Exploiting the capacity of 1mm PMMA step-index polymer optical fibers

Three different techniques are discussed that are currently under investigation at Siemens Corporate Technology – Information and Communications in order to exploit the bandwidth capacity of 1 mm PMMA Step-Index Polymer Optical Fiber (SI-POF). By using Adaptive Multitone Modulation (AMTM) a record result of 540 Mb/s transmission over 100 m of SI-POF is achieved

Produção e beneficiamento da própolis

O aumento no conhecimento sobre os benefícios da própolis para a saúde  humana tornou o mercado desse produto crescente em todo o mundo. Entretanto, também fez crescer a exigência com relação a sua qualidade, que por falta de conhecimento poderá ser afetada no processo de produção,  beneficiamento e armazenagem. A diversidade da flora apícola brasileira proporciona uma produção de  própolis com componentes diferenciados de acordo com a região onde é produzida. Por sua excelente qualidade, a própolis catarinense já é reconhecida tanto no mercado interno quanto externo. Com um mercado  consolidado e crescente, a atividade torna-se uma boa alternativa de renda para as famílias rurais.Este trabalho busca divulgar as mais recentes técnicas de produção e beneficiamento da própolis a fim de aprimorar o desenvolvimento da atividade por parte dos produtores e enriquecer o conhecimento dos técnicos  da área.

40-Gb/s Transmission over 100m Graded-Index Plastic Optical Fiber based on Discrete Multitone Modulation

Spectral-efficient 40-Gb/s discrete multitone transmission over 100m of graded-index plastic optical fiber is experimentally demonstrated by intensity-modulation of a 10-GHz DFBlaser (1302nm) and direct-detection with a 25-μm large diameter photodetector

A surface acoustic wave-driven micropump for particle uptake investigation under physiological flow conditions in very small volumes

Static conditions represent an important shortcoming of many in vitro experiments on the cellular uptake of nanoparticles. Here, we present a versatile microfluidic device based on acoustic streaming induced by surface acoustic waves (SAWs). The device offers a convenient method for introducing fluid motion in standard cell culture chambers and for mimicking capillary blood flow. We show that shear rates over the whole physiological range in sample volumes as small as 200 mu L can be achieved. A precise characterization method for the induced flow profile is presented and the influence of flow on the uptake of Pt-decorated CeO2 particles by endothelial cells (HMEC-1) is demonstrated. Under physiological flow conditions the particle uptake rates for this system are significantly lower than at low shear conditions. This underlines the vital importance of the fluidic environment for cellular uptake mechanisms

Wind Erosion: Its Control in Minnesota

This archival publication may not reflect current scientific knowledge or recommendations. Current information available from the University of Minnesota Extension: https://www.extension.umn.edu

Influence of Castor canadensis on northern lower Michigan forest succession

General EcologyForests undergo a natural progression, called ecological succession, in which they experience a gradual change in community species composition (Luken 1990). As the tree community cycles through each stage of succession, the surrounding habitat cycles and transforms with it (Barnes and Wagner 2004). Our study focuses on how Castor canadensis (North American beaver) affects the direction of forest succession in northern lower Michigan. We counted, identified, and measured the diameter of standing and felled trees at four known beaver sites in the vicinity of Pellston, MI. In addition, we counted and identified 50 randomly selected juvenile trees at each site. Our results showed that C. Canadensis have a preference for Populus tremuloides (trembling aspen) (chi-square: p=0.008) and early successional tree species (chi-square: p=0.000) and show no foraging preference based on tree diameter (Mann-Whitney U: p=0.109). By comparing adult tree species to juvenile tree species, we also found that the species composition prior to and during beaver interference differs significantly from future forest species composition (chi-square: p=0.016). Given these results, we conclude that the foraging preferences of C. canadensis caused a premature progression of forest succession.http://deepblue.lib.umich.edu/bitstream/2027.42/78379/1/Breyer_Ruddy_Silver_2010.pd