94 research outputs found
Conservation process of archaeological waterlogged wood studied by spectroscopy and gradient NMR methods
Interactions between microfibrillar cellulose and carboxymethyl cellulose in an aqueous suspension
New microstructures with interesting, unique and stable textures, particularly relevant to food systems were created by redispersing Microfibrillar cellulose (MFC). This paper reports the interactions between microfibrillar cellulose and carboxymethyl cellulose (CMC) in redispersed aqueous suspensions, by using rheological measurements on variable ratios of MFC/CMC and correlating these with apparent water mobility as determined by time domain NMR. MFC is a network of cellulose fibrils produced by subjecting pure cellulose pulp to high-pressure mechanical homogenisation. A charged polymer such as CMC reduces the aggregation of microfibrillar/fibre bundles upon drying. Small amplitude oscillatory rheological analysis showed the viscoelastic gel-like behaviour of suspensions which was independent of the CMC content in the MFC suspension. A viscous synergistic effect was observed when CMC was added to MFC before drying, leading to improved redispersibility of the suspension. Novel measurements of NMR relaxation suggested that the aggregated microfibrillar/fibre bundles normally dominate the relaxation times (T2). The dense microfibrillar network plays an important role in generating stable rheological properties and controlling the mobility of the polymer and hence the apparent mobility of the water in the suspensions
Effectiveness and Cost of Organized Outreach for Colorectal Cancer Screening: A Randomized, Controlled Trial.
The Legal Position of Trade Unions in Enterprises in the Light of the Labour Code of the German Democratic Republic
Digitalizacja i deponowanie archiwalnych zeszytów RPEiS sfinansowane przez MNiSW w ramach realizacji umowy nr 541/P-DUN/201
Investigations of the growth and interactions of bismuth thin films on gold, chromium, and mylar substrates
Palaeohydrology and landscape development in the middle course of the Radunia basin, North Poland
Geomorphological mapping, three diatom analyses and two 14C dates have been used to describe the development of the relief and the palaeohydrology of the middle course of the Radunia valley in North Poland. Chalk layers found in large areas of the Radunia basin proved to originate from a water phase which covered the valley bottom for some time from the very beginning of the postglacial period. It was at the latest during the Boreal Chronozone, however, that the previously uniform water level was divided into smaller basins, in accordance with a regressive trend. Relief changes during the rest of the postglacial period were mainly due to fluvial processes, the results of which indicate fairly constant hydrological conditions at this tim
Development of the Bolszewka and Goscicina valleys compared with the morphology of the adjacent area
Deep Space One High-Voltage Bus Management
The design of the High Voltage Power Converter Unit on DS1 allows both the spacecraft avionics and ion propulsion to operate in a stable manner near the PPP of the solar array. This approach relies on a fairly well-defined solar array model to determine the projected PPP. The solar array voltage set-points have to be updated every week to maintain operation near PPP. Stable operation even to the LEFT of the Peak Power Point is achievable so long as you do not change the operating power level of the ion engine. The next step for this technology is to investigate the use of onboard autonomy to determine the optimum SA voltage regulation set-point (i.e. near the PPP); this is for future missions that have one or more ion propulsion subsystems
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