198 research outputs found
Probing on green long persistent Eu /Dy 31 doped Sr 3 SiAl 4 O 11 emerging phosphor for security applications
No full textHerein, a novel green emitting long-persistent Sr3SiAl4O11:Eu2+/Dy3+ phosphor was synthesized in a single phase form using facile solid state reaction method under the reducing atmosphere of 10% H2 and 90% N2. The resulting phosphor exhibits hyper-sensitive strong broad green emission, peaking at 510 nm upon 340 nm excitation wavelength, which is attributed to the 4f65d1-4f7 transitions of emission center of europium (Eu2+) ions. Moreover, the incorporation of dysprosium (Dy3+) ions, which act as effective hole trap centers with appropriate depth, largely enhances the photoluminescence characteristics and greatly improves the persistent intense luminescence behavior of Sr3SiAl4O11:Eu2+/Dy3+ phosphor under ultraviolet (UV) excitation. In addition, with the optimum doping concentration and sufficient UV excitation time period, the as-synthesized phosphor can be persisted afterglow for time duration ∼4 h with maximum luminescence intensity. Thus, these results suggest that this phosphor could be expected as an ultimate choice for next generation advanced luminescent materials in security applications such as latent finger-marks detection, photo-masking induced phosphorescent images, and security code detection. Probing on green long persistent Eu /Dy 31 doped Sr 3 SiAl 4 O 11 emerging phosphor for security applications. Available from: https://www.researchgate.net/publication/279230500_Probing_on_green_long_persistent_Eu_Dy_31_doped_Sr_3_SiAl_4_O_11_emerging_phosphor_for_security_applications [accessed Mar 29, 2017]
Sunlight-activated Eu2+/Dy3+ doped SrAl2O4 water resistant phosphorescent layer for optical displays and defence applications
No full textHerein, we introduce a strategy for the fabrication of a sunlight-activated green luminescent Eu2+/Dy3+ doped strontium aluminate (Sr1-x-yAl2O4:Eu-x(2+)/Dy-y(3+)) assisted long persistent, transparent, flexible and water resistant phosphorescent layer via a customized solid state reaction-solution casting method. The XRD result of as-synthesized phosphor shows a pure monoclinic crystal structure with the space group P2(1). This as-synthesized phosphor exhibits green afterglow emission with a broad band peaking similar to 528 nm upon a broad range of excitation wavelengths from 368-418 nm, which is ascribed to the characteristic 4f(6)5d(1) -> 4f(7) electronic dipole allowed transition of Eu2+ ions. Moreover, the role of Dy3+ as an auxiliary activator significantly prolongs the afterglow duration to a large extent by increasing the number of electron traps and their trap depths in the vicinity of Eu2+. Accordingly, a brighter afterglow intensity with a time more than 5 hours is observed for the optimal concentration of Eu2+/Dy3+ in Sr1-x-yAl2O4:Eux(2+)/Dyy(3+), (x = 0.1 and y = 0.2) in the long persistent phosphor. The incorporation of the sunlight-activated as-synthesized Sr0.7Al2O4:Eu-0.1(2+)/Dy-0.2(3+) phosphor in a commercially available PVC gold medium offers a highly dispersive transparent luminescent paint, which can be used for the spray coating of monuments, as well as for the fabrication of transparent, flexible and water resistant phosphorescent layers. Hence, these striking features of the luminescent paint, as well as the flexible transparent phosphorescent layer could be potentially utilized in optical displays and defence applications
R16. Formulation and Evaluation of Doxorubicin HCl Nanoliposomes by Ethanol Injection Method
Full text linkCorresponding author (Pharmaceutics and Drug delivery): Arun Kumar Kotha, [email protected]://egrove.olemiss.edu/pharm_annual_posters/1015/thumbnail.jp
Fabrication of a Flexible UV Band-Pass Filter Using Surface Plasmon Metal-Polymer Nanocomposite Films for Promising Laser Applications
No full textWe introduce a strategy for the fabrication of silver/polycarbonate (Ag/PC) nanocomposite flexible films of (20 +/- 0.01) mu m thickness with different filling factor of surface plasmon metal using customized solution cast thermal evaporation method. Structural characterizations confirmed the good crystallinity with cubic phase of Ag nanoparticles in PC films. Moreover, the microstructural evolutions of nanocomposite films are investigated by transmission electron microscopy, which indicates that the metal fraction is in the form of fractals. Additionally, the surface plasmonic behavior of nanocomposite films has been explored in detail to examine the distribution of Ag nanoparticles in PC film by spectroscopic technique. Furthermore, the obtained transmittance spectral features of this nanocomposite film are suitable for the applications of band-pass filter at 320 nm UV range, which is highly desirable for a HeCd laser
A Long-Period Waveguide Grating Sensor for Accurate Simultaneous Detection of Dual Analytes
No full textTo the best of our knowledge, we are the first to report the existence of two dispersion turning points (DTPs) in an optimized planar waveguide long-period grating (LPG) sensor for the lowest order cladding mode. Using numerical simulation, we investigate the potential of the sensor structure for bulk refractive index (RI) and surface sensing, with the goal of predicting its possible application as an integrated photonic biosensor. The proposed sensor exhibits an exceptionally high RI sensitivity of ≈7500 nm/RIU ( ≈ 10 000 nm/RIU) near lower (higher) DTP. The surface sensitivity, which is incredibly high in this form of structure, is found to be 6.5 nm/nm (7 nm/nm) near lower (higher) DTP for the RI relevant for biosensing. Utilizing the sensing characteristics of both the DTP, we propose a dual-slot biosensor by cascading two LPGs having different grating periods. The proposed biosensor shows two independent dual-resonance phenomena and is, therefore, capable of simultaneous detection of dual analytes. Utilizing the proposed dual-slot biosensor, we present simulation results for specific detection of Hepatitis B antigen and deoxyribonucleic acid (DNA) hybridization simultaneously. The proposed biosensor will reduce the sensor cost as well as detection time, since a single source and detector are required to sense two different analytes at once
A commercial approach towards fabrication of bulk and nano phosphors converted highly-efficient white LEDs
No full textHerein, we report a strategy to synthesize a highly efficient yellow light emitting Y3−xAl5O12:Cex (x = 0.03 to 0.3) based bulk as well as nano (rod-shaped) phosphors, which are the main component of solid state white light-emitting diodes (WLEDs). The as-synthesized phosphors were well characterized by several experimental techniques related to material characterization and spectroscopy. The bulk and nano phosphors emit with maximum photoluminescence intensities at 549 and 530 nm, respectively, upon excitation at a wavelength of 468 nm. These phosphors exhibit higher photoluminescence intensity as compared to commercially available bulk phosphors coated on WLED strips. Moreover, the integration of commercially available InGaN blue LED strips with the synthesized bulk and nano phosphors demonstrates better CIE coordinates and lower colour temperature with high brightness (>81% quantum yield) compared to commercially available WLED-based strips, lanterns and torches. These highly efficient light-emitting phosphors are a feasible candidate for potential use in commercial WLED applications
Lifetime alcohol consumption and severity in alcohol dependence syndrome
No full textIntroduction: Alcohol dependence syndrome is a major public health issue globally and is responsible for significant morbidity and mortality. The total dose of alcohol consumed has been linked to liver diseases, pancreatitis, and other alcohol-related medical consequences. However, this has not been studied in relation to severity of dependence; although it is well known that alcohol causes neuronal damage, which in turn potentiates dependence. Thus, there is a need to study the relationship between the amount of alcohol consumed and severity of dependence. Materials and Methods: A total of 165 consecutive cases of alcohol dependence syndrome were studied in a General Hospital Psychiatry Unit at a tertiary care hospital. Addiction Severity Index (ASI) was used to evaluate the severity of alcohol dependence, and Life Time Alcohol Consumption (LTAC) was evaluated by taking careful history. Correlation coefficients were calculated between ASI and LTAC. Group differences were analyzed using t-test. Results: There was a significant correlation between ASI and LTAC (r = 0.162, P = 0.032), which was highly significant in the subgroup without medical complications (r = 0.250, P = 0.003). A similar correlation in the medical complications subgroup was not significant. Conclusions: Lifetime alcohol consumption co-related with the severity of alcohol dependence, particularly in those presenting without medical complications (i.e., those with behavioral and social consequences, and injuries)
Appl Opt
No full textWe show the presence of hybridization between fundamental TE and first higher-order TM modes in a dielectric loaded plasmonic waveguide of appropriately chosen core dimensions. Furthermore, a critical hybridization point is achieved at which both modes have nearly equal fraction of the TE and TM polarizations. Exploiting the interference among such modes, we propose the design of a compact and highly sensitive modal interferometer. The bulk and surface sensitivities of the proposed sensor are found to be ∼ 3 − 10 µ m / R I U for refractive index (RI) ∼ 1.33 − 1.36 and ∼ 0.7 n m / n m for an adsorbed layer of RI 1.45, respectively. The proposed sensor gives robust performance against fabrication imperfections and is stable against temperature fluctuations due to extremely low temperature cross-sensitivity ( ∼ 10 − 15 p m / ∘ C for a temperature change up to ∼ 100 ∘ C )
The Intra and Extracellular Mechanisms 1 of Microbially-Synthesized 2 Nanomaterials and Their Purification
Full text link12 Nanotechnology is the most important scientific breakthrough in the 21st century which has led 13 to changes and advances in various fields of application. Generally, nanomaterials (NMs) with
14 specific shapes, sizes, and compositions are required for nanotechnology. Synthesis of NMs 15 using conventional chemical and physical methods involves high costs, the use of hazardous 16 substances, and environmental damage. In contrast, the green synthesis approach provides a
17 sustainable method for synthesizing NMs such as the utilization of biodegradable waste and 18 microorganisms. Nowadays, microbially-synthesized NMs have been recognized as an 19 effective and eco-friendly method suitable for the large-scale fabrication of biocompatible 20 nanostructures. Various microorganisms such as yeast, fungi, algae, and bacteria can serve as 21 potential stabilizing and reducing agents for synthesizing NMs. This chapter contributes to 22 recent developments in the green synthesis of various NMs using microorganisms, focusing on 23 intracellular or extracellular mechanisms and the purification of NMs. The characterization,
24 applications, and prospects for NMs biosynthesis are also discussed in this chapter
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