AHP method application in selection of appropriate material handling equipment in selected industrial enterprise

Wireless Networks - The paper deals with handling equipment that can be used to transport/handle the final products in a selected industrial enterprise. The suitable handling equipment listed in...     

Dynamic mechanical properties for polyurethane elastomers applied in elastomeric mortar

Dynamic mechanical properties of a polyurethane (PU) elastomer and a mortar processed with the same elastomer (modified polytetramethylene ether glycol (PTMEG)) were studied. The results obtained showed that the liquid aromatic amine ETHACURE® 300, used as cure agent, can be used to substitute the aromatic amine MOCA®, which is usually used as cure agent in high performance elastomers. The resulting mortar produced with ETHACURE® 300 presents similar dynamic‐mechanical thermal properties when compared with MOCA ®. However, dynamic‐mechanical thermal analysis studies showed that the mortar developed with ETHACURE® 300 presents some advantages such as the low values of tan δ, indicating a good capacity of recovery of the strain after retreating an applied force. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

In vitro dissolution method fitted to in vivo absorption profile of rivaroxaban immediate-release tablets applying in silico data

Objective: This study aimed to develop and validate an in vitro dissolution method based on in silico–in vivo data to determine whether an in vitro–in vivo relationship could be established for rivaroxaban in immediate-release tablets.

Significance: Oral drugs with high permeability but poorly soluble in aqueous media, such as the anticoagulant rivaroxaban, have a major potential to reach a high level of in vitro–in vivo relationship. Currently, there is no study on scientific literature approaching the development of RIV dissolution profile based on its in vivo performance.

Methods and results: Drug plasma concentration values were modeled using computer simulation with adjustment of pharmacokinetic properties. Those values were converted into drug fractions absorbed by the Wagner–Nelson deconvolution approach. Gradual and continuous dissolution of RIV tablets was obtained with a 30?rpm basket on 50?mM sodium acetate +0.2% SDS, pH 6.5 medium. Dissolution was conducted for up to 180?min. The fraction absorbed was plotted against the drug fraction dissolved, and a linear point-to-point regression (R²?=?0.9961) obtained.

Conclusion: The in vitro dissolution method designed promoted a more convenient dissolution profile of RIV tablets, whereas it suggests a better relationship with in vivo performance.     

Controlling Cell Behavior Through the Design of Polymer Surfaces

Polymers have gained a remarkable place in the biomedical field as materials for the fabrication of various devices and for tissue engineering applications. The initial acceptance or rejection of an implantable device is dictated by the crosstalk of the material surface with the bioentities present in the physiological environment. Advances in microfabrication and nanotechnology offer new tools to investigate the complex signaling cascade induced by the components of the extracellular matrix and consequently allow cellular responses to be tailored through the mimicking of some elements of the signaling paths. Patterning methods and selective chemical modification schemes at different length scales can provide biocompatible surfaces that control cellular interactions on the micrometer and sub‐micrometer scales on which cells are organized. In this review, the potential of chemically and topographically structured micro‐ and nanopolymer surfaces are discussed in hopes of a better understanding of cell–biomaterial interactions, including the recent use of biomimetic approaches or stimuli‐responsive macromolecules. Additionally, the focus will be on how the knowledge obtained using these surfaces can be incorporated to design biocompatible materials for various biomedical applications, such as tissue engineering, implants, cell‐based biosensors, diagnostic systems, and basic cell biology. The review focusses on the research carried out during the last decade.     

The economics of the CDM levy: Revenue potential,tax incidence and distortionary effects

A levy on the Clean Development Mechanism and other carbon trading schemes is a potential source of finance for climate change adaptation. An adaptation levy of 2% is currently imposed on all CDM transactions which could raise around $500 million between now and 2012. This paper analyses the scope for raising further adaptation finance from the CDM, the economic costs (deadweight loss) of such a measure and the incidence of the levy, that is, the economic burden the levy would impose on the buyers and sellers of credits. We find that a levy of 2% could raise up to $2 billion a year in 2020 if there are no restrictions on demand. This could rise to $10 billion for a 10% tax. Restrictions on credit demand (called supplementarity limits, the requirement that most emission abatement should happen domestically) curtail trade volumes and consequently tax revenues. They also alter the economic impact of the CDM levy. Without supplementarity restrictions sellers (developing countries) bear two-thirds of the cost of the tax. If there are supplementarity limits they can pass on the tax burden to buyers (developed countries) more or less in full. Without supplementarity restrictions the distortionary effect of the levy (its deadweight loss) rises sharply with the tax rate. With them the deadweight loss is close to zero.     

Identification of Fiber Breakage in Fiber Reinforced Plastic by Low-Amplitude Filtering of Acoustic Emission Data

A new low-amplitude filtering technique has been developed for the identification of fiber breakage in fiber reinforced plastics from acoustic emission data. In this approach, the acoustic emission hits associated with fiber breakage are separated from the hits associated with other failure mechanisms by filtering out the low amplitude hits from the measured data. The lowest remaining amplitude upon the cumulative plot of the remaining hits vs. load coinciding with the cumulative signal strength vs. load plot is taken as the borderline between fiber breakage hits and non-fiber breakage hits. Experiments were conducted on unidirectional-fiber specimens and complex-fiber specimens to examine the efficacy of the proposed technique. Evaluation of the experimental results by visual inspection and extensive scanning electron microscope studies verifies the low-amplitude filtering technique as a reliable tool for identifying fiber breakage in fiber reinforced plastics.     

Lipase/acyltransferase‐catalysed interesterification of fat blends containing n‐3 polyunsaturated fatty acids

The lipase/acyltransferase from Candida parapsilosis is an original biocatalyst that preferentially catalyses alcoholysis over hydrolysis in biphasic aqueous/organic media. In this study, the performance of the immobilised biocatalyst in the interesterification in solvent‐free media of fat blends rich in n‐3 polyunsaturated fatty acids (n‐3 PUFA) was investigated. The interesterification activity of this biocatalyst at a water activity (a_w) of 0.97 was similar to that of commercial immobilised lipases at a_w values lower than 0.5. Thus, the biocatalyst was further used at an a_w of 0.97. Response surface modelling of interesterification was carried out as a function of medium formulation, reaction temperature (55–75 °C) and time (30–120 min). Reaction media were blends of palm stearin (PS), palm kernel oil and triacylglycerols (TAG) rich in n‐3 PUFA (“EPAX 4510TG”; EPAX AS, Norway). The best results in terms of decrease in solid fat content were observed for longer reaction time (>80 min), lower temperature (55–65 °C), higher “EPAX 4510TG” content and lower PS concentration. Reactions at higher temperature led to final interesterified fat blends with lower free fatty acid contents. TAG with high equivalent carbon number (ECN) were consumed while acylglycerols of lower ECN were produced.     

Octanitrocubane: A New Nitrocarbon

Octanitrocubane, the first new nitrocarbon in 18 years, is introduced as a potential explosive of great power. Its synthesis and characterization are described.