Private Security Preparedness for Disasters Caused by Fire

The subject of the research was the examination of the factors of influence on the preparedness of the private security for disasters caused by fire. In addition to determining the preparedness index, there are deeper insights into the interrelationships between various selected variables and the level of preparedness of members of the private security. Using the random sampling method, 300 adult members of the private security were selected, and they participated in the research. The results of the research indicate that members of private security were not sufficiently prepared to react to fires. The research results could be used as a starting point for conducting further research in this area since the improvement in training of security personnel plays an important role in disaster control and prevention, thereby producing safer and more secure work environment and society

Multicomponent Modelling Kinetics and Simultaneous Thermal Analysis of Apricot Kernel Shell Pyrolysis

Apricot kernel shells are naturally available source of biomass with potential for conversion to clean energy through a thermo-chemical process such as pyrolysis. To facilitate further process development, an advanced mathematical model which represents the process kinetics is developed and validated on the thermal decomposition studies using simultaneous thermal analysis, over a temperature range of 30-900 °C, at four heating rates of 5, 10, 15 and 20 °C min−1, under argon atmosphere. Model-free analysis and numerically developed methods were utilized for determination of effective activation energies, pre-exponential factors and the fractional contribution. A novel approach is introduced in order to determine actual pseudo-components of studied biomass that are included in its composition. The comparative study of the obtained kinetic results was also presented. The results obtained strongly indicated that the pseudo-component reaction modelling method could be employed to predict the experimental devolatilization rate and biomass composition with a high likelihood of success

The non-isothermal combustion process of hydrogen peroxide treated animal bones. Kinetic analysis

The non-isothermal combustion process of hydrogen peroxide (H(2)O(2)) treated animal bones was investigated by TG-DTA techniques. The kinetic triplet for the investigated combustion process was established, using different calculation methods. The investigated process occurs through three reaction stages. It was established that the first stage can be described by the reaction model, which contains two competing reactions with different values of the apparent activation energy, whereas the second reaction stage can be described by the third order reaction model, f(alpha)=(1 - alpha)(3). The hydrogen peroxide treatment reduced the kinetic complexity of organic phase degradation, compared to the same process in untreated bones. From interpretation of TG-DTA results, the third reaction stage can be attributed to the combustion of organic components, which arises from degradation of residual organic material. The appearance of the compensation effect for the investigated process, clearly shows the existence of three characteristic branches attributed to the different reaction stages. It was concluded that the degradation and combustion processes do not happen as a single thermal transformation. (C) 2011 Elsevier B.V. All rights reserved

The non-isothermal thermogravimetric tests of animal bones combustion. Part II. Statistical analysis: Application of the Weibull mixture model

The possibility of applying the Weibull mixture model for the fitting of the non-isothermal conversion data for the combustion process of animal bone samples has been investigated. It has been found that the conversion data at the different heating rates for the investigated samples, can be successfully described by the linear combination of few Weibull distribution functions. An optimal fitting of the conversion data has been obtained by a mixture of three Weibull distribution functions. It was established that the conversion curves calculated by the proposed model, are in good agreement with the raw conversion data of the investigated bone samples. The alterations of distribution parameters in the Weibull mixture model, indicate a probably change of the kinetic nature of the particular reaction stage. A model with a continuous distribution of the apparent activation energies (E-a) can adequately represents the individually stages of the complex combustion process. The characterization of the estimated distribution curves, enable us to receive the additional informations about the kinetic behaviour of individual reaction stages, which does not attainable from the results of conventional kinetic analysis. (C) 2010 Elsevier B.V. All rights reserved

Experimental study of low-rank coals using simultaneous thermal analysis (TG–DTA) techniques under air conditions and radiation level characterization

Simultaneous thermal analysis (TG–DTA) of low-rank coals from different annual periods (2015 and 2018) which originate from Kolubara and Nikola Tesla A (TENT A) coal-fired power plants was studied to identify their combustion characteristics and self-ignition risks. In order to investigate kinetics of thermo-oxidative degradation, model-free models including the Friedman and Kissinger–Akahira–Sunose methods were applied. In accordance with obtained kinetic results, numerical optimization of combustion process was implemented. Homogeneous and heterogeneous types of ignition were identified for the tested coals, and factors that affect their occurrence are the used heating rate and volatile matter content. From thermal susceptibility graph, it was found that the tested coals expand in a wide range of self-ignition risk, depending on their coal rank. The youngest coal (TENT A (2018)) has the largest propensity to self-ignite among high-ranking coals. It was found that less tendency of 2018 coals to show true isokinetic temperature in comparison with 2015 coals is a consequence of intraparticle diffusion limitations, and change of char properties, at higher conversion values. Gamma spectrometry analysis of coals showed that higher concentration of 40K radionuclide (which is in mineral composition) may contribute through its deposition on available sites, decreasing surface area for reaction with oxidizing species. © 2020, Akadémiai Kiadó, Budapest, Hungary

Characterization analysis of Poplar fluff pyrolysis products. Multi-component kinetic study

This paper describes the pyrolysis of Poplar fluff (from Populus alba) using on-line apparatus, and carbonization process at 850 degrees C using the fixed bed reactor. Characteristics of pyrolysis products were examined. Elemental and chemical analyses were shown that Poplar fluff has higher energy content characterized by increased content of fibrous structure (particularly cellulose). Independent parallel reactions model very well describes devolatilization process. It was found that increased amount of extractives can significantly affect on increased release of light gaseous products, but declining hydrocarbons, mostly the alkanes. Liquid product is mainly composed of phenolics, aldehydes, acids, esters and ketones. The carbonization process produces the great abundance of polycyclic aromatic hydrocarbons (PAH's), where naphthalene is the most abundant. Mechanism for PAH's formation was suggested. This study represents the first step in a much wider and more comprehensive way in thermal conversion processes of this type of fuel

Characterization analysis of Poplar fluff pyrolysis products. Multi-component kinetic study

This paper describes the pyrolysis of Poplar fluff (from Populus alba) using on-line apparatus, and carbonization process at 850 degrees C using the fixed bed reactor. Characteristics of pyrolysis products were examined. Elemental and chemical analyses were shown that Poplar fluff has higher energy content characterized by increased content of fibrous structure (particularly cellulose). Independent parallel reactions model very well describes devolatilization process. It was found that increased amount of extractives can significantly affect on increased release of light gaseous products, but declining hydrocarbons, mostly the alkanes. Liquid product is mainly composed of phenolics, aldehydes, acids, esters and ketones. The carbonization process produces the great abundance of polycyclic aromatic hydrocarbons (PAH's), where naphthalene is the most abundant. Mechanism for PAH's formation was suggested. This study represents the first step in a much wider and more comprehensive way in thermal conversion processes of this type of fuel

The non-isothermal thermogravimetric tests of animal bones combustion. Part. I. Kinetic analysis

The non-isothermal combustion of animal bones was investigated by simultaneous thermogravimetric and differential thermal analysis (TG-DTA), in the temperature range Delta T = 20-650 degrees C. The full kinetic triplet (A, E(alpha) and f(alpha)) for the investigated process was established, using different calculation procedures: isoconversional (model-free) and the Kissingers methods. The non-isothermal process occured through three reaction stages (I, II and III). Stage I was described by a reaction model, which contains two competing reactions with different values of the apparent activation energy. The autocatalytic two-parameter Sestak-Berggren (SB) model (conversion function f(alpha) = alpha(0.62)(1-alpha)(3.22)). best described the second (II) reaction stage of bone samples. This stage, which corresponds to the degradation process of organic components (mainly collagen), exhibited the autocatalytic branching effect, with increasing complexity. Stage III, attributed to the combustion process of organic components, was best described by an n-th reaction order model with parameter n = 1.5 (f(alpha) = (1 - alpha()1.5). The appearance of compensation effect clearly showed the existence of three characteristic branches attributed to the dehydration, degradation and combustion processes, respectively, without noticable changes in mineral phase. The isothermal predictions of bone combustion process, at four different temperatures (T(iso) = 200, 300, 400 and 450 degrees C) were established in this paper. It was concluded that the shapes of the isothermal conversion curves at lower temperatures (200-300 degrees C) were similar, whereas became more complex with further temperature increase due to organic phase degradation. (C) 2009 Elsevier B.V. All rights reserved

Sintering behaviour of nanosized HAP powder

The influences of temperature and time on sintering behaviour of nanosized HAP powder were investigate in this paper. The calcium hydroxyapatite powder, with the average crystallite size of 34 +/- 1 nm, was uniaxially pressed at a pressure of 500 MPa. Obtained green compacts were sintered at temperature ranging from 1000 degrees C to 1200 degrees C in air atmosphere at various times. According to the results of scanning electron microscopy, X-ray and FTIR analyses, it is shown that HAP compacts with dense microstructure and average grain size below 250 nm is obtained

Thermo-oxidative evolution and physico-chemical characterization of seashell waste for application in commercial sectors

Thermo-oxidative degradation of mollusk shells to CaO through intermediate phase of CaCO3 has been investigated using various analytical techniques. Powders of shells species (Dosinia exoleta and Ostrea edulis), with particle size fractions of 0.045 - 0.125 mm, 0.125-0.2 mm, and 0.2-1 mm, were subjected to degradation at the various heating rates (5, 10, 15 and 20 degrees C min(-1)). Degradation pathway of this carbonate-rich waste material has not yet been analyzed in detail at particulate level. Understanding transformation process in air should lead to control over yield and morphology of final product. Thermogravimetric analysis (TGA) and X-ray diffraction (XRD) techniques were used to benchmark transformation steps at different heating rates and final decarbonation temperatures, while scanning electron microscope (SEM) was used to analyze the effect of temperature on evolution of morphological changes for particles of different fractions. It was found that sintering in the presence of carbon dioxide (CO2) could be triggered by agglomeration of CaO crystals, enhanced by CO2 adsorption that increases surface energy