Adhesion and Removal of Particles from Surfaces Under Humidity Controlled Air Stream

The adhesion and the removal of individual micrometer-sized particles on a plane substrate are studied using an air shear flow cell. Laminar isothermal compressible flow characterization enables us to analyze the effect of various parameters such as particle size, air humidity, surface nature and surface charge on the aerodynamic forces required to remove the particles from the substrate. The results show that the increase of humidity (up to a critical value) favors particle removal when particles adhere under strong electrostatic forces on a non-conductive charged substrate. On the contrary, the existence of a capillary force disfavors particle removal beyond this critical humidity. The increase of the humidity disfavors the removal of particles in contact with an uncharged substrate. The results are interpreted in terms of a global adhesion force using a force and torque balance on a single particle in contact with a plane substrate. Moreover, the use of a high-speed video recording system enables us to determine the particle removal mechanisms as a function of the particle Reynolds number.     

Melt‐stable poly(1,4‐dioxan‐2‐one) (co)polymers by ring‐opening polymerization via continuous reactive extrusion

Bulk polymerization of ?‐caprolactone (CL), 1,4‐dioxan‐2‐one (PDX), and mixtures of PDX and CL was carried out by initiation with Al(O^secBu)₃ in a co‐rotating twin‐screw extruder through a fast single‐step process. Both homopolymerizations and copolymerization of PDX and CL proceed very rapidly and reach almost complete (co)‐ monomer(s) conversion as soon as 8 mol% of CL are added in the feed. Even though poly(1,4‐dioxan‐2‐one) (PPDX) is known to thermally degrade mainly through unzipping depolymerization promoted from the hydroxyl end‐groups and yielding PDX monomer, it turns out that the thermal stability of PPDX chains is substantially improved by the copolymerization of PDX with limited amounts of CL. Interestingly, DSC analysis of the so‐obtained P(PDX‐co‐CL) copolymers has demonstrated that a CL molar fraction as high as 11 mol% does not prevent the crystallization of the resulting copolymer, which retains a melting temperature close to 95°C. This last observation has been explained by the formation of a blocky‐like copolymer structure, in which short PPDX and PCL sequences are randomly distributed. POLYM. ENG. SCI., 45:622–629, 2005. © 2005 Society of Plastics Engineers.     

《可持续发展设计指南》选载(之十)如何为可持续性发展楼房挑选高效能源机械设施

一、提高末端用户能源效率中国目前每年要消耗约1.8亿吨原煤用于城市居住和商用建筑的供暖。与西欧或北美同等寒冷程度气候地区的建筑相比,中国每单位建筑面积所消耗的能量至少是其两倍,舒适度却低得多。在冬季,燃煤集中供暖设施所排     

流-固耦合问题的ALE有限元分析

基于任意Lagrange-Euler描述(ALE),建立了分析流-固耦合问题的预报-更正算法.采用ALE描述下的Galerkin/最小二乘有限元法,完成了对具有运动边界的不可压缩粘性流的数值模拟;并提出基于更新Lagrange列式的伪弹性体法来计算网格运动;通过在耦合界面上对流体和固体分别施加Dirichlet和Neumann边界条件,建立了流-固耦合关系,并数值模拟了流道中与流速垂直的悬臂梁的流-固耦合过程,数值算例的结果验证了本文方法的有效性.     

Tracking the Molecular Fingerprint of Head and Neck Cancer for Recurrence Detection in Liquid Biopsies

The 5-year relative survival for patients with head and neck cancer, the seventh most common form of cancer worldwide, was reported as 67% in developed countries in the second decade of the new millennium. Although surgery, radiotherapy, chemotherapy, or combined treatment often elicits an initial satisfactory response, relapses are frequently observed within two years. Current surveillance methods, including clinical exams and imaging evaluations, have not unambiguously demonstrated a survival benefit, most probably due to a lack of sensitivity in detecting very early recurrence. Recently, liquid biopsy monitoring of the molecular fingerprint of head and neck squamous cell carcinoma has been proposed and investigated as a strategy for longitudinal patient care. These innovative methods offer rapid, safe, and highly informative genetic analysis that can identify small tumors not yet visible by advanced imaging techniques, thus potentially shortening the time to treatment and improving survival outcomes. In this review, we provide insights into the available evidence that the molecular tumor fingerprint can be used in the surveillance of head and neck squamous cell carcinoma. Challenges to overcome, prior to clinical implementation, are also discussed.     

Temporal relation algebra for audiovisual content analysis

Multimedia Tools and Applications - The context of this work is to characterize the content and the structure of audiovisual documents by analysing the temporal relationships between basic events...     

Line of sight controller tuning using Bayesian optimisation: application to a double stage stabilisation platform

The inertial stabilisation of the line of sight of an imager fixed on a mobile carrier is considered in order to acquire good quality images despite the disturbances generated by the carrier. A double stage mechanical stabilisation architecture is proposed, where a second stabilisation stage, based on a piezoelectric actuator, is added to the usual structure. The piezoelectric actuator transfer function and hysteresis are characterised through experiments. In order to design the controllers of both stages, a high-level image quality criterion (the modulation transfer function (MTF)) is considered, together with design constraints on the main variables of interest. The criterion and the constraints are evaluated by realistic simulations based on some input and noise profiles measured on a real-life system. The MTF evaluation being time-consuming, a Bayesian optimisation method specially dedicated to expensive-to-evaluate functions is used to obtain the parameters of the controllers. The obtain experimental results are displayed and their performances discussed.