The characteristics of the UV illumination-assisted degradation of Malachite green (MG) on highly active nanostructured-anatase TiO 2 , bulk Polyaniline (PAni), PAni nanoparticles and PAni-TiO 2 nanocomposites have been studied. Dodecylbenzene sulphonic acid doped PAni-TiO 2 nanocomposites were synthesized by a water-assisted self-assembly method. Samples were characterized using transmission electron microscopy, X-ray diffraction studies, Fourier Transform Infra red spectroscopy and photoluminescence studies. Photoluminescence intensity of TiO 2 nanoparticles was found to decrease with the increase of PAni in the nanocomposite which can be attributed to the reduction of electron-hole pair recombination at the interface of PAni and TiO 2 due to electron transfer from TiO 2 to PAni. Exposure to UV light brought about the photocatalytic oxidation of MG in contact with bulk PAni, PAni and TiO 2 nanoparticles, and PAni-TiO 2 nanocomposites. The decrease in absorbance was measured, and its kinetics was analyzed using the Langmuir-Hinshelwood kinetic model. PAni-TiO 2 nanocomposites exhibit higher photocatalytic activity than pure TiO 2 nanoparticles, bulk PAni and PAni nanoparticles under the same degradation condition for MG. The enhanced photocatalytic activity of nanocomposites is attributed to the electron transfer from TiO 2 to PAni resulting in enhancing the oxidative property of the TiO 2 nanoparticles.

In recent times, considerable research efforts have been focused on the exploration of novel optical properties of nanocrystalline SnO 2 particles such as photoluminescence (PL). In the present work, spherical SnO 2 nanoparticles are synthesized by solid state reaction at different temperatures using tin chloride dihydrate and sodium hydroxide flakes as precursors. Transmission electron micrograph shows uniform and spherical SnO 2 nanoparticles of diameter 30-40 nm. Micro-Raman spectra show an inverse relationship of line-width with SnO 2 particle size. The band gap of SnO 2 is calculated by plotting (ahn) 2 vs. hn and extrapolating the linear portion of it to a = 0 and found it to be 3.76-4.24 eV. Photoluminescence intensity increases with the increase of solid state reaction temperature up to 873 K. This is attributed to the generation of the oxygen ion vacancies in SnO 2 .

In the present work polyaniline (PAni) nanofibers have been synthesized by interfacial polymerization technique. Pellets are made from PAni nanofibers and characterized by XRD, TEM, UV-Vis spectroscopy, Photoluminescence spectroscopy and Four-probe conductivity measurements. XRD results show the increase in the degree of crystallinity with the increase of concentration of dopant acid. It also shows peak broadening, which indicates reduction of fiber diameter with increasing dopant concentration. TEM micrograph confirms the formation of PAni nanofibers of diameter around 20-30 nanometer. The UV-Visible spectra show three prominent peaks at 320nm, 430nm and 800nm, which confirm the formation of a single broad polaronic band in the band-gap of the PAni nanofibers. Four-probe measurements show that the electrical conductivity of PAni nanofibers increases with doping. PL spectra show a broad peak in violet region ( = 405nm) and indicate a decrease of fiber diameter with the increase in HCl concentration.

Polyaniline nanofibre-tin oxide (PAni-SnO 2) nanocomposites are synthesized and mixed with polyvinyl alcohol (PVA) as stabilizer to cast free-standing films. Composite films are characterized by X-ray diffraction studies (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), photoluminescence spectroscopy (PL) and UV-visible spectroscopy. XRD confirms the formation of PAni nanofibre-SnO 2 nanocomposite. From TEM images, diameter of the polyaniline nanofibre and SnO 2 nanoparticles in the PAni-SnO 2 nanocomposite are found to be 20-60 nm. SEM results show fibrous morphology of the PAni nanofibre and spherical morphology of polyaniline-SnO 2 composites. The nanocomposites exhibit high relative photoluminescence intensity in violet as well as green-yellow region of visible spectrum. From electrical conductivity measurement, it is confirmed that PAni nanofibre-SnO 2 nanocomposite follows Mott's one-dimensional variable range hopping (VRH) model.

Background: Organ donation is defined as “When a person allows an organ of theirs to be removed, legally, either by consent while the donor is alive or after death with the assent of the next of the kin.” Common transplantations after organ donations include kidney, heart, liver, pancreas, intestines, lungs, bones, bone marrow, skin, and cornea. Although some organs such as kidney and tissues like part of the liver, pancreas, lungs, and intestines can be donated while the donor is alive, most of the donations occur only after the donor's death. In India, the legislative foundation for brain death and organ donation was officially established, under Transplantation of Human Organs Act, 1994 amended in 2011. It provided a much-needed legal and transparent system for organ donation. India's organ donation rate (ODR) stands at an abysmal 0.34 per million populations (PMP) when compared with donation rate of 36 PMP in countries like Spain. While in the rest of the country, states like Tamil Nadu, Maharashtra, Andhra Pradesh, and Gujarat have made efforts to ramp up their ODR, by facilitating public and private health sector activities, such vision is still a far cry for the states in the North-Eastern part of India. Materials and Methods: This study on awareness of organ donation was conducted in one of the premiere educational institutes at Guwahati. A predesigned performa (questionnaire) was used to collect data from 360 individual, of which 180 participants were undergraduate students and 180 participants were faculties having postgraduate degree. Results: The results show that 79.17% (285) of participants were aware about organ donation, and out of all participants, families of only three have donated organ in the past 5 years. A total number of 12 (3.33%) participants have signed up for organ donation. A significant portion of the study population (12.5%) opined that there might be some religious beliefs which are preventing certain strata of local population from donating or accepting organs. More than half (186) (51.67%) of the study group opined that there is lack of awareness among people which may be one of the reasons for low rates of organ donation. Conclusion: Organ donation programs are at a very primordial stage in India and are almost negligible in its North-Eastern region. It is high time for the policy makers and other stake holders of a global giant like India to understand the magnitude of the benefits from these programs. Making tangible policies that are reflected nationally, emphasizing attention to both the organ donors and recipients, is the need of the hour.