Decomposition based parallel processing technique for efficient collaborative optimization

International Nuclear Information System (INIS)

Park, Hyung Wook; Kim, Sung Chan; Kim, Min Soo; Choi, Dong Hoon

2000-01-01

In practical design studies, most of designers solve multidisciplinary problems with complex design structure. These multidisciplinary problems have hundreds of analysis and thousands of variables. The sequence of process to solve these problems affects the speed of total design cycle. Thus it is very important for designer to reorder original design processes to minimize total cost and time. This is accomplished by decomposing large multidisciplinary problem into several MultiDisciplinary Analysis SubSystem (MDASS) and processing it in parallel. This paper proposes new strategy for parallel decomposition of multidisciplinary problem to raise design efficiency by using genetic algorithm and shows the relationship between decomposition and Multidisciplinary Design Optimization(MDO) methodology

Parallel processing based decomposition technique for efficient collaborative optimization

International Nuclear Information System (INIS)

Park, Hyung Wook; Kim, Sung Chan; Kim, Min Soo; Choi, Dong Hoon

2001-01-01

In practical design studies, most of designers solve multidisciplinary problems with large sized and complex design system. These multidisciplinary problems have hundreds of analysis and thousands of variables. The sequence of process to solve these problems affects the speed of total design cycle. Thus it is very important for designer to reorder the original design processes to minimize total computational cost. This is accomplished by decomposing large multidisciplinary problem into several MultiDisciplinary Analysis SubSystem (MDASS) and processing it in parallel. This paper proposes new strategy for parallel decomposition of multidisciplinary problem to raise design efficiency by using genetic algorithm and shows the relationship between decomposition and Multidisciplinary Design Optimization(MDO) methodology

In situ measurement of the effect of LiOH on the stability of zircaloy-2 surface film in PWR water

International Nuclear Information System (INIS)

Saario, T.; Taehtinen, S.

1997-01-01

Surface films on the metals play a major role in corrosion assisted cracking. A new method called Contact Electric Resistance (CER) method has been recently developed for in situ measurement of the electric resistance of surface films in high temperature and high pressure environments. The technique has been used to determine in situ the electric resistance of films on metals when in contact with water and dissolved anions, during formation and destruction of oxides and hydrides and during electroplating of metals. Electric resistance data can be measured with a frequency of the order of one hertz, which makes it possible to investigate in situ the kinetics of surface film related processes which are dependent on the environment, temperature, pH and electrochemical potential. This paper presents the results of the CER investigation on the effects of LiOH on the stability of Zircaloy-2 surface film in water with 2000 ppm H 3 BO 3 . At 300 deg. C the LiOH concentrations higher than 10 -2 M (roughly 70 ppm of Li + ) were found to markedly reduce the electric resistance of the Zircaloy-2 surface film during a test period of less than two hours. The decrease of the film resistance is very abrupt, possibly indicating a phase transformation. Moreover, the advantages of the CER technique over the other competing techniques which rely on the measurement of current are discussed. (author)

In situ measurement of the effect of LiOH on the stability of zircaloy-2 surface film in PWR water

Energy Technology Data Exchange (ETDEWEB)

Saario, T; Taehtinen, S [Technical Research Centre of Finland, Espoo (Finland)

1997-02-01

Surface films on the metals play a major role in corrosion assisted cracking. A new method called Contact Electric Resistance (CER) method has been recently developed for in situ measurement of the electric resistance of surface films in high temperature and high pressure environments. The technique has been used to determine in situ the electric resistance of films on metals when in contact with water and dissolved anions, during formation and destruction of oxides and hydrides and during electroplating of metals. Electric resistance data can be measured with a frequency of the order of one hertz, which makes it possible to investigate in situ the kinetics of surface film related processes which are dependent on the environment, temperature, pH and electrochemical potential. This paper presents the results of the CER investigation on the effects of LiOH on the stability of Zircaloy-2 surface film in water with 2000 ppm H{sub 3}BO{sub 3}. At 300 deg. C the LiOH concentrations higher than 10{sup -2} M (roughly 70 ppm of Li{sup +}) were found to markedly reduce the electric resistance of the Zircaloy-2 surface film during a test period of less than two hours. The decrease of the film resistance is very abrupt, possibly indicating a phase transformation. Moreover, the advantages of the CER technique over the other competing techniques which rely on the measurement of current are discussed. (author).

The processing of aluminum gasarites via thermal decomposition of interstitial hydrides

Science.gov (United States)

Licavoli, Joseph J.

Gasarite structures are a unique type of metallic foam containing tubular pores. The original methods for their production limited them to laboratory study despite appealing foam properties. Thermal decomposition processing of gasarites holds the potential to increase the application of gasarite foams in engineering design by removing several barriers to their industrial scale production. The following study characterized thermal decomposition gasarite processing both experimentally and theoretically. It was found that significant variation was inherent to this process therefore several modifications were necessary to produce gasarites using this method. Conventional means to increase porosity and enhance pore morphology were studied. Pore morphology was determined to be more easily replicated if pores were stabilized by alumina additions and powders were dispersed evenly. In order to better characterize processing, high temperature and high ramp rate thermal decomposition data were gathered. It was found that the high ramp rate thermal decomposition behavior of several hydrides was more rapid than hydride kinetics at low ramp rates. This data was then used to estimate the contribution of several pore formation mechanisms to the development of pore structure. It was found that gas-metal eutectic growth can only be a viable pore formation mode if non-equilibrium conditions persist. Bubble capture cannot be a dominant pore growth mode due to high bubble terminal velocities. Direct gas evolution appears to be the most likely pore formation mode due to high gas evolution rate from the decomposing particulate and microstructural pore growth trends. The overall process was evaluated for its economic viability. It was found that thermal decomposition has potential for industrialization, but further refinements are necessary in order for the process to be viable.

LiOH - H2O2 - H2O trinary system study for the selection of optimal conditions of lithium peroxide synthesis

International Nuclear Information System (INIS)

Nefedov, R A; Ferapontov, Yu A; Kozlova, N P

2016-01-01

Using solubility method the decay kinetics of peroxide products contained in liquid phase of LiOH - H 2 O 2 - H 2 O trinary system with 2 to 6% by wt hydrogen peroxide content in liquid phase in 21 to 33 °C temperature range has been studied. Conducted studies have allowed to determine temperature and concentration limits of solid phase existence of Li 2 O 2 ·H 2 O content, distinctness of which has been confirmed using chemical and qualitative X- ray phase analysis. Stabilizing effect of solid phase of Li 2 O 2 ·H 2 O content on hydrogen peroxide decay contained in liquid phase of LiOH - H 2 O 2 - H 2 O trinary system under conditions of experiments conducted has been shown. (paper)

LiOH - H2O2 - H2O trinary system study for the selection of optimal conditions of lithium peroxide synthesis

Science.gov (United States)

Nefedov, R. A.; Ferapontov, Yu A.; Kozlova, N. P.

2016-01-01

Using solubility method the decay kinetics of peroxide products contained in liquid phase of LiOH - H2O2 - H2O trinary system with 2 to 6% by wt hydrogen peroxide content in liquid phase in 21 to 33 °C temperature range has been studied. Conducted studies have allowed to determine temperature and concentration limits of solid phase existence of Li2O2·H2O content, distinctness of which has been confirmed using chemical and qualitative X- ray phase analysis. Stabilizing effect of solid phase of Li2O2·H2O content on hydrogen peroxide decay contained in liquid phase of LiOH - H2O2 - H2O trinary system under conditions of experiments conducted has been shown.

Cascade reactor: granule fabrication processes

International Nuclear Information System (INIS)

Erlandson, O.D.; Winkler, E.O.; Maya, I.; Pitts, J.H.

1985-01-01

A key feature of Cascade is the granular blanket. Of the many blanket material options open to Cascade, fabrication of Li 2 O granules was felt to offer the greatest challenge. The authors explored available methods for initial Li 2 O granule fabrication. They identified three cost-effective processes for fabricating Li 2 O granules: the VSM drop-melt furnace process, which is based on melting and spheroidizing irregularly shaped Li 2 O feed granules; the LiOH process, which spheroidizes liquefied LiOH and uses GA Technologies' sphere-forming procedures; and the Li 2 CO 3 sol-gel process, used for making spherical fuel particles for the high-temperature gas-cooled reactor (HTGR). Each process is described below

Decomposition of Variance for Spatial Cox Processes.

Science.gov (United States)

Jalilian, Abdollah; Guan, Yongtao; Waagepetersen, Rasmus

2013-03-01

Spatial Cox point processes is a natural framework for quantifying the various sources of variation governing the spatial distribution of rain forest trees. We introduce a general criterion for variance decomposition for spatial Cox processes and apply it to specific Cox process models with additive or log linear random intensity functions. We moreover consider a new and flexible class of pair correlation function models given in terms of normal variance mixture covariance functions. The proposed methodology is applied to point pattern data sets of locations of tropical rain forest trees.

Capturing molecular multimode relaxation processes in excitable gases based on decomposition of acoustic relaxation spectra

Science.gov (United States)

Zhu, Ming; Liu, Tingting; Wang, Shu; Zhang, Kesheng

2017-08-01

Existing two-frequency reconstructive methods can only capture primary (single) molecular relaxation processes in excitable gases. In this paper, we present a reconstructive method based on the novel decomposition of frequency-dependent acoustic relaxation spectra to capture the entire molecular multimode relaxation process. This decomposition of acoustic relaxation spectra is developed from the frequency-dependent effective specific heat, indicating that a multi-relaxation process is the sum of the interior single-relaxation processes. Based on this decomposition, we can reconstruct the entire multi-relaxation process by capturing the relaxation times and relaxation strengths of N interior single-relaxation processes, using the measurements of acoustic absorption and sound speed at 2N frequencies. Experimental data for the gas mixtures CO2-N2 and CO2-O2 validate our decomposition and reconstruction approach.

Raman spectra from very concentrated aqueous NaOH and from wet and dry, solid, and anhydrous molten, LiOH, NaOH, and KOH.

Science.gov (United States)

Walrafen, George E; Douglas, Rudolph T W

2006-03-21

High-temperature, high-pressure Raman spectra were obtained from aqueous NaOH solutions up to 2NaOHH2O, with X(NaOH)=0.667 at 480 K. The spectra corresponding to the highest compositions, X(NaOH)> or =0.5, are dominated by H3O2-. An IR xi-function dispersion curve for aqueous NaOH, at 473 K and 1 kbar, calculated from the data of Franck and Charuel indicates that the OH- ion forms H3O2- by preferential H bonding with nonhydrogen-bonded OH groups. Raman spectra from wet to anhydrous, solid LiOH, NaOH, and KOH yield sharp, symmetric OH- stretching peaks at 3664, 3633, and 3596 cm(-1), respectively, plus water-related, i.e., H3O2-, peaks near LiOH, 3562 cm(-1), NaOH, 3596 cm(-1), and, KOH, 3500 cm(-1). Absence of H3O2- peaks from the solid assures that the corresponding melt is anhydrous. Raman spectra from the anhydrous melts yield OH- stretching peak frequencies: LiOH, 3614+/-4 cm(-1), 873 K; NaOH, 3610+/-2 cm(-1), 975 K; and, KOH, 3607+/-2 cm(-1), 773 K, but low-frequency asymmetry due to ion-pair interactions is present which is centered near 3550 cm(-1). The ion-pair-related asymmetry corresponds to the sole IR maximum near 3550 cm(-1) from anhydrous molten NaOH, at 623 K. Bose-Einstein correction of published low-frequency Raman data from molten LiOH revealed an acoustic phonon, near 205 cm(-1), related to restricted translation of OH- versus Li+, and an optical phonon, at 625 cm(-1) and tau approximately 0.05 ps, due to protonic precession and/or pendular motion. Strong H bonding between water and the O atom of OH- forms H3O2-, but the proton of OH- does not bond with H significantly. Large Raman bandwidths (aqueous solutions) are explained in terms of inhomogeneous broadening due to proton transfer in a double well. Vibrational assignments are presented for H3O2-.

Parallel finite elements with domain decomposition and its pre-processing

International Nuclear Information System (INIS)

Yoshida, A.; Yagawa, G.; Hamada, S.

1993-01-01

This paper describes a parallel finite element analysis using a domain decomposition method, and the pre-processing for the parallel calculation. Computer simulations are about to replace experiments in various fields, and the scale of model to be simulated tends to be extremely large. On the other hand, computational environment has drastically changed in these years. Especially, parallel processing on massively parallel computers or computer networks is considered to be promising techniques. In order to achieve high efficiency on such parallel computation environment, large granularity of tasks, a well-balanced workload distribution are key issues. It is also important to reduce the cost of pre-processing in such parallel FEM. From the point of view, the authors developed the domain decomposition FEM with the automatic and dynamic task-allocation mechanism and the automatic mesh generation/domain subdivision system for it. (author)

IMF-Slices for GPR Data Processing Using Variational Mode Decomposition Method

Directory of Open Access Journals (Sweden)

Xuebing Zhang

2018-03-01

Full Text Available Using traditional time-frequency analysis methods, it is possible to delineate the time-frequency structures of ground-penetrating radar (GPR data. A series of applications based on time-frequency analysis were proposed for the GPR data processing and imaging. With respect to signal processing, GPR data are typically non-stationary, which limits the applications of these methods moving forward. Empirical mode decomposition (EMD provides alternative solutions with a fresh perspective. With EMD, GPR data are decomposed into a set of sub-components, i.e., the intrinsic mode functions (IMFs. However, the mode-mixing effect may also bring some negatives. To utilize the IMFs’ benefits, and avoid the negatives of the EMD, we introduce a new decomposition scheme termed variational mode decomposition (VMD for GPR data processing for imaging. Based on the decomposition results of the VMD, we propose a new method which we refer as “the IMF-slice”. In the proposed method, the IMFs are generated by the VMD trace by trace, and then each IMF is sorted and recorded into different profiles (i.e., the IMF-slices according to its center frequency. Using IMF-slices, the GPR data can be divided into several IMF-slices, each of which delineates a main vibration mode, and some subsurface layers and geophysical events can be identified more clearly. The effectiveness of the proposed method is tested using synthetic benchmark signals, laboratory data and the field dataset.

Improved Empirical Mode Decomposition Algorithm of Processing Complex Signal for IoT Application

OpenAIRE

Yang, Xianzhao; Cheng, Gengguo; Liu, Huikang

2015-01-01

Hilbert-Huang transform is widely used in signal analysis. However, due to its inadequacy in estimating both the maximum and the minimum values of the signals at both ends of the border, traditional HHT is easy to produce boundary error in empirical mode decomposition (EMD) process. To overcome this deficiency, this paper proposes an enhanced empirical mode decomposition algorithm for processing complex signal. Our work mainly focuses on two aspects. On one hand, we develop a technique to obt...

Danburite decomposition by sulfuric acid

International Nuclear Information System (INIS)

Mirsaidov, U.; Mamatov, E.D.; Ashurov, N.A.

2011-01-01

Present article is devoted to decomposition of danburite of Ak-Arkhar Deposit of Tajikistan by sulfuric acid. The process of decomposition of danburite concentrate by sulfuric acid was studied. The chemical nature of decomposition process of boron containing ore was determined. The influence of temperature on the rate of extraction of boron and iron oxides was defined. The dependence of decomposition of boron and iron oxides on process duration, dosage of H 2 SO 4 , acid concentration and size of danburite particles was determined. The kinetics of danburite decomposition by sulfuric acid was studied as well. The apparent activation energy of the process of danburite decomposition by sulfuric acid was calculated. The flowsheet of danburite processing by sulfuric acid was elaborated.

Analysis of benzoquinone decomposition in solution plasma process

International Nuclear Information System (INIS)

Bratescu, M.A.; Saito, N.

2016-01-01

The decomposition of p-benzoquinone (p-BQ) in Solution Plasma Processing (SPP) was analyzed by Coherent Anti-Stokes Raman Spectroscopy (CARS) by monitoring the change of the anti-Stokes signal intensity of the vibrational transitions of the molecule, during and after SPP. Just in the beginning of the SPP treatment, the CARS signal intensities of the ring vibrational molecular transitions increased under the influence of the electric field of plasma. The results show that plasma influences the p-BQ molecules in two ways: (i) plasma produces a polarization and an orientation of the molecules in the local electric field of plasma and (ii) the gas phase plasma supplies, in the liquid phase, hydrogen and hydroxyl radicals, which reduce or oxidize the molecules, respectively, generating different carboxylic acids. The decomposition of p-BQ after SPP was confirmed by UV-visible absorption spectroscopy and liquid chromatography

Analysis of benzoquinone decomposition in solution plasma process

Science.gov (United States)

Bratescu, M. A.; Saito, N.

2016-01-01

The decomposition of p-benzoquinone (p-BQ) in Solution Plasma Processing (SPP) was analyzed by Coherent Anti-Stokes Raman Spectroscopy (CARS) by monitoring the change of the anti-Stokes signal intensity of the vibrational transitions of the molecule, during and after SPP. Just in the beginning of the SPP treatment, the CARS signal intensities of the ring vibrational molecular transitions increased under the influence of the electric field of plasma. The results show that plasma influences the p-BQ molecules in two ways: (i) plasma produces a polarization and an orientation of the molecules in the local electric field of plasma and (ii) the gas phase plasma supplies, in the liquid phase, hydrogen and hydroxyl radicals, which reduce or oxidize the molecules, respectively, generating different carboxylic acids. The decomposition of p-BQ after SPP was confirmed by UV-visible absorption spectroscopy and liquid chromatography.

Investigation by Raman Spectroscopy of the Decomposition Process of HKUST-1 upon Exposure to Air

Directory of Open Access Journals (Sweden)

Michela Todaro

2016-01-01

Full Text Available We report an experimental investigation by Raman spectroscopy of the decomposition process of Metal-Organic Framework (MOF HKUST-1 upon exposure to air moisture (T=300 K, 70% relative humidity. The data collected here are compared with the indications obtained from a model of the process of decomposition of this material proposed in literature. In agreement with that model, the reported Raman measurements indicate that for exposure times longer than 20 days relevant irreversible processes take place, which are related to the occurrence of the hydrolysis of Cu-O bonds. These processes induce small but detectable variations of the peak positions and intensities of the main Raman bands of the material, which can be related to Cu-Cu, Cu-O, and O-C-O stretching modes. The critical analyses of these changes have permitted us to obtain a more detailed description of the process of decomposition taking place in HKUST-1 upon interaction with moisture. Furthermore, the reported Raman data give further strong support to the recently proposed model of decomposition of HKUST-1, contributing significantly to the development of a complete picture of the properties of this considerable deleterious effect.

Sublimation and thermal decomposition of ammonia borane: Competitive processes controlled by pressure

Energy Technology Data Exchange (ETDEWEB)

Kondrat’ev, Yu.V.; Butlak, A.V.; Kazakov, I.V.; Timoshkin, A.Y., E-mail: a.y.timoshkin@spbu.edu

2015-12-20

Highlights: • We measured sublimation enthalpy of ammonia borane at 357 K by drop-calorimetry. • We determined activation energy for ammonia borane decomposition by tensimetry. • At 357 K decomposition and sublimation are competitive and depend on the pressure. • We propose new values for the Δ{sub f}H° of solid ammonia borane and polyamidoborane. - Abstract: Thermal behavior of ammonia borane BH{sub 3}NH{sub 3} (AB) has been studied by calorimetry, tensimetry and mass spectrometry methods. It is shown, that depending on vapor pressure in the system two competitive processes are taking place at 357 K. At atmospheric pressure thermal decomposition with hydrogen evolution is the dominant process: BH{sub 3}NH{sub 3(s)} = 1/n (BH{sub 2}NH{sub 2}){sub n(s)} + H{sub 2(g)} (1). At low pressures (circa 4 mTorr) the major process is endothermic sublimation of AB: BH{sub 3}NH{sub 3(s)} = BH{sub 3}NH{sub 3(g)} (2). At intermediate pressures both processes occur simultaneously. Enthalpies for the processes (1) and (2) have been determined by drop-calorimetry method: Δ{sub (1)}H{sub 357}° = −24.8 ± 2.3 kJ mol{sup −1} and Δ{sub sub}H{sub 357}°(BH{sub 3}NH{sub 3}) = 76.3 ± 3.0 kJ mol{sup −1}. Solid products after sublimation and decomposition have been characterized by IR and NMR spectroscopy; gaseous forms were studied by mass spectrometry. Activation energy of 94 ± 11 kJ mol{sup −1} for the process (1) in range 327–351 K was determined by static tensimetry method. Based on the analysis of available thermodynamic characteristics, new values for the standard formation enthalpy of solid AB −133.4 ± 5.2 kJ mol{sup −1} and polyamidoborane −156.7 ± 5.8 kJ mol{sup −1} are recommended.

Investigation by raman spectroscopy of the decomposition process of HKUST-1 upon exposure to air

OpenAIRE

Todaro, M.; Alessi, A.; Sciortino, L.; Agnello, S.; Cannas, M.; Gelardi, F.; Buscarino, G.

2016-01-01

We report an experimental investigation by Raman spectroscopy of the decomposition process of Metal-Organic Framework (MOF) HKUST-1 upon exposure to air moisture (T=300 K, 70% relative humidity). The data collected here are compared with the indications obtained from a model of the process of decomposition of this material proposed in literature. In agreement with that model, the reported Raman measurements indicate that for exposure times longer than 20 days relevant irreversible processes t...

Preliminary application of Structure from Motion and GIS to document decomposition and taphonomic processes.

Science.gov (United States)

Carlton, Connor D; Mitchell, Samantha; Lewis, Patrick

2018-01-01

Over the past decade, Structure from Motion (SfM) has increasingly been used as a means of digital preservation and for documenting archaeological excavations, architecture, and cultural material. However, few studies have tapped the potential of using SfM to document and analyze taphonomic processes affecting burials for forensic sciences purposes. This project utilizes SfM models to elucidate specific post-depositional events that affected a series of three human cadavers deposited at the South East Texas Applied Forensic Science Facility (STAFS). The aim of this research was to test the ability for untrained researchers to employ spatial software and photogrammetry for data collection purposes. For a series of three months a single lens reflex (SLR) camera was used to capture a series of overlapping images at periodic stages in the decomposition process of each cadaver. These images are processed through photogrammetric software that creates a 3D model that can be measured, manipulated, and viewed. This project used photogrammetric and geospatial software to map changes in decomposition and movement of the body from original deposition points. Project results indicate SfM and GIS as a useful tool for documenting decomposition and taphonomic processes. Results indicate photogrammetry is an efficient, relatively simple, and affordable tool for the documentation of decomposition. Copyright © 2017 Elsevier B.V. All rights reserved.

Highly oriented Bi-system bulk sample prepared by a decomposition-crystallization process

International Nuclear Information System (INIS)

Xi Zhengping; Zhou Lian; Ji Chunlin

1992-01-01

A decomposition-crystallization method, preparing highly oriented Bi-system bulk sample is reported. The effects of processing parameter, decomposition temperature, cooling rate and post-treatment condition on texture and superconductivity are investigated. The method has successfully prepared highly textured Bi-system bulk samples. High temperature annealing does not destroy the growing texture, but the cooling rate has some effect on texture and superconductivity. Annealing in N 2 /O 2 atmosphere can improve superconductivity of the textured sample. The study on the superconductivity of the Bi(Pb)-Sr-Ca-Cu-O bulk material has been reported in numerous papers. The research on J c concentrates on the tape containing the 2223 phase, with very few studies on the J c of bulk sample. The reason for the lack of studies is that the change of superconducting phases at high temperatures has not been known. The authors have reported that the 2212 phase incongruently melted at about 875 degrees C and proceeded to orient the c-axis perpendicular to the surface in the process of crystallization of the 2212 phase. Based on that result, a decomposition-crystallization method was proposed to prepare highly oriented Bi-system bulk sample. In this paper, the process is described in detail and the effects of processing parameters on texture and superconductivity are reported

Thermal decomposition of uranylnitrate by the Spray-Dryer process

International Nuclear Information System (INIS)

Wildhagen, G.R.S.; Silva, G.C. da

1988-01-01

The proposal of this work consist in the thermal decomposition of uranyl nitrate solutions by the Spray-Dryer process aiming the production of highly reactive fluidized UO 3 , adequate for the use in posterior of reduction to UO 2 and hydrofluorination to UF 4 , in a fluidized bed for the obtention of UF 6 in the cicle of nuclear fuels. (author) [pt

Thermal decomposition of supported lithium nitrate catalysts

Energy Technology Data Exchange (ETDEWEB)

Ruiz, Maria Lucia [INTEQUI (CONICET-UNSL), 25 de Mayo 384, V. Mercedes, 5730, San Luis (Argentina); Lick, Ileana Daniela [CINDECA (CONICET-UNLP), Calle 47 No 257, La Plata, 1900, Buenos Aires (Argentina); Ponzi, Marta Isabel [INTEQUI (CONICET-UNSL), 25 de Mayo 384, V. Mercedes, 5730, San Luis (Argentina); Castellon, Enrique Rodriguez; Jimenez-Lopez, Antonio [Departamento de Quimica Inorganica, Cristalografia y Mineralogia. Facultad de Ciencias, Universidad de Malaga, Campus de Teatinos, 29071 Malaga (Spain); Ponzi, Esther Natalia, E-mail: eponzi@quimica.unlp.edu.ar [CINDECA (CONICET-UNLP), Calle 47 No 257, La Plata, 1900, Buenos Aires (Argentina)

2010-02-20

New catalysts for soot combustion were prepared by impregnation of different supports (SiO{sub 2}, ZrO{sub 2} and ZrO{sub 2}.nH{sub 2}O) with a LiNO{sub 3} solution and then characterized by means of FTIR, XPS, TGA and UV-vis spectroscopy, whereby the presence of lithium nitrate in the prepared catalysts was identified and quantified. The soot combustion rate using this series of catalysts (LiNO{sub 3}/support) was compared with the activity of a series of impregnated catalysts prepared using LiOH (Li{sub 2}O/supports). Catalysts prepared using LiNO{sub 3} are found to be more active than those prepared using LiOH. The catalytic performance was also studied with a NO/O{sub 2} mixture in the feed, demonstrating that NO increases the combustion rate of soot, probably as a consequence of lithium oxide forming an 'in situ' nitrate ion.

Decomposition Characteristics of Benzene, Toluene and Xylene in an Atmospheric Pressure DC Corona Discharge II. Characteristics of Deposited By-products and Decomposition Process

OpenAIRE

SAKAI, Seiji; TAKAHASHI, Kazuhiro; SATOH, Kohki; ITOH, Hidenori

2016-01-01

Gaseous by-products and deposited material obtained from the decomposition of benzene, toluene and xylene in an atmospheric pressure DC corona discharge were minutely investigated by gas chromatograph mass spectrometry and infrared absorption spectroscopy, and the decomposition processes of benzene, toluene and xylene were estimated. It was found that carbon dioxide (CO2), carbon monoxide (CO), formic acid (HCOOH) and formic anhydride ((CHO)2) were the major gaseous by-products from benzene, ...

The influence of bismuth oxide doping on the rechargeability of aqueous cells using MnO2 cathode and LiOH electrolyte

International Nuclear Information System (INIS)

Minakshi, Manickam; Mitchell, David R.G.

2008-01-01

Bi-doped manganese dioxide (MnO 2 ) has been prepared from γ-MnO 2 by physical admixture of bismuth oxide (Bi 2 O 3 ). The doping improved the cycling ability of the aqueous cell. These results are discussed and compared with the electrochemical behavior of bismuth-free MnO 2 . Batteries using the traditional potassium hydroxide (KOH) electrolyte are non-rechargeable. However, with lithium hydroxide (LiOH) as an electrolyte, the cell becomes rechargeable. Furthermore, the incorporation of bismuth into MnO 2 in the LiOH cell was found to result in significantly longer cycle life, compared with cells using undoped MnO 2 . The Bi-doped cell exhibited a greater capacity after 100 discharge cycles, than the undoped cell after just 40 cycles. X-ray diffraction and the microscopic analysis suggest that the presence of Bi 3+ ions reduces the magnitude of structural changes occurring in MnO 2 during cycling. Comparison with additives assessed in our previous studies (titanium disulfide (TiS 2 ); titanium boride (TiB 2 )) shows that the best rechargeability behavior is obtained for the current Bi-doped MnO 2 . As the size of Bi 3+ ions (0.96 A) is much larger than Mn 3+ (0.73 A) or Mn 2+ (0.67 A) they have effectively prevented the formation of non-rechargeable products

The neural basis of novelty and appropriateness in processing of creative chunk decomposition.

Science.gov (United States)

Huang, Furong; Fan, Jin; Luo, Jing

2015-06-01

Novelty and appropriateness have been recognized as the fundamental features of creative thinking. However, the brain mechanisms underlying these features remain largely unknown. In this study, we used event-related functional magnetic resonance imaging (fMRI) to dissociate these mechanisms in a revised creative chunk decomposition task in which participants were required to perform different types of chunk decomposition that systematically varied in novelty and appropriateness. We found that novelty processing involved functional areas for procedural memory (caudate), mental rewarding (substantia nigra, SN), and visual-spatial processing, whereas appropriateness processing was mediated by areas for declarative memory (hippocampus), emotional arousal (amygdala), and orthography recognition. These results indicate that non-declarative and declarative memory systems may jointly contribute to the two fundamental features of creative thinking. Copyright © 2015 Elsevier Inc. All rights reserved.

Effect of LiOH, NaOH and KOH on corrosion and oxide microstructure of Zr-based alloys

International Nuclear Information System (INIS)

Jeong, Y.H.; Kim, H.G.; Jung, Y.H.; Ruhmann, H.

1999-01-01

Long-term corrosion test, SIMS analysis, and TEM microstructural study were carried out to investigate the corrosion characteristics and mechanism of Zr alloys in alkali hydroxides. The corrosion tests were performed in solutions of LiOH, NaOH, KOH, RbOH, and CsOH at 350 deg. C for 500 days. SIMS analysis was performed for the specimens prepared to have an equal oxide thickness. TEM studies on the specimens with an equal oxide thickness in various solutions in both pre- and post-transition regimes were also conducted. The corrosion rate in alkali hydroxide solutions was observed to decrease as the ionic radius of alkali cation was increased. The penetration depth of cation into the oxide decreases with increasing the ionic radius of cation. Even though the oxide thickness was equal, the different oxide morphologies were observed in specimens. Namely, in LiOH solution the oxide morphology was transformed early from columnar to equiaxed structure. However, in KOH solution the columnar structure was maintained up to post-transition regime. Based on the corrosion test, SIMS analysis, and microstructural study, the cation is considered to control the corrosion in a alkali hydroxide solution and its effect is dependent on the concentration of alkali and the oxide thickness. The slight acceleration of the corrosion rate at a low concentration is thought to be caused by cation incorporation into oxide while the significant acceleration at a high concentration is due to the transformation of oxide microstructure that would be induced by cation incorporation. KOH was shown not to affect significantly the corrosion and the hydrogen pickup of Zircaloy. Therefore, it has a potential for PWR application only from the point of view of Zircaloy corrosion. (author)

Kinetic analysis of overlapping multistep thermal decomposition comprising exothermic and endothermic processes: thermolysis of ammonium dinitramide.

Science.gov (United States)

Muravyev, Nikita V; Koga, Nobuyoshi; Meerov, Dmitry B; Pivkina, Alla N

2017-01-25

This study focused on kinetic modeling of a specific type of multistep heterogeneous reaction comprising exothermic and endothermic reaction steps, as exemplified by the practical kinetic analysis of the experimental kinetic curves for the thermal decomposition of molten ammonium dinitramide (ADN). It is known that the thermal decomposition of ADN occurs as a consecutive two step mass-loss process comprising the decomposition of ADN and subsequent evaporation/decomposition of in situ generated ammonium nitrate. These reaction steps provide exothermic and endothermic contributions, respectively, to the overall thermal effect. The overall reaction process was deconvoluted into two reaction steps using simultaneously recorded thermogravimetry and differential scanning calorimetry (TG-DSC) curves by considering the different physical meanings of the kinetic data derived from TG and DSC by P value analysis. The kinetic data thus separated into exothermic and endothermic reaction steps were kinetically characterized using kinetic computation methods including isoconversional method, combined kinetic analysis, and master plot method. The overall kinetic behavior was reproduced as the sum of the kinetic equations for each reaction step considering the contributions to the rate data derived from TG and DSC. During reproduction of the kinetic behavior, the kinetic parameters and contributions of each reaction step were optimized using kinetic deconvolution analysis. As a result, the thermal decomposition of ADN was successfully modeled as partially overlapping exothermic and endothermic reaction steps. The logic of the kinetic modeling was critically examined, and the practical usefulness of phenomenological modeling for the thermal decomposition of ADN was illustrated to demonstrate the validity of the methodology and its applicability to similar complex reaction processes.

Effects of terrestrial isopods (Crustacea: Oniscidea on leaf litter decomposition processes

Directory of Open Access Journals (Sweden)

Khaleid F. Abd El-Wakeil

2015-03-01

Full Text Available The leaf litter decomposition is carried out by the combined action of microorganisms and decomposer invertebrates such as earthworms, diplopods and isopods. The present work aimed to evaluate the impact of terrestrial isopod on leaf litter decomposition process. In Lab experimental food sources from oak and magnolia leaves litter were prepared. Air dried leaf litter were cut to 9 mm discs and sterilized in an autoclave then soaked in distilled water or water percolated through soil and left to decompose for 2, 4 and 6 weeks. 12 groups from two isopods species Porcellio scaber and Armadillidium vulgare, were prepared with each one containing 9 isopods. They were fed individually on the prepared food for 2 weeks. The prepared food differed in Carbon stable isotope ratio (δ13C, C%, N% and C/N ratios. At the end of the experiment, isopods were dissected and separated into gut, gut content and rest of the body. The δ13C for the prepared food, faecal pellets, remaining food, gut content, gut and rest of isopod were compared. The feeding activities of the two isopods were significantly different among isopods groups. Consumption and egestion ratios of magnolia leaf were higher than oak leaf. P. scaber consumed and egested litter higher than A. vulgare. The present results suggested that the impact of isopods and decomposition processes is species and litter specific.

Decomposition studies of group 6 hexacarbonyl complexes. Pt. 2. Modelling of the decomposition process

Energy Technology Data Exchange (ETDEWEB)

Usoltsev, Ilya; Eichler, Robert; Tuerler, Andreas [Paul Scherrer Institut (PSI), Villigen (Switzerland); Bern Univ. (Switzerland)

2016-11-01

The decomposition behavior of group 6 metal hexacarbonyl complexes (M(CO){sub 6}) in a tubular flow reactor is simulated. A microscopic Monte-Carlo based model is presented for assessing the first bond dissociation enthalpy of M(CO){sub 6} complexes. The suggested approach superimposes a microscopic model of gas adsorption chromatography with a first-order heterogeneous decomposition model. The experimental data on the decomposition of Mo(CO){sub 6} and W(CO){sub 6} are successfully simulated by introducing available thermodynamic data. Thermodynamic data predicted by relativistic density functional theory is used in our model to deduce the most probable experimental behavior of the corresponding Sg carbonyl complex. Thus, the design of a chemical experiment with Sg(CO){sub 6} is suggested, which is sensitive to benchmark our theoretical understanding of the bond stability in carbonyl compounds of the heaviest elements.

New kinetic insight into the spontaneous oxidation process of lithium in air by EPMA

Energy Technology Data Exchange (ETDEWEB)

Otero, Manuel [IFEG, Facultad de Matemáticas, Astronomía y Física, Universidad Nacional de Córdoba, Córdoba (Argentina); INFICQ, Departamento de Matemáticas y Física, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba (Argentina); Lener, German [INFAP, Facultad de Ciencias Físico Matemáticas y Naturales, Universidad Nacional de San Luis, San Luis (Argentina); Trincavelli, Jorge, E-mail: trincavelli@famaf.unc.edu.ar [IFEG, Facultad de Matemáticas, Astronomía y Física, Universidad Nacional de Córdoba, Córdoba (Argentina); Barraco, Daniel [IFEG, Facultad de Matemáticas, Astronomía y Física, Universidad Nacional de Córdoba, Córdoba (Argentina); Nazzarro, Marcelo Sandro; Furlong, Octavio [INFAP, Facultad de Ciencias Físico Matemáticas y Naturales, Universidad Nacional de San Luis, San Luis (Argentina); Leiva, Ezequiel Pedro Marcos [INFICQ, Departamento de Matemáticas y Física, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba (Argentina)

2016-10-15

Highlights: • EPMA measurements and Monte Carlo simulations were applied to study the corrosion process of Li in air. • The kinetic mechanism of corrosion was discussed. • A diffusion process of water through LiOH was found and quantitatively studied. - Abstract: The exposure of metallic lithium to ambient air produces a fast corrosion reaction of the surface that continues to the bulk of the material. This spontaneous process was explored by means of X-ray Photoelectron Spectroscopy (XPS) and Electron Probe Micro-Analysis (EPMA). The combination of these techniques and Monte Carlo simulations allowed observing the formation of a film of lithium hydroxide (LiOH) and studying the growth within the material during the first 300 s. The corrosion is mainly due to the reaction of lithium with water and the diffusion of water through the growing LiOH film is the rate determining step. On the basis of a kinetic analysis we studied the mechanism of reaction and inferred a diffusion coefficient of D = (5.1 ± 0.4) × 10{sup −12} cm{sup 2}/s in agreement with results from the literature obtained using different techniques.

Experiments of HI decomposition in Iodine-sulfur process

International Nuclear Information System (INIS)

Yoon, Ho Joon

2006-02-01

We performed an experimental study on the HI concentration and decomposition in Iodine-Sulfur process for thermochemical hydrogen production, which is the most expensive and energy consuming stage. For breaking azeotropic restrain, a partial condensing type, perforated plate type, and packed bed distillation column are employed. A Liebig-type condenser was used for a partial condensing distillation test. The perforated plate distillation column has 40 mm diameter and 5 stages with 8 holes per a plate. The packed bed distillation column has 40 mm diameter and was filled with 5 mm glass beads. While no distillation methods are able to change azeotropic conditions at atmospheric pressure, HI decomposition took place in a reboiler at 480 .deg. C. The vapor-liquid equilibrium curve was obtained from the experiment with binary mixtures (HI/H 2 O) at atmospheric pressure. Almost pure H 2 O was evaporated at the lower temperature than 125 .deg. C, and above that temperature binary mixtures (HI/H 2 O) were evaporated until the leftover solution became HI acid of 0.157mol, which was an azeotropic concentration of HI. With a consideration of heat loss, enthalpy of vaporization at azeotropic condition was estimated as 1131 kJ/kg

Experiments of HI decomposition in Iodine-sulfur process

Energy Technology Data Exchange (ETDEWEB)

Yoon, Ho Joon

2006-02-15

We performed an experimental study on the HI concentration and decomposition in Iodine-Sulfur process for thermochemical hydrogen production, which is the most expensive and energy consuming stage. For breaking azeotropic restrain, a partial condensing type, perforated plate type, and packed bed distillation column are employed. A Liebig-type condenser was used for a partial condensing distillation test. The perforated plate distillation column has 40 mm diameter and 5 stages with 8 holes per a plate. The packed bed distillation column has 40 mm diameter and was filled with 5 mm glass beads. While no distillation methods are able to change azeotropic conditions at atmospheric pressure, HI decomposition took place in a reboiler at 480 .deg. C. The vapor-liquid equilibrium curve was obtained from the experiment with binary mixtures (HI/H{sub 2}O) at atmospheric pressure. Almost pure H{sub 2}O was evaporated at the lower temperature than 125 .deg. C, and above that temperature binary mixtures (HI/H{sub 2}O) were evaporated until the leftover solution became HI acid of 0.157mol, which was an azeotropic concentration of HI. With a consideration of heat loss, enthalpy of vaporization at azeotropic condition was estimated as 1131 kJ/kg.

SDE decomposition and A-type stochastic interpretation in nonequilibrium processes

Science.gov (United States)

Yuan, Ruoshi; Tang, Ying; Ao, Ping

2017-12-01

An innovative theoretical framework for stochastic dynamics based on the decomposition of a stochastic differential equation (SDE) into a dissipative component, a detailed-balance-breaking component, and a dual-role potential landscape has been developed, which has fruitful applications in physics, engineering, chemistry, and biology. It introduces the A-type stochastic interpretation of the SDE beyond the traditional Ito or Stratonovich interpretation or even the α-type interpretation for multidimensional systems. The potential landscape serves as a Hamiltonian-like function in nonequilibrium processes without detailed balance, which extends this important concept from equilibrium statistical physics to the nonequilibrium region. A question on the uniqueness of the SDE decomposition was recently raised. Our review of both the mathematical and physical aspects shows that uniqueness is guaranteed. The demonstration leads to a better understanding of the robustness of the novel framework. In addition, we discuss related issues including the limitations of an approach to obtaining the potential function from a steady-state distribution.

Safety measures for integrity test apparatus for IS process. Sulfuric acid decomposition section

International Nuclear Information System (INIS)

Noguchi, Hiroki; Kubo, Shinji; Iwatsuki, Jin; Onuki, Kaoru

2013-07-01

Hazardous substances such as sulfuric acid, sulfur dioxide and hydrogen iodide acid are employed in thermochemical Iodine-Sulfur (IS) process. It is necessary to take safety measure against workers and external environments to study experimentally on IS process. Presently we have been conducting to verify the soundness of main components made of engineering material in actual corrosive condition. An integrity test apparatus for the components of sulfuric acid decomposition was set up. We will use the hazardous substances such as sulfuric acid and sulfur dioxide and perform the experiment in pressurized condition in this integrity test. Safety measures for the test apparatus, operation and abnormal situation were considered prior to starting the test. This report summarized the consideration results for the safety measures on the integrity test apparatus for the components of sulfuric acid decomposition. (author)

Decomposition of business process models into reusable sub-diagrams

Directory of Open Access Journals (Sweden)

Wiśniewski Piotr

2017-01-01

Full Text Available In this paper, an approach to automatic decomposition of business process models is proposed. According to our method, an existing BPMN diagram is disassembled into reusable parts containing the desired number of elements. Such elements and structure can work as design patterns and be validated by a user in terms of correctness. In the next step, these component models are categorised considering their parameters such as resources used, as well as input and output data. The classified components may be considered a repository of reusable parts, that can be further applied in the design of new models. The proposed technique may play a significant role in facilitating the business process redesign procedure, which is of a great importance regarding engineering and industrial applications.

Industrial and simulation analysis of the nitrogen trichloride decomposition process in electrolytic chlorine production

International Nuclear Information System (INIS)

Tavares Neto, J.I.H.; Brito, K.D.; Vasconcelos, L.G.S.; Alves, J.J.N.; Fossy, M.F.; Brito, R.P.

2007-01-01

This work presents the dynamic simulation of the thermal decomposition of nitrogen trichloride (NCl 3 ) during electrolytic chlorine (Cl 2 ) production, using an industrial plant as a case study. NCl 3 is an extremely unstable and explosive compound and the decomposition process has the following main problems: changeability of the reactor temperature and loss of solvent. The results of this work will be used to establish a more efficient and safe control strategy and to analyze the loss of solvent during the dynamic period. The implemented model will also be used to study the use of a new solvent, considering that currently used solvent will be prohibited from commercial use in 2010. The process was simulated by using the commercial simulator Aspen TM and the simulations were validated with plant data. From the results of the simulation it can be concluded that the rate of decomposition depends strongly on the temperature of the reactor, which has a stronger relationship to the liquid Cl 2 (reflux) and gaseous Cl 2 flow rates which feed the system. The results also showed that the loss of solvent changes strongly during the dynamic period

Multiresolution signal decomposition schemes

NARCIS (Netherlands)

J. Goutsias (John); H.J.A.M. Heijmans (Henk)

1998-01-01

textabstract[PNA-R9810] Interest in multiresolution techniques for signal processing and analysis is increasing steadily. An important instance of such a technique is the so-called pyramid decomposition scheme. This report proposes a general axiomatic pyramid decomposition scheme for signal analysis

Design and cost of the sulfuric acid decomposition reactor for the sulfur based hydrogen processes - HTR2008-58009

International Nuclear Information System (INIS)

Hu, T. Y.; Connolly, S. M.; Lahoda, E. J.; Kriel, W.

2008-01-01

The key interface component between the reactor and chemical systems for the sulfuric acid based processes to make hydrogen is the sulfuric acid decomposition reactor. The materials issues for the decomposition reactor are severe since sulfuric acid must be heated, vaporized and decomposed. SiC has been identified and proven by others to be an acceptable material. However, SiC has a significant design issue when it must be interfaced with metals for connection to the remainder of the process. Westinghouse has developed a design utilizing SiC for the high temperature portions of the reactor that are in contact with the sulfuric acid and polymeric coated steel for low temperature portions. This design is expected to have a reasonable cost for an operating lifetime of 20 years. It can be readily maintained in the field, and is transportable by truck (maximum OD is 4.5 meters). This paper summarizes the detailed engineering design of the Westinghouse Decomposition Reactor and the decomposition reactor's capital cost. (authors)

Processes controlling the production of aromatic water-soluble organic matter during litter decomposition

NARCIS (Netherlands)

Klotzbücher, T.; Kaiser, K.; Filley, T.R.; Kalbitz, K.

2013-01-01

Dissolved organic matter (DOM) plays a fundamental role for many soil processes. For instance, production, transport, and retention of DOM control properties and long-term storage of organic matter in mineral soils. Production of water-soluble compounds during the decomposition of plant litter is a

Thermal decomposition of beryllium perchlorate tetrahydrate

International Nuclear Information System (INIS)

Berezkina, L.G.; Borisova, S.I.; Tamm, N.S.; Novoselova, A.V.

1975-01-01

Thermal decomposition of Be(ClO 4 ) 2 x4H 2 O was studied by the differential flow technique in the helium stream. The kinetics was followed by an exchange reaction of the perchloric acid appearing by the decomposition with potassium carbonate. The rate of CO 2 liberation in this process was recorded by a heat conductivity detector. The exchange reaction yielding CO 2 is quantitative, it is not the limiting one and it does not distort the kinetics of the process of perchlorate decomposition. The solid products of decomposition were studied by infrared and NMR spectroscopy, roentgenography, thermography and chemical analysis. A mechanism suggested for the decomposition involves intermediate formation of hydroxyperchlorate: Be(ClO 4 ) 2 x4H 2 O → Be(OH)ClO 4 +HClO 4 +3H 2 O; Be(OH)ClO 4 → BeO+HClO 4 . Decomposition is accompained by melting of the sample. The mechanism of decomposition is hydrolytic. At room temperature the hydroxyperchlorate is a thick syrup-like compound crystallizing after long storing

Decomposition of 1,4-dioxane by advanced oxidation and biochemical process.

Science.gov (United States)

Kim, Chang-Gyun; Seo, Hyung-Joon; Lee, Byung-Ryul

2006-01-01

This study was undertaken to determine the optimal decomposition conditions when 1,4-dioxane was degraded using either the AOPs (Advanced Oxidation Processes) or the BAC-TERRA microbial complex. The advanced oxidation was operated with H2O2, in the range 4.7 to 51 mM, under 254 nm (25 W lamp) illumination, while varying the reaction parameters, such as the air flow rate and reaction time. The greatest oxidation rate (96%) of 1,4-dioxane was achieved with H2O2 concentration of 17 mM after a 2-hr reaction. As a result of this reaction, organic acid intermediates were formed, such as acetic, propionic and butyric acids. Furthermore, the study revealed that suspended particles, i.e., bio-flocs, kaolin and pozzolan, in the reaction were able to have an impact on the extent of 1,4-dioxane decomposition. The decomposition of 1,4-dioxane in the presence of bio-flocs was significantly declined due to hindered UV penetration through the solution as a result of the consistent dispersion of bio-particles. In contrast, dosing with pozzolan decomposed up to 98.8% of the 1,4-dioxane after 2 hr of reaction. Two actual wastewaters, from polyester manufacturing, containing 1,4-dioxane in the range 370 to 450 mg/L were able to be oxidized by as high as 100% within 15 min with the introduction of 100:200 (mg/L) Fe(II):H202 under UV illumination. Aerobic biological decomposition, employing BAC-TERRA, was able to remove up to 90% of 1,4-dioxane after 15 days of incubation. In the meantime, the by-products (i.e., acetic, propionic and valeric acid) generated were similar to those formed during the AOPs investigation. According to kinetic studies, both photo-decomposition and biodegradation of 1,4-dioxane followed pseudo first-order reaction kinetics, with k = 5 x 10(-4) s(-1) and 2.38 x 10(-6) s(-1), respectively. It was concluded that 1,4-dioxane could be readily degraded by both AOPs and BAC-TERRA, and that the actual polyester wastewater containing 1,4-dioxane could be successfully

A new decomposition method for parallel processing multi-level optimization

International Nuclear Information System (INIS)

Park, Hyung Wook; Kim, Min Soo; Choi, Dong Hoon

2002-01-01

In practical designs, most of the multidisciplinary problems have a large-size and complicate design system. Since multidisciplinary problems have hundreds of analyses and thousands of variables, the grouping of analyses and the order of the analyses in the group affect the speed of the total design cycle. Therefore, it is very important to reorder and regroup the original design processes in order to minimize the total computational cost by decomposing large multidisciplinary problems into several MultiDisciplinary Analysis SubSystems (MDASS) and by processing them in parallel. In this study, a new decomposition method is proposed for parallel processing of multidisciplinary design optimization, such as Collaborative Optimization (CO) and Individual Discipline Feasible (IDF) method. Numerical results for two example problems are presented to show the feasibility of the proposed method

Controlled decomposition and oxidation: A treatment method for gaseous process effluents

Science.gov (United States)

Mckinley, Roger J. B., Sr.

1990-01-01

The safe disposal of effluent gases produced by the electronics industry deserves special attention. Due to the hazardous nature of many of the materials used, it is essential to control and treat the reactants and reactant by-products as they are exhausted from the process tool and prior to their release into the manufacturing facility's exhaust system and the atmosphere. Controlled decomposition and oxidation (CDO) is one method of treating effluent gases from thin film deposition processes. CDO equipment applications, field experience, and results of the use of CDO equipment and technological advances gained from the field experiences are discussed.

A Dynamic Simulation Program for a Hydriodic Acid Concentration and Decomposition Process in the VHTR-SI Process

International Nuclear Information System (INIS)

Chang, Ji Woon; Shin, Young Joon; Lee, Tae Hoon; Lee, Ki Young; Kim, Yong Wan; Chang, Jong Hwa; Youn, Cheung

2011-01-01

The Sulfur-Iodine (SI) cycle which can produce hydrogen by using nuclear heat consists of a Bunsen reaction (Section 1), a sulfur acid concentration and decomposition (Section 2), and a hydriodic acid concentration and decomposition (Section 3). The heat required in the SI process can be supplied through an intermediate heat exchanger (IHX) by a Very High Temperature Gas Cooled Reactor (VHTR). The Korea Atomic Energy Research Institute-Dynamic Simulation Code (KAERI-DySCo) based on the Visual C++ is an integration application software that simulates the dynamic behavior of the SI process. KAERI-DySCo was prepared to solve dynamic problem of the seven chemical reactors which consist of Sections 2 and 3. Section 3 is the key part of the SI process, because the strong non-ideality and the partial immiscibility of the binary HI.H 2 O and the ternary HI.I 2 .H 2 O (HIX solution) mixture make it difficult to model and simulate the dynamic behavior of the system. Therefore, it is necessary to compose separately a dynamic simulation program for Section 3 in KAERI-DySCo optimization. In this paper, a simulation program to analyze the dynamic behavior of Section 3 is introduced using the prepared KAERI-DySCo, and results of dynamic simulation are represented by running the program

A sustainable process to utilize ferrous sulfate waste from titanium oxide industry by reductive decomposition reaction with pyrite

International Nuclear Information System (INIS)

Huang, Penghui; Deng, Shaogang; Zhang, Zhiye; Wang, Xinlong; Chen, Xiaodong; Yang, Xiushan; Yang, Lin

2015-01-01

Highlights: • A newly developed treating process of ferrous sulfate was proposed. • The reaction process was discussed by thermodynamic analysis. • Thermodynamic analysis was compared with experiments results. • The kinetic model of the decomposition reaction was determined. • The reaction mechanism of autocatalytic reactions was explored. - Abstract: Ferrous sulfate waste has become a bottleneck in the sustainable development of the titanium dioxide industry in China. In this study, we propose a new method for the reductive decomposition of ferrous sulfate waste using pyrite. Thermodynamics analysis, tubular reactor experiments, and kinetics analysis were performed to analyze the reaction process. The results of the thermodynamic simulation showed that the reaction process and products were different when molar ratio of FeSO_4/FeS_2 was changed. The suitable molar ratio of FeSO_4/FeS_2 was 8–12. The reaction temperature of ferrous sulfate with pyrite was 580–770 K and the main products were Fe_3O_4 and SO_2. The simulation results agreed well with the experimental results. The desulphurization rate reached 98.55% and main solid products were Fe_3O_4 at 823.15 K when mole ratio of FeSO_4/FeS_2 was 8. Nano-sized magnetite was obtained at this condition. The kinetic model was investigated by isoconversional methods. The average E value was 244.34 kJ mol"−"1. The ferrous sulfate decomposition process can be treated as autocatalytic reaction mechanism, which corresponded to the expanded Prout–Tompson (Bna) model. The reaction mechanism of autocatalytic reactions during the process of ferrous sulfate decomposition were explored, the products of Fe oxide substances are the catalyst components.

Decomposition mechanism of trichloroethylene based on by-product distribution in the hybrid barrier discharge plasma process

Energy Technology Data Exchange (ETDEWEB)

Han, Sang-Bo [Industry Applications Research Laboratory, Korea Electrotechnology Research Institute, Changwon, Kyeongnam (Korea, Republic of); Oda, Tetsuji [Department of Electrical Engineering, The University of Tokyo, Tokyo 113-8656 (Japan)

2007-05-15

The hybrid barrier discharge plasma process combined with ozone decomposition catalysts was studied experimentally for decomposing dilute trichloroethylene (TCE). Based on the fundamental experiment for catalytic activities on ozone decomposition, MnO{sub 2} was selected for application in the main experiments for its higher catalytic abilities than other metal oxides. A lower initial TCE concentration existed in the working gas; the larger ozone concentration was generated from the barrier discharge plasma treatment. Near complete decomposition of dichloro-acetylchloride (DCAC) into Cl{sub 2} and CO{sub x} was observed for an initial TCE concentration of less than 250 ppm. C=C {pi} bond cleavage in TCE gave a carbon single bond of DCAC through oxidation reaction during the barrier discharge plasma treatment. Those DCAC were easily broken in the subsequent catalytic reaction. While changing oxygen concentration in working gas, oxygen radicals in the plasma space strongly reacted with precursors of DCAC compared with those of trichloro-acetaldehyde. A chlorine radical chain reaction is considered as a plausible decomposition mechanism in the barrier discharge plasma treatment. The potential energy of oxygen radicals at the surface of the catalyst is considered as an important factor in causing reactive chemical reactions.

Aging-driven decomposition in zolpidem hemitartrate hemihydrate and the single-crystal structure of its decomposition products.

Science.gov (United States)

Vega, Daniel R; Baggio, Ricardo; Roca, Mariana; Tombari, Dora

2011-04-01

The "aging-driven" decomposition of zolpidem hemitartrate hemihydrate (form A) has been followed by X-ray powder diffraction (XRPD), and the crystal and molecular structures of the decomposition products studied by single-crystal methods. The process is very similar to the "thermally driven" one, recently described in the literature for form E (Halasz and Dinnebier. 2010. J Pharm Sci 99(2): 871-874), resulting in a two-phase system: the neutral free base (common to both decomposition processes) and, in the present case, a novel zolpidem tartrate monohydrate, unique to the "aging-driven" decomposition. Our room-temperature single-crystal analysis gives for the free base comparable results as the high-temperature XRPD ones already reported by Halasz and Dinnebier: orthorhombic, Pcba, a = 9.6360(10) Å, b = 18.2690(5) Å, c = 18.4980(11) Å, and V = 3256.4(4) Å(3) . The unreported zolpidem tartrate monohydrate instead crystallizes in monoclinic P21 , which, for comparison purposes, we treated in the nonstandard setting P1121 with a = 20.7582(9) Å, b = 15.2331(5) Å, c = 7.2420(2) Å, γ = 90.826(2)°, and V = 2289.73(14) Å(3) . The structure presents two complete moieties in the asymmetric unit (z = 4, z' = 2). The different phases obtained in both decompositions are readily explained, considering the diverse genesis of both processes. Copyright © 2010 Wiley-Liss, Inc.

Bifunctional Characteristics of Al2O3 supported Ni in the HI Decomposition of Sulfur-Iodine Process

Directory of Open Access Journals (Sweden)

Park Chu-Sik

2016-01-01

Full Text Available The Sulfur-Iodine process is in need of catalytic reactor for HI decomposition because the HI decomposition reaction rate is very slow. Nickel as an alternative catalyst for platinum was investigated in this study. Al2O3 supported Ni catalysts were prepared by impregnation method. Ni amounts loaded over Al2O3 were in the range of 0.1~20 wt. %. HI decompositions were carried out in the temperature range of 573 ~ 773 K using the fixed-bed quartz reactor. The difference of catalysts before and after the reaction was analyzed using BET, CO/H2 chemisorption, XRD, XRF and SEM. It was confirmed by XRD and SEM-EDX analysis that Ni was converted to NiI2 during the HI decomposition. Catalyst deactivation due to the formation of NiI2 leads to a reduction of HI conversion. Although Ni of catalyst converted to NiI2, HI decomposition with low loading (up to 3 wt. % catalyst showed a little decrease of HI conversion. However, with more than 5 wt. % catalyst, the initial HI conversion was considerably decreased. In the particular case of 20 wt. %, the initial conversion was increased close to 60 %, which is higher than 20 % as an equilibrium conversion at 723 K. These results showed that Ni had not only a catalytic function for HI decomposition, but also function as a sorbent to absorb I2 produced from HI.

Decomposition Technology Development of Organic Component in a Decontamination Waste Solution

International Nuclear Information System (INIS)

Jung, Chong Hun; Oh, W. Z.; Won, H. J.; Choi, W. K.; Kim, G. N.; Moon, J. K.

2007-11-01

Through the project of 'Decomposition Technology Development of Organic Component in a Decontamination Waste Solution', the followings were studied. 1. Investigation of decontamination characteristics of chemical decontamination process 2. Analysis of COD, ferrous ion concentration, hydrogen peroxide concentration 3. Decomposition tests of hardly decomposable organic compounds 4. Improvement of organic acid decomposition process by ultrasonic wave and UV light 5. Optimization of decomposition process using a surrogate decontamination waste solution

Danburite decomposition by hydrochloric acid

International Nuclear Information System (INIS)

Mamatov, E.D.; Ashurov, N.A.; Mirsaidov, U.

2011-01-01

Present article is devoted to decomposition of danburite of Ak-Arkhar Deposit of Tajikistan by hydrochloric acid. The interaction of boron containing ores of Ak-Arkhar Deposit of Tajikistan with mineral acids, including hydrochloric acid was studied. The optimal conditions of extraction of valuable components from danburite composition were determined. The chemical composition of danburite of Ak-Arkhar Deposit was determined as well. The kinetics of decomposition of calcined danburite by hydrochloric acid was studied. The apparent activation energy of the process of danburite decomposition by hydrochloric acid was calculated.

Decomposition Technology Development of Organic Component in a Decontamination Waste Solution

Energy Technology Data Exchange (ETDEWEB)

Jung, Chong Hun; Oh, W. Z.; Won, H. J.; Choi, W. K.; Kim, G. N.; Moon, J. K

2007-11-15

Through the project of 'Decomposition Technology Development of Organic Component in a Decontamination Waste Solution', the followings were studied. 1. Investigation of decontamination characteristics of chemical decontamination process 2. Analysis of COD, ferrous ion concentration, hydrogen peroxide concentration 3. Decomposition tests of hardly decomposable organic compounds 4. Improvement of organic acid decomposition process by ultrasonic wave and UV light 5. Optimization of decomposition process using a surrogate decontamination waste solution.

Preparation of lithium indium oxide via a rheological phase route and its electrochemical characteristics in LiOH and Li{sub 2}SO{sub 4} solutions

Energy Technology Data Exchange (ETDEWEB)

Zhang, Guo-Qing [Department of Chemistry and Environment Science of Yangtze Normal University, 408100 Chongqing (China); College of Chemistry and Chemical Engineering of Chongqing University, Chongqing 400030 (China); Zhang, Sheng-Tao [College of Chemistry and Chemical Engineering of Chongqing University, Chongqing 400030 (China); Wu, Xing-Fa [Department of Chemistry and Environment Science of Yangtze Normal University, 408100 Chongqing (China)

2010-01-15

Submicrometer-sized lithium indium oxide (LiInO{sub 2}) powder via a rheological phase method using trilithium citrate tetra hydrate (C{sub 6}H{sub 5}Li{sub 3}O{sub 7} . 4H{sub 2}O) and indium oxide (In{sub 2}O{sub 3}) has been prepared in this work for the first time. The optimal pyrolyzing temperature range to prepare crystalline LiInO{sub 2} is between 650 and 900 C, which was confirmed by thermal gravimetric and differential thermogravimetric analysis of the precursor and X-ray diffraction analysis. The pure phase LiInO{sub 2} sample obtained has a uniform particle morphology and submicrosize, which was observed by scanning electron microscopy. The electrochemical studies show that a new pair of cathodic and anodic peaks at 0.23 and 0.38 V (vs. saturated calomel electrode) was obviously observed from the cyclic voltammetry curve of LiInO{sub 2} in 1 M LiOH solution, indicating a battery characteristic of the material in this electrolyte. While in 1 M Li{sub 2}SO{sub 4} solution, the sample presents a supercapacitive characteristic within the same potential range. The reasons for different electrochemical behaviors in these two electrolytes can be attributed to the fact that the reaction of lithium ion insertion/extraction into/out of a LiInO{sub 2} electrode takes place in the bulk material in LiOH electrolyte solution, whereas it takes place on the electrode/electrolyte interface for Li{sub 2}SO{sub 4} electrolyte case. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

Accelerated decomposition techniques for large discounted Markov decision processes

Science.gov (United States)

Larach, Abdelhadi; Chafik, S.; Daoui, C.

2017-12-01

Many hierarchical techniques to solve large Markov decision processes (MDPs) are based on the partition of the state space into strongly connected components (SCCs) that can be classified into some levels. In each level, smaller problems named restricted MDPs are solved, and then these partial solutions are combined to obtain the global solution. In this paper, we first propose a novel algorithm, which is a variant of Tarjan's algorithm that simultaneously finds the SCCs and their belonging levels. Second, a new definition of the restricted MDPs is presented to ameliorate some hierarchical solutions in discounted MDPs using value iteration (VI) algorithm based on a list of state-action successors. Finally, a robotic motion-planning example and the experiment results are presented to illustrate the benefit of the proposed decomposition algorithms.

Three-dimensional decomposition models for carbon productivity

International Nuclear Information System (INIS)

Meng, Ming; Niu, Dongxiao

2012-01-01

This paper presents decomposition models for the change in carbon productivity, which is considered a key indicator that reflects the contributions to the control of greenhouse gases. Carbon productivity differential was used to indicate the beginning of decomposition. After integrating the differential equation and designing the Log Mean Divisia Index equations, a three-dimensional absolute decomposition model for carbon productivity was derived. Using this model, the absolute change of carbon productivity was decomposed into a summation of the absolute quantitative influences of each industrial sector, for each influence factor (technological innovation and industrial structure adjustment) in each year. Furthermore, the relative decomposition model was built using a similar process. Finally, these models were applied to demonstrate the decomposition process in China. The decomposition results reveal several important conclusions: (a) technological innovation plays a far more important role than industrial structure adjustment; (b) industry and export trade exhibit great influence; (c) assigning the responsibility for CO 2 emission control to local governments, optimizing the structure of exports, and eliminating backward industrial capacity are highly essential to further increase China's carbon productivity. -- Highlights: ► Using the change of carbon productivity to measure a country's contribution. ► Absolute and relative decomposition models for carbon productivity are built. ► The change is decomposed to the quantitative influence of three-dimension. ► Decomposition results can be used for improving a country's carbon productivity.

The platinum catalysed decomposition of hydrazine in acidic media

International Nuclear Information System (INIS)

Ananiev, A.V.; Tananaev, I.G.; Brossard, Ph.; Broudic, J.C.

2000-01-01

Kinetic study of the hydrazine decomposition in the solutions of HClO 4 , H 2 SO 4 and HNO 3 in the presence of Pt/SiO 2 catalyst has been undertaken. It was shown that the kinetics of the hydrazine catalytic decomposition in HClO 4 and H 2 SO 4 are identical. The process is determined by the heterogeneous catalytic auto-decomposition of N 2 H 4 on the catalyst's surface. The platinum catalysed hydrazine decomposition in the nitric acid solutions is a complex process, including heterogeneous catalytic auto-decomposition of N 2 H 4 , reaction of hydrazine with catalytically generated nitrous acid and the catalytic oxidation of hydrazine by nitric acid. The kinetic parameters of these reactions have been determined. The contribution of each reaction in the total process is determined by the liquid phase composition and by the temperature. (authors)

A review of plutonium oxalate decomposition reactions and effects of decomposition temperature on the surface area of the plutonium dioxide product

International Nuclear Information System (INIS)

Orr, R.M.; Sims, H.E.; Taylor, R.J.

2015-01-01

Plutonium (IV) and (III) ions in nitric acid solution readily form insoluble precipitates with oxalic acid. The plutonium oxalates are then easily thermally decomposed to form plutonium dioxide powder. This simple process forms the basis of current industrial conversion or ‘finishing’ processes that are used in commercial scale reprocessing plants. It is also widely used in analytical or laboratory scale operations and for waste residues treatment. However, the mechanisms of the thermal decompositions in both air and inert atmospheres have been the subject of various studies over several decades. The nature of intermediate phases is of fundamental interest whilst understanding the evolution of gases at different temperatures is relevant to process control. The thermal decomposition is also used to control a number of powder properties of the PuO_2 product that are important to either long term storage or mixed oxide fuel manufacturing. These properties are the surface area, residual carbon impurities and adsorbed volatile species whereas the morphology and particle size distribution are functions of the precipitation process. Available data and experience regarding the thermal and radiation-induced decompositions of plutonium oxalate to oxide are reviewed. The mechanisms of the thermal decompositions are considered with a particular focus on the likely redox chemistry involved. Also, whilst it is well known that the surface area is dependent on calcination temperature, there is a wide variation in the published data and so new correlations have been derived. Better understanding of plutonium (III) and (IV) oxalate decompositions will assist the development of more proliferation resistant actinide co-conversion processes that are needed for advanced reprocessing in future closed nuclear fuel cycles. - Highlights: • Critical review of plutonium oxalate decomposition reactions. • New analysis of relationship between SSA and calcination temperature. • New SEM

Hydrothermal decomposition of industrial jarosite in alkaline media: The rate determining step of the process kinetics

Directory of Open Access Journals (Sweden)

González-Ibarra A.A.

2016-01-01

Full Text Available This work examines the role of NaOH and Ca(OH2 on the hydrothermal decomposition of industrial jarosite deposited by a Mexican company in a tailings dam. The industrial jarosite is mainly composed by natrojarosite and contains 150 g Ag/t, showing a narrow particle size distribution, as revealed by XRD, fire assay, SEM-EDS and laser-diffraction analysis. The effect of the pH, when using NaOH or Ca(OH2 as alkalinizing agent was studied by carrying out decomposition experiments at different pH values and 60°C in a homogeneous size particle system (pH = 8, 9, 10 and 11 and in a heterogeneous size particle system (pH = 11. Also, the kinetic study of the process and the controlling step of the decomposition reaction when NaOH and Ca(OH2 are used was determined by fitting the data obtained to the shrinking core model for spherical particles of constant size. These results, supported by chemical (EDS, morphological (SEM and mapping of elements (EDS analysis of a partially reacted jarosite particle allowed to conclude that when NaOH is used, the process kinetics is controlled by the chemical reaction and when Ca(OH2 is used, the rate determining step is changed to a diffusion control through a layer of solid products.

Early stage litter decomposition across biomes

Science.gov (United States)

Ika Djukic; Sebastian Kepfer-Rojas; Inger Kappel Schmidt; Klaus Steenberg Larsen; Claus Beier; Björn Berg; Kris Verheyen; Adriano Caliman; Alain Paquette; Alba Gutiérrez-Girón; Alberto Humber; Alejandro Valdecantos; Alessandro Petraglia; Heather Alexander; Algirdas Augustaitis; Amélie Saillard; Ana Carolina Ruiz Fernández; Ana I. Sousa; Ana I. Lillebø; Anderson da Rocha Gripp; André-Jean Francez; Andrea Fischer; Andreas Bohner; Andrey Malyshev; Andrijana Andrić; Andy Smith; Angela Stanisci; Anikó Seres; Anja Schmidt; Anna Avila; Anne Probst; Annie Ouin; Anzar A. Khuroo; Arne Verstraeten; Arely N. Palabral-Aguilera; Artur Stefanski; Aurora Gaxiola; Bart Muys; Bernard Bosman; Bernd Ahrends; Bill Parker; Birgit Sattler; Bo Yang; Bohdan Juráni; Brigitta Erschbamer; Carmen Eugenia Rodriguez Ortiz; Casper T. Christiansen; E. Carol Adair; Céline Meredieu; Cendrine Mony; Charles A. Nock; Chi-Ling Chen; Chiao-Ping Wang; Christel Baum; Christian Rixen; Christine Delire; Christophe Piscart; Christopher Andrews; Corinna Rebmann; Cristina Branquinho; Dana Polyanskaya; David Fuentes Delgado; Dirk Wundram; Diyaa Radeideh; Eduardo Ordóñez-Regil; Edward Crawford; Elena Preda; Elena Tropina; Elli Groner; Eric Lucot; Erzsébet Hornung; Esperança Gacia; Esther Lévesque; Evanilde Benedito; Evgeny A. Davydov; Evy Ampoorter; Fabio Padilha Bolzan; Felipe Varela; Ferdinand Kristöfel; Fernando T. Maestre; Florence Maunoury-Danger; Florian Hofhansl; Florian Kitz; Flurin Sutter; Francisco Cuesta; Francisco de Almeida Lobo; Franco Leandro de Souza; Frank Berninger; Franz Zehetner; Georg Wohlfahrt; George Vourlitis; Geovana Carreño-Rocabado; Gina Arena; Gisele Daiane Pinha; Grizelle González; Guylaine Canut; Hanna Lee; Hans Verbeeck; Harald Auge; Harald Pauli; Hassan Bismarck Nacro; Héctor A. Bahamonde; Heike Feldhaar; Heinke Jäger; Helena C. Serrano; Hélène Verheyden; Helge Bruelheide; Henning Meesenburg; Hermann Jungkunst; Hervé Jactel; Hideaki Shibata; Hiroko Kurokawa; Hugo López Rosas; Hugo L. Rojas Villalobos; Ian Yesilonis; Inara Melece; Inge Van Halder; Inmaculada García Quirós; Isaac Makelele; Issaka Senou; István Fekete; Ivan Mihal; Ivika Ostonen; Jana Borovská; Javier Roales; Jawad Shoqeir; Jean-Christophe Lata; Jean-Paul Theurillat; Jean-Luc Probst; Jess Zimmerman; Jeyanny Vijayanathan; Jianwu Tang; Jill Thompson; Jiří Doležal; Joan-Albert Sanchez-Cabeza; Joël Merlet; Joh Henschel; Johan Neirynck; Johannes Knops; John Loehr; Jonathan von Oppen; Jónína Sigríður Þorláksdóttir; Jörg Löffler; José-Gilberto Cardoso-Mohedano; José-Luis Benito-Alonso; Jose Marcelo Torezan; Joseph C. Morina; Juan J. Jiménez; Juan Dario Quinde; Juha Alatalo; Julia Seeber; Jutta Stadler; Kaie Kriiska; Kalifa Coulibaly; Karibu Fukuzawa; Katalin Szlavecz; Katarína Gerhátová; Kate Lajtha; Kathrin Käppeler; Katie A. Jennings; Katja Tielbörger; Kazuhiko Hoshizaki; Ken Green; Lambiénou Yé; Laryssa Helena Ribeiro Pazianoto; Laura Dienstbach; Laura Williams; Laura Yahdjian; Laurel M. Brigham; Liesbeth van den Brink; Lindsey Rustad; al. et

2018-01-01

Through litter decomposition enormous amounts of carbon is emitted to the atmosphere. Numerous large-scale decomposition experiments have been conducted focusing on this fundamental soil process in order to understand the controls on the terrestrial carbon transfer to the atmosphere. However, previous studies were mostly based on site-specific litter and methodologies...

1.7. Acid decomposition of kaolin clays of Ziddi Deposit. 1.7.1. The hydrochloric acid decomposition of kaolin clays and siallites

International Nuclear Information System (INIS)

Mirsaidov, U.M.; Mirzoev, D.Kh.; Boboev, Kh.E.

2016-01-01

Present article of book is devoted to hydrochloric acid decomposition of kaolin clays and siallites. The chemical composition of kaolin clays and siallites was determined. The influence of temperature, process duration, acid concentration on hydrochloric acid decomposition of kaolin clays and siallites was studied. The optimal conditions of hydrochloric acid decomposition of kaolin clays and siallites were determined.

A review of plutonium oxalate decomposition reactions and effects of decomposition temperature on the surface area of the plutonium dioxide product

Energy Technology Data Exchange (ETDEWEB)

Orr, R.M.; Sims, H.E.; Taylor, R.J., E-mail: robin.j.taylor@nnl.co.uk

2015-10-15

Plutonium (IV) and (III) ions in nitric acid solution readily form insoluble precipitates with oxalic acid. The plutonium oxalates are then easily thermally decomposed to form plutonium dioxide powder. This simple process forms the basis of current industrial conversion or ‘finishing’ processes that are used in commercial scale reprocessing plants. It is also widely used in analytical or laboratory scale operations and for waste residues treatment. However, the mechanisms of the thermal decompositions in both air and inert atmospheres have been the subject of various studies over several decades. The nature of intermediate phases is of fundamental interest whilst understanding the evolution of gases at different temperatures is relevant to process control. The thermal decomposition is also used to control a number of powder properties of the PuO{sub 2} product that are important to either long term storage or mixed oxide fuel manufacturing. These properties are the surface area, residual carbon impurities and adsorbed volatile species whereas the morphology and particle size distribution are functions of the precipitation process. Available data and experience regarding the thermal and radiation-induced decompositions of plutonium oxalate to oxide are reviewed. The mechanisms of the thermal decompositions are considered with a particular focus on the likely redox chemistry involved. Also, whilst it is well known that the surface area is dependent on calcination temperature, there is a wide variation in the published data and so new correlations have been derived. Better understanding of plutonium (III) and (IV) oxalate decompositions will assist the development of more proliferation resistant actinide co-conversion processes that are needed for advanced reprocessing in future closed nuclear fuel cycles. - Highlights: • Critical review of plutonium oxalate decomposition reactions. • New analysis of relationship between SSA and calcination temperature. �

Mathematical modelling of the decomposition of explosives

International Nuclear Information System (INIS)

Smirnov, Lev P

2010-01-01

Studies on mathematical modelling of the molecular and supramolecular structures of explosives and the elementary steps and overall processes of their decomposition are analyzed. Investigations on the modelling of combustion and detonation taking into account the decomposition of explosives are also considered. It is shown that solution of problems related to the decomposition kinetics of explosives requires the use of a complex strategy based on the methods and concepts of chemical physics, solid state physics and theoretical chemistry instead of empirical approach.

Kinetics of the decomposition reaction of phosphorite concentrate

Directory of Open Access Journals (Sweden)

Huang Run

2014-01-01

Full Text Available Apatite is the raw material, which is mainly used in phosphate fertilizer, and part are used in yellow phosphorus, red phosphorus, and phosphoric acid in the industry. With the decrease of the high grade phosphorite lump, the agglomeration process is necessary for the phosphorite concentrate after beneficiation process. The decomposition behavior and the phase transformation are of vital importance for the agglomeration process of phosphorite. In this study, the thermal kinetic analysis method was used to study the kinetics of the decomposition of phosphorite concentrate. The phosphorite concentrate was heated under various heating rate, and the phases in the sample heated were examined by the X-ray diffraction method. It was found that the main phases in the phosphorite are fluorapatiteCa5(PO43F, quartz SiO2,and dolomite CaMg(CO32.The endothermic DSC peak corresponding to the mass loss caused by the decomposition of dolomite covers from 600°C to 850°C. The activation energy of the decomposition of dolomite, which increases with the increase in the extent of conversion, is about 71.6~123.6kJ/mol. The mechanism equation for the decomposition of dolomite agrees with the Valensi equation and G-B equation.

DECOMPOSITION STUDY OF CALCIUM CARBONATE IN COCKLE SHELL

Directory of Open Access Journals (Sweden)

MUSTAKIMAH MOHAMED

2012-02-01

Full Text Available Calcium oxide (CaO is recognized as an efficient carbon dioxide (CO2 adsorbent and separation of CO2 from gas stream using CaO based adsorbent is widely applied in gas purification process especially at high temperature reaction. CaO is normally been produced via thermal decomposition of calcium carbonate (CaCO3 sources such as limestone which is obtained through mining and quarrying limestone hill. Yet, this study able to exploit the vast availability of waste resources in Malaysia which is cockle shell, as the potential biomass resources for CaCO3 and CaO. In addition, effect of particle size towards decomposition process is put under study using four particle sizes which are 0.125-0.25 mm, 0.25-0.5 mm, 1-2 mm, and 2-4 mm. Decomposition reactivity is conducted using Thermal Gravimetric Analyzer (TGA at heating rate of 20°C/minutes in inert (Nitrogen atmosphere. Chemical property analysis using x-ray fluorescence (XRF, shows cockle shell is made up of 97% Calcium (Ca element and CaO is produced after decomposition is conducted, as been analyzed by x-ray diffusivity (XRD analyzer. Besides, smallest particle size exhibits the highest decomposition rate and the process was observed to follow first order kinetics. Activation energy, E, of the process was found to vary from 179.38 to 232.67 kJ/mol. From Arrhenius plot, E increased when the particle size is larger. To conclude, cockle shell is a promising source for CaO and based on four different particles sizes used, sample at 0.125-0.25 mm offers the highest decomposition rate.

Crop residue decomposition in Minnesota biochar amended plots

OpenAIRE

S. L. Weyers; K. A. Spokas

2014-01-01

Impacts of biochar application at laboratory scales are routinely studied, but impacts of biochar application on decomposition of crop residues at field scales have not been widely addressed. The priming or hindrance of crop residue decomposition could have a cascading impact on soil processes, particularly those influencing nutrient availability. Our objectives were to evaluate biochar effects on field decomposition of crop residue, using plots that were amended with ...

Decomposing a Chunk into Its Elements and Reorganizing Them As a New Chunk: The Two Different Sub-processes Underlying Insightful Chunk Decomposition

Directory of Open Access Journals (Sweden)

Xiaofei Wu

2017-11-01

Full Text Available Familiar chunks can be processed highly efficiently, and this automatic process can prohibit the problem solver from developing novel and original ways to creatively solve difficult problems. For this reason, the role of the reverse process, chunk decomposition (CD, the process by which familiar patterns are broken down into their component elements in order to be regrouped in another meaningful manner, has been generally recognized as part of the creative process. However, previous studies on this issue have mainly focused on the decomposition process of CD (the D-process, while the reorganization process of CD has been greatly neglected or has not been distinctively identified in previous work. In this paper, we argue that the R-process could be equally as important as the D-process for CD. Even if a problem solver manages to decompose a familiar chunk into its elements, he or she still may not solve the problem if these elements are not successfully organized in a new and meaningful manner. To investigate whether the cognitive mechanism of the R-process is different from that of the D-process, we designed an experiment for detecting the effects of chunk tightness, which is regarded as the key factor in CD and which can be experimentally manipulated by the radical-level (loose and stroke-level (tight Chinese character CD tasks in the D-process, the R-process, and the more purified organization task (the O-process task that does not involve the decomposition process. Our results showed that the stroke-level (tight task was more difficult than the radical-level (loose task for the D-process. However, for the R-process, the stroke- and radical-level tasks showed no differences in performance. Moreover, for the more purified reorganization task, the O-process task, the radical-level organization and reorganization could be even more difficult than the stroke-level organization and reorganization. This result demonstrated that the cognitive

Noise-assisted data processing with empirical mode decomposition in biomedical signals.

Science.gov (United States)

Karagiannis, Alexandros; Constantinou, Philip

2011-01-01

In this paper, a methodology is described in order to investigate the performance of empirical mode decomposition (EMD) in biomedical signals, and especially in the case of electrocardiogram (ECG). Synthetic ECG signals corrupted with white Gaussian noise are employed and time series of various lengths are processed with EMD in order to extract the intrinsic mode functions (IMFs). A statistical significance test is implemented for the identification of IMFs with high-level noise components and their exclusion from denoising procedures. Simulation campaign results reveal that a decrease of processing time is accomplished with the introduction of preprocessing stage, prior to the application of EMD in biomedical time series. Furthermore, the variation in the number of IMFs according to the type of the preprocessing stage is studied as a function of SNR and time-series length. The application of the methodology in MIT-BIH ECG records is also presented in order to verify the findings in real ECG signals.

Adaptive variational mode decomposition method for signal processing based on mode characteristic

Science.gov (United States)

Lian, Jijian; Liu, Zhuo; Wang, Haijun; Dong, Xiaofeng

2018-07-01

Variational mode decomposition is a completely non-recursive decomposition model, where all the modes are extracted concurrently. However, the model requires a preset mode number, which limits the adaptability of the method since a large deviation in the number of mode set will cause the discard or mixing of the mode. Hence, a method called Adaptive Variational Mode Decomposition (AVMD) was proposed to automatically determine the mode number based on the characteristic of intrinsic mode function. The method was used to analyze the simulation signals and the measured signals in the hydropower plant. Comparisons have also been conducted to evaluate the performance by using VMD, EMD and EWT. It is indicated that the proposed method has strong adaptability and is robust to noise. It can determine the mode number appropriately without modulation even when the signal frequencies are relatively close.

Maximum production rate optimization for sulphuric acid decomposition process in tubular plug-flow reactor

International Nuclear Information System (INIS)

Wang, Chao; Chen, Lingen; Xia, Shaojun; Sun, Fengrui

2016-01-01

A sulphuric acid decomposition process in a tubular plug-flow reactor with fixed inlet flow rate and completely controllable exterior wall temperature profile and reactants pressure profile is studied in this paper by using finite-time thermodynamics. The maximum production rate of the aimed product SO 2 and the optimal exterior wall temperature profile and reactants pressure profile are obtained by using nonlinear programming method. Then the optimal reactor with the maximum production rate is compared with the reference reactor with linear exterior wall temperature profile and the optimal reactor with minimum entropy generation rate. The result shows that the production rate of SO 2 of optimal reactor with the maximum production rate has an increase of more than 7%. The optimization of temperature profile has little influence on the production rate while the optimization of reactants pressure profile can significantly increase the production rate. The results obtained may provide some guidelines for the design of real tubular reactors. - Highlights: • Sulphuric acid decomposition process in tubular plug-flow reactor is studied. • Fixed inlet flow rate and controllable temperature and pressure profiles are set. • Maximum production rate of aimed product SO 2 is obtained. • Corresponding optimal temperature and pressure profiles are derived. • Production rate of SO 2 of optimal reactor increases by 7%.

Ozone decomposition

Directory of Open Access Journals (Sweden)

Batakliev Todor

2014-06-01

Full Text Available Catalytic ozone decomposition is of great significance because ozone is a toxic substance commonly found or generated in human environments (aircraft cabins, offices with photocopiers, laser printers, sterilizers. Considerable work has been done on ozone decomposition reported in the literature. This review provides a comprehensive summary of the literature, concentrating on analysis of the physico-chemical properties, synthesis and catalytic decomposition of ozone. This is supplemented by a review on kinetics and catalyst characterization which ties together the previously reported results. Noble metals and oxides of transition metals have been found to be the most active substances for ozone decomposition. The high price of precious metals stimulated the use of metal oxide catalysts and particularly the catalysts based on manganese oxide. It has been determined that the kinetics of ozone decomposition is of first order importance. A mechanism of the reaction of catalytic ozone decomposition is discussed, based on detailed spectroscopic investigations of the catalytic surface, showing the existence of peroxide and superoxide surface intermediates

A review of plutonium oxalate decomposition reactions and effects of decomposition temperature on the surface area of the plutonium dioxide product

Science.gov (United States)

Orr, R. M.; Sims, H. E.; Taylor, R. J.

2015-10-01

Plutonium (IV) and (III) ions in nitric acid solution readily form insoluble precipitates with oxalic acid. The plutonium oxalates are then easily thermally decomposed to form plutonium dioxide powder. This simple process forms the basis of current industrial conversion or 'finishing' processes that are used in commercial scale reprocessing plants. It is also widely used in analytical or laboratory scale operations and for waste residues treatment. However, the mechanisms of the thermal decompositions in both air and inert atmospheres have been the subject of various studies over several decades. The nature of intermediate phases is of fundamental interest whilst understanding the evolution of gases at different temperatures is relevant to process control. The thermal decomposition is also used to control a number of powder properties of the PuO2 product that are important to either long term storage or mixed oxide fuel manufacturing. These properties are the surface area, residual carbon impurities and adsorbed volatile species whereas the morphology and particle size distribution are functions of the precipitation process. Available data and experience regarding the thermal and radiation-induced decompositions of plutonium oxalate to oxide are reviewed. The mechanisms of the thermal decompositions are considered with a particular focus on the likely redox chemistry involved. Also, whilst it is well known that the surface area is dependent on calcination temperature, there is a wide variation in the published data and so new correlations have been derived. Better understanding of plutonium (III) and (IV) oxalate decompositions will assist the development of more proliferation resistant actinide co-conversion processes that are needed for advanced reprocessing in future closed nuclear fuel cycles.

In-situ and self-distributed: A new understanding on catalyzed thermal decomposition process of ammonium perchlorate over Nd{sub 2}O{sub 3}

Energy Technology Data Exchange (ETDEWEB)

Zou, Min, E-mail: zoumin3362765@163.com; Wang, Xin, E-mail: wangx@mail.njust.edu.cn; Jiang, Xiaohong, E-mail: jxh0668@sina.com; Lu, Lude, E-mail: lulude17@yahoo.com

2014-05-01

Catalyzed thermal decomposition process of ammonium perchlorate (AP) over neodymium oxide (Nd{sub 2}O{sub 3}) was investigated. Catalytic performances of nanometer-sized Nd{sub 2}O{sub 3} and micrometer-sized Nd{sub 2}O{sub 3} were evaluated by differential scanning calorimetry (DSC). In contrast to universal concepts, catalysts in different sizes have nearly similar catalytic activities. Based on structural and morphological variation of the catalysts during the reaction, combined with mass spectrum analyses and studies of unmixed style, a new understanding of this catalytic process was proposed. We believed that the newly formed chloride neodymium oxide (NdOCl) was the real catalytic species in the overall thermal decomposition of AP over Nd{sub 2}O{sub 3}. Meanwhile, it was the “self-distributed” procedure which occurred within the reaction that also worked for the improvement of overall catalytic activities. This work is of great value in understanding the roles of micrometer-sized catalysts used in heterogeneous reactions, especially the solid–solid reactions which could generate a large quantity of gaseous species. - Graphical abstract: In-situ and self-distributed reaction process in thermal decomposition of AP catalyzed by Nd{sub 2}O{sub 3}. - Highlights: • Micro- and nano-Nd{sub 2}O{sub 3} for catalytic thermal decomposition of AP. • No essential differences on their catalytic performances. • Structural and morphological variation of catalysts digs out catalytic mechanism. • This catalytic process is “in-situ and self-distributed” one.

Challenges of including nitrogen effects on decomposition in earth system models

Science.gov (United States)

Hobbie, S. E.

2011-12-01

Despite the importance of litter decomposition for ecosystem fertility and carbon balance, key uncertainties remain about how this fundamental process is affected by nitrogen (N) availability. Nevertheless, resolving such uncertainties is critical for mechanistic inclusion of such processes in earth system models, towards predicting the ecosystem consequences of increased anthropogenic reactive N. Towards that end, we have conducted a series of experiments examining nitrogen effects on litter decomposition. We found that both substrate N and externally supplied N (regardless of form) accelerated the initial decomposition rate. Faster initial decomposition rates were linked to the higher activity of carbohydrate-degrading enzymes associated with externally supplied N and the greater relative abundances of Gram negative and Gram positive bacteria associated with green leaves and externally supplied organic N (assessed using phospholipid fatty acid analysis, PLFA). By contrast, later in decomposition, externally supplied N slowed decomposition, increasing the fraction of slowly decomposing litter and reducing lignin-degrading enzyme activity and relative abundances of Gram negative and Gram positive bacteria. Our results suggest that elevated atmospheric N deposition may have contrasting effects on the dynamics of different soil carbon pools, decreasing mean residence times of active fractions comprising very fresh litter, while increasing those of more slowly decomposing fractions including more processed litter. Incorporating these contrasting effects of N on decomposition processes into models is complicated by lingering uncertainties about how these effects generalize across ecosystems and substrates.

Efficient photoreductive decomposition of N-nitrosodimethylamine by UV/iodide process

International Nuclear Information System (INIS)

Sun, Zhuyu; Zhang, Chaojie; Zhao, Xiaoyun; Chen, Jing; Zhou, Qi

2017-01-01

Highlights: • N-nitrosodimethylamine (NDMA) was effectively decomposed by UV/iodide process. • NDMA was completely converted to nontoxic end products by UV/iodide process. • The photoreductive process was mainly attributed to the attack of hydrated electrons on the photoexcited NDMA. • The elimination of toxic intermediates was greatly enhanced as pH increased, but its effect on NDMA removal was negligible. - Abstract: N-nitrosodimethylamine (NDMA) has aroused extensive concern as a disinfection byproduct due to its high toxicity and elevated concentration levels in water sources. This study investigates the photoreductive decomposition of NDMA by UV/iodide process. The results showed that this process is an effective strategy for the treatment of NDMA with 99.2% NDMA removed within 10 min. The depletion of NDMA by UV/iodide process obeyed pseudo-first-order kinetics with a rate constant (k_1) of 0.60 ± 0.03 min"−"1. Hydrated electrons (e_a_q"−) generated by the UV irradiation of iodide were proven to play a critical role. Dimethylamine (DMA) and nitrite (NO_2"−) were formed as the main intermediate products, which completely converted to formate (HCOO"−), ammonium (NH_4"+) and nitrogen (N_2). Therefore, not only the high efficiencies in NDMA destruction, but the elimination of toxic intermediates make UV/iodide process advantageous. A photoreduction mechanism was proposed: NDMA initially absorbed photons to a photoexcited state, and underwent a cleavage of N−NO bond under the attack of e_a_q"−. The solution pH had little impact on NDMA removal. However, alkaline conditions were more favorable for the elimination of DMA and NO_2"−, thus effectively reducing the secondary pollution.

Thermal Plasma decomposition of fluoriated greenhouse gases

Energy Technology Data Exchange (ETDEWEB)

Choi, Soo Seok; Watanabe, Takayuki [Tokyo Institute of Technology, Yokohama (Japan); Park, Dong Wha [Inha University, Incheon (Korea, Republic of)

2012-02-15

Fluorinated compounds mainly used in the semiconductor industry are potent greenhouse gases. Recently, thermal plasma gas scrubbers have been gradually replacing conventional burn-wet type gas scrubbers which are based on the combustion of fossil fuels because high conversion efficiency and control of byproduct generation are achievable in chemically reactive high temperature thermal plasma. Chemical equilibrium composition at high temperature and numerical analysis on a complex thermal flow in the thermal plasma decomposition system are used to predict the process of thermal decomposition of fluorinated gas. In order to increase economic feasibility of the thermal plasma decomposition process, increase of thermal efficiency of the plasma torch and enhancement of gas mixing between the thermal plasma jet and waste gas are discussed. In addition, noble thermal plasma systems to be applied in the thermal plasma gas treatment are introduced in the present paper.

Decomposition of residual oil by large scale HSC plant

Energy Technology Data Exchange (ETDEWEB)

Washimi, Koichi; Ogata, Yoshitaka; Limmer, H.; Schuetter, H. (Toyo Engineering Corp., funabashi, Japan VEB Petrolchemisches Kombinat Schwedt, Schwedt (East Germany))

1989-07-01

Regarding large scale and high decomposition ratio visbreaker HSC, characteristic points and operation conditions of a new plant in East Germany were introduced. As for the characteristics of the process, high decomposition ratio and stable decpmposed oil, availability of high sulfur content oil or even decomposed residuum of visbreaker, stableness of produced light oil with low content of unsaturated components, low investment with low running cost, were indicated. For the realization of high decomposition ratio, designing for suppressing the decomposition in heating furnace and accelaration of it in soaking drum, high space velocity of gas phase for better agitation, were raised. As the main subject of technical development, design of soaking drum was indicated with main dimensions for the designing. Operation conditions of the process in East Germany using residual oil supplied from already working visbreaker for USSR crude oil were introduced. 6 refs., 4 figs., 2 tabs.

Soil fauna and plant litter decomposition in tropical and subalpine forests

Science.gov (United States)

G. Gonzalez; T.R. Seastedt

2001-01-01

The decomposition of plant residues is influenced by their chemical composition, the physical-chemical environment, and the decomposer organisms. Most studies interested in latitudinal gradients of decomposition have focused on substrate quality and climate effects on decomposition, and have excluded explicit recognition of the soil organisms involved in the process....

Kinetic Analysis of Isothermal Decomposition Process of Sodium Bicarbonate Using the Weibull Probability Function—Estimation of Density Distribution Functions of the Apparent Activation Energies

Science.gov (United States)

Janković, Bojan

2009-10-01

The decomposition process of sodium bicarbonate (NaHCO3) has been studied by thermogravimetry in isothermal conditions at four different operating temperatures (380 K, 400 K, 420 K, and 440 K). It was found that the experimental integral and differential conversion curves at the different operating temperatures can be successfully described by the isothermal Weibull distribution function with a unique value of the shape parameter ( β = 1.07). It was also established that the Weibull distribution parameters ( β and η) show independent behavior on the operating temperature. Using the integral and differential (Friedman) isoconversional methods, in the conversion (α) range of 0.20 ≤ α ≤ 0.80, the apparent activation energy ( E a ) value was approximately constant ( E a, int = 95.2 kJmol-1 and E a, diff = 96.6 kJmol-1, respectively). The values of E a calculated by both isoconversional methods are in good agreement with the value of E a evaluated from the Arrhenius equation (94.3 kJmol-1), which was expressed through the scale distribution parameter ( η). The Málek isothermal procedure was used for estimation of the kinetic model for the investigated decomposition process. It was found that the two-parameter Šesták-Berggren (SB) autocatalytic model best describes the NaHCO3 decomposition process with the conversion function f(α) = α0.18(1-α)1.19. It was also concluded that the calculated density distribution functions of the apparent activation energies ( ddfE a ’s) are not dependent on the operating temperature, which exhibit the highly symmetrical behavior (shape factor = 1.00). The obtained isothermal decomposition results were compared with corresponding results of the nonisothermal decomposition process of NaHCO3.

Thermal decomposition of lanthanide and actinide tetrafluorides

International Nuclear Information System (INIS)

Gibson, J.K.; Haire, R.G.

1988-01-01

The thermal stabilities of several lanthanide/actinide tetrafluorides have been studied using mass spectrometry to monitor the gaseous decomposition products, and powder X-ray diffraction (XRD) to identify solid products. The tetrafluorides, TbF 4 , CmF 4 , and AmF 4 , have been found to thermally decompose to their respective solid trifluorides with accompanying release of fluorine, while cerium tetrafluoride has been found to be significantly more thermally stable and to congruently sublime as CeF 4 prior to appreciable decomposition. The results of these studies are discussed in relation to other relevant experimental studies and the thermodynamics of the decomposition processes. 9 refs., 3 figs

Efficient photoreductive decomposition of N-nitrosodimethylamine by UV/iodide process

Energy Technology Data Exchange (ETDEWEB)

Sun, Zhuyu; Zhang, Chaojie, E-mail: myrazh@tongji.edu.cn; Zhao, Xiaoyun; Chen, Jing; Zhou, Qi

2017-05-05

Highlights: • N-nitrosodimethylamine (NDMA) was effectively decomposed by UV/iodide process. • NDMA was completely converted to nontoxic end products by UV/iodide process. • The photoreductive process was mainly attributed to the attack of hydrated electrons on the photoexcited NDMA. • The elimination of toxic intermediates was greatly enhanced as pH increased, but its effect on NDMA removal was negligible. - Abstract: N-nitrosodimethylamine (NDMA) has aroused extensive concern as a disinfection byproduct due to its high toxicity and elevated concentration levels in water sources. This study investigates the photoreductive decomposition of NDMA by UV/iodide process. The results showed that this process is an effective strategy for the treatment of NDMA with 99.2% NDMA removed within 10 min. The depletion of NDMA by UV/iodide process obeyed pseudo-first-order kinetics with a rate constant (k{sub 1}) of 0.60 ± 0.03 min{sup −1}. Hydrated electrons (e{sub aq}{sup −}) generated by the UV irradiation of iodide were proven to play a critical role. Dimethylamine (DMA) and nitrite (NO{sub 2}{sup −}) were formed as the main intermediate products, which completely converted to formate (HCOO{sup −}), ammonium (NH{sub 4}{sup +}) and nitrogen (N{sub 2}). Therefore, not only the high efficiencies in NDMA destruction, but the elimination of toxic intermediates make UV/iodide process advantageous. A photoreduction mechanism was proposed: NDMA initially absorbed photons to a photoexcited state, and underwent a cleavage of N−NO bond under the attack of e{sub aq}{sup −}. The solution pH had little impact on NDMA removal. However, alkaline conditions were more favorable for the elimination of DMA and NO{sub 2}{sup −}, thus effectively reducing the secondary pollution.

Decomposition of argentiferous plumbojarosite in Ca O media

International Nuclear Information System (INIS)

Patino, F.; Arenas, A.; Rivera, I.; Cordoba, D.A.; Hernandez, L.; Salinas, E.

1998-01-01

The decomposition of argentiferous plumbojarosite in CaO media is studied to determine the rates dependences with respect to concentration, energetic request and particle size. The alkaline decomposition process of jarosite phase can be represented by: Pb .05 Fe 3 (SO 4 ) 2 (OH) 6 (s) + 4 (OH) - (aq) → 0.5 Pb (OH) 2 (s) + 3 Fe (OH) 3 (s) + 2 SO 4 2- (aq). The resultant solids of the decomposition formed by a gel of iron and lead hydroxides, are amorphous and do not evolve to crystalline phases of lead ferrite type in the studied conditions. The alkaline decomposition process in CaO media is of zero order with respect to the OH - concentration for [OH - ] > 10 -3 M, presenting an order of ≅ 0.5 at lower concentrations. The temperature effect indicates an activation energy of 45 KJ/mol, while the observed rates in different sizes of aggregate, as well as the whole-one are practically identical. These dependences are indicative of chemical control of the reaction because they are incompatible with a control by diffusion in ashes cape. (Author)

High Performance Polar Decomposition on Distributed Memory Systems

KAUST Repository

Sukkari, Dalal E.

2016-08-08

The polar decomposition of a dense matrix is an important operation in linear algebra. It can be directly calculated through the singular value decomposition (SVD) or iteratively using the QR dynamically-weighted Halley algorithm (QDWH). The former is difficult to parallelize due to the preponderant number of memory-bound operations during the bidiagonal reduction. We investigate the latter scenario, which performs more floating-point operations but exposes at the same time more parallelism, and therefore, runs closer to the theoretical peak performance of the system, thanks to more compute-bound matrix operations. Profiling results show the performance scalability of QDWH for calculating the polar decomposition using around 9200 MPI processes on well and ill-conditioned matrices of 100K×100K problem size. We study then the performance impact of the QDWH-based polar decomposition as a pre-processing step toward calculating the SVD itself. The new distributed-memory implementation of the QDWH-SVD solver achieves up to five-fold speedup against current state-of-the-art vendor SVD implementations. © Springer International Publishing Switzerland 2016.

Basis of the biological decomposition of xenobiotica

International Nuclear Information System (INIS)

Mueller, R. von

1993-01-01

The ability of micro-organisms to decompose different molecules and to use them as a source of carbon, nitrogen, sulphur or energy is the basis for all biological processes for cleaning up contaminated soil. Therefore, the knowledge of these decomposition processes is an important precondition for judging which contamination can be treated biologically at all and which materials can be decomposed biologically. The decomposition schemes of the most important harmful material classes (aliphatic, aromatic and chlorinated hydrocarbons) are introduced and the consequences which arise for the practical application in biological cleaning up of contaminated soils are discussed. (orig.) [de

Decomposition techniques

Science.gov (United States)

Chao, T.T.; Sanzolone, R.F.

1992-01-01

Sample decomposition is a fundamental and integral step in the procedure of geochemical analysis. It is often the limiting factor to sample throughput, especially with the recent application of the fast and modern multi-element measurement instrumentation. The complexity of geological materials makes it necessary to choose the sample decomposition technique that is compatible with the specific objective of the analysis. When selecting a decomposition technique, consideration should be given to the chemical and mineralogical characteristics of the sample, elements to be determined, precision and accuracy requirements, sample throughput, technical capability of personnel, and time constraints. This paper addresses these concerns and discusses the attributes and limitations of many techniques of sample decomposition along with examples of their application to geochemical analysis. The chemical properties of reagents as to their function as decomposition agents are also reviewed. The section on acid dissolution techniques addresses the various inorganic acids that are used individually or in combination in both open and closed systems. Fluxes used in sample fusion are discussed. The promising microwave-oven technology and the emerging field of automation are also examined. A section on applications highlights the use of decomposition techniques for the determination of Au, platinum group elements (PGEs), Hg, U, hydride-forming elements, rare earth elements (REEs), and multi-elements in geological materials. Partial dissolution techniques used for geochemical exploration which have been treated in detail elsewhere are not discussed here; nor are fire-assaying for noble metals and decomposition techniques for X-ray fluorescence or nuclear methods be discussed. ?? 1992.

Drift and transmission FT-IR spectroscopy of forest soils: an approach to determine decomposition processes of forest litter

International Nuclear Information System (INIS)

Haberhauer, G.; Gerzabek, M.H.

1999-06-01

A method is described to characterize organic soil layers using Fourier transformed infrared spectroscopy. The applicability of FT-IR, either dispersive or transmission, to investigate decomposition processes of spruce litter in soil originating from three different forest sites in two climatic regions was studied. Spectral information of transmission and diffuse reflection FT-IR spectra was analyzed and compared. For data evaluation Kubelka Munk (KM) transformation was applied to the DRIFT spectra. Sample preparation for DRIFT is simpler and less time consuming in comparison to transmission FT-IR, which uses KBr pellets. A variety of bands characteristics of molecular structures and functional groups has been identified for these complex samples. Analysis of both transmission FT-IR and DRIFT, showed that the intensity of distinct bands is a measure of the decomposition of forest litter. Interferences due to water adsorption spectra were reduced by DRIFT measurement in comparison to transmission FT-IR spectroscopy. However, data analysis revealed that intensity changes of several bands of DRIFT and transmission FT-IR were significantly correlated with soil horizons. The application of regression models enables identification and differentiation of organic forest soil horizons and allows to determine the decomposition status of soil organic matter in distinct layers. On the basis of the data presented in this study, it may be concluded that FT-IR spectroscopy is a powerful tool for the investigation of decomposition dynamics in forest soils. (author)

The nitric acid decomposition of calcined danburite concentrate of Ak-Arkhar Deposit

International Nuclear Information System (INIS)

Kurbonov, A.S.; Mamatov, E.D.; Suleymani, M.; Borudzherdi, A.; Mirsaidov, U.M.

2011-01-01

Present article is devoted to nitric acid decomposition of calcined danburite concentrate of Ak-Arkhar Deposit of Tajikistan. The obtaining of boric acid from pre backed danburite concentrate by decomposition of nitric acid was studied. The chemical composition of danburite concentrate was determined. The laboratory study of danburite leaching by nitric acid was conducted. The influence of temperature, process duration, nitric acid concentration on nitric acid decomposition of calcined danburite concentrate of Ak-Arkhar Deposit was studied as well. The optimal conditions of nitric acid decomposition of calcined danburite concentrate of Ak-Arkhar Deposit, including temperature, process duration, nitric acid concentration and particle size were proposed.

First-principles study on the initial decomposition process of CH3NH3PbI3

Science.gov (United States)

Xue, Yuanbin; Shan, Yueyue; Xu, Hu

2017-09-01

Hybrid perovskites are promising materials for high-performance photovoltaics. Unfortunately, hybrid perovskites readily decompose in particular under humid conditions, and the mechanisms of this phenomenon have not yet been fully understood. In this work, we systematically studied the possible mechanisms and the structural properties during the initial decomposition process of MAPbI3 (MA = CH3NH3+) using first-principles calculations. The theoretical results show that it is energetically favorable for PbI2 to nucleate and crystalize from the MAPbI3 matrix ahead of other decomposition products. Additionally, the structural instability is an intrinsic property of MAPbI3, regardless of whether the system is exposed to humidity. We find that H2O could facilitate the desorption of gaseous components, acting as a catalyst to transfer the H+ ion. These results provide insight into the cause of the instability of MAPbI3 and may improve our understanding of the properties of hybrid perovskites.

Excimer laser decomposition of silicone

International Nuclear Information System (INIS)

Laude, L.D.; Cochrane, C.; Dicara, Cl.; Dupas-Bruzek, C.; Kolev, K.

2003-01-01

Excimer laser irradiation of silicone foils is shown in this work to induce decomposition, ablation and activation of such materials. Thin (100 μm) laminated silicone foils are irradiated at 248 nm as a function of impacting laser fluence and number of pulsed irradiations at 1 s intervals. Above a threshold fluence of 0.7 J/cm 2 , material starts decomposing. At higher fluences, this decomposition develops and gives rise to (i) swelling of the irradiated surface and then (ii) emission of matter (ablation) at a rate that is not proportioned to the number of pulses. Taking into consideration the polymer structure and the foil lamination process, these results help defining the phenomenology of silicone ablation. The polymer decomposition results in two parts: one which is organic and volatile, and another part which is inorganic and remains, forming an ever thickening screen to light penetration as the number of light pulses increases. A mathematical model is developed that accounts successfully for this physical screening effect

Kinetics of Roasting Decomposition of the Rare Earth Elements by CaO and Coal

Directory of Open Access Journals (Sweden)

Shuai Yuan

2017-06-01

Full Text Available The roasting method of magnetic tailing mixed with CaO and coal was used to recycle the rare earth elements (REE in magnetic tailing. The phase transformation and decomposition process were researched during the roasting processes. The results showed that the decomposition processes of REE in magnetic tailing were divided into two steps. The first step from 380 to 431 °C mainly entailed the decomposition of bastnaesite (REFCO3. The second step from 605 to 716 °C mainly included the decomposition of monazite (REPO4. The decomposition products were primarily RE2O3, Ce0.75Nd0.25O1.875, CeO2, Ca5F(PO43, and CaF2. Adding CaO could reduce the decomposition temperature of REFCO3 and REPO4. Meanwhile, the decomposition effect of CaO on bastnaesite and monazite was significant. Besides, the effects of the roasting time, roasting temperature, and CaO addition level on the decomposition rate were studied. The optimum technological conditions were a roasting time of 60 min; roasting temperature of 750 °C; and CaO addition level of 20% (w/w. The maximum decomposition rate of REFCO3 and REPO4 was 99.87%. The roasting time and temperature were the major factors influencing the decomposition rate. The kinetics process of the decomposition of REFCO3 and REPO4 accorded with the interfacial reaction kinetics model. The reaction rate controlling steps were divided into two steps. The first step (at low temperature was controlled by a chemical reaction with an activation energy of 52.67 kJ/mol. The second step (at high temperature was controlled by diffusion with an activation energy of 8.5 kJ/mol.

Comparison of the thermal decomposition processes of several aminoalcohol-based ZnO inks with one containing ethanolamine

Energy Technology Data Exchange (ETDEWEB)

Gómez-Núñez, Alberto [University of Barcelona, Department of Electronics, Martí i Franquès 1, E08028-Barcelona (Spain); Roura, Pere [University of Girona, Department of Physics, Campus Montilivi, Edif. PII, E17071-Girona, Catalonia (Spain); López, Concepción [University of Barcelona, Department of Inorganic Chemistry, Martí i Franquès 1, E08028-Barcelona (Spain); Vilà, Anna, E-mail: avila@el.ub.edu [University of Barcelona, Department of Electronics, Martí i Franquès 1, E08028-Barcelona (Spain)

2016-09-15

Highlights: • Four alternatives to ethanolamine as stabilizer for the chemical synthesis of ZnO with zinc acetate dihydrate are proposed: aminopropanol, aminomethyl butanol, aminophenol and aminobenzyl alcohol. • Thermal decomposition processes described. Nitrogen cyclic compounds result. • Molecule flexibility helps decomposition, and in particular aliphatic aminoalcohols (quite flexible) decompose the precursor at lower temperatures than aromatic ones (more rigid). • Aminopropanol, aminomethyl butanol and aminobenzyl crystallize ZnO at a lower temperature than ethanolamine. • Nitrogen cyclic specimens have been identified and evolve in all cases (included ethanolamine) at temperatures up to 600 °C. - Abstract: Four inks for the production of ZnO semiconducting films have been prepared with zinc acetate dihydrate as precursor salt and one among the following aminoalcohols: aminopropanol (APr), aminomethyl butanol (AMB), aminophenol (APh) and aminobenzyl alcohol (AB) as stabilizing agent. Their thermal decomposition process has been analyzed in situ by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and evolved gas analysis (EGA), whereas the solid product has been analysed ex-situ by X-ray diffraction (XRD) and infrared spectroscopy (IR). Although, except for the APh ink, crystalline ZnO is already obtained at 300 °C, the films contain an organic residue that evolves at higher temperature in the form of a large variety of nitrogen-containing cyclic compounds. The results indicate that APr can be a better stabilizing agent than ethanolamine (EA). It gives larger ZnO crystal sizes with similar carbon content. However, a common drawback of all the amino stabilizers (EA included) is that nitrogen atoms have not been completely removed from the ZnO film at the highest temperature of our experiments (600 °C).

Basic dye decomposition kinetics in a photocatalytic slurry reactor

International Nuclear Information System (INIS)

Wu, C.-H.; Chang, H.-W.; Chern, J.-M.

2006-01-01

Wastewater effluent from textile plants using various dyes is one of the major water pollutants to the environment. Traditional chemical, physical and biological processes for treating textile dye wastewaters have disadvantages such as high cost, energy waste and generating secondary pollution during the treatment process. The photocatalytic process using TiO 2 semiconductor particles under UV light illumination has been shown to be potentially advantageous and applicable in the treatment of wastewater pollutants. In this study, the dye decomposition kinetics by nano-size TiO 2 suspension at natural solution pH was experimentally studied by varying the agitation speed (50-200 rpm), TiO 2 suspension concentration (0.25-1.71 g/L), initial dye concentration (10-50 ppm), temperature (10-50 deg. C), and UV power intensity (0-96 W). The experimental results show the agitation speed, varying from 50 to 200 rpm, has a slight influence on the dye decomposition rate and the pH history; the dye decomposition rate increases with the TiO 2 suspension concentration up to 0.98 g/L, then decrease with increasing TiO 2 suspension concentration; the initial dye decomposition rate increases with the initial dye concentration up to a certain value depending upon the temperature, then decreases with increasing initial dye concentration; the dye decomposition rate increases with the UV power intensity up to 64 W to reach a plateau. Kinetic models have been developed to fit the experimental kinetic data well

Reaction mechanism of reductive decomposition of FGD gypsum with anthracite

International Nuclear Information System (INIS)

Zheng, Da; Lu, Hailin; Sun, Xiuyun; Liu, Xiaodong; Han, Weiqing; Wang, Lianjun

2013-01-01

Highlights: • The reaction mechanism was different if the molar ratio of C/CaSO 4 was different. • The yield of CaO rises with an increase in temperature. • The optimal ratio of C/CaSO 4 = 1.2:1. • The decomposition process is mainly apparent solid–solid reaction with liquid-phase involved. - Abstract: The process of decomposition reaction between flue gas desulfurization (FGD) gypsum and anthracite is complex, which depends on the reaction conditions and atmosphere. In this study, thermogravimetric analysis with Fourier transform infrared spectroscopy (TGA-FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM) and the experiment in a tubular reactor were used to characterize the decomposition reaction in a nitrogen atmosphere under different conditions. The reaction mechanism analysis showed that the decomposition reaction process and mechanism were different when the molar proportion of C/CaSO 4 was changed. The experiment results showed that appropriate increase in the C/CaSO 4 proportion and higher temperatures were suitable for the formation of the main production of CaO, which can help us to understand the solid state reaction mechanism better. Via kinetic analysis of the reaction between anthracite and FGD gypsum under the optimal molar ratio of C/CaSO 4 , the mechanism model of the reaction was confirmed and the decomposition process was a two-step reaction which was in accordance with apparent solid–solid reaction

Thermal decomposition of zirconium compounds with some aromatic hydroxycarboxylic acids

Energy Technology Data Exchange (ETDEWEB)

Koshel, A V; Malinko, L A; Karlysheva, K F; Sheka, I A; Shchepak, N I [AN Ukrainskoj SSR, Kiev. Inst. Obshchej i Neorganicheskoj Khimii

1980-02-01

By the thermogravimetry method investigated are processes of thermal decomposition of different zirconium compounds with mandelic, parabromomandelic, salicylic and sulphosalicylic acids. For identification of decomposition products the specimens have been kept at the temperature of effects up to the constant weight. Taken are IR-spectra, rentgenoarams, carried out is elementary analysis of decomposition products. It is stated that thermal decomposition of the investigated compounds passes in stages; the final product of thermolysis is ZrO/sub 2/. Nonhydrolized compounds are stable at heating in the air up to 200-265 deg. Hydroxy compounds begin to decompose at lower temperature (80-100 deg).

Hydrothermal decomposition of liquid crystal in subcritical water

International Nuclear Information System (INIS)

Zhuang, Xuning; He, Wenzhi; Li, Guangming; Huang, Juwen; Lu, Shangming; Hou, Lianjiao

2014-01-01

Highlights: • Hydrothermal technology can effectively decompose the liquid crystal of 4-octoxy-4'-cyanobiphenyl. • The decomposition rate reached 97.6% under the optimized condition. • Octoxy-4'-cyanobiphenyl was mainly decomposed into simple and innocuous products. • The mechanism analysis reveals the decomposition reaction process. - Abstract: Treatment of liquid crystal has important significance for the environment protection and human health. This study proposed a hydrothermal process to decompose the liquid crystal of 4-octoxy-4′-cyanobiphenyl. Experiments were conducted with a 5.7 mL stainless tube reactor and heated by a salt-bath. Factors affecting the decomposition rate of 4-octoxy-4′-cyanobiphenyl were evaluated with HPLC. The decomposed liquid products were characterized by GC-MS. Under optimized conditions i.e., 0.2 mL H 2 O 2 supply, pH value 6, temperature 275 °C and reaction time 5 min, 97.6% of 4-octoxy-4′-cyanobiphenyl was decomposed into simple and environment-friendly products. Based on the mechanism analysis and products characterization, a possible hydrothermal decomposition pathway was proposed. The results indicate that hydrothermal technology is a promising choice for liquid crystal treatment

Thermal decomposition of ammonium diuranate, uranyl nitrate hexahydrate and uranyl peroxide

International Nuclear Information System (INIS)

Yulianto, T.; Mutiara, E.

2011-01-01

The behaviors of three types of starting powder had been investigated during their thermal decomposition processes in nitrogen, air, and hydrogen. The powder types were the products of uranyl nitrate precipitation, i.e. ADU (ammonium diuranate), UNH (uranyl nitrate hexahydrate), and UPO (uranyl peroxide). The objective of the investigation was to find out the best atmosphere that would result in good quality powder in a thermal decomposition process with the lowest temperature and the shortest period of time in order to reduce the cost of UO 2 powder preparation. Before the thermal decomposition process was initiated, all powder types were characterized for their crystal structures. The investigation was conducted by TG-DTA instrument at temperature up to 800°C and the heating rate of 10°C/minute. The crystal structures were identified by X-Ray Diffractometer with Cu-Ka radiation. The specific surface area of the powder was also observed using BET method, especially for the powder that underwent the process in hydrogen heated up to 800°C. The Results showed that the process took place faster in hydrogen, and UNH required lower thermal decomposition temperature in relations with other types of powder. (author)

Radiolytic decomposition of 4-bromodiphenyl ether

International Nuclear Information System (INIS)

Tang Liang; Xu Gang; Wu Wenjing; Shi Wenyan; Liu Ning; Bai Yulei; Wu Minghong

2010-01-01

Polybrominated diphenyl ethers (PBDEs) spread widely in the environment are mainly removed by photochemical and anaerobic microbial degradation. In this paper, the decomposition of 4-bromodiphenyl ether (BDE -3), the PBDEs homologues, is investigated by electron beam irradiation of its ethanol/water solution (reduction system) and acetonitrile/water solution (oxidation system). The radiolytic products were determined by GC coupled with electron capture detector, and the reaction rate constant of e sol - in the reduction system was measured at 2.7 x 10 10 L · mol -1 · s -1 by pulsed radiolysis. The results show that the BDE-3 concentration affects strongly the decomposition ratio in the alkali solution, and the reduction system has a higher BDE-3 decomposition rate than the oxidation system. This indicates that the BDE-3 was reduced by effectively capturing e sol - in radiolytic process. (authors)

Microbial community functional change during vertebrate carrion decomposition.

Directory of Open Access Journals (Sweden)

Jennifer L Pechal

Full Text Available Microorganisms play a critical role in the decomposition of organic matter, which contributes to energy and nutrient transformation in every ecosystem. Yet, little is known about the functional activity of epinecrotic microbial communities associated with carrion. The objective of this study was to provide a description of the carrion associated microbial community functional activity using differential carbon source use throughout decomposition over seasons, between years and when microbial communities were isolated from eukaryotic colonizers (e.g., necrophagous insects. Additionally, microbial communities were identified at the phyletic level using high throughput sequencing during a single study. We hypothesized that carrion microbial community functional profiles would change over the duration of decomposition, and that this change would depend on season, year and presence of necrophagous insect colonization. Biolog EcoPlates™ were used to measure the variation in epinecrotic microbial community function by the differential use of 29 carbon sources throughout vertebrate carrion decomposition. Pyrosequencing was used to describe the bacterial community composition in one experiment to identify key phyla associated with community functional changes. Overall, microbial functional activity increased throughout decomposition in spring, summer and winter while it decreased in autumn. Additionally, microbial functional activity was higher in 2011 when necrophagous arthropod colonizer effects were tested. There were inconsistent trends in the microbial function of communities isolated from remains colonized by necrophagous insects between 2010 and 2011, suggesting a greater need for a mechanistic understanding of the process. These data indicate that functional analyses can be implemented in carrion studies and will be important in understanding the influence of microbial communities on an essential ecosystem process, carrion decomposition.

Decomposition of aboveground biomass of a herbaceous wetland stand

OpenAIRE

KLIMOVIČOVÁ, Lucie

2010-01-01

The master?s thesis is part of the project GA ČR č. P504/11/1151- Role of plants in the greenhouse gas budget of a sedge fen. This thesis deals with the decomposition of aboveground vegetation in a herbaceous wetland. The decomposition rate was established on the flooded part of the Wet Meadows near Třeboň. The rate of the decomposition processes was evaluated using the litter-bag method. Mesh bags filled with dry plant matter were located in the vicinity of the automatic meteorological stati...

Advanced Oxidation: Oxalate Decomposition Testing With Ozone

International Nuclear Information System (INIS)

Ketusky, E.; Subramanian, K.

2012-01-01

At the Savannah River Site (SRS), oxalic acid is currently considered the preferred agent for chemically cleaning the large underground Liquid Radioactive Waste Tanks. It is applied only in the final stages of emptying a tank when generally less than 5,000 kg of waste solids remain, and slurrying based removal methods are no-longer effective. The use of oxalic acid is preferred because of its combined dissolution and chelating properties, as well as the fact that corrosion to the carbon steel tank walls can be controlled. Although oxalic acid is the preferred agent, there are significant potential downstream impacts. Impacts include: (1) Degraded evaporator operation; (2) Resultant oxalate precipitates taking away critically needed operating volume; and (3) Eventual creation of significant volumes of additional feed to salt processing. As an alternative to dealing with the downstream impacts, oxalate decomposition using variations of ozone based Advanced Oxidation Process (AOP) were investigated. In general AOPs use ozone or peroxide and a catalyst to create hydroxyl radicals. Hydroxyl radicals have among the highest oxidation potentials, and are commonly used to decompose organics. Although oxalate is considered among the most difficult organic to decompose, the ability of hydroxyl radicals to decompose oxalate is considered to be well demonstrated. In addition, as AOPs are considered to be 'green' their use enables any net chemical additions to the waste to be minimized. In order to test the ability to decompose the oxalate and determine the decomposition rates, a test rig was designed, where 10 vol% ozone would be educted into a spent oxalic acid decomposition loop, with the loop maintained at 70 C and recirculated at 40L/min. Each of the spent oxalic acid streams would be created from three oxalic acid strikes of an F-area simulant (i.e., Purex = high Fe/Al concentration) and H-area simulant (i.e., H area modified Purex = high Al/Fe concentration) after nearing

ADVANCED OXIDATION: OXALATE DECOMPOSITION TESTING WITH OZONE

Energy Technology Data Exchange (ETDEWEB)

Ketusky, E.; Subramanian, K.

2012-02-29

At the Savannah River Site (SRS), oxalic acid is currently considered the preferred agent for chemically cleaning the large underground Liquid Radioactive Waste Tanks. It is applied only in the final stages of emptying a tank when generally less than 5,000 kg of waste solids remain, and slurrying based removal methods are no-longer effective. The use of oxalic acid is preferred because of its combined dissolution and chelating properties, as well as the fact that corrosion to the carbon steel tank walls can be controlled. Although oxalic acid is the preferred agent, there are significant potential downstream impacts. Impacts include: (1) Degraded evaporator operation; (2) Resultant oxalate precipitates taking away critically needed operating volume; and (3) Eventual creation of significant volumes of additional feed to salt processing. As an alternative to dealing with the downstream impacts, oxalate decomposition using variations of ozone based Advanced Oxidation Process (AOP) were investigated. In general AOPs use ozone or peroxide and a catalyst to create hydroxyl radicals. Hydroxyl radicals have among the highest oxidation potentials, and are commonly used to decompose organics. Although oxalate is considered among the most difficult organic to decompose, the ability of hydroxyl radicals to decompose oxalate is considered to be well demonstrated. In addition, as AOPs are considered to be 'green' their use enables any net chemical additions to the waste to be minimized. In order to test the ability to decompose the oxalate and determine the decomposition rates, a test rig was designed, where 10 vol% ozone would be educted into a spent oxalic acid decomposition loop, with the loop maintained at 70 C and recirculated at 40L/min. Each of the spent oxalic acid streams would be created from three oxalic acid strikes of an F-area simulant (i.e., Purex = high Fe/Al concentration) and H-area simulant (i.e., H area modified Purex = high Al/Fe concentration

Hourly forecasting of global solar radiation based on multiscale decomposition methods: A hybrid approach

International Nuclear Information System (INIS)

Monjoly, Stéphanie; André, Maïna; Calif, Rudy; Soubdhan, Ted

2017-01-01

This paper introduces a new approach for the forecasting of solar radiation series at 1 h ahead. We investigated on several techniques of multiscale decomposition of clear sky index K_c data such as Empirical Mode Decomposition (EMD), Ensemble Empirical Mode Decomposition (EEMD) and Wavelet Decomposition. From these differents methods, we built 11 decomposition components and 1 residu signal presenting different time scales. We performed classic forecasting models based on linear method (Autoregressive process AR) and a non linear method (Neural Network model). The choice of forecasting method is adaptative on the characteristic of each component. Hence, we proposed a modeling process which is built from a hybrid structure according to the defined flowchart. An analysis of predictive performances for solar forecasting from the different multiscale decompositions and forecast models is presented. From multiscale decomposition, the solar forecast accuracy is significantly improved, particularly using the wavelet decomposition method. Moreover, multistep forecasting with the proposed hybrid method resulted in additional improvement. For example, in terms of RMSE error, the obtained forecasting with the classical NN model is about 25.86%, this error decrease to 16.91% with the EMD-Hybrid Model, 14.06% with the EEMD-Hybid model and to 7.86% with the WD-Hybrid Model. - Highlights: • Hourly forecasting of GHI in tropical climate with many cloud formation processes. • Clear sky Index decomposition using three multiscale decomposition methods. • Combination of multiscale decomposition methods with AR-NN models to predict GHI. • Comparison of the proposed hybrid model with the classical models (AR, NN). • Best results using Wavelet-Hybrid model in comparison with classical models.

Interacting effects of insects and flooding on wood decomposition.

Science.gov (United States)

Michael Ulyshen

2014-01-01

Saproxylic arthropods are thought to play an important role in wood decomposition but very few efforts have been made to quantify their contributions to the process and the factors controlling their activities are not well understood. In the current study, mesh exclusion bags were used to quantify how arthropods affect loblolly pine (Pinus taeda L.) decomposition rates...

Characteristic of root decomposition in a tropical rainforest in Sarawak, Malaysi

Science.gov (United States)

Ohashi, Mizue; Makita, Naoki; Katayam, Ayumi; Kume, Tomonori; Matsumoto, Kazuho; Khoon Kho, L.

2016-04-01

Woody roots play a significant role in forest carbon cycling, as up to 60 percent of tree photosynthetic production can be allocated to belowground. Root decay is one of the main processes of soil C dynamics and potentially relates to soil C sequestration. However, much less attention has been paid for root litter decomposition compared to the studies of leaf litter because roots are hidden from view. Previous studies have revealed that physico-chemical quality of roots, climate, and soil organisms affect root decomposition significantly. However, patterns and mechanisms of root decomposition are still poorly understood because of the high variability of root properties, field environment and potential decomposers. For example, root size would be a factor controlling decomposition rates, but general understanding of the difference between coarse and fine root decompositions is still lacking. Also, it is known that root decomposition is performed by soil animals, fungi and bacteria, but their relative importance is poorly understood. In this study, therefore, we aimed to characterize the root decomposition in a tropical rainforest in Sarawak, Malaysia, and clarify the impact of soil living organisms and root sizes on root litter decomposition. We buried soil cores with fine and coarse root litter bags in soil in Lambir Hills National Park. Three different types of soil cores that are covered by 1.5 cm plastic mesh, root-impermeable sheet (50um) and fungi-impermeable sheet (1um) were prepared. The soil cores were buried in February 2013 and collected 4 times, 134 days, 226 days, 786 days and 1151 days after the installation. We found that nearly 80 percent of the coarse root litter was decomposed after two years, whereas only 60 percent of the fine root litter was decomposed. Our results also showed significantly different ratio of decomposition between different cores, suggesting the different contribution of soil living organisms to decomposition process.

Implementation of domain decomposition and data decomposition algorithms in RMC code

International Nuclear Information System (INIS)

Liang, J.G.; Cai, Y.; Wang, K.; She, D.

2013-01-01

The applications of Monte Carlo method in reactor physics analysis is somewhat restricted due to the excessive memory demand in solving large-scale problems. Memory demand in MC simulation is analyzed firstly, it concerns geometry data, data of nuclear cross-sections, data of particles, and data of tallies. It appears that tally data is dominant in memory cost and should be focused on in solving the memory problem. Domain decomposition and tally data decomposition algorithms are separately designed and implemented in the reactor Monte Carlo code RMC. Basically, the domain decomposition algorithm is a strategy of 'divide and rule', which means problems are divided into different sub-domains to be dealt with separately and some rules are established to make sure the whole results are correct. Tally data decomposition consists in 2 parts: data partition and data communication. Two algorithms with differential communication synchronization mechanisms are proposed. Numerical tests have been executed to evaluate performance of the new algorithms. Domain decomposition algorithm shows potentials to speed up MC simulation as a space parallel method. As for tally data decomposition algorithms, memory size is greatly reduced

Energetic contaminants inhibit plant litter decomposition in soil.

Science.gov (United States)

Kuperman, Roman G; Checkai, Ronald T; Simini, Michael; Sunahara, Geoffrey I; Hawari, Jalal

2018-05-30

Individual effects of nitrogen-based energetic materials (EMs) 2,4-dinitrotoluene (2,4-DNT), 2-amino-4,6-dinitrotoluene (2-ADNT), 4-amino-2,6-dinitrotoluene (4-ADNT), nitroglycerin (NG), and 2,4,6,8,10,12-hexanitrohexaazaisowurtzitane (CL-20) on litter decomposition, an essential biologically-mediated soil process, were assessed using Orchard grass (Dactylis glomerata) straw in Sassafras sandy loam (SSL) soil, which has physicochemical characteristics that support "very high" qualitative relative bioavailability for organic chemicals. Batches of SSL soil were separately amended with individual EMs or acetone carrier control. To quantify the decomposition rates, one straw cluster was harvested from a set of randomly selected replicate containers from within each treatment, after 1, 2, 3, 4, 6, and 8 months of exposure. Results showed that soil amended with 2,4-DNT or NG inhibited litter decomposition rates based on the median effective concentration (EC50) values of 1122 mg/kg and 860 mg/kg, respectively. Exposure to 2-ADNT, 4-ADNT or CL-20 amended soil did not significantly affect litter decomposition in SSL soil at ≥ 10,000 mg/kg. These ecotoxicological data will be helpful in identifying concentrations of EMs in soil that present an acceptable ecological risk for biologically-mediated soil processes. Published by Elsevier Inc.

An integrated condition-monitoring method for a milling process using reduced decomposition features

International Nuclear Information System (INIS)

Liu, Jie; Wu, Bo; Hu, Youmin; Wang, Yan

2017-01-01

Complex and non-stationary cutting chatter affects productivity and quality in the milling process. Developing an effective condition-monitoring approach is critical to accurately identify cutting chatter. In this paper, an integrated condition-monitoring method is proposed, where reduced features are used to efficiently recognize and classify machine states in the milling process. In the proposed method, vibration signals are decomposed into multiple modes with variational mode decomposition, and Shannon power spectral entropy is calculated to extract features from the decomposed signals. Principal component analysis is adopted to reduce feature size and computational cost. With the extracted feature information, the probabilistic neural network model is used to recognize and classify the machine states, including stable, transition, and chatter states. Experimental studies are conducted, and results show that the proposed method can effectively detect cutting chatter during different milling operation conditions. This monitoring method is also efficient enough to satisfy fast machine state recognition and classification. (paper)

Microbial community assembly and metabolic function during mammalian corpse decomposition

Energy Technology Data Exchange (ETDEWEB)

Metcalf, J. L.; Xu, Z. Z.; Weiss, S.; Lax, S.; Van Treuren, W.; Hyde, E. R.; Song, S. J.; Amir, A.; Larsen, P.; Sangwan, N.; Haarmann, D.; Humphrey, G. C.; Ackermann, G.; Thompson, L. R.; Lauber, C.; Bibat, A.; Nicholas, C.; Gebert, M. J.; Petrosino, J. F.; Reed, S. C.; Gilbert, J. A.; Lynne, A. M.; Bucheli, S. R.; Carter, D. O.; Knight, R.

2015-12-10

Vertebrate corpse decomposition provides an important stage in nutrient cycling in most terrestrial habitats, yet microbially mediated processes are poorly understood. Here we combine deep microbial community characterization, community-level metabolic reconstruction, and soil biogeochemical assessment to understand the principles governing microbial community assembly during decomposition of mouse and human corpses on different soil substrates. We find a suite of bacterial and fungal groups that contribute to nitrogen cycling and a reproducible network of decomposers that emerge on predictable time scales. Our results show that this decomposer community is derived primarily from bulk soil, but key decomposers are ubiquitous in low abundance. Soil type was not a dominant factor driving community development, and the process of decomposition is sufficiently reproducible to offer new opportunities for forensic investigations.

Microbial community assembly and metabolic function during mammalian corpse decomposition

Science.gov (United States)

Metcalf, Jessica L; Xu, Zhenjiang Zech; Weiss, Sophie; Lax, Simon; Van Treuren, Will; Hyde, Embriette R.; Song, Se Jin; Amir, Amnon; Larsen, Peter; Sangwan, Naseer; Haarmann, Daniel; Humphrey, Greg C; Ackermann, Gail; Thompson, Luke R; Lauber, Christian; Bibat, Alexander; Nicholas, Catherine; Gebert, Matthew J; Petrosino, Joseph F; Reed, Sasha C.; Gilbert, Jack A; Lynne, Aaron M; Bucheli, Sibyl R; Carter, David O; Knight, Rob

2016-01-01

Vertebrate corpse decomposition provides an important stage in nutrient cycling in most terrestrial habitats, yet microbially mediated processes are poorly understood. Here we combine deep microbial community characterization, community-level metabolic reconstruction, and soil biogeochemical assessment to understand the principles governing microbial community assembly during decomposition of mouse and human corpses on different soil substrates. We find a suite of bacterial and fungal groups that contribute to nitrogen cycling and a reproducible network of decomposers that emerge on predictable time scales. Our results show that this decomposer community is derived primarily from bulk soil, but key decomposers are ubiquitous in low abundance. Soil type was not a dominant factor driving community development, and the process of decomposition is sufficiently reproducible to offer new opportunities for forensic investigations.

Kinetics of thermal decomposition of aluminium hydride: I-non-isothermal decomposition under vacuum and in inert atmosphere (argon)

International Nuclear Information System (INIS)

Ismail, I.M.K.; Hawkins, T.

2005-01-01

Recently, interest in aluminium hydride (alane) as a rocket propulsion ingredient has been renewed due to improvements in its manufacturing process and an increase in thermal stability. When alane is added to solid propellant formulations, rocket performance is enhanced and the specific impulse increases. Preliminary work was performed at AFRL on the characterization and evaluation of two alane samples. Decomposition kinetics were determined from gravimetric TGA data and volumetric vacuum thermal stability (VTS) results. Chemical analysis showed the samples had 88.30% (by weight) aluminium and 9.96% hydrogen. The average density, as measured by helium pycnometery, was 1.486 g/cc. Scanning electron microscopy showed that the particles were mostly composed of sharp edged crystallographic polyhedral such as simple cubes, cubic octahedrons and hexagonal prisms. Thermogravimetric analysis was utilized to investigate the decomposition kinetics of alane in argon atmosphere and to shed light on the mechanism of alane decomposition. Two kinetic models were successfully developed and used to propose a mechanism for the complete decomposition of alane and to predict its shelf-life during storage. Alane decomposes in two steps. The slowest (rate-determining) step is solely controlled by solid state nucleation of aluminium crystals; the fastest step is due to growth of the crystals. Thus, during decomposition, hydrogen gas is liberated and the initial polyhedral AlH 3 crystals yield a final mix of amorphous aluminium and aluminium crystals. After establishing the kinetic model, prediction calculations indicated that alane can be stored in inert atmosphere at temperatures below 10 deg. C for long periods of time (e.g., 15 years) without significant decomposition. After 15 years of storage, the kinetic model predicts ∼0.1% decomposition, but storage at higher temperatures (e.g. 30 deg. C) is not recommended

Multiresolution signal decomposition transforms, subbands, and wavelets

CERN Document Server

Akansu, Ali N; Haddad, Paul R

2001-01-01

The uniqueness of this book is that it covers such important aspects of modern signal processing as block transforms from subband filter banks and wavelet transforms from a common unifying standpoint, thus demonstrating the commonality among these decomposition techniques. In addition, it covers such ""hot"" areas as signal compression and coding, including particular decomposition techniques and tables listing coefficients of subband and wavelet filters and other important properties.The field of this book (Electrical Engineering/Computer Science) is currently booming, which is, of course

Decomposition of oxalate precipitates by photochemical reaction

International Nuclear Information System (INIS)

Jae-Hyung Yoo; Eung-Ho Kim

1999-01-01

A photo-radiation method was applied to decompose oxalate precipitates so that it can be dissolved into dilute nitric acid. This work has been studied as a part of partitioning of minor actinides. Minor actinides can be recovered from high-level wastes as oxalate precipitates, but they tend to be coprecipitated together with lanthanide oxalates. This requires another partitioning step for mutual separation of actinide and lanthanide groups. In this study, therefore, some experimental work of photochemical decomposition of oxalate was carried out to prove its feasibility as a step of partitioning process. The decomposition of oxalic acid in the presence of nitric acid was performed in advance in order to understand the mechanistic behaviour of oxalate destruction, and then the decomposition of neodymium oxalate, which was chosen as a stand-in compound representing minor actinide and lanthanide oxalates, was examined. The decomposition rate of neodymium oxalate was found as 0.003 mole/hr at the conditions of 0.5 M HNO 3 and room temperature when a mercury lamp was used as a light source. (author)

Thermal decomposition of biphenyl (1963); Decomposition thermique du biphenyle (1963)

Energy Technology Data Exchange (ETDEWEB)

Clerc, M [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1962-06-15

The rates of formation of the decomposition products of biphenyl; hydrogen, methane, ethane, ethylene, as well as triphenyl have been measured in the vapour and liquid phases at 460 deg. C. The study of the decomposition products of biphenyl at different temperatures between 400 and 460 deg. C has provided values of the activation energies of the reactions yielding the main products of pyrolysis in the vapour phase. Product and Activation energy: Hydrogen 73 {+-} 2 kCal/Mole; Benzene 76 {+-} 2 kCal/Mole; Meta-triphenyl 53 {+-} 2 kCal/Mole; Biphenyl decomposition 64 {+-} 2 kCal/Mole; The rate of disappearance of biphenyl is only very approximately first order. These results show the major role played at the start of the decomposition by organic impurities which are not detectable by conventional physico-chemical analysis methods and the presence of which accelerates noticeably the decomposition rate. It was possible to eliminate these impurities by zone-melting carried out until the initial gradient of the formation curves for the products became constant. The composition of the high-molecular weight products (over 250) was deduced from the mean molecular weight and the dosage of the aromatic C - H bonds by infrared spectrophotometry. As a result the existence in tars of hydrogenated tetra, penta and hexaphenyl has been demonstrated. (author) [French] Les vitesses de formation des produits de decomposition du biphenyle: hydrogene, methane, ethane, ethylene, ainsi que des triphenyles, ont ete mesurees en phase vapeur et en phase liquide a 460 deg. C. L'etude des produits de decomposition du biphenyle a differentes temperatures comprises entre 400 et 460 deg. C, a fourni les valeurs des energies d'activation des reactions conduisant aux principaux produits de la pyrolyse en phase vapeur. Produit et Energie d'activation: Hydrogene 73 {+-} 2 kcal/Mole; Benzene 76 {+-} 2 kcal/Mole; Metatriphenyle, 53 {+-} 2 kcal/Mole; Decomposition du biphenyle 64 {+-} 2 kcal/Mole; La

The thermal decomposition behavior of ammonium perchlorate and of an ammonium-perchlorate-based composite propellant

Energy Technology Data Exchange (ETDEWEB)

Behrens, R.; Minier, L.

1998-03-24

The thermal decomposition of ammonium perchlorate (AP) and ammonium-perchlorate-based composite propellants is studied using the simultaneous thermogravimetric modulated beam mass spectrometry (STMBMS) technique. The main objective of the present work is to evaluate whether the STMBMS can provide new data on these materials that will have sufficient detail on the reaction mechanisms and associated reaction kinetics to permit creation of a detailed model of the thermal decomposition process. Such a model is a necessary ingredient to engineering models of ignition and slow-cookoff for these AP-based composite propellants. Results show that the decomposition of pure AP is controlled by two processes. One occurs at lower temperatures (240 to 270 C), produces mainly H{sub 2}O, O{sub 2}, Cl{sub 2}, N{sub 2}O and HCl, and is shown to occur in the solid phase within the AP particles. 200{micro} diameter AP particles undergo 25% decomposition in the solid phase, whereas 20{micro} diameter AP particles undergo only 13% decomposition. The second process is dissociative sublimation of AP to NH{sub 3} + HClO{sub 4} followed by the decomposition of, and reaction between, these two products in the gas phase. The dissociative sublimation process occurs over the entire temperature range of AP decomposition, but only becomes dominant at temperatures above those for the solid-phase decomposition. AP-based composite propellants are used extensively in both small tactical rocket motors and large strategic rocket systems.

Influence of nitrogen dioxide on the thermal decomposition of ammonium nitrate

OpenAIRE

Igor L. Kovalenko

2015-01-01

In this paper results of experimental studies of ammonium nitrate thermal decomposition in an open system under normal conditions and in NO2 atmosphere are presented. It is shown that nitrogen dioxide is the initiator of ammonium nitrate self-accelerating exothermic cyclic decomposition process. The insertion of NO2 from outside under the conditions of nonisothermal experiment reduces the characteristic temperature of the beginning of self-accelerating decomposition by 50...70 °C. Using metho...

Continuous-variable quantum Gaussian process regression and quantum singular value decomposition of nonsparse low-rank matrices

Science.gov (United States)

Das, Siddhartha; Siopsis, George; Weedbrook, Christian

2018-02-01

With the significant advancement in quantum computation during the past couple of decades, the exploration of machine-learning subroutines using quantum strategies has become increasingly popular. Gaussian process regression is a widely used technique in supervised classical machine learning. Here we introduce an algorithm for Gaussian process regression using continuous-variable quantum systems that can be realized with technology based on photonic quantum computers under certain assumptions regarding distribution of data and availability of efficient quantum access. Our algorithm shows that by using a continuous-variable quantum computer a dramatic speedup in computing Gaussian process regression can be achieved, i.e., the possibility of exponentially reducing the time to compute. Furthermore, our results also include a continuous-variable quantum-assisted singular value decomposition method of nonsparse low rank matrices and forms an important subroutine in our Gaussian process regression algorithm.

Effect of catalyst for the decomposition of VOCs in a NTP reactor

International Nuclear Information System (INIS)

Mohanty, Suchitra; Das, Smrutiprava; Paikaray, Rita; Sahoo, Gourishankar; Samantaray, Subrata

2015-01-01

Air pollution has become a major cause of human distress both directly and indirectly. VOCs are becoming the major air pollutants. So the decomposition of VOCs is present need of our society. Non-thermal plasma reactor (NTP) is proven to be effective for low concentration VOCs decomposition. For safe and effective application of DBD, optimization of treatment process requires different plasma parameter characterization. So electron temperature and electron density parameters of VOCs show the decomposition path ways. In this piece of work by taking the emission spectra and comparing the line intensity ratios, the electron temperature and density were determined. Also the decomposition rate in terms of the deposited products on the dielectric surface was studied. Decomposition rate increases in presence of catalyst as compared to the pure compound in presence of a carrier gas. Decomposition process was studied by UV-VIS, FTIR, OES Spectroscopic methods and by GCMS. Deposited products are analyzed by UV-VIS and FTIR spectroscopy. Plasma parameters like electron temperature, density are studied with OES. And gaseous products are studied by GCMS showing the peaks for the by products. (author)

Reactivity continuum modeling of leaf, root, and wood decomposition across biomes

Science.gov (United States)

Koehler, Birgit; Tranvik, Lars J.

2015-07-01

Large carbon dioxide amounts are released to the atmosphere during organic matter decomposition. Yet the large-scale and long-term regulation of this critical process in global carbon cycling by litter chemistry and climate remains poorly understood. We used reactivity continuum (RC) modeling to analyze the decadal data set of the "Long-term Intersite Decomposition Experiment," in which fine litter and wood decomposition was studied in eight biome types (224 time series). In 32 and 46% of all sites the litter content of the acid-unhydrolyzable residue (AUR, formerly referred to as lignin) and the AUR/nitrogen ratio, respectively, retarded initial decomposition rates. This initial rate-retarding effect generally disappeared within the first year of decomposition, and rate-stimulating effects of nutrients and a rate-retarding effect of the carbon/nitrogen ratio became more prevalent. For needles and leaves/grasses, the influence of climate on decomposition decreased over time. For fine roots, the climatic influence was initially smaller but increased toward later-stage decomposition. The climate decomposition index was the strongest climatic predictor of decomposition. The similar variability in initial decomposition rates across litter categories as across biome types suggested that future changes in decomposition may be dominated by warming-induced changes in plant community composition. In general, the RC model parameters successfully predicted independent decomposition data for the different litter-biome combinations (196 time series). We argue that parameterization of large-scale decomposition models with RC model parameters, as opposed to the currently common discrete multiexponential models, could significantly improve their mechanistic foundation and predictive accuracy across climate zones and litter categories.

Signature of a spinodal decomposition in the multifragmentation process of very heavy nuclear systems

International Nuclear Information System (INIS)

Tabacaru, G.

2000-12-01

A dynamical description of the multifragmentation process shows that mechanical instabilities are responsible for spinodal decomposition of a nuclear system that spend sufficient time in the low-density region. The Xe + Sn system at 32 MeV/A incident energy, measured with INDRA multidetector, was chosen to prove experimentally this hypothesis. High performance techniques in energy calibration of Silicon detectors and CsI(Tl) scintillators were developed in order to exploit the excellent detection qualities of the multidetector. For the first time, the contribution of δ rays to the light output emitted by scintillators was quantitatively derived. Multifragmentation events coming from a system composed by almost all of nucleons of the reaction entrance channel were selected using detection completeness and event shape criteria. The dynamical model BoB realistically simulates the spinodal instabilities. This model reproduces all of dynamic and static observables. More exclusive comparisons were made to constrain again the model. Reduced velocity correlation functions were studied and gave information about the topology of the fragments at freeze-out. Charge correlation of the fragments showed that a small proportion of events (0.1 %) emits equal-sized fragments. This was interpreted as a fossil signature of the spinodal decomposition in a finite system. Indirectly, this is a proof of a first order phase transition associated to the multifragmentation of hot nuclei. (author)

Decomposition and reduction of AUC in hydrogen

International Nuclear Information System (INIS)

Ge Qingren; Kang Shifang; Zhou Meng

1987-01-01

AUC (Ammonium Uranyl Carbonate) conversion processes have been adopted extensively in nuclear fuel cycle. The kinetics investigation of these processes, however, has not yet been reported in detail at the published literatures. In the present work, the decomposition kinetics of AUC in hydrogen has been determined by non-isothermal method. DSC curves are solved with computer by Ge Qingren method. The results show that the kinetics obeys Avrami-Erofeev equation within 90% conversion. The apparent activation energy and preexponent are found to be 113.0 kJ/mol and 7.11 x 10 11 s -1 respectively. The reduction kinetics of AUC decomposition product in hydrogen at the range of 450 - 600 deg C has been determined by isothermal thermogravimetric method. The results show that good linear relationship can be obtained from the plot of conversion vs time, and that the apparent activation energy is found to be 113.9 kJ/mol. The effects of particle size and partial pressure of hydrogen are examined in reduction of AUC decomposition product. The reduction mechanism and the structure of particle are discussed according to the kinetics behaviour and SEM (scanning electron microscope) photograph

DECOMPOSITION OF TARS IN MICROWAVE PLASMA – PRELIMINARY RESULTS

Directory of Open Access Journals (Sweden)

Mateusz Wnukowski

2014-07-01

Full Text Available The paper refers to the main problem connected with biomass gasification - a presence of tar in a product gas. This paper presents preliminary results of tar decomposition in a microwave plasma reactor. It gives a basic insight into the construction and work of the plasma reactor. During the experiment, researches were carried out on toluene as a tar surrogate. As a carrier gas for toluene and as a plasma agent, nitrogen was used. Flow rates of the gases and the microwave generator’s power were constant during the whole experiment. Results of the experiment showed that the decomposition process of toluene was effective because the decomposition efficiency attained above 95%. The main products of tar decomposition were light hydrocarbons and soot. The article also gives plans for further research in a matter of tar removal from the product gas.

Decomposition of Factors and Criteria for Evaluating the Process of Intellectualization of Enterprise Management Systems

Directory of Open Access Journals (Sweden)

Kuzmin Oleh Ye.

2017-03-01

Full Text Available The article presents the author’s vision of solving the scientific problem of determining factors of influence and forming criteria for evaluating the process of intellectualization of enterprise management systems. It is found that diagnostic evaluation of the process of intellectualization of enterprise management systems depends on the influence of factors of the internal environment of the management systems, personal motivation factors, and the external environment. There carried out decomposition of the process of intellectualization of management systems into separate constituents and group criteria for diagnosing and their detailed indicators are selected. The basic group criteria for evaluating the process of intellectualization of management systems include: knowledge potential of carriers of intelligence; human capital; intellectual competence level of the management personnel; motivation of carriers of intelligence; state of the management development; scientific and research potential; development of information and communication technologies; intellectual and economic activity; formation of intellectual capital; institutional development of the management system, formation of knowledge and innovation prospects; complexity of the intellectualization process.

Energetic Materials Effects on Essential Soil Processes: Decomposition of Orchard Grass (Dactylis glomerata) Litter in Soil Contaminated with Energetic Materials

Science.gov (United States)

2014-02-01

availabilities of their respective food sources (bacteria and fungi ), were also unaffected-or-increasing in soil with CL-20 treatments. This is...ENERGETIC MATERIALS EFFECTS ON ESSENTIAL SOIL PROCESSES: DECOMPOSITION OF ORCHARD...GRASS (DACTYLIS GLOMERATA) LITTER IN SOIL CONTAMINATED WITH ENERGETIC MATERIALS ECBC-TR-1199 Roman G. Kuperman Ronald T. Checkai Michael Simini

A simple method for decomposition of peracetic acid in a microalgal cultivation system.

Science.gov (United States)

Sung, Min-Gyu; Lee, Hansol; Nam, Kibok; Rexroth, Sascha; Rögner, Matthias; Kwon, Jong-Hee; Yang, Ji-Won

2015-03-01

A cost-efficient process devoid of several washing steps was developed, which is related to direct cultivation following the decomposition of the sterilizer. Peracetic acid (PAA) is known to be an efficient antimicrobial agent due to its high oxidizing potential. Sterilization by 2 mM PAA demands at least 1 h incubation time for an effective disinfection. Direct degradation of PAA was demonstrated by utilizing components in conventional algal medium. Consequently, ferric ion and pH buffer (HEPES) showed a synergetic effect for the decomposition of PAA within 6 h. On the contrary, NaNO3, one of the main components in algal media, inhibits the decomposition of PAA. The improved growth of Chlorella vulgaris and Synechocystis PCC6803 was observed in the prepared BG11 by decomposition of PAA. This process involving sterilization and decomposition of PAA should help cost-efficient management of photobioreactors in a large scale for the production of value-added products and biofuels from microalgal biomass.

Mechanism and kinetics of thermal decomposition of ammoniacal complex of copper oxalate

International Nuclear Information System (INIS)

Prasad, R.

2003-01-01

A complex precursor has been synthesized by dissolving copper oxalate in liquor ammonia followed by drying. The thermal decomposition of the precursor has been studied in different atmospheres, air/nitrogen. The mechanism of decomposition of the precursor in air is not as simple one as in nitrogen. In nitrogen, it involves endothermic deammoniation followed by decomposition to finely divided elemental particles of copper. Whereas in air, decomposition and simultaneous oxidation of the residual products (oxidative decomposition), make the process complex and relatively bigger particle of cupric oxide are obtained as final product. The products of decomposition in different atmospheres have been characterized by X-ray diffraction and particle size analysis. The stoichiometric formula, Cu(NH 3 ) 2 C 2 O 4 of the precursor is established from elemental analysis and TG measurements, and it is designated as copper amino oxalate (CAO). In nitrogen atmosphere, the deammoniation and decomposition have been found to be zero and first order, respectively. The values of activation energy have been found to be 102.52 and 95.38 kJ/mol for deammoniation and decomposition, respectively

Analysis of sulfur-iodine thermochemical cycle for solar hydrogen production. Part 1: decomposition of sulfuric acid

Energy Technology Data Exchange (ETDEWEB)

Huang, Cunping; T-Raissi, Ali [Central Florida Univ., Florida Solar Energy Center, Cocoa, FL (United States)

2005-05-01

The sulfur-iodine (S-I) thermochemical water splitting cycle is one of the most studied cycles for hydrogen (H{sub 2}) production. S-I cycle consists of four sections: (I) acid production and separation and oxygen purification, (II) sulfuric acid concentration and decomposition, (III) hydroiodic acid (HI) concentration, and (IV) HI decomposition and H{sub 2} purification. Section II of the cycle is an endothermic reaction driven by the heat input from a high temperature source. Analysis of the S-I cycle in the past thirty years have been focused mostly on the utilization of nuclear power as the high temperature heat source for the sulfuric acid decomposition step. Thermodynamic as well as kinetic considerations indicate that both the extent and rate of sulfuric acid decomposition can be improved at very high temperatures (in excess of 1000 deg C) available only from solar concentrators. The beneficial effect of high temperature solar heat for decomposition of sulfuric acid in the S-I cycle is described in this paper. We used Aspen Technologies' HYSYS chemical process simulator (CPS) to develop flowsheets for sulfuric acid (H{sub 2}SO{sub 4}) decomposition that include all mass and heat balances. Based on the HYSYS analyses, two new process flowsheets were developed. These new sulfuric acid decomposition processes are simpler and more stable than previous processes and yield higher conversion efficiencies for the sulfuric acid decomposition and sulfur dioxide and oxygen formation. (Author)

In-situ EXAFS study on the thermal decomposition of TiH2

International Nuclear Information System (INIS)

Zhou Yingli; Wu Min; An Pengfei; Zheng Lirong; Chu Shengqi; Zhang Jing; Hu Tiandou

2014-01-01

Thermal decomposition behaviors of TiH 2 powder under a flowing helium atmosphere and in a low vacuum condition have been studied using an in situ EXAFS technique. By an EXAFS analysis containing the multiple scattering paths including H atoms, the changes of the hydrogen stoichiometric ratio and the phase transformation sequence are obtained. The results demonstrate that the initial decomposition temperature is dependent on experimental conditions, which occurs, respectively, at about 300 and 400 °C in a low vacuum condition and under a flowing helium atmosphere. During the decomposition process of TiH 2 in a low vacuum condition, the sample experiences a phase change process: δ(TiH 2 ) → δ (TiH x ) → δ(TiH x )+ β(TiH x ) → δ(TiH x )+ β(TiH x ) + α(Ti) → β(TiH x ) + α(Ti) → α(Ti) + β(Ti). This study offers a way to detect the structural information of hydrogen. A detailed discussion about the decomposition process of TiH 2 is given in this paper. (authors)

Aligning observed and modelled behaviour based on workflow decomposition

Science.gov (United States)

Wang, Lu; Du, YuYue; Liu, Wei

2017-09-01

When business processes are mostly supported by information systems, the availability of event logs generated from these systems, as well as the requirement of appropriate process models are increasing. Business processes can be discovered, monitored and enhanced by extracting process-related information. However, some events cannot be correctly identified because of the explosion of the amount of event logs. Therefore, a new process mining technique is proposed based on a workflow decomposition method in this paper. Petri nets (PNs) are used to describe business processes, and then conformance checking of event logs and process models is investigated. A decomposition approach is proposed to divide large process models and event logs into several separate parts that can be analysed independently; while an alignment approach based on a state equation method in PN theory enhances the performance of conformance checking. Both approaches are implemented in programmable read-only memory (ProM). The correctness and effectiveness of the proposed methods are illustrated through experiments.

Character Decomposition and Transposition Processes in Chinese Compound Words Modulates Attentional Blink.

Science.gov (United States)

Cao, Hongwen; Gao, Min; Yan, Hongmei

2016-01-01

The attentional blink (AB) is the phenomenon in which the identification of the second of two targets (T2) is attenuated if it is presented less than 500 ms after the first target (T1). Although the AB is eliminated in canonical word conditions, it remains unclear whether the character order in compound words affects the magnitude of the AB. Morpheme decomposition and transposition of Chinese two-character compound words can provide an effective means to examine AB priming and to assess combinations of the component representations inherent to visual word identification. In the present study, we examined the processing of consecutive targets in a rapid serial visual presentation (RSVP) paradigm using Chinese two-character compound words in which the two characters were transposed to form meaningful words or meaningless combinations (reversible, transposed, or canonical words). We found that when two Chinese characters that form a compound word, regardless of their order, are presented in an RSVP sequence, the likelihood of an AB for the second character is greatly reduced or eliminated compared to when the two characters constitute separate words rather than a compound word. Moreover, the order of the report for the two characters is more likely to be reversed when the normal order of the two characters in a compound word is reversed, especially when the interval between the presentation of the two characters is extremely short. These findings are more consistent with the cognitive strategy hypothesis than the resource-limited hypothesis during character decomposition and transposition of Chinese two-character compound words. These results suggest that compound characters are perceived as a unit, rather than two separate words. The data further suggest that readers could easily understand the text with character transpositions in compound words during Chinese reading.

Empirical projection-based basis-component decomposition method

Science.gov (United States)

Brendel, Bernhard; Roessl, Ewald; Schlomka, Jens-Peter; Proksa, Roland

2009-02-01

Advances in the development of semiconductor based, photon-counting x-ray detectors stimulate research in the domain of energy-resolving pre-clinical and clinical computed tomography (CT). For counting detectors acquiring x-ray attenuation in at least three different energy windows, an extended basis component decomposition can be performed in which in addition to the conventional approach of Alvarez and Macovski a third basis component is introduced, e.g., a gadolinium based CT contrast material. After the decomposition of the measured projection data into the basis component projections, conventional filtered-backprojection reconstruction is performed to obtain the basis-component images. In recent work, this basis component decomposition was obtained by maximizing the likelihood-function of the measurements. This procedure is time consuming and often unstable for excessively noisy data or low intrinsic energy resolution of the detector. Therefore, alternative procedures are of interest. Here, we introduce a generalization of the idea of empirical dual-energy processing published by Stenner et al. to multi-energy, photon-counting CT raw data. Instead of working in the image-domain, we use prior spectral knowledge about the acquisition system (tube spectra, bin sensitivities) to parameterize the line-integrals of the basis component decomposition directly in the projection domain. We compare this empirical approach with the maximum-likelihood (ML) approach considering image noise and image bias (artifacts) and see that only moderate noise increase is to be expected for small bias in the empirical approach. Given the drastic reduction of pre-processing time, the empirical approach is considered a viable alternative to the ML approach.

Radiation decomposition of alcohols and chloro phenols in micellar systems

International Nuclear Information System (INIS)

Moreno A, J.

1998-01-01

The effect of surfactants on the radiation decomposition yield of alcohols and chloro phenols has been studied with gamma doses of 2, 3, and 5 KGy. These compounds were used as typical pollutants in waste water, and the effect of the water solubility, chemical structure, and the nature of the surfactant, anionic or cationic, was studied. The results show that anionic surfactant like sodium dodecylsulfate (SDS), improve the radiation decomposition yield of ortho-chloro phenol, while cationic surfactant like cetyl trimethylammonium chloride (CTAC), improve the radiation decomposition yield of butyl alcohol. A similar behavior is expected for those alcohols with water solubility close to the studied ones. Surfactant concentrations below critical micellar concentration (CMC), inhibited radiation decomposition for both types of alcohols. However radiation decomposition yield increased when surfactant concentrations were bigger than the CMC. Aromatic alcohols decomposition was more marked than for linear alcohols decomposition. On a mixture of alcohols and chloro phenols in aqueous solution the radiation decomposition yield decreased with increasing surfactant concentration. Nevertheless, there were competitive reactions between the alcohols, surfactants dimers, hydroxyl radical and other reactive species formed on water radiolysis, producing a catalytic positive effect in the decomposition of alcohols. Chemical structure and the number of carbons were not important factors in the radiation decomposition. When an alcohol like ortho-chloro phenol contained an additional chlorine atom, the decomposition of this compound was almost constant. In conclusion the micellar effect depend on both, the nature of the surfactant (anionic or cationic) and the chemical structure of the alcohols. The results of this study are useful for wastewater treatment plants based on the oxidant effect of the hydroxyl radical, like in advanced oxidation processes, or in combined treatment such as

Decompositions of manifolds

CERN Document Server

Daverman, Robert J

2007-01-01

Decomposition theory studies decompositions, or partitions, of manifolds into simple pieces, usually cell-like sets. Since its inception in 1929, the subject has become an important tool in geometric topology. The main goal of the book is to help students interested in geometric topology to bridge the gap between entry-level graduate courses and research at the frontier as well as to demonstrate interrelations of decomposition theory with other parts of geometric topology. With numerous exercises and problems, many of them quite challenging, the book continues to be strongly recommended to eve

Thermal decomposition of pyrite

International Nuclear Information System (INIS)

Music, S.; Ristic, M.; Popovic, S.

1992-01-01

Thermal decomposition of natural pyrite (cubic, FeS 2 ) has been investigated using X-ray diffraction and 57 Fe Moessbauer spectroscopy. X-ray diffraction analysis of pyrite ore from different sources showed the presence of associated minerals, such as quartz, szomolnokite, stilbite or stellerite, micas and hematite. Hematite, maghemite and pyrrhotite were detected as thermal decomposition products of natural pyrite. The phase composition of the thermal decomposition products depends on the terature, time of heating and starting size of pyrite chrystals. Hematite is the end product of the thermal decomposition of natural pyrite. (author) 24 refs.; 6 figs.; 2 tabs

Gamma ray induced decomposition of lanthanide nitrates

International Nuclear Information System (INIS)

Joshi, N.G.; Garg, A.N.

1992-01-01

Gamma ray induced decomposition of the lanthanide nitrates, Ln(NO 3 ) 3 .xH 2 O where Ln=La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Tm and Yb has been studied at different absorbed doses up to 600 kGy. G(NO 2 - ) values depend on the absorbed dose and the nature of the outer cation. It has been observed that those lanthanides which exhibit variable valency (Ce and Eu) show lower G-values. An attempt has been made to correlate thermal and radiolytic decomposition processes. (author). 20 refs., 3 figs., 1 tab

An optimization approach for fitting canonical tensor decompositions.

Energy Technology Data Exchange (ETDEWEB)

Dunlavy, Daniel M. (Sandia National Laboratories, Albuquerque, NM); Acar, Evrim; Kolda, Tamara Gibson

2009-02-01

Tensor decompositions are higher-order analogues of matrix decompositions and have proven to be powerful tools for data analysis. In particular, we are interested in the canonical tensor decomposition, otherwise known as the CANDECOMP/PARAFAC decomposition (CPD), which expresses a tensor as the sum of component rank-one tensors and is used in a multitude of applications such as chemometrics, signal processing, neuroscience, and web analysis. The task of computing the CPD, however, can be difficult. The typical approach is based on alternating least squares (ALS) optimization, which can be remarkably fast but is not very accurate. Previously, nonlinear least squares (NLS) methods have also been recommended; existing NLS methods are accurate but slow. In this paper, we propose the use of gradient-based optimization methods. We discuss the mathematical calculation of the derivatives and further show that they can be computed efficiently, at the same cost as one iteration of ALS. Computational experiments demonstrate that the gradient-based optimization methods are much more accurate than ALS and orders of magnitude faster than NLS.

Wood decomposition as influenced by invertebrates.

Science.gov (United States)

Ulyshen, Michael D

2016-02-01

The diversity and habitat requirements of invertebrates associated with dead wood have been the subjects of hundreds of studies in recent years but we still know very little about the ecological or economic importance of these organisms. The purpose of this review is to examine whether, how and to what extent invertebrates affect wood decomposition in terrestrial ecosystems. Three broad conclusions can be reached from the available literature. First, wood decomposition is largely driven by microbial activity but invertebrates also play a significant role in both temperate and tropical environments. Primary mechanisms include enzymatic digestion (involving both endogenous enzymes and those produced by endo- and ectosymbionts), substrate alteration (tunnelling and fragmentation), biotic interactions and nitrogen fertilization (i.e. promoting nitrogen fixation by endosymbiotic and free-living bacteria). Second, the effects of individual invertebrate taxa or functional groups can be accelerative or inhibitory but the cumulative effect of the entire community is generally to accelerate wood decomposition, at least during the early stages of the process (most studies are limited to the first 2-3 years). Although methodological differences and design limitations preclude meta-analysis, studies aimed at quantifying the contributions of invertebrates to wood decomposition commonly attribute 10-20% of wood loss to these organisms. Finally, some taxa appear to be particularly influential with respect to promoting wood decomposition. These include large wood-boring beetles (Coleoptera) and termites (Termitoidae), especially fungus-farming macrotermitines. The presence or absence of these species may be more consequential than species richness and the influence of invertebrates is likely to vary biogeographically. Published 2014. This article is a U.S. Government work and is in the public domain in the USA.

[Decomposition of corpses--a microbial degradation process with special reference to mummification, formation of adipocere and incomplete putrified corpes].

Science.gov (United States)

Schoenen, Dirk

2013-01-01

Decomposition of the human body is a microbial process. It is influenced by the environmental situation and it depends to a high degree on the exchange of substances between the corpse and the environment. Mummification occurs at low humidity or frost. Adipocere arises from lack of oxygen, incomplete putrified corpses develop when there is no exchange of air or water between the corpse and the environment.

The production of lithium oxide microspheres from the disintegration of a liquid jet

International Nuclear Information System (INIS)

Al-Ubaidi, M.R.; Anno, J.N.

1989-01-01

Microspheres of lithium hydroxide (LiOH) were produced from in-flight solidification of droplets formed by the disintegration of an acoustically driven, mechanically vibrated cylindrical liquid jet of molten LiOH. The molten material at 470 to 480 degrees C was fed through a 25-gauge (0.0267-cm bore diameter) nozzle, interiorly electroplated with silver, under ∼27.6-kPa (4-psig) pressure, and at a mechanical vibration frequency of 10 Hz. The resulting jet issued into a 5.5-cm-diam vertical glass drop tube entraining a 94.5 cm 3 /s (12 ft 3 /h) argon gas stream at 75 degrees C. The 100-cm-long drop tube was sufficient to allow the droplets of molten LiOH resulting from jet disintegration to solidify in-flight without catastrophic thermal shock, being then collected a solid microspheres. These LiOH microspheres were then vacuum processed to lithium oxide (Li 2 O). Preliminary experiments resulted in microspheres with diameters varying from 120 to 185 μm, but with evidence of impurity contamination occurring during the initial stages of the process

Azimuthal decomposition of optical modes

CSIR Research Space (South Africa)

Dudley, Angela L

2012-07-01

Full Text Available This presentation analyses the azimuthal decomposition of optical modes. Decomposition of azimuthal modes need two steps, namely generation and decomposition. An azimuthally-varying phase (bounded by a ring-slit) placed in the spatial frequency...

Advances in hydrogen production by thermochemical water decomposition: A review

International Nuclear Information System (INIS)

Rosen, Marc A.

2010-01-01

Hydrogen demand as an energy currency is anticipated to rise significantly in the future, with the emergence of a hydrogen economy. Hydrogen production is a key component of a hydrogen economy. Several production processes are commercially available, while others are under development including thermochemical water decomposition, which has numerous advantages over other hydrogen production processes. Recent advances in hydrogen production by thermochemical water decomposition are reviewed here. Hydrogen production from non-fossil energy sources such as nuclear and solar is emphasized, as are efforts to lower the temperatures required in thermochemical cycles so as to expand the range of potential heat supplies. Limiting efficiencies are explained and the need to apply exergy analysis is illustrated. The copper-chlorine thermochemical cycle is considered as a case study. It is concluded that developments of improved processes for hydrogen production via thermochemical water decomposition are likely to continue, thermochemical hydrogen production using such non-fossil energy will likely become commercial, and improved efficiencies are expected to be obtained with advanced methodologies like exergy analysis. Although numerous advances have been made on sulphur-iodine cycles, the copper-chlorine cycle has significant potential due to its requirement for process heat at lower temperatures than most other thermochemical processes.

Thermal decomposition of lutetium propionate

DEFF Research Database (Denmark)

Grivel, Jean-Claude

2010-01-01

The thermal decomposition of lutetium(III) propionate monohydrate (Lu(C2H5CO2)3·H2O) in argon was studied by means of thermogravimetry, differential thermal analysis, IR-spectroscopy and X-ray diffraction. Dehydration takes place around 90 °C. It is followed by the decomposition of the anhydrous...... °C. Full conversion to Lu2O3 is achieved at about 1000 °C. Whereas the temperatures and solid reaction products of the first two decomposition steps are similar to those previously reported for the thermal decomposition of lanthanum(III) propionate monohydrate, the final decomposition...... of the oxycarbonate to the rare-earth oxide proceeds in a different way, which is here reminiscent of the thermal decomposition path of Lu(C3H5O2)·2CO(NH2)2·2H2O...

Demonstration of base catalyzed decomposition process, Navy Public Works Center, Guam, Mariana Islands

Energy Technology Data Exchange (ETDEWEB)

Schmidt, A.J.; Freeman, H.D.; Brown, M.D.; Zacher, A.H.; Neuenschwander, G.N.; Wilcox, W.A.; Gano, S.R. [Pacific Northwest National Lab., Richland, WA (United States); Kim, B.C.; Gavaskar, A.R. [Battelle Columbus Div., OH (United States)

1996-02-01

Base Catalyzed Decomposition (BCD) is a chemical dehalogenation process designed for treating soils and other substrate contaminated with polychlorinated biphenyls (PCB), pesticides, dioxins, furans, and other hazardous organic substances. PCBs are heavy organic liquids once widely used in industry as lubricants, heat transfer oils, and transformer dielectric fluids. In 1976, production was banned when PCBs were recognized as carcinogenic substances. It was estimated that significant quantities (one billion tons) of U.S. soils, including areas on U.S. military bases outside the country, were contaminated by PCB leaks and spills, and cleanup activities began. The BCD technology was developed in response to these activities. This report details the evolution of the process, from inception to deployment in Guam, and describes the process and system components provided to the Navy to meet the remediation requirements. The report is divided into several sections to cover the range of development and demonstration activities. Section 2.0 gives an overview of the project history. Section 3.0 describes the process chemistry and remediation steps involved. Section 4.0 provides a detailed description of each component and specific development activities. Section 5.0 details the testing and deployment operations and provides the results of the individual demonstration campaigns. Section 6.0 gives an economic assessment of the process. Section 7.0 presents the conclusions and recommendations form this project. The appendices contain equipment and instrument lists, equipment drawings, and detailed run and analytical data.

Decomposition of aluminosilicate ores of Afghanistan by hydrochloric acid

International Nuclear Information System (INIS)

Mamatov, E.D.; Khomidi, A.K.

2015-01-01

Present article is devoted to decomposition of aluminosilicate ores of Afghanistan by hydrochloric acid. The physicochemical properties of initial aluminosilicate ores were studied by means of X-ray phase, differential-thermal analysis methods. The chemical and mineral composition of aluminosilicate ores was considered. The kinetics of acid decomposition of aluminosilicate ores composed of two stages was studied as well. The flowsheets of complex processing of aluminium comprising ores by means of chloric and acid methods were proposed.

New insight in the template decomposition process of large zeolite ZSM-5 crystals: an in situ UV-Vis/fluorescence micro-spectroscopy study

NARCIS (Netherlands)

Karwacki, L.|info:eu-repo/dai/nl/304824283; Weckhuysen, B.M.|info:eu-repo/dai/nl/285484397

2011-01-01

A combination of in situ UV-Vis and confocal fluorescence micro-spectroscopy was used to study the template decomposition process in large zeolite ZSM-5 crystals. Correlation of polarized light dependent UV-Vis absorption spectra with confocal fluorescence emission spectra in the 400–750 nm region

Tea polyphenols dominate the short-term tea (Camellia sinensis) leaf litter decomposition*

Science.gov (United States)

Fan, Dong-mei; Fan, Kai; Yu, Cui-ping; Lu, Ya-ting; Wang, Xiao-chang

2017-01-01

Polyphenols are one of the most important secondary metabolites, and affect the decomposition of litter and soil organic matter. This study aims to monitor the mass loss rate of tea leaf litter and nutrient release pattern, and investigate the role of tea polyphenols played in this process. High-performance liquid chromatography (HPLC) and classical litter bag method were used to simulate the decomposition process of tea leaf litter and track the changes occurring in major polyphenols over eight months. The release patterns of nitrogen, potassium, calcium, and magnesium were also determined. The decomposition pattern of tea leaf litter could be described by a two-phase decomposition model, and the polyphenol/N ratio effectively regulated the degradation process. Most of the catechins decreased dramatically within two months; gallic acid (GA), catechin gallate (CG), and gallocatechin (GC) were faintly detected, while others were outside the detection limits by the end of the experiment. These results demonstrated that tea polyphenols transformed quickly and catechins had an effect on the individual conversion rate. The nutrient release pattern was different from other plants which might be due to the existence of tea polyphenols. PMID:28124839

Tea polyphenols dominate the short-term tea (Camellia sinensis) leaf litter decomposition.

Science.gov (United States)

Fan, Dong-Mei; Fan, Kai; Yu, Cui-Ping; Lu, Ya-Ting; Wang, Xiao-Chang

Polyphenols are one of the most important secondary metabolites, and affect the decomposition of litter and soil organic matter. This study aims to monitor the mass loss rate of tea leaf litter and nutrient release pattern, and investigate the role of tea polyphenols played in this process. High-performance liquid chromatography (HPLC) and classical litter bag method were used to simulate the decomposition process of tea leaf litter and track the changes occurring in major polyphenols over eight months. The release patterns of nitrogen, potassium, calcium, and magnesium were also determined. The decomposition pattern of tea leaf litter could be described by a two-phase decomposition model, and the polyphenol/N ratio effectively regulated the degradation process. Most of the catechins decreased dramatically within two months; gallic acid (GA), catechin gallate (CG), and gallocatechin (GC) were faintly detected, while others were outside the detection limits by the end of the experiment. These results demonstrated that tea polyphenols transformed quickly and catechins had an effect on the individual conversion rate. The nutrient release pattern was different from other plants which might be due to the existence of tea polyphenols.

Application of Decomposition Methodology to Solve Integrated Process Design and Controller Design Problems for Reactor-Separator-Recycle System

DEFF Research Database (Denmark)

Abd.Hamid, Mohd-Kamaruddin; Sin, Gürkan; Gani, Rafiqul

2010-01-01

This paper presents the integrated process design and controller design (IPDC) for a reactor-separator-recycle (RSR) system and evaluates a decomposition methodology to solve the IPDC problem. Accordingly, the IPDC problem is solved by decomposing it into four hierarchical stages: (i) pre...... the design of a RSR system involving consecutive reactions, A B -> C and shown to provide effective solutions that satisfy design, control and cost criteria. The advantage of the proposed methodology is that it is systematic, makes use of thermodynamic-process knowledge and provides valuable insights......-analysis, (ii) design analysis, (iii) controller design analysis, and (iv) final selection and verification. The methodology makes use of thermodynamic-process insights and the reverse design approach to arrive at the final process-controller design decisions. The developed methodology is illustrated through...

Crop residue decomposition in Minnesota biochar-amended plots

Science.gov (United States)

Weyers, S. L.; Spokas, K. A.

2014-06-01

Impacts of biochar application at laboratory scales are routinely studied, but impacts of biochar application on decomposition of crop residues at field scales have not been widely addressed. The priming or hindrance of crop residue decomposition could have a cascading impact on soil processes, particularly those influencing nutrient availability. Our objectives were to evaluate biochar effects on field decomposition of crop residue, using plots that were amended with biochars made from different plant-based feedstocks and pyrolysis platforms in the fall of 2008. Litterbags containing wheat straw material were buried in July of 2011 below the soil surface in a continuous-corn cropped field in plots that had received one of seven different biochar amendments or a uncharred wood-pellet amendment 2.5 yr prior to start of this study. Litterbags were collected over the course of 14 weeks. Microbial biomass was assessed in treatment plots the previous fall. Though first-order decomposition rate constants were positively correlated to microbial biomass, neither parameter was statistically affected by biochar or wood-pellet treatments. The findings indicated only a residual of potentially positive and negative initial impacts of biochars on residue decomposition, which fit in line with established feedstock and pyrolysis influences. Overall, these findings indicate that no significant alteration in the microbial dynamics of the soil decomposer communities occurred as a consequence of the application of plant-based biochars evaluated here.

Crop residue decomposition in Minnesota biochar amended plots

Science.gov (United States)

Weyers, S. L.; Spokas, K. A.

2014-02-01

Impacts of biochar application at laboratory scales are routinely studied, but impacts of biochar application on decomposition of crop residues at field scales have not been widely addressed. The priming or hindrance of crop residue decomposition could have a cascading impact on soil processes, particularly those influencing nutrient availability. Our objectives were to evaluate biochar effects on field decomposition of crop residue, using plots that were amended with biochars made from different feedstocks and pyrolysis platforms prior to the start of this study. Litterbags containing wheat straw material were buried below the soil surface in a continuous-corn cropped field in plots that had received one of seven different biochar amendments or a non-charred wood pellet amendment 2.5 yr prior to start of this study. Litterbags were collected over the course of 14 weeks. Microbial biomass was assessed in treatment plots the previous fall. Though first-order decomposition rate constants were positively correlated to microbial biomass, neither parameter was statistically affected by biochar or wood-pellet treatments. The findings indicated only a residual of potentially positive and negative initial impacts of biochars on residue decomposition, which fit in line with established feedstock and pyrolysis influences. Though no significant impacts were observed with field-weathered biochars, effective soil management may yet have to account for repeat applications of biochar.

Generative Temporal Modelling of Neuroimaging - Decomposition and Nonparametric Testing

DEFF Research Database (Denmark)

Hald, Ditte Høvenhoff

The goal of this thesis is to explore two improvements for functional magnetic resonance imaging (fMRI) analysis; namely our proposed decomposition method and an extension to the non-parametric testing framework. Analysis of fMRI allows researchers to investigate the functional processes...... of the brain, and provides insight into neuronal coupling during mental processes or tasks. The decomposition method is a Gaussian process-based independent components analysis (GPICA), which incorporates a temporal dependency in the sources. A hierarchical model specification is used, featuring both...... instantaneous and convolutive mixing, and the inferred temporal patterns. Spatial maps are seen to capture smooth and localized stimuli-related components, and often identifiable noise components. The implementation is freely available as a GUI/SPM plugin, and we recommend using GPICA as an additional tool when...

Three-pattern decomposition of global atmospheric circulation: part I—decomposition model and theorems

Science.gov (United States)

Hu, Shujuan; Chou, Jifan; Cheng, Jianbo

2018-04-01

In order to study the interactions between the atmospheric circulations at the middle-high and low latitudes from the global perspective, the authors proposed the mathematical definition of three-pattern circulations, i.e., horizontal, meridional and zonal circulations with which the actual atmospheric circulation is expanded. This novel decomposition method is proved to accurately describe the actual atmospheric circulation dynamics. The authors used the NCEP/NCAR reanalysis data to calculate the climate characteristics of those three-pattern circulations, and found that the decomposition model agreed with the observed results. Further dynamical analysis indicates that the decomposition model is more accurate to capture the major features of global three dimensional atmospheric motions, compared to the traditional definitions of Rossby wave, Hadley circulation and Walker circulation. The decomposition model for the first time realized the decomposition of global atmospheric circulation using three orthogonal circulations within the horizontal, meridional and zonal planes, offering new opportunities to study the large-scale interactions between the middle-high latitudes and low latitudes circulations.

Decomposition of silica-alumina ores of Afghanistan by sulfuric acid

International Nuclear Information System (INIS)

Khomidi, A.K.; Mamatov, E.D.

2016-01-01

Present article is devoted to decomposition of silica-alumina ores of Afghanistan by sulfuric acid. Physicochemical properties of initial silica-alumina ores were studied by means of X-ray phase, differential thermal and silicate analysis. The influence of temperature, process duration and acid concentration on extraction rate of valuable components was considered. The optimal conditions of decomposition of silica-alumina ores of Afghanistan by sulfuric acid were proposed.

Catalytic activity of metal borides in the reaction of decomposition

International Nuclear Information System (INIS)

Labodi, I.; Korablev, L.I.; Tavadyan, L.A.; Blyumberg, Eh.A.

1982-01-01

Catalytic effect of CoB, MoB 2 , ZrB 2 and NbB 2 , prepared by the method of self-propagating high-temperature synthesis, on decomposition of tertiary butyl hydroperoxide has been studied. A technigue of determination of action mechanism of heterogeneous catalysts in liquid-phase process is suggested. It is established that CoB in contrast to other metal borides catalyzes only hydroperoxide decomposition into radicals

Comparison of decomposition rates between autopsied and non-autopsied human remains.

Science.gov (United States)

Bates, Lennon N; Wescott, Daniel J

2016-04-01

Penetrating trauma has been cited as a significant factor in the rate of decomposition. Therefore, penetrating trauma may have an effect on estimations of time-since-death in medicolegal investigations and on research examining decomposition rates and processes when autopsied human bodies are used. The goal of this study was to determine if there are differences in the rate of decomposition between autopsied and non-autopsied human remains in the same environment. The purpose is to shed light on how large incisions, such as those from a thorocoabdominal autopsy, effect time-since-death estimations and research on the rate of decomposition that use both autopsied and non-autopsied human remains. In this study, 59 non-autopsied and 24 autopsied bodies were studied. The number of accumulated degree days required to reach each decomposition stage was then compared between autopsied and non-autopsied remains. Additionally, both types of bodies were examined for seasonal differences in decomposition rates. As temperature affects the rate of decomposition, this study also compared the internal body temperatures of autopsied and non-autopsied remains to see if differences between the two may be leading to differential decomposition. For this portion of this study, eight non-autopsied and five autopsied bodies were investigated. Internal temperature was collected once a day for two weeks. The results showed that differences in the decomposition rate between autopsied and non-autopsied remains was not statistically significant, though the average ADD needed to reach each stage of decomposition was slightly lower for autopsied bodies than non-autopsied bodies. There was also no significant difference between autopsied and non-autopsied bodies in the rate of decomposition by season or in internal temperature. Therefore, this study suggests that it is unnecessary to separate autopsied and non-autopsied remains when studying gross stages of human decomposition in Central Texas

Kinetics and mechanism of thermal processes of nonreversible decomposition of the system N2O4-NO

International Nuclear Information System (INIS)

Nesterenko, V.B.; Nichipor, G.V.

1989-01-01

Consideration is given to kinetics and mechanism of decomposition of nitrogen oxide in gaseous phase at devated pressures and temperature, decomposition of N 2 O 4 -NO system under flow conditions, as well as to kinetics and mechanism of formation of nitrons oxide. 37 refs.; 13 figs.; 13 tabs

Hydrothermal decomposition of TBP and fixation of its decomposed residue by HHP technique

International Nuclear Information System (INIS)

Yamasaki, N.; Fujiki, M.; Nishioka, M.; Ioku, K.; Yanagisawa, K.; Kozai, N.; Muraoka, S.

1991-01-01

The tributyl phosphate (TBP) used for the fuel reprocessing by Purex process is discharged as spent solvent because of the chemical decomposition and the damage due to radiation. Alkaline hydrothermal treatment in oxygen which is the reaction in a closed system is effective for the decomposition of TBP as it can transform organic materials to stable inorganic ions. Hydrothermal hot pressing technique has been applied to the immobilization of various radioactive wastes. This work deals with the continuous treatment process for the decomposition of TBP waste and the immobilization of its decomposed residue under hydrothermal condition. These processes are outlined. The experiment and the results are reported. TBP was completely decomposed above 200degC, and COD value showed the maximum at 250degC. The reaction process consists of two steps of the hydrolysis of TBP and the oxidation of the formed organic material. (K.I.)

Preparation, Structure Characterization and Thermal Decomposition ...

African Journals Online (AJOL)

NJD

Decomposition Process of the Dysprosium(III) m-Methylbenzoate 1 ... A dinuclear complex [Dy(m-MBA)3phen]2·H2O was prepared by the reaction of DyCl3·6H2O, m-methylbenzoic acid and .... ing rate of 10 °C min–1 are illustrated in Fig. 4.

Trophic roles of scavenger beetles in relation to decomposition stages and seasons

Directory of Open Access Journals (Sweden)

Noelia I. Zanetti

2015-06-01

Full Text Available Carcasses represent a trophic and reproductive resource or shelter for arthropods, which are a representative component of the decomposition process. Four experiments, one per season, were conducted in a semi-rural area of Bahía Blanca, Argentina, to study the trophic roles of cadaveric beetles, evaluating the abundance, composition and dominance during all decomposition stages and seasons. Species of necrophagous, necrophilous and omnivorous habits were found. Abundance, composition and dominance of beetles in relation to their trophic roles changed according to seasons and decomposition stages. Guilds and patterns of succession were established in relation to those periods. Trophic roles could be an indicator of beetle associations with decomposition stages and seasons.

1.7.2. The hydrochloric acid decomposition of pre-baked kaolin clays and siallites

International Nuclear Information System (INIS)

Mirsaidov, U.M.; Mirzoev, D.Kh.; Boboev, Kh.E.

2016-01-01

Present article of book is devoted to hydrochloric acid decomposition of pre-baked kaolin clays and siallites. The chemical composition of kaolin clays and siallites was determined. The influence of temperature, process duration, acid concentration on hydrochloric acid decomposition of pre-baked kaolin clays and siallites was studied. The optimal conditions of hydrochloric acid decomposition of pre-baked kaolin clays and siallites were determined.

Theoretical and experimental study: the size dependence of decomposition thermodynamics of nanomaterials

International Nuclear Information System (INIS)

Cui, Zixiang; Duan, Huijuan; Li, Wenjiao; Xue, Yongqiang

2015-01-01

In the processes of preparation and application of nanomaterials, the decomposition reactions of nanomaterials are often involved. However, there is a dramatic difference in decomposition thermodynamics between nanomaterials and the bulk counterparts, and the difference depends on the size of the particles that compose the nanomaterials. In this paper, the decomposition model of a nanoparticle was built, the theory of decomposition thermodynamics of nanomaterials was proposed, and the relations of the size dependence of thermodynamic quantities for the decomposition reactions were deduced. In experiment, taking the thermal decomposition of nano-Cu 2 (OH) 2 CO 3 with different particle sizes (the range of radius is at 8.95–27.4 nm) as a system, the reaction thermodynamic quantities were determined, and the regularities of size dependence of the quantities were summarized. These experimental regularities consist with the above thermodynamic relations. The results show that there is a significant effect of the size of particles composing a nanomaterial on the decomposition thermodynamics. When all the decomposition products are gases, the differences in thermodynamic quantities of reaction between the nanomaterials and the bulk counterparts depend on the particle size; while when one of the decomposition products is a solid, the differences depend on both the initial particle size of the nanoparticle and the decomposition ratio. When the decomposition ratio is very small, these differences are only related to the initial particle size; and when the radius of the nanoparticles approaches or exceeds 10 nm, the reaction thermodynamic functions and the logarithm of the equilibrium constant are linearly associated with the reciprocal of radius, respectively. The thermodynamic theory can quantificationally describe the regularities of the size dependence of thermodynamic quantities for decomposition reactions of nanomaterials, and contribute to the researches and the

Thermal decomposition of rhenium (5) complexes with 1,2,4-triazole

International Nuclear Information System (INIS)

Amindzhanov, A.A.; Gagieva, S.Ch.; Kotegov, K.V.

1991-01-01

Processes of thermal decomposition of rhenium (5) complexes with 1,2,4-triazole were studied. Thermolysis products were identified on the basis of data of the element analysis, IR spectra, conductometry and other methods. It is ascertained that at the first stage of thermolysis of hydroxyl-containing monomer complexes removal of water molecules occurs, and at the second one - dimerization process with formation of Re-O-Re group. It is shown that the nature of halide ion practically does not affect the temperature of the start of intensive thermal decomposition of the complexes

Canonical Polyadic Decomposition With Auxiliary Information for Brain-Computer Interface.

Science.gov (United States)

Li, Junhua; Li, Chao; Cichocki, Andrzej

2017-01-01

Physiological signals are often organized in the form of multiple dimensions (e.g., channel, time, task, and 3-D voxel), so it is better to preserve original organization structure when processing. Unlike vector-based methods that destroy data structure, canonical polyadic decomposition (CPD) aims to process physiological signals in the form of multiway array, which considers relationships between dimensions and preserves structure information contained by the physiological signal. Nowadays, CPD is utilized as an unsupervised method for feature extraction in a classification problem. After that, a classifier, such as support vector machine, is required to classify those features. In this manner, classification task is achieved in two isolated steps. We proposed supervised CPD by directly incorporating auxiliary label information during decomposition, by which a classification task can be achieved without an extra step of classifier training. The proposed method merges the decomposition and classifier learning together, so it reduces procedure of classification task compared with that of respective decomposition and classification. In order to evaluate the performance of the proposed method, three different kinds of signals, synthetic signal, EEG signal, and MEG signal, were used. The results based on evaluations of synthetic and real signals demonstrated that the proposed method is effective and efficient.

Formation and decomposition of ammoniated ammonium ions

International Nuclear Information System (INIS)

Ikezoe, Yasumasa; Suzuki, Kazuya; Nakashima, Mikio; Yokoyama, Atsushi; Shiraishi, Hirotsugu; Ohno, Shin-ichi

1998-09-01

Structures, frequencies, and chemical reactions of ammoniated ammonium ions (NH 4 + .nNH 3 ) were investigated theoretically by ab initio molecular orbital calculations and experimentally by observing their formation and decomposition in a corona discharge-jet expansion process. The ab initio calculations were carried out using a Gaussian 94 program, which gave optimized structures, binding energies and harmonic vibrational frequencies of NH 4 + .nNH 3 . Effects of discharge current, the reactant gas and the diameter of the gas expanding pinhole were examined on the size n distribution of NH 4 + .nNH 3 . The results indicated that the cluster ion, in the jet expansion process, grew in size mostly equal to or less than one unit under experimental conditions employed. Effects of discharge current, pinhole diameter, flight time in vacuum and cluster size were examined on the decomposition rate of cluster ions formed. In our experimental conditions, the internal energies of cluster ions were mainly determined through exo- and/or endo-thermic reactions involved in the cluster formation process. (author)

Decomposition of methane hydrate for hydrogen production using microwave and radio frequency in-liquid plasma methods

International Nuclear Information System (INIS)

Rahim, Ismail; Nomura, Shinfuku; Mukasa, Shinobu; Toyota, Hiromichi

2015-01-01

This research involves two in-liquid plasma methods of methane hydrate decomposition, one using radio frequency wave (RF) irradiation and the other microwave radiation (MW). The ultimate goal of this research is to develop a practical process for decomposition of methane hydrate directly at the subsea site for fuel gas production. The mechanism for methane hydrate decomposition begins with the dissociation process of methane hydrate formed by CH_4 and water. The process continues with the simultaneously occurring steam methane reforming process and methane cracking reaction, during which the methane hydrate is decomposed releasing CH_4 into H_2, CO and other by-products. It was found that methane hydrate can be decomposed with a faster rate of CH_4 release using microwave irradiation over that using radio frequency irradiation. However, the radio frequency plasma method produces hydrogen with a purity of 63.1% and a CH conversion ratio of 99.1%, which is higher than using microwave plasma method which produces hydrogen with a purity of 42.1% and CH_4 conversion ratio of 85.5%. - Highlights: • The decomposition of methane hydrate is proposed using plasma in-liquid method. • Synthetic methane hydrate is used as the sample for decomposition in plasma. • Hydrogen can be produced from decomposition of methane hydrate. • Hydrogen purity is higher when using radio frequency stimulation.

Gas hydrates forming and decomposition conditions analysis

Directory of Open Access Journals (Sweden)

А. М. Павленко

2017-07-01

Full Text Available The concept of gas hydrates has been defined; their brief description has been given; factors that affect the formation and decomposition of the hydrates have been reported; their distribution, structure and thermodynamic conditions determining the gas hydrates formation disposition in gas pipelines have been considered. Advantages and disadvantages of the known methods for removing gas hydrate plugs in the pipeline have been analyzed, the necessity of their further studies has been proved. In addition to the negative impact on the process of gas extraction, the hydrates properties make it possible to outline the following possible fields of their industrial use: obtaining ultrahigh pressures in confined spaces at the hydrate decomposition; separating hydrocarbon mixtures by successive transfer of individual components through the hydrate given the mode; obtaining cold due to heat absorption at the hydrate decomposition; elimination of the open gas fountain by means of hydrate plugs in the bore hole of the gushing gasser; seawater desalination, based on the hydrate ability to only bind water molecules into the solid state; wastewater purification; gas storage in the hydrate state; dispersion of high temperature fog and clouds by means of hydrates; water-hydrates emulsion injection into the productive strata to raise the oil recovery factor; obtaining cold in the gas processing to cool the gas, etc.

Litterfall and litter decomposition in chestnut high forest stands in northern Portugal

Energy Technology Data Exchange (ETDEWEB)

Patricio, M. S.; Nunes, L. F.; Pereira, E. L.

2012-11-01

This research aimed to: estimate the inputs of litterfall; model the decomposition process and assess the rates of litter decay and turnover; study the litter decomposition process and dynamics of nutrients in old chestnut high forests. This study aimed to fill a gap in the knowledge of chestnut decomposition process as this type of ecosystems have never been modeled and studied from this point of view in Portugal. The study sites are located in the mountains of Marao, Padrela and Bornes in a west-to-east transect, across northern Portugal, from a more-Atlantic-to-lessmaritime influence. This research was developed on old chestnut high forests for quality timber production submitted to a silviculture management close-to-nature. We collected litterfall using littertraps and studied decomposition of leaf and bur litter by the nylon net bag technique. Simple and double exponential models were used to describe the decomposition of chestnut litterfall incubated in situ during 559 days. The results of the decomposition are discussed in relation to the initial litter quality (C, N, P, K, Ca, Mg) and the decomposition rates. Annually, the mature chestnut high-forest stands (density 360-1,260 tree ha1, age 55-73 years old) restore 4.9 Mg DM ha–1 of litter and 2.6 Mg ha{sup -}1 yr{sup -}1 of carbon to the soil. The two-component litter decay model proved to be more biologically realistic, providing a decay rate for the fast initial stage (46-58 yr{sup -}1for the leaves and 38-42 yr{sup -}1for the burs) and a decay rate related to the recalcitrant pool (0.45-0.60 yr{sup -}1for the leaves and 0.22-0.36 yr{sup -}1for the burs). This study pointed to some decay patterns and release of bioelements by the litterfall which can be useful for calibrating existing models and indicators of sustainability to improve both silvicultural and environmental approaches for the management of chestnut forests. (Author) 45 refs.

A Martingale Decomposition of Discrete Markov Chains

DEFF Research Database (Denmark)

Hansen, Peter Reinhard

We consider a multivariate time series whose increments are given from a homogeneous Markov chain. We show that the martingale component of this process can be extracted by a filtering method and establish the corresponding martingale decomposition in closed-form. This representation is useful fo...

Xylanase and cellulase activities during anaerobic decomposition of three aquatic macrophytes.

Science.gov (United States)

Nunes, Maíra F; da Cunha-Santino, Marcela B; Bianchini, Irineu

2011-01-01

Enzymatic activity during decomposition is extremely important to hydrolyze molecules that are assimilated by microorganisms. During aquatic macrophytes decomposition, enzymes act mainly in the breakdown of lignocellulolytic matrix fibers (i.e. cellulose, hemicellulose and lignin) that encompass the refractory fraction from organic matter. Considering the importance of enzymatic activities role in decomposition processes, this study aimed to describe the temporal changes of xylanase and cellulose activities during anaerobic decomposition of Ricciocarpus natans (freely-floating), Oxycaryum cubense (emergent) and Cabomba furcata (submersed). The aquatic macrophytes were collected in Óleo Lagoon, Luiz Antonio, São Paulo, Brazil and bioassays were accomplished.  Decomposition chambers from each species (n = 10) were set up with dried macrophyte fragments and filtered Óleo Lagoon water. The chambers were incubated at 22.5°C, in the dark and under anaerobic conditions. Enzymatic activities and remaining organic matter were measured periodically during 90 days. The temporal variation of enzymes showed that C. furcata presented the highest decay and the highest maximum enzyme production. Xylanase production was higher than cellulase production for the decomposition of the three aquatic macrophytes species.

Experimental investigation on the heterogeneous kinetic process of the low thermal decomposition of ammonium perchlorate particles

Energy Technology Data Exchange (ETDEWEB)

Longuet, Baptiste [Laboratoire Energetique Explosions et Structures Universite d' Orleans (Germany); Gillard, Philippe [Laboratoire Energetic Explosions et Structures, Universite d' Orleans, Bourges (France)

2009-02-15

The thermal decomposition of ammonium perchlorate has been extensively studied in the past. Nevertheless, the various results published illustrate, on the one hand, significant differences regarding the influence of different parameters on the decomposition and on the other hand, a lack of useful quantitative laws to predict the thermal behaviour of this crystal under a range of conditions (temperature, duration of exposure, presence of confinement). (Abstract Copyright [2009], Wiley Periodicals, Inc.)

Evaluating litter decomposition and soil organic matter dynamics in earth system models: contrasting analysis of long-term litter decomposition and steady-state soil carbon

Science.gov (United States)

Bonan, G. B.; Wieder, W. R.

2012-12-01

litterfall and model-derived climatic decomposition index. While comparison with the LIDET 10-year litterbag study reveals sharp contrasts between CLM4 and DAYCENT, simulations of steady-state soil carbon show less difference between models. Both CLM4 and DAYCENT significantly underestimate soil carbon. Sensitivity analyses highlight causes of the low soil carbon bias. The terrestrial biogeochemistry of earth system models must be critically tested with observations, and the consequences of particular model choices must be documented. Long-term litter decomposition experiments such as LIDET provide a real-world process-oriented benchmark to evaluate models and can critically inform model development. Analysis of steady-state soil carbon estimates reveal additional, but here different, inferences about model performance.

Global decomposition experiment shows soil animal impacts on decomposition are climate-dependent

Czech Academy of Sciences Publication Activity Database

Wall, D.H.; Bradford, M.A.; John, M.G.St.; Trofymow, J.A.; Behan-Pelletier, V.; Bignell, D.E.; Dangerfield, J.M.; Parton, W.J.; Rusek, Josef; Voigt, W.; Wolters, V.; Gardel, H.Z.; Ayuke, F. O.; Bashford, R.; Beljakova, O.I.; Bohlen, P.J.; Brauman, A.; Flemming, S.; Henschel, J.R.; Johnson, D.L.; Jones, T.H.; Kovářová, Marcela; Kranabetter, J.M.; Kutny, L.; Lin, K.-Ch.; Maryati, M.; Masse, D.; Pokarzhevskii, A.; Rahman, H.; Sabará, M.G.; Salamon, J.-A.; Swift, M.J.; Varela, A.; Vasconcelos, H.L.; White, D.; Zou, X.

2008-01-01

Roč. 14, č. 11 (2008), s. 2661-2677 ISSN 1354-1013 Institutional research plan: CEZ:AV0Z60660521; CEZ:AV0Z60050516 Keywords : climate decomposition index * decomposition * litter Subject RIV: EH - Ecology, Behaviour Impact factor: 5.876, year: 2008

Thermal decomposition of [Co(en)3][Fe(CN)6]∙ 2H2O: Topotactic dehydration process, valence and spin exchange mechanism elucidation.

Science.gov (United States)

Trávníček, Zdeněk; Zbořil, Radek; Matiková-Maľarová, Miroslava; Drahoš, Bohuslav; Cernák, Juraj

2013-01-01

The Prussian blue analogues represent well-known and extensively studied group of coordination species which has many remarkable applications due to their ion-exchange, electron transfer or magnetic properties. Among them, Co-Fe Prussian blue analogues have been extensively studied due to the photoinduced magnetization. Surprisingly, their suitability as precursors for solid-state synthesis of magnetic nanoparticles is almost unexplored. In this paper, the mechanism of thermal decomposition of [Co(en)3][Fe(CN)6] ∙∙ 2H2O (1a) is elucidated, including the topotactic dehydration, valence and spins exchange mechanisms suggestion and the formation of a mixture of CoFe2O4-Co3O4 (3:1) as final products of thermal degradation. The course of thermal decomposition of 1a in air atmosphere up to 600°C was monitored by TG/DSC techniques, (57)Fe Mössbauer and IR spectroscopy. As first, the topotactic dehydration of 1a to the hemihydrate [Co(en)3][Fe(CN)6] ∙∙ 1/2H2O (1b) occurred with preserving the single-crystal character as was confirmed by the X-ray diffraction analysis. The consequent thermal decomposition proceeded in further four stages including intermediates varying in valence and spin states of both transition metal ions in their structures, i.e. [Fe(II)(en)2(μ-NC)Co(III)(CN)4], Fe(III)(NH2CH2CH3)2(μ-NC)2Co(II)(CN)3] and Fe(III)[Co(II)(CN)5], which were suggested mainly from (57)Fe Mössbauer, IR spectral and elemental analyses data. Thermal decomposition was completed at 400°C when superparamagnetic phases of CoFe2O4 and Co3O4 in the molar ratio of 3:1 were formed. During further temperature increase (450 and 600°C), the ongoing crystallization process gave a new ferromagnetic phase attributed to the CoFe2O4-Co3O4 nanocomposite particles. Their formation was confirmed by XRD and TEM analyses. In-field (5 K / 5 T) Mössbauer spectrum revealed canting of Fe(III) spin in almost fully inverse spinel structure of CoFe2O4. It has been found that the thermal

Foreword - Acid decomposition of borosilicate ores

International Nuclear Information System (INIS)

Mirsaidov, U.M.; Kurbonov, A.S.; Mamatov, E.D.

2015-01-01

The elaboration and development of technology of processing of mineral raw materials have an important role for the industry of Tajikistan. The results of researches of the staff of Institute of Chemistry and Nuclear and Radiation Safety Agency of the Republic of Tajikistan were considered in present monograph. The physicochemical and technological aspects of processing of borosilicate raw materials of Ak-Arkhar Deposit of Tajikistan were considered. The necessary conditions of acid decomposition of raw materials were defined. The flowsheets for the processing of boron raw materials were proposed.

Decomposition methods for unsupervised learning

DEFF Research Database (Denmark)

Mørup, Morten

2008-01-01

This thesis presents the application and development of decomposition methods for Unsupervised Learning. It covers topics from classical factor analysis based decomposition and its variants such as Independent Component Analysis, Non-negative Matrix Factorization and Sparse Coding...... methods and clustering problems is derived both in terms of classical point clustering but also in terms of community detection in complex networks. A guiding principle throughout this thesis is the principle of parsimony. Hence, the goal of Unsupervised Learning is here posed as striving for simplicity...... in the decompositions. Thus, it is demonstrated how a wide range of decomposition methods explicitly or implicitly strive to attain this goal. Applications of the derived decompositions are given ranging from multi-media analysis of image and sound data, analysis of biomedical data such as electroencephalography...

Long-term decomposition of grass roots as affected by elevated atmospheric carbon dioxide

NARCIS (Netherlands)

Ginkel, van J.H.; Gorissen, A.; Veen, van J.A.

1996-01-01

Carbon input into the soil and decomposition processes under elevated CO2 are highly relevant for C sequestering in the soil. Plant growth and decomposition of root material under ambient and elevated atmospheric CO2 concentrations were monitored in wind tunnels. Grass roots (Lolium perenne L.) were

Porous layered double hydroxides synthesized using oxygen generated by decomposition of hydrogen peroxide

NARCIS (Netherlands)

Gonzalez Rodriguez, P.; de Ruiter, M.P.; Wijnands, Tom; ten Elshof, Johan E.

2017-01-01

Porous magnesium-aluminium layered double hydroxides (LDH) were prepared through intercalation and decomposition of hydrogen peroxide (H2O2). This process generates oxygen gas nano-bubbles that pierce holes in the layered structure of the material by local pressure build-up. The decomposition of the

Dictionary-Based Tensor Canonical Polyadic Decomposition

Science.gov (United States)

Cohen, Jeremy Emile; Gillis, Nicolas

2018-04-01

To ensure interpretability of extracted sources in tensor decomposition, we introduce in this paper a dictionary-based tensor canonical polyadic decomposition which enforces one factor to belong exactly to a known dictionary. A new formulation of sparse coding is proposed which enables high dimensional tensors dictionary-based canonical polyadic decomposition. The benefits of using a dictionary in tensor decomposition models are explored both in terms of parameter identifiability and estimation accuracy. Performances of the proposed algorithms are evaluated on the decomposition of simulated data and the unmixing of hyperspectral images.

Thermal decomposition of hydrotalcite with chromate, molybdate or sulphate in the interlayer

Energy Technology Data Exchange (ETDEWEB)

Frost, Ray L. [Inorganic Materials Research Program, School of Physical and Chemical Sciences, Queensland University of Technology, GPO Box 2434, Brisbane Queensland 4001 (Australia)]. E-mail: r.frost@qut.edu.au; Musumeci, Anthony W. [Inorganic Materials Research Program, School of Physical and Chemical Sciences, Queensland University of Technology, GPO Box 2434, Brisbane Queensland 4001 (Australia); Bostrom, Thor [Inorganic Materials Research Program, School of Physical and Chemical Sciences, Queensland University of Technology, GPO Box 2434, Brisbane Queensland 4001 (Australia); Adebajo, Moses O. [Inorganic Materials Research Program, School of Physical and Chemical Sciences, Queensland University of Technology, GPO Box 2434, Brisbane Queensland 4001 (Australia); Weier, Matt L. [Inorganic Materials Research Program, School of Physical and Chemical Sciences, Queensland University of Technology, GPO Box 2434, Brisbane Queensland 4001 (Australia); Martens, Wayde [Inorganic Materials Research Program, School of Physical and Chemical Sciences, Queensland University of Technology, GPO Box 2434, Brisbane Queensland 4001 (Australia)

2005-05-15

The thermal decomposition of hydrotalcites with chromate, molybdate and sulphate in the interlayer has been studied using thermogravimetric analysis coupled to a mass spectrometer measuring the gas evolution. X-ray diffraction shows the hydrotalcites have a d(0 0 3) spacing of 7.98 A with very small differences in the d-spacing between the three hydrotalcites. XRD was also used to determine the products of the thermal decomposition. For the sulphate-hydrotalcite decomposition the products were MgO and a spinel MgAl{sub 2}O{sub 4}, for the chromate interlayered hydrotalcite MgO, Cr{sub 2}O{sub 3} and spinel. For the molybdate interlayered hydrotalcite the products were MgO, spinel and MgMoO{sub 4}. EDX analyses enabled the formula of the hydrotalcites to be determined. Two processes are observed in the thermal decomposition namely dehydration and dehydroxylation and for the case of the sulphate interlayered hydrotalcite, a third process is the loss of sulphate. Both the dehydration and dehydroxylation take place in three steps each for each of the hydrotalcites.

Investigation into kinetics of decomposition of nitrates

International Nuclear Information System (INIS)

Belov, B.A.; Gorozhankin, Eh.V.; Efremov, V.N.; Sal'nikova, N.S.; Suris, A.L.

1985-01-01

Using the method of thermogravimetry, the decomposition of nitrates, Cd(NO 3 ) 2 x4H 2 O, La(NO 3 ) 2 x6H 2 O, Sr(NO 3 ) 2 , ZrO(NO 3 ) 2 x2H 2 O, Y(NO 3 ) 3 x6H 2 O, in particular, is studied in the 20-1000 deg C range. It is shown, that gaseous pyrolysis, products, remaining in the material, hamper greatly the heat transfer required for the decomposition which reduces the reaction order. An effective activation energy of the process is in a satisfactory agreement with the characteristic temperature of the last endotherm. Kinetic parameters are calculated by the minimization method using a computer

Young Children's Thinking About Decomposition: Early Modeling Entrees to Complex Ideas in Science

Science.gov (United States)

Ero-Tolliver, Isi; Lucas, Deborah; Schauble, Leona

2013-10-01

This study was part of a multi-year project on the development of elementary students' modeling approaches to understanding the life sciences. Twenty-three first grade students conducted a series of coordinated observations and investigations on decomposition, a topic that is rarely addressed in the early grades. The instruction included in-class observations of different types of soil and soil profiling, visits to the school's compost bin, structured observations of decaying organic matter of various kinds, study of organisms that live in the soil, and models of environmental conditions that affect rates of decomposition. Both before and after instruction, students completed a written performance assessment that asked them to reason about the process of decomposition. Additional information was gathered through one-on-one interviews with six focus students who represented variability of performance across the class. During instruction, researchers collected video of classroom activity, student science journal entries, and charts and illustrations produced by the teacher. After instruction, the first-grade students showed a more nuanced understanding of the composition and variability of soils, the role of visible organisms in decomposition, and environmental factors that influence rates of decomposition. Through a variety of representational devices, including drawings, narrative records, and physical models, students came to regard decomposition as a process, rather than simply as an end state that does not require explanation.

Cellular decomposition in vikalloys

International Nuclear Information System (INIS)

Belyatskaya, I.S.; Vintajkin, E.Z.; Georgieva, I.Ya.; Golikov, V.A.; Udovenko, V.A.

1981-01-01

Austenite decomposition in Fe-Co-V and Fe-Co-V-Ni alloys at 475-600 deg C is investigated. The cellular decomposition in ternary alloys results in the formation of bcc (ordered) and fcc structures, and in quaternary alloys - bcc (ordered) and 12R structures. The cellular 12R structure results from the emergence of stacking faults in the fcc lattice with irregular spacing in four layers. The cellular decomposition results in a high-dispersion structure and magnetic properties approaching the level of well-known vikalloys [ru

Decomposition of intact chicken feathers by a thermophile in combination with an acidulocomposting garbage-treatment process.

Science.gov (United States)

Shigeri, Yasushi; Matsui, Tatsunobu; Watanabe, Kunihiko

2009-11-01

In order to develop a practical method for the decomposition of intact chicken feathers, a moderate thermophile strain, Meiothermus ruber H328, having strong keratinolytic activity, was used in a bio-type garbage-treatment machine working with an acidulocomposting process. The addition of strain H328 cells (15 g) combined with acidulocomposting in the garbage machine resulted in 70% degradation of intact chicken feathers (30 g) within 14 d. This degradation efficiency is comparable to a previous result employing the strain as a single bacterium in flask culture, and it indicates that strain H328 can promote intact feather degradation activity in a garbage machine currently on the market.

An efficient hybrid sulfur process using PEM electrolysis with a bayonet decomposition reactor - HTR2008-58207

International Nuclear Information System (INIS)

Gorensek, M. B.; Summers, W. A.; Lahoda, E. J.; Bolthrunis, C. O.; Greyvenstein, R.

2008-01-01

The Hybrid Sulfur (HyS) Process is being developed to produce hydrogen by water-splitting using heat from advanced nuclear reactors. It has the potential for high efficiency and competitive hydrogen production cost, and has been demonstrated at a laboratory scale. As a two-step process, the HyS is one of the simplest thermochemical cycles. The sulfuric acid decomposition reaction is common to all sulfur cycles, including the Sulfur-Iodine (SI) cycle. What distinguishes the HyS Process from the other sulfur cycles is the use of sulfur dioxide (SO 2 ) to depolarize the anode of a water electrolyzer. The two critical HyS Process components are the SO 2 - depolarized electrolyzer (SDE), and the high-temperature decomposition reactor. A proton exchange membrane (PEM)- type SDE and a silicon carbide bayonet-type high-temperature decomposition reactor are being developed for DOE's Nuclear Hydrogen Initiative (NHI) by Savannah River National Laboratory (SRNL) and by Sandia National Laboratories (SNL), respectively. The ultimate goal of the NHI-sponsored work is to couple the SDE and the reactor in an integrated laboratory scale experiment to prove the technical readiness of the HyS cycle for the NGNP demonstration. This paper describes the flowsheet that is being prepared to combine these two components into a viable process and presents the latest performance projections and economics for a HyS Process coupled to a PBMR heat source. The basic flowsheet for this process has been described elsewhere [4]. It requires an acid concentration section because the SDE product, which is limited to no more than 50% H 2 SO 4 by cell voltage considerations, is too dilute to be fed directly to the bayonet, which needs at least 65% H 2 SO 4 in the feed for acceptable performance. Optimization involved trade-offs between decomposition reaction and acid concentration heat requirements. The PBMR heat source can split its heat output between the decomposition reaction and either steam

Laser-induced diffusion decomposition in Fe–V thin-film alloys

Energy Technology Data Exchange (ETDEWEB)

Polushkin, N.I., E-mail: nipolushkin@fc.ul.pt [Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisboa (Portugal); Instituto de Ciência e Engenharia de Materiais e Superfícies, 1049-001 Lisboa (Portugal); Duarte, A.C.; Conde, O. [Departamento de Física, Faculdade de Ciências, Universidade de Lisboa, 1749-016 Lisboa (Portugal); Instituto de Ciência e Engenharia de Materiais e Superfícies, 1049-001 Lisboa (Portugal); Alves, E. [Associação Euratom/IST e Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisboa (Portugal); Barradas, N.P. [Centro de Ciências e Tecnologias Nucleares, Instituto Superior Técnico, Universidade de Lisboa, 2695-066 Bobadela LRS (Portugal); García-García, A.; Kakazei, G.N.; Ventura, J.O.; Araujo, J.P. [Departamento de Física, Universidade do Porto e IFIMUP, 4169-007 Porto (Portugal); Oliveira, V. [Instituto de Ciência e Engenharia de Materiais e Superfícies, 1049-001 Lisboa (Portugal); Instituto Superior de Engenharia de Lisboa, 1959-007 Lisboa (Portugal); Vilar, R. [Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisboa (Portugal); Instituto de Ciência e Engenharia de Materiais e Superfícies, 1049-001 Lisboa (Portugal)

2015-05-01

Highlights: • Irradiation of an Fe–V alloy by femtosecond laser triggers diffusion decomposition. • The decomposition occurs with strongly enhanced (∼4 orders) atomic diffusivity. • This anomaly is associated with the metallic glassy state achievable under laser quenching. • The ultrafast diffusion decomposition is responsible for laser-induced ferromagnetism. - Abstract: We investigate the origin of ferromagnetism induced in thin-film (∼20 nm) Fe–V alloys by their irradiation with subpicosecond laser pulses. We find with Rutherford backscattering that the magnetic modifications follow a thermally stimulated process of diffusion decomposition, with formation of a-few-nm-thick Fe enriched layer inside the film. Surprisingly, similar transformations in the samples were also found after their long-time (∼10{sup 3} s) thermal annealing. However, the laser action provides much higher diffusion coefficients (∼4 orders of magnitude) than those obtained under standard heat treatments. We get a hint that this ultrafast diffusion decomposition occurs in the metallic glassy state achievable in laser-quenched samples. This vitrification is thought to be a prerequisite for the laser-induced onset of ferromagnetism that we observe.

Molecular Mechanisms in the shock induced decomposition of FOX-7

Science.gov (United States)

Mishra, Ankit; Tiwari, Subodh C.; Nakano, Aiichiro; Vashishta, Priya; Kalia, Rajiv; CACS Team

Experimental and first principle computational studies on FOX 7 have either involved a very small system consisting of a few atoms or they did not take into account the decomposition mechanisms under extreme conditions of temperature and pressure. We have performed a large-scale reactive MD simulation using ReaxFF-lg force field to study the shock decomposition of FOX 7. The chemical composition of the principal decomposition products correlates well with experimental observations. Furthermore, we observed that the production of N2 and H2O was inter molecular in nature and was through different chemical pathways. Moreover, the production of CO and CO2 was delayed due to production of large stable C,O atoms cluster. These critical insights into the initial processes involved in the shock induced decomposition of FOX-7 will greatly help in understanding the factors playing an important role in the insensitiveness of this high energy material. This research is supported by AFOSR Award No. FA9550-16-1-0042.

Polytypic transformations during the thermal decomposition of cobalt hydroxide and cobalt hydroxynitrate

International Nuclear Information System (INIS)

Ramesh, Thimmasandra Narayan

2010-01-01

The isothermal decomposition of cobalt hydroxide and cobalt hydroxynitrate at different intervals of temperature leads to the formation of Co 3 O 4 . The phase evolution during the decomposition process was monitored using powder X-ray diffraction. The transformation of cobalt hydroxide to cobalt oxide occurs via three phase mixture while cobalt hydroxynitrate to cobalt oxide occurs through a two phase mixture. The nature of the sample and its preparation method controls the decomposition mechanism. The comparison of topotactical relationship between the precursors to the decomposed product has been reported in relation to polytypism. - Graphical abstract: Isothermal thermal decomposition studies of cobalt hydroxide and cobalt hydroxynitrate at different intervals of temperature show the metastable phase formed prior to Co 3 O 4 phase.

Decomposition kinetics of plutonium hydride

Energy Technology Data Exchange (ETDEWEB)

Haschke, J.M.; Stakebake, J.L.

1979-01-01

Kinetic data for decomposition of PuH/sub 1/ /sub 95/ provides insight into a possible mechanism for the hydriding and dehydriding reactions of plutonium. The fact that the rate of the hydriding reaction, K/sub H/, is proportional to P/sup 1/2/ and the rate of the dehydriding process, K/sub D/, is inversely proportional to P/sup 1/2/ suggests that the forward and reverse reactions proceed by opposite paths of the same mechanism. The P/sup 1/2/ dependence of hydrogen solubility in metals is characteristic of the dissociative absorption of hydrogen; i.e., the reactive species is atomic hydrogen. It is reasonable to assume that the rates of the forward and reverse reactions are controlled by the surface concentration of atomic hydrogen, (H/sub s/), that K/sub H/ = c'(H/sub s/), and that K/sub D/ = c/(H/sub s/), where c' and c are proportionality constants. For this surface model, the pressure dependence of K/sub D/ is related to (H/sub s/) by the reaction (H/sub s/) reversible 1/2H/sub 2/(g) and by its equilibrium constant K/sub e/ = (H/sub 2/)/sup 1/2//(H/sub s/). In the pressure range of ideal gas behavior, (H/sub s/) = K/sub e//sup -1/(RT)/sup -1/2/ and the decomposition rate is given by K/sub D/ = cK/sub e/(RT)/sup -1/2/P/sup 1/2/. For an analogous treatment of the hydriding process with this model, it can be readily shown that K/sub H/ = c'K/sub e//sup -1/(RT)/sup -1/2/P/sup 1/2/. The inverse pressure dependence and direct temperature dependence of the decomposition rate are correctly predicted by this mechanism which is most consistent with the observed behavior of the Pu--H system.

Genotypic diversity of an invasive plant species promotes litter decomposition and associated processes.

Science.gov (United States)

Wang, Xiao-Yan; Miao, Yuan; Yu, Shuo; Chen, Xiao-Yong; Schmid, Bernhard

2014-03-01

Following studies that showed negative effects of species loss on ecosystem functioning, newer studies have started to investigate if similar consequences could result from reductions of genetic diversity within species. We tested the influence of genotypic richness and dissimilarity (plots containing one, three, six or 12 genotypes) in stands of the invasive plant Solidago canadensis in China on the decomposition of its leaf litter and associated soil animals over five monthly time intervals. We found that the logarithm of genotypic richness was positively linearly related to mass loss of C, N and P from the litter and to richness and abundance of soil animals on the litter samples. The mixing proportion of litter from two sites, but not genotypic dissimilarity of mixtures, had additional effects on measured variables. The litter diversity effects on soil animals were particularly strong under the most stressful conditions of hot weather in July: at this time richness and abundance of soil animals were higher in 12-genotype litter mixtures than even in the highest corresponding one-genotype litter. The litter diversity effects on decomposition were in part mediated by soil animals: the abundance of Acarina, when used as covariate in the analysis, fully explained the litter diversity effects on mass loss of N and P. Overall, our study shows that high genotypic richness of S. canadensis leaf litter positively affects richness and abundance of soil animals, which in turn accelerate litter decomposition and P release from litter.

Influence of nitrogen dioxide on the thermal decomposition of ammonium nitrate

Directory of Open Access Journals (Sweden)

Igor L. Kovalenko

2015-06-01

Full Text Available In this paper results of experimental studies of ammonium nitrate thermal decomposition in an open system under normal conditions and in NO2 atmosphere are presented. It is shown that nitrogen dioxide is the initiator of ammonium nitrate self-accelerating exothermic cyclic decomposition process. The insertion of NO2 from outside under the conditions of nonisothermal experiment reduces the characteristic temperature of the beginning of self-accelerating decomposition by 50...70 °C. Using method of isothermal exposures it is proved that thermal decomposition of ammonium nitrate in nitrogen dioxide atmosphere at 210 °C is autocatalytic (zero-order reaction. It was suggested that there is possibility of increasing the sensitivity and detonation characteristics of energy condensed systems based on ammonium nitrate by the insertion of additives which provide an earlier appearance of NO2 in the system.

Energy index decomposition methodology at the plant level

Science.gov (United States)

Kumphai, Wisit

Scope and method of study. The dissertation explores the use of a high level energy intensity index as a facility-level energy performance monitoring indicator with a goal of developing a methodology for an economically based energy performance monitoring system that incorporates production information. The performance measure closely monitors energy usage, production quantity, and product mix and determines the production efficiency as a part of an ongoing process that would enable facility managers to keep track of and, in the future, be able to predict when to perform a recommissioning process. The study focuses on the use of the index decomposition methodology and explored several high level (industry, sector, and country levels) energy utilization indexes, namely, Additive Log Mean Divisia, Multiplicative Log Mean Divisia, and Additive Refined Laspeyres. One level of index decomposition is performed. The indexes are decomposed into Intensity and Product mix effects. These indexes are tested on a flow shop brick manufacturing plant model in three different climates in the United States. The indexes obtained are analyzed by fitting an ARIMA model and testing for dependency between the two decomposed indexes. Findings and conclusions. The results concluded that the Additive Refined Laspeyres index decomposition methodology is suitable to use on a flow shop, non air conditioned production environment as an energy performance monitoring indicator. It is likely that this research can be further expanded in to predicting when to perform a recommissioning process.

Microbial biomass and soil fauna during the decomposition of cover crops in no-tillage system

Directory of Open Access Journals (Sweden)

Luciano Colpo Gatiboni

2011-08-01

Full Text Available The decomposition of plant residues is a biological process mediated by soil fauna, but few studies have been done evaluating its dynamics in time during the process of disappearance of straw. This study was carried out in Chapecó, in southern Brazil, with the objective of monitoring modifications in soil fauna populations and the C content in the soil microbial biomass (C SMB during the decomposition of winter cover crop residues in a no-till system. The following treatments were tested: 1 Black oat straw (Avena strigosa Schreb.; 2 Rye straw (Secale cereale L.; 3 Common vetch straw (Vicia sativa L.. The cover crops were grown until full flowering and then cut mechanically with a rolling stalk chopper. The soil fauna and C content in soil microbial biomass (C SMB were assessed during the period of straw decomposition, from October 2006 to February 2007. To evaluate C SMB by the irradiation-extraction method, soil samples from the 0-10 cm layer were used, collected on eight dates, from before until 100 days after residue chopping. The soil fauna was collected with pitfall traps on seven dates up to 85 days after residue chopping. The phytomass decomposition of common vetch was faster than of black oat and rye residues. The C SMB decreased during the process of straw decomposition, fastest in the treatment with common vetch. In the common vetch treatment, the diversity of the soil fauna was reduced at the end of the decomposition process.

Beta decomposition processes in Hf-rich Hf--Nb alloys

International Nuclear Information System (INIS)

Jones, W.B.; Taggart, R.; Polonis, D.H.

1978-01-01

The decomposition of the bcc β-phase by both athermal and isothermal processes has been investigated in Hf-rich Hf--Nb alloys. An all β-phase structure is retained in chill-cast alloys containing 30 to 50 at.% Nb (Cb), although electron diffraction streaking effects and the behavior of the temperature coefficient of electrical resistivity indicate the presence of a bcc lattice instability similar to that reported in solute lean Ti and Zr alloys. Aging a Hf 0 . 65 Nb 0 . 35 alloy at 400 and 600 0 C resulted in the direct precipitation of a fine dispersion of α-phase needles; this morphology differs from the discs of transition α (α/sub t/) which Carpenter et al observed in Nb-rich Nb 0 . 68 Hf 0 . 32 . During continued aging, the needles grow selectively to form colonies or groups of needles in which both the individual needles and the groups of needles have major axes aligned along (110)/sub β/ type directions. The initial α-phase particles exhibit the Burgers orientation relationship with the parent matrix; continued aging changes the electron diffraction patterns in a way that is similar to that observed in aged Ti--Mo and Ti--Mo--Al alloys where they were attributed to the α-phase having a different crystallographic relationship to the β-phase (Type 2 α-phase). The observed changes in the electron diffraction patterns of aged Hf 0 . 65 Nb 0 . 35 cannot be described as resulting from strained Burgers α-phase

Variance decomposition in stochastic simulators.

Science.gov (United States)

Le Maître, O P; Knio, O M; Moraes, A

2015-06-28

This work aims at the development of a mathematical and computational approach that enables quantification of the inherent sources of stochasticity and of the corresponding sensitivities in stochastic simulations of chemical reaction networks. The approach is based on reformulating the system dynamics as being generated by independent standardized Poisson processes. This reformulation affords a straightforward identification of individual realizations for the stochastic dynamics of each reaction channel, and consequently a quantitative characterization of the inherent sources of stochasticity in the system. By relying on the Sobol-Hoeffding decomposition, the reformulation enables us to perform an orthogonal decomposition of the solution variance. Thus, by judiciously exploiting the inherent stochasticity of the system, one is able to quantify the variance-based sensitivities associated with individual reaction channels, as well as the importance of channel interactions. Implementation of the algorithms is illustrated in light of simulations of simplified systems, including the birth-death, Schlögl, and Michaelis-Menten models.

Variance decomposition in stochastic simulators

Science.gov (United States)

Le Maître, O. P.; Knio, O. M.; Moraes, A.

2015-06-01

This work aims at the development of a mathematical and computational approach that enables quantification of the inherent sources of stochasticity and of the corresponding sensitivities in stochastic simulations of chemical reaction networks. The approach is based on reformulating the system dynamics as being generated by independent standardized Poisson processes. This reformulation affords a straightforward identification of individual realizations for the stochastic dynamics of each reaction channel, and consequently a quantitative characterization of the inherent sources of stochasticity in the system. By relying on the Sobol-Hoeffding decomposition, the reformulation enables us to perform an orthogonal decomposition of the solution variance. Thus, by judiciously exploiting the inherent stochasticity of the system, one is able to quantify the variance-based sensitivities associated with individual reaction channels, as well as the importance of channel interactions. Implementation of the algorithms is illustrated in light of simulations of simplified systems, including the birth-death, Schlögl, and Michaelis-Menten models.

Variance decomposition in stochastic simulators

Energy Technology Data Exchange (ETDEWEB)

Le Maître, O. P., E-mail: olm@limsi.fr [LIMSI-CNRS, UPR 3251, Orsay (France); Knio, O. M., E-mail: knio@duke.edu [Department of Mechanical Engineering and Materials Science, Duke University, Durham, North Carolina 27708 (United States); Moraes, A., E-mail: alvaro.moraesgutierrez@kaust.edu.sa [King Abdullah University of Science and Technology, Thuwal (Saudi Arabia)

2015-06-28

This work aims at the development of a mathematical and computational approach that enables quantification of the inherent sources of stochasticity and of the corresponding sensitivities in stochastic simulations of chemical reaction networks. The approach is based on reformulating the system dynamics as being generated by independent standardized Poisson processes. This reformulation affords a straightforward identification of individual realizations for the stochastic dynamics of each reaction channel, and consequently a quantitative characterization of the inherent sources of stochasticity in the system. By relying on the Sobol-Hoeffding decomposition, the reformulation enables us to perform an orthogonal decomposition of the solution variance. Thus, by judiciously exploiting the inherent stochasticity of the system, one is able to quantify the variance-based sensitivities associated with individual reaction channels, as well as the importance of channel interactions. Implementation of the algorithms is illustrated in light of simulations of simplified systems, including the birth-death, Schlögl, and Michaelis-Menten models.

Variance decomposition in stochastic simulators

KAUST Repository

Le Maî tre, O. P.; Knio, O. M.; Moraes, Alvaro

2015-01-01

This work aims at the development of a mathematical and computational approach that enables quantification of the inherent sources of stochasticity and of the corresponding sensitivities in stochastic simulations of chemical reaction networks. The approach is based on reformulating the system dynamics as being generated by independent standardized Poisson processes. This reformulation affords a straightforward identification of individual realizations for the stochastic dynamics of each reaction channel, and consequently a quantitative characterization of the inherent sources of stochasticity in the system. By relying on the Sobol-Hoeffding decomposition, the reformulation enables us to perform an orthogonal decomposition of the solution variance. Thus, by judiciously exploiting the inherent stochasticity of the system, one is able to quantify the variance-based sensitivities associated with individual reaction channels, as well as the importance of channel interactions. Implementation of the algorithms is illustrated in light of simulations of simplified systems, including the birth-death, Schlögl, and Michaelis-Menten models.

A thready affair: linking fungal diversity and community dynamics to terrestrial decomposition processes

NARCIS (Netherlands)

Van der Wal, A.; Geydan, T.D.; Kuyper, T.W.; De Boer, W.

2013-01-01

Filamentous fungi are critical to the decomposition of terrestrial organic matter and, consequently, in the global carbon cycle. In particular, their contribution to degradation of recalcitrant lignocellulose complexes has been widely studied. In this review, we focus on the functioning of

Long-term litter decomposition controlled by manganese redox cycling.

Science.gov (United States)

Keiluweit, Marco; Nico, Peter; Harmon, Mark E; Mao, Jingdong; Pett-Ridge, Jennifer; Kleber, Markus

2015-09-22

Litter decomposition is a keystone ecosystem process impacting nutrient cycling and productivity, soil properties, and the terrestrial carbon (C) balance, but the factors regulating decomposition rate are still poorly understood. Traditional models assume that the rate is controlled by litter quality, relying on parameters such as lignin content as predictors. However, a strong correlation has been observed between the manganese (Mn) content of litter and decomposition rates across a variety of forest ecosystems. Here, we show that long-term litter decomposition in forest ecosystems is tightly coupled to Mn redox cycling. Over 7 years of litter decomposition, microbial transformation of litter was paralleled by variations in Mn oxidation state and concentration. A detailed chemical imaging analysis of the litter revealed that fungi recruit and redistribute unreactive Mn(2+) provided by fresh plant litter to produce oxidative Mn(3+) species at sites of active decay, with Mn eventually accumulating as insoluble Mn(3+/4+) oxides. Formation of reactive Mn(3+) species coincided with the generation of aromatic oxidation products, providing direct proof of the previously posited role of Mn(3+)-based oxidizers in the breakdown of litter. Our results suggest that the litter-decomposing machinery at our coniferous forest site depends on the ability of plants and microbes to supply, accumulate, and regenerate short-lived Mn(3+) species in the litter layer. This observation indicates that biogeochemical constraints on bioavailability, mobility, and reactivity of Mn in the plant-soil system may have a profound impact on litter decomposition rates.

Kinetics of the thermal decomposition of nickel iodide

International Nuclear Information System (INIS)

Nakajima, Hayato; Shimizu, Saburo; Onuki, Kaoru; Ikezoe, Yasumasa; Sato, Shoichi

1984-01-01

Thermal decomposition kinetics of NiI 2 under constant I 2 partial pressure was studied by thermogravimetry. The reaction is considered as a reaction step of the thermochemical hydrogen production process in the Ni-I-S system. At temperatures from 775K to 869K and under I 2 pressures from 0 to 960Pa, the decomposition started at the NiI 2 pellet surface and the reactant-product interface moved interior at a constant rate until the decomposed fraction, α, reached 0.6. The overall reaction rate at a constant temperature can be expressed as the difference of the constant decomposition (forward) rate, which is proportional to the equilibrium dissociation pressure of NiI 2 , and the iodide formation (backward) rate, which is proportional to the I 2 pressure. The apparent activation energy of the decomposition was 147 kJ.mol -1 , which is very close to the heat of reaction, 152 kJ.mol -1 calculated from the equilibrium dissociation pressure. The electron microscopic observations, revealed that the reaction product obtained by decomposing NiI 2 under pure He atomosphere was composed of relatively well grown cubic Ni crystals. Whereas, the decomposed product obtained under I 2 -He mixture was composed of larger but disordered crystals. (author)

Synthesis and thermal decomposition study of dysprosium trifluoroacetate

DEFF Research Database (Denmark)

Opata, Y. A.; Grivel, J.-C.

2018-01-01

A study of the thermal decomposition process of dysprosium trifluoroacetate hydrate under flowing argon is presented. Thermogravimetry, differential thermal analysis, evolved gas analysis and ex-situ x-ray diffraction techniques have been employed in the investigation. Three main stages were...

Symmetric Tensor Decomposition

DEFF Research Database (Denmark)

Brachat, Jerome; Comon, Pierre; Mourrain, Bernard

2010-01-01

We present an algorithm for decomposing a symmetric tensor, of dimension n and order d, as a sum of rank-1 symmetric tensors, extending the algorithm of Sylvester devised in 1886 for binary forms. We recall the correspondence between the decomposition of a homogeneous polynomial in n variables...... of polynomial equations of small degree in non-generic cases. We propose a new algorithm for symmetric tensor decomposition, based on this characterization and on linear algebra computations with Hankel matrices. The impact of this contribution is two-fold. First it permits an efficient computation...... of the decomposition of any tensor of sub-generic rank, as opposed to widely used iterative algorithms with unproved global convergence (e.g. Alternate Least Squares or gradient descents). Second, it gives tools for understanding uniqueness conditions and for detecting the rank....

A novel method for EMG decomposition based on matched filters

Directory of Open Access Journals (Sweden)

Ailton Luiz Dias Siqueira Júnior

Full Text Available Introduction Decomposition of electromyography (EMG signals into the constituent motor unit action potentials (MUAPs can allow for deeper insights into the underlying processes associated with the neuromuscular system. The vast majority of the methods for EMG decomposition found in the literature depend on complex algorithms and specific instrumentation. As an attempt to contribute to solving these issues, we propose a method based on a bank of matched filters for the decomposition of EMG signals. Methods Four main units comprise our method: a bank of matched filters, a peak detector, a motor unit classifier and an overlapping resolution module. The system’s performance was evaluated with simulated and real EMG data. Classification accuracy was measured by comparing the responses of the system with known data from the simulator and with the annotations of a human expert. Results The results show that decomposition of non-overlapping MUAPs can be achieved with up to 99% accuracy for signals with up to 10 active motor units and a signal-to-noise ratio (SNR of 10 dB. For overlapping MUAPs with up to 10 motor units per signal and a SNR of 20 dB, the technique allows for correct classification of approximately 71% of the MUAPs. The method is capable of processing, decomposing and classifying a 50 ms window of data in less than 5 ms using a standard desktop computer. Conclusion This article contributes to the ongoing research on EMG decomposition by describing a novel technique capable of delivering high rates of success by means of a fast algorithm, suggesting its possible use in future real-time embedded applications, such as myoelectric prostheses control and biofeedback systems.

Surface spinodal decomposition in coherent metal-hydrogen and other alloys

International Nuclear Information System (INIS)

Kappus, W.; Horner, H.

1977-01-01

Spinodal decomposition in metal hydrides and alloys near a surface under the influence of elastic interactions is investigated. As long as the crystals remain coherent this process sets in prior to spinodal decomposition in the bulk. A statistical theory containing thermal fluctuations and nonlinear effects is developed and solutions are found in a mean field approximation. The theory is applied to niobium-hydride and a possible explanation for the appearance of quasiperiodic β-phase precipitates in quenched probes is given. (orig.) [de

Direct observation of thermal disorder and decomposition of black phosphorus

Science.gov (United States)

Yoo, Seung Jo; Kim, Heejin; Lee, Ji-Hyun; Kim, Jin-Gyu

2018-02-01

Theoretical research has been devoted to reveal the properties of black phosphorus as a two-dimensional nanomaterial, but little attention has been paid for the experimental characterization. In this study, the thermal disorder and decomposition of black phosphorus were examined using in situ heating transmission electron microscopy experiments. We observed that the breaking of crystallographic symmetry begins at 380 °C under vacuum condition, followed by the phosphorus evaporates after long-term heating at 400 °C. This decomposition process can be initiated by the surficial vacancy and proceeds toward both interlayer ([010]) and intralayer ([001]) directions. The results on the thermal behavior of black phosphorus provide useful guidance for thin film deposition and fabrication processes with black phosphorus.

4.3. Decomposition of danburite concentrate of Ak-Arkar Deposit by nitric acid

International Nuclear Information System (INIS)

Mirsaidov, U.M.; Kurbonov, A.S.; Mamatov, E.D.

2015-01-01

Present article is devoted to decomposition of danburite concentrate of Ak-Arkar Deposit by nitric acid. The influence of temperature on reaction process was studied. The dependence of extraction rate of oxides (B 2 O 3 , Al 2 O 3 , Fe 2 O 3 and Ca O) at nitric acid processing on temperature ranges from 25 to 95 deg C was defined. The dependence of extraction rate of oxides (B 2 O 3 , Al 2 O 3 , Fe 2 O 3 and Ca O) at nitric acid processing on process duration (5-60 minutes) was defined as well. The optimal conditions of decomposition of danburite concentrate by nitric acid were proposed.

Decomposition processes in soil of a healthy and a declining Phragmites australis stand

Czech Academy of Sciences Publication Activity Database

Šantrůčková, Hana; Picek, Tomáš; Šimek, Miloslav; Bauer, Václav; Kopecký, Jiří; Pechar, Libor; Lukavská, Jaroslava; Čížková, Hana

2001-01-01

Roč. 69, - (2001), s. 217-234 ISSN 0304-3770 R&D Projects: GA ČR GA206/96/0589 Institutional research plan: CEZ:AV0Z6066911 Keywords : decomposition * eutrophication * Phragmites australis Subject RIV: EH - Ecology, Behaviour Impact factor: 1.361, year: 2001

Subspace-Based Noise Reduction for Speech Signals via Diagonal and Triangular Matrix Decompositions

DEFF Research Database (Denmark)

Hansen, Per Christian; Jensen, Søren Holdt

We survey the definitions and use of rank-revealing matrix decompositions in single-channel noise reduction algorithms for speech signals. Our algorithms are based on the rank-reduction paradigm and, in particular, signal subspace techniques. The focus is on practical working algorithms, using both...... diagonal (eigenvalue and singular value) decompositions and rank-revealing triangular decompositions (ULV, URV, VSV, ULLV and ULLIV). In addition we show how the subspace-based algorithms can be evaluated and compared by means of simple FIR filter interpretations. The algorithms are illustrated...... with working Matlab code and applications in speech processing....

Some nonlinear space decomposition algorithms

Energy Technology Data Exchange (ETDEWEB)

Tai, Xue-Cheng; Espedal, M. [Univ. of Bergen (Norway)

1996-12-31

Convergence of a space decomposition method is proved for a general convex programming problem. The space decomposition refers to methods that decompose a space into sums of subspaces, which could be a domain decomposition or a multigrid method for partial differential equations. Two algorithms are proposed. Both can be used for linear as well as nonlinear elliptic problems and they reduce to the standard additive and multiplicative Schwarz methods for linear elliptic problems. Two {open_quotes}hybrid{close_quotes} algorithms are also presented. They converge faster than the additive one and have better parallelism than the multiplicative method. Numerical tests with a two level domain decomposition for linear, nonlinear and interface elliptic problems are presented for the proposed algorithms.

Thermal decomposition of gaseous ammonium nitrate at low pressure: kinetic modeling of product formation and heterogeneous decomposition of nitric acid.

Science.gov (United States)

Park, J; Lin, M C

2009-12-03

The thermal decomposition of ammonium nitrate, NH(4)NO(3) (AN), in the gas phase has been studied at 423-56 K by pyrolysis/mass spectrometry under low-pressure conditions using a Saalfeld reactor coated with boric acid. The sublimation of NH(4)NO(3) at 423 K was proposed to produce equal amounts of NH(3) and HNO(3), followed by the decomposition reaction of HNO(3), HNO(3) + M --> OH + NO(2) + M (where M = third-body and reactor surface). The absolute yields of N(2), N(2)O, H(2)O, and NH(3), which can be unambiguously measured and quantitatively calibrated under a constant pressure at 5-6.2 torr He are kinetically modeled using the detailed [H,N,O]-mechanism established earlier for the simulation of NH(3)-NO(2) (Park, J.; Lin, M. C. Technologies and Combustion for a Clean Environment. Proc. 4th Int. Conf. 1997, 34-1, 1-5) and ADN decomposition reactions (Park, J.; Chakraborty, D.; Lin, M. C. Proc. Combust. Inst. 1998, 27, 2351-2357). Since the homogeneous decomposition reaction of HNO(3) itself was found to be too slow to account for the consumption of reactants and the formation of products, we also introduced the heterogeneous decomposition of HNO(3) in our kinetic modeling. The heterogeneous decomposition rate of HNO(3), HNO(3) + (B(2)O(3)/SiO(2)) --> OH + NO(2) + (B(2)O(3)/SiO(2)), was determined by varying its rate to match the modeled result to the measured concentrations of NH(3) and H(2)O; the rate could be represented by k(2b) = 7.91 x 10(7) exp(-12 600/T) s(-1), which appears to be consistent with those reported by Johnston and co-workers (Johnston, H. S.; Foering, L.; Tao, Y.-S.; Messerly, G. H. J. Am. Chem. Soc. 1951, 73, 2319-2321) for HNO(3) decomposition on glass reactors at higher temperatures. Notably, the concentration profiles of all species measured could be satisfactorily predicted by the existing [H,N,O]-mechanism with the heterogeneous initiation process.

Thermal Decomposition of Gaseous Ammonium Nitrate at Low Pressure: Kinetic Modeling of Product Formation and Heterogeneous Decomposition of Nitric Acid

Science.gov (United States)

Park, J.; Lin, M. C.

2009-10-01

The thermal decomposition of ammonium nitrate, NH4NO3 (AN), in the gas phase has been studied at 423-56 K by pyrolysis/mass spectrometry under low-pressure conditions using a Saalfeld reactor coated with boric acid. The sublimation of NH4NO3 at 423 K was proposed to produce equal amounts of NH3 and HNO3, followed by the decomposition reaction of HNO3, HNO3 + M → OH + NO2 + M (where M = third-body and reactor surface). The absolute yields of N2, N2O, H2O, and NH3, which can be unambiguously measured and quantitatively calibrated under a constant pressure at 5-6.2 torr He are kinetically modeled using the detailed [H,N,O]-mechanism established earlier for the simulation of NH3-NO2 (Park, J.; Lin, M. C. Technologies and Combustion for a Clean Environment. Proc. 4th Int. Conf. 1997, 34-1, 1-5) and ADN decomposition reactions (Park, J.; Chakraborty, D.; Lin, M. C. Proc. Combust. Inst. 1998, 27, 2351-2357). Since the homogeneous decomposition reaction of HNO3 itself was found to be too slow to account for the consumption of reactants and the formation of products, we also introduced the heterogeneous decomposition of HNO3 in our kinetic modeling. The heterogeneous decomposition rate of HNO3, HNO3 + (B2O3/SiO2) → OH + NO2 + (B2O3/SiO2), was determined by varying its rate to match the modeled result to the measured concentrations of NH3 and H2O; the rate could be represented by k2b = 7.91 × 107 exp(-12 600/T) s-1, which appears to be consistent with those reported by Johnston and co-workers (Johnston, H. S.; Foering, L.; Tao, Y.-S.; Messerly, G. H. J. Am. Chem. Soc. 1951, 73, 2319-2321) for HNO3 decomposition on glass reactors at higher temperatures. Notably, the concentration profiles of all species measured could be satisfactorily predicted by the existing [H,N,O]-mechanism with the heterogeneous initiation process.

Litter Decomposition Rate of Avicennia marina and Rhizophora apiculata in Pulau Dua Nature Reserve, Banten

Directory of Open Access Journals (Sweden)

Febriana Siska

2016-05-01

Full Text Available Litter decomposition rate is useful method to determine forest fertility level. The aims of this study were to measure decomposition rate, and analyze the nutrient content released organic carbon, nitrogen, and phosphor from Avicennia marina and Rhizophora apiculata litters during the decomposition process. The research was conducted in the Pulau Dua Nature Reserve, Serang-Banten on A. marina and R. apiculata forest communities. Litter decomposition rate measurements performed in the field. Litter that has been obtained with the trap system is inserted into litter bag and than tied to the roots or trees to avoid drifting sea water. Litter decomposition rate was measured every 15 days and is accompanied by analysis of the content of organic C , total N and P. Our research results showed decomposition rate of A. marina (k= 0.83 was higher than that of R. apiculata (k= 0.41. Differences of  leaf anatomical structure and sea water salinity  influenced to the rate of litter decomposition. Organic C released was declined with longer of litter decomposition, on the contrary of releasing N and P nutrients.

1.6. The kinetics of hydrochloric acid decomposition of argillite of Chashma-Sang Deposit

International Nuclear Information System (INIS)

Mirsaidov, U.M.; Mirzoev, D.Kh.; Boboev, Kh.E.

2016-01-01

Present article of book is devoted to kinetics of hydrochloric acid decomposition of argillite of Chashma-Sang Deposit. It was defined that with temperature increasing the extraction rate of Al_2O_3 and Fe_2O_3 increases. The dependence of extraction rate of Al_2O_3 and Fe_2O_3 on process duration at hydrochloric acid decomposition of argillite was studied. The activation energy of the process was defined.

Decomposition of Multi-player Games

Science.gov (United States)

Zhao, Dengji; Schiffel, Stephan; Thielscher, Michael

Research in General Game Playing aims at building systems that learn to play unknown games without human intervention. We contribute to this endeavour by generalising the established technique of decomposition from AI Planning to multi-player games. To this end, we present a method for the automatic decomposition of previously unknown games into independent subgames, and we show how a general game player can exploit a successful decomposition for game tree search.

Identification of liquid-phase decomposition species and reactions for guanidinium azotetrazolate

International Nuclear Information System (INIS)

Kumbhakarna, Neeraj R.; Shah, Kaushal J.; Chowdhury, Arindrajit; Thynell, Stefan T.

2014-01-01

Highlights: • Guanidinium azotetrazolate (GzT) is a high-nitrogen energetic material. • FTIR spectroscopy and ToFMS spectrometry were used for species identification. • Quantum mechanics was used to identify transition states and decomposition pathways. • Important reactions in the GzT liquid-phase decomposition process were identified. • Initiation of decomposition occurs via ring opening, releasing N 2 . - Abstract: The objective of this work is to analyze the decomposition of guanidinium azotetrazolate (GzT) in the liquid phase by using a combined experimental and computational approach. The experimental part involves the use of Fourier transform infrared (FTIR) spectroscopy to acquire the spectral transmittance of the evolved gas-phase species from rapid thermolysis, as well as to acquire spectral transmittance of the condensate and residue formed from the decomposition. Time-of-flight mass spectrometry (ToFMS) is also used to acquire mass spectra of the evolved gas-phase species. Sub-milligram samples of GzT were heated at rates of about 2000 K/s to a set temperature (553–573 K) where decomposition occurred under isothermal conditions. N 2 , NH 3 , HCN, guanidine and melamine were identified as products of decomposition. The computational approach is based on using quantum mechanics for confirming the identity of the species observed in experiments and for identifying elementary chemical reactions that formed these species. In these ab initio techniques, various levels of theory and basis sets were used. Based on the calculated enthalpy and free energy values of various molecular structures, important reaction pathways were identified. Initiation of decomposition of GzT occurs via ring opening to release N 2

Decomposition of 14C-labeled organic substances in marine sediments

International Nuclear Information System (INIS)

Anon.

1986-01-01

The depth variation of total organic carbon (TOC), organic matter composition and porewater composition in marine sediments suggest that different components of the organic matter undergo decomposition at widely different rates. The decomposition of 14 C-labeled organic substances was followed in sediment microcosms in the laboratory. The substances used were chosen to simulate a portion of material settling to the sediment-water interface (a marine diatom) or hypothesized components of refractory sediment organic matter (melanoidins and a bacterial polymer). The microcosms were found to be good models of the sediment-water interface in terms of how well they mimicked sediment decomposition rates and processes. The decomposition of the labeled material and the natural sediment TOC were monitored over 1 month: the water overlying the sediment remained oxic, and net consumption of nitrate was small. There was no detectable sulfate reduction. The algae and the bacterial polymer were decomposed on average 9x faster than the melanoidins and 90x faster than the natural sediment TOC. The soluble fraction of the algae was decomposed more rapidly than the particulate material

Decomposition mechanisms and non-isothermal kinetics of LiHC_2O_4·H_2O

Institute of Scientific and Technical Information of China (English)

无

2012-01-01

The thermal decomposition process of LiHC2O4·H2O from 30 to 600 ℃ was investigated by the thermogravimetric and differential scanning calorimetry (TG-DSC). The phases decomposited at different temperature were characterized by X-ray diffraction (XRD), which indicated the decompositions at 150, 170, and 420℃, relating to LiHC2O4, Li2C2O4, Li2C2O4, and Li2CO3, respectively. Reaction mechanisms in the whole sintering process were determined, and the model fitting kinetic approaches were applied to data for non...

Further insights into the kinetics of thermal decomposition during continuous cooling.

Science.gov (United States)

Liavitskaya, Tatsiana; Guigo, Nathanaël; Sbirrazzuoli, Nicolas; Vyazovkin, Sergey

2017-07-26

Following the previous work (Phys. Chem. Chem. Phys., 2016, 18, 32021), this study continues to investigate the intriguing phenomenon of thermal decomposition during continuous cooling. The phenomenon can be detected and its kinetics can be measured by means of thermogravimetric analysis (TGA). The kinetics of the thermal decomposition of ammonium nitrate (NH 4 NO 3 ), nickel oxalate (NiC 2 O 4 ), and lithium sulfate monohydrate (Li 2 SO 4 ·H 2 O) have been measured upon heating and cooling and analyzed by means of the isoconversional methodology. The results have confirmed the hypothesis that the respective kinetics should be similar for single-step processes (NH 4 NO 3 decomposition) but different for multi-step ones (NiC 2 O 4 decomposition and Li 2 SO 4 ·H 2 O dehydration). It has been discovered that the differences in the kinetics can be either quantitative or qualitative. Physical insights into the nature of the differences have been proposed.

Preliminary assessment of the possibility of supporting the decomposition of biodegradable packaging

Directory of Open Access Journals (Sweden)

Niekraś Lidia

2017-01-01

Full Text Available This article presents a preliminary evaluation of the possibility of using grass biomass from a sports field as a compost ingredient which positively affects the degree of decomposition of the biodegradable wrappings. For 5 months the biodegradable bags were stored, both empty and filled with organic waste in the heap of grass clippings. After that period, fragments of the bags were observed under the microscope and then assessed the state of their decomposition. The results indicate that the biomass used favourably affected the process of bag degradation, however the speed of decomposition of the empty bags was quicker than the bags filled with the organic waste.

Bimetallic catalysts for HI decomposition in the iodine-sulfur thermochemical cycle

International Nuclear Information System (INIS)

Wang Laijun; Hu Songzhi; Xu Lufei; Li Daocai; Han Qi; Chen Songzhe; Zhang Ping; Xu Jingming

2014-01-01

Among the different kinds of thermochemical water-splitting cycles, the iodine-sulfur (IS) cycle has attracted more and more interest because it is one of the promising candidates for economical and massive hydrogen production. However, there still exist some science and technical problems to be solved before industrialization of the IS process. One such problem is the catalytic decomposition of hydrogen iodide. Although the active carbon supported platinum has been verified to present the excellent performance for HI decomposition, it is very expensive and easy to agglomerate under the harsh condition. In order to decrease the cost and increase the stability of the catalysts for HI decomposition, a series of bimetallic catalysts were prepared and studied at INET. This paper summarized our present research advances on the bimetallic catalysts (Pt-Pd, Pd-Ir and Pt-Ir) for HI decomposition. In the course of the study, the physical properties, structure, and morphology of the catalysts were characterized by specific surface area, X-ray diffractometer; and transmission electron microscopy, respectively. The catalytic activity for HI decomposition was investigated in a fixed bed reactor under atmospheric pressure. The results show that due to the higher activity and better stability, the active carbon supported bimetallic catalyst is more potential candidate than mono metallic Pt catalyst for HI decomposition in the IS thermochemical cycle. (author)

Treatment of off-gas evolved from thermal decomposition of sludge waste

International Nuclear Information System (INIS)

Doo-Seong Hwang; Yun-Dong Choi; Gyeong-Hwan Jeong; Jei-Kwon Moon

2013-01-01

Korea Atomic Energy Research Institute (KAERI) started a decommissioning program of a uranium conversion plant. The treatment of the sludge waste, which was generated during the operation of the plant, is one of the most important tasks in the decommissioning program of the plant. The major compounds of sludge waste are nitrate salts and uranium. The sludge waste is denitrated by thermal decomposition. The treatment of off-gas evolved from the thermal decomposition of nitrate salts in the sludge waste is investigated. The nitrate salts in the sludge were decomposed in two steps: the first decomposition is due to the ammonium nitrate, and the second is due to the sodium and calcium nitrate and calcium carbonate. The components of off-gas from the decomposition of ammonium nitrate at low temperature are NH 3 , N 2 O, NO 2 , and NO. In addition, the components from the decomposition of sodium and calcium nitrate at high temperature are NO 2 and NO. Off-gas from the thermal decomposition is treated by the catalytic oxidation of ammonia and selective catalytic reduction (SCR). Ammonia is converted into nitrogen oxides through the oxidation catalyst and all nitrogen oxides are removed by SCR treatment besides nitrous oxide, which is greenhouse gas. An additional process is needed to remove nitrous oxide, and the feeding rate of ammonia in SCR should be controlled properly for evolved nitrogen oxides. (author)

LEAF RESIDUE DECOMPOSITION OF SELECTED ATLANTIC FOREST TREE SPECIES

Directory of Open Access Journals (Sweden)

Helga Dias Arato

2018-02-01

Full Text Available ABSTRACT Biogeochemical cycling is essential to establish and maintain plant and animal communities. Litter is one of main compartments of this cycle, and the kinetics of leaf decomposition in forest litter depend on the chemical composition and environmental conditions. This study evaluated the effect of leaf composition and environmental conditions on leaf decomposition of native Atlantic Forest trees. The following species were analyzed: Mabea fistulifera Mart., Bauhinia forficata Link., Aegiphila sellowiana Cham., Zeyheria tuberculosa (Vell, Luehea grandiflora Mart. et. Zucc., Croton floribundus Spreng., Trema micrantha (L Blume, Cassia ferruginea (Schrad Schrad ex DC, Senna macranthera (DC ex Collad. H. S. Irwin and Barney and Schinus terebinthifolius Raddi (Anacardiaceae. For each species, litter bags were distributed on and fixed to the soil surface of soil-filled pots (in a greenhouse, or directly to the surface of the same soil type in a natural forest (field. Every 30 days, the dry weight and soil basal respiration in both environments were determined. The cumulative decomposition of leaves varied according to the species, leaf nutrient content and environment. In general, the decomposition rate was lowest for Aegiphila sellowiana and fastest for Bauhinia forficate and Schinus terebinthifolius. This trend was similar under the controlled conditions of a greenhouse and in the field. The selection of species with a differentiated decomposition pattern, suited for different stages of the recovery process, can help improve soil restoration.

Catalytic Decomposition of Hydroxylammonium Nitrate Ionic Liquid: Enhancement of NO Formation

Science.gov (United States)

2017-04-24

decomposition due to reduction in the acidity (i.e., [HNO3]) in the mixture. Reaction 2 has an activation barrier of Ea = 105 kJ/mol and is dominant at low...Propellants. Appl . Catal., B 2006, 62, 217−225. (15) Amariei, D.; Courtheóux, L.; Rossignol, S.; Kappenstein, C. Catalytic and Thermal Decomposition...Monopropellants: Thermal and Catalytic Decom- position Processes. Appl . Catal., B 2012, 127, 121−128. (19) Amrousse, R.; Katsumi, T.; Itouyama, N.; Azuma

Kinetics of methanol decomposition on Cu/ZnO/ZrO2 catalysts

International Nuclear Information System (INIS)

Grabowski, R.; Kozlowska, A.

2004-01-01

Interaction of methanol with Cu/ZnO/ZrO 2 (with different copper content) has been investigated by gravimetric and TPD methods. The TPD measurements of methanol adsorption on these catalysis show that it forms the complexes of two types. The first complex (I) decomposes at low temperature (453 K) yielding H 2 and CO 2 and second (II) decomposes at temperature (573 K) giving CO and H 2 . In the process of decomposition of the complex (I) takes part water which is adsorbed on the surface of the catalyst and the decomposition of the complex (II) occurs without participation of adsorbed water. Gravimetric measurements of methanol and that an increase of copper content leads to the changes in the kinetics of methanol adsorption and its decomposition. On the basis of gravimetric measurements a model of methanol adsorption and decomposition on Cu/ZnO/ZrO 2 catalyst has been proposed and the rate constants of methanol adsorption (k a ) and decomposition with and without participation of water (k 1 and k 2 ) have been determined. (author)

Signature of a spinodal decomposition in the multifragmentation process of very heavy nuclear systems; Signature fossile d'une decomposition spinodale dans la multifragmentation de systemes nucleaires tres lourds

Energy Technology Data Exchange (ETDEWEB)

Tabacaru, G

2000-12-01

A dynamical description of the multifragmentation process shows that mechanical instabilities are responsible for spinodal decomposition of a nuclear system that spend sufficient time in the low-density region. The Xe + Sn system at 32 MeV/A incident energy, measured with INDRA multidetector, was chosen to prove experimentally this hypothesis. High performance techniques in energy calibration of Silicon detectors and CsI(Tl) scintillators were developed in order to exploit the excellent detection qualities of the multidetector. For the first time, the contribution of {delta} rays to the light output emitted by scintillators was quantitatively derived. Multifragmentation events coming from a system composed by almost all of nucleons of the reaction entrance channel were selected using detection completeness and event shape criteria. The dynamical model BoB realistically simulates the spinodal instabilities. This model reproduces all of dynamic and static observables. More exclusive comparisons were made to constrain again the model. Reduced velocity correlation functions were studied and gave information about the topology of the fragments at freeze-out. Charge correlation of the fragments showed that a small proportion of events (0.1 %) emits equal-sized fragments. This was interpreted as a fossil signature of the spinodal decomposition in a finite system. Indirectly, this is a proof of a first order phase transition associated to the multifragmentation of hot nuclei. (author)

Decomposition of diesel oil by various microorganisms

Energy Technology Data Exchange (ETDEWEB)

Suess, A; Netzsch-Lehner, A

1969-01-01

Previous experiments demonstrated the decomposition of diesel oil in different soils. In this experiment the decomposition of /sup 14/C-n-Hexadecane labelled diesel oil by special microorganisms was studied. The results were as follows: (1) In the experimental soils the microorganisms Mycoccus ruber, Mycobacterium luteum and Trichoderma hamatum are responsible for the diesel oil decomposition. (2) By adding microorganisms to the soil an increase of the decomposition rate was found only in the beginning of the experiments. (3) Maximum decomposition of diesel oil was reached 2-3 weeks after incubation.

Measurement of the energy dependence of X-ray-induced decomposition of potassium chlorate.

Science.gov (United States)

Pravica, Michael; Bai, Ligang; Sneed, Daniel; Park, Changyong

2013-03-21

We report the first measurements of the X-ray induced decomposition of KClO3 as a function of energy in two experiments. KClO3 was pressurized to 3.5 GPa and irradiated with monochromatic synchrotron X-rays ranging in energy from 15 to 35 keV in 5 keV increments. A systematic increase in the decomposition rate as the energy was decreased was observed, which agrees with the 1/E(3) trend for the photoelectric process, except at the lowest energy studied. A second experiment was performed to access lower energies (10 and 12 keV) using a beryllium gasket; suggesting an apparent resonance near 15 keV or 0.83 Ǻ maximizing the chemical decomposition rate. A third experiment was performed using KIO3 to ascertain the anionic dependence of the decomposition rate, which was observed to be far slower than in KClO3, suggesting that the O-O distance is the critical factor in chemical reactions. These results will be important for more efficiently initiating chemical decomposition in materials using selected X-ray wavelengths that maximize decomposition to aid useful hard X-ray-induced chemistry and contribute understanding of the mechanism of X-ray-induced decomposition of the chlorates.

Multilinear operators for higher-order decompositions.

Energy Technology Data Exchange (ETDEWEB)

Kolda, Tamara Gibson

2006-04-01

We propose two new multilinear operators for expressing the matrix compositions that are needed in the Tucker and PARAFAC (CANDECOMP) decompositions. The first operator, which we call the Tucker operator, is shorthand for performing an n-mode matrix multiplication for every mode of a given tensor and can be employed to concisely express the Tucker decomposition. The second operator, which we call the Kruskal operator, is shorthand for the sum of the outer-products of the columns of N matrices and allows a divorce from a matricized representation and a very concise expression of the PARAFAC decomposition. We explore the properties of the Tucker and Kruskal operators independently of the related decompositions. Additionally, we provide a review of the matrix and tensor operations that are frequently used in the context of tensor decompositions.

Memory effect and fast spinodal decomposition

International Nuclear Information System (INIS)

Koide, T.; Krein, G.; Ramos, Rudnei O.

2007-01-01

We consider the modification of the Cahn-Hilliard equation when a time delay process through a memory function is taken into account. We then study the process of spinodal decomposition in fast phase transitions associated with a conserved order parameter. The introduced memory effect plays an important role to obtain a finite group velocity. Then, we discuss the constraint for the parameters to satisfy causality. The memory effect is seen to affect the dynamics of phase transition at short times and have the effect of delaying, in a significant way, the process of rapid growth of the order parameter that follows a quench into the spinodal region. (author)

Three-Component Decomposition Based on Stokes Vector for Compact Polarimetric SAR

Directory of Open Access Journals (Sweden)

Hanning Wang

2015-09-01

Full Text Available In this paper, a three-component decomposition algorithm is proposed for processing compact polarimetric SAR images. By using the correspondence between the covariance matrix and the Stokes vector, three-component scattering models for CTLR and DCP modes are established. The explicit expression of decomposition results is then derived by setting the contribution of volume scattering as a free parameter. The degree of depolarization is taken as the upper bound of the free parameter, for the constraint that the weighting factor of each scattering component should be nonnegative. Several methods are investigated to estimate the free parameter suitable for decomposition. The feasibility of this algorithm is validated by AIRSAR data over San Francisco and RADARSAT-2 data over Flevoland.

Responses of primary production, leaf litter decomposition and associated communities to stream eutrophication

International Nuclear Information System (INIS)

Dunck, Bárbara; Lima-Fernandes, Eva; Cássio, Fernanda; Cunha, Ana; Rodrigues, Liliana; Pascoal, Cláudia

2015-01-01

We assessed the eutrophication effects on leaf litter decomposition and primary production, and on periphytic algae, fungi and invertebrates. According to the subsidy-stress model, we expected that when algae and decomposers were nutrient limited, their activity and diversity would increase at moderate levels of nutrient enrichment, but decrease at high levels of nutrients, because eutrophication would lead to the presence of other stressors and overwhelm the subsidy effect. Chestnut leaves (Castanea sativa Mill) were enclosed in mesh bags and immersed in five streams of the Ave River basin (northwest Portugal) to assess leaf decomposition and colonization by invertebrates and fungi. In parallel, polyethylene slides were attached to the mesh bags to allow colonization by algae and to assess primary production. Communities of periphytic algae and decomposers discriminated the streams according to the trophic state. Primary production decomposition and biodiversity were lower in streams at both ends of the trophic gradient. - Highlights: • Algae and decomposers discriminated the streams according to the eutrophication level. • Primary production and litter decomposition are stimulated by moderate eutrophication. • Biodiversity and process rates were reduced in highly eutrophic streams. • Subsidy-stress model explained biodiversity and process rates under eutrophication. - Rates of leaf litter decomposition, primary production and richness of periphytic algae, fungi and invertebrates were lower in streams at both ends of the trophic gradient

Decomposition of tetrachloroethylene by ionizing radiation

International Nuclear Information System (INIS)

Hakoda, T.; Hirota, K.; Hashimoto, S.

1998-01-01

Decomposition of tetrachloroethylene and other chloroethenes by ionizing radiation were examined to get information on treatment of industrial off-gas. Model gases, airs containing chloroethenes, were confined in batch reactors and irradiated with electron beam and gamma ray. The G-values of decomposition were larger in the order of tetrachloro- > trichloro- > trans-dichloro- > cis-dichloro- > monochloroethylene in electron beam irradiation and tetrachloro-, trichloro-, trans-dichloro- > cis-dichloro- > monochloroethylene in gamma ray irradiation. For tetrachloro-, trichloro- and trans-dichloroethylene, G-values of decomposition in EB irradiation increased with increase of chlorine atom in a molecule, while those in gamma ray irradiation were almost kept constant. The G-value of decomposition for tetrachloroethylene in EB irradiation was the largest of those for all chloroethenes. In order to examine the effect of the initial concentration on G-value of decomposition, airs containing 300 to 1,800 ppm of tetrachloroethylene were irradiated with electron beam and gamma ray. The G-values of decomposition in both irradiation increased with the initial concentration. Those in electron beam irradiation were two times larger than those in gamma ray irradiation

Infrared multiphoton absorption and decomposition

International Nuclear Information System (INIS)

Evans, D.K.; McAlpine, R.D.

1984-01-01

The discovery of infrared laser induced multiphoton absorption (IRMPA) and decomposition (IRMPD) by Isenor and Richardson in 1971 generated a great deal of interest in these phenomena. This interest was increased with the discovery by Ambartzumian, Letokhov, Ryadbov and Chekalin that isotopically selective IRMPD was possible. One of the first speculations about these phenomena was that it might be possible to excite a particular mode of a molecule with the intense infrared laser beam and cause decomposition or chemical reaction by channels which do not predominate thermally, thus providing new synthetic routes for complex chemicals. The potential applications to isotope separation and novel chemistry stimulated efforts to understand the underlying physics and chemistry of these processes. At ICOMP I, in 1977 and at ICOMP II in 1980, several authors reviewed the current understandings of IRMPA and IRMPD as well as the particular aspect of isotope separation. There continues to be a great deal of effort into understanding IRMPA and IRMPD and we will briefly review some aspects of these efforts with particular emphasis on progress since ICOMP II. 31 references

Decomposition of Sodium Tetraphenylborate

International Nuclear Information System (INIS)

Barnes, M.J.

1998-01-01

The chemical decomposition of aqueous alkaline solutions of sodium tetraphenylborate (NaTPB) has been investigated. The focus of the investigation is on the determination of additives and/or variables which influence NaTBP decomposition. This document describes work aimed at providing better understanding into the relationship of copper (II), solution temperature, and solution pH to NaTPB stability

A Decomposition-Based Pricing Method for Solving a Large-Scale MILP Model for an Integrated Fishery

Directory of Open Access Journals (Sweden)

M. Babul Hasan

2007-01-01

The IFP can be decomposed into a trawler-scheduling subproblem and a fish-processing subproblem in two different ways by relaxing different sets of constraints. We tried conventional decomposition techniques including subgradient optimization and Dantzig-Wolfe decomposition, both of which were unacceptably slow. We then developed a decomposition-based pricing method for solving the large fishery model, which gives excellent computation times. Numerical results for several planning horizon models are presented.

Thermal decomposition of γ-irradiated lead nitrate

International Nuclear Information System (INIS)

Nair, S.M.K.; Kumar, T.S.S.

1990-01-01

The thermal decomposition of unirradiated and γ-irradiated lead nitrate was studied by the gas evolution method. The decomposition proceeds through initial gas evolution, a short induction period, an acceleratory stage and a decay stage. The acceleratory and decay stages follow the Avrami-Erofeev equation. Irradiation enhances the decomposition but does not affect the shape of the decomposition curve. (author) 10 refs.; 7 figs.; 2 tabs

Decomposing Nekrasov decomposition

International Nuclear Information System (INIS)

Morozov, A.; Zenkevich, Y.

2016-01-01

AGT relations imply that the four-point conformal block admits a decomposition into a sum over pairs of Young diagrams of essentially rational Nekrasov functions — this is immediately seen when conformal block is represented in the form of a matrix model. However, the q-deformation of the same block has a deeper decomposition — into a sum over a quadruple of Young diagrams of a product of four topological vertices. We analyze the interplay between these two decompositions, their properties and their generalization to multi-point conformal blocks. In the latter case we explain how Dotsenko-Fateev all-with-all (star) pair “interaction” is reduced to the quiver model nearest-neighbor (chain) one. We give new identities for q-Selberg averages of pairs of generalized Macdonald polynomials. We also translate the slicing invariance of refined topological strings into the language of conformal blocks and interpret it as abelianization of generalized Macdonald polynomials.

Decomposing Nekrasov decomposition

Energy Technology Data Exchange (ETDEWEB)

Morozov, A. [ITEP,25 Bolshaya Cheremushkinskaya, Moscow, 117218 (Russian Federation); Institute for Information Transmission Problems,19-1 Bolshoy Karetniy, Moscow, 127051 (Russian Federation); National Research Nuclear University MEPhI,31 Kashirskoe highway, Moscow, 115409 (Russian Federation); Zenkevich, Y. [ITEP,25 Bolshaya Cheremushkinskaya, Moscow, 117218 (Russian Federation); National Research Nuclear University MEPhI,31 Kashirskoe highway, Moscow, 115409 (Russian Federation); Institute for Nuclear Research of Russian Academy of Sciences,6a Prospekt 60-letiya Oktyabrya, Moscow, 117312 (Russian Federation)

2016-02-16

AGT relations imply that the four-point conformal block admits a decomposition into a sum over pairs of Young diagrams of essentially rational Nekrasov functions — this is immediately seen when conformal block is represented in the form of a matrix model. However, the q-deformation of the same block has a deeper decomposition — into a sum over a quadruple of Young diagrams of a product of four topological vertices. We analyze the interplay between these two decompositions, their properties and their generalization to multi-point conformal blocks. In the latter case we explain how Dotsenko-Fateev all-with-all (star) pair “interaction” is reduced to the quiver model nearest-neighbor (chain) one. We give new identities for q-Selberg averages of pairs of generalized Macdonald polynomials. We also translate the slicing invariance of refined topological strings into the language of conformal blocks and interpret it as abelianization of generalized Macdonald polynomials.

Influence of CNTs decomposition during reactive friction-stir processing of an Al-Mg alloy on the correlation between microstructural characteristics and microtextural components.

Science.gov (United States)

Khodabakhshi, F; Nosko, M; Gerlich, A P

2018-05-03

Multipass friction-stir processing was employed to uniformly disperse multiwalled carbon nanotubes (MW-CNTs) within an Al-Mg alloy metal matrix. Decomposition of MW-CNTs occurs in situ as a result of solid-state chemical reactions, forming fullerene (C60) and aluminium carbide (Al 4 C 3 ) phases during reactive high temperature severe plastic processing. The effects of this decomposition on the microstructural features, dynamic restoration mechanisms and crystallographic microtextural developments are studied for the first time by using electron backscatter diffraction (EBSD) and transmission electron microscopy (TEM) analysis. The formation of an equiaxed grain structure with an average size of ∼1.5 μm occurs within the stirred zone (SZ) under the influence of inclusions which hinder grain boundary migration via Zener-Smith pinning mechanisms during the discontinuous dynamic recrystallisation (DDRX). Formation of two strong Cubic and Brass microtextural components in the heat affected zone (HAZ) and thermomechanical affected zone (TMAZ) was noted as compared to the completely random and Cube components found in the base and SZ regions, respectively. The microstructural modification led to hardening and tensile strength improvement for the processed nanocomposite by ∼55% and 110%, respectively with respect to the annealed Al-Mg base alloy. © 2018 The Authors Journal of Microscopy © 2018 Royal Microscopical Society.

Freeman-Durden Decomposition with Oriented Dihedral Scattering

Directory of Open Access Journals (Sweden)

Yan Jian

2014-10-01

Full Text Available In this paper, when the azimuth direction of polarimetric Synthetic Aperature Radars (SAR differs from the planting direction of crops, the double bounce of the incident electromagnetic waves from the terrain surface to the growing crops is investigated and compared with the normal double bounce. Oriented dihedral scattering model is developed to explain the investigated double bounce and is introduced into the Freeman-Durden decomposition. The decomposition algorithm corresponding to the improved decomposition is then proposed. The airborne polarimetric SAR data for agricultural land covering two flight tracks are chosen to validate the algorithm; the decomposition results show that for agricultural vegetated land, the improved Freeman-Durden decomposition has the advantage of increasing the decomposition coherency among the polarimetric SAR data along the different flight tracks.

Influence of Cu(NO32 initiation additive in two-stage mode conditions of coal pyrolytic decomposition

Directory of Open Access Journals (Sweden)

Larionov Kirill

2017-01-01

Full Text Available Two-stage process (pyrolysis and oxidation of brown coal sample with Cu(NO32 additive pyrolytic decomposition was studied. Additive was introduced by using capillary wetness impregnation method with 5% mass concentration. Sample reactivity was studied by thermogravimetric analysis with staged gaseous medium supply (argon and air at heating rate 10 °C/min and intermediate isothermal soaking. The initiative additive introduction was found to significantly reduce volatile release temperature and accelerate thermal decomposition of sample. Mass-spectral analysis results reveal that significant difference in process characteristics is connected to volatile matter release stage which is initiated by nitrous oxide produced during copper nitrate decomposition.

Thermal decomposition of organic solvent with nitric acid in nuclear fuel reprocessing plants

Energy Technology Data Exchange (ETDEWEB)

Koike, Tadao; Nishio, Gunji; Takada, Junichi; Tukamoto, Michio; Watanabe, Kouji [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Miyata, Sadaichirou

1995-02-01

Since a thermal decomposition of organic solvent containing TBP (tributyl phosphate) with nitric acid and heavy metal nitrates is an exothermic reaction, it is possible to cause an explosive decomposition of TBP-complex materials formed by a nitration between the solvent and nitric acid, if the solvent involving TBP-complex is heated upto a thermal limit in an evaporator to concentrate a fuel liquid solution from the extraction process in the reprocessing plant. In JAERI, the demonstration test for explosive decomposition of TBP-complex by the nitration was performed to elucidate the safety margin of the evaporator in the event of hypothetical explosion under auspices of the Science and Technology Agency. The demonstration test was carried out by heating TBP/n-dodecane solvent mixed with nitric acid and uranium nitrate. In the test, the thermal decomposition behavior of the solvent was examined, and also a kinematic reaction constant and a heat formation of the TBP-complex decomposition were measured by the test. In the paper, a safety analysis of a model evaporator was conducted during accidental conditions under the explosive decomposition of the solvent. (author).

Litter Decomposition Rate of Karst Ecosystem at Gunung Cibodas, Ciampea Bogor Indonesia

Directory of Open Access Journals (Sweden)

Sethyo Vieni Sari

2016-05-01

Full Text Available The study aims to know the productivity of litter and litter decomposition rate in karst ecosystem. This study was conducted on three altitude of 200 meter above sea level (masl, 250 masl and 300 masl in karst ecosystem at Gunung Cibodas, Ciampea, Bogor. Litter productivity measurement performed using litter-trap method and litter-bag method was used to know the rate of decomposition. Litter productivity measurement results showed that the highest total of litter productivity measurement results was on altitude of 200 masl (90.452 tons/ha/year and the lowest was on altitude of 300 masl (25.440 tons/ha/year. The litter productivity of leaves (81.425 ton/ha/year showed the highest result than twigs (16.839 ton/ha/year, as well as flowers and fruits (27.839 ton/ha/year. The rate of decomposition was influenced by rainfall. The decomposition rate and the decrease of litter dry weight on altitude of 250 masl was faster than on the altitude of 200 masl and 300 masl. The dry weight was positively correlated to the rate of decomposition. The lower of dry weight would affect the rate of decomposition become slower. The average of litter C/N ratio were ranged from 28.024%--28.716% and categorized as moderate (>25. The finding indicate that the rate of decomposition in karst ecosystem at Gunung Cibodas was slow and based on C/N ratio of litter showed the mineralization process was also slow.

LMDI decomposition approach: A guide for implementation

International Nuclear Information System (INIS)

Ang, B.W.

2015-01-01

Since it was first used by researchers to analyze industrial electricity consumption in the early 1980s, index decomposition analysis (IDA) has been widely adopted in energy and emission studies. Lately its use as the analytical component of accounting frameworks for tracking economy-wide energy efficiency trends has attracted considerable attention and interest among policy makers. The last comprehensive literature review of IDA was reported in 2000 which is some years back. After giving an update and presenting the key trends in the last 15 years, this study focuses on the implementation issues of the logarithmic mean Divisia index (LMDI) decomposition methods in view of their dominance in IDA in recent years. Eight LMDI models are presented and their origin, decomposition formulae, and strengths and weaknesses are summarized. Guidelines on the choice among these models are provided to assist users in implementation. - Highlights: • Guidelines for implementing LMDI decomposition approach are provided. • Eight LMDI decomposition models are summarized and compared. • The development of the LMDI decomposition approach is presented. • The latest developments of index decomposition analysis are briefly reviewed.

Solar radiation influence on the decomposition process of diclofenac in surface waters

International Nuclear Information System (INIS)

Bartels, Peter; Tuempling, Wolf von

2007-01-01

Diclofenac can be detected in surface water of many rivers with human impacts worldwide. The observed decrease of the diclofenac concentration in waters and the formation of its photochemical transformation products under the impact of natural irradiation during one to 16 days are explained in this article. In semi-natural laboratory tests and in a field experiment it could be shown, that sunlight stimulates the decomposition of diclofenac in surface waters. During one day intensive solar radiation in middle European summer diclofenac decomposes in the surface layer of the water (0 to 5 cm) up to 83%, determined in laboratory exposition experiments. After two weeks in a field experiment, the diclofenac was not detectable anymore in the water surface layer (limit of quantification: 5 ng/L). At a water depth of 50 cm, within two weeks 96% of the initial concentration was degraded, while in 100 cm depth 2/3 of the initial diclofenac concentration remained. With the decomposition, stable and meta-stable photolysis products were formed and observed by UV detection. Beyond that the chemical structure of these products were determined. Three transformation products, that were not described in the literature so far, were identified and quantified with GC-MS

Probabilistic Round Trip Contamination Analysis of a Mars Sample Acquisition and Handling Process Using Markovian Decompositions

Science.gov (United States)

Hudson, Nicolas; Lin, Ying; Barengoltz, Jack

2010-01-01

A method for evaluating the probability of a Viable Earth Microorganism (VEM) contaminating a sample during the sample acquisition and handling (SAH) process of a potential future Mars Sample Return mission is developed. A scenario where multiple core samples would be acquired using a rotary percussive coring tool, deployed from an arm on a MER class rover is analyzed. The analysis is conducted in a structured way by decomposing sample acquisition and handling process into a series of discrete time steps, and breaking the physical system into a set of relevant components. At each discrete time step, two key functions are defined: The probability of a VEM being released from each component, and the transport matrix, which represents the probability of VEM transport from one component to another. By defining the expected the number of VEMs on each component at the start of the sampling process, these decompositions allow the expected number of VEMs on each component at each sampling step to be represented as a Markov chain. This formalism provides a rigorous mathematical framework in which to analyze the probability of a VEM entering the sample chain, as well as making the analysis tractable by breaking the process down into small analyzable steps.

Cellulose and cutisin decomposition in soil of Alopecuretum meadow

Directory of Open Access Journals (Sweden)

Zuzana Hrevušová

2012-01-01

Full Text Available Plant litter decomposition is a fundamental process to ecosystem functioning regulated by both abiotic and biotic factors. The aim of this study was to determine the decomposition of cellulose and protein (cutisin substrates on permanent Alopecuretum meadow under different methods of management. The treatments were following: 2 × cut, 2 × cut + NPK, 2 × mulch, 1 × cut, 1 × mulch (frequency of mowing per year and no-treated plots. Cutting or mulching was carried out in October, under the 2 × cut management also in May. In 2007–2009, cellulose and cutisin in mesh bags were placed in the soil and kept from April to October. Total mean ratios of decomposed cellulose and cutisin were 83 % and 40 % of primal substrate weight, respectively. The cellulose decomposition was affected by weather conditions, but not by applied management. The highest mean ratio of decomposed cellulose was found in 2009 (with increased amount of precipitation in May and July, the lowest in 2007. Coefficients of variation within a year and over the years were up to 22 % and 20 %, respectively. The cutisin decomposition was significantly affected by applied management in all three years. Higher rates of decomposition were noted in two times mowed treatments compared to one or not mowed treatments. Significant differences were found between years in 2× cut and 2 × cut + NPK treatments. Coefficients of variation within the year and over the years were both higher by cutisin than by cellulose samples (up to 50 and 42 %, respectively.

Exact complexity: The spectral decomposition of intrinsic computation

International Nuclear Information System (INIS)

Crutchfield, James P.; Ellison, Christopher J.; Riechers, Paul M.

2016-01-01

We give exact formulae for a wide family of complexity measures that capture the organization of hidden nonlinear processes. The spectral decomposition of operator-valued functions leads to closed-form expressions involving the full eigenvalue spectrum of the mixed-state presentation of a process's ϵ-machine causal-state dynamic. Measures include correlation functions, power spectra, past-future mutual information, transient and synchronization informations, and many others. As a result, a direct and complete analysis of intrinsic computation is now available for the temporal organization of finitary hidden Markov models and nonlinear dynamical systems with generating partitions and for the spatial organization in one-dimensional systems, including spin systems, cellular automata, and complex materials via chaotic crystallography. - Highlights: • We provide exact, closed-form expressions for a hidden stationary process' intrinsic computation. • These include information measures such as the excess entropy, transient information, and synchronization information and the entropy-rate finite-length approximations. • The method uses an epsilon-machine's mixed-state presentation. • The spectral decomposition of the mixed-state presentation relies on the recent development of meromorphic functional calculus for nondiagonalizable operators.

Effects of Nitrogen Addition on Leaf Decomposition of Single-Species and Litter Mixture in Pinus tabulaeformis Forests

Directory of Open Access Journals (Sweden)

Jinsong Wang

2015-12-01

Full Text Available The litter decomposition process is closely correlated with nutrient cycling and the maintenance of soil fertility in the forest ecosystem. In particular, the intense environmental concern about atmospheric nitrogen (N deposition requires a better understanding of its influence on the litter decomposition process. This study examines the responses of single-species litter and litter mixture decomposition processes to N addition in Chinese pine (Pinus tabulaeformis Carr. ecosystems. Chinese pine litter, Mongolian oak (Quercus mongolica Fisch. ex Ledeb. litter, and a pine–oak mixture were selected from a plantation and a natural forest of Chinese pine. Four N addition treatments, i.e., control (N0: 0 kg N ha−1·year−1, low-N (N1: 5 kg N ha−1·year−1, medium-N (N2: 10 kg N ha−1·year−1, and high-N (N3: 15 kg N ha−1·year−1, were applied starting May 2010. In the plantation, N addition significantly stimulated the decomposition of the Chinese pine litter. In the natural forest, N addition had variable effects on the decomposition of single-species litter and the litter mixture. A stimulatory effect of the high-N treatment on the Chinese pine litter decomposition could be attributed to a decrease in the substrate C:N ratio. However, an opposite effect was found for the Mongolian oak litter decomposition. The stimulating effect of N addition on the Chinese pine litter may offset the suppressive effect on the Mongolian oak litter, resulting in a neutral effect on the litter mixture. These results suggest that the different responses in decomposition of single-species litter and the litter mixture to N addition are mainly attributed to litter chemical composition. Further investigations are required to characterize the effect of long-term high-level N addition on the litter decomposition as N deposition is likely to increase rapidly in the region where this study was conducted.

Multiple Shooting and Time Domain Decomposition Methods

CERN Document Server

Geiger, Michael; Körkel, Stefan; Rannacher, Rolf

2015-01-01

This book offers a comprehensive collection of the most advanced numerical techniques for the efficient and effective solution of simulation and optimization problems governed by systems of time-dependent differential equations. The contributions present various approaches to time domain decomposition, focusing on multiple shooting and parareal algorithms.  The range of topics covers theoretical analysis of the methods, as well as their algorithmic formulation and guidelines for practical implementation. Selected examples show that the discussed approaches are mandatory for the solution of challenging practical problems. The practicability and efficiency of the presented methods is illustrated by several case studies from fluid dynamics, data compression, image processing and computational biology, giving rise to possible new research topics.  This volume, resulting from the workshop Multiple Shooting and Time Domain Decomposition Methods, held in Heidelberg in May 2013, will be of great interest to applied...

Thermal Decomposition of Radiation-Damaged Polystyrene

International Nuclear Information System (INIS)

J Abrefah, J.; Klinger, G.S.

2000-01-01

The radiation-damaged polystyrene material (''polycube'') used in this study was synthesized by mixing a high-density polystyrene (''Dylene Fines No. 100'') with plutonium and uranium oxides. The polycubes were used on the Hanford Site in the 1960s for criticality studies to determine the hydrogen-to-fissile atom ratios for neutron moderation during processing of spent nuclear fuel. Upon completion of the studies, two methods were developed to reclaim the transuranic (TRU) oxides from the polymer matrix: (1) burning the polycubes in air at 873 K; and (2) heating the polycubes in the absence of oxygen and scrubbing the released monomer and other volatile organics using carbon tetrachloride. Neither of these methods was satisfactory in separating the TRU oxides from the polystyrene. Consequently, the remaining polycubes were sent to the Hanford Plutonium Finishing Plant (PFP) for storage. Over time, the high dose of alpha and gamma radiation has resulted in a polystyrene matrix that is highly cross-linked and hydrogen deficient and a stabilization process is being developed in support of Defense Nuclear Facility Safety Board Recommendation 94-1. Baseline processes involve thermal treatment to pyrolyze the polycubes in a furnace to decompose the polystyrene and separate out the TRU oxides. Thermal decomposition products from this degraded polystyrene matrix were characterized by Pacific Northwest National Laboratory to provide information for determining the environmental impact of the process and for optimizing the process parameters. A gas chromatography/mass spectrometry (GC/MS) system coupled to a horizontal tube furnace was used for the characterization studies. The decomposition studies were performed both in air and helium atmospheres at 773 K, the planned processing temperature. The volatile and semi-volatile organic products identified for the radiation-damaged polystyrene were different from those observed for virgin polystyrene. The differences were in the

Effect of high heating rate on thermal decomposition behaviour of ...

Indian Academy of Sciences (India)

the thermal decomposition behaviour of the aforementioned powder at high heating rates was taken into considera- ... does not change the process of releasing hydrogen from titanium hydride ... from titanium hydride in a sequence of steps.

FDG decomposition products

International Nuclear Information System (INIS)

Macasek, F.; Buriova, E.

2004-01-01

In this presentation authors present the results of analysis of decomposition products of [ 18 ]fluorodexyglucose. It is concluded that the coupling of liquid chromatography - mass spectrometry with electrospray ionisation is a suitable tool for quantitative analysis of FDG radiopharmaceutical, i.e. assay of basic components (FDG, glucose), impurities (Kryptofix) and decomposition products (gluconic and glucuronic acids etc.); 2-[ 18 F]fluoro-deoxyglucose (FDG) is sufficiently stable and resistant towards autoradiolysis; the content of radiochemical impurities (2-[ 18 F]fluoro-gluconic and 2-[ 18 F]fluoro-glucuronic acids in expired FDG did not exceed 1%

Decomposition and Precipitation Process During Thermo-mechanical Fatigue of Duplex Stainless Steel

Czech Academy of Sciences Publication Activity Database

Weidner, A.; Kolmorgen, R.; Kuběna, Ivo; Kulawinski, D.; Kruml, Tomáš; Biermann, H.

47A, č. 5 (2016), s. 2112-2124 ISSN 1073-5623 R&D Projects: GA MŠk(CZ) ED1.1.00/02.0068; GA ČR GA15-08826S Institutional support: RVO:68081723 Keywords : FE-CR ALLOYS * SPINODAL DECOMPOSITION * COMPUTER-MODELS * ATOMIC-LEVEL * AGING EMBRITTLEMENT * FERRITE * BEHAVIOR * TEMPERATURE Subject RIV: JL - Materials Fatigue, Friction Mechanics Impact factor: 1.874, year: 2016 http://link.springer.com/article/10.1007/s11661-016-3392-z

Nanocrystalline transition metal oxides as catalysts in the thermal decomposition of ammonium perchlorate

Energy Technology Data Exchange (ETDEWEB)

Kapoor, Inder Pal Singh; Srivastava, Pratibha; Singh, Gurdip [Department of Chemistry, DDU Gorakhpur University, Gorakhpur (India)

2009-08-15

Nanocrystalline transition metal oxides (NTMOs) have been successfully prepared by three different methods: novel quick precipitation method (Cr{sub 2}O{sub 3} and Fe{sub 2}O{sub 3}); surfactant mediated method (CuO), and reduction of metal complexes with hydrazine as reducing agent (Mn{sub 2}O{sub 3}). The nano particles have been characterized by X-ray diffraction (XRD) which shows an average particle diameter of 35-54 nm. Their catalytic activity was measured in the thermal decomposition of ammonium perchlorate (AP). AP decomposition undergoes a two step process where the addition of metal oxide nanocrystals led to a shifting of the high temperature decomposition peak toward lower temperature. The kinetics of the thermal decomposition of AP and catalyzed AP has also been evaluated using model fitting and isoconversional method. (Abstract Copyright [2009], Wiley Periodicals, Inc.)

Rate of litter decomposition and microbial activity in an area of Caatinga

Directory of Open Access Journals (Sweden)

Patrícia Carneiro Souto

2013-12-01

Full Text Available In order to evaluate the decomposition of litter and microbial activity in an area of preserved Caatinga, an experiment was conducted in the Natural Heritage Private Reserve Tamanduá Farm in Santa Terezinha county, State of Paraiba. The decomposition rate was determined by using litter bags containing 30 g of litter, which were arranged on the soil surface in September 2003 and 20 bags were taken each month until September 2005. The collected material was oven dried and weighed to assess weight loss compared to initial weight. Microbial activity was estimated monthly by the quantification of carbon dioxide (CO2 released into the edaphic breathing process from the soil surface, and captured by KOH solution. Weight loss of litter after one year was 41.19% and, after two years, was 48.37%, indicating a faster decomposition in the first year. Data analysis showed the influence of season on litter decomposition and temperature on microbial activity.

Management intensity alters decomposition via biological pathways

Science.gov (United States)

Wickings, Kyle; Grandy, A. Stuart; Reed, Sasha; Cleveland, Cory

2011-01-01

Current conceptual models predict that changes in plant litter chemistry during decomposition are primarily regulated by both initial litter chemistry and the stage-or extent-of mass loss. Far less is known about how variations in decomposer community structure (e.g., resulting from different ecosystem management types) could influence litter chemistry during decomposition. Given the recent agricultural intensification occurring globally and the importance of litter chemistry in regulating soil organic matter storage, our objectives were to determine the potential effects of agricultural management on plant litter chemistry and decomposition rates, and to investigate possible links between ecosystem management, litter chemistry and decomposition, and decomposer community composition and activity. We measured decomposition rates, changes in litter chemistry, extracellular enzyme activity, microarthropod communities, and bacterial versus fungal relative abundance in replicated conventional-till, no-till, and old field agricultural sites for both corn and grass litter. After one growing season, litter decomposition under conventional-till was 20% greater than in old field communities. However, decomposition rates in no-till were not significantly different from those in old field or conventional-till sites. After decomposition, grass residue in both conventional- and no-till systems was enriched in total polysaccharides relative to initial litter, while grass litter decomposed in old fields was enriched in nitrogen-bearing compounds and lipids. These differences corresponded with differences in decomposer communities, which also exhibited strong responses to both litter and management type. Overall, our results indicate that agricultural intensification can increase litter decomposition rates, alter decomposer communities, and influence litter chemistry in ways that could have important and long-term effects on soil organic matter dynamics. We suggest that future

Effect of high heating rate on thermal decomposition behaviour of ...

Indian Academy of Sciences (India)

Effect of high heating rate on thermal decomposition behaviour of titanium hydride ... hydride powder, while switching it from internal diffusion to chemical reaction. ... TiH phase and oxides form on the powder surface, controlling the process.

One step process of decomposition and polymerization to fabricate SiO_2 hollow spheres/polyimide composite for foldable OLEDs

International Nuclear Information System (INIS)

Kim, Min Kyu; Kim, Dong Won; Moon, Soo Hyun; Shin, Dong-Wook; Oh, Tae Sik; Yoo, Ji Beom

2017-01-01

Graphical abstract: The SiO_2 hollow spheres and polyimide hybrid synthesized using one step process, simultaneous occurrence of decomposition and polymerization (SODP) is useful with a ultra-low dielectric constant and high thermal stability for flexible OLED. - Highlights: • We fabricated hybrid films of SHS/PI by using a one step process with SODP. • The film has ultralow dielectric constant (50 vol% at k = 1.67). • There is no collapse of SiO_2 hollow spheres in the PI matrix after bending test for 50,000 cycles. - Abstract: The fabrication of interlayer dielectrics (ILDs) in flexible organic light-emitting diodes (OLEDs) requires flexible materials with a low dielectric constant as well as materials with excellent electrical, thermal, and mechanical properties for optimal device performance. Hybrid films of SiO_2 hollow spheres (SHS)/polyimide (PI) were prepared using a one-step process, with simultaneous occurrence of decomposition (polystyrene, PS) and polymerization (PI) (SODP). No collapse of SiO_2 hollow spheres in PI was observed from 10 vol% to 60 vol% SHS in hybrid films. The dielectric constant of hybrid films was reduced from 3.45 to 1.67 and was saturated at above 50 vol% of SHS due to the maximum fill factor of SHS in the PI matrix. The thermal stability was excellent up to 500 °C due to the inherent thermal property of PI. After a bending test for 50,000 cycles at a bending radius of 1 mm, the SHS/PI hybrid films retained their dielectric constant and current density. These results indicate the hybrid film to be the most promising candidate for flexible ILDs with a low dielectric constant and high thermal stability for foldable OLEDs.

Preliminary radiation-oxidizing treatment influence on radiation-catalytic activity of zirconium during water decomposition process

International Nuclear Information System (INIS)

Garibov, A.A.; Aliyev, A.G.; Agayev, T.N.; Aliyev, S.M.; Velibekova, G.Z.

2004-01-01

The study of physical-chemical processes proceeding in contact of metal constructional materials nuclear reactors with water at simultaneous influence of temperature and radiation represents the large interest at the decision of problems material authority and safety of work of nuclear -power installations [1-2]. One of the widely widespread materials of active zone nuclear reactors is metal zirconium and its alloys. The influence of preliminary radiation processing on radiation, radiation -thermal and thermal processes of accumulation of molecular hydrogen and oxidation zirconium in contact with water is investigated at T=673 K and ρ=5mg/sm 3 [3-4]. Initial samples zirconium previously has been exposed by an irradiation in medium H 2 O 2 at D=20-410 kGy. The contribution of radiation processes in these contacts in process thermo-radiation decomposition of water and oxidation of materials of zirconium is revealed. It is established that the interaction of Zr metal, preliminary treated by radiation, with water at radiation -heterogeneous processes leads to passivity of a surface. The rate meanings of thermal, radiation -thermal processes and radiation-chemical yields of hydrogen are determined. It is revealed, that at radiation-heterogeneous processes in system Zr +H 2 O (ρ =5mg/sm 3 T=673 K) the increase of the absorbed doze up to 123 kGy results to reduction of a radiation -chemical yield of molecular hydrogen. The further increase of the absorbed doze results to increase of a radiation -chemical yield of hydrogen. The observable effect at the preliminary radiation of zirconium is connected to formation of oxide phase on a surface. The mechanism of radiation -heterogeneous processes proceeding in system Zr+H 2 O is suggested. (author)

Decomposition of heterogeneous organic matterand its long-term stabilization in soils

Science.gov (United States)

Sierra, Carlos A.; Harmon, Mark E.; Perakis, Steven S.

2011-01-01

Soil organic matter is a complex mixture of material with heterogeneous biological, physical, and chemical properties. Decomposition models represent this heterogeneity either as a set of discrete pools with different residence times or as a continuum of qualities. It is unclear though, whether these two different approaches yield comparable predictions of organic matter dynamics. Here, we compare predictions from these two different approaches and propose an intermediate approach to study organic matter decomposition based on concepts from continuous models implemented numerically. We found that the disagreement between discrete and continuous approaches can be considerable depending on the degree of nonlinearity of the model and simulation time. The two approaches can diverge substantially for predicting long-term processes in soils. Based on our alternative approach, which is a modification of the continuous quality theory, we explored the temporal patterns that emerge by treating substrate heterogeneity explicitly. The analysis suggests that the pattern of carbon mineralization over time is highly dependent on the degree and form of nonlinearity in the model, mostly expressed as differences in microbial growth and efficiency for different substrates. Moreover, short-term stabilization and destabilization mechanisms operating simultaneously result in long-term accumulation of carbon characterized by low decomposition rates, independent of the characteristics of the incoming litter. We show that representation of heterogeneity in the decomposition process can lead to substantial improvements in our understanding of carbon mineralization and its long-term stability in soils.

Photochemical decomposition of perfluorooctanoic acid in aqueous periodate with VUV and UV light irradiation

International Nuclear Information System (INIS)

Cao, M.H.; Wang, B.B.; Yu, H.S.; Wang, L.L.; Yuan, S.H.; Chen, J.

2010-01-01

The photochemical decomposition of perfluorooctanoic acid (PFOA) in aqueous periodate (IO 4 - ) was investigated under two types of low-pressure mercury lamps: one emits at 254 nm light (UV light) and the other emits both 254 nm and 185 nm light (VUV light). PFOA decomposed efficiently under VUV light irradiation while it decomposed poorly under UV light irradiation. The addition of IO 4 - significantly increased the rate of decomposition and defluorination of PFOA irradiated with UV light whereas it decreased both processes under VUV irradiation. Reactive radical (IO 3 ·) generated by photolysis of IO 4 - initiated the oxidation of PFOA in UV process. Aquated electrons (e aq - ), generated from water homolysis, scavenged IO 4 - resulting in decrease of reactive radical species production and PFOA decomposition. The shorter-chain perfluorocarboxylic acids (PFCAs) formed in a stepwise manner from long-chain PFCAs.

Initial insights into bacterial succession during human decomposition.

Science.gov (United States)

Hyde, Embriette R; Haarmann, Daniel P; Petrosino, Joseph F; Lynne, Aaron M; Bucheli, Sibyl R

2015-05-01

Decomposition is a dynamic ecological process dependent upon many factors such as environment, climate, and bacterial, insect, and vertebrate activity in addition to intrinsic properties inherent to individual cadavers. Although largely attributed to microbial metabolism, very little is known about the bacterial basis of human decomposition. To assess the change in bacterial community structure through time, bacterial samples were collected from several sites across two cadavers placed outdoors to decompose and analyzed through 454 pyrosequencing and analysis of variable regions 3-5 of the bacterial 16S ribosomal RNA (16S rRNA) gene. Each cadaver was characterized by a change in bacterial community structure for all sites sampled as time, and decomposition, progressed. Bacteria community structure is variable at placement and before purge for all body sites. At bloat and purge and until tissues began to dehydrate or were removed, bacteria associated with flies, such as Ignatzschineria and Wohlfahrtimonas, were common. After dehydration and skeletonization, bacteria associated with soil, such as Acinetobacter, were common at most body sites sampled. However, more cadavers sampled through multiple seasons are necessary to assess major trends in bacterial succession.

Effects of radionuclide contamination on leaf litter decomposition in the Chernobyl exclusion zone

OpenAIRE

Bonzom , Jean-Marc; Hättenschwiler , Stephan; Lecomte-Pradines , Catherine; Chauvet , Eric; Gaschak , Sergey; Beaugelin-Seiller , Karine; Della-Vedova , Claire; Dubourg , Nicolas; Maksimenko , Andrey; Garnier-Laplace , Jacqueline; Adam-Guillermin , Christelle

2016-01-01

International audience; The effects of radioactive contamination on ecosystem processes such as litter decomposition remain largely un- known. Because radionuclides accumulated in soil and plant biomass can be harmful for organisms, the function- ing of ecosystems may be altered by radioactive contamination. Here, we tested the hypothesis that decomposition is impaired by increasing levels of radioactivity in the environment by exposing uncontaminated leaf litter from silver birch and black a...

Leaf Litter Decomposition and Nutrient Dynamics Associated with Common Horticultural Cropland Agroforest Tree Species of Bangladesh

Directory of Open Access Journals (Sweden)

Md. Hasanuzzaman

2014-01-01

Full Text Available Mangifera indica, Zizyphus jujuba, Litchi chinensis, and Artocarpus heterophyllus are the most common cropland agroforest horticultural tree species of Bangladesh. This study focused on leaf litter decomposition and nutrient (N, P, and K dynamics during the decomposition process. This experiment was conducted for 180 days by using litter bag technique during dry and wet seasons. Mass loss was the highest (49% and 57% for A. heterophyllus and the lowest (25% was found for L. chinensis. The highest initial rates (0.75% and 2.35%/day of decomposition were observed for Z. jujuba and the lowest (0.50% and 0.79%/day for L. chinensis. The highest decay constant was observed for A. heterophyllus (2.14 and 2.34 and the lowest (0.88 and 0.94 for L. chinensis. Leaf litter of all the studied species showed a similar pattern (K > N > P of nutrient release during the decomposition process. Zizyphus jujuba showed comparatively higher return of N, P, and K than others. However, a significant (P<0.05 higher amount of mass loss, rate of decomposition, decay constant, and amount of nutrient return from leaf litter were observed during the wet season.

Investigation on the electrochemical activation process of Li1.20Ni0.32Co0.004Mn0.476O2

Directory of Open Access Journals (Sweden)

Daichun Tang

2014-08-01

Full Text Available The lithium-rich layered oxides are one of the most attractive cathode materials for lithium-ion batteries. Here, two types of Li1.20Ni0.32Co0.004Mn0.476O2 were synthesized using Li2CO3 and LiOH as lithium sources. An electrochemical activation process occurs in Li1.2Ni0.32Co0.004Mn0.476O2 prepared from Li2CO3 (LLO-1, while no obvious activation in Li1.2Ni0.32Co0.004Mn0.476O2 prepared from LiOH (LLO-2 is observed. Via advanced scanning transmission electron microscopy (STEM, we found that Li2MnO3-like structure is rich in the surface region of LLO-2. The study provides a direct explanation for the electrochemical activation of lithium-rich materials. The sample with more LiMO2-like phase at the surface region shows a better cycling performance. It is likely that more LiMO2-like phase at the surface region could stabilize the interface and improve the cycling performance of the Li-rich cathode materials.

Termites amplify effects of wood traits on decomposition rates among multiple bamboo and dicot woody species

NARCIS (Netherlands)

Liu, Guofang; Cornwell, W.K.; Cao, Kunfang; Hu, Yukun; van Logtestijn, R.S.P; Yang, Shijian; Xie, Xiufang; Zhang, Yalin; Ye, Duo; Pan, Xu; Ye, Xuehua; Huang, Zhenying; Dong, Ming; Cornelissen, J.H.C.

2015-01-01

Wood decomposition is a key process in the terrestrial carbon cycle, controlling carbon storage with feedback to climate. In (sub) tropical forest, termites are major players in wood decomposition, but their role relative to that of microbial decomposers and wood traits of different tree species is

Electrochemical corrosion of Zircaloy-2 under PWR water chemistry but at room temperature

International Nuclear Information System (INIS)

Waheed, Abdel-Aziz Fahmy; Kandil, Abdel-Hakim Taha; Hamed, Hani M.

2016-01-01

Highlights: • There is no simple relation between the corrosion rate and LiOH concentration. • At low concentration, 100 ppm Li, an increase of the rate is due to the pH impact. • LiOH in concentrated solution led to accelerated corrosion by pH effect and porosity. • Boron abates the lithium effect by pH neutralizing and participation in the corrosion. - Abstract: Electrochemical corrosion of Zircaloy-2 was tested at room temperature in lithium hydroxide (LiOH) concentrations that ranged from 2.2 to 7000 ppm and boric acid (H 3 BO 3 ) concentrations that ranged from 50 to 4000 ppm. Following the corrosion experiments, the oxide films of specimens were examined by SEM to examine the oxide existence. LiOH concentrations as high as 1 M (7000-ppm lithium) can lead to significantly increased electrochemical corrosion rate. It is suggested that the accelerated corrosion in concentrated solution is caused by the synergetic effect of LiOH, pH and porosity generation. In solutions containing 100 ppm of lithium, the presence of boron had an ameliorating effect on the corrosion rates of Zircaloy-2. Similar to acceleration of corrosion by lithium, the inhibition by boron is due to a combined effect of pH neutralizing and its participation in the corrosion process.

A Generic Decomposition Formula for Pricing Vanilla Options under Stochastic Volatility Models

Directory of Open Access Journals (Sweden)

Raúl Merino

2015-01-01

Full Text Available We obtain a decomposition of the call option price for a very general stochastic volatility diffusion model, extending a previous decomposition formula for the Heston model. We realize that a new term arises when the stock price does not follow an exponential model. The techniques used for this purpose are nonanticipative. In particular, we also see that equivalent results can be obtained by using Functional Itô Calculus. Using the same generalizing ideas, we also extend to nonexponential models the alternative call option price decomposition formula written in terms of the Malliavin derivative of the volatility process. Finally, we give a general expression for the derivative of the implied volatility under both the anticipative and the nonanticipative cases.

Classification Formula and Generation Algorithm of Cycle Decomposition Expression for Dihedral Groups

Directory of Open Access Journals (Sweden)

Dakun Zhang

2013-01-01

Full Text Available The necessary of classification research on common formula of group (dihedral group cycle decomposition expression is illustrated. It includes the reflection and rotation conversion, which derived six common formulae on cycle decomposition expressions of group; it designed the generation algorithm on the cycle decomposition expressions of group, which is based on the method of replacement conversion and the classification formula; algorithm analysis and the results of the process show that the generation algorithm which is based on the classification formula is outperformed by the general algorithm which is based on replacement conversion; it has great significance to solve the enumeration of the necklace combinational scheme, especially the structural problems of combinational scheme, by using group theory and computer.

Scoring of Decomposition: A Proposed Amendment to the Method When Using a Pig Model for Human Studies.

Science.gov (United States)

Keough, Natalie; Myburgh, Jolandie; Steyn, Maryna

2017-07-01

Decomposition studies often use pigs as proxies for human cadavers. However, differences in decomposition sequences/rates relative to humans have not been scientifically examined. Descriptions of five main decomposition stages (humans) were developed and refined by Galloway and later by Megyesi. However, whether these changes/processes are alike in pigs is unclear. Any differences can have significant effects when pig models are used for human PMI estimation. This study compared human decomposition models to the changes observed in pigs. Twenty pigs (50-90 kg) were decomposed over five months and decompositional features recorded. Total body scores (TBS) were calculated. Significant differences were observed during early decomposition between pigs and humans. An amended scoring system to be used in future studies was developed. Standards for PMI estimation derived from porcine models may not directly apply to humans and may need adjustment. Porcine models, however, remain valuable to study variables influencing decomposition. © 2016 American Academy of Forensic Sciences.

Fast heap transform-based QR-decomposition of real and complex matrices: algorithms and codes

Science.gov (United States)

Grigoryan, Artyom M.

2015-03-01

In this paper, we describe a new look on the application of Givens rotations to the QR-decomposition problem, which is similar to the method of Householder transformations. We apply the concept of the discrete heap transform, or signal-induced unitary transforms which had been introduced by Grigoryan (2006) and used in signal and image processing. Both cases of real and complex nonsingular matrices are considered and examples of performing QR-decomposition of square matrices are given. The proposed method of QR-decomposition for the complex matrix is novel and differs from the known method of complex Givens rotation and is based on analytical equations for the heap transforms. Many examples illustrated the proposed heap transform method of QR-decomposition are given, algorithms are described in detail, and MATLAB-based codes are included.

Photochemical decomposition of catecholamines

International Nuclear Information System (INIS)

Mol, N.J. de; Henegouwen, G.M.J.B. van; Gerritsma, K.W.

1979-01-01

During photochemical decomposition (lambda=254 nm) adrenaline, isoprenaline and noradrenaline in aqueous solution were converted to the corresponding aminochrome for 65, 56 and 35% respectively. In determining this conversion, photochemical instability of the aminochromes was taken into account. Irradiations were performed in such dilute solutions that the neglect of the inner filter effect is permissible. Furthermore, quantum yields for the decomposition of the aminochromes in aqueous solution are given. (Author)

The Living Dead: Bacterial Community Structure of a Cadaver at the Onset and End of the Bloat Stage of Decomposition

OpenAIRE

Hyde, Embriette R.; Haarmann, Daniel P.; Lynne, Aaron M.; Bucheli, Sibyl R.; Petrosino, Joseph F.

2013-01-01

Human decomposition is a mosaic system with an intimate association between biotic and abiotic factors. Despite the integral role of bacteria in the decomposition process, few studies have catalogued bacterial biodiversity for terrestrial scenarios. To explore the microbiome of decomposition, two cadavers were placed at the Southeast Texas Applied Forensic Science facility and allowed to decompose under natural conditions. The bloat stage of decomposition, a stage easily identified in taphono...

A comparison between decomposition rates of buried and surface remains in a temperate region of South Africa.

Science.gov (United States)

Marais-Werner, Anátulie; Myburgh, J; Becker, P J; Steyn, M

2018-01-01

Several studies have been conducted on decomposition patterns and rates of surface remains; however, much less are known about this process for buried remains. Understanding the process of decomposition in buried remains is extremely important and aids in criminal investigations, especially when attempting to estimate the post mortem interval (PMI). The aim of this study was to compare the rates of decomposition between buried and surface remains. For this purpose, 25 pigs (Sus scrofa; 45-80 kg) were buried and excavated at different post mortem intervals (7, 14, 33, 92, and 183 days). The observed total body scores were then compared to those of surface remains decomposing at the same location. Stages of decomposition were scored according to separate categories for different anatomical regions based on standardised methods. Variation in the degree of decomposition was considerable especially with the buried 7-day interval pigs that displayed different degrees of discolouration in the lower abdomen and trunk. At 14 and 33 days, buried pigs displayed features commonly associated with the early stages of decomposition, but with less variation. A state of advanced decomposition was reached where little change was observed in the next ±90-183 days after interment. Although the patterns of decomposition for buried and surface remains were very similar, the rates differed considerably. Based on the observations made in this study, guidelines for the estimation of PMI are proposed. This pertains to buried remains found at a depth of approximately 0.75 m in the Central Highveld of South Africa.

An effective secondary decomposition approach for wind power forecasting using extreme learning machine trained by crisscross optimization

International Nuclear Information System (INIS)

Yin, Hao; Dong, Zhen; Chen, Yunlong; Ge, Jiafei; Lai, Loi Lei; Vaccaro, Alfredo; Meng, Anbo

2017-01-01

Highlights: • A secondary decomposition approach is applied in the data pre-processing. • The empirical mode decomposition is used to decompose the original time series. • IMF1 continues to be decomposed by applying wavelet packet decomposition. • Crisscross optimization algorithm is applied to train extreme learning machine. • The proposed SHD-CSO-ELM outperforms other pervious methods in the literature. - Abstract: Large-scale integration of wind energy into electric grid is restricted by its inherent intermittence and volatility. So the increased utilization of wind power necessitates its accurate prediction. The contribution of this study is to develop a new hybrid forecasting model for the short-term wind power prediction by using a secondary hybrid decomposition approach. In the data pre-processing phase, the empirical mode decomposition is used to decompose the original time series into several intrinsic mode functions (IMFs). A unique feature is that the generated IMF1 continues to be decomposed into appropriate and detailed components by applying wavelet packet decomposition. In the training phase, all the transformed sub-series are forecasted with extreme learning machine trained by our recently developed crisscross optimization algorithm (CSO). The final predicted values are obtained from aggregation. The results show that: (a) The performance of empirical mode decomposition can be significantly improved with its IMF1 decomposed by wavelet packet decomposition. (b) The CSO algorithm has satisfactory performance in addressing the premature convergence problem when applied to optimize extreme learning machine. (c) The proposed approach has great advantage over other previous hybrid models in terms of prediction accuracy.

Investigating hydrogel dosimeter decomposition by chemical methods

International Nuclear Information System (INIS)

Jordan, Kevin

2015-01-01

The chemical oxidative decomposition of leucocrystal violet micelle hydrogel dosimeters was investigated using the reaction of ferrous ions with hydrogen peroxide or sodium bicarbonate with hydrogen peroxide. The second reaction is more effective at dye decomposition in gelatin hydrogels. Additional chemical analysis is required to determine the decomposition products

Partial differential equation-based approach for empirical mode decomposition: application on image analysis.

Science.gov (United States)

Niang, Oumar; Thioune, Abdoulaye; El Gueirea, Mouhamed Cheikh; Deléchelle, Eric; Lemoine, Jacques

2012-09-01

The major problem with the empirical mode decomposition (EMD) algorithm is its lack of a theoretical framework. So, it is difficult to characterize and evaluate this approach. In this paper, we propose, in the 2-D case, the use of an alternative implementation to the algorithmic definition of the so-called "sifting process" used in the original Huang's EMD method. This approach, especially based on partial differential equations (PDEs), was presented by Niang in previous works, in 2005 and 2007, and relies on a nonlinear diffusion-based filtering process to solve the mean envelope estimation problem. In the 1-D case, the efficiency of the PDE-based method, compared to the original EMD algorithmic version, was also illustrated in a recent paper. Recently, several 2-D extensions of the EMD method have been proposed. Despite some effort, 2-D versions for EMD appear poorly performing and are very time consuming. So in this paper, an extension to the 2-D space of the PDE-based approach is extensively described. This approach has been applied in cases of both signal and image decomposition. The obtained results confirm the usefulness of the new PDE-based sifting process for the decomposition of various kinds of data. Some results have been provided in the case of image decomposition. The effectiveness of the approach encourages its use in a number of signal and image applications such as denoising, detrending, or texture analysis.

Comparison of the decomposition VOC profile during winter and summer in a moist, mid-latitude (Cfb climate.

Directory of Open Access Journals (Sweden)

Shari L Forbes

Full Text Available The investigation of volatile organic compounds (VOCs associated with decomposition is an emerging field in forensic taphonomy due to their importance in locating human remains using biological detectors such as insects and canines. A consistent decomposition VOC profile has not yet been elucidated due to the intrinsic impact of the environment on the decomposition process in different climatic zones. The study of decomposition VOCs has typically occurred during the warmer months to enable chemical profiling of all decomposition stages. The present study investigated the decomposition VOC profile in air during both warmer and cooler months in a moist, mid-latitude (Cfb climate as decomposition occurs year-round in this environment. Pig carcasses (Sus scrofa domesticus L. were placed on a soil surface to decompose naturally and their VOC profile was monitored during the winter and summer months. Corresponding control sites were also monitored to determine the natural VOC profile of the surrounding soil and vegetation. VOC samples were collected onto sorbent tubes and analyzed using comprehensive two-dimensional gas chromatography--time-of-flight mass spectrometry (GC × GC-TOFMS. The summer months were characterized by higher temperatures and solar radiation, greater rainfall accumulation, and comparable humidity when compared to the winter months. The rate of decomposition was faster and the number and abundance of VOCs was proportionally higher in summer. However, a similar trend was observed in winter and summer demonstrating a rapid increase in VOC abundance during active decay with a second increase in abundance occurring later in the decomposition process. Sulfur-containing compounds, alcohols and ketones represented the most abundant classes of compounds in both seasons, although almost all 10 compound classes identified contributed to discriminating the stages of decomposition throughout both seasons. The advantages of GC × GC-TOFMS were

Trace Norm Regularized CANDECOMP/PARAFAC Decomposition With Missing Data.

Science.gov (United States)

Liu, Yuanyuan; Shang, Fanhua; Jiao, Licheng; Cheng, James; Cheng, Hong

2015-11-01

In recent years, low-rank tensor completion (LRTC) problems have received a significant amount of attention in computer vision, data mining, and signal processing. The existing trace norm minimization algorithms for iteratively solving LRTC problems involve multiple singular value decompositions of very large matrices at each iteration. Therefore, they suffer from high computational cost. In this paper, we propose a novel trace norm regularized CANDECOMP/PARAFAC decomposition (TNCP) method for simultaneous tensor decomposition and completion. We first formulate a factor matrix rank minimization model by deducing the relation between the rank of each factor matrix and the mode- n rank of a tensor. Then, we introduce a tractable relaxation of our rank function, and then achieve a convex combination problem of much smaller-scale matrix trace norm minimization. Finally, we develop an efficient algorithm based on alternating direction method of multipliers to solve our problem. The promising experimental results on synthetic and real-world data validate the effectiveness of our TNCP method. Moreover, TNCP is significantly faster than the state-of-the-art methods and scales to larger problems.

Multilevel index decomposition analysis: Approaches and application

International Nuclear Information System (INIS)

Xu, X.Y.; Ang, B.W.

2014-01-01

With the growing interest in using the technique of index decomposition analysis (IDA) in energy and energy-related emission studies, such as to analyze the impacts of activity structure change or to track economy-wide energy efficiency trends, the conventional single-level IDA may not be able to meet certain needs in policy analysis. In this paper, some limitations of single-level IDA studies which can be addressed through applying multilevel decomposition analysis are discussed. We then introduce and compare two multilevel decomposition procedures, which are referred to as the multilevel-parallel (M-P) model and the multilevel-hierarchical (M-H) model. The former uses a similar decomposition procedure as in the single-level IDA, while the latter uses a stepwise decomposition procedure. Since the stepwise decomposition procedure is new in the IDA literature, the applicability of the popular IDA methods in the M-H model is discussed and cases where modifications are needed are explained. Numerical examples and application studies using the energy consumption data of the US and China are presented. - Highlights: • We discuss the limitations of single-level decomposition in IDA applied to energy study. • We introduce two multilevel decomposition models, study their features and discuss how they can address the limitations. • To extend from single-level to multilevel analysis, necessary modifications to some popular IDA methods are discussed. • We further discuss the practical significance of the multilevel models and present examples and cases to illustrate

Hydrothermally Processed Oxide Nanostructures and Their Lithium–ion Storage Properties

Directory of Open Access Journals (Sweden)

Kim Yong-Jin

2010-01-01

Full Text Available Abstract Y- and Si-based oxide nanopowders were synthesized by a hydrothermal reaction of Y or Si powders with NaOH or LiOH aqueous solution. Nanoparticles with different morphology such as elongated nanospheres, flower-like nanoparticles and nanowires were produced by a control of processing parameters, in particular, the starting composition of solution. The preliminary result of electrochemical examination showed that the hydrothermally processed nanowires exhibit high initial capacities of Li-ion storage: 653 mAh/g for Y2O3 nanowires as anode materials and 186 mAh/g for Li2Si2O5 nanowires as cathode materials in a Li secondary cell. Compared to the powder with elongated sphere or flower-like shapes, the nanowires showed a higher Li-ion capacity and a better cycle property.

Thermic decomposition of biphenyl; Decomposition thermique du biphenyle

Energy Technology Data Exchange (ETDEWEB)

Lutz, M [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1966-03-01

Liquid and vapour phase pyrolysis of very pure biphenyl obtained by methods described in the text was carried out at 400 C in sealed ampoules, the fraction transformed being always less than 0.1 per cent. The main products were hydrogen, benzene, terphenyls, and a deposit of polyphenyls strongly adhering to the walls. Small quantities of the lower aliphatic hydrocarbons were also found. The variation of the yields of these products with a) the pyrolysis time, b) the state (gas or liquid) of the biphenyl, and c) the pressure of the vapour was measured. Varying the area and nature of the walls showed that in the absence of a liquid phase, the pyrolytic decomposition takes place in the adsorbed layer, and that metallic walls promote the reaction more actively than do those of glass (pyrex or silica). A mechanism is proposed to explain the results pertaining to this decomposition in the adsorbed phase. The adsorption seems to obey a Langmuir isotherm, and the chemical act which determines the overall rate of decomposition is unimolecular. (author) [French] Du biphenyle tres pur, dont la purification est decrite, est pyrolyse a 400 C en phase vapeur et en phase liquide dans des ampoules scellees sous vide, a des taux de decomposition n'ayant jamais depasse 0,1 pour cent. Les produits provenant de la pyrolyse sont essentiellement: l' hydrogene, le benzene, les therphenyles, et un depot de polyphenyles adherant fortement aux parois. En plus il se forme de faibles quantites d'hydrocarbures aliphatiques gazeux. On indique la variation des rendements des differents produits avec la duree de pyrolyse, l'etat gazeux ou liquide du biphenyle, et la pression de la vapeur. Variant la superficie et la nature des parois, on montre qu'en absence de liquide la pyrolyse se fait en phase adsorbee. La pyrolyse est plus active au contact de parois metalliques que de celles de verres (pyrex ou silice). A partir des resultats experimentaux un mecanisme de degradation du biphenyle en phase

Toluene decomposition performance and NOx by-product formation during a DBD-catalyst process.

Science.gov (United States)

Guo, Yufang; Liao, Xiaobin; Fu, Mingli; Huang, Haibao; Ye, Daiqi

2015-02-01

Characteristics of toluene decomposition and formation of nitrogen oxide (NOx) by-products were investigated in a dielectric barrier discharge (DBD) reactor with/without catalyst at room temperature and atmospheric pressure. Four kinds of metal oxides, i.e., manganese oxide (MnOx), iron oxide (FeOx), cobalt oxide (CoOx) and copper oxide (CuO), supported on Al2O3/nickel foam, were used as catalysts. It was found that introducing catalysts could improve toluene removal efficiency, promote decomposition of by-product ozone and enhance CO2 selectivity. In addition, NOx was suppressed with the decrease of specific energy density (SED) and the increase of humidity, gas flow rate and toluene concentration, or catalyst introduction. Among the four kinds of catalysts, the CuO catalyst showed the best performance in NOx suppression. The MnOx catalyst exhibited the lowest concentration of O3 and highest CO2 selectivity but the highest concentration of NOx. A possible pathway for NOx production in DBD was discussed. The contributions of oxygen active species and hydroxyl radicals are dominant in NOx suppression. Copyright © 2014. Published by Elsevier B.V.

Vegetation exerts a greater control on litter decomposition than climate warming in peatlands.

Science.gov (United States)

Ward, Susan E; Orwin, Kate H; Ostle, Nicholas J; Briones, J I; Thomson, Bruce C; Griffiths, Robert I; Oakley, Simon; Quirk, Helen; Bardget, Richard D

2015-01-01

Historically, slow decomposition rates have resulted in the accumulation of large amounts of carbon in northern peatlands. Both climate warming and vegetation change can alter rates of decomposition, and hence affect rates of atmospheric CO2 exchange, with consequences for climate change feedbacks. Although warming and vegetation change are happening concurrently, little is known about their relative and interactive effects on decomposition processes. To test the effects of warming and vegetation change on decomposition rates, we placed litter of three dominant species (Calluna vulgaris, Eriophorum vaginatum, Hypnum jutlandicum) into a peatland field experiment that combined warming.with plant functional group removals, and measured mass loss over two years. To identify potential mechanisms behind effects, we also measured nutrient cycling and soil biota. We found that plant functional group removals exerted a stronger control over short-term litter decomposition than did approximately 1 degrees C warming, and that the plant removal effect depended on litter species identity. Specifically, rates of litter decomposition were faster when shrubs were removed from the plant community, and these effects were strongest for graminoid and bryophyte litter. Plant functional group removals also had strong effects on soil biota and nutrient cycling associated with decomposition, whereby shrub removal had cascading effects on soil fungal community composition, increased enchytraeid abundance, and increased rates of N mineralization. Our findings demonstrate that, in addition to litter quality, changes in vegetation composition play a significant role in regulating short-term litter decomposition and belowground communities in peatland, and that these impacts can be greater than moderate warming effects. Our findings, albeit from a relatively short-term study, highlight the need to consider both vegetation change and its impacts below ground alongside climatic effects when

Primary decomposition of torsion R[X]-modules

Directory of Open Access Journals (Sweden)

William A. Adkins

1994-01-01

Full Text Available This paper is concerned with studying hereditary properties of primary decompositions of torsion R[X]-modules M which are torsion free as R-modules. Specifically, if an R[X]-submodule of M is pure as an R-submodule, then the primary decomposition of M determines a primary decomposition of the submodule. This is a generalization of the classical fact from linear algebra that a diagonalizable linear transformation on a vector space restricts to a diagonalizable linear transformation of any invariant subspace. Additionally, primary decompositions are considered under direct sums and tensor product.

Sponge-like silver obtained by decomposition of silver nitrate hexamethylenetetramine complex

International Nuclear Information System (INIS)

Afanasiev, Pavel

2016-01-01

Silver nitrate hexamethylenetetramine [Ag(NO 3 )·N 4 (CH 2 ) 6 ] coordination compound has been prepared via aqueous route and characterized by chemical analysis, XRD and electron microscopy. Decomposition of [Ag(NO 3 )·N 4 (CH 2 ) 6 ] under hydrogen and under inert has been studied by thermal analysis and mass spectrometry. Thermal decomposition of [Ag(NO 3 )·N 4 (CH 2 ) 6 ] proceeds in the range 200–250 °C as a self-propagating rapid redox process accompanied with the release of multiple gases. The decomposition leads to formation of sponge-like silver having hierarchical open pore system with pore size spanning from 10 µm to 10 nm. The as-obtained silver sponges exhibited favorable activity toward H 2 O 2 electrochemical reduction, making them potentially interesting as non-enzyme hydrogen peroxide sensors. - Graphical abstract: Thermal decomposition of silver nitrate hexamethylenetetramine coordination compound [Ag(NO 3 )·N 4 (CH 2 ) 6 ] leads to sponge like silver that possesses open porous structure and demonstrates interesting properties as an electrochemical hydrogen peroxide sensor. Display Omitted - Highlights: • [Ag(NO 3 )·N 4 (CH 2 ) 6 ] orthorhombic phase prepared and characterized. • Decomposition of [Ag(NO 3 )·N 4 (CH 2 ) 6 ] leads to metallic silver sponge with opened porosity. • Ag sponge showed promising properties as a material for hydrogen peroxide sensors.

Decomposition of toluene in a steady-state atmospheric-pressure glow discharge

International Nuclear Information System (INIS)

Trushkin, A. N.; Grushin, M. E.; Kochetov, I. V.; Trushkin, N. I.; Akishev, Yu. S.

2013-01-01

Results are presented from experimental studies of decomposition of toluene (C 6 H 5 CH 3 ) in a polluted air flow by means of a steady-state atmospheric pressure glow discharge at different water vapor contents in the working gas. The experimental results on the degree of C 6 H 5 CH 3 removal are compared with the results of computer simulations conducted in the framework of the developed kinetic model of plasma chemical decomposition of toluene in the N 2 : O 2 : H 2 O gas mixture. A substantial influence of the gas flow humidity on toluene decomposition in the atmospheric pressure glow discharge is demonstrated. The main mechanisms of the influence of humidity on C 6 H 5 CH 3 decomposition are determined. The existence of two stages in the process of toluene removal, which differ in their duration and the intensity of plasma chemical decomposition of C 6 H 5 CH 3 is established. Based on the results of computer simulations, the composition of the products of plasma chemical reactions at the output of the reactor is analyzed as a function of the specific energy deposition and gas flow humidity. The existence of a catalytic cycle in which hydroxyl radical OH acts a catalyst and which substantially accelerates the recombination of oxygen atoms and suppression of ozone generation when the plasma-forming gas contains water vapor is established.

Decomposition of toluene in a steady-state atmospheric-pressure glow discharge

Science.gov (United States)

Trushkin, A. N.; Grushin, M. E.; Kochetov, I. V.; Trushkin, N. I.; Akishev, Yu. S.

2013-02-01

Results are presented from experimental studies of decomposition of toluene (C6H5CH3) in a polluted air flow by means of a steady-state atmospheric pressure glow discharge at different water vapor contents in the working gas. The experimental results on the degree of C6H5CH3 removal are compared with the results of computer simulations conducted in the framework of the developed kinetic model of plasma chemical decomposition of toluene in the N2: O2: H2O gas mixture. A substantial influence of the gas flow humidity on toluene decomposition in the atmospheric pressure glow discharge is demonstrated. The main mechanisms of the influence of humidity on C6H5CH3 decomposition are determined. The existence of two stages in the process of toluene removal, which differ in their duration and the intensity of plasma chemical decomposition of C6H5CH3 is established. Based on the results of computer simulations, the composition of the products of plasma chemical reactions at the output of the reactor is analyzed as a function of the specific energy deposition and gas flow humidity. The existence of a catalytic cycle in which hydroxyl radical OH acts a catalyst and which substantially accelerates the recombination of oxygen atoms and suppression of ozone generation when the plasma-forming gas contains water vapor is established.

Earthworms modify microbial community structure and accelerate maize stover decomposition during vermicomposting.

Science.gov (United States)

Chen, Yuxiang; Zhang, Yufen; Zhang, Quanguo; Xu, Lixin; Li, Ran; Luo, Xiaopei; Zhang, Xin; Tong, Jin

2015-11-01

In the present study, maize stover was vermicomposted with the epigeic earthworm Eisenia fetida. The results showed that, during vermicomposting process, the earthworms promoted decomposition of maize stover. Analysis of microbial communities of the vermicompost by high-throughput pyrosequencing showed more complex bacterial community structure in the substrate treated by the earthworms than that in the control group. The dominant microbial genera in the treatment with the earthworms were Pseudoxanthomonas, Pseudomonas, Arthrobacter, Streptomyces, Cryptococcus, Guehomyces, and Mucor. Compared to the control group, the relative abundance of lignocellulose degradation microorganisms increased. The results indicated that the earthworms modified the structure of microbial communities during vermicomposting process, activated the growth of lignocellulose degradation microorganisms, and triggered the lignocellulose decomposition.

Combined effects of leaf litter and soil microsite on decomposition process in arid rangelands.

Science.gov (United States)

Carrera, Analía Lorena; Bertiller, Mónica Beatriz

2013-01-15

The objective of this study was to analyze the combined effects of leaf litter quality and soil properties on litter decomposition and soil nitrogen (N) mineralization at conserved (C) and disturbed by sheep grazing (D) vegetation states in arid rangelands of the Patagonian Monte. It was hypothesized that spatial differences in soil inorganic-N levels have larger impact on decomposition processes of non-recalcitrant than recalcitrant leaf litter (low and high concentration of secondary compounds, respectively). Leaf litter and upper soil were extracted from modal size plant patches (patch microsite) and the associated inter-patch area (inter-patch microsite) in C and D. Leaf litter was pooled per vegetation state and soil was pooled combining vegetation state and microsite. Concentrations of N and secondary compounds in leaf litter and total and inorganic-N in soil were assessed at each pooled sample. Leaf litter decay and soil N mineralization at microsites of C and D were estimated in 160 microcosms incubated at field capacity (16 month). C soils had higher total N than D soils (0.58 and 0.41 mg/g, respectively). Patch soil of C and inter-patch soil of D exhibited the highest values of inorganic-N (8.8 and 8.4 μg/g, respectively). Leaf litter of C was less recalcitrant and decomposed faster than that of D. Non-recalcitrant leaf litter decay and induced soil N mineralization had larger variation among microsites (coefficients of variation = 25 and 41%, respectively) than recalcitrant leaf litter (coefficients of variation = 12 and 32%, respectively). Changes in the canopy structure induced by grazing disturbance increased leaf litter recalcitrance, and reduced litter decay and soil N mineralization, independently of soil N levels. This highlights the importance of the combined effects of soil and leaf litter properties on N cycling probably with consequences for vegetation reestablishment and dynamics, rangeland resistance and resilience with implications

Differential Decomposition Among Pig, Rabbit, and Human Remains.

Science.gov (United States)

Dautartas, Angela; Kenyhercz, Michael W; Vidoli, Giovanna M; Meadows Jantz, Lee; Mundorff, Amy; Steadman, Dawnie Wolfe

2018-03-30

While nonhuman animal remains are often utilized in forensic research to develop methods to estimate the postmortem interval, systematic studies that directly validate animals as proxies for human decomposition are lacking. The current project compared decomposition rates among pigs, rabbits, and humans at the University of Tennessee's Anthropology Research Facility across three seasonal trials that spanned nearly 2 years. The Total Body Score (TBS) method was applied to quantify decomposition changes and calculate the postmortem interval (PMI) in accumulated degree days (ADD). Decomposition trajectories were analyzed by comparing the estimated and actual ADD for each seasonal trial and by fuzzy cluster analysis. The cluster analysis demonstrated that the rabbits formed one group while pigs and humans, although more similar to each other than either to rabbits, still showed important differences in decomposition patterns. The decomposition trends show that neither nonhuman model captured the pattern, rate, and variability of human decomposition. © 2018 American Academy of Forensic Sciences.

Exploring Patterns of Soil Organic Matter Decomposition with Students and the Public Through the Global Decomposition Project (GDP)

Science.gov (United States)

Wood, J. H.; Natali, S.

2014-12-01

The Global Decomposition Project (GDP) is a program designed to introduce and educate students and the general public about soil organic matter and decomposition through a standardized protocol for collecting, reporting, and sharing data. This easy-to-use hands-on activity focuses on questions such as "How do environmental conditions control decomposition of organic matter in soil?" and "Why do some areas accumulate organic matter and others do not?" Soil organic matter is important to local ecosystems because it affects soil structure, regulates soil moisture and temperature, and provides energy and nutrients to soil organisms. It is also important globally because it stores a large amount of carbon, and when microbes "eat", or decompose organic matter they release greenhouse gasses such as carbon dioxide and methane into the atmosphere, which affects the earth's climate. The protocol describes a commonly used method to measure decomposition using a paper made of cellulose, a component of plant cell walls. Participants can receive pre-made cellulose decomposition bags, or make decomposition bags using instructions in the protocol and easily obtained materials (e.g., window screen and lignin-free paper). Individual results will be shared with all participants and the broader public through an online database. We will present decomposition bag results from a research site in Alaskan tundra, as well as from a middle-school-student led experiment in California. The GDP demonstrates how scientific methods can be extended to educate broader audiences, while at the same time, data collected by students and the public can provide new insight into global patterns of soil decomposition. The GDP provides a pathway for scientists and educators to interact and reach meaningful education and research goals.

Dynamic Load Balancing Based on Constrained K-D Tree Decomposition for Parallel Particle Tracing

Energy Technology Data Exchange (ETDEWEB)

Zhang, Jiang; Guo, Hanqi; Yuan, Xiaoru; Hong, Fan; Peterka, Tom

2018-01-01

Particle tracing is a fundamental technique in flow field data visualization. In this work, we present a novel dynamic load balancing method for parallel particle tracing. Specifically, we employ a constrained k-d tree decomposition approach to dynamically redistribute tasks among processes. Each process is initially assigned a regularly partitioned block along with duplicated ghost layer under the memory limit. During particle tracing, the k-d tree decomposition is dynamically performed by constraining the cutting planes in the overlap range of duplicated data. This ensures that each process is reassigned particles as even as possible, and on the other hand the new assigned particles for a process always locate in its block. Result shows good load balance and high efficiency of our method.

3.6. The kinetics of sulfuric acid decomposition of calcined concentrate of borosilicate ore

International Nuclear Information System (INIS)

Mirsaidov, U.M.; Kurbonov, A.S.; Mamatov, E.D.

2015-01-01

Present article is devoted to kinetics of sulfuric acid decomposition of calcined concentrate of borosilicate ore. The experimental data of kinetics of extraction of boron oxide from danburite at sulfuric acid decomposition were obtained at 20-90 deg C temperature range and process duration 15-90 minutes. The flowsheet of obtaining of boric acid from borosilicate ores of Ak-Arkhar Deposit by sulfuric acid method was proposed.

Dynamics of phosphorus and bacterial phoX genes during the decomposition of Microcystis blooms in a mesocosm.

Directory of Open Access Journals (Sweden)

Jiangyu Dai

Full Text Available Cyanobacterial blooms are a worldwide environmental problem and frequently occur in eutrophic lakes. Organophosphorus mineralization regulated by microbial alkaline phosphatase provides available nutrients for bloom regeneration. To uncover the dynamics of bacterial alkaline phosphatase activity and microbial backgrounds in relation to organophosphorus mineralization during the decomposition process of cyanobacterial blooms, the response of alkaline phosphatase PhoX-producing bacteria were explored using a 23-day mesocosm experiment with three varying densities of Microcystis biomass from eutrophic Lake Taihu. Our study found large amounts of soluble reactive phosphorus and dissolved organophosphorus were released into the lake water during the decomposition process. Bacterial alkaline phosphatase activity showed the peak values during days 5~7 in groups with different chlorophyll-a densities, and then all decreased dramatically to their initial experimental levels during the last stage of decomposition. Bacterial phoX abundances in the three experimental groups increased significantly along with the decomposition process, positively related to the dissolved organic carbon and organophosphorus released by the Microcystis blooms. The genotypes similar to the phoX genes of Alphaproteobacteria were dominant in all groups, whereas the genotypes most similar to the phoX genes of Betaproteobacteria and Cyanobacteria were also abundant in the low density (~15 μg L-1 chlorophyll-a group. At the end of the decomposition process, the number of genotypes most similar to the phoX of Betaproteobacteria and Cyanobacteria increased in the medium (~150 μg L-1 chlorophyll-a and high (~1500 μg L-1 chlorophyll-a density groups. The released organophosphorus and increased bacterial phoX abundance after decomposition of Microcystis aggregates could potentially provide sufficient nutrients and biological conditions for algal proliferation and are probably related

Can visible light impact litter decomposition under pollution of ZnO nanoparticles?

Science.gov (United States)

Du, Jingjing; Zhang, Yuyan; Liu, Lina; Qv, Mingxiang; Lv, Yanna; Yin, Yifei; Zhou, Yinfei; Cui, Minghui; Zhu, Yanfeng; Zhang, Hongzhong

2017-11-01

ZnO nanoparticles is one of the most used materials in a wide range including antibacterial coating, electronic device, and personal care products. With the development of nanotechnology, ecotoxicology of ZnO nanoparticles has been received increasing attention. To assess the phototoxicity of ZnO nanoparticles in aquatic ecosystem, microcosm experiments were conducted on Populus nigra L. leaf litter decomposition under combined effect of ZnO nanoparticles and visible light radiation. Litter decomposition rate, pH value, extracellular enzyme activity, as well as the relative contributions of fungal community to litter decomposition were studied. Results showed that long-term exposure to ZnO nanoparticles and visible light led to a significant decrease in litter decomposition rate (0.26 m -1 vs 0.45 m -1 ), and visible light would increase the inhibitory effect (0.24 m -1 ), which caused significant decrease in pH value of litter cultures, fungal sporulation rate, as well as most extracellular enzyme activities. The phototoxicity of ZnO nanoparticles also showed impacts on fungal community composition, especially on the genus of Varicosporium, whose abundance was significantly and positively related to decomposition rate. In conclusion, our study provides the evidence for negatively effects of ZnO NPs photocatalysis on ecological process of litter decomposition and highlights the contribution of visible light radiation to nanoparticles toxicity in freshwater ecosystems. Copyright © 2017 Elsevier Ltd. All rights reserved.

Thermal Decomposition Behaviors and Burning Characteristics of AN/Nitramine-Based Composite Propellant

Science.gov (United States)

Naya, Tomoki; Kohga, Makoto

2015-04-01

Ammonium nitrate (AN) has attracted much attention due to its clean burning nature as an oxidizer. However, an AN-based composite propellant has the disadvantages of low burning rate and poor ignitability. In this study, we added nitramine of cyclotrimethylene trinitramine (RDX) or cyclotetramethylene tetranitramine (HMX) as a high-energy material to AN propellants to overcome these disadvantages. The thermal decomposition and burning rate characteristics of the prepared propellants were examined as the ratio of AN and nitramine was varied. In the thermal decomposition process, AN/RDX propellants showed unique mass loss peaks in the lower temperature range that were not observed for AN or RDX propellants alone. AN and RDX decomposed continuously as an almost single oxidizer in the AN/RDX propellant. In contrast, AN/HMX propellants exhibited thermal decomposition characteristics similar to those of AN and HMX, which decomposed almost separately in the thermal decomposition of the AN/HMX propellant. The ignitability was improved and the burning rate increased by the addition of nitramine for both AN/RDX and AN/HMX propellants. The increased burning rates of AN/RDX propellants were greater than those of AN/HMX. The difference in the thermal decomposition and burning characteristics was caused by the interaction between AN and RDX.

Pitfalls in VAR based return decompositions: A clarification

DEFF Research Database (Denmark)

Engsted, Tom; Pedersen, Thomas Quistgaard; Tanggaard, Carsten

in their analysis is not "cashflow news" but "inter- est rate news" which should not be zero. Consequently, in contrast to what Chen and Zhao claim, their decomposition does not serve as a valid caution against VAR based decompositions. Second, we point out that in order for VAR based decompositions to be valid......Based on Chen and Zhao's (2009) criticism of VAR based return de- compositions, we explain in detail the various limitations and pitfalls involved in such decompositions. First, we show that Chen and Zhao's interpretation of their excess bond return decomposition is wrong: the residual component...

Energetic materials under high pressures and temperatures: stability, polymorphism and decomposition of RDX

International Nuclear Information System (INIS)

Dreger, Z A

2012-01-01

A recent progress in understanding the response of energetic crystal of cyclotrimethylene trinitramine (RDX) to high pressures and temperatures is summarized. The optical spectroscopy and imaging studies under static compression and high temperatures provided new insight into phase diagram, polymorphism and decomposition mechanisms at pressures and temperatures relevant to those under shock compression. These results have been used to aid the understanding of processes under shock compression, including the shock-induced phase transition and identification of the crystal phase at decomposition. This work demonstrates that studies under static compression and high temperatures provide important complementary route for elucidating the physical and chemical processes in shocked energetic crystals.

Process for remediation of plastic waste

Science.gov (United States)

Pol, Vilas G [Westmont, IL; Thiyagarajan, Pappannan [Germantown, MD

2012-04-10

A single step process for degrading plastic waste by converting the plastic waste into carbonaceous products via thermal decomposition of the plastic waste by placing the plastic waste into a reactor, heating the plastic waste under an inert or air atmosphere until the temperature of 700.degree. C. is achieved, allowing the reactor to cool down, and recovering the resulting decomposition products therefrom. The decomposition products that this process yields are carbonaceous materials, and more specifically egg-shaped and spherical-shaped solid carbons. Additionally, in the presence of a transition metal compound, this thermal decomposition process produces multi-walled carbon nanotubes.

Simulated nitrogen deposition affects wood decomposition by cord-forming fungi.

Science.gov (United States)

Bebber, Daniel P; Watkinson, Sarah C; Boddy, Lynne; Darrah, Peter R

2011-12-01

Anthropogenic nitrogen (N) deposition affects many natural processes, including forest litter decomposition. Saprotrophic fungi are the only organisms capable of completely decomposing lignocellulosic (woody) litter in temperate ecosystems, and therefore the responses of fungi to N deposition are critical in understanding the effects of global change on the forest carbon cycle. Plant litter decomposition under elevated N has been intensively studied, with varying results. The complexity of forest floor biota and variability in litter quality have obscured N-elevation effects on decomposers. Field experiments often utilize standardized substrates and N-levels, but few studies have controlled the decay organisms. Decomposition of beech (Fagus sylvatica) blocks inoculated with two cord-forming basidiomycete fungi, Hypholoma fasciculare and Phanerochaete velutina, was compared experimentally under realistic levels of simulated N deposition at Wytham Wood, Oxfordshire, UK. Mass loss was greater with P. velutina than with H. fasciculare, and with N treatment than in the control. Decomposition was accompanied by growth of the fungal mycelium and increasing N concentration in the remaining wood. We attribute the N effect on wood decay to the response of cord-forming wood decay fungi to N availability. Previous studies demonstrated the capacity of these fungi to scavenge and import N to decaying wood via a translocating network of mycelium. This study shows that small increases in N availability can increase wood decomposition by these organisms. Dead wood is an important carbon store and habitat. The responses of wood decomposers to anthropogenic N deposition should be considered in models of forest carbon dynamics.

The Lévy-Itô decomposition in free probability

DEFF Research Database (Denmark)

Barndorff-Nielsen, Ole Eiler; Thorbjørnsen, Steen

2005-01-01

In this paper we prove the free analog of the Lévy-Itô decomposition for Lévy processes. A significant part of the proof consists of introducing free Poisson random measures, proving their existence and developing a theory of integration with respect to such measures. The existence of free Poisso...

An investigation on thermal decomposition of DNTF-CMDB propellants

Energy Technology Data Exchange (ETDEWEB)

Zheng, Wei; Wang, Jiangning; Ren, Xiaoning; Zhang, Laying; Zhou, Yanshui [Xi' an Modern Chemistry Research Institute, Xi' an 710065 (China)

2007-12-15

The thermal decomposition of DNTF-CMDB propellants was investigated by pressure differential scanning calorimetry (PDSC) and thermogravimetry (TG). The results show that there is only one decomposition peak on DSC curves, because the decomposition peak of DNTF cannot be separated from that of the NC/NG binder. The decomposition of DNTF can be obviously accelerated by the decomposition products of the NC/NG binder. The kinetic parameters of thermal decompositions for four DNTF-CMDB propellants at 6 MPa were obtained by the Kissinger method. It is found that the reaction rate decreases with increasing content of DNTF. (Abstract Copyright [2007], Wiley Periodicals, Inc.)

Thermal decomposition kinetics of strontium permanganate trihydrate, cadmium permanganate hexahydrate and calcium permanganate pentahydrate crystals

International Nuclear Information System (INIS)

Sakurai, K.R.; Schaeffer, D.A.; Herley, P.J.

1978-01-01

A thermogravimetric study of the kinetics of thermal nuclei formation and growth has been carried out for the dehydration and decomposition of single crystal strontium permanganate trihydrate, cadmium permanganate hexahydrate, and calcium permanganate pentahydrate. The isothermal dehydration of strontium parmanganate trihydrate occurs in two stages between 50 and 100 0 C. The dehydration kinetics suggest that the two dehydration stages are based on a single-step nucleation process followed by a growth process without nuclei overlap. The resulting activation energies are consistent with the proposed nucleation theory. For the dehydration kinetics of cadmium permanganate hexahydrate, an overlapping nucleation growth mechanism appears to be operating between 30 and 60 0 C. The results are irreproducible for the dehydration of calcium permanganate pentahydrate at 100 0 C. The thermal decomposition studies indicate that the data of the sigmoidal, isothermal fractional decomposition vs. time curves are reproducible for whole and ground crystals of each dehydrated permanganate. All of the data plots contain an induction or slow rate period, an acceleratory and a decay period. The induction period can be shortened by irradiation with 60 Co γ-rays prior to decomposition. Activation energies obtained for all three materials for the various thermal decomposition periods are found to be similar to those published previously on other alkali and alkaline-earth permanganates. (Auth.)

Universality of Schmidt decomposition and particle identity

Science.gov (United States)

Sciara, Stefania; Lo Franco, Rosario; Compagno, Giuseppe

2017-03-01

Schmidt decomposition is a widely employed tool of quantum theory which plays a key role for distinguishable particles in scenarios such as entanglement characterization, theory of measurement and state purification. Yet, its formulation for identical particles remains controversial, jeopardizing its application to analyze general many-body quantum systems. Here we prove, using a newly developed approach, a universal Schmidt decomposition which allows faithful quantification of the physical entanglement due to the identity of particles. We find that it is affected by single-particle measurement localization and state overlap. We study paradigmatic two-particle systems where identical qubits and qutrits are located in the same place or in separated places. For the case of two qutrits in the same place, we show that their entanglement behavior, whose physical interpretation is given, differs from that obtained before by different methods. Our results are generalizable to multiparticle systems and open the way for further developments in quantum information processing exploiting particle identity as a resource.

One step process of decomposition and polymerization to fabricate SiO{sub 2} hollow spheres/polyimide composite for foldable OLEDs

Energy Technology Data Exchange (ETDEWEB)

Kim, Min Kyu [SKKU Advanced Institute of Nanotechnology (SAINT) and Center for Human Interface Nano Technology (HINT), Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); Kim, Dong Won; Moon, Soo Hyun [School of Advanced Materials Science & Engineering, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); Shin, Dong-Wook [SKKU Advanced Institute of Nanotechnology (SAINT) and Center for Human Interface Nano Technology (HINT), Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); College of Engineering, Mathematics and Physical Sciences, University of Exeter, Stocker Road, Exeter EX4 4QL (United Kingdom); Oh, Tae Sik [School of Mechanical and ICT Convergence Engineering, Sunmoon University, Asan 336-708 (Korea, Republic of); Yoo, Ji Beom, E-mail: jbyoo@skku.edu [SKKU Advanced Institute of Nanotechnology (SAINT) and Center for Human Interface Nano Technology (HINT), Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); School of Advanced Materials Science & Engineering, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of)

2017-03-15

Graphical abstract: The SiO{sub 2} hollow spheres and polyimide hybrid synthesized using one step process, simultaneous occurrence of decomposition and polymerization (SODP) is useful with a ultra-low dielectric constant and high thermal stability for flexible OLED. - Highlights: • We fabricated hybrid films of SHS/PI by using a one step process with SODP. • The film has ultralow dielectric constant (50 vol% at k = 1.67). • There is no collapse of SiO{sub 2} hollow spheres in the PI matrix after bending test for 50,000 cycles. - Abstract: The fabrication of interlayer dielectrics (ILDs) in flexible organic light-emitting diodes (OLEDs) requires flexible materials with a low dielectric constant as well as materials with excellent electrical, thermal, and mechanical properties for optimal device performance. Hybrid films of SiO{sub 2} hollow spheres (SHS)/polyimide (PI) were prepared using a one-step process, with simultaneous occurrence of decomposition (polystyrene, PS) and polymerization (PI) (SODP). No collapse of SiO{sub 2} hollow spheres in PI was observed from 10 vol% to 60 vol% SHS in hybrid films. The dielectric constant of hybrid films was reduced from 3.45 to 1.67 and was saturated at above 50 vol% of SHS due to the maximum fill factor of SHS in the PI matrix. The thermal stability was excellent up to 500 °C due to the inherent thermal property of PI. After a bending test for 50,000 cycles at a bending radius of 1 mm, the SHS/PI hybrid films retained their dielectric constant and current density. These results indicate the hybrid film to be the most promising candidate for flexible ILDs with a low dielectric constant and high thermal stability for foldable OLEDs.

Generalized requirements and decompositions for the design of test parts for micro additive manufacturing research

DEFF Research Database (Denmark)

Thompson, Mary Kathryn; Clemmensen, Line Katrine Harder

2015-01-01

The design of experimental test parts to characterize micro additive manufacturing (AM) processes is challenging due to the influence of the manufacturing and metrology processes. This work builds on the lessons learned from a case study in the literature to derive generalized requirements and high...... level decompositions for the design of test parts and the design of experiments to characterize micro additive manufacturing processes. While the test parts and the experiments described are still work in progress, the generic requirements derived from them can serve as a starting point for the design...... of other micro additive manufacturing related studies and their decompositions can help structure future work....

A comparative study of the decomposition of pig carcasses in a methyl methacrylate box and open air conditions.

Science.gov (United States)

Li, Liangliang; Wang, Jiangfeng; Wang, Yu

2016-08-01

Analysis of the process of decomposition is essential in establishing the postmortem interval. However, despite the fact that insects are important players in body decomposition, their exact function within the decay process is still unclear. There is also limited knowledge as to how the decomposition process occurs in the absence of insects. In the present study, we compared the decomposition of a pig carcass in open air with that of one placed in a methyl methacrylate box to prevent insect contact. The pig carcass in the methyl methacrylate box was in the fresh stage for 1 day, the bloated stage from 2 d to 11 d, and underwent deflated decay from 12 d. In contrast, the pig carcass in open air went through the fresh, bloated, active decay and post-decay stages; and 22.3 h (0.93 d), 62.47 h (2.60 d), 123.63 h (5.15 d) and 246.5 h (10.27 d) following the start of the experiment respectively, prior to entering the skeletonization stage. A large amount of soft tissue were remained on the pig carcass in the methyl methacrylate box on 26 d, while only scattered bones remained on the pig carcass in open air. The results indicate that insects greatly accelerate the decomposition process. Copyright © 2016 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.

Interacting effects of insects and flooding on wood decomposition.

Directory of Open Access Journals (Sweden)

Michael D Ulyshen

Full Text Available Saproxylic arthropods are thought to play an important role in wood decomposition but very few efforts have been made to quantify their contributions to the process and the factors controlling their activities are not well understood. In the current study, mesh exclusion bags were used to quantify how arthropods affect loblolly pine (Pinus taeda L. decomposition rates in both seasonally flooded and unflooded forests over a 31-month period in the southeastern United States. Wood specific gravity (based on initial wood volume was significantly lower in bolts placed in unflooded forests and for those unprotected from insects. Approximately 20.5% and 13.7% of specific gravity loss after 31 months was attributable to insect activity in flooded and unflooded forests, respectively. Importantly, minimal between-treatment differences in water content and the results from a novel test carried out separately suggest the mesh bags had no significant impact on wood mass loss beyond the exclusion of insects. Subterranean termites (Isoptera: Rhinotermitidae: Reticulitermes spp. were 5-6 times more active below-ground in unflooded forests compared to flooded forests based on wooden monitoring stakes. They were also slightly more active above-ground in unflooded forests but these differences were not statistically significant. Similarly, seasonal flooding had no detectable effect on above-ground beetle (Coleoptera richness or abundance. Although seasonal flooding strongly reduced Reticulitermes activity below-ground, it can be concluded from an insignificant interaction between forest type and exclusion treatment that reduced above-ground decomposition rates in seasonally flooded forests were due largely to suppressed microbial activity at those locations. The findings from this study indicate that southeastern U.S. arthropod communities accelerate above-ground wood decomposition significantly and to a similar extent in both flooded and unflooded forests

Domain decomposition methods for solving an image problem

Energy Technology Data Exchange (ETDEWEB)

Tsui, W.K.; Tong, C.S. [Hong Kong Baptist College (Hong Kong)

1994-12-31

The domain decomposition method is a technique to break up a problem so that ensuing sub-problems can be solved on a parallel computer. In order to improve the convergence rate of the capacitance systems, pre-conditioned conjugate gradient methods are commonly used. In the last decade, most of the efficient preconditioners are based on elliptic partial differential equations which are particularly useful for solving elliptic partial differential equations. In this paper, the authors apply the so called covering preconditioner, which is based on the information of the operator under investigation. Therefore, it is good for various kinds of applications, specifically, they shall apply the preconditioned domain decomposition method for solving an image restoration problem. The image restoration problem is to extract an original image which has been degraded by a known convolution process and additive Gaussian noise.

Changes in bacterial and eukaryotic communities during sewage decomposition in Mississippi River water

Science.gov (United States)

Microbial decay processes are one of the mechanisms whereby sewage contamination is reduced in the environment. This decomposition process involves a highly complex array of bacterial and eukaryotic communities from both sewage and ambient waters. However, relatively little is kn...

Local Fractional Adomian Decomposition and Function Decomposition Methods for Laplace Equation within Local Fractional Operators

Directory of Open Access Journals (Sweden)

Sheng-Ping Yan

2014-01-01

Full Text Available We perform a comparison between the local fractional Adomian decomposition and local fractional function decomposition methods applied to the Laplace equation. The operators are taken in the local sense. The results illustrate the significant features of the two methods which are both very effective and straightforward for solving the differential equations with local fractional derivative.

Process and apparatus for pyrolytic decomposition and coking of mixtures of finely divided solid carbonaceous material and hydrocarbon oils

Energy Technology Data Exchange (ETDEWEB)

Fisher, A

1933-09-18

A process is described for pyrolytic decomposition and coking of mixtures of finely divided solid and semi-solid carbonaceous material and hydrocarbon oils, whereby the mixture is first heated to a high temperature; the heated products are introduced into a coking zone, where vapors are separated from nonvaporous residue afterwards to be cracked and condensed, characterized in that the mixture is heated to a high temperature under substantially noncoking conditions and that nonvaporous residue obtained in the coking zone is coked as a relatively thin layer on an externally intensely heated surface, preferably of heat-conducting, fireproof material, such as carborundum, fused-aluminum oxide, or clay.

Ab initio kinetics and thermal decomposition mechanism of mononitrobiuret and 1,5-dinitrobiuret

Energy Technology Data Exchange (ETDEWEB)

Sun, Hongyan, E-mail: hongyan.sun1@gmail.com, E-mail: ghanshyam.vaghjiani@us.af.mil; Vaghjiani, Ghanshyam L., E-mail: hongyan.sun1@gmail.com, E-mail: ghanshyam.vaghjiani@us.af.mil [Propellants Branch, Rocket Propulsion Division, Aerospace Systems Directorate, Air Force Research Laboratory, AFRL/RQRP, 10 E. Saturn Blvd., Edwards AFB, California 93524 (United States)

2015-05-28

Mononitrobiuret (MNB) and 1,5-dinitrobiuret (DNB) are tetrazole-free, nitrogen-rich, energetic compounds. For the first time, a comprehensive ab initio kinetics study on the thermal decomposition mechanisms of MNB and DNB is reported here. In particular, the intramolecular interactions of amine H-atom with electronegative nitro O-atom and carbonyl O-atom have been analyzed for biuret, MNB, and DNB at the M06-2X/aug-cc-pVTZ level of theory. The results show that the MNB and DNB molecules are stabilized through six-member-ring moieties via intramolecular H-bonding with interatomic distances between 1.8 and 2.0 Å, due to electrostatic as well as polarization and dispersion interactions. Furthermore, it was found that the stable molecules in the solid state have the smallest dipole moment amongst all the conformers in the nitrobiuret series of compounds, thus revealing a simple way for evaluating reactivity of fuel conformers. The potential energy surface for thermal decomposition of MNB was characterized by spin restricted coupled cluster theory at the RCCSD(T)/cc-pV∞ Z//M06-2X/aug-cc-pVTZ level. It was found that the thermal decomposition of MNB is initiated by the elimination of HNCO and HNN(O)OH intermediates. Intramolecular transfer of a H-atom, respectively, from the terminal NH{sub 2} group to the adjacent carbonyl O-atom via a six-member-ring transition state eliminates HNCO with an energy barrier of 35 kcal/mol and from the central NH group to the adjacent nitro O-atom eliminates HNN(O)OH with an energy barrier of 34 kcal/mol. Elimination of HNN(O)OH is also the primary process involved in the thermal decomposition of DNB, which processes C{sub 2v} symmetry. The rate coefficients for the primary decomposition channels for MNB and DNB were quantified as functions of temperature and pressure. In addition, the thermal decomposition of HNN(O)OH was analyzed via Rice–Ramsperger–Kassel–Marcus/multi-well master equation simulations, the results of which

Microbial decomposition and bio-remediation of chemical substances. Kagaku busshitsu no biseibutsu bunkai to bio remediation

Energy Technology Data Exchange (ETDEWEB)

Fujita, M [Osaka University, Osaka (Japan). Faculty of Engineering

1993-08-01

This paper summarizes studies on evaluation of breeding and bio-degradability of decomposition bacteria in bio-remediation, and births and deaths of microorganisms. Structural genes in a phenol decomposition path were separated by means of shotgun cloning. The phe B genes having been taken out were inserted into parent stocks to produce combined stocks for use in phenol decomposition. With 100 mg/l of phenol, the combined stocks showed better performance in both decomposition and multiplication than the parent stocks. When the phenol concentration increases, the rate controlling process changes and loses its effect. Decomposition of trichloroethylene progressed quickly with combined stocks derived from phe A, a phenol decomposed gene. Separated polyvinyl alcohol (PVA) decomposing bacteria were used for PVA decomposition. As a result, it was found that microorganisms are required that utilize intermediately produced low-molecular compounds for multiplication. Combined stocks with E. coli C600 stocks inserted with phe B were prepared to discuss births and deaths of microorganisms in activated sludge. A number of findings was obtained. 6 refs., 10 figs.

Thermal decomposition behaviors of magnesium borohydride doped with metal fluoride additives

International Nuclear Information System (INIS)

Zhang, Z.G.; Wang, H.; Liu, J.W.; Zhu, M.

2013-01-01

Highlights: • The decomposition proceeded through several distinct steps. • The mixed materials show a dramatically low initial hydrogen release temperature. • The additives react with the Mg–B–H compounds rather than acting as catalysts. • The reaction process was studied using an in situ TEM. - Abstract: The thermal decomposition behaviors of Magnesium borohydride [Mg(BH 4 ) 2 ] and metal fluoride doped mixtures were studied by temperature programmed desorption measurement/mass spectrometry (TPD/MS), differential scanning calorimetry (DSC) and in situ transmission electron microscope (TEM) observations. The decomposition and release of hydrogen proceeded through several distinct steps, including two polymorphic transitions, ionic Mg(BH 4 ) 2 melting with solid Mg–B–H amorphous phase formation and Mg–B–H decomposition. The addition of additives such as CaF 2 , ZnF 2 and TiF 3 resulted in a decrease in the hydrogen release temperature. ZnF 2 and TiF 3 reduced the initial hydrogen release temperature to ca. 50 °C. However, hydrogen release during the transformation from γ-Mg(BH 4 ) 2 to the amorphous Mg–B–H compounds at ca. 300 °C was only 4.5 wt.% in contrast to 9.8 wt.% for the direct decomposition of pure Mg(BH 4 ) 2 . TEM observations confirmed that ZnF 2 and TiF 3 reacted with amorphous Mg–B–H compounds rather than acting as catalysts

Constructive quantum Shannon decomposition from Cartan involutions

Energy Technology Data Exchange (ETDEWEB)

Drury, Byron; Love, Peter [Department of Physics, 370 Lancaster Ave., Haverford College, Haverford, PA 19041 (United States)], E-mail: plove@haverford.edu

2008-10-03

The work presented here extends upon the best known universal quantum circuit, the quantum Shannon decomposition proposed by Shende et al (2006 IEEE Trans. Comput.-Aided Des. Integr. Circuits Syst. 25 1000). We obtain the basis of the circuit's design in a pair of Cartan decompositions. This insight gives a simple constructive factoring algorithm in terms of the Cartan involutions corresponding to these decompositions.

Constructive quantum Shannon decomposition from Cartan involutions

International Nuclear Information System (INIS)

Drury, Byron; Love, Peter

2008-01-01

The work presented here extends upon the best known universal quantum circuit, the quantum Shannon decomposition proposed by Shende et al (2006 IEEE Trans. Comput.-Aided Des. Integr. Circuits Syst. 25 1000). We obtain the basis of the circuit's design in a pair of Cartan decompositions. This insight gives a simple constructive factoring algorithm in terms of the Cartan involutions corresponding to these decompositions

Programming Enhancements for Low Temperature Thermal Decomposition Workstation

International Nuclear Information System (INIS)

Igou, R.E.

1998-01-01

This report describes a new control-and-measurement system design for the Oak Ridge Y-12 Plant's Low Temperature Thermal Decomposition (LTTD) process. The new design addresses problems with system reliability stemming from equipment obsolescence and addresses specific functional improvements that plant production personnel have identified, as required. The new design will also support new measurement techniques, which the Y-12 Development Division has identified for future operations. The new techniques will function in concert with the original technique so that process data consistency is maintained

Using dynamic mode decomposition for real-time background/foreground separation in video

Science.gov (United States)

Kutz, Jose Nathan; Grosek, Jacob; Brunton, Steven; Fu, Xing; Pendergrass, Seth

2017-06-06

The technique of dynamic mode decomposition (DMD) is disclosed herein for the purpose of robustly separating video frames into background (low-rank) and foreground (sparse) components in real-time. Foreground/background separation is achieved at the computational cost of just one singular value decomposition (SVD) and one linear equation solve, thus producing results orders of magnitude faster than robust principal component analysis (RPCA). Additional techniques, including techniques for analyzing the video for multi-resolution time-scale components, and techniques for reusing computations to allow processing of streaming video in real time, are also described herein.

Decomposition characteristics of three different kinds of aquatic macrophytes and their potential application as carbon resource in constructed wetland.

Science.gov (United States)

Wu, Suqing; He, Shengbing; Zhou, Weili; Gu, Jianya; Huang, Jungchen; Gao, Lei; Zhang, Xu

2017-12-01

Decomposition of aquatic macrophytes usually generates significant influence on aquatic environment. Study on the aquatic macrophytes decomposition may help reusing the aquatic macrophytes litters, as well as controlling the water pollution caused by the decomposition process. This study verified that the decomposition processes of three different kinds of aquatic macrophytes (water hyacinth, hydrilla and cattail) could exert significant influences on water quality of the receiving water, including the change extent of pH, dissolved oxygen (DO), the contents of carbon, nitrogen and phosphorus, etc. The influence of decomposition on water quality and the concentrations of the released chemical materials both followed the order of water hyacinth > hydrilla > cattail. Greater influence was obtained with higher dosage of plant litter addition. The influence also varied with sediment addition. Moreover, nitrogen released from the decomposition of water hyacinth and hydrilla were mainly NH 3 -N and organic nitrogen while those from cattail litter included organic nitrogen and NO 3 - -N. After the decomposition, the average carbon to nitrogen ratio (C/N) in the receiving water was about 2.6 (water hyacinth), 5.3 (hydrilla) and 20.3 (cattail). Therefore, cattail litter might be a potential plant carbon source for denitrification in ecological system of a constructed wetland. Copyright © 2017 Elsevier Ltd. All rights reserved.

Time space domain decomposition methods for reactive transport - Application to CO2 geological storage

International Nuclear Information System (INIS)

Haeberlein, F.

2011-01-01

Reactive transport modelling is a basic tool to model chemical reactions and flow processes in porous media. A totally reduced multi-species reactive transport model including kinetic and equilibrium reactions is presented. A structured numerical formulation is developed and different numerical approaches are proposed. Domain decomposition methods offer the possibility to split large problems into smaller subproblems that can be treated in parallel. The class of Schwarz-type domain decomposition methods that have proved to be high-performing algorithms in many fields of applications is presented with a special emphasis on the geometrical viewpoint. Numerical issues for the realisation of geometrical domain decomposition methods and transmission conditions in the context of finite volumes are discussed. We propose and validate numerically a hybrid finite volume scheme for advection-diffusion processes that is particularly well-suited for the use in a domain decomposition context. Optimised Schwarz waveform relaxation methods are studied in detail on a theoretical and numerical level for a two species coupled reactive transport system with linear and nonlinear coupling terms. Well-posedness and convergence results are developed and the influence of the coupling term on the convergence behaviour of the Schwarz algorithm is studied. Finally, we apply a Schwarz waveform relaxation method on the presented multi-species reactive transport system. (author)

New mechanism for autocatalytic decomposition of H2CO3 in the vapor phase.

Science.gov (United States)

Ghoshal, Sourav; Hazra, Montu K

2014-04-03

In this article, we present high level ab initio calculations investigating the energetics of a new autocatalytic decomposition mechanism for carbonic acid (H2CO3) in the vapor phase. The calculation have been performed at the MP2 level of theory in conjunction with aug-cc-pVDZ, aug-cc-pVTZ, and 6-311++G(3df,3pd) basis sets as well as at the CCSD(T)/aug-cc-pVTZ level. The present study suggests that this new decomposition mechanism is effectively a near-barrierless process at room temperature and makes vapor phase of H2CO3 unstable even in the absence of water molecules. Our calculation at the MP2/aug-cc-pVTZ level predicts that the effective barrier, defined as the difference between the zero-point vibrational energy (ZPE) corrected energy of the transition state and the total energy of the isolated starting reactants in terms of bimolecular encounters, is nearly zero for the autocatalytic decomposition mechanism. The results at the CCSD(T)/aug-cc-pVTZ level of calculations suggest that the effective barrier, as defined above, is sensitive to some extent to the levels of calculations used, nevertheless, we find that the effective barrier height predicted at the CCSD(T)/aug-cc-pVTZ level is very small or in other words the autocatalytic decomposition mechanism presented in this work is a near-barrierless process as mentioned above. Thus, we suggest that this new autocatalytic decomposition mechanism has to be considered as the primary mechanism for the decomposition of carbonic acid, especially at its source, where the vapor phase concentration of H2CO3 molecules reaches its highest levels.

An Efficient Local Correlation Matrix Decomposition Approach for the Localization Implementation of Ensemble-Based Assimilation Methods

Science.gov (United States)

Zhang, Hongqin; Tian, Xiangjun

2018-04-01

Ensemble-based data assimilation methods often use the so-called localization scheme to improve the representation of the ensemble background error covariance (Be). Extensive research has been undertaken to reduce the computational cost of these methods by using the localized ensemble samples to localize Be by means of a direct decomposition of the local correlation matrix C. However, the computational costs of the direct decomposition of the local correlation matrix C are still extremely high due to its high dimension. In this paper, we propose an efficient local correlation matrix decomposition approach based on the concept of alternating directions. This approach is intended to avoid direct decomposition of the correlation matrix. Instead, we first decompose the correlation matrix into 1-D correlation matrices in the three coordinate directions, then construct their empirical orthogonal function decomposition at low resolution. This procedure is followed by the 1-D spline interpolation process to transform the above decompositions to the high-resolution grid. Finally, an efficient correlation matrix decomposition is achieved by computing the very similar Kronecker product. We conducted a series of comparison experiments to illustrate the validity and accuracy of the proposed local correlation matrix decomposition approach. The effectiveness of the proposed correlation matrix decomposition approach and its efficient localization implementation of the nonlinear least-squares four-dimensional variational assimilation are further demonstrated by several groups of numerical experiments based on the Advanced Research Weather Research and Forecasting model.

Decomposition of monolithic web application to microservices

OpenAIRE

Zaymus, Mikulas

2017-01-01

Solteq Oyj has an internal Wellbeing project for massage reservations. The task of this thesis was to transform the monolithic architecture of this application to microservices. The thesis starts with a detailed comparison between microservices and monolithic application. It points out the benefits and disadvantages microservice architecture can bring to the project. Next, it describes the theory and possible strategies that can be used in the process of decomposition of an existing monoli...

Comparative analysis of gradient-field-based orientation estimation methods and regularized singular-value decomposition for fringe pattern processing.

Science.gov (United States)

Sun, Qi; Fu, Shujun

2017-09-20

Fringe orientation is an important feature of fringe patterns and has a wide range of applications such as guiding fringe pattern filtering, phase unwrapping, and abstraction. Estimating fringe orientation is a basic task for subsequent processing of fringe patterns. However, various noise, singular and obscure points, and orientation data degeneration lead to inaccurate calculations of fringe orientation. Thus, to deepen the understanding of orientation estimation and to better guide orientation estimation in fringe pattern processing, some advanced gradient-field-based orientation estimation methods are compared and analyzed. At the same time, following the ideas of smoothing regularization and computing of bigger gradient fields, a regularized singular-value decomposition (RSVD) technique is proposed for fringe orientation estimation. To compare the performance of these gradient-field-based methods, quantitative results and visual effect maps of orientation estimation are given on simulated and real fringe patterns that demonstrate that the RSVD produces the best estimation results at a cost of relatively less time.

Introduction - Acid decomposition of borosilicate ores

International Nuclear Information System (INIS)

Mirsaidov, U.M.; Kurbonov, A.S.; Mamatov, E.D.

2015-01-01

The complex processing of mineral raw materials is an effective way for the extraction of valuable components. One of these raw materials are borosilicate ores from which the boric acid, aluminium and iron salts and building materials can be obtained. In the Institute of Chemistry of the Academy of Sciences of the Republic of Tajikistan the flowsheets of the processing of borosilicate raw materials by acid and chloric methods were elaborated. The acid methods of decomposition of borosilicate ores of Ak-Arkhar Deposit were considered in present monograph. The carried out researches on elaboration of physicochemical aspects and technological acid methods allowed to define the optimal ways of extraction of valuable products from borosilicate raw materials of Tajikistan.

On low-rank updates to the singular value and Tucker decompositions

Energy Technology Data Exchange (ETDEWEB)

O' Hara, M J

2009-10-06

The singular value decomposition is widely used in signal processing and data mining. Since the data often arrives in a stream, the problem of updating matrix decompositions under low-rank modification has been widely studied. Brand developed a technique in 2006 that has many advantages. However, the technique does not directly approximate the updated matrix, but rather its previous low-rank approximation added to the new update, which needs justification. Further, the technique is still too slow for large information processing problems. We show that the technique minimizes the change in error per update, so if the error is small initially it remains small. We show that an updating algorithm for large sparse matrices should be sub-linear in the matrix dimension in order to be practical for large problems, and demonstrate a simple modification to the original technique that meets the requirements.

Evaluation of Polarimetric SAR Decomposition for Classifying Wetland Vegetation Types

Directory of Open Access Journals (Sweden)

Sang-Hoon Hong

2015-07-01

Full Text Available The Florida Everglades is the largest subtropical wetland system in the United States and, as with subtropical and tropical wetlands elsewhere, has been threatened by severe environmental stresses. It is very important to monitor such wetlands to inform management on the status of these fragile ecosystems. This study aims to examine the applicability of TerraSAR-X quadruple polarimetric (quad-pol synthetic aperture radar (PolSAR data for classifying wetland vegetation in the Everglades. We processed quad-pol data using the Hong & Wdowinski four-component decomposition, which accounts for double bounce scattering in the cross-polarization signal. The calculated decomposition images consist of four scattering mechanisms (single, co- and cross-pol double, and volume scattering. We applied an object-oriented image analysis approach to classify vegetation types with the decomposition results. We also used a high-resolution multispectral optical RapidEye image to compare statistics and classification results with Synthetic Aperture Radar (SAR observations. The calculated classification accuracy was higher than 85%, suggesting that the TerraSAR-X quad-pol SAR signal had a high potential for distinguishing different vegetation types. Scattering components from SAR acquisition were particularly advantageous for classifying mangroves along tidal channels. We conclude that the typical scattering behaviors from model-based decomposition are useful for discriminating among different wetland vegetation types.

Decomposition in pelagic marine ecosytems

International Nuclear Information System (INIS)

Lucas, M.I.

1986-01-01

During the decomposition of plant detritus, complex microbial successions develop which are dominated in the early stages by a number of distinct bacterial morphotypes. The microheterotrophic community rapidly becomes heterogenous and may include cyanobacteria, fungi, yeasts and bactivorous protozoans. Microheterotrophs in the marine environment may have a biomass comparable to that of all other heterotrophs and their significance as a resource to higher trophic orders, and in the regeneration of nutrients, particularly nitrogen, that support 'regenerated' primary production, has aroused both attention and controversy. Numerous methods have been employed to measure heterotrophic bacterial production and activity. The most widely used involve estimates of 14 C-glucose uptake; the frequency of dividing cells; the incorporation of 3 H-thymidine and exponential population growth in predator-reduced filtrates. Recent attempts to model decomposition processes and C and N fluxes in pelagic marine ecosystems are described. This review examines the most sensitive components and predictions of the models with particular reference to estimates of bacterial production, net growth yield and predictions of N cycling determined by 15 N methodology. Directed estimates of nitrogen (and phosphorus) flux through phytoplanktonic and bacterioplanktonic communities using 15 N (and 32 P) tracer methods are likely to provide more realistic measures of nitrogen flow through planktonic communities

In situ study of glasses decomposition layer

International Nuclear Information System (INIS)

Zarembowitch-Deruelle, O.

1997-01-01

The aim of this work is to understand the involved mechanisms during the decomposition of glasses by water and the consequences on the morphology of the decomposition layer, in particular in the case of a nuclear glass: the R 7 T 7 . The chemical composition of this glass being very complicated, it is difficult to know the influence of the different elements on the decomposition kinetics and on the resulting morphology because several atoms have a same behaviour. Glasses with simplified composition (only 5 elements) have then been synthesized. The morphological and structural characteristics of these glasses have been given. They have then been decomposed by water. The leaching curves do not reflect the decomposition kinetics but the solubility of the different elements at every moment. The three steps of the leaching are: 1) de-alkalinization 2) lattice rearrangement 3) heavy elements solubilization. Two decomposition layer types have also been revealed according to the glass heavy elements rate. (O.M.)

The rate of synthesis and decomposition of tissue proteins in hypokinesia and increased muscular activity

Science.gov (United States)

Fedorov, I. V.; Chernyy, A. V.; Fedorov, A. I.

1978-01-01

During hypokinesia and physical loading (swimming) of rats, the radioactivity of skeletal muscle, liver, kidney, heart, and blood proteins was determined after administration of radioactive amino acids. Tissue protein synthesis decreased during hypokinesia, and decomposition increased. Both synthesis and decomposition increased during physical loading, but anabolic processes predominated in the total tissue balance. The weights of the animals decreased in hypokinesia and increased during increased muscle activity.

Prediction of electronically nonadiabatic decomposition mechanisms of isolated gas phase nitrogen-rich energetic salt: Guanidium-triazolate

Energy Technology Data Exchange (ETDEWEB)

Ghosh, Jayanta; Bhattacharya, Atanu, E-mail: atanub@ipc.iisc.ernet.in

2016-01-13

Highlights: • Decomposition mechanisms of model energetic salt, guanidium triazolate, are explored. • Decomposition pathways are electronically nonadiabatic. • CASPT2, CASMP2 and CASSCF methodologies are employed. • N{sub 2} and NH{sub 3} are predicted to be the most possible initial decomposition products. - Abstract: Electronically nonadiabatic decomposition pathways of guanidium triazolate are explored theoretically. Nonadiabatically coupled potential energy surfaces are explored at the complete active space self-consistent field (CASSCF) level of theory. For better estimation of energies complete active space second order perturbation theories (CASPT2 and CASMP2) are also employed. Density functional theory (DFT) with B3LYP functional and MP2 level of theory are used to explore subsequent ground state decomposition pathways. In comparison with all possible stable decomposition products (such as, N{sub 2}, NH{sub 3}, HNC, HCN, NH{sub 2}CN and CH{sub 3}NC), only NH{sub 3} (with NH{sub 2}CN) and N{sub 2} are predicted to be energetically most accessible initial decomposition products. Furthermore, different conical intersections between the S{sub 1} and S{sub 0} surfaces, which are computed at the CASSCF(14,10)/6-31G(d) level of theory, are found to play an essential role in the excited state deactivation process of guanidium triazolate. This is the first report on the electronically nonadiabatic decomposition mechanisms of isolated guanidium triazolate salt.

Litter production and decomposition in Eucalyptus urophylla x Eucalyptus globulus maidenii stand

Directory of Open Access Journals (Sweden)

Mauro Valdir Schumacher

2013-09-01

Full Text Available he sustainable wood production in commercial plantations requires knowledge of the nutrient cycling process, which also involves the production and decomposition of litter. This study verified the influence of climatic variables on litter production and t evaluated the rate of leaf litter decomposition in a stand of Eucalyptus urophylla x E. globulus maidenii. There were installed 4 plots of 20 m x 20 m, in each plot four litter traps to collect leaves were placed, thin branches and miscellaneous, beside this, each plot received 3 areas for coarse branches collection. The litter collected was used to calculate the deposition and the correlation between climate variables and deposition. The climatic variables used, on a monthly basis, were average temperature, average maximum temperature, average minimum temperature, rainfall, relative humidity, average wind speed, average solar radiation and average evapotranspiration, both supplied by an experimental station. For evaluation of the litter decomposition rate, four square samples of 0.25 m side in each plot were randomly collected and used for determining the decay coefficient (K, half life (t0,5 and decomposition time of 95% of litter (t0,95 . The monthly litter production was weakly correlated with climatic variables and the annual production was 7.4 Mg ha-1, with leaves as the major fraction (60%. The litter decomposition rate was considered slow.

High-purity Cu nanocrystal synthesis by a dynamic decomposition method

Science.gov (United States)

Jian, Xian; Cao, Yu; Chen, Guozhang; Wang, Chao; Tang, Hui; Yin, Liangjun; Luan, Chunhong; Liang, Yinglin; Jiang, Jing; Wu, Sixin; Zeng, Qing; Wang, Fei; Zhang, Chengui

2014-12-01

Cu nanocrystals are applied extensively in several fields, particularly in the microelectron, sensor, and catalysis. The catalytic behavior of Cu nanocrystals depends mainly on the structure and particle size. In this work, formation of high-purity Cu nanocrystals is studied using a common chemical vapor deposition precursor of cupric tartrate. This process is investigated through a combined experimental and computational approach. The decomposition kinetics is researched via differential scanning calorimetry and thermogravimetric analysis using Flynn-Wall-Ozawa, Kissinger, and Starink methods. The growth was found to be influenced by the factors of reaction temperature, protective gas, and time. And microstructural and thermal characterizations were performed by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and differential scanning calorimetry. Decomposition of cupric tartrate at different temperatures was simulated by density functional theory calculations under the generalized gradient approximation. High crystalline Cu nanocrystals without floccules were obtained from thermal decomposition of cupric tartrate at 271°C for 8 h under Ar. This general approach paves a way to controllable synthesis of Cu nanocrystals with high purity.

Spatial domain decomposition for neutron transport problems

International Nuclear Information System (INIS)

Yavuz, M.; Larsen, E.W.

1989-01-01

A spatial Domain Decomposition method is proposed for modifying the Source Iteration (SI) and Diffusion Synthetic Acceleration (DSA) algorithms for solving discrete ordinates problems. The method, which consists of subdividing the spatial domain of the problem and performing the transport sweeps independently on each subdomain, has the advantage of being parallelizable because the calculations in each subdomain can be performed on separate processors. In this paper we describe the details of this spatial decomposition and study, by numerical experimentation, the effect of this decomposition on the SI and DSA algorithms. Our results show that the spatial decomposition has little effect on the convergence rates until the subdomains become optically thin (less than about a mean free path in thickness)

Oxidative decomposition of aromatic hydrocarbons by electron beam irradiation

Science.gov (United States)

Han, Do-Hung; Stuchinskaya, Tatiana; Won, Yang-Soo; Park, Wan-Sik; Lim, Jae-Kyong

2003-05-01

Decomposition of aromatic volatile organic compounds (VOCs) under electron beam irradiation was studied in order to examine the kinetics of the process, to characterize the reaction product distribution and to develop a process of waste gas control technology. Toluene, ethylbenzene, o-, m-, p-xylenes and chlorobenzene were used as target materials. The experiments were carried out at doses ranging from 0.5 to 10 kGy, using a flow reactor utilized under electron beam irradiation. Maximum degrees of decomposition carried out at 10 kGy in air environment were 55-65% for “non-chlorinated” aromatic VOC and 85% for chlorobenzene. It was found that a combination of aromatic pollutants with chlorobenzene would considerably increase the degradation value up to nearly 50% compared to the same compounds in the absence of chlorine groups. Based on our experimental observation, the degradation mechanism of the aromatic compounds combined with chloro-compound suggests that a chlorine radical, formed from EB irradiation, induces a chain reaction, resulting in an accelerating oxidative destruction of aromatic VOCs.

Modeling of ferric sulfate decomposition and sulfation of potassium chloride during grate‐firing of biomass

DEFF Research Database (Denmark)

Wu, Hao; Jespersen, Jacob Boll; Jappe Frandsen, Flemming

2013-01-01

Ferric sulfate is used as an additive in biomass combustion to convert the released potassium chloride to the less harmful potassium sulfate. The decomposition of ferric sulfate is studied in a fast heating rate thermogravimetric analyzer and a volumetric reaction model is proposed to describe...... the process. The yields of sulfur oxides from ferric sulfate decomposition under boiler conditions are investigated experimentally, revealing a distribution of approximately 40% SO3 and 60% SO2. The ferric sulfate decomposition model is combined with a detailed kinetic model of gas‐phase KCl sulfation...... and a model of K2SO4 condensation to simulate the sulfation of KCl by ferric sulfate addition. The simulation results show good agreements with experiments conducted in a biomass grate‐firing reactor. The results indicate that the SO3 released from ferric sulfate decomposition is the main contributor to KCl...

Microbiological decomposition of bagasse after radiation pasteurization

International Nuclear Information System (INIS)

Ito, Hitoshi; Ishigaki, Isao

1987-01-01

Microbiological decomposition of bagasse was studied for upgrading to animal feeds after radiation pasteurization. Solid-state culture media of bagasse were prepared with addition of some amount of inorganic salts for nitrogen source, and after irradiation, fungi were infected for cultivation. In this study, many kind of cellulosic fungi such as Pleurotus ostreatus, P. flavellatus, Verticillium sp., Coprinus cinereus, Lentinus edodes, Aspergillus niger, Trichoderma koningi, T. viride were used for comparison of decomposition of crude fibers. In alkali nontreated bagasse, P. ostreatus, P. flavellatus, C. cinereus and Verticillium sp. could decompose crude fibers from 25 to 34 % after one month of cultivation, whereas other fungi such as A. niger, T. koningi, T. viride, L. edodes decomposed below 10 %. On the contrary, alkali treatment enhanced the decomposition of crude fiber by A. niger, T. koningi and T. viride to be 29 to 47 % as well as Pleurotus species or C. cinereus. Other species of mushrooms such as L. edodes had a little ability of decomposition even after alkali treatment. Radiation treatment with 10 kGy could not enhance the decomposition of bagasse compared with steam treatment, whereas higher doses of radiation treatment enhanced a little of decomposition of crude fibers by microorganisms. (author)

Microbiological decomposition of bagasse after radiation pasteurization

Energy Technology Data Exchange (ETDEWEB)

Ito, Hitoshi; Ishigaki, Isao

1987-11-01

Microbiological decomposition of bagasse was studied for upgrading to animal feeds after radiation pasteurization. Solid-state culture media of bagasse were prepared with addition of some amount of inorganic salts for nitrogen source, and after irradiation, fungi were infected for cultivation. In this study, many kind of cellulosic fungi such as Pleurotus ostreatus, P. flavellatus, Verticillium sp., Coprinus cinereus, Lentinus edodes, Aspergillus niger, Trichoderma koningi, T. viride were used for comparison of decomposition of crude fibers. In alkali nontreated bagasse, P. ostreatus, P. flavellatus, C. cinereus and Verticillium sp. could decompose crude fibers from 25 to 34 % after one month of cultivation, whereas other fungi such as A. niger, T. koningi, T. viride, L. edodes decomposed below 10 %. On the contrary, alkali treatment enhanced the decomposition of crude fiber by A. niger, T. koningi and T. viride to be 29 to 47 % as well as Pleurotus species or C. cinereus. Other species of mushrooms such as L. edodes had a little ability of decomposition even after alkali treatment. Radiation treatment with 10 kGy could not enhance the decomposition of bagasse compared with steam treatment, whereas higher doses of radiation treatment enhanced a little of decomposition of crude fibers by microorganisms.

Insight into litter decomposition driven by nutrient demands of symbiosis system through the hypha bridge of arbuscular mycorrhizal fungi.

Science.gov (United States)

Kong, Xiangshi; Jia, Yanyan; Song, Fuqiang; Tian, Kai; Lin, Hong; Bei, Zhanlin; Jia, Xiuqin; Yao, Bei; Guo, Peng; Tian, Xingjun

2018-02-01

Arbuscular mycorrhizal fungi (AMF) play an important role in litter decomposition. This study investigated how soil nutrient level affected the process. Results showed that AMF colonization had no significant effect on litter decomposition under normal soil nutrient conditions. However, litter decomposition was accelerated significantly under lower nutrient conditions. Soil microbial biomass in decomposition system was significantly increased. Especially, in moderate lower nutrient treatment (condition of half-normal soil nutrient), litters exhibited the highest decomposition rate, AMF hypha revealed the greatest density, and enzymes (especially nitrate reductase) showed the highest activities as well. Meanwhile, the immobilization of nitrogen (N) in the decomposing litter remarkably decreased. Our results suggested that the roles AMF played in ecosystem were largely affected by soil nutrient levels. At normal soil nutrient level, AMF exhibited limited effects in promoting decomposition. When soil nutrient level decreased, the promoting effect of AMF on litter decomposition began to appear, especially on N mobilization. However, under extremely low nutrient conditions, AMF showed less influence on decomposition and may even compete with decomposer microorganisms for nutrients.

Self-decomposition of radiochemicals. Principles, control, observations and effects

International Nuclear Information System (INIS)

Evans, E.A.

1976-01-01

The aim of the booklet is to remind the established user of radiochemicals of the problems of self-decomposition and to inform those investigators who are new to the applications of radiotracers. The section headings are: introduction; radionuclides; mechanisms of decomposition; effects of temperature; control of decomposition; observations of self-decomposition (sections for compounds labelled with (a) carbon-14, (b) tritium, (c) phosphorus-32, (d) sulphur-35, (e) gamma- or X-ray emitting radionuclides, decomposition of labelled macromolecules); effects of impurities in radiotracer investigations; stability of labelled compounds during radiotracer studies. (U.K.)

Fungal colonization and decomposition of leaves and stems of Salix arctica on deglaciated moraines in high-Arctic Canada

Science.gov (United States)

Osono, Takashi; Matsuoka, Shunsuke; Hirose, Dai; Uchida, Masaki; Kanda, Hiroshi

2014-06-01

Fungal colonization, succession, and decomposition of leaves and stems of Salix arctica were studied to estimate the roles of fungi in the decomposition processes in the high Arctic. The samples were collected from five moraines with different periods of development since deglaciation to investigate the effects of ecosystem development on the decomposition processes during the primary succession. The total hyphal lengths and the length of darkly pigmented hyphae increased during decomposition of leaves and stems and were not varied with the moraines. Four fungal morphotaxa were frequently isolated from both leaves and stems. The frequencies of occurrence of two morphotaxa varied with the decay class of leaves and/or stems. The hyphal lengths and the frequencies of occurrence of fungal morphotaxa were positively or negatively correlated with the contents of organic chemical components and nutrients in leaves and stems, suggesting the roles of fungi in chemical changes in the field. Pure culture decomposition tests demonstrated that the fungal morphotaxa were cellulose decomposers. Our results suggest that fungi took part in the chemical changes in decomposing leaves and stems even under the harsh environment of the high Arctic.

1-Chloronaphthalene decomposition in air using electron beam irradiation

International Nuclear Information System (INIS)

Chmielewski, A.G.; Sun, Y.; Bulka, S.; Zimek, Z.

2006-01-01

A method for the preparation of model gas containing 1-chloronaphthalene can be referred to 1,1-DCE (dichloroethene). A pulsed electron beam (EB) accelerator ILU-6 (2.0 MeV max., 20 kW max.) was used as an irradiation source. The absorbed dose rate inside the irradiation vessel was 10.835 kGy/min. Total absorbed dose was adjusted by changing irradiation time of the Pyrex glass vessels. 1-Chloronaphthalene concentration was analyzed using gas-chromatography. It has been found, that 1-chloronaphthalene can be decomposed in air or N 2 using EB irradiation. Decomposition efficiency of 1-chloronaphthalene in air is higher than that in N 2 . Positive charge transfer reactions and OH radicals' reaction may play a main role in 1-chloronaphthalene decomposition process

Decomposition of environmentally persistent perfluorooctanoic acid in water by photochemical approaches.

Science.gov (United States)

Hori, Hisao; Hayakawa, Etsuko; Einaga, Hisahiro; Kutsuna, Shuzo; Koike, Kazuhide; Ibusuki, Takashi; Kiatagawa, Hiroshi; Arakawa, Ryuichi

2004-11-15

The decomposition of persistent and bioaccumulative perfluorooctanoic acid (PFOA) in water by UV-visible light irradiation, by H202 with UV-visible light irradiation, and by a tungstic heteropolyacid photocatalyst was examined to develop a technique to counteract stationary sources of PFOA. Direct photolysis proceeded slowly to produce CO2, F-, and short-chain perfluorocarboxylic acids. Compared to the direct photolysis, H2O2 was less effective in PFOA decomposition. On the other hand, the heteropolyacid photocatalyst led to efficient PFOA decomposition and the production of F- ions and CO2. The photocatalyst also suppressed the accumulation of short-chain perfluorocarboxylic acids in the reaction solution. PFOA in the concentrations of 0.34-3.35 mM, typical of those in wastewaters after an emulsifying process in fluoropolymer manufacture, was completely decomposed by the catalyst within 24 h of irradiation from a 200-W xenon-mercury lamp, with no accompanying catalyst degradation, permitting the catalyst to be reused in consecutive runs. Gas chromatography/mass spectrometry (GC/MS) measurements showed no trace of environmentally undesirable species such as CF4, which has a very high global-warming potential. When the (initial PFOA)/(initial catalyst) molar ratio was 10: 1, the turnover number for PFOA decomposition reached 4.33 over 24 h of irradiation.

Reactive Goal Decomposition Hierarchies for On-Board Autonomy

Science.gov (United States)

Hartmann, L.

2002-01-01

As our experience grows, space missions and systems are expected to address ever more complex and demanding requirements with fewer resources (e.g., mass, power, budget). One approach to accommodating these higher expectations is to increase the level of autonomy to improve the capabilities and robustness of on- board systems and to simplify operations. The goal decomposition hierarchies described here provide a simple but powerful form of goal-directed behavior that is relatively easy to implement for space systems. A goal corresponds to a state or condition that an operator of the space system would like to bring about. In the system described here goals are decomposed into simpler subgoals until the subgoals are simple enough to execute directly. For each goal there is an activation condition and a set of decompositions. The decompositions correspond to different ways of achieving the higher level goal. Each decomposition contains a gating condition and a set of subgoals to be "executed" sequentially or in parallel. The gating conditions are evaluated in order and for the first one that is true, the corresponding decomposition is executed in order to achieve the higher level goal. The activation condition specifies global conditions (i.e., for all decompositions of the goal) that need to hold in order for the goal to be achieved. In real-time, parameters and state information are passed between goals and subgoals in the decomposition; a termination indication (success, failure, degree) is passed up when a decomposition finishes executing. The lowest level decompositions include servo control loops and finite state machines for generating control signals and sequencing i/o. Semaphores and shared memory are used to synchronize and coordinate decompositions that execute in parallel. The goal decomposition hierarchy is reactive in that the generated behavior is sensitive to the real-time state of the system and the environment. That is, the system is able to react

Programming Enhancements for Low Temperature Thermal Decomposition Workstation

Energy Technology Data Exchange (ETDEWEB)

Igou, R.E.

1998-10-01

This report describes a new control-and-measurement system design for the Oak Ridge Y-12 Plant's Low Temperature Thermal Decomposition (LTTD) process. The new design addresses problems with system reliability stemming from equipment obsolescence and addresses specific functional improvements that plant production personnel have identified, as required. The new design will also support new measurement techniques, which the Y-12 Development Division has identified for future operations. The new techniques will function in concert with the original technique so that process data consistency is maintained.

Scalable Domain Decomposition Preconditioners for Heterogeneous Elliptic Problems

Directory of Open Access Journals (Sweden)

Pierre Jolivet

2014-01-01

Full Text Available Domain decomposition methods are, alongside multigrid methods, one of the dominant paradigms in contemporary large-scale partial differential equation simulation. In this paper, a lightweight implementation of a theoretically and numerically scalable preconditioner is presented in the context of overlapping methods. The performance of this work is assessed by numerical simulations executed on thousands of cores, for solving various highly heterogeneous elliptic problems in both 2D and 3D with billions of degrees of freedom. Such problems arise in computational science and engineering, in solid and fluid mechanics. While focusing on overlapping domain decomposition methods might seem too restrictive, it will be shown how this work can be applied to a variety of other methods, such as non-overlapping methods and abstract deflation based preconditioners. It is also presented how multilevel preconditioners can be used to avoid communication during an iterative process such as a Krylov method.

Rolling Element Bearing Performance Degradation Assessment Using Variational Mode Decomposition and Gath-Geva Clustering Time Series Segmentation

Directory of Open Access Journals (Sweden)

Yaolong Li

2017-01-01

Full Text Available By focusing on the issue of rolling element bearing (REB performance degradation assessment (PDA, a solution based on variational mode decomposition (VMD and Gath-Geva clustering time series segmentation (GGCTSS has been proposed. VMD is a new decomposition method. Since it is different from the recursive decomposition method, for example, empirical mode decomposition (EMD, local mean decomposition (LMD, and local characteristic-scale decomposition (LCD, VMD needs a priori parameters. In this paper, we will propose a method to optimize the parameters in VMD, namely, the number of decomposition modes and moderate bandwidth constraint, based on genetic algorithm. Executing VMD with the acquired parameters, the BLIMFs are obtained. By taking the envelope of the BLIMFs, the sensitive BLIMFs are selected. And then we take the amplitude of the defect frequency (ADF as a degradative feature. To get the performance degradation assessment, we are going to use the method called Gath-Geva clustering time series segmentation. Afterwards, the method is carried out by two pieces of run-to-failure data. The results indicate that the extracted feature could depict the process of degradation precisely.

Decomposition dynamic of two aquatic macrophytes Trapa bispinosa Roxb. and Nelumbo nucifera detritus.

Science.gov (United States)

Zhou, Xiaohong; Feng, Deyou; Wen, Chunzi; Liu, Dan

2018-03-29

In freshwater ecosystems, aquatic macrophytes play significant roles in nutrient cycling. One problem in this process is nutrient loss in the tissues of untimely harvested plants. In this study, we used two aquatic species, Nelumbo nucifera and Trapa bispinosa Roxb., to investigate the decomposition dynamics and nutrient release from detritus. Litter bags containing 10 g of stems (plus petioles) and leaves for each species detritus were incubated in the pond from November 2016 to May 2017. Nine times litterbags were retrieved on days 6, 14, 25, 45, 65, 90, 125, 145, and 165 after the decomposition experiment for the monitoring of biomass loss and nutrient release. The results suggested that the dry masses of N. nucifera and T. bispinosa decomposed by 49.35-69.40 and 82.65-91.65%, respectively. The order of decomposition rate constants (k) is as follows: leaves of T. bispinosa (0.0122 day -1 ) > stems (plus petioles) of T. bispinosa (0.0090 day -1 ) > leaves of N. nucifera (0.0060 day -1 ) > stems (plus petioles) of N. nucifera (0.0030 day -1 ). Additionally, the orders of time for 50% dry mass decay, time for 95% dry mass decay, and turnover rate are as follows: leaves  0.05). In addition, the decomposition time had also significant effects on the detritus decomposition dynamic and nutrient release. However, the contributors of species and decomposition time on detritus decomposition were significantly different on the basis of their F values of two-way ANOVA results. This study can provide scientific bases for the aquatic plant scientific management in freshwater ecosystems of the East region of China.

Influence of concentration on the radiolytic decomposition of thiamine, riboflavin, and pyridoxine in aqueous solution

Directory of Open Access Journals (Sweden)

Guadalupe Albarrán

2014-10-01

Full Text Available Vitamin loss during irradiation has been claimed as a critical area in food irradiation technology, especially that of thiamine (B1, which has been considered as the most sensitive to radiation. Although it has been suggested that no vitamin deficiency could result from consuming irradiated food, a long debate on the loss of vitamins and other nutrients during food irradiation has been maintained by the lack of experimental studies monitoring decomposition rates at different concentrations and doses. Since thiamine, riboflavin, and pyridoxine are labile vitamins, this study has focused on their radiolytic decomposition in dilute aqueous solutions in the presence of air. The decomposition process was followed by HPLC and UV-spectroscopy. The results obtained in aqueous solutions showed a dependence of the decomposition as a nonlinear function of the dose. Of these three compounds, the decomposition was higher for thiamine than for riboflavin and even less in pyridoxine.

Ultrafine ferromagnetic iron oxide nanoparticles: Facile synthesis by low temperature decomposition of iron glycerolate

Energy Technology Data Exchange (ETDEWEB)

Bartůněk, Vilém, E-mail: vilem.bartunek@vscht.cz [Department of Inorganic Chemistry, Faculty of Chemical Technology, University of Chemistry and Technology, Technická 5, 166 28 Prague 6 (Czech Republic); Průcha, David [Department of Inorganic Chemistry, Faculty of Chemical Technology, University of Chemistry and Technology, Technická 5, 166 28 Prague 6 (Czech Republic); Švecová, Marie [Department of Analytical Chemistry, Faculty of Chemical Engineering, University of Chemistry and Technology, Technická 5, 166 28 Prague 6 (Czech Republic); Ulbrich, Pavel [Department of Biochemistry and Microbiology, Faculty of Food and Biochemical Technology, University of Chemistry and Technology, Technická 3, 166 28 Prague 6 (Czech Republic); Huber, Štěpán; Sedmidubský, David; Jankovský, Ondřej [Department of Inorganic Chemistry, Faculty of Chemical Technology, University of Chemistry and Technology, Technická 5, 166 28 Prague 6 (Czech Republic)

2016-09-01

We synthesized dark colored ultrafine – sub 10 nm iron oxide nanoparticles by a facile and low temperature process based on thermal decomposition of an affordable precursor – iron glycerolate. Simultaneous thermal analysis (STA) was used to study the thermal behaviour during the decomposition. The iron glycerolate was thoroughly analysed by various methods. The size of the iron nanoparticles was determined from XRD patterns and by transmission electron microscopy (TEM) and their composition has been confirmed by XPS. Magnetic properties of the nanoparticles were studied by vibrating sample magnetometry. The prepared single phase material exhibiting ferromagnetic properties is usable in a wide range of applications and may be suitable even for large scale industrial applications. - Highlights: • Iron glycerolate prepared and characterised. • Iron oxide nanoparticles prepared by thermal decomposition of iron glycerolate. • STA used to study the decomposition. • Products characterised by XRD, XPS, FT-IR, SEM and TEM. • Magnetic behaviour of monophasic samples determined.

Enzyme activities at different stages of plant biomass decomposition in three species of fungus-growing termites

DEFF Research Database (Denmark)

da Costa, Rafael R.; Hu, Haofu; Pilgaard, Bo

2018-01-01

contributing to the success of the termites as the main plant decomposers in the Old World. Here we evaluate which plant polymers are decomposed and which enzymes are active during the decomposition process in two major genera of fungus-growing termites. We find a diversity of active enzymes at different...... stages of decomposition and a consistent decrease in plant components during the decomposition process. Furthermore, our findings are consistent with the hypothesis that termites transport enzymes from the older mature parts of the fungus comb through young worker guts to freshly inoculated plant...... substrate. However, preliminary fungal RNAseq analyses suggest that this likely transport is supplemented with enzymes produced in situ Our findings support that the maintenance of an external fungus comb, inoculated with an optimal mix of plant material, fungal spores, and enzymes, is likely the key...

Modeling multipulsing transition in ring cavity lasers with proper orthogonal decomposition

International Nuclear Information System (INIS)

Ding, Edwin; Shlizerman, Eli; Kutz, J. Nathan

2010-01-01

A low-dimensional model is constructed via the proper orthogonal decomposition (POD) to characterize the multipulsing phenomenon in a ring cavity laser mode locked by a saturable absorber. The onset of the multipulsing transition is characterized by an oscillatory state (created by a Hopf bifurcation) that is then itself destabilized to a double-pulse configuration (by a fold bifurcation). A four-mode POD analysis, which uses the principal components, or singular value decomposition modes, of the mode-locked laser, provides a simple analytic framework for a complete characterization of the entire transition process and its associated bifurcations. These findings are in good agreement with the full governing equation.

Adaptive Fourier decomposition based R-peak detection for noisy ECG Signals.

Science.gov (United States)

Ze Wang; Chi Man Wong; Feng Wan

2017-07-01

An adaptive Fourier decomposition (AFD) based R-peak detection method is proposed for noisy ECG signals. Although lots of QRS detection methods have been proposed in literature, most detection methods require high signal quality. The proposed method extracts the R waves from the energy domain using the AFD and determines the R-peak locations based on the key decomposition parameters, achieving the denoising and the R-peak detection at the same time. Validated by clinical ECG signals in the MIT-BIH Arrhythmia Database, the proposed method shows better performance than the Pan-Tompkin (PT) algorithm in both situations of a native PT and the PT with a denoising process.

Thermal Decomposition Characteristics of Orthorhombic Ammonium Perchlorate (o-AP) and an 0-AP/HTPB-Based Propellant

International Nuclear Information System (INIS)

BEHRENS JR., RICHARD; MINIER, LEANNA M.G.

1999-01-01

A study to characterize the low-temperature reactive processes for o-AP and an AP/HTPB-based propellant (class 1.3) is being conducted in the laboratory using the techniques of simultaneous thermogravimetric modulated beam mass spectrometry (STMBMS) and scanning electron microscopy (SEM). The results presented in this paper are a follow up of the previous work that showed the overall decomposition to be complex and controlled by both physical and chemical processes. The decomposition is characterized by the occurrence of one major event that consumes up to(approx)35% of the AP, depending upon particle size, and leaves behind a porous agglomerate of AP. The major gaseous products released during this event include H(sub 2)O, O(sub 2), Cl(sub 2), N(sub 2)O and HCl. The recent efforts provide further insight into the decomposition processes for o-AP. The temporal behaviors of the gas formation rates (GFRs) for the products indicate that the major decomposition event consists of three chemical channels. The first and third channels are affected by the pressure in the reaction cell and occur at the surface or in the gas phase above the surface of the AP particles. The second channel is not affected by pressure and accounts for the solid-phase reactions characteristic of o-AP. The third channel involves the interactions of the decomposition products with the surface of the AP. SEM images of partially decomposed o-AP provide insight to how the morphology changes as the decomposition progresses. A conceptual model has been developed, based upon the STMBMS and SEM results, that provides a basic description of the processes. The thermal decomposition characteristics of the propellant are evaluated from the identities of the products and the temporal behaviors of their GFRs. First, the volatile components in the propellant evolve from the propellant as it is heated. Second, the hot AP (and HClO(sub 4)) at the AP-binder interface oxidize the binder through reactions that

Investigation of the decomposition reaction and dust explosion characteristics of crystalline benzoyl peroxides

International Nuclear Information System (INIS)

Lu, K.-T.; Chen, T.-C.; Hu, K.-H.

2009-01-01

The benzoyl peroxide (BPO) is widely used in the chemical industry. Many catastrophes have been caused by its thermal instability or reactive incompatibility in storage or thermal decomposition reaction. Thus, its hazard characteristics have to be clearly identified. First of all, the differential scanning calorimeter (DSC) is used to measure the heat of decomposition reaction, which can contribute to understanding the reaction characteristics of benzoyl peroxide. The accelerating rate calorimeter (ARC) is used to measure the rates of temperature and pressure rises of decomposition reaction, and then the kinetics parameters are estimated. Furthermore, the MIKE 3 apparatus and the 20-l-Apparatus are used to measure and analyze the dust explosion characteristics of benzoyl peroxide under room temperature and atmospheric pressure. Finally, Semenov's thermal explosion theory is applied to investigate the critical runaway condition and the stability criterion of decomposition reaction, and to build the relationship of critical temperature, convective heat transfer coefficient, heat transfer surface area and ambient temperature. These results contribute to improving the safety in the reaction, transportation and storage processes of benzoyl peroxide

High-temperature Raman study of L-alanine, L-threonine and taurine crystals related to thermal decomposition

Energy Technology Data Exchange (ETDEWEB)

Cavaignac, A.L.O. [Centro de Ciências Sociais, Saúde e Tecnologia, Universidade Federal do Maranhão, Imperatriz, MA 65900-410 (Brazil); Lima, R.J.C., E-mail: ricardo.lima.ufma@gmail.com [Centro de Ciências Sociais, Saúde e Tecnologia, Universidade Federal do Maranhão, Imperatriz, MA 65900-410 (Brazil); Façanha Filho, P.F. [Centro de Ciências Sociais, Saúde e Tecnologia, Universidade Federal do Maranhão, Imperatriz, MA 65900-410 (Brazil); Moreno, A.J.D. [Coordenação de Ciências Naturais, Universidade Federal do Maranhão, Bacabal, MA 65700-000 (Brazil); Freire, P.T.C. [Departamento de Física, Universidade Federal do Ceará, Fortaleza, CE 60455-760 (Brazil)

2016-03-01

In this work high-temperature Raman spectra are used to compare temperature dependence of the lattice mode wavenumber of L-alanine, L-threonine and taurine crystals. Anharmonic effects observed are associated with intermolecular N-H· · ·O hydrogen bond that plays an important role in thermal decomposition process of these materials. Short and strong hydrogen bonds in L-alanine crystal were associated with anharmonic effects in lattice modes leading to low thermal stability compared to taurine crystals. Connection between thermal decomposition process and anharmonic effects is furnished for the first time.

High-temperature Raman study of L-alanine, L-threonine and taurine crystals related to thermal decomposition

International Nuclear Information System (INIS)

Cavaignac, A.L.O.; Lima, R.J.C.; Façanha Filho, P.F.; Moreno, A.J.D.; Freire, P.T.C.

2016-01-01

In this work high-temperature Raman spectra are used to compare temperature dependence of the lattice mode wavenumber of L-alanine, L-threonine and taurine crystals. Anharmonic effects observed are associated with intermolecular N-H· · ·O hydrogen bond that plays an important role in thermal decomposition process of these materials. Short and strong hydrogen bonds in L-alanine crystal were associated with anharmonic effects in lattice modes leading to low thermal stability compared to taurine crystals. Connection between thermal decomposition process and anharmonic effects is furnished for the first time.

Magic Coset Decompositions

CERN Document Server

Cacciatori, Sergio L; Marrani, Alessio

2013-01-01

By exploiting a "mixed" non-symmetric Freudenthal-Rozenfeld-Tits magic square, two types of coset decompositions are analyzed for the non-compact special K\\"ahler symmetric rank-3 coset E7(-25)/[(E6(-78) x U(1))/Z_3], occurring in supergravity as the vector multiplets' scalar manifold in N=2, D=4 exceptional Maxwell-Einstein theory. The first decomposition exhibits maximal manifest covariance, whereas the second (triality-symmetric) one is of Iwasawa type, with maximal SO(8) covariance. Generalizations to conformal non-compact, real forms of non-degenerate, simple groups "of type E7" are presented for both classes of coset parametrizations, and relations to rank-3 simple Euclidean Jordan algebras and normed trialities over division algebras are also discussed.

Sponge-like silver obtained by decomposition of silver nitrate hexamethylenetetramine complex

Energy Technology Data Exchange (ETDEWEB)

Afanasiev, Pavel, E-mail: pavel.afanasiev@ircelyon.univ-lyon.fr

2016-07-15

Silver nitrate hexamethylenetetramine [Ag(NO{sub 3})·N{sub 4}(CH{sub 2}){sub 6}] coordination compound has been prepared via aqueous route and characterized by chemical analysis, XRD and electron microscopy. Decomposition of [Ag(NO{sub 3})·N{sub 4}(CH{sub 2}){sub 6}] under hydrogen and under inert has been studied by thermal analysis and mass spectrometry. Thermal decomposition of [Ag(NO{sub 3})·N{sub 4}(CH{sub 2}){sub 6}] proceeds in the range 200–250 °C as a self-propagating rapid redox process accompanied with the release of multiple gases. The decomposition leads to formation of sponge-like silver having hierarchical open pore system with pore size spanning from 10 µm to 10 nm. The as-obtained silver sponges exhibited favorable activity toward H{sub 2}O{sub 2} electrochemical reduction, making them potentially interesting as non-enzyme hydrogen peroxide sensors. - Graphical abstract: Thermal decomposition of silver nitrate hexamethylenetetramine coordination compound [Ag(NO{sub 3})·N{sub 4}(CH{sub 2}){sub 6}] leads to sponge like silver that possesses open porous structure and demonstrates interesting properties as an electrochemical hydrogen peroxide sensor. Display Omitted - Highlights: • [Ag(NO{sub 3})·N{sub 4}(CH{sub 2}){sub 6}] orthorhombic phase prepared and characterized. • Decomposition of [Ag(NO{sub 3})·N{sub 4}(CH{sub 2}){sub 6}] leads to metallic silver sponge with opened porosity. • Ag sponge showed promising properties as a material for hydrogen peroxide sensors.

A Longitudinal Study of Decomposition Odour in Soil Using Sorbent Tubes and Solid Phase Microextraction

Directory of Open Access Journals (Sweden)

Katelynn A. Perrault

2014-07-01

Full Text Available Odour profiling of decomposed remains is important for understanding the mechanisms that cadaver dogs and forensically-relevant insects use to locate decomposed remains. The decomposition odour profile is complex and has been documented in outdoor terrestrial environments. The purpose of this study was to perform longitudinal analysis of the volatile organic compound (VOC profile in soils associated with decomposed remains across all stages of decomposition. Two VOC collection techniques (sorbent tubes and solid phase microextraction were used to collect a wider analyte range and to investigate differences in collection techniques. Pig carcasses were placed in an outdoor research facility in Australia to model the decomposition process and VOCs were collected intermittently over two months. VOCs of interest were identified over the duration of the trial, showing distinct trends in compound evolution and disappearance. The collection techniques were complementary, representing different subsets of VOCs from the overall profile. Sorbent tubes collected more decomposition-specific VOCs and these compounds were more effective at characterising the matrix over an extended period. Using both collection techniques improves the likelihood of identifying the complete VOC profile of decomposition odour. Such information is important for the search and recovery of victim remains in various stages of decomposition.

Decomposition of rice residue in tropical soils, 2

International Nuclear Information System (INIS)

Yoneyama, Tadakatsu; Yoshida, Tomio

1977-01-01

The decomposition processes of intact rice residue (leaf blades) in the Maahas soil in the Philippines were investigated. Three sets of beakers simulating both lowland and upland conditions were incubated in the dark at 30 deg. C. One set of beakers had neither rice residue nor fertilizer. Pieces of leaf blades weighing 204 mg (dry weight) were inserted in the second set. Pieces of leaf blades were inserted in the third set, and 200 ppm of fertilizer nitrogen as 15 N-labelled ammonium sulfate was added. The experiment dealt with the nitrogen immobilization by rice residue under lowland and upland conditions. The rice residue which has contained low nitrogen absorbed nitrogen from the soil and from the added fertilizer (ammonium sulfate) during its decomposition under both conditions. Under the lowland condition, the amount of nitrogen immobilized was small during the first week, but became large after 2 or 3 weeks. Under the upland condition, the immobilized nitrogen reached its maximum during the first week, but the amount was not so large as that under the lowland condition. The added fertilizer stimulated the decrease of weight of the rice residue in the early incubation period, but retarded it later under both conditions. The absorption of fertilizer by the rice residue ceased at the early stage of residue decomposition, but the nitrogen content of the residue continued to increase. (Iwakiri, K.)

A Robust Color Image Watermarking Scheme Using Entropy and QR Decomposition

Directory of Open Access Journals (Sweden)

L. Laur

2015-12-01

Full Text Available Internet has affected our everyday life drastically. Expansive volumes of information are exchanged over the Internet consistently which causes numerous security concerns. Issues like content identification, document and image security, audience measurement, ownership, copyrights and others can be settled by using digital watermarking. In this work, robust and imperceptible non-blind color image watermarking algorithm is proposed, which benefit from the fact that watermark can be hidden in different color channel which results into further robustness of the proposed technique to attacks. Given method uses some algorithms such as entropy, discrete wavelet transform, Chirp z-transform, orthogonal-triangular decomposition and Singular value decomposition in order to embed the watermark in a color image. Many experiments are performed using well-known signal processing attacks such as histogram equalization, adding noise and compression. Experimental results show that proposed scheme is imperceptible and robust against common signal processing attacks.

Succession change of microorganisms on plant waste decomposition in simulation modelling field experiment

Science.gov (United States)

Vinogradova, Julia; Perminova, Evgenia; Khabibullina, Fluza; Kovaleva, Vera; Lapteva, Elena

2016-04-01

Plant waste decomposition processes are closely associated with living activity of soil microbiota in aboveground ecosystems. Functional activity of microorganisms and soil invertebrates determines plant material transformation rate whereby changes in plant material chemical composition during destruction - succession change of soil biota. The purpose of the work was revealing the mechanism of microorganisms succession change during plant waste decomposition in middle-taiga green-moss spruce forests and coniferous-deciduous secondary stands formed after earlier cut bilberry spruce forests. The study materials were undisturbed bilberry spruce forest (Sample Plot 1 - SP1) and coniferous-deciduous secondary stands which were formed after tree cutting activities of 2001-2002 (SP2) and 1969 and 1970 (SP3). Plant material decomposition intensity was determined in microcosms isolated into kapron bags with cell size of 1 mm. At SP1 and SP2, test material was living mosses and at SP3 - fallen birch and aspen leaves. Every test material was exposed for 2 years. Destruction rate was calculated as a weight loss for a particular time period. Composition of micromycetes which participated in plant material decomposition was assessed by the method of inoculation of soil extract to Getchinson's medium and acidified Czapek's medium (pH=4.5). Microbe number and biomass was analyzed by the method of luminescent microscopy. Chemical analysis of plant material was done in the certified Ecoanalytical Laboratory of the Institute of Biology Komi SC UrD RAS. Finally, plant material destruction intensity was similar for study plots and comprised 40-44 % weight loss for 2 years. The strongest differences in plant material decomposition rate between undisturbed spruce forests and secondary after-cut stands were observed at first stages of destruction process. In the first exposition year, mineralizing processes were most active in undisturbed spruce forest. Decomposition rate in cuts at that

On the hadron mass decomposition

Science.gov (United States)

Lorcé, Cédric

2018-02-01

We argue that the standard decompositions of the hadron mass overlook pressure effects, and hence should be interpreted with great care. Based on the semiclassical picture, we propose a new decomposition that properly accounts for these pressure effects. Because of Lorentz covariance, we stress that the hadron mass decomposition automatically comes along with a stability constraint, which we discuss for the first time. We show also that if a hadron is seen as made of quarks and gluons, one cannot decompose its mass into more than two contributions without running into trouble with the consistency of the physical interpretation. In particular, the so-called quark mass and trace anomaly contributions appear to be purely conventional. Based on the current phenomenological values, we find that in average quarks exert a repulsive force inside nucleons, balanced exactly by the gluon attractive force.

On the hadron mass decomposition

Energy Technology Data Exchange (ETDEWEB)

Lorce, Cedric [Universite Paris-Saclay, Centre de Physique Theorique, Ecole Polytechnique, CNRS, Palaiseau (France)

2018-02-15

We argue that the standard decompositions of the hadron mass overlook pressure effects, and hence should be interpreted with great care. Based on the semiclassical picture, we propose a new decomposition that properly accounts for these pressure effects. Because of Lorentz covariance, we stress that the hadron mass decomposition automatically comes along with a stability constraint, which we discuss for the first time. We show also that if a hadron is seen as made of quarks and gluons, one cannot decompose its mass into more than two contributions without running into trouble with the consistency of the physical interpretation. In particular, the so-called quark mass and trace anomaly contributions appear to be purely conventional. Based on the current phenomenological values, we find that in average quarks exert a repulsive force inside nucleons, balanced exactly by the gluon attractive force. (orig.)

A stochastic model for an urea decomposition system

Directory of Open Access Journals (Sweden)

VSS Yadavalli

2005-12-01

Full Text Available Availability is an important measure in describing the performance of a system. The availability of a decomposition process in an urea production system in the fertilizer industry is considered in this paper. The system contains four subsystems and is supported by a standby unit. An estimation study of the steady state availability of the system is performed and illustrated by means of a numerical example.

Bacterial Community Succession in Pine-Wood Decomposition.

Science.gov (United States)

Kielak, Anna M; Scheublin, Tanja R; Mendes, Lucas W; van Veen, Johannes A; Kuramae, Eiko E

2016-01-01

Though bacteria and fungi are common inhabitants of decaying wood, little is known about the relationship between bacterial and fungal community dynamics during natural wood decay. Based on previous studies involving inoculated wood blocks, strong fungal selection on bacteria abundance and community composition was expected to occur during natural wood decay. Here, we focused on bacterial and fungal community compositions in pine wood samples collected from dead trees in different stages of decomposition. We showed that bacterial communities undergo less drastic changes than fungal communities during wood decay. Furthermore, we found that bacterial community assembly was a stochastic process at initial stage of wood decay and became more deterministic in later stages, likely due to environmental factors. Moreover, composition of bacterial communities did not respond to the changes in the major fungal species present in the wood but rather to the stage of decay reflected by the wood density. We concluded that the shifts in the bacterial communities were a result of the changes in wood properties during decomposition and largely independent of the composition of the wood-decaying fungal communities.

Optimization and kinetics decomposition of monazite using NaOH

International Nuclear Information System (INIS)

MV Purwani; Suyanti; Deddy Husnurrofiq

2015-01-01

Decomposition of monazite with NaOH has been done. Decomposition performed at high temperature on furnace. The parameters studied were the comparison NaOH / monazite, temperature and time decomposition. From the research decomposition for 100 grams of monazite with NaOH, it can be concluded that the greater the ratio of NaOH / monazite, the greater the conversion. In the temperature influences decomposition 400 - 700°C, the greater the reaction rate constant with increasing temperature greater decomposition. Comparison NaOH / monazite optimum was 1.5 and the optimum time of 3 hours. Relations ratio NaOH / monazite with conversion (x) following the polynomial equation y = 0.1579x 2 – 0.2855x + 0.8301 (y = conversion and x = ratio of NaOH/monazite). Decomposition reaction of monazite with NaOH was second orde reaction, the relationship between temperature (T) with a reaction rate constant (k), k = 6.106.e - 1006.8 /T or ln k = - 1006.8/T + 6.106, frequency factor A = 448.541, activation energy E = 8.371 kJ/mol. (author)

Decomposition of clofibric acid in aqueous media by advance oxidation techniques: kinetics study and degradation pathway

International Nuclear Information System (INIS)

Syed, M.; Khan, A.M.; Khan, R.A.

2016-01-01

This study investigates the decomposition of clofibric acid (CLF) by different advanced oxidation processes (AOPs), such as UV (254 nm), VUV (185 nm), UV / TiO/sub 2/ and VUV / TiO/sub 2/. The removal efficiencies of applied AOPs were compared in the presence and absence of dissolved oxygen. The removal efficiency of the studied AOPs towards degradation of CLF were found in the order of VUV / TiO/sub 2/ + O/sub 2/ > VUV/TiO/sub 2/ + N/sub 2/ > VUV alone > UV / TiO/sub 2/ + O/sub 2/ > UV / TiO/sub 2/ +N/sub 2/ > UV alone. The decomposition kinetics of CLF was found to follow pseudo-first order rate law. VUV / TiO2 process was found to be most cheap and effective one for decomposition of CLF as compared to other applied AOPs in terms of electrical energy per order. Degradation products resulting from the degradation processes were also investigated using UPLC-MS /MS, accordingly degradation pathway was proposed. (author)

Combinatorial geometry domain decomposition strategies for Monte Carlo simulations

Energy Technology Data Exchange (ETDEWEB)

Li, G.; Zhang, B.; Deng, L.; Mo, Z.; Liu, Z.; Shangguan, D.; Ma, Y.; Li, S.; Hu, Z. [Institute of Applied Physics and Computational Mathematics, Beijing, 100094 (China)

2013-07-01

Analysis and modeling of nuclear reactors can lead to memory overload for a single core processor when it comes to refined modeling. A method to solve this problem is called 'domain decomposition'. In the current work, domain decomposition algorithms for a combinatorial geometry Monte Carlo transport code are developed on the JCOGIN (J Combinatorial Geometry Monte Carlo transport INfrastructure). Tree-based decomposition and asynchronous communication of particle information between domains are described in the paper. Combination of domain decomposition and domain replication (particle parallelism) is demonstrated and compared with that of MERCURY code. A full-core reactor model is simulated to verify the domain decomposition algorithms using the Monte Carlo particle transport code JMCT (J Monte Carlo Transport Code), which has being developed on the JCOGIN infrastructure. Besides, influences of the domain decomposition algorithms to tally variances are discussed. (authors)

Combinatorial geometry domain decomposition strategies for Monte Carlo simulations

International Nuclear Information System (INIS)

Li, G.; Zhang, B.; Deng, L.; Mo, Z.; Liu, Z.; Shangguan, D.; Ma, Y.; Li, S.; Hu, Z.

2013-01-01

Analysis and modeling of nuclear reactors can lead to memory overload for a single core processor when it comes to refined modeling. A method to solve this problem is called 'domain decomposition'. In the current work, domain decomposition algorithms for a combinatorial geometry Monte Carlo transport code are developed on the JCOGIN (J Combinatorial Geometry Monte Carlo transport INfrastructure). Tree-based decomposition and asynchronous communication of particle information between domains are described in the paper. Combination of domain decomposition and domain replication (particle parallelism) is demonstrated and compared with that of MERCURY code. A full-core reactor model is simulated to verify the domain decomposition algorithms using the Monte Carlo particle transport code JMCT (J Monte Carlo Transport Code), which has being developed on the JCOGIN infrastructure. Besides, influences of the domain decomposition algorithms to tally variances are discussed. (authors)

Dinner in the dark: Illuminating drivers of soil organic matter decomposition

NARCIS (Netherlands)

van der Wal, Annemieke; De Boer, Wietse

Abstract Soil organic matter (SOM) dynamics plays a crucial role in soil ecosystem functioning and global warming. SOM is normally degraded slowly, but its decomposition rate can change substantially after addition of easily decomposable C sources. This process, known as “the priming effect”, has

Decompositional equivalence: A fundamental symmetry underlying quantum theory

OpenAIRE

Fields, Chris

2014-01-01

Decompositional equivalence is the principle that there is no preferred decomposition of the universe into subsystems. It is shown here, by using simple thought experiments, that quantum theory follows from decompositional equivalence together with Landauer's principle. This demonstration raises within physics a question previously left to psychology: how do human - or any - observers agree about what constitutes a "system of interest"?

Calcined hydrotalcites for the catalytic decomposition of N{sub 2}O in simulated process streams

Energy Technology Data Exchange (ETDEWEB)

Armor, J.N.; Braymer, T.A.; Farris, T.S.; Li, Y.; Petrocelli, F.P.; Weist, E.L. [Air Products and Chemicals, Inc., Allentown, PA (United States); Kannan, S.; Swamy, C.S. [Department of Chemistry, Indian Institute of Technology, Madras (India)

1996-01-18

Various hydrotalcite based catalysts were prepared for testing for the catalytic decomposition of N{sub 2}O. Co-Al, Ni-Al, Co/Pd-Al, Co/Rh-Al, and Co/Mg-Al substituted hydrotalcites and Co-La-Al hydroxides offer very good activity at modest temperatures. Precalcination of these materials at ca. 450-500C, which destroys the hydrotalcite phase, is necessary for optimum activity and life. For Co substituted hydrotalcites, the optimal ratio of Co/Al is 3.0. The temperature for 50% conversion of N{sub 2}O of these calcined cobalt hydrotalcites is ca. 75C lower than for the previous highly active Co-ZSM-5. These calcined cobalt hydrotalcite materials display sustained life at temperatures in excess of 670C in an O{sub 2} rich, wet stream with high levels of N{sub 2}O (10%). Excess O{sub 2} does not seriously impact N{sub 2}O decomposition, but the combination of both water vapor and O{sub 2} does reduce activity by ca. 50%

A Long-Life Lithium-Air Battery in Ambient Air with a Polymer Electrolyte Containing a Redox Mediator.

Science.gov (United States)

Guo, Ziyang; Li, Chao; Liu, Jingyuan; Wang, Yonggang; Xia, Yongyao

2017-06-19

Lithium-air batteries when operated in ambient air generally exhibit poor reversibility and cyclability, because of the Li passivation and Li 2 O 2 /LiOH/Li 2 CO 3 accumulation in the air electrode. Herein, we present a Li-air battery supported by a polymer electrolyte containing 0.05 m LiI, in which the polymer electrolyte efficiently alleviates the Li passivation induced by attacking air. Furthermore, it is demonstrated that I - /I 2 conversion in polymer electrolyte acts as a redox mediator that facilitates electrochemical decomposition of the discharge products during recharge process. As a result, the Li-air battery can be stably cycled 400 times in ambient air (relative humidity of 15 %), which is much better than previous reports. The achievement offers a hope to develop the Li-air battery that can be operated in ambient air. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Increased rainfall variability and N addition accelerate litter decomposition in a restored prairie.

Science.gov (United States)

Schuster, Michael J

2016-03-01

Anthropogenic nitrogen deposition and projected increases in rainfall variability (the frequency of drought and heavy rainfall events) are expected to strongly influence ecosystem processes such as litter decomposition. However, how these two global change factors interact to influence litter decomposition is largely unknown. I examined how increased rainfall variability and nitrogen addition affected mass and nitrogen loss of litter from two tallgrass prairie species, Schizachyrium scoparium and Solidago canadensis, and isolated the effects of each during plant growth and during litter decomposition. I increased rainfall variability by consolidating ambient rainfall into larger events and simulated chronic nitrogen deposition using a slow-release urea fertilizer. S. scoparium litter decay was more strongly regulated by the treatments applied during plant growth than by those applied during decomposition. During plant growth, increased rainfall variability resulted in S. scoparium litter that subsequently decomposed more slowly and immobilized more nitrogen than litter grown under ambient conditions, whereas nitrogen addition during plant growth accelerated subsequent mass loss of S. scoparium litter. In contrast, S. canadensis litter mass and N losses were enhanced under either N addition or increased rainfall variability both during plant growth and during decomposition. These results suggest that ongoing changes in rainfall variability and nitrogen availability are accelerating nutrient cycling in tallgrass prairies through their combined effects on litter quality, environmental conditions, and plant community composition.

Communication strategies for angular domain decomposition of transport calculations on message passing multiprocessors

International Nuclear Information System (INIS)

Azmy, Y.Y.

1997-01-01

The effect of three communication schemes for solving Arbitrarily High Order Transport (AHOT) methods of the Nodal type on parallel performance is examined via direct measurements and performance models. The target architecture in this study is Oak Ridge National Laboratory's 128 node Paragon XP/S 5 computer and the parallelization is based on the Parallel Virtual Machine (PVM) library. However, the conclusions reached can be easily generalized to a large class of message passing platforms and communication software. The three schemes considered here are: (1) PVM's global operations (broadcast and reduce) which utilizes the Paragon's native corresponding operations based on a spanning tree routing; (2) the Bucket algorithm wherein the angular domain decomposition of the mesh sweep is complemented with a spatial domain decomposition of the accumulation process of the scalar flux from the angular flux and the convergence test; (3) a distributed memory version of the Bucket algorithm that pushes the spatial domain decomposition one step farther by actually distributing the fixed source and flux iterates over the memories of the participating processes. Their conclusion is that the Bucket algorithm is the most efficient of the three if all participating processes have sufficient memories to hold the entire problem arrays. Otherwise, the third scheme becomes necessary at an additional cost to speedup and parallel efficiency that is quantifiable via the parallel performance model

Generalized Fisher index or Siegel-Shapley decomposition?

International Nuclear Information System (INIS)

De Boer, Paul

2009-01-01

It is generally believed that index decomposition analysis (IDA) and input-output structural decomposition analysis (SDA) [Rose, A., Casler, S., Input-output structural decomposition analysis: a critical appraisal, Economic Systems Research 1996; 8; 33-62; Dietzenbacher, E., Los, B., Structural decomposition techniques: sense and sensitivity. Economic Systems Research 1998;10; 307-323] are different approaches in energy studies; see for instance Ang et al. [Ang, B.W., Liu, F.L., Chung, H.S., A generalized Fisher index approach to energy decomposition analysis. Energy Economics 2004; 26; 757-763]. In this paper it is shown that the generalized Fisher approach, introduced in IDA by Ang et al. [Ang, B.W., Liu, F.L., Chung, H.S., A generalized Fisher index approach to energy decomposition analysis. Energy Economics 2004; 26; 757-763] for the decomposition of an aggregate change in a variable in r = 2, 3 or 4 factors is equivalent to SDA. They base their formulae on the very complicated generic formula that Shapley [Shapley, L., A value for n-person games. In: Kuhn H.W., Tucker A.W. (Eds), Contributions to the theory of games, vol. 2. Princeton University: Princeton; 1953. p. 307-317] derived for his value of n-person games, and mention that Siegel [Siegel, I.H., The generalized 'ideal' index-number formula. Journal of the American Statistical Association 1945; 40; 520-523] gave their formulae using a different route. In this paper tables are given from which the formulae of the generalized Fisher approach can easily be derived for the cases of r = 2, 3 or 4 factors. It is shown that these tables can easily be extended to cover the cases of r = 5 and r = 6 factors. (author)

Technical and economic aspects of thermo-chemical decomposition of biomass in the processes of transformation of it in power-consuming energy/carriers by the use of the concentrated gel of sun radiation, has been considered

International Nuclear Information System (INIS)

Sultanova, K.D.; Mustafayeva, R.M.; Rzayev, P.F.

2007-01-01

Full text: The technical and economic assessment of process of thermo-chemical decomposition of biomass in the processes of transformation of it in power-consuming energy/carriers by the use of the concentrated gel of sun radiation, has been considered

Detecting the Extent of Cellular Decomposition after Sub-Eutectoid Annealing in Rolled UMo Foils

Energy Technology Data Exchange (ETDEWEB)

Kautz, Elizabeth J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Jana, Saumyadeep [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Devaraj, Arun [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Lavender, Curt A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Sweet, Lucas E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Joshi, Vineet V. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

2017-07-31

This report presents an automated image processing approach to quantifying microstructure image data, specifically the extent of eutectoid (cellular) decomposition in rolled U-10Mo foils. An image processing approach is used here to be able to quantitatively describe microstructure image data in order to relate microstructure to processing parameters (time, temperature, deformation).

[Litter decomposition and nutrient release in Acacia mangium plantations established on degraded soils of Colombia].

Science.gov (United States)

Castellanos-Barliza, Jeiner; León Peláez, Juan Diego

2011-03-01

Several factors control the decomposition in terrestrial ecosystems such as humidity, temperature, quality of litter and microbial activity. We investigated the effects of rainfall and soil plowing prior to the establishment of Acacia mangium plantations, using the litterbag technique, during a six month period, in forests plantations in Bajo Cauca region, Colombia. The annual decomposition constants (k) of simple exponential model, oscillated between 1.24 and 1.80, meanwhile k1 y k2 decomposition constants of double exponential model were 0.88-1.81 and 0.58-7.01. At the end of the study, the mean residual dry matter (RDM) was 47% of the initial value for the three sites. We found a slow N, Ca and Mg release pattern from the A. mangium leaf litter, meanwhile, phosphorus (P) showed a dominant immobilization phase, suggesting its low availability in soils. Chemical leaf litter quality parameters (e.g. N and P concentrations, C/N, N/P ratios and phenols content) showed an important influence on decomposition rates. The results of this study indicated that rainfall plays an important role on the decomposition process, but not soil plowing.

The functionalization of limonite to prepare NZVI and its application in decomposition of p-nitrophenol

Energy Technology Data Exchange (ETDEWEB)

Liu, Haibo; Chen, Tianhu, E-mail: chentianhu@hfut.edu.cn; Xie, Qiaoqin; Zou, Xuehua; Chen, Chen [Hefei University of Technology, Laboratory of Nanomineral and Environmental Material, School of Resources and Environmental Engineering (China); Frost, Ray L. [Queensland University of Technology, Science and Engineering Faculty, School of Chemistry, Physics and Mechanical Engineering (Australia)

2015-09-15

Nano zero valent iron (NZVI) was prepared by reducing natural limonite using hydrogen. X-ray fluorescence, thermogravimetry, X-ray diffraction, transmission electron microscope, temperature programmed reduction (TPR), field emission scanning electron microscope/energy disperse spectroscopy (FESEM/EDS) were utilized to characterize the natural limonite and reduced limonite. The ratios of Fe:O before and after reducing was determined using EDS. The reactivity of the NZVI was assessed by decomposition of p-nitrophenol (p-NP) and was compared with commercial iron powder. In this study, the results of TPR and FESEM/EDS indicated that NZVI can be prepared by reducing natural limonite using hydrogen. Most importantly, this NZVI was proved to have a good performance on decomposition of p-NP and the process of p-NP decomposition agreed well with the pseudo-first-order kinetic model. The reactivity of this NZVI for decomposition of p-NP was greatly superior to that of commercial iron powder.

In-situ electrochemical study of Zr1nb alloy corrosion in high temperature Li{sup +} containing water

Energy Technology Data Exchange (ETDEWEB)

Krausová, Aneta [University of Chemistry and Technology, Technická 3, 166 28 Prague 6 (Czech Republic); Macák, Jan, E-mail: macakj@vscht.cz [University of Chemistry and Technology, Technická 3, 166 28 Prague 6 (Czech Republic); Sajdl, Petr [University of Chemistry and Technology, Technická 3, 166 28 Prague 6 (Czech Republic); Novotný, Radek [JRC-IET, Westerduinveg 3, 1755 LE Petten (Netherlands); Renčiuková, Veronika [University of Chemistry and Technology, Technická 3, 166 28 Prague 6 (Czech Republic); Vrtílková, Věra [ÚJP a.s., Nad Kamínkou 1345, 156 10 Prague 5 (Czech Republic)

2015-12-15

Long-term in-situ corrosion tests were performed in order to evaluate the influence of lithium ions on the corrosion of zirconium alloy. Experiments were carried out in a high-pressure high-temperature loop (280 °C, 8 MPa) in a high concentration water solution of LiOH (70 and 200 ppm Li{sup +}) and in a simulated WWER primary coolant environment. The kinetic parameters characterising the oxidation process have been explored using in-situ electrochemical impedance spectroscopy and slow potentiodynamic polarization. Also, a suitable equivalent circuit was suggested, which would approximate the impedance characteristics of the corrosion of Zr–1Nb alloy. The Mott–Schottky approach was used to determine the semiconducting character of the passive film. - Highlights: • Zr1Nb alloy was tested in WWER coolant and in LiOH solutions at 280 °C. • Corrosion rates were estimated in-situ from electrochemical data. • Electrochemical data agreed well with weight gains and metallography data. • Increase of corrosion rate in LiOH appeared after short exposure (300–500 h). • Very high donor densities (1.1–1.2 × 10{sup 20} cm{sup −3}) of Zr oxide grown in LiOH were found.

Effects of radionuclide contamination on leaf litter decomposition in the Chernobyl exclusion zone

Energy Technology Data Exchange (ETDEWEB)

Bonzom, Jean-Marc, E-mail: jean-marc.bonzom@irsn.fr [Institut de Radioprotection et de Sûreté Nucléaire (IRSN), PRP-ENV/SERIS, Cadarache, Bât. 183, BP 3, 13115 St Paul-lez-Durance (France); Hättenschwiler, Stephan [Centre d' Ecologie Fonctionnelle et Evolutive (CEFE UMR 5175, CNRS–Université de Montpellier–Université Paul-Valéry Montpellier–EPHE), 1919 Route de Mende, F-34293 Montpellier (France); Lecomte-Pradines, Catherine [Institut de Radioprotection et de Sûreté Nucléaire (IRSN), PRP-ENV/SERIS, Cadarache, Bât. 183, BP 3, 13115 St Paul-lez-Durance (France); Chauvet, Eric [EcoLab, Université de Toulouse, CNRS, UPS, INPT, 118 Route de Narbonne, 31062 Toulouse cedex (France); Gaschak, Sergey [Chernobyl Center for Nuclear Safety, Radioactive Waste and Radioecology, International Radioecology Laboratory, 07100 Slavutych (Ukraine); Beaugelin-Seiller, Karine; Della-Vedova, Claire; Dubourg, Nicolas [Institut de Radioprotection et de Sûreté Nucléaire (IRSN), PRP-ENV/SERIS, Cadarache, Bât. 183, BP 3, 13115 St Paul-lez-Durance (France); Maksimenko, Andrey [Chernobyl Center for Nuclear Safety, Radioactive Waste and Radioecology, International Radioecology Laboratory, 07100 Slavutych (Ukraine); and others

2016-08-15

The effects of radioactive contamination on ecosystem processes such as litter decomposition remain largely unknown. Because radionuclides accumulated in soil and plant biomass can be harmful for organisms, the functioning of ecosystems may be altered by radioactive contamination. Here, we tested the hypothesis that decomposition is impaired by increasing levels of radioactivity in the environment by exposing uncontaminated leaf litter from silver birch and black alder at (i) eleven distant forest sites differing in ambient radiation levels (0.22–15 μGy h{sup −1}) and (ii) along a short distance gradient of radioactive contamination (1.2–29 μGy h{sup −1}) within a single forest in the Chernobyl exclusion zone. In addition to measuring ambient external dose rates, we estimated the average total dose rates (ATDRs) absorbed by decomposers for an accurate estimate of dose-induced ecological consequences of radioactive pollution. Taking into account potential confounding factors (soil pH, moisture, texture, and organic carbon content), the results from the eleven distant forest sites, and from the single forest, showed increased litter mass loss with increasing ATDRs from 0.3 to 150 μGy h{sup −1}. This unexpected result may be due to (i) overcompensation of decomposer organisms exposed to radionuclides leading to a higher decomposer abundance (hormetic effect), and/or (ii) from preferred feeding by decomposers on the uncontaminated leaf litter used for our experiment compared to locally produced, contaminated leaf litter. Our data indicate that radio-contamination of forest ecosystems over more than two decades does not necessarily have detrimental effects on organic matter decay. However, further studies are needed to unravel the underlying mechanisms of the results reported here, in order to draw firmer conclusions on how radio-contamination affects decomposition and associated ecosystem processes. - Highlights: • The effects of radioactivity on

Effects of radionuclide contamination on leaf litter decomposition in the Chernobyl exclusion zone

International Nuclear Information System (INIS)

Bonzom, Jean-Marc; Hättenschwiler, Stephan; Lecomte-Pradines, Catherine; Chauvet, Eric; Gaschak, Sergey; Beaugelin-Seiller, Karine; Della-Vedova, Claire; Dubourg, Nicolas; Maksimenko, Andrey

2016-01-01

The effects of radioactive contamination on ecosystem processes such as litter decomposition remain largely unknown. Because radionuclides accumulated in soil and plant biomass can be harmful for organisms, the functioning of ecosystems may be altered by radioactive contamination. Here, we tested the hypothesis that decomposition is impaired by increasing levels of radioactivity in the environment by exposing uncontaminated leaf litter from silver birch and black alder at (i) eleven distant forest sites differing in ambient radiation levels (0.22–15 μGy h −1 ) and (ii) along a short distance gradient of radioactive contamination (1.2–29 μGy h −1 ) within a single forest in the Chernobyl exclusion zone. In addition to measuring ambient external dose rates, we estimated the average total dose rates (ATDRs) absorbed by decomposers for an accurate estimate of dose-induced ecological consequences of radioactive pollution. Taking into account potential confounding factors (soil pH, moisture, texture, and organic carbon content), the results from the eleven distant forest sites, and from the single forest, showed increased litter mass loss with increasing ATDRs from 0.3 to 150 μGy h −1 . This unexpected result may be due to (i) overcompensation of decomposer organisms exposed to radionuclides leading to a higher decomposer abundance (hormetic effect), and/or (ii) from preferred feeding by decomposers on the uncontaminated leaf litter used for our experiment compared to locally produced, contaminated leaf litter. Our data indicate that radio-contamination of forest ecosystems over more than two decades does not necessarily have detrimental effects on organic matter decay. However, further studies are needed to unravel the underlying mechanisms of the results reported here, in order to draw firmer conclusions on how radio-contamination affects decomposition and associated ecosystem processes. - Highlights: • The effects of radioactivity on ecosystem processes

Multi-Fault Diagnosis of Rolling Bearings via Adaptive Projection Intrinsically Transformed Multivariate Empirical Mode Decomposition and High Order Singular Value Decomposition.

Science.gov (United States)

Yuan, Rui; Lv, Yong; Song, Gangbing

2018-04-16

Rolling bearings are important components in rotary machinery systems. In the field of multi-fault diagnosis of rolling bearings, the vibration signal collected from single channels tends to miss some fault characteristic information. Using multiple sensors to collect signals at different locations on the machine to obtain multivariate signal can remedy this problem. The adverse effect of a power imbalance between the various channels is inevitable, and unfavorable for multivariate signal processing. As a useful, multivariate signal processing method, Adaptive-projection has intrinsically transformed multivariate empirical mode decomposition (APIT-MEMD), and exhibits better performance than MEMD by adopting adaptive projection strategy in order to alleviate power imbalances. The filter bank properties of APIT-MEMD are also adopted to enable more accurate and stable intrinsic mode functions (IMFs), and to ease mode mixing problems in multi-fault frequency extractions. By aligning IMF sets into a third order tensor, high order singular value decomposition (HOSVD) can be employed to estimate the fault number. The fault correlation factor (FCF) analysis is used to conduct correlation analysis, in order to determine effective IMFs; the characteristic frequencies of multi-faults can then be extracted. Numerical simulations and the application of multi-fault situation can demonstrate that the proposed method is promising in multi-fault diagnoses of multivariate rolling bearing signal.

Reference-tracking feedforward control design for linear dynamical systems through signal decomposition

NARCIS (Netherlands)

Kasemsinsup, Y.; Romagnoli, R.; Heertjes, M.F.; Weiland, S.; Butler, H.

2017-01-01

In this work, we study a novel approach towards the reference-tracking feedforward control design for linear dynamical systems. By utilizing the superposition property and exploiting signal decomposition together with a quadratic optimization process, we obtain a feedforward design procedure for

Player Skill Decomposition in Multiplayer Online Battle Arenas

OpenAIRE

Chen, Zhengxing; Sun, Yizhou; El-nasr, Magy Seif; Nguyen, Truong-Huy D.

2017-01-01

Successful analysis of player skills in video games has important impacts on the process of enhancing player experience without undermining their continuous skill development. Moreover, player skill analysis becomes more intriguing in team-based video games because such form of study can help discover useful factors in effective team formation. In this paper, we consider the problem of skill decomposition in MOBA (MultiPlayer Online Battle Arena) games, with the goal to understand what player...

Physicochemical aspects of decomposition of silica-alumina ores of argillites and green clays of Chashma-Sang Deposit of the Republic of Tajikistan by hydrochloric and nitric acids

International Nuclear Information System (INIS)

Kayumov, A.M.

2018-01-01

The purpose of work is to study the processes of decomposition of silica-alumina ores of argillites and green clays of Chashma-Sang Deposit of the Republic of Tajikistan by hydrochloric and nitric acids in temperature interval 20-98 deg C with the using of methods of selective extraction of valuable materials; elaboration of rational conditions of decomposition of raw material. Physicochemical properties of initial aluminium comprising ores, intermediate and final products of processing of argillites and green clays have been studied. Kinetic parameters of processes at acidic decomposition of argillites and green clays have been studied as well. The kinetic parameters of processes of decomposition of green clays and argillites by nitric and hydrochloric acids have been calculated. The flowsheet of complex processing of green clays and argillites of Chashma-Sang Deposit has been elaborated.

Kinetic study of lithium-cadmium ternary amalgam decomposition

International Nuclear Information System (INIS)

Cordova, M.H.; Andrade, C.E.

1992-01-01

The effect of metals, which form stable lithium phase in binary alloys, on the formation of intermetallic species in ternary amalgams and their effect on thermal decomposition in contact with water is analyzed. Cd is selected as ternary metal, based on general experimental selection criteria. Cd (Hg) binary amalgams are prepared by direct contact Cd-Hg, whereas Li is formed by electrolysis of Li OH aq using a liquid Cd (Hg) cathodic well. The decomposition kinetic of Li C(Hg) in contact with 0.6 M Li OH is studied in function of ageing and temperature, and these results are compared with the binary amalgam Li (Hg) decomposition. The decomposition rate is constant during one hour for binary and ternary systems. Ageing does not affect the binary systems but increases the decomposition activation energy of ternary systems. A reaction mechanism that considers an intermetallic specie participating in the activated complex is proposed and a kinetic law is suggested. (author)

Functional traits drive the contribution of solar radiation to leaf litter decomposition among multiple arid-zone species.

Science.gov (United States)

Pan, Xu; Song, Yao-Bin; Liu, Guo-Fang; Hu, Yu-Kun; Ye, Xue-Hua; Cornwell, William K; Prinzing, Andreas; Dong, Ming; Cornelissen, Johannes H C

2015-08-18

In arid zones, strong solar radiation has important consequences for ecosystem processes. To better understand carbon and nutrient dynamics, it is important to know the contribution of solar radiation to leaf litter decomposition of different arid-zone species. Here we investigated: (1) whether such contribution varies among plant species at given irradiance regime, (2) whether interspecific variation in such contribution correlates with interspecific variation in the decomposition rate under shade; and (3) whether this correlation can be explained by leaf traits. We conducted a factorial experiment to determine the effects of solar radiation and environmental moisture for the mass loss and the decomposition constant k-values of 13 species litters collected in Northern China. The contribution of solar radiation to leaf litter decomposition varied significantly among species. Solar radiation accelerated decomposition in particular in the species that already decompose quickly under shade. Functional traits, notably specific leaf area, might predict the interspecific variation in that contribution. Our results provide the first empirical evidence for how the effect of solar radiation on decomposition varies among multiple species. Thus, the effect of solar radiation on the carbon flux between biosphere and atmosphere may depend on the species composition of the vegetation.

Decoupling the direct and indirect effects of climate on plant litter decomposition: Accounting for stress-induced modifications in plant chemistry.

Science.gov (United States)

Suseela, Vidya; Tharayil, Nishanth

2018-04-01

Decomposition of plant litter is a fundamental ecosystem process that can act as a feedback to climate change by simultaneously influencing both the productivity of ecosystems and the flux of carbon dioxide from the soil. The influence of climate on decomposition from a postsenescence perspective is relatively well known; in particular, climate is known to regulate the rate of litter decomposition via its direct influence on the reaction kinetics and microbial physiology on processes downstream of tissue senescence. Climate can alter plant metabolism during the formative stage of tissues and could shape the final chemical composition of plant litter that is available for decomposition, and thus indirectly influence decomposition; however, these indirect effects are relatively poorly understood. Climatic stress disrupts cellular homeostasis in plants and results in the reprogramming of primary and secondary metabolic pathways, which leads to changes in the quantity, composition, and organization of small molecules and recalcitrant heteropolymers, including lignins, tannins, suberins, and cuticle within the plant tissue matrix. Furthermore, by regulating metabolism during tissue senescence, climate influences the resorption of nutrients from senescing tissues. Thus, the final chemical composition of plant litter that forms the substrate of decomposition is a combined product of presenescence physiological processes through the production and resorption of metabolites. The changes in quantity, composition, and localization of the molecular construct of the litter could enhance or hinder tissue decomposition and soil nutrient cycling by altering the recalcitrance of the lignocellulose matrix, the composition of microbial communities, and the activity of microbial exo-enzymes via various complexation reactions. Also, the climate-induced changes in the molecular composition of litter could differentially influence litter decomposition and soil nutrient cycling. Compared

Multiresolution signal decomposition transforms, subbands, and wavelets

CERN Document Server

Akansu, Ali N

1992-01-01

This book provides an in-depth, integrated, and up-to-date exposition of the topic of signal decomposition techniques. Application areas of these techniques include speech and image processing, machine vision, information engineering, High-Definition Television, and telecommunications. The book will serve as the major reference for those entering the field, instructors teaching some or all of the topics in an advanced graduate course and researchers needing to consult an authoritative source.n The first book to give a unified and coherent exposition of multiresolutional signal decompos

2.4. The kinetics of hydrochloric-acid decomposition of calcined concentrate of boron raw material of Ak-Arkhar Deposit

International Nuclear Information System (INIS)

Mirsaidov, U.M.; Kurbonov, A.S.; Mamatov, E.D.

2015-01-01

Present article is devoted to kinetics of hydrochloric-acid decomposition of calcined concentrate of boron raw material of Ak-Arkhar Deposit. The experimental data of dependence of hydrochloric-acid decomposition of calcined boron raw material for boron oxide extraction on temperature (20-80 deg C) and process duration (15-60 min) were considered. It was defined that at temperature increasing the boron oxide extraction from borosilicate raw material increases from 24.1 till 86.8%. The constants of decomposition rate of boron raw material were calculated.

Multi hollow needle to plate plasmachemical reactor for pollutant decomposition

International Nuclear Information System (INIS)

Pekarek, S.; Kriha, V.; Viden, I.; Pospisil, M.

2001-01-01

Modification of the classical multipin to plate plasmachemical reactor for pollutant decomposition is proposed in this paper. In this modified reactor a mixture of air and pollutant flows through the needles, contrary to the classical reactor where a mixture of air and pollutant flows around the pins or through the channel plus through the hollow needles. We give the results of comparison of toluene decomposition efficiency for (a) a reactor with the main stream of a mixture through the channel around the needles and a small flow rate through the needles and (b) a modified reactor. It was found that for similar flow rates and similar energy deposition, the decomposition efficiency of toluene was increased more than six times in the modified reactor. This new modified reactor was also experimentally tested for the decomposition of volatile hydrocarbons from gasoline distillation range. An average efficiency of VOC decomposition of about 25% was reached. However, significant differences in the decomposition of various hydrocarbon types were observed. The best results were obtained for the decomposition of olefins (reaching 90%) and methyl-tert-butyl ether (about 50%). Moreover, the number of carbon atoms in the molecule affects the quality of VOC decomposition. (author)

A handbook of decomposition methods in analytical chemistry

International Nuclear Information System (INIS)

Bok, R.

1984-01-01

Decomposition methods of metals, alloys, fluxes, slags, calcine, inorganic salts, oxides, nitrides, carbides, borides, sulfides, ores, minerals, rocks, concentrates, glasses, ceramics, organic substances, polymers, phyto- and biological materials from the viewpoint of sample preparation for analysis have been described. The methods are systemitized according to decomposition principle: thermal with the use of electricity, irradiation, dissolution with participation of chemical reactions and without it. Special equipment for different decomposition methods is described. Bibliography contains 3420 references

Decomposition of silicon carbide at high pressures and temperatures

Energy Technology Data Exchange (ETDEWEB)

Daviau, Kierstin; Lee, Kanani K. M.

2017-11-01

We measure the onset of decomposition of silicon carbide, SiC, to silicon and carbon (e.g., diamond) at high pressures and high temperatures in a laser-heated diamond-anvil cell. We identify decomposition through x-ray diffraction and multiwavelength imaging radiometry coupled with electron microscopy analyses on quenched samples. We find that B3 SiC (also known as 3C or zinc blende SiC) decomposes at high pressures and high temperatures, following a phase boundary with a negative slope. The high-pressure decomposition temperatures measured are considerably lower than those at ambient, with our measurements indicating that SiC begins to decompose at ~ 2000 K at 60 GPa as compared to ~ 2800 K at ambient pressure. Once B3 SiC transitions to the high-pressure B1 (rocksalt) structure, we no longer observe decomposition, despite heating to temperatures in excess of ~ 3200 K. The temperature of decomposition and the nature of the decomposition phase boundary appear to be strongly influenced by the pressure-induced phase transitions to higher-density structures in SiC, silicon, and carbon. The decomposition of SiC at high pressure and temperature has implications for the stability of naturally forming moissanite on Earth and in carbon-rich exoplanets.

Note on Symplectic SVD-Like Decomposition

Directory of Open Access Journals (Sweden)

AGOUJIL Said

2016-02-01

Full Text Available The aim of this study was to introduce a constructive method to compute a symplectic singular value decomposition (SVD-like decomposition of a 2n-by-m rectangular real matrix A, based on symplectic refectors.This approach used a canonical Schur form of skew-symmetric matrix and it allowed us to compute eigenvalues for the structured matrices as Hamiltonian matrix JAA^T.

Technical Note: Linking climate change and downed woody debris decomposition across forests of the eastern United States

Science.gov (United States)

Russell, Matthew B.; Woodall, Christopher W.; D'Amato, Anthony W.; Fraver, Shawn; Bradford, John B.

2014-01-01

Forest ecosystems play a critical role in mitigating greenhouse gas emissions. Forest carbon (C) is stored through photosynthesis and released via decomposition and combustion. Relative to C fixation in biomass, much less is known about C depletion through decomposition of woody debris, particularly under a changing climate. It is assumed that the increased temperatures and longer growing seasons associated with projected climate change will increase the decomposition rates (i.e., more rapid C cycling) of downed woody debris (DWD); however, the magnitude of this increase has not been previously addressed. Using DWD measurements collected from a national forest inventory of the eastern United States, we show that the residence time of DWD may decrease (i.e., more rapid decomposition) by as much as 13% over the next 200 years, depending on various future climate change scenarios and forest types. Although existing dynamic global vegetation models account for the decomposition process, they typically do not include the effect of a changing climate on DWD decomposition rates. We expect that an increased understanding of decomposition rates, as presented in this current work, will be needed to adequately quantify the fate of woody detritus in future forests. Furthermore, we hope these results will lead to improved models that incorporate climate change scenarios for depicting future dead wood dynamics in addition to a traditional emphasis on live-tree demographics.

The design and implementation of signal decomposition system of CL multi-wavelet transform based on DSP builder

Science.gov (United States)

Huang, Yan; Wang, Zhihui

2015-12-01

With the development of FPGA, DSP Builder is widely applied to design system-level algorithms. The algorithm of CL multi-wavelet is more advanced and effective than scalar wavelets in processing signal decomposition. Thus, a system of CL multi-wavelet based on DSP Builder is designed for the first time in this paper. The system mainly contains three parts: a pre-filtering subsystem, a one-level decomposition subsystem and a two-level decomposition subsystem. It can be converted into hardware language VHDL by the Signal Complier block that can be used in Quartus II. After analyzing the energy indicator, it shows that this system outperforms Daubenchies wavelet in signal decomposition. Furthermore, it has proved to be suitable for the implementation of signal fusion based on SoPC hardware, and it will become a solid foundation in this new field.

The decomposition of estuarine macrophytes under different ...

African Journals Online (AJOL)

The aim of this study was to determine the decomposition characteristics of the most dominant submerged macrophyte and macroalgal species in the Great Brak Estuary. Laboratory experiments were conducted to determine the effect of different temperature regimes on the rate of decomposition of 3 macrophyte species ...

Decomposition and flame structure of hydrazinium nitroformate

NARCIS (Netherlands)

Louwers, J.; Parr, T.; Hanson-Parr, D.

1999-01-01

The decomposition of hydrazinium nitroformate (HNF) was studied in a hot quartz cell and by dropping small amounts of HNF on a hot plate. The species formed during the decomposition were identified by ultraviolet-visible absorption experiments. These experiments reveal that first HONO is formed. The

Novel route for layered double hydroxides preparation by enzymatic decomposition of urea

Science.gov (United States)

Vial, S.; Prevot, V.; Forano, C.

2006-05-01

This study presents a new route for the preparation of a series of layered double hydroxide materials with controlled textural properties. It concerns the biogenesis of hydrotalcite like phases by Jack bean urease through the enzymatic decomposition process of urea. Different conditions of LDH biogenesis are investigated (urease activity, urea concentration). A comparative study with the precipitation method based on the thermal decomposition of urea (90 °C) is conducted in order to asses the effect of the various urea hydrolysis conditions (kinetic, temperature) and the presence of enzyme in the reaction medium on the structural and textural properties of the as prepared LDH materials. Mechanisms of formation of the LDH phases for both synthesis processes are discussed on basis of their pH control. The PXRD and SEM analysis of samples prepared by the thermal process evidence higher crystallinity and greater particle sizes than LDH obtained in mild biogenic conditions. In the latter case, presence of urease or effect of some M(II) metals may inhibit the crystallization.

The triconnected abstraction of process models

OpenAIRE

Polyvyanyy, Artem; Smirnov, Sergey; Weske, Mathias

2009-01-01

Contents: Artem Polyvanny, Sergey Smirnow, and Mathias Weske The Triconnected Abstraction of Process Models 1 Introduction 2 Business Process Model Abstraction 3 Preliminaries 4 Triconnected Decomposition 4.1 Basic Approach for Process Component Discovery 4.2 SPQR-Tree Decomposition 4.3 SPQR-Tree Fragments in the Context of Process Models 5 Triconnected Abstraction 5.1 Abstraction Rules 5.2 Abstraction Algorithm 6 Related Work and Conclusions

Spectral decomposition of tent maps using symmetry considerations

International Nuclear Information System (INIS)

Ordonez, G.E.; Driebe, D.J.

1996-01-01

The spectral decompostion of the Frobenius-Perron operator of maps composed of many tents is determined from symmetry considerations. The eigenstates involve Euler as well as Bernoulli polynomials. The authors have introduced some new techniques, based on symmetry considerations, enabling the construction of spectral decompositions in a much simpler way than previous construction algorithms, Here we utilize these techniques to construct the spectral decomposition for one- dimensional maps of the unit interval composed of many tents. The construction uses the knowledge of the spectral decomposition of the r-adic map, which involves Bernoulli polynomials and their duals. It will be seen that the spectral decomposition of the tent maps involves both Bernoulli polynomials and Euler polynomials along with the appropriate dual states

Decomposition of forest products buried in landfills

International Nuclear Information System (INIS)

Wang, Xiaoming; Padgett, Jennifer M.; Powell, John S.; Barlaz, Morton A.

2013-01-01

Highlights: • This study tracked chemical changes of wood and paper in landfills. • A decomposition index was developed to quantify carbohydrate biodegradation. • Newsprint biodegradation as measured here is greater than previous reports. • The field results correlate well with previous laboratory measurements. - Abstract: The objective of this study was to investigate the decomposition of selected wood and paper products in landfills. The decomposition of these products under anaerobic landfill conditions results in the generation of biogenic carbon dioxide and methane, while the un-decomposed portion represents a biogenic carbon sink. Information on the decomposition of these municipal waste components is used to estimate national methane emissions inventories, for attribution of carbon storage credits, and to assess the life-cycle greenhouse gas impacts of wood and paper products. Hardwood (HW), softwood (SW), plywood (PW), oriented strand board (OSB), particleboard (PB), medium-density fiberboard (MDF), newsprint (NP), corrugated container (CC) and copy paper (CP) were buried in landfills operated with leachate recirculation, and were excavated after approximately 1.5 and 2.5 yr. Samples were analyzed for cellulose (C), hemicellulose (H), lignin (L), volatile solids (VS), and organic carbon (OC). A holocellulose decomposition index (HOD) and carbon storage factor (CSF) were calculated to evaluate the extent of solids decomposition and carbon storage. Samples of OSB made from HW exhibited cellulose plus hemicellulose (C + H) loss of up to 38%, while loss for the other wood types was 0–10% in most samples. The C + H loss was up to 81%, 95% and 96% for NP, CP and CC, respectively. The CSFs for wood and paper samples ranged from 0.34 to 0.47 and 0.02 to 0.27 g OC g −1 dry material, respectively. These results, in general, correlated well with an earlier laboratory-scale study, though NP and CC decomposition measured in this study were higher than

Decomposition of forest products buried in landfills

Energy Technology Data Exchange (ETDEWEB)

Wang, Xiaoming, E-mail: xwang25@ncsu.edu [Department of Civil, Construction, and Environmental Engineering, Campus Box 7908, North Carolina State University, Raleigh, NC 27695-7908 (United States); Padgett, Jennifer M. [Department of Civil, Construction, and Environmental Engineering, Campus Box 7908, North Carolina State University, Raleigh, NC 27695-7908 (United States); Powell, John S. [Department of Chemical and Biomolecular Engineering, Campus Box 7905, North Carolina State University, Raleigh, NC 27695-7905 (United States); Barlaz, Morton A. [Department of Civil, Construction, and Environmental Engineering, Campus Box 7908, North Carolina State University, Raleigh, NC 27695-7908 (United States)

2013-11-15

Highlights: • This study tracked chemical changes of wood and paper in landfills. • A decomposition index was developed to quantify carbohydrate biodegradation. • Newsprint biodegradation as measured here is greater than previous reports. • The field results correlate well with previous laboratory measurements. - Abstract: The objective of this study was to investigate the decomposition of selected wood and paper products in landfills. The decomposition of these products under anaerobic landfill conditions results in the generation of biogenic carbon dioxide and methane, while the un-decomposed portion represents a biogenic carbon sink. Information on the decomposition of these municipal waste components is used to estimate national methane emissions inventories, for attribution of carbon storage credits, and to assess the life-cycle greenhouse gas impacts of wood and paper products. Hardwood (HW), softwood (SW), plywood (PW), oriented strand board (OSB), particleboard (PB), medium-density fiberboard (MDF), newsprint (NP), corrugated container (CC) and copy paper (CP) were buried in landfills operated with leachate recirculation, and were excavated after approximately 1.5 and 2.5 yr. Samples were analyzed for cellulose (C), hemicellulose (H), lignin (L), volatile solids (VS), and organic carbon (OC). A holocellulose decomposition index (HOD) and carbon storage factor (CSF) were calculated to evaluate the extent of solids decomposition and carbon storage. Samples of OSB made from HW exhibited cellulose plus hemicellulose (C + H) loss of up to 38%, while loss for the other wood types was 0–10% in most samples. The C + H loss was up to 81%, 95% and 96% for NP, CP and CC, respectively. The CSFs for wood and paper samples ranged from 0.34 to 0.47 and 0.02 to 0.27 g OC g{sup −1} dry material, respectively. These results, in general, correlated well with an earlier laboratory-scale study, though NP and CC decomposition measured in this study were higher than

Sulphate decomposition and sodium oxide activity in soda-lime-silica glass metls

NARCIS (Netherlands)

Beerkens, R.G.C.

2003-01-01

Reaction equilibrium constants for the sulfate decomposition process, which releases oxygen and sulfur oxide gas in sodalimesilica glass melts, have been determined. The chemical solubility of SO2, probably in the form of sulfite ions in sodalimesilica melts, has also been determined. The chemical

Mycorrhizal associations of trees have different indirect effects on organic matter decomposition

Science.gov (United States)

Melanie K. Taylor; Richard A. Lankau; Nina Wurzburger; Franciska de Vries

2016-01-01

1. Organic matter decomposition is the main process by which carbon (C) is lost from terrestrialecosystems, and mycorrhizal associations of plants (i.e. arbuscular mycorrhizas (AM) and ectomycorrhizas(ECM)) may have different indirect effects on this loss pathway. AM and ECM plants differin the soil...

Sustainable fuel production by thermocatalytic decomposition of methane – A review

Directory of Open Access Journals (Sweden)

K. Srilatha

2017-12-01

Full Text Available Thermocatalytic Decomposition of Methane (TCD is a completely green single step technology for producing hydrogen and carbon nanomaterials. This paper review about the research in laboratory-scale on TCD, specifically the recent advances like co-feeding effect and regeneration of catalyst for enhancing the productivity of the entire process. Although a remarkable success on the laboratory-scale has been fulfilled, TCD for free greenhouse gas (GHG hydrogen production is still in its infancy. The necessity for commercialization of TCD is more than ever in the present-day condition of massive GHG emission. TCD generally studied over several types of catalysts, for example mono, bi, trimetallic, combination of metal–metal oxide, carbon and metal doped carbon catalysts. Catalyst Deactivation is the main problem found in TCD process. Regeneration of catalyst and co-feeding of methane with other hydrocarbon are the two main solutions placed helped in accordance to overcome deactivation problem. Higher amount of co-feed hydrocarbon in situ produce more amount of highly active carbon deposits which support further methane decomposition to produce extra hydrogen. The conversion rate of methane increases with increasing temperature and decreases with the flow rate in the co-feeding process in a comparable manner as observed in normal TCD. The presence of co-components in the post-reaction stream is an important challenge attempted in the co-feeding and regeneration. Keywords: Hydrogen, Catalysts, Thermocatalytic decomposition

Nutrient Dynamics and Litter Decomposition in Leucaena ...

African Journals Online (AJOL)

Nutrient contents and rate of litter decomposition were investigated in Leucaena leucocephala plantation in the University of Agriculture, Abeokuta, Ogun State, Nigeria. Litter bag technique was used to study the pattern and rate of litter decomposition and nutrient release of Leucaena leucocephala. Fifty grams of oven-dried ...

Climate fails to predict wood decomposition at regional scales

Science.gov (United States)

Mark A. Bradford; Robert J. Warren; Petr Baldrian; Thomas W. Crowther; Daniel S. Maynard; Emily E. Oldfield; William R. Wieder; Stephen A. Wood; Joshua R. King

2014-01-01

Decomposition of organic matter strongly influences ecosystem carbon storage1. In Earth-system models, climate is a predominant control on the decomposition rates of organic matter2, 3, 4, 5. This assumption is based on the mean response of decomposition to climate, yet there is a growing appreciation in other areas of global change science that projections based on...

Influence of different forest system management practices on leaf litter decomposition rates, nutrient dynamics and the activity of ligninolytic enzymes: a case study from central European forests.

Science.gov (United States)

Purahong, Witoon; Kapturska, Danuta; Pecyna, Marek J; Schulz, Elke; Schloter, Michael; Buscot, François; Hofrichter, Martin; Krüger, Dirk

2014-01-01

Leaf litter decomposition is the key ecological process that determines the sustainability of managed forest ecosystems, however very few studies hitherto have investigated this process with respect to silvicultural management practices. The aims of the present study were to investigate the effects of forest management practices on leaf litter decomposition rates, nutrient dynamics (C, N, Mg, K, Ca, P) and the activity of ligninolytic enzymes. We approached these questions using a 473 day long litterbag experiment. We found that age-class beech and spruce forests (high forest management intensity) had significantly higher decomposition rates and nutrient release (most nutrients) than unmanaged deciduous forest reserves (Pforest management (low forest management intensity) exhibited no significant differences in litter decomposition rate, C release, lignin decomposition, and C/N, lignin/N and ligninolytic enzyme patterns compared to the unmanaged deciduous forest reserves, but most nutrient dynamics examined in this study were significantly faster under such near-to-nature forest management practices. Analyzing the activities of ligninolytic enzymes provided evidence that different forest system management practices affect litter decomposition by changing microbial enzyme activities, at least over the investigated time frame of 473 days (laccase, Pforest system management practices can significantly affect important ecological processes and services such as decomposition and nutrient cycling.

VELOCITY FIELD OF COMPRESSIBLE MAGNETOHYDRODYNAMIC TURBULENCE: WAVELET DECOMPOSITION AND MODE SCALINGS

International Nuclear Information System (INIS)

Kowal, Grzegorz; Lazarian, A.

2010-01-01

We study compressible magnetohydrodynamic turbulence, which holds the key to many astrophysical processes, including star formation and cosmic-ray propagation. To account for the variations of the magnetic field in the strongly turbulent fluid, we use wavelet decomposition of the turbulent velocity field into Alfven, slow, and fast modes, which presents an extension of the Cho and Lazarian decomposition approach based on Fourier transforms. The wavelets allow us to follow the variations of the local direction of the magnetic field and therefore improve the quality of the decomposition compared to the Fourier transforms, which are done in the mean field reference frame. For each resulting component, we calculate the spectra and two-point statistics such as longitudinal and transverse structure functions as well as higher order intermittency statistics. In addition, we perform a Helmholtz- Hodge decomposition of the velocity field into incompressible and compressible parts and analyze these components. We find that the turbulence intermittency is different for different components, and we show that the intermittency statistics depend on whether the phenomenon was studied in the global reference frame related to the mean magnetic field or in the frame defined by the local magnetic field. The dependencies of the measures we obtained are different for different components of the velocity; for instance, we show that while the Alfven mode intermittency changes marginally with the Mach number, the intermittency of the fast mode is substantially affected by the change.

Bacterial community succession in pine-wood decomposition

Directory of Open Access Journals (Sweden)

Anna eKielak

2016-03-01

Full Text Available Though bacteria and fungi are common inhabitants of decaying wood, little is known about the relationship between bacterial and fungal community dynamics during natural wood decay. Based on previous studies involving inoculated wood blocks, strong fungal selection on bacteria abundance and community composition was expected to occur during natural wood decay. Here we focused on bacterial and fungal community compositions in pine wood samples collected from dead trees in different stages of decomposition. We showed that bacterial communities undergo less drastic changes than fungal communities during wood decay. Furthermore, we found that bacterial community assembly was a stochastic process at initial stage of wood decay and became more deterministic in later stages, likely due to environmental factors. Moreover, composition of bacterial communities did not respond to the changes in the major fungal species present in the wood but rather to the stage of decay reflected by the wood density. We concluded that the shifts in the bacterial communities were a result of the changes in wood properties during decomposition and largely independent of the composition of the wood-decaying fungal communities.

Uma Abordagem para a Decomposição de Processos de Nego̿cio para Execução em Nuvens Computacionais (in Portugese; An approach to business processes decomposition for cloud deployment)

NARCIS (Netherlands)

Povoa, Lucas Venezian; Lopes de Souza, Wanderley; Ferreira Pires, Luis; Duipmans, Evert F.; do Prado, Antonio Francisco

Due to safety requirements, certain data or activities of a business process should be kept within the user premises, while others can be allocated to a cloud environment. This paper presents a generic approach to business processes decomposition taking into account the allocation of activities and

Formation of volatile decomposition products by self-radiolysis of tritiated thymidine

International Nuclear Information System (INIS)

Shiba, Kazuhiro; Mori, Hirofumi

1997-01-01

In order to estimate the internal exposure dose in an experiment using tritiated thymidine, the rate of volatile 3 H-decomposition of several tritiated thymidine samples was measured. The decomposition rate of (methyl- 3 H)thymidine in water was over 80% in less than one year after initial analysis. (methyl- 3 H)thymidine was decomposed into volatile and non-volatile 3 H-decomposition products. The ratio of volatile 3 H-decomposition products increased with increasing the rate of the decomposition of (methyl- 3 H) thymidine. The volatile 3 H-decomposition products consisted of two components, of which the main component was tritiated water. Internal exposure dose caused by the inhalation of such volatile 3 H-decomposition products of (methyl- 3 H) thymidine was assumed to be several μSv. (author)

Are litter decomposition and fire linked through plant species traits?

Science.gov (United States)

Cornelissen, Johannes H C; Grootemaat, Saskia; Verheijen, Lieneke M; Cornwell, William K; van Bodegom, Peter M; van der Wal, René; Aerts, Rien

2017-11-01

Contents 653 I. 654 II. 657 III. 659 IV. 661 V. 662 VI. 663 VII. 665 665 References 665 SUMMARY: Biological decomposition and wildfire are connected carbon release pathways for dead plant material: slower litter decomposition leads to fuel accumulation. Are decomposition and surface fires also connected through plant community composition, via the species' traits? Our central concept involves two axes of trait variation related to decomposition and fire. The 'plant economics spectrum' (PES) links biochemistry traits to the litter decomposability of different fine organs. The 'size and shape spectrum' (SSS) includes litter particle size and shape and their consequent effect on fuel bed structure, ventilation and flammability. Our literature synthesis revealed that PES-driven decomposability is largely decoupled from predominantly SSS-driven surface litter flammability across species; this finding needs empirical testing in various environmental settings. Under certain conditions, carbon release will be dominated by decomposition, while under other conditions litter fuel will accumulate and fire may dominate carbon release. Ecosystem-level feedbacks between decomposition and fire, for example via litter amounts, litter decomposition stage, community-level biotic interactions and altered environment, will influence the trait-driven effects on decomposition and fire. Yet, our conceptual framework, explicitly comparing the effects of two plant trait spectra on litter decomposition vs fire, provides a promising new research direction for better understanding and predicting Earth surface carbon dynamics. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

Spectral Decomposition Algorithm (SDA)

Data.gov (United States)

National Aeronautics and Space Administration — Spectral Decomposition Algorithm (SDA) is an unsupervised feature extraction technique similar to PCA that was developed to better distinguish spectral features in...

Dynamics of root and leaf decomposition in chronosequence of rubber plantation (Hevea brasilensis) in SW China

International Nuclear Information System (INIS)

Moazzam, N.S.; Yiping, Z.; Liqing, S.; Moazzam, N.S.

2018-01-01

This study highlighted the dynamics of stand parameters as well as root and leaf litter decomposition in the chronosequence (49, 32, 24 and 12 years old plantations established in the year 1965, 1982, 1990 and 2002) of the rubber plantation in Xishuangbanna SW China. Litter trappers were installed on the study site to collect the leaf litter and litter bag experiment was carried out to investigate the rate of root and leaf litter decomposition. The study revealed significant variation of stand characteristics during the decomposition process. The monthly litter fall and root biomass (all categories; kg m-3) showed positive correlation with stand characteristics and age. Remaining leaf litter mass % in the litter bags reduced with the passage of time and was significantly different in the chronosequence. The highest root decomposition rate (55%) was shown by fine roots and minimum (32%) by coarse roots during the study period. The investigations on elemental composition of the leaf and root provides basic important information for rate of nutrient cycle along with decomposition rate in rubber plantation and result are quite helpful for simulating the below ground carbon stock of rubber plantation in SW China. (author)

4.2. The kinetics of nitric acid decomposition of calcined borosilicate raw material of Ak-Arkhar Deposit

International Nuclear Information System (INIS)

Mirsaidov, U.M.; Kurbonov, A.S.; Mamatov, E.D.

2015-01-01

Present article is devoted to kinetics of nitric acid decomposition of calcined borosilicate raw material of Ak-Arkhar Deposit. The dependence of nitric acid decomposition of calcined boric raw material for extraction of boron oxide on temperature (20-100 deg C) and process duration (15-60 minutes) was defined. It was defined that at temperature increasing the extraction rate of boron oxide increases from 20.8 to 78.6%.

Thermal decomposition of UO3-2H20

International Nuclear Information System (INIS)

Flament, T.A.

1998-01-01

The first part of the report summarizes the literature data regarding the uranium trioxide water system. In the second part, the experimental aspects are presented. An experimental program has been set up to determine the steps and species involved in decomposition of uranium oxide di-hydrate. Particular attention has been paid to determine both loss of free water (moisture in the fuel) and loss of chemically bound water (decomposition of hydrates). The influence of water pressure on decomposition has been taken into account

Large Scale Simulation of Hydrogen Dispersion by a Stabilized Balancing Domain Decomposition Method

Directory of Open Access Journals (Sweden)

Qing-He Yao

2014-01-01

Full Text Available The dispersion behaviour of leaking hydrogen in a partially open space is simulated by a balancing domain decomposition method in this work. An analogy of the Boussinesq approximation is employed to describe the connection between the flow field and the concentration field. The linear systems of Navier-Stokes equations and the convection diffusion equation are symmetrized by a pressure stabilized Lagrange-Galerkin method, and thus a balancing domain decomposition method is enabled to solve the interface problem of the domain decomposition system. Numerical results are validated by comparing with the experimental data and available numerical results. The dilution effect of ventilation is investigated, especially at the doors, where flow pattern is complicated and oscillations appear in the past research reported by other researchers. The transient behaviour of hydrogen and the process of accumulation in the partially open space are discussed, and more details are revealed by large scale computation.

Hydrogen production by photoelectrolytic decomposition of H2O using solar energy

Science.gov (United States)

Rauh, R. D.; Alkaitis, S. A.; Buzby, J. M.; Schiff, R.

1980-01-01

Photoelectrochemical systems for the efficient decomposition of water are discussed. Semiconducting d band oxides which would yield the combination of stability, low electron affinity, and moderate band gap essential for an efficient photoanode are sought. The materials PdO and Fe-xRhxO3 appear most likely. Oxygen evolution yields may also be improved by mediation of high energy oxidizing agents, such as CO3(-). Examination of several p type semiconductors as photocathodes revealed remarkable stability for p-GaAs, and also indicated p-CdTe as a stable H2 photoelectrode. Several potentially economical schemes for photoelectrochemical decomposition of water were examined, including photoelectrochemical diodes and two stage, four photon processes.

Steganography based on pixel intensity value decomposition

Science.gov (United States)

Abdulla, Alan Anwar; Sellahewa, Harin; Jassim, Sabah A.

2014-05-01

This paper focuses on steganography based on pixel intensity value decomposition. A number of existing schemes such as binary, Fibonacci, Prime, Natural, Lucas, and Catalan-Fibonacci (CF) are evaluated in terms of payload capacity and stego quality. A new technique based on a specific representation is proposed to decompose pixel intensity values into 16 (virtual) bit-planes suitable for embedding purposes. The proposed decomposition has a desirable property whereby the sum of all bit-planes does not exceed the maximum pixel intensity value, i.e. 255. Experimental results demonstrate that the proposed technique offers an effective compromise between payload capacity and stego quality of existing embedding techniques based on pixel intensity value decomposition. Its capacity is equal to that of binary and Lucas, while it offers a higher capacity than Fibonacci, Prime, Natural, and CF when the secret bits are embedded in 1st Least Significant Bit (LSB). When the secret bits are embedded in higher bit-planes, i.e., 2nd LSB to 8th Most Significant Bit (MSB), the proposed scheme has more capacity than Natural numbers based embedding. However, from the 6th bit-plane onwards, the proposed scheme offers better stego quality. In general, the proposed decomposition scheme has less effect in terms of quality on pixel value when compared to most existing pixel intensity value decomposition techniques when embedding messages in higher bit-planes.

Expert vs. novice: Problem decomposition/recomposition in engineering design

Science.gov (United States)

Song, Ting

The purpose of this research was to investigate the differences of using problem decomposition and problem recomposition among dyads of engineering experts, dyads of engineering seniors, and dyads of engineering freshmen. Fifty participants took part in this study. Ten were engineering design experts, 20 were engineering seniors, and 20 were engineering freshmen. Participants worked in dyads to complete an engineering design challenge within an hour. The entire design process was video and audio recorded. After the design session, members participated in a group interview. This study used protocol analysis as the methodology. Video and audio data were transcribed, segmented, and coded. Two coding systems including the FBS ontology and "levels of the problem" were used in this study. A series of statistical techniques were used to analyze data. Interview data and participants' design sketches also worked as supplemental data to help answer the research questions. By analyzing the quantitative and qualitative data, it was found that students used less problem decomposition and problem recomposition than engineer experts in engineering design. This result implies that engineering education should place more importance on teaching problem decomposition and problem recomposition. Students were found to spend less cognitive effort when considering the problem as a whole and interactions between subsystems than engineer experts. In addition, students were also found to spend more cognitive effort when considering details of subsystems. These results showed that students tended to use dept-first decomposition and experts tended to use breadth-first decomposition in engineering design. The use of Function (F), Behavior (B), and Structure (S) among engineering experts, engineering seniors, and engineering freshmen was compared on three levels. Level 1 represents designers consider the problem as an integral whole, Level 2 represents designers consider interactions between

Molecular C dynamics downstream: the biochemical decomposition sequence and its impact on soil organic matter structure and function.

Science.gov (United States)

Grandy, A Stuart; Neff, Jason C

2008-10-15

Advances in spectroscopic and other chemical methods have greatly enhanced our ability to characterize soil organic matter chemistry. As a result, the molecular characteristics of soil C are now known for a range of ecosystems, soil types, and management intensities. Placing this knowledge into a broader ecological and management context is difficult, however, and remains one of the fundamental challenges of soil organic matter research. Here we present a conceptual model of molecular soil C dynamics to stimulate inter-disciplinary research into the ecological implications of molecular C turnover and its management- and process-level controls. Our model describes three properties of soil C dynamics: 1) soil size fractions have unique molecular patterns that reflect varying degrees of biological and physical control over decomposition; 2) there is a common decomposition sequence independent of plant inputs or other ecosystem properties; and 3) molecular decomposition sequences, although consistent, are not uniform and can be altered by processes that accelerate or slow the microbial transformation of specific molecules. The consequences of this model include several key points. First, lignin presents a constraint to decomposition of plant litter and particulate C (>53 microm) but exerts little influence on more stable mineral-associated soil fractions stabilized onto mineral fractions has a distinct composition related more to microbially processed organic matter than to plant-related compounds. Third, disturbances, such as N fertilization and tillage, which alter decomposition rates, can have "downstream effects"; that is, a disturbance that directly alters the molecular dynamics of particulate C may have a series of indirect effects on C stabilization in silt and clay fractions.

Fringe pattern denoising via image decomposition.

Science.gov (United States)

Fu, Shujun; Zhang, Caiming

2012-02-01

Filtering off noise from a fringe pattern is one of the key tasks in optical interferometry. In this Letter, using some suitable function spaces to model different components of a fringe pattern, we propose a new fringe pattern denoising method based on image decomposition. In our method, a fringe image is divided into three parts: low-frequency fringe, high-frequency fringe, and noise, which are processed in different spaces. An adaptive threshold in wavelet shrinkage involved in this algorithm improves its denoising performance. Simulation and experimental results show that our algorithm obtains smooth and clean fringes with different frequencies while preserving fringe features effectively.

A study on the thermal decomposition behavior of derivatives of 1,5-diamino-1H-tetrazole (DAT): A new family of energetic heterocyclic-based salts

International Nuclear Information System (INIS)

Fischer, Gerd; Holl, Gerhard; Klapoetke, Thomas M.; Weigand, Jan J.

2005-01-01

The thermal decomposition of the highly energetic 1,5-diamino-4-methyl-1H-tetrazolium nitrate (2b), 1,5-diamino-4-methyl-1H-tetrazolium dinitramide (2c) and 1,5-diamino-4-methyl-1H-tetrazolium azide (2d) were investigated by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). Mass spectrometry and IR spectroscopy were used to identify the gaseous products. Decomposition appears in the cases of 2c and 2d to be initiated by a proton transfer to form the corresponding acid HN 3 and HN 3 O 4 whereas in the case of 2b a methyl group transfer to MeONO 2 is observed as initial process. The gaseous products after the exothermic decomposition are comparable and are in agreement of the possible decomposition pathways discussed for the corresponding compounds. For all processes, possible decomposition schemes are presented. The decomposition temperatures of 2b and 2c are significantly higher than that of 2d and were supported by evaluation the values of the activation energy according the method of Ozawa and Kissinger

Hydrothermal treatment of municipal solid waste incineration fly ash for dioxin decomposition

International Nuclear Information System (INIS)

Hu, Yuyan; Zhang, Pengfei; Chen, Dezhen; Zhou, Bin; Li, Jianyi; Li, Xian-wei

2012-01-01

Highlights: ► The first study to apply Fe-sulfate in hydrothermal treatment of municipal solid waste incineration fly ash for dioxin decomposition. ► The first study to comprehensively evaluate the effect of hydrothermal treatment on dioxin decomposition and heavy metal stabilization in municipal solid waste incineration fly ash. ► Gaussian software chemical computational simulation was performed to investigate the mechanism of dioxin decomposition based on quantum chemistry calculation, and to support the experimental data by the calculation results. - Abstract: Hydrothermal treatment of MSWI fly ash was performed in this paper with a purpose to reduce its dioxin content. First a hydrothermal reactor was set up with a mixture of ferric sulphate and ferrous sulphate serviced as the reactant, then the effects caused by reaction conditions such as reaction temperature, pre-treatment by water-washing and reactant dosage were checked; the results showed that as a promising technology, hydrothermal treatment exhibited considerable high efficiencies in decomposition of PCDDs/PCDFs and good stabilization of heavy metals as well. Experimental results also showed that for dioxin destruction, higher reaction temperature is the most important influencing factor followed by Fe addition, and pre-treatment of raw fly ash by water-washing increased the destruction efficiencies of dioxins only very slightly. Finally with help of Gaussian software chemical computational simulation was performed to investigate the mechanism of dioxin decomposition based on quantum chemistry calculation. The calculation results were supported by the experimental data. The leaching toxicities of hydrothermal products were higher than upper limits defined in the latest Chinese standard GB 16889-2008 for sanitary landfill disposal, thus an auxiliary process is suggested after the hydrothermal treatment for heavy metal stabilization.

Noise reduction in digital speckle pattern interferometry using bidimensional empirical mode decomposition

International Nuclear Information System (INIS)

Bernini, Maria Belen; Federico, Alejandro; Kaufmann, Guillermo H.

2008-01-01

We propose a bidimensional empirical mode decomposition (BEMD) method to reduce speckle noise in digital speckle pattern interferometry (DSPI) fringes. The BEMD method is based on a sifting process that decomposes the DSPI fringes in a finite set of subimages represented by high and low frequency oscillations, which are named modes. The sifting process assigns the high frequency information to the first modes, so that it is possible to discriminate speckle noise from fringe information, which is contained in the remaining modes. The proposed method is a fully data-driven technique, therefore neither fixed basis functions nor operator intervention are required. The performance of the BEMD method to denoise DSPI fringes is analyzed using computer-simulated data, and the results are also compared with those obtained by means of a previously developed one-dimensional empirical mode decomposition approach. An application of the proposed BEMD method to denoise experimental fringes is also presented

Biological decomposition of aqueous solutions from soil cleaning

International Nuclear Information System (INIS)

Kniebusch, M.M.; Sekoulov, I.

1993-01-01

The biological cleaning of process water from soil cleaning and from contaminated groundwater required the development of new types of reaction systems. With the introduced membrane biofilm reactor, even substances difficult to decompose can be removed from contaminated water. Previous investigations of the elimination of pyrene in the presence of n-hexadecane show an optimum temperature at 30 C. An increase of scale is possible based on the invesstigations carried out on the aerobic biological decomposition of polycyclic aromatic hydrocarbons. (orig.) [de

Tensor decompositions for the analysis of atomic resolution electron energy loss spectra

Energy Technology Data Exchange (ETDEWEB)

Spiegelberg, Jakob; Rusz, Ján [Department of Physics and Astronomy, Uppsala University, Box 516, S-751 20 Uppsala (Sweden); Pelckmans, Kristiaan [Department of Information Technology, Uppsala University, Box 337, S-751 05 Uppsala (Sweden)

2017-04-15

A selection of tensor decomposition techniques is presented for the detection of weak signals in electron energy loss spectroscopy (EELS) data. The focus of the analysis lies on the correct representation of the simulated spatial structure. An analysis scheme for EEL spectra combining two-dimensional and n-way decomposition methods is proposed. In particular, the performance of robust principal component analysis (ROBPCA), Tucker Decompositions using orthogonality constraints (Multilinear Singular Value Decomposition (MLSVD)) and Tucker decomposition without imposed constraints, canonical polyadic decomposition (CPD) and block term decompositions (BTD) on synthetic as well as experimental data is examined. - Highlights: • A scheme for compression and analysis of EELS or EDX data is proposed. • Several tensor decomposition techniques are presented for BSS on hyperspectral data. • Robust PCA and MLSVD are discussed for denoising of raw data.

Thermal decomposition of chromite spinel with chlorite admixture