A Review on Different Control Techniques Used for Pitch Control of Horizontal Axis Wind Turbine

In wind turbine technology, the pitch control mechanism of blades is a very important factor for the efficient power output of a wind turbine. Various control techniques can be implemented for pitch control. This paper deals with the study and review of different control methodologies used by the researchers and engineers to control the pitch angle of the blades of a horizontal axis wind turbine to optimize the power in low rated wind speed. This paper involves the study of PI, PID, Fuzzy logic control, Sliding mode control and Adaptive control methodologies

Modulated structure in the martensite phase of Ni1.8Pt0.2MnGa: a neutron diffraction study

7M orthorhombic modulated structure in the martensite phase of Ni1.8Pt0.2MnGa is reported by powder neutron diffraction study, which indicates that it is likely to exhibit magnetic field induced strain. The change in the unit cell volume is less than 0.5% between the austenite and martensite phases, as expected for a volume conserving martensite transformation. The magnetic structure analysis shows that the magnetic moment in the martensite phase is higher compared to Ni2MnGa, which is in good agreement with magnetization measurement

Deep Neck Space Infections-A Study in Diabetic Population in a Tertiary Care Centre

© 2017, Association of Otolaryngologists of India. This study is intended to analyze the clinical profile and outcomes of deep neck space infection in diabetic patients in our tertiary care centre. A prospective study of 1 year duration from 30th September 2015 to 30th September 2016 at department of Otorhinolaryngology, Gauhati Medical College and Hospital, Guwahati. A total of 45 diabetic patients who presented with DNSI are included in this study. Their demographic profile, etiology, bacteriology, treatment, duration of hospital stay, complications and outcomes have been analyzed. 45 patients were recorded; 32 (71.11%) were men, and 13 (45%) were women, with a mean age of 63.27 ± 7.55 years. There were 30 patients (66.67%) who had associated systemic diseases apart from diabetes mellitus. The parapharyngeal space in 13 patients (28.89%) was the most commonly involved space. Odontogenic infections in 18 patients (40%) and upper airway infections 9 patients (20%) were the two most common causes. Klebsiella pneumonia in 29 patients (64.44%), was the commonest organism isolated through pus cultures. All the patients except one (97.78%) came with abscess and underwent surgical drainage. One patient (2.22%) with carbuncle underwent regular dressing. Six patients (13.33%) had major complications. Those patients with other underlying systemic diseases or complications tended to have a longer hospital stay and were older. No cases of death has been reported. (mortality rate, 0%). DNSI patients with diabetes have a more severe clinical course. They are likely to have complications more frequently and a longer duration of hospital stay. In clinical practices while dealing with these patients more vigilance is required. On admission empirical antibiotics should cover K. pneumonia. Early surgical drainage remains the main method of treatment. Primary prevention can be achieved by orodental hygiene, regular dental check ups and in this part of the country by avoidance of substance abuse like tobacco chewing

Health Monitoring of Induction Motor Through Vibration Analysis

Machinery monitoring is the process of monitoring a parameter of condition in machinery, such that a significant change is indicative of a failure in development. Temperature, vibration, noise, current, voltage, acoustic emission, etc. – all these measurements are used for machine condition monitoring. Measuring vibration signals of the Non-Destructive Testing (NDT) method is widely used to detect machine faults. There are many studies for the prediction of mechanical wear, fault and failure in this area for several decades. Signal processing techniques are used to obtain vital characteristic information from the vibration signals. This paper attempts to summarize the results of an evaluation of vibration analysis techniques as a method for diagnosis for three-phase induction motors

Saving the Greater Adjutant Stork by Changing Perceptions and Linking to Assamese Traditions in India

https://ojs.ethnobiology.org/index.php/ebl/article/view/1648https://ojs.ethnobiology.org/index.php/ebl/article/view/164

Unoccupied electronic states of icosahedral Al-Pd-Mn quasicrystals: Evidence of image potential resonance and pseudogap

We study the unoccupied region of the electronic structure of the fivefold symmetric surface of an icosahedral (i) Al-Pd-Mn quasicrystal. A feature that exhibits parabolic dispersion with an effective mass of (1.15±0.1)me and tracks the change in the work function is assigned to an image potential resonance because our density functional calculation shows an absence of band gap in the respective energy region. We show that Sn grows pseudomorphically on i−Al−Pd−Mn as predicted by density functional theory calculations, and the energy of the image potential resonance tracks the change in the work function with Sn coverage. The image potential resonance appears much weaker in the spectrum from the related crystalline Al-Pd-Mn surface, demonstrating that its strength is related to the compatibility of the quasiperiodic wave functions in i−Al−Pd−Mn with the free-electron-like image potential states. Our investigation of the energy region immediately above EF provides unambiguous evidence for the presence of a pseudogap, in agreement with our density functional theory calculations