Analysis of corrosion resistant plasma polymer films on metals

To understand the corrosion resistance of plasma polymer film covered metals, the interface chemistry and adhesion, the morphology of the films and the barrier properties have to be studied. Combined methods of thin film spectroscopy, electrochemistry and microscopy are essential to provide the required complementary information. The aim of these analytical studies is the investigation of the detailed correlation between thin film and interface structure and the stability of the coated substrates in corrosive environments.     

Fractal features of carbon–nickel composite thin films

This work analyses the three‐dimensional (3‐D) surface texture of carbon–nickel (C–Ni) films grown by radio frequency (RF) magnetron co‐sputtering on glass substrates. The C–Ni thin films were deposited under different deposition times, from 50 to 600 s, at room temperature. Atomic force microscopy was employed to characterize the 3‐D surface texture data in connection with the statistical, and fractal analyses. It has been found that up to 180 s the sputtering occurs in more metal content mode and in greater than 180 s it occurs in more non‐metal content mode. This behavior demonstrated a strong link between the structural and morphological properties of C–Ni composite films and facilitates a deeper understanding of structure/property relationships and surface defects in prepared samples. Furthermore, these findings can be applied to research on the mechanisms to prepare and control high‐quality C–Ni films.     

Improving quality of DES S-boxes by cellular automata-based S-boxes

In the paper we use recently proposed cellular automata (CA) based methodology (Szaban and Seredynski in LNCS, vol. 5191, pp. 478–485, 2008) to design the 6×4 S-boxes functionally equivalent to S-boxes used in current cryptographic standard known as Data Encryption Standard (DES). We provide an exhaustive experimental analysis of the proposed CA-based S-boxes in terms of non-linearity, autocorrelation, balance and strict avalanche criterion, and compare results with ones corresponding to DES S-boxes. We show that the proposed CA-based S-boxes have cryptographic properties comparable to or better than classical S-box tables. The interesting feature of the proposed S-boxes is a dynamic flexible structure fully functionally realized by CA, while the classical DES S-boxes are represented by predefined unchangeable table structures.     

Information management system for new construction technologies

This paper presents an overview of a prototypical evaluation system intended for new construction technologies under consideration by the US Army Corps of Engineers. The system has been designed for implementation on MS-DOS driven micro-computers and is capable of determining the level of technology impact on the military construction programme within a given planning horizon. Potential civilian sector applications of this system are also desirable.     

Proteolytic Landscapes in Gastric Pathology and Cancerogenesis

Gastric cancer is a leading cause of cancer-related death, and a large proportion of cases are inseparably linked to infections with the bacterial pathogen and type I carcinogen Helicobacter pylori. The development of gastric cancer follows a cascade of transformative tissue events in an inflammatory environment. Proteases of host origin as well as H. pylori-derived proteases contribute to disease progression at every stage, from chronic gastritis to gastric cancer. In the present article, we discuss the importance of (metallo-)proteases in colonization, epithelial inflammation, and barrier disruption in tissue transformation, deregulation of cell proliferation and cell death, as well as tumor metastasis and neoangiogenesis. Proteases of the matrix metalloproteinase (MMP) and a disintegrin and metalloproteinase domain-containing protein (ADAM) families, caspases, calpain, and the H. pylori proteases HtrA, Hp1012, and Hp0169 cleave substrates including extracellular matrix molecules, chemokines, and cytokines, as well as their cognate receptors, and thus shape the pathogenic microenvironment. This review aims to summarize the current understanding of how proteases contribute to disease progression in the gastric compartment.     

Conversion of Formyl into Cyano groups in kojic acid derivatives and analogues

It has been revealed that N,N-dimethylhydrazones ( 1a - c , 3a , b ) derived from kojic acid analogs, such as substituted furans ( 3a , b ), 4-pyrones ( 1a , b ) and 4-pyridine ( 1c ), on oxididation with 3-chloroperoxybenzoic acid afford the corresponding nitriles ( 2a-c , 4a , b ). The method has preparative value. The mechanism of the reaction is presented.     

Morphology and properties of polylactide modified by thermal treatment, filling with layered silicates and plasticization

Polylactide (PLA) was modified physically by filling with inorganic additives—organomodified particles of clay, unmodified particles of clay as well as with a plasticizer—poly(ethylene glycol). The PLA-based systems were prepared by melt blending of PLA with other components. Combination of PLA with organomodified clay particles formed nanocomposite with intercalated nanostructure, while introducing microparticles led to microcomposite, respectively. The clay concentration was maintained at 3 wt% in the both systems. Additionally unfilled PLA, plasticized PLA and plasticized nanocomposite were prepared under the same blending conditions. For plasticization, 10 wt% of poly(ethylene glycol) was used. Two groups of the PLA samples and PLA-based systems featured by starting amorphous structure or semicrystalline structure were considered, respectively. The structure, thermal behavior, thermo-optical properties and dynamic mechanical response of the PLA-based systems were investigated and compared with unfilled PLA of the same thermo-mechanical history and with the neat (unprocessed) PLA. The influence of the composition and thermal treatment on the structure and physical properties of the considered samples was determined. The effect of aging on the structure and crystallization ability of the PLA material from its glassy amorphous state was evaluated as well. Temperature modulated differential scanning calorimetry, thermo-optical analysis, X-ray diffraction technique, dynamic mechanical analysis (DMTA) were used.     

An evaluation of MODIS and SeaWiFS bio-optical algorithms in the Baltic Sea

An extensive bio-optical data set from field measurements was used to evaluate the performance of standard Moderate Resolution Imaging Spectroradiometer (MODIS) and Sea-viewing Wide Field-of-view Sensor (SeaWiFS) ocean color (in-water) algorithms in the Baltic Sea, which represents an example of optically complex Case 2 waters with high concentration of colored dissolved organic matter (CDOM). The data set includes coincident measurements of radiometric quantities, chlorophyll a concentration (Chl a), and absorption coefficient of CDOM, which were taken on 25 cruises between 1993 and 2001. The data cover a wide range of variability with Chl a in surface waters from about 0.3 to 100 mg m⁻³. All the MODIS pigment algorithms examined as well as the SeaWiFS OC4v4 algorithm showed a systematic and large overestimation in chlorophyll retrievals. The mean systematic and random errors based on our entire data set exceeded 150% or even 200% in some cases, making these standard algorithms inadequate for pigment determinations in the Baltic. Although new parameterization of the standard pigment algorithms based on our field measurements in the Baltic resulted in a significant reduction of errors, the overall performance of such regionally tuned algorithms remained unsatisfactory. For example, the mean normalized bias (MNB) for the regionally tuned MODIS chlor_a_2 algorithm was reduced to 26% (from over 200% for the standard algorithm), but the root mean square (RMS) error was still large (>100%). The MODIS K_490 algorithm for estimating the diffuse attenuation coefficient of downwelling irradiance showed the best performance among all the algorithms examined. With the new coefficients based on our field data, the regional version of this algorithm showed an acceptable level of errors, MNB=4% and RMS=30%. In addition to the apparent problems of the standard in-water bio-optical algorithms, we found that the atmospheric correction currently in use for MODIS and SeaWiFS imagery usually fails to retrieve upwelling radiances emerging from the Baltic Sea. The match-up comparisons of the coincident in situ and satellite determinations of normalized water-leaving radiances showed generally poor agreement, especially in the blue spectral region. It appears that new approaches for ocean color algorithms are required in the Baltic Sea.