This paper describes the influences of some parameters relevant to biomass pyrolysis on the numerical solutions of the nonisothermal
nth-order distributed activation energy model (DAEM) involved the Weibull distribution. Investigated parameters are the integral
upper limit, the frequency factor, heating rate, the reaction order and the shape, scale and location parameters of the Weibull
distribution. Those influences can be used for the determination of the kinetic parameters of the nonisothermal nth-order Weibull DAEM from thermoanalytical data of biomass pyrolysis.
The dependence of the frequency factor on the temperature (A=A0Tm) has been examined and the errors involved in the activation energy calculated from some integral methods without considering
such dependence have been estimated. Investigated integral methods are the Coats-Redfern method, the Gorbachev-Lee-Beck method,
the Wanjun-Yuwen method and the Junmeng-Fusheng method. The results have shown that the error in the determination of the
activation energy calculated ignoring the dependence of the frequency factor on the temperature can be rather large and it
is dependent on x=E/RT and the exponent m.
The pyrolysis of wheat straw has been carried out by means of thermogravimetric analysis in inert atmosphere. The samples
were heated over a range of temperatures that includes the entire range of pyrolysis with three different heating rates of
5, 10 and 20 K min−1. The activation energy values as a function of the extent of conversion for the pyrolysis process of wheat straw have been
calculated by means of the Flynn–Wall–Ozawa isoconversional method, the Vyazovkin–Sbirrazzuoli isoconversional method and
an iterative isoconversional method presented in this article. The results have showed that there are small differences between
the activation energy values obtained from the three methods, and the pyrolysis process reveals a dependence of the activation
energy on conversion and have indicated the validity of the iterative integral isoconversional method. The effective activation
energy for the pyrolysis of wheat straw is 130–175 kJ mol−1 in the conversion range of 0.15–0.85. Furthermore, the prediction of the pyrolysis process under isothermal conditions from
the dependence of the activation energy on the extent of conversion has been presented.
We obtain two countable properties of spaces with a point-countable sn-network, establish the mapping relation between spaces with a point-countable wcs*-network of certain property and locally separable metric spaces, and partially correct a gap in .
The integral methods, which are obtained from the various approximations for the temperature integral, have been extensively
used in the non-isothermal kinetic analysis. In order to obtain the precision of the integral methods for the determination
of the activation energy, several authors have calculated the relative errors of the activation energy obtained from the integral
methods. However, in their calculations, the temperature integral at the starting temperature was neglected. In this work,
we have performed a systematic analysis of the precision of the activation energy calculated by the integral methods without
doing any simplifications.
The results have shown that the relative error involved in the activation energy determined from the integral methods depends
on two dimensionless quantities: the normalized temperature θ=T/T0, and the dimensionless activation energy x0=E/RT0 (where E is the activation energy, T is the temperature, T0 is the starting temperature, R is the gas constant).
Recently, Órfão obtained two simple equations for the estimation of the relative error in the activation energy calculated
by the integral methods . In this short communication, the validity of the equations has been evaluated by comparing the
results calculated by the equations with the results calculated by the equation from theoretical derivation without introducing
In this paper, a systematic analysis of the errors involved in the determination of the kinetic parameters (including the
activation energy and frequency factor) from five integral methods has been carried out. The integral methods analyzed here
are Coats-Redfern, Gorbachev, Wanjun-Yuwen-Hen-Zhiyong-Cunxin, Junmeng-Fusheng-Weiming-Fang, Junmeng-Fang and Junmeng-Fang-Weiming-Fusheng
method. The results have shown that the precision of the kinetic parameters calculated by the different integral methods is
dependent on u (E/RT), that is, on the activation energy and the average temperature of the process.
The accuracy of the newly proposed approximation is tested by numerical analyses. Compared with other existed approximations
for the general temperature integral, the new approximation is significantly more accurate than other approximations.
Food poisoning cases, due to consumption of food from animal sources that contains clenbuterol, have occurred frequently in China over the recent years, causing a certain degree of social panic. Several relevant ministries issued related documentation and took appropriate measures to crack down on the behaviour of illegal manufacture, sale, and use of clenbuterol. However, this behaviour continued due to great economic benefits and ethical problems. This paper investigates the industrial chain of production and sale of clenbuterol in China. Moreover, we discuss the impediments of and the governmental countermeasures being implemented in supervising the use of clenbuterol in China. The positive example in monitoring the use of clenbuterol in China may help to improve food safety management throughout China and other developing countries.
Authors:L. Ma, P. Xiao, J. Cai, X. Li, Z. Ji, Y. Xia, C. Yang, and J. Bao
Uniformity in the height of main stem and tillers is a key factor affecting ideal plant type, a key component in super high-yielding rice breeding. An understanding of the genetic basis of the panicle layer uniformity may thus contribute to breeding varieties with good plant type and high yield. In the present study, a doubled haploid (DH) population, derived from a cross between
rice variety Zhai-Ye-Qing 8 (ZYQ8) and
rice variety Jing-Xi 17 (JX17) was used to analyze quantitative trait loci (QTL) for panicle layer uniformity related traits. Six, four and three QTL were detected for the highest panicle height (HPH), lowest panicle height (LPH) and panicle layer dis-uniformity (PLD), respectively. qHPH-1-1 and qPLD-1 were located at the same interval on chromosome 1. The JX17 allele(s) of these QTL increased HPH and PLD by 2.57 and 1.26 cm, respectively. Similarly, qPLD-7 and qHPH-7 were located at the same interval on chromosome 7, where the ZYQ8 allele(s) increased HPH and PLD by 3.74 and 1.96 cm, respectively. These four QTL were unfavourable for panicle layer uniformity improvement because a decrease of the PLD was accompanied by decrease of the plant height. qPLD-6 and qLPH-6-1 were located at the same interval on chromosome 6, however here the JX17 allele(s) increased LPH, but decreased PLD, suggesting that this QTL was favourable for improvement of panicle layer uniformity. The markers identified in this study are potential for marker assisted breeding for the improvement of the panicle layer uniformity and ideal plant type.