Cobalt(ethylenediamine)sulfate: A Pillared Layered Coordination Polymer

A pillared-layered coordination polymer of formula Co(H₂NCH₂CH₂NH₂)SO₄ (1) has been synthesized under solvothermal condition, and fully characterized. The three-dimensional structure of 1 is built up from cobalt sulfate sheets, each of which is composed of regularly alternating CoO₄N₂ octahedra and SO₄ tetrahedra, with ethylenediamine pillars connecting the adjacent sheets. The coordinate covalent and hydrogen bonds have been revealed to exhibit an important role in the organization of the structure. The compound is found to be thermally stable up to, and above, 573 K and exhibits paramagnetic behavior at room temperature.     

Jxta-Overlay: An interface for efficient peer selection in P2P JXTA-based systems

In this paper we address the problem of the efficient peer selection in P2P distributed platforms. To this end, we have developed a P2P distributed platform using Sun's JXTA technology, which is endowed with resource brokerage strategies to efficiently select peers using four selection models: (a) economic scheduling model; (b) priced-based model; (c) peer-priority selection model; and, (d) random selection model. Next, we have deployed the P2P platform in a real network using nodes of the PlanetLab and have experimentally evaluated the performance of the peer selection models. The P2P platform offers a user-friendly interface for efficient peer selection and configuration of the P2P platform.     

CFD modelling of pump-around jet mixing tanks: a reliable model for overall mixing time prediction

Over the past two decades or so, computational fluid dynamics (CFD) has been employed to predict overall mixing times inside jet mixing tanks instead of non-universal mixing time correlations obtained by experiments. However, the numerical methods for jet mixing tank simulations were not clearly tested and the discretization errors of the previous CFD models were not assessed. So, in this paper, the suitable turbulence model and numerical methods for pump-around jet mixing tank simulations were investigated. Further, the discretization errors of the present CFD models were estimated with the help of grid convergence index (GCI). The results revealed that the realizable k-epsilon model, SIMPLE, second order upwind, and first order implicit were proper turbulence model and numerical methods for pump-around jet mixing tank simulations. From GCI analyses, the maximum discretization uncertainty in overall mixing time of the present CFD models was about ±0.08 s.     

Unsupervised segmentation method for cuboidal cell nuclei in histological prostate images based on minimum cross entropy

This paper presents a novel segmentation method for cuboidal cell nuclei in images of prostate tissue stained with hematoxylin and eosin. The proposed method allows segmenting normal, hyperplastic and cancerous prostate images in three steps: pre-processing, segmentation of cuboidal cell nuclei and post-processing. The pre-processing step consists of applying contrast stretching to the red (R) channel to highlight the contrast of cuboidal cell nuclei. The aim of the second step is to apply global thresholding based on minimum cross entropy to generate a binary image with candidate regions for cuboidal cell nuclei. In the post-processing step, false positives are removed using the connected component method. The proposed segmentation method was applied to an image bank with 105 samples and measures of sensitivity, specificity and accuracy were compared with those provided by other segmentation approaches available in the specialized literature. The results are promising and demonstrate that the proposed method allows the segmentation of cuboidal cell nuclei with a mean accuracy of 97%.     

Carbonized electrospun polyvinylpyrrolidone/metal hybrid nanofiber composites for electrochemical applications

Electrospinning is a very versatile and efficient method of fabricating nanofibers with the desired properties. Polyvinylpyrrolidone (PVP) in ethanol solution was electrospun into nanofibers and used as a precursor for the preparation of carbon nanofibers. Cobalt chloride was also incorporated with PVP nanofibers to produce carbon nanofiber composites with enhanced electrical conductivity and electrochemical properties. The surface morphology and physical properties of the electrospun nanofibers, carbonized nanofibers, and their composites were observed by scanning electron microscopy, transmission electron microscopy, and X‐ray diffraction. The electrochemical behavior of the carbon nanofiber composites was studied by drop‐casting on a working surface of the screen‐printed carbon electrode and examined by cyclic voltammetry and electrochemical impedance spectroscopy. The results indicated that carbon nanofiber composites were decorated with cobalt nanoparticles and enhanced the charge‐transfer efficiency on the electrode surface. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 45639.     

A direct volumetric method for the analysis of soap

Summary Glycol, or preferably its mixture with a solvent for hydrocarbons, such as isopropyl alcohol or chloroform, possesses high solvent power for soaps, which may be directly titrated with strong acids, either potentiometrically or with the use of methyl red or methyl orange. The ionization of the organic acid is suppressed so that salts of weak acids can be directly titrated by this method. The colors of the indicators are brighter and the end-point sharper than those in alcohol or water. Presented at the 19th Annual Fall Meeting of The American Oil Chemists’ Society, Nov. 7–9, 1945, in Chicago. Bristol-Myers Company post-doctorate fellow in chemistry.     

A combined morphologic and molecular approach for characterizing fungal microflora from a traditional Italian cheese (Fossa cheese)

Phenotypic and genotypic methods were used to identify filamentous fungi that characterize traditional Italian Fossa cheese and its ripening environment. After ageing for 60 days at a dairy, it was ripened for an additional three months in a pit. In the fully ripened cheese, moulds ranged from 3 to 3.4 log cfu g^?1 and Penicillium was the prevalent species. Pit environmental fungi ranged from 530 to 750 cfu m^?3 (air) and from 130 to 340 cfu cm^?2 (surfaces). The dominant pit strains were Alternaria spp., Aspergillus spp., Cladosporium spp. and Penicillium spp. Phylogenetic analyses of 18S rRNA gene and ITS1-5.8S-ITS2 regions highlighted Penicillium camemberti, Aspergillus nidulans and Aspergillus versicolor as traceable species occurring in both the cheese and pit environment, suggesting their involvement in the development of typical Fossa cheese characteristics. This approach may be used for the identification of microflora on other cheese varieties to better understand the fungal contribution in cheese ripening.     

Prospecting technologies for photovoltaic solar energy: Overview of its technical-commercial viability

There are many technologies that may emerge and eventually disappear over the years. This fact makes the monitoring of technological trends as well as the anticipation of the direction of technological change paramount. This article aims to carry out the prospection of technologies, focusing on its technical-commercial viability, for solar photovoltaic energy. The research method had a qualititative-quantitative approach with application of the Delphi technique. In the conduction of the Delphi technique, seven steps were followed, ranging from the selection of the specialists to the considerations of their opinions regarding the future of nine photovoltaic technologies. The results of the research indicate that in 2020, the cells monocrystalline, multicrystalline, and amorphous silicon; cadmium telluride; indium/copper selenide, indium, and gallium diselenide; and multicompound III-V cells will have technical and commercial viability and that dye-sensitized silicon nanowire and carbon nanostructure-based cells will not be viable. For the year 2025, monocrystalline and multicrystalline silicon cells and those of multicompounds III-V will still be technically and commercially viable. Silicon nanowire; amorphous silicon; cadmium telluride; indium/copper, selenium, and gallium diselenide dye-sensitized cells; and organic photovoltaic cells, including those based on carbon nanostructure, may be viable. This study is important, because the technological prospecting of the photovoltaic cells determines the possible trajectories of these cells, in a way that helps the companies of the sector to anticipate the strategic scenarios, thus facilitating the decision making process.