A simple and coherent approach to fluid mechanics is presented using a proper formalism of geometric algebra. The analogy between the equations of electromagnetism and fluid mechanics provides ...reinterpretation of the equations for two constituent (vorticity and the Lamb vector) fields. Identifying certain quantities as the source fields, the guiding Navier–Stokes (NS) equations of fluid mechanics can be formulated as a set of four geometrically distinct field equations, resembling exactly the Maxwell equations for the constituent magnetic and electric fields. The same set of equations works for all the cases of compressible, incompressible, viscous and the inviscid fluid motions with appropriately modified source terms. The analogy is completed by defining the combined ‘fluidomechanic’ bivector field in space–time algebra and further extended to the fluidic analogue of the Poynting theorem, Poynting vector and Lorentz force.
The notion of uncertainty in the description of a physical system has assumed prodigious importance in the development of quantum theory. Overcoming the early misunderstanding and confusion, the ...concept grew continuously and still remains an active and fertile research field. Curious new insights and correlations are gained and developed in the process with the introduction of new 'measures' of uncertainty or indeterminacy and the development of quantum measurement theory. In this article we intend to reach a fairly uptodate status report of this yet unfurling concept and its interrelation with some distinctive quantum features like nonlocality, steering and entanglement/inseparability. Some recent controversies are discussed and the grey areas are mentioned.
Cyclic oxoammonium salts and DMSO are known as important reagents for their diverse and unique reactivity. In the present work, we have studied the reaction of six- and five-membered oxoammonium ...salts with DMSO. The reaction includes ∼100% selective transfer of the O atom from the >N+O group to the S atom of DMSO and structural rearrangement of the remaining cationic framework, leading to the formation of hydrolytically unstable iminium salts. The logarithms of the bimolecular rate constants k of the reaction correlated linearly with the reduction potentials E >N+O/>NO• , a relationship known for other electrophile–nucleophile combinations. The kinetic data and results of the DFT calculations allow for the suggestion that the studied process proceeds via the prereactive charge-transfer complex >N+O···S (O)Me2 and its direct concerted rearrangement to the iminium salts. An alternative mechanism that includes intermediate steps with discrete nitrenium cations can be ruled out on the basis of product analysis and DFT computations. The obtained results allow a deeper understanding of the redox chemistry of a pair of nitroxide radicals-oxoammonium cations.
The generic term asbestos refers to a group of crystalline mineral silicates that occur naturally in various forms. Because of their properties of strength, heat and electrical resistance and their ...ability to withstand corrosion by acids and sea water, asbestos was used extensively both in the UK and worldwide.
To provide a historical perspective of this ubiquitous occupational hazard, consider the key changes in UK legislation aimed at improving the management of this occupational health risk and describe the evidence from the scientific literature concerning asbestos and disease.
Original articles, reviews (including reference textbooks) and scientific literature in PubMed and other principal medical science databases, 1960-2014, were searched. Publications by regulatory agencies and by governmental organizations were also considered and included where relevant.
Asbestos remains the biggest cause of cancer deaths worldwide. For malignant mesothelioma deaths alone, it is estimated that in the UK, between 2015 and 2020, the number of cases will peak at 2500 cases annually. It is not clear whether there is a safe level of asbestos fibres in air. Evidence for the efficacy of health surveillance is lacking.
Although the use of asbestos was banned in the UK in 1985 (amosite and crocidolite) and 1999 (chrysotile), it remains a significant occupational risk factor for work-related morbidity and mortality, causing both benign and malignant diseases, often with long latency. Further research is needed regarding exposure levels and health surveillance.
Translational control targeting the initiation phase is central to the regulation of gene expression. Understanding all of its aspects requires substantial technological advancements. Here we ...modified yeast translation complex profile sequencing (TCP-seq), related to ribosome profiling, and adapted it for mammalian cells. Human TCP-seq, capable of capturing footprints of 40S subunits (40Ss) in addition to 80S ribosomes (80Ss), revealed that mammalian and yeast 40Ss distribute similarly across 5′TRs, indicating considerable evolutionary conservation. We further developed yeast and human selective TCP-seq (Sel-TCP-seq), enabling selection of 40Ss and 80Ss associated with immuno-targeted factors. Sel-TCP-seq demonstrated that eIF2 and eIF3 travel along 5′ UTRs with scanning 40Ss to successively dissociate upon AUG recognition; notably, a proportion of eIF3 lingers on during the initial elongation cycles. Highlighting Sel-TCP-seq versatility, we also identified four initiating 48S conformational intermediates, provided novel insights into ATF4 and GCN4 mRNA translational control, and demonstrated co-translational assembly of initiation factor complexes.
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•Selective TCP-seq dissects translation mechanisms in mammals and yeast•40S-bound eIF2 and eIF3 traverse 5′ UTRs and sequentially dissociate at AUG codons•AUG recognition involves four conformational intermediates of the 48S PIC•Initiation factors can assemble co-translationally into higher-order complexes
Changing environmental conditions require reprogramming of gene expression for cells to adapt and survive. Translational control is central to this complex response. Wagner et al. developed assays capturing footprints of mRNA-bound ribosomal complexes associated with selected translation-promoting factors to uncover mechanisms underlying translation in the context of its regulatory potential.
Cobalt (Co) nanoparticles (NPs) were produced by a simple, one step hydrothermal method with the capping of oleic acid. Intrinsic structural, physiochemical and magnetic properties of Co NPs were ...investigated and demonstrated their applicability in biomedicine. X-ray diffraction, Raman spectroscopy and infrared (IR) spectroscopic studies confirm the single phase Co NPs with a high structural quality. The IR data revealed the capping of oleic acid via monodentate interaction. Small angle scattering studies suggest the existence of sticky hard sphere type of interaction among the Co NPs because of magnetic interaction which is further evidenced by electron microscopy imaging analyses. The Co NPs exhibit a ferromagnetic character over a wide range of temperature (20–300K). The temperature dependence of magnetic parameters namely, saturation magnetization, remanent magnetization, coercivity and reduced remanent magnetization were determined and correlated with structure of Co NPs. The Cytotoxicity studies demonstrate that these Co NPs exhibit the mild anti-proliferative character against the cancer cells (cisplatin resistant ovarian cancer (A2780/CP70)) and safe nature towards the normal cells. Haemolytic behavior of human red blood cells (RBC) revealed (<5%) haemolysis signifying the compatibility of Co NPs with human RBC which is an essential feature in vivo biomedical applications without creating any harmful effects in the human blood stream.
Flood events are the most frequent cause of damage to infrastructure compared to any other natural hazard, and global changes (climate, socioeconomic, technological) are likely to increase this ...damage. Transportation infrastructure systems are responsible for moving people, goods and services, and ensuring connection within and among urban areas. A failed link in these systems can impact the community by threatening evacuation capability, recovery operations and the overall economy. Bridges are critical links in the wider urban system since they are associated with little redundancy and a high (re)construction cost. Riverine bridges are particularly prone to failure during flood events; in fact, the risks to bridges from high river flows and erosion have been recognized as crucial at global level. The interaction of flow, structure and network is complex, and not fully understood. This study aims to establish a rigorous, multiphysics modeling approach for the assessment of the hydrodynamic forces impacting inundated bridges, and the subsequent structural response, while understanding the consequences of such impact on the surrounding network. The objectives of this study are to model hydrodynamic forces as demand on the bridge structure, to advance a performance evaluation of the structure under the modeled loading, and to assess the overall impact at systemic level. The flood-prone city of Carlisle (UK) is used as a case study and a proof of concept. Implications of the hydrodynamic impact on the performance and functionality of the surrounding transport network are discussed. This research will help to fill the gap between current guidance for design and assessment of bridges within the overall transport system.
Stability and electronic properties of small Pdn clusters (n = 1–5), adsorbed on different types of double vacancy (DV) defect graphene sheets are thoroughly investigated by both density functional ...theory (DFT) and molecular dynamics (MD). Defect bridge sites of DV(555-777) defect graphene sheet are identified to be the most favorable for Pd4 cluster adsorption. MD calculations, performed using a canonical ensemble, showed this system to be highly stable up to 800 K. Much better hybridization between C 2p and Pd 4d and 5s orbitals near Fermi level as well as higher charge transfer to graphene sheet was found to be the governing reason for enhanced stability of Pd4 cluster on DV(555-777) defect site. Comparative analysis of H2 storage on Pd4 cluster adsorbed pristine and DV(555-777) defect graphene sheet showed, while adsorption energy/H2 molecule for both cases lie well within desirable energy window for a hydrogen storage media, the later is much more efficient energetically as distorted in plane sp2 hybridization reduces the saturations of C–C bonds in the defect regions, making more electron density available for bonding; which leads to higher net charge gain of Pd4 cluster and higher charge sharing with H2 molecule.
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► DFT calculations reveal excellent stability of Pd4 clusters on defect graphene. ► Pd4 cluster distribution on DV(555-777) defect graphene is uniform and immobile. ► Pd4-DV graphene adsorbs upto five H2 with −0.639 eV adsorption energy per H2.
In this letter, we propose a novel method of refining the time-domain synthesis of individual source estimates from a single channel mixture. Employing a closed-loop architecture, the algorithm ...refines the synthesis of each source by iteratively estimating the phase of the sources, given the estimates of the source magnitude spectra and a single channel time-domain mixture. The performance of the algorithm is evaluated for harmonic musical mixtures, and considerable improvements to the synthesized estimates are obtained relative to phase binary masking, given accurate source magnitude spectra.
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