Higher-order nonlinear electromechanical effects in wurtzite GaN/AlN quantum dots

As we demonstrated earlier, conventional mathematical models based on linear approximations may be inadequate in the analysis of properties of low-dimensional nanostructures and band structure calculations. In this work, a general three-dimensional axisymmetric coupled electromechanical model accounting for lattice mismatch, spontaneous polarization and higher-order nonlinear electrostriction effects has been applied to analyze properties of GaN/AlN quantum dots coupled with wetting layer. The generalized model that accounts for five independent electrostriction coefficients has been solved numerically via a finite-element implementation. The results, exemplified for truncated conical GaN/AlN quantum dots, demonstrate that the effect of nonlinear electrostriction in GaN/AlN nanoheterostructure quantum dots could be significant. In particular, the influence of nonlinear electromechanical effects on optoelectronic properties is highlighted by the results on band structure calculations based on a multiband effective mass theory

Biochemically Induced Variations During Some Phenological Stages in Thompson Seedless Grapevines Grafted on Different Rootstocks

Phenological variation in Thompson Seedless grapevines grafted on different rootstocks and own rootedvines was assessed for two consecutive years and the reasons for such variations were studied throughbiochemical analysis. Uniform and early bud sprouting was recorded in the vines grafted on 110Rrootstock and on own roots, which was attributed to increased peroxidase activity and protein content inthe buds before bud burst. Increased fruitfulness on 110R rootstock and own rooted vines was attributedto the increased phosphorus and protein content of those vines and reduced vegetative vigour measuredin terms of shoot length, cane diameter and pruned biomass. Thompson Seedless grafted on Dogridgerootstock recorded the highest nitrogen content, increased shoot length, cane diameter and increasedpruned biomass attributing to reduced fruitfulness. The highest concentration of phenolic compoundsand amino acids was recorded in the fruits produced on 110R rootstock, while it was least on St. Georgeand own roots. Significant variation in the accumulation pattern of amino acids (especially proline andarginine) was observed, with the least proline/arginine ratio recorded on 110R rootstocks at the time ofharvest, indicating the variation in the days taken for fruit ripening on different rootstocks

Nanocrystalline MoBi2Se5 Ternary Mixed Metal Chalcogenide Thin-films for Solar Cell Applications

AbstractOptical, structural, morphological and photoelectrochemical properties were investigated of ternary MoBi2Se5 thin film prepared by simple arrested precipitation technique (APT). The precursors used were molybdenum, bismuth, triethanolamine complexes (TEA) along with organic additives. Ammonium molybdate, Bismuth nitrate and sodium selenosulphite were used as sources of Mo4+, Bi3+ and Se2− ions. The optical band gap of thin film was estimated to be 1.78eV. X-ray diffraction data reveals that the grown MoBi2Se5 thin film was highly nanocrystalline with orthorhombic structure. Scanning electron microscopy studies reveal that porous layer having elongated fibrous morphology with high surface area. The film was obtained with a well-defined composition, very close to the expected one. PEC application of prepared thin film were checked in Sulphide / Poly sulphide electrolyte which revealed that MoBi2Se5 thin film deposited on FTO coated glass exhibited maximum values of fill factor (FF) and conversion efficiency (η) with n type semiconductor nature

Structural and Optoelectronic Properties of Nanocrystalline CdTe Thin Films Synthesized by Using SILAR Technique

Nanocrystalline CdTe thin films were deposited on amorphous glass substrate using successive ionic layer adsorption and reaction (SILAR) technique. The films are characterized using XRD, FESEM, optical absorption techniques and electrical resistivity measurement. The XRD pattern revealed that nanocrystalline CdTe thin films has mixed phase of hexagonal and cubic crystal structure. The calculated crystallite size from the XRD measurement was found to be in the range of 9-12 nm. FESEM image showed uniform deposition of the material over entire glass substrate and film consists of interconnected spherical grains of nanometer size. Compositional analysis showed that the nanocrystalline CdTe thin film becomes cadmium deficient and tellurium richer. The optical absorption studies show that the films have a direct band gap of 1.51 eV. The room temperature resistivity of the synthesized nanocrystalline CdTe films measured by two probe method was found to 6.64 × 104 Ω.cm

Room Temperature Synthesized TiO2/Bi2Se3 Bilayer Thin Film by Simple Chemical Route: Study the Effect of Deposition Time of Bismuth Selenide on Physical Properties of Film

Simple chemical route namely Chemical Bath Deposition (CBD) has been successfully employed for deposition of Bismuth Selenide (Bi2Se3) nanoparticles on porous TiO2 at room temperature. The effect of deposition time of Bi2Se3 on structural, surface morphological and optical properties of TiO2/Bi2Se3 bilayer film has been systematically investigated. X-ray diffraction and energy dispersive X-ray spectra analysis was confirmed the Bi2Se3 nanoparticles are of effectively deposited on anatase TiO2 film. Field Emission Scanning Electron Microscopy (FESEM) images shows the TiO2 film uniformly covers by Bi2Se3 nanoparticles. Optical absorption spectrum is reflecting the considerable enhancement in absorption of visible light with increasing deposition time of Bi2Se3 on TiO2 thin film

Global surveillance of cancer survival 1995-2009: analysis of individual data for 25,676,887 patients from 279 population-based registries in 67 countries (CONCORD-2)

BACKGROUND: Worldwide data for cancer survival are scarce. We aimed to initiate worldwide surveillance of cancer survival by central analysis of population-based registry data, as a metric of the effectiveness of health systems, and to inform global policy on cancer control. METHODS: Individual tumour records were submitted by 279 population-based cancer registries in 67 countries for 25·7 million adults (age 15-99 years) and 75,000 children (age 0-14 years) diagnosed with cancer during 1995-2009 and followed up to Dec 31, 2009, or later. We looked at cancers of the stomach, colon, rectum, liver, lung, breast (women), cervix, ovary, and prostate in adults, and adult and childhood leukaemia. Standardised quality control procedures were applied; errors were corrected by the registry concerned. We estimated 5-year net survival, adjusted for background mortality in every country or region by age (single year), sex, and calendar year, and by race or ethnic origin in some countries. Estimates were age-standardised with the International Cancer Survival Standard weights. FINDINGS: 5-year survival from colon, rectal, and breast cancers has increased steadily in most developed countries. For patients diagnosed during 2005-09, survival for colon and rectal cancer reached 60% or more in 22 countries around the world; for breast cancer, 5-year survival rose to 85% or higher in 17 countries worldwide. Liver and lung cancer remain lethal in all nations: for both cancers, 5-year survival is below 20% everywhere in Europe, in the range 15-19% in North America, and as low as 7-9% in Mongolia and Thailand. Striking rises in 5-year survival from prostate cancer have occurred in many countries: survival rose by 10-20% between 1995-99 and 2005-09 in 22 countries in South America, Asia, and Europe, but survival still varies widely around the world, from less than 60% in Bulgaria and Thailand to 95% or more in Brazil, Puerto Rico, and the USA. For cervical cancer, national estimates of 5-year survival range from less than 50% to more than 70%; regional variations are much wider, and improvements between 1995-99 and 2005-09 have generally been slight. For women diagnosed with ovarian cancer in 2005-09, 5-year survival was 40% or higher only in Ecuador, the USA, and 17 countries in Asia and Europe. 5-year survival for stomach cancer in 2005-09 was high (54-58%) in Japan and South Korea, compared with less than 40% in other countries. By contrast, 5-year survival from adult leukaemia in Japan and South Korea (18-23%) is lower than in most other countries. 5-year survival from childhood acute lymphoblastic leukaemia is less than 60% in several countries, but as high as 90% in Canada and four European countries, which suggests major deficiencies in the management of a largely curable disease. INTERPRETATION: International comparison of survival trends reveals very wide differences that are likely to be attributable to differences in access to early diagnosis and optimum treatment. Continuous worldwide surveillance of cancer survival should become an indispensable source of information for cancer patients and researchers and a stimulus for politicians to improve health policy and health-care systems

Search for gravitational waves from Scorpius X-1 in the second Advanced LIGO observing run with an improved hidden Markov model

We present results from a semicoherent search for continuous gravitational waves from the low-mass x-ray binary Scorpius X-1, using a hidden Markov model (HMM) to track spin wandering. This search improves on previous HMM-based searches of LIGO data by using an improved frequency domain matched filter, the J-statistic, and by analyzing data from Advanced LIGO's second observing run. In the frequency range searched, from 60 to 650 Hz, we find no evidence of gravitational radiation. At 194.6 Hz, the most sensitive search frequency, we report an upper limit on gravitational wave strain (at 95% confidence) of h095%=3.47×10-25 when marginalizing over source inclination angle. This is the most sensitive search for Scorpius X-1, to date, that is specifically designed to be robust in the presence of spin wandering. © 2019 American Physical Society

Search for Tensor, Vector, and Scalar Polarizations in the Stochastic Gravitational-Wave Background

The detection of gravitational waves with Advanced LIGO and Advanced Virgo has enabled novel tests of general relativity, including direct study of the polarization of gravitational waves. While general relativity allows for only two tensor gravitational-wave polarizations, general metric theories can additionally predict two vector and two scalar polarizations. The polarization of gravitational waves is encoded in the spectral shape of the stochastic gravitational-wave background, formed by the superposition of cosmological and individually unresolved astrophysical sources. Using data recorded by Advanced LIGO during its first observing run, we search for a stochastic background of generically polarized gravitational waves. We find no evidence for a background of any polarization, and place the first direct bounds on the contributions of vector and scalar polarizations to the stochastic background. Under log-uniform priors for the energy in each polarization, we limit the energy densities of tensor, vector, and scalar modes at 95% credibility to Ω0T<5.58×10-8, Ω0V<6.35×10-8, and Ω0S<1.08×10-7 at a reference frequency f0=25 Hz. © 2018 American Physical Society

Erratum: "A Gravitational-wave Measurement of the Hubble Constant Following the Second Observing Run of Advanced LIGO and Virgo" (2021, ApJ, 909, 218)

[no abstract available

Large expert-curated database for benchmarking document similarity detection in biomedical literature search

Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency-Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical research.Peer reviewe