Metal contacts to lowly doped Si and ultra thin SOI

We present our investigations on the fabrication of ohmic and Schottky contacts of several metals on lowly doped bulk Si and SOI wafers. Through this paper we evaluate the fabrication of rectifying devices in which no doping is intentionally introduced

Sub 20 nm Short Channel Carbon Nanotube Transistors

Carbon nanotube field-effect transistors with sub 20 nm long channels and on/off current ratios of > 1000000 are demonstrated. Individual single-walled carbon nanotubes with diameters ranging from 0.7 nm to 1.1 nm grown from structured catalytic islands using chemical vapor deposition at 700 degree Celsius form the channels. Electron beam lithography and a combination of HSQ, calix[6]arene and PMMA e-beam resists were used to structure the short channels and source and drain regions. The nanotube transistors display on-currents in excess of 15 microA for drain-source biases of only 0.4 Volt.Comment: Nano Letters in pres

Local flexibility market design for aggregators providing multiple flexibility services at distribution network level

This paper presents a general description of local flexibility markets as a market-based management mechanism for aggregators. The high penetration of distributed energy resources introduces new flexibility services like prosumer or community self-balancing, congestion management and time-of-use optimization. This work is focused on the flexibility framework to enable multiple participants to compete for selling or buying flexibility. In this framework, the aggregator acts as a local market operator and supervises flexibility transactions of the local energy community. Local market participation is voluntary. Potential flexibility stakeholders are the distribution system operator, the balance responsible party and end-users themselves. Flexibility is sold by means of loads, generators, storage units and electric vehicles. Finally, this paper presents needed interactions between all local market stakeholders, the corresponding inputs and outputs of local market operation algorithms from participants and a case study to highlight the application of the local flexibility market in three scenarios. The local market framework could postpone grid upgrades, reduce energy costs and increase distribution grids’ hosting capacity.Postprint (published version

Shear band formation in porous thin-walled tubes subjected to dynamic torsion

In this paper, we have performed 3D finite element calculations of thin-walled tubes subjected to dynamic twisting to investigate the effect of porous microstructure on the formation of shear localization bands under simple shear conditions. For that purpose, we have incorporated into the finite element model the porous microstructures of four different additive manufactured metals – aluminium alloy AlSi10Mg, stainless steel 316L, titanium alloy Ti6Al4V and Inconel 718 – for which the void volume fraction varies from ≈ 0.001% to ≈ 2 %, and the voids size between ≈ 6 μm and ≈ 110 μm (Marvi-Mashhadi et al., 2021). For each microstructure, we have created up to 10 realizations varying the spatial location of the voids and the distribution of voids size. The matrix material is elastic/plastic, with yielding defined by the von Mises yield criterion and associated flow rule. The yield stress evolution is considered to be dependent on strain, strain rate and temperature, with parameters corresponding to Titanium and HY-100 Steel, taken from Molinari (1997) and Batra and Kim (1990), respectively. Moreover, we have assumed the deformation process to be adiabatic. The calculations have been performed for shear strain rates ranging from 100 s−1 to 10000 s−1. To the authors’ knowledge, this is the first study ever that simulates dynamic torsion testing of porous materials with actual representation of voids, providing new results which bring to light the influence of porosity on dynamic shear banding under simple shearing. Namely, the numerical calculations have shown that both the location of the shear band and the critical strain leading to the shear band formation depend on the spatial and size distribution of the voids in the specimen, evidencing the influence of material defects on the localization pattern. Notably, the shear band nucleation strain decreases with both the void volume fraction in the specimen and the size of the voids, the size of the largest pore being the main microstructural feature controlling the loss of load carrying capacity of the specimen. In addition, we have carried out a parametric analysis varying the temperature and strain rate sensitivities of the material, and the loading rate. For the strain rates investigated, increasing the loading speed leads to a mild decrease of the shear strain leading to shear band formation, while the strain rate sensitivity is shown to stabilize material behavior and delay localization. Moreover, the numerical results have made apparent that for the hardening materials considered, thermal softening is essential to trigger the shear band formation, so that the porous microstructure alone does not lead to shear localization.The research leading to these results has received funding from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme. Project PURPOSE, grant agreement 758056. J. C. Nieto-Fuentes acknowledges support from the CONEX-Plus programme funded by Universidad Carlos III de Madrid, Spain and the European Union's Horizon 2020 research and innovation programme, under the Marie Sklodowska-Curie grant agreement 801538

The Pharmacokinetics of ofloxacin, rifampicin, isoniazid and pyrazinmide when administered alone and in combination

The present study assesses the bioavailability of Ofloxacin (O) following single oral administration of the drug along with Rifampicin (R), or Isoniazid (H), or Pyrazinamide (Z) or a combination of three drugs. Information on the pharmacokinetics of O in the presence of R, H and Z based on the blood concentrations upto 8 hours, on the proportions of the doses of the drugs and their metabolites excreted in urine upto 8 hours and also the effect of O on the other antituberculosis (TB) drugs in terms of absorption and interactions are extensively studied. The bioavailability indices of these drugs are assessed. The investigation was undertaken in a total of 12 male healthy volunteers and each volunteer was investigated on four different occasions at weekly intervals. A partially balanced incomplete block design was employed and the allocation of O or the drug combinations was at random. Plasma concentrations of O, R, H and Z were determined. Urinary excretion of these drugs, together with their primary metabolites was also determined. Various pharmacokinetic parameters were calculated. The results have shown that the bioavailability of O is not impaired when administered with other antituberculosis drugs like R, H and Z and does not exercise any therapeutic penalty. The bioavailability of other anti-TB drugs like R, H and Z does not get affected when administered along with O. Human bioavailability studies, in general, provide direct straightforward information on the degree of absorption and biotransformation of drugs. The results of the present study indicate that the pharmacokinetic properties of O, R, H and Z as assessed after individual and combined administration of these drugs do not get affected or altered. Since there are no interactions among these drugs, the use of 0 in the treatment of pulmonary tuberculosis is justified

Solid-phase synthesis of C-terminal peptide amides using a photoremovable α-methylphenacylamido anchoring linkage

Polymer-supported solid-phase synthetic procedures have been developed for the synthesis of C-terminal peptide amides using a new photolytically removable a-methylphenacylamido anchoring linkage between the polymeric support and the growing peptide. The preparation of this new polymeric support involves a four-step polymer-analogous reaction starting from 2%-divinylbenzene-crosslinked polystyrene resin. The steps involved are (i) Friedel-Crafts reaction with 2-bromopropionyl chloride to give the 2-bromopropionyl resin, (ii) reaction of the 2-bromopropionyl resin with potassium phthalimide to give the phthalimidomethyl resin, (iii) hydrolysis with alcoholic potash to give the partially hydrolysed phthalamido resin and (iv) treatment with alcoholic HCl to give the 2-aminopropionyl resin. N-protected amino acids undergo coupling with this amino resin by the dicyclohexylcarbodiimide-mediated coupling. The acylated resins on irradiation at 350 nm in DMF released the attached carboxyl function in the C-terminal amide form. The mechanism of the photolytic deprotection involves a radical scission of the amide linkage adjacent to the phenacyl group. The synthetic utility of the new resin has been illustrated by the preparation of several N-protected amino acid amides and the C-terminal peptide amides, Boc-Pro-Val-NH2, Boc-Gly-Phe-Pro-NH2 and Boc-Leu-Ala-Gly-Val-NH2 in 70-74% yield

Isolation and full-length genome characterization of Sarscov-2 from covid-19 cases in northern Italy

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Coupling of a single-photon emitter in nanodiamond to surface plasmons of a nanochannel-enclosed silver nanowire

A finite element method is applied to study the coupling between a nitrogen vacancy (NV) single photon emitter in nanodiamond and surface plasmons in a silver nanowire embedded in an alumina nanochannel template. We investigate the effective parameters in the coupled system and present detailed optimization for the maximum transmitted power at a selected optical frequency (650 nm). The studied parameters include nanowire length, nanowire diameter, distance between the dipole and the nanowire, orientation of the emitter and refractive index of the surrounding. It is found that the diameter of the nanowire has a strong influence on the propagation of the surface plasmon polaritons and emission power from the bottom and top endings of the nanowire. © 2014 Optical Society of America