SVPWM control strategy for Novel Interleaved High Gain DC converter fed 3-level NPC Inverter for Renewable Energy Applications

The high-gain DC converter is a crucial step in the conversion process for raising the voltage from PV panels to the desired voltage level in renewable energy applications. This article proposes a three-phase grid connected PV system with a novel interleaved high gain DC converter fed 3-level Neutral-Point-Clamped (NPC) Inverter. The novel high-gain DC converter consists of an interleaved boost converter (IBC) at its input side, a switched capacitor cell, a passive clamp circuit, and a voltage multiplier unit (VMU). The interleaved arrangement eliminates the input current ripple, and the VMU is utilized to improve the overall voltage gain besides the reverse recovery problem of diodes. The proposed converter is operated at a duty cycle D = 0.6 and a high voltage conversion ratio of 17.5 which is ideal for sustainable energy applications. This paper uses the proposed converter for a grid-connected solar PV system with an NPC inverter controlled using Space Vector Pulse Width Modulation (SVPWM) technique. The SVPWM strategic approach is a prevalent modulation technique for NPC inverter due to its extensibility in choosing the ideal voltage vectors. It uses an active filter, which is more dependable, dynamically better behaved, and capable of operating accurately under distorted grid voltages under varying load conditions. The proposed grid-associated PV system with a novel interleaved converter and 3-level NPC inverter is employed in Matlab/SimPower System and experimentally verified. Power loss and efficiency calculations were performed on the DC converter side, and the efficiency was 96.07%. NPC inverters have a THD of 22.2%. Results from simulations and experiments indicate that the suggested topology can efficiently extricate the maximal amount of power from PV modules and inject energy into the grid system with excellent steady-state and dynamic performance.

Artificial Neural Network based SVPWM for Five Level Cascaded H-bridge Inverter fed Grid connected PV System

An Artificial Neural Network (ANN) based Space Vector Pulse Width Modulation (SVPWM) for five level cascaded H-bridge inverter (CHBI) fed grid connected photovoltaic (PV) system. The multilevel inverter topologies are offers better performance compare conventional two level inverter like reduced total harmonic distortion, less electromagnetic interferences and voltage stresses across switches are low. The ANN based SVPWM generates the switching pulses for cascaded H-bridge inverter; it improves the accuracy in reference vectors tuning and identification, which leads to improve the inverter output voltage, better utilization of dc-link voltage and controlled output current. The ANN control makes the implementation of SVPWM becomes simple and minimizes the intricacy in tracking reference vector and calculation of switching time; it is suitable for any type of non-linear systems. This proposed system is energized using PV system and it is boosted using dc-dc boost converter, and the output of CHBI is synchronized with grid connected system using coupled inductor. The simulation and experimental results of ANN based SVPWM for CHBI is verified using simulink-matlab and DSP processor.

Molecular inversion probe: a new tool for highly specific detection of plant pathogens

Highly specific detection methods, capable of reliably identifying plant pathogens are crucial in plant disease management strategies to reduce losses in agriculture by preventing the spread of diseases. We describe a novel molecular inversion probe (MIP) assay that can be potentially developed into a robust multiplex platform to detect and identify plant pathogens. A MIP has been designed for the plant pathogenic fungus Fusarium oxysporum f.sp. conglutinans and the proof of concept for the efficiency of this technology is provided. We demonstrate that this methodology can detect as little as 2.5 ng of pathogen DNA and is highly specific, being able to accurately differentiate Fusarium oxysporum f.sp. conglutinans from other fungal pathogens such as Botrytis cinerea and even pathogens of the same species such as Fusarium oxysporum f.sp. lycopersici. The MIP assay was able to detect the presence of the pathogen in infected Arabidopsis thaliana plants as soon as the tissues contained minimal amounts of pathogen. MIP methods are intrinsically highly multiplexable and future development of specific MIPs could lead to the establishment of a diagnostic method that could potentially screen infected plants for hundreds of pathogens in a single assay.

Molecular inversion probe-based SPR biosensing for specific, label-free and real-time detection of regional DNA methylation

DNA regional methylation can be detected in real-time and label-free using surface plasmon resonance biosensing coupled to molecular inversion probe based amplification.

Accurate detection of methylated cytosine in complex methylation landscapes

Monitoring DNA methylation can be a useful biomarker for disease diagnosis and prognosis. However, monitoring the methylation status of a specific cytosine biomarker is often confounded by heterogeneous peripheral DNA methylation. To address this issue, molecular inversion probes were designed with inosine strategically positioned to complement suspected DNA methylation sites. This enabled the methylation status of a specific cytosine to be accurately measured with a high level of specificity, irrespective of adjacent epigenetic modifications.

Quantitative considerations for suspension array assays

A novel format of a multiplex microbead assay that is capable of accurately and reproducibly measuring small changes in 10(8) copies of a nucleic acid is reported herein. The dynamic range of the assay was 32-fold greater than conventional multiplex microbead assays. The assay was modeled mathematically which enabled the accuracy of DNA quantification to be formally analysed using a logical theoretical framework. The assay was also evaluated on RNA extracts taken from stimulated macrophages, to demonstrate that changes in gene expression can be accurately monitored in a biological system. We believe the reproducibility and accuracy of the assay presented herein will be useful for high-throughput, multiplex sensitive detection of nucleic acids over a large dynamic range in a research or diagnostic setting.

Combined vaccination of cattle against FMD and rabies

Three groups of crossbred calves were vaccinated with FMD vaccine only, combined FMD + rabies vaccine and rabies vaccine alone. Efficacy of the vaccines was determined by serum antibody assay at different intervals postvaccination. The results of the study indicated that the immune response of animals to a single inoculation of FMD vaccine only as well as combined FMD + rabies vaccine was unsatisfactory due to maternally derived antibodies to FMD virus antigen. However two inoculations elicited a satisfactory antibody response to FMD virus antigens in both group of animals. Rabies antigen alone as well as combined FMD + rabies antigen induced satisfactory serum antibody titres to rabies antigen. There was no significantly different serological responses in animal administered FMD vaccine only, rabies vaccine only or combined FMD + rabies vaccine.