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•Peak impact load is solely depends on the impact energy level.•The perforation resistance is improved by stiffening grid honeycomb structure.•Damage tolerance capacity is attributed ...to the cell size of honeycomb structure.•Confined state of foam by the honeycomb structure influences mechanism of impact.•Interfacial bonding foam and honeycomb structure leads to improved energy transfer.
Syntactic foam core sandwich composites are potential materials for marine structural applications because of its high specific properties and better energy absorption characteristics. Sandwich composites used for marine structures (roofs, decks, hulls etc) may encounter low-velocity impact that may cause internal damages to the material. Internal damages that happen during impact are sometimes undetectable which may lead to the reduction in load carrying ability of the structure. Present investigation explores the possibilities of minimizing the extent of damages in syntactic foam core sandwich composites due to low-velocity-impact by enhancing its perforation resistance. This was achieved by integrating stiffening grid resin impregnated paper honeycomb (RIPH) structure in syntactic foam during manufacturing. The results showed that the peak impact load carrying capacity and damage tolerance capacity of sandwich composites is solely depends on the impact energy level. The extents of impact damage and energy dissipation mechanism of sandwich composites are significantly influenced by the cell size of resin impregnated paper honeycomb structure integrated syntactic foam core. Improved energy absorption characteristics and damage tolerance capacity of stiffened syntactic foam core sandwich composites are attributed to the cell size of RIPH structure.
Objectives: Noise-induced cochlear synaptopathy is studied extensively in animal models. The diagnosis of synaptopathy in humans is challenging and the roles of many noninvasive measures in ...identifying synaptopathy are being explored. The acoustic middle ear muscle reflex (MEMR) can be considered as a vital tool since noise exposure affects the low-spontaneous rate fibers that play an important role in elicitation of MEMR. The present study aimed at measuring MEMR threshold and MEMR strength. Design: The study participants were divided into two groups. All the participants had normal-hearing thresholds. The control group consisted of 25 individuals with no occupational noise exposure whereas noise exposure group had 25 individuals who were exposed to occupational noise of 85 dBA for a minimum period of 1 year. MEMR threshold and strength was assessed for pure tones (500 Hz and 1000 Hz) and broadband noise. Results: The results showed that the MEMR threshold was similar in both the groups. MEMR strength was reduced in noise exposure group compared to control group. Conclusions: The results of the study suggest that MEMR strength could be used as a sensitive measure in identifying cochlear synaptopathy with careful consideration of the stimulus characteristics.
Wireless Sensor Networks (WSNs) are applicable in numerous domains, including industrial automation where WSNs may be used for monitoring and control of industrial plants and equipment. However, the ...requirements in the industrial systems differ from the general WSN requirements. In recent years, standards have been defined by several industrial alliances. These standards are specified as frameworks with modifiable parts that can be defined based on the particular application of WSN. However, limited work has been done on defining industry-specific protocols that could be used as a part of these standards. In this survey, we discuss representative protocols that meet some of the requirements of the industrial applications. Since the industrial applications domain in itself is a vast area, we divide them into classes with similar requirements. We discuss these industrial classes, set of common requirements and various state-of-the-art WSN standards proposed to satisfy these requirements. We then present a broader view towards the WSN solution by discussing important functions like medium access control, routing, and transport in detail to give some insight into specific requirements and the classification of protocols based on certain factors. We list and discuss representative protocols for each of these functions that address requirements defined in the industrial classes. Security function is discussed in brief, mainly in relation to industrial standards. Finally, we identify unsolved challenges that are encountered during design of protocols and standards. In addition some new challenges are introduced and discussed.
Nanocrystalline materials have garnered significant recognition in the scientific and research community for developing X-ray sensors. The applicability of bismuth-based binary and ternary compounds ...has been extensively studied in X-ray imaging and cancer therapy applications owing to their high attenuation. Among the binary and ternary compounds of bismuth, the n-type semiconductor silver bismuth sulfide (AgBiS2) was studied for the detection of X-rays at lower doses, based on its total attenuation (μ = 3.07 cm2 g−1 at 70 keV), density (ρ = 7.02 g cm−3), and bandgap (Eg = 1.21 eV). The effect of grain size on X-ray sensing performance was examined to validate the effective size required for maximum attenuation of X-rays and successful extraction of induced mobility carriers. X-ray sensors with four different AgBiS2 grain sizes were cast on interdigitated electrodes (IDEs) and subjected to different doses of X-rays at 2 V bias to study its dose-dependent X-ray sensing nature using an intra-oral (70 kVp-AC) X-ray machine. AgBiS2-based X-ray sensor exhibited the highest sensitivity of 20.13 μC mGy−1 cm−3 with the lowest Noise-equivalent dose ratio (NED) of 0.08 μGy Hz−0.5, 0.20 mGy detection limit and a response time of 0.12 s. This outcome validates that AgBiS2 can be applied as a potential replacement for perovskites in direct X-ray detection.
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•Grain size effect on nano AgBiS2 was studied for direct conversion X-ray detection at 70 keV X-ray photon energy.•As-prepared AgBiS2 was heat treated at 150 °C for 15, 60, 90, and 180 min to study the grain size effect.•AgBiS2 with 54 nm size exhibits superior sensitivity (20.13 μC mGy−1 cm−3), NED (5 μGy Hz−0.5) and swift response (0.12 s) for 7.97 mGy dose.
Background: Extracorporeal membrane oxygenation (ECMO) has been used in patients with severe acute respiratory distress syndrome (ARDS) due to coronavirus disease 2019 (COVID-19) who fail ...conventional treatment. Methods: A retrospective observational study was designed in patients who underwent ECMO for severe COVID-19 ARDS in a tertiary care centre from September 2020 to July 2021. The primary outcome was to assess factors influencing clinical outcomes and survival to hospital discharge. Secondary outcomes were to assess the clinical profile and pre-ECMO features, ECMO characteristics and complications. Collected data were entered in Excel software and analysed using R software version 4.0.2 (R foundation for statistical computing, Vienna, Austria). Results: A total of 19 patients underwent ECMO. Ten patients survived and discharge. Survivors had a longer median (interquartile range IQR) duration (days) on ECMO, that is, 25 (7-50), compared to non-survivors, that is, 12 (1-34) (P = 0.133). We also noted that patients who survived had a longer median (IQR) duration (days) of intensive care unit (ICU) stay, that is, 41.5 (30-70), compared to non-survivors, that is, 9 (2-40) (P = 0.001). Conclusion: In our study, 52.3% of patients survived and discharge, and with ECMO outcomes for COVID-19 ARDS were at par with ECMO outcomes for non-COVID-19 ARDS despite requiring ECMO for longer duration and increased ICU length of stay.
Imaging spectrometry is a powerful tool among remote sensing techniques to analyze the chemical compositions and physical properties of the lunar regolith. Recalibration of the classical method ...byLucey and co-workers with Moon Mineralogy Mapper (M3) data provides an opportunity to understand the FeO, TiO2, and optical maturity distributions over the lunar nearside on a global scale. We estimated the chemical compositionsand optical maturity from the M3 spectral reflectance around the 1µm region. The standard chemical compositions of the lunar landing sites were estimated based on origin optimization and data fitting. We obtained an optimized origin of (0.08, 1.18) for FeO and (0.07, 0.71) for TiO2. The Spectrophotometric evaluations of Catharina and Cyrillus craters, located in the lunar nearside are categorized under the matured category. The estimation results reveal that the FeO wt % of the Catharina crater varies from 0.0002- 19.62, and that of the Cyrillus crater varies from 0.0001-12.32. TiO2wt% of Catharina crater varies from 0.01-86.12, while Cyrillus Crater varies from 0.01-4.34. The optical maturity (OMAT) of the Catharina crater varies from 0.0001- 0.19 to that of the Cyrillus Crater Varies from 0.01-0.17. The overall summary of the results points out that lunar regolith is a fabulous repository of FeO and TiO2 and quantitatively this metal abundance may be more than the anticipated values.
Objectives: Adverse effects of noise exposure on hearing and cognition are well documented in the literature. Recently, it has becoming increasingly evident that noise exposure deteriorates ...suprathreshold auditory skills, even though the hearing sensitivity is intact. This condition is termed as cochlear synaptopathy or hidden hearing loss, which is apparent in animal models. However, equivocal findings are reported in humans. This study aimed at assessing the working memory, attention abilities, and suprathreshold hearing abilities in normalhearing individuals with and without occupational noise exposure. We also explored the relationship between cognitive measures and suprathreshold auditory measures. Design: The study participants were divided into two groups. All the participants had normal-hearing thresholds. The control group consisted of 25 individuals with no occupational noise exposure, whereas the noise exposure group had 25 individuals exposed to occupational noise of 85 dBA for a minimum period of 1 year. Working memory was assessed using auditory digit span (forward and backward), operation span, and reading span. The Erikson flanker test was used to evaluate attention abilities. The suprathreshold hearing was assessed in terms of gap detection thresholds and sentence identification in noise. Results: The results showed that the noise exposure group performed poorly compared to the control group on all auditory and cognitive tasks except the reading span. Conclusion: The results of the study suggest that occupational noise exposure may hamper the cognitive skills and suprathreshold hearing abilities of the individual despite having normal peripheral hearing.
A small proportion of the population might have initially visited local practitioners from alternative systems of medicine, which again could have contributed to a missed or delayed diagnosis and ...treatment, ultimately adding to the increased mortality. ...social issues such as reluctance to transfer older people (especially those who are staying alone with relatively poor quality of life) with respiratory symptoms to a health-care facility due to the fear or stigma associated with contracting COVID-19 might have additionally increased the mortality tally. ...there is an unsubstantiated perception that human and political factors might have influenced the documentation to some extent in certain countries. ...the increased deaths in the second wave might have occurred not only due to the higher R0 and virulence of the delta strain (B.1.617.2) and laxity in COVID-19-appropriate behaviour (the public feeling that the game is over), but also due to the inadequate anticipation of the health systems and the logistical obstacles this creates both for health-care facilities and individuals in need of care.
AbstractVisualization experiments are conducted in a water channel to investigate the wake vortex characteristics of a flat plate and convex and concave curved plates. Three parameters—vortex size ...(Sv), vortex length (Lv), and Strouhal number (St)—are investigated in this study to deduce the effect of plate curvature and orientation. These parameters are estimated for both the upper and lower vortices by keeping the chord length (Lc) fixed and changing the plate diameter (D). Various plate configurations are demonstrated by altering the Lc/D ratio from 0 to 1; Lc/D=0, 6/13, 3/4, and 1. The Reynolds number (Re) based on chord length remains unchanged at 5,878 throughout the analysis. For each case of the Lc/D ratio, the angle of flow incidence of the plate (α) is varied from 0° to 30° in steps of 5°. For the convex plate, the combined effect of curvature and orientation is found to enhance the vortex shedding frequency by 70.7%, whereas vortices shrink by 26.71%, and the vortex length is reduced by 25.38%. The manipulations achieved for concave plates reveal comparatively lesser enhancement in shedding frequency; however, concave surfaces are observed to be more suitable for stretching the vortices toward the downstream. The modifications thus achieved have significant practical relevance in various applications. A shedding mechanism that partially interrupts Gerrard’s mechanism is also found to operate with concave plate configurations.
Kumar AKA. Endotracheal Cuff-pressure Monitoring in ICU: A Standard of Care Yet to be Standardized, and Often Neglected. Indian J Crit Care Med 2024;28(1):8-10.
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