Verification of ZVS boost converter with resonant circuit & modelling of an accurate two-diode PV array system simulator using MATLAB simulink

This thesis proposes a MATLAB Simulink simulator for Photo Voltaic (PV) Array system. The main contribution is the utilisation of a Two-Diode model to represent a PV cell. This model is preferred because of its better accuracy at low irradiance levels. A PV of Kyocera (KC200GT) 50*10 Array is taken & the characteristics curves are plotted. The same simulator can be interfaced with MPPT algorithms & Power Electronics converters for better efficiency. The P-V & I-V Curves of this simulator is found in exact with that given by the manufacturers. It is expected that the proposed work can be very useful for PV professionals who require a simple, fast & accurate PV simulator in order to design their systems. A detailed analysis of a resonant circuit based soft-switching boost-converter for PV applications is also performed. The converter operates at Zero Voltage Switching (ZVS) turn-on and turn-off of the main switch, & Zero Current Switching (ZCS) turn-on and ZVS turn-off of the auxiliary switch due to resonant circuit incorporated into the circuit. Detailed operation of the converters, analysis of various modes, simulation as well as experimental results for the design has also been aptly presented. The systems are modelled & simulated in MATLAB 2013a 64-bit version and the output waveforms are shown

Role of Mixed Cationic/Anionic Collector Systems on Hematite Flotation

The adsorption mechanism of mixed cationic alkyl diamine and anionic sulphate/oleate collectors was investigated on hematite through Hallimond flotation studies. The flotation response of hematite independently with cationic and anionic collectors and with mixed cationic/anionic collector systems is assessed. The Hallimond flotation response of hematite as a function of pH and collector concentration was investigated. The study revealed that hematite flotation recovery is maximum at acidic pH with sulphate, neutral pH 6-7 with oleate, and at basic pH about 9.5 with diamine. It is the first time that the hematite flotation results show increased adsorption of cationic collector in the presence of anionic collector apart from its own co-adsorption. The presence of oleate increased the diamine adsorption due to a decrease in the electrostatic head-head repulsion between the adjacent surface ammonium ions and thereby increasing the lateral tail-tail hydrophobic bonds. The increase in oleate concentration beyond diamine concentration leads to the formation of soluble 1:2 diamine-oleate complex or precipitate and the adsorption of these species decreased the flotation since the alkyl groups of these adsorbed species are randomly oriented at the surface

Flotation Of Quartz And Hematite: Adsorption Mechanism Of Mixed Cationic/Anionic Collector Systems

Using pure quartz and hematite minerals, the adsorption mechanism of mixed cationic/anionic reagent schemes was investigated through Hallimond flotation studies. The flotation response of quartz and hematite independently with cationic and anionic collectors as well as with mixed cationic/anionic collector systems is assessed. The flotation response as a function of pH and collector concentration was investigated. The single mineral flotation tests in the presence of anionic collectors, quartz does not respond to flotation but the C12 amine flotation of quartz was observed to be pH and concentration dependent. It was observed that hematite flotation recovery is maximum at acidic pH with sodium dodecyl sulphate (SDS), neutral pH with oleate, and at basic pH about 9.5 with C12 amine. Flotation results with both quartz and hematite indicate an increased adsorption of cationic collector in the presence of anionic collector apart from its own co-adsorption. The incorporation of oleate in between C12 amine molecules decreases the electrostatic head-head repulsion and thereby increasing the adsorption of C12 amine due to attractive tail-tail hydrophobic bonds, besides forming a closely packed adsorbed layer enhancing the hydrophobicity. The increase in oleate concentration beyond C12 amine concentration leads to the formation of soluble diamine-oleate complex / precipitate and the adsorption of these species decreased the flotation since the alkyl chains are in chaotical orientation with a conceivable number of head groups directing towards the solution phase

Iron oxide nanoparticles fabricated by electric explosion of wire: Focus on magnetic nanofluids

Nanoparticles of iron oxides (MNPs) were prepared using the electric explosion of wire technique (EEW). The main focus was on the fabrication of de-aggregated spherical nanoparticles with a narrow size distribution. According to XRD the major crystalline phase was magnetite with an average diameter of MNPs, depending on the fraction. Further separation of air-dry EEW nanoparticles was performed in aqueous suspensions. In order to provide the stability of magnetite suspension in water, we found the optimum concentration of the electrostatic stabilizer (sodium citrate and optimum pH level) based on zeta-potential measurements. The stable suspensions still contained a substantial fraction of aggregates which were disintegrated by the excessive ultrasound treatment. The separation of the large particles out of the suspension was performed by centrifuging. The structural features, magnetic properties and microwave absorption of MNPs and their aqueous solutions confirm that we were able to obtain an ensemble in which the magnetic contributions come from the spherical MNPs. The particle size distribution in fractionated samples was narrow and they showed a similar behaviour to that expected of the superparamagnetic ensemble. Maximum obtained concentration was as high as 5 % of magnetic material (by weight). Designed assembly of de-aggregated nanoparticles is an example of on-purpose developed magnetic nanofluid. Copyright © 2012 Author(s)

Trends in the profile of non hodgkins lymphoma in North and South India: a study from two tertiary care hospitals in India

Background: A number of environmental and chemical factors have been thought to been implicated in the occurrence of Non-Hodgkin’s Lymphomas (NHLs).To fill the knowledge gap in various aspect of the disease, this study was undertaken at this tertiary care centre in Delhi and Bangalore.Methods: This was a prospective observational study conducted in two defenses medical centre in India among patients of Non Hodgkins Lymphoma, registered at Command hospital Airforce Bangalore and Army Hospital (Research and Referral), New Delhi, between March 2016 and March 2019.Results: The disease showed a bimodal onset in both centres with 26 (26%) and 24 (24%) cases occurring in the age group of 31-40 years and 24 (24%) and 25 (25%) cases occurring in the age group of >60 years at CHAF (B) and AH (RR) respectively. B cell Lymphoma was the most common type of NHL seen in 85% and 89% patients, whereas T-cell lymphomas constituted 13% and 11% at CHAF (B) and AH (RR).  32(32%) patients presented with an Ann Arbor Stage 1 or 2 disease whereas 68(68%) patients were with Stage 3 or 4 disease at both the centers. IPI score was ≥3 in 45 % and 43% patients.Conclusions: NHL in India is a homogeneous and uniform disease. But there was increased detection of hepatosplenomegaly and associated hepatitis B/C in the southern part of India. Also, the occurrence of Cutaneous T cell lymphoma was only seen in the south India centre. The early stage NHLs has better survival and increase chance of complete response

Study on eggs of Japanese quail (Coturnix coturnix japonica) during incubation in the controlled laboratory conditions

Study on newly laid eggs of Japanese quail Coturnix coturnix japonica was undertaken for a period of 18 days on incubation in controlled laboratory conditions. The aim of the study was to evaluate the changes in egg weight, shell weight, yolk weight and embryo weight throughout the period of incubation. It had been found that as the embryo grows, the egg weight slowly goes down while embryo weight goes on increasing day by day. The study inferred that the shift or reduction in weight of egg is attributable to the progressive growth of embryo which utilizes its yolk contents for its growth. Apart from this, the shell weight also reduced from first day to last day in order to facilitate hatching of the embryo

Corporate governance and family firm performance during the Global Financial Crisis

We investigate the impact of corporate governance on accounting and market performance relationships of family firms during the Global Financial Crisis (GFC). We expect the monitoring aspects of corporate governance to complement the long-term orientation of family firms, improving the value relevance of accounting and market performance during times of exogenous financial shocks such as the GFC. We find that the family-firm value is more sensitive to book value than earnings changes. We also find better corporate governance, irrespective of whether it is a family firm or non-family firm, is associated with better accounting and market performance during the GFC

Endoscopic Proximal Adductor Lengthening for Chronic Adductor-Related Groin Pain

© 2018 Arthroscopy Association of North America Proximal adductor injuries are relatively common groin injuries in athletes. Various tenotomy techniques have been described including open, partial, and percutaneous approaches. Current techniques help most athletes return to sport; however, many develop adductor weakness. Moreover, the procedures lack full visualization of the tendon and do not allow for return to athletes’ preinjury level of play. We describe an endoscopic z-lengthening of the proximal adductor tendon with the potential to minimize complications associated with open procedures such as incisional pain and neurovascular injury while affording a more complete tenotomy than current percutaneous techniques. This is a safe and reproducible technique that allows for release of tension as a result of pathologic adductor tendon pathologies

Preheating of Sinter Mix

The importance of gas permeability in sinter mix is emphasised with reference to productivity of the Sinter machine. Based on the favourable experience of preheating of Sinter mix in U.S.S.R., the Sinter Plant Number 2 of Bhilai, in association with RDCIS, Ranchi, has evolved a system of preheating the mix in the bunker with the steam, resulting in 10oC increase

Efferocytes release extracellular vesicles to resolve inflammation and tissue injury via prosaposin-GPR37 signaling.

Macrophages release soluble mediators following efferocytic clearance of apoptotic cells to facilitate intercellular communication and promote the resolution of inflammation. However, whether inflammation resolution is modulated by extracellular vesicles (EVs) and vesicular mediators released by efferocytes is not known. We report that efferocyte-derived EVs express prosaposin, which binds to macrophage GPR37 to increase expression of the efferocytosis receptor Tim4 via an ERK-AP1-dependent signaling axis, leading to increased macrophage efferocytosis efficiency and accelerated resolution of inflammation. Neutralization and knockdown of prosaposin or blocking GRP37 abrogates the pro-resolution effects of efferocyte-derived EVs in vivo. Administration of efferocyte-derived EVs in a murine model of atherosclerosis is associated with an increase in lesional macrophage efferocytosis efficiency and a decrease in plaque necrosis and lesional inflammation. Thus, we establish a critical role for efferocyte-derived vesicular mediators in increasing macrophage efferocytosis efficiency and accelerating the resolution of inflammation and tissue injury