Online prediction of DGA results for intelligent condition monitoring of power transformers

Transformers form a major part of a power system in transmission as well as distribution of power. Considering the criticality, finance, and time involved in repair, periodic condition monitoring and maintenance of transformers are the key to ensure electrical safety as well as stable operation of the large interconnected power system. Dissolved Gas Analysis (DGA) is an established tool used to determine the incipient faults within the transformer by analyzing the concentration of different gases in the transformer oil and giving early warnings and diagnoses. Currently, transformers worldwide utilise online sensors to monitor dissolved gases and moisture content in oil. The online DGA sensor uses a small amount of oil from transformer to perform real-time DGA analysis and gives the ppm content of dissolved gases for further course of action. Considering the large quantity of assets and the huge amount of data produced, it is imperative to develop a tool to aid the operators in assimilating the available data for diagnosis and proactive decision making. The present study improvises AI techniques to predict future dissolved gas concentrations using real time DGA data collected from the transmission utility of the country. The prediction helps to forecast the trend of development of incipient faults in the transformer. The complete project scope is to develop a highly reliable diagnostic tool to emulate the decision-making ability of a human expert in transformer DGA analysis to enhance transformer life. In the present paper, models based on Auto-regressive Integrated Moving Average (ARIMA), Long Short-Term Memory (LSTM), and Vector Auto Regression (VAR) are implemented to predict DGA data of three in-service transformers. DGA data is forecasted for up to 8 monthly samples in the future, and the accuracy of results is compared with each other. The LSTM-VAR combined model is seen to provide the best results among them

Mucus-degrading Bacteroides link carbapenems to aggravated graft-versus-host disease

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Advances in Social Media Research:Past, Present and Future

Social media comprises communication websites that facilitate relationship forming between users from diverse backgrounds, resulting in a rich social structure. User generated content encourages inquiry and decision-making. Given the relevance of social media to various stakeholders, it has received significant attention from researchers of various fields, including information systems. There exists no comprehensive review that integrates and synthesises the findings of literature on social media. This study discusses the findings of 132 papers (in selected IS journals) on social media and social networking published between 1997 and 2017. Most papers reviewed here examine the behavioural side of social media, investigate the aspect of reviews and recommendations, and study its integration for organizational purposes. Furthermore, many studies have investigated the viability of online communities/social media as a marketing medium, while others have explored various aspects of social media, including the risks associated with its use, the value that it creates, and the negative stigma attached to it within workplaces. The use of social media for information sharing during critical events as well as for seeking and/or rendering help has also been investigated in prior research. Other contexts include political and public administration, and the comparison between traditional and social media. Overall, our study identifies multiple emergent themes in the existing corpus, thereby furthering our understanding of advances in social media research. The integrated view of the extant literature that our study presents can help avoid duplication by future researchers, whilst offering fruitful lines of enquiry to help shape research for this emerging field

Transient Midventricular Ballooning Syndrome: An Atypical Case of Stress Cardiomyopathy

Stress cardiomyopathy can cause significant morbidity in the functional life of patients. The most common finding is apical ballooning of the left ventricle on cardiac catheterization. Some cases present with atypical imaging findings. This report presents a case of atypical stress cardiomyopathy with midventricular hypokinesis

Redefining learning through social-emotional learning: A review

The present review aims to explore the role of social-emotional learning (SEL) in the education system by highlighting the competencies and skills that are required to augment emotional intelligence and social interaction and, appraising the role of teachers, learning contexts, and family. It draws attention to the core characteristics and the ingredients for the success of SEL programs and, yardsticks for comparison and selection of various frameworks. It discusses the potential limitations in the program implementation and, offers some general considerations relevant to various stakeholders to improve the program effectiveness in educational settings. Under a narrative general review approach, empirical articles, task force reports, and conceptual papers were explored to develop insights into how infusing SEL into the education system help students to learn competencies and skills they need to develop to manage their behaviours and emotions, build connections, and foster resilience. The review reveals that at its core, SEL instills the caliber to understand and deal with one’s own emotions and interactions with others and assists to be successful in the learning setting, in relationships, and as members of society. &nbsp

Relation of bone mineral density with homocysteine and cathepsin K levels in postmenopausal women

Background: Homocysteine (HCY) interferes with collagen cross-linking in bones and stimulates osteoclast activity. The activated osteoclasts secrete cathepsin K (CathK), a cysteine protease, in eminent quantity during bone resorption. Hyperhomocysteinemia may effect bone mineral density (BMD) through CathK. We, therefore, examined the relation between HCY and BMD along with CathK, 25-hydroxyvit-D (25[OH]D), intact parathyroid hormone (iPTH), and Vitamin B12. Materials and Methods: We recruited a total of 93 postmenopausal women between the age group of 45–60 years, attending the Endocrinology outpatient department at King George's Medical University, Lucknow. BMD was done by DXA scan using Hologic QDR1000 system. Based on the WHO criteria, patients were segregated into three groups as follows; normal bone mass, osteopenia, and osteoporosis. All women underwent routine biochemical laboratory parameters, HCY, Vitamin B12, and CathK levels. Results: Among 93 postmenopausal women, 56% (52) had osteoporosis. Nineteen percent (18) had normal BMD (mean age, 53.22 ± 8.5 years) and 23 (25%) had osteopenia (mean age 52.86 ± 6.67 years). The mean age in the osteoporetic group was 56.2 ± 6.9 years. The median (interquartile range) levels of HCY in the three groups were 14.5 μmol/L (12.2–24.7), 15.05 μmol/L (12.1–19.9) and 13.2 μmol/L (10.3–17.0), respectively. CathK levels were similar in three groups 7.6 ng/ml (7.0–80.5), 8.3 ng/ml (7.3–8.5), and 8.6 ng/ml (7.2–8.9). Both HCY and CathK were found positively associated with serum phosphorus (r = 0.584, P < 2.01 and r = 0.249, P < 0.05, respectively). Levels of HCY positively correlate with PTH (r = 0.303, P < 0.01) and inversely with Vitamin B12 (r = −0.248, P < 0.05). No significant association was seen between CathK level and 25(OH) D, iPTH, serum calcium. Conclusion: Low bone mass by DXA is a significant problem in postmenopausal females. HCY and CathK do not reliably correlate with bone loss in postmenopausal women although phosphorus metabolism may play a role

Effect of Hydrophobicity of Tails and Hydrophilicity of Spacer Group of Cationic Gemini Surfactants on Solvation Dynamics and Rotational Relaxation of Coumarin 480 in Aqueous Micelles

Solvation dynamics and rotational relaxation of coumarin 480 in aqueous micelles of cationic gemini surfactants with diethyl ether (EE) spacer group (<i>m</i>–EE–<i>m</i>) and tails with varying tail lengths (<i>m</i> = 12, 14, and 16) have been studied. Studies have been carried out by measuring UV–visible absorption, steady-state fluorescence and fluorescence anisotropy, time-resolved fluorescence and fluorescence anisotropy, ¹H NMR spectroscopy, and dynamic light scattering. Effects of hydrocarbon tail length and hydrophilicity of spacer group on solvation dynamics and rotational relaxation processes at inner side of the Stern layer of micelles have been studied. With increasing hydrophobicity of tails of surfactants, water molecules in the Stern layer become progressively more rigid, resulting in a decrease in the rate of solvation process with slow solvation as a major component. With increasing hydrophilicity of the spacer group of gemini surfactant, the extent of free water molecules is decreased, thereby making the duration of the solvation process longer. Solvation times in the micelles of gemini surfactants with hydrophilic spacer are almost 4 times longer compared to those in the micelles of their conventional counterpart. Rotational relaxation time increases with increasing tail length of surfactant as a result of increasing microviscosity of micelles with fast relaxation as a major component. With increasing hydrophilicity of the spacer group, the anisotropy decay becomes slower due to the formation of more compact micelles. Rotational relaxation in gemini micelles is also slower compared to that in their conventional counterpart. The anisotropy decay is found to be biexponential with lateral diffusion of the probe along the surface of the micelle as a slow component. Rotational motion of micelle as a whole is a very slow process, and the motion becomes further slower with increasing size of the micelle. The time constants for wobbling motion and lateral diffusion of the probe become longer with increasing microviscosity of micelles

Effect of Urea on Solvation Dynamics and Rotational Relaxation of Coumarin 480 in Aqueous Micelles of Cationic Gemini Surfactants with Different Spacer Groups

The present work highlights the effect of urea on solvation dynamics and the rotational relaxation of Coumarin 480 (C-480) in the Stern layer of aqueous micelles of cationic gemini surfactants, 12-4­(OH)<i>_n</i>-12 (<i>n</i> = 0, 1, 2). UV–visible absorption, steady-state fluorescence and fluorescence anisotropy, time-resolved fluorescence and fluorescence anisotropy, and dynamic light scattering measurements have been carried out for this study. The formation of micelles becomes disfavored in the presence of urea at high concentration. Solvation dynamics is bimodal in nature with fast solvation as a major component. The average solvation time increases, reaches a maximum, and then decreases with increasing concentration of urea because the degree of counterion dissociation also follows the same order with the addition of urea in the micellar solution. With increased degree of counterion dissociation, the extent of clustering of water molecules is increased, resulting in slower solvation process. The −OH group present in the spacer group of gemini surfactant controls the rate of solvation by shielding the water molecules from the probe molecules forming hydrogen bond. The microviscosity of micelles is decreased with increasing concentration of urea, as a result of which the rotational relaxation process becomes faster. In the presence of the −OH group in the spacer group, the microviscosity of micelles is enhanced, resulting in longer rotational relaxation time. Rotational relaxation process is bimodal in nature with the major contribution from the fast component to the fluorescence depolarization. Slow rotational relaxation is mainly due to the lateral diffusion of C-480 molecules along the surface of the micelle. The tumbling motion of the micelle as a whole is much slower than the lateral diffusion of C-480. Wobbling motion of C-480 becomes faster with increasing concentration of urea as a result of decreased microviscosity of micelles. The alignment of C-480 molecules in micelles might change with changing microviscosity