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.

Characterization of diurnal precipitation features will help us to understand the mechanism of rain formation. The diurnal variation signifies the precipitation characteristics over a region and is governed by physical processes related to climatological features and atmospheric dynamics of that area [1]. It has been observed that the total accumulation as well as the hourly rainfall is quite significant at 19:30 IST for the monsoon period. This indicates that the intense rain events are most frequent around that period (19:30 IST) during monsoon. In pre-monsoon season, the major precipitation occurs during the evening through night (16:30-22:30 IST) and reaches maximum around 17:30 IST in the evening. The ku-band earth-space propagation effects are studied in respect of the diurnal variation of rain rate at the present location. The mean attenuation (dB/min) in monsoon period reaches its peak at about 19:30 IST. The exceedances, of rain attenuation greater than 6 dB, are more during the morning and afternoon (6-12 IST) spans in the monsoon. The period (0-6 IST) can be marked significant in view of radio communication with minimal necessary fade margin as the attenuation exceedances are minimum in this period. The mean attenuation considering the pre-monsoon months of 2006-2010 shows maximum value at 19:30 IST. It is also noted that 90% of the total pre-monsoon rain takes place within 16:3022:30 IST. This particular criterion indicates the prevalence of convective events during the evening to late night period. The exceedance values of cross-polar enhancement show higher values mostly during morning hours (06 IST) in monsoon whereas in pre-monsoon occurrences are more in late evening and night. The standard deviation of scintillation follows the same pattern of precipitation but in a prior time slot as compared to precipitation. Fig. 1 shows that higher rain rate occurrences are dominant at early morning and late evening for monsoon period whereas lower rain rate occurrences presents all over the day. In regards to the time of occurrence, the pre-monsoon events are categorized as the afternoon and late evening rain events. These events are found to be associated with the distinct diurnal patterns of atmospheric parameters (CAPE and CIN, LWP and cloud depth). It has also been observed that lower and medium rain drops are mainly contributed to rainfall in monsoon season, whereas contributions of higher drops are significant in pre-monsoon. The observations of diurnal variations of rain and rain induced propagation impairments along with the variability of associated atmospheric parameters highlighted some of the unique features of tropical rain. The results also provide useful information of rain induced propagation characteristics which will help system designers to identify some time slots of the day during which satellite communication is possible with minimum fade margin.

Diurnal variations of rain-induced propagation and related atmospheric phenomena over a Tropical Location

The trifunctional L-cysteine containing carboxylic acid, amine and thiol is chemisorbed on the gold electrode surface via the thiol groups to form the self-assembled monolayer. Then the bilayer is assembled stepwise on the cysteine modified gold electrode. A layer of 3-marcaptopropanoic acid functionalized silver nanoparticles is covalently coupled with amine group of cysteine and other layer of amine functional group containing biotin or avidin molecules is covalently coupled with carboxylic acid functional groups of cysteine. The improvement of electrochemical properties are noted for the cysteine modified gold electrode coupled with biomolecules first followed by coupling with the functionalized silver nanopartciels. This modified gold electrode is used to study the electrochemical sensing response of respective complementary biomolecule immobilized gold electrode towards the biotin or avidin. As revealed the avidin modified electrode is found to have better sensing performences toward biotin in terms of sensinivity and detection limit over the other one. The sensitivity of 1.243 Ω and detection limit of 1.4 × 10-3 ng L-1 is observed for avidin sensing on biotin layer. For biotin sensing on avidin layer a sensitivity of 6.143 Ω and detection limit of 1.2 × 10-5 ng L-1 is obtained from the calibration plot. 

Highly sensitive electrochemical detection of biotin-avidin interaction on gold electrode modified with silver nanoparticles through bilayer assembly

Diurnal Variability of Rain and Rain-induced Propagation Impacts at a Tropical Location: A Seasonal Comparison

The precipitation radar(PR) onboard Tropical Rain Monitoring Mission( TRMM) estimates rainfall from space covering vast geographical area. It is necessary to compare such estimates with ground truth. In this paper PR estimated rain has been compared with that obtained from India Meteorological Department( IMD) and also disdrometer over Calcutta. PR estimated rainfall statistics have been presented along with IMD derived rainfall statistics. Regression relationships of rainfall have been derived as a function of surface temperature (DBT) and surface dew point temperature (DPT). Also rainfall phenomena have been studied as a signature of EL-NINO and LA-NINA occurrence.

http://ieeexplore.ieee.org/iel5/5398767/5407062/05407104.pdf

Comparison of TRMM estimated rainfall with ground truth over Calcutta

Background: Acquired demyelinating diseases (ADS) соnstitute а heterogeneous grоuр of central nervous system disorders of autoimmune origin that causes significant physical and cognitive disabilities. Early recognition and prompt management causes significant improvement in acute episodes of demyelinating disorders.
Methods: 33 children diagnosed with demyelinating disorders at Lokmanya Tilal municipal medical college and hospital in Mumbai were enrolled. The study was conducted between January 2013 and November 2022.  Demographic data, clinical profile, CSF study, serum antibody, radiological findings were collected and results were analyzed. Statistical Data was analysed using statistical software GraphPad in Stat.V3.0. Data were presented in tables and figures whenever needed.  P value <0.05 considered as significant.
Results: Of 33 patients, 21 (63%) were cases of acute disseminated encephalomyelitis (ADEM), 6 (18.1%) of transverse myelitis (TM), 1 case of ADEM + TM (3%), 3 (9%) of neuromyelitis optica, 1 (3%) of Optic neuritis and 1 (3%) of multiple sclerosis. ADEM patients presented with encephalopathy and multifocal neurological deficits, 40% were MOG positive. Two patients were of multiphasic ADEM. Patients of transverse myelitis had paraparesis or quadriparesis and sensory + bladder involvement. Patients with NMO presented with bilateral visual impairment with limb weakness and bladder involvement. Steroids were the primary treatment, 3 patients (9%) required intravenous immunoglobulin (IVIG) and 1 (3%) patient received plasma exchange therapy.
Conclusions: ADEM is the most common ADS. Early diagnosis and management with steroids therapy improves outcome in most of the patients. Non response to steroids warrants second line treatment options like IV Immunoglobulin (IVIG) or Therapeutic plasma exchange.

/pdf/a-retrospective-study-on-acquired-demyelinating-diseases-in-3dls5azu.pdf

Arpita Adhikari

Papers

Diurnal variations of rain-induced propagation and related atmospheric phenomena over a Tropical Location

Highly sensitive electrochemical detection of biotin-avidin interaction on gold electrode modified with silver nanoparticles through bilayer assembly

Diurnal Variability of Rain and Rain-induced Propagation Impacts at a Tropical Location: A Seasonal Comparison

Comparison of TRMM estimated rainfall with ground truth over Calcutta

A retrospective study on acquired demyelinating diseases in children