Oil shale semicoke, formed in retort furnaces, is a source of severe environmental pollution and is classified as a dangerous
solid waste. For the industrial application of oil shale semicoke in combustion, this present work focused on the thermal
analysis of its combustion characteristics. The pyrolysis and combustion experiments of semicoke were conducted in a Pyris
thermogravimetric analyzer. From the comparison of pyrolysis curves with combustion curves, the ignition mechanism of semicoke
samples prepared at different carbonization temperatures was deduced, and was found to be homogeneous for semicoke samples
obtained at lower carbonization temperature, shifting to heterogeneous with an increase in the carbonization temperature.
The effect of carbonization temperatures and heating rates on the combustion process was studied as well. At last, combustion
kinetic parameters of semicoke were calculated with the binary linear regression method, showing that activation energy will
increase with increasing the heating rate.
Dauricine has a variety of pharmacological properties including anti-inflammatory, anti-arrhythmic, and antihypertensive effects as well as reversing multidrug resistance (MDR) of cancer cells. While its therapeutic application is increasing, its bioavailability of different administration routes has not been studied. In the present study, we developed and validated a liquid chromatography/electrospray ionization mass spectrometry method (LC-MS/MS). Using this method, we quantified dauricine in rat plasma after administration via intravenous (i.v.) injection, per oral (p.o.), and intraperitoneal injection (i.p.). Our results indicated that this method detected plasma dauricine with a good linearity in the range of 1.95–1000.00 ng/mL (r = 0.9997). The extraction method showed an average intra- and inter-day recovery of 98.21–104.35% and 98.0–103.58%, respectively. Dauricine showed a fast absorption and widespread distribution after administration in all three tested routes. After intravenous administration (2.5, 5.0, 10.0 mg/kg), the pharmacokinetics of dauricine exhibited a first-order kinetics. In addition, dauricine showed a slow elimination with a long half-life (t1/2z) and double peaks phenomenon following p.o. and i.p. administration. Furthermore, using area under the plasma concentration-time curve (AUC), we calculated absolute bioavailability, which was over twofold higher when administered via i.p. than via p.o. administration. The newly obtained information from our study will provide important reference for dauricine dose and administration route in designing dauricine therapy for applicable diseases.
In this paper, pyrolysis characteristics of oil shale obtained from
Huadian, China, are investigated by thermogravimetry method. The effect of
operating conditions, such as particle size, heating rate on the pyrolysis
process is analyzed, and kinetic parameters of pyrolysis at different heating
rates are calculated using a two-stage Arrhenius model that is solved by the
On the basis of these experimental results
and theoretical analysis, a mathematical model, fully suitable for the pyrolysis
characteristics of oil shale, is developed: mass loss rate is described by
a two-stage intrinsic kinetics equation for reducing the calculation error;
pyrolytic heat value of volatile is contained in energy equation, and density
equation is considered as well, due to the release of a large amount of volatiles
in pyrolysis process. Thermogravimetric experimental data are used to validate
the described models.
Combustion and pyrolysis experiments of Huadian oil
shale have been conducted using a STA409 thermogravimetric analyzer. The effect
of various factors on combustion of oil shale is studied. Particle size has
little effect on combustion process of oil shale; starting temperature of
combustion mass loss and ignition temperature of oil shale decrease with increasing
O2 concentration of ambient gas; increase of heating
rate can result in ignition temperature, burn-out temperature and maximum
rate of combustion mass loss increasing. Homogeneous ignition mechanism of
oil shale is ascertained using a hot state microscope.
energy was determined using Arrhenius model that is solved by Freeman–Carroll
method. Calculation results show activation energy will increase with heating
Authors:D. Qi, X. Wieneke, X. Zhou, X. Jiang and P. Xue
Karst rocky desertification (KRD) is a process of soil desertification, which leads to the decline of soil quality and biomass. We conducted a plant community survey in KRD areas in Chongqing, China. Our aims were to determine key soil properties that shape plant communities and to identify essential leaf functional traits (LFTs) in responding to the progression of KRD. The vegetation survey was carried in a total of twenty study sites (five replicates for four stages of KRD) in the Wushan County in Chongqing, China. Leaves were collected from all the species in every site and measured/calculated for five LFTs, namely, specific leaf area, leaf area, leaf thickness, leaf tissue density, and leaf dry matter content. Soil samples were collected in triplicates in each site to measure soil properties. We found that the overall richness and diversity of community decreased along with the progression of KRD. Phanerophytes predominated in all the KRD areas. Soil pH was the main determinant of vegetation structure. Leaves with lower area yet higher density had the optimal adaptability in KRD regions, which can be planted as pioneer vegetation to restore land in KRD regions.
Co-combustion experiments of mixture of Huadian
oil shale and Heshan coal with high sulphur content have been conducted using
a thermogravimetric analyzer. The effects of five different Ca/S mol ratios
on the combustion characteristics of mixture fuel are analyzed using TG and
DTG curves. The results show that the initial temperature of combustion of
mixture fuel is decreased with an increase in the oil shale content of mixture
fuel. The combustion characteristic of mixture fuel is superior to that of
Heshan coal. Adding about 20 mass% Huadian oil shale into Heshan coal is feasible
for desulfurization of mixture fuel during combustion.
Authors:X. X. Han, X. M. Jiang, Z. G. Cui, J. W. Yan and J. G. Liu
For obtaining high shale oil yield as well as treating shale char efficiently and in an environmentally friendly way in a new comprehensive utilization system of oil shale, a series of fundamental experiments have been conducted for exploring the effects of retorting factors on shale oil yield and shale char characteristics. Based on these previous studies, in this article, combustion experiments of shale chars obtained under various retorting conditions were performed with a Q5000IR thermogravimetric analyzer and a Leitz II-A heatable stage microscope and the effects of retorting factors were discussed on the combustion characteristics of shale char. Among four studied retorting parameters, retorting temperature and residence time exert very significant influence on the combustion characteristics of shale char. Either elevating the retorting temperature from 430 to 520 °C or lengthening the residence time at a low retorting temperature will largely decrease residual organic matters within shale char, resulting in decreasing mass loss in the low-temperature stage of combustion process of shale char, an elevation of ignition temperature and a shift of ignition mechanism from homogeneous to heterogeneous. One set of retorting condition was also recommended as a reference for designing the comprehensive utilization system of oil shale studied in this work: retort temperature of 460–490 °C, residence time of 20–40 min, particle size of <3 mm, and low heating rate of <10 °C/min.
The production rates (numbers of atoms per gram of the respective elements per second) of 40 radioactive nuclides of 34 elements by neutron capture reactions in a reactor were determined from about 130 photopeaks of the -ray spectra. The ratios of these production rates were called R-matrix elements. These production rates and the respective thermal neutron capture cross sections were used to calculate the respective apparent neutron fluxes at the position of irradiation and the -matrix elements which were the ratios of these apparent neutron fluxes. These matrix elements express clearly the correlations among various elements and thus may be used in the mono-standard or small-number-standards method in neutron activation analysis.
Authors:L. Yu, S. Wang, X. Jiang, N. Wang and C. Zhang
Combustion experiments of three typical seaweeds (Gracilaria cacalia, Enteromorpha clathrata and Laminaria japonica) have been studied using a DTA-60H Thermal Analyzer and the combustion processes and characteristics are studied. Thermogravimetric
experiments are carried out on the samples with 0.18 mm particle size at the heating rate of 20°C min−1.
The results indicate that the ignition mode of seaweed is homogeneous and the combustion process is composed of dehydration,
the pyrolysis and combustion of volatile, transition stage, the combustion of char as well as the reaction at high temperature.
And the combustion characteristic parameters are obtained such as ignition temperature, maximum rate of combustion, burnout
temperature etc. The combustion models of these seaweeds are also analyzed. The combustion characteristics and model differences
between the seaweed and woody biomass are caused by the differences of volatile components. The combustibility indexes of
seaweeds calculated are better than that of woody biomass, and the index of Gracilaria cacalia is the best. At last, activation energies are determined using Arrhenius model that is solved by binary linear regression
Authors:W. He, F. Deng, G.-X. Liao, W. Lin, Y.-Y. Jiang and X.-G. Jian
New special engineering thermoplastics, poly(phthalazinone ether sulfone) (PPES) and poly(phthalazinone ether sulfone ketone)
(PPESK), containing phthalazinone are synthesized through step-polymerization. The kinetics of thermal degradation of PPES
and PPESK (1/1) in nitrogen is investigated at several heating rates by thermogravimetry (TG). It is concluded that, based
on using Satava’s theory, the thermal degradation mechanism of PPESK (1/1) is nucleation and growth, the order of reaction
of the degradation process is one (n = 1). In contrast, the thermal degradation mechanism of PPES is a phase boundary controlled reaction and the order of the
reaction is two (n = 2). The kinetic parameters, including reaction energy and frequency factor of thermal degradation reaction for PPES and
PPESK (1/1) are analyzed using isoconversional Friedman, Kissinger–Akahira–Sunose (K–A–S) and Ozawa method. In addition, the
study focus on the influence of heating rate and ratio of ketone/sulfone on thermal stability and the life estimation are