Ultrabright Linearly Polarized Photon Generation from a Nitrogen Vacancy Center in a Nanocube Dimer Antenna

We demonstrate an exceptionally bright photon source based on a single nitrogen- vacancy center (NV-center) in a nanodiamond (ND), placed in the nanoscale gap between two monocrystalline silver cubes in a dimer configuration. The system is operated near saturation at a stable photon rate of 850 kcps, while we further achieve strongly polarized emission and high single photon purity, evident by the measured auto-correlation with a g(2)(0)-value of 0.08. These photon source features are key parameters for quantum technological applications, such as secure communication based on quantum key distribution. The cube antenna is assembled with an atomic force microscope, which allows us to predetermine the dipole orientation of the NV-center and optimize cube positioning accordingly, while also tracking the evolution of emission parameters from isolated ND to the 1 and 2 cube configuration. The experiment is well described by finite element modelling, assuming an instrinsic quantum efficiency of 0.35. We attribute the large photon rate of the assembled photon source, to increased quantum efficiency of the NV-center and high antenna efficiency

Optimization of process parameters for enhanced biodegradation of acid red 119 by Bacillus thuringiensis SRDD

Developed Bacillus thuringiensis SRDD showed degradation of C.I. Acid red 119 and growth under the extremecondition of temperature 70°C, pH 3-8, heavy metals concentration of 0.8 mM, NaCl up to 900 mM and 1000 ppm dye. Cottonseed, caster cake and corn cake powders were found to be better and cheaper nutrient supplements for the Bacillus thuringiensisSRDD for biodegradation as compared to molasses. After development of the culture and the process, more than99% degradation was achieved in less than 2 hrs of contact time even on 18th cycles of addition of 100 ppm AR-119 dye. Thedeveloped process showed AR-119 biodegradation rate as high as 220 mg L-1 h-1, which is found to be 130 times more ascompared to the reported data. U.V., FTIR, TLC and HPLC analysis data confirmed biodegradation ability of the Bacillusthuringiensis for AR-119

Hawking Fluxes, Back reaction and Covariant Anomalies

Starting from the chiral covariant effective action approach of Banerjee and Kulkarni [Phys. Lett. B 659, 827(2008)], we provide a derivation of the Hawking radiation from a charged black hole in the presence of gravitational back reaction. The modified expressions for charge and energy flux, due to effect of one loop back reaction are obtained.Comment: 6 pages, no figures, minor changes and references added, to appear in Classical and Quantum Gravit

Role of the σ\sigma-resonance in determining the convergence of chiral perturbation theory

The dimensionless parameter $\xi = M_\pi^2/(16 \pi^2 F_\pi^2)$, where $F_\pi$ is the pion decay constant and $M_\pi$ is the pion mass, is expected to control the convergence of chiral perturbation theory applicable to QCD. Here we demonstrate that a strongly coupled lattice gauge theory model with the same symmetries as two-flavor QCD but with a much lighter $\sigma$-resonance is different. Our model allows us to study efficiently the convergence of chiral perturbation theory as a function of $\xi$. We first confirm that the leading low energy constants appearing in the chiral Lagrangian are the same when calculated from the $p$-regime and the $\epsilon$-regime as expected. However, $\xi \lesssim 0.002$ is necessary before 1-loop chiral perturbation theory predicts the data within 1%. For $\xi > 0.0035$ the data begin to deviate dramatically from 1-loop chiral perturbation theory predictions. We argue that this qualitative change is due to the presence of a light $\sigma$-resonance in our model. Our findings may be useful for lattice QCD studies.Comment: 5 pages, 6 figures, revtex forma

Assessment of Pesticide Use in Major Vegetables From Farmers\u27 Perception and Knowledge in Dhading District, Nepal

A field study was carried out to assess the pesticide use status in major vegetable crops from farmers\u27 perception and knowledge in Dhading, Nepal in 2019. Field study was carried with 100 commercial farmer\u27s using semi-structure questionnaire by face to face interview. This study was analyzed by categorization of farmers into small holder (51) and large holder (49) groups on the basis of mean area of vegetable cultivation (6.48 ropani). The highest amount of pesticides is needed in tomato in both large holders and small holders according to the farmer\u27s experience. Among the study farmer\u27s, 41% of them spray the pesticides by making a cocktail or mixed method and 56%  follow the waiting period of 3-5 days in both of the cases. A significant positive correlation was found at 5% level of significance between the knowledge and practice pattern of waiting period of the pesticides and negative correlation was found between the Personal Protective equipment score and health hazard score. Headache was the major health hazards faced by the farmers which was higher in small holders (66.7%) as compared to the large holders (46.9%). Mask was the most used PPE by the farmer\u27s i.e. by 83% in overall. Fourty three percent of the farmer\u27s throw the pesticide containers in secret place after using of it.The use of PPE was seen lower in small holders as compared to the large holders. This study reveals the necessities of suitable program and policies regarding the knowledge, safe handling and use of pesticide among the farmer\u27s level

Solar Light Induced Photo Catalytic Properties of α-Fe2O3 Nanoparticles for Degradation of Methylene Blue Dye

The present work describes α-Fe2O3 nanoparticles are prepared by chemical displacement method using CTAB as a stabilizing agent. Glutaric acid as fuel and metal salt like ferrous sulphate was used in synthesis. The structural, morphological, metal percentage and optical properties of as synthesized nanoparticles are investigated by using x-ray diffraction (XRD), UV-Visible Spectra; field emission gun Scanning electron microscopy (FEG-SEM) with EDS, Fourier transforms infrared spectroscopy (FTIR), High-resolution Transmission electron microscopy (HR-TEM) and Photoluminescence Spectroscopy (PL). The photocatalytic degradation of Methylene Blue dye was measured by visible absorption spectroscopy. To obtain the most favorable conditions for degradation of MB dye, the effect of various experimental parameters, i.e., pH, amount of nanoparticles, concentration of dye and light intensity on the rate of reaction was studied. A tentative mechanism for the photocatalytic degradation of Methylene Blue was proposed. Photocatalytic degradation of Methylene Blue dye followed pseudo first-order kinetics. It was found that the dye degradation gave the best results at a pH of 6.0, and using a 70 mW•cm–2 light intensity with 0.3 g of α-Fe2O3 nanoparticles. At room temperature, the photocatalytic degradation of Methylene Blue dye was observed about 92.3%

Calcaneal fractures: a management dilemma-minimally invasive approach for intra and extra articular calcaneal fractures

Background: Calcaneal fractures which constitutes 2% of total fractures are frequent and very debilitating if not treated properly. Calcaneal fractures generally affect younger population leading to significant man-days loss(around 2-5 years3) and in-turn leading significant economic burden on the society. The goal of treatment for calcaneal fractures is elimination of pain and restoration of normal foot shape, biomechanics, and walking ability. Wound related complications are common with open surgeries. After open reduction internal fixation with perimeter plates for displaced calcaneal fractures, wound edge necrosis is commonly observed with the extended lateral approach. Because of such high incidence of wound complications in open reduction of calcaneum fractures, minimally invasive approach takes priority over open reduction of these fractures.Methods: The study aimed to evaluate the results of minimally invasive approach for calcaneal fractures. To reduce the operative complications, 30 patients were treated with minimally invasive methods in both extra articular and intra-articular calcaneal fractures and the results were evaluated. All patients were evaluated clinically , functionally and radiologically 3D- CT reconstruction images.Results: All cases were followed up for 2 years at specified intervals. The outcome measures were evaluated by AOFAS scores10 with excellent result in 13 cases and good to fair results in the rest. Operated patients had no wound infection, no skin necrosis, 5 patients had mild subtalar arthrosis and 3 patients complained slight difficulty in wearing shoes. None of them have any gait abnormalities.Conclusions: Our study suggests that the minimally invasive methods will reduce the operative complication rates. The minimally invasive surgical intervention in an expert hand can yield better results with less complication rates

On the Sign Problem in the Hirsch-Fye Algorithm for Impurity Problems

We show that there is no fermion sign problem in the Hirsch and Fye algorithm for the single-impurity Anderson model. Beyond the particle-hole symmetric case for which a simple proof exists, this has been known only empirically. Here we prove the nonexistence of a sign problem for the general case by showing that each spin trace for a given Ising configuration is separately positive. We further use this insight to analyze under what conditions orbitally degenerate Anderson models or the two-impurity Anderson model develop a sign.Comment: 2 pages, no figure; published versio

Visualization of mRNA translation in living cells

The role of mRNA localization is presumably to effect cell asymmetry by synthesizing proteins in specific cellular compartments. However, protein synthesis has never been directly demonstrated at the sites of mRNA localization. To address this, we developed a live cell method for imaging translation of β-actin mRNA. Constructs coding for β-actin, containing tetracysteine motifs, were transfected into C2C12 cells, and sites of nascent polypeptide chains were detected using the biarsenial dyes FlAsH and ReAsH, a technique we call translation site imaging. These sites colocalized with β-actin mRNA at the leading edge of motile myoblasts, confirming that they were translating. β-Actin mRNA lacking the sequence (zipcode) that localizes the mRNA to the cell periphery, eliminated the translation there. A pulse-chase experiment on living cells showed that the recently synthesized protein correlated spatially with the sites of its translation. Additionally, localization of β-actin mRNA and translation activity was enhanced at cell contacts and facilitated the formation of intercellular junctions