Hybrid Approach in Microscale Transport Phenomena: Application to Biodiesel Synthesis in Micro-reactors

A hybrid engineering approach to the study of transport phenomena, based on the synergy among computational, analytical, and experimental methodologies is reviewed. The focus of the chapter is on fundamental analysis and proof of concept developments in the use of nano- and micro-technologies for energy efficiency and heat and mass transfer enhancement applications. The hybrid approach described herein combines improved lumped-differential modeling, hybrid numericalanalytical solution methods, mixed symbolic-numerical computations, and advanced experimental techniques for micro-scale transport phenomena. An application dealing with micro-reactors for continuous synthesis of biodiesel is selected to demonstrate the instrumental role of the hybrid approach in achieving improved design and enhanced performance

Mid-Crustal Focused Fluid Movement: Thermal Consequences and Silica Transport

Numerical models have been constructed to assess the thermal consequences and silica transport that would result if water released by regional metamorphic dehydration or cooling plutons were focused into large-scale (10 km) fracture zones. Two fracture zone model geometries have been considered, in one the fracture zone is planar, and in the other the fracture zone is radially symmetric. In both models dispersion and collection of fluids is simulated. The model results indicate that for planar or radially symmetric fracture zones, hydrothermal flow rates must approach 0.1 g/s (per m crack length) or 1 kg/s, respectively, to produce significant thermal effects. Given that regional metamorphic fluid fluxes are probably < 10−9 kg/m2−s, generation of a thermal ano-maly by fluids released during metamorphic dehydration into a planar fracture zone requires an unrealistic degree of lateral flow (>50 km). The collection area required to produce a detectable heating effect about a radially symmetric fracture zone is smaller (a radius of ∼ ∼ 15 km), but also implausibly large. These scales suggest tha

Network-Guided Analysis of Genes with Altered Somatic Copy Number and Gene Expression Reveals Pathways Commonly Perturbed in Metastatic Melanoma

Cancer genomes frequently contain somatic copy number alterations (SCNA) that can significantly perturb the expression level of affected genes and thus disrupt pathways controlling normal growth. In melanoma, many studies have focussed on the copy number and gene expression levels of the BRAF, PTEN and MITF genes, but little has been done to identify new genes using these parameters at the genome-wide scale. Using karyotyping, SNP and CGH arrays, and RNA-seq, we have identified SCNA affecting gene expression (‘SCNA-genes’) in seven human metastatic melanoma cell lines. We showed that the combination of these techniques is useful to identify candidate genes potentially involved in tumorigenesis. Since few of these alterations were recurrent across our samples, we used a protein network-guided approach to determine whether any pathways were enriched in SCNA-genes in one or more samples. From this unbiased genome-wide analysis, we identified 28 significantly enriched pathway modules. Comparison with two large, independent melanoma SCNA datasets showed less than 10% overlap at the individual gene level, but network-guided analysis revealed 66% shared pathways, including all but three of the pathways identified in our data. Frequently altered pathways included WNT, cadherin signalling, angiogenesis and melanogenesis. Additionally, our results emphasize the potential of the EPHA3 and FRS2 gene products, involved in angiogenesis and migration, as possible therapeutic targets in melanoma. Our study demonstrates the utility of network-guided approaches, for both large and small datasets, to identify pathways recurrently perturbed in cancer