Poly(ethylene naphthalate), PEN, is an industrial polyester which has been shown to scintillate in the blue wavelength region. Combined with measurements of a high intrinsic radiopurity, this has ...sparked interest in the material for use in low-background experiments.
The analysis of natural linear structures, termed "lineaments" in satellite images, provides important information to the geologist. In the satellite imaging process, important features of the ...observed tridimensional scene, including geological lineaments, are mapped into the resulting 2D image as sharp radiation variations or edge elements (edgels). Edgels are detected by a first-order differentiation operator and are linked together with those in the vicinity on a basis of orientation continuity. Lineaments are mapped into remotely sensed satellite images as long and continuous quasilinear features and can be described as a connected sequence of edgels whose direction may change gradually along the sequence. Parts of the same lineament can be occluded by geomorphological features and must be linked together, a major drawback with local and small neighborhood detectors. The authors propose a cellular neural network (CNN) architecture to offer a large directional neighborhood to the lineament detection algorithm. The CNN uses a large circular neighborhood coupled with a directional-induced gradient field to link together edgels with similar and continuous orientation. Missing edgels are restored if a surrounding lineament is detected.
Poly Ethylene Naphthalate (PEN) is an industrial polymer plastic which is investigated as a low background, transparent, scintillating and wavelength shifting structural material. PEN scintillates in ...the blue region and has excellent mechanical properties both at room and cryogenic temperatures. Thus, it is an ideal candidate for active structural components in experiments for the search of rare events like neutrinoless double-beta decay or dark matter recoils. Such optically active structures improve the identification and rejection efficiency of background events, like this improving the sensitivity of experiments. This paper reports on the production of radiopure and transparent PEN plates These structures can be used to mount germanium detectors operating in cryogenic liquids (LAr, LN). Thus, as first application PEN holders will be used to mount the Ge detectors in the LEGEND-200 experiment. The whole process from cleaning the raw material to testing the PEN active components under final operational conditions is reported.
The discovery of scintillation in the blue regime from polyethylene naphthalate (PEN), a commonly used high-performance industrial polyester plastic, has sparked considerable interest from the ...physics community as a new type of plastic scintillator material. This observation in addition to its good mechanical and radiopurity properties makes PEN an attractive candidate as an active structure scintillator for low-background physics experiments. This paper reports on investigations of its potential in terms of production tests of custom made tiles and various scintillation light output measurements. These investigations substantiate the high potential of usage of PEN in low-background experiments.
Knowledge of the conformational behaviour of proteins as a function of temperature is important in the thermal processing of foods. Equally important is their interfacial behaviour with surfaces ...under these same processing conditions. This paper describes electrochemical techniques developed to study these structurally related properties of proteins. The interfacial behaviour of α-lactalbumin and bovine serum albumin was studied on a platinum electrode using cyclic voltammetry over a temperature range from 273 to 363 K. It was found that both proteins adsorbed strongly on the metal surface. As the temperature was increased up to the denaturation temperature of the protein, the surface charge density for protein adsorption also increased due to the conformational unfolding. Above the temperature for denaturation, the surface charge density continued to increase. Mixtures of the two proteins resulted in a substantial increase in surface charge density above the denaturation temperatures.
A comparison of surface concentrations (Γ) of cyclic voltammetric measurements with those for ellipsometric measurements reported in the literature showed a similar behaviour with increasing adsorption with temperature. A value of 17 ± 4 carboxylate groups for the α-lactalbumin protein was determined from an analysis of the surface coverage which is consistent with the number of acidic residues on the protein.
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