scholarly journals Kinetics of Chemical Properties and Microbial Quantity in Soil Amended with Raw and Processed Pig Slurry

2009 ◽  
Vol 22 (5) ◽  
pp. 732-739 ◽  
Author(s):  
A. Suresh ◽  
Hong L Choi ◽  
Zhukun
Keyword(s):  
Chemical Properties ◽  
Pig Slurry ◽  
Kinetics Of

The effect of origin and physico-chemical properties on the kinetics of reduction of mixed NiO-Fe2O3 oxides with hydrogen

1986 ◽  
Vol 51 (10) ◽  
pp. 2098-2108 ◽  
Author(s):  
Milan Pospíšil ◽  
Jan Topinka
Keyword(s):  
Mixed Oxides ◽  
Mutual Influence ◽  
Spinel Phase ◽  
Chemical Properties ◽  
Inhibitory Effect ◽  
Chemical Parameters ◽  
Physico Chemical ◽  
Preliminary Annealing ◽  
Kinetics Of ◽  
Kinetics Of Reduction

We investigated the effect of origin and some physico-chemical parameters on the kinetics of reduction with hydrogen of two series of mixed NiO-Fe2O3 oxides differing by their composition, the character of their precursors (mixed crystalline nitrates and coprecipitated hydroxides) and their decomposition temperature.This effect manifested itself by different magnitudes of specific surfaces of the mixed oxides and coherent regions of present phases as well as by different oxidizing abilities of the surface and differences in morphology and phase composition of corresponding samples in both series investigated. Nonlinear or nonmonotonous composition dependences of physico-chemical parameters investigated point to a mutual influence of individual components, which is also a function of the system origin and which modifies its reactivity during its reduction with hydrogen. The kinetics of the reduction was studied thermogravimetrically at 320-410 °C. The reduction of oxides of the hydroxide origin is catalytically accelerated by primarily reduced nickel, whereas in corresponding samples of the nitrate series, the total NiO is bound to the spinel phase and the reduction is delayed. Experimental IR spectra, the effect of preliminary annealing and DTA of the mixed oxides point to an inhibitory effect of water, which is constitutionally bound in trace admixtures of the goethite phase, on the kinetics of reduction of samples in the hydroxide series.

Di-imide: Some Physical and Chemical Properties, and the Kinetics and Stoichiometry of the Gas-phase Decomposition

1973 ◽  
Vol 51 (21) ◽  
pp. 3605-3619 ◽  
Author(s):  
C. Willis ◽  
R. A. Back
Keyword(s):  
Gas Phase ◽  
Room Temperature ◽  
Chemical Properties ◽  
Phase Decomposition ◽  
Important Intermediate ◽  
Long Lifetime ◽  
Physical And Chemical ◽  
Text Formation ◽  
Kinetics Of

Preparation of di-imide by passing hydrazine vapor through a microwave discharge yields mixtures with NH3 containing typically about 15% N2H2, estimated from the gases evolved on decomposition. The behavior of the mixture (which melts at −65 °C) on warming from −196 to −30 °C suggests a strong interaction between the components. Measurements of magnetic susceptibility and e.p.r. experiments showed that N2H2 is not strongly paramagnetic, which with other observations points to a singlet rather than a triplet ground-state.Di-imide can be vaporized efficiently, together with NH3, by rapid warming, and the vapor is surprisingly long-lived, with a typical half-life of several minutes at room temperature. The near-u.v. (3200–4400 Å) absorption spectrum of the vapor was photographed; it shows well-defined but diffuse bands, with εmax = 6(± 3) at 3450 Å.Di-imide decomposes at room temperature in two ways:[Formula: see text][Formula: see text]Formation of NH3 was not observed but cannot be ruled out. The decomposition of the vapor is complicated by a sizeable and variable decomposition that occurs rapidly during the vaporization. The stoichiometry of this and the vapor-phase decomposition depends on total pressure and di-imide concentration. The kinetics of the decomposition of the vapor were studied from 22 to 200 °C by following the disappearance of N2H2 by absorption of light at 3450 Å, or the formation of N2H4 by absorption at 2400 Å, and by mass spectrometry. The kinetics are complex and can be either first- or second-order, or mixed, depending on surface conditions. The effect of olefin additives on the decomposition was studied, and is also complex.Mechanisms for the decomposition are discussed, including the possible role of trans-cis isomerization. The relatively long lifetime found for di-imide in the gas phase suggests that it may be an important intermediate in many reactions of hydronitrogen systems.

scholarly journals Soil chemical properties related to acidity under successive pig slurry application

2011 ◽  
Vol 35 (5) ◽  
pp. 1827-1836 ◽  
Author(s):  
Cledimar Rogério Lourenzi ◽  
Carlos Alberto Ceretta ◽  
Leandro Souza da Silva ◽  
Gustavo Trentin ◽  
Eduardo Girotto ◽  
...  
Keyword(s):  
Growth And Development ◽  
Soil Acidity ◽  
Chemical Properties ◽  
Pig Slurry ◽  
No Tillage ◽  
Surface Layers ◽  
Ph Values ◽  
Santa Maria ◽  
Potential Acidity

Pig slurry application as soil manure can alter the chemical properties of the soil and affect its acidity, modifying the environment for crop growth and development. The objective of this study was to evaluate the chemical properties related to soil acidity subjected to successive applications of pig slurry. The experiment was conducted in May 2000, in an experimental area of the Federal University of Santa Maria (UFSM) under no-tillage and lasted until January 2008. Nineteen surface applications of 0, 20, 40, and 80 m³ ha-1 of pig slurry were performed, during a period of 100 months and the soil sampled in the end (layers 0-2, 2-4, 4-6, 6-8, 8-10, 10-12, 12-14, 14-16, 16-18, 18-20, 20-25, 25-30, 30-35, 35-40, 40-50 and 50-60 cm). The application of pig slurry increased soil pH values, an effect that could reach the depth of 8 cm without affecting the potential acidity values. The applications also resulted in accumulation of Ca and Mg exchangeable levels in the surface layers, increasing base saturation and reducing Al saturation. Long-term applications induced an increase in organic matter in the deeper layers. However, the effect of this residue on the potential CEC was less significant and restricted to the surface layers.

Radiation damage in polyethylene as studied by electron spin resonance

1961 ◽  
Vol 262 (1309) ◽  
pp. 207-218 ◽  
Keyword(s):  
Electron Spin Resonance ◽  
Electron Spin ◽  
Alkyl Radical ◽  
Room Temperature ◽  
Chemical Properties ◽  
Resonance Method ◽  
Alkyl Radicals ◽  
Spin Resonance ◽  
Physical And Chemical ◽  
Kinetics Of

The electron spin resonance method was employed to study the nature, concentration and kinetics of the disappearance under varying conditions of radicals produced in polyethylene by fast electron irradiation at 77°K. The predominant radical species at 77°K is the alkyl radical —CH 2 —ĊH—CH 2 —. On being warmed to room temperature it disappears rapidly, revealing a more stable un­identified radical. The kinetics of the decay at room temperature of both radicals was observed. Their stabilities were found to vary in polyethylene samples of differing physical and chemical properties. G values for these radicals are given. Comparison was made with spectra obtained under similar conditions with two pure paraffins and a pure olefin to evaluate the effect of crystallinity branching, molecular weight and unsaturation. In the olefin there is evidence for a build-up of allyl radicals due to the encounter of an alkyl radical with main chain unsaturation. This supports the view that alkyl radicals are mobile, and cross-linking occurs when two such radicals meet.

Cropping, soil type and manure application effects on phosphorus export and bioavailability

2004 ◽  
Vol 84 (3) ◽  
pp. 295-305 ◽  
Author(s):  
A. R. Michaud ◽  
M. R. Laverdière
Keyword(s):  
Soil Type ◽  
Chemical Properties ◽  
Agricultural Practices ◽  
Holistic Approach ◽  
Management Control ◽  
Transport Processes ◽  
Rainfall Simulation ◽  
Pig Slurry ◽  
Soil P ◽  
High Level

A simulated rainfall study was conducted on an array of 36 runoff plots (6 m2 each) deployed on three benchmark soil series of the Missisquoi region in southwestern Québec. The split-plot experimental design tested the effects and interactions of pig slurry treatment as main plots (check vs. 59 kg P ha-1) and cropping (tilled vs. hay) as subplots, on runoff volume and concentrations in total suspended sediment (TSS), tot al phosphorus (TP), dissolved reactive soluble P (DRP), particulate P (PP) and bioavailable P (BioP). TP concentration in runoff ranged from a low of 1.17 mg L-1 average on non-amended Bedford hay, to a peak concentration average of 9.55 mg L-1 on manured and tilled Saint-Sébastien plots. Variance analysis indicated significant contributions of treatments in explaining TP concentration in runoff as follows: Soil type effect > Cropping effect > Soil × Cropping interaction > Manure effect. Erosion and sediment transport processes were identified as prime vectors of TP export . Manure effect alone accounted for 35% of overall DRP variability, while soil type alone accounted for 70% of variability in particulate P bioavaibility (BioP/PP). Among practical implications of this study is the importance of assessing PP bioavaibility to adequately predict the adverse impact of runoff on aquatic ecosystems. The high level of interaction among cropping and manure treatment and the site- specific influence of soil physical and chemical properties also calls for a holistic approach to nonpoint P risk assessment and management, that focusses on timely manure P management, control of soil P build-up and agricultural practices minimizing surface runoff. Key words: Phosphorus, P-index, rainfall simulation, runoff, erosion, bioavailability, sediment

scholarly journals Changes of Physico–Chemical Properties of Pig Slurry During Storage

2011 ◽  
Vol 34 (3) ◽  
pp. 179-183
Author(s):  
Mansyur Mansyur ◽  
Hong L Choi
Keyword(s):  
Chemical Properties ◽  
Pig Slurry ◽  
Physico Chemical

scholarly journals Kinetics of Transesterification of Croton megalocarpus Oil Using Alkaline Earth Catalysts with Conventional and Microwave Heating

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Anil Kumar ◽  
Henry K. Kiriamiti
Keyword(s):  
Microwave Irradiation ◽  
Alkaline Earth ◽  
Heterogeneous Catalysts ◽  
Methyl Esters ◽  
Chemical Properties ◽  
Reaction Rates ◽  
Conventional Heating ◽  
Reaction Rate Constants ◽  
Scanning Electron Micrography ◽  
Kinetics Of

Transesterification kinetics of Croton megalocarpus oil to produce fatty acid methyl esters (FAME) was studied using homogeneous NaOH and heterogeneous alkaline earth Nano MgO, MgO, Nano CaO, CaO, Reoxidized CaO, SrO, and BaO catalysts. Characteristic surface, bulk, and chemical properties of the heterogeneous catalysts were obtained which included surface area, pore properties, scanning electron micrography, X-ray diffraction, basic strength, and basicity. The catalyst porosity varied as Nano MgO > Nano CaO > MgO > CaO > CaO-RO > SrO > BaO and basicity as BaO > SrO > Nano CaO > CaO RO > CaO > Nano MgO > MgO. Catalysts NaOH, BaO, SrO, and Nano CaO gave a good FAME yield (>50%), and reaction order and rate constant have been reported for these catalysts, for both conventional heating and microwave irradiation. The overall reaction for NaOH was of 1st order for microwave irradiation with respect to triglyceride and of 2nd order with respect to triglyceride under conventional heating. For the heterogeneous catalysts, the overall reaction was of 3rd order, 2nd order with respect to triglyceride and 1st order with respect to methanol for both heating methods. Reaction rate constants for microwave irradiation were higher than those for conventional heating due to faster reaction rates under such heating. BaO was the most active heterogeneous catalyst, followed by SrO and Nano CaO, which was in accordance with their basicity.

scholarly journals Sublimation Kinetics of Zirconium Tetrafluoride

2014 ◽  
Vol 1019 ◽  
pp. 398-405
Author(s):  
C.J. Pretorius ◽  
A.D. Pienaar ◽  
P.L. Crouse ◽  
H.F. Niemand
Keyword(s):  
Chemical Properties ◽  
Inert Atmosphere ◽  
Nuclear Industry ◽  
Nuclear Grade ◽  
Accurate Estimation ◽  
Chemical Waste ◽  
Hazardous Chemical ◽  
Zirconium Tetrafluoride ◽  
Sublimation Kinetics ◽  
Kinetics Of

An important step of a new process being developed for the beneficiation of the mineral zircon (Zr (Hf)SiO4) to produce nuclear grade zirconium (Zr) metal, is the separation of the Zr from the hafnium (Hf). Zr ores typically contain between 1 and 3% Hf , whereas the use of Zr metal in the nuclear industry requires a Hf content <100 ppm, owing to its high neutron-capture cross section. The separation step is therefore key in the preparation of nuclear grade Zr, which is considered to be very difficult due to the various similarities in their chemical properties. The preparation of hafnium free zirconium relies on the traditional wet separation systems, for example solvent extraction systems. In contrast to the traditional aqueous chloride systems, Necsa focusses on dry fluoride-based processes. Dry processes have the advantage of producing much less hazardous chemical waste. In the work reported her, separation is achieved by sublimation/de-sublimation in the tetrafluoride form. The tetrafluoride is prepared by fluorination of plasma dissociated zircon (PDZ or Zr (Hf)O2•SiO2) with ammonium bifluoride (ABF). The separation involves the selective sublimation of the two tetrafluorides in an inert atmosphere under controlled conditions, and subsequent similarly selective desublimation. An accurate estimation of the sublimation rates the zirconium tetrafluoride (ZrF4) and hafnium tetrafluoride (HfF4) as a function of temperature is required since this forms the basis of the development of a sublimation model to determine whether the concept under consideration is theoretically possible. The sublimation kinetics of ZrF4is reported in this paper.

scholarly journals Soil chemical properties and maize yield under application of pig slurry biofertilizer

2016 ◽  
Vol 20 (1) ◽  
pp. 42-48 ◽  
Author(s):  
Marcelo E. Bócoli ◽  
José R. Mantovani ◽  
José M. Miranda ◽  
Douglas J. Marques ◽  
Adriano B. da Silva
Keyword(s):  
Block Design ◽  
Chemical Properties ◽  
Soil Surface ◽  
Maize Yield ◽  
Soil Chemical Properties ◽  
Nutrient Concentrations ◽  
Detectable Effect ◽  
Corn Yield ◽  
Pig Slurry ◽  
Randomized Block Design

ABSTRACT Organic materials subjected to a process of anaerobic digestion in a digester produce biofertilizer that can be used in agriculture as nutrient source. The objective of this study was to evaluate the effect of pig slurry biofertilizer on soil chemical properties and on corn yield and nutrient concentrations in leaves and kernels. The experiment was conducted in the field from November 2012 to April 2013, and was arranged in a randomized block design with seven treatments and four replicates. The treatments consisted of doses of pig slurry biofertilizer (0; 40; 80; 120; 160; 200 and 240 m3 ha-1), applied to the soil surface in a single application, at stage V2 of corn plants. Thirty-three days after biofertilization, soil samples were collected in each plot. Corn was harvested 129 days after sowing. Doses up to 240 m3 ha-1 of pig slurry biofertilizer applied to soil with good fertility did not influence soil chemical properties and corn yield. The use of pig slurry biofertilizer had no detectable effect on nutrient concentrations in corn leaves and kernels.

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