Search results for "laminar"

The yeastWickerhamomyces anomalusAS1 secretes a multifunctional exo-β-1,3-glucanase with implications for winemaking

2014

A multifunctional exo-β-1,3-glucanase (WaExg2) was purified from the culture supernatant of the yeast Wickerhamomyces anomalus AS1. The enzyme was identified by mass spectroscopic analysis of tryptic peptide fragments and the encoding gene WaEXG2 was sequenced. The latter codes for a protein of 427 amino acids, beginning with a probable signal peptide (17 aa) for secretion. The mature protein has a molecular mass of 47 456 Da with a calculated pI of 4.84. The somewhat higher mass of the protein in SDS–PAGE might be due to bound carbohydrates. Presumptive disulphide bridges confer a high compactness to the molecule. This explains the apparent smaller molecular mass (35 kDa) of the native enz…

1987

Mode I interlaminar fracture toughness of thin-ply laminates with CNT webs at the crack interface

2019

Abstract Pristine and functionalized carbon nanotube (CNT) webs were introduced at the interlaminar region of two different thin-ply carbon fibre reinforced polymer systems (NTPT 402 prepreg, and TeXtreme/SE84LV). The Mode I interlaminar fracture toughness (ILFT) for the NTPT 402 material was substantially lower. In contrast when SE84LV resin was used, the resistance curves were virtually unchanged and with no depreciation in the steady state value of the ILFT. This demonstrates that a careful choice of the resin is essential to permit the embedding of CNT webs in thin-ply laminates without compromising structural performance and opens a new way towards the development of multifunctional th…

Surface and bulk ordering in thin films of a symmetrical diblock copolymer

2013

Amphiphilic diblock copolymers have the ability to adapt their surface's molecular composition to the hydrophilicity of their environment. In the case of about equal volume fractions of the two polymer blocks, the bulk of these polymers is known to develop a laminar ordering. We report here our investigation of the relationship between bulk ordering and surface morphology/chemical composition in thin films of such an amphiphilic diblock copolymer. Upon annealing in vacuum, the expected lamella ordering in the bulk of the film is observed and we find the morphology of the film surface to be defined by the thickness of the as-deposited film: If the as-deposited thickness matches the height of…

Demo 86. Flujo laminar. Mezcla reversible de fluidos

2013

Objetivo: Observar la reversibilidad de la mezcla de fluidos cuando el proceso se lleva a cabo en régimen laminar.

Sorpcja miedzi w glonach morskich Laminaria ochroleuca bachelot de la pylaie= Sorption of copper in marine algae Laminaria ochroleuca bachelot de la …

2015

Przedmiotem badań było określenie stopnia zanieczyszczenia metalami ciężkimi ekosystemów wodnych, analizując próbki wody oraz osadów dennych zbiorników wód powierzchniowych na terenie parków miejskich rejonu Wałbrzycha. Zawartość metali w wodzie uszeregowano następująco: Zn > Cu > Pb > Ni > Cd. Wody z analizowanych stanowisk badawczych charakteryzowały się podwyższonym stężeniem kadmu, a zbiornik Nowe Miasto dodatkowo znaczącym stężeniem Pb. Koncentracje Cu, Ni oraz Zn nie stanowiły zagrożenia dla funkcjonowania ekosystemów wodnych. Koncentracja metali w osadach dennych stanowiła szereg: Zn > Pb > Cu > Ni > Cd. Badania osadów dennych, pobranych ze zbiorników, nie wykazały znaczącego zaniecz…

The seaweeds <i>Fucus vesiculosus</i> and <i>Ascophyllum nodosum</i> are significant contribu…

2013

Abstract. Based on the results of a pilot study in 2007, which found high mixing ratios of molecular iodine (I2) above the intertidal macroalgae (seaweed) beds at Mweenish Bay (Ireland), we extended the study to nine different locations in the vicinity of Mace Head Atmospheric Research Station on the west coast of Ireland during a field campaign in 2009. The mean values of I2 mixing ratio found above the macroalgae beds at nine different locations ranged from 104 to 393 ppt, implying a high source strength of I2. Such mixing ratios are sufficient to result in photochemically driven coastal new-particle formation events. Mixing ratios above the Ascophyllum nodosum and Fucus vesiculosus beds …

Quantification of myocardial blood flow and blood flow reserve in the presence of arterial dispersion: A simulation study

2002

Myocardial blood flow (MBF) can be quantified using dynamic T1-weighted MRI of diffusible tracers and a mathematical model of underlying vasculature. Quantification of MBF by means of T1- weighted MRI requires knowledge of the arterial input function (AIF). The AIF can be estimated from the left ventricular (LV) cavity. However, dispersion may occur between the LV and the tissue of interest because of the laminar blood flow profiles, branching of venules, and because of stenosis. To evaluate the influence of dispersion on the results of MBF quantification, a simulation study was performed. The dispersion was described as a convolution of the AIF with an exponential residue function. Synthet…

Vortex dynamics in rotating counterflow and plane Couette and Poiseuille turbulence in superfluid Helium

2008

An equation previously proposed to describe the evolution of vortex line density in rotating counterflow turbulent tangles in superfluid helium is generalized to incorporate nonvanishing barycentric velocity and velocity gradients. Our generalization is compared with an analogous approach proposed by Lipniacki, and with experimental results by Swanson et al. in rotating counterflow, and it is used to evaluate the vortex density in plane Couette and Poiseuille flows of superfluid helium.

Practical Strategies for Stable Operation of HFF-QCM in Continuous Air Flow

2013

Currently there are a few fields of application using quartz crystal microbalances (QCM). Because of environmental conditions and insufficient resolution of the microbalance, chemical sensing of volatile organic compounds in an open system was as yet not possible. In this study we present strategies on how to use 195 MHz fundamental quartz resonators for a mobile sensor platform to detect airborne analytes. Commonly the use of devices with a resonant frequency of about 10 MHz is standard. By increasing the frequency to 195 MHz the frequency shift increases by a factor of almost 400. Unfortunately, such kinds of quartz crystals tend to exhibit some challenges to obtain a reasonable signal-to…