Mechanistic cutting force model parameters evaluation in milling taking cutter radial runout into account

The simulation of the cutting process becomes a key aspect on production optimization. The search for optimal cutting parameters by simulation can be a very effective way of reducing the tuning time of the process and can demonstrate potential cost reduction. As the simulation of the microscopic behavior of the cut is still difficult to perform, most of the prediction techniques are based on mechanistic models of the cutting forces, whose parameters are deduced from experimental tests. The runout of the tool can be a parasite effect that lowers the precision of the identification of the cutting forces parameters. This paper shows the improvement of an identification algorithm given by the modeling of radial runout effect on the undeformed chip thickness. Two different models of cutter runout have been used and tested on experimental measurement performed on a static dynamometer. The adequacy between simulation and experiment is good and allows reliable prediction of cutting forces for different cutting conditions.     

Numerical modeling of wave propagation in anisotropic viscoelastic laminated materials in transient regime: Application to modeling ultrasonic testing of composite structures

Composite laminate structures remain an important family of materials used in cutting-edge industrial areas. Building efficient numerical modeling tools for high-frequency wave propagation in order to represent ultrasonic testing experiments of these materials remains a major challenge. In particular, incorporating attenuation phenomena within anisotropic plies, and thin intermediate isotropic layers between the plies often represent significant obstacles for standard numerical approaches. In our work, we address both issues by proposing a systematic study of the fully discrete propagators associated to the Kelvin-Voigt, Maxwell, and Zener models, and by incorporating effective transmission conditions between plies using the mortar element method. We illustrate the soundness of our approach by proposing intermediate one-dimensional and two-dimensional numerical evidence, and we apply it to a more realistic configuration of a curved laminate composite structure in a three-dimensional setting.     

Nanoengineering Calcium Peroxide-Based Site-Specific Delivery Platform to Efficiently Activate the cGAS-STING Pathway for Cancer Immunotherapy by Amplified Endoplasmic Reticulum Stress

Currently, the understanding of the cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) pathway's involvement in efficient immunotherapy mainly revolves around the role of mitochondria or nucleus modulation. Nonetheless, the role of endoplasmic reticulum (ER) stress in activating the cGAS-STING mechanism to boost immunity against tumors remains essentially unexplored. Herein, novel findings demonstrating that ER stress can be used as a strategy for stimulating the cGAS-STING pathway, thereby augmenting the immune response against cancer, are presented. To accomplish this objective, ER-targeting p-methylbenzene sulfonamide-tailored IR780 (p-780) is synthesized and it is loaded into CaO₂ nanoparticles, which are further functionalized with distearoyl phosphoethanolamine-polyethylene glycol（DSPE-PEG）-biotin to form PEG/CaO₂@p-780 NPs. The disruption of calcium homeostasis, coupled with the heightened levels of reactive oxygen species (ROS) mediated by p-780, along with hyperpyrexia, collectively contributes to the amplification of endoplasmic reticulum (ER) stress. This cascade of events effectively triggers the cGAS-STING pathway and, in parallel, facilitates the degradation of the programmed cell death 1 ligand 1 (PD-L1) protein. In addition, oxygen released through CaO₂ decomposition is expected to promote p-780–mediated phototherapy, while reversing the immunosuppressive tumor microenvironment associated with hypoxia. Furthermore, DSPE-PEG-biotin facilitates tumor site-specific drug delivery through active targeting mediated by the biotin receptor. Collectively, PEG/CaO₂@p-780 nanoparticles successfully activate systemic antitumor immunity by enhancing ER stress.     

Motion segmentation and qualitative dynamic scene analysis from an image sequence

This article deals with analysis of the dynamic content of a scene from an image sequence irrespective of the static or dynamic nature of the camera. The tasks involved can be the detection of moving objects in a scene observed by a mobile camera, or the identification of the movements of some relevant components of the scene relatively to the camera. This problem basically requires a motion-based segmentation step. We present a motion-based segmentation method relying on 2-D affine motion models and a statistical regularization approach which ensures stable motion-based partitions. This can be done without the explicit estimation of optic flow fields. Besides these partitions are linked in time. Therefore, the motion interpretation process can be performed on more than two successive frames. The ability to follow a given coherently moving region within an interval of several images of the sequence makes the interpretation process more robust and more comprehensive. Identification of the kinematic components of the scene is induced from an intermediate layer accomplishing a generic qualitative motion labeling. No 3-D measurements are required. Results obtained on several real-image sequences corresponding to complex outdoor situations are reported.     

Propane ammoxidation on bulk, diluted and supported VSb oxides

VSb oxides diluted with Mg, Al and Zr displayed substantially higher selectivity for propane ammoxidation to acrylonitrile than their bulk and supported analogues. Diluted catalysts were found to consist of oxide compounds of antimony with diluent element, such as AlSbO₄ or MgSb₂O₆, and small amounts of individual oxides of antimony and diluent element. No VSbO₄ phase was detected in their body in contrast with bulk and supported catalysts. It appears that better isolation of vanadium and antimony entities in the structure of diluted oxides was responsible for their enhanced catalytic behavior. Tungsten loaded to the surface of diluted catalysts further improved their selectivity through tuning the surface acidity.     

Modeling long term memory effects in microwave power amplifiers for system level simulations

Accurate and dynamic behavioral models of SSPAS become of prime importance in system level analysis and design of modern communication and detection systems. This paper describes a new method to characterize and reproduce nonlinear memory effects in behavioral models ofSspas. We highlight, in a first section, the detailed mathematical development, whose the starting point is the Volterra series expansion, and ends to the nonlinear impulse response notion. The new model extraction relies on envelope transient simulations or time-domain measurements of complex envelopes at externDut reference accesses. This modeling technique is simple and enables a good prediction of nonlinear memory effects and especially long term memory effects and nonlinear transient behaviors. Simulations and measurements based extractions of this model are presented through significant amplifier examples.     

Etude des microcircuits hyperfréquences en régime dynamique

A critical study of the transmissionlinematrix method has been carried out by the authors to apply it for a dynamical study of the microwaves microcircuits. As a consequence of this critical study the authors suggest important improvements on the following three points: the dynamical process initialization, the rapidity and precision of computer calculation, the treatment of the resulting time signal. The method being a dynamical one, a first selecting filtering of the information to be transmitted is performed by using the geometrical and electrical symetries. A fast Fourier transform and a simplification of the computation procedure give a gain in time and precision. At last a better reading of the frequency response spectra is obtained by treating with various windows of convolution the resulting time signal.     

cis-4,7,10,trans-13–22∶4 fatty acid distribution in phospholipids of pectinid species Aequipecten opercularis and Pecten maximus

The distribution of cis-4,7,10,trans-13-docosate-traenoic (c4,7,10,t13–22∶4), a peculiar FA previously isolated in the glycerophospholipids of some pectinid bivalves, was investigated in glycerophospholipid classes and subclasses of separated organs (gills, mantle, gonads, and muscle) of the queen scallop Aequipecten opercularis and the king scallop Pecten maximus. Plasmalogen (Pls) and diacyl + alkyl (Ptd) forms of serine, ethanolamine, and choline glycerophospholipids were isolated by HPLC and their FA compositions analyzed by GC-FID. Pls and Ptd forms of serine glycerophospholipids (PlsSer and PtdSer), and to a lesser extend the Pls form of ethanolamine glycerophospholipids (PlsEtn), were found to be specifically enriched with c4,7,10,t13–22∶4. This specificity was found to decrease in the tested organs in the following order: gills, mantle, gonad, and muscle. In gills, c4,7,10,t13–22∶4 was shown to be the main unsaturated FA of serine glycerophospholipids in both Pls and Ptd forms (23.8 and 19.4 mol%, respectively, for A. opercularis, and 21.0 and 26.2 mol% for P. maximus). These results represent the first comprehensive report on the FA composition of plasmalogen serine subclass isolated from pectinid bivalves. The specific association of the PlsSer with the c4,7,10,t13–22∶4 for the two pectinid species can be paralleled to the specific association of the PlsSer with the non-methylene interrupted (NMI) FA and 20∶1(n−11) observed in mussels, clams, and oysters (Kraffe, E., Soudant, P., and Marty, Y. (2004) Fatty Acids of Serine, Ethanolamine and Choline Plasmalogens in Some Marine Bivalves, Lipids 39, 59–66.) This, led us to hypothesize a similar functional significance for c4,7,10,t13–22∶4, NMI FA, and 20∶1(n−11) associated with PlsSer subclass of bivalves.     

Tuning Memristivity by Varying the Oxygen Content in a Mixed Ionic–Electronic Conductor

The rising interest shown for adaptable electronics and brain‐inspired neuromorphic hardware increases the need for new device architectures and functional materials to build such devices. The rational design of these memory components also benefits the comprehension and thus the control over the microscopic mechanisms at the origin of memristivity. In oxide‐based valence‐change memories, the control of the oxygen drift and diffusion kinetics is a key aspect in obtaining the gradual analog‐type change in resistance required for artificial synapse applications. However, only a few devices are designed with this in mind, as they are commonly built around ionic insulating active materials. This shortcoming is addressed by using a mixed ionic–electronic conductor as functional memristive material. This work demonstrates how the oxygen content in La₂NiO_4+δ (L2NO4), tuned through post‐annealing treatments, has a critical influence on the memory characteristics of L2NO4‐based memristive devices. The presence of interstitial oxygen point defects in L2NO4 affects both its structure and electrical properties. High oxygen stoichiometry in the pristine state leads to an increased electrical conductivity, ultimately resulting in an improved memory window with highly multilevel, analog‐type memory programing capabilities, desirable for analog computing and synaptic applications in particular.