Design and Development of Tilted Single Axis and Azimuth-Altitude Dual Axis Solar Tracking Systems
PROCEEDINGS OF THE FIRST IEEE INTERNATIONAL CONFERENCE ON POWER ELECTRONICS, INTELLIGENT CONTROL AND ENERGY SYSTEMS (ICPEICES 2016)
Authors: Ray, Shashwati; Tripathi, Abhishek Kumar
Abstract
The green energy also called the renewable energy, has gained much attention nowadays. Among the renewable energy solutions, solar energy is the very vital source that can be used to generate power. Electricity from the sun can be converted through photovoltaic (PV) module. The efficiency of solar module depends on sun intensity, if the intensity is more then efficiency is more. Since the position of sun continuously changes throughout the day, the intensity of sun rays is not uniform on PV module. So, for getting more sun rays on PV module solar tracker plays a much vital role. A solar tracker is a device for operating a solar photovoltaic panel, especially in solar cell applications and requires high degree of accuracy to ensure that the concentrated sunlight is dedicated precisely on to the power device. This paper describes in detail about the design, development and fabrication of two Prototype Solar Tracking Systems mounted with a single-axis and dual-axis solar tracking controllers to generate 10.3 volts, 1.5 watts capable of charging mobile batteries. The rays from the sun should fall perpendicularly onto the solar panels to maximize the capture of the rays and this is done by pointing the solar panels towards the sun and following its path ac ross the sky. The solar tracking systems -Tilted Single Axis Tracker (TSAT) and AzimuthAltitude Dual Axis Tracker (AADAT) are designed, implemented and experimentally tested. The design details of TSAT and AADAT are described which detect the sunlight using Light Dependent Resistor (LDR) sensors. The control circuit for the systems is based on Atmega8 Microcontroller which is programmed to detect the sunlight through the LDR sensors and then actuate the DC geared motor using L293D motor driver to position the solar panel where it can receive the maximum sunlight.
The kynurenine pathway is involved in bacterial meningitis
JOURNAL OF NEUROINFLAMMATION
Authors: Coutinho, Leonam G.; Christen, Stephan; Bellac, Caroline L.; Fontes, Fabrcia Lima; Soares de Souza, Fladjule Rejane; Grandgirard, Denis; Leib, Stephen L.; Agnez-Lima, Lucymara F.
Abstract
Background: Bacterial meningitis (BM) is characterized by an intense host inflammatory reaction, which contributes to the development of brain damage and neuronal sequelae. Activation of the kynurenine (KYN) pathway (KP) has been reported in various neurological diseases as a consequence of inflammation. Previously, the KP was shown to be activated in animal models of BM, and the association of the SNP AADAT + 401C/T (kynurenine aminotransferase II - KAT II) with the host immune response to BM has been described. The aim of this study was to investigate the involvement of the KP during BM in humans by assessing the concentrations of KYN metabolites in the cerebrospinal fluid (CSF) of BM patients and their relationship with the inflammatory response compared to aseptic meningitis (AM) and non-meningitis (NM) groups. Methods: The concentrations of tryptophan (TRP), KYN, kynurenic acid (KYNA) and anthranilic acid (AA) were assessed by HPLC from CSF samples of patients hospitalized in the Giselda Trigueiro Hospital in Natal (Rio Grande do Norte, Brazil). The KYN/TRP ratio was used as an index of indoleamine 2,3-dioxygenase (IDO) activity, and cytokines were measured using a multiplex cytokine assay. The KYNA level was also analyzed in relation to AADAT + 401C/T genotypes. Results: In CSF from patients with BM, elevated levels of KYN, KYNA, AA, IDO activity and cytokines were observed. The cytokines INF-gamma and IL-1Ra showed a positive correlation with IDO activity, and TNF-alpha and IL-10 were positively correlated with KYN and KYNA, respectively. Furthermore, the highest levels of KYNA were associated with the AADAT + 401 C/T variant allele. Conclusion: This study suggests a downward modulatory effect of the KP on CSF inflammation during BM.