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Two-dimensional materials are the thinnest unsupported crystalline solids that do not exhibit surface dangling bonds. The unique structure of these materials including graphene and its successors leads to novel optical, electrical properties in comparison to their bulk counterparts. The changes in the structural and physical properties thus highly influence the performance of the resulting devices. Particularly, they are characterized by intralayer covalent bonding and interlayer van der Waals bonding with superior interlayer (compared to intralayer) transport of fundamental excitations (charge, heat, spin, and light). These atomic sheets afford the ultimate thickness scalability for semiconductor devices while simultaneously providing an unmatched combination of device physics and mechanics [Akinwande et al., “Two-dimensional flexible nanoelectronics,” Nat. Commun. 5, 5678 (2014)]. Hence, these 2D layers could act as building blocks for future optoelectronic and photonic devices. Even though their unique structure confers various optoelectronic capabilities, the same structure impedes their characterizations as they are transparent and have a nanometre-scale thickness. The future application of these nanosheets will be dictated by our precise understanding of their optoelectronic properties through standardized characterization techniques. Among all the available characterization techniques, optical investigations are a powerful tool as the interaction between incident light beam and the material can provide us with information about the optoelectronic properties of the materials. The simplicity and the non-destructive nature of these techniques make them an important characterization tool. This chapter deals with the systematic study of various optical methods which are useful in investigating materials of the 2D family. The initial stage in characterizing 2D material is to locate them and count number of layers in the nanosheets. The first section describes the use of optical microscopy as an imaging technique and its usefulness in determining the thickness/layer number in a 2D layer stack. Methods to investigate nonlinear optical properties of 2D materials is discussed in the next section. Photoluminescence emission studies combined with density functional theory can be utilized to characterize the band structure of the 2D materials. Thus, the third section of this chapter describes the use of optical absorption and photoluminescence technique to investigate their electronic properties. Systematic discussion is put forward for the methods to ascertain particle size and surface charge of the materials in the last section.

Research on carbon material-based thin films with low light reflectance has received significant attention for the development of high absorber coatings for stray light control applications. Herein, we report a method for the successful fabrication of stable thin films comprised of carbon nanotubes (CNTs) and nanoscrolls (CNS) on an aluminium (Al) substrate, which exhibited low reflectance of the order of 2–3% in the visible and near-infrared (NIR) spectral bands. Changes in the structural and chemical composition of pristine single-walled carbon nanotube (SWCNT) samples were analyzed after each processing step. Spectroscopy, microscopy and microstructural studies demonstrated emergence of CNS and multi-walled carbon nanotubes (MWCNTs) due to the sequential chemical processing of the sample. Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) studies revealed the formation of CNS via curling and folding of graphene sheets. Microstructural investigations including SEM and atomic force microscopy (AFM) confirmed the presence of microcavities and pores on the surface of the film. These cavities and pores significantly contribute to the observed low reflectance value of CNTs, CNS compound films by trapping the incident light. Fundamental space environmental simulation tests (SEST) were performed on the coated films, that showed promising results with reflectance values almost unaltered in the visible and NIR spectral bands, demonstrating the durability of these films as potential candidates to be used in extreme space environmental conditions. This study describes the preparation, characterization, and testing of blended CNT and CNS coatings for low-light scattering applications.

The advent of nanotechnology opens up several research avenues. One of the promising outcomes of it is nanofluids. Remarkable research progress has been evidenced in recent years in this arena.Recently scientists have used nanoparticles as additives in transformer oils due to its enhanced thermophysical and excellent dielectric properties. This article portrays an overview of recentexperimental studies on the potentials of nanofluids as transformer oils. The effect of particle type and particle concentrations on the dielectric break down voltage and heat transfer characteristics is summarized.It has been observed that use of nanofluids could improve the efficiency of existing high voltage infrastructures with a low financial cost. &nbsp

The worldwide spread of COVID-19 first reported from Wuhan in China is attributed to migration and mobility of people In this article, we present how our understanding of migration and livelihood could be helpful in designing a mitigating strategy of economic and social impact of COVID-19 in India We conclude that there are many challenges migrants face during the spread of COVID-19 resulting from nationwide lockdown Many internal migrants faced problems such as lack of food, basic amenities, lack of health care, economic stress, lack of transportation facilities to return to their native places and lack of psychological support On the other hand, COVID-19 has also brought into sharp focus the emigrants from India and the major migration corridors India shares with the world as well There is a huge uncertainty about how long this crisis will last This article further provides some immediate measures and long term strategies to be adopted by the government such as improving public distribution system, strengthening public health system, integration of migrants with development, decentralisation as a strategy to provide health services, and providing support to return migrants to reintegrate them, and also strengthen the database on migration and migrant households © 2020 MIGRATION LETTERS Transnational Press London

This paper considers a single server perishable inventory system in which customers arrive in a homogeneous Poisson stream. The system has a production unit which produces a single item in an exponentially distributed time interval. At the time of arrival, a customer leads to service if the server is available with a positive level of inventory. Otherwise, the customer goes to a waiting place(orbit) of infinite capacity with pre-determined probability or exits the system with complementary probability. Each customer in the orbit tries to access the server in an exponentially distributed time interval. After every unsuccessful retrial, the customer returns to the orbit with a pre-allotted probability or is lost forever with complementary probability. An algorithmic solution to the problem is obtained using Matrix Analytic Method. The mean number of customer loss before and after entering the system, the rate of successful retrials among overall retrials and some other performance measures of the system are derived. The impacts of system parameters on different measures are numerically studied. A suitable cost function is constructed and the optimum control policy is numerically obtained.

Optical transmittance measurements of MoS2 nanostructures with varying film thickness are reported here. Optical transmittance value of the films containing assorted MoS2 nanostructures (revealed by SEM studies) was obtained from optical microscope images taken under white light with 100× magnification and also from the images acquired under an ordinary lens-laser combination. The relationship between the light exposed on the sample and the pixel intensities of the images are being exploited to establish a correspondence between average pixel intensity and the transmittance obtained by numerical coding. Our measurements show a transmittance variation in the range of 0.92–0.68 with sample thickness.

Objective To study the clinical profile and outcome of adolescent onset anorexia nervosa at a tertiary care center in Southern India. Method Review of hospital records of adolescents diagnosed with anorexia nervosa. Outcome was assessed for those with a follow-up of atleast one year, by outpatient visit or by a telephonic interview. Findings Data of 43 patients (28% males) with mean (SD) age at presentation of 13.4 (1.7) years were included. The mean (SD) BMI at presentation was 13.8 (3.2) kg/m2, the lowest being 8.3 kg/m2. 33 (76%) patients were hospitalized for nutritional rehabilitation. Of the 15 patients followed up 1-5 years later, one had died and 11 had achieved normal weight for age. Conclusions As compared to other studies, this study showed a higher proportion of boys with anorexia nervosa. Further research is necessary to understand factors affecting long-term outcome.

Study question Can antibiotic treatment failure of tubo-ovarian abscesses (TOA) be predicted based on clinical features at the time of diagnosis? Summary answer We propose a risk score including patient temperature, c-reactive protein and TOA size that could predict which patients are likely to fail parental antibiotic treatment. What is known already Current guidance is that the first line management of non-ruptured TOA is with parental antibiotics. However, it is reported that treatment failure rate is 20–30%. Alternative treatment modalities include radiological drainage or laparoscopic/open surgery. In patients who require intervention, outcomes, such as morbidity, length of hospital stay and fertility, are improved when this is performed early rather than later in their hospital admission. However, our current guidance is scant with regards to the decision making for interventional TOA management. Study design, size, duration This is a multicentre retrospective cohort study over 81 months (01/01/13- 30/09/19) identifying 214 consecutive patients admitted to hospitals in North-West London with diagnosed TOA. Participants/materials, setting, methods: Demographics, medical history, presenting symptoms, laboratory results, radiological findings, treatments administered, hospital length of stay and follow up data was collected. The patients were chronologically split with the first 150 being used for the development of our risk score. Univariate and bivariate analyses were employed to ascertain statistically significant variables in the failure of parental antibiotic. The remaining 64 patients were used for risk score validation. Main results and the role of chance Statistically significant variables were: temperature at admission (median= 37.1 °C vs 38.2 °C, p = 0.0001), C-reactive protein (CRP) at admission (151mg/L vs 243mg/L, p = 0.0001) and size of TOA (6.0cm vs 8.0cm, p = 0.0001). Those requiring intervention, stayed in hospital twice as long as those who did not (4 days vs 8 days, p Limitations, reasons for caution Being a retrospective study, which puts the data at risk of information and selection bias. Although there are merits to a multi-centre study, variation in patient management will invariably cause data heterogeneity. Wider implications of the findings: TOA patients may have their hospital management tailored early according to the postulated tool, alleviating uncertainty in their treatment as well as possibly reducing morbidity and length of hospital stay. Trial registration number Not applicable

Zoo is a place where animals are cared and looked after by a team of officials. It will also provide entertainment to tourists and the animal lovers to study animal behavior. It is used for learning purposes as well as for tourist revenue. It serves and takes care of many wild animals with the help of zoo administrators. The work of those zoo administrators is very difficult as they are dealing with wild animals in person. In this paper, we proposed an architecture to ease the animal administrator’s daily job by effectively collaborating the Internet of Things (Iot) and Artificial Intelligence (AI). Here we propose a novel and intelligent method for the health prediction of animals by a supervised machine learning algorithm. In addition to that, our architecture involves automatic feeding, cage temperature control, health monitoring of animals, real-time monitoring, and identification of virus infected animals. That helps to make the zoo expenses low. Moreover, in this era of the pandemic, the virus infected animals need to be separated from other animals as well as from the administrators to avoid spreading of the diseases. We also proposed an effective method by using RFID tag to identify virus infected animal and break the chain to prevent the spreading. So, our aim is to uplift the motto one world one health.

The cure kinetics of a composite solid propellant premix based on ammonium perchlorate, hydroxyl-terminated polybutadiene (HTPB) and diisocyanate system was investigated using a rheometer. The cross-linking kinetics of HTPB resin in the presence of tolylene diisocyanate in a propellant was studied under isothermal conditions in the temperature range of 60–70 °C by rheometry. The kinetic parameters of the curing reaction were calculated from the rheological measurements. These parameters were derived by a multiple regression analysis using a classical phenomenological model expanded by an empirically derived diffusion factor. The obtained kinetic parameters were used to generate a master equation capable of predicting the reaction profile at any given temperature. Excellent match between observed and predicted cure profiles in the entire temperature range validated the adequacy of the model.

Bisphenol S (BPS) is an organic chemical that has been used as a substitute for bisphenol A (BPA) in making polycarbonate plastics, epoxy resins, thermal receipt papers, and currency bills, as BPA has been reported to have dreadful effects on the living system. From this view point, the present study investigates whether BPS has the same or rather more toxic effects like BPA or not. Limited studies were carried out on the effect of BPS on fish. The hepatic antioxidant enzymes such as superoxide dismutase, catalase, glutathione S-transferase, glutathione reductase, and glutathione peroxidase (GPx), along with the nonenzymatic antioxidant, glutathione, in a freshwater fish, Labeo rohita, were selected as biomarkers. The results revealed that the sublethal exposure of BPS significantly influenced the activities of these biomarkers. Lipid peroxidation (LPO) products such as malondialdehyde and conjugate diene levels were also altered by the exposure. The alteration in the levels of antioxidants and LPO products after BPS exposure clearly showed that the fish experienced oxidative stress. Furthermore, the current study showed that BPS is a pollutant with oxidative potential by disrupting the antioxidant enzymes.

To study the clinical profile and outcome of adolescent onset anorexia nervosa at a tertiary care center in Southern India.Review of hospital records of adolescents diagnosed with anorexia nervosa. Outcome was assessed for those with a follow-up of atleast one year, by outpatient visit or by a telephonic interview.Data of 43 patients (28% males) with mean (SD) age at presentation of 13.4 (1.7) years were included. The mean (SD) BMI at presentation was 13.8 (3.2) kg/m2, the lowest being 8.3 kg/m2. 33 (76%) patients were hospitalized for nutritional rehabilitation. Of the 15 patients followed up 1-5 years later, one had died and 11 had achieved normal weight for age.As compared to other studies, this study showed a higher proportion of boys with anorexia nervosa. Further research is necessary to understand factors affecting long-term outcome.

Energetic ionic liquids (EILs) are widely investigated as hypergolic non-toxic bipropellant fuel along with green and non-toxic concentrated hydrogen peroxide oxidiser. These combinations of propellants are being pursued to replace conventional bipropellant fuels involving hydrazine class of fuels and nitric acid-based oxidisers. In the pursuit of less hazardous bipropellant fuels, caged ionic liquids like azoles, boranes, etc., are being used. They play a pivotal role in enhancing the performance of the propellant systems. In the oxidiser front, hydrogen peroxide is the promising candidate capable of replacing the toxic and hazardous storable propellant oxidisers currently in use. The combination of EILs and hydrogen peroxide can be potentially used in the emerging multimode propulsion concept for small satellite applications. This review describes the efforts pursued on less hazardous EIL based bipropellant fuels that are spontaneously ignitable or hypergolic with green oxidiser hydrogen peroxide. Focus is given to EILs with low vapour pressure, reduced toxicity, superior performance, and excellent combustion characteristics.

This paper considers a continuous review perishable inventory system with an infinite orbit. The replenishment of items in the inventory is governed by (s, Q) policy. The Markovian Arrival Process characterizes the arrival pattern of primary customers and the service time follows phase-type distribution. Inventoried items are subject to decay with some preassigned linear rate. The items are purchased from an outside source and lead time is exponentially distributed. An unsatisfied primary customer may enter an orbit or exit the system with a predetermined probability. The retrial customers, those who entered into the orbit, try to access the idle server with a linear rate. An unsatisfied retrial customer may enter or exit the orbit with prefixed probability based on the inventory level. Stationary probability vectors are obtained using the Matrix Analytic method. Numerical optimization of the profit function is carried out for different parameter values.

The 2019 Novel Coronavirus (2019-nCoV) outbreak affected a large number of deaths with millions of confirmed cases worldwide. Coronavirus Disease (COVID-19) is associated with respiratory illness that lead to severe pneumonia and Acute Respiratory Distress Syndrome (ARDS). Although related to the Severe Acute Respiratory Syndrome (SARS) and the Middle East Respiratory Syndrome (MERS), Covid-19 shows some unique pathogenetic, epidemiological and clinical features. On the basis of the phylogenetic relationship as well as genomic structures, the Covid-19 belongs to genera Betacoronavirus. Human Betacoronaviruses (SARS-CoV-2, SARS-CoV, and MERS-CoV) have shared similarities, yet differences also in their genomic and phenotypic level that influence the pathogenesis. To gain knowledge regarding the pathophysiology and virulence of the Covid-19 virus, it is absolutely necessary to understand its genetic makeup, transmission, virulence factors, risk factors, diagnosis, clinical presentations, outcome predictions, management of risk factors and ways to control the disease thus providing an insight to the current or future treatment and management protocols. To provide a review of the differences in pathogenesis, epidemiology and clinical features of Covid-19, its transmission and replication dynamics, genome organization, current clinical trials and vaccine development strategies, Immunoinformatics, diagnostics and ways to control the pandemic, inorder to raise an increasing awareness, both to the public and for scientific perspectives.

We report here on room temperature (RT) adsorption of Sn atoms on mechanically cleaved WS2 hexagonal crystal surface under ultra-high vacuum (UHV) conditions. Our in-situ low energy electron diffraction (LEED) and scanning tunneling microscopy (STM) studies clearly indicate atomic configurations of bare WS2 and Sn adsorbed surfaces. Bare WS2 displays an atomic periodicity with lattice constant, a, as 0.34 nm. RT adsorption of Sn indicates a nearly commensurate atomic adsorption on W or S sites with a lateral distance between two adsorbed Sn atoms as ∼0.325 nm and bond length of Sn with W/S as ∼40 pm. We do not find any evidence of Sn adsorption on the hollow sites of the hexagonal surface mesh of WS2. Analyses of the LEED spots and the FFT of the STM images reveal a stretched hexagonal surface after Sn adsorption.

This paper considers a continuous review perishable inventory system with (s, Q) policy. A finite buffer of size K is attached in-front of the server. Customers arrive according to a Poisson process and join the buffer depending on the number of items present in the inventory. That is, customer join the buffer with probability pi when the inventory level is i (1 ≤ i ≤ s) such that p1 s. The demands arrive during stock-out period are assumed to be lost. Again, procurement happens after random time and its distribution is supposed to be exponentially distubted. We constructed an appropriate profit function using relevant performance measures. Results are numerically studied.