Effect of precursor particle size and morphology on lithiation of Ni0.6Mn0.2Co0.2(OH)2

In this paper, Ni_0.6Mn_0.2Co_0.2(OH)₂ precursors with several different morphologies and particle sizes are mixed with Li₂CO₃ and heat treated for 5, 7.5 and 10 h. The effects of the precursor properties on the degree of lithiation, electrochemical properties and volumetric capacities of lithiated product are compared. Based on the characterization results, a small (3 μm), narrow span precursor can be lithiated in a short period of time (5 h) and has good initial discharge capacity (185 mA h g^??1) and capacity retention (93% for 55 cycles). In contrast, a large wide-span precursor requires over 10 h for full lithiation. A highly porous precursor can be lithiated faster than traditional large wide-span materials, and has low cation mixing and good crystallinity. However, the volumetric energy density of porous material is low after lithiation compared to the other tested materials. Capacity retention after washing correlated with crystallographic properties of the sample.

Graphic abstract

     

PVA/STMP based hydrogels as potential substitutes of human vitreous

PVA based hydrogels were synthesised using, as crosslinking agent, trisodium trimetaphosphate (STMP) to obtain potential substitutes for the vitreous body of the eye. The hydrogels, obtained using different amounts of STMP, were characterised by Infrared Spectroscopy which confirmed the successful occurrence of crosslinking reaction. The mechanical spectra of the fully hydrated samples confirmed covalently crosslinked systems (i.e. G′ > G″). The rheological analysis pointed out that only one of the hydrogels (PVA STMP 8:1) showed a behaviour similar to that of human vitreous. The hydrogel was also subjected to injection through a small needle, a procedure that is essential in the use of vitreous substitutes. Further analysis in terms of light transmittance, water content measurements, diffusion coefficient and cytotoxicity confirmed the applicability of such a hydrogel as vitreous substitute.     

Essential oil of Teucrium scorodonia L. ssp. scorodonia from Italy

The essential oil of the flowering aerial parts of Teucrium scorodonia L. ssp. scorodonia growing in Italy on Verrucano, was analyzed by GC and GC–MS. All the identified compounds were sesquiterpene hydrocarbons. The main ones were germacrene B (26.2%) and β-caryophyllene (25.2%).     

The rheological and physical properties of linear and branched polypropylene blends

The rheological, thermal, and mechanical properties of blends consisting of a linear high melt flow rate polypropylene (PP) and two branched PPs are characterized in detail. Blends containing branched PPs display evidence of miscibility in the melt state and exhibit high melt elasticity together with significant strain hardening in extensional deformation while retaining good flow properties. Out of the two blend systems examined the blends containing linear and branched PPs with similar melt flow rates have better mechanical properties, higher crystallization temperatures, and higher crystallinities. POLYM. ENG. SCI., 47:1133–1140, 2007. © 2007 Society of Plastics Engineers     

Interactive functional poly(vinylidene fluoride) membranes with modulated lysozyme affinity: a promising class of new interfaces for contactor crystallizers

BACKGROUND: One of the challenges of current researches in biotechnological fields is the achievement of regular and increasingly smaller protein crystals for genomics and biocatalyst applications. The membrane contactor‐based methodology appears to be a time‐effective and economically competitive technology for accomplishing this target. RESULTS: A new class of interactive polymeric interfaces enabling the nucleation of very small protein crystals in a short time through controlling attractive interactions is discussed. Specifically, the role of attractive interfacial forces between a model lysozyme solution and modified poly(vinylidene fluoride) membranes is examined. The insertion of amphiphilic motifs in the fluorinated membranes allows quicker agglomeration of protein crystals at the membrane surface reducing significantly the induction time for protein nucleation. The chemical nature of the modifier permits the modulation of the membrane affinity to the lysozyme, involving polar and non‐polar attractive interactions and preserving intrinsic structural features, transport properties and the hydrophobic character of the interfaces, according to the basics of membrane crystallization technology. The formation of critical nuclei is observed after 3 h and micro‐sized crystals are formed in less than 24 h. CONCLUSION: The experimental evidence suggests these membranes as a promising class of interactive interfaces that may rapidly bring advances in genomics research. Copyright © 2009 Society of Chemical Industry     

Reason, language and education: philosophical assumptions for new curricular orientations

A theory of reason, language and their interconnection constitutes a research topic of epistemological, ontological and metaphysical significance. It also represents a crucial point of contention between defenders and detractors of postmodernism. Therefore, in this article we set out to discuss its stakes and search for its most accomplished philosophical treatment, such as to clarify and justify new curricular premises and overcome disabling and obsolete dichotomies. To accomplish this task, we explore modernist and postmodernist conceptions of reason and single out Apel and Habermas's coupling of rationality and language and its convergence with Derrida's insights on thought and meaning. We argue that such a framework provides education with prospects for new and important curricular directions and emphases.     

Species-specific bacteria identification using differential mobility spectrometry and bioinformatics pattern recognition

As bacteria grow and proliferate, they release a variety of volatile compounds that can be profiled and used for speciation, providing an approach amenable to disease diagnosis through quick analysis of clinical cultures as well as patient breath analysis. As a practical alternative to mass spectrometry detection and whole cell pyrolysis approaches, we have developed methodology that involves detection via a sensitive, micromachined differential mobility spectrometer (microDMx), for sampling headspace gases produced by bacteria growing in liquid culture. We have applied pattern discovery/recognition algorithms (ProteomeQuest) to analyze headspace gas spectra generated by microDMx to reliably discern multiple species of bacteria in vitro: Escherichia coli, Bacillus subtilis, Bacillus thuringiensis, and Mycobacterium smegmatis. The overall accuracy for identifying volatile profiles of a species within the 95% confidence interval for the two highest accuracy models evolved was between 70.4 and 89.3% based upon the coordinated expression of between 5 and 11 features. These encouraging in vitro results suggest that the microDMx technology, coupled with bioinformatics data analysis, has potential for diagnosis of bacterial infections.