934 research outputs found
Iridium complexes bearing a PNP ligand, favoring facile C(sp^3)–H bond cleavage
Hydrogen iodide is lost upon reaction of PNP with IrI_3, where PNP = 2,6-bis-(di-t-butylphosphinomethyl)pyridine to give crystallographically characterized Ir(PNP)*(I)_2, which reacts with H_2 to give Ir(PNP)(H)(I)_2. Ir(PNP)(Cl)_3 is relatively inert towards the intramolecular C–H activation of the tert-butyl's of the PNP ligand
Evolving power dynamics in global health: From biomedical hegemony to market dynamics in global health financing; A response to the recent commentaries
Correspondence
A new swarm intelligence information technique for improving information balancedness on the skin lesions segmentation
Methods of image processing can recognize the images of melanoma lesions border in addition to the disease compared to a skilled dermatologist. New swarm intelligence technique depends on meta-heuristic that is industrialized to resolve composite real problems which are problematic to explain by the available deterministic approaches. For an accurate detection of all segmentation and classification of skin lesions, some dealings should be measured which contain, contrast broadening, irregularity quantity, choice of most optimal features, and so into the world. The price essential for the action of progressive disease cases is identical high and the survival percentage is low. Many electronic dermoscopy classifications are advanced depend on the grouping of form, surface and dye features to facilitate premature analysis of malignance. To overcome this problematic, an effective prototypical for accurate boundary detection and arrangement is obtainable. The projected classical recovers the optimization segment of accuracy in its pre-processing stage, applying contrast improvement of lesion area compared to the contextual. In conclusion, optimized features are future fed into of artifical bee colony (ABC) segmentation. Wide-ranging researches have been supported out on four databases named as, ISBI (2016, 2017, 2018) and PH2. Also, the selection technique outclasses and successfully indifferent the dismissed features. The paper shows a different process for lesions optimal segmentation that could be functional to a variation of images with changed possessions and insufficiencies is planned with multistep pre-processing stage
The Collapse of Atomically-Cooled Primordial Haloes. I. High Lyman-Werner Backgrounds
Pristine, atomically-cooled haloes are leading contenders for the sites of
primordial quasar formation because atomic cooling triggers rapid baryon
collapse that can create 10 - 10 M black hole seeds. However,
until now no numerical simulations with a wide range of halo spins and assembly
histories have followed the collapse for the times required to form a black
hole. We have now performed cosmological simulations of baryon collapse in
atomically-cooled haloes for times that are sufficient for supermassive stars
to form and die as direct-collapse black holes (DCBHs). Our simulations reveal
that fragmentation of the accretion disk at the center of the halo after
500 kyr is nearly ubiquitous and in most cases leads to the formation of binary
or multiple supermassive stellar systems. They also confirm that rapid baryon
collapse proceeds for the times required for these stars to form DCBHs. Our
discovery raises the exciting possibility of detecting gravitational waves from
DCBH mergers with LISA and tidal disruption events in the near infrared with
the James Webb Space Telescope and ground-based telescopes in the coming
decade.Comment: 13 pages, 10 figures, submitted to MNRA
Crystal structure of Li_2B_(12)H_(12): a possible intermediate species in the decomposition of LiBH_4
The crystal structure of solvent-free Li_2B_(12)H_(12) has been determined by powder X-ray diffraction and confirmed by a combination of neutron vibrational spectroscopy and first-principles calculations. This compound is a possible intermediate in the dehydrogenation of LiBH_4, and its structural characterization is crucial for understanding the decomposition and regeneration of LiBH_4. Our results reveal that the structure of Li_2B_(12)H_(12) differs from other known alkali-metal (K, Rb, and Cs) derivatives
ARTIFICIAL NEURAL NETWORK PREDICTION OF PERFORMANCE CHARACTERISTICS OF BIOFUEL PRODUCED FROM SWEET POTATOE (IPOMOEA BATATA)
Fossil fuel depletion and the harm it causes to the environment has led to the development of alternative fuels. In this research, biofuel (ethanol) was produced and characterized from sweat potatoes. Blends of premium motor spirit with 0% (E0), 2% (E2), 4% (E4), and 10% (E10) of the produced biofuel at various percentages were separately used to power a four-stroke, single-cylinder SI engine on an engine test bed, and data of the engine performance - brake power, brake torque, brake mean effective pressure (BMEP), and the exhaust gas temperature reported in each test. The results of the physicochemical analysis revealed that the physical state of the biofuel is colorless, the viscosity at 300C, density, calorific value, and pH level are 0.9834 mPa.s, 0.85 g/cm3,19 kJ/kg, and 1.82, respectively. It was observed that an increase in ethanol in the blend increases the performance of the engine, although the BMEP at E0 gave the highest value of 0.3 bar compared to other blends. An artificial neural network (ANN) model for predicting engine performance characteristics was developed, trained, validated, and tested using the reported data. The result of the ANN model revealed that the Levenberg-Marquardt training algorithm (LMTA) with 10 hidden layer neurons offers the best fit for the features for both training, validation, testing, and overall. With the R for training equal 1, validation equal to 0.99468, testing equal to 0.90103, and overall R equal to 0.93842 as compared to the rest in terms of the number of neurons and training algorithms.
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Evaluation of pre-analytical factors affecting plasma DNA analysis.
Pre-analytical factors can significantly affect circulating cell-free DNA (cfDNA) analysis. However, there are few robust methods to rapidly assess sample quality and the impact of pre-analytical processing. To address this gap and to evaluate effects of DNA extraction methods and blood collection tubes on cfDNA yield and fragment size, we developed a multiplexed droplet digital PCR (ddPCR) assay with 5 short and 4 long amplicons targeting single copy genomic loci. Using this assay, we compared 7 cfDNA extraction kits and found cfDNA yield and fragment size vary significantly. We also compared 3 blood collection protocols using plasma samples from 23 healthy volunteers (EDTA tubes processed within 1 hour and Cell-free DNA Blood Collection Tubes processed within 24 and 72 hours) and found no significant differences in cfDNA yield, fragment size and background noise between these protocols. In 219 clinical samples, cfDNA fragments were shorter in plasma samples processed immediately after venipuncture compared to archived samples, suggesting contribution of background DNA by lysed peripheral blood cells. In summary, we have described a multiplexed ddPCR assay to assess quality of cfDNA samples prior to downstream molecular analyses and we have evaluated potential sources of pre-analytical variation in cfDNA studies
Study on Sea Surface Temperature and Chlorophyll-a concentration along the south-west coast of India
Global climate change affects the oceanographic features and distribution of marine fishes as they are poikilothermic animals. Study of oceanographic variables in a localized region is more relevant in the context of ecological responses rather than global or continental variations. In this study, time series analysis of chlorophyll-a concentration (Chl-a) in sea water and sea surface temperature (SST) was performed separately for southern, middle and northern stratum along south-west coast of India using various statistical tools. The SST showed an increasing trend along the entire south-west coast of India after the year 1995. The northern and southern stratum of south-west coast were highly influenced by rising SST, whereas middle stratum in present scenario showed stable conditions in terms of Chl-a concentration. The study provides a baseline information about changing patterns of oceanographic features along the south-west coast of India giving a better understanding of changing global climatic conditions in coastal ecosystems
Design and Analysis of Wheel Rim with Magnesium Alloys (ZK60A) by Using Solidworks and Finite Element Method
A wheel rim is a highly stressed component in an automobile that is subjected to bending and torsional loads. Because of the long life and high stresses, as well as the need for weight reduction, material and manufacturing process selection is important in rim design. There are competitions among materials andmanufacturing processes, due to cost, performance, and weight. This is a direct result of industry demand for components that are lighter, to increase performance, and cheaper to produce, while at the same time maintaining fatigue strength and other functional requirements. Lighter wheels can improve handling by reducing unsprung mass , allowing suspension to follow the terrain more closely and thus improve grip, however not all alloy wheels are lighter than their steel equivalents. Reduction in overall vehicle mass can also help to reduce fuel consumption. Nowadays cars have been using steel alloy for its wheel rim. On moving with advancements the magnesium alloy can be used for the wheel rim .In this part structural analysis of wheel rim with magnesium alloy is done and compared the results with steel alloy. As magnesium alloy (ZK60A) matches the target of lighter wheel and having many benefits compared to othermetals, it can compete with exists
An Investigation on Design and Fabrication of Electromagnetic Internal Combustion Engines
This paper reports an investigation that was carried out in a magnetic engine is according to the concept appears to be a so-called "perpetual motion machine". Here you will find its images, patent, and also you will learn information from his production and testing. The Black pointer on the disk indicates the position of piston. It is evident that with the closed shutter the piston is located stably in the upper position, and shutter renders the valuable screening of magnets, fulfilling the functions described by me. Further, with the discovery of shutter piston accomplishes reciprocating motion. The stored energy of flywheel continues to move piston to the upper position. Work: the displacements of the shutter = of 0,444 the displacement of piston = 1,251
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