Introducing a design procedure for Archimedes Screw Turbine based on optimization algorithm

Archimedes screw turbines have gained popularity in generating power from flowing water. One aspect that hasn't been considered yet is optimizing those parameters that are considered assumptions in the prediction models. In this research, a simple procedure was introduced to design an appropriate Archimedes screw turbine for a given site using a prediction model and an optimization model. First, the mathematical efficiency prediction model of Archimedes screw turbines was developed and validated with experimental and real-world Archimedes screw turbine data. Then, the grey wolves optimization algorithm was developed to be used as an actual engineering application, sensitively analyzed, and coupled with the prediction model. The prediction models were evaluated. The model convergence was investigated, and then, the optimization parameters were found to get maximum efficiency. The results revealed that the optimum number of iterations and grey wolves are 200 and five, respectively. Also, the best values for the inner diameter to the outer diameter ratio, the pitch to the outer diameter ratio, tilt angle, and blade number were found in ranges: 0.43–0.56, 1–1.2, 20–22.5, and 2–4, respectively

Experimental investigation of PV/T and thermoelectric systems using CNT/ water nanofluids

This study investigated experimentally the thermal performance of a Photovoltaic-thermal (PV/T) and thermoelectric (TE) system using the application of two nanofluids. Single-walled Carbon nanotube/water (SWCNT/water) and multi-walled Carbon nanotube/water (MWCNT/water), with a mass fraction of 0.02% were assessed as the working fluid of the PV/T system. Examinations were done from 10:00 to 16:30 daily in November 2021 at Tarbiat Modares University, Tehran, Iran. Different parameters were measured during the experimental tests including fluid inlet and outlet temperatures, volume flow rate, solar irradiance, and ambient and cell surface temperatures. The results showed that the highest performance of the solar system was measured using the application of SWCNT/water nanofluid. The PV/T surface temperature decreased using nanofluids compared to pure water. It was found that the output generated power and efficiency improved using nanofluid application whereas application of SWCNT/water was more effective compared to MWCNT/water nanofluid. Also, the application of the two nanofluids improved the performance of the TE module compared to pure water. The highest values of TE electric current, voltage, generated power, and efficiency were obtained using the application of SWCNT/water nanofluid

Rational Design and Characterization of D-Phe-Pro-D-Arg-Derived Direct Thrombin Inhibitors

The tremendous social and economic impact of thrombotic disorders, together with the considerable risks associated to the currently available therapies, prompt for the development of more efficient and safer anticoagulants. Novel peptide-based thrombin inhibitors were identified using in silico structure-based design and further validated in vitro. The best candidate compounds contained both l- and d-amino acids, with the general sequence d-Phe(P3)-Pro(P2)-d-Arg(P1)-P1′-CONH2. The P1′ position was scanned with l- and d-isomers of natural or unnatural amino acids, covering the major chemical classes. The most potent non-covalent and proteolysis-resistant inhibitors contain small hydrophobic or polar amino acids (Gly, Ala, Ser, Cys, Thr) at the P1′ position. The lead tetrapeptide, d-Phe-Pro-d-Arg-d-Thr-CONH2, competitively inhibits α-thrombin's cleavage of the S2238 chromogenic substrate with a Ki of 0.92 µM. In order to understand the molecular details of their inhibitory action, the three-dimensional structure of three peptides (with P1′ l-isoleucine (fPrI), l-cysteine (fPrC) or d-threonine (fPrt)) in complex with human α-thrombin were determined by X-ray crystallography. All the inhibitors bind in a substrate-like orientation to the active site of the enzyme. The contacts established between the d-Arg residue in position P1 and thrombin are similar to those observed for the l-isomer in other substrates and inhibitors. However, fPrC and fPrt disrupt the active site His57-Ser195 hydrogen bond, while the combination of a P1 d-Arg and a bulkier P1′ residue in fPrI induce an unfavorable geometry for the nucleophilic attack of the scissile bond by the catalytic serine. The experimental models explain the observed relative potency of the inhibitors, as well as their stability to proteolysis. Moreover, the newly identified direct thrombin inhibitors provide a novel pharmacophore platform for developing antithrombotic agents by exploring the conformational constrains imposed by the d-stereochemistry of the residues at positions P1 and P1′

Search for neutral MSSM Higgs bosons decaying to a pair of tau leptons in pp collisions

Peer reviewe

Measurement of top quark–antiquark pair production in association with a W or Z boson in pp collisions at √s=8 TeV

Peer reviewe

Searches for electroweak production of charginos, neutralinos, and sleptons decaying to leptons and W, Z, and Higgs bosons in pp collisions at 8 TeV

Peer reviewe

Study of hadronic event-shape variables in multijet final states in pp collisions at √s=7 TeV

Peer reviewe

Measurement of prompt J/ψ pair production in pp collisions at √s = 7 Tev

Peer reviewe

Constraints on parton distribution functions and extraction of the strong coupling constant from the inclusive jet cross section in pp collisions at √s=7 TeV

Peer reviewe

Preparation and some properties of lithium vanadium bronzes

372-377Lithium vanadium bronzes with composition formula Lix V2O5 (0.04 ≤ x ≥ 0.92) have been prepared by solid-state reaction at 650°C in argon atmosphere. The products were characterized by X-ray powder diffraction and IR spectroscopy. The results reveal that four phases namely α-, β-, βʹ- and γ-phase are present in the studied range. The magnetic susceptibility for the investigated samples was measured using Gouy’s method. The values of the effective magnetic moments as calculated from experimental data indicate the presence of V4+ ions in all samples. The electrical conductivity as a function of temperature and lithium content was measured in the temperature range from-room temperature to 483 K. The electrical conductivity of the samples is found to be affected by lithium content. The values of the electrical conductivity increase with temperature for the investigated samples. The electronic and ionic conductions are discussed