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Effect of the mineralogical composition on the elastoplastic hydromechanical response of Opalinus Clay shale
No full textOpalinus Clay is the shale currently under investigation as the host formation for geological radioactive waste disposal in Switzerland. Its hydromechanical response has been widely studied, and the experimental results show a range of values whose dispersion needs to be clarified. This work aims to explain the dispersion in the literature results by correlating the hydro-mechanical response to the mineralogical variability of the tested specimens. Based on published microstructural studies, the Opalinus Clay shale is herein schematised as a sequence of two kinds of layers: the shaly (high in clay-mineral content) and the sandy (low in clay-mineral content) layers. The mineralogical composition, porosity and hydromechanical parameters are assigned to each layer type. The one-dimensional compressibility and the elastic response of combinations of layers are derived adopting an analytical solution for the stratified, transversely isotropic medium. The drained elastic properties are used to calibrate the approach, and the undrained elastic properties are derived and compared to literature data. Empirical correlations between the layer composition and the geomaterial strength are also drawn. It is shown that by adopting a layered structure with an alternation of two kinds of layers, most of the variability in the studied geomechanical properties of Opalinus Clay can be captured.LMSThis is an Open Access article under the terms of the Creative Commons Attribution Licens
Clinical factors associated with self selected gait speed and step variability in diabetic patients walking in a challenging environment
No full textLMA
Full Factorial Experimental Optimization of Gold Nanostructures Fabrication by Solid-State Dewetting for SERS
No full textThe optimization of nanostructures for a specific application is a rather complex task, often akin to shooting in the dark with the hope of hitting the right target, viz. the best performing nanostructure. This difficulty stems from the usually large number of experimental parameters that can be changed in a nanotechnology process. This is the case for example in the fabrication of plasmonic nanostructures for surface enhanced Raman scattering (SERS): the choice of metal, its thickness, the shape of the nanostructures as well as their distribution on the substrate are all parameters that determine the overall Raman enhancement. Even for a relatively simple design, exploring all possible combinations of parameters is a prohibitive task both in terms of nanofabrication time and costs. In that contribution, we focus on the large scale fabrication of plasmonic nanostructures using solid-state dewetting and demonstrate how a full factorial design technique can efficiently optimize the process. In that approach, a target response for optimization and two specific values for the n fabrication parameters are first chosen, leading to an initial set of 2n experiments [1]. Here, as experimental parameters we consider the gold film thickness, the annealing temperature and time, and the heating rate; with the objective of maximizing the intensity of the SERS signal, specifically the 1363 cm-1 vibrational band of Rhodamine 6G. The corresponding 16 experiments provide a model of the dependency of the Raman enhancement on the four experimental parameters considered here. In the classical optimization procedure by full factorial design, this dependency is chosen linear. The set of experimental parameters that is obtained in this first fit of linear model does not necessarily lead to the strongest Raman enhancement and another set of experiments may be required. However, the full factorial approach also provides the direction in the parameter space in which one needs to move these parameters to reach a better solution. After such a solution is found, the linear model may need to be refined using second order functions to clarify the optimum region. This is usually done with the central composite experimental design [2]. The optimization process for the fabricated samples is documented in detail by studying the morphology and optical properties of each sample by scanning electron microscopy and UV-Vis spectroscopy. The gold nanostructures we fabricated this way have typical dimensions in the 50 nm range, which is in good agreement with data reported in the literature [3]. Furthermore, the optimized plasmonic substrate can be used to identify non-resonant bioorganic macromolecules such as bovine serum albumin. This work reveals an effective approach to optimize nanofabrication processes for large-scale and cost-effective production of uniform and highly sensitive SERS substrates.NA
A low-temperature parylene-to-silicon dioxide bonding technique for high-pressure microfluidics
No full textWe introduce a new low-temperature (280 °C) parylene-to-SiO2 bonding process with high device yield (>90%) for the fabrication and integration of high-pressure-rated microfluidic chips. Pull tests demonstrate a parylene-to-SiO2 bonding strength of 10 ± 3 MPa. We apply this technique for bonding Pyrex and silicon wafers having multiple metal layers to fabricate standard packaged microfluidic devices. By performing electrochemical impedance spectroscopy of electrolyte solutions in such devices, we demonstrate that electrodes remain functional after the etching, bonding and dicing steps. We also develop a high-pressure microfluidic and electrical integration technology, eliminating special fluidic interconnections and wire-bonding steps. The burst pressure of the integrated system is statistically shown to be 7.6 ± 1.3 MPa, with a maximum achieved burst pressure of 11.1 MPa, opening perspectives for high-pressure applications of these types of microfluidic devices.LMIS
Cramer-Rao Bound for Location Estimation of a Mobile in Asynchronous DS-CDMA Systems
No full textCommercial applications for the location of subscribers ofwireless services continue to expand. Consequently, 'nding the Cramer- Rao bound (CRB), which serves as an optimality criterion for the location estimation problem, is of interest. In this article, we derive the CRB for the estimation of channel parameters and mobile position in an asynchronous direct sequence code division multiple access (DS-CDMA) system operating over fading channels. It is assumed that the location estimates are obtained from the bearings and/or propagation delays estimated at one or more cluster(s) of antenna array of arbitrary geometry. Among other applications, the CRB on the positioning accuracy may serve as a design tool to 'nd an optimum antenna placement, or to evaluate the practicability of a legal demand for emergency location.ESPLA
A Solution to Adaptive Mobile Manipulator Throwing
No full textMobile manipulator throwing is a promising method to increase the flexibility and efficiency of dynamic manipulation in factories. Its major challenge is to efficiently plan a feasible throw under a wide set of task specifications. We show that the mobile manipulator throwing problem can be simplified to a planar problem, hence greatly reducing the computational costs. Using machine learning approaches, we build a model of the object's inverted flying dynamics and the robot's kinematic feasibility, which enables throwing motion generation within 1 ms for given query of target position. Thanks to the computational efficiency of our method, we show that the system is adaptive under disturbance, via replanning on the fly for alternative solutions, instead of sticking to the original throwing plan.LAS
Evaluating Resistance of MCML Technology to Power Analysis Attacks Using a Simulation-Based Methodology
No full textThis paper explores the resistance of MOS Current Mode Logic (MCML) against attacks based on the observation of the power consumption. Circuits implemented in MCML, in fact, have unique characteristics both in terms of power consumption and the dependency of the power profile from the input signal pattern. Therefore, MCML is suitable to protect cryptographic hardware from Differential Power Analysis and similar side-channel attacks. In order to demonstrate the effectiveness of different logic styles against power analysis attacks, two full cores implementing the AES algorithm were realized and implemented with CMOS and MCML technology, and a set of different types of attack was performed using power traces derived from SPICE-level simulations. Although all keys were discovered for CMOS, MCML traces did not presents characteristic that can lead to a successful attack.LSMLA
Horse liver esterase catalyzed enantioselective hydrolysis of N,O-diacetyl-2-amino-1-arylethanol
No full textN,O-Diacetyl-2-amino-1-arylethanol can be efficiently resolved by horse liver esterase (HLE). A remarkable org. co-solvent effect on the enantioselectivity of HLE was obsd. [on SciFinder (R)]LSPNCAN 128:21714525-7Benzene, Its Derivatives, and Condensed Benzenoid CompoundsInstitut de Chimie des Substances Naturelles, CNRS,Gif-sur-Yvette,Fr.Journalwritten in English.202120-58-9P; 202120-59-0P Role: BPN (Biosynthetic preparation), PUR (Purification or recovery), RCT (Reactant), BIOL (Biological study), PREP (Preparation), RACT (Reactant or reagent) (horse liver esterase catalyzed enantioselective hydrolysis of N,O-diacetyl-2-amino-1-arylethanol); 9016-18-6 (Carboxyl esterase) Role: CAT (Catalyst use), USES (Uses) (horse liver esterase catalyzed enantioselective hydrolysis of N,O-diacetyl-2-amino-1-arylethanol); 7568-93-6; 36394-75-9 ((S)-2-Acetoxypropionyl chloride); 42564-51-2 (4-Fluoro-3-nitrobenzaldehyde) Role: RCT (Reactant), RACT (Reactant or reagent) (horse liver esterase catalyzed enantioselective hydrolysis of N,O-diacetyl-2-amino-1-arylethanol); 3306-05-6P; 55044-72-9P; 202120-55-6P; 202120-56-7P; 202120-57-8P; 204264-61-9P; 204264-63-1P; 204264-64-2P; 204264-65-3P; 204264-66-4P Role: RCT (Reactant), SPN (Synthetic preparation), PREP (Preparation), RACT (Reactant or reagent) (horse liver esterase catalyzed enantioselective hydrolysis of N,O-diacetyl-2-amino-1-arylethanol); 155073-71-5P; 157379-64-1P; 204264-57-3P; 204264-58-4P; 204264-59-5P; 204264-60-8P; 204264-62-0P Role: SPN (Synthetic preparation), PREP (Preparation) (horse liver esterase catalyzed enantioselective hydrolysis of N,O-diacetyl-2-amino-1-arylethanol); 64-17-5 (Ethanol); 67-64-1 (Acetone); 108-20-3 (Isopropyl ether); 110-54-3 (Hexane) Role: NUU (Other use, unclassified), USES (Uses) (solvent; horse liver esterase catalyzed enantioselective hydrolysis of N,O-diacetyl-2-amino-1-arylethanol
The effect of variability of urban systems characteristics in the network capacity
No full textRecent experimental analysis has shown that some types of urban networks exhibit a low scatter reproducible relationship between average network flow and density, known as the macroscopic fundamental diagram (MFD). It has also been shown that heterogeneity in the spatial distribution of density can significantly decrease the network flow for the same value of density. Analytical theories have been developed to explore the connection between network structure and an MFD for urban neighborhoods with cars controlled by traffic signals. However these theories have been applied only in cities with deterministic values of topological and control variables for the whole network and by ignoring the effect of turns. In our study we are aiming to generate an MFD for streets with variable link lengths and signal characteristics and understand the effect of variability for different cities and signal structures. Furthermore, this variability gives the opportunity to mimic the effect of turning movements. Route or network capacity can be significantly smaller than the capacity of a single link, because of the correlations developed through the different values of offsets. The above analysis would not be possible using standard traffic engineering techniques. This will be a key issue in planning the signal regimes such a way that maximizes the network capacity and/or the density range of the maximum capacity.LUT