14 research outputs found
Facile Rapid Synthesis of Polyaniline (PANI) Nanofibers
A Polyaniline (PANI) nanofibers have been successfully synthesized by a facile rapid oxidative polymerization of aniline hydrochloride and ammonium persulfate at high temperature (60 C). The structural and optical properties of PANI nanofibers are investigated by using X-ray diffraction (XRD), UV-VIS Spectroscopy and Fourier Transform Infrared Spectroscopy (FTIR). The XRD analysis ascertains formation of PANI with nanocrystalline nature with average crystallite size 30 nm. Further, FTIR pattern confirmed the formation of PANI. SEM analysis has revealed homogeneous fibrous morphology of PANI nanofibers, a well formed mesh of interconnected and entangled PANI nano-fibers over the scanned area. The UV-VIS spectroscopic analysis shows three major absorption peaks at 256.73, 361.17 and 480.95 nm confirmed the PANI formation with conducting state
Synthesis of Cuprous Oxide (Cu2O) Nanoparticles – a Review
Cuprous Oxide (Cu2O) a semiconductor material oxide; with unique optoelectronic properties; gains significant importance for its synthesis in view of its various technological and industrial applications. A few liquid phase methods for the synthesis of Cu2O nanoparticles are reviewed on the basis of materials, methodology, synthesis conditions and key findings. A comparative study of these methods is also performed following criteria of repeatability, safety, cost, time span and simplicity. Contextual to the above mentioned criteria, three liquid phase synthesis techniques were shortlisted and actually experimented (as reported) to synthesize the Cu2O nanoparticles. This was done to investigate the effectiveness, repeatability and stability of the synthesized Cu2O product as a function of ageing time. The synthesized Cu2O using all these techniques are prone to be unstable and undergo the rapid phase change to CuO phase which was ascertained from the shift of absorbance peak in UV-VIS spectra. The results have highlighted the urgent need to develop a facile, economical, scalable and safe method to synthesize stable Cu2O nanoparticles at room temperature
Facile Rapid Synthesis of Polyaniline (PANI) Nanofibers
A Polyaniline (PANI) nanofibers have been successfully synthesized by a facile rapid oxidative polymerization of aniline hydrochloride and ammonium persulfate at high temperature (60 C). The structural and optical properties of PANI nanofibers are investigated by using X-ray diffraction (XRD), UV-VIS Spectroscopy and Fourier Transform Infrared Spectroscopy (FTIR). The XRD analysis ascertains formation of PANI with nanocrystalline nature with average crystallite size 30 nm. Further, FTIR pattern confirmed the formation of PANI. SEM analysis has revealed homogeneous fibrous morphology of PANI nanofibers, a well formed mesh of interconnected and entangled PANI nano-fibers over the scanned area. The UV-VIS spectroscopic analysis shows three major absorption peaks at 256.73, 361.17 and 480.95 nm confirmed the PANI formation with conducting state
Synthesis of Cuprous Oxide (Cu2O) Nanoparticles – a Review
Cuprous Oxide (Cu2O) a semiconductor material oxide; with unique optoelectronic properties; gains significant importance for its synthesis in view of its various technological and industrial applications. A few liquid phase methods for the synthesis of Cu2O nanoparticles are reviewed on the basis of materials, methodology, synthesis conditions and key findings. A comparative study of these methods is also performed following criteria of repeatability, safety, cost, time span and simplicity. Contextual to the above mentioned criteria, three liquid phase synthesis techniques were shortlisted and actually experimented (as reported) to synthesize the Cu2O nanoparticles. This was done to investigate the effectiveness, repeatability and stability of the synthesized Cu2O product as a function of ageing time. The synthesized Cu2O using all these techniques are prone to be unstable and undergo the rapid phase change to CuO phase which was ascertained from the shift of absorbance peak in UV-VIS spectra. The results have highlighted the urgent need to develop a facile, economical, scalable and safe method to synthesize stable Cu2O nanoparticles at room temperature
Global, regional, and national sex differences in the global burden of tuberculosis by HIV status, 1990–2019: results from the Global Burden of Disease Study 2019
Background Tuberculosis is a major contributor to the global burden of disease, causing more than a million deaths annually. Given an emphasis on equity in access to diagnosis and treatment of tuberculosis in global health targets, evaluations of differences in tuberculosis burden by sex are crucial. We aimed to assess the levels and trends of the global burden of tuberculosis, with an emphasis on investigating differences in sex by HIV status for 204 countries and territories from 1990 to 2019.
Methods We used a Bayesian hierarchical Cause of Death Ensemble model (CODEm) platform to analyse 21 505 site-years of vital registration data, 705 site-years of verbal autopsy data, 825 site-years of sample-based vital registration data, and 680 site-years of mortality surveillance data to estimate mortality due to tuberculosis among HIV-negative individuals. We used a population attributable fraction approach to estimate mortality related to HIV and tuberculosis coinfection. A compartmental meta-regression tool (DisMod-MR 2.1) was then used to synthesise all available data sources, including prevalence surveys, annual case notifications, population-based tuberculin surveys, and tuberculosis cause-specific mortality, to produce estimates of incidence, prevalence, and mortality that were internally consistent. We further estimated the fraction of tuberculosis mortality that is attributable to independent effects of risk factors, including smoking, alcohol use, and diabetes, for HIV-negative individuals. For individuals with HIV and tuberculosis coinfection, we assessed mortality attributable to HIV risk factors including unsafe sex, intimate partner violence (only estimated among females), and injection drug use. We present 95% uncertainty intervals for all estimates.
Findings Globally, in 2019, among HIV-negative individuals, there were 1.18 million (95% uncertainty interval 1.08-1.29) deaths due to tuberculosis and 8.50 million (7.45-9.73) incident cases of tuberculosis. Among HIV-positive individuals, there were 217 000 (153 000-279 000) deaths due to tuberculosis and 1.15 million (1.01-1.32) incident cases in 2019. More deaths and incident cases occurred in males than in females among HIV-negative individuals globally in 2019, with 342 000 (234 000-425 000) more deaths and 1.01 million (0.82-1.23) more incident cases in males than in females. Among HIV-positive individuals, 6250 (1820-11 400) more deaths and 81 100 (63 300-100 000) more incident cases occurred among females than among males in 2019. Age-standardised mortality rates among HIV-negative males were more than two times greater in 105 countries and age-standardised incidence rates were more than 1.5 times greater in 74 countries than among HIV-negative females in 2019. The fraction of global tuberculosis deaths among HIV-negative individuals attributable to alcohol use, smoking, and diabetes was 4.27 (3.69-5.02), 6.17 (5.48-7.02), and 1.17 (1.07-1.28) times higher, respectively, among males than among females in 2019. Among individuals with HIV and tuberculosis coinfection, the fraction of mortality attributable to injection drug use was 2.23 (2.03-2.44) times greater among males than females, whereas the fraction due to unsafe sex was 1.06 (1.05-1.08) times greater among females than males. Interpretation As countries refine national tuberculosis programmes and strategies to end the tuberculosis epidemic, the excess burden experienced by males is important.
Interventions are needed to actively communicate, especially to men, the importance of early diagnosis and treatment. These interventions should occur in parallel with efforts to minimise excess HIV burden among women in the highest HIV burden countries that are contributing to excess HIV and tuberculosis coinfection burden for females. Placing a focus on tuberculosis burden among HIV-negative males and HIV and tuberculosis coinfection among females might help to diminish the overall burden of tuberculosis. This strategy will be crucial in reaching both equity and burden targets outlined by global health milestone
Novel Facile Technique for Synthesis of Stable Cuprous Oxide (Cu2O) Nanoparticles – an Ageing Effect
A novel facile method to synthesize stable phase of Cuprous Oxide (Cu2O) nanoparticles at room temperature is demonstrated. The structural and optical properties of (Cu2O) nanoparticles were investigated by using X-ray diffraction (XRD), UV-VIS Spectroscopy. XRD analysis has indexed nanocrystalline nature of cubical phase Cu2O with an average edge length of about 20 nm. The Scanning Electron Microscopy (SEM) measurements also ascertain the cubical morphology. The Fourier Transform Infrared Spectroscopy (FTIR) affirms the presence of characteristic functional group of Cu2O. The absorbance peak at 485 nm in UV-VIS spectra also confirms the Cu2O synthesis. Furthermore, UV-VIS absorbance spectra at different ageing time substantiate the phase stability of Cu2O nanoparticles. The ageing leads to blue shift of absorbance peak mainly due to decrease in Cu2O particle size with no additional absorbance peak in UV-VIS spectra indicating the formation of secondary phase. The reduction in particle size may be attributed to tiny conversion Cu2O to CuO. The energy band gap measurements from Tauc plots for Cu2O nanoparticles shows the increasing trend (2.5 eV to 2.8 eV) with ageing time (2 months), owing to quantum confinement effects
Швидкий вологий хімічний синтез наночастинок оксиду міді (Cu2O): вплив концентрації прекурсора
Швидкий синтез наночастинок Cu2O проводили методом вологого хімічного синтезу. В роботі
йдеться про вплив молярної концентрації прекурсора CuSO4 (0,05-0,15 моль) на структурні,
морфологічні та оптичні властивості наночастинок Cu2O. Рентгенодифракційний аналіз
синтезованого порошку Cu2O демонструє кубічну структуру з нанокристалічною природою. Середній
розмір кристалітів наночастинок Cu2O збільшується від 10 до 25 нм із збільшенням молярності
прекурсора. Аналіз скануючою електронною мікроскопією (SEM) показує утворення
нанокристалічного Cu2O зі збільшеним розміром частинок через збільшення молярності. FTIR
спектроскопічний аналіз встановлює наявність характерних функціональних груп у Cu2O. Спектри
UV-Vis показують характерний пік поглинання близько 485 нм, який відноситься до Cu2O.
Вимірювання енергетичної ширини забороненої зони з графіка Тауца виявляють її зменшення зі
збільшенням молярності прекурсора внаслідок збільшення розміру зерна. Енергетична ширина
забороненої зони зменшується з 2,94 до 2,64 еВ за рахунок збільшення розміру зерна в основному
через квантового розмірний ефект.Rapid synthesis of Cu2O nanoparticles was carried out by wet chemical synthesis technique. The effect
of CuSO4 precursor molar concentration (0.05-0.15 mol) on the structural, morphological and optical
properties of Cu2O nanoparticles is reported. X-ray diffraction analysis of the synthesized Cu2O powder
shows a cubic structure with nanocrystalline nature. The average crystallite size of Cu2O nanoparticles
increases from 10 to 25 nm with increasing precursor molarity. Scanning Electron Microscopic (SEM)
analysis shows nanocrystalline Cu2O formation with increased particle size due to rise in molarity. The
FTIR spectroscopic analysis ascertains the presence of characteristic functional groups in Cu2O. UV-Vis
spectra show a characteristic absorbance peak around 485 nm attributed to Cu2O. The energy band gap
measurements from the Tauc plot reveal a decrease in band gap energy with increasing precursor molarity
owing to increased grain size. The band gap energy decreases from 2.94 to 2.64 eV due to an increase in the
grain size mainly due to quantum confinement effect
SYNTHESIS AND CHARACTERIZATIONS OF PURE AND DOPED NANOCRYSTALLINE BiFeO3 CERAMICS BY SHS
The pure and Zn incorporated BiFeO3 ceramics were synthesized by self-propagating high temperature synthesis (SHS). The X-ray diffractometer (XRD) studies revealed that, both BiFeO3 and BiFe0.95Zn0.05O3 ceramics crystallizes in a single phase rhombhohedral structure. The room temperature ferroelectric and magnetic hysteresis loop evidenced coexistence of ferroelectricity and magnetism in single phase undoped and Zn doped BiFeO3. The M-H hysteresis loop of BiFe0.95Zn0.05O3 sample demonstrated a weak ferromagnetism at 300 K and 5 K respectively. The room temperature ferroelectric P-E hysteresis loops of BiFeO3 and BiFe0.95Zn0.05O3 exhibited an unsaturated behavior and suggests a partial reversal of polarization. A variation of dielectric constant with respect to temperature in BiFeO3 and BiFe0.95Zn0.05O3 ceramic delivers a dielectric anomaly around 480 and 450°C which is a consequence of antiferromagnetic to paramagnetic phase transition (TN). Moreover, for BiFeO3 the anomaly manifests a possible coupling between electric and magnetic dipole moments