Seminars

Abstract: Silicon based photovoltaic (PV) cells are expected to play a major role in the utilization of solar energy and the market for polysilicon is expected to grow rapidly in the next decade. Large scale production with capacity per plant of 10 000 mt/year or more are expected to be the norm in order to reduce the cost of production improve the energy efficiency and the by-product recovery and reuse in such processes. The reactor design and scaleup of these systems therefore becomes important.

Abstract: Sensing transduction and actuation in the next generation of “smart” micro-/nanoscale devices will require exquisite control and manipulation of interfacial functionality and topography. Here I will discuss our efforts to tune interfacial properties by modulating wetting or hydrodynamic interactions. The interactions dominant within a few nanometers of a fluid−surface interface dictate properties such as adhesion friction and spreading. Modulating such interactions therefore can lead to dramatic changes in response of the fluid−surface interface.

Abstract : Droplet microfluidic technology helps is achieving spatio-temporal control of pico to femto liters of chemicals in a pre-defined network topology. The next generation droplet based lab-on-chip devices can possibly revolutionize combinatorial drug screening and high throughput analysis of chemicals and cells. Ladder network is an example of a microfluidic device that is designed to achieve synchronization of pairs of drops. Ladder networks have two parallel channels that are interconnected by bypass channels.

Microstructured Reactors for Heterogeneous Reactions Abstract: In recent years the use of microstructured reactors to produce a variety of chemicals has significantly increased. The successful implementation of such reactors requires the integration of competencies from material science catalysis chemical engineering and mechanical engineering. In this talk the design fabrication and applications of two types of microstructured reactors ( viz. monoliths and microchannel reactors) will be presented.

Abstract: The 137 genes encoding 78 different ribosomal proteins (RPs) in the budding yeast Saccharomyces cerevisiae are tightly co-regulated at the transcriptional level yet their promoters display relatively little sequence conservation. Here we describe how the transcriptional output and regulation of this suite of genes is encoded in their promoter DNA. By analyzing ChIP-seq data for four different factors (RAP1 FHL1 IFH1 and HMO1) we identify two general promoter classes characterized by the presence or absence of the HMG-box protein HMO1.

Abstract: This colloquium presents our attempts at developing theoretical models and simulation methodologies to understand the dynamics of few interesting processes in condensed phase. The dynamics of polymer having different lengths crossing over a free energy barrier which is relevant to many biological processes like DNA translo- cation through membrane will be discussed. The first part of the talk deals with short chain crossing over a barrier to show the dependence of activation energy and the rate of the process on the chain length.

Abstract: When organic polymers are heat-treated beyond their degradation temperature in the absence of oxygen they yield volatile hydrocarbons as well as various solid carbon forms composed of three-dimensional graphenic networks. This thermochemical decomposition of organic materials is known as pyrolysis and conducting pyrolysis for obtaining high-quality carbon for technological applications is defined as PoCaTech.

Abstract: Part I: “Thermodynamic analysis of resource use in Indian society over four decades to assess efficiency irreversibility and emissions” Previous studies on the resource assessment of national economies using thermodynamic analysis methods have been found to useful for analysing how efficient the respective society is in utilizing the natural resources. These studies show that a larger fraction of the total resource used in the society gets wasted.

Abstract: Droplet-based microfluidics where reactants or biological species are encapsulated in thousands of tiny water droplets is witnessing a tremendous interest for applications in chemistry biology medicine and material science. To enable the development of robust droplet-based devices my laboratory has been investigating the dynamics of confined drops in a fluidic networks and constricted channels. In this talk I will discuss how we harness collective hydrodynamics of drops to engineer multi-functional microfluidic devices.

Abstract: Spincoating is a decades-old technology for making thin polymer films and is in turn a spin-off of the centuries-old technology of the potter's spinning wheel. It is one of a small handful of technologies for manufacturing-scale processing of polymer films. Make crystals with micrometer to nanometer lattice parameters using colloidal self-assembly is promising as a way to make photonic or magnetic materials. I will describe the unusual structure and dynamics of self-assembly when one drops a colloidal suspension on a spinning wheel.