Engineering of Solar-Energy Harvesting Tb3+-ion doped CdS Quantum Dot Glasses for Photodissociation of Hydrogen Sulphide

The photocatalytic properties of CdS quantum dots (Q-dots) and Tb3+-doped CdS Q-dots dispersed in a borosilicate glass matrix were investigated for the photodissociation of hydrogen sulfide (H2S) into hydrogen (H2) gas and elemental sulfur (S). The Q-dot-containing glass samples were fabricated using the conventional melt-quench method and isothermal annealing between 550 and 600 °C for 6 h for controlling the growth of CdS and Tb3+-ion-doped CdS Q-dots. The structure, electronic band gap, and spectroscopic properties of the Q-dots formed in the glass matrix after annealing were analyzed using Raman and UV–visible spectroscopies, X-ray powder diffraction, and transmission electron microscopy. With increasing annealing temperature, the average size range of the Q-dots increased, corresponding to the decrease of electronic band gap from 3.32 to 2.24 eV. For developing the model for photocatalytic energy exchange, the excited state lifetime and photoluminescence emission were investigated by exciting the CdS and Tb3+-doped CdS quantum states with a 450 nm source. The results from the photoluminescence and lifetime demonstrated that the Tb3+-CdS photodissociation energy exchange is more efficient from the excited Q-dot states compared to the CdS Q-dot glasses. Under natural sunlight, the hydrogen production experiment was conducted, and an increase of 26.2% in hydrogen evolution rate was observed from 0.02 wt % Tb3+-doped CdS (3867 μmol/h/0.5 g) heat-treated at 550 °C when compared to CdS Q-dot glass with a similar heat treatment temperature (3064 μmol/h/0.5 g). Furthermore, the photodegradation stability of 0.02 wt % Tb3+-CdS was analyzed by reusing the catalyst glass powders four times with little evidence of degradation

Explaining and predicting click-baitiness and click-bait virality

Purpose: In the age of social media, when publishers are vying for consumer attention, click-baits have become very common. Not only viral websites but also mainstream publishers, such as news channels, use click-baits for generating traffic. Therefore, click-bait detection and prediction of click-bait virality have become important challenges for social media platforms to keep the platform click-bait free and give a better user experience. The purpose of this study is to try exploring how the contents of the social media posts and the article can be used to explain and predict social media posts and the virality of a click-bait. Design/methodology/approach: This study has used 17,745 tweets from Twitter with 4,370 click-baits from top 27 publishers and applied econometric along with machine learning methods to explain and predict click-baitiness and click-bait virality. Findings: This study finds that language formality, readability, sentiment scores and proper noun usage of social media posts and various parts of the target article plays differential and important roles in click-baitiness and click-bait virality. Research limitations/implications: The paper contributes toward the literature of dark behavior in social media at large and click-bait prediction and explanation in particular. It focuses on the differential roles of the social media post, the article shared and the source in explaining click-baitiness and click-bait virality via psycho-linguistic framework. The paper also provides explanability to the econometric and machine learning predictive models, thus performing methodological contribution too. Practical implications: The paper helps social media managers create a mechanism to detect click-baits and also predict which ones of them can become viral so that corrective measures can be taken. Originality/value: To the best of the authors’ knowledge, this is one of the first papers which focus on both explaining and predicting click-baitiness and click-bait virality

Comparative analysis of non-absorbable 10-0 nylon sutures with absorbable 10-0 Vicryl sutures in pediatric cataract surgery

Purpose: The purpose of the study is to compare the efficiency as well as the rate and type of suture-related complications between 10-0 monofilament nylon (Aurolab Nylon Sutures, double arm, Aurolab) and 10-0 polyglactin 910 sutures (Vicryl, single arm, Aurolab) for pediatric cataract surgery. Methods: It is a prospective, comparative study performed in children who underwent surgery for congenital or developmental cataract from March 2013 to February 2016. Patients underwent suturing with either nylon or Vicryl in unilateral cases, but in most bilateral surgeries, one eye received Vicryl sutures while the other eye received nylon. The sutures were compared for their complications and the need for suture removal. Results: Forty-one children (72 eyes) were included in the study, of which 31 children (62 eyes) underwent bilateral surgery while 10 (10 eyes) underwent unilateral surgery. Sixty-four nylon sutures were placed in 32 children (34 eyes), of which 22 (34.4%) were removed due to suture-related complications, whereas 14 (19.7%) (P = 0.03) of the 71 Vicryl sutures placed in 32 children (38 eyes) needed suture removal at an average of 2.9 weeks with the earliest at 6 days postoperatively. The odds of Vicryl suture being removed was 0.42 times with respect to nylon. The most common reason encountered for suture removal in both the materials was sutures becoming loose (16.3%), followed by vascularization (14.1%), infiltration (1.5%), and opacification (4.4%). Conclusion: Absorbable suture such as 10-0 Vicryl is preferred over nonabsorbable suture 10-0 nylon for suturing incisions in pediatric cataract surgery, to avoid subjecting the child to repeated anesthesia

Management of a case of divergent strabismus fixus secondary to a congenital fibrosis of extraocular muscles type 2

A 17-year-old boy presented with a large exotropia with both eyes fixed in an abduction and upgaze, pupillary involvement since childhood. He had mild optic nerve hypoplasia in the right eye and situs inversus of the retinal vessels in the left optic disc. His ocular motility showed restriction of eye movements in all gazes. He was diagnosed with congenital fibrosis of extraocular muscles, type 2 (CFEOM2) and operated upon in a staged procedure with a satisfactory eye alignment using hang-back sutures in one eye and periosteal fixation in the other. This report highlights the surgical course and final outcome in this case of CFEOM2

β-Nitroacrylates: New Key Precursors of Indole-2-Carboxylates via Fischer Indole Synthesis

Indole 2-carboxylates are very important scaffolds that are widely investigated for their activities and are used as key intermediates of biologically active molecules. Herein, we report a new procedure for the preparation of this class of derivatives, via Fischer indole synthesis, starting from beta-nitroacrylates and arylhydrazines. The protocol permits the production of the title targets in satisfactory overall yields, avoids any wasteful aqueous work-up, and has with evident advantages from a sustainability point of view

beta-Nitroacrylates as key starting materials for the one-pot synthesis of densely functionalized penta-substituted anilines

The reaction of ylidene malononitriles with b-nitroacrylates, in Et3N/MeCN, affords the one-pot synthesis of a new class of penta-substituted, densely functionalized anilines in satisfactory to good overall yields. The method represents a very important improvement of the recent strategy for the preparation of anilines from conjugated nitroalkenes

Characterisation of spectroscopic and magneto-optical faraday rotation in Mn2+- doped CdS quantum dots in a silicate glass

We demonstrate the control of CdS and Mn2+-doped-CdS Q-dots in a silicate glass for magneto-optical applications. The microstructural properties of Q-dot glasses were investigated by X-Ray diffraction (XRD), Field Emission Transmission Electron Microscopy (FETEM) and the optical properties by UV–Visible–NIR and Photoluminescence (PL) spectroscopic techniques, respectively. The FETEM of the CdS QD–glass heat treated at 600oC reveals that the size of CdS and Mn2+-doped CdS Q-dots are in the range of 4-5 nm and 5-6 nm, respectively. The observed size distributions of Q-dots were in reasonable agreement with the data, derived from X-ray line broadening and estimated average Bohr radii using the UV–visible absorption data. Photoluminescence characteristics were investigated at room temperature by exciting the CdS and Mn2+-doped-CdS Q-dot glasses with a 420 nm excitation source, which yielded broad emission spectra in the visible and near-IR range (450-800 nm). We observed a red shift in the emission peak with increase in the Q-dot size, controlled by heat treatment temperature range (550-600oC). The room-temperature magneto-optical Faraday rotation measurements on Q-dots glasses were carried out using magnetic field strength up to 360 mT, and observed an increase in the value of Verdet constant, from 6.2 to 12.0°/T-cm, when comparing undoped CdS-Q-dot glass with Mn2+-doped CdS glass. The demonstration of enhanced Verdet constant in Q-dot silicate glasses with sub-Tesla field paves the path for engineering range magneto-optical devices for photonics, spintronics and sensors applications, in which the polarization of photons may be controlled with low-intensity magnetic field in optical waveguides

Quantum confinement of Bi2S3 in glass with magnetic behavior

The novel Bi2S3 quantum dots (QDs) glass nanosystems with unique magnetic properties have been investigated. The monodispersed QDs of size in the range of 3 to 15 nm were grown in the glass matrix. The optical study of these nanosystems clearly demonstrated the size quantization effect resulting in a pronounced band gap variation with QD size. The magnetic properties of the pristine glass and the Bi2S3 QD glass nanosystems were investigated by VSM and SQUID magnetometer. The pristine glass did not show any ferromagnetism while the Bi2S3 glass nanosystems showed significant and reproducible ferromagnetism. We also investigated the effect of the size of Bi2S3 QDs on the magnetic properties. The saturation magnetization for the 15 nm QD glass-nanosystem (124 memu/g) was observed to be higher as compared to the 3nm QD glass nanosystem (58.2 memu/g). The SQUID measurement gave the excellent hysteresis up to 300K. Surprisingly, the bulk Bi2S3 powder is diamagnetic in nature but Bi2S3 quantum dots glass nanosystem showed the ferromagnetic behavior for the first time. The investigated novel QD glass-nanosystem may have a potential application in spintronic devices and most importantly, this nanosystem can be fabricated in any usable shape as per the device requirement