emission depending on the N-content of crop residue.

  1. Mass transfer characteristics of a structured packing for ammonia rectification in ammonia-water absorption refrigeration systems

    Energy Technology Data Exchange (ETDEWEB)

    Sieres, Jaime; Fernandez-Seara, Jose [Area de Maquinas y Motores Termicos, E.T.S. de Ingenieros Industriales, University of Vigo, Campus Lagoas-Marcosende N9, 36310 Vigo (Spain)

    2007-01-15

    In ammonia-water absorption refrigeration systems a purification process of the vapours produced in the generator is required. One type of equipment to carry out the purification process is a packed column. However, detailed experimental studies at the normal operating conditions found in ammonia-water absorption refrigeration systems have not been found. An experimental facility has been designed and built to study the ammonia-water rectification in packed columns. Experimental tests have been performed at the normal operating conditions found in the high-pressure stage of a small power ammonia-water absorption refrigeration system. In this paper, the experimental set-up is described and experimental results of the height equivalent to a theoretical plate (HETP) and the volumetric mass transfer coefficient of a rectifying section with the Sulzer BX packing are presented. The HETP values and the experimental mass transfer coefficients are compared with different data and correlations proposed in the literature; it has been found that the differences are appreciable. (author)

  2. Salmonella and Campylobacter reduction and quality characteristics of poultry carcasses treated with various antimicrobials in a post-chill immersion tank.

    Science.gov (United States)

    Nagel, G M; Bauermeister, L J; Bratcher, C L; Singh, M; McKee, S R

    2013-08-01

    Innovations in poultry processing include implementation of antimicrobials in post-chill decontamination tanks. In this study, a total of 160 broiler carcasses were analyzed to evaluate the efficacy of five post-chill water treatments consisting of 0.004% (40ppm) total chlorine, 0.04% (400ppm) or 0.1% (1000ppm) peracetic acid (PAA), and 0.1% (1000ppm) or 0.5% (5000ppm) lysozyme against Salmonella and Campylobacter spp. In addition, sensory analysis was performed to evaluate any associated effects of the antimicrobials on quality attributes of chicken breast meat. Treatment with 0.04% and 0.1% PAA was most effective (P≤0.05) in reducing populations of Salmonella and Campylobacter as compared to the chlorine treatment at 0.004% and lysozyme treatments at 0.1% and 0.5%, as well as the water treatment and the positive control. Treatment with the various antimicrobials was not found to have negative (P≤0.05) impacts on sensory attributes. Results from this study suggest that utilizing PAA as an antimicrobial in a post-chill immersion tank is an effective application for reducing Salmonella and Campylobacter on carcasses while maintaining product quality.

  3. Tetraammineplatinum(II dichloride ammonia tetrasolvate

    Directory of Open Access Journals (Sweden)

    Tobias Grassl

    2014-07-01

    Full Text Available The title compound, [Pt(NH34]Cl2·4NH3, was crystallized in liquid ammonia from the salt PtCl2. The platinum cation is coordinated by four ammonia molecules, forming a square-planar complex. The chloride anions are surrounded by nine ammonia molecules, either bound within the platinum complex or solvent molecules. The solvent ammonia molecules are packed in such a way that an extended network of N—H...N and N—H...Cl hydrogen bonds is formed. The structure is isotypic with [Pd(NH34]Cl2·4NH3 [Grassl & Korber (2014. Acta Cryst. E70, i32].

  4. Towards an ammonia-mediated hydrogen economy?

    DEFF Research Database (Denmark)

    Christensen, Claus H.; Johannessen, Tue; Sørensen, Rasmus Zink;

    2006-01-01

    Materialization of a hydrogen economy could provide a solution to significant global challenges, In particular. the possibility of improving the efficiency and simultaneously minimizing the environmental impact of energy conversion processes, together with the opportunity to reduce the dependency...... of fossil fuels, are main drivers for the currently increasing research and development efforts. However. significant technological breakthroughs are necessary for making a hydrogen economy feasible. In particular, it is necessary to develop appropriate hydrogen storage and transportation technologies....... Recently, metal ammine salts were proposed as safe, reversible. high-density and low-cost hydrogen carriers. Here, we discuss how this development could provide a platform for using ammonia as a fuel for the hydrogen economy, We do that by comparing various possible hydrogen carriers with respect to energy...

  5. Ammonia-Free NOx Control System

    Energy Technology Data Exchange (ETDEWEB)

    S. Wu; Z. Fan; R. Herman

    2004-03-31

    Research is being conducted under United States Department of Energy (DOE) Contract DEFC26-03NT41865 to develop a new technology to achieve very low levels of NOx emissions from pulverized coal fired boiler systems by employing a novel system level integration between the PC combustion process and the catalytic NOx reduction with CO present in the combustion flue gas. The combustor design and operating conditions will be optimized to achieve atypical flue gas conditions. This approach will not only suppress NOx generation during combustion but also further reduce NOx over a downstream catalytic reactor that does not require addition of an external reductant, such as ammonia. This report describes the work performed during the January 1 to March 31, 2004 time period.

  6. Ammonia-Free NOx Control System

    Energy Technology Data Exchange (ETDEWEB)

    S. Wu

    2003-12-31

    Research is being conducted under United States Department of Energy (DOE) Contract DEFC26-03NT41865 to develop a new technology to achieve very low levels of NOx emissions from pulverized coal fired boiler systems by employing a novel system level integration between the PC combustion process and the catalytic NOx reduction with CO present in the combustion flue gas. The combustor design and operating conditions will be optimized to achieve atypical flue gas conditions. This approach will not only suppress NOx generation during combustion but also further reduce NOx over a downstream catalytic reactor that does not require addition of an external reductant, such as ammonia. This report describes the work performed during the October 1 to December 31, 2003 time period.

  7. Molecular characterization of microbial populations in full-scale biofilters treating iron, manganese and ammonia containing groundwater in Harbin, China.

    Science.gov (United States)

    Li, Xiang-kun; Chu, Zhao-rui; Liu, Ya-jun; Zhu, Meng-ting; Yang, Liu; Zhang, Jie

    2013-11-01

    In iron and manganese-containing groundwater treatment for drinking water production, biological filter is an effective process to remove such pollutants. Until now the exact microbial mechanism of iron and manganese removal, especially coupled with other pollutants, such as ammonia, has not been clearly understood. To assess this issue, the performance of a full-scale biofilter located in Harbin, China was monitored over four months. Microbial populations in the biofilter were investigated using T-RFLP and clone library technique. Results suggested that Gallionella, Leptothrix, Nitrospira, Hyphomicrobium and Pseudomonas are dominant in the biofilter and play major roles in the removal of iron, manganese and ammonia. The spatial distribution of microbial populations along the depth of the biofilter demonstrated the stratification of the removal of iron, manganese and ammonia. Additionally, the absence of ammonia-oxidizing bacteria in the biofilter implicated that ammonia-oxidizing archaea might be responsible for the oxidation of ammonia to nitrite.

  8. Atmospheric Amines and Ammonia Measured with a Chemical Ionization Mass Spectrometer (CIMS)

    Energy Technology Data Exchange (ETDEWEB)

    You, Y.; Kanawade, V. P.; de Gouw, J. A.; Guenther, Alex B.; Madronich, Sasha; Sierra-Hernandez, M. R.; Lawler, M.; Smith, James N.; Takahama, S.; Ruggeri, G.; Koss, A.; Olson, K.; Baumann, K.; Weber, R. J.; Nenes, A.; Guo, H.; Edgerton, Eric S.; Porcelli, L.; Brune, W. H.; Goldstein, Allen H.; Lee, S.-H

    2014-11-19

    We report ambient measurements of amines and ammonia with a fast response chemical ionization mass spectrometer (CIMS) in a Southeastern U.S. forest in Alabama and a moderately polluted Midwestern site during the summer. In the Alabama forest, mostly C3-amines (from pptv to tens of pptv) and ammonia (up to 2 ppbv) were detected on a daily basis. C3-amines and ammonia showed similar diurnal trends and temperature and wind direction dependences, and were not associated with transported CO and SO2 plumes. Consistent with temperature dependences, amine and ammonia in the gas and aerosol phases showed opposite diurnal trends, indicating gas-to-particle partitioning of amines and ammonia. Temperature dependences also imply reversible processes of amines and ammonia evaporation from soil surfaces in daytime and deposition of amines and ammonia to soil surfaces at nighttime. Various amines (C1-C6) at the pptv level were observed in the transported biomass burning plumes, showing that biomass burning can be a substantial source of amines in the Southeast U.S. At the moderately polluted Kent site, higher concentrations of amines (C1-C6, from pptv to tens of pptv) and ammonia (up to 6 ppbv) were detected. Diurnal variations of C1- to C3-amines and ammonia were correlated with the ambient temperature. C4- to C6-amines showed abrupt increases during the nighttime, suggesting that they were emitted from local sources. These abundant amines and ammonia may in part explain the frequent new particle formation events reported from Kent. Lower amine concentrations at the rural forested site highlight the importance of constraining anthropogenic sources of amines.

  9. Atmospheric amines and ammonia measured with a Chemical Ionization Mass Spectrometer (CIMS

    Directory of Open Access Journals (Sweden)

    Y. You

    2014-06-01

    Full Text Available We report ambient measurements of amines and ammonia with a~fast response chemical ionization mass spectrometer (CIMS in a southeastern US forest in Alabama and a~moderately polluted Midwestern site during the summer. In the Alabama forest, mostly C3-amines (from pptv to tens of pptv and ammonia (up to 2 ppbv were detected on a daily basis. C3-amines and ammonia showed similar diurnal trends and temperature and wind direction dependences, and were not associated with transported CO and SO2 plumes. Consistent with temperature dependences, amine and ammonia in the gas and aerosol phases showed opposite diurnal trends, indicating gas-to-particle partitioning of amines and ammonia. Temperature dependences also imply reversible processes of amines and ammonia evaporation from soil surfaces in daytime and deposition of amines and ammonia to soil surfaces at nighttime. Various amines (C1–C6 at the pptv level were observed in the transported biomass burning plumes, showing that biomass burning can be a substantial source of amines in the Southeast US. At the moderately polluted Kent site, higher concentrations of amines (C1–C6, from pptv to tens of pptv and ammonia (up to 6 ppbv were detected. Diurnal variations of C1- to C3-amines and ammonia were correlated with the ambient temperature. C4- to C6-amines showed abrupt increases during the nighttime, suggesting that they were emitted from local sources. These abundant amines and ammonia may in part explain the frequent new particle formation events reported from Kent. Lower amine concentrations at the rural forested site highlight the importance of constraining anthropogenic sources of amines.

  10. Use of methanol as cryoprotectant and its effect on sox genes and proteins in chilled zebrafish embryos.

    Science.gov (United States)

    Desai, Kunjan; Spikings, Emma; Zhang, Tiantian

    2015-08-01

    Methanol is a widely used cryoprotectant (CPA) in cryopreservation of fish embryos, however little is known about its effect at the molecular level. This study investigated the effect of methanol on sox gene and protein expression in zebrafish embryos (50% epiboly) when they were chilled for 3 h and subsequently warmed and cultured to the hatching stages. Initial experiments were carried out to evaluate the chilling tolerance of 50% epiboly embryos which showed no significant differences in hatching rates for up to 6 h chilling in methanol (0.2-, 0.5- and 1 M). Subsequent experiments in embryos that had been chilled for 3 h in 1 M methanol and warmed and cultured up to the hatching stages found that sox2 and sox3 gene expression were increased significantly in hatched embryos that had been chilled compared to non-chilled controls. Sox19a gene expression also remained above control levels in the chilled embryos at all developmental stages tested. Whilst stable sox2 protein expression was observed between non-chilled controls and embryos chilled for 3 h with or without MeOH, a surge in sox19a protein expression was observed in embryos chilled for 3 h in the presence of 1 M MeOH compared to non-chilled controls and then returned to control levels by the hatching stage. The protective effect of MeOH was increased with increasing concentrations. Effect of methanol at molecular level during chilling was reported here first time which could add new parameter in selection of cryoprotectant while designing cryopreservation protocol.

  11. Reducing ammonia emissions in Europe

    DEFF Research Database (Denmark)

    Jacobsen, Brian H.

    2011-01-01

    The NEC directive has set targets for the 2010 ammonia emissions from a number of European countries. The target will be reached by most EU-countries and the total emission for EU-27 has been reduced by 22% from 1990 to 2007. Denmark is one of the countries with the largest reductions since 1990...... to the high expectations at the outset. Despite this, the paper concludes that Denmark is likely to reduce emission by 50% from 1990 to 2020 and reach the likely 2020 NEC ceiling....

  12. Study on adsorption and desorption of ammonia on graphene

    Science.gov (United States)

    Zhang, Zhengwei; Zhang, Xinfang; Luo, Wei; Yang, Hang; He, Yanlan; Liu, Yixing; Zhang, Xueao; Peng, Gang

    2015-09-01

    The gas sensor based on pristine graphene with conductance type was studied theoretically and experimentally. The time response of conductance measurements showed a quickly and largely increased conductivity when the sensor was exposed to ammonia gas produced by a bubble system of ammonia water. However, the desorption process in vacuum took more than 1 h which indicated that there was a larger number of transferred carriers and a strong adsorption force between ammonia and graphene. The desorption time could be greatly shortened down to about 2 min by adding the flow of water-vapor-enriched air at the beginning of the recovery stage which had been confirmed as a rapid and high-efficiency desorption process. Moreover, the optimum geometries, adsorption energies, and the charge transfer number of the composite systems were studied with first-principle calculations. However, the theoretical results showed that the adsorption energy between NH3 and graphene was too small to fit for the experimental phenomenon, and there were few charges transferred between graphene and NH3 molecules, which was completely different from the experiment measurement. The adsorption energy between NH4 and graphene increased stage by stage which showed NH4 was a strong donor. The calculation suggested that H2O molecule could help a quick desorption of NH4 from graphene by converting NH4 to NH3 or (NH3)n(H2O)m groups, which was consistent with the experimental results. This study demonstrates that the ammonia gas produced by a bubble system of ammonia water is mainly ammonium groups of NH3 and NH4, and the NH4 moleculars are ideal candidates for the molecular doping of graphene while the interaction between graphene and the NH3 moleculars is weak.

  13. Studies on Ammonia Spectral Signatures Relevant to Jupiter's Clouds

    Science.gov (United States)

    Oza, A. U.; Marschall, J.; Wong, M. H.; Kalogerakis, K. S.

    2006-12-01

    Observational evidence and thermochemical models indicate an abundance of ammonia ice clouds in Jupiter's atmosphere. However, spectrally identifiable ammonia ice clouds are found covering less than 1% of Jupiter's atmosphere, notably in turbulent areas [1,2]. Current literature suggests two possible explanations: coating by a hydrocarbon haze and/or photochemical processing ("tanning")[2,3]. We are pursuing a research program investigating the above hypotheses. In the experiments, thin films of ammonia ices are deposited in a cryogenic apparatus, coated with hydrocarbons, and characterized by infrared spectroscopy. The ice films can be irradiated by ultraviolet light to study their photochemistry. The spectroscopic measurements aim to identify the processes that control the optical properties of the ice mixtures and quantify their dependence on the identity of the coating, the temperature, and the ice composition. We have observed a consistent suppression of the ammonia absorption feature at 3 μm with coverage by thin layers of hydrocarbons. Modeling calculations of the multi-layer thin films assist in the interpretation of the experimental results and reveal the role of optical interference in masking the aforementioned ammonia spectral feature. The implications of these results for Jupiter's atmosphere will be discussed. Funding from the NSF Planetary Astronomy Program under grant AST-0206270 and from the NASA Outer Planets Research Program under grant NNG06GF37G is gratefully acknowledged. The participation of Anand Oza (Princeton University) was made possible by the NSF Research Experiences for Undergraduates Program under grant PHY-0353745. 1. S. K. Atreya, A.-S. Wong, K. H. Baines, M. H. Wong, T. C. Owen, Planet. Space Science 53, 498 (2005). 2. K. H. Baines, R. W. Carlson, and L. W. Kamp, Icarus 159, 74 (2002). 3. A.-S. Wong, Y. L. Yung, and A. J. Friedson, Geophys. Res. Lett. 30, 1447 (2003).

  14. Study on adsorption and desorption of ammonia on graphene.

    Science.gov (United States)

    Zhang, Zhengwei; Zhang, Xinfang; Luo, Wei; Yang, Hang; He, Yanlan; Liu, Yixing; Zhang, Xueao; Peng, Gang

    2015-12-01

    The gas sensor based on pristine graphene with conductance type was studied theoretically and experimentally. The time response of conductance measurements showed a quickly and largely increased conductivity when the sensor was exposed to ammonia gas produced by a bubble system of ammonia water. However, the desorption process in vacuum took more than 1 h which indicated that there was a larger number of transferred carriers and a strong adsorption force between ammonia and graphene. The desorption time could be greatly shortened down to about 2 min by adding the flow of water-vapor-enriched air at the beginning of the recovery stage which had been confirmed as a rapid and high-efficiency desorption process. Moreover, the optimum geometries, adsorption energies, and the charge transfer number of the composite systems were studied with first-principle calculations. However, the theoretical results showed that the adsorption energy between NH3 and graphene was too small to fit for the experimental phenomenon, and there were few charges transferred between graphene and NH3 molecules, which was completely different from the experiment measurement. The adsorption energy between NH4 and graphene increased stage by stage which showed NH4 was a strong donor. The calculation suggested that H2O molecule could help a quick desorption of NH4 from graphene by converting NH4 to NH3 or (NH3)n(H2O)m groups, which was consistent with the experimental results. This study demonstrates that the ammonia gas produced by a bubble system of ammonia water is mainly ammonium groups of NH3 and NH4, and the NH4 moleculars are ideal candidates for the molecular doping of graphene while the interaction between graphene and the NH3 moleculars is weak.

  15. New insight in the microscopic mechanism of the catalytic synthesis of ammonia

    DEFF Research Database (Denmark)

    Hansen, Flemming Yssing; Henriksen, Niels Engholm; Billing, Gert D.

    1995-01-01

    Theoretical quantum calculations and molecular beam experiments of the dissociative chemisorption of N-2 molecules on catalytic active metal surfaces have given new insight in the fundamental process of the ammonia synthesis. This new approach to the study of catalytic process supplements...... to dissociation. Our analysis of the dissociation process suggests that it is not possible to define, in some well specified way, a precursor state at typical temperatures in the technical ammonia synthesis. The kinetic scheme for the complete ammonia synthesis without the precursor state can still account...... for the observed conversion to ammonia. We have constructed an empirical potential energy surface for N-2/Fe(111) which has barriers to dissociation even larger than for the previously studied N-2/Re system. It is shown that the presence of barriers is consistent with the observation that the activation energy...

  16. Ammonia removal from leachate solution using natural Chinese clinoptilolite.

    Science.gov (United States)

    Wang, Yuqiu; Liu, Shijun; Xu, Ze; Han, Tianwei; Chuan, Sun; Zhu, Tan

    2006-08-25

    This paper assesses the potential of natural Chinese clinoptilolite for ammonia removal from the leachate solution of sewage sludge. In batch study the effects of relevant parameters, such as contact time, initial ammonia concentration and particle size of clinoptilolite, were examined respectively. The results show that the data obtained from batch studies were fit to Langmuir and Freundlich isotherms and the Langmuir isotherms reflect more reasonable for ammonium ion uptake onto clinoptilolite; the clinoptilolite adsorption process has been proved effective, at laboratory scale, the maximum adsorption capacity of the clinoptilolite, for ammonium concentration ranging from 11.12 to 115.16 mg NH(4)-N L(-1) in leachate solution, was about 1.74 mg NH(4)-Ng(-1); the time to adsorption equilibrium was 2.5 h in leachate solution and 1.5 h more than for in NH(4)Cl synthetic solution; ammonium adsorption increased with decreasing clinoptilolite particle size; the ammonia removal capacity of clinoptilolite increased with increasing initial ammonia concentration. It is believed that as adsorption agent for NH(4)-N removal from sludge leachate, natural Chinese clinoptilolite can be feasible.

  17. REGENERATION OF AMMONIA SOLUTION FOR CO2 CAPTURE IN POSTCOMBUSTION

    Directory of Open Access Journals (Sweden)

    CAROL TORO

    2014-01-01

    Full Text Available This study investigated enthalpy of solutions and solubility for a NH3/CO2 system. Measurements were performed in a thermoregulated Lewis-type cell reactor, temperatures ranging from 278 to 303 K and mass concentrations from 2 wt% to 5 wt%. Enthalpies of solution of CO2 and solubility have been obtained as function of loading, α (moles CO2/mol NH3. Results show that ammonia solutions concentrations of 3 and 5 wt% promote the formation of ammonium bicarbonate. Beside, ammonia concentration of 2 wt% promotes the formation of ammonium carbonate. Therefore, to use ammonia concentrations of 3 and 5 wt% need less energy that a concentration of 2 wt% to reverse the reaction. Regeneration system was simulated using Aspen plus™ software for a pulverised coal fired power plant (CF in a post-combustion process. Model analysis established that NH3 heat duty is lower than MEA and MDEA ones. The energy consumption reaches 2.83 GJ•t-1 CO2. Regarding heat duty and ammonia losses, 3 wt% NH3 is the suitable concentration to capture CO2.

  18. System Modeling for Ammonia Synthesis Energy Recovery System

    Science.gov (United States)

    Bran Anleu, Gabriela; Kavehpour, Pirouz; Lavine, Adrienne; Ammonia thermochemical Energy Storage Team

    2015-11-01

    An ammonia thermochemical energy storage system is an alternative solution to the state-of-the-art molten salt TES system for concentrating solar power. Some of the advantages of this emerging technology include its high energy density, no heat losses during the storage duration, and the possibility of long storage periods. Solar energy powers an endothermic reaction to disassociate ammonia into hydrogen and nitrogen, which can be stored for future use. The reverse reaction is carried out in the energy recovery process; a hydrogen-nitrogen mixture flowing through a catalyst bed undergoes the exothermic ammonia synthesis reaction. The goal is to use the ammonia synthesis reaction to heat supercritical steam to temperatures on the order of 650°C as required for a supercritical steam Rankine cycle. The steam will flow through channels in a combined reactor-heat exchanger. A numerical model has been developed to determine the optimal design to heat supercritical steam while maintaining a stable exothermic reaction. The model consists of a transient one dimensional concentric tube counter-flow reactor-heat exchanger. The numerical model determines the inlet mixture conditions needed to achieve various steam outlet conditions.

  19. Genome-wide Association Analysis of Ten Chilling Tolerance Indices at the Germination and Seedling Stages in Maize

    Institute of Scientific and Technical Information of China (English)

    Juan Huang; Jianhua Zhang; Wenzhen Li; Wei Hu; Lichao Duan; Yang Feng; Fazhan Qiu

    2013-01-01

    Maize seedlings are very sensitive to chilling,especially during the transition phase from heterotrophic to autotrophic growth.Genetic dissection of the genetic basis of chilling tolerance would provide useful information for genetic improvement of maize inbreds.In this study,genome-wide association analysis was conducted to explore the genetic architecture of maize chilling tolerance at the seed germination and seedling stages with an association panel of 125 inbreds.Ten tolerance indices (ratios of the performance of 10 germination rates and seedling growth-related traits under chilling stress and control conditions)were investigated to assess the ability of chilling tolerance of the inbreds,and a total of 43 single nucleotide polymorphisms associated with chilling tolerance were detected,with none of them being related to chilling tolerance at both the germination and seedling stages simultaneously.Correlation analysis also revealed that the genetic basis of chilling tolerance at the seed germination stage is generally different from that at the seedling stage.In addition,a total of 40 candidate genes involving 31 of the 43 single nucleotide polymorphisms were predicted,and were grouped into five categories according to their functions.The possible roles of these candidate genes in chilling tolerance were also discussed.

  20. Running Club Warm Up Staves Off Winter's Chill

    CERN Multimedia

    2001-01-01

    Not deterred by winter's chill, over 900 runners met at the CERN Prévesin site for Escalade training. Think the sudden cold snap is a reason to stay indoors? Think again! The CERN running club has just recently had the honour of holding the November 11th Escalade training session, and with over 900 runners present at the Prévessin site it was clear that the chilly temperatures were no barrier whatsoever. The story behind Escalade training starts back in 1977 when a group of running enthusiasts from the Stade Genève club decided to organize a running race in the Old Town in conjunction with the Escalade festivities. They were told that no normal people would think of organizing a running race in the month of December, but fortunately they ignored the advice! From the initial 50 or so runners, these Escalade races have grown into an institution and now attract upwards of 15,000 people of all ages from 5 to over 80 each year. And with over 30% of each year's runners participat...

  1. Chilled disks in ultraluminous X-ray sources

    Science.gov (United States)

    Soria, Roberto; Kuncic, Zdenka; Gonçalves, Anabela C.

    2007-04-01

    The "soft-excess" component fitted to the X-ray spectra of many ultraluminous X-ray sources (ULXs) remains a controversial finding, which may reveal fundamental information either on the black hole (BH) mass or on the state of the accretion flow. In the simplest model, it was explained as thermal emission from a cool accretion disk around an intermediate-mass BH (about 1000 solar masses). We argue that this scenario is highly implausible, and discuss and compare the two most likely alternatives. 1) The soft-excess does come from a cool disk; however, the temperature is low not because of a high BH mass but because most of the accretion power is drained from the inner disk via magnetic torques, and channelled into jets and outflows ("chilled disk" scenario). Using a phenomenological model, we infer that ULXs contain BHs of about 50 solar masses accreting gas at about 10 times their Eddington rate. 2) The soft excess is in fact a soft deficit, if the power-law continuum is properly fitted. Such broad absorption features are caused by smeared absorption lines in fast, highly ionized outflows. This scenario has already been successfully applied to the soft excess in AGN. If so, this spectral feature reveals details of disk outflows,but is unrelated to the BH mass.

  2. Film with anthocyanins as an indicator of chilled pork deterioration

    Directory of Open Access Journals (Sweden)

    Luana Baptista Golasz

    2013-02-01

    Full Text Available An indicator can be defined as a substance which indicates the presence or absence of another substance or the degree of a certain reaction through characteristic changes, especially color. Therefore, the aim of this work is to evaluate the performance of a bio-based film with anthocyanin as an indicator of chilled pork deterioration. A film made of cassava starch, glycerol, and grape anthocyanins was prepared using the casting technique. Pork loin samples were put in Petri dishes containing an anthocyanin film on the bottom and stored at 4 ºC. Psychrotrophic microorganism count and the pH of the pork loin samples were analyzed for a 14 day- period. At the same time, the films were subjected to colorimetric analysis using D65 illuminant and the CIELAB system. Chroma and hue angle data for these films were evaluated by Anova and Dunnett's test. An increase in the microbial population and in the pH was observed over the storage period as result of pork deterioration. Color changes were also identified in the film. However, only at the beginning of the storage period was it possible to establish a correlation between film color and pork deterioration. The shelf life end-point could not be clearly detected by the film.

  3. Genome wide identification of chilling responsive microRNAs in Prunus persica

    Directory of Open Access Journals (Sweden)

    Barakat Abdelali

    2012-09-01

    species. Several conserved and non-conserved miRNAs and miRNA-regulated genes co-localize with Quantitative Trait Loci (QTLs for chilling requirement (CR-QTL and bloom date (BD-QTL. Conclusions In this work, we identified a large set of conserved and non-conserved miRNAs and describe their evolutionary footprint in angiosperm lineages. Several of these miRNAs were induced in winter buds and co-localized with QTLs for chilling requirement and bloom date thus making their gene targets potential candidates for mediating plant responses to cold stress. Several peach homologs of genes participating in the regulation of vernalization in Arabidopsis were identified as differentially expressed miRNAs targets, potentially linking these gene activities to cold responses in peach dormant buds. The non-conserved miRNAs may regulate cellular, physiological or developmental processes specific to peach and/or other tree species.

  4. Changes in visual quality, physiological and biochemical parameters assessed during the postharvest storage at chilling or non-chilling temperatures of three sweet basil (Ocimum basilicum L.) cultivars.

    Science.gov (United States)

    Fratianni, Florinda; Cefola, Maria; Pace, Bernardo; Cozzolino, Rosaria; De Giulio, Beatrice; Cozzolino, Autilia; d'Acierno, Antonio; Coppola, Raffaele; Logrieco, Antonio Francesco; Nazzaro, Filomena

    2017-08-15

    Leaves of three different sweet basil (Ocimum basilicum L.) cultivars (Italico a foglia larga, Cammeo, and Italiano classico) packed in macro-perforated polyethylene bags were stored at chilling (4°C) or non-chilling temperature (12°C) for 9days. During storage, visual quality, physiological (respiration rate, ethylene production, ammonium content) and chemical (antioxidant activity, total polyphenols and polyphenol profile) parameters were measured. Detached leaves stored at chilling temperature showed visual symptoms related to chilling injury, while ethylene production and ammonium content resulted associated to cultivar sensibility to damage at low temperature. Storage at 4°C caused a depletion in polyphenols content and antioxidant capability, which was preserved at 12°C. Regarding the polyphenols profile, stressful storage conditions did not enhance the phenolic metabolism. However, leaves stored at 12°C did not loss a significant amount of metabolites respect to fresh leaves, suggesting the possibility to extend the storability after the expiration date, for a possible recovery of bioactive compounds.

  5. Pre-storage application of oxalic acid alleviates chilling injury in mango fruit by modulating proline metabolism and energy status under chilling stress.

    Science.gov (United States)

    Li, Peiyan; Zheng, Xiaolin; Liu, Yan; Zhu, Yuyan

    2014-01-01

    Effects of oxalic acid on chilling injury, proline metabolism and energy status in mango fruit were investigated after mango fruit (Mangifera indica L. cv. Zill) were dipped in 5mM oxalic acid solution for 10min at 25°C and then stored at low temperature (10±0.5°C) for 49days thereafter transferred to 25°C for 4days. Pre-storage application of oxalic acid apparently inhibited the development of chilling injury, notably elevated proline accumulation actually associated with increase in Δ(1)-pyrroline-5-carboxylate synthetase (P5CS) activity and decrease in proline dehydrogenase (PDH) activity in the peel and the flesh, without activation of ornithine-δ-aminotransferase (OAT) activity, and maintained high ATP level and energy charge in the flesh during storage. It was suggested that these effects of oxalic acid might collectively contribute to improving chilling tolerance, thereby alleviating chilling injury and maintaining quality of mango fruit in long term cold storage.

  6. A major QTL introgressed from wild Lycopersicon hirsutum confers chilling tolerance to cultivated tomato (Lycopersicon esculentum).

    Science.gov (United States)

    John Goodstal, F; Kohler, Glenn R; Randall, Leslie B; Bloom, Arnold J; St Clair, Dina A

    2005-09-01

    Many plants of tropical or subtropical origin, such as tomato, suffer damage under chilling temperatures (under 10 degrees C but above 0 degrees C). An earlier study identified several quantitative trait loci (QTLs) for shoot turgor maintenance (stm) under root chilling in an interspecific backcross population derived from crossing chilling-susceptible cultivated tomato (Lycopersicon esculentum) and chilling-tolerant wild L. hirsutum. The QTL with the greatest phenotypic effect on stm was located in a 28 cM region on chromosome 9 (designated stm 9), and enhanced chilling-tolerance was conferred by the presence of the Lycopersicon hirsutum allele at this QTL. Here, near-isogenic lines (NILs) were used to verify the effect of stm 9, and recombinant sub-NILs were used to fine map its position. Replicated experiments were performed with NILs and sub-NILs in a refrigerated hydroponic tank in the greenhouse. Sub-NIL data was analyzed using least square means separations, marker-genotype mean t-tests, and composite interval mapping. A dominant QTL controlling shoot turgor maintenance under root chilling was confirmed on chromosome 9 using both NILs and sub-NILs. Furthermore, sub-NILs permitted localization of stm 9 to a 2.7 cM interval within the original 28 cM QTL region. If the presence of the L. hirsutum allele at stm 9 also confers chilling-tolerance in L. esculentum plants grown under field conditions, it has the potential to expand the geographic areas in which cultivated tomato can be grown for commercial production.

  7. Characterization of PSI recovery after chilling-induced photoinhibition in cucumber (Cucumis sativus L.) leaves.

    Science.gov (United States)

    Zhang, Zishan; Jia, Yujiao; Gao, Huiyuan; Zhang, Litao; Li, Haidong; Meng, Qingwei

    2011-11-01

    By simultaneously analyzing the chlorophyll a fluorescence transient and light absorbance at 820 nm as well as chlorophyll fluorescence quenching, we investigated the effects of different photon flux densities (0, 15, 200 μmol m(-2) s(-1)) with or without 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU) on the repair process of cucumber (Cucumis sativus L.) leaves after treatment with low temperature (6°C) combined with moderate photon flux density (200 μmol m(-2 )s(-1)) for 6 h. Both the maximal photochemical efficiency of Photosystem II (PSII) (F (v)/F (m)) and the content of active P700 (ΔI/I (o)) significantly decreased after chilling treatment under 200 μmol m(-2 )s(-1) light. After the leaves were transferred to 25°C, F (v)/F (m) recovered quickly under both 200 and 15 μmol m(-2 )s(-1) light. ΔI/I (o) recovered quickly under 15 μmol m(-2) s(-1) light, but the recovery rate of ΔI/I (o) was slower than that of F (v)/F (m). The cyclic electron transport was inhibited by chilling-light treatment obviously. The recovery of ΔI/I (o) was severely suppressed by 200 μmol m(-2) s(-1) light, whereas a pretreatment with DCMU effectively relieved this suppression. The cyclic electron transport around PSI recovered in a similar way as the active P700 content did, and the recovery of them was both accelerated by pretreatment with DCMU. The results indicate that limiting electron transport from PSII to PSI protected PSI from further photoinhibition, accelerating the recovery of PSI. Under a given photon flux density, faster recovery of PSII compared to PSI was detrimental to the recovery of PSI or even to the whole photosystem.

  8. Regeneration of ammonia borane from polyborazylene

    Science.gov (United States)

    Sutton, Andrew; Gordon, John C; Ott, Kevin C; Burrell, Anthony K

    2013-02-05

    Method of producing ammonia borane, comprising providing a reagent comprising a dehydrogenated material in a suitable solvent; and combining the reagent with a reducing agent comprising hydrazine, a hydrazine derivative, or combinations thereof, in a reaction which produces a mixture comprising ammonia borane.

  9. Method for releasing hydrogen from ammonia borane

    Science.gov (United States)

    Varma, Arvind; Diwan, Moiz; Shafirovich, Evgeny; Hwang, Hyun-Tae; Al-Kukhun, Ahmad

    2013-02-19

    A method of releasing hydrogen from ammonia borane is disclosed. The method comprises heating an aqueous ammonia borane solution to between about 80-135.degree. C. at between about 14.7 and 200 pounds per square inch absolute (psia) to release hydrogen by hydrothermolysis.

  10. Oxidative and nitrosative stress in ammonia neurotoxicity.

    Science.gov (United States)

    Skowrońska, Marta; Albrecht, Jan

    2013-04-01

    Increased ammonia accumulation in the brain due to liver dysfunction is a major contributor to the pathogenesis of hepatic encephalopathy (HE). Fatal outcome of rapidly progressing (acute) HE is mainly related to cytotoxic brain edema associated with astrocytic swelling. An increase of brain ammonia in experimental animals or treatment of cultured astrocytes with ammonia generates reactive oxygen and nitrogen species in the target tissues, leading to oxidative/nitrosative stress (ONS). In cultured astrocytes, ammonia-induced ONS is invariably associated with the increase of the astrocytic cell volume. Interrelated mechanisms underlying this response include increased nitric oxide (NO) synthesis which is partly coupled to the activation of NMDA receptors and increased generation of reactive oxygen species by NADPH oxidase. ONS and astrocytic swelling are further augmented by excessive synthesis of glutamine (Gln) which impairs mitochondrial function following its accumulation in there and degradation back to ammonia ("the Trojan horse" hypothesis). Ammonia also induces ONS in other cell types of the CNS: neurons, microglia and the brain capillary endothelial cells (BCEC). ONS in microglia contributes to the central inflammatory response, while its metabolic and pathophysiological consequences in the BCEC evolve to the vasogenic brain edema associated with HE. Ammonia-induced ONS results in the oxidation of mRNA and nitration/nitrosylation of proteins which impact intracellular metabolism and potentiate the neurotoxic effects. Simultaneously, ammonia facilitates the antioxidant response of the brain, by activating astrocytic transport and export of glutathione, in this way increasing the availability of precursors of neuronal glutathione synthesis.

  11. Ammonia sensors and their applications - a review

    NARCIS (Netherlands)

    Timmer, Björn; Olthuis, Wouter; Berg, van den Albert

    2005-01-01

    Many scientific papers have been written concerning gas sensors for different sensor applications using several sensing principles. This review focuses on sensors and sensor systems for gaseous ammonia. Apart from its natural origin, there are many sources of ammonia, like the chemical industry or i

  12. Ammonia and hydrogen sulfide removal using biochar

    Science.gov (United States)

    Reducing ammonia and hydrogen sulfide emissions from livestock facilities is an important issue for many communities and livestock producers. Ammonia has been regarded as odorous, precursor for particulate matter (PM), and contributed to livestock mortality. Hydrogen sulfide is highly toxic at elev...

  13. Complete genome sequence of Nitrosomonas sp. Is79, an ammonia oxidizing bacterium adapted to low ammonium concentrations

    NARCIS (Netherlands)

    Bollmann, A.; Sedlacek, C.J.; Norton, J.; Laanbroek, H.J.; Suwa, Y.; Stein, L.Y.; Klotz, M.G.; Arp, D.; Sayavedra-Soto, L.; Lu, M.; Bruce, D.; Detter, C.; Tapia, R.; Han, J.; Woyke, T.; Lucas, S.; Pitluck, S.; Pennacchio, L.; Nolan, M.; Land, M.L.; Huntemann, M.; Deshpande, S.; Han, C.; Chen, A.; Kyrpides, N.; Mavromatis, K.; Markowitz, V.; Szeto, E.; Ivanova, N.; Mikhailova, N.; Pagani, I.; Pati, A.; Peters, L.; Ovchinnikova, G.; Goodwin, L.

    2013-01-01

    Nitrosomonas sp. Is79 is a chemolithoautotrophic ammonia-oxidizing bacterium that belongs to the family Nitrosomonadaceae within the phylum Proteobacteria. Ammonia oxidation is the first step of nitrification, an important process in the global nitrogen cycle ultimately resulting in the production o

  14. Monnte Carlo Simulation of Kinetics of Ammonia Oxidative Decomposition over the Commercial Propylene Ammoxidation Catalyst(Mo-Bi)

    Institute of Scientific and Technical Information of China (English)

    罗正鸿; 詹晓力; 等

    2003-01-01

    Monte Carlo method is applied to investigate the kinetics of ammonia oxidative decomposition over the commercial propylene ammoxidation catalyst(Mo-Bi).The simulation is quite in agreement with experimetal results.Monte Carlo simulation proves that the process of ammonia oxidation decomposition is a two-step reaction.

  15. Bioaugmentation with an acetate-oxidising consortium as a tool to tackle ammonia inhibition of anaerobic digestion

    DEFF Research Database (Denmark)

    Fotidis, Ioannis; Karakashev, Dimitar Borisov; Angelidaki, Irini

    2013-01-01

    Ammonia is the major inhibitor of anaerobic digestion (AD) process in biogas plants. In the current study, the bioaugmentation of the ammonia tolerant SAO co-culture (i.e. Clostridium ultunense spp. nov. in association with Methanoculleus spp. strain MAB1) in a mesophilic up-flow anaerobic sludge...

  16. Trends in ammonia measurements in the Netherlands over the period 1993-2014

    Science.gov (United States)

    van Zanten, M. C.; Wichink Kruit, R. J.; Hoogerbrugge, R.; Van der Swaluw, E.; van Pul, W. A. J.

    2017-01-01

    emissions and concentrations of ammonia diverge. This divergence is for roughly a third accounted for by processes related to changes in chemical climate (see accompanying modelling paper by Wichink Kruit et al., 2016) but it is not clear what explains the remaining difference in trends. For 1993-2014, downward trends of wet deposition of ammonium and ammonium in aerosol are found to be 47% and 68%, respectively. A split into two periods is not found as is the case with the ammonia concentration. However, although statistically not significant, both wet deposition of ammonium and ammonium in aerosol show a leveling off in decline between 2005 and 2014.

  17. OXIDATIVE STABILITY OF CHILLED CHICKEN MEAT AFTER FEEDING OF SELECTED PLANTS

    Directory of Open Access Journals (Sweden)

    Mária Martonová

    2010-07-01

    Full Text Available  The effect of feeding of lemon balm (Melissa officinalis, L and combination of yarrow (Achillea millefolium L and hawthorn (Crataegus oxyacantha L on oxidative stability and sensory properties of produced poultry meat was investigated. Sixty one-day-old commercial broiler chicks (ROSS 308 were used in our experiment, divided into 3 groups, and fed 41 days, as follows: control (K was fed with standard diet without supplementation of plants; second group (M was fed with standard diet supplemented with grounded lemon balm in concentration 2 % per 1 kg; and third group was fed with standard diet supplemented with grounded yarrow (2 % and hawthorn (1 %. Results showed that supplementation with lemon balm, and mainly combination of yarrow and hawthorn in the diet significantly caused reduction of lipid oxidation processes in thigh meat during chilling storage of samples. In addition, supplementation of plants in the diet had positive effect on sensory quality of meat of broiler chickens.    doi:10.5219/38 

  18. Catalytic decomposition of ammonia in a fuel gas at high temperature and pressure

    Energy Technology Data Exchange (ETDEWEB)

    Mojtahedi, W.; Abbasian, J. [Enviropower Inc., Espoo (Finland)

    1995-11-01

    In connection with the purification of fuel gas for gas turbines in the IGCC process to meet NO{sub x} standards and maintain the thermal efficiency of the process, tests were carried out with a 7.5 cm pressurized reactor to decompose ammonia at high temperature (700-900{degree}C) and pressure (2 MPa) using Ni-based catalysts. The effects of temperature, pressure, ammonia concentration and gas residence time were determined. The simulated coal gas composition was varied to allow assessment of the effect of contaminants (sulfur compounds and tars) on the ammonia decomposition efficiency of five catalysts under otherwise identical operating conditions. The results show that two of the catalysts tested are capable of efficiently reducing the concentration of ammonia in the gas. 12 refs., 13 figs.

  19. Clinical utility of breath ammonia for evaluation of ammonia physiology in healthy and cirrhotic adults.

    Science.gov (United States)

    Spacek, Lisa A; Mudalel, Matthew; Tittel, Frank; Risby, Terence H; Solga, Steven F

    2015-12-01

    Blood ammonia is routinely used in clinical settings to assess systemic ammonia in hepatic encephalopathy and urea cycle disorders. Despite its drawbacks, blood measurement is often used as a comparator in breath studies because it is a standard clinical test. We sought to evaluate sources of measurement error and potential clinical utility of breath ammonia compared to blood ammonia. We measured breath ammonia in real time by quartz enhanced photoacoustic spectrometry and blood ammonia in 10 healthy and 10 cirrhotic participants. Each participant contributed 5 breath samples and blood for ammonia measurement within 1 h. We calculated the coefficient of variation (CV) for 5 breath ammonia values, reported medians of healthy and cirrhotic participants, and used scatterplots to display breath and blood ammonia. For healthy participants, mean age was 22 years (±4), 70% were men, and body mass index (BMI) was 27 (±5). For cirrhotic participants, mean age was 61 years (±8), 60% were men, and BMI was 31 (±7). Median blood ammonia for healthy participants was within normal range, 10 μmol L(-1) (interquartile range (IQR), 3-18) versus 46 μmol L(-1) (IQR, 23-66) for cirrhotic participants. Median breath ammonia was 379 pmol mL(-1) CO2 (IQR, 265-765) for healthy versus 350 pmol mL(-1) CO2 (IQR, 180-1013) for cirrhotic participants. CV was 17  ±  6%. There remains an important unmet need in the evaluation of systemic ammonia, and breath measurement continues to demonstrate promise to fulfill this need. Given the many differences between breath and blood ammonia measurement, we examined biological explanations for our findings in healthy and cirrhotic participants. We conclude that based upon these preliminary data breath may offer clinically important information this is not provided by blood ammonia.

  20. Effect of Polyamine Priming on Chilling Tolerance of Lolium perenne during Seed Imbibition

    Institute of Scientific and Technical Information of China (English)

    Yingfen WANG; Puchang WANG; Jiahai WU; Lili ZHAO; Bentian MO; Jun LI

    2012-01-01

    [Objective] This study aimed to investigate the effect of potyamine priming on physiological and biochemical variations of Lolium perenne embryos and seed germination. [Method] With annual Lolium perenne (Diamond T and Grazing-8000) as experimental materials, after priming with 0.5 mmol/L putrescine (Put), spermidine (Spd) and spermine (Spm) for 24 h and chilling imbibition at 5 ℃ for 12, 24, 36 and 48 h, the effect of Put, Spd and Spm priming on chilling tolerance and germination ability of annual Lolium perenne seeds during imbibition was investigated. [Result] Put, Spd and Spm priming improved the activities of peroxidase (POD), catalase (CAT), superoxide dismutase (SOD) and ascorbate peroxidase (APX) and content of soluble protein content under low temperature stress, significantly in-creased the germination rate, and shortened the average germination duration. After chilling imbibition for 48 h, compared with the control, the average germination rate of annual Lolium perenne seeds was improved by 15.5% and 12.0% after Put, Spd and Spm priming, and the average germination duration was shortened by 1.21 and 1.14 d. During seed imbibition, the chilling tolerance of Grazing-8000 was stronger than that of Diamond T. Overall, Put, Spd and Spm treatment could increase the chilling tolerance of annual Lolium perenne seeds during imbibition, and improve the germination ability of seeds under low temperature stress. [Conclusion] Results of this study provided theoretical basis for the application of seed priming technology in the production of annual ryegrass.

  1. Determination of Chilling and Heat Requirements of Pistachio (Pistacia vera L.) Cultivars

    Institute of Scientific and Technical Information of China (English)

    Majid Rahemi; Zahra Pakkish

    2009-01-01

    Determination of chilling and heat requirements of pistachio (Pistacia vera L.) cultivars is important for satisfactory growth and development, particularly when large-scale commercial production is desired. This experiment was conducted to determine chilling requirement inducing vegetative and flower buds of Kalle-Ghuchi, Owhadi, Ahmad-Ahgaei, and Akbari pistachio. Shoots with enough vegetative and flower buds were taken from pistachio trees during autumn 2007 and 2008 when temperature reached to≤15℃. Cuttings with flower buds were kept under (5±1)℃ for 0, 600, 650, 700, 750, 800, 850, 900, 950, 1000, 1050, 1100, 1150, 1200, 1250, and 1300 h, respectively, and cuttings with vegetative buds were kept at 51℃ until 1 500 h. The results indicated that pistachio eultivars requite chilling time between 750-1 400 h and heat requirements between 8 852-15 420 growing degree hours (GDH). Consequently, Kalle-Ghuehi had the lowest chilling (750-950 h), and heat (8 852-9 768 GDH) requirements, Ahmad-Aghaei and Owhadi had intermediate (1 000-1 250 h, 10 656-13 320 GDH) and Akbari had the highest chilling (1 200-1 400 h) and heat (11 863-15420 GDH) requirement.

  2. Quality indicators and shelf life of red octopus (Octopus maya in chilling storage

    Directory of Open Access Journals (Sweden)

    Mariel GULLIAN-KLANIAN

    2016-01-01

    Full Text Available Abstract There are no precedents concerning the quality of Octopus maya during chilled storage. This study evaluated the shelf life of the red octopus in chilling storage (4oC and the correlation of the sensory quality index with microbiological counting and the biochemical indicators (hypoxanthine, histamine and volatile amines. A total of 112 whole raw octopi (average weight of 896 g were randomly selected from seven batches and exposed to 4°C for 18, 24, 48, 72, 84, 96, and 100 h. The histamine concentration (91.7%, followed by the counts of psychrotrophic bacteria (5.5% and hypoxanthine (2.2%, were the predictors from the redundancy analysis that better explained the changes taking place during the chilling hours. After 72 h of chilling, the microbial count was determined to be log 4.7 CFU/g, and the octopus samples were classified as B quality (minor sensory quality defects based on the sensory quality scale. Although the samples were not classified as unacceptable at 100 h of refrigeration by the sensory index, the level of histamine reached the defect action level (5 mg/100 g as ruled by the International Food Safety Authorities. The shelf life of the red octopus in chilling storage was predicted to be 119 h.

  3. Soft Sensor for Ammonia Concentration at the Ammonia Converter Outlet Based on an Improved Group Search Optimization and BP Neural Network

    Institute of Scientific and Technical Information of China (English)

    阎兴頔; 杨文; 马贺贺; 侍洪波

    2012-01-01

    The ammonia synthesis reactor is the core unit in the whole ammonia synthesis production. The ammo- nia concentration at the ammonia converter outlet is a significant process variable, which reflects directly the pro- duction efficiency. However, it is hard to be measured reliably online in real applications. In this paper, a soft sensor based on BP neural network (BPNN) is applied to estimate the ammonia concentration. A modified group search optimization with nearest neighborhood (GSO-NH) is proposed to optimize the weights and thresholds of BPNN. GSO-NH is integrated with BPNN to build a soft sensor model. Finally, the soft sensor model based on BPNN and GSO-NH (GSO-NH-NN) is used to infer the outlet ammonia concentration in a real-world application. Three other modeling methods are applied for comparison with GSO-NH-NN. The results show that the soft sensor based on GSO-NH-NN has a good prediction performance with high accuracy. Moreover, the GSO-NH-NN also provides good generalization ability to other modeling problems in ammonia synthesis production.

  4. A novel way to synthesize Pb nanotapes in liquid ammonia

    Institute of Scientific and Technical Information of China (English)

    Lei Sun; Meng Lei Zhang; Xiao Jun Tao; Yan Bao Zhao

    2011-01-01

    Lead nanotapes were synthesized in liquid ammonia solvent in the presence of sodium metal at low temperature. The process was template free. Transmission electron microscopy (TEM) observations and X-ray diffraction (XRD) characterizations revealed that the as-prepared Pb nanotapes have average diameters in the range of 40-50 nm, and lengths up to several hundred nanometers, and exhibit cubic crystal structures.

  5. Backcross introgression of plastomic factors controlling chilling tolerance into elite cucumber (Cucumis sativus L.) germplasm: Early generation recovery of recurrent parent phenotytpe

    Science.gov (United States)

    Environmental stresses such as chilling temperatures can decrease germination, emergence, flower and fruit development, marketable yield, and postharvest fruit storage longevity in cucumber (Cucumis sativus L.). While response to chilling injury in cucumber is controlled by simple plastidic (matern...

  6. Distribution of ammonia oxidizers in relation to vegetation characteristics in the Qilian Mountains, northwestern China

    Science.gov (United States)

    Tai, X. S.; Mao, W. L.; Liu, G. X.; Chen, T.; Zhang, W.; Wu, X. K.; Long, H. Z.; Zhang, B. G.; Gao, T. P.

    2014-04-01

    Nitrogen is the major limiting nutrient in cold environments, and its availability is strongly dependent on nitrification. However, microbial communities driving this process remain largely uncharacterized in alpine meadow soils in northwestern China, namely those catalyzing the rate-limiting step of ammonia oxidation. In this study, ammonia-oxidizing communities in alpine meadow soils were characterized by real-time PCR and clone sequencing by targeting on amoA genes, which putatively encode ammonia monooxygenase subunit A. The results demonstrated that ammonia-oxidizing archaea (AOA) outnumbered ammonia-oxidizing bacteria (AOB) in the alpine meadow soils. Most of the AOA phylotypes detected in the study region fell within typical Group I.1b of Thaumarchaeota. Interestingly, a new ammonia-oxidizing archaeal group named "Kobresia meadow soil group" was found. Phylogenetic analysis of AOB communities exhibited a dominance of Nitrosospira-like sequences affiliated to beta-Proteobacteria. Compared with other alpine environments, Qilian Mountains had a great phylogenetic diversity of ammonia oxidizers. Principal Component Analysis (PCA) analysis showed that distinct AOA/AOB phylotype groups were attributed to different meadow types, reflecting an overall distribution of ammonia-oxidizing communities associated with meadow types. Redundancy Analysis (RDA) analysis showed that Axis 1 (90.9%) together with Axis 2 (9.1%) explained all the variables while Axis 1 exhibited a significant explanatory power. So that vegetation coverage mostly correlated to Axis 1 was the most powerful environmental factor in the study region. Characteristics of ammonia-oxidizing communities showed a close association with vegetation coverage.

  7. Exploration Test on Gold Extraction from Arsenopyrite Gold Concentrate with Oxidation Pressure Leaching Process in Ammonium Thiocyanate-Ammonia System%某毒砂金矿硫氰酸盐氨性体系加压氧化提金探索试验

    Institute of Scientific and Technical Information of China (English)

    胡燕清; 杨声海; 陈永明

    2012-01-01

    对某毒砂金矿进行了硫氰酸盐氨性体系氧压提取金的探索试验,考察了反应温度、Cu2+浓度、浸出时间、液固比、氨水浓度、氧分压和硫氰酸铵浓度等对金浸出率的影响.结果表明,在下述优化条件下金浸出率为61.7%,即硫氰酸铵浓度3 mol/L,液固比5:1,反应温度150℃,浸出时间6h,搅拌速度750r/min,氨水浓度4.64 mo/L,铜加入量1.5 g/L.而经400℃焙烧预处理后金浸出率达到86.2%.%The exploration test on gold extraction from arsenopyrite gold concentrate with oxidation pressure leaching process in ammonium thiocyanate-ammonia system was performed. The effects of leaching temperature,copper concentration, leaching time, ratio of liquid to solid (L/S), ammonia concentration, oxygen pressure, and the concentration of ammonium thiocyanate on gold leaching rate were studied. The results show that the gold leaching ratio is 61. 7% under the optimum conditions including NH4SCN concentration of 3 mol/L, L/S=5, leaching temperature of 150 °C , leaching time of 6 hours, stirring speed of 750 r/min, ammonia concentration of 4. 64 mol/L, and copper dosage of 1. 5 g/L. The gold leaching ratio can leach 86. 2% after the pretreatment of roasting at 400℃.

  8. Real-Time, In Situ Sensor for Control of Ammonia Slip in SCR Installations

    Energy Technology Data Exchange (ETDEWEB)

    James Daly

    2005-09-30

    In this program, we proposed to demonstrate a compact, rugged, low-cost ammonia sensor with better than {+-}0.2 ppmv lower detection limit and resolution. Extensive design and trade studies indicated that this measurement could be made by exploiting the infrared absorbance of ammonia at 1527 nm to determine concentration. Key features of the design were (1) a electronically-tunable, wavelength-agile diode laser-pumped fiber laser, (2) a unique, low-cost folded path optical cell, and (3) an InGaAs photodiode (light detector). The sensor would be designed to make in situ measurements of ammonia in flue gas just downstream from the catalyst. The design proved robust and was able to operate at pressures in the range 1-3 atm and temperatures up to 500 C. With extensive signal processing, the sensor was able to make unambiguous ammonia measurements. But the signal processing degraded response time to almost 3 seconds and the measurement ambient conditions limited achievable resolution to about 20 ppmv ammonia. Extensive re-design, including a much longer optical path length and more robust real-time signal processing would be required to make sub-ppm measurements using this approach. During the performance period of this project, conventional in-situ laser based monitors and thick film ceramic ammonia sensors have been introduced and have gained acceptance in real-time feed-forward control for this application.

  9. RNA Expression and Post-Transcriptional Editing Analyses of Cucumber Plastids Reveals Genetic Differences Associated with Chilling Tolerance

    Science.gov (United States)

    Tolerance to chilling injury in cucumber (Cucumis sativus L.) is associated with three plastomic single nucleotide polymorphisms (ptSNPs) at bp positions 4,813, 56,561, and 126,349 that are co-inherited. An understanding of the genetic expression of these ptSNPs as a response to chilling is critical...

  10. Effect of 1-methylcyclopropene and modified atmosphere packaging on chilling injury, and antioxidative defensive mechanism of sweet pepper

    Science.gov (United States)

    Sweet peppers (Capsicum annuum L.) are chilling sensitive vegetable, and develop injury when stored at temperatures less than 7 C. This study was conducted to investigate the effect of 1-methylcyclopropene (1-MCP) (650 ppb) and modified atmosphere packaging (MAP) on chilling injuries of sweet pepper...

  11. Chilling to zero degrees disrupts pollen formation but not meiotic microtubule arrays in Triticum aestivum L.

    Science.gov (United States)

    Barton, Deborah A; Cantrill, Laurence C; Law, Andrew M K; Phillips, Collin G; Sutton, Bruce G; Overall, Robyn L

    2014-12-01

    Throughout the wheat-growing regions of Australia, chilling temperatures below 2 °C occur periodically on consecutive nights during the period of floral development in spring wheat (Triticum aestivum L.). In this study, wheat plants showed significant reductions in fertility when exposed to prolonged chilling temperatures in controlled environment experiments. Among the cultivars tested, the Australian cultivars Kite and Hartog had among the lowest levels of seed set due to chilling and their responses were investigated further. The developmental stage at exposure, the chilling temperature and length of exposure all influenced the level of sterility. The early period of booting, and specifically the +4 cm auricle distance class, was the most sensitive and corresponded to meiosis within the anthers. The response of microtubules to chilling during meiosis in Hartog was monitored, but there was little difference between chilled and control plants. Other abnormalities, such as plasmolysis and cytomixis increased in frequency, were associated with death of developing pollen cells, and could contribute to loss of fertility. The potential for an above-zero chilling sensitivity in Australian spring wheat varieties could have implications for exploring the tolerance of wheat flower development to chilling and freezing conditions in the field.

  12. Thermal environment and air quality in office with personalized ventilation combined with chilled ceiling

    DEFF Research Database (Denmark)

    Lipczynska, Aleksandra; Kaczmarczyk, Jan; Melikov, Arsen Krikor

    2015-01-01

    with the temperature of 25°C. PV improved thermal conditions and was up to nearly 10 times more efficient in delivering clean air at workstations than mixing ventilation systems, which resulted in strong protection of occupants from the cross-infection. In the room space outside workstations no substantial differences......The thermal environment and air quality conditions provided with combined system of chilled ceiling and personalized ventilation (PV) were studied in a simulated office room for two occupants. The proposed system was compared with total volume HVAC solutions used today, namely mixing ventilation...... and chilled ceiling combined with mixing ventilation. The objective of the study was to evaluate whether PV can be the only ventilation system in the rooms equipped with chilled ceiling. The room air temperature was 26°C in cases with traditional systems and 28°C when PV was used. PV supplied air...

  13. Protection of ultrastructure in chilling-stressed banana leaves by salicylic acid

    Institute of Scientific and Technical Information of China (English)

    KANG Guo-zhang; WANG Zheng-xun; XIA Kuai-fei; SUN Gu-chou

    2007-01-01

    Objective: Chilling tolerance of salicylic acid (SA) in banana seedlings (Musa acuminata cv., Williams 8818) was investigated by changes in ultrastructure in this study. Methods: Light and electron microscope observation. Results: Pretreatment with 0.5 mmol/L SA under normal growth conditions (30/22 ℃) by foliar spray and root irrigation resulted in many changes in ultrastructure of banana cells, such as cells separation from palisade parenchymas, the appearance of crevices in cell walls, the swelling of grana and stromal thylakoids, and a reduction in the number of starch granules. These results implied that SA treatment at 30/22 ℃ could be a type of stress. During 3 d of exposure to 7 ℃ chilling stress under low light, however, cell ultrastructure of SA-pretreated banana seedlings showed less deterioration than those of control seedlings (distilled water-pretreated). Conclusion:SA could provide some protection for cell structure of chilling-stressed banana seedling.

  14. Umami and related components in "chilled" pork for the Japanese market.

    Science.gov (United States)

    Ngapo, T M; Vachon, L

    2016-11-01

    The aim of this study was to evaluate umami-related components and their evolution in Canadian pork destined for the Japanese market. Export quality pork loins for Japan were subjectively selected on-line for marbling, colour and firmness; remaining loins were retained for the domestic market. At 48h post-mortem, samples were aged 5d at 4.0°C (fresh) or 13, 28, 43 or 58d at -1.7°C (chilled). Meat qualities differed only in pH (exports to Japan. A lack of differences in EUC between domestic and export pork and between fresh and 43d chilled ageing demonstrates that Canadian chilled pork in Japan has the EUC of its fresh 5d counterpart.

  15. Chilling Tolerance of Cucumber During Germination is Related to Expression of Lysine Decarboxylase Gene

    Institute of Scientific and Technical Information of China (English)

    LU Ming-hui; LI Xiao-ming; CHEN Jin-feng; CHEN Long-zheng; QIAN Chun-tao

    2005-01-01

    Using cDNA-AFLP technique, a specific fragment was isolated from cucumber cultivar Changchun mici possessing chilling tolerance induced at low temperature (15℃). This fragment, named cctr 132, could not be induced in the chilling sensitive cucumber cultivar Beijing jietou. After recovering the fragment, sequencing and translating, the results of blastx and blastp in GenBank of NCBI indicated that CCTR132 had 88.37% identities and 100% positives with Oryza sativa putative lysine decarboxylase-like protein respectively, and PGGXGTXXE, the putative conserved domain of lysine decarboxylase family, was detected from CCTR132, suggesting the cucumber chilling tolerance during germination is related to the expression of the lysine decarboxylase gene.

  16. Ammonia gas permeability of meat packaging materials.

    Science.gov (United States)

    Karim, Faris; Hijaz, Faraj; Kastner, Curtis L; Smith, J Scott

    2011-03-01

    Meat products are packaged in polymer films designed to protect the product from exterior contaminants such as light, humidity, and harmful chemicals. Unfortunately, there is almost no data on ammonia permeability of packaging films. We investigated ammonia permeability of common meat packaging films: low-density polyethylene (LDPE; 2.2 mil), multilayer polyolefin (MLP; 3 mil), and vacuum (V-PA/PE; 3 mil, 0.6 mil polyamide/2.4 mil polyethylene). The films were fabricated into 10 × 5 cm pouches and filled with 50 mL deionized water. Pouches were placed in a plexiglass enclosure in a freezer and exposed to 50, 100, 250, or 500 ppm ammonia gas for 6, 12, 24, and 48 h at -17 ± 3 °C and 21 ± 3 °C. At freezing temperatures, no ammonia residues were detected and no differences in pH were found in the water. At room temperature, ammonia levels and pH of the water increased significantly (P packaging materials have low ammonia permeability and protect meat products exposed to ammonia leaks during frozen storage.

  17. Ammonia distribution and excretion in fish.

    Science.gov (United States)

    Randall, D J; Wright, P A

    1987-05-01

    This paper reviews the literature concerning ammonia production, storage and excretion in fish. Ammonia is the end product of protein catabolism and is stored in the body of fish in high concentrations relative to basal excretion rates. Ammonia, if allowed to accumulate, is toxic and is converted to less toxic compounds or excreted. Like other weak acids and bases, ammonia is distributed between tissue compartments in relation to transmembrane pH gradients. NH3 is generally equilibrated between compartments but NH4 (+) is distributed according to pH. Ammonia is eliminated from the blood upon passage through the gills. The mechanisms of branchial ammonia excretion vary between different species of fish and different environments, and primarily involves NH3 passive diffusion and NH4 (+)/Na(+) exchange. Water chemistry near the gill surface may also be important to ammonia excretion, but a more accurate measurement of the NH3 gradient across the gill epithelium is required before a more detailed analysis of NH3 and NH4 (+) excretion can be made.

  18. Resveratrol prevents ammonia toxicity in astroglial cells.

    Directory of Open Access Journals (Sweden)

    Larissa Daniele Bobermin

    Full Text Available Ammonia is implicated as a neurotoxin in brain metabolic disorders associated with hyperammonemia. Acute ammonia toxicity can be mediated by an excitotoxic mechanism, oxidative stress and nitric oxide (NO production. Astrocytes interact with neurons, providing metabolic support and protecting against oxidative stress and excitotoxicity. Astrocytes also convert excess ammonia and glutamate into glutamine via glutamine synthetase (GS. Resveratrol, a polyphenol found in grapes and red wines, exhibits antioxidant and anti-inflammatory properties and modulates glial functions, such as glutamate metabolism. We investigated the effect of resveratrol on the production of reactive oxygen species (ROS, GS activity, S100B secretion, TNF-α, IL-1β and IL-6 levels in astroglial cells exposed to ammonia. Ammonia induced oxidative stress, decreased GS activity and increased cytokines release, probably by a mechanism dependent on protein kinase A (PKA and extracellular signal-regulated kinase (ERK pathways. Resveratrol prevented ammonia toxicity by modulating oxidative stress, glial and inflammatory responses. The ERK and nuclear factor-κB (NF-κB are involved in the protective effect of resveratrol on cytokines proinflammatory release. In contrast, other antioxidants (e.g., ascorbic acid and trolox were not effective against hyperammonemia. Thus, resveratrol could be used to protect against ammonia-induced neurotoxicity.

  19. Impact of Physical-Chemical Properties on Ammonia Emissions of Dairy Manure

    Science.gov (United States)

    Koirala, K.

    2015-12-01

    Ammonia emission is a major concern due to its adverse effects on animal and human health. Ionic strength and suspended solids play key roles in the ammonia volatilization process. These two parameters, however, are usually lumped together in form of totalsolids. The objective of this study was to separate the contribution of suspended solids (SS) from that of ionic strength (IS) on ammonia volatilization in liquid dairy manure. A two-way factorial experiment was conducted to simultaneously test the effects of IS and SS on ammonium dissociation: a key element of the ammonia volatilization process. The fraction of ammonia (β) in total ammoniacal nitrogen (TAN) was experimentally determined in a convective emission chamber, for each level of SS and IS, at a constant wind speed of 1.5 m s-1, and air and liquid temperature of 25°C. The two way analysis of variance showed a significant effect of SS concentration (p = 0.04) on fraction of ammonia in the liquid dairy manure, while the effect of ionic strength was marginal (p = 0.05). The highest dissociation of ammonium was observed in manure with the lowest SS concentration (0%) and the lowest ionic strength (0.10 mol L-1). Significant increases in suspended solids concentration and ionic strength were necessary to influence the ammonium dissociation in dairy manure. Results revealed that substantially high content of suspended solids (> 3.0%) or relatively high dilution of manure with water (30%) were necessary for these two parameters to play significant rolesin the ammonia volatilization mechanism in liquid dairy manure. Results also showed that the β was more sensitive to the changes in suspended solids concentration than in the changes in ionic strength within the ranges of SS and IS examined in this study.Overall, the SS and IS effects on ammonium dissociation (and by extension on ammonia volatilization process) were thus found negligible within the normal ranges of liquid dairy manure characteristics.

  20. Delineating Effects of Ionic Strength and Suspended Solids on Ammonia Volatilization from Dairy Manure Slurry

    Science.gov (United States)

    Koirala, K.

    2014-12-01

    Ammonia emission is a major concern due to its adverse effects on animal and human health. Ionic strength and suspended solids play key roles in the ammonia volatilization process. These two parameters, however, are usually lumped together in form of total solids. The objective of this study was to separate the contribution of suspended solids (SS) from that of ionic strength (IS) on ammonia volatilization in liquid dairy manure. A two-way factorial experiment was conducted to simultaneously test the effects of IS and SS on ammonium dissociation: a key element of the ammonia volatilization process. The fraction of ammonia (β) in total ammoniacal nitrogen (TAN) was experimentally determined in a convective emission chamber, for each level of SS and IS, at a constant wind speed of 1.5 m s-1, and air and liquid temperature of 25°C. The two way analysis of variance showed a significant effect of SS concentration (p = 0.04) on fraction of ammonia in the liquid dairy manure, while the effect of ionic strength was marginal (p = 0.05). The highest dissociation of ammonium was observed in manure with the lowest SS concentration (0%) and the lowest ionic strength (0.10 mol L-1). Significant increases in suspended solids concentration and ionic strength were necessary to influence the ammonium dissociation in dairy manure. Results revealed that substantially high content of suspended solids (> 3.0%) or relatively high dilution of manure with water (30%) were necessary for these two parameters to play significant roles in the ammonia volatilization mechanism in liquid dairy manure. Results also showed that the β was more sensitive to the changes in suspended solids concentration than in the changes in ionic strength within the ranges of SS and IS examined in this study. Overall, the SS and IS effects on ammonium dissociation (and by extension on ammonia volatilization process) were thus found negligible within the normal ranges of liquid dairy manure characteristics.

  1. Microbiological shelf life of fresh, chilled reindeer meat (M. longissimus dorsi

    Directory of Open Access Journals (Sweden)

    Eva Wiklund

    2011-04-01

    Full Text Available In this pilot study loin muscles (M. longissimus dorsi from six reindeer calves (aged 4 months were used to determine shelf life of fresh, chilled reindeer meat stored at +4 °C, measured as microbiological quality (aerobic microorganisms and Escherichia coli. The loins were collected at boning 3 days post slaughter and divided in five pieces that were randomly assigned to five different storage times; sampling directly after packaging and after chilled storage for 2, 3, 4 and 5 weeks at +4 °C. Samples were vacuum packaged and transported chilled to Hjortens Laboratory in Östersund, Sweden (accredited by SWEDAC according to SS-EN ISO/IEC 17025:2005 for food analysis where the storage, microbiological sampling and analysis took place according to the protocols of Nordic Committee on Food Analysis (NMKL. The total amount of aerobic microorganisms at the first sampling directly after packaging (three days post slaughter was 3.4 ± 0.3 log10 CFU/g. After two and three weeks of vacuum packaged chilled storage at +4°C the microbiological quality of the samples was on the border-line to poor (6.8 ± 0.3 log10 CFU/g. At four and five weeks of chilled storage the levels of aerobic microorganisms were significantly highest (P≤0.05 and the limit for acceptable quality of 7 log10 CFU/g aerobic bacteria had been passed (7.3 ± 0.3 log10 CFU/g and 7.8 ± 0.3 log10 CFU/g, respectively. Very few of the reindeer meat samples were contaminated with Escherichia coli bacteria. The results from the present pilot study suggest that storage time for vacuum packaged fresh, chilled reindeer meat should not exceed 3 weeks at a temperature of +4 °C.

  2. Overexpression of thylakoidal ascorbate peroxidase shows enhanced resistance to chilling stress in tomato.

    Science.gov (United States)

    Duan, Ming; Feng, Hai-Long; Wang, Li-Yan; Li, Dong; Meng, Qing-Wei

    2012-06-15

    Photosynthesis provides a strong reducing power and a high risk for generation of reactive oxygen species (ROS) particularly under chilling stress. Ascorbate peroxidases (APXs) reduce H(2)O(2) to water and play an important role in the antioxidant system of plants. Though thylakoid ascorbate peroxidase (tAPX) has been thought to be key regulator of intracellular levels of H(2)O(2), its physiological significance in the response to chilling stress is still under discussion. To study the contribution of tAPX to the ROS scavenging, a tomato thylakoidal ascorbate peroxidase gene (LetAPX) was isolated and transgenic tomatoes were obtained. The LetAPX-GFP fusion protein was targeted to chloroplast in Arabidopsis mesophyll protoplast. RNA blotting analysis revealed that the LetAPX transcript expression was up-regulated by chilling, high light, exogenous salicylic acid (SA) and methyl viologen (MV). Over expression of LetAPX in tomatoes conferred tolerance to chilling stress by maintaining higher reduced glutathione (GSH) content, chlorophyll and APX activities compared with wild type (WT) plants. Furthermore, transgenic plants showed lower levels of hydrogen peroxide (H(2)O(2)) and ion leakage, lower malendialdehyde (MDA) content, higher net photosynthetic rate (Pn) and higher maximal photochemical efficiency of PSII (Fv/Fm). The oxidizable P700 decreased more obviously in WT than that in transgenic plants under chilling stress in low irradiance. The results suggested that over expression of tAPX played a key role both in alleviating photo inhibition of PSI and PSII and enhancing their tolerance to chilling stress.

  3. Overexpression of glycerol-3-phosphate acyltransferase gene improves chilling tolerance in tomato.

    Science.gov (United States)

    Sui, Na; Li, Meng; Zhao, Shi-Jie; Li, Feng; Liang, Hui; Meng, Qing-Wei

    2007-10-01

    A tomato (Lycopersicon esculentum Mill.) glycerol-3-phosphate acyltransferase gene (LeGPAT) was isolated. The deduced amino acid sequence revealed that LeGPAT contained four acyltransferase domains, showing high identities with GPAT in other plant species. A GFP fusion protein of LeGPAT was targeted to chloroplast in cowpea mesophyll protoplast. RNA gel blot showed that the mRNA accumulation of LeGPAT in the wild type (WT) was induced by chilling temperature. Higher expression levels were observed when tomato leaves were exposed to 4 degrees C for 4 h. RNA gel and western blot analysis confirmed that the sense gene LeGPAT was transferred into the tomato genome and overexpressed under the control of 35S-CaMV. Although tomato is classified as a chilling-sensitive plant, LeGPAT exhibited selectivity to 18:1 over 16:0. Overexpression of LeGPAT increased total activity of LeGPAT and cis-unsaturated fatty acids in PG in thylakoid membrane. Chilling treatment induced less ion leakage from the transgenic plants than from the WT. The photosynthetic rate and the maximal photochemical efficiency of PS II (Fv/Fm) in transgenic plants decreased more slowly during chilling stress and recovered faster than in WT under optimal conditions. The oxidizable P700 in both WT and transgenic plants decreased obviously at chilling temperature under low irradiance, but the oxidizable P700 recovered faster in transgenic plants than in the WT. These results indicate that overexpression of LeGPAT increased the levels of PG cis-unsaturated fatty acids in thylakoid membrane, which was beneficial for the recovery of chilling-induced PS I photoinhibition in tomato.

  4. Cook-chill, cook-freeze, cook-hold, sous vide: risks for hospital patients?

    Science.gov (United States)

    Wilkinson, P J; Dart, S P; Hadlington, C J

    1991-06-01

    Changes in eating habits and developments in food technology are occurring at the same time as an upward trend in foodborne infection in Britain. Vulnerable people such as the elderly and hospital patients are increasingly likely to consume food produced by new systems such as 'cook-chill' and 'cuisson sous vide'. The microbiological hazards of these systems are assessed as negligible, provided that production is controlled by appropriate methods such as the hazard analysis critical control point (HACCP) approach. The occurrence and control of bacterial contamination in a hospital cook-chill system is reviewed in this context.

  5. STUDY ON MORPHOLOGY OF CHROMIUM IN CHILLED Cu-0.14%-2.0%Cr ALLOYS

    Institute of Scientific and Technical Information of China (English)

    H.W.Yang; Z.K.Fan

    2004-01-01

    The morphology of chromium in chilled Cu-Cr alloys with 0.14%-2.0% Cr has been studied. The results showed that eutectic Cr phase takes a fibrous shape, and pre-eutectic Cr is dendritic in the studied chilled Cu-Cr alloy. During solute treatment of the eutectic and super-eutectic Cu-Cr alloys, only part of chromium particles dissolved in copper phase,some fiber and dendritic chromium still remained. Forging before solute treatment can reduce the size of primary Cr particles, which benefits the aging structure.

  6. Evaluating the ChillFish Biofeedback Game with Children with ADHD

    DEFF Research Database (Denmark)

    Sonne, Tobias; Jensen, Mads Møller

    2016-01-01

    Breathing exercises have been shown to have multiple benefits for children with Attention Deficit Hyperactivity Disorder (ADHD). However, these children can have issues retaining attention to such an exercise. In this paper we present a study of ChillFish, a respiration game for children with ADHD....... Our findings show tendencies that the game works in terms of having a calming effect. However, the study also highlighted issues of evaluating biofeedback games with children with ADHD that are not present when evaluating with adults. This work presents an iteration in the ChillFish development cycle...

  7. The Relationship Between Heat-induced Chilling Tolerance and Endogenous ABA Levels in Mangoes

    Institute of Scientific and Technical Information of China (English)

    ZHU Shi-jiang; JI Zuo-liang

    2002-01-01

    Heating "Zhihua" mangoes (Mangifera indica L. cv. Zhihua) in hot air at 38℃ for 12hours significantly reduced the development of chilling injury following storage for 12days at 2℃. Prolonging the heating up to 72hours acquired similar results. During the 12 days' storage at 2℃ following heating for 72hours, the membrane leakage of the mango peels showed little change, while it increased with time for the control fruits, and the endogenous ABA levels in the heated fruits were higher than that in the control. These results indicated that higher ABA rates were linked with stronger chilling tolerance in mangoes.

  8. Competition for ammonia influences the structure of chemotrophic communities in geothermal springs.

    Science.gov (United States)

    Hamilton, Trinity L; Koonce, Evangeline; Howells, Alta; Havig, Jeff R; Jewell, Talia; de la Torre, José R; Peters, John W; Boyd, Eric S

    2014-01-01

    Source waters sampled from Perpetual Spouter hot spring (pH 7.03, 86.4°C), Yellowstone National Park, WY, have low concentrations of total ammonia, nitrite, and nitrate, suggesting nitrogen (N) limitation and/or tight coupling of N cycling processes. Dominant small-subunit rRNA sequences in Perpetual Spouter source sediments are closely affiliated with the ammonia-oxidizing archaeon "Candidatus Nitrosocaldus yellowstonii" and the putatively nitrogen-fixing (diazotrophic) bacterium Thermocrinis albus, respectively, suggesting that these populations may interact at the level of the bioavailable N pool, specifically, ammonia. This hypothesis was evaluated by using a combination of geochemical, physiological, and transcriptomic analyses of sediment microcosms. Amendment of microcosms with allylthiourea, an inhibitor of ammonia oxidation, decreased rates of acetylene reduction (a proxy for N2 fixation) and nitrite production (a proxy for ammonia oxidation) and decreased transcript levels of structural genes involved in both nitrogen fixation (nifH) and ammonia oxidation (amoA). In contrast, amendment of microcosms with ammonia stimulated nitrite production and increased amoA transcript levels while it suppressed rates of acetylene reduction and decreased nifH transcript levels. Sequencing of amplified nifH and amoA transcripts from native sediments, as well as microcosms, at 2 and 4 h postamendment, indicates that the dominant and responsive populations involved in ammonia oxidation and N2 fixation are closely affiliated with Ca. Nitrosocaldus yellowstonii and T. albus, respectively. Collectively, these results suggest that ammonia-oxidizing archaea, such as Ca. Nitrosocaldus yellowstonii, have an apparent affinity for ammonia that is higher than that of the diazotrophs present in this ecosystem. Depletion of the bioavailable N pool through the activity of ammonia-oxidizing archaea likely represents a strong selective pressure for the inclusion of organisms capable of

  9. Bromocresol Green/Mesoporous Silica Adsorbent for Ammonia Gas Sensing via an Optical Sensing Instrument

    Directory of Open Access Journals (Sweden)

    Chun-Nan Kuo

    2011-04-01

    Full Text Available A meso-structured Al-MCM-41 material was impregnated with bromocresol green (BG dye and then incorporated into a UV-Vis DRA spectroscopic instrument for the online detection of ammonia gas. The absorption response of the Al-MCM-41/BG ammonia sensing material was very sensitive at the optical absorption wavelength of 630 nm. A high linear correlation was achieved for ppmv and sub-ppmv levels of ammonia gas. The response time for the quantitative detection of ammonia gas concentrations ranging from 0.25 to 2.0 ppmv was only a few minutes. The lower detection limit achieved was 0.185 ppmv. The color change process was fully reversible during tens of cycling tests. These features together make this mesoporous Al-MCM-41 material very promising for optical sensing applications.

  10. Bromocresol green/mesoporous silica adsorbent for ammonia gas sensing via an optical sensing instrument.

    Science.gov (United States)

    Chang, Yu-Chang; Bai, Hsunling; Li, Shou-Nan; Kuo, Chun-Nan

    2011-01-01

    A meso-structured Al-MCM-41 material was impregnated with bromocresol green (BG) dye and then incorporated into a UV-Vis DRA spectroscopic instrument for the online detection of ammonia gas. The absorption response of the Al-MCM-41/BG ammonia sensing material was very sensitive at the optical absorption wavelength of 630 nm. A high linear correlation was achieved for ppmv and sub-ppmv levels of ammonia gas. The response time for the quantitative detection of ammonia gas concentrations ranging from 0.25 to 2.0 ppmv was only a few minutes. The lower detection limit achieved was 0.185 ppmv. The color change process was fully reversible during tens of cycling tests. These features together make this mesoporous Al-MCM-41 material very promising for optical sensing applications.

  11. Comparative study on ammonia oxidation over Ni-based cermet anodes for solid oxide fuel cells

    Science.gov (United States)

    Molouk, Ahmed Fathi Salem; Yang, Jun; Okanishi, Takeou; Muroyama, Hiroki; Matsui, Toshiaki; Eguchi, Koichi

    2016-02-01

    In the current work, we investigate the performance of solid oxide fuel cells (SOFCs) with Ni‒yttria-stabilized zirconia (Ni-YSZ) and Ni‒gadolinia-dope ceria (Ni-GDC) cermet anodes fueled with H2 or NH3 in terms of the catalytic activity of ammonia decomposition. The cermet of Ni-GDC shows higher catalytic activity for ammonia decomposition than Ni-YSZ. In response to this, the performance of direct NH3-fueled SOFC improved by using Ni-GDC anode. Moreover, we observe further enhancement in the cell performance and the catalytic activity for ammonia decomposition with applying Ni-GDC anode synthesised by the glycine-nitrate combustion process. These results reveal that the high performance of Ni-GDC anode for the direct NH3-fueled SOFC results from its mixed ionic-electronic conductivity as well as high catalytic activity for ammonia decomposition.

  12. Ammonia Sensing Behaviors of TiO2-PANI/PA6 Composite Nanofibers

    Directory of Open Access Journals (Sweden)

    Fenglin Huang

    2012-12-01

    Full Text Available Titanium dioxide-polyaniline/polyamide 6 (TiO2-PANI/PA6 composite nanofibers were prepared by in situ polymerization of aniline in the presence of PA6 nanofibers and a sputtering-deposition process with a high purity titanium sputtering target. TiO2-PANI/PA6 composite nanofibers and PANI/PA6 composite nanofibers were fabricated for ammonia gas sensing. The ammonia sensing behaviors of the sensors were examined at room temperature. All the results indicated that the ammonia sensing property of TiO2-PANI/PA6 composite nanofibers was superior to that of PANI/PA6 composite nanofibers. TiO2-PANI/PA6 composite nanofibers had good selectivity to ammonia. It was also found that the content of TiO2 had a great influence on both the morphology and the sensing property of TiO2-PANI/PA6 composite nanofibers.

  13. Ammonia dynamics in magnesium ammine from DFT and neutron scattering

    DEFF Research Database (Denmark)

    Tekin, Adem; Hummelshøj, Jens Strabo; Jacobsen, Hjalte Sylvest;

    2010-01-01

    Energy storage in the form of ammonia bound in metal salts, so-called metal ammines, combines high energy density with the possibility of fast and reversible NH3 ab- and desorption kinetics. The mechanisms and processes involved in the NH3 kinetics are investigated by density functional theory (DFT...... structure for the uncharacterized low temperature phase of Mg(NH3)(6)Cl-2. It is found from DFT that the rotation of ammonia in the hexammine complex (n = 6) requires an activation energy of 0.09 eV in the low temperature phase of Mg(NH3)(6)Cl-2 and 0.002-0.12 eV in the high temperature phases; effectively......, 1 systems. DFT calculations involving bulk diffusion of NH3 correctly reproduces the trends observed in the experimental desorption enthalpies. In particular, for n = 6, 2, 1, there is a good agreement between activation barriers and experimental enthalpies. These results indicate...

  14. The role of ammonia in sulfuric acid ion induced nucleation

    Directory of Open Access Journals (Sweden)

    I. K. Ortega

    2008-06-01

    Full Text Available We have developed a new multi-step strategy for quantum chemical calculations on atmospherically relevant cluster structures that makes calculation for large clusters affordable with a good accuracy-to-computational effort ratio. We have applied this strategy to evaluate the relevance of ternary ion induced nucleation; we have also performed calculations for neutral ternary nucleation for comparison. The results for neutral ternary nucleation agree with previous results, and confirm the important role of ammonia in enhancing the growth of sulfuric acid clusters. On the other hand, we have found that ammonia does not enhance the growth of ionic sulfuric acid clusters. The results also confirm that ion-induced nucleation is a barrierless process at high altitudes, but at ground level there exists a barrier due to the presence of a local minimum on the free energy surface.

  15. Kinetics and thermodynamics of Si(111) surface nitridation in ammonia

    Science.gov (United States)

    Mansurov, Vladimir G.; Malin, Timur V.; Galitsyn, Yurij G.; Shklyaev, Alexander A.; Zhuravlev, Konstantin S.

    2016-05-01

    Kinetics and thermodynamics of Si(111) surface nitridation under an ammonia flux at different substrate temperatures are investigated by reflection high-energy electron diffraction. Two different stages of the nitridation process were revealed. The initial stage is the fast (within few seconds) formation of ordered two-dimensional SiN phase, occuring due to the topmost active surface Si atom (Sisurf) interaction with ammonia molecules. It is followed by the late stage consisting in the slow (within few minutes) amorphous Si3N4 phase formation as a result of the interaction of Si atoms in the lattice site (Siinc) with chemisorbed ammonia molecules. It was found that the ordered SiN phase formation rate decreases, as the temperature increases. The kinetic model of the initial stage was developed, in which the ordered SiN phase formation is the two-dimensional phase transition in the lattice gas with SiN cells. The enthalpy of the active surface Si atom generation on the clean Si(111) surface was estimated to be about 1.5 eV. In contrast, the amorphous Si3N4 phase formation is the normal (thermally activated) chemical process with the first-order kinetics, whose activation energy and pre-exponential factor are 2.4 eV and 108 1/s, respectively.

  16. Nitridation of chromium powder in ammonia atmosphere

    Institute of Scientific and Technical Information of China (English)

    Ling Li; Qiang Zhen; Rong Li

    2015-01-01

    CrN powder was synthesized by nitriding Cr metal in ammonia gas flow, and its chemical reaction mechanism and nitridation process were studied. Through thermodynamic calculations, the Cr−N−O predominance diagrams were constructed for different tempera-tures. Chromium nitride formed at 700−1200°C under relatively higher nitrogen and lower oxygen partial pressures. Phases in the products were then investigated using X-ray diffraction (XRD), and the Cr2N content varied with reaction temperature and holding time. The results indicate that the Cr metal powder nitridation process can be explained by a diffusion model. Further, Cr2N formed as an intermediate product because of an incomplete reaction, which was observed by high-resolution transmission electron microscopy (HRTEM). After nitriding at 1000°C for 20 h, CrN powder with an average grain size of 63 nm was obtained, and the obtained sample was analyzed by using a scanning electron microscope (SEM).

  17. Emissions, sinks and gas to particle conversion of amines and ammonia

    Science.gov (United States)

    Lee, S.

    2015-12-01

    Nitrogen-containing base compounds, amines and ammonia, play important roles in formation of secondary aerosols in the atmosphere, but their sources, sinks and atmospheric transformation processes are not well understood. Also, there are very limited analytical methods that are capable of measuring pptv or sub-pptv level of amines and ammonia. We have developed a chemical ionization mass spectrometer (CIMS) that can detect amines and ammonia at the pptv and sub-pptv level with a 1 min of integration time. Here, we report ambient measurements of amines and ammonia made in a moderately polluted continental site (Kent, Ohio) and in a rural Southeastern U.S. forest (Centreville, Alabama). Our finding indicate that there are much more abundant gas phase amines (C1-C6) and ammonia in the polluted site than in the rural forest, highlighting the importance of constraining anthropogenic emission sources of amines. At both locations, concentrations of these base compounds show clear temperature dependence, indicating strong gas-to-particle conversion processes. Compared to ammonia, amines can partition into aerosol phases even more effectively due to lower saturation vapor pressures. Measurements in the clean rural forest show that transported biomass burning plumes are the major source of amines. These nitrogen-containing compounds effectively undergo wet deposition in the atmosphere due to high solubilities.

  18. Ammonia-nitrogen and phosphates sorption from simulated reclaimed waters by modified clinoptilolite.

    Science.gov (United States)

    Huo, Hanxin; Lin, Hai; Dong, Yingbo; Cheng, Huang; Wang, Han; Cao, Lixia

    2012-08-30

    This paper presents the investigation of the ammonia-nitrogen and phosphates sorption from simulated reclaimed wastewater by modified clinoptilolite. The results showed that the modified clinoptilolite has a high sorption efficiency and removal performance. The ammonia-nitrogen and phosphates removal rate of the modified clinoptilolite reached to 98.46% and 99.80%, respectively. The surface of modified clinoptilolite became loose and some pores appeared, which enlarged the specific surface area; the contents of Na and Fe increased, and the contents of Ca and Mg decreased. The modified clinoptilolite possesses rapid sorption and slow balance characteristics and ammonia-nitrogen and phosphates sorption is more consistent with the Langmuir isotherm model. The adsorption kinetics of ammonia-nitrogen and phosphates follows the Elovich adsorption dynamics equation, which describes the sorption of ammonia-nitrogen and phosphates in aqueous solution as mainly a chemical sorption. Results from the thermodynamics experiment involving ammonia-nitrogen and phosphates sorption reveal that the process is a spontaneous and endothermic process, and is mainly driven by entropy effect.

  19. Ammonia-oxidizing archaea have more important role than ammonia-oxidizing bacteria in ammonia oxidation of strongly acidic soils.

    Science.gov (United States)

    Zhang, Li-Mei; Hu, Hang-Wei; Shen, Ju-Pei; He, Ji-Zheng

    2012-05-01

    Increasing evidence demonstrated the involvement of ammonia-oxidizing archaea (AOA) in the global nitrogen cycle, but the relative contributions of AOA and ammonia-oxidizing bacteria (AOB) to ammonia oxidation are still in debate. Previous studies suggest that AOA would be more adapted to ammonia-limited oligotrophic conditions, which seems to be favored by protonation of ammonia, turning into ammonium in low-pH environments. Here, we investigated the autotrophic nitrification activity of AOA and AOB in five strongly acidic soils (pHnitrification inhibitor dicyandiamide (DCD) completely inhibited the nitrification activity and CO(2) fixation by AOA, accompanied by decreasing thaumarchaeal amoA gene abundance. Bacterial amoA gene abundance decreased in all microcosms irrespective of DCD addition, and mostly showed no correlation with nitrate concentrations. Phylogenetic analysis of thaumarchaeal amoA gene and 16S rRNA gene revealed active (13)CO(2)-labeled AOA belonged to groups 1.1a-associated and 1.1b. Taken together, these results provided strong evidence that AOA have a more important role than AOB in autotrophic ammonia oxidation in strongly acidic soils.

  20. [Influence of ammonia on leaching behaviors of incineration fly ash and its geochemical modeling].

    Science.gov (United States)

    Guan, Zhen-Zhen; Chen, De-Zhen; Thomas, Astrup

    2013-06-01

    Incineration fly ash could be contaminated with NH3 that was slipped from the ammonia-based selective non-catalytic reduction(SNCR) process and from evaporation of municipal solid wastes' leachate involved in the wastes. This research was conducted to investigate the impacts of ammonia on leaching of dissolved organic carbon (DOC) and metals from incineration fly ash in the pH range of 3.66-12.44 with an active ammonia spike. A geochemical modeling software Visual MINTEQ was adopted to calculate the chemical speciation of metals under the leaching conditions to reveal the mechanism behind the impacts. It was proved that at pH > 9, the leaching of DOC increased significantly in the presence of high concentrations of ammonia (> or = 1 357 mg x L(-1)), but there was little effect when the ammonia level in eluates was not higher than 537 mg x L(-1). At pH or = 3 253 mg x L(-1)) mobilized Cd, Cu, Ni and Zn significantly due to the formation of soluble metal-ammonia complexes, and the leaching rates reached their peaks at pH around 9; however, ammonia had little impacts on Al and Pb leaching within this pH range. At pH > 12, for Cd, Cu, Ni and Zn, their leaching species were predominantly in the form of hydroxide complexes. Under the ammonia concentration of 3253 mg x L(-1), the Visual MINTEQ modeling results were compared with the experimental data, and it was proved that the leaching of Al, Pb and Zn was mainly controlled by precipitation/dissolution modeling, while Cd, Cu and Ni were controlled by precipitation/dissolution and surface complexation/precipitation processes; Visual MINTEQ modeling could well describe the leaching behaviors of Al, Cu, Pb and Zn from incineration fly ash.

  1. Changesin Myoglobin of Big Eye Tuna During Chilling Storage

    Directory of Open Access Journals (Sweden)

    Stevi Imelda Murniati Wodi

    2015-01-01

    Full Text Available Big eye tuna (Thunnus obesus is one of the species of tuna which is have some value added such as have potential to improve animal protein sources, have high economic values as well as an export commodity.Mishandling and misapplication of high temparatures on the tuna handling at the tropics and sub tropics climate was significantly decreasing the value of myoglobin and affecting the solubility of protein. Myoglobin is a globular protein that have small molecular weight size and it was an important factor for determining the quality of meat and influencing factors of purchasing power by the consumer. The purpose of this experiments is to determining the changes of myoglobin content and the water soluble proteins content at some parts of big eye tuna in 9 days chilling temperatures. The portion which is analized was the ventral area, dorsal area and tail area. Myoglobin content in all portion above, both light and dark meat was analized. The results shows the decreased value of myoglobin content from first handling (day zero until day ninth (days 9th experiment. Each myoglobin contentfrom white meat at at ventral, dorsal and tail meat was decreased from 121.68 mg/100 into 41.35 mg/100, 148.2 mg/100g into 52.01 mg/100g, 105.16 mg/100g into 31.34 gr/100gram, after day ninth. The myoglobin content from dark meat at ventral, dorsal and tail meat, was decreased, too ; from 418.64 mg/100 gr into 121.01 mg/100 g, 446.21 mg/100 g into 58.34 mg/100 r and 145.65 mg/100 gr into 87.98 mg/100g after day ninth.Water soluble protein was derived into protein bands with molecular weight 15,4 kDa and 14 kDa. Its suspected as the myoglobin protein. The molecular weight difference was caused from degradation of protein during the storage.Keywords: Big eye tuna, meat, storage, myoglobin

  2. Ammonia as a Suitable Fuel for Fuel Cells

    OpenAIRE

    Lan, Rong; Tao, Shanwen

    2014-01-01

    Ammonia, an important basic chemical, is produced at a scale of 150 million tons per year. Half of hydrogen produced in chemical industry is used for ammonia production. Ammonia containing 17.5 wt% hydrogen is an ideal carbon-free fuel for fuel cells. Compared to hydrogen, ammonia has many advantages. In this mini-review, the suitability of ammonia as fuel for fuel cells, the development of different types of fuel cells using ammonia as the fuel and the potential applications of ammonia fuel ...

  3. The aerosols' fate in a putative ammonia ocean on Titan

    Science.gov (United States)

    Ramírez, S. I.; Coll, P.; Buch, A.; Brassé, C.; Poch, O.; Raulin, F.

    2010-04-01

    A laboratory study on the chemical transformation of Titan's aerosol analogues placed under putative surface conditions of the satellite was performed. The surface of Titan was one of the targets of the Cassini-Huygens mission and of several of the Cassini orbiter instruments, especially ISS, VIMS and Radar. The first images revealed an interesting solid surface with features that suggest aeolian, tectonic, fluvial processes and even an impact structure[1]. Since then, more detailed descriptions of dunes, channels, lakes, impact craters and cryovolcanic structures have been documented[2]. The existence of an internal liquid water ocean, containing a few percent ammonia has been proposed[2, 3]. It has also been proposed that ammonia-water mixtures can erupt from the putative subsurface ocean leading to cryovolcanism[4]. The Cassini Titan Radar Mapper obtained Synthetic Aperture Radar (SAR) images during 2004 and 2005 that revealed a highly complex geology occurring at Titan's surface[5], among which cryovolcanic features play a central role. The composition of the cryomagma is mainly proposed to be a mixture of water ice and ammonia[6, 7, 8], although ammonia has not been directly detected on Titan, but suggested by recent Cassini-VIMS observations[9]. In order to understand the role that ammonia may play on the chemical transformation of atmospheric aerosols once they reach the surface, we designed the following protocol: laboratory analogues of Titan's aerosols were synthesized from a N2:CH4 (98:2) mixture irradiated under a continuous flow regime of 845 sccm inside which, a cold plasma of 180 W was established. The synthesized analogues were recovered and partitioned in several 10.0 mg samples that were placed in 4.0 mL-volume of aqueous ammonia solutions (25.00, 12.50, 6.25 and 3.125%) at different temperatures (298, 277, 253 and 93 K) for 10 weeks. After a derivatization process performed to the aerosols' refractory phase with N

  4. Ammonia Affects Astroglial Proliferation in Culture.

    Directory of Open Access Journals (Sweden)

    Guillermo Bodega

    Full Text Available Primary cultures of rat astroglial cells were exposed to 1, 3 and 5 mM NH4Cl for up to 10 days. Dose- and time-dependent reductions in cell numbers were seen, plus an increase in the proportion of cells in the S phase. The DNA content was reduced in the treated cells, and BrdU incorporation diminished. However, neither ammonia nor ammonia plus glutamine had any effect on DNA polymerase activity. iTRAQ analysis showed that exposure to ammonia induced a significant reduction in histone and heterochromatin protein 1 expression. A reduction in cell viability was also noted. The ammonia-induced reduction of proliferative activity in these cultured astroglial cells seems to be due to a delay in the completion of the S phase provoked by the inhibition of chromatin protein synthesis.

  5. 21 CFR 573.180 - Anhydrous ammonia.

    Science.gov (United States)

    2010-04-01

    ... silage. (2)(i) The food additive anhydrous ammonia is applied directly to corn plant material for use in... to corn plant material containing 28 to 38 percent dry matter. (iv) The silage treated with...

  6. Nitrocarburising in ammonia-hydrocarbon gas mixtures

    DEFF Research Database (Denmark)

    Pedersen, Hanne; Christiansen, Thomas; Somers, Marcel A. J.

    2010-01-01

    The present work investigates the possibility of nitrocarburising in ammonia-acetylene-hydrogen and ammoniapropene- hydrogen gas mixtures, where unsaturated hydrocarbon gas is the carbon source during nitrocarburising. Consequently, nitrocarburising is carried out in a reducing atmosphere...

  7. Aqueous Ammonia soaking of digested manure fibers

    DEFF Research Database (Denmark)

    Mirtsou-Xanthopoulou, Chrysoula; Jurado, Esperanza; Skiadas, Ioannis

    2012-01-01

    , their economical profitable operation relies on increasing the methane yield from manure, and especially of its solid fraction which is not so easily degradable. In the present study, Aqueous Ammonia Soaking was successfully applied on digested fibers separated from the effluent of a manure-fed, full......-scale anaerobic digester to enhance their methane productivity. Soaking in six different reagent concentrations in ammonia (5%, 10%, 15%, 20%, 25%, 32%) was applied for 3 days at 22°C. An overall methane yield increase from 85% to 110% was achieved compared to controls (digested manure fibers where AAS...... was not applied). The difference in reagent concentration at the range of 5-25% w/w in ammonia did not affect that much the overall methane yield resulting to an increase of 104-110% compared to the non AAS-treated fibers. Thus, an ammonia concentration as low as 5% is adequate for achieving the same increase...

  8. Ammonia and urea permeability of mammalian aquaporins

    DEFF Research Database (Denmark)

    Litman, Thomas; Søgaard, Rikke; Zeuthen, Thomas

    2009-01-01

    The human aquaporins,AQP3,AQP7, AQP8,AQP9, and possibly AQP10, are permeable to ammonia, and AQP7, AQP9, and possibly AQP3, are permeable to urea. In humans, these aquaporins supplement the ammonia transport of the Rhesus (Rh) proteins and the urea transporters (UTs). The mechanism by which...... ammonium is transported by aquaporins is not fully resolved. A comparison of transport equations, models, and experimental data shows that ammonia is transported in its neutral form, NH(3). In the presence of NH(3), the aquaporin stimulates H(+) transport. Consequently, this transport of H(+) is only...... significant at alkaline pH. It is debated whether the H(+) ion passes via the aquaporin or by some external route; the investigation of this problem requires the aquaporin-expressing cell to be voltage-clamped. The ammonia-permeable aquaporins differ from other aquaporins by having a less restrictive aromatic...

  9. Cambio en los patrones de crecimiento en una ciudad intermedia: el caso de Chillán en Chile Central

    Directory of Open Access Journals (Sweden)

    Gerardo Azócar

    2003-08-01

    Full Text Available Se identifican los patrones del crecimiento urbano de la ciudad de Chillán (Chile Central, el uso del suelo asociado a cada uno de ellos y los factores que guían el proceso de expansión urbana. Se cuantificaron los cambios en la superficie urbana construida en un período de 57 años (de 1943 hasta el 2000. Entre 1997 y el año 2000, se analizó el cambio en relación con el uso del suelo, la densidad de población y la condición socio-económica de los hogares. Se utilizaron fotografías aéreas, SIG (Arcview 3.2 y Arc-Info N.T e índice de análisis espacial (Spatially Explicit Landscape Index. Un análisis de regresión permitió estudiar la relación entre crecimiento urbano y crecimiento de poblaciónThe patterns of urban growth of Chillán city (Central Chile, the land use associated to each of them and the factors which guide the urban expansion process are identified. Changes in the built urban surface during a period of 57 years (from 1943 until 2000 were quantified. Between 1997 and 2000 were analyzed the changes of land use, population density and home socioeconomic conditions, utilizing aerial photographs, SIG (Arcview 3.2 and Arc-Info N.T and Spatially Explicit Landscape Index. A regression analysis allowed to study the relation between urban growth and population growth

  10. Recovery of gold from solutions with ammonia and thiosulfate using activated carbon; Recuperacion de oro a partir de disoluciones de amoniaco y tiosulfato utilizando carbon activado

    Energy Technology Data Exchange (ETDEWEB)

    Vargas, C.; Navarro, P.; Araya, E.; Pavez, F.; Alguacil, F. J.

    2006-07-01

    The recovery of gold from solutions containing thiosulfate and ammonia using granular activated carbon was studied,evaluating the adsorption and elution stages. The influence of ammonia and thiosulfate concentration and the presence of impurities such as copper and zinc were also evaluated. In the presence of ammonia there was a concentration which maximized the adsorption of gold, while thiosulfate and impurities presence was harmful for the adsorption of gold. during elution, ammonia and thiosulfate concentration, pH regulator and temperature were evaluated. Ammonia favored the process as long as thiosulfate showed a maximum starting from which the elution diminishes. The effect of the pH regulator was very important; If was revealed that when the pH was regulated with caustic ammonia, a synergic effect appeared which favored the elution. Temperature favored the elution process, with activation energy of 9.13 kJ/mol. (Author) 25 refs.

  11. Corrosion inhibitor for aqueous ammonia absorption system

    Science.gov (United States)

    Phillips, Benjamin A.; Whitlow, Eugene P.

    1998-09-22

    A method of inhibiting corrosion and the formation of hydrogen and thus improving absorption in an ammonia/water absorption refrigeration, air conditioning or heat pump system by maintaining the hydroxyl ion concentration of the aqueous ammonia working fluid within a selected range under anaerobic conditions at temperatures up to 425.degree. F. This hydroxyl ion concentration is maintained by introducing to the aqueous ammonia working fluid an inhibitor in an amount effective to produce a hydroxyl ion concentration corresponding to a normality of the inhibitor relative to the water content ranging from about 0.015 N to about 0.2 N at 25.degree. C. Also, working fluids for inhibiting the corrosion of carbon steel and resulting hydrogen formation and improving absorption in an ammonia/water absorption system under anaerobic conditions at up to 425.degree. F. The working fluids may be aqueous solutions of ammonia and a strong base or aqueous solutions of ammonia, a strong base, and a specified buffer.

  12. Contrasting effect of dark-chilling on chloroplast structure and arrangement of chlorophyll-protein complexes in pea and tomato : Plants with a different susceptibility to non-freezing temperature

    NARCIS (Netherlands)

    Garstka, Maciej; Venema, Jan Henk; Rumak, Izabela; Gieczewska, Katarzyna; Rosiak, Malgorzata; Koziol-Lipinska, Joanna; Kierdaszuk, Borys; Vredenberg, Wim J.; Mostowska, Agnieszka

    2007-01-01

    The effect of dark-chilling and subsequent photoactivation on chloroplast structure and arrangements of chlorophyll-protein complexes in thylakoid membranes was studied in chilling-tolerant (CT) pea and in chilling-sensitive (CS) tomato. Dark-chilling did not influence chlorophyll content and Chl a/

  13. Innovative ammonia stripping with an electrolyzed water system as pretreatment of thermally hydrolyzed wasted sludge for anaerobic digestion.

    Science.gov (United States)

    Park, Seyong; Kim, Moonil

    2015-01-01

    In this study, the anaerobic digestion of thermally hydrolyzed wasted sludge (THWS) with a high concentration of ammonia was carried out through combining with an ammonia stripping and an electrolyzed water system (EWS). The EWS produced acidic water (pH 2-3) at the anode and alkaline water (pH 11-12) at the cathode with an electro-diaphragm between the electrodes that could be applied to ammonia stripping. The ammonia stripping efficiency was strongly dependent on the pH and aeration rate, and the ammonium ion removal rate followed pseudo-first-order kinetics. From the BMP test, the methane yield of THWS after ammonia stripping using the EWS was 2.8 times higher than that of the control process (raw THWS without ammonia stripping). Furthermore, both methane yield and ammonium removal efficiency were higher in this study than in previous studies. Since ammonia stripping with the EWS does not require any chemicals for pH control, no precipitated sludge is produced and anaerobic microorganisms are not inhibited by cations. Therefore, ammonia stripping using the EWS could be an effective method for digestion of wastewater with a high concentration of ammonium nitrogen.

  14. Performance of Chilled Beam with Radial Swirl Jet and Diffuse Ceiling Air Supply in Heating Mode

    DEFF Research Database (Denmark)

    Bertheussen, Bård; Mustakallio, Panu; Melikov, Arsen Krikor

    2013-01-01

    The performance of diffuse ceiling air supply and chilled beam with swirl jet (CSW) in heating mode (winter situation) was studied and compared with regard to the generated indoor environment. An office mock-up with one occupant was simulated in a test room (4.5 x 3.95 x 3.5 m3 (L x W x H...

  15. [Customer satisfaction study in two roman hospitals: comparison between "cook & serve" and "cook & chill"].

    Science.gov (United States)

    Perata, E; Ferrari, P; Tarsitani, G

    2005-01-01

    We studied patient's satisfaction rate for hospital dishes comparing "cook & chill" method with "cook & serve". As principal instrument we used a comparative questionnaire, anonymous and self-compiled, which is able to evaluate the differences of customer satisfaction's rate between the two methods.

  16. Different responses of tobacco antioxidant enzymes to light and chilling stress

    NARCIS (Netherlands)

    Gechev, T; Willekens, H; Van Montagu, M; Inze, D; Van Camp, W; Toneva, [No Value; Minkov, [No Value

    2003-01-01

    The effect of elevated light treatment (25 degreesC, PPFD 360 mumol m(-2) sec(-1)) or chilling temperatures combined with elevated light (5 degreesC, PPFD 360 mumol m-2 sec-1) on the activity of six antioxidant enzymes, guaiacol peroxidases, and glutathione peroxidase (GPx, EC 1.11.1.9) protein accu

  17. Assessment of chilling injury and molecular marker analysis in cucumber cultivars (Cucumis sativus L.)

    Science.gov (United States)

    The responses to chilling temperature of 12 Korean cucumber varieties were compared to those of two U.S.A. (previously determined cold tolerant NC76 and 'Chipper'), and Chinese and Japanese germplasms. Seedlings of each entry were exposed to 4 degrees C (Experiment 1) and 1 degree C (Experiments 2 ...

  18. Can chilling tolerance of C4 photosynthesis in Miscanthus be transferred to sugarcane?

    Science.gov (United States)

    The goal of this study was to investigate if chilling tolerance of C4 photosynthesis in Miscanthus can be transferred to sugarcane. Net leaf CO2 uptake (Asat) and the maximum operating efficiency of photosystem II ('PSII) were measured in warm conditions (25 °C/20 °C), and then during and following ...

  19. Tappet Chill Depth Measuring by Magnetic Permeability and Inductance Displacement Meter

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    It is possible to measure different position along the axle direction of tappet. According to the maximum output of signal, the boundary of white iron structure and mottled iron structure can be deduced, and at the same time, it is possible to use inductance displacement meter to show the chill depth which is the distance from the boundary to the end.

  20. Georgia Institute of Technology chilled water system evaluation and master plan

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-05-15

    As the host of the Olympic Village for the 1996 Atlanta Olympics, Georgia Tech has experienced a surge in construction activities over the last three years. Over 1.3 million square feet of new buildings have been constructed on the Georgia Tech campus. This growth has placed a strain on the Georgia Tech community and challenged the facilities support staff charged with planning and organizing utility services. In concert with Olympic construction, utility planners have worked to ensure long term benefits for Georgia Tech facilities while meeting the short term requirements of the Olympic Games. The concentration of building construction in the northwest quadrant of the campus allowed planners to construct a satellite chilled water plant to serve the needs of this area and provide the opportunity to integrate this section of the campus with the main campus chilled water system. This assessment and master plan, funded in part by the US Department of Energy, has evaluated the chilled water infrastructure at Georgia Tech, identified ongoing problems and made recommendations for long term chilled water infrastructure development and efficiency improvements. The Georgia Tech office of Facilities and RDA Engineering, Inc. have worked together to assemble relevant information and prepare the recommendations contained in this document.