The solution of electromagnetic scattering by a homogeneous prolate (or oblate) spheroidal particle with an arbitrary size and refractive index is obtained for any angle of incidence by solving Maxwell's equations under given boundary conditions. The method used is that of separating the vector wave equations in the spheroidal coordinates and expanding them in terms of the spheroidal wavefunctions. The unknown coefficients for the expansion are determined by a system of equations derived from the boundary conditions regarding the continuity of tangential components of the electric and magnetic vectors across the surface of the spheroid. The solutions both in the prolate and oblate spheroidal coordinate systems result in a same form, and the equations for the oblate spheroidal system can be obtained from those for the prolate one by replacing the prolate spheroidal wavefunctions with the oblate ones and vice versa. For an oblique incidence, the polarized incident wave is resolved into two components, the TM mode for which the magnetic vector vibrates perpendicularly to the incident plane and the TE mode for which the electric vector vibrates perpendicularly to this plane. For the incidence along the rotation axis the resultant equations are given in the form similar to the one for a sphere given by the Mie theory. The physical parameters involved are the following five quantities: the size parameter defined by the product of the semifocal distance of the spheroid and the propagation constant of the incident wave, the eccentricity, the refractive index of the spheroid relative to the surrounding medium, the incident angle between the direction of the incident wave and the rotation axis, and the angles that specify the direction of the scattered wave.

Light Scattering by a Spheroidal Particle

This paper presents an overview of the work done on graphene in recent years. It explains the preparation techniques, the properties of graphene related to its physio-chemical structure and some key applications. Graphene, due to its outstanding electrical, mechanical and thermal properties, has been one of the most popular choices to develop the electrodes of a sensor. It has been used in different forms including nanoparticle and oxide forms. Along with the preparation and properties of graphene, the categorization of the applications has been done based on the type of sensors. Comparisons between different research studies for each type have been made to highlight their performances. The challenges faced by the current graphene-based sensors along with some of the probable solutions and their future opportunities are also briefly explained in this paper.

Graphene and its sensor-based applications: A review

Preparation of chitosan-TiO2 composite film with efficient antimicrobial activities under visible light for food packaging applications.

Pectin bionanocomposite films filled with various concentrations of two different types of halloysite nanotubes were prepared and characterized in this study as potential films for food packaging applications. The two types of halloysite nanotubes were long and thin (patch) (200–30 000 nm length) and short and stubby (Matauri Bay) (50–3000 nm length) with different morphological, physical, and dispersibility properties. Both matrix (pectin) and reinforcer (halloysite nanotubes) used in this study are considered as biocompatible, natural, and low-cost materials. Various characterization tests including Fourier transform infrared spectroscopy, field emission scanning electron microscopy, release kinetics, contact angle, and dynamic mechanical analysis were performed to evaluate the performance of the pectin films. Exceptional thermal, tensile, and contact angle properties have been achieved for films reinforced by patch halloysite nanotubes due to the patchy and lengthy nature of these tubes, which form a b...

Effect of Morphology and Size of Halloysite Nanotubes on Functional Pectin Bionanocomposites for Food Packaging Applications.

Pectins functionalized biomaterials; a new viable approach for biomedical applications: A review.

The outstanding multidisciplinary applicability of nanomaterials has paved the path for the rapid advancement of nanoscience during the last few decades. Such technological progress subsequently results in an inevitable environmental exposure of nanomaterials. Presently, nanomaterials are employed in an extensive range of commercial products. Safe and sustainable incorporation of nanomaterials in industrial products requires a profound and comprehensive understanding of their potential toxicity. Among different nanomaterials, carbon nanomaterials marked its notable superiority toward the development of state-of-the-art nanotechnology due to the significant contribution of each of the carbon allotropes with varied dimensionality. The zero-dimensional fullerene, one-dimensional carbon nanotube, and two-dimensional graphene possess an exclusive combination of distinctive properties that are utilized in most of the nanotechnology-based products nowadays. However, potential risk factors are associated with the production and the use of carbon nanomaterials. Consequently, the number of studies regarding the assessment of the toxicity of these nanomaterials has increased rapidly in the past decade. This chapter will summarize the recent scientific efforts on the toxicity evaluation of different carbon nanomaterials.

Toxicity of Carbon Nanomaterials

COVID-19 infections and severe acute respiratory syndrome or SARS have commenced a weird health crisis across the globe with numerous death reports and have caused a tremendous economic crash worldwide....

COVID-19 mitigation: Nanotechnological intervention, perspective, and future scope

Rainfall information is important in various fields such as agriculture, water resource management, and weather forecast. A proper and efficient forecast of precipitation occurrences and rainfall amounts is important in this connection. Information on the different phases of atmospheric water is necessary to characterize the impending precipitation. A multi-frequency microwave radiometer is capable of continuous monitoring of the brightness temperature of atmospheric emissions which is capable of sensing water vapour, liquid water and their evolution towards forming rain structures with different microphysical properties.

Identification and Estimation of Rainfall Intensity using Microwave Radiometric Measurements

Background: Guillain-Barré syndrome (GBS) is a group of clinical syndromes involving acute polyneu­ropathy secondary to an immune-mediated process. The aim of the research is to study clinical profile and outcome in children aged 1-12 years presenting with GBS.
Methods: It is a prospective plus retrospective observational study (5-year retrospective + 18 months prospective). All cases of GBS admitted from January 2020-july 2021 were enrolled for the study and retrospective cases were taken from case record from January 2015 onwards in a tertiary care centre.
Results: Total 45 children were enrolled. The male: female ratio was 1.64:1. Mean age at presentation was 6.3 years, in a range of 1.5 -11.5 years of age. History of antecedent illness prior to the occurrence of GBS was present in 93.3% patients with upper respiratory tract infection being most common seen in 53.3% patients. Following variants of GBS were seen on NCV study performed in 34 patients, the most common was AIDP in 46.7% patients, followed by AMAN in 22.2% subjects and AMSAN in 6.7% patients. All children presented with lower limb weakness which progressed to involve upper limbs. Other associated features like bulbar cranial nerve involvement, respiratory muscle weakness, sensory symptoms and autonomic disturbance (arrythmia, hypotension, tachycardia, bradycardia) was observed in 30,12,7,16 patients respectively. Out of the total 45 patients, 12 patients required mechanical ventilation.
Conclusions: Male predominance seen in GBS. AIDP the most common subtype of GBS. Respiratory distress and autonomic instability were associated with greater severity of Hughes disability score. Factors associated with poor outcome were sensory symptoms, autonomic instability, respiratory distress and bulbar cranial nerve involvement.

Study of clinical profile and outcome in children aged 1-12 years presenting with Guillain Barre syndrome

The propagation of satellite signals at frequencies above 10 GHz has been studied to investigate the characteristic features of tropical rain. The propagation effects, namely, attenuation, scintillation and depolarization caused by varying structures of rain have been investigated to indicate their interrelationship. The varying relationship between attenuation and scintillations indicates the evolution of turbulence during different types of rain events. Also, the rain-induced depolarization of the signal is related to rain attenuation in different manner during stratiform events, when the melting layer is present, than during convective events when large rain drops are mainly responsible for depolarization in the absence of melting layer.

https://www.ursi.org/Proceedings/ProcGA14/papers/ursi_paper2046.pdf

Arpita Adhikari

Papers

Toxicity of Carbon Nanomaterials

COVID-19 mitigation: Nanotechnological intervention, perspective, and future scope

Identification and Estimation of Rainfall Intensity using Microwave Radiometric Measurements

Study of clinical profile and outcome in children aged 1-12 years presenting with Guillain Barre syndrome

Earth-space propagation through rain and associated tropospheric processes at a tropical location