Viscoelastic properties and morphological characteristics of polymer‐modified bitumen blends

The state of dispersion, the viscoelastic properties and the mechanical properties (such as Young's modulus, ductibility, penetration, and Fraas breaking point) of polymer‐modified bitumen are investigated. Bitumen was modified with low‐density polyethylene from processed bags (PE_bags) and styrene‐butadiene random block copolymer (SBR). The blends were characterized by optical microscopy, dynamic mechanical thermal analysis (DMTA), and other conventional methods. Photomicrographs indicated that different morphologies were obtained; PE_bags gave dispersions with almost spherical polymer particles; whereas in the case of SBR, fibrillar domains were observed. DMTA measurements indicated significant changes of the storage and loss moduli of modified bitumen; depending on the polymer content in the bitumen matrix, these values were three to four times higher compared with neat bitumen. Blends with SBR showed a significantly increased resistance to cracking at low temperatures due to decrease of the glass transition temperature from ?14 to ?34°C. Contrary, PE_bags gave better results at higher temperatures where as a result of the increased resistance to permanent deformation the softening point of modified bitumen was shifted from 52 to 73°C. It was also investigated the influence of mixtures of PE_bags/SBR on the properties of bitumen as function of the composition and ratio between PE_bags and SBR. It was found that the best improvement in deformation resistance, permanent deformation, and cracking of bitumen was achieved with the addition of PE_bags/SBR mixture as the rubber increased the bitumen properties at low temperatures and the polyolefin at high temperatures. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Local and Global Lyapunov Exponents of Blood Flow

The Lyapunov exponents are calculated from numerically simulated and measured time series. The existing algorithms for the estimation of Lyapunov spectra have free parameters. Hence, their influence is analysed on various chaotic and quasi-periodic simulated signals. Furthermore, the exponents of a blood flow signal, measured on a healthy subject, are calculated over a wide range of parameter values. For the embedding dimension d 10, two typical spectra are observed for both the global and the local Lyapunov exponents. There are either 4 paired and 1 zero, or 5 paired exponents. At least one exponent equals zero within the calculation error.     

ICP/MS and ICP/AES elemental analysis (38 elements) of edible wild mushrooms growing in Poland

Thirty-eight elements, including toxic cadmium, lead, mercury, silver and thallium, were determined in 18 species of wild edible mushrooms collected from several sites in Pomorskie Voivodeship in northern Poland in 1994. Elements were determined by double focused high resolution inductively coupled plasma mass spectrometry (HR-ICP-MS) and inductively coupled plasma atomic emission spectroscopy (ICP-AES), after wet digestion of the dried samples with concentrated nitric acid in closed PTFE vessels using a microwave oven. K, P and Mg were present at levels of mg/g dry matter; Na, Zn, Ca, Fe, Cu, Mn, Rb, Ag, Cd, Hg, Pb, Cs, Sr, Al and Si were present at µg/g levels, while Tl, In, Bi, Th, U, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, La, Lu and Ba were present at ng/g levels.     

Antioxidant tannins from Rosaceae plant roots

Polyphenols were analyzed by HPLC after thioacidolysis of proanthocyanidins polymers and acid hydrolysis of phenolic acid esters. The predominant constitutive units of the procyanidins of Aruncus Silvester and Potentilla alba roots were (−)epicatechin, and Geum rivale and Waldsteinia geoides roots (+)catechin. The highest proanthocyanidin concentrations were found in Potentilla alba roots (close to 80 g/kg) and W. geoides (64 g/kg). Ellagic acid was present at high concentration in G. rivale (2.68 g/kg) and W. geoides (2.75 g/kg) in dried roots. The antioxidant activity, measured by the DPPH method, ranged from 0.72 (Filipendula vulgaris) to 4.40 (W. geoides) mM trolox equivalents/kg dried roots and, measured by the ABTS method, from 1.50 to 6.60 mM trolox equivalents per kg of dried roots.     

Effectiveness Assessment of a Modified Preservation Solution Containing Thyrotropin or Follitropin Based on Biochemical Analysis in Perfundates and Homogenates of Isolated Porcine Kidneys after Static Cold Storage

In this paper, we assess the nephroprotective effects of thyrotropin and follitropin during ischaemia. The studies were performed in vitro in a model of isolated porcine kidneys stored in Biolasol (FZNP, Biochefa, Sosnowiec, Poland) and modified Biolasol (TSH: 1 µg/L; FSH 1 µg/L). We used the static cold storage method. The study was carried out based on 30 kidneys. The kidneys were placed in 500 mL of preservation solution chilled to 4 °C. The samples for biochemical tests were collected during the first kidney perfusion (after 2 h of storage) and during the second perfusion (after 48 h of storage). The results of ALT, AST, and LDH activities confirm the effectiveness of Biolasol + p-TSH in maintaining the structural integrity of renal cell membranes. Significantly reduced biochemical parameters of kidney function, i.e., creatinine and protein concentrations were also observed after 48 h storage. The protective effect of Biasol + p-TSH is most pronounced after 2 h of storage, suggesting a mild course of damage thereafter. A mild deterioration of renal function was observed after 48 h. The results of our analyses did not show any protective effect of Biolasol + p-FSH on the kidneys during ischaemia.     

Sensory and rheological properties of Polish commercial mayonnaise

Sensory and rheological analyses were performed to compare seven commercial mayonnaises having various fat contents and containing, or not, thickening and stabilizing agents. It was found that mayonnaise samples differed in their sensory and rheological properties. The samples with a higher fat content scored higher in sensory analysis than the low-fat ones. The mayonnaises studied showed non-Newtonian, pseudoplastic flow with yield stress and thixotropy. All mayonnaises, although to a different degree, exhibited a decrease in the apparent viscosity at constant shear. The mayonnaise samples which contained thickeners and stabilizers had a greater rheological stability.     

Stahlleichtbau mit Verbundelementen

Der folgende Beitrag gibt einen Überblick über den Stahlleichtbau mit Verbundelementen. Im Vordergrund stehen hierbei Bauteile mit Blechdicken < 3 mm, die im Verbund mit OSB‐ oder Gipskartonplatten wirken. Durch die Verbundwirkung ergeben sich nennenswerte Verbesserungen der Tragfähigkeit und der Gebrauchstauglichkeit sowie der bauphysikalischen Eigenschaften. Weiterhin werden Sandwichelemente behandelt. Lightweight steel construction with composite elements. This paper contains an overview of lightweight steel structures acting compositely with other materials. Primarily members with wall thicknesses below 3 mm are covered. They act together with OSB‐ or gypsum‐boards. This leads to a significant improvement of the ultimate load as well as of the serviceability and building physics aspects. Furthermore sandwich panels are discussed.