Wyniki wyszukiwania - Biblioteka Nauki

1

Acid phosphatase of potato tubers (Solanum tuberosum L). Purification, properties, sugar and amino acid composition

100%

Kruzel M. , Morawiecka B.

Acta Biochimica Polonica

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1982

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tom 29

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nr 3-4

2

Pomiar współczynnika przejmowania ciepła w warunkach odparowania rozprężnego czynnika chłodniczego

100%

Kruzel M. , Dutkowski K.

Pomiary Automatyka Kontrola

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2014

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tom R. 60, nr 10

879--882

PL

W artykule przedstawiono wyniki badań eksperymentalnych lokalnego współczynnika przejmowania ciepła. Wymiana ciepła odbywała się między ogrzewaną ścianką kanału a przepływającym wewnątrz czynnikiem chłodniczym (R134a i R404A). Wykorzystano 12, wykonanych ze stali nierdzewnej, rurek o średnicy wewnętrznej w zakresie dw = 0,64 ÷ 2,30 mm. Rurki tej średnicy, tzw. minikanały wykorzystuje się do budowy miniaturowych wymienników ciepła. Badania przeprowadzone w zakresie gęstości strumienia masy (wp) = 350 ÷ 1400 kg/(m2s) i gęstości strumienia ciepła dochodzącej do q = 90 kW/m2 pozwoliły zaobserwować występowanie, nie obserwowanego w kanałach konwencjonalnych, zjawiska flashingu. Wykazano, że w strefie objętej występowaniem zjawiska flashingu warunki wymiany ciepła pogarszają się, a wartość lokalnego współczynnika przejmowania ciepła w tej strefie może spaść nawet o 50%.

EN

The paper presents the results of experimental investigations on the heat transfer coefficient. The heat was transferred between the heated channel wall and the refrigerant flowing inside the channel. Refrigerants R134a and R404A were used as a working fluid. During the experiments 12 tubes were used. The tubes were made of stainless steel and their inner diameter was: 0.45, 0.55, 0.80, 1.10, 1.15, 1.30, 1.35, 1.40, 1.60, 1.68, 1.94 and 2.30 mm. Channels with the above mentioned diameters are called minichannels and they are used to build miniaturized heat exchangers. The study was conducted in six series in which the mass flux density was changed (Table 1). During each series the heat flux density was stepwise increased and then decreased. Its maximum value was q = 90 kW/m2. This allowed obtaining the forced convection heat transfer or boiling phenomenon. In some cases, it was noted that the flashing phenomenon occurred. This phenomenon occurred when the local pressure was lower than the saturation pressure (at a given temperature). It revealed the evaporation of a liquid, not by applying heat from the wall, but by using the latent heat (heat of evaporation) [4, 5]. Reduction in the local pressure below the saturation pressure was common in minichannels. The reason is large pressure drops which occur in tubes of such small diameters. The flashing phenomenon was not observed inside conventional channels. The results of this study showed that in the zone of its occurrence the value of the local transfer coefficient decreased significantly (Figures 5 ÷ 8). During the experimental investigations the value of the local heat transfer coefficient decreased to 50%. From the conducted research it follows that the existence of the flashing phenomena in heat exchangers is harmful.

3

Heterogeneity of acid phosphatase from potato tubers

80%

Kubicz A. , Morawiecka B. , Kruzel M.

Acta Biochimica Polonica

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1974

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tom 21

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nr 2

4

Analiza skraplania czynników chłodniczych w obszarze pary przegrzanej

80%

Bohdal T. , Florianowicz M. , Kruzel M. , Marusiak A.

Chłodnictwo

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2012

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tom 47

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nr 01-02

5

Analysis of heat transfer coefficient during refrigerant condensation in vertical pipe minichannel

80%

Bohdal T. , Kruzel M. , Sikora M.

Journal of Mechanical and Energy Engineering

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2017

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tom Vol. 1, No 1

65--70

EN

This article presents the results of experimental research of R404A, R407C and R410A high-pressure refrigerants condensation in vertical pipe minichannels with an internal diameter d below 2,5 mm. The study determined the local and average heat transfer coefficient in the full range of vapor quality, x= 1-0. On the basis of experimental investigations, the dependence of heat transfer coefficient on the vapor quality x, the mass flux density G and the channel internal diameter d was obtained.

6

An investigation of heat transfer coefficient during refrigerants condensation in vertical pipe microchannel

80%

Bohdal T. , Kruzel M. , Sikora M.

Journal of Mechanical and Energy Engineering

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2017

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tom Vol. 1, No 2

163--169

EN

This article presents the results of experimental research of R404A, R407C and R410A high-pressure refrigerants condensation in vertical pipe microchannels with an internal diameter dw below 1 mm. The study determined the local and average heat transfer coefficient in the full range of vapor quality, x = 1-0. On the basis of experimental investigations, the dependence of heat transfer coefficient on the vapor quality x, the mass flux density G and the channel internal diameter dw was obtained.

7

The adjuvant activity of lactoferrin in the generation of DTH to ovalbumin can be inhibited by bovine serum albumin bearing alpha-D-mannopyranosyl residues

80%

Kocieba M. , Zimecki M. , Kruzel M. , Actor J.

Cellular and Molecular Biology Letters

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2002

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tom 07

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nr 4

EN

Lactoferrin (LF) is an iron-binding glycoprotein present in the cytoplasmic granules of neutrophils and in external secretions of mammals. Although the biological role of human and bovine lactoferrin has been extensively studied, there is still uncertainty as to the nature and function of lactoferrin receptors. We recently determined that methyl-α-D-mannopyranoside given intraperitoneally (i.p.) could suppress the adjuvant activity of LF in the generation of delayed-type hypersensitivity (DTH) to ovalbumin (OVA). We concluded that the lactoferrin effects in DTH are mediated by carbohydrate-recognizing receptors like the mannose receptor (MR). This study indicates that subcutaneous (s.c.) administration of very small doses of the Man-bovine serum albumin (Man-BSA) complex, together with a sensitizing dose of the antigen, gives the same effects as i.p. administration of methyl-α-D-mannopyranoside. The latter is also a blocker of MR, although of a much lower affinity to the receptor than Man-BSA. The blocking of the adjuvant effect of LF by the Man-BSA complex (when given together with the sensitising dose of antigen) suggests that the function of antigen-presenting cells in the skin (presumably immature dendritic cells expressing MR) is inhibited. The results of our study indicate that a receptor with an affinity for mannose is essential for the mediation of adjuvant lactoferrin function in the generation of DTH.

8

Badanie oporów przepływu podczas skraplania czynników chłodniczych w minikanałach pionowych

80%

Bohdal T. , Kruzel M. , Sikora M.

Chłodnictwo

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2019

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tom 54

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nr 1

9

The adjuvant activity of lactoferrin in the generation of DTH to ovalbumin can be inhibited by bovine serum albumin bearing alpha-D-mannopyranosyl residues

80%

Kocieba M. , Zimecki M. , Kruzel M.

Cellular and Molecular Biology Letters

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2002

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tom 07

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nr Suppl.

10

Lactoferrin regulates the immune responses in post-surgical patients

70%

Zimecki M. , Wlaszczyk A. , Wojciechowski R. , Dawiskiba J. , Kruzel M.

Archivum Immunologiae et Therapiae Experimentalis

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2001

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tom 49

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nr 4

11

Antiviral resistance of splenocytes in aged mice

61%

Zaczynska E. , Artym J. , Kocieba M. , Burster T. , Kruzel M. , Paprocka M. , Zimecki M.

Polish Journal of Microbiology

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2017

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tom 66

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nr 1

EN

We compared the susceptibility to viral infection of splenocytes, isolated from young versus old CBA mice, and evaluated the antiviral actions of lactoferrin in splenocytes infected with Encephalomyocarditis virus (EMCV). Recombinant mouse lactoferrin (rmLF) and bovine lactoferrin (bLF) were used. There were no differences in the susceptibility to EMCV infection in the studied age categories. Both types of lactoferrins were protective in young and old mice. The study confirmed the undisturbed viral resistance in old mice and the protective actions of lactoferrin in viral infection. The antiviral action of the homologous mouse lactoferrin was demonstrated for the first time.