Modelling and simulation of fluid flow through a circular cylinder with high reynolds number: a COMSOL multiphysics study

In this study, we intend to investigate the steady-state and laminar �ow of a viscous �uid through a circular cylinder �xed between two parallel plates keeping the aspect ratio of 1 : 5 from cylinder radius to height of the channel. �e two-dimensional, in�compressible �uid �ow problem has been simulated using COMSOL Multiphysics 5.4 which implements �nite element’s procedure. �e �ow pattern will be investigated by using the Reynolds number from 100 to 1000. �e reattachment length formed at the back of the cylinder and drag force when the �uid comes to strike with the front surface of the cylinder is expressed in terms of Reynolds numbers. We propose to calculate the velocity and the pressure before and after the cylinder. For this purpose, two�line graphs before and after the cylinder will be drawn to check the impact of cylinder on both velocity and pressure. It was found that the percentage change in the velocity as well as pressure before to after the cylinder is changing their behaviours at Re � 700. �e study is important because the empirical equations between the vortex’s lengths formed along the cylinder using the linear regression process obtained in this study may be used for future implementatio

A photoelectrochemical-thermoelectric device for semi-artificial CO2 fixation employing full solar spectrum utilization

Funding Information: We acknowledge support from the Leverhulme Trust for an Early Career Fellowship ( ECF-2021-072 to S.J.C. and ECF-2022-392 to L.S.), the Isaac Newton Trust (20.08(r) to S.J.C. and 22.08(c) to L.S.), the Cambridge Trust ( Cambridge Thai Foundation Award to C.P.), a Trinity-Henry Barlow Scholarship (to C.P.), the Cambridge Philosophical Society (to C.P.), the Program Management Unit for Human Resources and Institutional Development, Research, and Innovation ( B16F640166 to C.P.), the EPSRC Graphene CDT ( EP/L016087/1 to V.M.B.), St John\u2019s College Cambridge ( Title A Research Fellowship to V.A.), the European Research Council (ERC) for a Consolidator Grant (MatEnSAP, 682833 to E.R.) and a UKRI/ERC Advanced Grant ( EP/X030563/1 to E.R.), the Funda\u00E7\u00E3o para a Ci\u00EAncia e a Tecnologia (FCT, Portugal) for fellowship DFA/BD/7897/2020 (to R.R.M.), grant PTDC/BII-BBF/2050/2020 (to I.A.C.P.) and MOSTMICRO-ITQB unit ( UIDB/04612/2020 and UIDP/04612/2020 ), and Associated Laboratory LS4FUTURE ( LA/P/0087/2020 ). Funding Information: We acknowledge support from the Leverhulme Trust for an Early Career Fellowship (ECF-2021-072 to S.J.C. and ECF-2022-392 to L.S.), the Isaac Newton Trust (20.08(r) to S.J.C. and 22.08(c) to L.S.), the Cambridge Trust (Cambridge Thai Foundation Award to C.P.), a Trinity-Henry Barlow Scholarship (to C.P.), the Cambridge Philosophical Society (to C.P.), the Program Management Unit for Human Resources and Institutional Development, Research, and Innovation (B16F640166 to C.P.), the EPSRC Graphene CDT (EP/L016087/1 to V.M.B.), St John's College Cambridge (Title A Research Fellowship to V.A.), the European Research Council (ERC) for a Consolidator Grant (MatEnSAP, 682833 to E.R.) and a UKRI/ERC Advanced Grant (EP/X030563/1 to E.R.), the Funda\u00E7\u00E3o para a Ci\u00EAncia e a Tecnologia (FCT, Portugal) for fellowship DFA/BD/7897/2020 (to R.R.M.), grant PTDC/BII-BBF/2050/2020 (to I.A.C.P.) and MOSTMICRO-ITQB unit (UIDB/04612/2020 and UIDP/04612/2020), and Associated Laboratory LS4FUTURE (LA/P/0087/2020). Conceptualization, S.J.C. C.P. and E.R; investigation, S.J.C. C.P. V.M.B. L.S. and R.R.M.; resources, R.R.M. and I.A.C.P.; formal analysis, S.J.C. C.P. V.M.B. L.S. R.R.M.; writing \u2013 original draft, S.J.C. C.P. and E.R.; writing \u2013 review & editing, V.A. L.S. R.R.M. and I.A.C.P.; visualization, S.J.C. C.P. V.A. and L.S.; supervision, E.R.; funding acquisition, S.J.C. I.A.C.P. and E.R. The authors declare no competing interests. Publisher Copyright: © 2024 The Author(s)Natural and most artificial photosynthesis systems utilize a pair of light absorbers to convert CO2 into sugar and fuels. However, much of the solar energy is lost as unabsorbed (mainly infrared [IR]) irradiation and thermalization heat, limiting efficiency. Here, we show that a thermoelectric (TE) generator can harvest this waste heat toward unassisted CO2 reduction with a water-oxidizing BiVO4 photoanode upon irradiation by concentrated sunlight. We employ the enzyme formate dehydrogenase (FDh) as a model catalyst to achieve selective CO2-to-formate conversion with minimal overpotential. The catalytic activity of the FDh cathode and BiVO4 photoanode benefits from solar heating, enabling the bias-free semi-artificial FDh-TE-BiVO4 device to attain a 97% faradic yield for formate production under 3-sun irradiation. This work demonstrates unassisted CO2 reduction coupled to water oxidation using only a single semiconductor light absorber through effective waste heat utilization, overcoming the challenges of (non-)complementary light absorption and IR losses in both natural and artificial photosynthesis.proofinpres

In vitro activity of rhinacanthin analogues against drug resistant Plasmodium falciparum isolates from Northeast Thailand

Background New anti-malarial drugs are needed urgently to address the increasing challenges of drug-resistant falciparum malaria. Two rhinacanthin analogues containing a naphthoquinone moiety resembling atovaquone showed promising in-vitro activity against a P. falciparum laboratory reference strain (K1). The anti-malarial activity of these 2 compounds was further evaluated for P. falciparum field isolates from an area of multi-drug resistance in Northeast Thailand. Methods Using a pLDH enzyme-linked immunosorbent assay, four P. falciparum isolates from Northeast Thailand in 2018 were tested for in vitro sensitivity to the two synthetic rhinacanthin analogues 1 and 2 as well as established anti-malarials. Mutations in the P. falciparum cytochrome b gene, a marker for atovaquone (ATQ) resistance, were genotyped in all four field isolates as well as 100 other clinical isolates from the same area using PCR-artificial Restriction Fragment Length Polymorphisms. Pfkelch13 mutations, a marker for artemisinin (ART) resistance, were also examined in all isolates. Results The 50% inhibitory concentrations (IC50) of P. falciparum field isolates for rhinacanthin analogue 1 was 321.9–791.1 nM (median = 403.1 nM). Parasites were more sensitive to analogue 2: IC50 48.6–63.3 nM (median = 52.2 nM). Similar results were obtained against P. falciparum reference laboratory strains 3D7 and W2. The ART-resistant IPC-5202 laboratory strain was more sensitive to these compounds with a median IC50 45.9 and 3.3 nM for rhinacanthin analogues 1 and 2, respectively. The ATQ-resistant C2B laboratory strain showed high-grade resistance towards both compounds (IC50 > 15,000 nM), and there was a strong positive correlation between the IC50 values for these compounds and ATQ (r = 0.83–0.97, P P. falciparum cytochrome b mutations observed in the field isolates, indicating that P. falciparum isolates from this area remained ATQ-sensitive. Pfkelch13 mutations and the ring-stage survival assay confirmed that most isolates were resistant to ART. Conclusions Two rhinacanthin analogues showed parasiticidal activity against multi-drug resistant P. falciparum isolates, although less potent than ATQ. Rhinacanthin analogue 2 was more potent than analogue 1, and can be a lead compound for further optimization as an anti-malarial in areas with multidrug resistance

Les Houches 2013: Physics at TeV Colliders: Standard Model Working Group Report

This Report summarizes the proceedings of the 2013 Les Houches workshop on Physics at TeV Colliders. Session 1 dealt primarily with (1) the techniques for calculating standard model multi-leg NLO and NNLO QCD and NLO EW cross sections and (2) the comparison of those cross sections with LHC data from Run 1, and projections for future measurements in Run 2.Comment: Proceedings of the Standard Model Working Group of the 2013 Les Houches Workshop, Physics at TeV Colliders, Les houches 3-21 June 2013. 200 page

Search for the standard model Higgs boson in the H to ZZ to 2l 2nu channel in pp collisions at sqrt(s) = 7 TeV

A search for the standard model Higgs boson in the H to ZZ to 2l 2nu decay channel, where l = e or mu, in pp collisions at a center-of-mass energy of 7 TeV is presented. The data were collected at the LHC, with the CMS detector, and correspond to an integrated luminosity of 4.6 inverse femtobarns. No significant excess is observed above the background expectation, and upper limits are set on the Higgs boson production cross section. The presence of the standard model Higgs boson with a mass in the 270-440 GeV range is excluded at 95% confidence level.Comment: Submitted to JHE

Search for anomalous t t-bar production in the highly-boosted all-hadronic final state

A search is presented for a massive particle, generically referred to as a Z', decaying into a t t-bar pair. The search focuses on Z' resonances that are sufficiently massive to produce highly Lorentz-boosted top quarks, which yield collimated decay products that are partially or fully merged into single jets. The analysis uses new methods to analyze jet substructure, providing suppression of the non-top multijet backgrounds. The analysis is based on a data sample of proton-proton collisions at a center-of-mass energy of 7 TeV, corresponding to an integrated luminosity of 5 inverse femtobarns. Upper limits in the range of 1 pb are set on the product of the production cross section and branching fraction for a topcolor Z' modeled for several widths, as well as for a Randall--Sundrum Kaluza--Klein gluon. In addition, the results constrain any enhancement in t t-bar production beyond expectations of the standard model for t t-bar invariant masses larger than 1 TeV.Comment: Submitted to the Journal of High Energy Physics; this version includes a minor typo correction that will be submitted as an erratu

Combined search for the quarks of a sequential fourth generation

Results are presented from a search for a fourth generation of quarks produced singly or in pairs in a data set corresponding to an integrated luminosity of 5 inverse femtobarns recorded by the CMS experiment at the LHC in 2011. A novel strategy has been developed for a combined search for quarks of the up and down type in decay channels with at least one isolated muon or electron. Limits on the mass of the fourth-generation quarks and the relevant Cabibbo-Kobayashi-Maskawa matrix elements are derived in the context of a simple extension of the standard model with a sequential fourth generation of fermions. The existence of mass-degenerate fourth-generation quarks with masses below 685 GeV is excluded at 95% confidence level for minimal off-diagonal mixing between the third- and the fourth-generation quarks. With a mass difference of 25 GeV between the quark masses, the obtained limit on the masses of the fourth-generation quarks shifts by about +/- 20 GeV. These results significantly reduce the allowed parameter space for a fourth generation of fermions.Comment: Replaced with published version. Added journal reference and DO

Measurement of the t t-bar production cross section in the dilepton channel in pp collisions at sqrt(s) = 7 TeV

The t t-bar production cross section (sigma[t t-bar]) is measured in proton-proton collisions at sqrt(s) = 7 TeV in data collected by the CMS experiment, corresponding to an integrated luminosity of 2.3 inverse femtobarns. The measurement is performed in events with two leptons (electrons or muons) in the final state, at least two jets identified as jets originating from b quarks, and the presence of an imbalance in transverse momentum. The measured value of sigma[t t-bar] for a top-quark mass of 172.5 GeV is 161.9 +/- 2.5 (stat.) +5.1/-5.0 (syst.) +/- 3.6(lumi.) pb, consistent with the prediction of the standard model.Comment: Replaced with published version. Included journal reference and DO

Search for New Physics with Jets and Missing Transverse Momentum in pp collisions at sqrt(s) = 7 TeV

A search for new physics is presented based on an event signature of at least three jets accompanied by large missing transverse momentum, using a data sample corresponding to an integrated luminosity of 36 inverse picobarns collected in proton--proton collisions at sqrt(s)=7 TeV with the CMS detector at the LHC. No excess of events is observed above the expected standard model backgrounds, which are all estimated from the data. Exclusion limits are presented for the constrained minimal supersymmetric extension of the standard model. Cross section limits are also presented using simplified models with new particles decaying to an undetected particle and one or two jets

Measurement of the Z/gamma* + b-jet cross section in pp collisions at 7 TeV

The production of b jets in association with a Z/gamma* boson is studied using proton-proton collisions delivered by the LHC at a centre-of-mass energy of 7 TeV and recorded by the CMS detector. The inclusive cross section for Z/gamma* + b-jet production is measured in a sample corresponding to an integrated luminosity of 2.2 inverse femtobarns. The Z/gamma* + b-jet cross section with Z/gamma* to ll (where ll = ee or mu mu) for events with the invariant mass 60 < M(ll) < 120 GeV, at least one b jet at the hadron level with pT > 25 GeV and abs(eta) < 2.1, and a separation between the leptons and the jets of Delta R > 0.5 is found to be 5.84 +/- 0.08 (stat.) +/- 0.72 (syst.) +(0.25)/-(0.55) (theory) pb. The kinematic properties of the events are also studied and found to be in agreement with the predictions made by the MadGraph event generator with the parton shower and the hadronisation performed by PYTHIA.Comment: Submitted to the Journal of High Energy Physic