scholarly journals Sustainable Valorization of Animal Manure and Recycled Polyester: Co-pyrolysis Synergy

2019 ◽  
Vol 11 (8) ◽  
pp. 2280 ◽  
Author(s):  
Zuhal Akyürek
Keyword(s):  
Room Temperature ◽  
Animal Manure ◽  
Activation Energies ◽  
Cattle Manure ◽  
Synergistic Interactions ◽  
Kinetics Of Decomposition ◽  
Single Region ◽  
Fwo Method ◽  
Apparent Activation Energies ◽  
Kinetics Of

In this study sustainable valorization of cattle manure, recycled polyester, and their blend (1:1 wt.%) were examined by the thermogravimetric analysis (TGA) method. Pyrolysis tests were performed at 10, 30, and 50 °C/min heating rate from room temperature to 1000 °C under a nitrogen environment with a flow of 100 cm3/min. Kinetics of decomposition were analyzed by using Flynn–Wall–Ozawa (FWO) method. Based on activation energies and conversion points, a single region was established for recycled polyester while three regions of pyrolysis were obtained for cattle manure and their blend. Comparison between experimental and theoretical profiles indicated synergistic interactions during co-pyrolysis in the high temperature region. The apparent activation energies calculated by FWO method for cattle manure, recycled polyester. and their blend were 194.62, 254.22 and 227.21 kJ/mol, respectively. Kinetics and thermodynamic parameters, including E, ΔH, ΔG, and ΔS, have shown that cattle manure and recycled polyester blend is a remarkable feedstock for bioenergy.

THE INFRARED SPECTRUM AND THERMAL DECOMPOSITION OF HYDRAZINE PERCHLORATE HEMIHYDRATE

1966 ◽  
Vol 44 (20) ◽  
pp. 2435-2443 ◽  
Author(s):  
P. W. M. Jacobs ◽  
A. Russell-Jones
Keyword(s):  
Infrared Spectrum ◽  
Reaction Mechanisms ◽  
Low Temperatures ◽  
Room Temperature ◽  
Kcal Mole ◽  
Absorption Bands ◽  
Kinetics Of Decomposition ◽  
Salt Melts ◽  
Chemical Equation ◽  
Kinetics Of

The infrared spectrum of hydrazine perchlorate hemihydrate (HPH) has been determined and an assignment of the absorption bands made. Invacuo, HPH will partially dehydrate even at room temperature; when heated the remainder of the half-mole of water is lost at 61 °C. The dehydrated salt melts at 138 °C and decomposition ensues. The kinetics of decomposition may be followed in the temperature range 180–280 °C. The activation energy is 36.3 kcal/mole. At low temperatures the decomposition is represented by the chemical equation[Formula: see text]but when the temperature is high enough the rate of decomposition of the ammonium perchlorate formed becomes appreciable also. Possible reaction mechanisms are discussed.

Synthesis and kinetics of decomposition of some novel S-nitrosothiols

1999 ◽  
Vol 77 (5-6) ◽  
pp. 550-556 ◽  
Author(s):  
Andrew P Munro ◽  
D Lyn H. Williams
Keyword(s):  
Nitric Oxide ◽  
Room Temperature ◽  
Alternative Pathway ◽  
Copper Catalysis ◽  
Induction Periods ◽  
Kinetics Of Decomposition ◽  
Initial Generation ◽  
Kinetics Of ◽  
Reaction Schemes

TheS-nitrosothiols 2-acetamido-2-deoxy-S-nitroso-1-thio-β-D-glucopyranose 3,4,6-triacetate (GPSNO) and S-nitroso-N-carbamyl-D,L-penicillamine (SNCP) were synthesized by S-nitrosation of the corresponding thiols, isolated, and fully characterized. The nitrosothiol (TGSNO) from 1-thioglycerol was obtained as a red gelatinous liquid, which decomposed rapidly at room temperature and so was not characterized. The kinetics of decomposition of GPSNO showed that there is a surprisingly large thermal pathway overlaid with a Cu2+/RS- catalyzed reaction. The results strongly suggest that the product disulfide complexes Cu2+ (for which there is some spectral evidence), leading to incomplete conversion by that route. Ascorbate also acts as a Cu2+ reductant. Another S-nitroso sugar, S-nitroso-1-thio-β-D-glucose (SNTG), behaved very similarly from solutions generated and used in situ. The decomposition of TGSNO shows induction periods suggesting that slow initial generation of Cu+ (the true catalyst) is taking place. There appears to be also a significant alternative pathway (analogous to that found for GPSNO), where the rate appears to be independent of [Cu2+], but very unusually this pathway is effectively halted by addition of EDTA either at the start of the reaction or at a later time. Reaction schemes are put forward to account for these unusual reaction characteristics.Key words: S-nitrosothiols, nitric oxide, ascorbate, copper catalysis.

Interfacial reactions in multilayers intended for microelectronics devices

1998 ◽  
Vol 514 ◽  
Author(s):  
X. Federspiel ◽  
F. Voiron ◽  
M. Ignat ◽  
T. Marieb ◽  
H. Fujimoto
Keyword(s):  
Phase Formation ◽  
Reaction Rate ◽  
Experimental Approach ◽  
Intermetallic Phase ◽  
Activation Energies ◽  
Interfacial Reactions ◽  
Scanning Calorimetry ◽  
Back Scattering ◽  
Apparent Activation Energies ◽  
Kinetics Of

ABSTRACTThe knowledge of the reaction kinetics which can occur at an interface of a couple of materials, remains a crucial issue to establish the structural limits of a diffusion barrier intended for microelectronic structures.In the past years, the interfacial reactions activated at an interface of a couple of materials, as for example aluminum and titanium, have been analyzed extensively using different experimental tools, as for example: Ruthreford Back Scattering (thickness determination) and Differential Scanning Calorimetry (DSC). Then, these experimental methods were useful to deduce parameters, characterizing the interfacial reactions in bulk samples: apparent activation energies, enthalpy of formation. Because in thin films, the kinetics of the reactions that can be activated at an interface will be different; we studied interfacial reactions in submicronic Al/Ti layers.Taking advantage of the accuracy of the DSC (reaction rate determinations and detection of earlier stages of intermetallic phase formation), our experimental approach consisted in a series of isothermal and non-isothermal DSC experiments on submicron Al/Ti layered structures. From the reaction rate determination, analytical methods as the Kissinger Ozawa approach were used, to determine the apparent activation energies of the phase formation. Also the results allowed to model and discuss the first steps of the interfacial reaction.

ANIONIC POLYMERIZATION OF STYRENE

1960 ◽  
Vol 38 (10) ◽  
pp. 1891-1900 ◽  
Author(s):  
D. J. Worsfold ◽  
S. Bywater
Keyword(s):  
Absorption Spectra ◽  
Anionic Polymerization ◽  
Benzene Solution ◽  
Activation Energies ◽  
Ultraviolet Absorption ◽  
First Order ◽  
Initiation And Propagation ◽  
Apparent Activation Energies ◽  
Kinetics Of

A study of the kinetics of the initiation and propagation reactions in the polymerization of styrene by butyllithium in benzene solution has been made. The initiation has been shown to be first order in styrene and 0.155 order in butyllithium, the propagation to be first order in styrene and half order with respect to active chain ends. The apparent activation energies of the two reactions have been shown to be 18,000 calories and 14,300 calories respectively. The ultraviolet absorption spectra of colored species produced has been measured and compared with others found in similar systems.

Kinetics of Subcritical Crack Growth and Deformation in a High Strength Steel

1973 ◽  
Vol 95 (1) ◽  
pp. 2-9 ◽  
Author(s):  
J. D. Landes ◽  
R. P. Wei
Keyword(s):  
Experimental Data ◽  
Steady State ◽  
Crack Growth ◽  
Subcritical Crack Growth ◽  
Activation Energies ◽  
Steady State Creep ◽  
Deformation Kinetics ◽  
Deformation Processes ◽  
Apparent Activation Energies ◽  
Kinetics Of

The kinetics of subcritical crack growth under sustained loading in a chemically inert environment (dehumidified argon) and the companion deformation kinetics were determined to examine the possible relationship between the crack growth and deformation processes in an AISI 4340 steel tempered at 400 deg F (∼205 degC). Crack growth experiments were carried out over a range of temperatures from 20 to 140 deg C, using the crack tip stress intensity factor K to chacterize the mechanical crack driving force. Deformation kinetics were determined as a function of deformed structure either at constant load or by a strain rate cycling procedure over the same range of temperatures. Detectable crack growth (with rates above 10−5 ipm) in dehumidified argon occurred at K levels exceeding about 70 percent of Kc at room temperature and 50 percent of Kc at the higher temperatures. Crack growth exhibited transient, steady-state and tertiary stages of growth, akin to creep, in agreement with the results of Li, et al. Experimental data indicate that subcritical crack growth in dehumidified argon is controlled by thermally activated processes, with apparent activation energies in the range of 11,000 to 18,000 cal/mole. This range of apparent activation energies is in general agreement with an observed range of 12,000 to 28,000 cal/mole for steady-state creep in this material. The apparent activation energies for steady-state creep were found to be dependent on flow stress and structure. Based on the similarity between the observed crack growth and deformation behaviors and on the order of magnitude agreement between the apparent activation energies, it is reasonable to consider that subcritical crack growth in inert environments is controlled by the time dependent deformation processes occurring at the crack tip. A model for relating steady-state crack growth and steady-state creep is suggested, and is shown to correlate well with experimental data.

Non-Isothermal Kinetics Analysis of α→β Transformation in Zirconium Alloy

2020 ◽  
Vol 993 ◽  
pp. 344-350
Author(s):  
Zong Pei Wu ◽  
Zhu Qing Cheng ◽  
Zhong Bo Yang ◽  
Wei Yi ◽  
Xiao Lu Xu
Keyword(s):  
Activation Energy ◽  
Room Temperature ◽  
Kinetic Mechanism ◽  
Isothermal Kinetics ◽  
Scanning Calorimetry ◽  
Temperature Ranges ◽  
One Step ◽  
Fwo Method ◽  
Kinetics Of ◽  
Dsc Curves

Differential scanning calorimetry (DSC) was used to study non-isothermal kinetics of α→β transformation of Zr-0.5wt%Sn-0.15wt%Nb-0.5wt%Fe-0.25wt%V alloy. The DSC curves were measured from room temperature to 1030 °C at the heating rate of 15, 20, 30, 50°C /min respectively. The Flynn-Wall-Ozawa (FWO) method was used to get the activation energy (E) of α→β transformation at different conversion ratios. Then the values of activation energy obtained were modified by Ozawa iterative equation. The kinetic mechanism functions of α→β transformation were investigated by Criado-Ortega methods. The results show that the activation energy is related to conversion ratios. It means α→β transformation is not a simple one-step reaction but a complex multi-step reaction. The most probable kinetic mechanism functions are different in different temperature ranges, which are -ln(1-x) for ≤830 °C, [-ln(1-x)]1/2 for 834~848 °C, [-ln(1-x)]2/5for 850~856 °C and [-ln(1-x)]1/3 for 858~868 °C respectively.

COMPARATIVE STUDY ON PYROLYSIS BEHAVIOR AND KINETICS OF TWO MACROALGAE BIOMASS (ULVA CF. FLEXUOSA AND HY. EDULIS) USING THERMOGRAVIMETRIC ANALYSIS

2018 ◽  
Vol 80 (2) ◽  
Author(s):  
Amira Nabila Roslee ◽  
Nur Farizan Munajat
Keyword(s):  
Thermogravimetric Analysis ◽  
Activation Energies ◽  
Peninsular Malaysia ◽  
Thermochemical Conversion ◽  
Algae Biomass ◽  
Model Free ◽  
Conversion System ◽  
Apparent Activation Energies ◽  
Kinetics Of ◽  
Macro Algae

Preliminary pyrolysis studies of macroalgae biomass (Ulva cf. flexuosa and Hy. edulis) which were collected from several coastlines of Peninsular Malaysia were performed by using thermogravimetric analysis (TGA). The corresponding kinetic parameters were calculated through three model-free methods, namely Kissinger, Kissinger-Akahira-Sunose (KAS), and Flynn-Wall-Ozawa (FWO). The TGA curves of both species exhibited three degradation stages: dehydration, devolatilization, and residual decomposition. The devolatilization stage is where the main pyrolysis occurred at a temperature around 150-590oC and released the total volatiles of 56.93% and 54.92% for Ulva cf. flexuosa and Hy. Edulis.  The calculation of activation energy from Kissinger method for Ulva cf. flexuosa was 180.24 kJ/mol while 194.86 kJ/mol for Hy. edulis. The apparent activation energies for KAS and FWO methods are increased by increasing the pyrolysis conversion with average activation energies of 241.17 kJ/mol and 253.65kJ/mol for Ulva cf. flexuosa, while for Hy. edulis, are 244.75 kJ/mol and 258.9 kJ/mol. This study provides the basis for the further application for designing and modeling in thermochemical conversion system of macro algae biomass.

scholarly journals Strahleninaktivierung von Ribonuclease bei erhöhten Temperaturen und unterschiedlichen Dosisraten

1968 ◽  
Vol 23 (7) ◽  
pp. 949-952 ◽  
Author(s):  
Klaus Kürzinger ◽  
Horst Jung
Keyword(s):  
Dose Rate ◽  
Cross Section ◽  
Room Temperature ◽  
Activation Energies ◽  
The Other ◽  
Radical Reactions ◽  
Kcal Mole ◽  
Apparent Activation Energies ◽  
Mev Protons ◽  
Dose Rate Effect

The radiosensitivity of dry ribonuclease was determined at various temperatures between 120 °K and 440 °K using 2 MeV protons. Within this temperature range the inactivation cross section S (T) of ribonuclease may be described as a function of temperature by the expression S(T) = (1.28 + 16·e-1000/RT+14000·e-6500/7RT)·10-14 cm2 .This result indicates that the observed radiation damage to ribonuclease is produced by three different mechanisms, one being independent of temperature, the other two having apparent activation energies of 1 kcal/mole and 6.5 kcal/mole, respectively. From these relatively small activation energies the conclusion may be drawn that radical reactions contribute to the inactivation of enzymes in the dry state. Experiments with Co gamma radiation showed that the radiosensitivity of ribonuclease at 77 °K depends on dose rate; at room temperature a dose rate effect was not observed.

Investigation of irradiation-induced nucleation processes in silicon and germanium

1995 ◽  
Vol 53 ◽  
pp. 224-225
Author(s):  
Harry A. Atwater ◽  
C.M. Yang ◽  
K.V. Shcheglov
Keyword(s):  
Room Temperature ◽  
Crystal Size ◽  
Initial Distribution ◽  
Engineering Control ◽  
Size Evolution ◽  
Silicon And Germanium ◽  
Ge Quantum Dot ◽  
And Control ◽  
Germanium Quantum Dots ◽  
Kinetics Of

Studies of the initial stages of nucleation of silicon and germanium have yielded insights that point the way to achievement of engineering control over crystal size evolution at the nanometer scale. In addition to their importance in understanding fundamental issues in nucleation, these studies are relevant to efforts to (i) control the size distributions of silicon and germanium “quantum dots𠇍, which will in turn enable control of the optical properties of these materials, (ii) and control the kinetics of crystallization of amorphous silicon and germanium films on amorphous insulating substrates so as to, e.g., produce crystalline grains of essentially arbitrary size.Ge quantum dot nanocrystals with average sizes between 2 nm and 9 nm were formed by room temperature ion implantation into SiO2, followed by precipitation during thermal anneals at temperatures between 30°C and 1200°C[1]. Surprisingly, it was found that Ge nanocrystal nucleation occurs at room temperature as shown in Fig. 1, and that subsequent microstructural evolution occurred via coarsening of the initial distribution.

Comparative Labelling and Biokinetic Studies of 99mTc-EDTA(Sn) and 99mTc-DTPA(Sn)

1977 ◽  
Vol 16 (01) ◽  
pp. 30-35 ◽  
Author(s):  
N. Agha ◽  
R. B. R. Persson
Keyword(s):  
Complex Formation ◽  
Significant Influence ◽  
Room Temperature ◽  
Ph Value ◽  
Maximum Activity ◽  
Reduction Step ◽  
Labelling Yield ◽  
Different Temperatures ◽  
Kinetics Of

SummaryGelchromatography column scanning has been used to study the fractions of 99mTc-pertechnetate, 99mTcchelate and reduced hydrolyzed 99mTc in preparations of 99mTc-EDTA(Sn) and 99mTc-DTPA(Sn). The labelling yield of 99mTc-EDTA(Sn) chelate was as high as 90—95% when 100 μmol EDTA · H4 and 0.5 (Amol SnCl2 was incubated with 10 ml 99mTceluate for 30—60 min at room temperature. The study of the influence of the pH-value on the fraction of 99mTc-EDTA shows that pH 2.8—2.9 gave the best labelling yield. In a comparative study of the labelling kinetics of 99mTc-EDTA(Sn) and 99mTc- DTPA(Sn) at different temperatures (7, 22 and 37°C), no significant influence on the reduction step was found. The rate constant for complex formation, however, increased more rapidly with increased temperature for 99mTc-DTPA(Sn). At room temperature only a few minutes was required to achieve a high labelling yield with 99mTc-DTPA(Sn) whereas about 60 min was required for 99mTc-EDTA(Sn). Comparative biokinetic studies in rabbits showed that the maximum activity in kidneys is achieved after 12 min with 99mTc-EDTA(Sn) but already after 6 min with 99mTc-DTPA(Sn). The long-term disappearance of 99mTc-DTPA(Sn) from the kidneys is about five times faster than that for 99mTc-EDTA(Sn).

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