On the Kramers-Kronig transform with logarithmic kernel for the reflection phase in the Drude model

We use the Kramers-Kronig transform (KKT) with logarithmic kernel to obtain the reflection phase and, subsequently, the complex refractive index of a bulk mirror from reflectance. However, there remains some confusion regarding the formulation for this analysis. Assuming the damped Drude model for the dielectric constant and the oblique incidence case, we calculate the additional terms: phase at zero frequency and Blashke factor and we propose a reformulated KKT within this model. Absolute reflectance in the s-polarization case of a gold film is measured between 40 and 350 eV for various glancing angles using synchrotron radiation and its complex refractive index is deduced using the reformulated KKT that we propose. The results are discussed with respect to the data available in the literature.Comment: 18 pages, piblished in j. Mod. Opt. 57, 1504 (2010

Cr/Sc multilayer radiator for parametric EUV radiation in "water-window" spectral range

The results of experimental investigation of parametric radiation generated by 5.7 MeV electrons in a multilayer structure consisting of 100 Cr/Sc bi-layers deposited on a Si3N4 membrane are presented. The multilayer structure was specially created for generation of parametric radiation with photon energy in "water-window" spectral rang

Thermal, mechanical and viscoelastic properties of citric acid-crosslinked starch/cellulose composite foams

In this work, biodegradable starch/cellulose composite foams were fabricated at 220 °C by compression moulding gelatinised starch containing cellulose fibres as a reinforcing agent and citric acid as a cross-linking agent. It was found that the stiffness, tensile strength, flexural strength, and hydrophobicity of the starch/cellulose composite foams increased, and water absorption capacity decreased with an increase in the concentration of citric acid. The tensile strength increased from 1.76 MPa for 0 % citric acid to 2.25 MPa for the starch/cellulose composite foam crosslinked with 5 % (w/w) citric acid. Similarly, the flexural modulus also increased from 445 MPa to 601.1 MPa, and the flexural strength from 3.76 MPa to 7.61 MPa, for the composite foam crosslinked with 5 % (w/w) citric acid. The crosslinked composite foams showed better thermal stability compared to the non-crosslinked composite foam. The resulting composite foams could be used as a biodegradable alternative to expanded polystyrene packaging

Investigation of the thermal stability of Mg/Co periodic multilayers for EUV applications

We present the results of the characterization of Mg/Co periodic multilayers and their thermal stability for the EUV range. The annealing study is performed up to a temperature of 400\degree C. Images obtained by scanning transmission electron microscopy and electron energy loss spectroscopy clearly show the good quality of the multilayer structure. The measurements of the EUV reflectivity around 25 nm (~49 eV) indicate that the reflectivity decreases when the annealing temperature increases above 300\degreeC. X-ray emission spectroscopy is performed to determine the chemical state of the Mg atoms within the Mg/Co multilayer. Nuclear magnetic resonance used to determine the chemical state of the Co atoms and scanning electron microscopy images of cross sections of the Mg/Co multilayers reveal changes in the morphology of the stack from an annealing temperature of 305\degreee;C. This explains the observed reflectivity loss.Comment: Published in Applied Physics A: Materials Science \& Processing Published at http://www.springerlink.com.chimie.gate.inist.fr/content/6v396j6m56771r61/ 21 page

Thermo-mechanical, morphological and water absorption properties of thermoplastic starch/cellulose composite foams reinforced with PLA

Expanded polystyrene foams are lightweight and cheap, but they have excellent strength and insulation properties. However, their inability to biodegrade in traditional landfill situations makes their disposal problematic. Starch, a polysaccharide, has the potential to replace synthetic thermoplastics for some applications but starch-based foams are hydrophilic, which limits their applications. In this work, polylactide (PLA), a sustainably derived and industrially compostable polymer, was added to starch/cellulose composite foams to enhance their water barrier properties. PLA powder at various weight % was mixed with moistened starch and cellulose mixture, and composite foams were prepared by compression moulding at 220 °C. The thermomechanical and viscoelastic properties of the produced foam materials were analysed by thermogravimetric analysis, dynamic mechanical thermal analysis, mechanical testing, and also by the 3-point compressive mechanical quasi-static testing. It was found that the tensile strength of the composite foams increased with an increase in the PLA loading, which increased from 2.50 MPa for 0% PLA to 3.27 MPa for 9.72% PLA loading. The flexural strength also increased from 345.91 kPa for the 0% PLA to 378.53 kPa for the composite foam containing 4.86% PLA; beyond which the flexural strength started decreasing with an increase in PLA loading. Similarly, the stiffness of the starch/cellulose composite also increased with an increase in PLA loading up to 4.86%, and further increase in PLA loading decreased the stiffness. The flexural modulus of the composite foams increased from 522 MPa for 0% PLA loading to 542.85 MPa for the 4.86% PLA loading. The thermal stability of the starch/cellulose composite foams also increased and the water absorbency decreased with the increased PLA loading

Anterolateral ligament reconstruction does not delay functional recovery, rehabilitation, and return to sport after anterior cruciate ligament reconstruction. A matched-pair analysis from the SANTI (Scientific ACL Network International) Study Group

Purpose: To determine whether the addition of an anterolateral ligament reconstruction (ALLR) resulted in delayed functional recovery (based on the Knee Santy Athletic Return to Sport [K-STARTS] score) at 6 months after anterior cruciate ligament reconstruction (ACLR). Methods: A retrospective analysis of prospectively collected data from consecutive pa- tients who underwent an ACLR between September 2017 and December 2020 was conducted. Patients who received an isolated hamstring autograft (isolated ACLR group) were propensity matched in a 1:1 ratio to patients who received a hamstring autograft ACLR combined with an ALLR (ACLR-ALLR group). Outcome measures included the Tegner Activity Scale and the K-STARTS testda validated composite return-to-sports test (including the Anterior Cruciate LigamenteReturn to Sport After Injury scale, Qualitative Assessment of Single-Leg Landing tool, limb symmetry index, and ability to change direction using the Modified Illinois Change of Direction Test). Results: The study included 111 matched pairs. At 6 months postoperatively, there were no significant differences between groups in the overall K-STARTS score (65.4 for isolated ACLR vs 61.2 for ACLR-ALLR, P 1⁄4 .087) or the Tegner Activity Scale score (3.7 for isolated ACLR vs 3.8 for ACLR-ALLR, P 1⁄4 .45). In addition, an evaluation of the subscales of the K-STARTS score revealed no disadvantage across the domains of neuromuscular control, limb symmetry index, agility, or psychological readiness to return to sport when an ALLR was performed. Conclusions: The addition of ALLR at the time of ACLR does not delay functional recovery. Spe- cifically, at 6 months postoperatively, there was no disadvantage in patients undergoing ALLR-ACLR, when compared with those undergoing isolated ACLR, with respect to neuromuscular control, limb symmetry indices (hop tests), agility, or psychological readiness to return to sport

Introduction of Zr in nanometric periodic Mg/Co multilayers

We study the introduction of a third material, namely Zr, within a nanometric periodic Mg/Co structure designed to work as optical component in the extreme UV (EUV) spectral range. Mg/Co, Mg/Zr/Co, Mg/Co/Zr and Mg/Zr/Co/Zr multilayers are designed, then characterized in terms of structural quality and optical performances through X-ray and EUV reflectometry measurements respectively. For the Mg/Co/Zr structure, the reflectance value is equal to 50% at 25.1 nm and 45deg of grazing incidence and reaches 51.3% upon annealing at 200deg C. Measured EUV reflectivity values of tri-layered systems are discussed in terms of material order within a period and compared to the predictions of the theoretical model of Larruquert. Possible applications are pointed out.Comment: 19 page