From temperature analysis of polyacrylamide gel electrophoresis data for rigid-rod DNA analytes, it is proposed that an entropic force term is responsible for the discrepancy between Ogston-Morris-Rodbard-Chrambach model predictions and experimental results. This entropic force originates from reduction of the orientational freedom of anisotropic analytes in small pores of polyacrylamide gels. Time-dependent fluorescence anisotropy decay measurements confirm that, even in the absence of an external field, orientation of anisotropic analytes is restricted in polyacrylamide gels. A new comprehensive model is proposed that takes this effect into consideration. Predictions based on this model are found to compare favorably with experimental data for linear and three-arm asymmetrically branched rigid-rod DNA analytes covering a broad range of molecular aspect ratios and sizes. A new length scale is also proposed for describing the effect of analyte topology on electrophoretic mobility. This length scale reduces to the analyte radius of gyration in the limiting cases of spherically symmetric and linear rigid-rod species. Based on these results, a general approach is proposed for interpreting gel electrophoresis data of charged analytes possessing simple and complex topologies. 相似文献
Commercial Udel® poly(ether sulfone) (PSU) was filled with three different commercially available multiwalled carbon nanotubes (MWCNTs) by small scale melt mixing. The MWCNTs were as grown NC 7000 and two of its derivatives prepared by ball milling treatment. One of them was unmodified (NC 3150); the other was amino modified (NC 3152). The main difference beside the reactivity was the reduced aspect ratio of NC 3150 and NC 3152 caused by ball milling process. All PSU/MWCNT composites with similar filler content were prepared under fixed processing conditions and comparative analysis of their electrical and mechanical properties were performed and were correlated with their microstructure, characterized by optical microscopy, scanning electron microscopy (SEM), and transmission electron microscopy (TEM). A non-uniform MWCNT dispersion was observed in all composites. The MWCNTs were present in form of agglomerates in the size of 10–60 μm whereas the deagglomerated part was homogeneously distributed in the PSU matrix. The differences in the agglomeration states correlate with the variations of properties between different PSU/MWCNT composites. The lowest electrical percolation threshold of 0.25–0.5 wt.% was observed for the shortened non-functionalized MWCNT composites and the highest for amine-modified MWCNT composites (ca. 1.5 wt.%). The tensile behavior of the three composites was only slightly altered with CNT loading as compared to the pure PSU. However, the elongation at break showed a reduction with MWCNT loading and the reduction was least for composite with best MWCNT dispersion. 相似文献
Solid hydrogen peroxide complexes based on poly(N‐vinylpyrrolidone) and poly(4‐vinylpyridine) were prepared and used as solid hydroxylating reagents. These solid hydrogen peroxide equivalents are found to be much safer, convenient and efficient reagent systems for the ipso‐hydroxylation of arylboronic acids to the corresponding phenols in high yields at a faster rate. The versatility of the reagents has been further expanded for the one‐pot synthesis of halophenols. Density functional theory calculations were carried out on hydrogen peroxide complexes of N‐ethylpyrrolidone and 4‐ethylpyridine as models to get a better understanding of structure and behavior of hydrogen peroxide complexes of the polymers poly(N‐vinylpyrrolidone) and poly(4‐vinylpyridine) compared to aqueous hydrogen peroxide. 相似文献
Digital microfluidic biochip is a promising alternative to the traditional cumbersome laboratory equipment. Such automated biochips are used in many critical applications. Hence dependability is an essential attribute before the chip is in use. Due to mixed integration technologies, these chips have some unique failures. Hence robust offline and online tests are proposed to check the health of the biochips. When a chip undergoes a test in offline mode, then the entire biochip should be available for testing, whereas for the online mode test droplet might be stalled due to unavailability of the next cell in the routing path. However, in both the scenarios one or more droplets route across the chip and the arrival time is also recorded at the destination. So here we have proposed two test schemes to know the correctness of any biochip. Diagnosability is an important feature to find the exact position of the faulty electrode. Our proposed scheme reduces the overall testing and diagnosis time significantly. It also provides an alternative routing path in biochip for fault tolerance.
The effect of fortification of dietary fibre (DF) on dough rheology, quality characteristics and in vitro starch digestibility of bread was studied. Bread was prepared incorporating DF (2–4 g per 100 g of flour mixture). Rheological study of dough showed an increase in dough stiffness and elasticity with higher incorporation of the DF. The results of chemical composition revealed that addition of DF increased total DF (19.65 g per 100 g) content of bread. However, incorporation of 2 g per 100 g DF of flour mixture with 66 g per 100 g moisture showed higher water retention and specific volume of 86.76% and 5.83 cm3 g−1, respectively, which was close to control bread. Improved textural property with acceptable sensory attributes was observed for bread fortified with 2 g per 100 g DF of flour mixture and 66 g per 100 g moisture content. Incorporation of DF (2–4 g per 100 g of flour mixture) showed a decrease in rapidly digestible starch (RDS) and an increase in slowly digestible starch (SDS) content with lower predicted glycaemic index (pGI) than control bread. 相似文献
Wireless Personal Communications - A novel approach to design dual-band as well as a triple-band BPF with improved isolation is ventured in this paper. In dual-band filter, dual mode property of... 相似文献
Cloud computing is on the horizon of the domain of information technology over the recent few years, giving different remotely accessible services to the cloud users. The quality-of-service (QoS) maintaining of a cloud service provider is the most dominating research issue today. The QoS embraces with different issues like virtual machine (VM) allocation, optimization of response time and throughput, utilizing processing capability, load balancing etc. VM allocation policy deals with the allocation of VMs to the hosts in different datacenters. This paper highlights a new VM allocation policy that distributes the load of VMs among hosts which improves the utilization of hosts’ processing capability as well as makespan and throughput of cloud system. The experimental results are obtained by utilizing trace based simulation in CloudSim 3.0.3 and compared with existing VM allocation policies. 相似文献
In present multi-core devices, the individual processors do not need to operate at the highest possible frequencies. Instead there is a need to reduce the power, complexity and area of individual processor components like caches. In this paper we propose a low area, high performance cache replacement policy for embedded processors called Hierarchical Non-Most-Recently-Used (H-NMRU). The H-NMRU is a parameterizable policy where we can trade-off performance with area. We extended the Dinero cache simulator with the H-NMRU policy and performed architectural exploration with a set of cellular and multimedia benchmarks. On a 16 way cache, a two level H-NMRU policy where the first and second levels have 8 and 2 branches, respectively, performs as good as the Pseudo-LRU policy with storage area saving of 27%. Compared to true LRU, H-NMRU on a 16 way cache saves huge amount of area (82%) with marginal increase of cache misses (3%). Similar result was also noticed on other cache like structures like branch target buffers. Therefore, the two level H-NMRU cache replacement policy (with associativity/2 and 2 branches on the two levels) is a very attractive option for caches on embedded processors with associativities greater than 4. We present a case-study where it can be used on the L2 cache with substantial gain in performance and area for single and dual core platforms. 相似文献