The knowledge of the main mechanical constants of a rock mass (such as strength, deformability and the Poisson's ratio) is one of the most important for rock engineering design on or in rock mass. Until now, several empirical relationships were determined for calculating these material constants based on both the quality of the studied rock mass (ie. RMR or GSI values) IntroductionLarge scale rock mass characterization introduces material parameters related to mechanical properties. The most important properties are the deformation modulus; the unconfined strength and the Poisson's ratio value of the rock mass in interest. These material parameters are frequently related to laboratory data characteristics of intact rock samples and to the classical rock mass classification systems (e.g. RQD, Q, RMR or GSI). These rock mass quality measures quantify the relation between the rock mass and the intact rock.The established empirical relations between the mechanical parameters of rock masses (unconfined compressive strength, deformation modulus) and the rock mass classification systems (RMR or GSI values) show exponential increasing deformation modulus and compressive strength with the increasing quality of the rock mass.The paper summarizes the observed correlations published between the mechanical properties of rock masses and one of the rock mass classification systems. It was found, that the deformation modulus and the strength of a rock mass data may reflect a simple exponential relationship of the observed quantities. According to analysis of different proposed equations a new formula is suggested and the modification ratio (i.e. ratio of the deformation modulus and the strength of rock mass) is also determined.However, it is important to note, that there are huge differences between the published date and the empirical formulas. The reason for this variance is the difference in situ testing methods, that may give different values of mechanical parameters even for the same rock mass. According to Bieniawski [1], even a single testing method, such as flat jack test, can lead to a widely scattering results even where the rock mass is very uniform. The other reason for the discrepancy in the different calculation methods is the directional effect. Most rock masses are anisotropic and do not have single deformation modulus [2].There is no mechanical (physical) interpretation of the above empirical equations but these were analysed by e.g. [3]. Recently, Ván and Vásárhelyi [4] suggested a damage mechanical approach to analyse them. In this paper their method will be also presented.
En la presente investigación se analiza la velocidad de articulación, es decir, la rapidez de la producción de los signos lingüísticos, en el habla semiespontánea. Comparamos la velocidad media de cuatro dialectos del español (madrileño, andaluz, mexicano y rioplatense), para tener la respuesta a la pregunta si se habla más rápidamente en Europa que en América. Además, investigamos la velocidad de articulación de estudiantes hungaroparlantes de nivel B2 para ver si sus valores son más lentos que los de los nativos, y si es necesario el desarrollo de las competencias comunicativas de los alumnos. Nuestros resultados muestran que (i) no hay una diferencia considerable entre los cuatro dialectos del español analizados, aunque el español mexicano resulta ser el más rápido; (ii) la velocidad de habla de los estudiantes húngaros es significativamente más lenta que el valor medio de la velocidad de cualquier dialecto analizado del español.
Tilmicosin is a widely used antibiotic in veterinary applications. Its antimicrobial activity is ranged from Gram-positive and some Gram-negative bacteria towards activities against Mycoplasma and Chlamydia. Adsorption affinity of tilmicosin antibiotics towards bovine serum albumin was investigated by both spectroscopic (UV-vis, Photoluminescence) and calorimetric methods. The interaction was determined on the basis of quenching of albumin by tilmicosin. Results confirm noncovalent binding of tilmicosin on bovine serum albumin with 1:1 stoichiometry associated with pK = 4.5, highlighting possible removal of tilmicosin molecules from the albumin surface through exchange reactions by known competitor molecules. Calorimetric measurements have confirmed the weak interaction between tilmicosin and albumin and reflect enhanced denaturation of the albumin in the presence of tilmicosin antibiotic. This process is associated with the decreased activation energy of conformational transition of the albumin. It opens a new, very quick reaction pathway without any significant effect on the product by noncovalent binding the tilmicosin molecules to the protein molecules. Results highlight the medical importance of these investigations by considerable docking of the selected antibiotic molecules on serum albumins. Although the binding may cause toxic effects in living bodies, the strength of the binding is weak enough to find competitor molecules for effective removals from their surface.
With the intent of making data acquisition for fractal geometry-based discrete fracture network (DFN) modeling time-efficient and automatized, a new method was established. For the automation of data retrieval from the images of the studied surfaces, a series of image-processing operations and MATLAB algorithms have been developed. The method allows the retrieval of more than 1,000 fracture-length data/cm2 of one sample in several minutes. This methodology tends to be a useful tool in studies of fracture network geometries. DFN models of a supposed excavated and/or environmental damage zone, designed with the use of data supplied by the above method, are presented in this work as an example.
In this study, we analyze the so-called “syllable contraction”, that is, the reduction of a sequence of two identical vowels to the duration of a single sound, across word boundaries. We investigate the phenomenon in the semi-spontaneous speech of speakers of the following dialects of Spanish: Madrilenian, Andalusian, Mexican and Rioplatense. Furthermore, we compare their results with the oral (also semi-spontaneous) production of B2 (CEFR) level Hungarian learners of Spanish. We raise the following research hypotheses: (i) syllable contraction is a common phenomenon in all of the four analyzed dialects; however, (ii) it does not appear (or only occasionally) in the speech of the Hungarian learners. For our analysis, we used fifty recordings (interviews) of ninety-nine minutes in total, and we examined them in the phonetic-acoustic software Praat. Our results support both of the hypotheses partially: (i) syllable contraction appears in all of the analyzed dialects, but only in less than half of the cases; (ii) although the phenomenon appears in the oral production of the Hungarian learners, we found only one example of syllable contraction in the Hungarian informants’ speech.
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