Wyniki wyszukiwania - Biblioteka Nauki

1

Effect of mixing intensity onto kinetics of flock growth in an agitated tank

100%

Sulc R. , Svacina O.

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2010

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tom Vol. 31, z. 2

261-271

EN

The effect of mixing intensity onto kinetics of flock growth and shape characterized by the fractal dimension was investigated. The experiments were carried out in a baffled tank agitated by a Rushton turbine at the mixing intensities 40, 64 and 95 W/m3 and kaolin concentration of 0.44 g/dm3. The size and shape of flocks were investigated by image analysis. The flock growth kinetic data was fitted according to generalized correlation proposed by the authors. The dependences * fA = 85.66V 1/2, df eq max = 0.623V - 1/4 and [NtF]max = 1245 were found for model parameters. The fractal dimension Df2 was found to be independent of flocculation time and mixing intensity and its value of 1.469 -0.037 was determined as an average for the given conditions.

PL

Badano wpływ intensywności mieszania na kształt i kinetykę wzrostu kłaczków zawiesiny kaolinu w wodzie (stężenie 0,44 g/dm3) charakteryzowanych przez rozmiar fraktalny. W badaniach użyto zbiornika z przegrodami wyposażonym w turbinę Rushtona. Intensywności mieszania wynosiły 40, 64 i 95 W/m3. Zmierzone parametry kinetyczne wzrostu kłaczków analizowano za pomocą ogólnej korelacji zaproponowanej przez autorów. Dla parametrów modelu wyznaczono zależności * 85,66 1/4 fVA i [NtF]max = 1245. Wymiar fraktalny Df2 = 1,469-0,037 wyznaczono jako wartość średnią w określonych warunkach.

2

Inflow waters in the deep regions of the southern Baltic Sea - transport and transformations

80%

Piechura J. , Beszczyńska-Möller A.

Oceanologia

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2003

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tom No. 45 (4)

593-621

EN

A medium-sized inflow (about 200 km3 according to IOW data, - personal communication) of saline water into the southern Baltic Sea occurred during January 2003. Unlike any previously observed inflow, this one brought very cold water, of temperatures around 1-2°C and less. Since the temperature of the deep water in the southern Baltic before the inflow was exceptionally high (11-12°C), the inflowing waters produced dramatic changes and a steep temperature gradient. The movement of the inflowing waters through the deep basins and channels of the Baltic Sea from the Arkona Basin to the Gdansk Deep during next 4-8 months is described. Frequent mesoscale structures and intensive mixing followed the eastward transport of the inflow water, particularly in the Bornholm Deep and Słupsk Furrow. The present paper is based on data collected during of 6 cruises r/v "Oceania" between December 2002 and August 2003. The last cruise in August took place in order to assess the long-term consequences of the inflow.

3

On asymptotic cyclicity of doubly stochastic operators

80%

Bartoszek W.

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1999

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tom 72

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nr 2

145-152

EN

It is proved that a doubly stochastic operator P is weakly asymptotically cyclic if it almost overlaps supports. If moreover P is Frobenius-Perron or Harris then it is strongly asymptotically cyclic.

4

Inflow waters in the deep regions of the southern Baltic Sea - transport and transformations (corrected version)

80%

Piechura J. , Beszczyńska-Möller A.

Oceanologia

|

2004

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tom No. 46 (1)

113-141

EN

A medium-sized inflow (about 200 km3 according to IOW data, - personal communication) of saline water into the southern Baltic Sea occurred during January 2003. Unlike any previously observed inflow, this one brought very cold water, of temperatures around 1-2oC and less. Since the temperature of the deep water in the southern Baltic before the inflow was exceptionally high (11-12oC), the inflowing waters produced dramatic changes and a steep temperature gradient. The movement of the inflowing waters through the deep basins and channels of the Baltic Sea from the Arkona Basin to the Gdańsk Deep during next 4-8 months is described. Frequent mesoscale structures and intensive mixing followed the eastward transport of the inflow water, particularly in the Bornholm Deep and Słupsk Furrow. The present paper is based on data collected during 6 cruises r/v "Oceania" between December 2002 and August 2003. The last cruise in August took place in order to assess the long-term consequences of the inflow.

5

Mieszanie gazów w mieszalniku statycznym

80%

Hehlmann J. , Sąsiadek B. , Kujawska E. , Zasępa J.

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tom Nr 3s

64-65

EN

This paper presents researches of ammonia and air mixing process in the static agitator of own construction with original mixing elements [1]. There have been also examined pressure drops of process media in the agitator. The equations useful in agitator designing for required process parameters have been elaborated.

6

A simulation study of mixing granular materials

80%

Kostek R. , Landowski B.

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tom Vol. 6, no 3

57-64

EN

Mixing the granular materials is a critical process in many industries, especially in pharmaceutical one, where homogeneous blends of ingredients are required. The homogenisation process is time and energy consuming, thus this article is focused on the process. The mixing process has been simulated with the discrete element method – DEM, which gives an opportunity to study the granular flow of mixed ingredients. Following stages of the mixing process have been presented for various shapes of blenders and analysed, which gives an opportunity to understand the process and mechanisms of homogenisation. Apart from the three basic mechanisms of homogenisation: diffusion, convection and shear, one more has been found.

7

Effects of mixing on complex chemical reactions. Problem of micromixing models

80%

Bałdyga J. , Makowski Ł.

Inżynieria Chemiczna i Procesowa

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2006

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tom T. 27, z. 2

363-376

EN

A modified, non-equilibrium model of micromixing has been applied to describe mixing and chemical reaction in a stirred tank reactor. Modification of the model is based on taking into consideration effects of turbulent shear on dissipation of the passive scalar. Predictions of the model have been compared with the experimental data and results of simulations neglecting shear effect.

PL

Zmodyfikowany nierównowagowy model mikromieszania wykorzystano do opisu procesów mieszania i mieszania z reakcją chemiczną w reaktorze zbiornikowym z mieszadłem. Modyfikacja modelu polega na uwzględnieniu wpływu ścinania na przebieg mieszania. Wyniki modelowania porównano z wynikami otrzymanymi dla modelu zaniedbującego ten efekt oraz z wynikami badań doświadczalnych.

8

Dyspergowanie gazu w cieczy w aparacie z dwoma oddzielnie napędzanymi mieszadłami

80%

Kamieński J. , Spytkowski S.

|

2011

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tom Nr 4

26-27

PL

Przeprowadzono badania dyspersji gazu w cieczy w aparacie, w którym znajdują się dwa oddzielnie napędzane mieszadła. Gaz wprowadzano pod górne mieszadło wyznaczając, przy jakich częstościach jego obrotów gaz dociera do dna aparatu. Stan ten przyjęto za graniczny, badając jak wpływa nań położenie i kierunki obrotów mieszadeł, wydatek gazu oraz częstość obrotów dolnego mieszadła. Stwierdzono, że osiąga się go przy tym niższych częstościach obrotów mieszadła dyspergującego gaz, im szybciej obraca się dolne mieszadło.

EN

Researches on mixing in gas-liquid system in a vessel with two independently driven impellers were carried out. Gas was fed under upper stirrer and the impeller rotational frequency for the case when gas reached the vessel bottom was determined. These conditions were accepted as a critical state and influence of mixer direction of rotation, its location in the vessel, gas flow rate and bottom stirrer direction of rotation on it was investigated. It was confirmed that critical conditions were achieved for a lower rotation speed of upper impeller and a higher rotation speed of bottom one.

9

Efektywność wytwarzania zawiesiny w smukłym aparacie

80%

Kamieński J. , Spytkowski S.

|

2009

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tom Nr 6

94-95

PL

Przedstawiono wyniki badań nad unoszeniem cząstek ciała stałego z dna zbiornika aparatu, w którym znajdują się dwa oddzielnie napędzane mieszadła obrotowe. Analizowano jak obecność górnego mieszadła wpływa na stopień zmieszania układu i efektywność mieszania.

EN

Mixing of liquid-solid system in a mixing vessel with two independently driven impellers was investigated. An influence of upper impeller on the system mixing index and the efficiency of mixing was analysed.

10

Word Blending in Formal Languages

70%

Enaganti S. K. , Kari L. , Ng T. , Wang Z.

Fundamenta Informaticae

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2020

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tom Vol. 171, nr 1-4

151--173

EN

In this paper we define and investigate a binary word operation that formalizes an experimentally observed outcome of DNA computations, performed to generate a small gene library, and implemented using a DNA recombination technique called Cross-pairing Polymerase Chain Reaction (XPCR). The word blending between two words αωγ1 and γ2ωβ that share a non-empty overlap w, results in αωβ. Interestingly, this phenomenon has been observed independently in linguistics, under the name “blend word” or “portmanteau”, and is responsible for the creation of words in the English language such as smog (smoke + fog), labradoodle (labrador + poodle), and Brangelina (Brad + Angelina). Technically, word blending is related to the binary word operation Latin product, the crossover operation, and simple splicing. We study closure properties of the families in the Chomsky hierarchy under word blending, language equations involving this operation, and its descriptional state complexity when applied to regular languages. We also define iterated word blending and show that, for a given alphabet, there are finitely many languages that can be obtained from an initial language by iterated word blending.

11

Effect of Impeller Shape on Solid Particle Suspension

70%

Rieger F. , Jirout T. , Ceres D. , Seichter P.

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nr 1

139-152

EN

This paper deals with the effect of impeller shape on off-bottom particle suspension. On the basis of numerous suspension measurements, correlations are proposed for calculating the just-suspended impeller speed for a standard pitched four-blade turbine and three types of hydrofoil impellers produced by TECHMIX for several particle sizes and for a wide range of particle concentrations. The suspension efficiency of the tested impellers is compared with the efficiency of a standard pitched blade turbine on the basis of the power consumption required for off-bottom suspension of solid particles. It is shown that the standard pitched blade turbine needs highest power consumption, i.e. it exhibits less efficiency for particle suspension than hydrofoil impellers produced by TECHMIX.

12

Badania intensywności turbulencji cieczy w mieszalnikach z dwoma mieszadłami

70%

Talaga J. , Wójtowicz R. , Duda A.

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tom R. 105, z. 2-M

361-370

PL

W pracy zaprezentowano wyniki badań doświadczalnych dotyczących intensywności (stopnia) turbulencji cieczy w mieszalniku, w którym przepływ generowany był przez układ dwóch mieszadeł zamocowanych na jednym wale. Badania przeprowadzono dla różnych rodzajów mieszadeł i różnych odległości ich wzajemnego usytuowania. Dokonano oceny i porównania stopni turbulencji cieczy w mieszalniku dla badanych układów mieszadeł.

EN

In the paper the results of experimental investigations of liquid turbulence intensity (turbulence degree) for a stirred vessel equipped with two impellers located on the same shaft are presented. The investigations were carried out for various impeller systems and various distance between the impellers. Also the assessment and comparison of the turbulence degrees obtained for different impeller systems were done.

13

Study of the Process of Hydraulic Mixing in Anaerobic Digester of Biogas Plant

70%

Karaeva J. V. , Khalitova G. R. , Kovalev D. A. , Trakhunova I. A.

|

2015

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nr 1

14

Cyrkulacja cieczy w mieszalniku w warunkach superpozycji przepływów generowanych przez dwa mieszadła

60%

Talaga J. , Wójtowicz R. , Duda A.

|

2006

|

tom Nr 6s

236-238

EN

Investigations results of liquid mixing in a vessel equipped with two impellers producing radial or axial flow and located on the same shaft are presented in the paper. The turbulence intensity of liquid flow generated by various combinations of impellers is compared.

15

Zmiana jakości niejednorodnych układów ziarnistych w czasie transportu

60%

Gajda S. , Ratuszny P.

|

tom T. 90, nr 9

1639-1641

16

Heat transfer investigations in a liquid that is mixed by means of a reciprocating agitator

60%

Lechowska J. , Kordas M. , Rakoczy R.

|

tom Nr 5

186--188

EN

Experimental results of heat transfer coefficients in a mixer equipped with the reciprocating agitator are presented in the paper. Investigations showed the influence of different configurations of a new-type reciprocating agitator on heat transfer process. The data obtained were elaborated in a form of dimensionless correlations describing the effect of operating conditions and liquid axial flow.

PL

Przedstawiono wyniki pomiarów wartości współczynnika wnikania ciepła w mieszalniku wyposażonym w mieszadło posuwisto-zwrotne. Na podstawie uzyskanych wyników pokazano wpływ konfiguracji geometrycznej testowanego mieszadła na proces wymiany ciepła. Dane opracowano w formie równania korelacyjnego uwzględniającego wpływ analizowanych warunków procesowych i przepływu mieszanej cieczy przez mieszalnik.

17

Uniwersalne stanowisko do badań mieszanin skladników ziarnistych

60%

Zimniak J.

|

tom Nr 1-2

97-98

PL

W pracy zaprezentowano stanowisko badawcze do oceny stopnia zmieszania materiałów ziarnistych. Uniwersalne stanowisko pozwala także na ocenę energochłonności mieszania jak również strat energii (pomiar momentu obrotowego na wejściu i wyjściu).

EN

In the paper a measuring setup for the estimation of mixing degree of grainy components is presented. The universal measuring setup permits also the estimation of mixing energy consumption and energy losses (measurements of input and output torque).

18

Wpływ stężenia hydrokoloidu na moc mieszania oraz parametry reologiczne wodnych roztworów gumy guar

60%

Nowak M. , Kijowska K. , Kabziński M. , Ptaszek P.

|

2018

|

tom Nr 2

31--33

PL

Przeanalizowano wpływ stężenia hydrokoloidu na właściwości reologiczne wybranego modelowego układu spożywczego poddawanego mieszaniu długotrwałemu. Użyto wodnych roztworów gumy guar. Mieszanie przeprowadzono w warunkach skokowo wzrastającej liczby obrotów mieszadła wstęgowego. Moc mieszania oraz parametry reologiczne obliczono na podstawie uzyskanych w pomiarach wartości momentu obrotowego przyłożonego na wale mieszadła oraz prędkości obrotowej mieszadła. Wyniki w postaci krzywych płynięcia posłużyły do wyznaczenia wartości parametrów równania Ostwalda-de Waele. Dane eksperymentalne opisano ponadto równaniami empirycznymi podającymi zależności średnich mocy chwilowych oraz średnich lepkości pozornych od stężenia gumy guar w poszczególnych układach.

EN

An influence of hydrocolloid concentration on rheological properties of model food fluids under long-term mixing is analyzed in the paper. Aqueous solutions of guar gum were used as model food fluids. The helical ribbon stirrer rotational speed was increased step by step. The mixing power and rheological parameters were calculated on a base of measured values of torque and rotational speed of the stirrer. The flow curves were used for the calculation of Ostwald-de Waele equation parameters. Moreover, the experimental data were described by power monomials and their coefficients were determined.

19

Wytwarzanie zawiesiny flotującej w mieszalniku o niestandardowej geometrii

60%

Szaferski W. , Broniarz-Press L. , Dulska D.

|

tom T. 90, nr 9

1686-1688

20

Poprawa właściwości kształtek wtryskowych z poli(tereftalanu etylenu) w wyniku zmieszania polimerów o różnych masach cząsteczkowych

60%

Wąsicki A. , Napieralski W.

|

tom T. 78, nr 11

402-404