WorldWideScience

Sample records for cicc performance degradation

  1. JINR CICC in computational chemistry and nanotechnology problems: DL_POLY performance for different communication architectures

    Science.gov (United States)

    Dushanov, E.; Kholmurodov, Kh.; Aru, G.; Korenkov, V.; Smith, W.; Ohno, Y.; Narumi, T.; Morimoto, G.; Taiji, M.; Yasuoka, K.

    2009-05-01

    This report compares the performance of the DL_POLY general-purpose molecular dynamics simulation package on the LIT JINR computing cluster CICC with various communication systems. The comparison involved two cluster architectures: Gigabit Ethernet and InfiniBand technologies, respectively. The code performance tests include some comparison of the CICC cluster with the special-purpose computer MDGRAPE-3 developed at RIKEN for a high-speed acceleration of the MD (molecular dynamics) without a fixed cutoff. The DL_POLY benchmark covers a set of typical MD system simulations detailed below.

  2. Comparisons of internal self-field magnetic flux densities between recent Nb{sub 3}Sn fusion magnet CICC cable designs

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, S. P. [National Fusion Research Institute, Daejeon (Korea, Republic of)

    2016-09-15

    The Cable-In-Conduit-Conductor (CICC) for the ITER tokamak Central Solenoid (CS) has undergone design change since the first prototype conductor sample was tested in 2010. After tests showed that the performance of initial conductor samples degraded rapidly without stabilization, an alternate design with shorter sub-cable twist pitches was tested and discovered to satisfy performance requirements, namely that the minimum current sharing temperature (Tcs) remained above a given limit under DC bias. With consistent successful performance of ITER CS conductor CICC samples using the alternate design, an attempt is made here to revisit the internal electromagnetic properties of the CICC cable design to identify any correlation with conductor performance. Results of this study suggest that there may be a simple link between the Nb3Sn CICC internal self-field and its Tcs performance. The study also suggests that an optimization process should exist that can further improve the performance of Nb3Sn based CICC.

  3. Self Field Measurements by Hall Sensors on the SeCRETS Long Sample CICCs in SULTAN

    NARCIS (Netherlands)

    Ilyin, Yu. A.; Nijhuis, A.; Kate, ten H.H.J.; Bruzzone, P.

    2002-01-01

    The aim of this work is to determine the existence and degree of the current unbalance of two types of cable-in-conduit conductors (CICC) of the SeCRETS long sample experiment, and its influence on the conductors' performance. The self-field measurements are performed by using six sets of annular Ha

  4. Performance Degradation of LSCF Cathodes

    Energy Technology Data Exchange (ETDEWEB)

    Alinger, Matthew

    2013-09-30

    This final report summarizes the progress made during the October 1, 2008 - September 30, 2013 period under Cooperative Agreement DE-NT0004109 for the U. S. Department of Energy/National Energy Technology Laboratory (USDOE/NETL) entitled “Performance Degradation of LSCF Cathodes”. The primary objective of this program is to develop a performance degradation mitigation path for high performing, cost-effective solid oxide fuel cells (SOFCs). Strategies to mitigate performance degradation are developed and implemented. In addition, thermal spray manufacturing of SOFCs is explored. Combined, this work establishes a basis for cost-effective SOFC cells.

  5. Thermal hydraulic characteristics study of prototype NET and CEA cable-in-conduit conductors (CICCs)

    Energy Technology Data Exchange (ETDEWEB)

    Maekawa, Ryuji

    1995-10-31

    The thermal hydraulic characteristics of low temperature helium in a Cable-in-Conduit Conductor (CICC) significantly affects the overall design and performance of the associated large scale superconducting magnet system. It is essential to understand the transient and steady state behavior of the helium in the conductor. Throughout the development of CICCs, the reduction of flow impedance has been one of the key factors to improving the overall pressure drop. The newly developed CICC for the ITER project has a hybrid cooling scheme: a central channel that is surrounded by bundles, for which the thermal hydraulic characteristics are not well understood. This thesis describes an experimental and analytical investigation of thermal hydraulic characteristics of low temperature helium in conventional and hybrid CICCS. Pressure drop measurements for both NET and CEA conductors have been conducted, using low temperature helium and liquid nitrogen to obtain a range of Reynolds numbers. The results are correlated with classical friction factor and Reynolds number analysis. The flow impedance reduction of the CEA conductor is described by measures of a developed flow model. Thermally induced flow in the CEA conductor has been studied with an inductive heating method. The induced velocity in the central channel is measured by a Pitot tube with steady state Reynolds number up to {approximately}7000. The transient pressure wave propagation has been recorded with pressure transducers placed equally along the conductor. The supercritical helium temperature in the central channel has been measured with the thermometer probe. However, the reduction of the central channel area significantly affects the overall thermal hydraulic characteristics of the conductor. The results suggest the importance of the central channel. A transient heat transfer experiment studied the.transverse heat transfer mechanism in the CEA conductor. The temperatures in the central channel and bundle region

  6. Thermal hydraulic characteristics study of prototype NET and CEA cable-in-conduit conductors (CICCs)

    Energy Technology Data Exchange (ETDEWEB)

    Maekawa, Ryuji

    1995-10-31

    The thermal hydraulic characteristics of low temperature helium in a Cable-in-Conduit Conductor (CICC) significantly affects the overall design and performance of the associated large scale superconducting magnet system. It is essential to understand the transient and steady state behavior of the helium in the conductor. Throughout the development of CICCs, the reduction of flow impedance has been one of the key factors to improving the overall pressure drop. The newly developed CICC for the ITER project has a hybrid cooling scheme: a central channel that is surrounded by bundles, for which the thermal hydraulic characteristics are not well understood. This thesis describes an experimental and analytical investigation of thermal hydraulic characteristics of low temperature helium in conventional and hybrid CICCS. Pressure drop measurements for both NET and CEA conductors have been conducted, using low temperature helium and liquid nitrogen to obtain a range of Reynolds numbers. The results are correlated with classical friction factor and Reynolds number analysis. The flow impedance reduction of the CEA conductor is described by measures of a developed flow model. Thermally induced flow in the CEA conductor has been studied with an inductive heating method. The induced velocity in the central channel is measured by a Pitot tube with steady state Reynolds number up to {approximately}7000. The transient pressure wave propagation has been recorded with pressure transducers placed equally along the conductor. The supercritical helium temperature in the central channel has been measured with the thermometer probe. However, the reduction of the central channel area significantly affects the overall thermal hydraulic characteristics of the conductor. The results suggest the importance of the central channel. A transient heat transfer experiment studied the.transverse heat transfer mechanism in the CEA conductor. The temperatures in the central channel and bundle region

  7. Solder-Filling of a Cicc Cable for the Efda Dipole Magnet

    Science.gov (United States)

    Bauer, P.; Bruzzone, P.; Cau, F.; Weiss, K.; Portone, A.; Salpietro, E.; Vogel, M.; Vostner, A.

    2008-03-01

    Several prototype Cable-In-Conduit-Conductors (CICC) for the superconducting EDIPO (Efda DIPOle) revealed a degradation of their critical current (Ic) increasing with each loading cycle. The strong Lorentz-forces during operation in combination with the limited support of the single strands against these forces are thought to be the cause of the permanent degradation of the brittle Nb3Sn superconductor from which the multi-stranded CICC are made. In summer 2006 EFDA started to explore the possibility to remedy the Ic degradation by solder-filling the conductor in order to mechanically stabilize the twisted-strand cable inside the conduit. This solution was not considered as the main one, but as an emergency solution to be applied to the completed magnet, should every other option fail. The solder-filling approach was previously applied with success in some cases. Some issues, however, needed to be clarified before this solution could be proposed for the EDIPO project. The most important among them are the choice of solder material, details of the solder filling process, and the thermo-mechanical implications of a solder-filled, high-field, high-current cable. This work, being reported here, made use not only of simulation but also of experiments, such as the mechanical testing of solder filled cables at cryogenic temperatures.

  8. Optimisation of ITER Nb3Sn CICCs for coupling loss, transverse electromagnetic load and axial thermal contraction

    CERN Document Server

    Nijhuis, A; Rolando, G

    2011-01-01

    The ITER cable-in-conduit conductors (CICCs) are built up from sub-cable bundles, wound in different stages, which are twisted to counter coupling loss caused by time-changing external magnet fields. The selection of the twist pitch lengths has major implications for the performance of the cable in the case of strain sensitive superconductors, i.e. Nb3Sn, as the electromagnetic and thermal contraction loads are large but also for the heat load from the AC coupling loss. Reduction of the transverse load and warm-up cool-down degradation can be reached by applying longer twist pitches in a particular sequence for the sub-stages, offering a large cable transverse stiffness, adequate axial flexibility and maximum allowed lateral strand support. Analysis of short sample (TF conductor) data reveals that increasing the twist pitch can lead to a gain of the effective axial compressive strain of more than 0.3 % with practically no degradation from bending. For reduction of the coupling loss, specific choices of the ca...

  9. STRUCTURAL PERFORMANCE OF DEGRADED REINFORCED CONCRETE MEMBERS.

    Energy Technology Data Exchange (ETDEWEB)

    Braverman, J.I.; Miller, C.A.; Ellingwood, B.R.; Naus, D.J.; Hofmayer, C.H.; Bezler, P.; Chang, T.Y.

    2001-03-22

    This paper describes the results of a study to evaluate, in probabilistic terms, the effects of age-related degradation on the structural performance of reinforced concrete members at nuclear power plants. The paper focuses on degradation of reinforced concrete flexural members and shear walls due to the loss of steel reinforcing area and loss of concrete area (cracking/spalling). Loss of steel area is typically caused by corrosion while cracking and spalling can be caused by corrosion of reinforcing steel, freeze-thaw, or aggressive chemical attack. Structural performance in the presence of uncertainties is depicted by a fragility (or conditional probability of failure). The effects of degradation on the fragility of reinforced concrete members are calculated to assess the potential significance of various levels of degradation. The fragility modeling procedures applied to degraded concrete members can be used to assess the effects of degradation on plant risk and can lead to the development of probability-based degradation acceptance limits.

  10. Analysis of ITER NbTi and Nb3Sn CICCs experimental minimum quench energy with JackPot, MCM and THEA models

    Science.gov (United States)

    Bagni, T.; Duchateau, J. L.; Breschi, M.; Devred, A.; Nijhuis, A.

    2017-09-01

    Cable-in-conduit conductors (CICCs) for ITER magnets are subjected to fast changing magnetic fields during the plasma-operating scenario. In order to anticipate the limitations of conductors under the foreseen operating conditions, it is essential to have a better understanding of the stability margin of magnets. In the last decade ITER has launched a campaign for characterization of several types of NbTi and Nb3Sn CICCs comprising quench tests with a singular sine wave fast magnetic field pulse and relatively small amplitude. The stability tests, performed in the SULTAN facility, were reproduced and analyzed using two codes: JackPot-AC/DC, an electromagnetic-thermal numerical model for CICCs, developed at the University of Twente (van Lanen and Nijhuis 2010 Cryogenics 50 139-148) and multi-constant-model (MCM) (Turck and Zani 2010 Cryogenics 50 443-9), an analytical model for CICCs coupling losses. The outputs of both codes were combined with thermal, hydraulic and electric analysis of superconducting cables to predict the minimum quench energy (MQE) (Bottura et al 2000 Cryogenics 40 617-26). The experimental AC loss results were used to calibrate the JackPot and MCM models and to reproduce the energy deposited in the cable during an MQE test. The agreement between experiments and models confirm a good comprehension of the various CICCs thermal and electromagnetic phenomena. The differences between the analytical MCM and numerical JackPot approaches are discussed. The results provide a good basis for further investigation of CICC stability under plasma scenario conditions using magnetic field pulses with lower ramp rate and higher amplitude.

  11. CICC Joint Development and Test for the Test Facility

    Institute of Scientific and Technical Information of China (English)

    武玉; 翁佩德

    2005-01-01

    The superconducting joint of the NbTi Cable-in -conduit Conductor (CICC) has been developed and tested on the magnet test facility at Institute of Plasma Physics, Chinese Academy of Sciences. The CICC is composed of (2NbTi+1Cu)×3×3×(6+1tube) strands each with 0.85 mm in diameter, which has been developed for a central solenoid model coil. The effective length of the joint is about 500 mm. There have been two common fabrication modes,one of them is to integrate the 2 CICC terminals with the copper substrate via lead-soldering, and the other is to mechanically compress the above two parts into an integrated unit. In the current range from 2 kA to 10 kA the joint resistance changes slightly. Up to now, 11 TF magnets, a central solenoid model coil, a central solenoid prototype coil, and a large PF model coil of PF large coil have been completed via the latter joint in the test facility.

  12. Control of contact resistance by strand surface coating in 36-strand NbTi CICCs

    NARCIS (Netherlands)

    Nijhuis, Arend; Kate, ten Herman H.J.; Duchateau, Jean-Luc; Decool, Patrick

    2001-01-01

    The stability and AC loss of NbTi cable-in-conduit conductors (CICCs) is largely determined by the interstrand contact resistance (Rc). Rc is predominantly established by the strand surface properties. Five 36-strand CICCs, fully identical except for the plating of the strand surface or the presence

  13. Identification on two yeasts CICC32991 and CICC32993 isolated from Paracel Islands wild Noni (Morinda citrifolia L.) Seeds%两株西沙群岛野生诺尼种子内生酵母CICC32991与CICC32993的多相分类鉴定

    Institute of Scientific and Technical Information of China (English)

    白飞荣; 刘洋; 姚粟; 李辉; 谭望桥; 程池

    2014-01-01

    目的 通过多相鉴定方法对分离自我国西沙群岛野生诺尼种子内的两株酵母(CICC32991,CICC32993)进行准确鉴定.方法 包括形态学观察试验、生理生化特征试验、以及核糖体DNA序列系统发育学分析等技术.结果 形态学和生理生化试验结果显示CICC32991为Eremothecium sp.,CICC32993为Kodamaea ohmeri;系统发育分析显示CICC32991为Eremothecium coryli,CICC32993为Kodamaea ohmeri.结论 综合各试验结果表明菌株CICC32991为Eremothecium coryli;CICC32993为奥默柯达菌(Kodamaea ohmeri).

  14. Analysis of Current Redistribution in a CICC under Transient Heat Pulses

    CERN Document Server

    Bottura, L; Marinucci, C

    2004-01-01

    We have performed experiments and simulations of the current distribution process in a CICC with the aim to understand better the coupled thermal, hydraulic and electric process that leads to a stable or unstable transient cable behaviour. The cable, wound from 128 Nb3Sn and pure copper strands, has been tested in the SULTAN facility. A resistive heater, glued on the jacket of the conductor, has been used to start the transient, and the response has been monitored with arrays of Hall plates. In this paper we report the results of simulations, especially the computed Hall signals, and compare them to the experimental data. Based on the experimental results and their interpretation we postulate that large temperature gradients must develop in the helium stream in the cable cross sections during the transient heat pulse.

  15. Genome shuffling of Clostridium acetobutylicum CICC 8012 for improved production of acetone-butanol-ethanol (ABE).

    Science.gov (United States)

    Gao, Xiaofeng; Zhao, Hai; Zhang, Guohua; He, Kaize; Jin, Yanling

    2012-08-01

    Genome shuffling was applied to increase ABE production of the strict anaerobe C. acetobutylicum CICC 8012. By using physical and chemical mutagenesis, strains with superior streptomycin sulfate, 2-deoxy-D-glucose and butanol tolerance levels were isolated. These strains were used for genome shuffling. The best performing strain F2-GA was screened after two rounds of genome shuffling. With 55 g glucose/l as carbon source, F2-GA produced 22.21 g ABE/l in 72 h and ABE yield reached 0.42 g/g which was about 34.53 % improvement compared to the wild type. Fermentation parameters and gene expression of several key enzymes in ABE metabolic pathways were varied significantly between F2-GA and the wild type. These results demonstrated the potential use of genome shuffling to microbial breeding which were difficult to deal with traditional methods.

  16. Evaluation of the performance degradation at PAFC effect of catalyst degradation on electrode performance

    Energy Technology Data Exchange (ETDEWEB)

    Nishizaki, K.; Uchida, H.; Watanabe, M. [Yamanashi Univ., Kofu (Japan)] [and others

    1996-12-31

    Aiming commercialization of Phosphoric Acid Fuel Cell (PAFC) power plant, many researches and developments have been contributed. Over 20000 hours operations have been demonstrated by many PAFC power plants. But there is no effective method for the estimation of lifetime of electrochemical cells without a practical long-term operation. Conducted by New Energy and Industrial Technology Development Organization (NEDO), cooperative research projects aiming development of PAFC lifetime estimation method have started since 1995 FY in Japan. As part of this project, this work has been performed to clarify basic phenomena of the performance degradation at PAFCs jointly by Yamanashi University, Phosphoric Acid Fuel Cell Technology Research Association (PAFC-TRA) and PAFC manufacturers (Toshiba Co., Mitsubishi Electric Co, Fuji Electric Co.). Among several main causes of the cell performance degradation, effects of catalyst degradation (reduction in metal surface area, dealloying, changes in catalyst support) on PAFC cathode performances are discussed in this work.

  17. Successful performances of the EU-AltTF sample, a large size Nb3Sn cable-in-conduit conductor with rectangular geometry

    Science.gov (United States)

    della Corte, A.; Corato, V.; Di Zenobio, A.; Fiamozzi Zignani, C.; Muzzi, L.; Polli, G. M.; Reccia, L.; Turtù, S.; Bruzzone, P.; Salpietro, E.; Vostner, A.

    2010-04-01

    One of the design features which yet offers interesting margins for performance optimization of cable-in-conduit conductors (CICCs), is their geometry. For relatively small size Nb3Sn CICCs, operating at high electromagnetic pressure, such as those for the EDIPO project, it has been experimentally shown that a design based on a rectangular layout with higher aspect ratio leads to the best performance, especially in terms of degradation with electromagnetic loads. To extend this analysis to larger size Nb3Sn CICCs, we manufactured and tested, in the SULTAN facility, an ITER toroidal field (TF) cable, inserted into a thick stainless steel tube and then compacted to a high aspect ratio rectangular shape. Besides establishing a new record in Nb3Sn CICC performances for ITER TF type cables, the very good test results confirmed that the conductor properties improve not only by lowering the void fraction and raising the cable twist pitch, as already shown during the ITER TFPRO and the EDIPO test campaigns, but also by the proper optimization of the conductor shape with respect to the electromagnetic force distribution. The sample manufacturing steps, along with the main test results, are presented here.

  18. Successful performances of the EU-AltTF sample, a large size Nb{sub 3}Sn cable-in-conduit conductor with rectangular geometry

    Energy Technology Data Exchange (ETDEWEB)

    Della Corte, A; Corato, V; Di Zenobio, A; Fiamozzi Zignani, C; Muzzi, L; Polli, G M; Reccia, L; Turtu, S [Associazione EURATOM-ENEA sulla Fusione, Via E Fermi 45, 00044 Frascati, Rome (Italy); Bruzzone, P [EPFL-CRPP, Fusion Technology, 5232 Villigen PSI (Switzerland); Salpietro, E [European Fusion Development Agreement, Close Support Unit, Boltzmannstrasse 2, 85748 Garching (Germany); Vostner, A, E-mail: antonio.dellacorte@enea.i [Fusion for Energy, c/ Josep Pla 2, Edificio B3, 08019 Barcelona (Spain)

    2010-04-15

    One of the design features which yet offers interesting margins for performance optimization of cable-in-conduit conductors (CICCs), is their geometry. For relatively small size Nb{sub 3}Sn CICCs, operating at high electromagnetic pressure, such as those for the EDIPO project, it has been experimentally shown that a design based on a rectangular layout with higher aspect ratio leads to the best performance, especially in terms of degradation with electromagnetic loads. To extend this analysis to larger size Nb{sub 3}Sn CICCs, we manufactured and tested, in the SULTAN facility, an ITER toroidal field (TF) cable, inserted into a thick stainless steel tube and then compacted to a high aspect ratio rectangular shape. Besides establishing a new record in Nb{sub 3}Sn CICC performances for ITER TF type cables, the very good test results confirmed that the conductor properties improve not only by lowering the void fraction and raising the cable twist pitch, as already shown during the ITER TFPRO and the EDIPO test campaigns, but also by the proper optimization of the conductor shape with respect to the electromagnetic force distribution. The sample manufacturing steps, along with the main test results, are presented here.

  19. Stability in a long length NbTi CICC

    CERN Document Server

    Bottura, L; Gislon, P; Spadoni, M; Bellucci, P; Muzzi, L; Turtu, S; Catitti, A; Chiarelli, S; Della Corte, A; Di Ferdinando, E

    2001-01-01

    A crucial issue for a superconducting coil in order to be safely used in the magnetic system of a fusion reactor is stability against all foreseen disturbances. To simulate the fusion machine conditions, including off-normal events, e.g. plasma disruptions, the energy deposition has to be spread over a "long length" cable in conduit conductor (CICC) and a background magnetic field is needed. We have therefore designed and built an experiment consisting of an instrumented NbTi test module inserted in a pair of co-axial pulsed copper coils. A 0.6 m diameter superconducting coil provides a background magnetic field up to 3 T. Calibration of the energy inductively coupled between the pulsed coils and the module has been obtained measuring the system temperature increase just after the pulse by means of thermometers positioned along the conductor. Stability vs. operating current I/sub op/ has been examined for different helium temperatures and different background magnetic fields. The finite element code Gandalf f...

  20. Performance of supercritical methanol in polyurethane degradation

    Directory of Open Access Journals (Sweden)

    Liu Lu

    2016-01-01

    Full Text Available Polyurethane is a group of block copolymer which is composed of diisocyanate, chain extender, and polyol, including polyurethane foam, polyurethane elastomer, waterborne polyurethane, etc. This research focused on thermoplastic polyurethane elastomer (TPU which is formed with 4,4’-diphenylmethane diisocyanate (MDI, poly(1,4-butanediol-hexanedioic acid diolpolyester(PBA and extended with 1,4-butanediol(BDO.The degradation of TPU was carried out with the help of methanol as the supercritical solvent. The SEM of the reaction residues revealed the process of the depolymerisation. The products were measured by GC-MS and found out to be PBA, BDO and 4,4’-methylene diphenyl carbamate(MDC which is themethylate of MDI.GC-FID, HPLC-UV and GPC were used to further analysis. The experimental results showed that supercritical methanol performed outstandingly in TPU recycling, it needed lower temperature and shorter time than regular methods. At 230°C/70min, over 90% raw materials of TPU could be recovered.

  1. A Calculation of Steady Pressure Drop and an Analysis of HT-7U CICC

    Institute of Scientific and Technical Information of China (English)

    武玉

    2002-01-01

    Under the condition of steady state, the pressure drop of coolant is mainly caused by friction along the cable. In the CICC (cable-in-conduit-conductor), helium flow .within the conductor consists of two parallel interconnected tubes.The velocity distribution has some differece between the central channel and conductor space. The region of Reynolds number is from 103 to 106. This paper describes the calculation of pressure drop of HT-7U CICC at various mass flows. It is assumed that the coolant flows in two parallel, rough tubes during the calculation.

  2. The AC losses measurement and analysis of superconducting NbTi CICC for HT-TU superconducting Tokamak

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Superconducting TF and PF coils have been measured in SULTAN test facility. Segregated copper strands are included in four NbTi CICC and this is a technical innovation. Two AC losses measurement methods, calorimetric and electromagnetic methods, have been used in the experiments, and a broad frequency range (from 0.05 Hz to 6 Hz) is covered in sample test. The purpose of this experiment was to investigate AC losses of TF and PF CICC conductor including segregated copper and to check the design of PF and TF CICC coated with different resistive barriers (Pb-30Sn-2Sb and Ni plating on NbTi strands).

  3. Isolation and Identification of a High-temperature Resistant Bacterium CICC 10853%一株耐高温菌CICC 10853的分离和鉴定

    Institute of Scientific and Technical Information of China (English)

    都海渤; 张欣; 李赞; 刘毅; 刘波; 李金霞; 姚粟; 程池

    2016-01-01

    从斜面培养基中分离到一株耐高温菌CICC 10853,对该菌株的分类地位进行了研究.通过形态学、生理生化特征、16S rRNA和recN基因序列分析的多相鉴定技术,将其鉴定为噬热地芽胞杆菌(Geobacillus thermoleovorans),为后续对该菌的生物学功能研究奠定基础.

  4. Numerical estimation of stability and improvement for coolant passage design in Hollow type CICC; Hollow gata CICC no reikyaku ryuro kaizen to anteisei no suchiteki kento

    Energy Technology Data Exchange (ETDEWEB)

    Miyauchi, M. [Yamagata Univ., Yamagata (Japan); Yoshiki, H. [The Univ. of Tokyo, Tokyo (Japan)

    1999-06-07

    The Hollow type CICC has a central channel (Hole) and is separated from surrounding bundle by a spiral tape with a gap, heat of a strand can effectively be convected to the Hole zone. However, even strong convection currents are induced in two ends of a thermal generating zone, but the heat is accumulated in the central part, and stability margin drops while relatively a long time heat has input for about 100 msec. In this study, the helium deposit inside the heating zone is reduced by a little design changing of the spiral tape that separates the bundle and the hole and efforts of improving stability of low energy density against heating are attempted. The instability caused by low energy and a long time heat invasion of the CICC appears also in simulation of Zanino at el. using a MITHRANDIR code. At this time, a method for calculating overflow of helium flowing to the bundle/Hole taking references of a branch current model and a joint flow model that are used in engine simulations is developed. (NEDO)

  5. Impact of Environmental Factors on Biofilm Formation by Bifidobacterium Longium CICC6069%环境因素对长双歧杆菌CICC6069生物膜生成的影响

    Institute of Scientific and Technical Information of China (English)

    徐文生; 张艳艳; 黄漫青; 艾启俊; 王晓东; 张磊; 仝其根

    2012-01-01

    Objective: The impact of different environmental factor on biofilm formation by Bifidabacterium longium CICC 6069 was studied. Methods: The nutritional and environmental conditions of Bifidobacterium longium CICC 6069 culture were changed by systematically adding or removing the medium compounds from MRS or TSB, to determine the impact of different environmental conditions on biofilm formation by Bifidobacterium longium CICC 6069. Results: Biofilm assays indicated that in vitro biofilm formation by Bifidobacterium longium CICC 6069 was modulated by environmental conditions. Glucose, osmolarity and MgS04 increased in biofilm formation, while an inhibitory effect of EDTA, soy peptone and pH on biofilm formation could be observed. MnS04 on biofilm formation was shown to be medium dependent. Conclusion: The biofilm formation by Bifidubaclermm longium CICC 6069 was dependent on environment conditions. Different environmental factors had different impact on biofilm formation by Bifidobacterium longium CICC 6069, among them, glucose, NaCl and MgSO4 were significantly affected.%目的:研究不同环境因子对长双歧杆菌CICC6069生物膜生成能力的影响.方法:通过增添或删除培养基MRS和TSB的组成成分,改变双歧杆菌培养的营养和环境条件,测定不同条件对双歧杆菌生物膜生成的影响.结果:不同环境因子对双歧杆菌生物膜生成的影响不同,葡萄糖、MgSO4及渗透压可促进长双歧杆菌CICC6069生物膜的生成;EDTA、大豆蛋白胨及pH可抑制长双歧杆菌生物膜的生成;MnSO4对双歧杆菌生物膜生成的影响有培养基依赖性.结论:长双歧杆菌CICC6069生物膜的生成依赖环境条件,不同环境因子对长双歧杆菌生物膜的生成有不同的影响.其中,MgSO4、NaCl、葡萄糖对双歧杆菌生物膜生成的影响比较显著.

  6. Performance and Degradation Analysis of Operating PV Systems

    Science.gov (United States)

    Da Silva Freire, Felipe

    The environmental concerns together with the decrease in technology cost lead the solar market to growth rapidly along the last decade. The photovoltaic (PV) systems are one of the solar energy alternatives and the silicon solar cells are currently the most widespread technology. Photovoltaic (PV) modules are considered the most reliable component of a photovoltaic system. The reliability and lifetime depends on the modules energy conversion performance and degradation modes. The analysis of monitoring data give insights about the PV system performance along its service time. The comparison between this data and mathematical models configure a way to predict the futures and new PV installations performance. The goal of this study is to understand the PV systems performance and degradation along its lifetime. A mathematical model was employed to predict the power output of a real, relatively new operating PV system with respect to environmental parameters temperature, irradiance and cloud coverage. The model used is based on one diode ideality factor and takes into account the parasitic series resistance. The results have been compared with the actual PV output data collected for the year 2014 and show good correlation. As the model predicts the system power output assuming the system in new conditions, the deviation in performance of the real data in comparison to the modeling results need to be further investigated for systems in service for longer time. For this propose, the study presents a condensed review of various causes of degradation in silicon PV modules and techniques to observe and investigate these degradation mechanisms. Major effects on output performance exhibit increase in observed ideality factor n2 and recombination current J02 primarily caused by decrease in minority carrier lifetime, shunts and increase in series resistance. The study further, investigates the governing degradation modes on a ten years old PV crystalline silicon module

  7. Design and fabrication of indigenous 30 kA Nb3Sn CICC for fusion relevant superconducting magnet

    Science.gov (United States)

    Raj, P.; Ghate, M.; Pradhan, S.; Singh, A.; Hussain, M. M.

    2017-02-01

    “Magnet Technology Development Group” is engaged in focused research and development of indigenous fusion relevant superconducting magnet at Institute for Plasma Research in association with various R&D organizations. The fusion relevant superconducting magnet is under development using a cable in conduit conductor (CICC) with operating current of 30 kA at 12 T and 4.22 K. The 30 kA CICC has been designed in square cross-section (30 mm × 30 mm) consisting twisted Nb3Sn strands and copper strands as superconducting cable, SS316LN tubes as jacket material and SS304L foil as wrapping around the cabled strands. It has been designed on the basis of required critical design parameters, operation requirements and mechanical consideration during its fabrication. Cabling technology required for twisting of Nb3Sn and Copper strand in required configuration of cable is discussed in this paper. The effect of heat treatment on SS316LN jacket material as well as on Nb3Sn strands is mentioned in paper. 100 m long Nb3Sn based CICC is manufactured by pulled through technology on dedicated jacketing line. The manufacturing parameters and quality procedures for development of CICCs is successfully established and have been demonstrated with fabrication of 100 m Nb3Sn based CICC without any technical difficulties.

  8. Numerical investigation on transverse heat transfer properties in cross section of full size Nb3Sn CICC ITER conductor

    Directory of Open Access Journals (Sweden)

    Shuming Jia

    2015-05-01

    Full Text Available The contact mechanical characteristics in the cross section of the Nb3Sn cable are sensitive to the cryogenic cooling and cyclic transverse electromagnetic loads, which may affect the cable’s performance. In this paper, based on a proposed discrete dynamic model (DEM, where the contact heat transfer among strands and the convective heat transfer in liquid helium are taken into account, the cooling process under two heat transfer mechanisms is performed. Simulation results show that the temperature variation of Poloidal Field Insert Sample (PFIS cable with time agrees well with the existing experimental results, and the role of contact heat transfer cannot be neglected during cryogenic cooling. It is obtained from the further analysis that the effect of contact heat transfer becomes more prominent with the decrease of mass flow rate of liquid helium, which leads to the stress status within cable changed significantly. With the temperature boundary condition imposed on the cable radial direction, the effective thermal conductivity (ETC of cable can be obtained. It can be found that the ETC increases with increasing the transverse loads and is sensitive to the low temperature environment, while it is not affected by load cycles basically. These results may provide the guide for the design and application of the future CICC conductors.

  9. Model helicopter performance degradation with simulated ice shapes

    Science.gov (United States)

    Tinetti, Ana F.; Korkan, Kenneth D.

    1987-01-01

    An experimental program using a commercially available model helicopter has been conducted in the Texas A&M University Subsonic Wind Tunnel to investigate main rotor performance degradation due to generic ice. The simulated ice, including both primary and secondary formations, was scaled by chord from previously documented artificial ice accretions. Base and iced performance data were gathered as functions of fuselage incidence, blade collective pitch, main rotor rotational velocity, and freestream velocity. It was observed that the presence of simulated ice tends to decrease the lift to equivalent drag ratio, as well as thrust coefficient for the range of velocity ratios tested. Also, increases in torque coefficient due to the generic ice formations were observed. Evaluation of the data has indicated that the addition of roughness due to secondary ice formations is crucial for proper evaluation of the degradation in main rotor performance.

  10. Model helicopter performance degradation with simulated ice shapes

    Science.gov (United States)

    Tinetti, Ana F.; Korkan, Kenneth D.

    1987-01-01

    An experimental program using a commercially available model helicopter has been conducted in the Texas A&M University Subsonic Wind Tunnel to investigate main rotor performance degradation due to generic ice. The simulated ice, including both primary and secondary formations, was scaled by chord from previously documented artificial ice accretions. Base and iced performance data were gathered as functions of fuselage incidence, blade collective pitch, main rotor rotational velocity, and freestream velocity. It was observed that the presence of simulated ice tends to decrease the lift to equivalent drag ratio, as well as thrust coefficient for the range of velocity ratios tested. Also, increases in torque coefficient due to the generic ice formations were observed. Evaluation of the data has indicated that the addition of roughness due to secondary ice formations is crucial for proper evaluation of the degradation in main rotor performance.

  11. MARKOV CHAIN MODELING OF PERFORMANCE DEGRADATION OF PHOTOVOLTAIC SYSTEM

    Directory of Open Access Journals (Sweden)

    E. Suresh Kumar

    2012-01-01

    Full Text Available Modern probability theory studies chance processes for which theknowledge of previous outcomes influence predictions for future experiments. In principle, when a sequence of chance experiments, all of the past outcomes could influence the predictions for the next experiment. In Markov chain type of chance, the outcome of a given experiment can affect the outcome of the next experiment. The system state changes with time and the state X and time t are two random variables. Each of these variables can be either continuous or discrete. Various degradation on photovoltaic (PV systems can be viewed as different Markov states and further degradation can be treated as the outcome of the present state. The PV system is treated as a discrete state continuous time system with four possible outcomes, namely, s1 : Good condition, s2 : System with partial degradation failures and fully operational, s3 : System with major faults and partially working and hence partial output power, s4 : System completely fails. The calculation of the reliability of the photovoltaic system is complicated since the system have elements or subsystems exhibiting dependent failures and involving repair and standby operations. Markov model is a better technique that has much appeal and works well when failure hazards and repair hazards are constant. The usual practice of reliability analysis techniques include FMEA((failure mode and effect analysis, Parts count analysis, RBD ( reliability block diagram , FTA( fault tree analysis etc. These are logical, boolean and block diagram approaches and never accounts the environmental degradation on the performance of the system. This is too relevant in the case of PV systems which are operated under harsh environmental conditions. This paper is an insight into the degradation of performance of PV systems and presenting a Markov model of the system by means of the different states and transitions between these states.

  12. Two General Architectures for Intelligent Machine Performance Degradation Assessment

    Directory of Open Access Journals (Sweden)

    Yanwei Xu

    2015-01-01

    Full Text Available Markov model is of good ability to infer random events whose likelihood depends on previous events. Based on this theory, hidden Markov model serves as an extension of Markov model to present an event from observations rather than states in Markov model. Moreover, due to successful applications in speech recognition, it attracts much attention in machine fault diagnosis. This paper presents two architectures for machine performance degradation assessment, which can be used to minimize machine downtime, reduce economic loss, and improve productivity. The major difference between the two architectures is whether historical data are available to build hidden Markov models. In case studies, bearing data as well as available historical data are used to demonstrate the effectiveness of the first architecture. Then, whole life gearbox data without historical data are employed to demonstrate the effectiveness of the second architecture. The results obtained from two case studies show that the presented architectures have good abilities for machine performance degradation assessment.

  13. Performance degradation of Geiger-mode APDs at cryogenic temperatures

    CERN Document Server

    Bondar, A; Dolgov, A; Shekhtman, L; Shemyakina, E; Sokolov, A; Breskin, A; Thers, D

    2014-01-01

    Two-phase Cryogenic Avalanche Detectors (CRADs) with THGEM multipliers, optically read out with Geiger-mode APDs (GAPDs), were proposed as potential technique for charge recording in rare-event experiments. In this work we report on the degradation of the GAPD performance at cryogenic temperatures revealed in the course of the study of two-phase CRAD in Ar, with combined THGEM/GAPD-matrix multiplier; the GAPDs recorded secondary scintillation photons from the THGEM holes in the Near Infrared. The degradation effect, namely the loss of the GAPD pulse amplitude, depended on the incident X-ray photon flux. The critical counting rate of photoelectrons produced at the 4.4 mm2 GAPD, degrading its performance at 87 K, was estimated as 10000 per second. This effect was shown to result from the considerable increase of the pixel quenching resistor of this CPTA-made GAPD type. Though not affecting low-rate rare-event experiments, the observed effect may impose some limitations on the performance of CRADs with GAPD-base...

  14. Environmentally degradable, high-performance thermoplastics from phenolic phytomonomers.

    Science.gov (United States)

    Kaneko, Tatsuo; Thi, Tran Hang; Shi, Dong Jian; Akashi, Mitsuru

    2006-12-01

    Aliphatic polyesters, such as poly(lactic acid), which degrade by hydrolysis, from naturally occurring molecules form the main components of biodegradable plastics. However, these polyesters have become substitutes for only a small percentage of the currently used plastic materials because of their poor thermal and mechanical properties. Polymers that degrade into natural molecules and have a performance closer to that of engineering plastics would be highly desirable. Although the use of a high-strength filler such as a bacterial cellulose or modified lignin greatly increases the plastic properties, it is the matrix polymer that determines the intrinsic properties of the composite. The introduction of an aromatic component into the thermoplastic polymer backbone is an efficient method to intrinsically improve the material performance. Here, we report the preparation of environmentally degradable, liquid crystalline, wholly aromatic polyesters. The polyesters were derived from polymerizable plant-derived chemicals--in other words, 'phytomonomers' that are widely present as lignin biosynthetic precursors. The mechanical performance of these materials surpasses that of current biodegradable plastics, with a mechanical strength, sigma, of 63 MPa, a Young's modulus, E, of 16 GPa, and a maximum softening temperature of 169 degrees C. On light irradiation, their mechanical properties improved further and the rate of hydrolysis accelerated.

  15. Grid Security and Integration with Minimal Performance Degradation

    CERN Document Server

    Sanyal, Sugata; Abraham, Ajith; Paprzycki, Marcin

    2011-01-01

    Computational grids are believed to be the ultimate framework to meet the growing computational needs of the scientific community. Here, the processing power of geographically distributed resources working under different ownerships, having their own access policy, cost structure and the likes, is logically coupled to make them perform as a unified resource. The continuous increase of availability of high-bandwidth communication as well as powerful computers built of low-cost components further enhance chances of computational grids becoming a reality. However, the question of grid security remains one of the important open research issues. Here, we present some novel ideas about how to implement grid security, without appreciable performance degradation in grids. A suitable alternative to the computationally expensive encryption is suggested, which uses a key for message authentication. Methods of secure transfer and exchange of the required key(s) are also discussed.

  16. Investigation of performance degradation in metallized film capacitors

    Energy Technology Data Exchange (ETDEWEB)

    Godec, M. [Institute of Metals and Technology, Lepi Pot 11, 1000 Ljubljana (Slovenia); Mandrino, Dj., E-mail: djordje.mandrino@imt.si [Institute of Metals and Technology, Lepi Pot 11, 1000 Ljubljana (Slovenia); Gaberšček, M. [National Institute of Chemistry, Hajdrihova 19, 1000 Ljubljana (Slovenia)

    2013-05-15

    Zn–Al metallized film capacitors in two different production stages were investigated to explain the decrease of capacitors performance with time. Unsealed and sealed capacitors with different aluminium content in metallization layer were investigated. Scanning electron microscopy (SEM) was used to image the surface of the metallization layers, energy dispersive X-ray spectroscopy (EDS) was used to determine the chemical composition and Auger electron spectroscopy (AES) was used to determine the chemical composition of the top of the metallization layers as well as to estimate the degree of oxidation. It was found that air humidity degraded the metallization layer of unsealed capacitors, especially at lower Al contents. Sealed capacitors were exposed to high electric fields, typical for standard usage. It was found – rather unexpectedly – that the performance was decreased by increasing Al content. A crystallographic explanation was proposed.

  17. Investigation of performance degradation in metallized film capacitors

    Science.gov (United States)

    Godec, M.; Mandrino, Dj.; Gaberšček, M.

    2013-05-01

    Zn-Al metallized film capacitors in two different production stages were investigated to explain the decrease of capacitors performance with time. Unsealed and sealed capacitors with different aluminium content in metallization layer were investigated. Scanning electron microscopy (SEM) was used to image the surface of the metallization layers, energy dispersive X-ray spectroscopy (EDS) was used to determine the chemical composition and Auger electron spectroscopy (AES) was used to determine the chemical composition of the top of the metallization layers as well as to estimate the degree of oxidation. It was found that air humidity degraded the metallization layer of unsealed capacitors, especially at lower Al contents. Sealed capacitors were exposed to high electric fields, typical for standard usage. It was found - rather unexpectedly - that the performance was decreased by increasing Al content. A crystallographic explanation was proposed.

  18. Performance degradation of ferrofluidic feedthroughs in a mixed irradiation field

    Science.gov (United States)

    Simos, Nikolaos; Fernandes, S.; Mittig, Wolfgang; Pellemoine, Frederique; Avilov, M.; Kostin, M.; Mausner, L.; Ronningen, R.; Schein, M.; Bollen, G.

    2017-01-01

    Ferrofluidic feedthrough (FF) rotary seals containing either NdFeB or SmCo-type permanent magnets have been considered for use in the target and beam dump systems of the Facility for Rare Isotope Beams (FRIB). To evaluate their performance under irradiation three FF seals were irradiated in a mixed field consisting of fast neutrons, protons and γ-rays to an average absorbed dose of 0.2, 2.0, and 20.0 MGy at the Brookhaven Linac Isotope Producer facility (BLIP). The radiation types and energy profiles mimic those expected at the FRIB facility. Degradation of the operational performance of these devices due to irradiation is expected to be the result of the de-magnetization of the permanent magnets contained within the seal and the changes in the ferrofluid properties. Post-irradiation performance was evaluated by determining the ferrofluidic seal vacuum tightness and torque under static and dynamic conditions. The study revealed that the ferrofluidic feedthrough seal irradiated to a dose of 0.2 MGy maintained its vacuum tightness under both static and rotational condition while the one irradiated to a dose of 2.0 MGy exhibited signs of ferrofluid damage but no overall performance loss. At 20 MGy dose the effects of irradiation on the ferrofluid properties (viscosity and particle agglomeration) were shown to be severe. Furthermore, limited de-magnetization of the annular shaped Nd2Fe14B and Sm2Co17 magnets located within the irradiated FFs was observed for doses of 0.2 MGy and 20 MGy respectively.

  19. Isolation and Identification of a Endophytic Bacterial Strain CICC 10594 from Paracel Islands Wild Noni (Morinda citrifolia L.) Seeds%一株西沙群岛野生诺尼种子的内生细菌CICC10594的分离与鉴定

    Institute of Scientific and Technical Information of China (English)

    曹艳花; 刘洋; 翟磊; 张明娟; 谭望桥; 程池

    2014-01-01

    以中国西沙群岛野生诺尼种子的内生细菌菌株CICC 10594为研究对象,利用基于形态学观察、生理生化特征鉴定及系统发育学分析的微生物多相分类鉴定技术,对CICC 10594的分类地位进行了鉴定与分析,结果显示,CICC10594为阴沟肠杆菌.

  20. Fuzzy regression modeling for tool performance prediction and degradation detection.

    Science.gov (United States)

    Li, X; Er, M J; Lim, B S; Zhou, J H; Gan, O P; Rutkowski, L

    2010-10-01

    In this paper, the viability of using Fuzzy-Rule-Based Regression Modeling (FRM) algorithm for tool performance and degradation detection is investigated. The FRM is developed based on a multi-layered fuzzy-rule-based hybrid system with Multiple Regression Models (MRM) embedded into a fuzzy logic inference engine that employs Self Organizing Maps (SOM) for clustering. The FRM converts a complex nonlinear problem to a simplified linear format in order to further increase the accuracy in prediction and rate of convergence. The efficacy of the proposed FRM is tested through a case study - namely to predict the remaining useful life of a ball nose milling cutter during a dry machining process of hardened tool steel with a hardness of 52-54 HRc. A comparative study is further made between four predictive models using the same set of experimental data. It is shown that the FRM is superior as compared with conventional MRM, Back Propagation Neural Networks (BPNN) and Radial Basis Function Networks (RBFN) in terms of prediction accuracy and learning speed.

  1. Improving Quality of Service from TCP/IP Performance Degradation

    Directory of Open Access Journals (Sweden)

    Prof.N..Penchalaiah

    2011-02-01

    Full Text Available TCP is currently the dominate congestion control protocol for the Internet. However, as the Internet evolves into a high-speed wired-cum-wireless hybrid network, performance degradation problems of TCP have appeared, such as underutilizing high-speed links, regarding wireless loss as congestion signal, and unfairness among flows with different RTTs. In order to improve the quality of service for such highspeed hybrid networks, we propose a router-assisted congestion control protocol called Quick Flow Control Protocol (QFCP. The convergence of many traditional services over IPbased infrastructures drastically increases the amount of IP data traffic to be delivered to user clients, thus raising questions about the management of quality of service in such networks. Quality of service will be of primary importance in order to ensure right operation, and to face the occurrence of congestion conditions, due to bandwidth demandingmultimedia services. in this paper, shows that QFCP can significantly shorten flow completion time, fairly allocate bandwidth resource, and be robust to non-congestion related loss. Also we consider a possible scenarios in which multiple multimedia and control streams are conveyed over the same HAN, and study a possible solution for the implementation of an easily manageable QoS framework, that relies on a QoS router based on open source software.

  2. Organic solar cells: Degradation processes and approaches to enhance performance

    Science.gov (United States)

    Fungura, Fadzai

    Organic solar cells (OSCs) have attracted a lot of attention due to their potential as flexible, lightweight, and low-cost renewable energy sources. Significant improvements have been made in increasing the devices' power conversion efficiency (PCE) and extensive efforts to understand degradation mechanisms and increase OSCs' lifetimes are ongoing. OSCs with higher than 10% efficiency have been reported. Enhanced stability and efficiency of inverted poly(3-hexylthiophene) (P3HT) solar cells with Cesium (Cs) halides were achieved by spin-coating Bphen (4,7-di(phenyl)-1,10-phenanthroline) on the halide layer and adding an 100nm polystyrene beads layer on the blank side of the OSC. To investigate photodegradation in a low-bandgap polymer, PBDTTT-EFT (benzo[1,2-b:4,5-b']dithiophene (BDT) and thieno[3,4-b]-thiophene), PBDTTT-EFT:PCBM bulk heterojunction (BHJ) solar cells were irradiated under 1X sun intensity and their electronic measurements were monitored over time. The electronic measurements revealed an increase in deep defect density in the polymer and at the donor-acceptor (D/A) interface of BHJ SCs and an increase in charge recombination as well as a decrease in external quantum efficiency, charge collection, short circuit current, open circuit voltage and hole mobility. Filtering blue and UV light resulted in drastically reduced photodegradation. Electron paramagnetic resonance measurements were performed on the photodegraded polymer and BHJ films, and revealed for the first time experimental evidence for metastable carbon dangling bonds (g=2.0029+/-0.0004) formed by blue/UV irradiation of the films. Dark EPR showed an increase in densities of other spin-active sites in the polymer, fullerene and polymer:fullerene blends in agreement with electronic measurements. The EPR results revealed that the carbon dangling bonds were at the D/A interface. These studies helped to better understand degradation mechanisms in a low-bandgap polymer, PBDTTT-EFT, ways to enhance

  3. Mechanochemical degradation of tetrabromobisphenol A: Performance, products and pathway

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Kunlun; Huang, Jun; Zhang, Wang; Yu, Yunfei; Deng, Shubo [State Key Joint Laboratory of Environment Simulation and Pollution Control (SKLESPC), School of Environment, POPs Research Center, Tsinghua University, Beijing 100084 (China); Yu, Gang, E-mail: yg-den@tsinghua.edu.cn [State Key Joint Laboratory of Environment Simulation and Pollution Control (SKLESPC), School of Environment, POPs Research Center, Tsinghua University, Beijing 100084 (China)

    2012-12-15

    Highlights: Black-Right-Pointing-Pointer Fe + SiO{sub 2} shows better performance than CaO in mechanochemical destruction of TBBPA. Black-Right-Pointing-Pointer Nonhazardous inorganic carbon and soluble bromide were the final products. Black-Right-Pointing-Pointer Raman and FTIR imply the generation of inorganic carbon and removal of bromine atom. Black-Right-Pointing-Pointer Tri-BBPA, bi-BBPA, mono-BBPA, BPA were the main intermediates during ball milling. Black-Right-Pointing-Pointer The bromine was balanced and the degradation pathway was proposed. - Abstract: Tetrabromobisphenol A (TBBPA) is the most widely used brominated flame retardant (BFR), which has received more and more concerns due to its high lipophilicity, persistency and endocrine disrupting property in the environment. Considering the possible need for the safe disposal of TBBPA containing wastes in the future, the potential of mechanochemical (MC) destruction as a promising non-combustion technology was investigated in this study. TBBPA was co-ground with calcium oxide (CaO) or the mixture of iron powder and quartz sand (Fe + SiO{sub 2}) in a planetary ball mill at room temperature. The method of Fe + SiO{sub 2} destructed over 98% of initial TBBPA after 3 h and acquired 95% debromination rate after 5 h, which showed a better performance than the CaO method. Raman spectra and Fourier transform infrared spectroscopy (FTIR) demonstrated the generation of inorganic carbon with the disappearance of benzene ring and C-Br bond, indicating the carbonization and debromination process during mechanochemical reaction. LC-MS-MS screening showed that the intermediates of the treatment with Fe + SiO{sub 2} were tri-, bi-, mono-brominated BPA, BPA and other fragments. Finally all the intermediates were also destroyed after 5 h grinding. The bromine balance was calculated and a possible reaction pathway was proposed.

  4. Evaluation of the performance degradation at PAFC effect of electrolyte fill-level on electrode performance

    Energy Technology Data Exchange (ETDEWEB)

    Kitai, Takashi; Uchida, Hiroyuki; Watanabe, Masahiro [Yamanashi Univ., Kofu (Japan)] [and others

    1996-12-31

    As a complimentary research project to the demonstration project of 5MW and 1MW PAFC plants, the mechanism and rate of deterioration of the cells and stacks have been studied from 1995 FY, with the objective of establishing an estimation method for the service life-time of the cell stacks. This work has been performed in the Basic Research Project, as part of that project on PAFC`s, selecting four subjects (Electrocatalysts degradation, Electrolyte fill-level, Cell material corrosion, Electrolyte loss) as the essential factors relating to the life-time. In this report, we will exhibit the effect of the electrolyte fill-level on the electrode performances.

  5. Characterization, Genome Sequence, and Analysis of Escherichia Phage CICC 80001, a Bacteriophage Infecting an Efficient L-Aspartic Acid Producing Escherichia coli.

    Science.gov (United States)

    Xu, Youqiang; Ma, Yuyue; Yao, Su; Jiang, Zengyan; Pei, Jiangsen; Cheng, Chi

    2016-03-01

    Escherichia phage CICC 80001 was isolated from the bacteriophage contaminated medium of an Escherichia coli strain HY-05C (CICC 11022S) which could produce L-aspartic acid. The phage had a head diameter of 45-50 nm and a tail of about 10 nm. The one-step growth curve showed a latent period of 10 min and a rise period of about 20 min. The average burst size was about 198 phage particles per infected cell. Tests were conducted on the plaques, multiplicity of infection, and host range. The genome of CICC 80001 was sequenced with a length of 38,810 bp, and annotated. The key proteins leading to host-cell lysis were phylogenetically analyzed. One protein belonged to class II holin, and the other two belonged to the endopeptidase family and N-acetylmuramoyl-L-alanine amidase family, respectively. The genome showed the sequence identity of 82.7% with that of Enterobacteria phage T7, and carried ten unique open reading frames. The bacteriophage resistant E. coli strain designated CICC 11021S was breeding and its L-aspartase activity was 84.4% of that of CICC 11022S.

  6. Cobetia marina CICC10367渗透压冲击下羟基四氢嘧啶的合成及释放%Hydroxyectoine synthesis and release under osmotic shock in Cobetia marina CICC10367

    Institute of Scientific and Technical Information of China (English)

    郎亚军; 任亚男; 柏林; 张苓花

    2009-01-01

    [目的]筛选获得耐受渗透压冲击的羟基四氢嘧啶合成菌株,利用"细菌挤奶"工艺提高羟基四氢嘧啶的产率.[方法]从盐池中分离羟基四氢嘧啶合成菌株,并对其进行形态、生理生化及16s rDNA鉴定.考察了培养基及其Nacl浓度对羟基四氢嘧啶合成的影响,在优化的条件下利用"细菌挤奶"工艺制备羟基四氢嘧啶.[结果]筛选获得的一株羟基四氢嘧啶合成菌株,鉴定为Cobetia marina CICC10367(C.marina CICC10367).NaCl浓度为90 g/L的、谷氨酸单钠为唯一碳氮源的培养基有利于羟基四氢嘧啶合成,最高合成量为694.5 mg/L 6次渗透压冲击的细菌挤奶,羟基四氢嘧啶的总合成量4179.O mg/L,产率597.0 mg/L/d,羟基四氢嘧啶对底物的转化率为80.2 mg/g.[结论]筛选获得的菌株C.marina CICC10367在NaCl诱导下合成羟基四氢嘧啶,该菌株耐受渗透压冲击,利用细菌挤奶工艺显著地提高了该菌株羟基四氢嘧啶的产率和转化率.%[Objective]To obtain hydroxyectoine-producing strain with tolerance to osmotic shock and improve hydroxyectoine productivity by adopting "bacteria milking" process.[Methods]We isolated a strain from salt lake, and then carried out the identifications of morphology, physiological and biochemical characteristics of the strain. We also investigated the effects of the medium and its NaCl concentration on the hydroxyectoine synthesis of this strain. Under optimal condition, hydroxyectoine was produced by adopting "bacteria milking" process.[Results]A hydroxyectoine-producing strain was obtained and identified as Cobetia marina CICC10367 ( C. marina CICC10367) . It could enhance hydroxyeceoine synthesis when the medium adopting monosodium glutamate as the sole source of carbon and nitrogen at 90 g/L NaCl. The highest synthesized hydroxyectoine concentration was 694.5 mg/L in the above described medium. After the "bacteria milking" process of six osmotic shock, the total concentration of

  7. Performance of BTX degraders under substrate versatility conditions.

    Science.gov (United States)

    Maliyekkal, Shihabudeen M; Rene, Eldon R; Philip, Ligy; Swaminathan, T

    2004-06-18

    A microbial consortium acclimatized with benzene, toluene or xylene (BTX) was employed to study the degradation pattern of these compounds individually under aerobic conditions. Batch and continuous experiments were conducted to evaluate the adaptability of the enriched cultures under substrate versatility conditions. The bio-kinetic parameters obtained under substrate versatility conditions were compared with those of a single substrate condition. Similar degradation patterns were observed for all the substrates with inhibition occurring at higher concentration (approximately 150 mg/L for benzene and xylene, and approximately 200 mg/L for toluene). Toluene degradation was highest, followed by benzene and xylene in the aqueous phase. Adaptation to a more toxic compound like benzene and xylene improved the utilization of toluene. On the other hand, microbes grown on a less toxic compound (toluene) grew at a lower rate in the presence of more toxic compounds. Suitable kinetic parameters such as micro(max) (maximum specific growth rate per hour), Ks (half saturation constant, mg/L), and KI (threshold substrate inhibition constant, mg/L) were determined using Haldane and Levenspiel substrate inhibition models. The Haldane equation seems to be an adequate expression for the system. The degradation behavior of pollutants in the gas phase was also evaluated using a toluene acclimatized biotrickling filter operated in continuous mode. The biotrickling filter acclimatized with toluene could degrade benzene and xylene with a lower elimination capacity. But, the system could recover its original efficiency quite fast even after a prolonged shock loading. The degradation was better for toluene, followed by benzene and xylene.

  8. Screw Performance Degradation Assessment Based on Quantum Genetic Algorithm and Dynamic Fuzzy Neural Network

    Directory of Open Access Journals (Sweden)

    Xiaochen Zhang

    2015-01-01

    Full Text Available To evaluate the performance of ball screw, screw performance degradation assessment technology based on quantum genetic algorithm (QGA and dynamic fuzzy neural network (DFNN is studied. The ball screw of the CINCINNATIV5-3000 machining center is treated as the study object. Two Kistler 8704B100M1 accelerometers and a Kistler 8765A250M5 three-way accelerometer are installed to monitor the degradation trend of screw performance. First, screw vibration signal features are extracted both in time domain and frequency domain. Then the feature vectors can be obtained by principal component analysis (PCA. Second, the initialization parameters of the DFNN are optimized by means of QGA. Finally, the feature vectors are inputted to DFNN for training and then get the screw performance degradation model. The experiment results show that the screw performance degradation model could effectively evaluate the performance of NC machine screw.

  9. Performance Degradation Assessment of Rolling Element Bearings Based on an Index Combining SVD and Information Exergy

    Directory of Open Access Journals (Sweden)

    Bin Zhang

    2014-10-01

    Full Text Available Performance degradation assessment of rolling element bearings is vital for the reliable and cost-efficient operation and maintenance of rotating machines, especially for the implementation of condition-based maintenance (CBM. For robust degradation assessment of rolling element bearings, uncertainties such as those induced from usage variations or sensor errors must be taken into account. This paper presents an information exergy index for bearing performance degradation assessment that combines singular value decomposition (SVD and the information exergy method. Information exergy integrates condition monitoring information of multiple instants and multiple sensors, and thus performance degradation assessment uncertainties are reduced and robust degradation assessment results can be obtained using the proposed index. The effectiveness and robustness of the proposed information exergy index are validated through experimental case studies.

  10. A 600-m Jacketing Line of Cable-in-conduit Conductor (CICC) and the First 600-m Dummy Cable

    Science.gov (United States)

    Chen, Si-yue; Wu, Jie-feng; Chen, Xing-qian; Zhang, Pin; He, Wei; Wang, Hai-jing; Xu, Xue-fu; Yi, Zian; Gao, Da-ming

    2002-02-01

    A cable-in-conduit conductor (CICC) production line was designed and constructed in Institute of Plasma Physics of Chinese Academy of Sciences (IPPCAS) by the end of 2000. It can produce a length of 600 meters and three kinds of sections of 20.8±0.1 × 20.8±0.1, 20.4±0.1 × 20.4±0.1 and 18.6 ± 0.1 × 18.6 ± 0.1 mm2. If the rollers of the shaping machine are changed, it can also produce other sizes of CICCs. So-called inserting-cable technology is adopted in this production line, where the procedures consist of tube pre-treatment (cleaning, pressure and leakage testing, end cutting), conduits butt-welding, six kinds of quality checking (endoscopy, dye penetration, pressure control, leakage testing, ultrasonic inspection and x-ray testing), cable inserting, shaping (compacting & squaring), pre-bending & winding and final checking. Now all the instruments and facilities required for these technologies have been installed and got ready. Some key technologies have been explored and good results obtained. Some short samples were produced and a 600 meters long sample was made out in August, 2001.

  11. Genome Sequence of Paenibacillus polymyxa Strain CICC 10580, Isolated from the Fruit of Noni (Morinda citrifolia L.) Grown in the Paracel Islands.

    Science.gov (United States)

    Xu, Youqiang; Liu, Yang; Yao, Su; Li, Jinxia; Cheng, Chi

    2014-01-01

    Noni is a plant reported to have nutritional and therapeutic properties. Paenibacillus polymyxa CICC 10580 is a strain that was isolated from the fruit of noni and showed comprehensive antagonistic activity against many pathogens. Its genome was sequenced and assembled (6.10 Mb). The coding sequences (CDSs) correlated with antagonistic activity were annotated.

  12. Development of biodegradable materials; balancing degradability and performance

    Energy Technology Data Exchange (ETDEWEB)

    Mayer, J.M.; Allen, A.L.; Dell, P.A.; McCassie, J.E.; Shupe, A.E.; Stenhouse, P.J. Stenhouse, Welch, E.A.; Kaplan, D.L. [Army Natick Research Development, MA (United States)

    1993-12-31

    The development of biodegradable materials suitable for packaging must take into consideration various performance criteria such as mechanical and barrier properties, as well as rate of biodegradability in given environments. Individual or blended biopolymer films were obtained commercially or blown into film in the laboratory and tested for tensile strength, ultimate elongation and oxygen barrier. These films were then subjected to accelerated marine biodegradation tests as well as simulated marine respirometry. Starch/ethylene vinyl alcohol films exhibited good mechanical and excellent oxygen barrier properties, but were very slow to biodegrade in the simulated and excellent oxygen barrier properties, but were very slow to biodegrade in the simulated marine environment. Polyhydroxyalkanoates had good mechanical properties, average oxygen barrier and good biodegradability. Data indicate that performance and biodegradability of packaging can be tailored to needs by combining individual biopolymers in different proportions in blends and laminates.

  13. Driver performance-based assessment of thermal display degradation effects

    Science.gov (United States)

    Ruffner, John W.; Massimi, Michael S.; Choi, Yoon S.; Ferrett, Donald A.

    1998-07-01

    The Driver's Vision Enhancer (DVE) is a thermal sensor and display combination currently being procured for use in U.S. Army combat and tactical wheeled vehicles. During the DVE production process, a given number of sensor or display pixels may either vary from the desired luminance values (nonuniform) or be inactive (nonresponsive). The amount and distribution of pixel luminance nonuniformity (NU) and nonresponsivity (NR) allowable in production DVEs is a significant cost factor. No driver performance-based criteria exist for determining the maximum amount of allowable NU and NR. For safety reasons, these characteristics are specified conservatively. This paper describes an experiment to assess the effects of different levels of display NU and NR on Army drivers' ability to identify scene features and obstacles using a simulated DVE display and videotaped driving scenarios. Baseline, NU, and NR display conditions were simulated using real-time image processing techniques and a computer graphics workstation. The results indicate that there is a small, but statistically insignificant decrease in identification performance with the NU conditions tested. The pattern of the performance-based results is consistent with drivers' subjective assessments of display adequacy. The implications of the results for specifying NU and NR criteria for the DVE display are discussed.

  14. Storage life of power switching transistors based on performance degradation data

    Science.gov (United States)

    Haochun, Qi; Xiaoling, Zhang; Xuesong, Xie; Changzhi, Lü; Chengju, Chen; Li, Zhao

    2014-04-01

    NPN-type small and medium power switching transistors in 3DK series are used to conduct analyses and studies of accelerating degradation. Through three group studies of accelerating degradation in different temperature-humidity constant stresses, the failure sensitive parameters of transistors are identified and the lifetime of samples is extrapolated from the performance degradation data. Average lifetimes in three common distributions are given, when, combined with the Hallberg-Peck temperature-humidity model, the storage lifetime of transistor samples in the natural storage condition is extrapolated between 105-107 h. According to its definition, the accelerating factor is 1462 in 100°C/100% relative humidity (RH) stress condition, and 25°C/25% RH stress condition. Finally, the degradation causes of performance parameters of the test samples are analyzed. The findings can provide certain references for the storage reliability of domestic transistors.

  15. AI-2 Key Enzyme S-Ribosylhomocysteinase from Strain Klebsiella pneumoniae CICC 10011 Producing 2,3-Butanediol

    Institute of Scientific and Technical Information of China (English)

    DAI Jian-ying; ZHANG Li-fu; XIU Zhi-long

    2011-01-01

    S-Ribosylhomocysteinase(LuxS) is the key enzyme in the synthetic pathway of a quorum sensing autoin ducer AI-2. LuxS from a 2,3-butanediol produced strain Klebisella pneumoniae CICC 10011 was cloned and charac terized. The luxS gene is composed of 540 bp with 172 amino acids encoded. The Km value for S-ribosylhomo-cysteine(SRH) was (27+1) μmol/L, kcat was (0.112±0.004) s-1 and kcat/Km was 4.4×103 L.mol-1 s-1 at 25 ℃. LuxS was activated by divalent metal ions, the highest activity was detected with Co2+ form, followed by Mg2+, Ba2+, Mn2+,Fe2+ and Ca2+, and activation constant for Co2+ is (16±2) μmol/L.

  16. Performance Degradation Tests of Phosphoric Acid Doped PBI Membrane Based High Temperature PEM Fuel Cells

    DEFF Research Database (Denmark)

    Zhou, Fan; Araya, Samuel Simon; Grigoras, Ionela

    2014-01-01

    Degradation tests of two phosphoric acid (PA) doped PBI membrane based HT-PEM fuel cells were reported in this paper to investigate the effects of start/stop and the presence of methanol in the fuel to the performance degradation. Continuous tests with H2 and simulated reformate which was composed...... of H2, water steam and methanol as the fuel were performed on both single cells. 12-h-startup/12-h-shutdown dynamic tests were performed on the first single cell with pure dry H2 as the fuel and on the second single cell with simulated reformate as the fuel. Along with the tests electrochemical...... techniques such as polarization curves and electrochemical impedance spectroscopy (EIS) were employed to study the degradation mechanisms of the fuel cells. Both single cells showed an increase in the performance in the H2 continuous tests, because of a decrease in the ORR kinetic resistance probably due...

  17. Preparation and Photocatalytic Performance of MWCNTs/TiO2 Nanocomposites for Degradation of Aqueous Substrate

    Directory of Open Access Journals (Sweden)

    Qiannan Duan

    2016-01-01

    Full Text Available In this study, multiwalled carbon nanotubes (MWCNTs/TiO2 nanocomposites were obtained by constant volumetric wet impregnation processes. The prepared catalysts were characterized by scanning electron microscopy (SEM and X-ray photoelectron spectroscopy (XPS. The effect of reaction conditions on photocatalytic performance of the catalysts was investigated by the degradation of methyl orange (MO under UV irradiation, in a new type of reactor with unique structure. The results showed that the prepared nanocomposite exhibited higher MO degradation efficiency than that of pure nano-TiO2. Besides, in batch experiments of influencing factors, including ionic strength, oxidant amount, and response times, the presence of H2O2 would contribute to increasing the MO degradation rate of MWCNTs/TiO2 samples. Ionic concentration and long reaction times are adverse to the MO degradation in the processes.

  18. Demonstration and Validation of a High-Performance Floor-Sealant System to Reduce Concrete Degradation

    Science.gov (United States)

    2015-05-01

    System to Reduce Concrete Degradation Final Report on Project F10-AR02 Co ns tr uc tio n En gi ne er in g R es ea rc h La bo ra to ry Clint...of a High-Performance Floor-Sealant System to Reduce Concrete Degradation Final Report on Project F10-AR02 Clint A. Wilson and Susan A. Drozdz...Under Project F10-AR02, “Application of an Innovative, High Performance Concrete Floor Sealant at Hunter Army Airfield, Georgia” ERDC/CERL TR-15-9 ii

  19. Photocatalytic performance of graphene/TiO{sub 2}-Ag composites on amaranth dye degradation

    Energy Technology Data Exchange (ETDEWEB)

    Roşu, Marcela-Corina, E-mail: marcela.rosu@itim-cj.ro; Socaci, Crina; Floare-Avram, Veronica; Borodi, Gheorghe; Pogăcean, Florina; Coroş, Maria; Măgeruşan, Lidia; Pruneanu, Stela

    2016-08-15

    Ternary nanocomposites containing TiO{sub 2}, silver and graphene with different reduction levels were prepared and used as photocatalysts for amaranth azo dye degradation, under UV and natural light exposure. The obtained materials were characterized by TEM, XRD, FTIR and UV-Vis spectroscopy, confirming the successful formation of the nanocomposites. HPLC analysis along with UV-Vis spectroscopy were employed to quantify the concentration of non-degraded dye in solution. The graphene/TiO{sub 2}-Ag nanocomposites proved to have remarkable photocatalytic activities for amaranth degradation under UV and solar irradiation (85.3–98% of dye has disappeared in the first 2 h). Also, significant removal efficiencies (between 40.5 and 71.8%) of photocatalysts, in day light conditions, were demonstrated. The best result for amaranth dye degradation was obtained with the reduced graphene/TiO{sub 2}-Ag catalyst (up to 99.9%). Based on the degradation products analysis, a photodegradation pathway of amaranth dye was also proposed. - Highlights: • Graphene/TiO{sub 2}-Ag composites were prepared by a combined chemical-thermal method. • The composites showed improved light-absorption characteristics. • A significant degradation performance of amaranth was obtained with these composites under UV and natural light exposure. • Graphene/TiO{sub 2}-Ag composites offer a high potential for various photocatalytic applications in pollutant removal processes.

  20. A Framework for Evaluating the Effects of Degraded Digital I and C Systems on Human Performance

    Energy Technology Data Exchange (ETDEWEB)

    OHara,J.; Gunther, B.; Hughes, N.; Barnes, V.

    2009-04-09

    New and advanced reactors will use integrated digital instrumentation and control (I&C) systems to support operators in their monitoring and control functions. Even though digital systems are typically highly reliable, their potential for degradation or failure could significantly affect operator situation awareness and performance and, consequently, impact plant safety. The U.S. Nuclear Regulatory Commission has initiated a research project to investigate the effects of degraded I&C systems on human performance and plant operations. The ultimate objective of this project is to develop the technical basis for human factors review guidance for conditions of degraded I&C, including complete failure. Based on the results of this effort, NRC will determine the need for developing new guidance or revising NUREG-0800, NUREG-0711, NUREG-0700 and other pertinent NRC review guidance. This paper reports on the first phase of the research, the development of a framework for linking degraded I&C system conditions to human performance. The framework consists of three levels: I&C subsystems, human-system interfaces, and human performance. Each level is composed of a number of discrete elements. This paper will describe the elements at each level and their integration. In the next phase of the research, the framework will be used to systematically investigate the human performance consequences of various classes of failures.

  1. Bearing performance degradation assessment based on time-frequency code features and SOM network

    Science.gov (United States)

    Zhang, Yan; Tang, Baoping; Han, Yan; Deng, Lei

    2017-04-01

    Bearing performance degradation assessment and prognostics are extremely important in supporting maintenance decision and guaranteeing the system’s reliability. To achieve this goal, this paper proposes a novel feature extraction method for the degradation assessment and prognostics of bearings. Features of time-frequency codes (TFCs) are extracted from the time-frequency distribution using a hybrid procedure based on short-time Fourier transform (STFT) and non-negative matrix factorization (NMF) theory. An alternative way to design the health indicator is investigated by quantifying the similarity between feature vectors using a self-organizing map (SOM) network. On the basis of this idea, a new health indicator called time-frequency code quantification error (TFCQE) is proposed to assess the performance degradation of the bearing. This indicator is constructed based on the bearing real-time behavior and the SOM model that is previously trained with only the TFC vectors under the normal condition. Vibration signals collected from the bearing run-to-failure tests are used to validate the developed method. The comparison results demonstrate the superiority of the proposed TFCQE indicator over many other traditional features in terms of feature quality metrics, incipient degradation identification and achieving accurate prediction. Highlights • Time-frequency codes are extracted to reflect the signals’ characteristics. • SOM network served as a tool to quantify the similarity between feature vectors. • A new health indicator is proposed to demonstrate the whole stage of degradation development. • The method is useful for extracting the degradation features and detecting the incipient degradation. • The superiority of the proposed method is verified using experimental data.

  2. Optimization of fermentation process for L-malic acid with xylose by Aspergillus parasiticus CICC40365%寄生曲霉CICC40365利用木糖产L-苹果酸的发酵条件优化

    Institute of Scientific and Technical Information of China (English)

    吴悦; 潘丽军; 李兴江; 姜绍通

    2014-01-01

    [目的]为提高L-苹果酸产量及木糖利用率,以寄生曲霉(Aspergillus parasiticusCICC40365)为菌种,木糖为碳源,对其发酵工艺及木糖代谢途径进行初步研究.[方法]采用单因素试验和响应曲面法(Box-Behnken设计)对培养基和发酵条件进行优化.[结果]获得最佳培养基配方为:木糖100.0 g/L、硫酸铵2.0 g/L、酵母浸粉3.0 g/L、硫酸镁0.20 g/L、硫酸锰0.15 g/L、硫酸亚铁0.08 g/L、碳酸钙80.00 g/L,L-苹果酸的产量为53.58 g/L,较优化前提高40.5%.发酵条件较好组合为:接种量为8%(体积比)、摇瓶装液量60 mL/250 mL、发酵温度32℃ 、摇床转速170 r/rmin、发酵周期8d,L-苹果酸的产量为55.47 g/L. Mg2+、Mn2+对木糖代谢中相关酶的影响研究结果表明,木酮糖激酶在该菌株代谢木糖过程中起着重要作用.[结论]寄生曲霉CICC40365能够较好地利用木糖发酵产L-苹果酸,其产量及木糖的利用效率均得到提高.

  3. Thermal-hydraulic analysis of transients in the HELIOS loop including a CICC section representative of the JT-60SA Central Solenoid

    Science.gov (United States)

    Carli, S.; Bonifetto, R.; Hoa, C.; Savoldi, L.; Zanino, R.

    2015-12-01

    The HELIOS facility at CEA Grenoble is a supercritical helium (SHe) loop which is being used to investigate the effects on the cryogenic cooling system of the pulsed heat loads which are typical of superconducting tokamak operation. In the standard configuration, the magnet heat load is simulated by electrical heaters wrapped around a section of cryoline. In the present work, the resistively heated section is substituted in the HELIOS model of the 4C code, already validated for the standard configuration of HELIOS, by a sub-size winding structure made of JT-60SA Cable-In-Conduit Conductors (CICCs). The new model is then used to highlight the differences in the circuit behaviour when the heated pipe is substituted by an actual magnet wound with CICCs, checking the representativeness of the control strategies developed for the present HELIOS configuration. The use of CICCs will be shown to produce an intrinsic smoothing of the temperature profiles which is not affecting the capability of the control strategies to smooth the heat loads to the cryoplant.

  4. Degradation and performance evaluation of PV module in desert climate conditions with estimate uncertainty in measuring

    Directory of Open Access Journals (Sweden)

    Fezzani Amor

    2017-01-01

    Full Text Available The performance of photovoltaic (PV module is affected by outdoor conditions. Outdoor testing consists installing a module, and collecting electrical performance data and climatic data over a certain period of time. It can also include the study of long-term performance under real work conditions. Tests are operated in URAER located in desert region of Ghardaïa (Algeria characterized by high irradiation and temperature levels. The degradation of PV module with temperature and time exposure to sunlight contributes significantly to the final output from the module, as the output reduces each year. This paper presents a comparative study of different methods to evaluate the degradation of PV module after a long term exposure of more than 12 years in desert region and calculates uncertainties in measuring. Firstly, this evaluation uses three methods: Visual inspection, data given by Solmetric PVA-600 Analyzer translated at Standard Test Condition (STC and based on the investigation results of the translation equations as ICE 60891. Secondly, the degradation rates calculated for all methods. Finally, a comparison between a degradation rates given by Solmetric PVA-600 analyzer, calculated by simulation model and calculated by two methods (ICE 60891 procedures 1, 2. We achieved a detailed uncertainty study in order to improve the procedure and measurement instrument.

  5. Electrochemical performance of nickel/metal hydride batteries under unconventional conditions and degradation analysis

    Institute of Scientific and Technical Information of China (English)

    李丽; 吴锋; 杨凯; 王敬; 陈实

    2004-01-01

    The charge-discharge performance and cycle stability of D size Ni/MH batteries at -20 ℃, 25 ℃ and 55℃ were examined. The results show that the decline rate of Ni/MH battery discharge capacity at -20 ℃ and 55 ℃ are 12.1% and 13.6% ,and the average discharge voltage decreases by a value of 0.13 V and 0.06 V respectively,cycling stability declines obviously at various temperatures. The capacity degradation of Ni/MH batteries under low temperature is reversible, belonging to transient degradation and that of high and normal temperatures are not reversible, belonging to permanent degradation. Electrochemical impedance spectroscopy, scanning electron microscope and energy dispersive X-ray analyzer were introduced to study the main causes of cycling deterioration of Ni/MH batteries.

  6. Isolation, Characterization, and Degradation Performance of the 17β-Estradiol-Degrading Bacterium Novosphingobium sp. E2S

    Directory of Open Access Journals (Sweden)

    Shunyao Li

    2017-01-01

    Full Text Available A 17β-estradiol (E2-degrading bacterium E2S was isolated from the activated sludge in a sewage treatment plant (STP. The morphology, biological characteristics, and 16S ribosomal RNA (rRNA gene sequence of strain E2S indicated that it belonged to the genus Novosphingobium. The optimal degrading conditions were 30 °C and pH 7.0. The ideal inoculum volume was 5% (v/v, and a 20-mL degradation system was sufficient to support the removal ability of strain E2S. The addition of extra NaCl to the system did not benefit the E2 degradation in batch culture by this strain. Strain E2S exhibited high degradation efficiency with initial substrate concentrations of 10–50 mg·L−1. For example, in mineral salt medium containing 50 mg·L−1 of E2, the degradation efficiency was 63.29% after seven days. In cow manure samples supplemented with 50 mg·L−1 of E2, strain E2S exhibited 66.40% degradation efficiency after seven days. The finding of the E2-degrading strain E2S provided a promising method for removing E2 from livestock manure in order to reduce the potential environmental risks of E2.

  7. Performance and Mechanism of UV/Immobilized Cu-TiO2 System to Degradation Histidine

    Directory of Open Access Journals (Sweden)

    Cheng Liu

    2016-01-01

    Full Text Available More and more attention is paid to dissolved organic nitrogen (DON and some specific categories of amino acids are considered to be the direct precursors of nitrogenous disinfection byproducts (N-DBPs. Histidine was chosen to study the efficiency and mechanism of amino acid in UV/Cu-TiO2 system. Moreover, the influences of pH, organics, and inorganic ion on the photocatalytic efficiency were also investigated. The results show that the degradation rate of DON in the UV/Cu-TiO2 system was about 50% after 60 min, and it was much lower than that of histidine (72%, which indicated that a part of degraded histidine was oxidized to other N-containing organics. The optimal pH value was 7.0 for the photodegradation of histidine, and the presence of organic compound and inorganic ion would decrease the degradation performance to some extent. After 6 h irradiation, histidine was totally degraded into NH4+, and in the following 2 h, NH4+ was oxidized to NO3- firstly and then NO3- was reduced to N2 and overflowed from water, which should be attributed to the doping of Cu in the TiO2 and provided a way to totally degrade the DON from the water.

  8. Insights into the Mechanism and Kinetics of Thermo-Oxidative Degradation of HFPE High Performance Polymer.

    Science.gov (United States)

    Kunnikuruvan, Sooraj; Parandekar, Priya V; Prakash, Om; Tsotsis, Thomas K; Nair, Nisanth N

    2016-06-02

    The growing requisite for materials having high thermo-oxidative stability makes the design and development of high performance materials an active area of research. Fluorination of the polymer backbone is a widely applied strategy to improve various properties of the polymer, most importantly the thermo-oxidative stability. Many of these fluorinated polymers are known to have thermo-oxidative stability up to 700 K. However, for space and aerospace applications, it is important to improve its thermo-oxidative stability beyond 700 K. Molecular-level details of the thermo-oxidative degradation of such polymers can provide vital information to improve the polymer. In this spirit, we have applied quantum mechanical and microkinetic analysis to scrutinize the mechanism and kinetics of the thermo-oxidative degradation of a fluorinated polymer with phenylethenyl end-cap, HFPE. This study gives an insight into the thermo-oxidative degradation of HFPE and explains most of the experimental observations on the thermo-oxidative degradation of this polymer. Thermolysis of C-CF3 bond in the dianhydride component (6FDA) of HFPE is found to be the rate-determining step of the degradation. Reaction pathways that are responsible for the experimentally observed weight loss of the polymer is also scrutinized. On the basis of these results, we propose a modification of HFPE polymer to improve its thermo-oxidative stability.

  9. Evaluation of Lithium-ion Battery Second Life Performance and Degradation

    DEFF Research Database (Denmark)

    Martinez-Laserna, Egoitz; Sarasketa-Zabala, Elixabet; Stroe, Daniel Loan

    2016-01-01

    the effects of lithium-ion (Li-ion) battery State of Health (SOH) and ageing history over the second life performance on two different applications: a residential demand management application and a power smoothing renewable integration application. The performance and degradation of second life batteries......Reusing electric vehicle batteries once they have been retired from the automotive application is stated as one of the possible solutions to reduce electric vehicle costs. Many publications in the literature have analyzed the economic viability of such a solution, and some car manufacturers have...... recently started running several projects to demonstrate the technical viability of the so-called battery second life. Nevertheless, the performance and degradation of second life batteries remain an unknown topic and one of the biggest gaps in the literature. The present work aims at evaluating...

  10. Evaluation of Lithium-ion Battery Second Life Performance and Degradation

    DEFF Research Database (Denmark)

    Martinez-Laserna, Egoitz; Sarasketa-Zabala, Elixabet; Stroe, Daniel Loan

    2016-01-01

    Reusing electric vehicle batteries once they have been retired from the automotive application is stated as one of the possible solutions to reduce electric vehicle costs. Many publications in the literature have analyzed the economic viability of such a solution, and some car manufacturers have...... recently started running several projects to demonstrate the technical viability of the so-called battery second life. Nevertheless, the performance and degradation of second life batteries remain an unknown topic and one of the biggest gaps in the literature. The present work aims at evaluating...... the effects of lithium-ion (Li-ion) battery State of Health (SOH) and ageing history over the second life performance on two different applications: a residential demand management application and a power smoothing renewable integration application. The performance and degradation of second life batteries...

  11. Synthesis of Pt3Ni Microspheres with High Performance for Rapid Degradation of Organic Dyes

    Science.gov (United States)

    Wang, Min; Yang, Yushi; Long, Jia; Mao, Zhou; Qiu, Tong; Wu, Qingzhi; Chen, Xiaohui

    2015-05-01

    In this study, Pt3Ni microspheres consisted of nanoparticles were synthesized without addition of surfactants via the solvothermal route. The obtained sample was characterized by X-ray diffraction (XRD), inductively coupled plasma-atomic emission spectrometer (ICP-AES), X-ray photoelectron spectroscopy (XPS), and field-emission scanning electron microscopy (FESEM). Furthermore, the catalytic performance of as-synthesized Pt3Ni microspheres was evaluated on the degradation of different organic dyes (methylene blue, methyl orange, Congo red, and rhodamine B). The results show that different dyes were rapidly decomposed by Pt3Ni microspheres in different pathways. Among different dyes, the formation and further degradation of the intermediates was observed during the degradation of methylene blue and methyl orange, suggesting the indirect degradation process of these dyes. This study provides not only a promising catalyst for the removal of organic contaminants for environment remediation, but also new insights for Pt3Ni alloy as a high-performance catalyst in organic synthesis.

  12. Synthesis of Pt3Ni microspheres with high performance for rapid degradation of organic dyes.

    Science.gov (United States)

    Wang, Min; Yang, Yushi; Long, Jia; Mao, Zhou; Qiu, Tong; Wu, Qingzhi; Chen, Xiaohui

    2015-12-01

    In this study, Pt3Ni microspheres consisted of nanoparticles were synthesized without addition of surfactants via the solvothermal route. The obtained sample was characterized by X-ray diffraction (XRD), inductively coupled plasma-atomic emission spectrometer (ICP-AES), X-ray photoelectron spectroscopy (XPS), and field-emission scanning electron microscopy (FESEM). Furthermore, the catalytic performance of as-synthesized Pt3Ni microspheres was evaluated on the degradation of different organic dyes (methylene blue, methyl orange, Congo red, and rhodamine B). The results show that different dyes were rapidly decomposed by Pt3Ni microspheres in different pathways. Among different dyes, the formation and further degradation of the intermediates was observed during the degradation of methylene blue and methyl orange, suggesting the indirect degradation process of these dyes. This study provides not only a promising catalyst for the removal of organic contaminants for environment remediation, but also new insights for Pt3Ni alloy as a high-performance catalyst in organic synthesis.

  13. Transverse heat transfer coefficient in the dual channel ITER TF CICCs. Part III: Direct method of assessment

    Science.gov (United States)

    Lewandowska, Monika; Malinowski, Leszek

    2016-01-01

    The data resulting from the thermal-hydraulic test of the ITER TF CICC are used to determine the flow partition and the overall effective heat transfer coefficient (hBC) between bundle and central channel in a direct way, i.e. by analysis of the heat transfer between both flow channels, based on the mass and energy balance equations and the readings of thermometers located inside the cable. In cases without a local heat source in the considered cable segment the obtained hBC values were consistent with those obtained in earlier studies by analysis of experimental data using indirect methods. It was also observed that the transverse heat transfer was strongly enhanced in a cable segment heated from outside. This phenomenon results from the mass transfer from the bundle region to the central channel. The experimental hBC data obtained for the case without a heat source in the considered segment were also compared with those calculated using various heat transfer correlations.

  14. Thermogravimetric investigation on the degradation properties and combustion performance of bio-oils.

    Science.gov (United States)

    Ren, Xueyong; Meng, Jiajia; Moore, Andrew M; Chang, Jianmin; Gou, Jinsheng; Park, Sunkyu

    2014-01-01

    The degradation properties and combustion performance of raw bio-oil, aged bio-oil, and bio-oil from torrefied wood were investigated through thermogravimetric analysis. A three-stage process was observed for the degradation of bio-oils, including devolatilization of the aqueous fraction and light compounds, transition of the heavy faction to solid, and combustion of carbonaceous residues. Pyrolysis kinetics parameters were calculated via the reaction order model and 3D-diffusion model, and combustion indexes were used to qualitatively evaluate the thermal profiles of tested bio-oils for comparison with commercial oils such as fuel oils. It was found that aged bio-oil was more thermally instable and produced more combustion-detrimental carbonaceous solid. Raw bio-oil and bio-oil from torrefied wood had comparable combustion performance to fuel oils. It was considered that bio-oil has a potential to be mixed with or totally replace the fuel oils in boilers.

  15. Performance and degradation characteristics of blue-violet laser diodes grown by molecular beam epitaxy

    Energy Technology Data Exchange (ETDEWEB)

    Tan, W.S.; Kauer, M.; Hooper, S.E.; Smeeton, T.M.; Bousquet, V.; Rossetti, M.; Heffernan, J. [Sharp Laboratories of Europe Ltd., Edmund Halley Road, Oxford Science Park, Oxford, OX4 4GB (United Kingdom); Xiu, H.; Humphreys, C.J. [Department of Materials Science and Metallurgy, University of Cambridge, Pembroke Street, Cambridge, CB2 3QZ (United Kingdom)

    2009-06-15

    This paper reports the state of the art performance for blue-violet laser diodes (LD) grown by molecular beam epitaxy. Improvements in device design and growth have resulted in a threshold current density of 3.6 kA/cm{sup 2}, which translates into improved cw lifetime of up to 42 hours. Reducing the internal loss resulted in a high cw slope efficiency of 1.08 W/A and a maximum cw output power of 145 mW. To obtain a better understanding of the LD failure mechanism, degraded LDs were analysed using surface mapping techniques such as photoluminescence and electroluminescence on a micrometric scale, which allows the identification of failure regions. These measurements revealed increased nonradiative recombination in localized regions and increased current injection non-uniformities as possible mechanisms for LD performance degradation after aging. (copyright 2009 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  16. Direct Synthesis, Characterization and Catalytic Performance of Iron-Containing SBA-15 for Phenol Degradation

    Institute of Scientific and Technical Information of China (English)

    XIE Huan-ling; XU Wen-guo

    2008-01-01

    An iron-containing SBA-15(Fe-SBA-15) has been synthesized via one-pot hydrothermal method under weak acidic conditions. A series of characterizations show nanocomposite materials of iron particles supported over mesostructured materials. The catalytic activity of these iron-containing SBA-15 materials has been tested for the heterogeneous Fenton degradation of phenolic aqueous solutions. The catalytic performance has been monitored in terms of phenol conversion, whereas the catalytic stability was evaluated by catalyst recycle. The influence of concentration of hydrogen peroxide, catalyst loading, catalyst prepared with different Fe/Si molar ratios in the gel and pH values of the solution on phenol conversion has been studied. Achieving a good catalytic performance accompanied with a noteworthy stability, Fe-SBA-15 materials prepared by this method are shown as the successful catalyst for degradation of phenolic aqueous solutions by Fenton process.

  17. Defect-induced performance degradation of 4H-SiC Schottky barrier diode particle detectors

    Science.gov (United States)

    Iwamoto, N.; Johnson, B. C.; Hoshino, N.; Ito, M.; Tsuchida, H.; Kojima, K.; Ohshima, T.

    2013-04-01

    The formation and evolution of defects in 4H-SiC Schottky barrier diode high-energy particle detectors have been investigated and correlated with the detectors' properties. Low temperature annealing at 300 °C is found to significantly recover the charge collection efficiency as degraded by 1 MeV electron irradiation. At higher temperatures, an anneal-induced degradation in the detector's performance is observed. Current-voltage, capacitance-voltage, and deep level transient spectroscopy (DLTS) measurements are used to ascertain the effect of defects on the detector performance. The latter reveals that the DLTS defect levels, EH1 and EH3, are related to the initial recovery of the charge collection efficiency.

  18. Performance degradation of superlattice MOSFETs due to scattering in the contacts

    Science.gov (United States)

    Long, Pengyu; Huang, Jun Z.; Jiang, Zhengping; Klimeck, Gerhard; Rodwell, Mark J. W.; Povolotskyi, Michael

    2016-12-01

    Ideal, completely coherent quantum transport calculations had predicted that superlattice MOSFETs (SL-MOSFET) may offer steep subthreshold swing performance below 60 mV/dec to around 39 mV/dec. However, the high carrier density in the superlattice source suggests that scattering may significantly degrade the ideal device performance. Such effects of electron scattering and decoherence in the contacts of SL-MOSFETs are examined through a multi-scale quantum transport model developed in NEMO5. This model couples the NEGF-based quantum ballistic transport in the channel to a quantum mechanical density of states dominated reservoir, which is thermalized through strong scattering with local quasi-Fermi levels determined by drift-diffusion transport. The simulations show that scattering increases the electron transmission in the nominally forbidden minigap, therefore, degrading the subthreshold swing (S.S.) and the ON/OFF DC current ratio. This degradation varies with both the scattering rate and the length of the scattering dominated regions. Different SL-MOSFET designs are explored to mitigate the effects of such deleterious scattering. Specifically, shortening the spacer region between the superlattice and the channel from 3.5 nm to 0 nm improves the simulated S.S. from 51 mV/dec. to 40 mV/dec.

  19. 1株西沙群岛野生诺尼种子内生细菌CICC 10599的分离与鉴定%Identification of endophytic bacterial strain CICC 10599 isolated from Paracel islands wild Noni (Morinda citrifolia L.) seeds

    Institute of Scientific and Technical Information of China (English)

    刘洋; 曹艳花; 姚粟; 翟磊; 张明娟; 张欣; 程池

    2014-01-01

    以分离自我国西沙群岛野生诺尼种子的内生细菌菌株CICC 10599为对象,利用基于形态学观察、生理生化特征鉴定及系统发育学分析的微生物多相分类鉴定技术,对CICC 10599分类地位进行研究,将其鉴定为分散泛菌(Pantoea dispersa),为今后开展针对该菌的生物学功能研究奠定资源基础.

  20. 糖化酶生产菌种CICC2462的5.8S rRNA分子生物学鉴定%5.8S rRNA Molecular Biotechnology Applied for Identification of Glucoamylase Producer (CICC2462)

    Institute of Scientific and Technical Information of China (English)

    姚粟; 程池

    2005-01-01

    CICC2462是我国酶制剂企业普遍采用的生产菌种,由于其不产孢子的特点,对该菌种的鉴定目前尚无定论.文中利用分子生物学技术对该菌种进行鉴定:经菌丝体DNA提取、PCR扩增和序列测定,得到ITS1-5.8S-ITS2序列(约600bp).利用BIOEDIT,TREEVIEW,CLUSTAL X等序列分析软件对该序列进行处理和分析,并将序列提交NCBI(National Center for Biotechnology Information),进行核酸序列同源性比较.经分析认为CICC2462为黑曲霉变种(Aspergillus niger var.).

  1. Degradation Behavior of Electrochemical Performance of Sealed-Type Nickel/Metal Hydride Batteries

    Institute of Scientific and Technical Information of China (English)

    李丽; 吴锋; 杨凯

    2003-01-01

    The degradation mechanism of electrochemical performance of sealed-type nickel/metal hydride batteries was investigated. The results indicate that the degradation behavior of Ni/MH battery is not only owing to the lack of electrolyte, but also the deterioration of the active materials on the positive and negative electrodes of Ni/MH batteries. Scanning electron micrographs (SEM), X-ray diffraction (XRD) and laser granularity analyses are presented. The particle pulverization and oxidation during charge/discharge are identified as the main causes for deterioration of the negative and positive electrode in nickel/metal hydride batteries, as well as the cross-section cracking of both anode and cathode.

  2. Unveiling the irreversible performance degradation of organo-inorganic halide perovskite films and solar cells during heating and cooling processes.

    Science.gov (United States)

    Mamun, Abdullah Al; Ava, Tanzila Tasnim; Byun, Hye Ryung; Jeong, Hyeon Jun; Jeong, Mun Seok; Nguyen, Loi; Gausin, Christine; Namkoong, Gon

    2017-07-26

    While organo-inorganic halide perovskite solar cells show great potential to meet future energy needs, their thermal instability raises serious questions about their commercialization viability. At present, the stability of perovskite solar cells has been studied under various environmental conditions including humidity and temperature. Nonetheless, understanding of the performance of CH3NH3PbI3-xClx perovskite solar cells is limited. This study reports the irreversible performance degradation of CH3NH3PbI3-xClx perovskite solar cells during the heating and cooling processes under AM 1.5 and unveils what triggers the irreversible performance degradation of solar cells. Particularly, the primary cause of the irreversible performance degradation of CH3NH3PbI3-xClx is quantitatively analyzed by monitoring in real time the development of deteriorated crystallinity, charge trapping/detrapping, trap depth, and the PbI2 phase, namely a critical signal of perovskite degradation while varying the temperature of the perovskite films and solar cells. Most surprisingly, it is revealed that the degradation of both perovskite films and solar cells was triggered at ∼70 °C. Remarkably, even after the device temperature cooled down to room temperature, the degraded performance of the solar cells persisted with increasing charge trapping and further development of the PbI2 phase. Identification of the irreversible performance degradation of perovskite solar cells provides guidance for future development of more stable perovskite solar cells.

  3. Open-source FCPEM-Performance & Durability Model Consideration of Membrane Properties on Cathode Degradation

    Energy Technology Data Exchange (ETDEWEB)

    Knights, Shanna [Ballard Fuel Cell Systems, Bend, OR (United States); Harvey, David [Ballard Fuel Cell Systems, Bend, OR (United States)

    2017-01-20

    The durability of PEM fuel cells is a primary requirement for large scale commercialization of these power systems in transportation and stationary market applications which target operational lifetimes of 5,000 hours and 60,000 hours by 2020, respectively. Key degradation modes contributing to fuel cell lifetime limitations have been largely associated with the platinum-based cathode catalyst layer. Furthermore, as fuel cells are driven to low cost materials and lower catalyst loadings in order to meet the cost targets for commercialization, the catalyst durability has become even more important. While over the past few years significant progress has been made in identifying the underlying causes of fuel cell degradation and key parameters that greatly influence the degradation rates, many gaps with respect to knowledge of the driving mechanisms still exist; in particular, the acceleration of the mechanisms due to different membrane compositions remains an area not well understood. The focus of this project extension was to enhance the predictive capability of the PEM Fuel Cell Performance & Durability Model called FC-APOLLO (Application Package for Open-source Long Life Operation) by including interaction effects of membrane transport properties such as water transport, changes in proton conductivity, and overall water uptake/adsorption and the state of the catalyst layer local conditions to further understand the driving forces for platinum dissolution.

  4. Effect of Twist Pitch in the Strands on the Saturation and Losses in the Nb3Sn Strands for the ITER TF CICC

    Energy Technology Data Exchange (ETDEWEB)

    Martovetsky, N N

    2007-12-06

    the transport current is higher than the cryostability limit (by Stekly), or if there are enough losses to bring the temperature above the current sharing temperature taking into account limited heat capacity of the CICC, the strand will not recover, and the CICC will go normal. Conservatively, we will consider that if we find an instantaneous unstable situation, it is not acceptable. In presence of a transport current, the situation is sensitive to the direction of the strand twist, direction of the pulsed field and direction of the transport current. Recently, ITER decided to increase the twist pitch of the TF strands from 15 mm to 30 mm to improve the stability of the strands against the longitudinal field. In this report we will quantify the effects of this proposed change and perform a trade off study. The issue is that by increasing the twist pitch of the strands we not only increase the coupling losses in the transverse magnetic field, as expected in classical multifilamentary composite superconductors, but also increase the hysteresis losses in the strands with internal tin. In classical multifilamentary superconductors, twist pitch change should not cause an increase of the hysteresis losses in the transverse field. However the high Nb3Sn content internal tin strands develop transverse links, which couple the filaments into clusters. These links turn out to contribute a significant fraction to hysteresis losses [5]. If we project the results of [5] onto the ITER proposal to increase the twist pitch from 15 to 30 mm, we should expect the hysteresis losses to increase by a factor of two, which will likely disqualify strands with 30 mm twist pitch. This very strand twisted to 15 mm twist pitch would likely pass the ITER criteria. So, increasing the twist pitch has a very negative consequence and we need to make sure that it is absolutely necessary. Recently, A. Vostner (private communication) reported preliminary results on the losses in candidate TF strands. In

  5. Kinetic evaluation and process performance of an upflow anaerobic filter reactor degrading terephthalic acid.

    Science.gov (United States)

    Davutluoglu, Orkun I; Seckin, Galip

    2014-01-01

    The anaerobic degradation of terephthalic acid (TA) as the sole organic carbon source was studied in an upflow anaerobic filter (UAF) reactor. The reactor was seeded with biomass obtained from a full-scale upflow anaerobic sludge bed (UASB) reactor and was used to treat wastewater from a petrochemical facility producing dimethyl terephthalate. The UAF reactor was operated for 252 d with a constant hydraulic retention time of 24 h, and the organic loading rate (OLR) was gradually increased from 1 to 10 g-chemical oxygen demand (COD)/L d. After a lag period of approximately 40 d, the COD removal efficiency increased exponentially and high removal rate values (≈90%) were obtained, except for at highest OLR (10 g-COD/L d). The high removal rates and the robustness of the reactor performance could be attributed to the formation of biofilm as well as granular sludge. The methane production rates (0.22 to 2.15 L/d) correlated well with the removed OLRs (0.3 to 6.8 g-COD/L d) during the various phases of treatment, indicating that the main mechanism of TA degradation occurs via methanogenic reactions. The average methane content of the produced biogas was 70.3%. The modified Stover-Kincannon model was found to be applicable for the anaerobic degradation of TA in UAFs (Umax = 64.5, KB = 69.1 g-COD/L d and Ymax = 0.27 L-CH4/g-CODremoved). These results suggest that UAF reactors are among the most effective reactor configurations for the anaerobic degradation of TA.

  6. Performance degradation of high-power lithium-ion cells-Electrochemistry of harvested electrodes

    Science.gov (United States)

    Abraham, D. P.; Knuth, J. L.; Dees, D. W.; Bloom, I.; Christophersen, J. P.

    The performance of 18650-type high-power lithium-ion cells is being evaluated as part of the U.S. Department of Energy's (DOEs) Advanced Technology Development (ATD) program. In this article, we present accelerated aging data acquired on 18650-cells containing LiNi 0.8Co 0.15Al 0.05O 2- or LiNi 0.8Co 0.1Al 0.1O 2-based positive electrodes, MAG-10 graphite-based negative electrodes, and 1.2-M LiPF 6 in EC:EMC (3:7 by wt.) electrolyte. Capacity and impedance data acquired on electrodes harvested from these cells highlight the contributions of the positive and negative electrodes to the degradation of cell performance. We also describe test methodologies used to examine the electrochemical characteristics of the harvested electrodes. Identifying and optimizing cell components responsible for performance degradation should enable the development of new lithium-ion cell chemistries that will meet the 15-year cell calendar life goal established by DOEs FreedomCar initiative.

  7. Performance degradation of high-power lithium-ion cells - Electrochemistry of harvested electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Abraham, D.P.; Knuth, J.L.; Dees, D.W.; Bloom, I. [Argonne National Laboratory, Argonne, IL 60439 (United States); Christophersen, J.P. [Idaho National Laboratory, Idaho Falls, ID 83415 (United States)

    2007-07-10

    The performance of 18650-type high-power lithium-ion cells is being evaluated as part of the U.S. Department of Energy's (DOEs) Advanced Technology Development (ATD) program. In this article, we present accelerated aging data acquired on 18650-cells containing LiNi{sub 0.8}Co{sub 0.15}Al{sub 0.05}O{sub 2}- or LiNi{sub 0.8}Co{sub 0.1}Al{sub 0.1}O{sub 2}-based positive electrodes, MAG-10 graphite-based negative electrodes, and 1.2-M LiPF{sub 6} in EC:EMC (3:7 by wt.) electrolyte. Capacity and impedance data acquired on electrodes harvested from these cells highlight the contributions of the positive and negative electrodes to the degradation of cell performance. We also describe test methodologies used to examine the electrochemical characteristics of the harvested electrodes. Identifying and optimizing cell components responsible for performance degradation should enable the development of new lithium-ion cell chemistries that will meet the 15-year cell calendar life goal established by DOEs FreedomCar initiative. (author)

  8. Investigation of Material Performance Degradation for High-Strength Aluminum Alloy Using Acoustic Emission Method

    Directory of Open Access Journals (Sweden)

    Yibo Ai

    2015-02-01

    Full Text Available Structural materials damages are always in the form of micro-defects or cracks. Traditional or conventional methods such as micro and macro examination, tensile, bend, impact and hardness tests can be used to detect the micro damage or defects. However, these tests are destructive in nature and not in real-time, thus a non-destructive and real-time monitoring and characterization of the material damage is needed. This study is focused on the application of a non-destructive and real-time acoustic emission (AE method to study material performance degradation of a high-strength aluminum alloy of high-speed train gearbox shell. By applying data relative analysis and interpretation of AE signals, the characteristic parameters of materials performance were achieved and the failure criteria of the characteristic parameters for the material tensile damage process were established. The results show that the AE method and signal analysis can be used to accomplish the non-destructive and real-time detection of the material performance degradation process of the high-strength aluminum alloy. This technique can be extended to other engineering materials.

  9. Performance degradation of a typical twin engine commuter type aircraft in measured natural icing conditions

    Science.gov (United States)

    Ranaudo, R. J.; Mikkelsen, K. L.; Mcknight, R. C.; Perkins, P. J., Jr.

    1984-01-01

    The performance of an aircraft in various measured icing conditions was investigated. Icing parameters such as liquid water content, temperature, cloud droplet sizes and distributions were measured continuously while in icinig. Flight data wre reduced to provide plots of the aircraft drag polars and lift curves (CL vs. alpha) for the measured 'iced' condition as referenced to the uniced aircraft. These data were also reduced to provide plots of thrust horsepower required vs. single engine power available to show how icing affects engine out capability. It is found that performance degradation is primarily influenced by the amount and shape of the accumulated ice. Glaze icing caused the greatest aerodynamic performance penalties in terms of increased drag and reduction in lift while aerodynamic penalties due to rime icing were significantly lower. Previously announced in STAR as N84-13173

  10. The application of a general mathematical morphological particle as a novel indicator for the performance degradation assessment of a bearing

    Science.gov (United States)

    Li, Hongru; Wang, Yukui; Wang, Bing; Sun, Jian; Li, Yaolong

    2017-01-01

    Bearing performance degradation assessment is a key step of condition-based maintenance. In this paper, a novel indicator of bearing performance degradation assessment is presented based on the mathematical morphology (MM) theory for higher efficiency. Because the traditional mathematical morphology particle (MMP) is unable to exactly describe the bearing's performance degradation, we extended its definition to the general space to address the limited ability of the former definition. On the basis of the innovative definition, we used the morphology erosion operation instead of the morphology open operation to calculate the general mathematical morphology particle (GMMP) of the bearing's whole life data. The analysis of the simulation and practical application demonstrated that the proposed index is feasible and effective to indicate the performance degradation of the bearing.

  11. Photocatalytic performance of crystalline titania polymorphs in the degradation of hazardous pharmaceuticals and dyes

    Science.gov (United States)

    Thuong Huyen Tran, Thi; Kosslick, Hendrik; Schulz, Axel; Liem Nguyen, Quang

    2017-03-01

    In the present work, nano-sized TiO2 polymorphs (anatase, brookite, and rutile) were synthesized via hydrothermal treatment of an amorphous titania. Three polymorphs were characterized by XRD, Raman spectroscopy, SEM, UV–Vis DRS, and N2-sorption measurements. The photocatalytic degradation experiments were performed with low catalyst concentration, high organic loading under a 60 W UV–Vis solarium lamp irradiation. The photocatalytic degradation was monitored by UV–Vis spectroscopy and TOC measurements. Cinnamic acid, ibuprofen, phenol, diatrizoic acid and the dyes rhodamine B and rose bengal were used as model pollutants. The formation of intermediates was studied by ESI-TOF-MS measurements. The presence of active species was checked by quenching the activity by addition of scavengers. The photocatalytic activity decreased in the order: anatase  ⩾  brookite  >  rutile, with growing recalcitrance of organic compounds. The differences in the activity are more pronounced in the degree of mineralization. The valence band holes and superoxide radicals were the major active species in the photocatalytic treatment with anatase and brookite, whereas hydroxyl radicals and superoxide radicals contributed mainly in the treatment with rutile explaining the lower activity of rutile. The complementary use of UV–Vis spectroscopy and TOC measurements was required to obtain a comprehensive realistic assessment on the photocatalytic performance of catalyst. Invited talk at 8th International Workshop on Advanced Materials Science and Nanotechnology (IWAMSN2016), 8–12 November 2016, Ha Long City, Vietnam.

  12. [Electricity generation and contaminants degradation performances of a microbial fuel cell fed with Dioscorea zingiberensis wastewater].

    Science.gov (United States)

    Li, Hui; Zhu, Xiu-Ping; Xu, Nan; Ni, Jin-Ren

    2011-01-01

    The electricity generation performance of a microbial fuel cell (MFC) utilizing Dioscorea zingiberensis wastewater was studied with an H-shape reactor. Indexes including pH, conductivity, oxidation peak potential and chemical oxygen demand (COD) of the anolyte were monitored to investigate the contaminants degradation performance of the MFC during the electricity generation process, besides, contaminant ingredients in anodic influent and effluent were analyzed by GC-MS and IR spectra as well. The maximum power density of the MFC could achieve 118.1 mW/m2 and the internal resistance was about 480 omega. Connected with a 1 000 omega external resistance, the output potential was about 0.4 V. Fed with 5 mL Dioscorea zingiberensis wastewater, the electricity generation lasted about 133 h and the coulombic efficiency was about 3.93%. At the end of electricity generation cycle, COD decreased by 90.1% while NH4(+) -N decreased by 66.8%. Furfural compounds, phenols and some other complicated organics could be decomposed and utilized in the electricity generation process, and the residual contaminants in effluent included some long-chain fatty acids, esters, ethers, and esters with benzene ring, cycloalkanes, cycloolefins, etc. The results indicate that MFC, which can degrade and utilize the organic contaminants in Dioscorea zingiberensis wastewater simultaneously, provides a new approach for resource recovery treatment of Dioscorea zingiberensis wastewater.

  13. Preparation and Electrocatalytic Performance of Bi-Modified Quartz Column Particle Electrode for Phenol Degradation

    Directory of Open Access Journals (Sweden)

    Jiguo Huang

    2015-01-01

    Full Text Available Bismuth oxide (Bi2O3 and its composites have good electrocatalytic performance. Quartz column is a good kind of catalyst carrier with the characteristics of high mechanical strength and good stability. A novel Bi-modified quartz column particle electrode (BQP was prepared by the dipping-calcination method. The characterization results revealed that Bi2O3 was successfully loaded on quartz column. The optimum preparation condition was calcining at 550°C for 4 h. Electrocatalytic performance was evaluated by the degradation of phenol and the results indicated that the triclinic phase of Bi2O3 showed the best electrocatalytic property. Besides, when the dosage concentration of the particle electrode was 125 g/L and the electrolytic voltage was 12 V, the degradation rate of phenol (200 mg/L reached the highest (94.25%, compared with 70.00% of that in two-dimensional (2D system. In addition, the removal rate of chemical oxygen demand (COD was 75.50%, compared with 53.30% of that in 2D system. The reusability and regeneration of BQP were investigated and the results were good. Mechanism of enhanced electrochemical oxidation by BQP was evaluated by the capture of hydroxyl radical.

  14. Effect of particle size of Martian dust on the degradation of photovoltaic cell performance

    Science.gov (United States)

    Gaier, James R.; Perez-Davis, Marla E.

    1991-01-01

    Glass coverglass and SiO2 covered and uncovered silicon photovoltaic (PV) cells were subjected to conditions simulating a Mars dust storm, using the Martian Surface Wind Tunnel, to assess the effect of particle size on the performance of PV cells in the Martian environment. The dust used was an artificial mineral of the approximate elemental composition of Martian soil, which was sorted into four different size ranges. Samples were tested both initially clean and initially dusted. The samples were exposed to clear and dust laden winds, wind velocities varying from 23 to 116 m/s, and attack angles from 0 to 90 deg. It was found that transmittance through the coverglass approximates the power produced by a dusty PV cell. Occultation by the dust was found to dominate the performance degradation for wind velocities below 50 m/s, whereas abrasion dominates the degradation at wind velocities above 85 m/s. Occultation is most severe at 0 deg (parallel to the wind), is less pronounced from 22.5 to 67.5 deg, and is somewhat larger at 90 deg (perpendicular to the wind). Abrasion is negligible at 0 deg, and increases to a maximum at 90 deg. Occultation is more of a problem with small particles, whereas large particles (unless they are agglomerates) cause more abrasion.

  15. Performance evaluation of active sub-Terahertz systems in Degraded Visual Environments (DVE)

    Science.gov (United States)

    Ceolato, Romain; Tanguy, Bernard; Martin, Christian; Huet, Thierry; Chervet, Patrick; Durand, Gerard; Riviere, Nicolas; Hespel, Laurent; Diakonova, Nina; But, Dmitry; Knap, Wojciech; Meilhan, Jerome; Delplanque, Baptiste; Oden, Jonathan; Simoens, François

    2016-05-01

    This paper addresses the problem of critical operations in Degraded Visual Environment (DVE). DVE usually refer when the perception of a pilot is degraded by environmental factors, including the presence of obscurants from bad weather (e.g. fog, rain, snow) or accidental events (e.g. brownout, whiteout, smoke). Critical operations in DVE are a growing field of research as it is a cause of numerous fatal accidents for operational forces. Due to the lack of efficient sources and sensors in the Terahertz (THz) region, this domain has remained an unexplored part of the electromagnetic spectrum. Recently, the potential use of sub-Terahertz waves has been proposed to see through dense clouds of obscurants (e.g. sand, smoke) in DVE conditions. In order to conduct a performance evaluation of sub-Terahertz systems, several sub-terahertz systems (e.g. bolometer-array cameras, liquid helium cooled bolometers) were operated in artificial controlled DVE conditions at ONERA facilities. The purpose of this paper is to report field experiments results in controlled DVE conditions: attenuation measurements from 400 GHz to 700 GHz with a performance evaluation of different sub-Terahertz systems are presented.

  16. Impact of scaling on the performance and reliability degradation of metal-contacts in NEMS devices

    KAUST Repository

    Dadgour, Hamed F.

    2011-04-01

    Nano-electro-mechanical switches (NEMS) offer new possibilities for the design of ultra energy-efficient systems; however, thus far, all the fabricated NEMS devices require high supply voltages that limit their applicability for logic designs. Therefore, research is being conducted to lower the operating voltages by scaling down the physical dimensions of these devices. However, the impact of device scaling on the electrical and mechanical properties of metal contacts in NEMS devices has not been thoroughly investigated in the literature. Such a study is essential because metal contacts play a critical role in determining the overall performance and reliability of NEMS. Therefore, the comprehensive analytical study presented in this paper highlights the performance and reliability degradations of such metal contacts caused by scaling. The proposed modeling environment accurately takes into account the impact of roughness of contact surfaces, elastic/plastic deformation of contacting asperities, and various inter-molecular forces between mating surfaces (such as Van der Waals and capillary forces). The modeling results are validated and calibrated using available measurement data. This scaling analysis indicates that the key contact properties of gold contacts (resistance, stiction and wear-out) deteriorate "exponentially" with scaling. Simulation results demonstrate that reliable (stiction-free) operation of very small contact areas (≈ 6nm x 6nm) will be a daunting task due to the existence of strong surface forces. Hence, contact degradation is identified as a major problem to the scaling of NEMS transistors. © 2011 IEEE.

  17. A 600-m Jacketing Line of Cable-In-Conduit Con-ductor (CICC) and the First 600-m Dummy Cable

    Institute of Scientific and Technical Information of China (English)

    陈思跃; 吴杰锋; 陈行倩; 张平; 何畏; 王海京; 徐学富; 易子安; 高大明

    2002-01-01

    A cable-in-conduit conductor( CICC )production line was designed and constructed in Institute of Plasma Physics of Chinese Academy of Sciences (IPPCAS) by the end of 2000. It can produce a length of 600 meters and three kinds of sections of 20.8±0.1×20.8±0.1,20.4±0.1×20.4±0.1 and 18.6 ± 0.1 × 18.6 ±0.1mm2. If the rollers of the shaping machine are changed, it can also produce other sizes of CICCs. So-called inserting-cable technology is adopted in this production line, where the procedures consist of tube pre-treatment (cleaning, pressure and leakage testing, end cutting), conduits butt-welding, six kinds of quality checking (endoscopy, dye penetration, pressure control, leakage testing, ultrasonic inspection and X-ray testing), cable inserting, shaping (compacting & squaring), pre-bending & winding and final checking. Now all the instruments and facilities required for these technologies have been installed and got ready. Some key technologies have been explored and good results obtained. Some short samples were produced and a 600 meters long sample was made out in August, 2001.

  18. Steady state performance, photo-induced performance degradation and their relation to transient hysteresis in perovskite solar cells

    Science.gov (United States)

    Jena, Ajay Kumar; Kulkarni, Ashish; Ikegami, Masashi; Miyasaka, Tsutomu

    2016-03-01

    Hysteresis in current-voltage curves of perovskite solar cells is a serious concern as it creates confusions about actual cell performance and raises questions on its reliability. Although a lot of effort has been made to understand the origin of hysteresis, knowing whether hysteresis affects the cell performance while they are in practical use (operated constantly at maximum power point) is not yet examined. In the present study, we investigate steady state performance and performance stability of perovskite solar cells (planar architecture with varying perovskite film thickness and TiO2 mesoscopic structure with different TiO2 compact layer thickness exhibiting hysteresis of different magnitudes) operating across an external load in relation to hysteresis. The planar cells with larger hysteresis exhibit a steady state current that closely matches the value determined on forward voltage scan. Cyclic photocurrent-dark current measurements on cells with hysteresis of different magnitudes reveal that photo-induced electrical instability (not material degradation), which might be originated from ion migration or photo-induced traps formation, is not related to hysteresis. Performance of the cells is recovered partially or fully, depending on the device structure, on storage in dark. TiO2 meso-structure cells tend to show complete recovery while the planar cells recover partially.

  19. Performance of Fluidized bed Fenton process in Degrading Acid Blue 113

    Science.gov (United States)

    Bello, M. M.; Raman, A. A.

    2017-06-01

    The performance of a fluidized bed Fenton process in degrading Acid Blue 113 (AB 113) was investigated. Fluidized bed Fenton process is a modification of conventional Fenton oxidation, aimed at reducing sludge generation and improving process performance. Response surface methodology was used to study the effects of operational parameter on the color removal from the dye. Dimensionless factors, Dye/Fe2+, H2O2/Fe2+ and pH were used as the independent variables in Box-Behnken Design (BDD). Reduced quadratic model was developed to predict the color removal. The process could remove up to 99 % of the initial color. The most significant factor for color removal was found to be Dye/Fe2+, followed by H2O2/Fe2+. Unlike conventional Fenton, the initial pH of the solution does not have a significant effect on the color removal.

  20. Performance Degradation Tests of Phosphoric Acid Doped Polybenzimidazole Membrane Based High Temperature Polymer Electrolyte Membrane Fuel Cells

    DEFF Research Database (Denmark)

    Zhou, Fan; Araya, Samuel Simon; Grigoras, Ionela

    2015-01-01

    Degradation tests of two phosphoric acid (PA) doped PBI membrane based HT-PEM fuel cells were reported in this paper to investigate the effects of start/stop and the presence of methanol in the fuel to the performance degradation of the HT-PEM fuel cell. Continuous tests with pure dry H2...... and methanol containing H2 which was composed of H2, steam and methanol as the fuel were performed on both single cells. After the continuous tests, 12-h-startup/12-h-shutdown dynamic tests were performed on the first single cell with H2 as the fuel and on the second single cell with methanol containing H2...... as the fuel. Along with the degradation tests, electrochemical techniques such as polarization curves and electrochemical impedance spectroscopy (EIS) were employed to study the degradation mechanisms of the fuel cells. The results of the tests showed that both single cells experienced an increase...

  1. Au-decorated sodium titanate nanotubes as high-performance selective photocatalysts for pollutant degradation

    Science.gov (United States)

    El Rouby, Waleed M. A.; Comesaña-Hermo, Miguel; Testa-Anta, Martín; Carbó-Argibay, Enrique; Salgueiriño, Verónica; Pérez-Lorenzo, Moisés; Correa-Duarte, Miguel A.

    2017-04-01

    The bioaccumulation of polycyclic aromatic compounds originating from textile processing industries is nowadays a major environmental problem worldwide. In order to tackle this situation, several inorganic semiconductors have been tested as photocatalysts for the degradation of these harmful pollutants in the search of sustainable and cost-effective solutions. Nevertheless, these semiconductor materials often involve important limitations, such as poor efficiency and selectivity, which, in the end, substantially restrict their implementation at the industrial scale. As an alternative, we herein report the fabrication and application of Au-decorated titanate nanotubes (TNTs) as high-performance architectures for the selective degradation of organic contaminants. This synthetic strategy is intended to establish a synergetic integration of the physicochemical and photocatalytic features of these hybrid nanostructures, by combining the remarkable adsorption capabilities of TNTs with the enhanced light-harvesting efficiency provided by the incorporation of a noble metal component. The obtained results evidence the great potential that rationally designed plasmonic composites may have for the development of selective environmental remediation technologies and in particular on the current challenges faced by the wastewater treatment sector.

  2. Enhanced Photocatalytic Performance of NiO-Decorated ZnO Nanowhiskers for Methylene Blue Degradation

    OpenAIRE

    I. Abdul Rahman; Ayob, M. T. M.; Radiman, S.

    2014-01-01

    ZnO nanowhiskers were used for photodecomposition of methylene blue in aqueous solution under UV irradiation. The rate of methylene blue degradation increased linearly with time of UV irradiation. 54% of degradation rate was observed when the ZnO nanowhiskers were used as photocatalysts for methylene blue degradation for 80 min under UV irradiation. The decoration of p-type NiO nanoparticles on n-type ZnO nanowhiskers significantly enhanced photocatalytic activity and reached 72% degradation ...

  3. A novel method for machine performance degradation assessment based on fixed cycle features test

    Science.gov (United States)

    Liao, Linxia; Lee, Jay

    2009-10-01

    This paper presents a novel machine performance degradation scheme based on fixed cycle features test (FCFT). Instead of monitoring the machine under constant working load, FCFT introduces a new testing method which obtains data during the transient periods of different working loads. A novel performance assessment method based on those transient data without failure history is proposed. Wavelet packet analysis (WPA) is applied to extract features which capture the dynamic characteristics from the non-stationary vibration data. Principal component analysis (PCA) is used to reduce the dimension of the feature space. Gaussian mixture model (GMM) is utilized to approximate the density distribution of the lower-dimensional feature space which consists of the major principal components. The performance index of the machine is calculated based on the overlap between the distribution of the baseline feature space and that of the testing feature space. Bayesian information criterion (BIC) is used to determine the number of mixtures for the GMM and a density boosting method is applied to achieve better accuracy of the distribution estimation. A case study for a chiller system performance assessment is used as an example to validate the effectiveness of the proposed method.

  4. Improvement of Bioremediation Performance for the Degradation of Petroleum Hydrocarbons in Contaminated Sediments

    Directory of Open Access Journals (Sweden)

    Laura Rocchetti

    2011-01-01

    Full Text Available Microcosm bioremediation strategies were applied to sediments contaminated with hydrocarbons. Experiments were performed in aerobic conditions in a single-step treatment and in a two-step anaerobic-aerobic treatment. In aerobic conditions, either inorganic nutrients or composts were added to the microcosms, while, in the first anaerobic phase of the two-step experiment, acetate and/or allochthonous sulfate-reducing bacteria were used. After the treatment under anaerobic conditions, samples were exposed to aerobic conditions in the presence of compost. In the aerobic treatments, 81% hydrocarbon biodegradation was observed after 43 days in the presence of inorganic nutrients. In aerobic conditions in the presence of mature compost, hydrocarbon biodegradation was 51% after 43 days of treatment, whereas it was 47% after 21 days with fresh compost. The two-step experiment allowed us to obtain a hydrocarbon degradation of 91%, after a first anaerobic step with an inoculum of sulfate-reducing prokaryotes.

  5. Impact of Charge Degradation on the Life Cycle Climate Performance of a Residential Air-Conditioning System

    Energy Technology Data Exchange (ETDEWEB)

    Beshr, Mohamed [University of Maryland, College Park; Aute, Vikrant [University of Maryland, College Park; Abdelaziz, Omar [ORNL; Fricke, Brian A [ORNL; Radermacher, Reinhard [University of Maryland, College Park

    2014-01-01

    Vapor compression systems continuously leak a small fraction of their refrigerant charge to the environment, whether during operation or servicing. As a result of the slow leak rate occurring during operation, the refrigerant charge decreases until the system is serviced and recharged. This charge degradation, after a certain limit, begins to have a detrimental effect on system capacity, energy consumption, and coefficient of performance (COP). This paper presents a literature review and a summary of previous experimental work on the effect of undercharging or charge degradation of different vapor compression systems, especially those without a receiver. These systems include residential air conditioning and heat pump systems utilizing different components and refrigerants, and water chiller systems. Most of these studies show similar trends for the effect of charge degradation on system performance. However, it is found that although much experimental work exists on the effect of charge degradation on system performance, no correlation or comparison between charge degradation and system performance yet exists. Thus, based on the literature review, three different correlations that characterize the effect of charge on system capacity and energy consumption are developed for different systems as follows: one for air-conditioning systems, one for vapor compression water-to-water chiller systems, and one for heat pumps. These correlations can be implemented in vapor compression cycle simulation tools to obtain a better prediction of the system performance throughout its lifetime. In this paper, these correlations are implemented in an open source tool for life cycle climate performance (LCCP) based design of vapor compression systems. The LCCP of a residential air-source heat pump is evaluated using the tool and the effect of charge degradation on the results is studied. The heat pump is simulated using a validated component-based vapor compression system model and

  6. Soil burial method for plastic degradation performed by Pseudomonas PL-01, Bacillus PL-01, and indigenous bacteria

    Science.gov (United States)

    Shovitri, Maya; Nafi'ah, Risyatun; Antika, Titi Rindi; Alami, Nur Hidayatul; Kuswytasari, N. D.; Zulaikha, Enny

    2017-06-01

    Lately, plastic bag is becoming the most important pollutant for environment since it is difficult to be naturally degraded due to it consists of long hydrocarbon polymer chains. Our previous study indicated that our pure isolate Pseudomonas PL-01 and Bacillus PL-01 could degrade about 10% plastic bag. This present study was aimed to find out whether Pseudomonas PL01 and Bacillus PL01 put a positive effect to indigenous bacteria from marginal area in doing plastic degradation with a soil burial method. Beach sand was used as a representative marginal area, and mangrove sediment was used as a comparison. Plastics were submerged into unsterile beach sand with 10% of Pseudomonas PL-01 or Bacillus PL-01 containing liquid minimal salt medium (MSM) separately, while other plastics were submerged into unsterile mangrove sediments. After 4, 8, 12 and 16 weeks, their biofilm formation on their plastic surfaces and plastic degradation were measured. Results indicated that those 2 isolates put positive influent on biofilm formation and plastic degradation for indigenous beach sand bacteria. Bacillus PL-01 put higher influent than Pseudomonas PL-01. Plastic transparent was preferable degraded than black and white plastic bag `kresek'. But anyhow, indigenous mangrove soil bacteria showed the best performance in biofilm formation and plastic degradation, even without Pseudomonas PL-01 or Bacillus PL-01 addition. Fourier Transform Infrared (FTIR) analysis complemented the results; there were attenuated peaks with decreasing peaks transmittances. This FTIR peaks indicated chemical functional group changes happened among the plastic compounds after 16 weeks incubation time.

  7. Mechanisms of temperature performance degradation in terahertz quantum-cascade lasers

    Science.gov (United States)

    Indjin, D.; Harrison, P.; Kelsall, R. W.; Ikonić, Z.

    2003-03-01

    Electron transport in a terahertz GaAs/AlGaAs quantum-cascade laser is calculated using a fully self-consistent intersubband scattering model. Subband populations, carrier transition rates, and current densities are calculated and all relevant intra- and interperiod electron-electron and electron-LO-phonon scattering mechanisms are included. Employing an energy balance equation that includes the influence of both electron-LO-phonon and electron-electron scattering, the method also enables evaluation of the average electron temperature of the nonequilibrium carrier distributions in the device. In particular, the influence of the lattice temperature on the degradation of population inversion and device performance is investigated. The threshold currents, electric-field-current-density characteristics, and temperature-dependent performance are in good qualitative and quantitative agreement with measurement in a recent experimental realization [Köhler et al., Nature (London) 417, 156 (2002)]. Calculations indicate that an important mechanism limiting its operating temperature is the increase of leakage current from the injector to low levels in the active region, and this feature should be improved in future designs.

  8. Sonocatalytic performance of Er-doped ZnO for degradation of a textile dye.

    Science.gov (United States)

    Khataee, Alireza; Saadi, Shabnam; Safarpour, Mahdie; Joo, Sang Woo

    2015-11-01

    Pure and erbium (Er)-doped ZnO samples were synthesized through a sonochemical method and characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV-Vis spectroscopy, and X-ray photoelectron spectroscopy (XPS) analysis. The synthesized samples were used as a catalyst for the sonocatalytic decolorization of Reactive Orange 29 (RO29) as a model organic pollutant. The decolorization efficiency was 63%, 68%, 88%, and 75% for undoped, 2%, 4%, and 6% Er-doped ZnO, respectively. The effect of different experimental parameters including catalyst content, dye concentration and ultrasound power was investigated on the sonocatalytic decolorization of RO29. Among several radical scavengers (i.e. chloride, carbonate and sulfate anions and t-butanol), the chloride anion showed the most inhibitive effect on the sonocatalysis performance. Improvement of the sonocatalytic process by K2S2O8 and H2O2 enhancers was also studied. The reusability of the synthesized sonocatalyst was evaluated in several consecutive runs, and a decline of only 4% was observed in the process performance after five runs. The intermediates produced during the degradation of RO29 were identified by GC-MS analysis.

  9. Evaluation of the performance degradation at PAFC effect of operating conditions on acid loss

    Energy Technology Data Exchange (ETDEWEB)

    Miyoshi, Hideaki; Uchida, Hiroyuki; Watanabe, Masahiro [Yamanashi Univ., Kofu (Japan)] [and others

    1996-12-31

    As a complimentary research project to the demonstration project of 5MW and 1 MW PAFC plants, the mechanism and rate of deterioration of the cells and stacks have been studied from 1995 FY conducted by NEDO, with the objective of establishing an estimation method for the service life-time of the cell stacks. As part of this project, this work has been performed to clarify basic phenomena of the performance degradation at PAFCs jointly by Yamanashi University, PAFC-TRA and PAFC manufacturers. The acid loss into exhaust gases is one of life limiting factors in PAFCs. To design the cells of long-life, it is important to estimate the phosphoric acid loss and to contrive ideas eliminating it. With the objective of obtaining basic data for simulating the acid loss in the large size cells, the effect of the operating conditions on the acid loss into exhaust gases has been studied experimentally by using a single cell with an active electrode area of 100 cm{sup 2}.

  10. Effects of electrode geometry on the performance of dielectric barrier/packed-bed discharge plasmas in benzene degradation

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Nan [Institute of Electrostatics and Special Power, Dalian University of Technology, Dalian 116024 (China); Lu, Na; Shang, Kefeng [Institute of Electrostatics and Special Power, Dalian University of Technology, Dalian 116024 (China); Key Laboratory of Industrial Ecology and Environmental Engineering, Ministry of Education of the People' s Republic of China, Dalian 116024 (China); Li, Jie, E-mail: lijie@dlut.edu.cn [Institute of Electrostatics and Special Power, Dalian University of Technology, Dalian 116024 (China); Key Laboratory of Industrial Ecology and Environmental Engineering, Ministry of Education of the People' s Republic of China, Dalian 116024 (China); Wu, Yan [Institute of Electrostatics and Special Power, Dalian University of Technology, Dalian 116024 (China); Key Laboratory of Industrial Ecology and Environmental Engineering, Ministry of Education of the People' s Republic of China, Dalian 116024 (China)

    2013-11-15

    Highlights: • Benzene was successfully degraded by dielectric barrier/packed-bed discharge plasmas. • Different electrode geometry has distinct effect on plasmas oxidation performance. • Benzene degradation and energy performance were enhanced when using the coil electrode. • The reaction products were well determined by online FTIR analysis. -- Abstract: In this study, the effects of electrode geometry on benzene degradation in a dielectric barrier/packed-bed discharge plasma reactor with different electrodes were systematically investigated. Three electrodes were employed in the experiments, these were coil, bolt, and rod geometries. The reactor using the coil electrode showed better performance in reducing the dielectric loss in the barrier compared to that using the bolt or rod electrodes. In the case of the coil electrode, both the benzene degradation efficiency and energy yield were higher than those for the other electrodes, which can be attributed to the increased role of surface mediated reactions. Irrespective of the electrode geometry, the packed-bed discharge plasma was superior to the dielectric barrier discharge plasma in benzene degradation at any specific applied voltage. The main gaseous products of benzene degradation were CO, CO{sub 2}, H{sub 2}O, and formic acid. Discharge products such as O{sub 3}, N{sub 2}O, N{sub 2}O{sub 5}, and HNO{sub 3} were also detected in the outlet gas. Moreover, the presence of benzene inhibited the formation of ozone because of the competing reaction of oxygen atoms with benzene. This study is expected to offer an optimized approach combining dielectric barrier discharge and packed-bed discharge to improve the degradation of gaseous pollutants.

  11. Analysis and interpretation of the performance degradation of glass Resistive Plate Chambers operated in streamer mode

    CERN Document Server

    Calcaterra, A; Patteri, P; Piccolo, M; Della Mea, G; Restello, S; Ferri, F; Musella, P; Redaelli, N; Tabarelli de Fatis, T; Tinti, G; Mannocchi, G; Trinchero, G

    2007-01-01

    The long-term stability of Resistive Plate Chambers (RPCs) with glass electrodes was studied for one year with a dedicated test station hosting about 10 m2 of detectors. RPCs were operated in streamer mode with a ternary gas mixture containing argon (27%), isobutane (9%) and tetrafluoroethane (64%). Environmental conditions were kept under control and, in particular, the water pollution in the gas, deemed responsible for the degradation of glass RPC performance, was monitored never to exceed 30 ppm in the exhaust line. Evidence for a substantial aging of the detectors was observed, resulting in a loss of efficiency correlated to an increased rate of spurious streamers. This can be ascribed to the chemical attack of the glass surface by hydrofluoric acid formed in the streamer process, as confirmed by detailed morphological and chemical analyses of the electrode surface. Our results strengthen the indication that the instability of glass RPCs in the long term is related to the use of fluorocarbons as quenching...

  12. Modeling and Simulation of HVAC Faulty Operations and Performance Degradation due to Maintenance Issues

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Liping; Hong, Tianzhen

    2013-01-01

    Almost half of the total energy used in the U.S. buildings is consumed by heating, ventilation and air conditionings (HVAC) according to EIA statistics. Among various driving factors to energy performance of building, operations and maintenance play a significant role. Many researches have been done to look at design efficiencies and operational controls for improving energy performance of buildings, but very few study the impacts of HVAC systems maintenance. Different practices of HVAC system maintenance can result in substantial differences in building energy use. If a piece of HVAC equipment is not well maintained, its performance will degrade. If sensors used for control purpose are not calibrated, not only building energy usage could be dramatically increased, but also mechanical systems may not be able to satisfy indoor thermal comfort. Properly maintained HVAC systems can operate efficiently, improve occupant comfort, and prolong equipment service life. In the paper, maintenance practices for HVAC systems are presented based on literature reviews and discussions with HVAC engineers, building operators, facility managers, and commissioning agents. We categorize the maintenance practices into three levels depending on the maintenance effort and coverage: 1) proactive, performance-monitored maintenance; 2) preventive, scheduled maintenance; and 3) reactive, unplanned or no maintenance. A sampled list of maintenance issues, including cooling tower fouling, boiler/chiller fouling, refrigerant over or under charge, temperature sensor offset, outdoor air damper leakage, outdoor air screen blockage, outdoor air damper stuck at fully open position, and dirty filters are investigated in this study using field survey data and detailed simulation models. The energy impacts of both individual maintenance issue and combined scenarios for an office building with central VAV systems and central plant were evaluated by EnergyPlus simulations using three approaches: 1) direct

  13. Preparation and photocatalytic degradation performance of Ag3PO4 with a two-step approach

    Science.gov (United States)

    Li, Jiwen; Ji, Xiaojing; Li, Xian; Hu, Xianghua; Sun, Yanfang; Ma, Jingjun; Qiao, Gaowei

    2016-05-01

    Ag3PO4 photocatalysts were prepared via two and one-step through a facile ion-exchange route. The photocatalysts were then characterized through powder X-ray diffraction, scanning electron microscopy and UV-vis diffuse reflectance spectroscopy. The photocatalytic activity of the samples was evaluated on the basis of the photocatalytic degradation of methyl orange (MO) and methylene blue (MB) under solar irradiation. The MO degradation rate of the Photocatalyst synthesized by the two-step ion-exchange route was 89.18% in 60 min. This value was four times that of the Photocatalyst synthesized by the one-step approach.The MB degradation rate was 97% in 40 min. After six cycling runs were completed, the MO degradation rate was 73%

  14. Electrocatalytic performance of PbO films in the degradation of ...

    African Journals Online (AJOL)

    2012-11-16

    Nov 16, 2012 ... Keywords: Electrochemical degradation; hydroxyl radicals; organic pollutants; lead dioxide; ... the use of photocatalytic oxidation, using TiO2 as catalyst ..... SAEZ C (2005) Electrochemical synthesis of peroxodiphosphate.

  15. Environmental biodegradability of diesel oil: composition and performances of degradative micro-floras; Biodegradabilite du gazole dans l'environnement: composition et performances des microflores degradatrices

    Energy Technology Data Exchange (ETDEWEB)

    Penet, S.

    2004-09-01

    The large use of petroleum products makes them a significant source of pollutants in ground water and soils. Biodegradation studies are therefore relevant either to evaluate possibilities of natural attenuation or define bio-remediation strategies. In this study, the possible relationship between the environmental microflora structures and their capabilities for diesel oil biodegradation was investigated. The degradation capacities, i.e. kinetics and extent of biodegradation, were evaluated in closed batch systems by hydrocarbon consumption and CO{sub 2} production, both determined by gas chromatography. The intrinsic biodegradability of different types of diesel oils and the degradation capacities of microflora from ten polluted and ten unpolluted soils samples were determined. The data showed that: i) diesel oil was biodegradable, ii) n-alkanes were totally degraded by each microflora, the final amount of residual hydrocarbons being variable, iii) polluted-soil samples exhibited a slightly higher degradation rate (80%) that polluted-soil samples (67%) or activated sludge (64%). In order to define the contribution of various bacterial groups to diesel oil degradation, enrichment cultures were performed on hydrocarbons representative from the structural classes of diesel oil: hexadecane for n-alkanes, pristane for iso-alkanes, decalin for cyclo-alkanes, phenanthrene for aromatics. By using a 16S rDNA-sequencing method, the bacterial structures of the adapted microflora were determined and compared to that of the native microflora. A marked effect of the selection pressure was observed on the diversity of the microflora, each microflora harboring a major and specific bacterial group. The degradation capacities of the adapted microflora and the occurrence of genes coding for initial hydrocarbon oxidation (alkB, nahAc, cypP450) were also studied. No clear relationship between microflora genes and degradation performances was noted. This seemed to indicate that

  16. A Hyper-cross-linked Polynaphthalene Semiconductor with Excellent Visible-Light Photocatalytic Performance in the Degradation of Organic Dyes.

    Science.gov (United States)

    Zhang, Lei; Huang, Xin-Hua; Hu, Jin-Song; Song, Jian; Kim, Il

    2017-02-28

    Hyper-cross-linked polynaphthalene nanoparticles (PNNs) capable of catalyzing the degradation of organic pollutants upon exposure to visible light have been developed. The nascent and metal-free PNNs with a porous structure, high specific surface area, and narrow bandgap are chemically and thermally stable in the catalytic system, which make it promising as a kind of excellent photocatalytic material compared to conventional photocatalysts. The photocatalytic activity of the as-obtained PNNs exhibits remarkable photocatalytic performance for the degradation of rhodamine B (RhB) and methyl blue (MB) under the irradiation of visible light. The easy preparation, high catalytic activity, and recyclability of the PNNs open new opportunities in the visible-light-promoted degradation of organic pollutants.

  17. Enhanced Photocatalytic Performance of NiO-Decorated ZnO Nanowhiskers for Methylene Blue Degradation

    Directory of Open Access Journals (Sweden)

    I. Abdul Rahman

    2014-01-01

    Full Text Available ZnO nanowhiskers were used for photodecomposition of methylene blue in aqueous solution under UV irradiation. The rate of methylene blue degradation increased linearly with time of UV irradiation. 54% of degradation rate was observed when the ZnO nanowhiskers were used as photocatalysts for methylene blue degradation for 80 min under UV irradiation. The decoration of p-type NiO nanoparticles on n-type ZnO nanowhiskers significantly enhanced photocatalytic activity and reached 72% degradation rate of methylene blue by using the same method. NiO-decorated ZnO was recycled for second test and shows 66% degradation from maximal peak of methylene blue within the same period. The increment of photocatalytic activity of NiO-decorated ZnO nanowhiskers was explained by the extension of the electron depletion layer due to the formation of nanoscale p-n junctions between p-type NiO and n-type ZnO. Hence, these products provide new alternative proficient photocatalysts for wastewater treatment.

  18. Electrochemical performance and capacity degradation mechanism of single-phase La-Mg-Ni-based hydrogen storage alloys

    Science.gov (United States)

    Liu, Jingjing; Li, Yuan; Han, Da; Yang, Shuqin; Chen, Xiaocui; Zhang, Lu; Han, Shumin

    2015-12-01

    La-Mg-Ni-based hydrogen storage alloys are a promising candidate for the negative electrode materials of nickel metal hydride batteries. However, their fast capacity degradation hinders them from more extensive application. In this study, the electrochemical performance and capacity degradation mechanism of single-phase La2MgNi9, La3MgNi14 and La4MgNi19 alloys are studied from the perspective of their constituent subunits. It is found that the rate capability and cycling stability of the alloy electrodes increase with higher [LaNi5]/[LaMgNi4] subunit ratio, while the discharge capacity shows a reverse trend. Degradation study shows that the inter-molecular strains in the alloys are the main reason that leads to the fast capacity degradation of La-Mg-Ni-based alloys. The strains are caused by the difference in the expansion/contraction properties between [LaNi5] and [LaMgNi4] subunits during charge/discharge which is mainly observed in the H-dissolved solid solution instead of hydride. It is also found that the strains can be relieved by adjusting [LaNi5]/[LaMgNi4] subunit ratio of the alloys, thus achieving less pulverization and oxidation, and better cycling stability. We expect our findings can inspire new thoughts on improving the electrochemical performance of La-Mg-Ni-based alloys by tuning their superlattice structures.

  19. The Effect of Degraded Digital Instrumentation and Control systems on Human-system Interfaces and Operator Performance

    Energy Technology Data Exchange (ETDEWEB)

    OHara, J.M.; Gunther, B.; Martinez-Guridi, G. (BNL); Xing, J.; Barnes, V. (NRC)

    2010-11-07

    Integrated digital instrumentation and control (I&C) systems in new and advanced nuclear power plants (NPPs) will support operators in monitoring and controlling the plants. Even though digital systems typically are expected to be reliable, their potential for degradation or failure significantly could affect the operators performance and, consequently, jeopardize plant safety. This U.S. Nuclear Regulatory Commission (NRC) research investigated the effects of degraded I&C systems on human performance and on plant operations. The objective was to develop technical basis and guidance for human factors engineering (HFE) reviews addressing the operator's ability to detect and manage degraded digital I&C conditions. We reviewed pertinent standards and guidelines, empirical studies, and plant operating experience. In addition, we evaluated the potential effects of selected failure modes of the digital feedwater control system of a currently operating pressurized water reactor (PWR) on human-system interfaces (HSIs) and the operators performance. Our findings indicated that I&C degradations are prevalent in plants employing digital systems, and the overall effects on the plant's behavior can be significant, such as causing a reactor trip or equipment to operate unexpectedly. I&C degradations may affect the HSIs used by operators to monitor and control the plant. For example, deterioration of the sensors can complicate the operators interpretation of displays, and sometimes may mislead them by making it appear that a process disturbance has occurred. We used the findings as the technical basis upon which to develop HFE review guidance.

  20. Performance of the In Situ Microcosm Technique for Measuring the Degradation of Organic Chemicals in Aquifers

    DEFF Research Database (Denmark)

    Nielsen, Per H.; Christensen, Thomas Højlund; Albrechtsen, Hans-Jørgen

    1996-01-01

    An in situ microcosm (ISM) consists of a stainless steel cylinder isolating about 2 L of the aquifer and is equipped with valves allowing for loading and sampling from the ground surface. During the last five years, this technique has been used frequently to study the degradation of organic...... chemicals in polluted and pristine aquifers representing different redox environments. The ISM technique has great potential for providing field-relevant degradation potentials and rate constants, but care must be taken in using the equipment and interpreting the results. This paper provides details...

  1. Effects of camelina meal supplementation on ruminal forage degradability, performance, and physiological responses of beef cattle.

    Science.gov (United States)

    Cappellozza, B I; Cooke, R F; Bohnert, D W; Cherian, G; Carroll, J A

    2012-11-01

    Three experiments compared ruminal, physiological, and performance responses of beef steers consuming hay ad libitum and receiving grain-based supplements without (control) or with (CAM) the inclusion of camelina meal. In Exp. 1, 9 steers fitted with ruminal cannulas received CAM (2.04 kg of DM/d; n = 5) or control (2.20 kg of DM/d; n = 4). Steers receiving CAM had reduced (P = 0.01) total DMI and tended to have reduced (P = 0.10) forage DMI compared with control. No treatment effects were detected (P ≥ 0.35) for ruminal hay degradability parameters. In Exp. 2, 14 steers fed CAM (1.52 kg of DM/d; n = 7) or control (1.65 kg of DM/d; n = 7) were assigned to a corticotropin-releasing hormone (CRH; 0.1 μg/kg of BW) and a thyrotropin-releasing hormone (TRH; 0.33 μg/kg of BW) challenge. Steers fed CAM had greater (P infusion, plasma haptoglobin concentrations tended (P = 0.10) to be reduced and ceruloplasmin concentrations increased at a lesser rate in CAM steers compared with control (treatment × time; P infusion, no treatment effects were detected (P ≥ 0.55) for serum thyrotropin-stimulating hormone, triiodothyronine, and thyroxine. In Exp. 3, 60 steers were allocated to 20 pens. Pens were assigned randomly to receive CAM (2.04 kg of DM/steer daily; n = 10) or control (2.20 kg of DM/steer daily; n = 10) during preconditioning (PC; d -28 to 0). On d 0, steers were transported for 24 h. Upon arrival, pens were assigned randomly to receive CAM or control during feedlot receiving (FR; d 1 to 29). During PC, CAM steers had reduced (P < 0.01) forage and total DMI, and tended to have reduced (P = 0.10) ADG compared with control. Plasma linolenic acid concentrations increased during PC for CAM steers, but not for control (treatment × day; P = 0.02). During FR, steers fed CAM during PC had reduced (P < 0.01) forage and total DMI, but tended (P = 0.10) to have greater G:F compared with control. Steers fed CAM during FR had greater (P < 0.05) plasma concentrations of PUFA

  2. Laccase-catalyzed decolorization of malachite green: performance optimization and degradation mechanism.

    Directory of Open Access Journals (Sweden)

    Jie Yang

    Full Text Available Malachite green (MG was decolorized by laccase (LacA of white-rot fungus Cerrena sp. with strong decolorizing ability. Decolorization conditions were optimized with response surface methodology. A highly significant quadratic model was developed to investigate MG decolorization with LacA, and the maximum MG decolorization ratio of 91.6% was predicted under the conditions of 2.8 U mL(-1 LacA, 109.9 mg L(-1 MG and decolorization for 172.4 min. Kinetic studies revealed the Km and kcat values of LacA toward MG were 781.9 mM and 9.5 s(-1, respectively. UV-visible spectra confirmed degradation of MG, and the degradation mechanism was explored with liquid chromatography-mass spectrometry (LC-MS analysis. Based on the LC-MS spectra of degradation products, LacA catalyzed MG degradation via two simultaneous pathways. In addition, the phytotoxicity of MG, in terms of inhibition on seed germination and seedling root elongation of Nicotiana tabacum and Lactuca sativa, was reduced after laccase treatment. These results suggest that laccase of Cerrena was effective in decolorizing MG and promising in bioremediation of wastewater in food and aquaculture industries.

  3. Recommendations for Exploring the Disfluency Hypothesis for Establishing Whether Perceptually Degrading Materials Impacts Performance

    Science.gov (United States)

    Dunlosky, John; Mueller, Michael L.

    2016-01-01

    The target articles explore a common hypothesis pertaining to whether perceptually degrading materials will improve reasoning, memory, and metamemory. Outcomes are mixed, yet some evidence was garnered in support of a version of the disfluency hypothesis that includes moderators, and along with evidence from prior research, researchers will likely…

  4. Microstructure and degradation performance of biodegradable Mg-Si-Sr implant alloys.

    Science.gov (United States)

    Gil-Santos, Andrea; Marco, Iñigo; Moelans, Nele; Hort, Norbert; Van der Biest, Omer

    2017-02-01

    In this work the microstructure and degradation behavior of several as-cast alloy compositions belonging to the Mg rich corner of the Mg-Si-Sr system are presented and related. The intermetallic phases are identified and analyzed describing the microstructure evolution during solidification. It is intended in this work to obtain insight in the behavior of the ternary alloys in in vitro tests and to analyze the degradation behavior of the alloys under physiologically relevant conditions. The as-cast specimens have been exposed to immersion tests, both mass loss (ML) and potentiodynamic polarization (PDP). The degradation rate (DR) have been assessed and correlated to microstructure features, impurity levels and alloy composition. The initial reactions resulted to be more severe while the degradation stabilizes with time. A higher DR is related with a high content of the Mg17Sr2 phase and with the presence of coarse particles of the intermetallics Mg2Si, MgSiSr and MgSi2Sr. Specimens with a higher DR typically have higher levels of impurities and alloy contents.

  5. Performance and dye-degrading bacteria isolation of a hybrid membrane process

    Energy Technology Data Exchange (ETDEWEB)

    You, Sheng-Jie, E-mail: sjyou@cycu.edu.tw [Department of Bioenvironmental Engineering and R and D Center for Membrane Technology, Chung Yuan Christian University, No. 200, Rd. Chung-Pei, Chungli 320, Taiwan (China); Teng, Jun-Yu, E-mail: nickprometheus@yahoo.com.tw [Department of Civil Engineering, Chung Yuan Christian University, Chungli 320, Taiwan (China)

    2009-12-15

    Textile dyeing wastewater contains harmful compounds, which are toxic to both marine organisms and human beings if it discharged into an aquatic environmental without suitable treatment. In this study, the wastewater containing the azo dye, Reactive Black 5 (RB5), was partially treated in an anaerobic sequencing batch reactor which was further treated either in an aerobic membrane bioreactors (AOMBR) or in combined aerobic membrane bioreactor/reverse osmosis (AOMBR/RO) process. The results showed that in the anaerobic sequencing batch reactor the RB5 dye was degraded to form aromatic amine intermediate metabolites, which were further mineralized in the AOMBR. It was also observed that although all effluents from the AOMBR and AOMBR/RO processes met the Taiwan EPA's effluent criteria, irrespective of which membranes were used in the aerobic tank, the effluent from the AOMBR/RO process met the criteria for reuse for toilet flushing, landscaping, irrigation, and cooling water purposes, where as the AOMBR effluent only met the criteria for cooling water due to incomplete color removal. Five anaerobic high dye-degrading bacteria were isolated, which were identified to be the same species of Lactococcus lactis by 16S rRNA sequencing. The L. lactis showed complete degradation of RB5 and further studies showed that it can also able to degrade Reactive Red 120 and Reactive Yellow 84 efficiently within 6 h.

  6. Validated Stability-indicating High-performance Liquid Chromatographic Method for Estimation of Degradation Behaviour of Eberconazole Nitrate and Mometasone Furoate in Cream Formulation

    OpenAIRE

    Sharma, N.; Rao, S. S.; Vaghela, B

    2013-01-01

    The objective of current investigation was to study the degradation behaviour of eberconazole nitrate and mometasone furoate under different International Conference on harmonisation recommended stress condition using reverse phase high performance liquid chromatographic method and to establish validated stability-indicating high performance liquid chromatographic method to determine purity of eberconazole nitrate and mometasone furoate in presence of its impurities, forced degradation produc...

  7. Reduction of polarization-induced performance degradation in WDM PON utilizing MQW-SLD-based broadband source.

    Science.gov (United States)

    Park, Paul K J; Jun, S B; Kim, Hoon; Jung, D K; Lee, W R; Chung, Y C

    2007-10-17

    We report on the reduction of polarization-induced performance degradation in WDM PON utilizing MQW-SLD-based ASE source for injection locking to FPLD. The results show that, to suppress the polarization-induced Q penalty sufficiently less than 0.5 dB, the MQW-SLD output should be depolarized within the locking range of the wavelength-locked FPLD.

  8. [Effects of Oil Pollutants on the Performance of Marine Benthonic Microbial Fuel Cells and Its Acceleration of Degradation].

    Science.gov (United States)

    Meng, Yao; Fu, Yu-bin; Liang, Sheng-kang; Chen, Wei; Liu, Zhao-hui

    2015-08-01

    Degradation of oil pollutants under the sea is slow for its oxygen-free environment which has caused long-term harm to ocean environment. This paper attempts to accelerate the degradation of the sea oil pollutants through electro catalysis by using the principle of marine benthonic microbial fuel cells (BMFCs). The influence of oil pollutants on the battery performance is innovatively explored by comparing the marine benthonic microbial fuel cells ( BMFCs-A) containing oil and oil-free microbial fuel cells (BMFCs-B). The acceleration effect of BMFCs is investigated by the comparison between the oil-degrading rate and the number of heterotrophic bacteria of the BMFCs-A and BMFCs-B on their anodes. The results show that the exchange current densities in the anode of the BMFCs-A and BMFCs-B are 1. 37 x 10(-2) A x m(-2) and 1.50 x 10(-3) A x m(-2) respectively and the maximum output power densities are 105.79 mW x m(-2) and 83.60 mW x m(-2) respectively. The exchange current densities have increased 9 times and the maximum output power density increased 1. 27 times. The anti-polarization ability of BMFCs-A is improved. The heterotrophic bacteria numbers of BMFCs-A and BMFCs-C on their anodes are (66 +/- 3.61) x 10(7) CFU x g(-1) and (7.3 +/- 2.08) x 10(7) CFU x g(-1) respectively and the former total number has increased 8 times, which accelerates the oil-degrading rate. The degrading rate of the oil in the BMFCs-A is 18.7 times higher than that in its natural conditions. The BMFCs can improve its electrochemical performance, meanwhile, the degradation of oil pollutants can also be accelerated. A new model of the marine benthonic microbial fuel cells on its acceleration of oil degradation is proposed in this article.

  9. Performance Degradation of the Repeated Recycled Aggregate Concrete with 70% Replacement of Three-generation Recycled Coarse Aggregate

    Institute of Scientific and Technical Information of China (English)

    ZHU Pinghua; ZHANG Xinxin; WU Junyong; WANG Xinjie

    2016-01-01

    The feasibility of using different generations recycled coarse aggregate (RCA) on structural concrete was fully evaluated by studying the performance of the recycled coarse aggregates and their corresponding concretes, the different generations of RCA were recycled by following the repeated mode of ‘concrete-waste concrete-coarse aggregate-concrete’. Moreover, the focus was on ‘three generations’ of repeated RCAs, the RCA was produced by crushing and regenerating the artiifcial accelerated degraded concrete, the process was designed to follow the nature degradation of the concrete with a coupling action of accelerated carbonation and bending load. The properties ofx-generation (x=1, 2 or 3) of repeated RCA were systematically investigated and the compressive and splitting tensile strengths of relating structural concretes(with 70% replacement ofx-generation of RCA) were studied accordingly. The results show a competent compressive and splitting tensile strength of 30 MPa at 28th day of structural concretes with all generations of repeated RAC. And the gradual degraded performance of the repeated RCAs was observed with an increased numbers of repetition (1﹥2﹥3 generations), the overall performances of all repeated RCAs fulifll the ClassⅢaccording to Chinese Standards GB25177-2010. Our gained insight demonstrates a feasibility of using at least 3 generations of repeated RCA for the production of normal structural concrete.

  10. Identification on endophytic bacterial strain CICC 10707 isolated from Paracel Islands wild Noni(Morinda citrifolia L.)seeds%一株西沙群岛野生诺尼种子内生细菌CICC 10707的分离与多相鉴定

    Institute of Scientific and Technical Information of China (English)

    张欣; 刘洋; 姚粟; 曹艳花; 谭望桥; 程池

    2014-01-01

    对分离自我国西沙群岛野生诺尼种子的内生细菌菌株CICC 10707的分类地位进行了研究,为今后研究该菌的生物学功能奠定了基础.利用基于形态学、分子生物学及生理生化特征的微生物多相分类鉴定技术,将其鉴定为草螺菌属(Herbaspirillum sp.)中的织片草螺菌(Herbaspirillum seropedicae),该菌具有氧化酶和接触酶活性,且能够利用甘露糖、葡萄糖、赤藓糖醇等多种碳源物质.

  11. Excellent waste biomass-degrading performance of Trichoderma asperellum T-1 during submerged fermentation.

    Science.gov (United States)

    Wang, Qun; Chen, Liang; Yu, Daobing; Lin, Hui; Shen, Qi; Zhao, Yuhua

    2017-12-31

    The random disposal and incineration of agricultural residues cause resources waste and environmental pollution. The potential of waste biomass for the production of alternative liquid fuels is increasing and the bioconversion of lignocellulose to fermentable monomeric sugars is essential for second-generation biofuel production. Here, natural and pretreated switch grass or rice straw were fermented by both Trichoderma asperellum T-1 and Trichoderma reesei QM6a, with the fermentation results highlighted the potential of T. asperellum T-1 in the degradation of natural waste lignocellulosic materials. In fermenting different substrates, the filter paper activity, β-glucosidase activity, xylanase activity and carboxymethyl cellulase activity of T-1 can respectively reach 1.88, 8.00, 7.15 and 20.52 times that of QM6a. Although acid pretreatment could improve the enzyme activities of both T-1 and QM6a, its effect on T-1 was much smaller than that on QM6a. Moreover, strain T-1 fermented the natural rice straw better than the pretreated rice straw. Therefore, T-1 is considered to be more suitable for the degradation of natural biomass, especially for the degradation of rice straw. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and scanning electron microscopy (SEM) showed that the cellulase series secreted by T. asperellum T-1 was more abundant, and its substrate deconstruction ability was stronger than T. reesei QM6a. All these results suggest the potential of T. asperellum T-1 in the degradation of natural waste lignocellulosic material, with practical benefits in terms of cost and pollution reduction. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Evidence for age-related performance degradation of (241)Am foil sources commonly used in UK schools.

    Science.gov (United States)

    Whitcher, R; Page, R D; Cole, P R

    2014-06-01

    The characteristics of alpha radiation have for decades been demonstrated in UK schools using small sealed (241)Am sources. There is a small but steady number of schools who report a considerable reduction in the alpha count rate detected by an end-window GM detector compared with when the source was new. This cannot be explained by incorrect apparatus or set-up, foil surface contamination, or degradation of the GM detector. The University of Liverpool and CLEAPSS collaborated to research the cause of this performance degradation. The aim was to find what was causing the performance degradation and the ramifications for both the useful and safe service life of the sources. The research shows that these foil sources have greater energy straggling with a corresponding reduction in spectral peak energy. A likely cause for this increase in straggling is a significant diffusion of the metals over time. There was no evidence to suggest the foils have become unsafe, but precautionary checks should be made on old sources.

  13. Investigation of performance degradation of SOFC using chromium-containing alloy interconnects

    DEFF Research Database (Denmark)

    Beeaff, D.R.; Dinesen, A.; Hendriksen, Peter Vang

    2007-01-01

    -side interconnect plate and the other sample containing a similar fuel cell but no steel interconnect. The interconnect-bearing sample was evaluated for thermochemical compatibility of cell components, including interconnect materials, under conditions typical of and/or expected during the lifetime of an installed......O filler. Longterm degradation of each sample was determined using a current density of 250 mA.cm(-2) using humidified hydrogen as the fuel and air as the oxygen source. Additionally, the stack element was cycled and an investigation into the effect of cathode atmosphere was undertaken to elucidate...

  14. Preparation, microstructure and degradation performance of biomedical magnesium alloy fine wires

    Directory of Open Access Journals (Sweden)

    Jing Bai

    2014-10-01

    Full Text Available With the development of new biodegradable Mg alloy implant devices, the potential applications of biomedical Mg alloy fine wires are realized and explored gradually. In this study, we prepared three kinds of Mg alloy fine wires containing 4 wt% RE(Gd/Y/Nd and 0.4 wt% Zn with the diameter less than 0.4 μm through casting, hot extruding and multi-pass cold drawing combined with intermediated annealing process. Their microstructures, mechanical and degradation properties were investigated. In comparison with the corresponding as-extruded alloy, the final fine wire has significantly refined grain with an average size of 3–4 μm, and meanwhile shows higher yield strength but lower ductility at room temperature. The degradation tests results and surface morphologies observations indicate that Mg–4Gd–0.4Zn and Mg–4Nd–0.4Zn fine wires have similar good corrosion resistance and the uniform corrosion behavior in SBF solution. By contrast, Mg–4Y–0.4Zn fine wire shows a poor corrosion resistance and the pitting corrosion behavior.

  15. Hydraulic performance of a proposed in situ photocatalytic reactor for degradation of MTBE in water.

    Science.gov (United States)

    Lim, Leonard Lik Pueh; Lynch, Rod

    2011-01-01

    Methyl tert-butyl ether (MTBE) groundwater remediation projects often require a combination of technologies resulting in increasing the project costs. A cost-effective in situ photocatalytic reactor design, Honeycomb II, is proposed and tested for its efficiency in MTBE degradation at various flows. This study is an intermediate phase of the research in developing an in situ photocatalytic reactor for groundwater remediation. It examines the effect of the operating variables: air and water flow and double passages through Honeycomb II, on the MTBE removal. MTBE vaporisation is affected by not only temperature, Henry's law constant and air flow to volume ratio but also reactor geometry. The column reactor achieved more than 84% MTBE removal after 8 h at flows equivalent to horizontal groundwater velocities slower than 21.2 cm d⁻¹. Despite the contrasting properties between a photocatalytic indicator methylene blue and MTBE, the reactor efficiency in degrading both compounds showed similar responses towards flow (equivalent groundwater velocity and hydraulic residence time (HRT)). The critical HRT for both compounds was approximately 1 d, which corresponded to a velocity of 21.2 cm d⁻¹. A double pass through both new and used catalysts achieved more than 95% MTBE removal after two passes in 48 h. It also verified that the removal efficiency can be estimated via the sequential order of the removal efficiency of one pass obtained in the laboratory. This study reinforces the potential of this reactor design for in situ groundwater remediation.

  16. Comparative Performance of Three Magnesium Compounds on Thermal Degradation Behavior of Red Gum Wood

    Directory of Open Access Journals (Sweden)

    Yiqiang Wu

    2014-01-01

    Full Text Available The effect of basic magnesium carbonate (BMC, magnesium hydroxide (MH, and magnesium chloride hydrate (MCH on thermal degradation of red gum wood was studied using cone calorimetry, Thermogravimetric-differential scanning calorimetry (TG-DSC analysis, and X-ray diffraction (XRD characterization. The results showed common fire retardation actions of the three compounds by releasing incombustible gas and/or water vapor to dilute combustible gas in the flaming zone, and by converting to MgO, which had a satisfactory protective wall effect on the wood. Individually, BMC absorbed heat from the wood at the pre-decomposition stage and, thus, slowed down wood pyrolysis process. It slightly increased the char yield by charring in both the charring stage and the char calcination stage. MH lost water at about 270 °C, close to the temperature at which wood thermally degraded. MH rendered wood char quickly, and the compact char layer impeded further carbonization and burning of inner wood. MCH promoted charring with Mg2+ as a Lewis acid, and increased wood char yield. MCH also released Cl· free radical and HCl at 167 °C, which easily coordinated with combustion reaction radical, and slowed down, even inhibited, the combustion chain reaction.

  17. Characterization and performance of a toluene-degrading biofilm developed on pumice stones

    Directory of Open Access Journals (Sweden)

    Sacceddu Pasquale

    2005-01-01

    Full Text Available Abstract Background Hydrocarbon-degrading biofilms in the treatment of contaminated groundwaters have received increasing attention due to the role played in the so-called "biobarriers". These are bioremediation systems in which a microbial consortium adherent to a solid support is placed across the flow of a contaminated plume, thus promoting biodegradation of the pollutant. Results A microbial consortium adherent to pumice granules (biofilm developed from a toluene-enriched microflora in a mini-scale system, following continuous supply of a mineral medium containing toluene, over a 12-month period. Observation by scanning electron microscopy, together with quantification of the biomass attached to pumice, evidenced the presence of abundant exopolymeric material surrounding the cells in the biofilm. Toluene removal monitored during 12-month operation, reached 99%. Identification of the species, based on comparative 16S ribosomal DNA (rDNA sequence analysis, revealed that Rhodococcus erythropolis and Pseudomonas marginalis were the predominant bacterial species in the microbial consortium. Conclusion A structurally complex toluene-degrading biofilm, mainly formed by Rhodococcus erythropolis and Pseudomonas marginalis, developed on pumice granules, in a mini-scale apparatus continuously fed with toluene.

  18. Preparation, microstructure and degradation performance of biomedical magnesium alloy fine wires

    Institute of Scientific and Technical Information of China (English)

    Jing Bai; Zhejun Tang; Lingling Yin; Ye Lu; Yiwei Gan; Feng Xue; Chenglin Chu; Jingli Yan; Kai Yan; Xiaofeng Wan

    2014-01-01

    With the development of new biodegradable Mg alloy implant devices, the potential applications of biomedical Mg alloy fine wires are realized and explored gradually. In this study, we prepared three kinds of Mg alloy fine wires containing 4 wt%RE(Gd/Y/Nd) and 0.4 wt%Zn with the diameter less than 0.4μm through casting, hot extruding and multi-pass cold drawing combined with intermediated annealing process. Their microstructures, mechanical and degradation properties were investigated. In comparison with the corresponding as-extruded alloy, the final fine wire has significantly refined grain with an average size of 3–4μm, and meanwhile shows higher yield strength but lower ductility at room temperature. The degradation tests results and surface morphologies observations indicate that Mg–4Gd–0.4Zn and Mg–4Nd–0.4Zn fine wires have similar good corrosion resistance and the uniform corrosion behavior in SBF solution. By contrast, Mg–4Y–0.4Zn fine wire shows a poor corrosion resistance and the pitting corrosion behavior.

  19. Degradation Behavior of Moroxydine Hydrochloride in Rice Plant and Field Water Using High Performance Liquid Chromatography-Tandem Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    ZHAO Lin

    2014-10-01

    Full Text Available Through field experiments, which were conducted in Zhaodong County of Heilongjiang Province, Zhulou County of Henan Province and Jurong County of Jiangsu Province, the degradation dynamics of moroxydine hydrochloride in rice plant and field water were investigated.The detection was performed by tandem mass spectrometry with electrospray ionization in positive mode(ESI+. The results showed that the average recoveries of rice plant and field water at three spiked levels (0.005, 0.05, 0.5 mg·kg -1were found in the range of 92.50%-109.20% with RSD 6.10%-6.90% and 86.40%-107.2% with RSD 0.73%-3.10%, respectively. Limits of detection(LODof plant and water were 0.005 mg·kg -1. The degradation kinetic equation showed that the half-life of moroxydine hydrochloride in rice plant and field water was 1.2-4.7 d,1.0-3.5 d, respectively. The moroxydine hydrochloride was proved to be an easily degradable pesticide.

  20. Bearing performance degradation assessment based on a combination of empirical mode decomposition and k-medoids clustering

    Science.gov (United States)

    Rai, Akhand; Upadhyay, S. H.

    2017-09-01

    Bearing is the most critical component in rotating machinery since it is more susceptible to failure. The monitoring of degradation in bearings becomes of great concern for averting the sudden machinery breakdown. In this study, a novel method for bearing performance degradation assessment (PDA) based on an amalgamation of empirical mode decomposition (EMD) and k-medoids clustering is encouraged. The fault features are extracted from the bearing signals using the EMD process. The extracted features are then subjected to k-medoids based clustering for obtaining the normal state and failure state cluster centres. A confidence value (CV) curve based on dissimilarity of the test data object to the normal state is obtained and employed as the degradation indicator for assessing the health of bearings. The proposed outlook is applied on the vibration signals collected in run-to-failure tests of bearings to assess its effectiveness in bearing PDA. To validate the superiority of the suggested approach, it is compared with commonly used time-domain features RMS and kurtosis, well-known fault diagnosis method envelope analysis (EA) and existing PDA classifiers i.e. self-organizing maps (SOM) and Fuzzy c-means (FCM). The results demonstrate that the recommended method outperforms the time-domain features, SOM and FCM based PDA in detecting the early stage degradation more precisely. Moreover, EA can be used as an accompanying method to confirm the early stage defect detected by the proposed bearing PDA approach. The study shows the potential application of k-medoids clustering as an effective tool for PDA of bearings.

  1. Degradation of surface-active compounds in a constructed wetland determined using high performance liquid chromatography and extraction spectrophotometry.

    Science.gov (United States)

    Šíma, Jan; Pazderník, Marek; Tříska, Jan; Svoboda, Lubomír

    2013-01-01

    Degradation of anionic and nonionic surfactants in a constructed wetland with horizontal subsurface flow was studied using high performance liquid chromatography and extraction spectrophotometry. The ratio of individual homologues of linear alkylbenzene sulfonates (LAS) and the efficiency of their removal were studied. Tridecyl-, dodecyl-, undecyl-, and decylbenzene sulfonates were removed with efficiencies of 92.9%, 84.3%, 64.7%, and 41.1%, respectively. These differences are due to sequential shortening of the alkyl chain in homologues during degradation (the higher homologue can provide the lower one). The formation of sulfophenyl carboxylic acids during ω-oxidation of the alkyl chain followed by successive α- and/or β-oxidation is also a possible mechanism for removal of LAS. Solid phase extraction using Chromabond® HR-P columns was used for preconcentration of the analytes prior to their determination by HPLC. Methylene blue active compounds were determined using extraction spectrophotometry. The average efficiency of their removal was 84.9% in this case. The efficiency of nonionic surfactant removal (98.2%) was significantly higher in comparison to that for anionic surfactants. The concentration of the endocrine disruptor nonylphenol (a product of nonylphenol polyethoxylate surfactant degradation) determined in the profile of the wetland was beneath the limit of detection (0.4 μg/L). The average outflow concentrations of anionic and nonionic surfactants determined by spectrophotometry were 0.54 and 0.021 mg/L, respectively. The average outflow concentrations of decyl- and tridecylbenzene sulfonates determined by HPLC were 0.195 and 0.015 mg/L. Efficiencies of 86.4% and 92.2% were obtained for removal of organic compounds as indicated by chemical and biochemical oxygen demand (COD(Cr) and BOD(5)). These results demonstrate the suitability of the constructed wetland for degrading surface-active compounds.

  2. A study of enhanced performance of VUV/UV process for the degradation of micropollutants from contaminated water

    Energy Technology Data Exchange (ETDEWEB)

    Bagheri, Mehdi; Mohseni, Madjid, E-mail: madjid.mohseni@ubc.ca

    2015-08-30

    Highlights: • Developing a comprehensive CFD simulation tool for VUV/UV photoreactors modeling. • Analysing impact of reactor hydrodynamics on the AOP performance of VUV/UV process. • Cutting the energy cost of VUV/UV process by means of improved-photoreactor design. • Experimentally verifying the CFD results using a VUV/UV prototype photoreactor. - Abstract: VUV/UV is a chemical-free and straightforward solution for the degradation of emerging contaminants from water sources. The objective of this work was to investigate the feasibility of VUV/UV advanced oxidation process for the effective degradation of a target micropollutant, atrazine, under continuous flow operation of 0.5–6.5 L/min. To provide an in-depth understanding of process, a comprehensive computational fluid dynamics (CFD) model, incorporating flow hydrodynamics, 185 nm VUV and 254 nm UV radiation propagation along with a complete kinetic scheme, was developed and validated experimentally. The experimental degradation rates and CFD predicted values showed great consistency with less than 2.9% average absolute relative deviation (AARD). Utilizing the verified model, energy-efficiency of the VUV/UV process under a wide range of reactor configurations was assessed in terms of electrical energy-per-order (EEO), ·OH concentration as well as delivered UV and VUV dose distributions. Thereby, the extent of mixing and circulation zones was found as key parameter controlling the treatment economy and energy-efficiency of the VUV/UV process. Utilizing a CFD-driven baffle design strategy, an improved VUV/UV process with up to 72% reduction in the total electrical energy requirement of atrazine degradation was introduced and verified experimentally.

  3. High bacterial biodiversity increases degradation performance of hydrocarbons during bioremediation of contaminated harbor marine sediments.

    Science.gov (United States)

    Dell'Anno, Antonio; Beolchini, Francesca; Rocchetti, Laura; Luna, Gian Marco; Danovaro, Roberto

    2012-08-01

    We investigated changes of bacterial abundance and biodiversity during bioremediation experiments carried out on oxic and anoxic marine harbor sediments contaminated with hydrocarbons. Oxic sediments, supplied with inorganic nutrients, were incubated in aerobic conditions at 20 °C and 35 °C for 30 days, whereas anoxic sediments, amended with organic substrates, were incubated in anaerobic conditions at the same temperatures for 60 days. Results reported here indicate that temperature exerted the main effect on bacterial abundance, diversity and assemblage composition. At higher temperature bacterial diversity and evenness increased significantly in aerobic conditions, whilst decreased in anaerobic conditions. In both aerobic and anaerobic conditions, biodegradation efficiencies of hydrocarbons were significantly and positively related with bacterial richness and evenness. Overall results presented here suggest that bioremediation strategies, which can sustain high levels of bacterial diversity rather than the selection of specific taxa, may significantly increase the efficiency of hydrocarbon degradation in contaminated marine sediments.

  4. Facile Synthesis and High Photocatalytic Degradation Performance of ZnO-SnO2 Hollow Spheres

    Science.gov (United States)

    Jin, Changqing; Ge, Chenghai; Jian, Zengyun; Wei, Yongxing

    2016-11-01

    ZnO-SnO2 hollow spheres were successfully synthesized through a hydrothermal method-combined carbon sphere template. The samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and Fourier transform infrared spectroscopy (FT-IR). The average diameter of hollow spheres is about 150 nm. The photocatalytic activity of the as-prepared samples was investigated by photodegrading Rhodamine B. The results indicated that the photocatalytic activities of ZnO-SnO2 hollow spheres are higher than ZnO hollow spheres. The degradation efficiency of the hollow spheres could reach 99.85% within 40 min, while the ZnO hollow spheres need 50 min.

  5. Method and system for detecting a failure or performance degradation in a dynamic system such as a flight vehicle

    Science.gov (United States)

    Miller, Robert H. (Inventor); Ribbens, William B. (Inventor)

    2003-01-01

    A method and system for detecting a failure or performance degradation in a dynamic system having sensors for measuring state variables and providing corresponding output signals in response to one or more system input signals are provided. The method includes calculating estimated gains of a filter and selecting an appropriate linear model for processing the output signals based on the input signals. The step of calculating utilizes one or more models of the dynamic system to obtain estimated signals. The method further includes calculating output error residuals based on the output signals and the estimated signals. The method also includes detecting one or more hypothesized failures or performance degradations of a component or subsystem of the dynamic system based on the error residuals. The step of calculating the estimated values is performed optimally with respect to one or more of: noise, uncertainty of parameters of the models and un-modeled dynamics of the dynamic system which may be a flight vehicle or financial market or modeled financial system.

  6. A GM (1, 1 Markov Chain-Based Aeroengine Performance Degradation Forecast Approach Using Exhaust Gas Temperature

    Directory of Open Access Journals (Sweden)

    Ning-bo Zhao

    2014-01-01

    Full Text Available Performance degradation forecast technology for quantitatively assessing degradation states of aeroengine using exhaust gas temperature is an important technology in the aeroengine health management. In this paper, a GM (1, 1 Markov chain-based approach is introduced to forecast exhaust gas temperature by taking the advantages of GM (1, 1 model in time series and the advantages of Markov chain model in dealing with highly nonlinear and stochastic data caused by uncertain factors. In this approach, firstly, the GM (1, 1 model is used to forecast the trend by using limited data samples. Then, Markov chain model is integrated into GM (1, 1 model in order to enhance the forecast performance, which can solve the influence of random fluctuation data on forecasting accuracy and achieving an accurate estimate of the nonlinear forecast. As an example, the historical monitoring data of exhaust gas temperature from CFM56 aeroengine of China Southern is used to verify the forecast performance of the GM (1, 1 Markov chain model. The results show that the GM (1, 1 Markov chain model is able to forecast exhaust gas temperature accurately, which can effectively reflect the random fluctuation characteristics of exhaust gas temperature changes over time.

  7. Performance and Degradation of A Lithium-Bromine Rechargeable Fuel Cell Using Highly Concentrated Catholytes

    CERN Document Server

    Bai, Peng

    2016-01-01

    Lithium-air batteries have been considered as ultimate solutions for the power source of long-range electrified transportation, but state-of-the-art prototypes still suffer from short cycle life, low efficiency and poor power output. Here, a lithium-bromine rechargeable fuel cell using highly concentrated bromine catholytes is demonstrated with comparable specific energy, improved power density, and higher efficiency. The cell is similar in structure to a hybrid-electrolyte Li-air battery, where a lithium metal anode in nonaqueous electrolyte is separated from aqueous bromine catholytes by a lithium-ion conducting ceramic plate. The cell with a flat graphite electrode can discharge at a peak power density around 9mW cm-2 and in principle could provide a specific energy of 791.8 Wh kg-1, superior to most existing cathode materials and catholytes. It can also run in regenerative mode to recover the lithium metal anode and free bromine with 80-90% voltage efficiency, without any catalysts. Degradation of the sol...

  8. New horizon for high performance Mg-based biomaterial with uniform degradation behavior: Formation of stacking faults

    Science.gov (United States)

    Zhang, Jinghuai; Xu, Chi; Jing, Yongbin; Lv, Shuhui; Liu, Shujuan; Fang, Daqing; Zhuang, Jinpeng; Zhang, Milin; Wu, Ruizhi

    2015-09-01

    Designing the new microstructure is an effective way to accelerate the biomedical application of magnesium (Mg) alloys. In this study, a novel Mg-8Er-1Zn alloy with profuse nano-spaced basal plane stacking faults (SFs) was prepared by combined processes of direct-chill semi-continuous casting, heat-treatment and hot-extrusion. The formation of SFs made the alloy possess outstanding comprehensive performance as the biodegradable implant material. The ultimate tensile strength (UTS: 318 MPa), tensile yield strength (TYS: 207 MPa) and elongation (21%) of the alloy with SFs were superior to those of most reported degradable Mg-based alloys. This new alloy showed acceptable biotoxicity and degradation rate (0.34 mm/year), and the latter could be further slowed down through optimizing the microstructure. Most amazing of all, the uniquely uniform in vitro/vivo corrosion behavior was obtained due to the formation of SFs. Accordingly we proposed an original corrosion mechanism for the novel Mg alloy with SFs. The present study opens a new horizon for developing new Mg-based biomaterials with highly desirable performances.

  9. Degradation of the performance of microchannel heat exchangers due to flow maldistribution

    DEFF Research Database (Denmark)

    Nielsen, Kaspar Kirstein; Engelbrecht, Kurt; Christensen, Dennis;

    2012-01-01

    The effect of flow maldistribution on the performance of microchannel parallel plate heat exchangers is investigated using an established single blow numerical model and cyclic steady-state regenerator experiments. It is found that as the variation of the individual channel thickness...... in a particular stack (heat exchanger) increases the actual performance of the heat exchanger decreases significantly, deviating from the expected nominal performance. We show that this is due to both the varying fluid flow velocities in each individual channel and the thermal cross talk between the channels...

  10. Performance and carcass characteristics of Nellore young bulls fed different sources of oils, protected or not from rumen degradation

    Directory of Open Access Journals (Sweden)

    Bruna Laurindo Rosa

    2013-02-01

    Full Text Available The objective was to evaluate the addition of vegetable oils protected or not from rumen degradation in the diet of feedlot-finished young bulls and their effects on performance and carcass characteristics. Thirty-five Nellore males of 402.69±14.90 kg initial weight and 18±2 months of age were utilized. The animals were confined for 96 days, after 28 days of adaptation, and slaughtered at 532.17±30.25 kg. Experimental diets were: control (715 g total digestible nutrients - TDN/kg of dry matter - DM, with addition of soybean oil or fresh linseed oil, and with the addition of the same oils protected from rumen degradation (765 g TDN/kg DM. All diets were formulated with the same amount of protein and with a roughage:concentrate ratio of 40:60, with sugarcane as the only roughage. The addition of oil, regardless of the type and processing, resulted in greater body weight gain (1.17 and 1.41 kg/animal/day, better feed (0.11 and 0.14 kg weight gain/kg DM ingested and protein efficiency (0.86 and 1.09 kg weight gain/kg crude protein ingested, heavier carcasses (280.3 and 298.0 kg, with better yield (54.5 and 55.5% and thicker subcutaneous fat (5.1 and 7.5 mm backfat thickness and with heavier prime cuts, for control diet and the other treatments, respectively. The use of soybean or linseed oil protected or not from rumen degradation only changed the intake of a few nutrients and carcass yield and depth. Thus the addition of energy sources in the diet is beneficial for finishing feedlot bulls. For this addition, either soybean or linseed oils can be used, and the processing of these oils is only useful to facilitate the mixing with the other ingredients of the diet.

  11. Investigation of electrolyte leaching in the performance degradation of phosphoric acid-doped polybenzimidazole membrane-based high temperature fuel cells

    Science.gov (United States)

    Jeong, Yeon Hun; Oh, Kyeongmin; Ahn, Sungha; Kim, Na Young; Byeon, Ayeong; Park, Hee-Young; Lee, So Young; Park, Hyun S.; Yoo, Sung Jong; Jang, Jong Hyun; Kim, Hyoung-Juhn; Ju, Hyunchul; Kim, Jin Young

    2017-09-01

    Precise monitoring of electrolyte leaching in high-temperature polymer electrolyte membrane fuel cell (HT-PEMFC) devices during lifetime tests is helpful in making a diagnosis of their quality changes and analyzing their electrochemical performance degradation. Here, we investigate electrolyte leaching in the performance degradation of phosphoric acid (PA)-doped polybenzimidazole (PBI) membrane-based HT-PEMFCs. We first perform quantitative analyses to measure PA leakage during cell operation by spectrophotometric means, and a higher PA leakage rate is detected when the current density is elevated in the cell. Second, long-term degradation tests under various current densities of the cells and electrochemical impedance spectroscopy (EIS) analysis are performed to examine the influence of PA loss on the membrane and electrodes during cell performance degradation. The combined results indicate that PA leakage affect cell performance durability, mostly due to an increase in charge transfer resistance and a decrease in the electrochemical surface area (ECSA) of the electrodes. Additionally, a three-dimensional (3-D) HT-PEMFC model is applied to a real-scale experimental cell, and is successfully validated against the polarization curves measured during various long-term experiments. The simulation results highlight that the PA loss from the cathode catalyst layer (CL) is a significant contributor to overall performance degradation.

  12. Effect of different levels of rapidly degradable carbohydrates calculated by a simple rumen model on performance of lactating dairy cows

    NARCIS (Netherlands)

    Doorenbos, J.; Martín-Tereso, J.; Dijkstra, J.; Laar, van H.

    2017-01-01

    Aggregating rumen degradation characteristics of different carbohydrate components into the term modeled rapidly degradable carbohydrates (mRDC) can simplify diet formulation by accounting for differences in rate and extent of carbohydrate degradation within and between feedstuffs. This study

  13. Fire performance, microstructure and thermal degradation of an epoxy based nano intumescent fire retardant coating for structural applications

    Energy Technology Data Exchange (ETDEWEB)

    Aziz, Hammad, E-mail: engr.hammad.aziz03@gmail.com; Ahmad, Faiz, E-mail: faizahmad@petronas.com.my; Yusoff, P. S. M. Megat; Zia-ul-Mustafa, M. [Department of Mechanical Engineering, Universiti Teknologi PETRONAS, Bandar Seri Iskandar, Tronoh 31750, Perak (Malaysia)

    2015-07-22

    Intumescent fire retardant coating (IFRC) is a passive fire protection system which swells upon heating to form expanded multi-cellular char layer that protects the substrate from fire. In this research work, IFRC’s were developed using different flame retardants such as ammonium polyphosphate, expandable graphite, melamine and boric acid. These flame retardants were bound together with the help of epoxy binder and cured together using curing agent. IFRC was then reinforced with nano magnesium oxide and nano alumina as inorganic fillers to study their effect towards fire performance, microstructure and thermal degradation. Small scale fire test was conducted to investigate the thermal insulation of coating whereas fire performance was calculated using thermal margin value. Field emission scanning electron microscopy was used to examine the microstructure of char obtained after fire test. Thermogravimetric analysis was conducted to investigate the residual weight of coating. Results showed that the performance of the coating was enhanced by reinforcement with nano size fillers as compared to non-filler based coating. Comparing both nano size magnesium oxide and nano size alumina; nano size alumina gave better fire performance with improved microstructure of char and high residual weight.

  14. Fire performance, microstructure and thermal degradation of an epoxy based nano intumescent fire retardant coating for structural applications

    Science.gov (United States)

    Aziz, Hammad; Ahmad, Faiz; Yusoff, P. S. M. Megat; Zia-ul-Mustafa, M.

    2015-07-01

    Intumescent fire retardant coating (IFRC) is a passive fire protection system which swells upon heating to form expanded multi-cellular char layer that protects the substrate from fire. In this research work, IFRC's were developed using different flame retardants such as ammonium polyphosphate, expandable graphite, melamine and boric acid. These flame retardants were bound together with the help of epoxy binder and cured together using curing agent. IFRC was then reinforced with nano magnesium oxide and nano alumina as inorganic fillers to study their effect towards fire performance, microstructure and thermal degradation. Small scale fire test was conducted to investigate the thermal insulation of coating whereas fire performance was calculated using thermal margin value. Field emission scanning electron microscopy was used to examine the microstructure of char obtained after fire test. Thermogravimetric analysis was conducted to investigate the residual weight of coating. Results showed that the performance of the coating was enhanced by reinforcement with nano size fillers as compared to non-filler based coating. Comparing both nano size magnesium oxide and nano size alumina; nano size alumina gave better fire performance with improved microstructure of char and high residual weight.

  15. Evaluation of the performance degradation at PAFC investigation of dealloying process of electrocatalysts with in-situ XRD

    Energy Technology Data Exchange (ETDEWEB)

    Nakajima, Noriyuki; Uchida, Hiroyuki; Watanabe, Masahiro [Yamanashi Univ., Kofu (Japan)] [and others

    1996-12-31

    As a complementary research project to the demonstration project of 5MW and 1 MW PAFC plants, the mechanism and rate of deterioration of the cells and stacks have been studied from 1995 FY, with the objective of establishing an estimation method for the service life-time of the cell stacks. This work has been performed in the Basic Research Project, as part of that project on PAFC`s, selecting four subjects (Electrocatalysts degradation, Electrolyte fill-level, Cell material corrosion, Electrolyte loss) as the essential factors relating to the life-time. In this study, the effect of temperature and potential on the dealloying process of electrocatalysts was examined in H{sub 3}PO{sub 4} electrolyte with X-ray diffraction measurement.

  16. Synthesis of S-doped WO3 nanowires with enhanced photocatalytic performance towards dye degradation

    Science.gov (United States)

    Han, Fugui; Li, Heping; Fu, Li; Yang, Jun; Liu, Zhong

    2016-05-01

    In this letter, S-doped WO3 nanowires (S-WO3) were prepared using a hydrothermal method followed by a low-temperature solid-state annealing treatment. The synthesized S-WO3 was characterized by SEM, EDX, XRD, XPS, Raman spectroscopy, UV-vis DRS and photocurrent responses. The results indicated that S could enhance the light harvesting capacity of WO3 nanowires. The photocatalytic performance of the S-WO3 was investigated by photodegradation of methyl orange (MO) under visible light irradiation. Results demonstrated that the photocatalytic activity of the S-WO3 nanowires is much higher than that of pure WO3 nanowires.

  17. The Effects of Degraded Digital Instrumentation and Control Systems on Human-system Interfaces and Operator Performance: HFE Review Guidance and Technical Basis

    Energy Technology Data Exchange (ETDEWEB)

    O' Hara, J.M.; W. Gunther, G. Martinez-Guridi

    2010-02-26

    New and advanced reactors will use integrated digital instrumentation and control (I&C) systems to support operators in their monitoring and control functions. Even though digital systems are typically highly reliable, their potential for degradation or failure could significantly affect operator performance and, consequently, impact plant safety. The U.S. Nuclear Regulatory Commission (NRC) supported this research project to investigate the effects of degraded I&C systems on human performance and plant operations. The objective was to develop human factors engineering (HFE) review guidance addressing the detection and management of degraded digital I&C conditions by plant operators. We reviewed pertinent standards and guidelines, empirical studies, and plant operating experience. In addition, we conducted an evaluation of the potential effects of selected failure modes of the digital feedwater system on human-system interfaces (HSIs) and operator performance. The results indicated that I&C degradations are prevalent in plants employing digital systems and the overall effects on plant behavior can be significant, such as causing a reactor trip or causing equipment to operate unexpectedly. I&C degradations can impact the HSIs used by operators to monitor and control the plant. For example, sensor degradations can make displays difficult to interpret and can sometimes mislead operators by making it appear that a process disturbance has occurred. We used the information obtained as the technical basis upon which to develop HFE review guidance. The guidance addresses the treatment of degraded I&C conditions as part of the design process and the HSI features and functions that support operators to monitor I&C performance and manage I&C degradations when they occur. In addition, we identified topics for future research.

  18. Examination of Impact of Flooding attack on MANET and to accentuate on Performance Degradation

    Directory of Open Access Journals (Sweden)

    Bhuvaneshwari. K

    2013-01-01

    Full Text Available Mobile Adhoc Networks (MANET are new paradigm of wireless networks providing unrestricted mobility to nodes with no fixed or centralized infrastructure. Each node participating in the network acts as router to route the data from source to destination. This characteristic makes MANET more vulnerable to routing attacks. Flooding attack is one such attack which consumes more resource like bandwidth, battery power, etc. Reactive routing protocols like Adhoc On Demand Distance Vector (AODV and Dynamic Source Routing (DSR used in MANET has route discovery scheme and this makes it more easy for malicious node to launch flooding attack by flooding the route request packets(RREQ in the network. In this paper, the behavior of flooding attack and the performance impact of flooding attack on AODV protocol is studied. The NS2 network simulator is used to evaluate the impact of flooding attack on AODV.

  19. Control mechanism to prevent correlated message arrivals from degrading signaling no. 7 network performance

    Science.gov (United States)

    Kosal, Haluk; Skoog, Ronald A.

    1994-04-01

    Signaling System No. 7 (SS7) is designed to provide a connection-less transfer of signaling messages of reasonable length. Customers having access to user signaling bearer capabilities as specified in the ANSI T1.623 and CCITT Q.931 standards can send bursts of correlated messages (e.g., by doing a file transfer that results in the segmentation of a block of data into a number of consecutive signaling messages) through SS7 networks. These message bursts with short interarrival times could have an adverse impact on the delay performance of the SS7 networks. A control mechanism, Credit Manager, is investigated in this paper to regulate incoming traffic to the SS7 network by imposing appropriate time separation between messages when the incoming stream is too bursty. The credit manager has a credit bank where credits accrue at a fixed rate up to a prespecified credit bank capacity. When a message arrives, the number of octets in that message is compared to the number of credits in the bank. If the number of credits is greater than or equal to the number of octets, then the message is accepted for transmission and the number of credits in the bank is decremented by the number of octets. If the number of credits is less than the number of octets, then the message is delayed until enough credits are accumulated. This paper presents simulation results showing delay performance of the SS7 ISUP and TCAP message traffic with a range of correlated message traffic, and control parameters of the credit manager (i.e., credit generation rate and bank capacity) are determined that ensure the traffic entering the SS7 network is acceptable. The results show that control parameters can be set so that for any incoming traffic stream there is no detrimental impact on the SS7 ISUP and TCAP message delay, and the credit manager accepts a wide range of traffic patterns without causing significant delay.

  20. Identification of heat-induced degradation products from purified betanin, phyllocactin and hylocerenin by high-performance liquid chromatography/electrospray ionization mass spectrometry.

    Science.gov (United States)

    Herbach, Kirsten M; Stintzing, Florian C; Carle, Reinhold

    2005-01-01

    Betanin, phyllocactin (malonylbetanin) and hylocerenin (3-hydroxy-3-methylglutarylbetanin) were isolated from purple pitaya (Hylocereus polyrhizus [Weber] Britton and Rose) juice, and their degradation products generated by heating at 85 degrees C were subsequently monitored by high-performance liquid chromatography/electrospray ionization tandem mass spectrometry. Thermal degradation of phyllocactin and hylocerenin in purified solution excluding the alleged protective effects by the juice matrix is reported for the first time. Betanin was predominantly degraded by hydrolytic cleavage, while decarboxylation and dehydrogenation were of minor relevance. In contrast, hylocerenin showed a strong tendency to decarboxylation and dehydrogenation, hydrolytic cleavage of the aldimine bond occurring secondarily. Phyllocactin degradation was most complex because of additional decarboxylation of the malonic acid moiety as well as generation and subsequent degradation of betanin due to phyllocactin demalonylation. Upon prolonged heating, all betacyanins under observation formed degradation products characterized by an additional double bond at C2-C3. Hydrolytic cleavage of the aldimine bond of phyllocactin and hylocerenin yielded previously unknown acylated cyclo-dopa derivatives traceable by positive ionization, while application of ESI(-) facilitated the detection of a glycosylated aminopropanal derivative and dopamine, which have never been described before as betanin degradation products.

  1. Salinity as a structuring factor for the composition and performance of bacterioplankton degrading riverine DOC.

    Science.gov (United States)

    Langenheder, Silke; Kisand, Veljo; Wikner, Johan; Tranvik, Lars J

    2003-07-01

    Abstract The impact of salinity on the composition and functional performance (biomass production, growth efficiency and growth rates) of bacterial communities was investigated using batch cultures growing on dissolved organic carbon from a river draining into the Northern Baltic Sea. The cultures were adjusted to riverine or estuarine salinity levels and inoculated with bacteria from these two environments. Bacterial growth efficiencies differed in response to salinity and the origin of the inoculum. When salinity was adjusted to correspond to the salinity at the site where the inoculum was retrieved, growth efficiency was relatively high (11.5+/-2.6%). However, when bacteria were confronted with a shift in salinity, growth efficiency was lower (7.5+/-2.0%) and more of the utilized carbon was respired. In contrast, growth rates were higher when bacteria were exposed to a change in salinity. The composition of the bacterial communities developing in the batch cultures differed, as shown by 16S rDNA DGGE, depending on the origin of the inoculum and salinity. Reverse and direct DNA-DNA hybridization revealed salinity optima in the growth of specific bacterial strains as well as broader phylogenetic groups. Strains belonging to the alpha- and beta-Proteobacteria, Actinobacteria and gamma-Proteobacteria other than the genus Pseudomonas showed higher relative abundance under freshwater conditions, whereas strains of the genus Pseudomonas and the Cytophaga-Flavobacterium-Bacteroides group were favored by estuarine conditions. Generally, our results demonstrate functional changes associated with changes in community composition. We suggest that even moderate changes in salinity affect bacterial community composition, which subsequently leads to altered growth characteristics.

  2. A new method to improve the performance of multi-GNSS pseudorange positioning in signal-degraded environment

    Science.gov (United States)

    Liu, Hui; Xu, Longwei; Shu, Bao; Zhang, Ming; Qian, Chuang

    2016-08-01

    -area, the new method may not improve the accuracy remarkably. However, it can make great contributions in signal-degraded environments. In order to compare the performance of ISB- and ISSB-corrected methods in environment with limited visible satellites, we simulate several scenarios (different satellites participant or various receivers) with only four participant satellites in the positioning solution. By the ISSB-corrected method, the 3D RMS of positioning results with four satellites is about 15 m, while it is usually worse than 25 m for the ISB-corrected method. In an urban vehicular test, the horizontal positioning error of the ISSB-corrected method is less than 20 m; and the ISB-corrected method may reach up to 70 m.

  3. Performance and metabolite profile of dairy cows fed tropical grasses and concentrates containing crude protein with low or high degradability

    Directory of Open Access Journals (Sweden)

    Raphael dos Santos Gomes

    Full Text Available ABSTRACT Ten Holstein-Zebu crossbred cows distributed into two simultaneous Latin squares (5 × 5 as a 2 × 2 factorial arrangement formed by chopped sugarcane or elephant grass silage, both with high or low protein degradability supplements and a corn silage as a control treatment, were compared using orthogonal contrasts. The studied variables were the performance, plasma concentrations of urea-N, glucose, and creatinine, urine-N and milk urea-N, and the nychthemeral variation in NH3-N in the rumen fluid of dairy cows. Nutrient intake, milk production, and milk composition were affected by the treatments. The total mixed ration containing elephant grass silage combined with rumen undegradable protein (RUP provided balanced amounts of carbon and nitrogen in the rumen. This effect may explain the 18% increase in milk yield compared with the other treatments. The diurnal pattern of ruminal NH3-N was interpreted with a sinusoid model. In general, cows fed elephant grass silage exhibited higher concentrations of blood plasma and milk urea-N than animals fed sugarcane. The cows that consumed elephant grass silage with rumen degradable protein concentrate showed a higher milk urea-N compared with animals that consumed elephant grass silage with the RUP concentrate. The use of diets based on corn silage leads to a better use of nitrogen compounds because these diets resulted in lower levels of urea-N in the plasma, urine, and milk at the same level of milk production compared with diets containing elephant grass silage or chopped sugarcane as roughages. In sugarcane-based diets, even greater nitrogen losses in the urine are observed, despite the presence of readily fermentable carbohydrates in the diet.

  4. A distributed real-time model of degradation in a solid oxide fuel cell, part II: Analysis of fuel cell performance and potential failures

    Science.gov (United States)

    Zaccaria, V.; Tucker, D.; Traverso, A.

    2016-09-01

    Solid oxide fuel cells are characterized by very high efficiency, low emissions level, and large fuel flexibility. Unfortunately, their elevated costs and relatively short lifetimes reduce the economic feasibility of these technologies at the present time. Several mechanisms contribute to degrade fuel cell performance during time, and the study of these degradation modes and potential mitigation actions is critical to ensure the durability of the fuel cell and their long-term stability. In this work, localized degradation of a solid oxide fuel cell is modeled in real-time and its effects on various cell parameters are analyzed. Profile distributions of overpotential, temperature, heat generation, and temperature gradients in the stack are investigated during degradation. Several causes of failure could occur in the fuel cell if no proper control actions are applied. A local analysis of critical parameters conducted shows where the issues are and how they could be mitigated in order to extend the life of the cell.

  5. Analysis of Cable-in-Conduit Conductors' DC Performance in Light of Strand's Experimental Properties

    Institute of Scientific and Technical Information of China (English)

    TAN Yunfei; WENG Peide; LIU Fang; LI Shaolei

    2007-01-01

    Conductor qualification will be carried out with four Cable-in-Conduit Conductor (CICC) samples made of superconducting strands. The direct current (DC) performance of these samples will be tested in the SULTAN facility. The critical current densities of the strands can be well simulated by empirical equations. In this paper, a model is illustrated to predict the DC behaviour of the cable in light of the single strand's experimental properties. The simulation results were compared with experimental results.

  6. Facile synthesis of hierarchical porous TiO(2) ceramics with enhanced photocatalytic performance for micropolluted pesticide degradation.

    Science.gov (United States)

    Xing, Zipeng; Zhou, Wei; Du, Fan; Zhang, Linlin; Li, Zhenzi; Zhang, Hang; Li, Wei

    2014-10-08

    In this research, hierarchical porous TiO2 ceramics were successfully synthesized through a camphene-based freeze-drying route. The well-dispersed TiO2 slurries were first frozen and dried at room temperature, followed by high-temperature sintering. The ceramics were analyzed by X-ray diffraction, Raman spectroscopy, scanning electron microscopy, and transmission electron microscopy. Results indicated that the obtained TiO2 ceramics could inhibit undesirable anatase-to-rutile phase transformation and grain growth even at temperatures as high as 800 °C. In this experiment, optimal compressive strength and porosity of the TiO2 ceramics were produced with the initial TiO2 slurry content of ∼15 wt %. The resultant TiO2 ceramics performed excellently in the photodegradation of atrazine and thiobencarb, and the total organic carbon removal efficiency was up to 95.7% and 96.7%, respectively. More importantly, the TiO2 ceramics were easily recyclable. No obvious changes of the photocatalytic performance were observed after six cycles. Furthermore, the ceramics also effectively degraded other pesticides such as dimethoate, lindane, dipterex, malathion, and bentazone. These hierarchical porous TiO2 ceramics have potential applications in environmental cleanup.

  7. In-situ synthesis of nanomagnetites on poly(amidoamine)-modified graphite oxides and their novel catalytic performances towards the degradation of p-nitroaniline

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Xiang, E-mail: liuxiang@ahut.edu.cn; Zhao, Tiantian; Cheng, Heming; Zhu, Chaoqun; Li, Shun; Cui, Ping, E-mail: cokecp@sohu.com

    2015-02-01

    Graphical abstract: - Highlights: • Hybrids of modified GO and in-situ synthesized magnetite were prepared. • The hybrid performed light-free catalyses on degradation of p-nitroaniline. • Air and aqueous medium were indispensible for the degradation. • The degradation performed fluently without adding H{sub 2}O{sub 2} or pH adjusting. • Such novel properties differed from those of most reported GO hybrids. - Abstract: An approach of loading nanomagnetites (NMs), obtained by in-situ synthesis, on graphite oxides (GO) or poly(amidoamine)-modified GO (pGO) was described in detail in this work. Compared with the GO-NM, the pGO-NM hybrids performed excellent catalysis on degradation of aqueous p-nitroaniline in surrounding air and aqueous medium with a mechanical agitation without light irradiations and additional hydrogen peroxides. These properties differed tremendously from those of most reported metallic oxide-GO hybrids. The catalytic decomposing of the p-nitroaniline was recorded by the successive measurements of an ultraviolet–visible spectrometer. The chemical modifications on GO were investigated with infrared and X-ray photoelectron spectrometers. The hybrids of GO-NM and pGO-NM are estimated with ultraviolet–visible spectrometer, X-ray diffraction, transmission electron microscopy, cyclic voltammetry measurements and thermogravimetric analyses. The experimental results showed that the dissolved oxygen and water were involved in the degradation, which provided solid evidences for the mechanism discussion.

  8. Ultra-performance liquid chromatography quadrupole time-of-flight MS for identification of electron beam from accelerator degradation products of aflatoxin B1.

    Science.gov (United States)

    Wang, Ruiqi; Liu, Ruijie; Chang, Ming; Jin, Qingzhe; Huang, Jianhua; Liu, Yuanfa; Wang, Xingguo

    2015-02-01

    Electron beam irradiation was proven to be a successful method in aflatoxin degradation in earlier researches. However, the exact nature of the result radiation products generated by the aflatoxins remains unknown. Based on ultra-performance liquid chromatography quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF MS) analysis, the solution of aflatoxin B1 (AFB1) in acetonitrile irradiated by electron beam degraded to two kinds of major products. The doses employed were in the range of 0 (control) to 8.60 kGy. The absorbed doses were monitored with FWT-60-00 radio-chromic dosimeters. By using UPLC-Q-TOF MS, accurate masses and proposed molecular formula for the degradation products, 261.1233 m/z (C14H13O5) and 299.1104 m/z (C17H15O5), were obtained from low mass error and high matching properties. Structural formula for the radio-degradation products and the degradation pathways leading to the compounds were proposed, based on the molecular formula and MS-MS spectra. The results showed that electron beam (EB) irradiation is an effective method for degrading AFB1.

  9. Improving Photocatalytic Performance in Degradation of Methylene Blue using Magnetite Fe-doped ZnO/Montmorillonite Nanocomposite

    Science.gov (United States)

    Pratiwi, M. I.; Afifah, N.; Saleh, R.

    2017-05-01

    In this work, we have successfully synthesized Fe:ZnO/Montmorillonite (MMT) nanocomposite with various loading of magnetite (Fe3O4) using co-precipitation method. The as-prepared samples were characterized by some measurements such as X-ray Diffraction (XRD), Burneur-Emment-Teller (BET) surface area analysis, and Fourier Transform Infrared Spectroscopy (FTIR). The XRD result shows that the diffraction pattern of nanocomposites exhibit characteristic from hexagonal wurtzite structure of ZnO and cubical spinel structure of Fe3O4. However, the diffraction pattern from MMT could not be detected using XRD measurement. The presence of MMT in the nanocomposite was further confirmed in the FTIR spectra. Furthermore, the photocatalytic performance of the samples was also checked for degrading methylene blue (MB) under UV light irradiation. The result shows that incorporation of Fe3O4 in Fe:ZnO/MMT has better photocatalytic efficiency than Fe:ZnO/MMT alone. Stability of the nanocomposites was also monitored after several cycle processes.

  10. Enhanced ozonation degradation of di-n-butyl phthalate by zero-valent zinc in aqueous solution: performance and mechanism.

    Science.gov (United States)

    Wen, Gang; Wang, Sheng-Jun; Ma, Jun; Huang, Ting-Lin; Liu, Zheng-Qian; Zhao, Lei; Su, Jun-Feng

    2014-01-30

    Enhanced ozonation degradation of di-n-butyl phthalate (DBP) by zero-valent zinc (ZVZ) has been investigated using a semi-continuous reactor in aqueous solution. The results indicated that the combination of ozone (O3) and ZVZ showed an obvious synergetic effect, i.e. an improvement of 54.8% on DBP degradation was obtained by the O3/ZVZ process after 10min reaction compared to the cumulative effect of O3 alone and O2/ZVZ. The degradation efficiency of DBP increased gradually with the increase of ZVZ dosage, enhanced as solution pH increasing from 2.0 to 10.0, and more amount of DBP was degraded with the initial concentration of DBP arising from 0.5 to 2.0mgL(-1). Recycling use of ZVZ resulted in the enhancement of DBP degradation, because the newly formed zinc oxide took part in the reaction. The mechanism investigation demonstrated that the enhancement effect was attributed to the introduction of ZVZ, which could promote the utilization of O3, enhance the formation of superoxide radical by reducing O2 via one-electron transfer, accelerate the production of hydrogen peroxide and the generation of hydroxyl radical. Additionally, the newly formed zinc oxide on ZVZ surface also contributed to the enhancement of DBP degradation in the recycling use of ZVZ. Most importantly, the O3/ZVZ process was also effective in enhanced ozonation degradation of DBP under the background of actual waters.

  11. Performance and long term degradation of 7 W micro-tubular solid oxide fuel cells for portable applications

    Science.gov (United States)

    Torrell, M.; Morata, A.; Kayser, P.; Kendall, M.; Kendall, K.; Tarancón, A.

    2015-07-01

    Micro-tubular SOFCs have shown an astonishing thermal shock resistance, many orders of magnitude larger than planar SOFCs, opening the possibility of being used in portable applications. However, only few studies have been devoted to study the degradation of large-area micro-tubular SOFCs. This work presents microstructural, electrochemical and long term degradation studies of single micro-tubular cells fabricated by high shear extrusion, operating in the intermediate range of temperatures (T∼700 °C). A maximum power of 7 W per cell has been measured in a wide range of fuel utilizations between 10% and 60% at 700 °C. A degradation rate of 360 mW/1000 h (8%) has been observed for cells operated over more than 1500 h under fuel utilizations of 40%. Higher fuel utilizations lead to strong degradations associated to nickel oxidation/reduction processes. Quick thermal cycling with heating ramp rates of 30 °C /min yielded degradation rates of 440 mW/100 cycles (9%). These reasonable values of degradation under continuous and thermal cycling operation approach the requirements for many portable applications including auxiliary power units or consumer electronics opening this typically forbidden market to the SOFC technology.

  12. PEM fuel cell degradation

    Energy Technology Data Exchange (ETDEWEB)

    Borup, Rodney L [Los Alamos National Laboratory; Mukundan, Rangachary [Los Alamos National Laboratory

    2010-01-01

    The durability of PEM fuel cells is a major barrier to the commercialization of these systems for stationary and transportation power applications. While significant progress has been made in understanding degradation mechanisms and improving materials, further improvements in durability are required to meet commercialization targets. Catalyst and electrode durability remains a primary degradation mode, with much work reported on understanding how the catalyst and electrode structure degrades. Accelerated Stress Tests (ASTs) are used to rapidly evaluate component degradation, however the results are sometimes easy, and other times difficult to correlate. Tests that were developed to accelerate degradation of single components are shown to also affect other component's degradation modes. Non-ideal examples of this include ASTs examining catalyst degradation performances losses due to catalyst degradation do not always well correlate with catalyst surface area and also lead to losses in mass transport.

  13. EFFECT OF DIETARY SUPPLEMENTATION OF NON-STARCH POLYSACCHARIDE DEGRADING ENZYMES ON GROWTH PERFORMANCE OF BROILER CHICKS

    Directory of Open Access Journals (Sweden)

    M. A. Nadeem, M. I. Anjum, A. G. Khan and A. Azim

    2005-10-01

    Full Text Available An experiment was conducted to study the performance and carcass parameters of broilers chicks fed diets with and without supplementing non-starch polysaccharide degrading enzymes (NSPDE at the rate of 0.5 g/kg diet. A total of 300 day-old broiler chicks were randomly divided into 12 sets (replicates each comprising 25 chicks and three sets per treatment group, reared on deep litter from 1-42 days post-hatch. Group A was fed diets without NSPDE supplementation, while group B was fed diets supplemented with NSPDE (0.5 g/kg. Group C was fed diets containing 50 kcal/kg less metabolizable energy (ME without NSPDE and group D was fed diets having 50 kcal/kg less ME with NSPDE (0.5 g/kg supplementation. Feed and water were provided ad libitum. Feed intake and feed conversion ratio (FCR from 1-28 days and 1-42 days was significantly (p<0.05 improved in chicks fed NSPDE supplemented diets (groups B and D compared to non-supplemented diets (groups A and C. However, during 29-42 days of growing period enzymes supplementation did not influence feed intake and FCR. Body weight gain, dressing percentage and relative weights of heart, gizzard and shank at 42 days of age was found to be non-significantly different among all groups. However, liver weight reduced significantly (p<0.05 in NSPDE supplemented groups. The study suggested that NSPDE supplementation was beneficial in enhancing feed utilization during the starter phase, while its effects on weight gain, dressing percentage and weights of organs, except liver weight, were found to be non-significant.

  14. Effect of different levels of rapidly degradable carbohydrates calculated by a simple rumen model on performance of lactating dairy cows.

    Science.gov (United States)

    Doorenbos, J; Martín-Tereso, J; Dijkstra, J; van Laar, H

    2017-07-01

    Aggregating rumen degradation characteristics of different carbohydrate components into the term modeled rapidly degradable carbohydrates (mRDC) can simplify diet formulation by accounting for differences in rate and extent of carbohydrate degradation within and between feedstuffs. This study sought to evaluate responses of lactating dairy cows to diets formulated with increasing levels of mRDC, keeping the supply of other nutrients as constant as possible. The mRDC content of feedstuffs was calculated based on a simple rumen model including soluble, washable, and nonwashable but potentially degradable fractions, as well as the fractional degradation and passage rates, of sugar, starch, neutral detergent fiber, and other carbohydrates. The mRDC term effectively represents the total amount of carbohydrates degraded in the rumen within 2 h after ingestion. Fifty-two lactating Holstein cows (of which 4 were rumen fistulated) were assigned to 4 treatments in a 4 × 4 Latin square design. Treatments were fed as a total mixed ration consisting of 25.4% corn silage, 23.1% grass silage, 11.6% grass hay, and 39.9% concentrate on a dry matter basis. Differences in mRDC were created by exchanging nonforage neutral detergent fiber-rich ingredients (mainly sugar beet pulp) with starch-rich ingredients (mainly wheat) and by exchanging corn (slowly degradable starch) with wheat (rapidly degradable starch) in the concentrate, resulting in 4 treatments that varied in dietary mRDC level of 167, 181, 194, or 208 g/kg of dry matter. Level of mRDC did not affect dry matter intake. Fat- and protein-corrected milk production and milk fat and lactose yield were greatest at 181 mRDC and decreased with further increases in mRDC. Milk protein yield and concentration increased with increasing mRDC level. Mean rumen pH and diurnal variation in ruminal pH did not differ between treatments. Total daily meal time and number of visits per meal were smaller at 181 and 194 mRDC. Despite milk

  15. Effects of material thickness and processing method on poly(lactic-co-glycolic acid) degradation and mechanical performance.

    Science.gov (United States)

    Shirazi, Reyhaneh Neghabat; Aldabbagh, Fawaz; Ronan, William; Erxleben, Andrea; Rochev, Yury; McHugh, Peter

    2016-10-01

    In this study, the effects of material thickness and processing method on the degradation rate and the changes in the mechanical properties of poly(lactic-co-glycolic acid) material during simulated physiological degradation were investigated. Two types of poly(lactic-co-glycolic acid) materials were considered: 0.12 mm solvent-cast films and 1 mm compression-moulded plates. The experimental results presented in this study were compared to the experimental results of Shirazi et al. (Acta Biomaterialia 10(11):4695-703, 2014) for 0.25 mm solvent-cast films. These experimental observations were used to validate the computational modelling predictions of Shirazi et al. (J Mech Behav Biomed Mater 54: 48-59, 2016) on critical diffusion length scale and also to refine the model parameters. The specific material processing methods considered here did not have a significant effect on the degradation rate and the changes in mechanical properties during degradation; however, they influenced the initial molecular weight and they determined the stiffness and hardness of the poly(lactic-co-glycolic acid) material. The experimental observations strongly supported the computational modelling predictions that showed no significant difference in the degradation rate and the changes in the elastic modulus of poly(lactic-co-glycolic acid) films for thicknesses larger than 100 μm.

  16. Effect of the combined probiotics with aflatoxin B₁-degrading enzyme on aflatoxin detoxification, broiler production performance and hepatic enzyme gene expression.

    Science.gov (United States)

    Zuo, Rui-yu; Chang, Juan; Yin, Qing-qiang; Wang, Ping; Yang, Yu-rong; Wang, Xiao; Wang, Guo-qiang; Zheng, Qiu-hong

    2013-09-01

    In order to degrade aflatoxin B₁ (AFB₁), AFB₁-degrading microbes (probiotics) such as Lactobacillus casei, Bacillus subtilis and Pichia anomala, and the AFB₁-degrading enzyme from Aspergillus oryzae were selected and combined to make feed additive. Seventy-five 43-day-old male Arbor Acres broilers were randomly divided into 5 groups, 15 broilers for each group. The broilers were given with 5 kinds of diets such as the basal diet, 400 μg/kg AFB₁ supplement without feed additive, and 200, 400, 800 μg/kg AFB₁ supplement with 0.15% feed additive. The feeding experimental period was 30 d, which was used to determine production performance of broilers. In addition, serum, liver and chest muscle were selected for measuring AFB₁ residues, gene expressions, microscopic and antioxidant analyses. The results showed that adding 0.15% feed additive in broiler diets could significantly relieve the negative effect of AFB₁ on chicken's production performance and nutrient metabolic rates (P<0.05). It could also improve AFB₁ metabolism, hepatic cell structure, antioxidant activity, and many hepatic enzyme gene expressions involved in oxidoreductase, apoptosis, cell growth, immune system and metabolic process (P<0.05). It could be concluded that the feed additive was able to degrade AFB₁ and improve animal production.

  17. Enhanced performance of g-C3N4/TiO2 photocatalysts for degradation of organic pollutants under visible light☆

    Institute of Scientific and Technical Information of China (English)

    Gaixue Song; Zhenyu Chu; Wanqin Jin; Hongqi Sun

    2015-01-01

    Photocatalytic degradation is one of the most promising remediation technologies in terms of advanced oxida-tion processes (AOPs) for water treatment. In this study, novel graphitic carbon nitride/titanium dioxide (g-C3N4/TiO2) composites were synthesized by a facile sonication method. The physicochemical properties of the photocatalyst with different mass ratios of g-C3N4 to TiO2 were investigated by X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscopy (TEM), N2 sorption, Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), and UV–vis DRS. The photocatalytic performances were evaluated by degradation of methylene blue. It was found that g-C3N4/TiO2 with a mass ratio of 1.5:1 exhib-ited the best degradation performance. Under UV, the degradation rate of g-C3N4/TiO2 was 6.92 and 2.65 times higher than g-C3N4 and TiO2, respectively. While under visible light, the enhancement factors became 9.27 (to g-C3N4) and 7.03 (to TiO2). The improved photocatalytic activity was ascribed to the interfacial charge transfer between g-C3N4 and TiO2. This work suggests that hybridization can produce promising solar materials for envi-ronmental remediation.

  18. Clear correspondence between gated-diode R-G current and performance degradation of SOI n-MOSFETs after F-N stress tests

    Institute of Scientific and Technical Information of China (English)

    He Jin; Ma Chenyue; Wang Hao; Chen Xu; Zhang Chenfei; Lin Xinnan; Zhang Xing

    2009-01-01

    A clear correspondence between the gated-diode generation-recombination (R-G) current and the per-formance degradation of an SOI n-channel MOS transistor after F-N stress tests has been demonstrated. Due to the increase of interface traps after F-N stress tests, the R-G current of the gated-diode in the SOI-MOSFET architecture increases while the performance characteristics of the MOSFET transistor such as the saturation drain current and sub-threshold slope are degraded. From a series of experimental measurements of the gated-diode and SOI-MOSFET DC characteristics, a linear decrease of the drain saturation current and increase of the threshold volt-age as well as a like-line rise of the sub-threshold swing and a corresponding degradation in the trans-conductance are also observed. These results provide theoretical and experimental evidence for us to use the gated-diode tool to monitor SOI-MOSFET degradation.

  19. A Doping Lattice of Aluminum and Copper with Accelerated Electron Transfer Process and Enhanced Reductive Degradation Performance

    Science.gov (United States)

    Zhang, Lin; Gao, Xue; Zhang, Zhixuan; Zhang, Mingbo; Cheng, Yiqian; Su, Jixin

    2016-08-01

    Treatment of azo dye effluents has received increasing concerns over the years due to their potential harms to natural environment and human health. The present study described the degrading ability of the as-synthesized crystalline Al-Cu alloys for removal of high-concentration Acid Scarlet 3R in alkaline aqueous solutions and its degradation mechanism. Al-Cu alloy particles with Al/Cu ratios 19:1 were successfully synthesized by high-energy mechanical milling. Characterization results showed that 10 h mechanical alloying process could lead to the formation of crystalline Al(Cu) solid solution. Batch experiment results confirmed the excellent ability of Al-Cu alloy particles for the degradation of 3R in aqueous solution. Under a certain condition ([Al-Cu]0 = 2 g/L, [3R]0 = 200 mg/L, [NaCl]0 = 25 g/L, initial pH = 10.9), the 3R could be completely degraded within only 3 min. It was also found that the degradation reaction followed zero-order kinetics model with respect to the initial dye concentration. The intermediate compounds were identified by UV-vis, FT-IR and HPLC-MS, and a pathway was proposed. Additionally, post-treatment Al-Cu alloy particles were characterized by SEM and TEM, and the results showed that the degradation might be attributed to the corrosion effect of Al-Cu alloys.

  20. Novel membrane bioreactor with gas/liquid two-phase flow for high-performance degradation of phenol

    Energy Technology Data Exchange (ETDEWEB)

    Leonard, D.; Mercier-Bonin, M.; Lindley, N.D.; Lafforgue, C. [Inst. National des Sciences Appliquees, Toulouse (France)

    1998-09-01

    The use of a membrane bioreactor with cell retention to achieve high biomass concentrations has been examined for phenol degradation by the bacteria Alcaligenes eutrophus. This process is particularly interesting for toxic substrates as the hydraulic dilution rate and the growth rate are independently controlled. In the case of a transitory excess of phenol, this potentially toxic situation can be overcome by modifying the substrate concentration or the dilute rate without any loss of cells. The injection of a gas phase at the filter inlet increased both the permeate flow rate and the oxygen transfer capacity. This has enabled the cell concentration to reach a maximum value of 60 g L{sup {minus}1} with a hydraulic dilution rate of 0.5 h{sup {minus}1} and a phenol feed concentration of 8 g L{sup {minus}1}. The volumetric productivity of this process corresponds to a phenol degradation rate approaching 100 kg m{sup {minus}3} day{sup {minus}1}. The on-line measurement of the characteristic yellow color of 2-hydroxymuconate semialdehyde, a metabolic intermediate of the phenol degradation pathway, in the permeate provides an interesting basis for process control of phenol supply into the reactor since the color intensity correlates directly to the specific rate of phenol degradation.

  1. Preparation and photocatalytic degradation performance of Ag{sub 3}PO{sub 4} with a two-step approach

    Energy Technology Data Exchange (ETDEWEB)

    Li, Jiwen; Ji, Xiaojing; Li, Xian; Hu, Xianghua; Sun, Yanfang; Ma, Jingjun, E-mail: mjjwjpmartin@sina.com; Qiao, Gaowei

    2016-05-30

    Highlights: • Ag{sub 3}PO{sub 4} photocatalysts were synthesized via one-step and two-step ion-exchange reaction. • Photocatalytic properties of Ag{sub 3}PO{sub 4} photocatalysts was investigated, the result indicated the Ag{sub 3}PO{sub 4} (2) was higher than that of Ag{sub 3}PO{sub 4} (1) under the same experimental condition. • Ag{sub 3}PO{sub 4} (2) particles were larger than Ag{sub 3}PO{sub 4} (1) particles and many polygonal-shaped surfaces could be clearly observed in the Ag{sub 3}PO{sub 4} (2) particles. - Abstract: Ag{sub 3}PO{sub 4} photocatalysts were prepared via two and one-step through a facile ion-exchange route. The photocatalysts were then characterized through powder X-ray diffraction, scanning electron microscopy and UV–vis diffuse reflectance spectroscopy. The photocatalytic activity of the samples was evaluated on the basis of the photocatalytic degradation of methyl orange (MO) and methylene blue (MB) under solar irradiation. The MO degradation rate of the Photocatalyst synthesized by the two-step ion-exchange route was 89.18% in 60 min. This value was four times that of the Photocatalyst synthesized by the one-step approach.The MB degradation rate was 97% in 40 min. After six cycling runs were completed, the MO degradation rate was 73%.

  2. A study of enhanced performance of VUV/UV process for the degradation of micropollutants from contaminated water.

    Science.gov (United States)

    Bagheri, Mehdi; Mohseni, Madjid

    2015-08-30

    VUV/UV is a chemical-free and straightforward solution for the degradation of emerging contaminants from water sources. The objective of this work was to investigate the feasibility of VUV/UV advanced oxidation process for the effective degradation of a target micropollutant, atrazine, under continuous flow operation of 0.5-6.5L/min. To provide an in-depth understanding of process, a comprehensive computational fluid dynamics (CFD) model, incorporating flow hydrodynamics, 185nm VUV and 254nm UV radiation propagation along with a complete kinetic scheme, was developed and validated experimentally. The experimental degradation rates and CFD predicted values showed great consistency with less than 2.9% average absolute relative deviation (AARD). Utilizing the verified model, energy-efficiency of the VUV/UV process under a wide range of reactor configurations was assessed in terms of electrical energy-per-order (EEO), OH concentration as well as delivered UV and VUV dose distributions. Thereby, the extent of mixing and circulation zones was found as key parameter controlling the treatment economy and energy-efficiency of the VUV/UV process. Utilizing a CFD-driven baffle design strategy, an improved VUV/UV process with up to 72% reduction in the total electrical energy requirement of atrazine degradation was introduced and verified experimentally.

  3. Acidic hydrolysis of bromazepam studied by high performance liquid chromatography. Isolation and identification of its degradation products.

    Science.gov (United States)

    Panderi, I; Archontaki, H; Gikas, E; Parissi-Poulou, M

    1998-06-01

    A kinetic study on the acidic hydrolysis of bromazepam was carried out in 0.01 M hydrochloric acid solution at 25 and 95 degrees C. A reversed-phase HPLC method was developed and validated for the determination of bromazepam and its degradation products. Bromazepam degraded by a consecutive reaction with a reversible first step. Two degradation products were isolated and identified by infrared, 1H and 13C nuclear magnetic resonance and mass spectroscopy. Spectroscopic data indicated that N-(4-bromo-2-(2-pyridylcarbonyl)phenyl)-2-aminoacetamide was the intermediate degradation product of this acid hydrolysis, whereas 2-amino-5-bromophenyl-2-pyridylmethanone was the final one. Therefore, the mechanism of this acid-catalysed hydrolysis involved initial cleavage of the 4,5-azomethine bond, followed by slow breakage of the 1,2-amide bond. Statistical evaluation of the HPLC method revealed its good linearity and reproducibility. Detection limits were 3.8 x 10(-7) M for bromazepam, 6.25 x 10(-7) M for the intermediate and 8.16 x 10(-7) M for the benzophenone derivative.

  4. CdS quantum dots confined in mesoporous TiO2 with exceptional photocatalytic performance for degradation of organic polutants.

    Science.gov (United States)

    Zhou, Panpan; Xie, Yu; Fang, Jing; Ling, Yun; Yu, Changling; Liu, Xiaoming; Dai, Yuhua; Qin, Yuancheng; Zhou, Dan

    2017-07-01

    In this paper, the mesoporous TiO2 with different concentration of CdS quantum dots (i.e., x% CdS/TiO2) was successfully fabricated by the sol-gel method. The composition, structure and morphology of the nanocomposites were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), UV-vis diffuse reflectance spectroscopy (UV-Vis/DRS) and nitrogen physical adsorption test and so on. The proportion of CdS and TiO2 is very important for the photocatalytic performance. As a result, the photocatalytic degradation performance from the most to the least is in the order of 2% CdS/TiO2, 4% CdS/TiO2, 8% CdS/TiO2, pure TiO2 and 1% CdS/TiO2. The photocatalytic (PC) activity of the 2% CdSTiO2 is characterized by photocatalytic degradation of methyl orange, which can be completely degraded within 45 min better than 60 min TiO2 takes. It is also much better than CdS. Moreover, other four organic pollutants, such as methylthionine chloride, bisphenol A, rhodamine B, malachite green can also be degraded quickly on the condition of 2% CdS/TiO2. What's more, the chemical stability and cycling capability of 2% CdS/TiO2 are reflected by five cyclic degradation of methyl orange.

  5. Structural characterisation of degradation products formed upon di-n-butyl phthalate radiolysis by high-performance liquid chromatography electro-spray tandem mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Tintaru, A.; Charles, L. [Univ Aix Marseille 1, CNRS, Lab Chim Provence Spectrometries Appl Chim Struct, UMR 6264, F-13397 Marseille (France); Univ Aix Marseille 2, CNRS, Lab Chim Provence Spectrometries Appl Chim Struct, UMR 6264, F-13397 Marseille (France); Labed, V. [CEA Marcoule, DTCD SPDE L2ED, F-30207 Bagnols Sur Ceze (France)

    2010-07-01

    Complete text of publication follows: Structural characterisation of 15 degradation products, formed upon di-n-butyl phthalate (DBP) radiolysis, has been achieved using a high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) coupling. The dissociation behaviour of protonated DBP was first established to be further used to characterise structural deviation in the degradation products. Based on accurate mass measurements, compounds shown by HPLC-MS analysis were all found to be DBP oxidation products, amongst which various sets of isomers could be distinguished. Collision-induced dissociation experiments performed on each electro-sprayed molecule first allowed unambiguous definition of the location of the additional oxygen atoms; that is, in the alkyl branch or on the aromatic ring. Although location of the oxygen atom in the alkyl branches could not always be precisely determined, relative abundances of some product ions allowed oxygenated functions to be identified

  6. Study on the growth performance of the broiler after feeding of okara meal containing with or without non-starch polysaccharides degrading enzyme

    Directory of Open Access Journals (Sweden)

    Subodh Kumar Sinha

    2013-12-01

    Full Text Available Aim: The objective was to study the growth performance of the broiler birds after feeding Okara meal containing with or without non-starch polysaccharides degrading enzyme. Materials and Methods: 220 day-old broiler chicks were individually weighed and divided randomly into five treatment groups (T1 , T2 , T3 , T4 and T5 consisting of 44 chicks each which was further subdivided into four replicates of 11 chicks. The feed consumption in each replicates of five groups was recorded daily for a total period of 6 weeks experimental feeding. Results: The average total feed consumption of six weeks was 3948.10±7.60, 4088.76±8.30, 4415.33±9.44, 4381.24±9.25 and 4728.76±10.05 (g in groups T1 , T2 , T3 , T4 and T5 respectively. The differences were statistically non-significant (P>0.05 among the various groups. The average total body weight gain and average daily weight gain in birds of group T4 were significantly higher (P<0.01 than birds of other groups except T3 group. It showed that 25 percent replacement of ground nut cake with Okara meal and addition of non-starch polysaccharides degrading enzyme (provizyme-bro had positive effect on growth performance of birds. The increase in weight in broilers of enzyme added group T4 in comparison to their counterpart without enzyme group (T2 and T3 attributed to degradation of non-starch polysaccharides in ration, thereby, enhancing the utilization of other nutrients. Conclusion: The findings indicated that 25 percent replacement of ground nut cake with Okara meal and addition of nonstarch polysaccharides degrading enzyme had positive effect on growth performance of birds. So, Okara meal feeding had no adverse effect on growth performance of the broilers. [Vet World 2013; 6(6.000: 325-328

  7. Adaptive hidden Markov model-based online learning framework for bearing faulty detection and performance degradation monitoring

    Science.gov (United States)

    Yu, Jianbo

    2017-01-01

    This study proposes an adaptive-learning-based method for machine faulty detection and health degradation monitoring. The kernel of the proposed method is an "evolving" model that uses an unsupervised online learning scheme, in which an adaptive hidden Markov model (AHMM) is used for online learning the dynamic health changes of machines in their full life. A statistical index is developed for recognizing the new health states in the machines. Those new health states are then described online by adding of new hidden states in AHMM. Furthermore, the health degradations in machines are quantified online by an AHMM-based health index (HI) that measures the similarity between two density distributions that describe the historic and current health states, respectively. When necessary, the proposed method characterizes the distinct operating modes of the machine and can learn online both abrupt as well as gradual health changes. Our method overcomes some drawbacks of the HIs (e.g., relatively low comprehensibility and applicability) based on fixed monitoring models constructed in the offline phase. Results from its application in a bearing life test reveal that the proposed method is effective in online detection and adaptive assessment of machine health degradation. This study provides a useful guide for developing a condition-based maintenance (CBM) system that uses an online learning method without considerable human intervention.

  8. 丙酮丁醇梭菌Clostridium acetobutylicum CICC 8012发酵鲜芭蕉芋生产丁醇%Optimization of Butanol Production from Canna edulis Ker by Clostridium acetobutylicum Using Response Surface Methodology

    Institute of Scientific and Technical Information of China (English)

    龙飞; 靳艳玲; 赵云; 郜晓峰; 李宇浩; 陈谦; 赵海

    2013-01-01

    以非粮作物鲜芭蕉芋为原料,利用丙酮丁醇梭菌CICC 8012发酵生产丁醇.采用中心组合实验设计(CCD),选取初始糖浓度、接种量、中性红、乙酸铵为主要影响因素,对发酵条件进行优化,建立以丁醇产量为响应值的数学模型.对模型求解得到:初始糖浓度62.25 g/L,接种量为10.81%,中性红为0.81 g/L,乙酸铵为0.574 g/L时,最终的丁醇产量为12.83 g/L.验证实验结果表明,在优化条件下丁醇发酵产量达到12.73 g/L,证明了模型可靠有效.%Raw Canna edulis Ker, one of the non-food crops, was utilized in this study to produce butanol by Clostridium acetobutylicum CICC 8012. Central Composite Design (CCD) was adopted to optimize experiment conditions including four crucial factors which were initial sugar concentration, inoculation volume, neutral red and ammonium acetate. According to the results of the model, the optimal conditions of butanol fermentation were that: initial sugar concentration 62.25 g/L, inoculation volume 10.81%, neutral red usage 0.81 g/L, ammonium acetate usage 0.574 g/L and final butanol yield of 12.83 g/L. In the verification experiment, the butanol yield of 12.73 g/L was obtained under the optimal conditions, which indicated that the model was reliable and effective. Fig 3, Tab 5, Ref 24

  9. Batteries: Imaging degradation

    Science.gov (United States)

    Shearing, Paul R.

    2016-11-01

    The degradation and failure of Li-ion batteries is strongly associated with electrode microstructure change upon (de)lithiation. Now, an operando X-ray tomography approach is shown to correlate changes in the microstructure of electrodes to cell performance, and thereby predict degradation pathways.

  10. Syntrophy in Methanogenic Degradation

    NARCIS (Netherlands)

    Worm, P.; Müller, N.; Plugge, C.M.; Stams, A.J.M.; Schink, B.

    2010-01-01

    This chapter deals with microbial communities of bacteria and archaea that closely cooperate in methanogenic degradation and perform metabolic functions in this community that neither one of them could carry out alone. The methanogenic degradation of fatty acids, alcohols, most aromatic compounds, a

  11. 耐热石油降解混合菌群的降解性能研究%Study on Degrading Performance of A Thermophilic Oil-Degrading Bacterial Group

    Institute of Scientific and Technical Information of China (English)

    李政; 赵朝成; 张云波; 刘春爽; 赵东风

    2011-01-01

    针对极端环境下石油污染土壤的生物修复,从克拉玛依油田石油污染土壤中筛选获得一组最适生长温度为45~55℃、最高耐受温度为75℃的耐热石油降解混合菌群KLO-8,该混合菌群由4株单菌组成,16S rDNA序列分析鉴定表明,其中3株为芽孢杆菌(Bacillus sp.)、1株为地芽孢杆菌(Geobacillus sp.).考察了KLO-8的降解性能,结果表明:最佳培养时间为7d;最佳氮磷比为3:1;初始pH值偏碱性更利于原油的降解,最佳初始pH值为8;原油浓度不高于10 g·L-1时降解效果较好;添加表面活性剂(十二烷基苯磺酸钠)能够提高混合菌群的降油效果,最佳添加浓度为50mg·L-1.气相色谱—模拟蒸馏分析结果表明,KLO-8对C11~C37的正构烷烃降解效果显著,随着碳原子数的增加,混合菌群对原油中正构烷烃的利用率逐渐降低.%For bioremediation of oil-contaminated soil under extreme conditions,a thermophilic oil-degrading bacterial group KLO-8 composed of four single strains was isolated from Karamay Oilfield oil-contaminated soil. Its optimal growth temperature was 45 - 55 °C ,and its highest resistant temperature was 75℃. Based on 16S rDNA sequence analysis, three single strains of KLO-8 was Bacillus sp. , one strain was Geobacillus sp.. The degrading performance of KLO-8 were discussed. The results showed that the optimal culture time was 7 d,the optimal nitrogen-phosphorus ratio was 3∶1,the initial pH value leaning alkalinity was more propitious to crude oil degradation and the optimal initial pH value was 8,the crude oil concentration below 10 g· L-1 was suitable,the addition of surfactant (sodium dodecyl benzene sulfonate) was able to improve the crude oil degradation rate and the optimal concentration was 50 mg ·L-1. Gas chromatogram-simulation distillation analysis result showed that KLO-8 was able to degrade the n-alkanes ranging from C11 to C37 and the degradation decreased with the long-chain alkanes

  12. Application of Cerebellar Model Articulation Controller(CMAC) with a Modified Algorithm in Monitoring Machine Performance Degradation

    Institute of Scientific and Technical Information of China (English)

    ZHANG Jing-yong; ZHANG Lei; CAO Qi-xin; Jay Lee

    2005-01-01

    On the basis of CMAC-PDM (Pattern Discrimination Model), a novel algorithm of CMAC for monitoring machine degradation is proposed in this paper. The output of CMAC with the novel algorithm represents the state of a machine and PDM is not needed. The principle was explained by analyzing the modified mapping process of CMAC. The novel CMAC is applied to a tool condition monitoring system and two methodologies (novel CMAC and CMAC-PDM) are compared. The results prove that the novel algorithm is feasible and its computational complexity is reduced significantly.

  13. Stability and Degradation of Caffeoylquinic Acids under Different Storage Conditions Studied by High-Performance Liquid Chromatography with Photo Diode Array Detection and High-Performance Liquid Chromatography with Electrospray Ionization Collision-Induced Dissociation Tandem Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Meng Xue

    2016-07-01

    Full Text Available Caffeoylquinic acids (CQAs are main constituents in many herbal medicines with various biological and pharmacological effects. However, CQAs will degrade or isomerize when affected by temperature, pH, light, etc. In this study, high-performance liquid chromatography with photodiode array detection (HPLC-PDA and high-performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS was utilized to study the stability and degradation of CQAs (three mono-acyl CQAs and four di-acyl CQAs under various ordinary storage conditions (involving different temperatures, solvents, and light irradiation. The results indicated that the stability of CQAs was mainly affected by temperature and light irradiation, while solvents did not affect it in any obvious way under the conditions studied. Mono-acyl CQAs were generally much more stable than di-acyl CQAs under the same conditions. Meanwhile, the chemical structures of 30 degradation products were also characterized by HPLC-MSn, inferring that isomerization, methylation, and hydrolysis were three major degradation pathways. The result provides a meaningful clue for the storage conditions of CQAs standard substances and samples.

  14. A floating macro/mesoporous crystalline anatase TiO2 ceramic with enhanced photocatalytic performance for recalcitrant wastewater degradation.

    Science.gov (United States)

    Xing, Zipeng; Zhou, Wei; Du, Fan; Qu, Yang; Tian, Guohui; Pan, Kai; Tian, Chungui; Fu, Honggang

    2014-01-14

    A macro/mesoporous anatase TiO2 ceramic floating photocatalyst has been successfully synthesized using highly thermally stable mesoporous TiO2 powder as a precursor, followed by a camphene-based freeze-casting process and high-temperature calcinations. The ceramics are characterized in detail by X-ray diffraction, Raman spectra, scanning electron microscopy, transmission electron microscopy and N2 adsorption-desorption isotherms. The results indicate that the TiO2 ceramics present hierarchical macro/mesoporous structures, which maintain high porosity and high compressive strength at the optimal sintering temperature of 800 °C. The ordered mesoporous TiO2 network still possesses high thermal stability and inhibits the anatase-to-rutile phase transformation during calcinations. The obtained ceramics exhibit good adsorptive and photocatalytic activity for the degradation of octane and rhodamine B, and the total organic carbon removal ratio is up to 98.8% and 98.6% after photodegradation for 3 h, respectively. The roles of active species in the photocatalytic process are compared using different types of active species scavengers, and the degradation mechanism is also proposed. Furthermore, the ceramics are recyclable, and no clear changes are observed after ten cycles. In addition, the ceramics are also active in the photodegradation of phenol, thiobencarb, and atrazine. Therefore, these novel floating photocatalysts will have wide applications, including the removal of floating organic pollutants from the wastewater surfaces or the removal of soluble organic pollutants from wastewater.

  15. Isolation, plant colonization potential, and phenanthrene degradation performance of the endophytic bacterium Pseudomonas sp. Ph6-gfp

    Science.gov (United States)

    Sun, Kai; Liu, Juan; Gao, Yanzheng; Jin, Li; Gu, Yujun; Wang, Wanqing

    2014-06-01

    This investigation provides a novel method of endophyte-aided removal of polycyclic aromatic hydrocarbons (PAHs) from plant bodies. A phenanthrene-degrading endophytic bacterium Pseudomonas sp. Ph6 was isolated from clover (Trifolium pratense L.) grown in a PAH-contaminated site. After being marked with the GFP gene, the colonization and distribution of strain Ph6-gfp was directly visualized in plant roots, stems, and leaves for the first time. After ryegrass (Lolium multiflorum Lam.) roots inoculation, strain Ph6-gfp actively and internally colonized plant roots and transferred vertically to the shoots. Ph6-gfp had a natural capacity to cope with phenanthrene in vitro and in planta. Ph6-gfp degraded 81.1% of phenanthrene (50 mg.L-1) in a culture solution within 15 days. The inoculation of plants with Ph6-gfp reduced the risks associated with plant phenanthrene contamination based on observations of decreased concentration, accumulation, and translocation factors of phenanthrene in ryegrass. Our results will have important ramifications in the assessment of the environmental risks of PAHs and in finding ways to circumvent plant PAH contamination.

  16. Visible-light-induced photocatalytic performances of ZnO-CuO nanocomposites for degradation of 2,4-dichlorophenol

    Institute of Scientific and Technical Information of China (English)

    E. D. Sherly; J. Judith Vijaya; L.John Kennedy

    2015-01-01

    Nanostructured ZnO and CuO, and coupled oxides, i.e., ZnCu, Zn2Cu, and ZnCu2, with ZnO:CuO molar ratios of 1:1, 2:1, and 1:2, respectively, were successfully prepared through a simple, one-step, mi-crowave-assisted urea–nitrate combustion synthesis, without the use of organic solvents or surfac-tants. The prepared samples were characterized using X-ray diffraction, X-ray photoelectron spec-troscopy, scanning electron microscopy, energy-dispersive X-ray analysis, transmission electron microscopy, Fourier-transform infrared spectroscopy, diffuse reflectance spectroscopy, and photo-luminescence spectroscopy. The optical absorption of ZnO extended into the visible region after CuO loading. The photocatalytic activities of ZnO, CuO, and the coupled oxides were evaluated based on photodegradation of 2,4-dichlorophenol under visible-light irradiation. The coupled metal oxide Zn2Cu showed the best photocatalytic activity;this was mainly attributed to the extended photore-sponsive range and the increased charge separation rate in the nanocomposite. The photocatalytic degradation process obeyed pseudo-first-order kinetics. The results suggest that the coupled metal oxide Zn2Cu has potential applications as an efficient catalytic material with high efficiency and recyclability for the photocatalytic degradation of organic pollutants in aqueous solution under visible-light irradiation.

  17. Stress degradation studies of Telmisartan and Metoprolol extended release tablets by a validated stability indicating reverse phase-high performance liquid chromatography method

    Directory of Open Access Journals (Sweden)

    Kabeer Ahmed Shaikh

    2014-01-01

    Full Text Available Background and Aim: A sensitive reverse phase high-performance liquid chromatographic method has been developed for the simultaneous determination of Telimisartan and Metoprolol in tablet dosage form. Materials and Method: The chromatographic separation was achieved on Inertsil ODS 3V, 150 x 4.6 mm, 5μ analytical column. Mobile phase consisting of mobile phase A- 0.05M sodium dihydrogen phosphate buffer pH 3.0 and mobile phase B-Acetonitrile, with gradient program time in min /Mobile phase B% 0/22, 4/45, 6/45,18/22, 20/22. Detector was set at 222nm. Results and Conclusion: The described method shows excellent linearity over a range of 80-2 μg mL−1 for Telmisartan and 100-4 μg mL−1 for Metoprolol. The correlation coefficient for Telmisartan is 0.9998 and Metoprolol is 0.9999. The proposed method was found to be suitable for determination of Telmisartan and Metoprolol in tablet dosage form. Forced degradation of the drug product was conducted in accordance with the ICH guideline. Acidic, basic, hydrolytic, oxidative, thermal and photolytic degradation was used to assess the stability indicating power of the method. The drug product was found to be stable in acid, oxidation, thermal and photolytic stress condition and found degradation in base hydrolysis stress condition.

  18. Facile fabrication, characterization, and enhanced photoelectrocatalytic degradation performance of highly oriented TiO2 nanotube arrays

    Science.gov (United States)

    Zhao, Qidong; Li, Xinyong; Wang, Ning; Hou, Yang; Quan, Xie; Chen, Guohua

    2009-11-01

    Highly ordered TiO2 nanotube arrays were successfully fabricated using ethanol and water mixture electrolytes (40 vol% ethanol and 0.2 wt% hydrofluoric acid) by a facile electrochemical anodization method. The as-prepared nanotube arrays were grown perpendicular to the titanium substrate with about 90 nm in diameter, 20 nm in wall thickness, and around 500 nm in length. The formation mechanism of the samples is briefly discussed. A blue shift in the spectrum of UV-Vis absorption was observed with respect to a piece of the sol-gel derived TiO2 film. Moreover, photocurrent response and photoelectrocatalytic degradation of methyl orange under ultraviolet light irradiation were adopted to evaluate the photoelectrocatalytic properties of the TiO2 nanotube arrays. We demonstrate that the highly ordered TiO2 nanotube arrays possess much better photoelectrocatalytic activity than the sol-gel derived TiO2 film and good stability.

  19. Oxygen-Induced Degradation in C60-Based Organic Solar Cells: Relation Between Film Properties and Device Performance.

    Science.gov (United States)

    Bastos, João P; Voroshazi, Eszter; Fron, Eduard; Brammertz, Guy; Vangerven, Tim; Van der Auweraer, Mark; Poortmans, Jef; Cheyns, David

    2016-04-20

    Fullerene-based molecules are the archetypical electron-accepting materials for organic photovoltaic devices. A detailed knowledge of the degradation mechanisms that occur in C60 layers will aid in the development of more stable organic solar cells. Here, the impact of storage in air on the optical and electrical properties of C60 is studied in thin films and in devices. Atmospheric exposure induces oxygen-trap states that are 0.19 eV below the LUMO of the fullerene C60. Moreover, oxygen causes a 4-fold decrease of the exciton lifetime in C60 layers, resulting in a 40% drop of short-circuit current from optimized planar heterojunction solar cells. The presence of oxygen-trap states increases the saturation current of the device, resulting in a 20% loss of open-circuit voltage. Design guidelines are outlined to improve air stability for fullerene-containing devices.

  20. Performance Degradation of Thermal Parameters during Cycle Ageing of High Energy Density Ni-Mn-Co based Lithium-Ion Battery Cells

    DEFF Research Database (Denmark)

    Stanciu, Tiberiu; Stroe, Daniel Loan; Swierczynski, Maciej Jozef

    2016-01-01

    as well, since the thermal management of the battery is crucial for the safety of the EV driver. Moreover, the thermal management system can significantly lower the degradation rate of the battery pack and thus reduce costs. In this paper, the thermal characterization of a commercially available Nickel......-Manganese-Cobalt (NMC) based Li-ion battery cell was performed under different operating conditions: state-of-charge (SOC) levels, charge/discharge current rates and operating temperatures. Moreover, by carrying out accelerated cycle ageing tests on a total of nine NMC-based Li-ion battery cells, the effect of ageing...

  1. History of adaptation determines short-term shifts in performance and community structure of hydrogen-producing microbial communities degrading wheat straw.

    Science.gov (United States)

    Valdez-Vazquez, Idania; Morales, Ana L; Escalante, Ana E

    2017-03-14

    This study addresses the question of ecological interest for the determination of structure and diversity of microbial communities that degrade lignocellulosic biomasses to produce biofuels. Two microbial consortia with different history, native of wheat straw (NWS) and from a methanogenic digester (MD) fed with cow manure, were contrasted in terms of hydrogen performance, substrate disintegration and microbial diversity. NWS outperformed the hydrogen production rate of MD. Microscopic images revealed that NWS acted on the cuticle and epidermis, generating cellulose strands with high crystallinity, while MD degraded deeper layers, equally affecting all polysaccharides. The bacterial composition markedly differed according to the inocula origin. NWS almost solely comprised hydrogen producers of the phyla Firmicutes and Proteobacteria, with 38% members of Enterococcus. After hydrogen fermentation, NWS comprised 8% Syntrophococcus, an acetogen that cleaves aryl ethers of constituent groups on the aromatic components of lignin. Conversely, MD comprised thirteen phyla, primarily including Firmicutes with H2 -producing members, and Bacteroidetes with non-H2 -producing members, which reduced the hydrogen performance. Overall, the results of this study provide clear evidence that the history of adaptation of NWS enhanced the hydrogen performance from untreated wheat straw. Further, native wheat straw communities have the potential to refine cellulose fibers and produce biofuels simultaneously. © 2017 The Authors. Microbial Biotechnology published by John Wiley & Sons Ltd and Society for Applied Microbiology.

  2. A validated stability-indicating high performance liquid chromatographic method for moxifloxacin hydrochloride and ketorolac tromethamine eye drops and its application in pH dependent degradation kinetics

    Directory of Open Access Journals (Sweden)

    Jayant B Dave

    2013-01-01

    Full Text Available Background and Aim: A fixed dose combination of moxifloxacin hydrochloride and ketorolac tromethamine is used in ratio of 1:1 as eye drops for the treatment of the reduction of post operative inflammatory conditions of the eye. A simple, precise, and accurate High Performance Liquid Chromatographic (HPLC method was developed and validated for determination of moxifloxacin hydrochloride and ketorolac tromethamine in eye drops. Materials and Methods: Isocratic HPLC separation was achieved on a ACE C 18 column (C 18 (5 μm, 150 mm×4.6 mm, i.d. using the mobile phase 10 mM potassium di-hydrogen phosphate buffer pH 4.6-Acetonitrile (75:25 v/v at a flow rate of 1.0 mL/min. The detection was performed at 307 nm. Drugs were subjected to acid, alkali and neutral hydrolysis, oxidation and photo degradation. Moreover, the proposed HPLC method was utilized to investigate the pH dependent degradation kinetics of moxifloxacin hydrochloride and ketorolac tromethamine in buffer solutions at different pH values like 2.0, 6.8 and 9.0. Results and Conclusion: The retention time (t R of moxifloxacin hydrochloride and ketorolac tromethamine were 3.81±0.01 and 8.82±0.02 min, respectively. The method was linear in the concentration range of 2-20 μ/mL each for moxifloxacin hydrochloride and ketorolac tromethamine with a correlation coefficient of 0.9996 and 0.9999, respectively. The method was validated for linearity, precision, accuracy, robustness, specificity, limit of detection and limit of quantitation. The drugs could be effectively separated from different degradation products and hence the method can be used for stability analysis. Different kinetics parameters like apparent first-order rate constant, half-life and t 90 (time for 90% potency left were calculated.

  3. Role of polyaniline on the photocatalytic degradation and stability performance of the polyaniline/silver/silver phosphate composite under visible light.

    Science.gov (United States)

    Bu, Yuyu; Chen, Zhuoyuan

    2014-10-22

    Polyaniline/silver/silver phosphate (PANI/Ag/Ag3PO4) composite was prepared by in situ depositing silver phosphate (Ag3PO4) nanoparticles on the surface of polyaniline (PANI). The best photocatalytic Rhodamine B degradation performance is obtained by the 20 wt % PANI/Ag/Ag3PO4 composite, which is approximately 4 times higher than that of pure Ag3PO4. Meanwhile, the photocatalytic stability of Ag3PO4 is significantly improved by introducing PANI into the PANI/Ag/Ag3PO4 composite. The dramatic promotion of the photocatalytic degradation performance and the photocatalytic stability can be attributed to the formation of a heterojunction electric field between PANI and Ag3PO4, which is approximately 90 mV and points from Ag3PO4 to PANI. The existence of this electric field can dramatically enhance the separation efficiency of the photogenerated electron-hole pairs, accelerate the transfer of photogenerated holes from Ag3PO4 to PANI and therefore inhibit the self-oxidation of Ag3PO4.

  4. Analysis of the Material Factors in the Degradation of SOFC Performance%浅析SOFC性能衰减的材料因素

    Institute of Scientific and Technical Information of China (English)

    高克卿; 刘晓天; 赵二庆; 樊丽权; 熊岳平

    2013-01-01

    Based on the cell operating conditions, the material factors which influence the cell performance of SOFC including the chemical stability of materials at solid-gas interface in redox atmosphere, the diffusion and reaction between the interface of solid-solid materials, and degradation caused by the external chemical substances brought into the cells at triple phase boundary are mainly analyzed. Given that under the current state of the research it is urgent to explore the material factors on degradation of cell performance to meet demands in SOFC applications.%从SOFC工作状态出发,分析了材料在氧化还原气氛中的固-气界面化学稳定性、材料间固-固界面的扩散与相互反应的特性,以及外部化学物质的介入对三相界面反应的干扰等三方面因素对电池性能可能产生的影响.作者认为,注重探究实用的SOFC电池性能衰减材料因素有助于我国SOFC电堆的研制.

  5. Classification of fault location and the degree of performance degradation of a rolling bearing based on an improved hyper-sphere-structured multi-class support vector machine

    Science.gov (United States)

    Wang, Yujing; Kang, Shouqiang; Jiang, Yicheng; Yang, Guangxue; Song, Lixin; Mikulovich, V. I.

    2012-05-01

    Effective classification of a rolling bearing fault location and especially its degree of performance degradation provides an important basis for appropriate fault judgment and processing. Two methods are introduced to extract features of the rolling bearing vibration signal—one combining empirical mode decomposition (EMD) with the autoregressive model, whose model parameters and variances of the remnant can be obtained using the Yule-Walker or Ulrych-Clayton method, and the other combining EMD with singular value decomposition. Feature vector matrices obtained are then regarded as the input of the improved hyper-sphere-structured multi-class support vector machine (HSSMC-SVM) for classification. Thereby, multi-status intelligent diagnosis of normal rolling bearings and faulty rolling bearings at different locations and the degrees of performance degradation of the faulty rolling bearings can be achieved simultaneously. Experimental results show that EMD combined with singular value decomposition and the improved HSSMC-SVM intelligent method requires less time and has a higher recognition rate.

  6. Validated Stability-indicating High-performance Liquid Chromatographic Method for Estimation of Degradation Behaviour of Eberconazole Nitrate and Mometasone Furoate in Cream Formulation

    Directory of Open Access Journals (Sweden)

    N Sharma

    2013-01-01

    Full Text Available The objective of current investigation was to study the degradation behaviour of eberconazole nitrate and mometasone furoate under different International Conference on harmonisation recommended stress condition using reverse phase high performance liquid chromatographic method and to establish validated stability-indicating high performance liquid chromatographic method to determine purity of eberconazole nitrate and mometasone furoate in presence of its impurities, forced degradation products and placebo in pharmaceutical dosage forms. The method was developed using Hypersil BDS, C18, 150Χ4.6 mm, 5 μ as stationary phase with mobile phase containing a gradient mixture of solvent A and B. 0.01 M phosphate buffer with 0.1% triethyl amine, adjusted pH 7.0 with phosphoric acid was used as buffer. Buffer pH 7.0 was used as solvent A and methanol:acetonitrile in 150:850 v/v ratios were used as solvent B. The eluted compounds were monitored at 240 nm. The run time was 50 min. The developed method was validated as per international conference on harmonization guidelines with respect to specificity, linearity, limit of detection, limit of quantification, accuracy, precision and robustness.

  7. Validated Stability-indicating High-performance Liquid Chromatographic Method for Estimation of Degradation Behaviour of Eberconazole Nitrate and Mometasone Furoate in Cream Formulation.

    Science.gov (United States)

    Sharma, N; Rao, S S; Vaghela, B

    2013-01-01

    The objective of current investigation was to study the degradation behaviour of eberconazole nitrate and mometasone furoate under different International Conference on harmonisation recommended stress condition using reverse phase high performance liquid chromatographic method and to establish validated stability-indicating high performance liquid chromatographic method to determine purity of eberconazole nitrate and mometasone furoate in presence of its impurities, forced degradation products and placebo in pharmaceutical dosage forms. The method was developed using Hypersil BDS, C18, 150Χ4.6 mm, 5 μ as stationary phase with mobile phase containing a gradient mixture of solvent A and B. 0.01 M phosphate buffer with 0.1% triethyl amine, adjusted pH 7.0 with phosphoric acid was used as buffer. Buffer pH 7.0 was used as solvent A and methanol:acetonitrile in 150:850 v/v ratios were used as solvent B. The eluted compounds were monitored at 240 nm. The run time was 50 min. The developed method was validated as per international conference on harmonization guidelines with respect to specificity, linearity, limit of detection, limit of quantification, accuracy, precision and robustness.

  8. The Role of FeS in Initial Activation and Performance Degradation of Na-NiCl2 Batteries

    Energy Technology Data Exchange (ETDEWEB)

    Li, Guosheng [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Lu, Xiaochuan [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Kim, Jin Yong [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Engelhard, Mark H. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Lemmon, John P. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Sprenkle, Vincent L. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2014-12-25

    The role of iron sulfide (FeS) in initial cell activation and degradation in the Na-NiCl2 battery was investigated in this work. The research focused on identifying the effects of the FeS level on the electrochemical performance and morphological changes in the cathode. The x-ray photoelectron spectroscopy study along with battery tests revealed that FeS plays a critical role in initial battery activation by removing passivation layers on Ni particles. It was also found that the optimum level of FeS in the cathode resulted in minimum Ni particle growth and improved battery cycling performance. The results of electrochemical characterization indicated that sulfur species generated in situ during initial charging, such as polysulfide and sulfur, are responsible for removing the passivation layer. Consequently, the cells containing elemental sulfur in the cathode exhibited similar electrochemical behavior during initial charging compared to that of the cells containing FeS.

  9. Microwave-induced crystallization of AC/TiO{sub 2} for improving the performance of rhodamine B dye degradation

    Energy Technology Data Exchange (ETDEWEB)

    Tian, Fei [School of Chemistry and Chemical Engineering, Shihezi University, Shihezi 832003 (China); Wu, Zhansheng, E-mail: wuzhans@126.com [School of Chemistry and Chemical Engineering, Shihezi University, Shihezi 832003 (China); Chen, Qiuyu; Yan, Yujun [School of Chemistry and Chemical Engineering, Shihezi University, Shihezi 832003 (China); Cravotto, Giancarlo; Wu, Zhilin [Dipartimento di Scienza e Tecnologia del Farmaco, University of Turin, Torino 10125 (Italy)

    2015-10-01

    Graphical abstract: - Highlights: • Mixed phase titania coated with AC was obtained by microwave irradiation method. • The TiO{sub 2} nanoparticles were spherical and well distributed on the surface of AC. • The light absorption edges of AC/TiO{sub 2} showed red-shift compared to the pure TiO{sub 2}. • Higher surface and TiO{sub 2} content of AC/TiO{sub 2} could improve photocatalytic efficiency. - Abstract: Titanium dioxide (TiO{sub 2}) deposition on activated carbon (AC) is widely used for pollutant photodegradation. In this study, a simple and efficient method for preparing AC/TiO{sub 2} composites under microwave irradiation was developed for photocatalytic degradation of rhodamine B (RhB) under UV light. Results of X-ray diffraction, scanning electron microscopy, and transmission electron microscopy revealed that TiO{sub 2} nanoparticles are anatase and rutile, with a spherical shape and a particle size of 20–50 nm and are well distributed on the AC surface. The UV–vis spectrum of TiO{sub 2} coated on AC showed an evident red-shift and exhibited stronger optical absorption capacity than pure TiO{sub 2}. The AC/TiO{sub 2} nanoparticles prepared at a microwave power of 700 W for 15 min exhibited 98% efficiency in removing RhB dye under UV irradiation for 30 min. The high photocatalytic activity of AC/TiO{sub 2}-700 W could be mainly attributed to the high sorption capacity of the mesoporous carbon material and high TiO{sub 2} content, which could produce higher quantity of ·OH. This study provides a rapid synthesis technique to prepare AC/TiO{sub 2} and a novel method to improve photocatalytic efficiency via synergistic effect for other catalytic systems.

  10. Performance of photocatalytic reactors using immobilized TiO2 film for the degradation of phenol and methylene blue dye present in water stream.

    Science.gov (United States)

    Ling, Chin Mei; Mohamed, Abdul Rahman; Bhatia, Subhash

    2004-11-01

    TiO2 thin film photocatalyst was successfully synthesized and immobilized on glass reactor tube using sol-gel method. The synthesized TiO2 coating was transparent, which enabled the penetration of ultra-violet (UV) light to the catalyst surface. Two photocatalytic reactors with different operating modes were tested: (a) tubular photocatalytic reactor with re-circulation mode and (b) batch photocatalytic reactor. A new proposed TiO2 synthesized film formulation of 1 titanium isopropoxide: 8 isopropanol: 3 acetyl acetone: 1.1 H2O: 0.05 acetic acid (in molar ratio) gave excellent photocatalytic activity for degradation of phenol and methylene blue dye present in the water. The half-life time, t1/2 of photocatalytic degradation of phenol was 56 min at the initial phenol concentration of 1000 microM in the batch reactor. In the tubular photocatalytic reactor, 5 re-circulation passes with residence time of 2.2 min (single pass) degraded 50% of 40-microM methylene blue dye. Initial phenol concentration, presence of hydrogen peroxide, presence of air bubbling and stirring speed as the process variables were studied in the batch reactor. Initial methylene blue concentration, pH value, light intensity and reaction temperature were studied as the process variables in the tubular reactor. The synthesized TiO2 thin film was characterized using SEM, XRD and EDX analysis. A comparative performance between the synthesized TiO2 thin film and commercial TiO2 particles (99% anatase) was evaluated under the same experimental conditions. The TiO2 film was equally active as the TiO2 powder catalyst.

  11. Intermittent degradation and schizotypy

    Directory of Open Access Journals (Sweden)

    Matthew W. Roché

    2015-06-01

    Full Text Available Intermittent degradation refers to transient detrimental disruptions in task performance. This phenomenon has been repeatedly observed in the performance data of patients with schizophrenia. Whether intermittent degradation is a feature of the liability for schizophrenia (i.e., schizotypy is an open question. Further, the specificity of intermittent degradation to schizotypy has yet to be investigated. To address these questions, 92 undergraduate participants completed a battery of self-report questionnaires assessing schizotypy and psychological state variables (e.g., anxiety, depression, and their reaction times were recorded as they did so. Intermittent degradation was defined as the number of times a subject’s reaction time for questionnaire items met or exceeded three standard deviations from his or her mean reaction time after controlling for each item’s information processing load. Intermittent degradation scores were correlated with questionnaire scores. Our results indicate that intermittent degradation is associated with total scores on measures of positive and disorganized schizotypy, but unrelated to total scores on measures of negative schizotypy and psychological state variables. Intermittent degradation is interpreted as potentially derivative of schizotypy and a candidate endophenotypic marker worthy of continued research.

  12. Ultrahigh-performance liquid chromatography-ultraviolet absorbance detection-high-resolution-mass spectrometry combined with automated data processing for studying the kinetics of oxidative thermal degradation of thyroxine in the solid state.

    Science.gov (United States)

    Neu, Volker; Bielow, Chris; Reinert, Knut; Huber, Christian G

    2014-12-01

    Levothyroxine as active pharmaceutical ingredient of formulations used for the treatment of hypothyroidism is distributed worldwide and taken by millions of people. An important issue in terms of compound stability is its capability to react with ambient oxygen, especially in case of long term compound storage at elevated temperature. In this study we demonstrate that ultrahigh-performance liquid chromatography coupled to UV spectrometry and high-resolution mass spectrometry (UHPLC-UV-HRMS) represent very useful approaches to investigate the influence of ambient oxygen on the degradation kinetics of levothyroxine in the solid state at enhanced degradation conditions. Moreover, the impurity pattern of oxidative degradation of levothyroxine is elucidated and classified with respect to degradation kinetics at different oxygen levels. Kinetic analysis of thyroxine bulk material at 100 °C reveals bi-phasic degradation kinetics with a distinct change in degradation phases dependent on the availability of oxygen. The results clearly show that contact of the bulk material to ambient oxygen is a key factor for fast compound degradation. Furthermore, the combination of time-resolved HRMS data and automated data processing is shown to allow insights into the kinetics and mechanism of impurity formation on individual compound basis. By comparing degradation profiles, four main classes of profiles linked to reaction pathways of thyroxine degradation were identifiable. Finally, we show the capability of automated data processing for the matching of different stressing conditions, in order to extract information about mechanistic similarities. As a result, degradation kinetics is influenced by factors like availability of oxygen, stressing time, or stressing temperature, while the degradation mechanisms appear to be conserved.

  13. Cognitive Performance Degradation on Sonar Operator and Torpedo Data Control Unit Operator after One Night of Sleep Deprivation

    Science.gov (United States)

    1985-09-01

    AViOVA- STENBERGS SHORT TERM MEMORY SLANNING IV AROVA-CODE SUBSTITUTION TEST o . . . . . . . . . 39 V AhOVA-AIR COMBAT MANEUVERING TSST ........ 󈧭 °6...LIST OP PIGURES 5.1 Performance On The Mathematical Addition Test o o o 36 5.2 Performance On The Stenbergs Memory Test . .... 38 5.3 Performanc, On...QNNING TEST: This test has been adopte4 from Stenberg’s Short Term .emory Scanruing Test. Stenberg assumes thaL if the selection of a response

  14. 余度舵机系统的性能降级与可靠性分析%Performance Degradation and Reliability Analysis for Redundant Actuation System

    Institute of Scientific and Technical Information of China (English)

    王少萍; 崔明山; 石健; 康明

    2005-01-01

    Redundant actuator is the key component of Fly-By-Wire (FBW) system in which exists the inherent force fighting among different redundant channels at colligation point. This paper establishes the mathematical model of quad redundant actuator (QRA), investigates the force equalization algorithm and carries out the performance degradation simulation and reliability analysis under the first failure and the second failure. The results indicate that the optimal equalization algorithm can solve the force fighting effectively, and the QRA can operate at degradation performance continuously under the first failure and the second failure. With the dynamic fault tree analysis, this paper calculates the reliability based on the performance of QRA and proves that the redundant actuator has very high reliability and safety.%余度舵机是电传飞控系统的关键部件,其通道间存在着较严重的力纷争现象.在建立四余度舵机数学模型的基础上,研究了力均衡算法,对四余度舵机一次故障、二次故障情况下的性能降级和可靠性进行了仿真分析.仿真结果标明,优化的力均衡算法可以有效解决力纷争的问题,四余度舵机可以在一次故障、二次故障的情况下持续工作.采用动态故障树分析方法进行了四余度舵机可靠性分析,证明了其具有非常高的可靠性.

  15. Electron density window for best frequency performance, lowest phase noise and slowest degradation of GaN heterostructure field-effect transistors

    Science.gov (United States)

    Matulionis, Arvydas

    2013-07-01

    The problems in the realm of nitride heterostructure field-effect transistors (HFETs) are discussed in terms of a novel fluctuation-dissipation-based approach impelled by a recent demonstration of strong correlation of hot-electron fluctuations with frequency performance and degradation of the devices. The correlation has its genesis in the dissipation of the LO-mode heat accumulated by the non-equilibrium longitudinal optical phonons (hot phonons) confined in the channel that hosts the high-density hot-electron gas subjected to a high electric field. The LO-mode heat causes additional scattering of hot electrons and facilitates defect formation in a different manner than the conventional heat contained mainly in the acoustic phonon mode. We treat the heat dissipation problem in terms of the hot-phonon lifetime responsible for the conversion of the non-migrant hot phonons into migrant acoustic modes and other vibrations. The lifetime is measured over a wide range of electron density and supplied electric power. The optimal conditions for the dissipation of the LO-mode heat are associated with the plasmon-assisted disintegration of hot phonons. Signatures of plasmons are experimentally resolved in fluctuations, dissipation, hot-electron transport, transistor frequency performance, transistor phase noise and transistor reliability. In particular, a slower degradation and a faster operation of GaN-based HFETs take place inside the electron density window where the resonant plasmon-assisted ultrafast dissipation of the LO-mode heat comes into play. A novel heterostructure design for the possible improvement of HFET performance is proposed, implemented and tested.

  16. Synthesis and photocatalytic performance of reduced graphene oxide-TiO2 nanocomposites for orange II degradation under UV light irradiation.

    Science.gov (United States)

    Li, Tengfei; Wang, Tiecheng; Qu, Guangzhou; Liang, Dongli; Hu, Shibin

    2017-03-30

    To enhance the photocatalytic activity of TiO2, reduced graphene oxide-TiO2 (RGO-TiO2) composites with sandwich-like structure were synthesized using a simple solvothermal method. The morphology, crystalline information, and structural property of the photocatalyst were characterized by field emission scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and Fourier transmission infrared spectroscopy. The photocatalytic performances of the RGO-TiO2 composites were evaluated by the degradation of orange II (AO7) in water under UV light irradiation. The results showed that the RGO-TiO2 composites exhibited much higher photocatalytic activity than TiO2 and that the removal efficiency of AO7 could reach above 95% only after 20 min of UV light irradiation under the optimum condition. The improved photocatalytic activity might be attributed to the improved charge transfer and significant separation of the photoinduced electrons and holes in the presence of a two-dimensional graphene network. The results of recycling experiments show that RGO-TiO2 composites have a high photostability, which is expected in the practical application. Radical trapping experiments indicated that ·OH plays a crucial role in the process of AO7 degradation.

  17. Kinetic analysis and degradation pathway for m-dichlorobenzene removal by Brevibacillus agri DH-1 and its performance in a biotrickling filter.

    Science.gov (United States)

    Yang, Bai-Ren; Sun, Zhu-Qiu; Wang, Li-Ping; Li, Zhao-Xia; Ding, Cheng

    2017-05-01

    A strain, Brevibacillus agri DH-1, isolated from dry lands was used to remove m-dichlorobenzene. After 48h culturing, the concentrations of m-dichlorobenzene decreased from 26-130 to 7.87-28.87mg/L and dry cell weight for bacterial growth reached 52.43-75.05mg/L. The growth and degradation kinetics were analyzed by the fitting of Haldane-Andrews model and pseudo first-order model. A degradation pathway was proposed according to major intermediates (phenol), chloride ion variation, ring-opening enzyme activity, and high mineralization (0.47gCl-/gm-dichlorobenzene, 0.65 gco2/gm-dichlorobenzene, 0.15 gDCW/gm-dichlorobenzene). In addition, the performance in a biotrickling filter (BTF) was evaluated through removal efficiency and pressure drop values with increasing inlet loading rate from 4.10 to 122.57g/m(3)/h at three empty bed residence time points (30s, 60s, and 90s). The results demonstrated that strain DH-1 possessed high removal efficiency and stable operation in a BTF.

  18. Degradation mechanism of a high-performance real micro gas sensor, as determined by spatially resolved XAFS.

    Science.gov (United States)

    Wada, Takahiro; Murata, Naoyoshi; Uehara, Hiromitsu; Suzuki, Takuya; Nitani, Hiroaki; Niwa, Yasuhiro; Uo, Motohiro; Asakura, Kiyotaka

    2016-03-14

    Of late, battery-driven high-performance gas sensors have gained acceptability in practical usage, whose atomic-scale structure has been revealed by μ-fluorescence X-ray absorption fine structure analysis. We studied the chemical distribution of Pd species in the Pd/Al2O3 catalyst overlayer in the real gas sensor at various degrees of deterioration. In a freshly prepared sensor, all Pd species were in the PdO form; in a heavily deteriorated sensor, Pd/Al2O3 in the external region changed to metallic Pd particles, while the PdO structure in the inner region near the heater remained unchanged. The Pd species distribution was in agreement with the simulated thermal distribution. Temperature control was crucial to maintain the high performance of the gas sensor. The improved sensor allows homogeneous heating and has a lifetime of more than 5 years.

  19. Performance-degradation model for Li4Ti5O12-based battery cells used in wind power applications

    DEFF Research Database (Denmark)

    Stroe, Daniel Ioan; Swierczynski, Maciej Jozef; Stan, Ana-Irina

    2012-01-01

    Energy storage systems based on Lithium-ion batteries have the potential to mitigate the negative impact of wind power grid integration on the power system stability, which is caused by the characteristics of the wind. This paper presents a performance model for a Li4Ti5O12/LiMO2 battery cell....... For developing the performance model an EIS-based electrical modelling approach was followed. The obtained model is able to predict with high accuracy charge and discharge voltage profiles for different ages of the battery cell and for different charging/discharging current rates. Moreover, the ageing behaviour...... of the battery cell was analysed for the case of accelerated cycling ageing with a certain mission profile....

  20. Common Degradative Pathways of Morpholine, Thiomorpholine, and Piperidine by Mycobacterium aurum MO1: Evidence from 1H-Nuclear Magnetic Resonance and Ionspray Mass Spectrometry Performed Directly on the Incubation Medium

    Science.gov (United States)

    Combourieu, Bruno; Besse, Pascale; Sancelme, Martine; Godin, Jean-Philippe; Monteil, André; Veschambre, Henri; Delort, Anne-Marie

    2000-01-01

    In order to see if the biodegradative pathways for morpholine and thiomorpholine during degradation by Mycobacterium aurum MO1 could be generalized to other heterocyclic compounds, the degradation of piperidine by this strain was investigated by performing 1H-nuclear magnetic resonance directly with the incubation medium. Ionspray mass spectrometry, performed without purification of the samples, was also used to confirm the structure of some metabolites during morpholine and thiomorpholine degradation. The results obtained with these two techniques suggested a general pathway for degradation of nitrogen heterocyclic compounds by M. aurum MO1. The first step of the degradative pathway is cleavage of the C—N bond; this leads formation of an intermediary amino acid, which is followed by deamination and oxidation of this amino acid into a diacid. Except in the case of thiodiglycolate obtained from thiomorpholine degradation, the dicarboxylates are completely mineralized by the bacterial cells. A comparison with previously published data showed that this pathway could be a general pathway for degradation by other strains of members of the genus Mycobacterium. PMID:10919768

  1. AN Alternative to "Suppression": Modeling Methodology for Assessing Indirect Effects of Weapons and Human Performance Degradation

    Science.gov (United States)

    1990-08-01

    as any effect beyond physical damage which affects personnel. And these effects are the result of general combat stress, a near miss , or other related...comalbat ftinctions t, hrough such ruechanisnis as cornmbat stress, or a near miss causing alteration in - physi- cal environment and thus contributing to...effect where any or all combat, functions that a soldier performs are affected. Tihe other causative mechanism, the near miss with its related factors

  2. Accurate mass analysis of ethanesulfonic acid degradates of acetochlor and alachlor using high-performance liquid chromatography and time-of-flight mass spectrometry

    Science.gov (United States)

    Thurman, E.M.; Ferrer, I.; Parry, R.

    2002-01-01

    Degradates of acetochlor and alachlor (ethanesulfonic acids, ESAs) were analyzed in both standards and in a groundwater sample using high-performance liquid chromatography-time-of-flight mass spectrometry with electrospray ionization. The negative pseudomolecular ion of the secondary amide of acetochlor ESA and alachlor ESA gave average masses of 256.0750??0.0049 amu and 270.0786??0.0064 amu respectively. Acetochlor and alachlor ESA gave similar masses of 314.1098??0.0061 amu and 314.1153??0.0048 amu; however, they could not be distinguished by accurate mass because they have the same empirical formula. On the other hand, they may be distinguished using positive-ion electrospray because of different fragmentation spectra, which did not occur using negative-ion electrospray.

  3. Performance Degradation of Thermal Parameters during Cycle Ageing of High Energy Density Ni-Mn-Co based Lithium-Ion Battery Cells

    DEFF Research Database (Denmark)

    Stanciu, Tiberiu; Stroe, Daniel Loan; Swierczynski, Maciej Jozef

    2016-01-01

    The accelerated demand for electrifying the transportation sector, coupled with the continuous improvement of rechargeable batteries’ characteristics, have made modern high-energy Lithium-ion (Li-ion) batteries the standard choice for hybrid and electric vehicles (EVs). Consequently, Li......-ion batteries’ electrochemical and thermal characteristics are very important topics, putting them at the forefront of the research. Along with the electrical performance of Li-ion battery cells, their thermal behavior needs to be accurately predicted during operation and over the lifespan of the application...... as well, since the thermal management of the battery is crucial for the safety of the EV driver. Moreover, the thermal management system can significantly lower the degradation rate of the battery pack and thus reduce costs. In this paper, the thermal characterization of a commercially available Nickel...

  4. Comparative Kinetic Studies and Performance Evaluation of Biofilm and Biomass Characteristics of Pseudomonas fluorescens in Degrading Synthetic Phenolic Effluent in Inverse Fluidized Bed Biofilm Reactor.

    Science.gov (United States)

    Begum, S Sabarunisha; Radha, K V

    2016-05-01

    The bioremediation potential of Pseudomonas fluorescens was studied in an Inverse Fluidized Bed Biofilm Reactor under batch recirculation conditions using synthetic phenolic effluent of various concentrations (400, 600, 800, 1000 and 1200 mg/l). The performance of the reactor was investigated and the characteristics of biomass and biofilm were determined by evaluating biofilm dry density and thickness, bioparticle density, suspended and attached biomass concentration, chemical oxygen demand and phenol removal efficiency. Biodegradation kinetics had been studied for suspended biomass culture and biofilm systems with respect to its specific growth and substrate consumption rates. Suspended biomass followed substrate inhibition kinetics and the experimental data fitted well with the Haldane model. The degradation kinetic behavior of biofilm revealed that a well adapted biofilm system with effective control of biofilm thickness in an inverse fluidized bed biofilm reactor overcomes substrate inhibition effects by tolerating higher phenol concentration and fitted well to the Monod model.

  5. New horizon for high performance Mg-based biomaterial with uniform degradation behavior: Formation of stacking faults

    OpenAIRE

    Jinghuai Zhang; Chi Xu; Yongbin Jing; Shuhui Lv; Shujuan Liu; Daqing Fang; Jinpeng Zhuang; Milin Zhang; Ruizhi Wu

    2015-01-01

    Designing the new microstructure is an effective way to accelerate the biomedical application of magnesium (Mg) alloys. In this study, a novel Mg–8Er–1Zn alloy with profuse nano-spaced basal plane stacking faults (SFs) was prepared by combined processes of direct-chill semi-continuous casting, heat-treatment and hot-extrusion. The formation of SFs made the alloy possess outstanding comprehensive performance as the biodegradable implant material. The ultimate tensile strength (UTS: 318 MPa), t...

  6. Grating-based guided-mode resonance devices and degradation of their performance in real-life conditions

    DEFF Research Database (Denmark)

    Ivinskaya, Aliaksandra; Bergmann, René; Kafka, Jan Robert

    2014-01-01

    Guided-mode resonances in structures having periodicity along at least one dimension were widely employed in the last decade in various optical devices. Initially it was shown that at frequencies close to the second order band gap periodic structures can feature total reflection of light due...... of an infinite periodic structure illuminated by a plane wave. To see how grating-based components can perform in real life we take into account two critical factors: the finite size of the grating and the Gaussian shape of the light source replacing a plane wave. These factors can significantly change...

  7. Effect of feeding tannin degrading bacterial culture (Streptococcus gallolyticus strain TDGB 406) on nutrient utilization, urinary purine derivatives and growth performance of goats fed on Quercus semicarpifolia leaves.

    Science.gov (United States)

    Kumar, K; Chaudhary, L C; Agarwal, N; Kamra, D N

    2014-10-01

    To study the effect of supplementation of tannin degrading bacterial culture (Streptococcus gallolyticus strain TDGB 406) on growth performance, nutrient utilization and urinary purine derivatives of goats fed on oak (Quercus semicarpifolia) leaves. For growth study, eighteen billy goats (4 month old, average body weight 9.50 ± 1.50 kg) were distributed into three groups of six animals each. The animals of group 1 served as control while animals of groups 2 (T1) and 3 (T2) were given (@ 5 ml/kg live weight) autoclaved and live culture of isolate TDGB 406 (10(6) cells/ml) respectively. The animals were fed measured quantity of dry oak leaves as the main roughage source and ad libitum maize hay along with fixed quantity of concentrate mixture. The feeding of live culture of isolate TDGB 406 (probiotic) did not affect dry matter intake and digestibility of nutrients except that of dry matter and crude protein, which was higher in T2 group as compared to control. All the animals were in positive nitrogen balance. There was no significant effect of feeding isolate TDGB 406 on urinary purine derivatives (microbial protein production) in goats. The body weight gain and average live weight gain was significantly higher (p = 0.071) in T2 group as compared to control. Feed conversion efficiency was also better in the goats fed on live culture of TDGB 406 (T2). The feeding of tannin degrading bacterial isolate TDGB 406 as probiotic resulted in improved growth performance and feed conversion ratio in goats fed on oak leaves as one of the main roughage source. Journal of Animal Physiology and Animal Nutrition © 2013 Blackwell Verlag GmbH.

  8. Influence of late gestation drylot rations differing in protein degradability and fat content on beef cow and subsequent calf performance.

    Science.gov (United States)

    Wilson, T B; Faulkner, D B; Shike, D W

    2015-12-01

    Spring-calving, mature cows ( = 191 total) and their progeny were used to evaluate the effects of late gestation drylot rations differing in RUP and fat content on cow performance as well as performance and carcass characteristics of subsequent progeny. Cows were blocked by BW and anticipated calving date and assigned to 16 pens. Pens were randomly allotted to 1 of 2 treatments: limit-fed corn coproducts and ground cornstalks (COP; TDN = 64.4%, CP = 11.1%, RDP = 60.2% of CP, and fat = 5.1%) or limit-fed ground mixed, cool-season grass hay (HY; TDN = 55.7%, CP = 9.5%, RDP = 86.0% of CP, and fat = 2.3%). Treatments were limit fed as isocaloric, isonitrogenous rations from 88 ± 11 d prepartum to calving. All cows were fed a common diet postpartum. Cow BW and BCS were collected at the beginning of the feeding period, within 48 h after calving, and at breeding. Calf BW was collected at birth and at 64 ± 11 and 124 ± 11 d of age. Milk production was determined using the weigh-suckle-weigh technique at 64 ± 11 and 124 ± 11 d postpartum. At 124 ± 11 d of age, steers ( = 68) and nonreplacement heifer calves ( = 25) were weaned and placed on a common feedlot diet with individual feed intake monitored using GrowSafe. Feedlot calves were slaughtered at a commercial facility 35 ± 10 d after a minimum ultrasound 12-rib fat thickness estimation of 0.9 cm. After calving, cow BW was greater ( Calf birth BW was greater ( = 0.04) for those born to cows fed COP with no difference ( = 0.43) in percentage of unassisted births across treatment. Cows fed HY were lighter ( feed were not different ( ≥ 0.23), and as a result, no difference ( = 0.21) in feedlot ADG was detected. Feedlot DMI and G:F were not different ( ≥ 0.19) across treatments. Feedlot calf health was monitored with no differences ( ≥ 0.68) in morbidity and mortality observed. No differences ( ≥ 0.27) were detected for HCW, LM area, backfat, marbling score, yield grade, or KPH. Increased dietary RUP and fat

  9. Visible-light photocatalytic degradation performances and thermal stability due to the synergetic effect of TiO2 with conductive copolymers of polyaniline and polypyrrole.

    Science.gov (United States)

    Deng, Fang; Min, Lujuan; Luo, Xubiao; Wu, Shaolin; Luo, Shenglian

    2013-09-21

    Conductive polypyrrole-polyaniline/TiO2 nanocomposites (PPy-PANI/TiO2) were prepared by in situ oxidative copolymerization of pyrrole and aniline monomers in the presence of TiO2. For comparison studies, polypyrrole/TiO2 (PPy/TiO2) and polyaniline/TiO2 (PANI/TiO2) were also prepared. The samples were characterized by X-ray diffraction, transmission electron microscopy, UV-vis diffuse reflectance spectroscopy, zeta potential analysis, Fourier transform infrared spectroscopy, thermogravimetric analysis and photocurrent tests. In contrast to PPy/TiO2 and PANI/TiO2, PPy-PANI/TiO2 exhibits obvious absorption in the visible-light range, and is much superior to PPy/TiO2 and PANI/TiO2 in thermal stability. It is found that PPy-PANI/TiO2 performs well in the visible-light photocatalytic degradation of 4-nitrophenol. The optimized pyrrole : aniline : TiO2 molar ratio for best performance is 0.75 : 0.25 : 100. The efficacy of PPy-PANI/TiO2 is attributed to its conductivity, conjugated structure, as well as to the synergy amidst polypyrrole, polyaniline and TiO2.

  10. 纸及秸秆基可降解营养钵的降解性能试验%Degradation performance experiment of paper and straw-based seedling pot

    Institute of Scientific and Technical Information of China (English)

    蒋希芝; 赵永富; 曲萍; 李澧

    2016-01-01

    选取纸质、不腐熟秸秆和腐熟秸秆3种生物基可降解营养钵,对其降解率、分子结构及结晶度进行分析。通过土埋降解试验、红外图谱分析及X射线衍射分析,对比研究不同类型生物基可降解营养钵的降解特性。结果表明,纸质营养钵降解率最终高达85%,降解效果最好。不腐熟秸秆营养钵的降解率为78%,大于腐熟秸秆营养钵的降解率47%。降解试验前后对比发现,生物基营养钵的红外吸收峰强度均不同程度的降低,分子结构发生变化,3340和2920 cm−1处吸收峰强度降低说明纤维素、半纤维素发生降解,1650 cm−1处的吸收峰降低说明木质素发生降解。经8周降解试验,纸质营养钵X射线衍射峰变化明显,强度明显降低,降解效果较好,不腐熟秸秆营养钵和腐熟秸秆营养钵在2θ=27°均出现新的衍射峰,晶型发生变化。生物基可降解营养钵降解性能优异,可有效改善环境污染问题。%Most of the articles about the degradation performance of biodegradable nursery pots were focused on degradation morphology, strength of pot body, changes of soil, effect of raising seedings and so on. However, it rarely study on degradation rate, molecular structure of degradation process and changes of crystallinity. In order to study the degradation performance of biodegradable nursery pots, three types containing paper pot, undecomposed straw pot and decomposed straw pot were used to carry out the experiment in this paper. The degradation rate, molecular structure and crystallinity were evaluated and analyzed through the experiments of degradation test in soil, Fourier infrared scanning and x-ray diffraction. It is necessary to have a further research on degradation performance of biodegradable nursery containers and mechanism of degradation. The results showed that the degradation rate of paper pot with the best degradation property was growing at a rate of

  11. Vanadium Oxide Electrochemical Capacitors: An Investigation into Aqueous Capacitive Degradation, Alternate Electrolyte-Solvent Systems, Whole Cell Performance and Graphene Oxide Composite Electrodes

    Science.gov (United States)

    Engstrom, Allison Michelle

    Vanadium oxide has emerged as a potential electrochemical capacitor material due to its attractive pseudocapacitive performance; however, it is known to suffer from capacitive degradation upon sustained cycling. In this work, the electrochemical cycling behavior of anodically electrodeposited vanadium oxide films with various surface treatments in aqueous solutions is investigated at different pH. Quantitative compositional analysis and morphological studies provide additional insight into the mechanism responsible for capacitive degradation. Furthermore, the capacitance and impedance behavior of vanadium oxide electrochemical capacitor electrodes is compared for both aqueous and nonaqueous electrolyte-solvent systems. Alkali metal chloride and bromide electrolytes were studied in aqueous systems, and nonaqueous systems containing alkali metal bromides were studied in polar aprotic propylene carbonate (PC) or dimethyl sulfoxide (DMSO) solvents. The preferred aqueous and nonaqueous systems identified in the half-cell studies were utilized in symmetric vanadium oxide whole-cells. An aqueous system utilizing a 3.0 M NaCl electrolyte at pH 3.0 exhibited an excellent 96% capacitance retention over 3000 cycles at 10 mV s-1. An equivalent system tested at 500 mV s-1 displayed an increase in capacitance over the first several thousands of cycles, and eventually stabilized over 50,000 cycles. Electrodes cycled in nonaqueous 1.0 M LiBr in PC exhibited mostly non-capacitive charge-storage, and electrodes cycled in LiBr-DMSO exhibited a gradual capacitive decay over 10,000 cycles at 500 mV s-1. Morphological and compositional analyses, as well as electrochemical impedance modeling, provide additional insight into the cause of the cycing behavior. Lastly, reduced graphene oxide and vanadium oxide nanowire composites have been successfully synthesized using electrophoretic deposition for electrochemical capacitor electrodes. The composite material was found to perform with a

  12. Performance of electrochemical oxidation and photocatalysis in terms of kinetics and energy consumption. New insights into the p-cresol degradation.

    Science.gov (United States)

    Escudero, Carlos J; Iglesias, Olalla; Dominguez, Sara; Rivero, Maria J; Ortiz, Inmaculada

    2017-06-15

    This work reports the comparative performance of two Advanced Oxidation Processes (AOPs), electrochemical oxidation and photocatalysis, as individual technological alternatives for the treatment of effluents containing p-cresol. First, the influence of operating parameters in the oxidation and mineralization yield was carried out together with kinetic analysis. Boron Doped Diamond (BDD), RuO2 and Pt as anodic materials, Na2SO4 and NaCl as supporting electrolytes and different current densities were evaluated in electrochemical oxidation whereas the effect of TiO2 concentration and radiation was studied in the photocatalytic degradation. Then, the parameter Electrical Energy per Order (EEO) was calculated to compare the energy consumption in both AOPs, concluding that under the studied conditions the electrochemical treatment with BDD, Na2SO4 and 125 A m(-2) showed the best energy efficiency, with an EEO of 5.83 kW h m(-3) order(-1) for p-cresol and 58.05 kW h m(-3) order(-1) for DOC removal, respectively. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Ultrasonic-assisted preparation of plasmonic ZnO/Ag/Ag2WO4 nanocomposites with high visible-light photocatalytic performance for degradation of organic pollutants.

    Science.gov (United States)

    Pirhashemi, Mahsa; Habibi-Yangjeh, Aziz

    2017-04-01

    In this work, plasmonic ternary ZnO/Ag/Ag2WO4 nanocomposites as efficient visible-light-driven photocatalysts prepared by a facile ultrasonic-irradiation method. The as-prepared samples were characterized by XRD, SEM, TEM, EDX, XPS, UV-vis DRS, FT-IR, and PL techniques. The photocatalytic performance of the prepared ZnO/Ag/Ag2WO4 nanocomposites were evaluated by photodegradations of rhodamine B, methylene blue, methyl orange, and fuchsine under visible-light irradiation. The optimal nanocomposite with 15wt% of Ag/Ag2WO4 to ZnO showed the highest photocatalytic activity for RhB degradation, which is about 95 and 19 times higher than those of the Ag/Ag2WO4 and ZnO samples, respectively. The highly enhanced activity of the ZnO/Ag/Ag2WO4 (15%) nanocomposite was attributed to the surface plasmon resonance effect of metallic silver and the formation of heterojunctions between the counterparts, which effectively suppresses recombination of the photogenerated charge carriers. Lastly, the plasmon-enhanced photocatalytic mechanism associated with the ZnO/Ag/Ag2WO4 nanocomposites was discussed.

  14. Anaerobic digestion of sludge differing in inorganic solids content: performance comparison and the effect of inorganic suspended solids content on degradation.

    Science.gov (United States)

    Duan, Nina; Dai, Xiaohu; Dong, Bin; Dai, Lingling

    2016-11-01

    High inorganic suspended solids (ISS) content of sludge in many areas (especially with combined sewage systems) results in low VS/TS (volatile solids, VS; total solids, TS) levels and raises concerns about its effect on anaerobic digestion. The performances of sludge anaerobic digestion with different feeding VS/TS levels as well as the effect of ISS content on the anaerobic degradation process were investigated in completely stirred tank reactors by semi-continuous and batch experiments. In semi-continuous experiment with sludge at VS/TS of 61.4%, 45.0, 30.0% and 15.0%, biogas yield, VS reduction and methane content decreased logarithmically with the feeding VS/TS decreasing; slightly higher volatile fatty acid concentration was observed at VS/TS 15%. Results of the batch experiments suggested that acetogenesis and methanogenesis are obviously affected by high ISS addition, while hydrolysis is less affected. The retardment of substrate conversion rate is probably attributed to decreased mass transfer efficiency at high ISS content.

  15. UPLC and LC-MS studies on degradation behavior of irinotecan hydrochloride and development of a validated stability-indicating ultra-performance liquid chromatographic method for determination of irinotecan hydrochloride and its impurities in pharmaceutical dosage forms.

    Science.gov (United States)

    Kumar, Navneet; Sangeetha, Dhanaraj; Reddy, Sunil P

    2012-10-01

    The objective of the current investigation was to study the degradation behavior of irinotecan hydrochloride under different International Conference on Harmonization (ICH) recommended stress conditions using ultra-performance liquid chromatography and liquid chromatography-mass spectrometry and to establish a validated stability-indicating reverse-phase ultra-performance liquid chromatographic method for the quantitative determination of irinotecan hydrochloride and its seven impurities and degradation products in pharmaceutical dosage forms. Irinotecan hydrochloride was subjected to the stress conditions of oxidative, acid, base, hydrolytic, thermal and photolytic degradation. Irinotecan hydrochloride was found to degrade significantly in oxidative and base hydrolysis and photolytic degradation conditions. The degradation products were well resolved from the main peak and its impurities, thus proving the stability-indicating power of the method. Chromatographic separation was achieved on a Waters Acquity BEH C8 (100 × 2.1 mm) 1.7-µm column with a mobile phase containing a gradient mixture of solvent A (0.02M KH(2)PO(4) buffer, pH 3.4) and solvent B (a mixture of acetonitrile and methanol in the ratio of 62:38 v/v). The mobile phase was delivered at a flow rate of 0.3 mL/min with ultraviolet detection at 220 nm. The run time was 8 min, within which irinotecan and its seven impurities and degradation products were satisfactorily separated. The developed method was validated as per ICH guidelines with respect to specificity, linearity, limit of detection, limit of quantification, accuracy, precision and robustness. This method was also suitable for the assay determination of irinotecan hydrochloride in pharmaceutical dosage forms.

  16. ICH GUIDANCE IN PRACTICE: DEVELOPMENT OF A VALIDATED STABILITY-INDICATING HIGH-PERFORMANCE LIQUID CHROMATOGRAPHIC ASSAY METHOD FOR FEBUXOSTAT AND DEGRADATION KINETIC STUDY IN ACID HYDROLYTIC CONDITION

    Directory of Open Access Journals (Sweden)

    Megha V. Sheth* and Jigar J. Pandya

    2013-02-01

    Full Text Available The degradation behavior of Febuxostat was investigated under different stress degradation (hydrolytic, oxidative, photolytic and thermal conditions recommended by International Conference on Harmonization (ICH using HPLC and LCMS. Febuxostat was found to degrade significantly in acidic and alkaline conditions as well as in neutral hydrolysis. The drug was stable to dry heat, photolytic degradation and under oxidative condition. Resolution of drug and the degradation products formed under different stress studies were successfully achieved on a C-18 column utilizing Methanol- water (with 0.02%v/v TFA in the ratio of 95:5 and at the detection wavelength of 315 nm. The method was validated with respect to linearity, precision, accuracy, selectivity and specificity. The degradation kinetic of Febuxostat in acidic condition at different temperature was studied. The reaction order for Febuxostat in aqueous solvent system followed pseudo first order degradation kinetic. The catalytic rate constant and half-life at particular condition were determined. The Arrhenius plot showed the temperature dependence of Febuxostat.

  17. Effect of different combinations of soybean-maize silage on its chemical composition, nutrient intake, degradability, and performance of Pelibuey lambs.

    Science.gov (United States)

    Martínez-García, Carlos Galdino; Valencia-Núñez, Keyla; Bastida-López, Jesús; Estrada-Flores, Julieta Gertrudis; Miranda-de la Lama, Genaro Cvabodni; Cruz-Monterrosa, Rosy Gabriela; Rayas-Amor, Adolfo Armando

    2015-12-01

    Sheep raising in the state of Guerrero, México, is a primary activity that is worth about US$3,251,931 annually. The objective of the present study was to evaluate the chemical composition, degradability, nutrient intake, and animal performance of Pelibuey lambs fed on different combinations of maize-soybean silages. Twenty-one combinations of maize silage (MS) and soybean silage (SS) were evaluated at day 45 post-ensiling; in each combination, MS was replaced by 5 % of SS. The 21 combinations were analysed for crude protein (CP) and chemical composition. In order to obtain a statistical criterion of potential treatments for the animal feeding test, a cluster analysis was performed based on the CP contents of all combinations at day 45 post-ensiling. From cluster analysis, four treatments were selected T1 = 100-0 % (MS/SS), T8 = 65-35 %, T12 = 45-55 %, and T16 = 25-75 %. Results indicated that cluster analysis was useful for identifying the potential treatments for animal feeding based on the crude protein content. The dry matter (DM), organic matter (OM), and acid detergent lignin (ADL) contents did not declined significantly (P > 0.05) during the fermentation of silages but CP content decreased from day 0 to 45 post-ensiling. The treatment with the highest estimated microbial crude protein synthesis was T8 and it showed the highest metabolizable energy intake, high feed efficiency with a forage-concentrate ratio of 84:16.

  18. Ag/g-C3N4 catalyst with superior catalytic performance for the degradation of dyes: a borohydride-generated superoxide radical approach

    Science.gov (United States)

    Fu, Yongsheng; Huang, Ting; Zhang, Lili; Zhu, Junwu; Wang, Xin

    2015-08-01

    dissolved oxygen in the presence of BH4- and the synergistic effect of Ag nanoparticles and g-C3N4. Electronic supplementary information (ESI) available: The typical experimental details for the color reaction between the ferrous irons (Fe2+) and nitric oxide (NO); MO photodegradation performances in the presence of Ag/g-C3N4 or Ag/g-C3N4/TiO2 nanocomposites; TEM image of the pure g-C3N4 catalyst; The remaining MO, MB and NDY-GL in solution after reaching the adsorption-desorption equilibrium in the dark for 60 min with stirring; Catalytic degradation of MB and NDY-GL over the Ag/g-C3N4-4 catalyst in the presence of BH4- in the dark and under visible light irradiation. See DOI: 10.1039/c5nr03260a

  19. Enhanced Photocatalytic Performance of the Graphene-V2O5 Nanocomposite in the Degradation of Methylene Blue Dye under Direct Sunlight.

    Science.gov (United States)

    Shanmugam, Mahalingam; Alsalme, Ali; Alghamdi, Abdulaziz; Jayavel, Ramasamy

    2015-07-15

    A simple and efficient solution mixing method has been developed for the synthesis of the G-V2O5 nanocomposite. By this method, one-dimensional V2O5 rods are decorated onto the two-dimensional graphene sheets. The synthesized nanocomposites are characterized by XRD, SEM with elemental mapping, TEM, FT-IR, Raman, BET, and XPS analyses. The photocatalytic activity of the G-V2O5 nanocomposite studied with methylene blue dye shows strong degradation efficiency with direct sunlight irradiation compared to UV and visible light sources. The mechanism of methylene blue dye degradation by the G-V2O5 nanocomposite has been elucidated through the kinetics of the degradation process by calculating the rate constant and half-life time of the degradation process.

  20. Decoration of Au nanoparticles onto BiOCl sheets for enhanced photocatalytic performance under visible irradiation for the degradation of RhB dye

    National Research Council Canada - National Science Library

    Kang, Suhee; Pawar, Rajendra C; Lee, Caroline Sunyong

    2016-01-01

    .... Their ability to degrade a wide range of organic pollutants stems from key properties such as high visible light absorption, the ability to generate hot electrons and the formation of a Schottky...

  1. High performance degradation of azo dye Acid Orange 7 and sulfanilic acid in a laboratory scale reactor after seeding with cultured bacterial strains.

    Science.gov (United States)

    Coughlin, Michael F; Kinkle, Brian K; Bishop, Paul L

    2003-06-01

    Bacterial strains 1CX and SAD4i--previously isolated from the mixed liquor of a municipal sewage treatment plant--are capable of degrading the azo dye Acid Orange 7 (AO7) and sulfanilic acid, respectively. A rotating drum bioreactor (RDBR), operating under continuous flow and nutrient conditions designed to simulate the effluent from a dye manufacturing plant, was seeded with strains 1CX and SAD4i, forming a biofilm capable of degrading AO7 and sulfanilic acid. In addition, an RDBR containing a pre-existing biofilm capable of degrading AO7, but not sulfanilic acid, was seeded with strain SAD4i alone. Strain SAD4i was incorporated into the existing biofilm and degraded the sulfanilic acid resulting from the degradation of AO7 by indigenous members of the biofilm. The ability to seed a bioreactor with bacterial strains capable of degrading azo dyes, and resulting by-products, in a mixed microbial community suggests that this process could have commercial applications.

  2. Selection and Performance-Degradation Modeling of LiMO2/Li4Ti5O12 and LiFePO4/C Battery Cells as Suitable Energy Storage Systems for Grid Integration With Wind Power Plants

    DEFF Research Database (Denmark)

    Swierczynski, Maciej Jozef; Stroe, Daniel Ioan; Stan, Ana-Irina

    2014-01-01

    as the requirement criterion while Li–ion batteries where found as the devices which could best fulfil this requirement. Since accurate and fast battery performance models are indispensable for studying the virtual power plant behavior under different operating conditions, impedance-based performance......-degradation models were developed for the two most suitable Li–ion chemistries for the primary frequency regulation service: LiMO2 /Li4Ti5O12 and LiFePO4/C....

  3. FEMCAM Analysis of SULTAN Test Results for ITER Nb3SN Cable-conduit Conductors

    Energy Technology Data Exchange (ETDEWEB)

    Yuhu Zhai, Pierluigi Bruzzone, Ciro Calzolaio

    2013-03-19

    Performance degradation due to filament fracture of Nb3 Sn cable-in-conduit conductors (CICCs) is a critical issue in large-scale magnet designs such as ITER which is currently being constructed in the South of France. The critical current observed in most SULTAN TF CICC samples is significantly lower than expected and the voltage-current characteristic is seen to have a much broader transition from a single strand to the CICC. Moreover, most conductors exhibit the irreversible degradation due to filament fracture and strain relaxation under electromagnetic cyclic loading. With recent success in monitoring thermal strain distribution and its evolution under the electromagnetic cyclic loading from in situ measurement of critical temperature, we apply FEMCAM which includes strand filament breakage and local current sharing effects to SULTAN tested CICCs to study Nb3 Sn strain sensitivity and irreversible performance degradation. FEMCAM combines the thermal bending effect during cool down and the EM bending effect due to locally accumulating Lorentz force during magnet operation. It also includes strand filament fracture and related local current sharing for the calculation of cable n value. In this paper, we model continuous performance degradation under EM cyclic loading based on strain relaxation and the transition broadening upon cyclic loading to the extreme cases seen in SULTAN test data to better quantify conductor performance degradation.

  4. Isolation of Diesel Degrading Strain Acinetobacter sp. AK5 and Its Degrading Performance%柴油降解菌Acinetobacter sp. AK5的筛选及其降解性能研究

    Institute of Scientific and Technical Information of China (English)

    徐晓宇; 陈敬华

    2014-01-01

    从污水处理厂的活性污泥中分离到一株柴油降解菌,通过生理生化鉴定和16S rDNA序列分析,鉴定该菌为不动杆菌Acinetobacter sp. AK5。检测了不同pH值、NaCl浓度、培养时间和各种柴油浓度下Acinertobacter sp. AK5的柴油降解情况。结果表明,该菌的最适生长初始pH值为5-9,适合NaCl浓度为3%-4%,柴油浓度为5 g/L时,该菌7 d柴油降解率可达99%,柴油浓度为20 g/L时,7 d柴油降解率也可达67%。AK5在人工海水培养基中及无机盐培养基中生长状态良好,在海水和淡水石油污染的生物修复中具有很好的应用前景。%A diesel degradable bacterial strain was isolated from activated sludge and identified as Acinetobacter sp. AK5 through physiological, biochemical identification and 16S rDNA sequence analysis. Experiments of the different pH values, NaCl concentrations, culture time and diesel concentrations were detected to evaluate the diesel degradability by Acinetobacter sp. AK5. The results show that the optimal initial pH scope for the bacterial growth is from 5 to 9, the optimum NaCl concentrations is between 3%and 4%. When the diesel concentration is 5 g/L, the 7 d diesel degradation rate can reach 99%, while when the concentration of diesel is 20 g/L, 7 d diesel degradation rate can be 67%. The Acinetobacter sp. AK5 can grow well in artificial seawater medium and inorganic salt culture medium, therefore it has promising application prospect in seawater and freshwater oil pollution treatment.

  5. Preparation of Graphene/TiO2 Composite Nanomaterials and Its Photocatalytic Performance for the Degradation of 2,4-Dichlorophenoxyacetic Acid

    Directory of Open Access Journals (Sweden)

    Donggen Huang

    2016-01-01

    Full Text Available The graphene (GR was prepared by an improved electrochemical stripping method using a high-purity graphite rod as raw material and high temperature heat reduction in hydrogen atmosphere, and the graphene/TiO2 (GR/TiO2 composite nanomaterials were manufactured by the method of sol-gel and high temperature crystallization in hydrogen atmosphere using butyl titanate and electrolysis graphene as precursors. The physical and chemical properties of the composites had been characterized by using X-ray diffraction (XRD, Fourier transform infrared spectroscopy (FTIR, UV-Vis spectrophotometer (UV-Vis, scanning electron microscopy (SEM, Transmission Electron Microscope (TEM,  and specific surface area (SSA by BET method. The photocatalytic properties of GR/TiO2 composites nanomaterials in anoxic water were studied by using 2,4-dichlorophenoxyacetic acid (2,4-D as probe. The results showed that graphite was well intercalated and peeled by a facile electrolysis method in different electric field environment; a well dispersed and rings structure of graphene was prepared by coupling ultrasound-assisted changing voltage electrochemical stripping technology. The as-prepared GR/TiO2 composites had good performance for the photocatalytic degradation of 2,4-D in anoxic water; the chlorines were removed from benzene ring; the middle products of dichlorophenol, chlorophenol, phloroglucinol, and so forth were produced from the photocatalytic redox reaction of 2,4-D in anoxic water; parts of 2,4-D were decomposed completely, and CO2 and H2O were produced.

  6. Fibrin-genipin adhesive hydrogel for annulus fibrosus repair: performance evaluation with large animal organ culture, in situ biomechanics, and in vivo degradation tests

    Directory of Open Access Journals (Sweden)

    M Likhitpanichkul

    2014-07-01

    Full Text Available Annulus fibrosus (AF defects from annular tears, herniation, and discectomy procedures are associated with painful conditions and accelerated intervertebral disc (IVD degeneration. Currently, no effective treatments exist to repair AF damage, restore IVD biomechanics and promote tissue regeneration. An injectable fibrin-genipin adhesive hydrogel (Fib-Gen was evaluated for its performance repairing large AF defects in a bovine caudal IVD model using ex vivo organ culture and biomechanical testing of motion segments, and for its in vivo longevity and biocompatibility in a rat model by subcutaneous implantation. Fib-Gen sealed AF defects, prevented IVD height loss, and remained well-integrated with native AF tissue following approximately 14,000 cycles of compression in 6-day organ culture experiments. Fib-Gen repair also retained high viability of native AF cells near the repair site, reduced nitric oxide released to the media, and showed evidence of AF cell migration into the gel. Biomechanically, Fib-Gen fully restored compressive stiffness to intact levels validating organ culture findings. However, only partial restoration of tensile and torsional stiffness was obtained, suggesting opportunities to enhance this formulation. Subcutaneous implantation results, when compared with the literature, suggested Fib-Gen exhibited similar biocompatibility behaviour to fibrin alone but degraded much more slowly. We conclude that injectable Fib-Gen successfully sealed large AF defects, promoted functional restoration with improved motion segment biomechanics, and served as a biocompatible adhesive biomaterial that had greatly enhanced in vivo longevity compared to fibrin. Fib-Gen offers promise for AF repairs that may prevent painful conditions and accelerated degeneration of the IVD, and warrants further material development and evaluation.

  7. Drift Degradation Analysis

    Energy Technology Data Exchange (ETDEWEB)

    D. Kicker

    2004-09-16

    Degradation of underground openings as a function of time is a natural and expected occurrence for any subsurface excavation. Over time, changes occur to both the stress condition and the strength of the rock mass due to several interacting factors. Once the factors contributing to degradation are characterized, the effects of drift degradation can typically be mitigated through appropriate design and maintenance of the ground support system. However, for the emplacement drifts of the geologic repository at Yucca Mountain, it is necessary to characterize drift degradation over a 10,000-year period, which is well beyond the functional period of the ground support system. This document provides an analysis of the amount of drift degradation anticipated in repository emplacement drifts for discrete events and time increments extending throughout the 10,000-year regulatory period for postclosure performance. This revision of the drift degradation analysis was developed to support the license application and fulfill specific agreement items between the U.S. Nuclear Regulatory Commission (NRC) and the U.S. Department of Energy (DOE). The earlier versions of ''Drift Degradation Analysis'' (BSC 2001 [DIRS 156304]) relied primarily on the DRKBA numerical code, which provides for a probabilistic key-block assessment based on realistic fracture patterns determined from field mapping in the Exploratory Studies Facility (ESF) at Yucca Mountain. A key block is defined as a critical block in the surrounding rock mass of an excavation, which is removable and oriented in an unsafe manner such that it is likely to move into an opening unless support is provided. However, the use of the DRKBA code to determine potential rockfall data at the repository horizon during the postclosure period has several limitations: (1) The DRKBA code cannot explicitly apply dynamic loads due to seismic ground motion. (2) The DRKBA code cannot explicitly apply loads due to thermal

  8. High-performance liquid chromatography/high-resolution multiple stage tandem mass spectrometry using negative-ion-mode hydroxide-doped electrospray ionization for the characterization of lignin degradation products.

    Science.gov (United States)

    Owen, Benjamin C; Haupert, Laura J; Jarrell, Tiffany M; Marcum, Christopher L; Parsell, Trenton H; Abu-Omar, Mahdi M; Bozell, Joseph J; Black, Stuart K; Kenttämaa, Hilkka I

    2012-07-17

    In the search for a replacement for fossil fuel and the valuable chemicals currently obtained from crude oil, lignocellulosic biomass has become a promising candidate as an alternative biorenewable source for crude oil. Hence, many research efforts focus on the extraction, degradation, and catalytic transformation of lignin, hemicellulose, and cellulose. Unfortunately, these processes result in the production of very complex mixtures. Further, while methods have been developed for the analysis of mixtures of oligosaccharides, this is not true for the complex mixtures generated upon degradation of lignin. For example, high-performance liquid chromatography/multiple stage tandem mass spectrometry (HPLC/MS(n)), a tool proven to be invaluable in the analysis of complex mixtures derived from many other biopolymers, such as proteins and DNA, has not been implemented for lignin degradation products. In this study, we have developed an HPLC separation method for lignin degradation products that is amenable to negative-ion-mode electrospray ionization (ESI doped with NaOH), the best method identified thus far for ionization of lignin-related model compounds without fragmentation. The separated and ionized compounds are then analyzed by MS(3) experiments to obtain detailed structural information while simultaneously performing high-resolution measurements to determine their elemental compositions in the two parts of a commercial linear quadrupole ion trap/Fourier-transform ion cyclotron resonance mass spectrometer. A lignin degradation product mixture was analyzed using this method, and molecular structures were proposed for some components. This methodology significantly improves the ability to analyze complex product mixtures that result from degraded lignin.

  9. Polysaccharide Degradation

    Science.gov (United States)

    Stone, Bruce A.; Svensson, Birte; Collins, Michelle E.; Rastall, Robert A.

    An overview of current and potential enzymes used to degrade polysaccharides is presented. Such depolymerases are comprised of glycoside hydrolases, glycosyl transferases, phosphorylases and lyases, and their classification, active sites and action patterns are discussed. Additionally, the mechanisms that these enzymes use to cleave glycosidic linkages is reviewed as are inhibitors of depolymerase activity; reagents which react with amino acid residues, glycoside derivatives, transition state inhibitors and proteinaceous inhibitors. The characterization of various enzymes of microbial, animal or plant origin has led to their widespread use in the production of important oligosaccharides which can be incorporated into food stuffs. Sources of polysaccharides of particular interest in this chapter are those from plants and include inulin, dextran, xylan and pectin, as their hydrolysis products are purported to be functional foods in the context of gastrointestinal health. An alternative use of degraded polysaccharides is in the treatment of disease. The possibility exists to treat bacterial exopolysaccharide with lyases from bacteriophage to produce oligosaccharides exhibiting bioactive sequences. Although this area is currently in its infancy the knowledge is available to investigate further.

  10. Thermal Degradation and Fire Performance of Cross-linking Polystyrene%交联聚苯乙烯的热分解与燃烧性能研究

    Institute of Scientific and Technical Information of China (English)

    楚广成; 李英飞; 马乐; 刘继纯

    2011-01-01

    采用二乙烯基苯(DVB)为交联剂,与苯乙烯(St)单体进行共聚合成了一系列交联聚苯乙烯(PS).采用热重分析,高温热分解、水平燃烧、氧指数、锥形量热分析等方法研究了交联PS的热分解行为和燃烧性能.结果表明:与线型PS相比,交联PS的热分解温度提高,成炭量增加,热稳定性显著增强;交联PS在燃烧时熔融滴落和发烟量显著减少,热释放速率、质量损失速率和燃烧速率降低,氧指教增加,阻燃性能增强;当St/DVB的质量比为100/3时得到的交联PS的阻燃性能最隹;交联PS在燃烧时生成的大量炭残余物覆盖在聚合物表面形成保护层,对热量传递、氧气和燃料分子的迁移产生屏蔽和阻隔作用,降低了聚合物的热分解速率,提高了其阻燃性能.%A series of cross-Iinking polystyrene (PS) materials were synthesized by taking copolymerizing styrene (St) as monomer and divinyl benzene(OVB) as cross-linking agent. The thermal degradation behavior and fire performance of cross-linking PS were studied by means of thermogravimetry, high-temperature pyrolysis, horizontal burning, oxygen index and cone calorimetry. The results show that both degradation temperature and char residue amoynt of cross-linking PS increase, and the thermal stability of cross-linking PS is enhanced noticeably, compared with linear PS; the cross-linking PS produces much less melt-dripping and smoke during burning; the heat release rate (HRR), mass loss rate (MLR) and burning rate all decrease, while the oxygen index value increases, which indicate that the flame retardancy of cross linking PS Is enhanced compared with its linear counterpart; it is found that the cross-linking PS exhibits optimal flame retardancy when the mass ratio of St/DVB is 100/3; the cross linking PS produces much char residue during combustion, which covers on the surface of the polymer material and forms a protection layer; the shielding and obstructing effects of the

  11. Biological characteristics and degradation performance of a degrading strain%降解菌株P-2生物学特性及其降解性能研究

    Institute of Scientific and Technical Information of China (English)

    田连生; 陈菲

    2012-01-01

    To degrade pesticide residues in soil and solve the problem of excessive pesticide residues in agricultural byproducts, a bacterium was screened and isolated from the carbendazim polluted soil. The effect of some factors on its growth biodegradation characteristics in vitro were studied, including initial pH, culture temperature, inoculum size, extra carbon source, nitrogen source. The results showed that this strain could grow by using carbendazim as the carbon source. It could degrade 60. 6% of 100 mg o L-1 carbendazim in mineral culture medium in 5 d, but could degrade 91 % by adding peptone as nitrogen source. The optimal pH and culture temperature for carbendazim biodegradation were 5. 1 - 8. 1 and 25 - 40 ℃ respectively. The biodegradation speed was related positively to the biomass yield.%为降解土壤中农药残留,解决农副产品农药超标问题,采用富集培养法分离筛选出1株能够降解多菌灵的菌株P-2,研究初始pH、培养温度、接种量、外加碳源、氮源对其生长量和降解特性的影响.结果表明:该菌株能以多菌灵为碳源生长,在基础培养基中培养5d时对100 mg·L-1的多菌灵降解率达60.6%,而另外加入氮源蛋白胨,可提高降解率达91%.降解多菌灵的适宜条件为温度25~40℃、pH 5.1~8.1,且降解率与菌体生长量呈正相关关系.

  12. Sun light degradation of 4-chloroaniline in waters and its effect on toxicity. A high performance liquid chromatography - Diode array - Tandem mass spectrometry study

    Energy Technology Data Exchange (ETDEWEB)

    Gosetti, Fabio, E-mail: fabio.gosetti@mfn.unipmn.i [University of Piemonte Orientale, DISAV Dipartimento di Scienze dell' Ambiente e della Vita, viale T. Michel 11, 15121 Alessandria (Italy); Bottaro, Michela; Gianotti, Valentina; Mazzucco, Eleonora; Frascarolo, Paolo; Zampieri, Davide; Oliveri, Caterina; Viarengo, Aldo; Gennaro, Maria Carla [University of Piemonte Orientale, DISAV Dipartimento di Scienze dell' Ambiente e della Vita, viale T. Michel 11, 15121 Alessandria (Italy)

    2010-02-15

    This paper studies the degradation reactions that 4-chloroaniline can naturally undergo in waters for the action of sun light. 10.00 mg L{sup -1} 4-chloroaniline aqueous solution, without any addition of organic solvent, are undergone to photoirradiation under conditions that simulate sun light. The degradation pathway, followed by HPLC-DAD-MS/MS methods, is complex since the pollutant gives rise to many photoproducts: the predominant species are characterized by m/z values of 217 (P5) and 218 (P6) and are compatible with dimeric structures of 4-chloroaniline. Vibrio fischeri tests indicate that the photoproducts of 4-chloroaniline are characterized by a toxicity level significantly greater than the precursor. - The study investigates the degradation of 4-chloroaniline in waters induced by the action of sun light, to evaluate a potential increase of toxicity due to the photodegradation effect.

  13. Fabrication of Ag2O/TiO2 with enhanced photocatalytic performances for dye pollutants degradation by a pH-induced method

    Science.gov (United States)

    Ren, Hai-Tao; Yang, Qing

    2017-02-01

    Ag2O/TiO2 composites synthesized in this study were applied into the photocatalytic degradation of methyl orange (MO) under UV and visible light irradiation. X-ray diffraction, X-ray photoelectron spectroscopy and transmission electron microscope analysis demonstrated that Ag2O nanoparticles were well distributed on the surface of TiO2 and the heterostructure of Ag2O/TiO2 was formed. Compared with the pure TiO2 and Ag2O, the 3% and 50% Ag2O/TiO2 composite displayed much higher photocatalytic activities in MO degradation under UV and visible light irradiation, respectively. The degradation rate constant of 50% composite was 0.01508 min-1 under visible light, which was almost 20.1 and 1.2 times more than that of the pure TiO2 and Ag2O, respectively. Moreover, the formation of Ag(0) on the surface of Ag2O under illumination contributed to the high stability of Ag2O/TiO2 photocatalysts. It was also found that hydroxyl radicals during the photocatalytic process played the predominant role in MO degradation. The enhanced photochemical activities were attributed to the formation of the heterostructure between Ag2O and TiO2, the strong visible light absorption and the high separation efficiency of photogenerated electron-hole pairs resulted from the highly dispersed Ag2O particles.

  14. Trichloroethene Degradation in a Two-Step System by Methylosinus trichosporium OB3b. Optimization of System Performance : Use of Formate and Methane

    NARCIS (Netherlands)

    Sipkema, E.M.; Koning, W. de; Hylckama Vlieg, J.E.T. van; Ganzeveld, K.J.; Janssen, D.B.; Beenackers, A.A.C.M.

    1999-01-01

    The breakdown of dissolved TCE in a two-step bioremediation system is described. In the first reactor, the organism Methylosinus trichosporium OB3b is grown; in the second reactor, consisting of three 17-L column reactors in series, the cells degrade TCE. A special design allowed both for the additi

  15. Origin of the performances degradation of two-dimensional-based metal-oxide-semiconductor field effect transistors in the sub-10 nm regime: A first-principles study

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Anh Khoa Augustin [Semiconductor Physics Laboratory, Department of Physics and Astronomy, University of Leuven, Celestijnenlaan 200 D, B-3001 Leuven (Belgium); IMEC, 75 Kapeldreef, B-3001 Leuven (Belgium); Pourtois, Geoffrey [IMEC, 75 Kapeldreef, B-3001 Leuven (Belgium); Department of Chemistry, Plasmant Research Group, University of Antwerp, B-2610 Wilrijk-Antwerp (Belgium); Agarwal, Tarun [IMEC, 75 Kapeldreef, B-3001 Leuven (Belgium); Department of Electrical Engineering, University of Leuven, Kasteelpark Arenberg 10, B-3001 Leuven (Belgium); Afzalian, Aryan [TSMC, Kapeldreef 75, B-3001 Leuven (Belgium); Radu, Iuliana P. [IMEC, 75 Kapeldreef, B-3001 Leuven (Belgium); Houssa, Michel [Semiconductor Physics Laboratory, Department of Physics and Astronomy, University of Leuven, Celestijnenlaan 200 D, B-3001 Leuven (Belgium)

    2016-01-25

    The impact of the scaling of the channel length on the performances of metal-oxide-semiconductor field effect transistors, based on two-dimensional (2D) channel materials, is theoretically investigated, using density functional theory combined with the non-equilibrium Green's function method. It is found that the scaling of the channel length below 10 nm leads to strong device performance degradations. Our simulations reveal that this degradation is essentially due to the tunneling current flowing between the source and the drain in these aggressively scaled devices. It is shown that this electron tunneling process is modulated by the effective mass of the 2D channel material, and sets the limit of the scaling in future transistor designs.

  16. Detection of pump degradation

    Energy Technology Data Exchange (ETDEWEB)

    Casada, D. [Oak Ridge National Lab., TN (United States)

    1995-04-01

    There are a variety of stressors that can affect the operation of centrifugal pumps. Although these general stressors are active in essentially all centrifugal pumps, the stressor level and the extent of wear and degradation can vary greatly. Parameters that affect the extent of stressor activity are manifold. In order to assure the long-term operational readiness of a pump, it is important to both understand the nature and magnitude of the specific degradation mechanisms and to monitor the performance of the pump. The most commonly applied method of monitoring the condition of not only pumps, but rotating machinery in general, is vibration analysis. Periodic or continuous special vibration analysis is a cornerstone of most pump monitoring programs. In the nuclear industry, non-spectral vibration monitoring of safety-related pumps is performed in accordance with the ASME code. Pump head and flow rate are also monitored, per code requirements. Although vibration analysis has dominated the condition monitoring field for many years, there are other measures that have been historically used to help understand pump condition; advances in historically applied technologies and developing technologies offer improved monitoring capabilities. The capabilities of several technologies (including vibration analysis, dynamic pressure analysis, and motor power analysis) to detect the presence and magnitude of both stressors and resultant degradation are discussed.

  17. Electrochemical performance and degradation of (La0.6Sr0.4)0.99CoO3 − δ as porous SOFC-cathode

    DEFF Research Database (Denmark)

    Hjalmarsson, Per; Mogensen, Mogens Bjerg; Søgaard, Martin

    2008-01-01

    This paper shows that measured impedance in porous (La0.6Sr0.4)(0.99)CoO3-delta cathodes can be dependent on both gas diffusion and electrode kinetics at temperatures above 700 degrees C or below ambient pO(2)S if electrode kinetics are fast. The reaction mechanism is discussed on the basis...... of measured temperature- and pO(2)-dependences. The degradation was found to be related exclusively to the electrode kinetics and measured about 0.5-1.5 m Omega cm(2) days(-1) depending on temperature with a higher rate measured in moisturised air. We speculate on degradation mechanism that involves formation...

  18. Degradation of linear alkylabenzene sulfonate (LAS) and its compounds in Donghu Lake (Hubei, P.R.C.) determined by high performance liquid chromatography (HPLC)

    Science.gov (United States)

    Ayfer, Yediler; Xu, Ying; Zhang, Yongyuan; Chen, Junjian

    1990-06-01

    Commercial linear alkylbenzene sulfonate (LAS), mixture of alkylchain lengths and phenyl position isomers (C10-C13), is widely used as a major constituent of household and industrial detergents in the People's Republic of China. Degradation process and behaviour of LAS compounds during an 82-hour lake water die-away study, with an added LAS concentration of 1.5mg·L-1, was quantified and accomplished by HPLO-UV after extractionon the SepPek C18 reversed-phase cartridges. The degradation rate became progressively faster with increasing chain length. The technique described in this study is fast, sensitive and specific, and can be used to determine low levels of LAS and for establishing water quality criteria and standards relating to LAS and its compounds.

  19. Characterization of process-related impurities including forced degradation products of alogliptin benzoate and the development of the corresponding reversed-phase high-performance liquid chromatography method.

    Science.gov (United States)

    Zhou, YuXia; Zhou, WenTao; Sun, LiLi; Zou, QiaoGen; Wei, Ping; OuYang, PingKai

    2014-06-01

    The characterization of process-related impurities and forced degradants of alogliptin benzoate (Alb) in bulk drugs and a stability-indicating HPLC method for the separation and quantification of all the impurities were investigated. Alb was found to be unstable under acid and alkali stress conditions and two major degradation products (Imp-F and Imp-G) were observed. The optimum separation was achieved on Kromasil C18 (250 × 4.6 mm, 5 μm) using 0.1% perchloric acid (pH adjusted to 3.0 with triethylamine) and acetonitrile as a mobile phase in gradient mode. The proposed method was found to be stability indicating, precise, linear (0.10-75.0 μg/mL), accurate, sensitive, and robust for the quantitation of Alb and its process-related substances and degradation products. The structures of 11 impurities were characterized and confirmed by NMR spectroscopy, MS, and IR spectroscopy, and the most probable formation mechanisms of all impurities were proposed according to the synthesis route. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Microwave-assisted in situ synthesis of reduced graphene oxide-BiVO{sub 4} composite photocatalysts and their enhanced photocatalytic performance for the degradation of ciprofloxacin

    Energy Technology Data Exchange (ETDEWEB)

    Yan, Yan [School of Chemistry and Chemical Engineering, Jiangsu University, Xuefu Road 301, Zhenjiang, 212013 (China); Sun, Shaofang [School of Chemistry and Chemical Engineering, Jiangsu University, Xuefu Road 301, Zhenjiang, 212013 (China); School of Environmental Science and Engineering, Chang’an University, Yanta Road 126, Xi’an, 710054 (China); Song, Yang; Yan, Xu [School of Chemistry and Chemical Engineering, Jiangsu University, Xuefu Road 301, Zhenjiang, 212013 (China); Guan, Weisheng [School of Environmental Science and Engineering, Chang’an University, Yanta Road 126, Xi’an, 710054 (China); Liu, Xinlin [School of Material Science and Engineering, Jiangsu University, Xuefu Road 301, Zhenjiang, 212013 (China); Shi, Weidong, E-mail: swd1978@ujs.edu.cn [School of Chemistry and Chemical Engineering, Jiangsu University, Xuefu Road 301, Zhenjiang, 212013 (China)

    2013-04-15

    Highlights: ► Microwave-assisted in situ growth of RGO-BiVO{sub 4} composite was proposed. ► A relatively small particle size with organic-additives free. ► Graphene was formed during the microwave-heating by oxygen capture. ► GB-2 sample exhibits the highest CIP degradation ratio (3 times over pure BiVO{sub 4}). ► The enhancements of activities result from the effective charge separation. -- Abstract: To improve the photodegradation efficiency for ciprofloxacin (CIP), a new-type microwave-assisted in situ growth method is developed for the preparation of reduced graphene oxide (RGO) -BiVO{sub 4} composite photocatalysts. The as-produced RGO-BiVO{sub 4} composite photocatalysts show extremely high enhancement of CIP degradation ratio over the pure BiVO{sub 4} photocatalyst under visible light. Specially, the 2 wt% RGO-BiVO{sub 4} composite photocatalyst exhibits the highest CIP degradation ratio (68.2%) in 60 min, which is over 3 times than that (22.7%) of the pure BiVO{sub 4} particles. The enhancement of photocatalytic activities of RGO-BiVO{sub 4} photocatalysts can be attributed to the effective separation of electron–hole pairs rather than the improvement of light absorption.

  1. Heat treatment effects on the characteristics and sonocatalytic performance of TiO2 in the degradation of organic dyes in aqueous solution.

    Science.gov (United States)

    Abdullah, Ahmad Zuhairi; Ling, Pang Yean

    2010-01-15

    The ambient sonocatalytic degradation of congo red, methyl orange, and methylene blue by titanium dioxide (TiO(2)) catalyst at initial concentrations between 10 and 50mg/L, catalyst loadings between 1.0 and 3.0mg/L and hydrogen peroxide (H(2)O(2)) concentrations up to 600 mg/L is reported. A 20 kHz ultrasonic processor at 50 W was used to accelerate the reaction. The catalysts were exposed to heat treatments between 400 and 1000 degrees C for up to 4h to induce phase change. Sonocatalysts with small amount of rutile phase showed better sonocatalytic activity but excessive rutile phase should be avoided. TiO(2) heated to 800 degrees C for 2h showed the highest sonocatalytic activity and the degradation of dyes was influenced by their chemical structures, chemical phases and characteristics of the catalysts. Congo red exhibited the highest degradation rate, attributed to multiple labile azo bonds to cause highest reactivity with the free radicals generated. An initial concentration of 10mg/L, 1.5 g/L of catalyst loading and 450 ppm of H(2)O(2) gave the best congo red removal efficiency of above 80% in 180 min. Rate coefficients for the sonocatalytic process was successfully established and the reused catalyst showed an activity drop by merely 10%.

  2. Enhanced photocatalytic performance of morphologically tuned Bi2S3 NPs in the degradation of organic pollutants under visible light irradiation.

    Science.gov (United States)

    Sarkar, Arpita; Ghosh, Abhisek Brata; Saha, Namrata; Srivastava, Divesh N; Paul, Parimal; Adhikary, Bibhutosh

    2016-12-01

    Here in, morphologically tuned Bi2S3 NPs were successfully synthesized from a single-source precursor complex [Bi(ACDA)3] [HACDA=2-aminocyclopentene-1-dithiocarboxylic acid] by decomposing in various solvents using a simple solvothermal method. The as-obtained products were characterized by XRD, TEM, UV-vis spectroscopy and BET surface area measurements. Structural analyses revealed that the as-prepared Bi2S3 NPs can be tuned to different morphologies by varying various solvents and surfactants. The interplay of factors that influenced the size and morphology of the nanomaterials has been studied. Moreover, mastery over the morphology of nanoparticles enables control of their properties and enhancement of their usefulness for a given application. These materials emerged as a highly active visible light-driven photocatalyst towards degradation of methylene blue dye and the efficiencies are dependent on size and surface area of the NPs. In addition, photocatalytic degradation of highly toxic dichlorodiphenyltrichloroethane was studied using synthesized Bi2S3 NPs as catalyst and the rate of degradation has been found to be much better compared to that exhibited by commercial WO3. We believe that this new synthesis approach can be extended to the synthesis of other metal sulfide nanostructures and open new opportunities for device applications.

  3. CuAu–ZnO–graphene nanocomposite: A novel graphene-based bimetallic alloy-semiconductor catalyst with its enhanced photocatalytic degradation performance

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Hong [College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000 (China); Ye, Xiaoliang [College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000 (China); College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005 (China); Duan, Kaiyue; Xue, Muyin; Du, Yongling; Ye, Weichun [College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000 (China); Wang, Chunming, E-mail: wangcm@lzu.edu.cn [College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000 (China)

    2015-07-05

    Graphical abstract: In this work, we have successfully synthesized a novel graphene-based bimetallic alloy-semiconductor catalyst: CuAu–ZnO–Gr nanocomposite, and which behaved an enhanced photocatalytic activity. - Highlights: • A bimetallic alloy-based catalyst: CuAu–ZnO–Gr is synthesized. • CuAu–ZnO–Gr behaves an enhanced photocatalytic activity. • The detailed explanation of photocatalytic mechanism of CuAu–ZnO–Gr. - Abstract: The bimetallic alloy CuAu nanoparticles (NPs) can produce more photogenerated electrons when compared with single metal Au NPs. Moreover, graphene (Gr) sheets can help the charge separation and slow down the recombination of the electron hole pairs of ZnO. Hence, a novel graphene-based bimetallic alloy-semiconductor catalyst: CuAu–ZnO–Gr nanocomposite is synthesized. Due to the synergistic effect among CuAu NPs, ZnO nanopyramids, and Gr sheets, CuAu–ZnO–Gr behaves an enhanced photocatalytic activity for the photocatalytic degradation of synthetic colorants methyl orange (MO), methylene blue (MB), indigotin (IN), sunset yellow (SY), and tartrazine (TT) under the simulated sunlight irradiation. Furthermore, the apparent rate constants (k{sub app}) of MO, MB, IN, SY, and TT degradation are estimated respectively. In addition, the as-prepared CuAu–ZnO–Gr nanocomposite is characterized by X-ray diffraction, UV–vis spectrum, transmission electron microscopy, energy dispersive X-ray analysis (EDX), and EDX mapping. As a result of the facile synthesis route and the enhanced photocatalytic activity, this new material CuAu–ZnO–Gr can be a promising photocatalyst for the degradation of dyes.

  4. Degradation analysis of thin film photovoltaic modules

    Energy Technology Data Exchange (ETDEWEB)

    Radue, C., E-mail: chantelle.radue@nmmu.ac.z [Department of Physics, PO Box 77000, Nelson Mandela Metropolitan University, Port Elizabeth 6031 (South Africa); Dyk, E.E. van [Department of Physics, PO Box 77000, Nelson Mandela Metropolitan University, Port Elizabeth 6031 (South Africa)

    2009-12-01

    Five thin film photovoltaic modules were deployed outdoors under open circuit conditions after a thorough indoor evaluation. Two technology types were investigated: amorphous silicon (a-Si:H) and copper indium gallium diselenide (CIGS). Two 14 W a-Si:H modules, labelled Si-1 and Si-2, were investigated. Both exhibited degradation, initially due to the well-known light-induced degradation described by Staebler and Wronski [Applied Physics Letters 31 (4) (1977) 292], and thereafter due to other degradation modes such as cell degradation. The various degradation modes contributing to the degradation of the a-Si:H modules will be discussed. The initial maximum power output (P{sub MAX}) of Si-1 was 9.92 W, with the initial light-induced degradation for Si-1 approx30% and a total degradation of approx42%. For Si-2 the initial P{sub MAX} was 7.93 W, with initial light-induced degradation of approx10% and a total degradation of approx17%. Three CIGS modules were investigated: two 20 W modules labelled CIGS-1 and CIGS-2, and a 40 W module labelled CIGS-3. CIGS-2 exhibited stable performance while CIGS-1 and CIGS-3 exhibited degradation. CIGS is known to be stable over long periods of time, and thus the possible reasons for the degradation of the two modules are discussed.

  5. Detailed numerical simulation of the effect of defects created by electron irradiation on the performance degradation of a p{sup +}-n-n{sup +} GaAs solar cell

    Energy Technology Data Exchange (ETDEWEB)

    Meftah, A.F.; Sengouga, N.; Meftah, A.M. [Laboratory of Metallic and Semiconducting Materials, Faculty of Science and Engineering, Mohamed Kheider University, B.P. 145, 07000 Biskra (Algeria); Belghachi, A. [Laboratory of Semiconductor Devices Physics, Physics Department, University of Bechar, P.O. Box 417, Bechar 08000 (Algeria)

    2009-11-15

    Solar cells exposed to irradiation undergo severe degradation in their performance due to induced structural defects. To predict this effect, the current-voltage characteristics under AM0 illumination for a constant dose of electron irradiation are numerically calculated. From these characteristics the following solar cell output parameters: the short circuit current density J{sub sc}, the open circuit voltage V{sub oc}, the fill factor FF and the conversion efficiency {eta} are extracted. The irradiation induced defects introduce in the energy gap either recombination centres or traps. The irradiation induced degradation is widely attributed to the first type of defects. A strategy is adopted to check the truthfulness of this by simulating the effect of each single trap level separately on the output parameters of the cell. The simulation results show that only the shallowest deep electron trap is responsible for the degradation of J{sub sc} while V{sub oc} is mostly affected by other electron and hole traps especially the deepest one. This more detailed study is an extension of another work in which the effect of a group instead of individual levels is investigated. (author)

  6. Effect of Fe-doped TiO2 nanoparticle derived from modified hydrothermal process on the photocatalytic degradation performance on methylene blue.

    Science.gov (United States)

    Li, Zhijie; Shen, Wenzhong; He, Wensen; Zu, Xiaotao

    2008-07-15

    Anatase Fe-doped TiO2 nanoparticles with 10-15 nm particles sizes were directly prepared with amorphous TiO2 nanoparticles and Fe(NO3)3.9H2O by hydrothermal method. The TiO2 crystallite grain sizes decreased with the increase of Fe contents. When Fe contents increased, the diffuse reflectance spectra of Fe-doped TiO2 nanoparticles displayed a red shift in the band gap transition. And the absorbing band edge moved to visible range when the Fe contents were more than 2 mol%. XPS analysis showed that Fe3+ was not on the surface of TiO2 nanoparticles, but inserting into the matrix interior. As a result, the photoactivity degradation of MB on Fe-doped TiO2 nanoparticles decreased.

  7. Fabrication of high-performance CuInSe{sub 2} nanocrystals-modified TiO{sub 2} NTs for photocatalytic degradation applications

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Zeming; Tong, Xi; Sheng, Pengtao; Li, Weili; Yin, Xuehua; Zou, Jianmei; Cai, Qingyun, E-mail: qycai0001@hnu.edu.cn

    2015-10-01

    Graphical abstract: - Highlights: • CuInSe{sub 2} nanocrystals with high photocatalytic activity were synthesized and immobilized onto TiO{sub 2} nanotube arrays. • The highly photocatalytic activity of CuInSe{sub 2}/TiO{sub 2} photoelectrode was evaluated in the hydrogen generation and photocatalytic degradation of 2,4-D and 9-AnCOOH. • The CuInSe{sub 2}/TiO{sub 2} photoelectrode possesses high photoelectrical efficiency and stability over the reported ones. - Abstract: CuInSe{sub 2} nanocrystals (NCs) were prepared by colloidal synthesis and immobilized onto TiO{sub 2} nanotube arrays (NTs). Photoelectrical properties of the co-sensitized photoelectrode were investigated. The photocatalytic activities were investigated through the photocatalytic degradation of 2,4-dichlorophenoxyacetic acid (2,4-D) and anthracene-9-carboxylic acid (9-AnCOOH). The high photoelectrical efficiency is mainly due to the high absorption toward visible light and the decrease in electron–hole pairs recombination. A well maintained opened TiO{sub 2} tube-mouth configuration favors the high photoelectrical efficiency and stability of the CuInSe{sub 2}/TiO{sub 2} NT photoelectrode. The co-sensitized CuInSe{sub 2}/TiO{sub 2} NT photoelectrode displays excellent water splitting ability, 229.35 μM/cm{sup 2} hydrogen gas was achieved in 210 min. The formation of hydroxyl radicals (• OH) on the surface of the CuInSe{sub 2}/TiO{sub 2} NT photoelectrode under visible-light illumination was detected.

  8. Serological studies on chloridazon-degrading bacteria.

    Science.gov (United States)

    Layh, G; Böhm, R; Eberspächer, J; Lingens, F

    1983-01-01

    Agglutination tests and immunofluorescence tests with antisera against four strains of chloridazon-degrading bacteria revealed the serological uniformity of a group of 22 chloridazon-degrading bacterial strains. No serological relationship could be found between chloridazon-degrading bacteria and representatives of other Gram-negative bacteria. This was demonstrated by agglutination tests, including testing of the antiserum against Acinetobacter calcoaceticus, and by immunofluorescence tests, including testing of the sera against Pseudomonas and Acinetobacter strains. The tests were performed with 31 representatives of different Gram-negative bacteria, and with 22 strains of chloridazon-degrading bacteria as antigens. Differences in the extent of agglutination reactions and antibody titres among chloridazon-degrading bacterial strains together with cross-adsorption xperiments, suggest a rough classification of chloridazon-degrading bacteria into two subgroups. On the basis of immunofluorescence data, a linkage-map was worked out to represent serological relationships in the group of chloridazon-degrading strains.

  9. Dye stability and performances of dye-sensitized solar cells with different nitrogen additives at elevated temperatures - Can sterically hindered pyridines prevent dye degradation?

    Energy Technology Data Exchange (ETDEWEB)

    Tuyet Nguyen, Phuong; Lund, Torben [Department of Science, Systems and Models, Roskilde University, 4000 Roskilde (Denmark); Rand Andersen, Anders [University of Southern Denmark, Institute of Sensors, Signals and Electrotechnics (SENSE), Niels Bohrs Alle 1, 5230 Odense M (Denmark); Danish Technological Institute, Plastics Technology, Gregersensvej 2630 Taastrup (Denmark); Morten Skou, Eivind [University of Southern Denmark, Department of Chemical Engineering, Biotechnology and Enviromental Technology, Niels Bohrs Alle 1, 5230 Odense M (Denmark)

    2010-10-15

    The homogeneous kinetics of the nucleophilic substitution reactions between the ruthenium dye N719 and eight pyridines and 1-methylbenzimidazole have been investigated in 3-methoxypropionitrile at 100 C. The half lives of N719 with the additives 4-tert-butylpyridine (0.5 M) and 1-methylbenzimidazole (0.5 M) were 57 and 160 h, respectively. Sterically hindered pyridines like 2,6-lutidine did not react with N719. The efficiencies of dye-sensitized solar cells (DSC, area=8.0 cm{sup 2}) prepared with 1-methylbenzimidazole (MBI), 4-tert-butylpyridine (4-TBP), 2,6-lutidine and without any additive were 7.1%, 6.2%, 6.0% and 4.8%, respectively. The cells were stored in dark at 85 C and their I-V curves and impedance spectra were measured at regular time intervals. The N719 dye degradation in the cells were monitored by a new dye extraction protocol combined with analysis of the dye extract by HPLC coupled to mass spectrometry. After 300 h storage in dark at 85 C 40% of the initial amount of N719 dye was degraded in DSC cells prepared with MBI and the efficiency was decreased to 40% of its initial value. DSC cells prepared with 2,6-lutidine or no additives showed smaller thermal dye and efficiency stability at elevated temperatures than DSC cells prepared with the none sterically hindered additives MBI and 4-TBP. In the cells prepared with 2,6-lutidine or no additive higher contents of the iodo products [RuL{sub 2}(NCS)(iodide)]{sup +} and [RuL{sub 2}(3-MPN)(iodide)]{sup +} were found than in cells prepared with 4-TBP and MBI. It is suggested that sterically hindered pyridines have smaller complexation constants with I{sub 3}{sup -} than unsterically hindered additives. This may explain the observed faster nucleophilic substitution rates of uncomplexed I{sub 3}{sup -} with N719 in DSC cells prepared with sterically hindered pyridines. The EIS analysis showed that the lifetime of the injected electrons in the TiO{sub 2}{tau}{sub eff} is reduced by a thermally induced change

  10. Coral reef degradation and metabolic performance of the scleractinian coral Porites lutea under anthropogenic impact along the NE coast of Hainan Island, South China Sea

    KAUST Repository

    Roder, Cornelia

    2013-04-01

    Hainan\\'s coast provides favorable climatic, geochemical and biogeographic conditions for the development of extensive coral reefs in China. Observations in five reefs along the NE coast of Hainan showed, however, that the overall density of mobile macrofauna is low and key functional groups such as browsing, scraping or excavating herbivore fish are missing altogether. Coral diseases, partial mortality or tissue degradation are abundant and growth of macroalgal space competitors extensive. Signs of eutrophication, siltation and destructive fishing practices are evident resulting in a strongly altered environment unfavorable for coral recruitment success and survival. Acclimation to the anthropogenically altered conditions in the massive coral Porites lutea occurs at the cost of a decreased photosynthesis: respiration ratio reducing the regenerative capacity of these key framebuilding organisms. Even though, on the organismal level, corals are able to cope with these stressful conditions, a shift is imminent on the ecosystem level from a coral reef to a macroalgae-dominated community if land-based disturbance prevails unabated. © 2012 Elsevier Ltd.

  11. Coral reef degradation and metabolic performance of the scleractinian coral Porites lutea under anthropogenic impact along the NE coast of Hainan Island, South China Sea

    Science.gov (United States)

    Roder, Cornelia; Wu, Zhongjie; Richter, Claudio; Zhang, Jing

    2013-04-01

    Hainan's coast provides favorable climatic, geochemical and biogeographic conditions for the development of extensive coral reefs in China. Observations in five reefs along the NE coast of Hainan showed, however, that the overall density of mobile macrofauna is low and key functional groups such as browsing, scraping or excavating herbivore fish are missing altogether. Coral diseases, partial mortality or tissue degradation are abundant and growth of macroalgal space competitors extensive. Signs of eutrophication, siltation and destructive fishing practices are evident resulting in a strongly altered environment unfavorable for coral recruitment success and survival. Acclimation to the anthropogenically altered conditions in the massive coral Porites lutea occurs at the cost of a decreased photosynthesis: respiration ratio reducing the regenerative capacity of these key framebuilding organisms. Even though, on the organismal level, corals are able to cope with these stressful conditions, a shift is imminent on the ecosystem level from a coral reef to a macroalgae-dominated community if land-based disturbance prevails unabated.

  12. One-pot synthesis of BiOCl half-shells using microemulsion droplets as templates with highly photocatalytic performance for the degradation of ciprofloxacin

    Science.gov (United States)

    Mao, Danjun; Yu, Anqing; Ding, Shanshan; Wang, Fei; Yang, Shaogui; Sun, Cheng; He, Huan; Liu, Yazi; Yu, Kai

    2016-12-01

    Ultrathin BiOCl half-shells have been synthesized via an ionic liquid-in-water (IL/W) microemulsion, applying the liquid-liquid boundary of the emulsion system as a template. Surfactant TX-100 acted as the stabilizer of the IL-microemulsion, which is of critical importance for the formation of BiOCl half-shells. The hollow structures were characterized using X-ray diffraction, scanning and transmission electron microscopy, diffuse reflectance spectroscopy and specific surface area, respectively. Possible formation mechanisms for the BiOCl half-shells were discussed. Moreover, the ultrathin BiOCl half-shells exhibited distinctly enhanced photocatalytic efficiency toward the degradation of colourless ciprofloxacin (CIP, a representative broad-spectrum antibiotic agent) under solar light irradiation as compared to BiOCl nanosheets. The photogenerated reactive species are verified by scavenger experiments, which reveals that rad O2- and h+ were the two major photoactive species toward the photodegradation of CIP over ultrathin BiOCl half-shells under solar-light. The enhanced activities of ultrathin BiOCl half-shells were mainly ascribed to the synergistic effect of the increased light-harvesting, larger BET surface area, faster separation and transfer of electron-hole pairs. It is hoped that the ionic liquid microemulsion-mediated route can be extended to the purposive design and fabrication of other halogen-containing inorganic hollow materials.

  13. 基于改进灰色模型的机场柔性道面性能衰减研究%On prediction model of flexible airport pavement performance degradation based on improved gray forecast model

    Institute of Scientific and Technical Information of China (English)

    刘志业

    2015-01-01

    The paper adopts the annual traffic growth ratio and soil matrix CBR,modifies the gray models,establishes the airport asphalt concrete pavement performance degradation model after the large-scale repair,and proves by the examples that the model can reflect the performance deg-radation law of the flexible pavement with high forecast accuracy and it meets the demands for the airport pavement maintenance.%采用年交通增长率和土基 CBR 两个指标,对灰色模型进行了修正,建立了大修后的机场沥青混凝土道面性能衰减模型,通过实例验证表明,该模型预测精度高,能客观反映机场柔性道面的性能衰减规律,满足机场道面养护工作的要求。

  14. Antimisting kerosene: Low temperature degradation and blending

    Science.gov (United States)

    Yavrouian, A.; Parikh, P.; Sarohia, V.

    1988-01-01

    The inline filtration characteristics of freshly blended and degraded antimisting fuels (AMK) at low temperature are examined. A needle valve degrader was modified to include partial recirculation of degraded fuel and heat addition in the bypass loop. A pressure drop across the needle valve of up to 4,000 psi was used. The pressure drop across a 325 mesh filter screen placed inline with the degrader and directly downstream of the needle valve was measured as a function of time for different values of pressure drop across the needle valve. A volume flux of 1 gpm/sq in was employed based on the frontal area of the screen. It was found that, at ambient temperatures, freshly blended AMK fuel could be degraded using a single pass degradation at 4,000 psi pressure drop across the needle valve to give acceptable filterability performance. At fuel temperatures below -20 C, degradation becomes increasingly difficult and a single pass technique results in unacceptable filtration performance. Recirculation of a fraction of the degraded fuel and heat addition in the bypass loop improved low temperature degradation performance. The problem is addressed of blending the AMK additive with Jet A at various base fuel temperatures.

  15. Photothermal degradation studies of encapsulants

    Science.gov (United States)

    Liang, R. H.

    1984-01-01

    The reliability physics program at JPL is outlined. The overall objectives and approaches are given in the program. The objectives, approaches and conclusions are given for two specific parts of the programs. These two parts are mechanistic studies of photothermal degradation and performance characteristics of materials with respect to photothermal stresses.

  16. Long-term Performance of PVC and CSPE Cables used in Nuclear Power Plants: the Effect of Degradation and Plasticizer migration

    Energy Technology Data Exchange (ETDEWEB)

    Ekelund, Maria

    2009-10-15

    Enormous amounts of low voltage cables installed in a Swedish nuclear power plant are reaching their expected lifetimes. Since the cables are crucial to operational safety, it is of great importance that the actual condition of the installed cables is determined. In this study, cables based on poly(vinyl chloride) plasticized with di(2-ethylhexyl)phthalate (DEHP) were examined with respect to the degradation mechanisms responsible for the ageing of the insulation. This was achieved by studying samples that underwent accelerated ageing by different analytical methods, such as indenter modulus measurements, tensile testing, infrared spectroscopy, differential scanning calorimetry and liquid chromatography, to assess the condition of the cables. The results were unambiguous; the main deterioration mechanism differed for the jacket and the core insulation. The immediate increase in stiffness of the jacket insulation suggests that loss of plasticizer was the dominant cause for degradation. The core insulation on the other hand showed much smaller changes in the mechanical properties due to thermal ageing with an activation energy of the change in the indenter modulus matching that of the dehydrochlorination process. The electrical functionality during high-energy line break accident was correlated to the mechanical properties of the cable and this correlation was used to establish a lifetime criterion. The mechanical data showed Arrhenius temperature dependence with activation energies of 80 kJ/mol and 100 kJ/mol for the jacketing and 130 kJ/mol for the core insulation. These activation energies were used to extrapolate the lifetimes to service temperatures (20 deg C to 50 deg C). Plasticizer migration was determined as the lifetime controlling mechanism at the service temperatures. Experimental data, obtained by extraction of DEHP followed by liquid chromatography, were analysed by numerical methods to gain a better understanding of the migration. The analysis showed

  17. 9F 燃气轮机性能劣化的分析%Analysis of 9F Gas Turbine Performance Degradation

    Institute of Scientific and Technical Information of China (English)

    沙俊辉; 章焰; 章恂

    2014-01-01

    There was a case of one 9F class combined cycle unit abnormal degradation , through the comprehensive analysis and screen-ing, the leakage of inlet air filtering system of compressor was pointed out .After inspection and treatment , the decay rate of unit output and efficiency came back to normal .By comprehensive analysis as well as establishing the mathematical model of unit output degrada -tion after compressor water wash , results show that the leakage of inlet air filtering system to unit load capacity have significant impact , and it put forward the method applicable to analyze the combined cycle unit output change .%针对某台9F级联合循环机组出力不足的问题,通过全面的分析和排查,指出了压气机进气过滤系统存在泄漏,经检查处理后取得了明显效果,机组出力及运行效率的衰减速度恢复正常。通过压气机水洗后机组出力衰减的综合分析,建立了机组出力衰减数学模型,论证了压气机进气过滤系统泄漏对机组带负荷能力可能产生的重大影响,提出了适用于运行现场的联合循环机组出力变化的分析方法。

  18. Proteína degradável no rúmen associada a fontes de amido de alta ou baixa degradabilidade: digestibilidade in vitro e desempenho de novilhos em crescimento Rumen degradable protein associated to starch sources of different ruminal degradability: in vitro digestibility and performance of growing steers

    Directory of Open Access Journals (Sweden)

    Saul Ferreira Caldas Neto

    2007-04-01

    Full Text Available Objetivou-se avaliar os efeitos de teores crescentes de proteína degradável no rúmen (PDR = 47, 52, 57 e 62% associados a fontes de amido de baixa (milho ou de alta (farinha de varredura de mandioca - FVM degradabilidade ruminal em rações com 50:50% volumoso:concentrado sobre a digestibilidade in vitro da MS (DIVMS e o ganho de peso de novilhos em crescimento. Para determinação da DIVMS, foi utilizada a técnica de dois estádios de Tilley & Terry (1963. As médias obtidas para a DIVMS foram submetidas às análises de variância e regressão em função do teor de PDR da ração. Para o ensaio de desempenho animal, foram utilizados 32 novilhos mestiços (Nelore x Red Angus, não-castrados (275 kg de PV, alojados em duplas, em delineamento experimental inteiramente casualizado. Não foi observado efeito do teor de PDR de dietas contendo milho sobre a DIVMS, indicando que não houve deficiência de nitrogênio e que, possivelmente, a digestibilidade da fonte de amido (milho foi o fator limitante. Observou-se efeito quadrático do teor de PDR sobre a DIVMS para as dietas contendo FVM, o que indica a ocorrência do efeito de sincronização entre a disponibilidade de energia e nitrogênio, permitindo aumento da atividade microbiana nos níveis mais elevados de PDR na ração e melhor utilização da energia proveniente da fonte de amido de alta degradabilidade ruminal. Não foi observado efeito dos diferentes teores de PDR e da fonte de amido de alta degradabilidade ruminal sobre o consumo de MS, o ganho de peso médio e a conversão alimentar dos animais.The objective of this study was to evaluate the effects of increasing levels of rumen-degradable protein (RDP = 47, 52, 57 and 62% associated to starch sources of low (corn and high (cassava by-product (CBP ruminal degradability on in vitro DM digestibility (IVDMD and average daily gain of growing steers. In vitro DM digestibility was determined by using the Tilley and Terry (1963 technique

  19. Methods of Analysis by the U.S. Geological Survey Organic Geochemistry Research Group-Update and Additions to the Determination of Chloroacetanilide Herbicide Degradation Compounds in Water Using High-Performance Liquid Chromatography/Mass Spectrometry

    Science.gov (United States)

    Lee, E.A.; Kish, J.L.; Zimmerman, L.R.; Thurman, E.

    2001-01-01

    An analytical method using high-performance liquid chromatography/mass spectrometry (HPLC/MS) was developed by the U.S. Geological Survey in 1999 for the analysis of selected chloroacetanilide herbicide degradation compounds in water. These compounds were acetochlor ethane sulfonic acid (ESA), acetochlor oxanilic acid (OXA), alachlor ESA, alachlor OXA, metolachlor ESA, and metolachlor OXA. The HPLC/MS method was updated in 2000, and the method detection limits were modified accordingly. Four other degradation compounds also were added to the list of compounds that can be analyzed using HPLC/MS; these compounds were dimethenamid ESA, dimethenamid OXA, flufenacet ESA, and flufenacet OXA. Except for flufenacet OXA, good precision and accuracy were demonstrated for the updated HPLC/MS method in buffered reagent water, surface water, and ground water. The mean HPLC/MS recoveries of the degradation compounds from water samples spiked at 0.20 and 1.0 ?g/L (microgram per liter) ranged from 75 to 114 percent, with relative standard deviations of 15.8 percent or less for all compounds except flufenacet OXA, which had relative standard deviations ranging from 11.3 to 48.9 percent. Method detection levels (MDL's) using the updated HPLC/MS method varied from 0.009 to 0.045 ?g/L, with the flufenacet OXA MDL at 0.072 ?g/L. The updated HPLC/MS method is valuable for acquiring information about the fate and transport of the parent chloroacetanilide herbicides in water.

  20. FeAsO4 Photocatalyst and Its Photocatalytic Performance in Degradation of Rhodamine B Dyes%光催化剂FeAsO4降解罗丹明B染料的性能研究

    Institute of Scientific and Technical Information of China (English)

    封朝霞; 李大塘; 彭斌

    2016-01-01

    A novel visible-light-responsive photocatalyst FeAsO4 was prepared by co-precipitation method.The results of UV -visible diffuse reflectance spectrum showed that it can absorb visible light of 400 ~500 nm.The photocatalytic activity of FeAsO4 was tested in degradation of rhodamine B dyes.The results demonstrated that it had high activity, it can completely degrade rhodamine B dyes in 40 ~50 min.The photocatalytic efficiency can be attributed to the combined effect of intrinsic photocatalytic performance of FeAsO4 and rhodamine B self-sensitization in the photocatalytic degradation process.%采用并流沉淀法制备了新型可见光催化剂 FeAsO4。通过紫外-可见漫反射光谱得知,它能吸收400~500 nm 之间的可见光。通过可见光光催化降解罗丹明 B 评价了该光催化剂的光催化活性,其结果表明,它具有高的光催化活性,能在40~50 min 内就将罗丹明 B 基本降解完全,这主要归因于在光催化降解过程中, FeAsO4的光催化与罗丹明 B 分子自身敏化的共同作用。

  1. Environmental Degradation of High Temperature Composites

    Science.gov (United States)

    1992-04-01

    A study was performed to assess the effect of galvanic corrosion phenomena on the strength of graphite/bismaleimide( BMI ) composites . The results...indicate that degradation occurred in BMI composites galvanically coupled to aluminum alloys. The mechanism responsible for the degradation involves

  2. Performance of Polymeric Metalloporphyrins for Photocatalytic Oxidative Degradation of Wasted-Water%高分子金属卟啉光催化氧化处理废水

    Institute of Scientific and Technical Information of China (English)

    金星龙; 朱琨; 房彦军; 杨瑞强; 陈慧

    2001-01-01

    将高分子金属卟啉聚中位四(4,4’-联苯二磺酰基)氧基苯基钴卟啉用于多相光催化体系,在温和条件下成功地降解了有机染料吖啶橙.实验结果表明,降解反应符合一级动力学方程lnct=2.52052-0.565 46t(R=-0.997 04),经8h的反应以后,染料溶液完全褪色.将此光催化剂用于混合染料、染料废水、化工厂废水及生活污水的处理,脱色率可达68%,COD去除率可达58%.通过对高压汞灯、碘钨灯和自然光等各种光源进行比较,发现在太阳光照射下,金属卟啉光催化氧化降解有机污染物的效率更高、速度更快、降解更完全.%In heterogeneous phot ocatalytic oxidation system, acridineorange (AO) was degraded successfully by polymeric metalloporphyrin Co [meso-tetra (4, 4'-biphenylbisulfonyl) phenylporphyrin] ( PCoTBPBSOPP) under mild conditions. The results indicated that the photodegra dation of AO obeys the first order law with equation as lnct=2.520 52-0.565 46t (R=-0.997?04). AO was decolored and decomposed completel y after 8 h. Since PCoTBPBSOPP was applied to treat textile, industrial and dome stic wasted-water, it was found that the average decolorization ratio of the dyes wasted-water is up to 68% and the average removal of COD re aches 58%. By comparison with high-pressure mercury lamp (HPML), iodine tungste n lamp (ITL) and natural sunlight(NSL), AO can be decomposed rapidly under irradiatio n with NSL. It is proved that the polymeric metalloporphyrins have a potential effective application in treating the wasted-water under natural conditons.

  3. Routine low-level monitoring of polar pesticides and pesticide degradates by HPLC/ESI-MS: Evaluating long-term performance

    Science.gov (United States)

    Furlong, E.T.; Martin, Jeffrey D.; Werner, S.L.; Gates, Paul M.

    2002-01-01

    The sensitivity and selective determination of polar pesticides were analyzed using high-performance liquid chromatography/electrospray ionization-mass spectrometry (HPLC/ESI-MS). The effects of multiple operators and instruments on method performance were evaluated using 440 pairs of fortified reagent-water and blank reagent-water samples. The influence of varying environmental matrices on recovery and precision were also analyzed using 200 fortified ambient water samples and duplicate ambient water samples. The results show that compound stability in filtered water was matrix-, chemical class- and compound-dependent which ranged from 1 day to 2 weeks.

  4. Clad Degradation - FEPs Screening Arguments

    Energy Technology Data Exchange (ETDEWEB)

    E. Siegmann

    2004-03-17

    The purpose of this report is to document the screening of the cladding degradation features, events, and processes (FEPs) for commercial spent nuclear fuel (CSNF). This report also addresses the effect of some FEPs on both the cladding and the CSNF, DSNF, and HLW waste forms where it was considered appropriate to address the effects on both materials together. This report summarizes the work of others to screen clad degradation FEPs in a manner consistent with, and used in, the Total System Performance Assessment-License Application (TSPA-LA). This document was prepared according to ''Technical Work Plan for Waste Form Degradation Modeling, Testing, and Analyses in Support of LA'' (BSC 2004a [DIRS 167796]).

  5. S-naproxen-ss-1-O-acyl glucuronide degradation kinetic studies by stopped-flow high-performance liquid chromatography-H-1 NMR and high-performance liquid chromatography-UV

    DEFF Research Database (Denmark)

    Mortensen, R. W.; Corcoran, O.; Cornett, Claus

    2001-01-01

    )) were 0.025 (hydrolysis of S-nap-g) and 0.0058 (hydrolysis of all acyl-migrated isomers). D2O and MeCN decreased the magnitude of all nine kinetic rate constants by up to 80%. The kinetic rate constants for the degradation of S-nap-g in the mobile phase used for HPLC-H-1 NMR determined using HPLC-UV...... could predict the results obtained by the dynamic stopped-flow HPLC-H-1 NMR experiments of the individual acyl-migrated isomers. It is therefore recommended that beta -1-O-acyl glucuronide degradation kinetics be investigated by HPLC-UV methods once the identification and elution order of the isomers...... order rate constants in the chemical equilibrium between six species (S-nap-g, its alpha/beta -2-O-acyl, alpha/beta -3-O-acyl, alpha/beta -4-O-acyl, and alpha -1-O-acyl-migration isomers, and S-naproxen aglycone) were determined by HPLC-UV studies in 25 mM potassium phosphate buffer, pH 7.40, 25 m...

  6. Thermal battery degradation mechanisms

    Energy Technology Data Exchange (ETDEWEB)

    Missert, Nancy A. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Brunke, Lyle Brent [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-09-01

    Diffuse reflectance IR spectroscopy (DRIFTS) was used to investigate the effect of accelerated aging on LiSi based anodes in simulated MC3816 batteries. DRIFTS spectra showed that the oxygen, carbonate, hydroxide and sulfur content of the anodes changes with aging times and temperatures, but not in a monotonic fashion that could be correlated to phase evolution. Bands associated with sulfur species were only observed in anodes taken from batteries aged in wet environments, providing further evidence for a reaction pathway facilitated by H2S transport from the cathode, through the separator, to the anode. Loss of battery capacity with accelerated aging in wet environments was correlated to loss of FeS2 in the catholyte pellets, suggesting that the major contribution to battery performance degradation results from loss of active cathode material.

  7. Sulfate addition as an effective method to improve methane fermentation performance and propionate degradation in thermophilic anaerobic co-digestion of coffee grounds, milk and waste activated sludge with AnMBR.

    Science.gov (United States)

    Li, Qian; Li, Yu-You; Qiao, Wei; Wang, Xiaochang; Takayanagi, Kazuyuki

    2015-06-01

    This study was conducted to investigate the effects of sulfate on propionate degradation and higher organic loading rate (OLR) achievement in a thermophilic AnMBR for 373days using coffee grounds, milk and waste activated sludge (WAS) as the co-substrate. Without the addition of sulfate, the anaerobic system failed at an OLR of 14.6g-COD/L/d, with propionate accumulating to above 2.23g-COD/L, and recovery by an alkalinity supplement was not successful. After sulfate was added into substrates at a COD/SO4(2-) ratio of 200:1 to 350:1, biogas production increased proportionally with OLR increasing from 4.06 to 15.2g-COD/L/d. Propionic acid was maintained at less than 100mg-COD/L due to the effective conversion of propionic acid to methane after the sulfate supplement was added. The long-term stable performance of the AnMBR indicated that adding sulfate was beneficial for the degradation of propionate and achieving a higher OLR under the thermophilic condition. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. Rhizobium borbori sp. nov., aniline-degrading bacteria isolated from activated sludge.

    Science.gov (United States)

    Zhang, Guo Xia; Ren, Sui Zhou; Xu, Mei Ying; Zeng, Guo Qu; Luo, Hui Dong; Chen, Jin Lin; Tan, Zhi Yuan; Sun, Guo Ping

    2011-04-01

    Three aniline-degrading bacteria, strains DN316(T), DN316-1 and DN365, were isolated from activated sludge. According to 16S rRNA gene sequence-based phylogenetic analysis, the isolates belonged to the genus Rhizobium, with Rhizobium ( = Agrobacterium) radiobacter LMG 140(T) as the closest relative, with 96.5 % sequence similarity. Phylogenetic analysis of the representative strain DN316(T) using sequences of the glnA, thrC and recA genes and the 16S-23S intergenic spacer region confirmed the phylogenetic arrangement obtained from analysis of the 16S rRNA gene. DNA-DNA relatedness between DN316(T) and R. radiobacter LMG 140(T) was 43.7 %, clearly indicating that the representative strain DN316(T) represents a novel species. Phenotypic and biochemical characterization of the isolates and insertion sequence-PCR fingerprinting patterns showed several distinctive features that differentiated them from closely related species. The major components of the cellular fatty acids were C(18 : 1)ω7c (57.10 %), C(16 : 0) (11.31 %) and C(19 : 0) cyclo ω8c (10.13 %). Based on our taxonomic analysis, the three isolates from activated sludge represent a novel species of the genus Rhizobium, for which the name Rhizobium borbori sp. nov. is proposed. The type strain is DN316(T) ( = CICC 10378(T)  = LMG 23925(T)).

  9. Degradation of microbial polyesters.

    Science.gov (United States)

    Tokiwa, Yutaka; Calabia, Buenaventurada P

    2004-08-01

    Microbial polyhydroxyalkanoates (PHAs), one of the largest groups of thermoplastic polyesters are receiving much attention as biodegradable substitutes for non-degradable plastics. Poly(D-3-hydroxybutyrate) (PHB) is the most ubiquitous and most intensively studied PHA. Microorganisms degrading these polyesters are widely distributed in various environments. Although various PHB-degrading microorganisms and PHB depolymerases have been studied and characterized, there are still many groups of microorganisms and enzymes with varying properties awaiting various applications. Distributions of PHB-degrading microorganisms, factors affecting the biodegradability of PHB, and microbial and enzymatic degradation of PHB are discussed in this review. We also propose an application of a new isolated, thermophilic PHB-degrading microorganism, Streptomyces strain MG, for producing pure monomers of PHA and useful chemicals, including D-3-hydroxycarboxylic acids such as D-3-hydroxybutyric acid, by enzymatic degradation of PHB.

  10. Performance-degradation model for Li{sub 4}Ti{sub 5}O{sub 12}-based battery cells used in wind power applications

    Energy Technology Data Exchange (ETDEWEB)

    Stroe, D.I.; Swierczynski, M.; Stan, A.I.; Teodorescu, R.; Andreasen, S.J. [Aalborg Univ. (Denmark). Dept. of Energy Technology

    2012-07-01

    Energy storage systems based on Lithium-ion batteries have the potential to mitigate the negative impact of wind power grid integration on the power system stability, which is caused by the characteristics of the wind. This paper presents a performance model for a Li{sub 4}Ti{sub 5}O{sub 12}/LiMO{sub 2} battery cell. For developing the performance model an EIS-based electrical modelling approach was followed. The obtained model is able to predict with high accuracy charge and discharge voltage profiles for different ages of the battery cell and for different charging/ discharging current rates. Moreover, the ageing behaviour of the battery cell was analysed for the case of accelerated cycling ageing with a certain mission profile.

  11. Ensemble LUT classification for degraded document enhancement

    Science.gov (United States)

    Obafemi-Ajayi, Tayo; Agam, Gady; Frieder, Ophir

    2008-01-01

    The fast evolution of scanning and computing technologies have led to the creation of large collections of scanned paper documents. Examples of such collections include historical collections, legal depositories, medical archives, and business archives. Moreover, in many situations such as legal litigation and security investigations scanned collections are being used to facilitate systematic exploration of the data. It is almost always the case that scanned documents suffer from some form of degradation. Large degradations make documents hard to read and substantially deteriorate the performance of automated document processing systems. Enhancement of degraded document images is normally performed assuming global degradation models. When the degradation is large, global degradation models do not perform well. In contrast, we propose to estimate local degradation models and use them in enhancing degraded document images. Using a semi-automated enhancement system we have labeled a subset of the Frieder diaries collection.1 This labeled subset was then used to train an ensemble classifier. The component classifiers are based on lookup tables (LUT) in conjunction with the approximated nearest neighbor algorithm. The resulting algorithm is highly effcient. Experimental evaluation results are provided using the Frieder diaries collection.1

  12. 一株芘的高效降解菌的选育及其降解性能研究%Breeding of a high-performance pyrene-degrading strain and its biodegradation performance

    Institute of Scientific and Technical Information of China (English)

    唐玉斌; 马姗姗; 王晓朝; 陈芳艳

    2011-01-01

    A preponderant pyrene-degrading strain B-1 was isolated and purified from activated sludge collected from aeration basin of a coking plant to provide microorganism resource and scientific basis for bioremediation of the environment polluted by polycyclic aromatic hydrocarbons. Strain B-1 could grow and breed in liquid mineral salt medium with pyrene as sole carbon source and resist pyrene with concentration up to about 130 mg/L. Strain B-1 was initially identified as Bacillus by the results of morphological observation, physio-biochemical test and 16S rDNA sequence analysis. The incubation amount, initial pyrene concentration of liquid medium, pH and salinity are the factors to affect pyrene degradation efficiency. Under the conditions of incubation amount of 15% (V/V), initial pyrene concentration of 20 ~100 mg/L and temperature of 30℃, strain B-1 could preserve high degradation activities of pyrene in the range of the pH 4 ~ 11 and the salinity less than 1%. With the initial pyrene concentration of 80 mg/L, incubation amount of 13% V/V), pyrene degradation percentage by strain B1 was 92.4% after 10 days.%旨在为多环芳烃污染环境的生物修复提供微生物资源和科学依据,从某焦化厂曝气池的活性污泥中分离纯化出一株降解芘的优势菌株B-1,该菌株可在以芘为惟一碳源的培养基中生长繁殖,能利用芘的最高浓度为130 mg/L左右.经形态学观察、生理生化实验及l6S rDNA序列分析,初步判断菌株B-1为芽胞杆菌属.投菌量、芘初始浓度、pH和盐度是影响芘降解效率的因素.在投菌量为15%(V/V)、芘初始浓度为20~100 mg/L和温度为30℃的条件下,该菌在pH为4~11、盐度在1%以内可保持对芘良好的降解能力.当芘初始浓度为80 mg/L,投菌量为13%(V/V),历时10 d,芘的降解效率可达92.4%.

  13. Performance analysis on carrier phase-based tightly-coupled GPS/BDS/INS integration in GNSS degraded and denied environments.

    Science.gov (United States)

    Han, Houzeng; Wang, Jian; Wang, Jinling; Tan, Xinglong

    2015-04-14

    The integration of Global Navigation Satellite Systems (GNSS) carrier phases with Inertial Navigation System (INS) measurements is essential to provide accurate and continuous position, velocity and attitude information, however it is necessary to fix ambiguities rapidly and reliably to obtain high accuracy navigation solutions. In this paper, we present the notion of combining the Global Positioning System (GPS), the BeiDou Navigation Satellite System (BDS) and low-cost micro-electro-mechanical sensors (MEMS) inertial systems for reliable navigation. An adaptive multipath factor-based tightly-coupled (TC) GPS/BDS/INS integration algorithm is presented and the overall performance of the integrated system is illustrated. A twenty seven states TC GPS/BDS/INS model is adopted with an extended Kalman filter (EKF), which is carried out by directly fusing ambiguity fixed double-difference (DD) carrier phase measurements with the INS predicted pseudoranges to estimate the error states. The INS-aided integer ambiguity resolution (AR) strategy is developed by using a dynamic model, a two-step estimation procedure is applied with adaptively estimated covariance matrix to further improve the AR performance. A field vehicular test was carried out to demonstrate the positioning performance of the combined system. The results show the TC GPS/BDS/INS system significantly improves the single-epoch AR reliability as compared to that of GPS/BDS-only or single satellite navigation system integrated strategy, especially for high cut-off elevations. The AR performance is also significantly improved for the combined system with adaptive covariance matrix in the presence of low elevation multipath related to the GNSS-only case. A total of fifteen simulated outage tests also show that the time to relock of the GPS/BDS signals is shortened, which improves the system availability. The results also indicate that TC integration system achieves a few centimeters accuracy in positioning based

  14. Performance Analysis on Carrier Phase-Based Tightly-Coupled GPS/BDS/INS Integration in GNSS Degraded and Denied Environments

    Directory of Open Access Journals (Sweden)

    Houzeng Han

    2015-04-01

    Full Text Available The integration of Global Navigation Satellite Systems (GNSS carrier phases with Inertial Navigation System (INS measurements is essential to provide accurate and continuous position, velocity and attitude information, however it is necessary to fix ambiguities rapidly and reliably to obtain high accuracy navigation solutions. In this paper, we present the notion of combining the Global Positioning System (GPS, the BeiDou Navigation Satellite System (BDS and low-cost micro-electro-mechanical sensors (MEMS inertial systems for reliable navigation. An adaptive multipath factor-based tightly-coupled (TC GPS/BDS/INS integration algorithm is presented and the overall performance of the integrated system is illustrated. A twenty seven states TC GPS/BDS/INS model is adopted with an extended Kalman filter (EKF, which is carried out by directly fusing ambiguity fixed double-difference (DD carrier phase measurements with the INS predicted pseudoranges to estimate the error states. The INS-aided integer ambiguity resolution (AR strategy is developed by using a dynamic model, a two-step estimation procedure is applied with adaptively estimated covariance matrix to further improve the AR performance. A field vehicular test was carried out to demonstrate the positioning performance of the combined system. The results show the TC GPS/BDS/INS system significantly improves the single-epoch AR reliability as compared to that of GPS/BDS-only or single satellite navigation system integrated strategy, especially for high cut-off elevations. The AR performance is also significantly improved for the combined system with adaptive covariance matrix in the presence of low elevation multipath related to the GNSS-only case. A total of fifteen simulated outage tests also show that the time to relock of the GPS/BDS signals is shortened, which improves the system availability. The results also indicate that TC integration system achieves a few centimeters accuracy in

  15. The Science of Battery Degradation

    Energy Technology Data Exchange (ETDEWEB)

    Sullivan, John P. [Sandia National Lab. (SNL-CA), Livermore, CA (United States). Materials Physics; El Gabaly Marquez, Farid [Sandia National Lab. (SNL-CA), Livermore, CA (United States). Materials Physics; McCarty, Kevin [Sandia National Lab. (SNL-CA), Livermore, CA (United States). Materials Physics; Sugar, Joshua Daniel [Sandia National Lab. (SNL-CA), Livermore, CA (United States). Materials Physics; Talin, Alec A. [Sandia National Lab. (SNL-CA), Livermore, CA (United States). Materials Physics; Fenton, Kyle R. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Power Sources Design and Development; Nagasubramanian, Ganesan [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Power Sources Design and Development; Harris, Charles Thomas [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Nanosystems Synthesis/Analysis; Jungjohann, Katherine Leigh [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Nanosystems Synthesis/Analysis; Hayden, Carl C. [Sandia National Lab. (SNL-CA), Livermore, CA (United States). Combustion Chemistry Dept.; Kliewer, Christopher Jesse [Sandia National Lab. (SNL-CA), Livermore, CA (United States). Combustion Chemistry Dept.; Hudak, Nicholas S. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Power Sources Research and Development; Leung, Kevin [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Nanostructure Physics; McDaniel, Anthony H. [Sandia National Lab. (SNL-CA), Livermore, CA (United States). Hydrogen and Combustion Technology; Tenney, Craig M. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Chemical and Biological Systems; Zavadil, Kevin R. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Advanced Materials Lab.

    2015-01-01

    This report documents work that was performed under the Laboratory Directed Research and Development project, Science of Battery Degradation. The focus of this work was on the creation of new experimental and theoretical approaches to understand atomistic mechanisms of degradation in battery electrodes that result in loss of electrical energy storage capacity. Several unique approaches were developed during the course of the project, including the invention of a technique based on ultramicrotoming to cross-section commercial scale battery electrodes, the demonstration of scanning transmission x-ray microscopy (STXM) to probe lithium transport mechanisms within Li-ion battery electrodes, the creation of in-situ liquid cells to observe electrochemical reactions in real-time using both transmission electron microscopy (TEM) and STXM, the creation of an in-situ optical cell utilizing Raman spectroscopy and the application of the cell for analyzing redox flow batteries, the invention of an approach for performing ab initio simulation of electrochemical reactions under potential control and its application for the study of electrolyte degradation, and the development of an electrochemical entropy technique combined with x-ray based structural measurements for understanding origins of battery degradation. These approaches led to a number of scientific discoveries. Using STXM we learned that lithium iron phosphate battery cathodes display unexpected behavior during lithiation wherein lithium transport is controlled by nucleation of a lithiated phase, leading to high heterogeneity in lithium content at each particle and a surprising invariance of local current density with the overall electrode charging current. We discovered using in-situ transmission electron microscopy that there is a size limit to lithiation of silicon anode particles above which particle fracture controls electrode degradation. From electrochemical entropy measurements, we discovered that entropy

  16. The Science of Battery Degradation.

    Energy Technology Data Exchange (ETDEWEB)

    Sullivan, John P; Fenton, Kyle R [Sandia National Laboratories, Albuquerque, NM; El Gabaly Marquez, Farid; Harris, Charles Thomas [Sandia National Laboratories, Albuquerque, NM; Hayden, Carl C.; Hudak, Nicholas [Sandia National Laboratories, Albuquerque, NM; Jungjohann, Katherine Leigh [Sandia National Laboratories, Albuquerque, NM; Kliewer, Christopher Jesse; Leung, Kevin [Sandia National Laboratories, Albuquerque, NM; McDaniel, Anthony H.; Nagasubramanian, Ganesan [Sandia National Laboratories, Albuquerque, NM; Sugar, Joshua Daniel; Talin, Albert Alec; Tenney, Craig M [Sandia National Laboratories, Albuquerque, NM; Zavadil, Kevin R. [Sandia National Laboratories, Albuquerque, NM

    2015-01-01

    This report documents work that was performed under the Laboratory Directed Research and Development project, Science of Battery Degradation. The focus of this work was on the creation of new experimental and theoretical approaches to understand atomistic mechanisms of degradation in battery electrodes that result in loss of electrical energy storage capacity. Several unique approaches were developed during the course of the project, including the invention of a technique based on ultramicrotoming to cross-section commercial scale battery electrodes, the demonstration of scanning transmission x-ray microscopy (STXM) to probe lithium transport mechanisms within Li-ion battery electrodes, the creation of in-situ liquid cells to observe electrochemical reactions in real-time using both transmission electron microscopy (TEM) and STXM, the creation of an in-situ optical cell utilizing Raman spectroscopy and the application of the cell for analyzing redox flow batteries, the invention of an approach for performing ab initio simulation of electrochemical reactions under potential control and its application for the study of electrolyte degradation, and the development of an electrochemical entropy technique combined with x-ray based structural measurements for understanding origins of battery degradation. These approaches led to a number of scientific discoveries. Using STXM we learned that lithium iron phosphate battery cathodes display unexpected behavior during lithiation wherein lithium transport is controlled by nucleation of a lithiated phase, leading to high heterogeneity in lithium content at each particle and a surprising invariance of local current density with the overall electrode charging current. We discovered using in-situ transmission electron microscopy that there is a size limit to lithiation of silicon anode particles above which particle fracture controls electrode degradation. From electrochemical entropy measurements, we discovered that entropy

  17. Comparison of a xylanase and a complex of non starch polysaccharide-degrading enzymes with regard to performance and bacterial metabolism in weaned piglets.

    Science.gov (United States)

    Vahjen, Wilfried; Osswald, Tanja; Schäfer, Klaus; Simon, Ortwin

    2007-04-01

    Weaned piglets were fed a wheat based diet either non-supplemented or supplemented with a multi-enzyme preparation or a xylanase mono-enzyme preparation, respectively. Both enzyme preparations increased live weight gain nonsignificantly, but only animals of the xylanase group showed a trend (p = 0.076) for an improved feed conversion. Only precaecal digestibility of total amino acids was improved significantly when the mono-enzyme preparation was added. Improvements of digestibility of crude fat, crude protein and starch did not reach the significance level. Both enzyme preparations reduced jejunal viscosity, however viscosity in the colon was only reduced by the mono-enzyme preparation. Both enzymes significantly reduced Lactobacillus spp. cell numbers as well as bacterial metabolites in the stomach and showed similar nonsignificant modifications in jejunum contents except for acetate in the mono-enzyme group. Total jejunal bile acids were unchanged. Compared to the control, the ratio of the main conjugated to the main deconjugated bile acid was significantly higher in the mono-enzyme group. This study has shown that the mono- and multi-enzyme preparation can lead to improved performance in wheat based diets for piglets. Like in poultry, the main mode of action seems to be the reduction of small intestinal viscosity. However, the generation of fermentable carbohydrates by the multi-enzyme preparation may mask beneficial effects on performance due to the development of an active bile acid deconjugating microbiota in the small intestine.

  18. Nanostructural features degrading the performance of superconducting radio frequency niobium cavities revealed by transmission electron microscopy and electron energy loss spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Trenikhina, Y., E-mail: yuliatr@fnal.gov [Physics Department, Illinois Institute of Technology, Chicago, Illinois 60616 (United States); Fermi National Accelerator Laboratory, Batavia, Illinois 60510 (United States); Romanenko, A., E-mail: aroman@fnal.gov [Fermi National Accelerator Laboratory, Batavia, Illinois 60510 (United States); Kwon, J.; Zuo, J.-M. [Materials Science and Engineering Department, University of Illinois, Urbana, Illinois 61801 (United States); Zasadzinski, J. F. [Physics Department, Illinois Institute of Technology, Chicago, Illinois 60616 (United States)

    2015-04-21

    Nanoscale defect structure within the magnetic penetration depth of ∼100 nm is key to the performance limitations of niobium superconducting radio frequency cavities. Using a unique combination of advanced thermometry during cavity RF measurements, and TEM structural and compositional characterization of the samples extracted from cavity walls, we discover the existence of nanoscale hydrides in electropolished cavities limited by the high field Q slope, and show the decreased hydride formation in the electropolished cavity after 120 °C baking. Furthermore, we demonstrate that adding 800 °C hydrogen degassing followed by light buffered chemical polishing restores the hydride formation to the pre-120 °C bake level. We also show absence of niobium oxides along the grain boundaries and the modifications of the surface oxide upon 120 °C bake.

  19. Biocompatible/Degradable Silk Fibroin:Poly(Vinyl Alcohol)-Blended Dielectric Layer Towards High-Performance Organic Field-Effect Transistor

    Science.gov (United States)

    Zhuang, Xinming; Huang, Wei; Yang, Xin; Han, Shijiao; Li, Lu; Yu, Junsheng

    2016-10-01

    Biocompatible silk fibroin (SF):poly(vinyl alcohol) (PVA) blends were prepared as the dielectric layers of organic field-effect transistors (OFETs). Compared with those with pure SF dielectric layer, an optimal threshold voltage of ~0 V, high on/off ratio of ~104, and enhanced field-effect mobility of 0.22 cm2/Vs of OFETs were obtained by carefully controlling the weight ratio of SF:PVA blends to 7:5. Through the morphology characterization of dielectrics and organic semiconductors by utilizing atom force microscopy and electrical characterization of the devices, the performance improvement of OFETs with SF:PVA hybrid gate dielectric layers were attributed to the smooth and homogeneous morphology of blend dielectrics. Furthermore, due to lower charge carrier trap density, the OFETs based on SF:PVA-blended dielectric exhibited a higher bias stability than those based on pure SF dielectric.

  20. Reproductive performance of South African indigenous goats inoculated with DHP-degrading rumen bacteria and maintained on Leucaena leucocephala/grass mixture and natural pasture.

    Science.gov (United States)

    Akingbade, A A.; Nsahlai, I V.; Bonsi, M L.K.; Morris, C D.; du Toit, L P.

    2001-01-01

    This study examined the reproductive performance of dihydroxy pyridone (DHP)-inoculated South African indigenous (SAIG) female goats maintained on two dietary treatments: (i) Leucaena leucocephala/grass mixture and (ii) natural pasture prior to conception, and during gestation. Leucaena leucocephala/grass mixture was nutritionally superior (crude protein and mineral elements) than the natural pasture. The average daily gain, products of pregnancy and foetal development in gravid goats raised on leucaena/grass mixture were significantly (PLeucaena leucocephala/grass mixture. Leucaena/grass mixture fed goats had kids that were heavier at birth than their counterparts on natural pasture. Pre-weaning kid mortality over the period of study was significantly (PLeucaena leucocephala/grass mixture treatment. Colostrum from kidded goats fed leucaena was viscous and difficult to sample. The absence of mimosine toxicity symptoms suggests a possibility of safe use of leucaena as a feed resource to DHP-inoculated SAIG.

  1. Compendium of photovoltaic degradation rates: Photovoltaic degradation rates

    Energy Technology Data Exchange (ETDEWEB)

    Jordan, Dirk C. [National Renewable Energy Laboratory (NREL), 15013 Denver West Parkway Golden CO 80401 USA; Kurtz, Sarah R. [National Renewable Energy Laboratory (NREL), 15013 Denver West Parkway Golden CO 80401 USA; VanSant, Kaitlyn [Colorado School of Mines, 1500 Illinois Street Golden CO 8040 USA; Newmiller, Jeff [DNV GL, 2420 Camino Ramon, Suite 300 San Ramon CA 95483 USA

    2016-02-07

    Published data on photovoltaic (PV) degradation measurements were aggregated and re-examined. The subject has seen an increased interest in recent years resulting in more than 11 000 degradation rates in almost 200 studies from 40 different countries. As studies have grown in number and size, we found an impact from sampling bias attributable to size and accuracy. Because of the correlational nature of this study we examined the data in several ways to minimize this bias. We found median degradation for x-Si technologies in the 0.5-0.6%/year range with the mean in the 0.8-0.9%/year range. Hetero-interface technology (HIT) and microcrystalline silicon (..mu..c-Si) technologies, although not as plentiful, exhibit degradation around 1%/year and resemble thin-film products more closely than x-Si. Several studies showing low degradation for copper indium gallium selenide (CIGS) have emerged. Higher degradation for cadmium telluride (CdTe) has been reported, but these findings could reflect a convolution of less accurate studies and longer stabilization periods for some products. Significant deviations for beginning-of-life measurements with respect to nameplate rating have been documented over the last 35 years. Therefore, degradation rates that use nameplate rating as reference may be significantly impacted. Studies that used nameplate rating as reference but used solar simulators showed less variation than similar studies using outdoor measurements, even when accounting for different climates. This could be associated with confounding effects of measurement uncertainty and soiling that take place outdoors. Hotter climates and mounting configurations that lead to sustained higher temperatures may lead to higher degradation in some, but not all, products. Wear-out non-linearities for the worst performing modules have been documented in a few select studies that took multiple measurements of an ensemble of modules during the lifetime of the system. However, the majority

  2. Performance investigation on clipping and RIN induced degradation for a single- and two-tone IM-DD SCM optical link

    Science.gov (United States)

    Qazi, Gausia; Sharma, Ajay K.; Shah (Smieee), H. Najeeb-Ud-Din; Uddin, Moin

    2014-05-01

    Subcarrier multiplexing (SCM) is preferred multiplexing approach for its simplicity and cost effectiveness in optical broadband transmission. In this work four basic SCM based intensity modulation direct detection (IM-DD) systems models have been devised to investigate laser source induced noise mechanisms. These system models reveal unique spectral behavioural characteristics associated to harmonic distortion (HD), inter-modulation distortion (IMD), clipping and random intensity noise (RIN) mechanisms. Response of clipping and RIN mechanisms to changes in system operational and laser design parameters show a direct dependence of clipping spillover on modulation current and an insensitivity of the RIN spectrum to changes in carrier amplitude. High bias currents are shown to reduce negative influence of clipping and RIN peak power while shifting RIN peak above subcarrier operating range of frequencies but increases RIN spectrum width. Low laser quantum efficiency is observed to favor clipping and RIN induced distortion while RIN peak position is insensitive to laser quantum efficiency. With active layer volume there will exists a tradeoff between clipping spillover and RIN peak power on one hand and RIN peak position and RIN spectral width on the other hand. High laser carrier lifetime will favor clipping spillover reduction. All the results so obtained can be exploited for identifying a suitable laser design in a suitable system model for achieving better system performance for the SCM based IM-DD systems.

  3. Bacterial Degradation of Pesticides

    DEFF Research Database (Denmark)

    Knudsen, Berith Elkær

    . Bioaugmentation i.e. addition of specific degrader organisms, has been suggested as an environmentally friendly and economically competitive strategy for cleaning polluted sites. Several organisms have been isolated, capable of degrading different compounds. However the capacity to degrade the desired compound...... SRS2, Variovorax SRS16 and Arthrobacter globiformis D47. The degradation capacity of each strain individually as well as two- and three-member consortia was studied in a sand column set up. Glass beads were added to the set up to create a dry patch, separating the organisms and the diuron-spiked sand...

  4. Energy use and production, demography and the world-market oil price-influencing twenty years of economic performance and environment degradation in Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Lopez Lemus, Luis Gerardo [SUNY College of Environmental Science & Forestry (United States)

    1997-07-01

    I present a compilation of data describing Mexico's economic performance as it relates to demographic and natural resource characteristics. Statistical correlations suggest that long term economic output and energy efficiency are influenced mostly by human population numbers and fuel consumption rate, although its fluctuations have been clearly driven by those of the world-market oil price throughout 1970-90. Neither energy production, agricultural yield, OPEC's oil price or forest coverage appeared important in determining Mexican GDP response for this 20-year period. Significant relations of these fluctuations were found also in the rates of deforestation, air pollution and agricultural production, being all of these variables seemingly independent of the intrinsic human population growth rate. I discuss how Mexico could bridge the GDP gap with its current Nafta partners from this system-energy perspective. [Spanish] Presento una coleccion de datos que describen el comportamiento de la economia de Mexico relacionado con las caracteristicas demograficas y de sus recursos naturales. Las correlaciones estadisticas sugieren que la produccion economica a largo plazo y la eficiencia de la energia estan influenciadas principalmente por las cifras de poblacion humana y por el regimen de consumo de combustible, si bien sus fluctuaciones han sido claramente impulsadas por los precios del petroleo en mercado mundial a traves de 1970 a 1990. Ni la produccion de energia, el rendimiento agricola, el precio del petroleo de OPEC o la extension de los bosques resultaron importantes en la determinacion de la respuesta del PIB de Mexico para este periodo de 20 anos. Se encontraron relaciones significativas de estas fluctuaciones tambien en los regimenes de deforestacion, contaminacion del aire y produccion agricola, siendo todas esta variables de forma similar independientes de regimen intrinseco del crecimiento de la poblacion humana. Analizo como podria Mexico salvar la

  5. Nucleotide polymorphisms in a pine ortholog of the Arabidopsis degrading enzyme cellulase KORRIGAN are associated with early growth performance in Pinus pinaster.

    Science.gov (United States)

    Cabezas, José Antonio; González-Martínez, Santiago C; Collada, Carmen; Guevara, María Angeles; Boury, Christophe; de María, Nuria; Eveno, Emmanuelle; Aranda, Ismael; Garnier-Géré, Pauline H; Brach, Jean; Alía, Ricardo; Plomion, Christophe; Cervera, María Teresa

    2015-09-01

    We have carried out a candidate-gene-based association genetic study in Pinus pinaster Aiton and evaluated the predictive performance for genetic merit gain of the most significantly associated genes and single nucleotide polymorphisms (SNPs). We used a second generation 384-SNP array enriched with candidate genes for growth and wood properties to genotype mother trees collected in 20 natural populations covering most of the European distribution of the species. Phenotypic data for total height, polycyclism, root-collar diameter and biomass were obtained from a replicated provenance-progeny trial located in two sites with contrasting environments (Atlantic vs Mediterranean climate). General linear models identified strong associations between growth traits (total height and polycyclism) and four SNPs from the korrigan candidate gene, after multiple testing corrections using false discovery rate. The combined genomic breeding value predictions assessed for the four associated korrigan SNPs by ridge regression-best linear unbiased prediction (RR-BLUP) and cross-validation accounted for up to 8 and 15% of the phenotypic variance for height and polycyclic growth, respectively, and did not improve adding SNPs from other growth-related candidate genes. For root-collar diameter and total biomass, they accounted for 1.6 and 1.1% of the phenotypic variance, respectively, but increased to 15 and 4.1% when other SNPs from lp3.1, lp3.3 and cad were included in RR-BLUP models. These results point towards a desirable integration of candidate-gene studies as a means to pre-select relevant markers, and aid genomic selection in maritime pine breeding programs. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  6. Degrading and non-degrading sex in popular music: a content analysis.

    Science.gov (United States)

    Primack, Brian A; Gold, Melanie A; Schwarz, Eleanor B; Dalton, Madeline A

    2008-01-01

    Those exposed to more degrading sexual references in popular music are more likely to initiate intercourse at a younger age. The purpose of this study was to perform a content analysis of contemporary popular music with particular attention paid to the prevalence of degrading and non-degrading sexual references. We also aimed to determine if sexual references of each subtype were associated with other song characteristics and/or content. We used Billboard magazine to identify the top popular songs in 2005. Two independent coders each analyzed all of these songs (n = 279) for degrading and non-degrading sexual references. As measured with Cohen's kappa scores, inter-rater agreement on degrading vs. non-degrading sex was substantial. Mentions of substance use, violence, and weapon carrying were also coded. Of the 279 songs identified, 103 (36.9%) contained references to sexual activity. Songs with references to degrading sex were more common than songs with references to non-degrading sex (67 [65.0%] vs. 36 [35.0%], p Rhythm & Blues/Hip-Hop (27.8%). Compared with songs that had no mention of sexual activity, songs with degrading sex were more likely to contain references to substance use, violence, and weapon carrying. Songs with non-degrading sex were no more likely to mention these other risk behaviors. References to sexual activity are common in popular music, and degrading sexual references are more prevalent than non-degrading references. References to degrading sex also frequently appear with references to other risky behaviors.

  7. Degradation of ochratoxin a by Brevibacterium species.

    Science.gov (United States)

    Rodriguez, Hector; Reveron, Ines; Doria, Francesca; Costantini, Antonella; De Las Rivas, Blanca; Muňoz, Rosario; Garcia-Moruno, Emilia

    2011-10-12

    The ability to degrade ochratoxin A was studied in different bacteria with a well-known capacity to transform aromatic compounds. Strains belonging to Rhodococcus, Pseudomonas, and Brevibacterium genera were grown in liquid synthetic culture medium containing ochratoxin A. Brevibacterium spp. strains showed 100% degradation of ochratoxin A. Ochratoxin α was detected and identified by high-performance liquid chromatography-mass spectrometry (HPLC-MS) as a degradation product in the cell-free supernatants. The degradation of ochratoxin A is of public concern for food and environmental safety, because it could contribute to the development of new biological ochratoxin A detoxification systems in foodstuffs. In this study, the degradation of ochratoxin A by bacteria belonging to the food chain was demonstrated for the first time.

  8. Effects of thermo-resistant non-starch polysaccharide degrading multi-enzyme on growth performance, meat quality, relative weights of body organs and blood profile in broiler chickens.

    Science.gov (United States)

    Mohammadi Gheisar, M; Hosseindoust, A; Kim, I H

    2016-06-01

    This research was conducted to study the performance and carcass parameters of broiler chickens fed diets supplemented with heat-treated non-starch polysaccharide degrading enzyme. A total of 432 one-day old Ross 308 broiler chickens were allocated to five treatments: (i) CON (basal diet), (ii) E1: CON + 0.05% multi-enzyme, (iii) E2: CON + 0.1% multi-enzyme, (iv) E3: CON + 0.05% thermo-resistant multi-enzyme and (v) E4: CON + 0.1% thermo-resistant multi-enzyme, each treatment consisted of six replications and 12 chickens in each replication. The chickens were housed in three floor battery cages during 28-day experimental period. On days 1-7, gain in body weight (BWG) improved by feeding the diets supplemented with thermo-resistant multi-enzyme. On days 7-21 and 1-28, chickens fed the diets containing thermo-resistant multi-enzyme showed improved (p thermo-resistant multi-enzyme affected the percentage of drip loss on d 1 (p thermo-resistant multi-enzyme did not affect the relative weights of organs but compared to CON group, relative weight of breast muscle increased and abdominal fat decreased (p thermo-resistant multi-enzyme showed higher (p thermo-resistant multi-enzyme improved performance of broiler chickens.

  9. Rate of NDF degradation

    DEFF Research Database (Denmark)

    Weisbjerg, Martin Riis; Koukolová, V; Lund, Peter

    2007-01-01

    Degradation profiles for NDF were estimated for 83 samples of grass/grass-clover, 27 samples of cereal whole crop and 14 samples of maize whole crop.......Degradation profiles for NDF were estimated for 83 samples of grass/grass-clover, 27 samples of cereal whole crop and 14 samples of maize whole crop....

  10. Individual differneces in degraded speech perception

    Science.gov (United States)

    Carbonell, Kathy M.

    One of the lasting concerns in audiology is the unexplained individual differences in speech perception performance even for individuals with similar audiograms. One proposal is that there are cognitive/perceptual individual differences underlying this vulnerability and that these differences are present in normal hearing (NH) individuals but do not reveal themselves in studies that use clear speech produced in quiet (because of a ceiling effect). However, previous studies have failed to uncover cognitive/perceptual variables that explain much of the variance in NH performance on more challenging degraded speech tasks. This lack of strong correlations may be due to either examining the wrong measures (e.g., working memory capacity) or to there being no reliable differences in degraded speech performance in NH listeners (i.e., variability in performance is due to measurement noise). The proposed project has 3 aims; the first, is to establish whether there are reliable individual differences in degraded speech performance for NH listeners that are sustained both across degradation types (speech in noise, compressed speech, noise-vocoded speech) and across multiple testing sessions. The second aim is to establish whether there are reliable differences in NH listeners' ability to adapt their phonetic categories based on short-term statistics both across tasks and across sessions; and finally, to determine whether performance on degraded speech perception tasks are correlated with performance on phonetic adaptability tasks, thus establishing a possible explanatory variable for individual differences in speech perception for NH and hearing impaired listeners.

  11. Simultaneous determination of 19 triazine pesticides and degradation products in processed cereal samples from Chinese total diet study by isotope dilution–high performance liquid chromatography–linear ion trap mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Li, Peng [College of Veterinary Medicine, China Agricultural University, Beijing 100193 (China); China National Center for Food Safety Risk Assessment, Beijing 100021 (China); Yang, Xin, E-mail: beijing-yangxin@163.com [China National Center for Food Safety Risk Assessment, Beijing 100021 (China); Miao, Hong; Zhao, Yunfeng [China National Center for Food Safety Risk Assessment, Beijing 100021 (China); Key Lab of Food Safety Risk Assessment, Ministry of Health, Beijing 100021 (China); Liu, Wei [Shandong Province Environmental Monitoring Centre, Jinan 250013 (China); Wu, Yongning, E-mail: china_cdc@yahoo.cn [College of Veterinary Medicine, China Agricultural University, Beijing 100193 (China); China National Center for Food Safety Risk Assessment, Beijing 100021 (China); Key Lab of Food Safety Risk Assessment, Ministry of Health, Beijing 100021 (China)

    2013-06-05

    Graphical abstract: -- Highlights: •19 triazines were determined in cereal samples from Chinese TDS for the first time. •Isotope dilution technique and HPLC–LIT-MS{sup 3} method are both applied in this study. •CCαs and CCβs are much lower in this work than those of the previous publications. -- Abstract: A selective and sensitive isotope dilution–high performance liquid chromatography–linear ion trap mass spectrometry (Isotope Dilution–HPLC–LIT-MS{sup 3}) method was developed for the simultaneous determination of 19 triazine pesticides and their degradation products in processed cereal samples from Chinese total diet study (TDS). The method integrated the addition of isotope internal standards, liquid–liquid extraction (LLE), clean-up with MCX solid-phase extraction (SPE) cartridges and HPLC–LIT-MS{sup 3} analysis with selected reaction monitoring (SRM) mode. Matrix-matched calibration curves showed good linearity (R{sup 2} ≥ 0.9940) verified by applying the Mandel's fitting test (p > 0.087) performed at the 95% confidence level. Decision limits (CCαs) and detection capabilities (CCβs) of the 19 triazine pesticides and their degradation products fell in the ranges of 0.0020–0.4200 μg kg{sup −1} and 0.0024–0.4500 μg kg{sup −1}, respectively. Recoveries ranged from 70.1% to 112.8%, with the relative standard deviations (RSDs) ranging from 1.5% to 13.5%. Furthermore, the proposed method was applied to analyzing the proposed cereal samples from the fourth Chinese TDS. Eleven triazines were detected in six cereal samples with the concentrations ranging from 0.013 to 0.987 μg kg{sup −1}. This method can also be used for the further determination of the triazines in other food group composites, and ultimately served as a methodological foundation for assessing the triazines in the average Chinese diet in the general population.

  12. Controlled fabrication and enhanced photocatalystic performance of BiVO{sub 4}@CeO{sub 2} hollow microspheres for the visible-light-driven degradation of rhodamine B

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Jie [School of Science, Minzu University of China, Beijing 100081 (China); Wang, Wenzhong, E-mail: wzhwangmuc@163.com [School of Science, Minzu University of China, Beijing 100081 (China); Wang, Jun, E-mail: wangjun2@nbu.edu.cn [Faculty of Sciences, Ningbo University, Zhejiang, Ningbo 315211 (China); Liang, Yujie [School of Science, Minzu University of China, Beijing 100081 (China)

    2015-09-15

    Graphical abstract: - Highlights: • m-BiVO{sub 4}@CeO{sub 2} hollow microspheres were firstly fabricated. • m-BiVO{sub 4}@CeO{sub 2} was used for photocatalytic degradation of rhodamine B. • The photocatalytic activity of heterogeneous hollow microspheres is enhanced. • Photocatalytic mechanism on m-BiVO{sub 4}@CeO{sub 2} by visible light irradiation was proposed. • Efficient separation of photoexcited charges results in enhanced catalytic activity. - Abstract: m-BiVO{sub 4}@CeO{sub 2} hollow microspheres have been fabricated by a facile low-temperature co-precipitation method and subsequent annealing process. The composition, morphology and size of the as-fabricated m-BiVO{sub 4}@CeO{sub 2} hollow microspheres were characterized by X-ray powder diffraction (XRD) and scanning electron microscopy (SEM). The vibrational features and the electronic state of the as-obtained m-BiVO{sub 4}@CeO{sub 2} hollow microspheres were studied by Raman spectra and X-ray photoelectron spectroscopy (XPS). Band-gap energy of the as-prepared m-BiVO{sub 4}@CeO{sub 2} hollow microspheres was evaluated by UV–vis spectrum. The visible-light-driven photocatalystic performances were evaluated by degradation for RhB dye molecules, demonstrating that the as-fabricated m-BiVO{sub 4}@CeO{sub 2} hollow microspheres exhibit the enhanced photocatalystic activity, compared to the obtained pure m-BiVO{sub 4} microspheres. The separation of photoinduced electron–hole pairs and transfer between CeO{sub 2} and BiVO{sub 4} has been discussed in detail, in order to have in-depth understanding on the enhanced photocatalytic performance. The results indicate that the enhanced photocatalystic activity of the as-fabricated m-BiVO{sub 4}@CeO{sub 2} hollow microspheres is attributed to the efficient separation of the photoexcited electrons and holes.

  13. Analysis and Its Application of Performance Degradation in BPSK Communication Systems under Monofrequency Interference%单频干扰下BPSK接收性能恶化分析及应用

    Institute of Scientific and Technical Information of China (English)

    郑磊; 苏彦; 朴廷彝; 李斌; 李春来

    2011-01-01

    The performance degradation in the presence of monofrequency interference on BPSK communication systems is analyzed in this paper. In partioular, a new method more accurate and applicable than the methods presented before is derived here, by assuming the jamming phase as a uniformly distributed random variable. MATLAB simulations and measurements in the ground station of CE - 1 ( Chang' E lunar mission of China) are carried out. The results are in good agreement with our theoreucal results. showing that the approach developed here is useful for investigating the effect of monofrequency interference on BPSK communication systems. It is successfully used in evaluating the performance degradation in CE - 1 BPSK communication system interfered by monofrequency signal from the Japanese lunar orbiter SELENE , and supports the negotiation about the signal frequency between CE - 1 and SELENE, as well as the interference rejection design of the earth station of CE - 1.%为了提高现有单频干扰下BPSK接收性能恶化分析方法的准确性和实用性,本文引入干扰信号相位作为随机变量,得出了新的分析方法.该方法首次准确量化了单频干扰下BPSK接收性能的恶化程度,普遍适用于BPSK调制体制下的卫星通信系统.给出了MATLAB数值仿真和现场实测结果.将其应用到探月工程嫦娥一号(CE-1)任务中,对CE-1通信系统受日本SELENE月球探测器信号干扰进行了准确的定量分析,为地面接收站的抗干扰设计以及中日双方探测器频率协调工作提供了依据.

  14. Controlled synthesis of Ag{sub 3}PO{sub 4}/BiVO{sub 4} composites with enhanced visible-light photocatalytic performance for the degradation of RhB and 2, 4-DCP

    Energy Technology Data Exchange (ETDEWEB)

    Qi, Xuemei [School of Chemistry and Chemical Engineering, Shanghai Key Lab of Electrical Insulation and Thermal Aging, Shanghai Jiao Tong University, Shanghai 200240 (China); School of Environmental and Chemical Engineering, Shanghai University of Electric Power, Shanghai 200090 (China); Gu, Miaoli [School of Environmental and Chemical Engineering, Shanghai University of Electric Power, Shanghai 200090 (China); Zhu, Xinyuan [School of Chemistry and Chemical Engineering, Shanghai Key Lab of Electrical Insulation and Thermal Aging, Shanghai Jiao Tong University, Shanghai 200240 (China); Wu, Jiang, E-mail: qixuemei@shiep.edu.cn [School of Energy and Mechanical Engineering, Shanghai University of Electric Power, Shanghai 200090 (China); Wu, Qiang; Long, Huimin; He, Kai [School of Environmental and Chemical Engineering, Shanghai University of Electric Power, Shanghai 200090 (China)

    2016-08-15

    Highlights: • Ag{sub 3}PO{sub 4}/BiVO{sub 4} composites were synthesized by in-situ precipitation method. • Ag{sub 3}PO{sub 4}/BiVO{sub 4} is more efficient than pure Ag{sub 3}PO{sub 4} and BiVO{sub 4} for RhB and 2, 4-DCP degradation. • Ag{sub 3}PO{sub 4}/BiVO{sub 4} can act as a high performance and low cost photocatalyst. - Abstract: Ag{sub 3}PO{sub 4}/BiVO{sub 4} composites were fabricated by in-situ precipitation method. Results showed that Ag{sub 3}PO{sub 4}/BiVO{sub 4} composites exhibited higher photocatalytic activity than that of pure BiVO{sub 4} and Ag{sub 3}PO{sub 4} sample under visible light irradiation. The effect of Ag{sub 3}PO{sub 4}:BiVO{sub 4} ratio on the photocatalytic activity was systemically studied and the optimum molar ratio of Ag{sub 3}PO{sub 4}:BiVO{sub 4} was 1:5. The Ag{sub 3}PO{sub 4}/BiVO{sub 4}-5 exhibited excellent photocatalytic activity for the degradation of Rhodamine B (ca. 92% in 30 min) and 2, 4-dichlorophenol (ca. 84% in 180 min) under visible light irradiation. The enhanced photocatalytic activity could be mainly ascribed to the suitable Ag{sub 3}PO{sub 4}/BiVO{sub 4} heterojunction interface and the smaller particles of Ag{sub 3}PO{sub 4} compared to pure Ag{sub 3}PO{sub 4} particles which could promote the separation of photoinduced electron-hole pairs. The Ag{sub 3}PO{sub 4}/BiVO{sub 4} composite can significantly reduce the silver consumption compared to the pure Ag{sub 3}PO{sub 4}. It is worth noting that Ag{sub 3}PO{sub 4}/BiVO{sub 4} composite can act as a high performance and low cost visible-light-driven photocatalyst for environmental remediation.

  15. Techniques to maintain functionality during degraded performance

    Science.gov (United States)

    McCoy, Joseph R.; White, Joshua S.

    2010-04-01

    In technology the notion of beyond state-of-the-art often begins when a paradigm is shifted. In this paper the authors present their work which has fundamentally enabled an enterprise to insure operational viability under the very real cyber facts: "we are under constant attack, it is a hostile space and we can control the point of contact." That point of contact is the optical bit stream which is currently beyond the scope of the standard cyber toolset. EverisTM, in working with our customers, has developed the tools to capture, view, analyze, and control the correlative (interdependent network, metadata, data and users) information as it traverses the core, regional, and global fiber optic networks. This capability to visualize below the operational picture afforded by current network intrusion detection systems can be combined with real-time intervention at the network core yielding prioritization, identification, and authentication of authentication. This directly translates into sophisticated end user interaction across the interdependencies often viewed as the "cloud". Everis has demonstrated unique applications based on this capability that includes mitigation of DDOS (Distributed Denial of Service), identification of "forged" IP (Internet Protocol) addresses, malicious executable destruction, WAN (Wide Area Network) IPS (Intrusion Prevention System) and connectionless routing vs. connection based switching.

  16. Modeling Performance Degradation in Nickel Hydrogen Cells

    Science.gov (United States)

    1991-05-01

    Corporation by B. K. Janousek, Principal Director, Electronics Technology Center. Paul M. Propp was the project officer for tile Mission-Oriented Investigation...published only tbr tile exchange and stimulation of ideas. QUANG BUI, Lt, USAF P o PROPP MOIE Program Manager Wright Lab West Coast Office UNCLASSIFIED

  17. Hall effect degradation of rail gun performance

    Science.gov (United States)

    Witalis, E. A.; Gunnarsson, Patrik

    1993-01-01

    The paper discusses the Hall effect and shows it to be significant in the low-density and high-field trailing part of a plasma armature. Without the Hall effect a simple armature model is derived. It exhibits properties expected from classical MHD theory and shows that the purely relativistic electric charge buildup on the rails is a fundamental gun property, leading to V(breech) = 1.5 V(muzzle). The mathematics involved in accounting for Hall effect phenomena is described. These are of two types: the Hall-skewing of the armature current and the superimposed plasma flow rotation. For decreasing gun current the two effects efficiently combine to eject armature plasma rearwards, thus creating conditions for arc separation and parasitic arcs.

  18. Thermal Degradation of Lignocellulosic Fuels: Biopolymers Contribution

    OpenAIRE

    Leroy, Valérie; Leoni, Eric; Cancellieri, Dominique

    2010-01-01

    In wildland fire modelling and forest fuel hazard studies, the thermal degradation of the solid is a fundamental stage. Two ways are suitable: the first one considers the thermal degradation of the whole fuel giving a complex mixture of gas, tars and chars; the second one considers the thermal degradation as the sum of the contributions from the principal components of the fuel. Our aim was to verify the validity of the second approach. DSC analyses were performed in order to get the enthalpy...

  19. Silk structure and degradation.

    Science.gov (United States)

    Liu, Bin; Song, Yu-wei; Jin, Li; Wang, Zhi-jian; Pu, De-yong; Lin, Shao-qiang; Zhou, Chan; You, Hua-jian; Ma, Yan; Li, Jin-min; Yang, Li; Sung, K L Paul; Zhang, Yao-guang

    2015-07-01

    To investigate the structure of silk and its degradation properties, we have monitored the structure of silk using scanning electron microscopy and frozen sections. Raw silk and degummed raw silk were immersed in four types of degradation solutions for 156 d to observe their degradation properties. The subcutaneous implants in rats were removed after 7, 14, 56, 84, 129, and 145 d for frozen sectioning and subsequent staining with hematoxylin and eosin (H.E.), DAPI, Beta-actin and Collagen I immunofluorescence staining. The in vitro weight loss ratio of raw silk and degummed raw silk in water, PBS, DMEM and DMEM containing 10% FBS (F-DMEM) were, respectively, 14%/11%, 12.5%/12.9%, 11.1%/14.3%, 8.8%/11.6%. Silk began to degrade after 7 d subcutaneous implantation and after 145 d non-degraded silk was still observed. These findings suggest the immunogenicity of fibroin and sericin had no essential difference. In the process of in vitro degradation of silk, the role of the enzyme is not significant. The in vivo degradation of silk is related to phagocytotic activity and fibroblasts may be involved in this process to secrete collagen. This study also shows the developing process of cocoons and raw silk.

  20. PERFORMANCE

    Directory of Open Access Journals (Sweden)

    M Cilli

    2014-10-01

    Full Text Available This study aimed to investigate the kinematic and kinetic changes when resistance is applied in horizontal and vertical directions, produced by using different percentages of body weight, caused by jumping movements during a dynamic warm-up. The group of subjects consisted of 35 voluntary male athletes (19 basketball and 16 volleyball players; age: 23.4 ± 1.4 years, training experience: 9.6 ± 2.7 years; height: 177.2 ± 5.7 cm, body weight: 69.9 ± 6.9 kg studying Physical Education, who had a jump training background and who were training for 2 hours, on 4 days in a week. A dynamic warm-up protocol containing seven specific resistance movements with specific resistance corresponding to different percentages of body weight (2%, 4%, 6%, 8%, 10% was applied randomly on non consecutive days. Effects of different warm-up protocols were assessed by pre-/post- exercise changes in jump height in the countermovement jump (CMJ and the squat jump (SJ measured using a force platform and changes in hip and knee joint angles at the end of the eccentric phase measured using a video camera. A significant increase in jump height was observed in the dynamic resistance warm-up conducted with different percentages of body weight (p 0.05. In jump movements before and after the warm-up, while no significant difference between the vertical ground reaction forces applied by athletes was observed (p>0.05, in some cases of resistance, a significant reduction was observed in hip and knee joint angles (p<0.05. The dynamic resistance warm-up method was found to cause changes in the kinematics of jumping movements, as well as an increase in jump height values. As a result, dynamic warm-up exercises could be applicable in cases of resistance corresponding to 6-10% of body weight applied in horizontal and vertical directions in order to increase the jump performance acutely.

  1. Hydrogen degradation of high strength weldable steels

    OpenAIRE

    J. Ćwiek

    2007-01-01

    Purpose: Purpose of this paper is presentation of hydrogen degradation issue of high strength steels andespecially their welded joints. Establishing of applicable mechanisms of hydrogen-enhanced cracking was theaim of performed research.Design/methodology/approach: High strength quenched and tempered steels grade S690Q were used. Weldedjoints were prepared with typical technology used in shipyards. Susceptibility to hydrogen degradation in seawater under cathodic polarization was evaluated wi...

  2. SPECIFIC DEGRADATION OF WATERSHEDS

    Institute of Scientific and Technical Information of China (English)

    Boubacar KANE; Pierre Y.JULIEN

    2007-01-01

    An extensive database of reservoir sedimentation surveys throughout continental United States is compiled and analyzed to determine specific degradation SD relationships as function of mean annual rainfall R, drainage area A, and watershed slope S. The database contains 1463 field measurements and specific degradation relationships are defined as function of A, R and S. Weak trends and significant variability in the data are noticeable. Specific degradation measurements are log normally distributed with respect to R, A, and S and 95% confidence intervals are determined accordingly. The accuracy of the predictions does not significantly increase as more independent variables are added to the regression analyses.

  3. Thraustochytrid protists degrade hydrocarbons

    Digital Repository Service at National Institute of Oceanography (India)

    Raikar, M.T.; Raghukumar, S.; Vani, V.; David, J.J.; Chandramohan, D.

    Although thraustochytrid protists are known to be of widespread occurrence in the sea, their hydrocarbon-degrading abilities have never been investigated. We isolated thraustochytrids from coastal waters and sediments of Goa coast by enriching MPN...

  4. How do polymers degrade?

    Science.gov (United States)

    Lyu, Suping

    2011-03-01

    Materials derived from agricultural products such as cellulose, starch, polylactide, etc. are more sustainable and environmentally benign than those derived from petroleum. However, applications of these polymers are limited by their processing properties, chemical and thermal stabilities. For example, polyethylene terephthalate fabrics last for many years under normal use conditions, but polylactide fabrics cannot due to chemical degradation. There are two primary mechanisms through which these polymers degrade: via hydrolysis and via oxidation. Both of these two mechanisms are related to combined factors such as monomer chemistry, chain configuration, chain mobility, crystallinity, and permeation to water and oxygen, and product geometry. In this talk, we will discuss how these materials degrade and how the degradation depends on these factors under application conditions. Both experimental studies and mathematical modeling will be presented.

  5. Degradation of implant materials

    CERN Document Server

    Eliaz, Noam

    2012-01-01

    This book surveys the degradation of implant materials, reviewing in detail such failure mechanisms as corrosion, fatigue and wear, along with monitoring techniques. Surveys common implant biomaterials, as well as procedures for implant retrieval and analysis.

  6. System Optimization of Metal Material Mechanical Performance Degradation Testing Using Nonlinear Ultrasonic%金属材料力学性能退化非线性超声检测实验系统优化

    Institute of Scientific and Technical Information of China (English)

    颜丙生; 吴斌; 李佳锐; 何存富

    2011-01-01

    Material degradation is usually preceded by some kind of nonlinear mechanical behavior. When a single sinusoidal ultrasonic wave is launched to a nonlinear medium , the wave will be distorted as it propagates , so higher harmonics will be generated. But the ultrasonic nonlinearity parameter is very small and to be confused easily from measurement system nonlinearity. The project researched the measurement method of nonlinearlity parameters, developed a robust experimental procedure. Experimental system was optimized by the selection of instruments and design of test fixture. There is linear relationship between amplitudes of the second-harmonic waves and the squared fundamental waves as a function of increasing input ,roltage amplitude , the system is reIiable. Using this method,ultrasonic nonlinearity parameteR of a group of LY12 aluminum samples monotonic loaded were measured. The experimental results show that there is a significant increase in ultrasonic nonlinearity parameter linked to applied stress level;ultrasonic nonlinearity parameter can characterize the mechanical performance degradation degree of LY12 aluminum.%材料早期力学性能退化总是伴随着某种形式的材料非线性力学行为,从而引起超声波传播的非线性,即高频谐波的产生.查超声非线性系数非常小,易被测量系统的非线性干扰淹没.通过实验仪器的选择和夹具的设计,改进了一套非线性超声测试实验系统.在相同条件下测得同一试件在不同输入电压下的二次谐波幅值和基波幅值平方近似线性关系,表明实验系统是可靠的.利用该系统进行了一组LY12铝合金拉伸试件非线性超声检测实验.在塑性阶段,随着拉伸应力的增大超声非线性系数显著增加.实验结果表明,超声非线性系数可以表征金属材料的力学性能退化程度.

  7. Environmental degradation in biocomposites

    CSIR Research Space (South Africa)

    John, Maya J

    2017-06-01

    Full Text Available molecular chain scission, surface oxidation, and breakdown of molecules to form active radicals. The main degradation processes occurring by weathering includes photoradiation, thermal degradation, photooxidation, and hydrolysis [22,23]. The effect... which exhibits transitions from glassy stage to a rubbery stage at its glass transition temperature. ● Weathering Composites commonly used in automotive and aerospace applications are subjected to varying conditions of sunlight, rain, moisture...

  8. Bacteria and lignin degradation

    Institute of Scientific and Technical Information of China (English)

    Jing LI; Hongli YUAN; Jinshui YANG

    2009-01-01

    Lignin is both the most abundant aromatic (phenolic) polymer and the second most abundant raw material.It is degraded and modified by bacteria in the natural world,and bacteria seem to play a leading role in decomposing lignin in aquatic ecosystems.Lignin-degrading bacteria approach the polymer by mechanisms such as tunneling,erosion,and cavitation.With the advantages of immense environmental adaptability and biochemical versatility,bacteria deserve to be studied for their ligninolytic potential.

  9. PEM Degradation Investigation Final Technical Report

    Energy Technology Data Exchange (ETDEWEB)

    Dan Stevenson; Lee H Spangler

    2007-11-02

    The objectives of this paper are: (1) Develop a system capable of measuring current and voltage performance for each membrane in a Polymer Electrolyte Membranes (PEM) fuel cell stack and record the performance of each individual cell; (2) Develop a single cell PEM FC to allow in situ synchrotron x-ray measurements of the cell in operation and to perform spatially resolved x-ray measurements on fuel cell elements before and after degradation; and (3) Perform initial magnetic resonance microimaging experiments on membrane materials. The Montana State University PEM Membrane Degradation program is geared towards determining how and why membranes in fuel cells degrade and fail. By monitoring every individual membrane in a fuel cell 2000 times/sec while the cell is subjected to real-world type use, we hope to: (1) cause the types of degradation users see, but in a controlled environment; (2) determine an electrical signature that will identify what causes failure, or at least warns of impending failure; (3) allows us to perform advanced x-ray and MRI characterization of the degraded membranes to provide information that may result in improvements of the membrane material; and (4) perhaps allow design of electronic control systems that will prevent fuel cells from operating under conditions where damage is likely to occur.

  10. Polyanhydride degradation and erosion.

    Science.gov (United States)

    Göpferich, A; Tessmar, J

    2002-10-16

    It was the intention of this paper to give a survey on the degradation and erosion of polyanhydrides. Due to the multitude of polymers that have been synthesized in this class of material in recent years, it was not possible to discuss all polyanhydrides that have gained in significance based on their application. It was rather the intention to provide a broad picture on polyanhydride degradation and erosion based on the knowledge that we have from those polymers that have been intensively investigated. To reach this goal this review contains several sections. First, the foundation for an understanding of the nomenclature are laid by defining degradation and erosion which was deemed necessary because many different definitions exist in the current literature. Next, the properties of major classes of anhydrides are reviewed and the impact of geometry on degradation and erosion is discussed. A complicated issue is the control of drug release from degradable polymers. Therefore, the aspect of erosion-controlled release and drug stability inside polyanhydrides are discussed. Towards the end of the paper models are briefly reviewed that describe the erosion of polyanhydrides. Empirical models as well as Monte-Carlo-based approaches are described. Finally it is outlined how theoretical models can help to answer the question why polyanhydrides are surface eroding. A look at the microstructure and the results from these models lead to the conclusion that polyanhydrides are surface eroding due to their fast degradation. However they switch to bulk erosion once the device dimensions drop below a critical limit.

  11. DDE remediation and degradation.

    Science.gov (United States)

    Thomas, John E; Ou, Li-Tse; All-Agely, Abid

    2008-01-01

    DDT and its metabolites, DDD and DDE, have been shown to be recalcitrant to degradation. The parent compound, DDT, was used extensively worldwide starting in 1939 and was banned in the United States in 1973. The daughter compound, DDE, may result from aerobic degradation, abiotic dehydrochlorination, or photochemical decomposition. DDE has also occurred as a contaminant in commercial-grade DDT. The p,p'-DDE isomer is more biologically active than the o,p-DDE, with a reported half-life of -5.7 years. However, when DDT was repeatedly applied to the soil, the DDE concentration may remain unchanged for more than 20 yr. Remediation of DDE-contaminated soil and water may be done by several techniques. Phytoremediation involves translocating DDT, DDD, and DDE from the soil into the plant, although some aquatic species (duckweed > elodea > parrot feather) can transform DDT into predominantly DDD with some DDE being formed. Of all the plants that can uptake DDE, Cucurbita pepo has been the most extensively studied, with translocation values approaching "hyperaccumulation" levels. Soil moisture, temperature, and plant density have all been documented as important factors in the uptake of DDE by Cucurbita pepo. Uptake may also be influenced positively by amendments such as biosurfactants, mycorrhizal inoculants, and low molecular weight organic acids (e.g., citric and oxalic acids). DDE microbial degradation by dehalogenases, dioxygenases, and hydrolases occurs under the proper conditions. Although several aerobic degradation pathways have been proposed, none has been fully verified. Very few aerobic pure cultures are capable of fully degrading DDE to CO2. Cometabolism of DDE by Pseudomonas sp., Alicaligens sp., and Terrabacter sp. grown on biphenyl has been reported; however, not all bacterial species that produce biphenyl dioxygenase degraded DDE. Arsenic and copper inhibit DDE degradation by aerobic microorganisms. Similarly, metal chelates such as EDTA inhibit the

  12. Mycotoxin-degradation profile of Rhodococcus strains.

    Science.gov (United States)

    Cserháti, M; Kriszt, B; Krifaton, Cs; Szoboszlay, S; Háhn, J; Tóth, Sz; Nagy, I; Kukolya, J

    2013-08-16

    Mycotoxins are secondary fungal metabolites that may have mutagenic, carcinogenic, cytotoxic and endocrine disrupting effects. These substances frequently contaminate agricultural commodities despite efforts to prevent them, so successful detoxification tools are needed. The application of microorganisms to biodegrade mycotoxins is a novel strategy that shows potential for application in food and feed processing. In this study we investigated the mycotoxin degradation ability of thirty-two Rhodococcus strains on economically important mycotoxins: aflatoxin B1, zearalenone, fumonisin B1, T2 toxin and ochratoxin A, and monitored the safety of aflatoxin B1 and zearalenone degradation processes and degradation products using previously developed toxicity profiling methods. Moreover, experiments were performed to analyse multi-mycotoxin-degrading ability of the best toxin degrader/detoxifier strains on aflatoxin B1, zearalenone and T2 toxin mixtures. This enabled the safest and the most effective Rhodococcus strains to be selected, even for multi-mycotoxin degradation. We concluded that several Rhodococcus species are effective in the degradation of aromatic mycotoxins and their application in mycotoxin biodetoxification processes is a promising field of biotechnology.

  13. Microbial Aspects of Anaerobic BTEX Degradation

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Combined with conventional methods, developments in both geochemical (delineation of redox processes) and molecular microbial methods (analysis of 16S rDNA genes and functional genes) have allowed us to study in details microorganisms and genes involved in the anaerobic degradation of benzene, toluene, ethylbenzene and xylene (BTEX) under specific redox conditions. This review summarizes recent research in this field. The potential for anaerobic BTEX degradation is widely spread. Specific groups of microorganisms appear to be involved in degradation under different redox conditions. Members of the Azoarcus/Thauera cluster perform BTEX degradation under denitrifying conditions, Geobacteraceae under Fe (III) reducing conditions and Desulfobacteriaceae under sulfate reducing conditions. The information so far obtained on biochemistry and molecular genetics of BTEX degradation indicates that each BTEX compound is funneled into the central benzyol-CoA pathway by a different peripheral pathway. The peripheral pathways of per BTEX compound show similarities among different physiological groups of microorganisms. We also describe how knowledge obtained on the microbial aspects of BTEX degradation can be used to enhance and monitor anaerobic BTEX degradation.

  14. Research development of friction factor correlation in a CICC and it's application in EAST%CICC中摩擦因子准则关系式的研究进展及在EAST超导磁体中的运用

    Institute of Scientific and Technical Information of China (English)

    李君君; 王秋良; 李建刚; 庄明; 胡良兵; 周芷伟; 邱立龙

    2012-01-01

    Saturated iron -core superconducting fault current limiters have some superior performance features, such as very low operation loss at normal power transmission, high impedance at fault current limiting, immediately reacting, and fast recovering. Thinks to its working mechanism, there is no risk of quench to the superconductor coil on the impact of the fault current, so complex mechanical, electrical and thermal protection measures can be avoided. The complicity to deal with a quench of superconductor might be a severe technical barrier for other types of superconducting fault current limiiers. In addition, the reactor of the device is mainly composed by iron cores and copper coils, which can be built with the technology for conventional transformers or reactors. For these reasons, this kind of superconducting fault current limiters is considered the most practically viable device in industrial applications. In this paper, the fundamental principles, the structures and the performance features of saturated iron core SFCLs are introduced. The specifications, testing results, and the operational status of a 35kV790MVA superconducting fault current limiter thai has been running for about 3 years at Fuji substation, are also presented.%介绍了CICC中摩擦因子准则关系的发展历程.在EAST超导磁体的流量模拟中,运用了修正的Katheder关系式和多孔介质模型关系式,并与实验测量值进行了比较.

  15. Polymer Composites Corrosive Degradation: A Computational Simulation

    Science.gov (United States)

    Chamis, Christos C.; Minnetyan, Levon

    2007-01-01

    A computational simulation of polymer composites corrosive durability is presented. The corrosive environment is assumed to manage the polymer composite degradation on a ply-by-ply basis. The degradation is correlated with a measured pH factor and is represented by voids, temperature and moisture which vary parabolically for voids and linearly for temperature and moisture through the laminate thickness. The simulation is performed by a computational composite mechanics computer code which includes micro, macro, combined stress failure and laminate theories. This accounts for starting the simulation from constitutive material properties and up to the laminate scale which exposes the laminate to the corrosive environment. Results obtained for one laminate indicate that the ply-by-ply degradation degrades the laminate to the last one or the last several plies. Results also demonstrate that the simulation is applicable to other polymer composite systems as well.

  16. Hot carrier degradation in semiconductor devices

    CERN Document Server

    2015-01-01

    This book provides readers with a variety of tools to address the challenges posed by hot carrier degradation, one of today’s most complicated reliability issues in semiconductor devices.  Coverage includes an explanation of carrier transport within devices and book-keeping of how they acquire energy (“become hot”), interaction of an ensemble of colder and hotter carriers with defect precursors, which eventually leads to the creation of a defect, and a description of how these defects interact with the device, degrading its performance. • Describes the intricacies of hot carrier degradation in modern semiconductor technologies; • Covers the entire hot carrier degradation phenomenon, including topics such as characterization, carrier transport, carrier-defect interaction, technological impact, circuit impact, etc.; • Enables detailed understanding of carrier transport, interaction of the carrier ensemble with the defect precursors, and an accurate assessment of how the newly created defects imp...

  17. Degradation Behavior of Thermal Stabilized Polyacrylonitrile Fibers

    Directory of Open Access Journals (Sweden)

    LEI Shuai

    2017-05-01

    Full Text Available In the temperature range of 300-800℃, 40%-50% of the mass lost during the processing of polyacrylonitrile based carbon fiber (PANCF. Understanding the degradation behavior will be valuable in understanding the formation mechanism of pseudo-graphite structure, and providing theoretic basis for producing high performance carbon fiber and increasing the carbonization yield. The simulation of the degradation progress was carried out on the thermogravimetric analyzer (TGA, the results show that there are two degradation steps for PAN fiber stabilized in air, and controlled by cyclization coefficient and oxygen content. The cyclization coefficient and oxygen content are effective to the density of carbon fiber by influencing the degradation behavior, which cause defects in the fiber. The higher cyclization coefficient leads to form less structural defects and higher density of the fiber; on the contrary, the higher oxygen content leads to form more structural defects and lower density of the fiber.

  18. Degradation Processes in Corona-Charged Electret Filter-Media

    OpenAIRE

    Warren J. Jasper, Ph.D; Roger Barker, Ph.D.; Anushree Mohan; Juan Hinestroza, Ph.D.

    2007-01-01

    The degradation of filtration performance for coronachargedelectret filter media exposed to ethyl benzenewas assessed. Nonwoven corona-charged polypropylenefiber mats were exposed to ethyl-benzene using acustom made apparatus. Evaluated scenarios includedethyl-benzene vapor and liquid exposures. The filtrationperformance was evaluated using DOP as a testaerosol to measure filtration performance. It was observedthat significant filtration degradation occurredonly when liquid ethyl benzene came...

  19. Microbial degradation of herbicides.

    Science.gov (United States)

    Singh, Baljinder; Singh, Kashmir

    2016-01-01

    Herbicides remain the most effective, efficient and economical way to control weeds; and its market continues to grow even with the plethora of generic products. With the development of herbicide-tolerant crops, use of herbicides is increasing around the world that has resulted in severe contamination of the environment. The strategies are now being developed to clean these substances in an economical and eco-friendly manner. In this review, an attempt has been made to pool all the available literature on the biodegradation of key herbicides, clodinafop propargyl, 2,4-dichlorophenoxyacetic acid, atrazine, metolachlor, diuron, glyphosate, imazapyr, pendimethalin and paraquat under the following objectives: (1) to highlight the general characteristic and mode of action, (2) to enlist toxicity in animals, (3) to pool microorganisms capable of degrading herbicides, (4) to discuss the assessment of herbicides degradation by efficient microbes, (5) to highlight biodegradation pathways, (6) to discuss the molecular basis of degradation, (7) to enlist the products of herbicides under degradation process, (8) to highlight the factors effecting biodegradation of herbicides and (9) to discuss the future aspects of herbicides degradation. This review may be useful in developing safer and economic microbiological methods for cleanup of soil and water contaminated with such compounds.

  20. Hydrocarbon degradation, plant colonization and gene expression of alkane degradation genes by endophytic Enterobacter ludwigii strains

    Energy Technology Data Exchange (ETDEWEB)

    Yousaf, Sohail [AIT Austrian Institute of Technology GmbH, Bioresources Unit, A-2444 Seibersdorf (Austria); Afzal, Muhammad [AIT Austrian Institute of Technology GmbH, Bioresources Unit, A-2444 Seibersdorf (Austria); National Institute for Biotechnology and Genetic Engineering (NIBGE), Faisalabad (Pakistan); Reichenauer, Thomas G. [AIT Austrian Institute of Technology GmbH, Environmental Resources and Technologies Unit, A-2444 Seibersdorf (Austria); Brady, Carrie L. [Forestry and Agricultural Biotechnology Institute, Department of Microbiology and Plant Pathology, University of Pretoria, Pretoria (South Africa); Sessitsch, Angela, E-mail: angela.sessitsch@ait.ac.at [AIT Austrian Institute of Technology GmbH, Bioresources Unit, A-2444 Seibersdorf (Austria)

    2011-10-15

    The genus Enterobacter comprises a range of beneficial plant-associated bacteria showing plant growth promotion. Enterobacter ludwigii belongs to the Enterobacter cloacae complex and has been reported to include human pathogens but also plant-associated strains with plant beneficial capacities. To assess the role of Enterobacter endophytes in hydrocarbon degradation, plant colonization, abundance and expression of CYP153 genes in different plant compartments, three plant species (Italian ryegrass, birdsfoot trefoil and alfalfa) were grown in sterile soil spiked with 1% diesel and inoculated with three endophytic E. ludwigii strains. Results showed that all strains were capable of hydrocarbon degradation and efficiently colonized the rhizosphere and plant interior. Two strains, ISI10-3 and BRI10-9, showed highest degradation rates of diesel fuel up to 68% and performed best in combination with Italian ryegrass and alfalfa. All strains expressed the CYP153 gene in all plant compartments, indicating an active role in degradation of diesel in association with plants. - Highlights: > E. ludwigii strains efficiently colonized plants in a non-sterile soil environment. > E. ludwigii strains efficiently expressed alkane degradation genes in plants. > E. ludwigii efficiently degraded alkane contaminations and promoted plant growth. > E. ludwigii interacted more effectively with Italian ryegrass than with other plants. > Degradation activity varied with plant and microbial genotype as well as with time. - Enterobacter ludwigii strains belonging to the E. cloacae complex are able to efficiently degrade alkanes when associated with plants and to promote plant growth.

  1. Motor degradation prediction methods

    Energy Technology Data Exchange (ETDEWEB)

    Arnold, J.R.; Kelly, J.F.; Delzingaro, M.J.

    1996-12-01

    Motor Operated Valve (MOV) squirrel cage AC motor rotors are susceptible to degradation under certain conditions. Premature failure can result due to high humidity/temperature environments, high running load conditions, extended periods at locked rotor conditions (i.e. > 15 seconds) or exceeding the motor`s duty cycle by frequent starts or multiple valve stroking. Exposure to high heat and moisture due to packing leaks, pressure seal ring leakage or other causes can significantly accelerate the degradation. ComEd and Liberty Technologies have worked together to provide and validate a non-intrusive method using motor power diagnostics to evaluate MOV rotor condition and predict failure. These techniques have provided a quick, low radiation dose method to evaluate inaccessible motors, identify degradation and allow scheduled replacement of motors prior to catastrophic failures.

  2. Antifoam degradation testing

    Energy Technology Data Exchange (ETDEWEB)

    Lambert, D. P. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River Ecology Lab. (SREL); Zamecnik, J. R. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River Ecology Lab. (SREL); Newell, D. D. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River Ecology Lab. (SREL); Williams, M. S. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River Ecology Lab. (SREL)

    2015-08-20

    This report describes the results of testing to quantify the degradation products resulting from the dilution and storage of Antifoam 747. Antifoam degradation is of concern to the Defense Waste Processing Facility (DWPF) due to flammable decomposition products in the vapor phase of the Chemical Process Cell vessels, as well as the collection of flammable and organic species in the offgas condensate. The discovery that hexamethyldisiloxane is formed from the antifoam decomposition was the basis for a Potential Inadequacy in the Safety Analysis declaration by the DWPF.

  3. Photovoltaic Degradation Risk: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Jordan, D. C.; Kurtz, S. R.

    2012-04-01

    The ability to accurately predict power delivery over the course of time is of vital importance to the growth of the photovoltaic (PV) industry. Important cost drivers include the efficiency with which sunlight is converted into power, how this relationship changes over time, and the uncertainty in this prediction. An accurate quantification of power decline over time, also known as degradation rate, is essential to all stakeholders - utility companies, integrators, investors, and researchers alike. In this paper we use a statistical approach based on historical data to quantify degradation rates, discern trends and quantify risks related to measurement uncertainties, number of measurements and methodologies.

  4. Photochemical processes for atrazine degradation: methodological approach.

    Science.gov (United States)

    Héquet, V; Gonzalez, C; Le Cloirec, P

    2001-12-01

    Numerous studies have been carried out on s-triazines, and more specifically on atrazine, with the long-term objective of resolving the problems caused by these herbicides: removing them from drinking water. However, applications have remained too limited. So far, processes based on photochemical degradation have been little implemented. We, therefore, investigated the development of photochemical processes, emphasizing their capacity to degrade triazine by photolytic and photocatalytic mode. The study sought to assess the performance of these ssstems. Experiments ts showed that according to a medium pressure mercury source (UV-Vis irradiation), the photolytic degradation of atrazine was very efficient, with a best atrazine degradation half-life shorter that 5 min. The main degradation pathway was deshalogenation. The photocatalytic degradation of atrazine under irradiation over 290 nm in the presence of titanium dioxide was shown to be efficient too, with a half-life of about 20 min. In this case an experimental design was conducted so as to assess the influence of various parameters: pH, water medium, and amount of catalyst. There has been observational evidence for the efficiency of the processes investigated here and for potential technological developments as regards drinking water treatment.

  5. Structural elucidation of gemifloxacin mesylate degradation product.

    Science.gov (United States)

    Paim, Clésio Soldateli; Führ, Fernanda; Martins, Magda Targa; Gnoatto, Simone; Bajerski, Lisiane; Garcia, Cássia Virginia; Steppe, Martin; Schapoval, Elfrides Eva Scherman

    2016-03-01

    Gemifloxacin mesylate (GFM), chemically (R,S)-7-[(4Z)-3-(aminomethyl)-4-(methoxyimino)-1-pyrrolidinyl]-1-cyclopropyl-6-fluoro-1,4-dihydro-4-oxo-1,8-naphthyridine-3-carboxylic acid methanesulfonate, is a synthetic broad-spectrum antibacterial agent. Although many papers have been published in the literature describing the stability of fluorquinolones, little is known about the degradation products of GFM. Forced degradation studies of GFM were performed using radiation (UV-A), acid (1 mol L(-1) HCl) and alkaline conditions (0.2 mol L(-1) NaOH). The main degradation product, formed under alkaline conditions, was isolated using semi-preparative LC and structurally elucidated by nuclear magnetic resonance (proton - (1) H; carbon - (13) C; correlate spectroscopy - COSY; heteronuclear single quantum coherence - HSQC; heteronuclear multiple-bond correlation - HMBC; spectroscopy - infrared, atomic emission and mass spectrometry techniques). The degradation product isolated was characterized as sodium 7-amino-1-pyrrolidinyl-1-cyclopropyl-6-fluoro-1,4-dihydro-4-oxo-1,8-naphthyridine-3-carboxylate, which was formed by loss of the 3-(aminomethyl)-4-(methoxyimino)-1-pyrrolidinyl ring and formation of the sodium carboxylate. The structural characterization of the degradation product was very important to understand the degradation mechanism of the GFM under alkaline conditions. In addition, the results highlight the importance of appropriate protection against hydrolysis and UV radiation during the drug-development process, storage, handling and quality control.

  6. Environmentally benign chitosan as reductant and supporter for synthesis of Ag/AgCl/chitosan composites by one-step and their photocatalytic degradation performance under visible-light irradiation

    Science.gov (United States)

    Wang, Hao; Wu, Yuhan; Wu, Pengcheng; Chen, Shanshan; Guo, Xuhong; Meng, Guihua; Peng, Banghua; Wu, Jianning; Liu, Zhiyong

    2017-06-01

    A novel Ag/AgCl/chitosan composite photocatalyst was successfully prepared by a simple one-step method. During this progress, environmentally benign chitosan not only served as reductant to reduce Ag+ to Ag0 species, but also acted as supporter for Ag/AgCl nanoparticles. XRD, SEM, EDX, UV-vis DRS and XPS were employed to characterize the as-prepared simples. SEM images of Ag/AgCl/chitosan composites revealed that Ag/AgCl nanoparticles were successfully loaded onto chitosan without obvious aggregation. All Ag/AgCl/chitosan composites exhibited efficient photocatalytic activity for the degradation of rhodamine B (RhB) under visible-light irradiation. The result of photocatalytic degradation experiment indicated that 20% of the mass ratio of AgCl to chitosan was the optimum, and after 40 min photocatalytic reaction, the degradation rate reached about 96%.

  7. Bacterial Degradation of Pesticides

    DEFF Research Database (Denmark)

    Knudsen, Berith Elkær

    could potentially improve bioremediation of BAM. An important prerequisite for bioaugmentation is the potential to produce the degrader strain at large quantities within reasonable time. The aim of manuscript II, was to optimize the growth medium for Aminobacter MSH1 and to elucidate optimal growth...

  8. One dimensional CdS nanowire@TiO2 nanoparticles core-shell as high performance photocatalyst for fast degradation of dye pollutants under visible and sunlight irradiation.

    Science.gov (United States)

    Arabzadeh, Abbas; Salimi, Abdollah

    2016-10-01

    In this study, one-dimensional CdS nanowires@TiO2 nanoparticles core-shell structures (1D CdS NWs@TiO2 NPs) were synthesized by a facile wet chemical-solvothermal method. The different aspects of the properties of CdS NWs@TiO2 NPs were surveyed by using a comprehensive range of characterization techniques including X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), UV-vis spectroscopy, scanning electron microscopy (SEM), fluorescence spectroscopy, energy dispersive X-ray spectroscopy (EDX), Cyclic Voltammetry (CV) and amperometry. The as-prepared nanostructure was applied as an effective photocatalyst for degradation of methyl orange (MO), methylene blue (MB) and rhodamine B (Rh B) under visible and sunlight irradiation. The results indicated significantly enhanced photocatalytic activity of CdS NWs@TiO2 NPs for degradation of MO, MB and Rh B compared to CdS NWs. The enhanced photocatalytic activity could be attributed to the enhanced sunlight absorbance and the efficient charge separation of the formed heterostructure between CdS NWs and TiO2. The results showed that MO, Rh B and MB were almost completely degraded after 2, 2 and 3min of exposure to sunlight, respectively; while under visible light irradiation (3W blue LED lamp) the dyes were decomposed with less half degradation rate. The catalytic activity was retained even after three degradation cycles of organic dyes, demonstrating that the proposed nanocomposite can be effectively used as efficient photocatalyst for removal of environmental pollutions caused by organic dyes under sunlight irradiation and it could be an important addition to the field of wastewater treatment. We hope the present study may open a new window of such 1-D semiconductor nanocomposites to be used as visible light photocatalysts in the promising field of organic dyes degradation.

  9. Detection of pump degradation

    Energy Technology Data Exchange (ETDEWEB)

    Greene, R.H.; Casada, D.A.; Ayers, C.W. [and others

    1995-08-01

    This Phase II Nuclear Plant Aging Research study examines the methods of detecting pump degradation that are currently employed in domestic and overseas nuclear facilities. This report evaluates the criteria mandated by required pump testing at U.S. nuclear power plants and compares them to those features characteristic of state-of-the-art diagnostic programs and practices currently implemented by other major industries. Since the working condition of the pump driver is crucial to pump operability, a brief review of new applications of motor diagnostics is provided that highlights recent developments in this technology. The routine collection and analysis of spectral data is superior to all other technologies in its ability to accurately detect numerous types and causes of pump degradation. Existing ASME Code testing criteria do not require the evaluation of pump vibration spectra but instead overall vibration amplitude. The mechanical information discernible from vibration amplitude analysis is limited, and several cases of pump failure were not detected in their early stages by vibration monitoring. Since spectral analysis can provide a wealth of pertinent information concerning the mechanical condition of rotating machinery, its incorporation into ASME testing criteria could merit a relaxation in the monthly-to-quarterly testing schedules that seek to verify and assure pump operability. Pump drivers are not included in the current battery of testing. Operational problems thought to be caused by pump degradation were found to be the result of motor degradation. Recent advances in nonintrusive monitoring techniques have made motor diagnostics a viable technology for assessing motor operability. Motor current/power analysis can detect rotor bar degradation and ascertain ranges of hydraulically unstable operation for a particular pump and motor set. The concept of using motor current or power fluctuations as an indicator of pump hydraulic load stability is presented.

  10. Plasma Induced Degradation of Benzidine in Aqueous Solution

    Institute of Scientific and Technical Information of China (English)

    高锦章; 盖克; 杨武; 董彦杰

    2003-01-01

    The degradation of benzidine in aqueous solution by the low temperature plasmawas examined. The results showed that the concentration of medium and the value of pH have anappreciable effect on the degradation of benzidine. What is more important is that iron ions actingas a catalyst play an important role in this reaction. For exploring the degradation mechanismof benzidine, some of the intermediate products were recorded by HPLC(high performance liquidchromatography).

  11. Development and application of a validated stability-indicating high-performance liquid chromatographic method using photodiode array detection for simultaneous determination of granisetron, methylparaben, propylparaben, sodium benzoate, and their main degradation products in oral pharmaceutical preparations.

    Science.gov (United States)

    Hewala, Ismail; El-Fatatry, Hamed; Emam, Ehab; Mabrouk, Mokhtar

    2011-01-01

    A simple, rapid, and sensitive RP-HPLC method using photodiode array detection was developed and validated for the simultaneous determination of granisetron hydrochloride, 1-methyl-1H-indazole-3-carboxylic acid (the main degradation product of granisetron), sodium benzoate, methylparaben, propylparaben, and 4-hydroxybenzoic acid (the main degradation product of parabens) in granisetron oral drops and solutions. The separation of the compounds was achieved within 8 min on a SymmetryShield RP18 column (100 x 4.6 mm id, 3.5 microm particle size) using the mobile phase acetonitrile--0.05 M KH2PO4 buffered to pH 3 using H3PO4 (3+7, v/v). The photodiode array detector was used to test the purity of the peaks, and the chromatograms were extracted at 240 nm. The method was validated, and validation acceptance criteria were met in all cases. The robust method was successfully applied to the determination of granisetron and preservatives, as well as their degradation products in different batches of granisetron oral drops and solutions. The method proved to be sensitive for determination down to 0.04% (w/w) of granisetron degradation product relative to granisetron and 0.03% (w/w) 4-hydroxybenzoic acid relative to total parabens.

  12. Atmospheric degradation mechanism of organic sulfur compounds

    Energy Technology Data Exchange (ETDEWEB)

    Benter, T.; Arsene, C.

    2002-02-01

    In the present work a detailed product study has been performed on the OH radical initiated oxidation of dimethyl sulphide and dimethyl sulphoxide, under different conditions of temperature, partial pressure of oxygen and NO{sub x} concentration, in order to better define the degradation mechanism of the above compounds under conditions which prevail in the atmosphere. (orig.)

  13. Degradation of toluene-2,4-diamine by persulphate: kinetics, intermediates and degradation pathway.

    Science.gov (United States)

    Jiang, Yong-hai; Zhang, Jin-bao; Xi, Bei-dou; An, Da; Yang, Yu; Li, Ming-xiao

    2015-01-01

    In this study, the degradation of toluene-2,4-diamine (TDA) by persulphate (PS) in an aqueous solution at near-neutral pH was examined. The result showed that the degradation rate of TDA increased with increasing PS concentrations. The optimal dosage of PS in the reaction system was determined by efficiency indicator (I) coupling in the consumption of PS and decay half-life of TDA. Calculation showed that 0.74 mM of PS was the most effective dosage for TDA degradation, at that level the maximum I of 24.51 was obtained. PS can oxidize TDA for an extended reaction time period. Under neutral condition without activation, four degradation intermediates, 2,4-diamino-3-hydroxy-5-sulfonicacidtoluene, 2,4-diaminobenzaldehyde, 2,4-bis(vinylamino)benzaldehyde and 3,5-diamino-4-hydroxy-2-pentene, were identified by high-performance liquid chromatography-mass spectrometry. The tentative degradation pathway of TDA was proposed as well. It was found that hydroxyl radical played an important role in degradation of TDA with the activation of Fe2+, whereas PS anion and sulphate radicals were responsible for the degradation without activation of Fe2+.

  14. Degradation of aromatic compounds and degradative pathway of 4-nitrocatechol by Ochrobactrum sp. B2.

    Science.gov (United States)

    Zhong, Qiuzan; Zhang, Haiyan; Bai, Wenqin; Li, Mei; Li, Baotong; Qiu, Xinghui

    2007-12-01

    The potential capacity of a soil methyl parathion-degrading bacterium strain, Ochrobactrum sp. B2, for degrading various aromatic compounds were investigated. The results showed B2 was capable of degrading diverse aromatic compounds, but amino-substituted benzene compounds, at a concentration up to 100 mg L(-1) in 4 days. B2 could use 4-nitrocatechol (4-NC) as a sole carbon and energy source with release of nitrite ion. The pathway for 4-NC degradation via 1,2,4-benzenetriol (BT) and hydroquinone (HQ) formation in B2 was proposed based on the identification and quantification of intermediates by gas chromatography-mass spectrometry (GC-MS), and high performance liquid chromatography (HPLC). Degradation studies carried out on a plasmid-cured derivative showed that the genes for 4-NC degradative pathway was plasmid-borne in B2, suggesting that B2 degrades both p-nitrophenol and 4-NC by enzymes encoded by genes on the same plasmid.

  15. Endocytic collagen degradation

    DEFF Research Database (Denmark)

    Madsen, Daniel H.; Jürgensen, Henrik J.; Ingvarsen, Signe;

    2012-01-01

    it crucially important to understand both the collagen synthesis and turnover mechanisms in this condition. Here we show that the endocytic collagen receptor, uPARAP/Endo180, is a major determinant in governing the balance between collagen deposition and degradation. Cirrhotic human livers displayed a marked......Fibrosis of the liver and its end-stage, cirrhosis, represent major health problems worldwide. In these fibrotic conditions, activated fibroblasts and hepatic stellate cells display a net deposition of collagen. This collagen deposition is a major factor leading to liver dysfunction, thus making...... up-regulation of uPARAP/Endo180 in activated fibroblasts and hepatic stellate cells located close to the collagen deposits. In a hepatic stellate cell line, uPARAP/Endo180 was shown to be active in, and required for, the uptake and intracellular degradation of collagen. To evaluate the functional...

  16. Nylon separators. [thermal degradation

    Science.gov (United States)

    Lim, H. S.

    1977-01-01

    A nylon separator was placed in a flooded condition in K0H solution and heated at various high temperatures ranging from 60 C to 110 C. The weight decrease was measured and the molecular weight and decomposition product were analyzed to determine: (1) the effect of K0H concentration on the hydrolysis rate; (2) the effect of K0H concentration on nylon degradation; (3) the activation energy at different K0H concentrations; and (4) the effect of oxygen on nylon degradation. The nylon hydrolysis rate is shown to increase as K0H concentration is decreased 34%, giving a maximum rate at about 16%. Separator hydrolysis is confirmed by molecular weight decrease in age of the batteries, and the reaction of nylon with molecular oxygen is probably negligible, compared to hydrolysis. The extrapolated rate value from the high temperature experiment correlates well with experimental values at 35 degrees.

  17. TALSPEAK Solvent Degradation

    Energy Technology Data Exchange (ETDEWEB)

    Leigh R. Martin; Bruce J. Mincher

    2009-09-01

    Understanding the radiolytic degradation behavior of organic molecules involved in new or existing schemes for the recycle of used nuclear fuels is of significant interest for sustaining a closed nuclear fuel cycle. Here we have conducted several lines of investigation to begin understanding the effects of radiolysis on the aqueous phase of the TALSPEAK process for the separation of the trivalent lanthanides from the trivalent actinides. Using the 60-Co irradiator at the INL, we have begun to quantify the effects of radiation on the aqueous phase complexants used in this separation technique, and how this will affect the actinide lanthanide separation factor. In addition we have started to develop methodologies for stable product identification, a key element in determining the degradation pathways. We have also introduced a methodology to investigate the effects of alpha radiolysis that has previously received limited attention.

  18. Force degradation behavior of glucocorticoid deflazacort by UPLC: isolation, identification and characterization of degradant by FTIR, NMR and mass analysis

    Science.gov (United States)

    Deshmukh, Rajesh; Sharma, Lata; Tekade, Muktika; Kesharwani, Prashant; Trivedi, Piyush; Tekade, Rakesh K.

    2016-01-01

    Abstract In this investigation, sensitive and reproducible methods are described for quantitative determination of deflazacort in the presence of its degradation product. The method was based on high performance liquid chromatography of the drug from its degradation product on reverse phase using Acquity UPLC BEH C18 columns (1.7 µm, 2.1 mm × 150 mm) using acetonitrile and water (40:60 V/V) at a flow rate of 0.2 mL/minute in UPLC. UV detection was performed at 240.1 nm. Deflazacort was subjected to oxidative, acid, base, hydrolytic, thermal and photolytic degradation. The drug was found to be stable in water and thermal stress, as well as under neutral stress conditions. However, forced-degradation study performed on deflazacort showed that the drug degraded under alkaline, acid and photolytic stress. The degradation products were well resolved from the main peak, which proved the stability-indicating power of the method. The developed method was validated as per ICH guidelines with respect to accuracy, linearity, limit of detection, limit of quantification, accuracy, precision and robustness, selectivity and specificity. Apart from the aforementioned, the results of the present study also emphasize the importance of isolation characterization and identification of degradant. Hence, an attempt was made to identify the degradants in deflazacort. One of the degradation products of deflazacort was isolated and identified by the FTIR, NMR and LC-MS study. PMID:28276670

  19. Biogeochemical Cycles in Degraded Lands

    Science.gov (United States)

    Davidson, Eric A.; Vieira, Ima Celia G.; ReisdeCarvalho, Claudio Jose; DeanedeAbreuSa, Tatiana; deSouzaMoutinho, Paulo R.; Figueiredo, Ricardo O.; Stone, Thomas A.

    2004-01-01

    The objectives of this project were to define and describe the types of landscapes that fall under the broad category of "degraded lands" and to study biogeochemical cycles across this range of degradation found in secondary forests. We define degraded land as that which has lost part of its capacity of renovation of a productive ecosystem, either in the context of agroecosystems or as native communities of vegetation. This definition of degradation permits evaluation of biogeochemical constraints to future land uses.

  20. Concentrated Light for Accelerated Photo Degradation of Polymer Materials

    DEFF Research Database (Denmark)

    Madsen, Morten Vesterager; Tromholt, Thomas; Norrman, Kion

    2013-01-01

    Concentrated light is used to perform photochemical degradation of polymer solar cell materials with acceleration factors up to 1200. At constant temperature the photon efficiency in regards to photo degradation is constant for 1–150 suns and oxygen diffusion rates are not a limiting factor. Acce...

  1. Ordered bulk degradation via autophagy

    DEFF Research Database (Denmark)

    Dengjel, Jörn; Kristensen, Anders Riis; Andersen, Jens S

    2008-01-01

    at proteasomal and lysosomal degradation ample cross-talk between the two degradation pathways became evident. Degradation via autophagy appeared to be ordered and regulated at the protein complex/organelle level. This raises several important questions such as: can macroautophagy itself be specific and what...

  2. Anaerobic lipid degradation through acidification and methanization.

    Science.gov (United States)

    Kim, Ijung; Kim, Sang-Hyoun; Shin, Hang-Sik; Jung, Jin-Young

    2010-01-01

    In biological wastewater treatment high lipid concentration is known to inhibit microorganisms and cause active biomass flotation. To reduce lipid inhibition, a two-phase anaerobic system, consisting of an anaerobic sequencing batch reactor (ASBR) and an upflow anaerobic sludge blanket (UASB) reactor, was applied to synthetic dairy wastewater. During 153 days of operation, the two-phase system showed stable performance in lipid degradation. In the ASBR, a 13% lipid removal efficiency and 10% double bond removal efficiency were maintained. In the UASB, the chemical oxygen demand (COD), lipid and volatile fatty acid (VFA) removal efficiencies were more than 80%, 70% and 95%, respectively, up to organic loading rate 6.5 g COD/L/day. There were no operational problems such as serious scum formation or sludge washout. Protein degradation occurred prior to degradation during acidogenesis.

  3. Accelerated degradation studies of encapsulation polymers

    Science.gov (United States)

    Weiss, Karl-Anders; Huelsmann, Jan Philip; Kaltenbach, Thomas; Philipp, Daniel; Schuhmacher, Tanja; Wirth, Jochen; Koehl, Michael

    2008-08-01

    The estimation of PV-modules lifetime facilitates the further development and helps to lower risks for producers and investors. One base for this extensive testing and simulation work is the knowledge of the chemical degradation processes and their kinetics, as well as of the permeation of water and oxygen into the module, especially of the encapsulant. Besides ethylen-vinylacetate copolymer (EVA), which is the dominant material for encapsulation, new materials become available and need the assessment of their properties and the durability impact. Accelerated durability tests were performed on different EVA materials. The paper reports on several measurement methods for analysis of the polymers that were used, FT-IR with attenuated total reflection (ATR), and Raman microscopy, e.g. It is very important to identify degradation products and intermediates in order to identify the leading degradation processes and their kinetics as well as potential interactions between different processes. Another important factor for the degradation of the PV-modules and the concerned polymers in particular is the permeation of reactive substances, especially of water vapor, into and inside the modules. The paper shows results of permeation measurements of the new materials, as well as FEM-based numerical simulations of the humidity diffusion within a PV-module what is an important step towards the calculation of the chemical degradation using numerical simulation tools in the future.

  4. Degradation of textile dyes by cyanobacteria

    Directory of Open Access Journals (Sweden)

    Priscila Maria Dellamatrice

    Full Text Available Abstract Dyes are recalcitrant compounds that resist conventional biological treatments. The degradation of three textile dyes (Indigo, RBBR and Sulphur Black, and the dye-containing liquid effluent and solid waste from the Municipal Treatment Station, Americana, São Paulo, Brazil, by the cyanobacteria Anabaena flos-aquae UTCC64, Phormidium autumnale UTEX1580 and Synechococcus sp. PCC7942 was evaluated. The dye degradation efficiency of the cyanobacteria was compared with anaerobic and anaerobic-aerobic systems in terms of discolouration and toxicity evaluations. The discoloration was evaluated by absorption spectroscopy. Toxicity was measured using the organisms Hydra attenuata, the alga Selenastrum capricornutum and lettuce seeds. The three cyanobacteria showed the potential to remediate textile effluent by removing the colour and reducing the toxicity. However, the growth of cyanobacteria on sludge was slow and discoloration was not efficient. The cyanobacteria P. autumnale UTEX1580 was the only strain that completely degraded the indigo dye. An evaluation of the mutagenicity potential was performed by use of the micronucleus assay using Allium sp. No mutagenicity was observed after the treatment. Two metabolites were produced during the degradation, anthranilic acid and isatin, but toxicity did not increase after the treatment. The cyanobacteria showed the ability to degrade the dyes present in a textile effluent; therefore, they can be used in a tertiary treatment of effluents with recalcitrant compounds.

  5. Degradation of textile dyes by cyanobacteria.

    Science.gov (United States)

    Dellamatrice, Priscila Maria; Silva-Stenico, Maria Estela; Moraes, Luiz Alberto Beraldo de; Fiore, Marli Fátima; Monteiro, Regina Teresa Rosim

    Dyes are recalcitrant compounds that resist conventional biological treatments. The degradation of three textile dyes (Indigo, RBBR and Sulphur Black), and the dye-containing liquid effluent and solid waste from the Municipal Treatment Station, Americana, São Paulo, Brazil, by the cyanobacteria Anabaena flos-aquae UTCC64, Phormidium autumnale UTEX1580 and Synechococcus sp. PCC7942 was evaluated. The dye degradation efficiency of the cyanobacteria was compared with anaerobic and anaerobic-aerobic systems in terms of discolouration and toxicity evaluations. The discoloration was evaluated by absorption spectroscopy. Toxicity was measured using the organisms Hydra attenuata, the alga Selenastrum capricornutum and lettuce seeds. The three cyanobacteria showed the potential to remediate textile effluent by removing the colour and reducing the toxicity. However, the growth of cyanobacteria on sludge was slow and discoloration was not efficient. The cyanobacteria P. autumnale UTEX1580 was the only strain that completely degraded the indigo dye. An evaluation of the mutagenicity potential was performed by use of the micronucleus assay using Allium sp. No mutagenicity was observed after the treatment. Two metabolites were produced during the degradation, anthranilic acid and isatin, but toxicity did not increase after the treatment. The cyanobacteria showed the ability to degrade the dyes present in a textile effluent; therefore, they can be used in a tertiary treatment of effluents with recalcitrant compounds. Copyright © 2016 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda. All rights reserved.

  6. Development of forced degradation and stability indicating studies of drugs-A review

    Institute of Scientific and Technical Information of China (English)

    Blessy Mn; Ruchi D. Patel; Prajesh N. Prajapati; Y.K. Agrawal

    2014-01-01

    Forced degradation is a degradation of new drug substance and drug product at conditions more severe than accelerated conditions. It is required to demonstrate specificity of stability indicating methods and also provides an insight into degradation pathways and degradation products of the drug substance and helps in elucidation of the structure of the degradation products. Forced degradation studies show the chemical behavior of the molecule which in turn helps in the development of formulation and package. In addition, the regulatory guidance is very general and does not explain about the performance of forced degradation studies. Thus, this review discusses the current trends in performance of forced degradation studies by providing a strategy for conducting studies on degradation mechanisms and also describes the analytical methods helpful for development of stability indicating method.

  7. Statistical modeling for degradation data

    CERN Document Server

    Lio, Yuhlong; Ng, Hon; Tsai, Tzong-Ru

    2017-01-01

    This book focuses on the statistical aspects of the analysis of degradation data. In recent years, degradation data analysis has come to play an increasingly important role in different disciplines such as reliability, public health sciences, and finance. For example, information on products’ reliability can be obtained by analyzing degradation data. In addition, statistical modeling and inference techniques have been developed on the basis of different degradation measures. The book brings together experts engaged in statistical modeling and inference, presenting and discussing important recent advances in degradation data analysis and related applications. The topics covered are timely and have considerable potential to impact both statistics and reliability engineering.

  8. Bacterial degradation of detergent compounds.

    Science.gov (United States)

    Goodnow, R A; Harrison, A P

    1972-10-01

    A survey for surfactant degradation among aerobic bacteria has been undertaken. Tests have been made in peptone medium where such a degradation, if it occurs, will be gratuitous. Tallow-alkyl-sulfate, alkyl-ethoxylate-sulfate, and linear-alkyl-benzene-sulfonate were used. Forty-five strains of 34 species in 19 genera degrade one or more of these detergent compounds. With some species, the surfactant inhibits degradation without inhibiting growth, whereas with one species slight degradation took place even at a toxic concentration of surfactant.

  9. Legume-Cereal Intercropping Improves Forage Yield, Quality and Degradability.

    Directory of Open Access Journals (Sweden)

    Jie Zhang

    Full Text Available Intercropping legume with cereal is an extensively applied planting pattern in crop cultivation. However, forage potential and the degradability of harvested mixtures from intercropping system remain unclear. To investigate the feasibility of applying an intercropping system as a forage supply source to ruminants, two consecutive experiments (experiments 1 and 2 involving a field cultivation trial and a subsequent in vivo degradable experiment were conducted to determine the forage production performance and the ruminally degradable characteristics of a harvested mixture from an alfalfa/corn-rye intercropping system. In experiment 1, the intercropping system was established by alternating alfalfa and corn or rye with a row ratio of 5:2. Dry matter (DM and nutrient yields were determined. In experiment 2, forages harvested from the different treatments were used as feedstuff to identify nutrient degradation kinetics and distribution of components between the rapidly degradable (a, potentially degradable (b and the degradation rate constant (c of 'b' fraction by in sacco method in Small-Tail Han wether Sheep. The intercropping system of alfalfa and corn-rye provided higher forage production performance with net increases of 9.52% and 34.81% in DM yield, 42.13% and 16.74% in crude protein (CP yield, 25.94% and 69.99% in degradable DM yield, and 16.96% and 5.50% in degradable CP yield than rotation and alfalfa sole cropping systems, respectively. In addition, the harvest mixture from intercropping system also had greater 'a' fraction, 'b' fraction, 'c' values, and effective degradability (E value of DM and CP than corn or rye hay harvested from rotation system. After 48-h exposure to rumen microbes, intercropping harvest materials were degraded to a higher extent than separately degraded crop stems from the sole system as indicated by visual microscopic examination with more tissues disappeared. Thus, the intercropping of alfalfa and corn

  10. Legume-Cereal Intercropping Improves Forage Yield, Quality and Degradability.

    Science.gov (United States)

    Zhang, Jie; Yin, Binjie; Xie, Yuhuai; Li, Jing; Yang, Zaibin; Zhang, Guiguo

    2015-01-01

    Intercropping legume with cereal is an extensively applied planting pattern in crop cultivation. However, forage potential and the degradability of harvested mixtures from intercropping system remain unclear. To investigate the feasibility of applying an intercropping system as a forage supply source to ruminants, two consecutive experiments (experiments 1 and 2) involving a field cultivation trial and a subsequent in vivo degradable experiment were conducted to determine the forage production performance and the ruminally degradable characteristics of a harvested mixture from an alfalfa/corn-rye intercropping system. In experiment 1, the intercropping system was established by alternating alfalfa and corn or rye with a row ratio of 5:2. Dry matter (DM) and nutrient yields were determined. In experiment 2, forages harvested from the different treatments were used as feedstuff to identify nutrient degradation kinetics and distribution of components between the rapidly degradable (a), potentially degradable (b) and the degradation rate constant (c) of 'b' fraction by in sacco method in Small-Tail Han wether Sheep. The intercropping system of alfalfa and corn-rye provided higher forage production performance with net increases of 9.52% and 34.81% in DM yield, 42.13% and 16.74% in crude protein (CP) yield, 25.94% and 69.99% in degradable DM yield, and 16.96% and 5.50% in degradable CP yield than rotation and alfalfa sole cropping systems, respectively. In addition, the harvest mixture from intercropping system also had greater 'a' fraction, 'b' fraction, 'c' values, and effective degradability (E value) of DM and CP than corn or rye hay harvested from rotation system. After 48-h exposure to rumen microbes, intercropping harvest materials were degraded to a higher extent than separately degraded crop stems from the sole system as indicated by visual microscopic examination with more tissues disappeared. Thus, the intercropping of alfalfa and corn-rye exhibited a greater

  11. CLAD DEGRADATION - FEPS SCREENING ARGUMENTS

    Energy Technology Data Exchange (ETDEWEB)

    R. Schreiner

    2004-10-21

    The purpose of this report is to evaluate and document the screening of the clad degradation features, events, and processes (FEPs) with respect to modeling used to support the Total System Performance Assessment-License Application (TSPA-LA). This report also addresses the effect of certain FEPs on both the cladding and the commercial spent nuclear fuel (CSNF), DOE-owned spent nuclear fuel (DSNF), and defense high-level waste (DHLW) waste forms, as appropriate to address the effects on multiple materials and both components (FEPs 2.1.09.09.0A, 2.1.09.11.0A, 2.1.11.05.0A, 2.1.12.02.0A, and 2.1.12.03.0A). These FEPs are expected to affect the repository performance during the postclosure regulatory period of 10,000 years after permanent closure. Table 1-1 provides the list of cladding FEPs, including their screening decisions (include or exclude). The primary purpose of this report is to identify and document the analysis, screening decision, and TSPA-LA disposition (for included FEPs) or screening argument (for excluded FEPs) for these FEPs related to clad degradation. In some cases, where a FEP covers multiple technical areas and is shared with other FEP reports, this report may provide only a partial technical basis for the screening of the FEP. The full technical basis for shared FEPs is addressed collectively by the sharing FEP reports. The screening decisions and associated TSPA-LA dispositions or screening arguments from all of the FEP reports are cataloged in a project-specific FEPs database.

  12. Seonamhaeicola algicola sp. nov., a complex-polysaccharide-degrading bacterium isolated from Gracilaria blodgettii, and emended description of the genus Seonamhaeicola.

    Science.gov (United States)

    Zhou, Yan-Xia; Du, Zong-Jun; Chen, Guan-Jun

    2016-05-01

    A novel Gram-stain-negative, yellow, rod-shaped, facultatively anaerobic, gliding bacterial strain, designated Gy8T, was isolated from the surface of Gracilaria blodgettii. This bacterium was able to degrade various polysaccharides, especially agar and alginate. The major cellular fatty acids (>10 % of the total fatty acids) were C15 : 0, iso-C15 : 0, C15 : 0 3-OH and iso-C15 : 1. The major menaquinone was MK-6. The DNA G+C content was 35.3 mol%. The major polar lipids consisted of phosphatidylethanolamine and two unknown polar lipids. Strain Gy8T showed highest 16S rRNA gene sequence similarity to Seonamhaeicola aphaedonensis AH-M5T (95.6 %), and these two strains formed a distinct branch in phylogenetic trees generated with the neighbour-joining, maximum-likelihood and maximum-parsimony algorithms. The novel strain and the reference type strain of the single species described to date in the genus Seonamhaeicola contained MK-6 as the major menaquinone, iso-C15 : 0 and iso-C15 : 1 as the major fatty acids, and phosphatidylethanolamine and an unknown lipid as the major polar lipids. Based on phenotypic, chemotaxonomic and phylogenetic analysis, strain Gy8T is considered to represent a novel species within the genus Seonamhaeicola in the family Flavobacteriaceae, phylum Bacteroidetes, for which the name Seonamhaeicola algicola sp. nov. is proposed. The type strain is Gy8T ( = KCTC 42396T = CICC 23816T).

  13. Degradation of copepod fecal pellets

    DEFF Research Database (Denmark)

    Poulsen, Louise K.; Iversen, Morten

    2008-01-01

    Copepod fecal pellets are often degraded at high rates within the upper part of the water column. However, the identity of the degraders and the processes governing the degradation remain unresolved. To identify the pellet degraders we collected water from Oresund (Denmark) approximately every...... second month from July 2004 to July 2005. These water samples were divided into 5 fractions (pellet degradation rate and species composition of the plankton from triplicate incubations of each fraction and a known, added...... amount of fecal pellets. The total degradation rate of pellets by the natural plankton community of Oresund followed the phytoplankton biomass, with maximum degradation rate during the spring bloom (2.5 +/- 0.49 d(-1)) and minimum (0.52 +/- 0.14 d(-1)) during late winter. Total pellet removal rate ranged...

  14. Photothermal degradation studies

    Science.gov (United States)

    Liang, R. H.

    1985-01-01

    Key reaction intermediates of photooxidation identified and characterized by laser flash Electron Spin Resonance (ESR) spectroscopy were discussed. Effects of temperature and ultraviolet intensity were studied in order to develop meaningful accelerated testing procedures for encapsulant evaluation. In a program to study the failure of Tedlar/ethylene vinyl acetate (EVA)/stainless steel modules, failure modes similar to those observed outdoors in real-time conditions were simulated in accelerated testing. An experimental technique was developed to quantitatively assess the extent of degradation.

  15. Rat myocardial protein degradation.

    Science.gov (United States)

    Steer, J H; Hopkins, B E

    1981-07-01

    1. Myocardial protein degradation rates were determined by following tyrosine release from rat isolated left hemi-atria in vitro. 2. After two 20 min preincubations the rate of tyrosine release from hemi-atria was constant for 4 h. 3. Skeletal muscle protein degradation was determined by following tyrosine release from rat isolated hemi-diaphragm (Fulks, Li & Goldberg, 1975). 4. Insulin (10(-7) M) inhibited tyrosine release from hemi-atria and hemi-diaphragm to a similar extent. A 48 h fast increased tyrosine release rate from hemi-diaphragm and decreased tyrosine release rate from hemi-atria. Hemi-diaphragm tyrosine release was inhibited by 15 mmol/l D-glucose but a variety of concentrations of D-glucose (0, 5, 15 mmol/l) had no effect on tyrosine release from hemi-atria. Five times the normal plasma levels of the branched-chain amino acids leucine, isoleucine and valine had no effect on tyrosine release from either hemi-atria or hemi-diaphragm.

  16. Degradability of dental ceramics.

    Science.gov (United States)

    Anusavice, K J

    1992-09-01

    The degradation of dental ceramics generally occurs because of mechanical forces or chemical attack. The possible physiological side-effects of ceramics are their tendency to abrade opposing dental structures, the emission of radiation from radioactive components, the roughening of their surfaces by chemical attack with a corresponding increase in plaque retention, and the release of potentially unsafe concentrations of elements as a result of abrasion and dissolution. The chemical durability of dental ceramics is excellent. With the exception of the excessive exposure to acidulated fluoride, ammonium bifluoride, or hydrofluoric acid, there is little risk of surface degradation of virtually all current dental ceramics. Extensive exposure to acidulated fluoride is a possible problem for individuals with head and/or neck cancer who have received large doses of radiation. Such fluoride treatment is necessary to minimize tooth demineralization when saliva flow rates have been reduced because of radiation exposure to salivary glands. Porcelain surface stains are also lost occasionally when abraded by prophylaxis pastes and/or acidulated fluoride. In each case, the solutes are usually not ingested. Further research that uses standardized testing procedures is needed on the chemical durability of dental ceramics. Accelerated durability tests are desirable to minimize the time required for such measurements. The influence of chemical durability on surface roughness and the subsequent effect of roughness on wear of the ceramic restorations as well as of opposing structures should also be explored on a standardized basis.

  17. Assessment of the degradation efficiency of full-scale biogas plants: A comparative study of degradation indicators.

    Science.gov (United States)

    Li, Chao; Nges, Ivo Achu; Lu, Wenjing; Wang, Haoyu

    2017-07-29

    Increasing popularity and applications of the anaerobic digestion (AD) process has necessitated the development and identification of tools for obtaining reliable indicators of organic matter degradation rate and hence evaluate the process efficiency especially in full-scale, commercial biogas plants. In this study, four biogas plants (A1, A2, B and C) based on different feedstock, process configuration, scale and operational performance were selected and investigated. Results showed that the biochemical methane potential (BMP) based degradation rate could be use in incisively gauging process efficiency in lieu of the traditional degradation rate indicators. The BMP degradation rates ranged from 70 to 90% wherein plants A2 and C showed the highest throughput. This study, therefore, corroborates the feasibility of using the BMP degradation rate as a practical tool for evaluating process performance in full-scale biogas processes and spots light on the microbial diversity in full-scale biogas processes. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Towards heat-stable oxytocin formulations: analysis of degradation kinetics and identification of degradation products.

    Science.gov (United States)

    Hawe, Andrea; Poole, Robert; Romeijn, Stefan; Kasper, Piotr; van der Heijden, Rob; Jiskoot, Wim

    2009-07-01

    To investigate degradation kinetics of oxytocin as a function of temperature and pH, and identify the degradation products. Accelerated degradation of oxytocin formulated at pH 2.0, 4.5, 7.0 and 9.0 was performed at 40, 55, 70 and 80 degrees C. Degradation rate constants were determined from RP-HPLC data. Formulations were characterized by HP-SEC, UV absorption and fluorescence spectroscopy. Degradation products were identified by ESI-MS/MS. The loss of intact oxytocin in RP-HPLC was pH- and temperature-dependent and followed (pseudo) first order kinetics. Degradation was fastest at pH 9.0, followed by pH 7.0, pH 2.0 and pH 4.5. The Arrhenius equation proved suitable to describe the kinetics, with the highest activation energy (116.3 kJ/mol) being found for pH 4.5 formulations. At pH 2.0 deamidation of Gln(4), Asn(5), and Gly(9)-NH2, as well as combinations thereof were found. At pH 4.5, 7.0 and 9.0, the formation of tri- and tetrasulfide-containing oxytocin as well as different types of disulfide and dityrosine-linked dimers were found to occur. Beta-elimination and larger aggregates were also observed. At pH 9.0, mono-deamidation of Gln(4), Asn(5), and Gly(9)-NH2 additionally occurred. Multiple degradation products of oxytocin have been identified unequivocally, including various deamidated species, intramolecular oligosulfides and covalent aggregates. The strongly pH dependent degradation can be described by the Arrhenius equation.

  19. RESEARCH ON DEGRADATION PERFORMANCE OF BIODEGRADABLE MATERIALS-POLYLACTIC ACID AND ITS COPOLYMERS%生物降解材料聚乳酸及其共聚物的降解研究

    Institute of Scientific and Technical Information of China (English)

    李金良; 周才根

    2011-01-01

    The fundamental nature, biodegradable process and machanism of PLA were introduced. The research progress of biodegrade method of PLA at home and abroad was reviewed. The effecting factors of PLA degradation were discussed. The development and application prospect of PLA were outlooked.%论述了聚乳酸(PLA)的基本性质、降解过程、降解机理,综述了国内外PLA降解方法的研究进展,探讨了降解的影响因素,并展望了PLA的开发和应用前景.

  20. A thermal degradation study of Y and La methanesulfonates

    OpenAIRE

    MATOS, JIVALDO do R.; ROBSON F. DE FARIAS

    2006-01-01

    The synthesis, characterization and thermal degradation of yttrium and lanthanum methanesulfonates is reported. The prepared salts were characterized by elemental analysis and infrared spectroscopy. The thermal degradation study was performed using thermogravimetry (TG), differential thermal analysis (DTA) and differential scanning calorimetry (DSC).Using the thermogravimetric data, a kinetic study of the dehydration ofY and Lamethanesulfonates was performed employing the Coats–Redfern and Zs...

  1. Degradation of SiGe devices by proton irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Ohyama, Hidenori; Hayama, Kiyoteru [Kumamoto National Coll. of Technology, Nishigoshi (Japan); Vanhellemont, J.; Takami, Yasukiyo; Sunaga, Hiromi; Nashiyama, Isamu; Uwatoko, Yoshiya; Poortmans, J.; Caymax, M.

    1997-03-01

    The degradation and recovery behavior of strained Si{sub 1-x}Ge{sub x} diodes and heterojunction bipolar transistors (HBTs) by irradiated by protons are studied. The degradation of device performance and the generation of lattice defects are reported as a function of fluence and germanium content and also compared extensively with previous results obtained on electron and neutron irradiated devices. In order to study the recovery behavior of the irradiated devices, isochronal annealing is performed. The radiation source dependence of the degradation is discussed taking into account the number of knock-on atoms and the nonionizing energy loss (NIEL). (author)

  2. Liquid chromatography and liquid chromatography-mass spectrometry analysis of donepezil degradation products

    Directory of Open Access Journals (Sweden)

    Mladenović Aleksandar R.

    2015-01-01

    Full Text Available This study describes the investigation of degradation products of donepezil (DP using stability indicating RP-HPLC method for determination of donepezil, which is a centrally acting reversible acetylcholinesterase inhibitor. In order to investigate the stability of drug and formed degradation products, a forced degradation study of drug sample and finished product under different forced degradation conditions has been conducted. Donepezil hydrochloride and donepezil tablets were subjected to stress degradation conditions recommended by International Conference on Harmonization (ICH. Donepezil hydrochloride solutions were subjected to acid and alkali hydrolysis, chemical oxidation and thermal degradation. Significant degradation was observed under alkali hydrolysis and oxidative degradation conditions. Additional degradation products were observed under the conditions of oxidative degradation. The degradation products observed during forced degradation studies were monitored using the high performance liquid chromatography (HPLC method developed. The parent method was modified in order to obtain LC-MS compatible method which was used to identify the degradation products from forced degradation samples using high resolution mass spectrometry. The mass spectrum provided the precise mass from which derived molecular formula of drug substance and degradation products formed and proved the specificity of the method unambiguously. [Projekat Ministarstva nauke Republike Srbije, br. 172013

  3. Autochthonous arbuscular mycorrhizal fungi and Bacillus thuringiensis from a degraded Mediterranean area can be used to improve physiological traits and performance of a plant of agronomic interest under drought conditions.

    Science.gov (United States)

    Armada, Elisabeth; Azcón, Rosario; López-Castillo, Olga M; Calvo-Polanco, Mónica; Ruiz-Lozano, Juan Manuel

    2015-05-01

    Studies have shown that some microorganisms autochthonous from stressful environments are beneficial when used with autochthonous plants, but these microorganisms rarely have been tested with allochthonous plants of agronomic interest. This study investigates the effectiveness of drought-adapted autochthonous microorganisms [Bacillus thuringiensis (Bt) and a consortium of arbuscular mycorrhizal (AM) fungi] from a degraded Mediterranean area to improve plant growth and physiology in Zea mays under drought stress. Maize plants were inoculated or not with B. thuringiensis, a consortium of AM fungi or a combination of both microorganisms. Plants were cultivated under well-watered conditions or subjected to drought stress. Several physiological parameters were measured, including among others, plant growth, photosynthetic efficiency, nutrients content, oxidative damage to lipids, accumulation of proline and antioxidant compounds, root hydraulic conductivity and the expression of plant aquaporin genes. Under drought conditions, the inoculation of Bt increased significantly the accumulation of nutrients. The combined inoculation of both microorganisms decreased the oxidative damage to lipids and accumulation of proline induced by drought. Several maize aquaporins able to transport water, CO2 and other compounds were regulated by the microbial inoculants. The impact of these microorganisms on plant drought tolerance was complementary, since Bt increased mainly plant nutrition and AM fungi were more active improving stress tolerance/homeostatic mechanisms, including regulation of plant aquaporins with several putative physiological functions. Thus, the use of autochthonous beneficial microorganisms from a degraded Mediterranean area is useful to protect not only native plants against drought, but also an agronomically important plant such as maize.

  4. Novel g-C3N4/Ag2SO4 nanocomposites: Fast microwave-assisted preparation and enhanced photocatalytic performance towards degradation of organic pollutants under visible light.

    Science.gov (United States)

    Akhundi, Anise; Habibi-Yangjeh, Aziz

    2016-11-15

    Graphite carbon nitride (g-C3N4)/Ag2SO4 nanocomposites, as highly enhanced visible-light-driven photocatalysts, were prepared by a fast microwave-assisted method. The resulting g-C3N4/Ag2SO4 nanocomposites were characterized by X-ray diffraction, energy dispersive analysis of X-rays, scanning electron microscopy, transmission electron microscopy, thermogravimetric analysis, Fourier transform-infrared spectroscopy, and ultraviolet-visible diffuse reflectance spectroscopy techniques. Moreover, charge separation efficiency was studied by photoluminescence measurements. Photocatalytic activity of the g-C3N4/Ag2SO4 (40%) nanocomposite in degradation of rhodamine B, methylene blue, and fuchsine is about 6, 3.8, and 3.3-folds greater than that of the g-C3N4 under visible-light illumination. Effect of microwave irradiation time, calcination temperature, and scavengers of the reactive species on the degradation reaction was also evaluated. The enhanced photocatalytic activity was mainly ascribed to the matching band energies of g-C3N4 and Ag2SO4 which leads to an improved separation of photogenerated electron-hole pairs. Finally, the optimized nanocomposite was recycled for five times without remarkable decrease of the photocatalytic activity.

  5. Fe/Cu催化还原降解饮用水中溴氯乙腈的性能研究%Performance Study of Bromochloracetonitrile Degradation in Drinking Water by Fe/Cu Catalytic Reduction

    Institute of Scientific and Technical Information of China (English)

    丁春生; 马海龙; 傅洋平; 赵世督; 李东兵

    2015-01-01

    为了降低饮用水在氯消毒过程中产生的消毒副产物(DBPs)溴氯乙腈(BCAN)对人体带来的健康危害,采用 Fe/ Cu 催化还原的方法降解饮用水中低浓度的 BCAN,考察了 BCAN 的降解效果和其影响因素,探讨了其降解机制及动力学规律.结果表明,Fe/ Cu 具有更强的还原降解 BCAN 的能力,与零价铁相比, Fe/ Cu(质量比为10:1)的降解效率是其1.5倍.随着 Fe/ Cu 投加量的增加,BCAN 的去除率有明显的提高,对于初始浓度为20μg•L -1的 BCAN 溶液,当 Fe/ Cu(质量比为10:1)投加量由5 g•L -1增加到10 g•L -1,反应150 min 后,去除率由51.1%增加到89.5%. BCAN 降解效率随着温度的升高逐渐提高,BCAN 初始浓度的变化对 Fe/ Cu 去除 BCAN 的去除效果影响不大,Fe/ Cu 降解 BCAN 符合一级反应动力学规律.%The paper used the method of iron copper catalyst reduction to degrade low concentrations of bromochloracetonitrile (BCAN) to lighten the damage to human being, which is a kind of disinfection by-products (DBPs) produced during the chlorination process of drinking water. The removal efficiency of BCAN and its influencing factors were investigated. The mechanism of degradation and kinetics were also explored. The results indicated that iron copper had a greater degradation ability towards BCAN, and the degradation rate of iron copper (mass ratio of 10: 1) was 1. 5 times that of the zero-valent iron. The removal of BCAN increased obviously with the increase of Fe/ Cu dosage. When the initial concentration was set at 20 μg•L - 1 , after a reaction time of 150 min, removal of BCAN was improved from 51. 1% to 89. 5% with the increase of iron copper (mass ratio of 10: 1) dosage from 5 g•L - 1 to 10 g•L - 1 . The temperature also had great impact on BCAN removal and the removal increased with the increase of temperature. However, BCAN removal did not change a lot with the variation of the initial concentration of BCAN when it was at

  6. DEGRADATION OF SHAPE MEMORY EFFECT

    OpenAIRE

    VanderMeer, R.

    1982-01-01

    An important parameter for deciding whether or not a SME alloy is suitable for practical applications is the magnitude of the strain reversa1 accompanying martensite reversion. This research is concerned with elucidating metallurgical factors that cause degradation of this heat-activated recovery strain, ER. After explaining what is meant by degradation, two manifestations of degradation recently identified in near-monotectoid uranium-niobium alloys will be described. The first was associated...

  7. Transcellular degradation of axonal mitochondria.

    Science.gov (United States)

    Davis, Chung-ha O; Kim, Keun-Young; Bushong, Eric A; Mills, Elizabeth A; Boassa, Daniela; Shih, Tiffany; Kinebuchi, Mira; Phan, Sebastien; Zhou, Yi; Bihlmeyer, Nathan A; Nguyen, Judy V; Jin, Yunju; Ellisman, Mark H; Marsh-Armstrong, Nicholas

    2014-07-01

    It is generally accepted that healthy cells degrade their own mitochondria. Here, we report that retinal ganglion cell axons of WT mice shed mitochondria at the optic nerve head (ONH), and that these mitochondria are internalized and degraded by adjacent astrocytes. EM demonstrates that mitochondria are shed through formation of large protrusions that originate from otherwise healthy axons. A virally introduced tandem fluorophore protein reporter of acidified mitochondria reveals that acidified axonal mitochondria originating from the retinal ganglion cell are associated with lysosomes within columns of astrocytes in the ONH. According to this reporter, a greater proportion of retinal ganglion cell mitochondria are degraded at the ONH than in the ganglion cell soma. Consistently, analyses of degrading DNA reveal extensive mtDNA degradation within the optic nerve astrocytes, some of which comes from retinal ganglion cell axons. Together, these results demonstrate that surprisingly large proportions of retinal ganglion cell axonal mitochondria are normally degraded by the astrocytes of the ONH. This transcellular degradation of mitochondria, or transmitophagy, likely occurs elsewhere in the CNS, because structurally similar accumulations of degrading mitochondria are also found along neurites in superficial layers of the cerebral cortex. Thus, the general assumption that neurons or other cells necessarily degrade their own mitochondria should be reconsidered.

  8. Aerobic degradation of polychlorinated biphenyls

    Energy Technology Data Exchange (ETDEWEB)

    Pieper, D.H. [Dept. of Environmental Microbiology, German Research Center for Biotechnology, Braunschweig (Germany)

    2005-04-01

    The microbial degradation of polychlorinated biphenyls (PCBs) has been extensively studied in recent years. The genetic organization of biphenyl catabolic genes has been elucidated in various groups of microorganisms, their structures have been analyzed with respect to their evolutionary relationships, and new information on mobile elements has become available. Key enzymes, specifically biphenyl 2,3-dioxygenases, have been intensively characterized, structure/sequence relationships have been determined and enzymes optimized for PCB transformation. However, due to the complex metabolic network responsible for PCB degradation, optimizing degradation by single bacterial species is necessarily limited. As PCBs are usually not mineralized by biphenyl-degrading organisms, and cometabolism can result in the formation of toxic metabolites, the degradation of chlorobenzoates has received special attention. A broad set of bacterial strategies to degrade chlorobenzoates has recently been elucidated, including new pathways for the degradation of chlorocatechols as central intermediates of various chloroaromatic catabolic pathways. To optimize PCB degradation in the environment beyond these metabolic limitations, enhancing degradation in the rhizosphere has been suggested, in addition to the application of surfactants to overcome bioavailability barriers. However, further research is necessary to understand the complex interactions between soil/sediment, pollutant, surfactant and microorganisms in different environments. (orig.)

  9. Afforestation of degraded grass land

    Energy Technology Data Exchange (ETDEWEB)

    Basappa, B.

    1983-01-01

    The suitability of 11 species was tested for planting on degraded land at Kogilemane in Belur Taluk, Karnataka. The soil was alkaline with no humus, litter or topsoil. The original vegetation was grass with the stemless palm Phoenix acaulis, still present at 600 plants per acre. Seedlings 4-6 months old and raised in polythene bags were planted in pits in July 1981; Bambusa vulgaris was planted as 8-month-old cuttings. No fertilizer was applied. The most successful species after the first season was Acacia auriculiformis. Satisfactory survival and growth were also obtained with Cassia siamea, Peltoforum ferruginum, Leucaena leucocephala (although this was later heavily damaged by wild rabbits) and Toona ciliata. The bamboo survived well but there was no culm formation during the experiment. In 1982 only 3 of the species were tested: A. auriculiformis, L. leucocephala (because of its fast growth rate) and Casuarina equisetifolia (which performed badly in 1981 but is suited to alkaline soils). All 3 species performed satisfactorily.

  10. Dryland degradation: Measurement and effects on ecosystems

    Science.gov (United States)

    Noojipady, P.; Prince, S. D.; Rishmawi, K.

    2012-12-01

    Production (NPP) which, in turn, is used as a surrogate for land condition. The land surface is classified into homogeneous land capability units based on the physical environment and the maximum NPP found in the unit is used as the best estimator of the potential NPP. Other parts of the unit are scaled relative to the maximum. This technique, known as Local NPP Scaling (LNS), has been applied in southern Africa, the Sahel , and in various stages of completion in SW USA, Negev and Queensland. The effects of the degradation on surface fluxes of water, energy and carbon dioxide have been assessed in the Sahel. The provisional conclusions are that there are, indeed areas of drylands that are performing below expectation from their physical environment and that limited parts of these areas have entered into a long-term, maybe permanent degraded state. Furthermore, a key factor is the loss of soil moisture.

  11. Contribution of ethylamine degrading bacteria to atrazine degradation in soils.

    Science.gov (United States)

    Smith, Daniel; Crowley, David E

    2006-11-01

    Bacterial communities that cooperatively degrade atrazine commonly consist of diverse species in which the genes for atrazine dechlorination and dealkylation are variously distributed among different species. Normally, the first step in degradation of atrazine involves dechlorination mediated by atzA, followed by stepwise dealkylation to yield either N-ethylammelide or N-isopropylammelide. As the liberated alkylamine moieties are constituents of many organic molecules other than atrazine, it is possible that a large number of alkylamine-degrading bacteria other than those previously described might contribute to this key step in atrazine degradation. To examine this hypothesis, we isolated 82 bacterial strains from soil by plating soil water extracts on agar media with ethylamine as a sole carbon source. Among the relatively large number of isolates, only 3 were able to degrade N-ethylammelide, and in each case were shown to carry the atzB gene and atzC genes. The isolates, identified as Rhizobium leguminosarum, Flavobacterium sp., and Arthrobacter sp., were all readily substituted into an atrazine-degrading consortium to carry out N-ethylammelide degradation. The distribution of these genes among many different species in the soil microbial population suggests that these genes are highly mobile and over time may lead to generation of various atrazine-degrading consortia.

  12. Automated Degradation Diagnosis in Character Recognition System Subject to Camera Vibration

    Directory of Open Access Journals (Sweden)

    Chunmei Liu

    2014-01-01

    Full Text Available Degradation diagnosis plays an important role for degraded character processing, which can tell the recognition difficulty of a given degraded character. In this paper, we present a framework for automated degraded character recognition system by statistical syntactic approach using 3D primitive symbol, which is integrated by degradation diagnosis to provide accurate and reliable recognition results. Our contribution is to design the framework to build the character recognition submodels corresponding to degradation subject to camera vibration or out of focus. In each character recognition submodel, statistical syntactic approach using 3D primitive symbol is proposed to improve degraded character recognition performance. In the experiments, we show attractive experimental results, highlighting the system efficiency and recognition performance by statistical syntactic approach using 3D primitive symbol on the degraded character dataset.

  13. Transitioning from anatomic landmarks to ultrasound guided central venous catheterizations: guidelines applied to clinical practice.

    Science.gov (United States)

    Oom, Rodrigo; Casaca, Rui; Barroca, Rita; Carvalhal, Sara; Santos, Catarina; Abecasis, Nuno

    2017-07-14

    Centrally inserted central catheter (CICC) insertion is a commonly performed procedure that may give rise to different complications. Despite the suggestion of guidelines to use ultrasound guidance (USG) for vascular access, not all centers use it systematically. The aim of this study is to illustrate the experience with ultrasound in CICC placement at a high-volume oncological center, in a country where the landmark technique is standard. Retrospective analysis of a prospective database was performed on CICC placement under USG in the Central Venous Catheter Unit of Instituto Português de Oncologia de Lisboa Francisco Gentil, from 2012 to 2015. Three thousand five hundred and seventy-two procedures were recorded. From 2728 CICC placements, 1187 (43.5%) were done using USG. The majority of CICC placements were successful without immediate complications (96.1%). In 55 cases (4.6%), more than three attempts were necessary to puncture the vein. Pneumothorax occurred in 5 cases (0.4%) and arterial puncture was registered in 41 cases (3.5%). An increasing use of USG for placing CICCs was planned and observed over the years and, in the last year of the study, 67.3% of the CICC placements were with USG. CICC placement with USG is a safe and effective technique. Despite some resistance that is observed, these results support that it is worth following the guidelines that advocate the use of the USG in the placement of CICC.

  14. Research of Isolation and Degradation Conditions of Petroleum Degrading Marine

    Science.gov (United States)

    Fangrui, Guo

    2017-01-01

    A novel petroleum-degrading microbial strain was isolated from sediment samples in estuary of Bohai Sea estuary beaches. The strain was primarily identified as Alcanivorax sp. and named Alcanivorax sp. H34. Effect of PH values, temperature, nitrogen and phosphorus concentrations on degradation of H34 were investigated. The paraffinic components average degradation rate of H34 ungrowth cells under optimized conditions was studied. The results showed that the optimal growth conditions of H34 are were temperature of 30°C, initial PH of 7.0, nitrogen concentration of 3g/L, phosphorus concentration of 3g/L, and paraffinic components average degradation rates of H34 ungrowth cells was 41.6%, while total degradation rate was 45.5%.

  15. Modeling Degradation in Solid Oxide Electrolysis Cells

    Energy Technology Data Exchange (ETDEWEB)

    Manohar S. Sohal; Anil V. Virkar; Sergey N. Rashkeev; Michael V. Glazoff

    2010-09-01

    Idaho National Laboratory has an ongoing project to generate hydrogen from steam using solid oxide electrolysis cells (SOECs). To accomplish this, technical and degradation issues associated with the SOECs will need to be addressed. This report covers various approaches being pursued to model degradation issues in SOECs. An electrochemical model for degradation of SOECs is presented. The model is based on concepts in local thermodynamic equilibrium in systems otherwise in global thermodynamic no equilibrium. It is shown that electronic conduction through the electrolyte, however small, must be taken into account for determining local oxygen chemical potential, , within the electrolyte. The within the electrolyte may lie out of bounds in relation to values at the electrodes in the electrolyzer mode. Under certain conditions, high pressures can develop in the electrolyte just near the oxygen electrode/electrolyte interface, leading to oxygen electrode delamination. These predictions are in accordance with the reported literature on the subject. Development of high pressures may be avoided by introducing some electronic conduction in the electrolyte. By combining equilibrium thermodynamics, no equilibrium (diffusion) modeling, and first-principles, atomic scale calculations were performed to understand the degradation mechanisms and provide practical recommendations on how to inhibit and/or completely mitigate them.

  16. Research on Light Degradation Performance of Ag/TiO2--PVA Composite Membrane%Ag/TiO2-PVA复合膜的光降解性能研究

    Institute of Scientific and Technical Information of China (English)

    高婷; 仉春华; 黄文静; 冯佳琪; 林雪钰

    2012-01-01

    In this paper,ascorbic acid reduction method and photochemical deposition method are used to prepare TiO2/ Ag--PVA composite membrane. Ag is doped into TiO2 and polypropylene non--woven fabrics (NWF) is used as base membrane. The purpose is to reduce loss of TiO2 and to enhance the absorption of sunlight. TiO2/Ag--PVA composite membrane is characterized by SEM and XRD. The photocatalytic degradation impact of TiO2/Ag--PVA composite membrane using UV light and simulated sunlight as light source on organic dyes (reactive blue and methyl orange) is studied to investigate its catalytic action. The analysis results of SEM and XRD show ~hat TiO2/Ag--PVA composite membrane can be effectively formed on the surface of polypropylene non--woven fabrics by using the above two meth- ods. But the load of Ag/TiO2 on TiO2/Ag--PVA composite membrane prepared by ascorbic acid method is higher than that of by photochemical deposition method. Experimental results of dye wastewater treatment show that TiO2/Ag- PVA composite membrane has good catalytic action to UV degradation in reactive turquoise blue wastewater and methyl orange wastewater. Its catalytic action to nature light degradation in reactive turquoise blue wastewater is not obvious, but the catalytic action to nature light degradation in methyl orange wastewater is obvious.%分别采用抗坏血酸还原法和光化学沉积法,将Ag掺杂到TiO2中,以聚丙烯无纺布为基膜,制备了Ag/TiO2—PVA复合膜以减少TiO2的流失和提高对太阳光的吸收,并对Ag/TiO2-PVA复合膜进行了SEM和XRD表征,以紫外光、模拟太阳光为光源,分别研究了Ag/TiO2-PVA复合膜对有机染料活性翠兰、甲基橙的光催化降解效果,以考察Ag/TiO2-PVA复合膜的催化作用。SEM和XRD的分析结果表明:上述两种方法均能有效地在聚丙烯无纺布表面形成Ag/TiO2-PVA复合膜,抗坏血酸法制备的Ag/TiO2—PVA复合膜的Ag/TiO2负载量高于光

  17. Study on Degradation Performance of Star-Shaped Polymer of ESO and Lactide%ESO-丙交酯星形聚合物的降解性能研究

    Institute of Scientific and Technical Information of China (English)

    张贝; 付春华; 王远亮

    2011-01-01

    环氧大豆油-丙交酯(ESO-丙交酯)星形聚合物是一种新型支化高分子材料,它的应用与其降解性能有着重要关系.影响降解的因素很多,本文选用磷酸缓冲液进行了实时体外降解实验,将聚(D,L-乳酸)( PDLLA)与其支化后得到的ESO-丙交酯星形聚合物的降解实验进行对比,研究发现对于表面形态、pH、分子量及失重率,支化ESO-丙交酯星形聚合物的变化程度慢于PDLLA,这对于ESO-丙交酯进一步应用具有非常重要的指导意义.%Star-Shaped Polymer of epoxidized soybean oil (ESO) and Lactide is a new material. Its degradation function has an importance to its applications. There are many factors affecting its degradation. This paper is mainly aimed at investigation in which the surface morphology, pH, molecular weight and weight loss rate, branching ESO lactide star polymers the degree of change were studied. It was found through the experiments that, the changing rates of the branching ESO-lactide star polymers were slower than the degree of PDLLA change compared to the surface morphology, pH, molecular weight and weight loss rate. This has a guiding significance to the further application of ESO-lactide.

  18. ASSAYING OF AUTOPHAGIC PROTEIN DEGRADATION

    NARCIS (Netherlands)

    C. Bauvy; A.J. Meijer; P. Codogno

    2009-01-01

    Macroautophagy is a three-step process: (1) autophagosomes form and mature, (2) the autophagosomes fuse with lysosomes, and (3) the autophagic cargo is degraded in the lysosomes. It is this lysosomal degradation of the autophagic cargo that constitutes the autophagic flux. As in the case of metaboli

  19. MOSFET Degradation Under RF Stress

    NARCIS (Netherlands)

    Sasse, G.T.; Kuper, F.G.; Schmitz, Jurriaan

    2008-01-01

    We report on the degradation of MOS transistors under RF stress. Hot-carrier degradation, negative-bias temperature instability, and gate dielectric breakdown are investigated. The findings are compared to established voltage- and field-driven models. The experimental results indicate that the

  20. Photocatalytic degradation of methylene blue with a nanocomposite system: synthesis, photocatalysis and degradation pathways.

    Science.gov (United States)

    Xia, Shengjie; Zhang, Lianyang; Pan, Guoxiang; Qian, Pingping; Ni, Zheming

    2015-02-21

    Three different composites, including a calcined FeOOH supported ZnAl layered double hydroxide (FeOOH-LDO), a calcined ZnAl layered double hydroxide (ZnAl-LDO) and a calcined ZnFeAl layered double hydroxide (ZnFeAl-LDO), were synthesized via a sol-gel method, and their activity for the visible light photocatalytic degradation of methylene blue (MB) was studied. The composites were characterized by PXRD, SEM, and BET techniques, confirming the formation of highly crystalline structures. The activity performance of MB degradation was in the following order: FeOOH-LDO (∼95%) > ZnFeAl-LDO (∼60%) > ZnAl-LDO (∼23%). In addition, a possible photocatalytic degradation reaction mechanism for MB was also proposed. Moreover, the frontier electron densities on the atoms of MB were calculated, which were in satisfactory agreement with the postulated mechanism.

  1. Degradation of carbofuran by ozonation.

    Science.gov (United States)

    Suneethi, S; Joseph, Kurian

    2009-04-01

    Degradation of commercial grade carbofuran (2, 3 dihydro-2, 2-dimethyl-7 benzo furanyl-N-methyl carbamate) in aqueous solution by ozone oxidation was investigated using bench scale experiments. The degradation rate was strongly influenced by the ozone dosage, pH, initial concentration of carbofuran and contact time of ozonation. Carbofuran solution of 200ppm concentration was degraded by 79% within 10 minutes consuming 87 mg of ozone at pH 4. The associated TOC reduction was observed to be 53%. Ammonium (20 mg/L) and nitrate (30 mg/L) ions were detected in the effluent as degradation products of ozonation. The results support the effectiveness of ozonation for degradation of organic pesticides such as carbofuran.

  2. Enzymatic degradation of endomorphins.

    Science.gov (United States)

    Janecka, Anna; Staniszewska, Renata; Gach, Katarzyna; Fichna, Jakub

    2008-11-01

    Centrally acting plant opiates, such as morphine, are the most frequently used analgesics for the relief of severe pain, even though their undesired side effects are serious limitation to their usefulness. The search for new therapeutics that could replace morphine has been mainly focused on the development of peptide analogs or peptidomimetics with high selectivity for one receptor type and high bioavailability, that is good blood-brain barrier permeability and enzymatic stability. Drugs, in order to be effective, must be able to reach the target tissue and to remain metabolically stable to produce the desired effects. The study of naturally occurring peptides provides a rational and powerful approach in the design of peptide therapeutics. Endogenous opioid peptides, endomorphin-1 and endomorphin-2, are two potent and highly selective mu-opioid receptor agonists, discovered only a decade ago, which display potent analgesic activity. However, extensive studies on the possible use of endomorphins as analgesics instead of morphine met with failure due to their instability. This review deals with the recent investigations that allowed determine degradation pathways of endomorphins in vitro and in vivo and propose modifications that will lead to more stable analogs.

  3. Bacterial degradation of aminopyrine.

    Science.gov (United States)

    Blecher, H; Blecher, R; Wegst, W; Eberspaecher, J; Lingens, F

    1981-11-01

    1. Four strains of bacteria growing with aminopyrine as sole source of carbon were isolated from soil and were identified as strains of Phenylobacterium immobilis. 2. Strain M13 and strain E, the type species of Phenylobacterium immobilis (DSM 1986), which had been isolated by enrichment with chloridazon (5-amino-4-chloro-2-phenyl-2H-pyridazin-3-one) were used to investigate the bacterial degradation of aminopyrine. 3. Three metabolites were isolated and identified as: 4-(dimethylamino)-1,2-dihydro-1,5-dimethyl-2-(2,3-dihydro-2,3-dihydroxy-4,6-cyc lohexadien-1-yl)-3H-pyrazol-3-one, 4-(dimethylamino)-1,2-dihydro-1,5-dimethyl-2-(2,3-dihydroxyphenyl)-3H-pyrazol-3 -one and 4-(dimethylamino)-1,2-dihydro-1,5-dimethyl-3H-pyrazol-3-one. 4. An enzyme extract from cells of strain m13 was shown to further metabolize the catechol derivative of aminopyrine, with the formation of 2-pyrone-6-carboxylic acid. 5. Results indicate that the benzene ring of aminopyrine is the principal site of microbial metabolism.

  4. Overlay degradation induced by film stress

    Science.gov (United States)

    Huang, Chi-hao; Liu, Yu-Lin; Luo, Shing-Ann; Yang, Mars; Yang, Elvis; Hung, Yung-Tai; Luoh, Tuung; Yang, T. H.; Chen, K. C.

    2017-03-01

    The semiconductor industry has continually sought the approaches to produce memory devices with increased memory cells per memory die. One way to meet the increasing storage capacity demand and reduce bit cost of NAND flash memories is 3D stacked flash cell array. In constructing 3D NAND flash memories, increasing the number of stacked layers to build more memory cell number per unit area necessitates many high-aspect-ratio etching processes accordingly the incorporation of thick and unique etching hard-mask scheme has been indispensable. However, the ever increasingly thick requirement on etching hard-mask has made the hard-mask film stress control extremely important for maintaining good process qualities. The residual film stress alters the wafer shape consequently several process impacts have been readily observed across wafer, such as wafer chucking error on scanner, film peeling, materials coating and baking defects, critical dimension (CD) non-uniformity and overlay degradation. This work investigates the overlay and residual order performance indicator (ROPI) degradation coupling with increasingly thick advanced patterning film (APF) etching hard-mask. Various APF films deposited by plasma enhanced chemical vapor deposition (PECVD) method under different deposition temperatures, chemicals combinations, radio frequency powers and chamber pressures were carried out. And -342MPa to +80MPa film stress with different film thicknesses were generated for the overlay performance study. The results revealed the overlay degradation doesn't directly correlate with convex or concave wafer shapes but the magnitude of residual APF film stress, while increasing the APF thickness will worsen the overlay performance and ROPI strongly. High-stress APF film was also observed to enhance the scanner chucking difference and lead to more serious wafer to wafer overlay variation. To reduce the overlay degradation from ever increasingly thick APF etching hard-mask, optimizing the

  5. Degradation Characterization of Thermal Interface Greases: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    DeVoto, Douglas J [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Major, Joshua [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Paret, Paul P [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2017-08-03

    Thermal interface materials (TIMs) are used in power electronics packaging to minimize thermal resistance between the heat generating component and the heat sink. Thermal greases are one such class. The conformability and thin bond line thickness (BLT) of these TIMs can potentially provide low thermal resistance throughout the operation lifetime of a component. However, their performance degrades over time due to pump-out and dry-out during thermal and power cycling. The reliability performance of greases through operational cycling needs to be quantified to develop new materials with superior properties. NREL, in collaboration with DuPont, has performed thermal and reliability characterization of several commercially available thermal greases. Initial bulk and contact thermal resistance of grease samples were measured, and then the thermal degradation that occurred due to pump-out and dry-out during temperature cycling was monitored. The thermal resistances of five different grease materials were evaluated using NREL's steady-state thermal resistance tester based on the ASTM test method D5470. Greases were then applied, utilizing a 2.5 cm x 2.5 cm stencil, between invar and aluminum plates to compare the thermomechanical performance of the materials in a representative test fixture. Scanning Acoustic microscopy, thermal, and compositional analyses were performed periodically during thermal cycling from -40 degrees Celcius to 125 degrees Celcius. Completion of this characterization has allowed for a comprehensive evaluation of thermal greases both for their initial bulk and contact thermal performance, as well as their degradation mechanisms under accelerated thermal cycling conditions.

  6. Degradation Characteristics of Wood Using Supercritical Alcohols

    Directory of Open Access Journals (Sweden)

    Jeeban Poudel

    2012-11-01

    Full Text Available In this work, the characteristics of wood degradation using supercritical alcohols have been studied. Supercritical ethanol and supercritical methanol were used as solvents. The kinetics of wood degradation were analyzed using the nonisothermal weight loss technique with heating rates of 3.1, 9.8, and 14.5 °C/min for ethanol and 5.2, 11.3, and 16.3 °C/min for methanol. Three different kinetic analysis methods were implemented to obtain the apparent activation energy and the overall reaction order for wood degradation using supercritical alcohols. These were used to compare with previous data for supercritical methanol. From this work, the activation energies of wood degradation in supercritical ethanol were obtained as 78.0–86.0, 40.1–48.1, and 114 kJ/mol for the different kinetic analysis methods used in this work. The activation energies of wood degradation in supercritical ethanol were obtained as 78.0–86.0, 40.1–48.1, and 114 kJ/mol. This paper also includes the analysis of the liquid products obtained from this work. The characteristic analysis of liquid products on increasing reaction temperature and time has been performed by GC-MS. The liquid products were categorized according to carbon numbers and aromatic/aliphatic components. It was found that higher conversion in supercritical ethanol occurs at a lower temperature than that of supercritical methanol. The product analysis shows that the majority of products fall in the 2 to 15 carbon number range.

  7. Forced Degradation of Flavonol Glycosides Extraced from Ginkgo biloba

    Institute of Scientific and Technical Information of China (English)

    JIN Ye; ZHANG Wei-yu; MENG Qing-fan; LI Dan-hui; GARG Sajay; TENG Li-rong; WEN Jing-yuan

    2013-01-01

    The degradation of flavonol glycosides extracted from Ginkgo biloba was performed under different conditions and the degraded products were determined by reversed-phase high performance liquid chromatography (RP-HPLC) method.Four stress conditions including acid(0.1 mol/L HCl),base(0.1 mol/L NaOH),temperature (70 ℃) and oxidation(0.03% H2O2,volume fraction) were used for the forced degradation studies.The pH stabilities of the flavonol glycosides were determined in phosphate buffers of varying pH values from 4.5 to 7.4.The degradation rate constants and half-life of three Ginkgo flavonol aglycones(quercetin,kaempferol and isorhamnetin) which represent Ginkgo flavonol glycosides were calculated in forced degradation and pH-stability studies of them.The resuits indicate that the three substances were more stable when incubated under acid condition and showed pH-dependent stability.The degradation was observed to follow first-order kinetics in all degradation studies.The stability results could provide important bases on development,preparation and storage of products of Ginkgo biloba extract and should be significantly considered during the further formulation development.

  8. Preparation of modified PAN nonwoven Fe complex and its photocatalytic performance on formaldehyde degradation%改性PAN非织造布铁配合物可见光降解甲醛气体

    Institute of Scientific and Technical Information of China (English)

    韩旭; 韩振邦; 赵晓明

    2016-01-01

    使用盐酸羟胺对聚丙烯腈非织造布(nPAN)进行了化学改性,并将所得改性聚丙烯腈非织造布(AO-nPAN)与Fe(Ⅲ)配位制得改性聚丙烯腈非织造布铁配合物(Fe-nPAN),分别使用扫描电镜(SEM)、傅立叶红外光谱(FTIR)、X射线衍射(XRD)和UV-Vis吸收光谱对Fe-nPAN进行了表征,然后将其作为光催化剂应用于甲醛气体的氧化降解反应中.结果表明:提高Fe(Ⅲ)初始浓度、反应温度和AO-nPAN的增重率都能够增加Fe-nPAN的Fe(Ⅲ)配合量.Fe-nPAN中偕胺肟基团与Fe(Ⅲ)发生了配位反应,使其在可见光区有明显的吸收带.增加Fe(Ⅲ)配合量和可见光强度都能够促进甲醛的降解反应,而且与PAN纱线制备的铁配合物催化剂相比,Fe-nPAN明显具有更高的催化活性.%Polyacrylonitrile nonwoven (nPAN) were chemically modified with hydroxylamine, and the obtained amidoximated polyacrylonitrile nonwoven (AO-nPAN) were coordinated with Fe (Ⅲ) to prepare modified nPAN supported Fe complexes (Fe-nPAN). The complexes were characterized using Scanning electron microscope (SEM), Fourier Transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and UV-vis absorption spectra, and then employed as photocatalysts in the oxidative degradation of formaldehyde. The results indicated that increasing Fe (Ⅲ) concentration, reaction temperature and weight gain rate of AO-nPAN led to higher Fe (Ⅲ) content of Fe-nPAN. The amidoxime groups were coordinated with Fe (Ⅲ) in Fe-nPAN, which gave the catalyst a remarkable absorption in the visible region. Increasing both Fe (Ⅲ) content of Fe-nPAN and visible irradiation could significantly accelerate the formaldehyde degradation, and the catalyst exhibited much higher photocatalytic activity than the PAN yarn Fe complex under similar conditions.

  9. SENSITIVITY ANALYSIS FOR SALTSTONE DISPOSAL UNIT COLUMN DEGRADATION ANALYSES

    Energy Technology Data Exchange (ETDEWEB)

    Flach, G.

    2014-10-28

    PORFLOW related analyses supporting a Sensitivity Analysis for Saltstone Disposal Unit (SDU) column degradation were performed. Previous analyses, Flach and Taylor 2014, used a model in which the SDU columns degraded in a piecewise manner from the top and bottom simultaneously. The current analyses employs a model in which all pieces of the column degrade at the same time. Information was extracted from the analyses which may be useful in determining the distribution of Tc-99 in the various SDUs throughout time and in determining flow balances for the SDUs.

  10. Crystallinity dependent thermal degradation in organic solar cell

    Science.gov (United States)

    Lee, Hyunho; Sohn, Jiho; Tyagi, Priyanka; Lee, Changhee

    2017-01-01

    An operating solar cell undergoes solar heating; thus, the degradation study of organic photo-voltaic (OPV) with a thermal stress is required for their practical applications. We present a thermal degradation study on OPVs fabricated with photo-active polymers having different crystalline phase. Light intensity dependent analysis for different thermal stress duration is performed. In crystalline, the degradation majorly occurs due to drop in open-circuit voltage while in amorphous one it is due to drop in short-circuit current. Physical mechanism in both systems is explained and supported by the X-ray diffraction, morphological and optical characterization.

  11. Photoassisted Fenton degradation of polystyrene.

    Science.gov (United States)

    Feng, Hui-Min; Zheng, Jia-Chuan; Lei, Ngai-Yu; Yu, Lei; Kong, Karen Hoi-Kuan; Yu, Han-Qing; Lau, Tai-Chu; Lam, Michael H W

    2011-01-15

    Fenton and photoassisted Fenton degradation of ordinary hydrophobic cross-linked polystyrene microspheres and sulfonated polystyrene beads (DOWEX 50WX8) have been attempted. While the Fenton process was not able to degrade these polystyrene materials, photoassisted Fenton reaction (mediated by broad-band UV irradiation from a 250 W Hg(Xe) light source) was found to be efficient in mineralizing cross-linked sulfonated polystyrene materials. The optimal loadings of the Fe(III) catalyst and the H(2)O(2) oxidant for such a photoassisted Fenton degradation were found to be 42 μmol-Fe(III) and 14.1 mmol-H(2)O(2) per gram of the sulfonated polystyrene material. The initial pH for the degradation was set at pH 2.0. This photoassisted Fenton degradation process was also able to mineralize commonly encountered polystyrene wastes. After a simple sulfonation pretreatment, a mineralization efficiency of >99% (by net polymer weight) was achieved within 250 min. The mechanism of this advanced oxidative degradation process was investigated. Sulfonate groups introduced to the surface of the treated polystyrene polymer chains were capable of rapidly binding the cationic Fe(III) catalyst, probably via a cation-exchange mechanism. Such a sorption of the photoassisted Fenton catalyst was crucial to the heterogeneous degradation process.

  12. The effect of anodized Ti on output performance of biomedical compatible triboelectric nanogenerators used for controlling the degradation of Mg-3wt%Zn-0.8wt%Zr

    Science.gov (United States)

    Liu, Guoxu; Sun, Jing; Chen, Minfang; Zhao, Yue; Li, Wei

    2015-12-01

    Triboelectric nanogenerators (TENGs) can convert amorphous mechanical energy into electrical energy and solve the issue of source power for biological electronics implanted in the human body. Biomedical metal Ti was selected as the bottom plate, to fabricate a TENG with a poly-L-lactic-acid (PLLA) Ti structure. The Ti sheets were treated with a two-step anodization method, and the growth of titanium dioxide nanotube arrays (TNTAs) was controlled by variation in anodic oxidation time. The results showed that the output voltage and current of the PLLA-TNTAs biocompatible triboelectric nanogenerator (BCTENG), prepared by the two-step anodization method under 60 V for 6 h, can reach 220.6 V and 15.1 μA, respectively. The output voltage and current increased by 96.3% and 91.1%, respectively, compared with TENGs prepared without using the anode oxidation method. The choice of materials and modification of the surface morphology of the TENG components was found to be critical for increasing the triboelectrically generated surface charge. The output of the BCTENG can regulate degradation of magnesium alloys freely by using cathodic protection.

  13. Crystallization-mediated amorphous CuxO (x = 1, 2)/crystalline CuI p-p type heterojunctions with visible light enhanced and ultraviolet light restrained photocatalytic dye degradation performance

    Science.gov (United States)

    Wang, Hongli; Cai, Yun; Zhou, Jian; Fang, Jun; Yang, Yang

    2017-04-01

    We report simple and cost-effective fabrication of amorphous CuxO (x = 1, 2)/crystalline CuI p-p type heterojunctions based on crystallization-mediated approaches including antisolvent crystallization and crystal reconstruction. Starting from CuI acetonitrile solution, large crystals in commercial CuI can be easily converted to aggregates consisting of small particles by the crystallization processes while the spontaneous oxidation of CuI by atmospheric/dissolved oxygen can induce the formation of trace CuxO on CuI surface. As a proof of concept, the as-fabricated CuxO/CuI heterojunctions exhibit effective photocatalytic activity towards the degradation of methyl blue and other organic pollutants under visible light irradiation, although the wide band-gap semiconductor CuI is insensible to visible light. Unexpectedly, the CuxO/CuI heterojunctions exhibit restrained photocatalytic activity when ultraviolet light is applied in addition to the visible. It is suggested that the CuxO/CuI interface can enhance the spatial separation of the electron-hole pairs with the excitation of CuxO under visible light and prolong the lifetime of photogenerated charges with high redox ability. The present work represents a critically important step in advancing the crystallization technique for potential mass production of semiconductor heterojunctions in a mild manner.

  14. Degradation of α-Naphthol by Plasma in Aqueous Solution

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Degradation of α-naphthol induced by plasma in aqueous solution was investigatedin different initial concentration with contact glow discharge electrolysis(CGDE). The resultsshowed that the degradation of α-naphthol obeyed the first-rate law. Some of predominant products were analyzed by a high performance liquid chromatography (HPLC). A path of α-naphtholdisappearance caused by plasma was proposed according to the detected intermediate products.

  15. Petroleum pollutant degradation by surface water microorganisms.

    Science.gov (United States)

    Antić, Malisa P; Jovancićević, Branimir S; Ilić, Mila; Vrvić, Miroslav M; Schwarzbauer, Jan

    2006-09-01

    type petroleum, such a trend has not been observed. The most intensive degradation of n-alkanes and isoprenoid aliphatic alkanes (in paraffinic oil) and isoprenoids (in naphthenic oil) was observed using the inorganic medium Kp in the light; the microbial conversion is somewhat lower with Kp in the dark; with organic medium Bh in the light the degradation is of low intensity; with the same medium in the dark the degradation is hardly to be seen. Steranes and triterpanes were not affected by microbial degradation under the conditions used in our experiments. Obviously, the petroleum biodegradation was restricted to the acyclic aliphatics (n-alkanes and isoprenoids). Phormidium foveolarum (filamentous Cyanobacteria--blue-green algae) and Achanthes minutissima (diatoms, algae), microbial cultures isolated as dominant algae from a surface water in a wastewater canal of an oil refinery and a nitrogen plant, have degradable effects dominantly involving petroleum hydocarbons. Petroleum microbiological degradation is more intensive when inorganic medium (in the light) is applied. Having in mind that the inorganic pollutants have been released into the canal as well, this medium reflects more the natural environmental conditions. Polycyclic alkanes of sterane and triterpane type, in spite of the fact that these compounds could be degraded, have remained unchanged regarding abundance and distribution. Since this is the case even for naphthenic type petroleum (which is depleted in n-alkanes), it can be concluded that the biodegradation of petroleum type pollutants, under natural conditions, will be restrained to the n-alkane and isoprenoid degradation. Performed experiments and simulations of petroleum microbiological degradation may serve for the prediction of the fate of petroleum type pollutants, as well as for definition of conditions for bioremediation of some environmental segments.

  16. Degradation of phenol via wet-air oxidation over CuO/CeO2-ZrO2 nanocatalyst synthesized employing ultrasound energy: physicochemical characterization and catalytic performance.

    Science.gov (United States)

    Parvas, Mohsen; Haghighi, Mohammad; Allahyari, Somaiyeh

    2014-01-01

    Catalytic wet air oxidation (CWAO) of phenol was carried out under atmospheric pressure of oxygen at 160 degrees C in a stirred batch reactor over copper catalysts supported by CeO2-ZrO2. The copper with different loadings were impregnated over the composite support by a sonication process. The catalysts were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), energy dispersive X-ray analysis (EDX), Brunauer-Emmett-Teller (BET) specific surface area and Fourier-transformed infrared analyses. Characteristic peaks attributed to copper were not found in XRD patterns even at high loadings, but based on EDX results, the existence of copper particles was confirmed. It means that sonochemical synthesis method even at high loadings produced small copper particles with low crystallinity and excellent dispersion over the CeO2-ZrO2 composite. FESEM micrographs indicated just slight enhancement in particle size at high loadings of Cu. Blank CWAO experiments illustrated low conversion of phenol using bare CeO2-ZrO2 support. Although some agglomeration of particles was found at high loadings of copper but owning to the fact that almost all ZrO2 particles incorporated into the CeO2 lattice at high contents of Cu, catalyst activity not only did not decrease but also the phenol conversion reached to the higher values. The optimal catalyst loading for phenol degradation was found to be 9 g/l. Complete conversion of phenol was achieved using CuO/CeO2-ZrO2 in 9 g/l catalyst loading with initial phenol concentration of 1000 ppm after 3 h of reaction.

  17. Ecosystemic approaches to land degradation

    Energy Technology Data Exchange (ETDEWEB)

    Puigdefabregas, J.; Barrio, G. del; Hill, J.

    2009-07-01

    Land degradation is recognized as the main outcome of desertification. However available procedures for its assessment are still unsatisfactory because are often too costly for surveying large areas and rely on specific components of the degradation process without being able to integrate them in a unique process. One of the objectives of De Survey project is designing and implementing operational procedures for desertification surveillance, including land degradation. A strategic report was compiled and reproduced here for selecting the most appropriate approaches to the project conditions. The report focuses on using attributes of ecosystem maturity as a natural way to integrate the different drivers of land degradation in simple indices. The review surveys different families of attributes concerned with water and energy fluxes through the ecosystem, its capacity to sustain biomass and net primary productivity, and its capacity to structure the space. Finally, some conclusions are presented about the choice criteria of the different approaches in the framne of operational applications. (Author) 20 refs.

  18. Plant biomass degradation by fungi.

    Science.gov (United States)

    Mäkelä, Miia R; Donofrio, Nicole; de Vries, Ronald P

    2014-11-01

    Plant biomass degradation by fungi has implications for several fields of science. The enzyme systems employed by fungi for this are broadly used in various industrial sectors such as food & feed, pulp & paper, detergents, textile, wine, and more recently biofuels and biochemicals. In addition, the topic is highly relevant in the field of plant pathogenic fungi as they degrade plant biomass to either gain access to the plant or as carbon source, resulting in significant crop losses. Finally, fungi are the main degraders of plant biomass in nature and as such have an essential role in the global carbon cycle and ecology in general. In this review we provide a global view on the development of this research topic in saprobic ascomycetes and basidiomycetes and in plant pathogenic fungi and link this to the other papers of this special issue on plant biomass degradation by fungi. Copyright © 2014 Elsevier Inc. All rights reserved.

  19. Bacterial isolates degrading aliphatic polycarbonates.

    Science.gov (United States)

    Suyama, T; Hosoya, H; Tokiwa, Y

    1998-04-15

    Bacteria that degrade an aliphatic polycarbonate, poly(hexamethylene carbonate), were isolated from river water in Ibaraki. Prefecture, Japan, after enrichment in liquid medium containing poly(hexamethylene carbonate) suspensions as carbon source, and dilution to single cells. Four of the strains, 35L, WFF52, 61A and 61B2, degraded poly(hexamethylene carbonate) on agar plate containing suspended poly(hexamethylene carbonate). Degradation of poly(hexamethylene carbonate) was confirmed by gel permeation chromatography. Besides poly(hexamethylene carbonate), the strains were found to degrade poly(tetramethylene carbonate). The strains were characterized morphologically, physiologically, and by 16S rDNA sequence analysis. Strains 35L and WFF52 were tentatively identified as Pseudomonas sp. and Variovorax sp., respectively, while strains 61A and 61B2 constitute an unidentified branch within the beta subclass of the Proteobacteria.

  20. Chitin Degradation In Marine Bacteria

    DEFF Research Database (Denmark)

    Paulsen, Sara; Machado, Henrique; Gram, Lone

    2015-01-01

    Introduction: Chitin is the most abundant polymer in the marine environment and the second most abundant in nature. Chitin does not accumulate on the ocean floor, because of microbial breakdown. Chitin degrading bacteria could have potential in the utilization of chitin as a renewable carbon...... and nitrogen source in the fermentation industry.Methods: Here, whole genome sequenced marine bacteria were screened for chitin degradation using phenotypic and in silico analyses.Results: The in silico analyses revealed the presence of three to nine chitinases in each strain, however the number of chitinases...... chitin regulatory system.Conclusions: This study has provided insight into the ecology of chitin degradation in marine bacteria. It also served as a basis for choosing a more efficient chitin degrading production strain e.g. for the use of chitin waste for large-scale fermentations....

  1. [Isolation of an anthracene-degrading strain Aspergillus fumigatus A10 and its degradation characteristics].

    Science.gov (United States)

    Qiang, Jing; Yin, Hua; Peng, Hui; Ye, Jin-Shao; Qin, Hua-Ming; He, Bao-Yan; Zhang, Na

    2009-05-15

    An anthracene-degrading strain (A10) was isolated from contaminated environment and identified as Aspergillus fumigatus. The experimental results showed that the biodegradation rate of anthracene increased with the increasing time. Between 12-84 h interval, the biodegradation performed rapidly, while after this, the increase of biodegradation rate tended to become slow, and ultimately the biodegradation rate could achieve approximately 83%. The degradatinn rate of anthracene reached 79.37% within 5 days when the initial concentration of anthracene in mineral salts medium (MSM) was 10 mg/L, the inoculum dosage was 50 g/L (wet weight) and the cell age was 36 h. The concentration of anthracene had notable influence on degradation function of strain A10 and the highest degradation rate (92.17%) was achieved when anthracene concentration was 5 mg/L. The degradation rate could maintain about 60% with initial pH of MSM in the range of 5.0-7.5, and also, the anthracene could be better broken down when the temperature was 30 degrees C and dissolved oxygen was 4.30 mg/L. Certain amount of nutrition salts promoted the biodegradation of anthracene to some extent. Addition of lactose as co-metabolic substrate most favorably accelerated degradation of anthracene by about 37.15%. The mechanism research revealed that the biodegradation by strain A10 was a dynamic process in which extracellular sorption and intracellular degradation were included. FT-IR analysis exhibited that the structure of anthracene changed with the action of microbe, generating a series of metabolites, such as aromatic acid, aromatic ketone, aromatic aldehyde with one or two benzene rings, as well as saturated hydrocarbons.

  2. Mathematical modelling of paper degradation in books

    OpenAIRE

    Nimmo, A J

    2015-01-01

    Paper cannot be prevented from degrading and does not necessarily degrade uniformly across its volume. It has been established that as paper degrades, VOCs (Volatile Organic Compounds) are produced. This body of work studies paper degradation with respect to the role VOCs play. The thesis investigates how a VOC a ecting the paper's acidity can in turn a ect the degradation rate and through modelling the VOC concentration pro le, the degradation pro le is found. To create the model from a chem...

  3. Working session 1: Tubing degradation

    Energy Technology Data Exchange (ETDEWEB)

    Kharshafdjian, G. [Atomic Energy of Canada, Mississauga, Ontario (Canada); Turluer, G. [IPSN, Fontenay-aux-Roses (France)

    1997-02-01

    A general introductory overview of the purpose of the group and the general subject area of SG tubing degradation was given by the facilitator. The purpose of the session was described as to {open_quotes}develop conclusions and proposals on regulatory and technical needs required to deal with the issues of SG tubing degradation.{close_quotes} Types, locations and characteristics of tubing degradation in steam generators were briefly reviewed. The well-known synergistic effects of materials, environment, and stress and strain/strain rate, subsequently referred to by the acronym {open_quotes}MESS{close_quotes} by some of the group members, were noted. The element of time (i.e., evolution of these variables with time) was emphasized. It was also suggested that the group might want to consider the related topics of inspection capabilities, operational variables, degradation remedies, and validity of test data, and some background information in these areas was provided. The presentation given by Peter Millet during the Plenary Session was reviewed; Specifically, the chemical aspects and the degradation from the secondary side of the steam generator were noted. The main issues discussed during the October 1995 EPRI meeting on secondary side corrosion were reported, and a listing of the potential SG tube degradations was provided and discussed.

  4. Sonolytic degradation of 2-chlorobiphenyl

    Institute of Scientific and Technical Information of China (English)

    张光明; 华天星; 常爱敏

    2004-01-01

    The sonolytic degradation of 2-chlorobiphenyl was investigated. Mass spectroscopy was used to detect the products of sonolytic degradation of 2-chlorobiphenyl. The results show that the products of sonolytic degradation, such as biphenyl, ethyl benzene, diethylbiphenyl, dibutylbiphenyl, phenol, propylphenol and di-tert-butyl phenol are produced by thermolysis and hydroxyl free radical reactions, in which biphenyl counts for almost 40%(mole fraction) of the mother compound and others are at trace level. Rapid accumulation of chloride ion shows quick dechlorination, and 78% organic chlorine is converted into chloride ion. Free radical scavengers, bicarbonate and carbonate, decrease the reaction rate of sonolytic degradation of 2-chlorobiphenyl significantly, and the pseudo 1st order rate constant of sonolytic degradation of 2-chlorobiphenyl decreases linearly with the natural logarithm of the concentration of the added free radical scavenger, showing that the pyrolysis and hydroxyl free radical reaction are the two major pathways for the sonolytic degradation of 2-chlorobiphenyl, in which the hydroxyl radical concentration is estimated to be 1 × 10 10mol/L.

  5. PV Degradation Curves: Non-Linearities and Failure Modes

    Energy Technology Data Exchange (ETDEWEB)

    Jordan, Dirk C.; Silverman, Timothy J.; Sekulic, Bill; Kurtz, Sarah R.

    2016-09-03

    Photovoltaic (PV) reliability and durability have seen increased interest in recent years. Historically, and as a preliminarily reasonable approximation, linear degradation rates have been used to quantify long-term module and system performance. The underlying assumption of linearity can be violated at the beginning of the life, as has been well documented, especially for thin-film technology. Additionally, non-linearities in the wear-out phase can have significant economic impact and appear to be linked to different failure modes. In addition, associating specific degradation and failure modes with specific time series behavior will aid in duplicating these degradation modes in accelerated tests and, eventually, in service life prediction. In this paper, we discuss different degradation modes and how some of these may cause approximately linear degradation within the measurement uncertainty (e.g., modules that were mainly affected by encapsulant discoloration) while other degradation modes lead to distinctly non-linear degradation (e.g., hot spots caused by cracked cells or solder bond failures and corrosion). The various behaviors are summarized with the goal of aiding in predictions of what may be seen in other systems.

  6. Mechanism of the carbonate-based-electrolyte degradation and its effects on the electrochemical performance of Li1+x(NiaCobMn1-a-b)1-xO2 cells

    Science.gov (United States)

    Peng, H.-J.; Villevieille, C.; Trabesinger, S.; Wolf, H.; Leitner, K.; Novák, P.

    2016-12-01

    In lithium-ion batteries with carbonate electrolytes, the formation of lithium alkoxides at the anode impairs the electrochemical performance and the cycle life of the cells through destabilisation of the cathode-electrolyte interface. To fully understand the effect of electrolyte composition on the stability of the cathode-electrolyte interface, and therefore to minimise alkoxide formation and improve cycling stability, we study different carbonate solvents and mixtures thereof. Electrolytes that promote the formation of ethoxide are found to be more detrimental to the cell performance than those forming methoxide. The presence of cyclic carbonates in the electrolyte-solvent mixture alleviates the detrimental effects of ethoxide-forming solvents on the electrochemical performance of Li1.05(Ni0.33Co0.33Mn0.33)0.95O2 by reducing the solubility of the ethoxide.

  7. Performance degradation modeling based method for optimizing equipment inspection%一种基于性能退化建模的设备最优监测时机确定方法

    Institute of Scientific and Technical Information of China (English)

    张正新; 胡昌华; 周志杰; 张昭

    2012-01-01

    Aiming at overcoming the difficulty of failure data acquisition and the reasonless of inspection and maintenance strategy of long-life, high-cost, high-reliability equipment, the degradation failure process was modeled, and the reliability, as well as residual useful life was evaluated by using the periodic inspection data on the basis of drift Brownian-movement. Moreover, when the inspection and maintenance cost and reliability requirement of a equipment are considered, this paper proposed a method for best inspection interval decision-making through minimizing the unit time expect inspection and maintenance cost. The reliability, residual useful life during the storage and the best inspection interval after the last inspection of the gyroscope in an inertial platform were gained using the menstrual inspection data. And the applicability of the proposed method is validated accordingly.%为了克服长寿命、高成本、高可靠性设备失效数据获取困难和监测维护策略不合理的缺点,基于漂移布朗运动,利用设备的周期性能监测数据,对设备的退化失效过程进行建模,评估设备服役期内的可靠性、剩余有效寿命,并综合考虑设备的监测维护成本和可靠性的要求,以单位时间期望监测维护成本最小为目标,提出了确定最优监测间隔的方法.使用某型号惯性平台存储时月监测数据及提出的方法,得到了其关键部件陀螺仪的可靠性和剩余有效寿命的评估结果,以及最新监测点之后的最优监测间隔,从而验证了所提方法的有效性.

  8. Degradation of household biowaste in reactors.

    Science.gov (United States)

    Krzystek, L; Ledakowicz, S; Kahle, H J; Kaczorek, K

    2001-12-28

    Household derived biowaste was degraded by biological methods. The system involves the combined method of low-solids (up to 10% w/v of total solids (TS)) anaerobic digestion and aerobic degradation for the recovery of energy (biogas) and the production of fine humus-like material which can be used as a soil amender or a substrate for further thermal treatment (pyrolysis, gasification). The performance of batch and continuous processes carried out in bioreactors (stirred tank reactor, air-lift) of working volume 6 and 18 dm(3), at different temperatures (25-42 degrees C) was monitored by reduction of TS, volatile solids, chemical oxygen demand, total organic carbon, C/N in time. The application of continuous process with recirculation (33%) caused that for residence time of 8-16 h the obtained degree of organic load reduction was similar to that obtained after 72-96 h of the batch process. The experimental data of batch aerobic degradation was also subjected to kinetic analysis. The sequence of the two processes: aerobic and anaerobic or anaerobic and aerobic showed that the degree of organic load reduction was similar in both cases, while the amount of produced biogas was four times higher when the first stage was anaerobic. The final product after dewatering was subjected to pyrolysis and gasification. The gases obtained were characterised by a high heat of combustion of about 11-15 MJ Nm(-3).

  9. Degradation of various dyes using Laccase enzyme.

    Science.gov (United States)

    Dhaarani, S; Priya, A K; Rajan, T Vel; Kartic, D Navamani

    2012-10-01

    Disposal of untreated dyeing effluent in water bodies, from textile industries, cause serious environmental and health hazards. The chemical structures of dye molecules are designed to resist fading on exposure to light or chemical attack, and they prove to be quite resistant towards microbial degradation. Therefore, current conventional biological processes may not be able to meet wastewater discharge criteria and reuse. An enzymatic treatment undergoes oxidative cleavage avoiding formation of toxic amines. Laccase is a multi-copper containing protein that catalyzes the oxidation of a wide range of aromatic substrates concomitantly with the reduction of molecular oxygen to water. UV visible spectral analysis of various synthetic dyes was performed in the study and wavelengths of maximum absorbance determined. Laccase enzyme was obtained from the fungi Pleorotus ostreatus. The enzyme showed high efficiency against Malachite Green, Basic Red and Acid Majanta with decolorization capacities of 97%, 94% and 94% respectively. Further, these dyes can be used for optimization of degradation parameters and analysis of degradation products.

  10. DSNF AND OTHER WASTE FORM DEGRADATION ABSTRACTION

    Energy Technology Data Exchange (ETDEWEB)

    J. CUNNANE

    2004-11-19

    Several hundred distinct types of DOE-owned spent nuclear fuel (DSNF) may potentially be disposed in the Yucca Mountain repository. These fuel types represent many more types than can be viably individually examined for their effect on the Total System Performance Assessment for the License Application (TSPA-LA). Additionally, for most of these fuel types, there is no known direct experimental test data for the degradation and dissolution of the waste form in repository groundwaters. The approach used in the TSPA-LA model is, therefore, to assess available information on each of 11 groups of DSNF, and to identify a model that can be used in the TSPA-LA model without differentiating between individual codisposal waste packages containing different DSNF types. The purpose of this report is to examine the available data and information concerning the dissolution kinetics of DSNF matrices for the purpose of abstracting a degradation model suitable for use in describing degradation of the DSNF inventory in the Total System Performance Assessment for the License Application. The data and information and associated degradation models were examined for the following types of DSNF: Group 1--Naval spent nuclear fuel; Group 2--Plutonium/uranium alloy (Fermi 1 SNF); Group 3--Plutonium/uranium carbide (Fast Flux Test Facility-Test Fuel Assembly SNF); Group 4--Mixed oxide and plutonium oxide (Fast Flux Test Facility-Demonstration Fuel Assembly/Fast Flux Test Facility-Test Demonstration Fuel Assembly SNF); Group 5--Thorium/uranium carbide (Fort St. Vrain SNF); Group 6--Thorium/uranium oxide (Shippingport light water breeder reactor SNF); Group 7--Uranium metal (N Reactor SNF); Group 8--Uranium oxide (Three Mile Island-2 core debris); Group 9--Aluminum-based SNF (Foreign Research Reactor SNF); Group 10--Miscellaneous Fuel; and Group 11--Uranium-zirconium hydride (Training Research Isotopes-General Atomics SNF). The analyses contained in this document provide an &apos

  11. Redox regulation of insulin degradation by insulin-degrading enzyme.

    Directory of Open Access Journals (Sweden)

    Crystal M Cordes

    Full Text Available Insulin-degrading enzyme (IDE is a thiol sensitive peptidase that degrades insulin and amyloid β, and has been linked to type 2 diabetes mellitus and Alzheimer's disease. We examined the thiol sensitivity of IDE using S-nitrosoglutathione, reduced glutathione, and oxidized glutathione to distinguish the effects of nitric oxide from that of the redox state. The in vitro activity of IDE was studied using either partially purified cytosolic enzyme from male Sprague-Dawley rats, or purified rat recombinant enzyme. We confirm that nitric oxide inhibits the degrading activity of IDE, and that it affects proteasome activity through this interaction with IDE, but does not affect the proteasome directly. Oxidized glutathione inhibits IDE through glutathionylation, which was reversible by dithiothreitol but not by ascorbic acid. Reduced glutathione had no effect on IDE, but reacted with partially degraded insulin to disrupt its disulfide bonds and accelerate its breakdown to trichloroacetic acid soluble fragments. Our results demonstrate the sensitivity of insulin degradation by IDE to the redox environment and suggest another mechanism by which the cell's oxidation state may contribute to the development of, and the link between, type 2 diabetes and Alzheimer's disease.

  12. Photovoltaic failure and degradation modes: PV failure and degradation modes

    Energy Technology Data Exchange (ETDEWEB)

    Jordan, Dirk C. [National Renewable Energy Laboratory (NREL), 15013 Denver West Parkway Golden Colorado 80401 USA; Silverman, Timothy J. [National Renewable Energy Laboratory (NREL), 15013 Denver West Parkway Golden Colorado 80401 USA; Wohlgemuth, John H. [National Renewable Energy Laboratory (NREL), 15013 Denver West Parkway Golden Colorado 80401 USA; Kurtz, Sarah R. [National Renewable Energy Laboratory (NREL), 15013 Denver West Parkway Golden Colorado 80401 USA; VanSant, Kaitlyn T. [Colorado School of Mines, 1500 Illinois Street Golden Colorado 8040 USA

    2017-01-30

    The extensive photovoltaic field reliability literature was analyzed and reviewed. Future work is prioritized based upon information assembled from recent installations, and inconsistencies in degradation mode identification are discussed to help guide future publication on this subject. Reported failure rates of photovoltaic modules fall mostly in the range of other consumer products; however, the long expected useful life of modules may not allow for direct comparison. In general, degradation percentages are reported to decrease appreciably in newer installations that are deployed after the year 2000. However, these trends may be convoluted with varying manufacturing and installation quality world-wide. Modules in hot and humid climates show considerably higher degradation modes than those in desert and moderate climates, which warrants further investigation. Delamination and diode/j-box issues are also more frequent in hot and humid climates than in other climates. The highest concerns of systems installed in the last 10 years appear to be hot spots followed by internal circuitry discoloration. Encapsulant discoloration was the most common degradation mode, particularly in older systems. In newer systems, encapsulant discoloration appears in hotter climates, but to a lesser degree. Thin-film degradation modes are dominated by glass breakage and absorber corrosion, although the breadth of information for thin-film modules is much smaller than for x-Si.

  13. Degradation in photoelectrochemical devices: review with an illustrative case study

    Science.gov (United States)

    Nandjou, Fredy; Haussener, Sophia

    2017-03-01

    The durability, reliability, and robustness of photoelectrochemical (PEC) devices are key factors for advancing the practical large-scale implementation of cost-competitive solar fuel production. We review the known degradation mechanisms occurring in water-splitting photoelectrochemical devices. The degradation of single components is discussed in detail, and the parameters and conditions which influence it are presented. Device short-term durability depends on the semiconductor material and its interface with the electrolyte. Catalyst and electrolyte degradations are considerable challenges for long-term durability. We highlight how PEC device design choices can affect the salience of alternative degradation mechanisms. The PEC device architecture and the initial operating design point are crucial for observed device performance loss. Device degradation behavior is further impacted by irradiation intensity and concentration, and by current density and concentration. Enhancing a physical understanding of degradation phenomena and investigating their effect on component properties is of utmost importance for predicting performance loss and tackling the durability challenge of PEC devices.

  14. Biodegradability of degradable plastic waste.

    Science.gov (United States)

    Agamuthu, P; Faizura, Putri Nadzrul

    2005-04-01

    Plastic waste constitutes the third largest waste volume in Malaysian municipal solid waste (MSW), next to putrescible waste and paper. The plastic component in MSW from Kuala Lumpur averages 24% (by weight), whereas the national mean is about 15%. The 144 waste dumps in the country receive about 95% of the MSW, including plastic waste. The useful life of the landfills is fast diminishing as the plastic waste stays un-degraded for more than 50 years. In this study the compostability of polyethylene and pro-oxidant additive-based environmentally degradable plastics (EDP) was investigated. Linear low-density polyethylene (LLDPE) samples exposed hydrolytically or oxidatively at 60 degrees C showed that the abiotic degradation path was oxidative rather than hydrolytic. There was a weight loss of 8% and the plastic has been oxidized as shown by the additional carbonyl group exhibited in the Fourier transform infra red (FTIR) Spectrum. Oxidation rate seemed to be influenced by the amount of pro-oxidant additive, the chemical structure and morphology of the plastic samples, and the surface area. Composting studies during a 45-day experiment showed that the percentage elongation (reduction) was 20% for McD samples [high-density polyethylene, (HDPE) with 3% additive] and LL samples (LLDPE with 7% additive) and 18% reduction for totally degradable plastic (TDP) samples (HDPE with 3% additive). Lastly, microbial experiments using Pseudomonas aeroginosa on carbon-free media with degradable plastic samples as the sole carbon source, showed confirmatory results. A positive bacterial growth and a weight loss of 2.2% for degraded polyethylene samples were evident to show that the degradable plastic is biodegradable.

  15. [Degradation of benzothiazole in electro-assisted microbial reactor].

    Science.gov (United States)

    Liu, Chun-Miao; Ding, Jie; Liu, Xian-Shu; Cheng, Wang-Bin

    2014-11-01

    The oxidative degradation of benzothiazole (BTH) in a single-chamber electro-assisted microbial reactor was investigated. The effects of applied voltage and COD/BTH ratio on the performance of degrading benzothiazole were studied. The research showed that BTH was oxidized to 2-hydroxy-benzothiazole (OHBT), then thiazole ring scission, and BTH translated into 2-methylsulfonylaniline eventually. The degrading of benzothiazole was in conformity with the pseudo first-order kinetic model, and the pseudo first-order kinetic constant can be increased by raising the applied voltage and co-metabolism. When the applied voltage was 0.7 V and COD/BTH ratio was 30, the degradation rate was 96% in 48 h, achieving the detoxification of BTH, and that is advantageous to the biochemical treatment.

  16. Resolving Turbine Degradation

    Energy Technology Data Exchange (ETDEWEB)

    Walker, Matthew [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Kruizenga, Alan Michael [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Withey, Elizabeth Ann [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-08-01

    The supercritical carbon dioxide (S-CO2) Brayton Cycle has gained significant attention in the last decade as an advanced power cycle capable of achieving high efficiency power conversion. Sandia National Laboratories, with support from the U.S. Department of Energy Office of Nuclear Energy (US DOE-NE), has been conducting research and development in order to deliver a technology that is ready for commercialization. Root cause analysis has been performed on the Recompression Loop at Sandia National Laboratories. It was found that particles throughout the loop are stainless steel, likely alloy 316 based upon the elemental composition. Deployment of a filter scheme is underway to both protect the turbomachinery and also for purposes of determining the specific cause for the particulate. Shake down tests of electric resistance (ER) as a potential in-situ monitoring scheme shows promise in high temperature systems. A modified instrument was purchased and held at 650°C for more than 1.5 months to date without issue. Quantitative measurements of this instrument will be benchmarked against witness samples in the future, but all qualitative trends to date are as to be expected. ER is a robust method for corrosion monitoring, but very slow at responding and can take several weeks under conditions to see obvious changes in behavior. Electrochemical noise was identified as an advanced technique that should be pursued for the ability to identify transients that would lead to poor material performance.

  17. Service Degradation in Context Management Frameworks

    DEFF Research Database (Denmark)

    Shawky, Ahmed; Olsen, Rasmus Løvenstein; Pedersen, Jens Myrup

    2011-01-01

    Context aware network services are a new and inter-esting way to enhance network users experience. A context aware application/service enhances network performance in relation to dynamic context information, e.g. mobility, location and device information as it senses and reacts to environment...... changes. The reliability of the information accessed is a key factor in achieving reliable context aware application. This paper will review the service degradation in Context Management Frameworks (CMF) and the effect of high network utilization, with particular focus on the reliability of the accessed...

  18. Advanced Cell Development and Degradation Studies

    Energy Technology Data Exchange (ETDEWEB)

    J. E. O' Brien; C. M. Stoots; J. S. Herring; R. C. O' Brien; K. G. Condie; M. Sohal; G. K. Housley; J. J. Hartvigsen; D. Larsen; G. Tao; B. Yildiz; V. Sharma; P. Singh; N. Petigny; T. L. Cable

    2010-09-01

    The Idaho National Laboratory (INL) has been researching the application of solid-oxide electrolysis cells for large-scale hydrogen production from steam over a temperature range of 800 to 900ºC. From 2003 – 2009, this work was sponsored by the DOE Nuclear Hydrogen Initiative (NHI). Starting in 2010, the HTE research program has been sponsored by the Next Generation Nuclear Plant (NGNP) program. HTSE research priorities in FY10 are centered on understanding and reducing cell and stack performance degradation to an acceptable level to advance the technology readiness level of HTSE and to justify further large-scale demonstration activities. This report provides a summary of our FY10 experimental program, which has been focused on advanced cell and stack development and degradation studies. Advanced cell and stack development activities are under way at five technology partners: MSRI, Versa Power, Ceramatec, NASA Glenn, and St. Gobain. Performance evaluation of the advanced technology cells and stacks has been performed by the technology partners, by MIT and the University of Connecticut and at the INL HTE Laboratory. Summaries of these development activities and test results are presented.

  19. Hydrocarbon degradation by antarctic bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Cavanagh, J.A.E.; Nichols, P.D.; McMeekin, T.A.; Franzmann, P.D. [Univ. of Tasmania (Australia)] [and others

    1996-12-31

    Bacterial cultures obtained from sediment samples collected during a trial oil spill experiment conducted at Airport beach, Eastern Antarctica were selectively enriched for n-alkane-degrading and phenanthrenedegrading bacteria. Samples were collected from a control site and sites treated with different hydrocarbon mixtures - Special Antarctic blend (SAB), BP-Visco and orange roughy oils. One set of replicate sites was also treated with water from Organic Lake which had previously been shown to contain hydrocarbon-degrading bacteria. No viable bacteria were obtained from samples collected from sites treated with orange roughy oil. Extensive degradation of n-alkanes by enrichment cultures obtained from sites treated with SAB and BP-Visco occurred at both 25{degrees}C and 10{degrees}C. Extensive degradation of phenanthrene also occurred in enrichment cultures from these sites grown at 25{degrees}C. Concurrent increases of polar lipid in these cultures were also observed. The presence of 1,4-naphthaquinone and 1-naphthol during the growth of the cultures on phenanthrene is unusual and warrants further investigation of the mechanism of phenanthrene-degradation by these Antarctic bacteria.

  20. Analysis on the Performance Degradation of the Urban Planning Based on the Social Perspective%基于社会视角的城市规划绩效弱化分析

    Institute of Scientific and Technical Information of China (English)

    张馨心

    2013-01-01

      本文运用多学科融贯的综合研究方法,多层次、多侧面、多视角地剖析城市规划社会绩效弱化的原因,并为城市规划机制调整策略的提出提供理论支撑。论文按照提出问题——分析问题——解决问题的技术路线进行研究。参照城市规划的社会效益,发现城市规划社会绩效弱化表现在目标偏离、作用错估、权威受损与利益失衡等方面。同时,系统地分析了规划绩效弱化的原因包括对基本目标把握上的失衡、制度建设方面的不完善、学科的发展及专业队伍建设的问题以及来自规划工作领域之外的因素的影响等。在此基础上,提出了包括提高城市规划科学性以及完善城市规划制度等提升城市规划绩效的策略。%Multidisciplinary penetration into the integrated of the research methods, this paper, multi-level, many side, multiple points of view to analyze the urban planning causes weakening of social performance, and adjust the strategy for urban planning mechanism is put forward to provide theoretical support. Thesis according to ask questions - analysis problem - the technical route is studied to solve the problem. Found referring to the social benefits of urban planning, urban planning and social performance weakening performance in the target deviation, miscalculation, authority and benefit unbalance, etc. At the same time, systematical y analyses the reasons of the weakening performance planning including basic goals grasp on imbalances, imperfect system construction aspect, the development of science and professional team of the construction of the problem and the influence of factors outside the work area from planning, etc. On this basis, proposed including improving scientific urban planning and improve the system of urban planning, etc. Improve the performance of urban planning strategy.

  1. Seismic Fragility Analysis of a Degraded Condensate Storage Tank

    Energy Technology Data Exchange (ETDEWEB)

    Nie, J.; Braverman, J.; Hofmayer, C.; Choun, Y-S.; Kim, M.K.; Choi, I-K.

    2011-05-16

    The Korea Atomic Energy Research Institute (KAERI) and Brookhaven National Laboratory are conducting a collaborative research project to develop seismic capability evaluation technology for degraded structures and components in nuclear power plants (NPPs). One of the goals of this collaboration endeavor is to develop seismic fragility analysis methods that consider the potential effects of age-related degradation of structures, systems, and components (SSCs). The essential part of this collaboration is aimed at achieving a better understanding of the effects of aging on the performance of SSCs and ultimately on the safety of NPPs. A recent search of the degradation occurrences of structures and passive components (SPCs) showed that the rate of aging related degradation in NPPs was not significantly large but increasing, as the plants get older. The slow but increasing rate of degradation of SPCs can potentially affect the safety of the older plants and become an important factor in decision making in the current trend of extending the operating license period of the plants (e.g., in the U.S. from 40 years to 60 years, and even potentially to 80 years). The condition and performance of major aged NPP structures such as the containment contributes to the life span of a plant. A frequent misconception of such low degradation rate of SPCs is that such degradation may not pose significant risk to plant safety. However, under low probability high consequence initiating events, such as large earthquakes, SPCs that have slowly degraded over many years could potentially affect plant safety and these effects need to be better understood. As part of the KAERI-BNL collaboration, a condensate storage tank (CST) was analyzed to estimate its seismic fragility capacities under various postulated degradation scenarios. CSTs were shown to have a significant impact on the seismic core damage frequency of a nuclear power plant. The seismic fragility capacity of the CST was developed

  2. Radiation degradation of silk protein

    Energy Technology Data Exchange (ETDEWEB)

    Pewlong, W.; Sudatis, B. [Office of Atomic Energy for Peace, Bangkok (Thailand); Takeshita, Hidefumi; Yoshii, Fumio; Kume, Tamikazu [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment

    2000-03-01

    Silk fibroin fiber from the domesticated silkworm Bombyx mori was irradiated using an electron beam accelerator to investigate the application of the radiation degradation technique as a means to solubilize fibroin. The irradiation caused a significant degradation of the fiber. The tensile strength of fibroin fiber irradiated up to 2500 kGy decreased rapidly with increasing dose. The presence of oxygen in the irradiation atmosphere enhanced degradation of the tensile strength. The solubilization of irradiated fibroin fiber was evaluated using the following three kinds of solutions: a calcium chloride solution(CaCl{sub 2}/C{sub 2}H{sub 5}OH/H{sub 2}O=1:2:8 in mole ratio), a hydrochloric acid (0.5 N) and a distilled water. Dissolution of fibroin fiber into these solutions was significantly enhanced by irradiation. Especially, an appreciable amount of water soluble proteins was extracted by a distilled water. (author)

  3. Photocatalytic degradation investigation of dicofol

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Photocatalytic degradation of dicofol was investigated on TiO2 nano particles(TiO2-NPs)under UV light irradiation.It was shown that dicofol could be completely degraded into inorganic chloride ion under the condition of 0.25 mg/mL TiO2-NPs,2 h irradiation of 400 W high pressure mercury lamp with a wavelength of 365 nm and air at a rate of 100 mL/min.The effects of the experimental conditions,including the amount of TiO2-NPs,irradiation time and the intensity of light,were studied.The apparent photodegradation rate constant was 0.167/min under the optimal condition.The photocatalytic degradation mechanism of dicofol was also discussed.

  4. Operationalizing measurement of forest degradation

    DEFF Research Database (Denmark)

    Dons, Klaus; Smith-Hall, Carsten; Meilby, Henrik

    2015-01-01

    Quantification of forest degradation in monitoring and reporting as well as in historic baselines is among the most challenging tasks in national REDD+ strategies. However, a recently introduced option is to base monitoring systems on subnational conditions such as prevalent degradation activities....... In Tanzania, charcoal production is considered a major cause of forest degradation, but is challenging to quantify due to sub-canopy biomass loss, remote production sites and illegal trade. We studied two charcoal production sites in dry Miombo woodland representing open woodland conditions near human...... settlements and remote forest with nearly closed canopies. Supervised classification and adaptive thresholding were applied on a pansharpened QuickBird (QB) image to detect kiln burn marks (KBMs). Supervised classification showed reasonable detection accuracy in the remote forest site only, while adaptive...

  5. Degradation Processes in Corona-Charged Electret Filter-Media

    Directory of Open Access Journals (Sweden)

    Warren J. Jasper, Ph.D

    2007-12-01

    Full Text Available The degradation of filtration performance for coronachargedelectret filter media exposed to ethyl benzenewas assessed. Nonwoven corona-charged polypropylenefiber mats were exposed to ethyl-benzene using acustom made apparatus. Evaluated scenarios includedethyl-benzene vapor and liquid exposures. The filtrationperformance was evaluated using DOP as a testaerosol to measure filtration performance. It was observedthat significant filtration degradation occurredonly when liquid ethyl benzene came into direct contactwith the filter media. No significant changes in thepressure drop or filtration efficiency was observed forany of the exposure scenarios in which the fibers wereonly exposed to ethyl benzene in the vapor phase.

  6. Degradation of circulating thyroglobulin

    Energy Technology Data Exchange (ETDEWEB)

    Taura, M.; Yamashita, S.; Kubo, I.; Izumi, M.; Nagataki, S.

    1985-10-01

    In order to elucidate whether the derivatives of rat Tg in the peripheral circulation affect the results of kinetic studies of Tg, the present study was performed to investigate kinetics of rat Tg after separation of 19S Tg from its derivatives using gel-filtration. Radiolabeled Tg was obtained from thyroids of rats injected with SVI 24 hours before death, and subsequently purified by ammonium sulfate precipitation. The plasma samples obtained at varying time intervals after intravenous injection of SVI-rat Tg were fractionated on a Sephacryl S-300 column. As determined by sucrose density gradient, 99% of in vivo radiolabeled Tg was 19S. On gel-filtration, the injected labeled Tg and plasma samples obtained within two hours after injection showed a single peak in an identical area. A second peak in an area corresponding to a molecular weight of 60,000 to 70,000 appeared within six hours, and became as high as the first within 24 hours. In the second peak, 22.8% radioactivity was precipitated by anti-rat Tg antibody, and 14.4% of radioactivity of its TCA precipitate was not extracted by n-butanol. Thus, the second peak could affect the results of Tg kinetic studies which utilize TCA precipitation, n-butanol extraction or RIA procedures. The half life of rat Tg in the present study was calculated from the disappearance curves of radioactivity of 19S Tg separated from other radioactive substances.

  7. Different degradation behaviors of InGaN/GaN MQWs blue and violet LEDs

    Energy Technology Data Exchange (ETDEWEB)

    Huang Liubing [State Key Laboratory of Artificial Microstructure and Mesoscopic Physics, School of Physics, Peking University, Beijing 100871 (China); Yu Tongjun, E-mail: tongjun@pku.edu.c [State Key Laboratory of Artificial Microstructure and Mesoscopic Physics, School of Physics, Peking University, Beijing 100871 (China); Chen Zhizhong; Qin Zhixin; Yang Zhijian; Zhang Guoyi [State Key Laboratory of Artificial Microstructure and Mesoscopic Physics, School of Physics, Peking University, Beijing 100871 (China)

    2009-12-15

    InGaN/GaN multiple quantum wells (MQWs) blue and violet light-emitting diodes (LEDs) were stressed under the injection current density of 26.5 A/cm{sup 2} for about 400 h at room temperature. Degradation behaviors of blue and violet LEDs were compared. Two stages of degradation were identified in the blue and violet LEDs. At the initial stage, the violet LEDs degraded very fast, but the blue LEDs degraded relatively slow. At later stage, both blue and violet LEDs showed similar degradation rates. Analyses of the L-I and I-V characteristics revealed that the increase of effective nonradiative recombination centers in the active regions was responsible for both blue and violet LED degradations. Rapid degradation of violet LEDs at early stage resulted from dramatical increase of the effective nonradiative centers. More indium in the MQWs might be helpful for better reliability performance of blue LEDs.

  8. Photoassisted Degradation of a Herbicide Derivative, Dinoseb, in Aqueous Suspension of Titania

    Directory of Open Access Journals (Sweden)

    Niyaz A. Mir

    2012-01-01

    Full Text Available The titanium dioxide (TiO2 photoassisted degradation of herbicide dinoseb has been examined in aqueous suspensions under UV light irradiation. The degradation kinetics were studied under various conditions such as substrate concentration, type of catalyst, catalyst dosage, pH, and light intensity as well as in presence of electron acceptors such as hydrogen peroxide, potassium bromate, and potassium persulphate under continuous air purging, and the degradation rates were found to be strongly influenced by these parameters. The Degussa P25 was found to be more efficient photocatalyst as compared to other photocatalysts tested. Dinoseb was found to degrade efficiently in acidic pH and all the electron acceptors studied enhanced the degradation rate. The results manifested that the photocatalysis of dinoseb followed pseudo-first-order kinetics. A qualitative study of the degradation products generated during the process was performed by GC-MS, and a degradation mechanism was proposed.

  9. Bioenergetics and pathway of acid blue 113 degradation by Staphylococcus lentus.

    Science.gov (United States)

    Sekar, Sudharshan; Mahadevan, Surianarayanan; Shanmugam, Bhuvanesh Kumar; Mandal, Asit Baran

    2012-01-01

    Bioreaction calorimetric studies of degradation of the dye acid blue 113 by Staphylococcus lentus are reported for the first time. The heat released during the dye degradation process can be successfully measured using reaction calorimeter. Power time and oxygen uptake rate (OUR) profile followed each other suggesting that heat profiles could monitor the progress of the dye degradation in biocalorimetry. The shifts observed in power-time profile indicated three distinct phases of the bioprocess indicating simultaneous utilization of glucose (primary) and dye (secondary carbon source). Secretion of azoreductase enzyme enhanced the degradation process. Optimization of aeration and agitation rates was observed to be vital to efficient dye degradation. The degradative pathway for acid blue 113 by S. lentus was delineated via high-performance liquid chromatography (HPLC), Fourier transform infrared spectroscopy (FT-IR), and gas chromatography coupled with mass spectrometry (GC-MS) analyses. Interestingly the products of degradation were found to have low toxicity, as per cytotoxicity measurements.

  10. Bacterial degradation of fungicide captan.

    Science.gov (United States)

    Megadi, Veena B; Tallur, Preeti N; Mulla, Sikandar I; Ninnekar, Harichandra Z

    2010-12-22

    The phthalimide fungicide captan has been widely used to control plant pathogenic fungi. A strain of Bacillus circulans utilized the fungicide captan as sole source of carbon and energy. The organism degraded captan by a pathway involving its initial hydrolysis to yield cis-1,2,3,6-tetrahydrophthalimide, a compound without fungicidal activity. The formation of this compound was confirmed by HPLC, IR, NMR, and mass spectral analysis. The results also revealed that cis-1,2,3,6-tetrahydrophthalimide was further degraded to o-phthalic acid by a protocatechuate pathway. These findings indicated that there was a complete mineralization of fungicide captan by B. circulans.

  11. Generic Degraded Congiguration Probability Analysis for DOE Codisposal Waste Package

    Energy Technology Data Exchange (ETDEWEB)

    S.F.A. Deng; M. Saglam; L.J. Gratton

    2001-05-23

    In accordance with the technical work plan, ''Technical Work Plan For: Department of Energy Spent Nuclear Fuel Work Packages'' (CRWMS M&O 2000c), this Analysis/Model Report (AMR) is developed for the purpose of screening out degraded configurations for U.S. Department of Energy (DOE) spent nuclear fuel (SNF) types. It performs the degraded configuration parameter and probability evaluations of the overall methodology specified in the ''Disposal Criticality Analysis Methodology Topical Report'' (YMP 2000, Section 3) to qualifying configurations. Degradation analyses are performed to assess realizable parameter ranges and physical regimes for configurations. Probability calculations are then performed for configurations characterized by k{sub eff} in excess of the Critical Limit (CL). The scope of this document is to develop a generic set of screening criteria or models to screen out degraded configurations having potential for exceeding a criticality limit. The developed screening criteria include arguments based on physical/chemical processes and probability calculations and apply to DOE SNF types when codisposed with the high-level waste (HLW) glass inside a waste package. The degradation takes place inside the waste package and is long after repository licensing has expired. The emphasis of this AMR is on degraded configuration screening and the probability analysis is one of the approaches used for screening. The intended use of the model is to apply the developed screening criteria to each DOE SNF type following the completion of the degraded mode criticality analysis internal to the waste package.

  12. Effect of insoluble-low fermentable fiber from corn-ethanol distillation origin on energy, fiber, and amino acid digestibility, hindgut degradability of fiber, and growth performance of pigs.

    Science.gov (United States)

    Gutierrez, N A; Kerr, B J; Patience, J F

    2013-11-01

    Extensive use of corn coproducts in swine diets increases the concentration of dietary fiber, raising concerns on energy and nutrient digestibility and, ultimately, pig performance. A digestion trial was conducted to determine the effect of increasing levels of insoluble-low fermentable fiber from corn in the diet, using corn bran with solubles (CBS) from the corn-ethanol distillation industry, on digestibility of energy, fiber, and AA, and hindgut fermentation of fiber in diets fed to growing pigs. Fifteen growing pigs (BW=28.7 kg) arranged in a 3-period incomplete block design and fitted with a T-cannula in the distal ileum were provided 5 diets (n=9) containing either a corn-casein basal or the basal diet with 10, 20, 30, or 40% CBS. Fecal and ileal digesta samples were collected. Two subsequent 28-d growth trials determined the effects of increasing dietary fiber from CBS in 2 sets of 7 diets formulated either with declining (growing phase: 2,387 to 2,133 kcal NE/kg; finishing phase: 2,499 to 2,209 kcal NE/kg) or constant dietary NE (growing phase≈2,390 kcal NE/kg; finishing phase≈2,500 kcal NE/kg) on growth performance and apparent total tract digestibility (ATTD) of energy in 70 growing (BW=48.9 kg; n=10 per diet) and 70 finishing (BW=102.0 kg; n=10) pigs. Results indicated that increasing fiber from corn lowered (Pcorn also reduced ATTD of GE, DM, CP, NDF, and TDF (Pcorn, regardless of the NE content of diets. In conclusion, the dietary level of insoluble-low fermentable dietary fiber from corn origin decreased the digestibility of dietary AA, and the ability of the growing pig to ferment corn dietary fiber. In spite of the reduction in digestibility of energy and nutrients with insoluble-low fermentable fiber level from corn, growth performance was not impaired when the energy supply is adequately balanced in the diet using the NE system.

  13. Determination of efficiencies, loss mechanisms, and performance degradation factors in chopper controlled dc vehical motors. Section 2: The time dependent finite element modeling of the electromagnetic field in electrical machines: Methods and applications. Ph.D. Thesis

    Science.gov (United States)

    Hamilton, H. B.; Strangas, E.

    1980-01-01

    The time dependent solution of the magnetic field is introduced as a method for accounting for the variation, in time, of the machine parameters in predicting and analyzing the performance of the electrical machines. The method of time dependent finite element was used in combination with an also time dependent construction of a grid for the air gap region. The Maxwell stress tensor was used to calculate the airgap torque from the magnetic vector potential distribution. Incremental inductances were defined and calculated as functions of time, depending on eddy currents and saturation. The currents in all the machine circuits were calculated in the time domain based on these inductances, which were continuously updated. The method was applied to a chopper controlled DC series motor used for electric vehicle drive, and to a salient pole sychronous motor with damper bars. Simulation results were compared to experimentally obtained ones.

  14. [Degradation and biosynthesis of L-phenylalanine by chloridazon-degrading bacteria].

    Science.gov (United States)

    Buck, R; Eberspächer, J; Lingens, F

    1979-07-01

    Incubating chloridazon-degrading bacteria with L-phenylalanine leads to the accumulation of L-2,3-dihydroxyphenylalanine, o-tyrosine and m-tyrosine in the medium. Incubating the bacteria with N-acetyl-L-phenylalanine leads to N-acetyl-(2,3-dihydroxyphenyl)alanine. Using phenylacetic acid as substrate leads to the accumulation of malonic acid. The products are isolated by gel chromatography and high performance liquid chromatography. 2,3-Dihydroxy-L-phenylalanine is attacked by a catechol 2,3-dioxygenase in the presence of Fe2. An unstable yellow compound is formed in this reaction. This meta-cleavage-product is again cleaved by a hydrolase, leading to aspartic acid and 4-hydroxy-2-oxovaleric acid. Both products were isolated fromthe reaction buffer by amino acid analysis and high performance liquid chromatography. The dioxygenase and hydrolase were partially purified and characterized. A new degradation pathway for phenylalanine is discussed and compared with known pathways. The enzymes chorismate mutase, prephenate dehydratase and prephenate dehydrogenase are characterized and inhibition as well as repression are investigated. Only prephenate dehydrogenase is inhibited by phenylalanine, tyrosine and tryptophane. Chorismate mutase is repressed by phenylalanine, prephenate dehydrogenase by phenylalanine and tyrosine. Prephenate dehydratase is not repressed by aromatic amino acids. Regulation of aromatic amino acid biosynthesis in connection with phenylalanine degradation is discussed.

  15. Fungal Laccases Degradation of Endocrine Disrupting Compounds

    Directory of Open Access Journals (Sweden)

    Gemma Macellaro

    2014-01-01

    Full Text Available Over the past decades, water pollution by trace organic compounds (ng/L has become one of the key environmental issues in developed countries. This is the case of the emerging contaminants called endocrine disrupting compounds (EDCs. EDCs are a new class of environmental pollutants able to mimic or antagonize the effects of endogenous hormones, and are recently drawing scientific and public attention. Their widespread presence in the environment solicits the need of their removal from the contaminated sites. One promising approach to face this challenge consists in the use of enzymatic systems able to react with these molecules. Among the possible enzymes, oxidative enzymes are attracting increasing attention because of their versatility, the possibility to produce them on large scale, and to modify their properties. In this study five different EDCs were treated with four different fungal laccases, also in the presence of both synthetic and natural mediators. Mediators significantly increased the efficiency of the enzymatic treatment, promoting the degradation of substrates recalcitrant to laccase oxidation. The laccase showing the best performances was chosen to further investigate its oxidative capabilities against micropollutant mixtures. Improvement of enzyme performances in nonylphenol degradation rate was achieved through immobilization on glass beads.

  16. Toxicity of fluorescent tracers and their degradation byproducts

    Directory of Open Access Journals (Sweden)

    Philippe Gombert

    2017-01-01

    Full Text Available Tracer tests are frequently used to delineate catchment area of water supply springs in karstic zones. In the karstic chalk of Normandy, the main tracers used are fluorescent: uranine, sulforhodamine B, naphtionate, and Tinopal®. In this area, a statistical analysis shows that less than half of the injected tracers joins the monitored restitution points and enters the drinking water system where they undergo chlorination. Most of the injected tracers is absorbed in the rock matrix or is thrown out of the aquifer via karstic springs: then it can join superficial waters where it is degraded due to the sun and air action. The paper presents firstly the laboratory degradation of a first batch of fluorescent tracers in contact with chlorine, in order to simulate their passage through a water treatment system for human consumption. A second batch of the same tracers is subjected to agents of natural degradation: ultraviolet illumination, sunlight and air sparging. Most tracers is degraded, and toxicity and ecotoxicity tests (on rats, daphniae and algae are performed on degradation byproducts. These tests do not show any acute toxicity but a low to moderate ecotoxicity. In conclusion, the most used fluorescent tracers of the Normandy karstic chalk and their artificial and natural degradation byproducts do not exhibit significant toxicity to humans and the aquatic environment, at the concentrations generally noted at the restitution points.

  17. Plant biomass degradation by fungi

    NARCIS (Netherlands)

    Mäkelä, Miia R; Donofrio, Nicole; de Vries, Ronald P; van den Brink, J.

    2014-01-01

    Plant biomass degradation by fungi has implications for several fields of science. The enzyme systems employed by fungi for this are broadly used in various industrial sectors such as food & feed, pulp & paper, detergents, textile, wine, and more recently biofuels and biochemicals. In addition, the

  18. Polymeric Materials - introduction and degradation

    DEFF Research Database (Denmark)

    Kontogeorgis, Georgios

    1999-01-01

    These notes support the polymer part of the courses 91742 and 91762 (Materials and Corrosion/degradation of materials) taught in IFAKthey contain a short introduction on group contribution methods for estimating properties of polymers, polymer thermodynamics, viscoelasticity models as well...

  19. Methods of degrading napalm B

    Science.gov (United States)

    Tyndall, Richard L.; Vass, Arpad

    1995-01-01

    Methods of degrading napalm and/or trinitrotoluene involve contacting the waste with specific intra-amoebic isolates of ATCC 40908 and/or dispersants derived therefrom. Useful isolates include is deposited as ATCC 77529, NAP-1 deposited as ATCC 77526 and 13 deposited as ATCC 77527.

  20. Photoelectrocatalytic degradation of Rose Bengal

    Institute of Scientific and Technical Information of China (English)

    LIU Hui-ling; ZHOU Ding; LI Xiang-zhong; YUE Ping-tao

    2003-01-01

    An innovative photoelectrode, TiO2/Ti mesh electrode, was prepared by galvanostaticanodisation. The morphology and the crystalline texture of the TiO2 film on mesh electrode were examined by scanning electronic microscopy and Raman spectroscopy respectively. The examination results indicated that the structure and properties of the film depended on anodisation rate, and the anatase was the dominant component under the controlled experimental conditions. Degradation of Rose Bengal(RB) in photocatalytic(PC) and photoelectrocatalytic(PEC) reaction was investigated, the results demonstrated that electric biasing could improve the efficiency of photocatalytic reaction. The measurement results of TOC in photoelectrocatalytic degradation showed that the mineralisation of RB was complete relatively. The comparison between the degradation efficiency of RB in PEC process and that in aqueous TiO2 dispersion was conducted. The results showed that the apparent first-order rate constant of RB degradation in PEC process was larger than that in aqueous dispersion with 0.1%-0.3% TiO2 powder, but was smaller than that in aqueous dispersion with 1.0% TiO2.

  1. Environmental Degradation of Solar Reflectors

    Science.gov (United States)

    Bouquet, F. L.

    1985-01-01

    Report presents results of study of atmospheric degradation of large solar reflectors for power generators. Three general types of reflective surfaces investigated. Report also describes computer buildup and removal (by rain and dew) of contamination from reflectors. Data used to determine effects of soil buildup and best method and frequency of washing at various geographic locations.

  2. Abiotic degradation of antibiotic ionophores

    DEFF Research Database (Denmark)

    Bohn, Pernille; Bak, Søren A; Björklund, Erland

    2013-01-01

    Hydrolytic and photolytic degradation were investigated for the ionophore antibiotics lasalocid, monensin, salinomycin, and narasin. The hydrolysis study was carried out by dissolving the ionophores in solutions of pH 4, 7, and 9, followed by incubation at three temperatures of 6, 22, and 28 °C f...... because they absorb light of environmentally irrelevant wavelengths....

  3. Polymeric Materials - introduction and degradation

    DEFF Research Database (Denmark)

    Kontogeorgis, Georgios

    1999-01-01

    These notes support the polymer part of the courses 91742 and 91762 (Materials and Corrosion/degradation of materials) taught in IFAKthey contain a short introduction on group contribution methods for estimating properties of polymers, polymer thermodynamics, viscoelasticity models as well...

  4. Plant biomass degradation by fungi

    NARCIS (Netherlands)

    Mäkelä, Miia R; Donofrio, Nicole; de Vries, Ronald P; van den Brink, J.

    2014-01-01

    Plant biomass degradation by fungi has implications for several fields of science. The enzyme systems employed by fungi for this are broadly used in various industrial sectors such as food & feed, pulp & paper, detergents, textile, wine, and more recently biofuels and biochemicals. In addition, the

  5. Microcantilever sensors for fast analysis of enzymatic degradation of poly (D, L-lactide)

    DEFF Research Database (Denmark)

    Bose, Sanjukta; Keller, Stephan Sylvest; Boisen, Anja

    2015-01-01

    In this work we have performed a detailed analysis of enzymatic degradation of amorphous poly (d, l-lactide) (PDLLA) by measuring the resonance frequencies of polymer coated microcantilevers before and after degradation. The miniaturized cantilever system provides a fast analysis of the biodegrad......In this work we have performed a detailed analysis of enzymatic degradation of amorphous poly (d, l-lactide) (PDLLA) by measuring the resonance frequencies of polymer coated microcantilevers before and after degradation. The miniaturized cantilever system provides a fast analysis...... of the biodegradation rate of PDLLA with a minute amount of sample and without the need of thermal and chemical acceleration. The degradation rate of the polymer has been estimated by multilayer cantilever theory and model simulation. A bulk degradation rate of 0.24 μg mm-2 hour-1 is estimated which agrees well...

  6. A review of proton exchange membrane water electrolysis on degradation mechanisms and mitigation strategies

    Science.gov (United States)

    Feng, Qi; Yuan, Xiao-Zi; Liu, Gaoyang; Wei, Bing; Zhang, Zhen; Li, Hui; Wang, Haijiang

    2017-10-01

    Proton exchange membrane water electrolysis (PEMWE) is an advanced and effective solution to the primary energy storage technologies. A better understanding of performance and durability of PEMWE is critical for the engineers and researchers to further advance this technology for its market penetration, and for the manufacturers of PEM water electrolyzers to implement quality control procedures for the production line or on-site process monitoring/diagnosis. This paper reviews the published works on performance degradations and mitigation strategies for PEMWE. Sources of degradation for individual components are introduced. With degradation causes discussed and degradation mechanisms examined, the review emphasizes on feasible strategies to mitigate the components degradation. To avoid lengthy real lifetime degradation tests and their high costs, the importance of accelerated stress tests and protocols is highlighted for various components. In the end, R&D directions are proposed to move the PEMWE technology forward to become a key element in future energy scenarios.

  7. Responses of non-starch polysaccharide-degrading enzymes on digestibility and performance of growing pigs fed a diet based on corn, soya bean meal and Chinese double-low rapeseed meal.

    Science.gov (United States)

    Fang, Z F; Peng, J; Liu, Z L; Liu, Y G

    2007-08-01

    This study was conducted to investigate the effect of two distinct enzyme preparations on nutrients' digestibility and growth performance of growing pigs fed diets based on corn, soya bean meal and Chinese double-low rapeseed meal (DLRM). The two enzyme preparations were Enzyme R, a preparation extracted from fermentation of a non-GMO fungus Penicillum funiculosum, developed for multi-grain and multi-animal species; and Enzyme P, a xylanase preparation from Trichoderma longibrachiatum, for pigs fed corn-based diets only. Both enzymes were tested at 0, 0.25 and 0.50 g/kg feed using 70 crossbred male pigs (Large Yorkshire x Landrace) in five dietary treatments and seven replicates in each treatment, for growth period from 27 to 68 kg live weight in 49 days. Results showed that the supplementation of both enzymes (1) increased total-tract digestibility of dietary energy from 77.5% (control) to 81.4% (Enzyme R, p Enzyme P, p Enzyme R, p Enzyme P, p Enzyme R, p Enzyme P, p Enzyme R) and 2.00 (p > 0.05) and feed conversion ratio from 2.50 (control) to 2.42 (Enzyme R) and 2.36 (Enzyme P, p enzyme efficacy between the two enzyme preparations. The present study demonstrated beneficial effects of applying xylanase-based enzymes to improve feeding values of pig diets based on corn, soya bean meal and DLRM.

  8. Effects of Oil Pollutants on the Performance of Marine Benthonic Microbial Fuel Cells and Its Acceleration of Degradation%石油污染物对海底微生物燃料电池性能的影响及加速降解效应

    Institute of Scientific and Technical Information of China (English)

    孟瑶; 付玉彬; 梁生康; 陈伟; 柳昭慧

    2015-01-01

    海底石油污染物在缺氧环境下导致其生物降解过程缓慢,对海洋环境造成长期危害.本文利用海底微生物燃料电池(BMFCs)原理,尝试通过电催化作用提高海底石油污染物的降解速率.对比测试了含油电池装置(BMFCs-A)与无油电池装置(BMFCs-B)的电化学性能,研究了石油污染物对电池性能的影响;比较了含油通路(BMFCs-A)和断路状态下(BMFCs-C)的石油降解率和细菌聚集量,分析了 BMFCs 对石油污染物降解的加速作用.结果表明,BMFCs-A 和 BMFCs-B 阳极的交换电流密度分别为1.37×10-2 A·m -2和1.50×10-3 A·m -2,最大输出功率密度分别是105.79 mW·m -2和83.60 mW·m -2,BMFCs-A 装置的抗极化能力增强,交换电流密度提高近9倍,最大输出功率密度提高1.27倍. BMFCs-A 和 BMFCs-C 阳极表面的异养菌数量分别是(66±3.61)×107 CFU·g -1和(7.3±2.08)×107 CFU·g -1,细菌数量增加了8倍,高的异养菌数量导致石油降解加速进行,BMFCs 的石油降解率是自然条件下的18.7倍. BMFCs 在电化学性能提高的同时,加速石油污染物的降解.本文同时提出了一种海底微生物燃料电池对石油污染物加速降解的新模式.%Degradation of oil pollutants under the sea is slow for its oxygen-free environment which has caused long-term harm to ocean environment. This paper attempts to accelerate the degradation of the sea oil pollutants through electro catalysis by using the principle of marine benthonic microbial fuel cells (BMFCs). The influence of oil pollutants on the battery performance is innovatively explored by comparing the marine benthonic microbial fuel cells (BMFCs-A) containing oil and oil-free microbial fuel cells (BMFCs-B). The acceleration effect of BMFCs is investigated by the comparison between the oil-degrading rate and the number of heterotrophic bacteria of the BMFCs-A and BMFCs-B on their anodes. The results show that the exchange current densities in the anode of the

  9. Facile one-pot fabrication and high photocatalytic performance of vanadium doped TiO2-based nanosheets for visible-light-driven degradation of RhB or Cr(VI)

    Science.gov (United States)

    Lu, Dingze; Zhao, Bin; Fang, Pengfei; Zhai, Shengbin; Li, Delong; Chen, Zhiqiang; Wu, Wenhui; Chai, Wuqiong; Wu, Yichu; Qi, Ning

    2015-12-01

    Vanadium doped TiO2-based nanosheets (V-TNSs) with different V/Ti ratios were prepared by a facile one-pot hydrothermal method using vanadium nitrate and P25 as the vanadium precursor and titanium precursor, respectively. The results indicated that as-synthesized photocatalysts exhibited sheet-like structure with large specific surface area (270-340 cm2/g) and small thickness (4-5 nm). XPS results revealed that vanadium exists in the form of V4+ and V5+, and the binding energies of Tisbnd O bonds have been changed with the concentration of vanadium. Vanadium doping resulted in considerable enhancement of visible light absorption, red-shift, and the band-gap of photocatalysts reduced from 3.18 eV to 2.91 eV. The density functional theory (DFT) calculations for band structure and total energy also provided a good explanation and further confirmation for the experimental results. It has been found that the photo-activity increased gradually with the concentration of vanadium, and then decreased after attaining a maximum with an optimal content of vanadium at 1.0 at.% for RhB or Cr(VI). The reaction rate Kapp of 1.0%-V-TNSs are 9.27-fold and 3.26-fold as compared to undoped TNSs under UV-vis and visible light irradiation, respectively. The cyclic tests that performed six times demonstrated high stability and reusability of the photocatalysts. A possible alternate mechanism for the enhancement of the photocatalytic activity under visible-light irradiation was also proposed.

  10. The effect of protease, amylase, and nonstarch polysaccharide-degrading enzyme supplementation on nutrient utilization and growth performance of broiler chickens fed corn-soybean meal-based diets.

    Science.gov (United States)

    Kaczmarek, S A; Rogiewicz, A; Mogielnicka, M; Rutkowski, A; Jones, R O; Slominski, B A

    2014-07-01

    A study was conducted to determine if amylase and protease addition would improve nutrient digestion during the first 2 wk of growth. The experimental treatments included a control corn-soybean meal-based diet and diets supplemented with either amylase or amylase plus protease. No effect of enzyme supplementation was observed on BW gain and feed conversion ratio. This was corroborated by similar ileal starch and protein digestibility values, which averaged 96.8, 96.8, and 96.9% and 83.9, 80.1, and 79.6%, respectively, for the control and for the amylase or amylase plus protease supplemented diets. Total tract digestibility of starch averaged 97.8, 97.7 and 97.7% for the 3 diets and was followed by a similar diet with AMEn values of 3,129, 3,129, and 3,106 kcal/kg. In another study, a 2(3) factorial arrangement of 8 dietary treatments was used to evaluate the effect of corn particle size (conventional or coarse vs. fine) and the addition of a nonstarch polysaccharide enzyme, amylase, or both on growth performance and nutrient utilization of broiler chickens from 1 to 21 d of age. Chickens fed a diet containing a conventionally ground corn (geometric mean diameter of 736 µm) showed higher (P starch digestion in the upper gut. Addition of nonstarch polysaccharide enzymes was effective for both diets, with the most pronounced effects observed in feed conversion ratio for the conventional corn-containing diet (1.27 vs. 1.23) and BW gain (750 vs. 789 g/bird) for the fine corn-containing diet. This was followed by the same magnitude of difference in diet AMEn content, which increased from 2,972 to 3,042 and 2,852 to 3,009 kcal/kg following enzyme addition.

  11. Resorbable composites with bioresorbable glass fibers for load-bearing applications. In vitro degradation and degradation mechanism.

    Science.gov (United States)

    Lehtonen, Timo J; Tuominen, Jukka U; Hiekkanen, Elina

    2013-01-01

    An in vitro degradation study of three bioresorbable glass fiber-reinforced poly(l-lactide-co-dl-lactide) (PLDLA) composites was carried out in simulated body fluid (SBF), to simulate body conditions, and deionized water, to evaluate the nature of the degradation products. The changes in mechanical and chemical properties were systematically characterized over 52 weeks dissolution time to determine the degradation mechanism and investigate strength retention by the bioresorbable glass fiber-reinforced PLDLA composite. The degradation mechanism was found to be a combination of surface and bulk erosion and does not follow the typical core-accelerated degradation mechanism of poly(α-hydroxyacids). Strength retention by bioresorbable glass fiber-reinforced PLDLA composites can be tailored by changing the oxide composition of the glass fibers, but the structure-property relationship of the glass fibers has to be understood and controlled so that the phenomenon of ion leaching can be utilized to control the degradation rate. Therefore, these high performance composites are likely to open up several new possibilities for utilizing resorbable materials in clinical applications which could not be realized in the past.

  12. 高效液相色谱-质谱联用技术对缬草三酯稳定性的研究%Investigation of the long-term stability and forced degradation of valtrate by high performance liquid chromatography coupled with triple quadrupole tandem mass spectrometry

    Institute of Scientific and Technical Information of China (English)

    王菲菲; 王明娟; 张聿梅; 王琰; 于健东; 王瑞忠; 程显龙; 汪祺; 郑笑为

    2014-01-01

    Valtrate is the main drug quality control for the qualitative and quantitative analysis of Valerian medicines in the Chinese Pharmacopoeia 2010.However,valtrate is unstable under some conditions.We,for the first time,systemically evaluated the stability of two bath reference standards (RS) by high performance liquid chromatography coupled with a triple quadrupole mass spectrometer (HPLC-MS/MS).The forced degradations of valtrate were performed to evaluate its optimal storage,transportation and experiment conditions according to ICH guideline.The developed HPLC method was validated to determine the degradation products.Valtrate RS was sensitive to alkaline and thermal conditions,but it was relatively stable under acidic,oxidation and photolysis conditions.A total of nine degradation components were identified under alkaline hydrolysis (N l-N4) and thermal degradation (B1-B5).The information obtained in this work would be valuable to minimize the decomposition of valtrate during the processes of preparation,storage,distribution and utilization.It was highly suggested to store valtrate with a single dose packing in brown closed ampoule at-20 ℃C.Under the above-mentioned storage condition,valtrate could be stable for up to 3 years.%缬草三酯属于多酰基类环烯醚萜化合物.中国药典2010年版一部蜘蛛香项下收载缬草三酯作为质量控制对照品使用.然而,结构不稳定是该类对照品发放中亟待解决的问题.本文通过高效液相色谱-质谱联用的方法对缬草三酯的稳定性进行了研究.根据ICH导则要求,使用加速稳定性实验对缬草三酯适宜贮存条件、运输和实验条件进行研究.结果表明,缬草三酯在碱性和加热条件下不稳定,而在酸性、氧化和强光照射条件下保持相对稳定.实验中有九个缬草三酯降解产物被检出,其中N1-N4为碱性水解时产生,B1-B5为热降解中产生.研究结果为本对照品的稳定性分析提供了

  13. Varying Conditions for Hexanoic Acid Degradation with BioTiger™

    Energy Technology Data Exchange (ETDEWEB)

    Foreman, Koji [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Milliken, Charles [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Brigmon, Robin [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2016-07-27

    BioTiger™ (BT) is a consortium of 12 bacteria designed for petroleum waste biodegradation. BT is currently being studied and could be considered for bioremediation of the Athabasca oil sands refineries in Canada and elsewhere. The run off ponds from the petroleum extraction processes, called tailings ponds, are a mixture of polycyclic aromatic hydrocarbons, naphthenic acids, hydrocarbons, toxic chemicals like heavy metals, water, and sand. Due to environmental regulations the oil industry would like to separate and degrade the hazardous chemical species from the tailings ponds while recycling the water. It has been shown that BT at 30 C° is able to completely degrade 10 mM hexanoic acid (HA) cometabolically with 0.2% yeast extract (w/v) in 48 hours when starting at 0.4 OD 600nm. After establishing this stable degradation capability, variations were tested to explore the wider parameters of BT activity in temperature, pH, intermediate degradation, co-metabolic dependence, and transfer stability. Due to the vast differences in temperature at various points in the refineries, a wide range of temperatures were assessed. The results indicate that BT retains the ability to degrade HA, a model surrogate for tailings pond contaminants, at temperatures ranging from 15°C to 35°C. Hexanamide (HAM) was shown to be an intermediate generated during the degradation of HA in an earlier work and HAM is completely degraded after 48 hours, indicating that HAM is not the final product of HA degradation. Various replacements for yeast extract were attempted. Glucose, a carbon source; casein amino acids, a protein source; additional ammonia, mimicking known media; and additional phosphate with Wolffe’s vitamins and minerals all showed no significant degradation of HA compared to control. Decreasing the yeast extract concentration (0.05%) demonstrated limited but significant degradation. Finally, serial inoculations of BT were performed to determine the stability of degradation

  14. Varying Conditions for Hexanoic Acid Degradation with BioTiger™

    Energy Technology Data Exchange (ETDEWEB)

    Foreman, Koji [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Milliken, Charles [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Brigmon, Robin [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2016-07-27

    BioTiger™ (BT) is a consortium of 12 bacteria designed for petroleum waste biodegradation. BT is currently being studied and could be considered for bioremediation of the Athabasca oil sands refineries in Canada and elsewhere. The run-off ponds from the petroleum extraction processes, called tailings ponds, are a mixture of polycyclic aromatic hydrocarbons, naphthenic acids, hydrocarbons, toxic chemicals like heavy metals, water, and sand. Due to environmental regulations the oil industry would like to separate and degrade the hazardous chemical species from the tailings ponds while recycling the water. It has been shown that BT at 30 C° is able to completely degrade 10 mM hexanoic acid (HA) co-metabolically with 0.2% yeast extract (w/v) in 48 hours when starting at 0.4 OD 600nm. After establishing this stable degradation capability, variations were tested to explore the wider parameters of BT activity in temperature, pH, intermediate degradation, co-metabolic dependence, and transfer stability. Due to the vast differences in temperature at various points in the refineries, a wide range of temperatures were assessed. The results indicate that BT retains the ability to degrade HA, a model surrogate for tailings pond contaminants, at temperatures ranging from 15°C to 35°C. Hexanamide (HAM) was shown to be an intermediate generated during the degradation of HA in an earlier work and HAM is completely degraded after 48 hours, indicating that HAM is not the final product of HA degradation. Various replacements for yeast extract were attempted. Glucose, a carbon source; casein amino acids, a protein source; additional ammonia, mimicking known media; and additional phosphate with Wolffe’s vitamins and minerals all showed no significant degradation of HA compared to control. Decreasing the yeast extract concentration (0.05%) demonstrated limited but significant degradation. Finally, serial inoculations of BT were performed to determine the stability of degradation

  15. Ciprofloxacin in hospital effluent: degradation by ozone and photoprocesses.

    Science.gov (United States)

    Vasconcelos, Tibiriçá G; Kümmerer, Klaus; Henriques, Danielle M; Martins, Ayrton F

    2009-09-30

    There are several papers in the literature that have recorded satisfactory results for the degradation of different pharmaceuticals in aqueous solutions by means of oxidation processes; however, only a few of them relied on real samples in carrying out their investigations. This study examines the results of the performance of photo-induced oxidation, heterogeneous photocatalysis, ozonation and peroxone in degrading the fluoroquinolone antimicrobial ciprofloxacin (CIP) in a hospital effluent. The real samples were collected from the treatment system of the University Hospital of Santa Maria (HUSM). Liquid chromatography with fluorescence detection (LC-FLD) was used to monitor the decrease of the CIP concentration. As expected, photo-induced oxidation was much slower than the other processes in bringing about total CIP degradation. Both heterogeneous photocatalysis and peroxone led to almost complete CIP degradation after 60 min treatment. Ozonation showed the best performance: total degradation after 30 min treatment. This was an unexpected result in view of the greater capacity of the other two processes to generate hydroxyl radicals. However, this finding supports a result in the literature that has tended to be overlooked. The by-products formed during the application of the processes were found to be very similar. Moreover, on the basis of the data obtained from the literature, there is some evidence to suggest that the by-products are derived from the oxidation of the piperazine group.

  16. Photocatalytic degradation of atrazine by porphyrin and phthalocyanine complexes.

    Science.gov (United States)

    Héquet, V; Le Cloirec, P; Gonzalez, C; Meunier, B

    2000-08-01

    This study principally focused on a new kind of photochemical reaction catalyst: porphyrin and phthalocyanine complexes. In a first step, the preparation of the catalysts was optimized. A resin has been chosen to be the support of the complexes. Efficiency of catalytic activity is performed on the degradation of a pesticide: atrazine. The best atrazine degradation occurs with 4.6% of complexes versus substrate. The role of the surface has also been shown to be important. Then, their performances were demonstrated in terms of kinetics and degradation routes, compared to a classical catalyst: titanium dioxide. This study seeks to assess the efficiency of these systems both in a mercury lamp reactor and under solar irradiation which reduces energy costs. The best atrazine degradation half-life found for the complexes is about 200 min with the iron phthalocyanine. These catalysts exhibit particular oxidation activities. Indeed, the degradation routes have been found different between the semi-conductor and the metallic complexes. These complexes are able to cleave the triazinic ring more efficiently than the titanium dioxide.

  17. Resistance to peroxide degradation of Hyflon ® Ion membranes

    Science.gov (United States)

    Merlo, L.; Ghielmi, A.; Cirillo, L.; Gebert, M.; Arcella, V.

    Perfluorosulfonic acid (PFSA) membranes have been used for 40 years as solid electrolytes in low temperature fuel cells and are considered from the scientific community superior to other polymeric products due to their good combination between chemical resistance and proton conductivity. In recent years, development of the class of PFSA membranes known as 'short side chain' membranes has been restarted from Solvay Solexis (Hyflon ® Ion). Although PFSA are highly stable, still, decay in fuel cell performance might be detected over time due to membrane degradation, especially under certain working conditions. Different degradation mechanisms, mainly based on Nafion ® structure, have been proposed by several Authors and both ex situ and in situ test protocols have been developed to perform accelerated testing. The generally accepted opinion is that the degradation problem is mostly related to peroxide radical attack. A short review of the degradation mechanisms is first presented in this work. For the first time a campaign of chemical degradation tests (open circuit voltage fuel cell operation and ex situ Fenton tests) on the short-side-chain PFSA is presented and discussed, both for standard extruded and chemical stabilized membranes.

  18. Enhanced regeneration of degraded polymer solar cells by thermal annealing

    Science.gov (United States)

    Kumar, Pankaj; Bilen, Chhinder; Feron, Krishna; Zhou, Xiaojing; Belcher, Warwick J.; Dastoor, Paul C.

    2014-05-01

    The degradation and thermal regeneration of poly(3-hexylethiophene) (P3HT):[6,6]-phenyl-C61-butyric acid methyl ester (PCBM) and P3HT:indene-C60 bisadduct (ICBA) polymer solar cells, with Ca/Al and Ca/Ag cathodes and indium tin oxide/poly(ethylene-dioxythiophene):polystyrene sulfonate anode have been investigated. Degradation occurs via a combination of three primary pathways: (1) cathodic oxidation, (2) active layer phase segregation, and (3) anodic diffusion. Fully degraded devices were subjected to thermal annealing under inert atmosphere. Degraded solar cells possessing Ca/Ag electrodes were observed to regenerate their performance, whereas solar cells having Ca/Al electrodes exhibited no significant regeneration of device characteristics after thermal annealing. Moreover, the solar cells with a P3HT:ICBA active layer exhibited enhanced regeneration compared to P3HT:PCBM active layer devices as a result of reduced changes to the active layer morphology. Devices combining a Ca/Ag cathode and P3HT:ICBA active layer demonstrated ˜50% performance restoration over several degradation/regeneration cycles.

  19. Practical vision based degraded text recognition system

    Science.gov (United States)

    Mohammad, Khader; Agaian, Sos; Saleh, Hani

    2011-02-01

    Rapid growth and progress in the medical, industrial, security and technology fields means more and more consideration for the use of camera based optical character recognition (OCR) Applying OCR to scanned documents is quite mature, and there are many commercial and research products available on this topic. These products achieve acceptable recognition accuracy and reasonable processing times especially with trained software, and constrained text characteristics. Even though the application space for OCR is huge, it is quite challenging to design a single system that is capable of performing automatic OCR for text embedded in an image irrespective of the application. Challenges for OCR systems include; images are taken under natural real world conditions, Surface curvature, text orientation, font, size, lighting conditions, and noise. These and many other conditions make it extremely difficult to achieve reasonable character recognition. Performance for conventional OCR systems drops dramatically as the degradation level of the text image quality increases. In this paper, a new recognition method is proposed to recognize solid or dotted line degraded characters. The degraded text string is localized and segmented using a new algorithm. The new method was implemented and tested using a development framework system that is capable of performing OCR on camera captured images. The framework allows parameter tuning of the image-processing algorithm based on a training set of camera-captured text images. Novel methods were used for enhancement, text localization and the segmentation algorithm which enables building a custom system that is capable of performing automatic OCR which can be used for different applications. The developed framework system includes: new image enhancement, filtering, and segmentation techniques which enabled higher recognition accuracies, faster processing time, and lower energy consumption, compared with the best state of the art published

  20. Analysing degradation effects in charge-redistribution SAR ADCs

    NARCIS (Netherlands)

    Khan, M.A.; Kerkhoff, Hans G.

    2013-01-01

    Aging-sensitive technology nodes that are resulting in performance degradations in their electronic system implementations require aging simulations in advance for a more dependable design. Simulating time-domain aging effects in these electronic systems, especially in complex analog and mixed-signa

  1. Analysing degradation effects in charge-redistribution SAR ADCs

    NARCIS (Netherlands)

    Khan, Muhammad Aamir; Kerkhoff, Hans G.

    2013-01-01

    Aging-sensitive technology nodes that are resulting in performance degradations in their electronic system implementations require aging simulations in advance for a more dependable design. Simulating time-domain aging effects in these electronic systems, especially in complex analog and mixed-signa

  2. Enhanced degradation of phenol by Sphingomonas sp. GY2B with resistance towards suboptimal environment through adsorption on kaolinite.

    Science.gov (United States)

    Gong, Beini; Wu, Pingxiao; Huang, Zhujian; Li, Yuewu; Dang, Zhi; Ruan, Bo; Kang, Chunxi; Zhu, Nengwu

    2016-04-01

    The effects of clay minerals on microbial degradation of phenol under unfavorable environmental conditions were investigated. Degradation of phenol by Sphingomonas sp. GY2B adsorbed on kaolinite, montmorillonite, and vermiculite were evaluated in comparison with free bacteria under optimal conditions. Kaolinite was found to be the most effective in accelerating degradation rate (reducing the degradation time) as well as improving degradation efficiency (increasing the percentage of phenol degraded), with GY2B/kaolinite complex achieving a degradation efficiency of 96% within 6 h. GY2B adsorbed on kaolinite was more competent than free GY2B in degradation under conditions with high phenol concentrations and at alkaline pH. Kaolinite reduced the time required for degradation by 8-12 h and improved the degradation efficiency by as much as 82% at high phenol concentrations. Meanwhile, the GY2B/kaolinite complex reduced the degradation time by 24 h and improved the degradation efficiency by 46% at pH 12. The improvement was partially due to the buffering effects of kaolinite. It was also shown that Cr(VI) and kaolinite synergistically enhanced the degradation by GY2B, with Cr(VI) and kaolinite both increasing the degradation rate and kaolinite being primarily responsible for enhanced degradation efficiency. These results showed one of the common clay minerals, kaolinite, is able to significantly improve the microbial degradation performance, and protect microorganisms against unfavorable environment. Kaolinite can collaborate with Cr(VI) to further improve the microbial degradation performance. It is implied that clay minerals have great potential to be applied in enhancing the biodegradation of phenol.

  3. Avaliação de híbridos de milho obtidos do cruzamento entre linhagens com diferentes níveis de degradabilidade da matéria seca Performance of corn hybrids obtained from crosses of lines with different dry matter degradabilities

    Directory of Open Access Journals (Sweden)

    Marcelo Cruz Mendes

    2008-01-01

    matter degradation (DEF of the whole plant. This investigation had the objective of evaluating agronomic, bromatologic, and rumen degradability of dry matter of commercial corn hybrids, recommended for silage production, and also experimental hybrids from crosses of lines of high and low degradability. It was evaluated the performance of eighteen experimental hybrids and five commercial hybrids recommend for silage production. The experiment was established in 2003/2004 crop season in randomized block design with three replications. The experimental plot was constituted of four rows 5.0 meters long. Corn plants were harvested at 20 cm from soil level at milk line at half grain stage. The silages were incubated in situ for 0, 6, 12, 24 and 96 hours in the rumen of three fistulated cows. Effective degradability was calculated based on 0.05%/h of passage rate. It was observed that among cultivars there were hybrids, that present good potential for silage production with high effective matter degradation (DEF of the whole plant, independently of grain texture. The strategy of synthesizing hybrids aiming at high dry matter effective degradability based on lines with high DEF is correct. The low correlation between effective degradability with a agronomic, and bromatologic characteristics indicate the need for better use of DEF in order to select corn hybrids of high quality of silage production.

  4. Learner intuitions about energy degradation

    CERN Document Server

    Daane, Abigail R; Vokos, Stamatis

    2013-01-01

    A primary learning goal for energy in K-12 science instruction is that energy cannot be created or destroyed. However, learners' everyday ideas about energy often involve energy being "used up" or "wasted." In physics, the concept of energy degradation can connect those everyday ideas to the principle of energy conservation. Learners' spontaneous discussions of aspects of energy degradation and the second law of thermodynamics include ideas concerning the inaccessibility, usefulness and dispersion of energy. These ideas have motivated us to introduce new learning goals into our K-12 teacher professional development courses. We identify alignments between these learning goals and learners' informal ideas and discuss instructional implications created by these alignments. Our aim is to create stronger ties between formal physics knowledge and sociopolitical issues by making these learning goals a priority in our professional development.

  5. Radiation degradation of silk protein

    Energy Technology Data Exchange (ETDEWEB)

    Wachiraporn Pewlong; Boonya Sudatis [Office of Atomic Energy for Peace, Bangkok (Thailand); Takeshita, Hidefumi; Yoshii, Fumio; Kume, Tamikazu [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment

    2000-09-01

    Silk fibroin fiber from the domesticated silkworm Bombyx mori was irradiated in the dose range up to 2500 kGy using an electron beam accelerator to apply the radiation degradation technique as a means to solubilize fibroin. The tensile strength of irradiated fibroin fiber decreased with increasing dose and the presence of oxygen in the irradiation atmosphere enhanced the degradation. The solubilization of irradiated fibroin fiber was evaluated using the following three kinds of solutions: calcium chloride solution (CaCl{sub 2}/C{sub 2}H{sub 5}OH/H{sub 2}O = 1 : 2 : 8 in mole ratio), hydrochloric acid (0.5N) and distilled water. Dissolution of fibroin fiber into these solutions was significantly enhanced by irradiation. Especially, an appreciable amount of water-soluble protein was extracted by distilled water. (author)

  6. Microstructural degradation in compound tubes

    Energy Technology Data Exchange (ETDEWEB)

    Salonen, J.; Auerkari, P. [VTT Manufacturing Technology, Espoo (Finland)

    1996-12-31

    In order to quantify microstructural degradation at high temperatures, samples of SA 210 / AISI 304 L compound tube material were annealed in the temperature range 540-720 deg C for 1 to 1 000 hours. The hardness of the annealed material was measured and the micro structure of the samples was investigated with optical and scanning electron microscopy. Microstructural degradation was characterised by the carbide structure in the ferritic-pearlitic base material and by the depth of decarburised and carburised zones of the compound tube interface. The observed changes were quantified in terms of their time and temperature dependence and diffusion coefficients of the process. The results can be used in estimating the extent of thermal exposure of high-temperature components after long-term service or after incidences of overheating. (orig.) (4 refs.)

  7. PEM Degradation Investigation Final Technical Report

    Energy Technology Data Exchange (ETDEWEB)

    Dan Stevenson; Lee H Spangler

    2010-10-18

    This project conducted fundamental studies of PEM MEA degradation. Insights gained from these studies were disseminated to assist MEA manufacturers in understanding degradation mechanisms and work towards DOE 2010 fuel cell durability targets.

  8. Assessment of Land Degradation and Soil Conservation ...

    African Journals Online (AJOL)

    Assessment of Land Degradation and Soil Conservation Management Practices ... Journal of Environmental Extension ... chemical and biological perspectives: The farmers are aware of the effects of land degradation on crop production.

  9. Experimental studies on urea degradation in seawater

    Digital Repository Service at National Institute of Oceanography (India)

    Rajendran, A.; Joseph, T.; Reddy, C.V.G.

    The rate of urea degradation in seawater was studied under various conditions and the kinetics of urea degradation was evaluated. Urea decomposition experiments showed that the rates and quantity of ammonium oxidation were slower in the relatively...

  10. Mechanical Properties of Degraded PMR-15 Resin

    Science.gov (United States)

    Tsuji, Luis C.

    2000-01-01

    Thermo-oxidative aging produces a nonuniform degradation state in PMR-15 resin. A surface layer, usually attributed to oxidative degradation, forms. This surface layer has different properties from the inner material. A set of material tests was designed to separate the properties of the oxidized surface layer from the properties of interior material. Test specimens were aged at 316 C in either air or nitrogen, for durations of up to 800 hr. The thickness of the oxidized surface layer in air aged specimens, and the shrinkage and coefficient of thermal expansion (CTE) of nitrogen aged specimens were measured directly. The nitrogen-aged specimens were assumed to have the same properties as the interior material in the air-aged specimens. Four-point-bend tests were performed to determine modulus of both the oxidized surface layer and the interior material. Bimaterial strip specimens consisting of oxidized surface material and unoxidized interior material were constructed and used to determine surface layer shrinkage and CTE. Results confirm that the surface layer and core materials have substantially different properties.

  11. Review on biological degradation of mycotoxins

    Directory of Open Access Journals (Sweden)

    Cheng Ji

    2016-09-01

    Full Text Available The worldwide contamination of feeds and foods with mycotoxins is a significant problem. Mycotoxins pose huge health threat to animals and humans. As well, mycotoxins bring enormous economic losses in food industry and animal husbandry annually. Thus, strategies to eliminate or inactivate mycotoxins in food and feed are urgently needed. Traditional physical and chemical methods have some limitations such as limited efficacy, safety issues, losses in the nutritional value and the palatability of feeds, as well as the expensive equipment required to implement these techniques. Biological degradation of mycotoxins has shown promise because it works under mild, environmentally friendly conditions. Aflatoxin (AF, zearalenone (ZEA and deoxynivalenol (DON are considered the most economically important mycotoxins in terms of their high prevalence and significant negative effects on animal performance. Therefore, this review will comprehensively describe the biological degradation of AF, ZEA and DON by microorganisms (including fungi and bacteria and specific enzymes isolated from microbial systems that can convert mycotoxins with varied efficiency to non- or less toxic products. Finally, some strategies and advices on existing difficulties of biodegradation research are also briefly proposed in this paper.

  12. Degradation of bulk diffusion length in CZ silicon solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Reiss, J.H.; King, R.R.; Mitchell, K.W. [Siemens Solar Industries, Camarillo, CA (United States)

    1995-08-01

    Commercially-produced, unencapsulated, CZ silicon solar cells can lose 3 to 4% of their initial efficiency after exposure to light. After this initial, rapid ( < 30 min.) decrease, the cell power output remains stable. The cell performance recovers in a matter of hours in the dark at room temperature, and degrades again under light exposure. The different conditions under which CZ silicon cells degrade, and the reverse process, annealing, are characterized with the methods of spectral response and current-voltage (I-V) measurements. Iron impurities are a possible cause of this effect.

  13. Degradation nonuniformity in the solar diffuser bidirectional reflectance distribution function.

    Science.gov (United States)

    Sun, Junqiang; Chu, Mike; Wang, Menghua

    2016-08-01

    The assumption of angular dependence stability of the solar diffuser (SD) throughout degradation is critical to the on-orbit calibration of the reflective solar bands (RSBs) in many satellite sensors. Recent evidence has pointed to the contrary, and in this work, we present a thorough investigative effort into the angular dependence of the SD degradation for the Visible Infrared Imaging Radiometer Suite (VIIRS) onboard the Suomi National Polar-orbiting Partnership (SNPP) satellite and for the twin Moderate-resolution Imaging Spectroradiometer (MODIS) onboard Terra and Aqua spacecrafts. One common key step in the RSB calibration is the use of the SD degradation performance measured by an accompanying solar diffuser stability monitor (SDSM) as a valid substitute for the SD degradation factor in the direction of the RSB view. If SD degradations between these two respective directions do not maintain the same relative relationship over time, then the unmitigated use of the SDSM-measured SD degradation factor in the RSB calibration calculation will generate bias, and consequently, long-term drift in