The connection between an event structure semantics and an operational semantics forTCSP

The relation between an operational interleaving semantics forTSCP based on a transition system and a compositional true concurrency semantics based on event structures is studied. In particular we extend the consistency result of Goltz and Loogan [15] forTCSP processes without recursion to the general case. Thus we obtain for everyTCSP processP that its operational meaningO(P) and the interleaving behaviourO( M3P3) which is derived from the event structureM3P3 associated withP are bisimilar.     

Pharmaceutical residues in the Danube River Basin in Serbia - a two-year survey

Pharmaceuticals are emerging contaminants with damaging effects to the environment and human health. Their presence in surface and especially groundwaters is regarded as detrimental, as they can ultimately reach drinking water. The aim of this work was to monitor pharmaceutical contamination of the Danube River and its tributaries in Serbia, and to assess the potential of their passing through all natural filtrations and reaching the groundwater. A total of 70 surface and groundwater samples was collected at 38 sampling sites at the Danube in Serbia. They were taken in five sampling campaigns performed in summer and autumn of 2009 and winter, spring and autumn of 2010. Samples were analyzed using a previously developed method which includes solid-phase extraction followed by liquid chromatography-tandem mass spectrometry.     

A Variational Approach to Remove Outliers and Impulse Noise

We consider signal and image restoration using convex cost-functions composed of a non-smooth data-fidelity term and a smooth regularization term. We provide a convergent method to minimize such cost-functions. In order to restore data corrupted with outliers and impulsive noise, we focus on cost-functions composed of an ?₁ data-fidelity term and an edge-preserving regularization term. The analysis of the minimizers of these cost-functions provides a natural justification of the method. It is shown that, because of the ?₁ data-fidelity, these minimizers involve an implicit detection of outliers. Uncorrupted (regular) data entries are fitted exactly while outliers are replaced by estimates determined by the regularization term, independently of the exact value of the outliers. The resultant method is accurate and stable, as demonstrated by the experiments. A crucial advantage over alternative filtering methods is the possibility to convey adequate priors about the restored signals and images, such as the presence of edges. Our variational method furnishes a new framework for the processing of data corrupted with outliers and different kinds of impulse noise.     

Functionality of chitosan-halloysite nanocomposite films for sustained delivery of antibiotics: The effect of chitosan molar mass

This study was designed to investigate functionality of tetracycline-loaded chitosan-halloysite nanocomposite films, with focus on evaluating the influence of chitosan molar mass on films applicability for sustained local antibiotic delivery. The films were prepared by casting and solvent evaporation using low, medium, and high molar mass chitosan. SEM analysis revealed compact, nonporous and rough surface of the nanocomposite films due to the presence of halloysite agglomerates and tetracycline crystals. Increasing chitosan molar mass led to higher values of elongation at break (from 21.65 ± 2.65 to 34.48 ± 2.34%), tensile strength (from 134.8 ± 13.21 to 246.36 ± 14.69 MPa), and elastic modulus (from 633.79 ± 128.37 to 716.55 ± 60.76 MPa) of the nanocomposite films. FT-IR, XRPD, and thermal analyses confirmed molar mass dependent chitosan-halloysite interactions and improved thermal stability of the nanocomposite films in comparison with chitosan films. The nanocomposite films released tetracycline in a sustained manner, with the slowest release achieved from the films consisting of low molar mass chitosan. Chitosan molar mass was confirmed to be a functionality-related characteristic of chitosan-halloysite nanocomposite films as potential sustained-release carriers for topical delivery of antibiotics. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48406.     

Factors affecting oil extraction/water adsorption in sequential extraction processing of corn

The sequential extraction process (SEP) uses ethanol to extract oil and protein from cracked, flaked, and dried corn, and the dried corn simultaneously dehydrates the ethanol. Value-added co-products are possible, potentially making production of fuel ethanol more economical. The effects of solvent-to-corn (S/C) ratio, corn moisture content (MC), and number of extraction stages on ethanol drying, oil recovery, and protein loss during the simultaneous oil extraction/water adsorption step of SEP were evaluated. Extractions were carried out by using both aqueous ethanol and ethanol/hexane blends at 56°C. The S/C ratios tested were 3∶1, 2∶1 (control), 1.5∶1, and 1∶1 (w/w). More anhydrous ethanol, greater oil yields, and less co-extracted protein were obtained with higher S/C ratios. Less anhydrous ethanol and lower moisture adsorption capacities were obtained when the corn MC was ≥1.12%. Oil yields gradually decreased with drier corn, whereas protein loss increased when corn MC was <1.12%. Reducing the number of extraction stages from seven (original SEP) to five did not affect ethanol drying capability, oil yields, and protein co-extracted with oil. Using ethanol/hexane blends resulted in more anhydrous ethanol, higher oil yields, and less protein co-extracted with oil.     

Trading-off security and performance in barrier slicing for remote software entrusting

Network applications often require that a trust relationship is established between a trusted host (e.g., the server) and an untrusted host (e.g., the client). The remote entrusting problem is the problem of ensuring the trusted host that whenever a request from an untrusted host is served, the requester is in a genuine state, unaffected by malicious modifications or attacks. Barrier slicing helps solve the remote entrusting problem. The computation of the sensitive client state is sliced and moved to the server, where it is not possible to tamper with it. However, this solution might involve unacceptable computation and communication costs for the server, especially when the slice to be moved is large. In this paper, we investigate the trade-off between security loss and performance overhead associated with moving only a portion of the barrier slice to the server and we show that this trade-off can be reduced to a multi-objective optimization problem. We describe how to make decisions in practice with reference to a case study, for which we show how to choose among the alternative options.     

Weakly Constrained Minimization: Application to the Estimation of Images and Signals Involving Constant Regions

We focus on the question of how the shape of a cost-function determines the features manifested by its local (and hence global) minimizers. Our goal is to check the possibility that the local minimizers of an unconstrained cost-function satisfy different subsets of affine constraints dependent on the data, hence the word weak. A typical example is the estimation of images and signals which are constant on some regions. We provide general conditions on cost-functions which ensure that their minimizers can satisfy weak constraints when noisy data range over an open subset. These cost-functions are non-smooth at all points satisfying the weak constraints. In contrast, the local minimizers of smooth cost-functions can almost never satisfy weak constraints. These results, obtained in a general setting, are applied to analyze the minimizers of cost-functions, composed of a data-fidelity term and a regularization term. We thus consider the effect produced by non-smooth regularization, in comparison with smooth regularization. In particular, these results explain the stair-casing effect, well known in total-variation methods. Theoretical results are illustrated using analytical examples and numerical experiments.     

Modification of glassy carbon properties under low energy proton irradiation

Glassy carbon plates were irradiated with 15 keV H⁺ ion-beam in the fluence range of 1 × 10¹⁶–3 × 10¹⁸ ion cm⁻². The influence of ion irradiation on surface morphology and topology was examined by scanning electron and atomic force microscopy. Structural changes were monitored by Raman spectrometry, while changes of wettability and the content of surface oxygen complexes were examined by contact angle measurements and temperature programmed desorption. Elastic recoil detection analysis was applied for determination of hydrogen concentration profiles in irradiated samples. Cyclic voltammetry was used for the assessment of the electrochemical properties of modified glassy carbon electrodes. It was concluded that there is critical fluence range (2 × 10¹⁷–5 × 10¹⁷ ion cm⁻²) inside of which significant changes of glassy carbon properties occur.