Derating factor for cable crossings with consideration of longitudinal heat flow in cable screen

In this paper, an extension of the previously published method for the calculation of the derating factors for cables crossing external heat sources is proposed. The extension takes into account the longitudinal heat flow in cable metallic screen. The proposed algorithm is illustrated in a numerical example considering a practical situation of a high voltage cable crossing a steam pipe.     

GIS Integrated Modelling of a Himalayan Landscape

Land-surface modelling is traditionally based on reductionistic cause-effect models developed for the temperate region. Sustainable management of vulnerable and extreme regions demands a new holistic approach relying on first principles and integration of processes and patterns. In this article remotely sensed data and GIS are combined for creating digital data sets of elevation and vegetation over the Himalayan Sutlej river and its tributaries. GIS-coupled models are used for distributed estimates of precipitation,and modelling of the basin water cycle. Based on the derived data and their scale and error, an expert system incorporating fuzzy logic is used for index-related erosion modelling. It is concluded that GIS integrated modelling can pave the way to sustainable landscape management.     

Calcitonin gene-related peptide and alpha-CGRP mRNA expression in cranial motoneurons after hypoglossal nerve injury during postnatal development

Changes in calcitonin gene-related peptide (CGRP) immunoreactivity and alpha-CGRP mRNA expression were determined in the hypoglossal nucleus after the nerve was crushed or transected in rats at 10, 14 and 21 days postnatal. alpha-CGRP mRNA expression was determined in normal, noninjured, hypoglossal nuclei at the three ages and after both injuries in 10 and 21 days postnatal rats. Reinnervation and neuronal survival were assayed. Although the three age groups expressed comparable levels of alpha-CGRP mRNA and its peptide in intact, hypoglossal nuclei, axonal injury produced age-dependent alterations in alpha-CGRP mRNA and CGRP. In the 21 days postnatal rats, changes in alpha-CGRP mRNA and peptide mimicked those reported in adult motoneurons after the same injuries. CGRP was elevated until reinnervation after nerve crush, whereas biphasic elevations occurred after nerve transection. In 21 days postnatal rats, increases in alpha-CGRP mRNA preceded elevations of the peptide but a greater increase resulted initially after nerve transection. An upregulation of alpha-CGRP mRNA also developed initially after both injuries in 10 days postnatal rats but subsequent elevations of alpha-CGRP mRNA did not materialize. In contrast, CGRP immunoreactivity did not increase after either injury in 10 days postnatal rats and, in fact decreased. Levels of CGRP immunoreactivity did not differ from normal amounts after either nerve injury in 14 days postnatal rats. Substantial neuronal cell loss occurred after each injury in 10 and 14 days postnatal rats but was not found in 21 days postnatal rats. Tongue reinnervation by surviving motoneurons was established after all injury paradigms except 10 days postnatal transection. The current findings demonstrate an age-dependent correlation between injury-induced expression of CGRP and hypoglossal motoneuron survival.     

Experimental exposure to diesel exhaust increases arterial stiffness in man

Introduction  

Exposure to air pollution is associated with increased cardiovascular morbidity, although the underlying mechanisms are unclear. Vascular dysfunction reduces arterial compliance and increases central arterial pressure and left ventricular after-load. We determined the effect of diesel exhaust exposure on arterial compliance using a validated non-invasive measure of arterial stiffness.     

Luminescent properties of praseodymium doped Y_2O_3 and LaAlO_3 nanocrystallites and polymer composites

Luminescent properties of Y2O3 and LaAlO3 nanopowders doped with Pr3+ ions and PMMA-based composite materials doped with these powders were reported.The set of active nanopowders differing in praseodymium ions concentration was prepared using sol-gel method and carefully characterized with respect to emission properties in the visible spectral range.In particular,the excitation and emission spectra were measured together with fluorescence decay profiles and the differences between optical properties of thes...     

Synthesis of polycaprolactone-grafted microfibrillated cellulose for use in novel bionanocomposites--influence of the graft length on the mechanical properties

In the present work, microfibrillated cellulose (MFC) made from bleached sulfite softwood dissolving pulp was utilized to reinforce a poly(ε-caprolactone) (PCL) biopolymer matrix. To improve the dispersibility of the hydrophilic MFC in the nonpolar matrix and the interfacial adhesion in the composite material, we covalently grafted the MFC with PCL via ring-opening polymerization (ROP) of ε-caprolactone (ε-CL). To be able to investigate the effect of the PCL graft length on the mechanical properties of the composite material, we performed ROP to different molecular weights of the grafts. Bionanocomposites containing 0, 3, and 10 wt % MFC were prepared via hot pressing using both unmodified and PCL grafted MFC (MFC-g-PCL) as reinforcement. PCL grafting resulted in improved dispersion of the MFC in a nonpolar solvent and in the PCL matrix. The mechanical testing of the biocomposites showed an improvement in the mechanical properties for the PCL grafted MFC in comparison to ungrafted MFC. It was also shown that there was an impact on the mechanical properties with respect to the PCL graft lengths, and the strongest biocomposites were obtained after reinforcement with MFC grafted with the longest PCL graft length.     

Polyesters with small structural variations improve the mechanical properties of polylactide

Improving the properties of biodegradable polymeric materials is needed to obtain materials competitive with current bulk plastics. Low‐molecular weight polyesters with small differences in their backbone were synthesized using a straight‐forward method and were subsequently blended with polylactide (PLA). The materials showed an improved ductility of up to 100% points and otherwise retained material properties. The changes in mechanical properties were shown to match the miscibility range of the materials and can be predicted by the solubility parameters of the materials up to a polyester content of roughly 10% w/w. The thermal stability of all the low‐molecular weight polyesters was higher than that of PLA, and most 25% w/w blends showed a thermal degradation behavior similar to that of neat PLA. Low‐molecular weight polyesters were demonstrated as being potential enhancers of the properties of PLA, while the materials degradability was maintained. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013