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In this paper, a strain-modified Si/Si0.97C0.03 asymmetrical superlattice exotic type (p + -i-p-n +) avalanche photodetector has been designed for applications on the infrared wavelength region. The photoelectric characteristics of the device are studied by developing a self-consistent quantum phenomena-based drift–diffusion model in conjunction with PSpice simulator. The overall performance of the device has been boosted significantly by introducing strain engineering which enhances the out-plane mobility of the charge particles in the intrinsic/active region of the device. The strain is produced in the intrinsic/active region by inclusion of small amount of carbon (C) into the pure Si material. The proposed strain-modified exotic avalanche photodetector exhibits better performance in terms of quantum efficiency (0.671) and photo-responsivity (0.645 A/W) compared to its planer unstrained Si counterpart (quantum efficiency: 0.481, photo-responsivity: 0.524A/W) at 1800 nm wavelength. Additionally, a 3 × 4 array of photodetectors has been designed using this device and its optoelectronic properties are studied in the IR wavelength region. The superiority of the performance of the 3 × 4 array of photodetectors is established in terms of better quantum efficiency (0.872) and better photo-responsivity (0.851 A/W). The validity of quantum phenomena-based drift–diffusion model is established by comparing the simulated data with experimental findings under similar operating conditions. The developed device can be used in defense as well as biomedical industries for sensing applications. [ABSTRACT FROM AUTHOR]

The effects of optical illumination on the terahertz characteristics of GaN-based IMPact Avalanche Transit Time (ATT) (IMPATT) oscillator are studied. The analysis has shown that when compared to predominant electron photocurrent in TM IMPATT, hole-dominated photoleakage current in FC IMPATT is important in modulating the high-frequency characteristics of the GaN-based terahertz device and optically illuminated FC IMPATT has shown more pronounced shift of avalanche phase delay.

The use of Artificial Intelligence (AI) in combination with Internet of Things (IoT) drastically reduces the need to test the COVID samples manually, saving not only time but money and ultimately lives. In this paper, the authors have proposed a novel methodology to identify the COVID-19 patients with an annotated stage to enable the medical staff to manually activate a geo-fence around the subject thus ensuring early detection and isolation. The use of radiography images with pathology data used for COVID-19 identification forms the first-ever contribution by any research group globally. The novelty lies in the correct stage classification of COVID-19 subjects as well. The present analysis would bring this AI Model on the edge to make the facility an IoT-enabled unit. The developed system has been compared and extensively verified thoroughly with those of clinical observations. The significance of radiography imaging for detecting and identification of COVID-19 subjects with severity score tag for stage classification is mathematically established. In a Nutshell, this entire algorithmic workflow can be used not only for predictive analytics but also for prescriptive analytics to complete the entire pipeline from the diagnostic viewpoint of a doctor. As a matter of fact, the authors have used a supervised based learning approach aided by a multiple hypothesis based decision fusion based technique to increase the overall system's accuracy and prediction. The end to end value chain has been put under an IoT based ecosystem to leverage the combined power of AI and IoT to not only detect but also to isolate the coronavirus affected individuals. To emphasize further, the developed AI model predicts the respective categories of a coronavirus affected patients and the IoT system helps the point of care facilities to isolate and prescribe the need of hospitalization for the COVID patients. [ABSTRACT FROM AUTHOR]

Abstract Background Despite recent achievement in economic progress in India, the fruit of development has failed to secure a better nutritional status among all children of the country. Growing evidence suggest there exists a socio-economic gradient of childhood malnutrition in India. The present paper is an attempt to measure the extent of socio-economic inequality in chronic childhood malnutrition across major states of India and to realize the role of household socio-economic status (SES) as the contextual determinant of nutritional status of children. Methods Using National Family Health Survey-3 data, an attempt is made to estimate socio-economic inequality in childhood stunting at the state level through Concentration Index (CI). Multi-level models; random-coefficient and random-slope are employed to study the impact of SES on long-term nutritional status among children, keeping in view the hierarchical nature of data. Main findings Across the states, a disproportionate burden of stunting is observed among the children from poor SES, more so in urban areas. The state having lower prevalence of chronic childhood malnutrition shows much higher burden among the poor. Though a negative correlation (r = -0.603, p < .001) is established between Net State Domestic Product (NSDP) and CI values for stunting; the development indicator is not always linearly correlated with intra-state inequality in malnutrition prevalence. Results from multi-level models however show children from highest SES quintile posses 50 percent better nutritional status than those from the poorest quintile. Conclusion In spite of the declining trend of chronic childhood malnutrition in India, the concerns remain for its disproportionate burden on the poor. The socio-economic gradient of long-term nutritional status among children needs special focus, more so in the states where chronic malnutrition among children apparently demonstrates a lower prevalence. The paper calls for state specific policies which are designed and implemented on a priority basis, keeping in view the nature of inequality in childhood malnutrition in the country and its differential characteristics across the states.

This paper proposes a strained Si-based single drift nano-mixed tunnel avalanche transit time (MITATT) oscillator capable of generating high RF power in the terahertz regime, inaccessible by conventional Si devices. The authors have developed a quantum modified classical drift-diffusion model to study the nanoscale properties of strained Si oscillator. The study reveals that 14.72-GW/m2 RF power could be generated from 0.715-THz strain-engineered Si oscillator. Such performance enhancement of the Si device is due to selective incorporation of trace amounts of Ge in the Si active region. This generates in-plane biaxial strain which in turn degrades the in-plane electron mobility, hence unsuitable for conventional MOSFETs. However, such strain remarkably enhances the out-of-plane mobility, and uniqueness of the current research is the utilization of in-plane strain to boost up the out-of-plane mobility depending on geometry and dimensions of the oscillator’s active region. The model incorporates parasitic series resistance and elevates junction temperature effects on terahertz properties of the device. Incorporation of the strained layer in the active region reduces the parasitic series resistance effect on high frequency properties of the oscillator. Validity of the developed model is established by comparing simulated data with the corresponding experimental observations. The authors have further studied photo irradiation effects on terahertz characteristics of the new class of devices. The structure-induced quantum confinement effect has made the Si-based active region to behave as a partially direct bandgap material, and therefore, a significant improvement is observed in optical sensitivity. To the best of the authors’ knowledge, this is the first report on strain-engineered asymmetrically doped Si/SiGe based avalanche photosensor in the high-frequency terahertz domain. [ABSTRACT FROM AUTHOR]

The mm-wave as well as noise properties of IMPATT diodes for the D-band are efficiently determined, with 4H-SiC and wurtzite type GaN as base materials, using advanced computer simulation techniques developed by the authors. The breakdown voltage (180 V) and efficiency (14.7%) is higher in case of 4H-SiC as compared to wz-GaN based diode having the breakdown voltage (153 V) and efficiency (13.7%). The study indicates that 4H-SiC IMPATT diode is capable of generating high RF power density of about 8.383x1010 W/m² as compared to GaN IMPATT diode that is capable to develop the power density 6.847x1010 W/m² for the same frequency of operation. It is also observed that wz-GaN exhibits better noise behavior 7.42x10-16 V²⋅s than SiC (5.16x10-15 V²⋅s) for IMPATT operation at 140 GHz. A tradeoff between the power output and noise from the device reveals that wz-GaN would be a suitable base material for high power application of IMPATT diode with moderate noise. [ABSTRACT FROM AUTHOR]

The present study was undertaken to determine the anti-ulcer and antioxidant potential of GutGard, a standardized extract of Glycyrrhiza glabra commonly known as licorice. Effect of various doses (12.5, 25, and 50 mg/kg, po) of GutGard was studied on gastric ulcers in pylorus ligation-, cold-restraint stress- and indomethacin induced gastric mucosal injury in rats. Anti-ulcer activity was evaluated by measuring the ulcer index, gastric content, total acidity, and pH of gastric fluid. GutGard dose dependently decreased gastric content, total acidity, ulcer index and increased pH of gastric fluid in pylorus ligation ulcer model. In cold-restraint stress- and indomethacin induced ulcer models all the doses of GutGard decreased the ulcer index and increased the pH of gastric fluid. The antioxidant activity was evaluated by the oxygen radical absorbance capacity (ORAC) assay. GutGardT exhibited potent antioxidant activity with high hydrophilic and lipophilic ORAC value. GutGard possessed anti-ulcerogenic properties that might be afforded via cytoprotective mechanism by virtue of its antioxidant properties. These results supported the ethnomedical uses of licorice in the treatment of gastric ulcer.