36 research outputs found

    Basis Weight Gain Tuning Using Different Types of Conventional Controllers

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    Paper making is a vast, multidisciplinary technology that has expanded tremendously in recent years approaching to reach 20 million tons by 2020. As per demand implementation of necessary tools to optimize papermaking process and to increase the control precision, the precondition for stable operation and quality production is necessary. In the present work, an effort has been made to analyse gain tuning of Basis Weight output relative to the changing values of basis weight valve opening with step and variable input. The effects of the three constants KP, KD and KI for different types of conventional controllers as P, PD and PID controller are examined by adding a disturbance to the control system. The effects of various scaling gains are studied on the output of the system and are tuned to get the optimum output both for the step input as well as the varying input. Simulation results show that P, PD and PID controllers provide automatic tuning to preserve good performance for various operating conditions. An analysis of practical performance indices is presented by comparing results of three different conventional controllers. The system developed can be used to serve as platform for Control engineering techniques used in industries

    Entrepreneurship Through Start-ups in Hill Areas Using Photovoltaic Systems

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    There is large potential for generating solar power in Uttarakhand (India) endowed with natural resources. The extensive use of solar energy through solar PV panels in Distributed and Renewable Electricity Generation is significant to utilize multi climatic zones of hilly areas. In this regard, UREDA (Uttarakhand Renewable Energy Development Agency) targets to achieve a huge boost of solar PV battery backup with approved subsidy budget of INR 6 billion to 50 billion by 2019/20 under JNNSM (Jawaharlal Nehru National Solar Mission). This investment will increase productivity, enhance employment opportunities and improve quality of education. However, maximization of power output from panels used for same is achieved through use of MPPT (Maximum Power Point Trackers). The commercially installed solar power systems can be made to accomplish higher efficiency by implementing MPPT systems in start ups. In this paper, the effort is made to use MPPT system designed by intelligent controller for implementation in PV based utility systems. The regulated voltage output from MPPT system is obtained irrespective of fluctuations in environment. These variations are tested for changing temperature and irradiance due to shading or partial unavailability of sun. The results of same have been optimized through MATLAB/SIMULINK. The model designed is intended to be a beneficial source for PV engineers and researchers to provide high efficiency with the use of MPPT

    Comparison of MPPT Systems in Error Optimization using PID, Fuzzy and Hybrid Fuzzy in Multivariable Environment

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    Recent surveys conducted in the field of Power Control and Engineering show that photovoltaic (PV) systems are currently being discussed worldwide and research on the same is being carried globally. It is necessary to optimize the expanding use of photovoltaic systems through error detection in Maximum Power Point Tracking (MPPT) systems. Through this paper, an attempt is made to develop an efficient photovoltaic MPPT system using hybrid fuzzy technique to extract maximum power under a multivariable environment (changing temperature and irradiance). The MPPT system using Hybrid Controller (combining PID & FLC) has an increased efficiency and optimized output in comparison to the MPPT system using PID and Fuzzy individually. The system has explored a concept of computing academic performance indices with three MPPT models for future research based on global MPP calculation. Citation: Sharma, C., and Jain, A. (2018). Comparison of MPPT Systems in Error Optimization using PID, Fuzzy and Hybrid Fuzzy in Multivariable Environment. Trends in Renewable Energy, 4, 8-21. DOI: 10.17737/tre.2018.4.3.004

    Modeling of Buck Converter Models in MPPT using PID and FLC

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    PV has become universal for power utility applications in comparison to conventional technologies when it comes to economic competitiveness. As the efficiency of solar PV panel is low, it becomes mandatory to extract maximum power from the PV panel at any given period of time. Maximum Power and efficiency in Photovoltaics can be improved by Maximum Power Point tracking even under distributed temperature and irradiance functions. The paper attempts to compare two different Buck converter models based on predictive control. The two converter models using State space differential equation and direct component in MATLAB/SIMULINK are optimized through PID and FLC to obtain increased gain and desired converter output. A PV system connected with Buck converter using an intelligent controller (FLC) for extracting maximum power at different environmental conditions is proposed and the results are compared with conventional PID controller

    Entrepreneurship Through Start-ups in Hill Areas Using Photovoltaic Systems

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    There is large potential for generating solar power in Uttarakhand (India) endowed with natural resources. The extensive use of solar energy through solar PV panels in Distributed and Renewable Electricity Generation is significant to utilize multi climatic zones of hilly areas. In this regard, UREDA (Uttarakhand Renewable Energy Development Agency) targets to achieve a huge boost of solar PV battery backup with approved subsidy budget of INR 6 billion to 50 billion by 2019/20 under JNNSM (Jawaharlal Nehru National Solar Mission). This investment will increase productivity, enhance employment opportunities and improve quality of education. However, maximization of power output from panels used for same is achieved through use of MPPT (Maximum Power Point Trackers). The commercially installed solar power systems can be made to accomplish higher efficiency by implementing MPPT systems in start ups. In this paper, the effort is made to use MPPT system designed by intelligent controller for implementation in PV based utility systems. The regulated voltage output from MPPT system is obtained irrespective of fluctuations in environment. These variations are tested for changing temperature and irradiance due to shading or partial unavailability of sun. The results of same have been optimized through MATLAB/SIMULINK. The model designed is intended to be a beneficial source for PV engineers and researchers to provide high efficiency with the use of MPPT

    Modified helix-loop-helix motifs of calmodulin: the influence of the exchange of helical regions on calcium-binding affinity

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    The four calcium-binding sites, called the helix-loop-helix, or the EF-hand motifs, of calmodulin differ in their ion-binding affinities; this has been thought to arise due to the variations in the sequences of the loop regions where the ion binds. We focus attention here on the role of the flanking helical regions on the calcium-binding affinities. Peptides were synthesized in a manner that simulates the E and F helical flanks of site 4 (the strongest calcium-binding site of the calmodulin) to sandwich the loop sequences of sites 1, 2, 3 and 4 so as to produce peptides named 414, 424, 434 and 444, as well as using the helical flanks of site 1 (the weakest site) to produce peptides 111, 121, 131 and 141. Calcium binding was monitored using the calcium-mimic dye Stains-all (4,4,4',5'-dibenzo-3,3'-diethyl-9-methyl-thiacarbocya-nine bromide). Binding abilities were seen to increase several-fold when the E and F helices of site 1 were replaced by those of site 4 (i.e., 111-414). In contrast, the intensity of circular dichroism induced in the absorption bands of the bound achiral dye decreased significantly when the helical flanks of site 4 were replaced with those of site 1 (i.e., 444-141). The helical flanks of site 4 impart greater binding ability to a given loop region, while the helical flanks of site 1 tend to weaken it

    Antibacterial activity of green tea (Camellia sinensis) extracts against various bacteria isolated from environmental sources

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    Tea is cultivated in many countries of the world. India is largest tea (black tea) producer in world followed by Japan (green tea) and China. In the present study Camellia assamica (Green tea) leaves extracts were tested for antibacterial activity against various bacteria isolated from environmental sources. Different bacteria were isolated from sewage samples collected from different places at Solan Himachal Pradesh. Isolated bacteria were identified by Gram staining and biochemical tests. A total of six bacteria were identified at Department of Microbiology at SILB Solan (H.P) Green tea leaves extracts were tested for antibacterial activity. Tea leaves were collected from Palampur, Himachal Pradesh. Three different extracts were prepared by using standardized protocols. All the extracts were tested for antibacterial activity by disc diffusion method. Antibacterial assay was performed at 10µl, 20µl, and 30µl concentrations. Significant antibacterial activity was reported for all extracts with results. Aqueous extracts has shown little antibacterial activity against six bacteria isolated. Maximum antibacterial activity was found in methanolic extracts. Our study reflects the chemotherapeutic use of green tea.  Â

    Visualización en tres dimensiones, los mapas de amenaza volcánica educan al ciudadano común

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    Even the most reliable volcanic hazard map will be of little use, unless it is presented in terms that are useful to politics, emergency management officials and citizens. The Volcanic Hazard Map of the Nevado del Ruiz Volcano (Colombia), was superimposed on Landsat TM 5 data and digital elevation models, in order to generate perspective views for making the volcanic hazard situations comprehensible to the common people.This 3-D visualization methodology could be used with any volcanic hazard map available. The products generated help to improve the communication between volcanologists and people not familiar with volcanoes, in order to avoid confusion, misunderstanding and strained relations between scientists and persons responsible for the public welfare, during any volcanic emergency crisis.Hasta el mapa de amenaza volcánica más confiable, será de poca utilidad si es presentado de una forma que no lo haga útil para políticos, oficiales que manejan situaciones de emergencia y ciudadanos comunes. Se realizó la superposición del Mapa de Amenaza Volcánica del Volcán Nevado del Ruiz (Colombia), sobre imágenes Landsat TM y modelos digitales de elevación, para generar vistas en perspectiva que hagan comprensibles para el público en general, las situaciones de amenaza volcánica.Esta metodología de visualización en tres dimensiones, podría utilizarse en cualquier mapa de amenaza volcánica disponible. Los productos generados ayudan a mejorar la comunicación entre vulcanólogos y gente no familiarizada con los volcanes, para evitar confusiones, malos entendidos y malas relaciones entre científicos y personas a cargo de la seguridad pública, durante cualquier crisis de emergencia volcánica. &nbsp

    Infliximab versus second intravenous immunoglobulin for treatment of resistant Kawasaki disease in the USA (KIDCARE): a randomised, multicentre comparative effectiveness trial

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    Background Although intravenous immunoglobulin (IVIG) is effective therapy for Kawasaki disease, 10–20% of patients have recrudescent fever as a sign of persistent inflammation and require additional treatment. We aimed to compare infliximab with a second infusion of IVIG for treatment of resistant Kawasaki disease. Methods In this multicentre comparative effectiveness trial, patients (aged 4 weeks to 17 years) with IVIG resistant Kawasaki disease and fever at least 36 h after completion of their first IVIG infusion were recruited from 30 hospitals across the USA. Patients were randomly assigned (1:1) to second IVIG (2 g/kg over 8–12 h) or intravenous infliximab (10 mg/kg over 2 h without premedication), by using a randomly permuted block randomisation design with block size of two or four. Patients with fever 24 h to 7 days following completion of first study treatment crossed over to receive the other study treatment. The primary outcome measure was resolution of fever at 24 h after initiation of study treatment with no recurrence of fever attributed to Kawasaki disease within 7 days post-discharge. Secondary outcome measures included duration of fever from enrolment, duration of hospitalisation after randomisation, and changes in markers of inflammation and coronary artery Z score. Efficacy was analysed in participants who received treatment and had available outcome values. Safety was analysed in all randomised patients who did not withdraw consent. This clinical trial is registered with ClinicalTrials.gov, NCT03065244. Findings Between March 1, 2017, and Aug 31, 2020, 105 patients were randomly assigned to treatment and 103 were included in the intention-to-treat population (54 in the infliximab group, 49 in the second IVIG group). Two patients randomised to infliximab did not receive allocated treatment. The primary outcome was met by 40 (77%) of 52 patients in the infliximab group and 25 (51%) of 49 patients in the second IVIG infusion group (odds ratio 0·31, 95% CI 0·13–0·73, p=0·0076). 31 patients with fever beyond 24 h received crossover treatment: nine (17%) in the infliximab group received second IVIG and 22 (45%) in second IVIG group received infliximab (p=0·0024). Three patients randomly assigned to infliximab and two to second IVIG with fever beyond 24h did not receive crossover treatment. Mean fever days from enrolment was 1·5 (SD 1·4) for the infliximab group and 2·5 (2·5) for the second IVIG group (p=0·014). Mean hospital stay was 3·2 days (2·1) for the infliximab group and 4·5 days (2·5) for the second IVIG group (p<0·001). There was no difference between treatment groups for markers of inflammation or coronary artery outcome. 24 (44%) of 54 patients in the infliximab group and 33 (67%) of 49 in the second IVIG group had at least one adverse event. A drop in haemoglobin concentration of at least 2g/dL was seen in 19 (33%) of 58 patients who received IVIG as either their first or second study treatment (three of whom required transfusion) and in three (7%) of 43 who received only infliximab (none required transfusion; p=0·0028). Haemolytic anaemia was the only serious adverse events deemed definitely or probably related to study treatment, and was reported in nine (15%) of 58 patients who received IVIG as either their first or second study treatment and none who received infliximab only. Interpretation Infliximab is a safe, well tolerated, and effective treatment for patients with IVIG resistant Kawasaki disease, and results in shorter duration of fever, reduced need for additional therapy, less severe anaemia, and shorter hospitalisation compared with second IVIG infusion
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