Market Based Control of PV Inverters in a Distribution System

A growing energy crisis, a rapid climate change, and a constant depletion of fossil fuel necessitates the role of renewable energy resources like PV (Photovoltaics) and wind energy to form a group of distributed sources of generation. These circumstances promote the use of renewable resources meeting the environmental commitments in terms of checking pollution and toxic footprints. A group of PV and wind energy generation units may work together as micro players to form smart grid systems and participate in an existing distribution system to meet a portion of the daily energy demand. This will help in minimizing the network losses during transmission and in improving energy efficiency of the overall distribution system. However, owing to the inherent characteristics of power variability of these renewable energy sources which results in voltage variability in the distribution system, there is a need to design a distribution system that minimizes voltage spikes. This thesis examines a potential market-based approach to the control of PV Inverters in a distribution system to stabilize fluctuations in voltage. An algorithm that closely imitates the behavior of an economic system is applied to the system to manage voltage variability. More traditional approaches of mitigating voltage variability are studied and compared to understand the feasibility of the market-based control approach method on this distribution system

Synthesis and Structural Characterization of Highly Tetragonal (1-x)Bi(Zn1/2Ti1/2)O3-xPbTiO3 Piezoceramics

We present here the comprehensive X-ray diffraction (XRD) and dielectric measurement of (1-x)Bi(Zn1/2Ti1/2)O3-xPbTiO3 (BZT-xPT) piezoceramics with x=0.65, 0.70, 0.75 and 0.80. Powder X-ray diffraction data reveals the tetragonal structure (space group P4mm) of BZT-xPT ceramics for all the compositions.Comment: 2 Pages, 4 Figure

A Framework for Classification of Heterogeneous Calcium Dynamics

G-protein coupled receptors are the target receptors for designing almost 45% of the drug in current drug market. For drug screening using cell-based assays, fluorescent imaging of GPCR mediated calcium dynamics in single cells can be used to obtain the dose-response profile. However, construction of a dose-response function based on single cell responses is rather challenging as the cells in a population respond heterogeneously to the drug. Here we developed a live cell imaging-based approach to quantify the heterogeneity of the HeLa cell population in response to GPCR mediated drugs. First, we found that activation of CXCR4 by SDF-1α induces calcium responses in Hela cells. We measured the temporal dynamics of cytosolic calcium through time-lapse imaging using confocal microscopy for various drug doses

When to branch: seasonal control of shoot architecture in trees

Long-lived perennial plants optimize their shoot architecture by responding to seasonal cues. The main strategy used by plants of temperate and boreal regions with respect to surviving the extremely unfavourable conditions of winter comprises the protection of their apical and lateral meristematic tissues. This involves myriads of transcriptional, translational and metabolic changes in the plants because shoot architecture is controlled by multiple pathways that regulate processes such as bud formation and flowering, small RNAs, environmental factors (especially light quality, photoperiod and temperature), hormones, and sugars. Recent studies have begun to reveal how these pathways are recruited for the seasonal adaptation and regulation of shoot architecture in perennial plants, including the role of a regulatory module consisting of antagonistic players terminal flower 1 (TFL1) and like-ap1 (LAP1) in the hybrid aspen. Here, we review recent progress in our understanding of the genetic control of shoot architecture in perennials compared to in annuals