Search

Low-fidelity engineering wake models are often combined with linear superposition laws to predict wake velocities across wind farms under steady atmospheric conditions. While convenient for wind farm planning and long-term performance evaluation, such models are unable to capture the time-varying nature of the waked velocity field, as they are agnostic to the complex aerodynamic interactions among wind turbines and the effects of atmospheric boundary layer turbulence. To account for such effects while remaining amenable to conventional system-theoretic tools for flow estimation and control, we propose a new class of data-enhanced physics-based models for the dynamics of wind farm flow fluctuations. Our approach relies on the predictive capability of the stochastically forced linearized Navier–Stokes equations around static base flow profiles provided by conventional engineering wake models. We identify the stochastic forcing into the linearized dynamics via convex optimization to ensure statistical consistency with higher-fidelity models or experimental measurements while preserving model parsimony. We demonstrate the utility of our approach in completing the statistical signature of wake turbulence in accordance with large-eddy simulations of turbulent flow over a cascade of yawed wind turbines. Our numerical experiments provide insight into the significance of spatially distributed field measurements in recovering the statistical signature of wind farm turbulence and training stochastic linear models for short-term wind forecasting. [ABSTRACT FROM AUTHOR]

The article addresses the study by Kainth et al on the use of paracetamol for treating patent ductus arteriosus (PDA) in preterm neonates, noting several observations. Topics include the impact of changes in fluid management protocols on PDA incidence and outcomes, the definition and clinical features of hemodynamically significant PDA (hsPDA), and the need for a comprehensive assessment of paracetamol's potential side effects.

Engineering properties of soils coated with naturally occurring or artificially manufactured particles can significantly differ from those of uncoated soils. This study aims at evaluating the effect of iron oxide coatings on the thermal conductivity of silica sands. Laboratory thermal needle probe tests were conducted on uncoated, goethite coated and hematite coated Ottawa 20/30 and Ottawa 100/200 sands. Test results demonstrated that the thermal conductivity (k) of all tested materials increases with increasing applied vertical stress, and the k of hematite coated sands was greater than that of uncoated sands under the similar relative density. However, the measured k of both uncoated and coated sands is a single function of porosity regardless of applied stress level, reflecting the limited effect of applied stress and iron oxide mineral coating on the k of tested materials. Simple resistances in series model was employed to explain the observed test results, and the results of this study was compared with k of previous studies on uncoated natural soils. [ABSTRACT FROM AUTHOR]

The automotive industry is facing a crucial time. The transformation from internal combustion engines to new electrical technologies requires enormous investment, and hence the IC engines are likely to serve as a means of transportation for the coming decades. The search for sustainable green alternative fuel and operating parameter optimization is a current feasible solution and is a critical issue among the scientific community. Engine experiments are complicated, costly, and time-consuming, especially when the global economy is drastically down due to the COVID-19 pandemic and putting the limitation of social distancing. Industries are looking for proven computational solutions to address these issues. Recently, artificial neural network has been proven beneficial in several areas of engineering to reduce the time and experimentation cost. The IC engine is one of them. ANN has been used to predict and analyze different characteristics such as performance, combustion, and emissions of the IC engine to save time and energy. The complex nature of ANN may lead to computation time, energy, and space. Recent studies are centered on changing the network topology, deep learning, and design of ANN to get the highest performance. The present study summarizes the application of ANN to predict and optimize the complicated characteristics of various types of engines with different fuels. The study aims to investigate the network topologies adopted to design the model and thereafter statistical evaluation of the developed ANN models. A comparison of the ANN model with other prediction models is also presented. [ABSTRACT FROM AUTHOR]

A recent article published in Indian Pediatrics examines the impact of temperature variation on neonatal dehydration in Mysuru, India. The study, which has a small sample size of 55 neonates, found that seasonal temperatures can affect dehydration levels. However, the study is limited in scope and does not provide a broader contextual analysis. The article suggests that a multicenter study across India could provide a better understanding of temperature variations and potentially lead to the development of protocols or standards of care to minimize neonatal morbidity. [Extracted from the article]

In this letter, the capture/emission time constant ($\tau$), which depends on electronic coupling between the materials and structural/energetic disorder at the donor–acceptor interface, is considered in the model of hybrid organic/inorganic quantum dot (QD) solar cells as a factor that is responsible for degradation in solar cell parameters via an undesirable s-shape in the current–voltage (I–V) characteristic. In the model, charge transport is described by a drift-diffusion approximation and a set of coupled rate equations in transport layers and QDs, respectively. The analysis has revealed that the magnitude of accumulated photo-generated electrons at the QD interface and imbalanced carrier extraction from the active region is the key factors for the appearance of s-kink in the I–V characteristic. [ABSTRACT FROM AUTHOR]

Objective: To describe clinical features and early neurological outcomes in neonatal Chikungunya.Methods: Clinical, pathological and radiological details of neonates with acute encephalitic features and typical rash, later diagnosed as Chikungunya, are presented. Neurodevelopmental evaluation and imaging was done at discharge/three months.Results: Abnormal neurological examination with fever was typical presentation in all 13 babies with/without seizures/peri-oral rashes; 12 had persistent neurological abnormalities at discharge. A follow-up at three months revealed continued neurodevelopmental deficits. Neuroimaging abnormalities were seen in eight out of ten cases.Conclusions: Perinatal Chikungunya should be considered in neonates presenting within first week with fever, encephalopathy and perioral rashes with/without seizures with history of maternal Chikungunya within last week before delivery. [ABSTRACT FROM AUTHOR]

We have investigated the electrical characteristics of Metal/Ferroelectric/High-k/Si capacitor structures using sputtered Lead-Zirconate-Titanate (Pb[Zr0.35Ti0.65]O3or PZT) and HfO2thin films as ferroelectric and high-k material respectively. C-V, I-V characterization has been carried out to investigate the memory window and the leakage characteristics. The dependence of the memory window and leakage current on the buffer layer thickness and device annealing temperature has been studied. X-Ray diffraction (XRD) data demonstrate crystallization of HfO2film and increase in defects in the PZT film after N2annealing in the temperature range of 600°C–700°C. The maximum memory window of 6.8 V is observed in the M/Fe/High-k/S structure with 8 nm buffer layer as compared to the 2.3 V in the M/Fe/S structure, annealed at the same temperature i.e. 500°C. This device is observed to be capable of handling the voltage of 38 V before breakdown as compared to the 17 V in M/Fe/S structure. The leakage current density of the order 10−6A/cm2is observed for the voltage sweep of +20 V. [ABSTRACT FROM PUBLISHER]

Objective We studied the epidemiology of paediatric firework-related injury in the urban population of Delhi during the festival of lights ( Diwali). Methods In this prospective observational study, data were collected on the day of Diwali for two consecutive years, 2010 and 2011. All children with firework injuries coming to the emergency room were included in the study. Data were recorded in a predesigned proforma. Results Of the 65 cases, 75% were males and 25% were females; most children were more than 10 years of age and majority (90%) of them were unsupervised. Half (49%) of the cases were due to misuse of the fireworks or erratic behaviour, among which the most common observed mode was igniting cracker while holding it (18 cases; 24% of total injuries), which led to injuries to the hand and palm. Device failure was the next common cause for firework injuries, including unexpected blast of the crackers and string bomb as the most common. Overall, the most commonly injured body sites were hands (62%), face (32%) and eyes (10%). Crackers and string bomb mainly caused injuries to hands; fountains and gunpowder caused injuries to the face. Sixty (94%) children were managed conservatively and 5 (6%) required skin grafting and tendon repair. Conclusion We recommend parental supervision especially for males, wearing non-synthetic and non-flowing clothes, promoting branded crackers and educational campaigns in schools to curtail the rising trend in firework-related injuries in the paediatric population. [ABSTRACT FROM AUTHOR]