Wyniki wyszukiwania - BazTech

1

Wpływ wielkości komórek na dezintegrację drożdży piekarniczych w młynie perełkowym

Trawińska A., Kacprowicz A., Solecki M.

Przemysł Chemiczny

|

2017

|

T. 96, nr 9

1898--1901

PL

Przedstawiono wyniki badań nad uwalnianiem związków wewnątrzkomórkowych i rozrywaniem ścian komórkowych w zależności od wielkości mikroorganizmów. Badania wykonano dla drożdży piekarniczych Saccharomyces cerevisiae. Stężenie suchej masy w zawiesinie mikroorganizmów wynosiło 0,002 g/cm³. Fazę ciągłą zawiesiny stanowił roztwór wodny zawierający 0,15 M NaCl i 4 mM K₂HPO₄. Proces dezintegracji prowadzono w poziomym młynie perełkowym. Kinetykę rozrywania komórek wyznaczano na podstawie liczby żywych mikroorganizmów. Stopień uwolnienia białka określano metodą Bradforda. Potwierdzono, że w przypadku większych rozmiarów komórek występują większe szybkości dezintegracji drożdży. Wykazano, że opis procesu oparty na średnicy minimalnej (elipsoidalny model komórek) jest korzystniejszy niż opis oparty na średnicy średniej (kulisty model komórek).

EN

The Saccharomyces cerevisiae baker yeast microorganisms were disintegrated in a horizontal bead mill to study the relationship between the release of intracellular compds. and cell wall disruption depending on the size of microorganisms. The concn. of the microorganism dry mass in the suspension was 0.002 g/cm³. The continuous phase of the slurry was an aq. soln. of 0.15 M NaCl and 4 mM K₂HPO₄. Kinetics of cell disruption were detd. by the no. of live microorganisms. The degree of protein release was detd. by the Bradford method. The yeast disintegration rate increased with increasing the cell size. The process model based on min. diam. (ellipsoidal cell model) was more efficient than the mean diam.-based model (spherical cell model).

2

Wpływ stężenia zawiesiny na przebieg uwalniania związków z komórek mikroorganizmów podczas dezintegracji ultradźwiękowej

Kacprowicz A., Trawińska A., Urbaniak M., Solecki M.

Przemysł Chemiczny

|

2017

|

T. 96, nr 12

2514--2518

PL

Przedstawiono wyniki badań dezintegracji komórek drożdży piekarskich Saccharomyces cerevisiae w homogenizatorze ultradźwiękowym. Doświadczenia przeprowadzono dla stężeń suchej biomasy z zakresu 0,03-0,05 g/cm³. Stopień dezintegracji określano na podstawie pomiarów absorbancji światła o długości fali 260 nm. Kinetykę procesu uwalniania związków wewnątrzkomórkowych opisano liniowym równaniem różniczkowym pierwszego rzędu. W przypadku największych stężeń zawiesiny zaobserwowano odchylenia przebiegu procesu od zaproponowanego modelu. Dla przeprowadzonych eksperymentów uzyskano dopasowanie mieszczące się zakresie 0,97-0,99. Wykazano wzrost stałej szybkości procesu uwalniania kwasów nukleinowych ze zwiększaniem stężenia zawiesiny drożdży.

EN

Baking yeast Saccharomyces cerevisiae were suspended in saline soln. (dry matter concn. 0.03-0.05 g/cm³) and then disintegrated in ultrasonic homogenizer to release nucleic acids. The degree of disintegration was detd. by measuring the absorbance of light at a wavelength of 260 nm. Linear of first order differential equations were used to describe the kinetics of disintegration (coeff. of determination 0.97-0.99). An increase of suspension concn. resulted in increasing the process rate.

3

Chemical Degradation and Processes of Erosion of Post-Mine Territories After Mining Exploration of Iron Ore

Pusz A., Rogalski D., Trawińska A.

Journal of Ecological Engineering

|

2017

|

Vol. 18, nr 6

71--79

EN

The subjects of this study were uncultivated mining waste heaps which are remnants of the territories abandoned after the exploration of iron ore. The aim of this analysis was the assessment of the influence of these objects on the soil located in the nearest surroundings, as well as estimation of the level of their degradation. It was ascertained that direct geomechanical degradation exists in the examined object, which is connected with soil profile destruction in consequence of transformation of hitherto existing geomorphological conditions, deformation of natural shape of territory, density of soil levels and deformation of the spatial layout. As a result of the examination, it was pointed out that chemical degradation as well as degradation of ecological structure occur on the analyzed territory. Progressing processes of water erosion on the side of waste heap are the consequence of improperly profiled, steep slopes causing the uncontrolled flow of rainwater, lack of flora and dense, micrograiny structure of soils which prevents the effective infiltration of water. Penetration of water into the ground causes the creation of channels which, in dry periods, can become additional pathways for the possible landslides.

4

Speaker identification based on artificial neural networks. Case study: the Polish vowel (pilot study)

Salapa K., Trawińska A., Roterman I., Tadeusiewicz R.

Bio-Algorithms and Med-Systems

|

2014

|

Vol. 10, no. 2

91--99

EN

Current statistical methods and technologies used for speaker identification via dynamic formant frequency often involve classic multivariate analyses that must meet a number of criteria in order to be considered trustworthy. The authors propose more advanced classification techniques, including artificial neural networks. Owing to iterative learning algorithms, neural networks can be trained to detect highly complex, nonlinear relations hidden in input data. This study specifically considers feed-forward multilayer perceptron and radial basic function network models. The investigation involves an analysis of the Polish vowel (stressed or unstressed) in selected contexts described by the four lowest formant frequencies. Results indicate high accuracy of neural networks as a speaker identification tool reaching up to 100%. In addition, the authors have determined that the accuracy of classification is similar when based on a single context to when input data are aggregated over several different contexts.

5

Forensic voice comparison by means of artificial neural networks

Sałapa K, Trawińska A., Roterman-Konieczna I.

Bio-Algorithms and Med-Systems

|

2013

|

Vol. 9, no. 4

191--197

EN

This article examines the effectiveness of artificial neural networks (ANNs) as forensic voice comparison techniques. This study specifically considers feed-forward multilayer perceptron (MLP) and radial basic function (RBF) network models. Formant frequencies of Polish vowel e (stressed or unstressed) in selected contexts were used as predictors. This has already been confirmed in an earlier investigation that determined that dynamic formant frequencies of vowels are powerful elements in distinguishing the voice. It has been concluded that neural networks might assist in distinguishing speakers from the others with very good accuracy, reaching 100%. MLP models should be given preference. The results of the investigation have shown the influence of vowel e triads on the effectiveness of correct classification rates. In addition, the authors have determined that the accuracy of classification is greater when based on a single context than for similar input data aggregated over several different contexts.