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He Chen, Jianbo Kou, Man Hu and Guowei Shu

, I., Marco, M. (2010). Can encapsulation lengthen the shelf-life of probiotic bacteria in dry products. International journal of food microbiology, 136 (3), 364-367. 7. Altieri, C., Bevilacqua, A., D’Amato, D. (2008). Modelling the survival of starter lactic acid bacteria and Bifidobacterium bifidum in single and simultaneous cultures. Food Microbiology, 25 (5), 729-734. 8. Almeida, B.M., Erthal S.R., Padaa O.E. (2008). Response surface methodology (RSM) as a tool for optimization in analytical chemistry. Talanta, 76 (2), 965-977. 9. Ye Chunlin

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Guowei Shu, Zhuo Wang, Li Chen, Qian Zhang and Ni Xin

). Determination of antioxidant and radical scavenging activity of basil (ocimum basilicum l. family lamiaceae) assayed by different methodologies. Phytother Res. 21(4), 354-361. DOI: 10.1002/ptr.2069 6. Haenlein, G. F. W. (2004). Goat milk in human nutrition. Small Ruminant Res. 51(2), 155-163. DOI: 10.1016/j.smallrumres.2003.08.010 7. Halliwell, B. (2012). Free radicals and antioxidants: updating a personal view. Nutr. Rev. 70(5), 257. DOI: 10.1111/j.1753-4887.2012.00476.x 8. Halliwell, B. (2013). The antioxidant paradox: less paradoxical now?. Brit. J

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Archives of Mining Sciences

The Journal of Committee of Mining of Polish Academy of Sciences

Open access

Helen Weldemichael, Shimelis Admassu and Melaku Alemu

methodology (RSM) as applied to consumer acceptability data. LWT 41:1485–1492. 12. Edward,V.A., Huch, M., Dortu, C., Thonart, P., Egounlety, M., Holzapfel, W.H., Franz C.M.A.P.(2010). Biomass production and small-scale testing of freeze-dried lactic acid bacteria starter strains for cassava fermentations. Food Control 22:389-395. 13. Ei-Gendy, N.S., Madian, H.R., Abu Amr, S.S. (2013). Design and optimization of a process for sugarcane molasses fermentation by Saccharomyces cerevisiae using response surface methodology. International Journal of Microbiology

Open access

Jan Drzewiecki, Jacek Myszkowski, Andrzej Pytlik and Mateusz Pytlik

Abstract

This paper presents the results of testing the explosion effects of two explosive charges placed in an environment with specified values of confining pressure. The aim of this study is to determine the impact of variable environmental conditions on the suitability of particular explosives for their use in the prevention of natural hazards in hard coal mining. The research results will contribute to improving the efficiency of currently adopted technologies of natural hazard prevention and aid in raising the level of occupational safety. To carry out the subject matter measurements, a special test stand was constructed which allows the value of the initial pressure inside the chamber, which constitutes its integral part, to be altered before the detonation of the charge being tested. The obtained characteristics of the pressure changes during the explosion of the analysed charge helped to identify the work (energy) which was produced during the process. The test results are a valuable source of information, opening up new possibilities for the use of explosives, the development of innovative solutions for the construction of explosive charges and their initiation.

Open access

Ionel-Lucian Cioca and Roland Iosif Moraru

In order to meet statutory requirements concerning the workers health and safety, it is necessary for mine managers within Valea Jiului coal basin in Romania to address the potential for underground fires and explosions and their impact on the workforce and the mine ventilation systems. Highlighting the need for a unified and systematic approach of the specific risks, the authors are developing a general framework for fire/explosion risk assessment in gassy mines, based on the quantification of the likelihood of occurrence and gravity of the consequences of such undesired events and employing Root-Cause analysis method. It is emphasized that even a small fire should be regarded as being a major hazard from the point of view of explosion initiation, should a combustible atmosphere arise. The developed methodology, for the assessment of underground fire and explosion risks, is based on the known underground explosion hazards, fire engineering principles and fire test criteria for potentially combustible materials employed in mines.

Open access

Agnieszka Surowiak and Marian Brożek

). Stark U., Muller A., 2005. Effective methods for measurement of particle size and shape. Aufbereitungs Technik, 45, p. 6-16. Surowiak A., 2007. Influence of particles physical and geometrical properties distribution on the separation efficiency of jigging process on the example of coal. Ph, D Thesis, Main Library of University of Science and Technology, Cracow, Poland, (in Polish). Surowiak A., Brozek M., 2014. Methodology of calculation the terminal settling velocity distribution of spherical for high values of the Reynold’s number

Open access

Agnieszka Surowiak and Marian Brożek

Abstract

The particle settling velocity is the feature of separation in such processes as flowing classification and jigging. It characterizes material forwarded to the separation process and belongs to the so-called complex features because it is the function of particle density and size. i.e. the function of two simple features. The affiliation to a given subset is determined by the values of two properties and the distribution of such feature in a sample is the function of distributions of particle density and size. The knowledge about distribution of particle settling velocity in jigging process is as much important factor as knowledge about particle size distribution in screening or particle density distribution in dense media beneficiation.

The paper will present a method of determining the distribution of settling velocity in the sample of spherical particles for the turbulent particle motion in which the settling velocity is expressed by the Newton formula. Because it depends on density and size of particle which are random variable of certain distributions, the settling velocity is a random variable. Applying theorems of probability, concerning distributions function of random variables, the authors present general formula of probability density function of settling velocity for the turbulent motion and particularly calculate probability density function for Weibull’s forms of frequency functions of particle size and density. Distribution of settling velocity will calculate numerically and perform in graphical form.

The paper presents the simulation of calculation of settling velocity distribution on the basis of real distributions of density and projective diameter of particles assuming that particles are spherical.

Open access

Alicja Nowak and Agnieszka Surowiak

Abstract

The necessity of obtaining many types of products of various granulation requires - more than in case of majority of other processes of mineral processing - constructing complex, multileveled technological systems of classification. They may consist of operations conducted by means of classifying devices of various types or devices of the same type and the same or various constructing parameters. The paper presents the results of three-staged process of suspension separation of solid phase granulation < 60 μm in two series of investigation conducted in hydrocyclones of the cylindrical part diameter D = 30 mm. The effects of classification as separation efficiency, yields and losses of finest fractions in separation products, sizes of given separation particles and factors of separation efficiency were compared in case when the diameters of hydrocyclones underflow nozzles were the same for each classification stage and in case when these diameters were bigger for each individual separation level. The main purpose of the paper was the attempt of describing real separation curves obtained experimentally by model functions for various work conditions of hydrocyclones systems. To determine the characteristics of separation the approximation functions were used to approximate the separation curves. They were function describing Weibull distribution function for the experimental series “a” (equation 8) and function describing logistic distribution function for experimental series “b” (equation 9). Basing on the approximated separation curves the factors of separation efficiency were calculated, which were probable error (Ep), imperfection (I), characteristic particles (d25, d75) and cut points (d50). The yields of fractions < 20 μm and < 2 μm were calculated in hydrocyclones overflows. It was stated that it is impossible to obtain very high (like > 80%) contents of ultrafine fraction < 2 μm in overflow of nth separation level - even by high yields of this fraction in individual overflows and high separation efficiency - if the contents of this fraction in the feed of 1st classification level is very small. Applying the Hancock equation (1) the technological efficiency of obtaining fraction < 20 μm and < 2 μm in hydrocyclones overflows was calculated.

Open access

Ebrahim Ghasemi, Mohammad Ataei and Kourosh Shahriar

underground coal mines . Safety Science, Vol. 55, p. 26-33. Saaty T.L., 1980. The analytic hierarchy process . Mcgraw-Hill, New York. Saboya Jr F., Alves M.G., Pinto W.D., 2006. Assessment of failure susceptibility of soil slops using fuzzy logic . Engineering Geology, Vol. 86, p. 211-224. Sadiq R., Husain T., 2005. A fuzzy-based methodology for an aggregative environmental risk assessment: a case study of drilling waste . Environmental Modelling and Software, Vol. 20, p. 33-46. Shahriar K., Bakhtavar E., 2009. Geotechnical risks in underground