Stable passive mode-locked fiber lasers(MLFLs) employing graphene saturable absorber (SA) are demonstrated. The graphene were dispersed in de-ionized water by two different dispersants including fluorinated mica clay (Mica) and poly(oxyethylene)-segmented imide (POEM). Using the SA made by graphene dispersed in Mica with thickness and concentration product (TCP) of 36 (£gm*wt%), the MLFLs exhibited pulsewidth, 3-dB spectral bandwidth, and modulation depth (MD) of 382 fs, 6.80 nm, and 2.57%, respectively. The graphene dispersed in POEM provides a TCP of 38 (£gm*wt%) to make the MLFLs deliver pulsewidth, 3-dB spectral bandwidth, and MD of 422 fs, 6.35 nm, and 1.70%, respectively. In comparison, the graphene SA dispersed by Mica performs a better MLFL pulse quality than that dispersed by POEM. Lastly, for investigating the dispersed uniformity between Mica and POEM, we randomly chose 9 pieces and measured the MLFL performance. The result showed that using the SA made by graphene dispersed in Mica with TCP of 36 (£gm*wt%), the MLFLs exhibited pulsewidth of 393¡Ó14 fs, By contrast, the graphene dispersed in POEM provided a TCP of 38 (£gm*wt%) to make the MLFLs delivered pulsewidth of 442¡Ó32 fs. This result reveals that graphene SA film dispersed by Mica exhibited better uniformity than POEM. The MLFL of 21-layes CVD process graphene SA showed a pulsewidth of 432.47 fs, a bandwidth of 6.16nm, and a time-bandwidth product (TBP) of 0.323. This result showed that the solution blending process graphene SA exhibited better MLFL performance than CVD.

In this paper, we propose an early retransmission scheme to improve TCP's performance in delivering time-sensitive media. Our extensive ns2 simulations show significant improvement. When integrated into a traditional TCP variant, namely TCP-SACK, the early retransmission scheme can substantially reduce the latency caused by retransmission timeout. As a result, it can help TCP-SACK achieve a considerably higher success rate in delivering real time media. Early Retransmission also enhances the performance of a delay-based TCP variant, namely PERT. Furthermore, we also explore the improvement brought by employing a fine-grained retransmission timer, and compare it with ER. We find out that ER outperforms the fine grained timer in a variety of conditions and the combination of the two can further improve performance.

The purpose of this study is to develop a tool that will assist in the development of traffic control plans. Using information from TxDOT Dallas District and several other sources, a GIS-based map has been assembled that combines data from many different formats into one user-friendly environment. The capability provided in the tool includes geometric properties of all TxDOT-controlled freeway segments, as well as daily and hourly demand data and capacity information specific to both general and HOV lanes. By selecting a segment on the map and opening the tool, the user can easily navigate through the collection of data in just seconds, which will significantly reduce the amount of time required by the traffic engineer to gather site-specific information when analyzing temporary traffic control. / text

TCP genes comprise a large family of genes that have been implicated in a diverse range of plant developmental pathways ranging from lateral branching (Doebley et al, 1997) to organ symmetry (Luo et al, 1999) and leaf curvature (Nath et al, 2003; Palatnik et al, 2003). I studied three closely related Arabidopsis TCP genes, one of which was recovered in an enhancer trap screen to identify downstream targets of the regulator of inflorescence architecture, BREVIPEDICELLUS (Douglas and Riggs, 2005). The enhancer trap marker line served as a reporter for TCP15 expression. Data mining has revealed a possible link between TCP15 and the hormone auxin. Using the DR5::GUS molecular reporter for auxin accumulation I found that TCP15 and the related TCP14 genes limit auxin maxima in seedling and reproductive tissues and that auxin transport is necessary for correct TCP15 expression. The closely related TCP8 gene was found to regulate leaf shape as demonstrated by decreased leaf index values. The rounder leaves of tcp8 plants also exhibited increased adaxial trichome and stomatal densities resulting in significantly decreased spacing between adjacent cells. tcp8 leaves showed increased serration density suggesting that TCP8 limits marginal outgrowth. Vein patterning was also perturbed in the mutants. Vein loops were rounder and smaller, and decreased loop subdivision indicated that vein patterning is retarded in the mutant. TCP8 evokes organ-specific effects on vascular patterning as mutant rosette leaves showed increased vascular complexity, whereas mutant cauline leaves showed decreased vein complexity. These results suggest that TCP8 is necessary for correct leaf development. The Arabidopsis genome contains 24 TCP genes, many of which have not been characterized. Studies of these genes will lead to the identification of additional factors necessary to control plant architecture and enable us to optimize plant growth and yield using genetic engineering.

TCP genes comprise a large family of genes that have been implicated in a diverse range of plant developmental pathways ranging from lateral branching (Doebley et al, 1997) to organ symmetry (Luo et al, 1999) and leaf curvature (Nath et al, 2003; Palatnik et al, 2003). I studied three closely related Arabidopsis TCP genes, one of which was recovered in an enhancer trap screen to identify downstream targets of the regulator of inflorescence architecture, BREVIPEDICELLUS (Douglas and Riggs, 2005). The enhancer trap marker line served as a reporter for TCP15 expression. Data mining has revealed a possible link between TCP15 and the hormone auxin. Using the DR5::GUS molecular reporter for auxin accumulation I found that TCP15 and the related TCP14 genes limit auxin maxima in seedling and reproductive tissues and that auxin transport is necessary for correct TCP15 expression. The closely related TCP8 gene was found to regulate leaf shape as demonstrated by decreased leaf index values. The rounder leaves of tcp8 plants also exhibited increased adaxial trichome and stomatal densities resulting in significantly decreased spacing between adjacent cells. tcp8 leaves showed increased serration density suggesting that TCP8 limits marginal outgrowth. Vein patterning was also perturbed in the mutants. Vein loops were rounder and smaller, and decreased loop subdivision indicated that vein patterning is retarded in the mutant. TCP8 evokes organ-specific effects on vascular patterning as mutant rosette leaves showed increased vascular complexity, whereas mutant cauline leaves showed decreased vein complexity. These results suggest that TCP8 is necessary for correct leaf development. The Arabidopsis genome contains 24 TCP genes, many of which have not been characterized. Studies of these genes will lead to the identification of additional factors necessary to control plant architecture and enable us to optimize plant growth and yield using genetic engineering.

Diss. (sammanfattning) Sundsvall : Mittuniversitetet, 2008. / Härtill 5 uppsatser.

Techn. University, Diss., 2004--Berlin.

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No description available.