Influence of Process Parameters on the Deformation of Copper Foils in Flexible-Pad Laser Shock Forming

This paper investigates a new microforming technique, Flexible-Pad Laser Shock Forming (FPLSF), to produce mi-crofeatures on metallic foils without rigid punches and dies. FPLSF uses the laser-induced shock pressure and a flexi-ble-pad to plastically deform metal foils into hemispherical microcraters. In order to understand the deformation characteristics of metal foils in FPLSF, it is necessary to analyze the influence of process parameters on the foil deformation. In this paper, the effects of parameters such as the flexible-pad thickness, confinement layer medium, confinement layer thickness and the number of laser pulses on the depth, diameter and shape of the craters formed on copper foils were investigated. It is found that the flexible-pad thickness should be greater than its threshold value to maximize the deformation of foils. By comparing two different confinement media, namely water and glass, it is observed that hemispherical craters were formed on the copper foils at different laser fluence values tested when using water as the confinement; whereas shockwave ripples were formed on the copper foil at higher laser fluence while using the glass confinement. Using water as confinement medium, an increase in confinement thickness from 4 mm to 7 mm resulted in 48% increase of the crater depth at 7.3 J/cm2. However, at 13.6 J/cm2, reduction in crater depth was observed for thickness greater than 6 mm after an initial increasing trend. Regarding the number of pulses, it is found that increasing the number of pulses from 1 to 3 resulted only in a small increase (less than 1%) in crater depth at 7.3 J/cm2 and 13.6 J/cm2 laser fluence whereas 19.3% increase in depth was observed at larger laser fluence (20.9 J/cm2). It is also observed that the optimum number of pulses to achieve maximum deformation is varying with the laser fluence

Intercompréhension et analogies entre langues voisines : entre transparences et opacités. Le cas des séquences figées

Notre contribution a pour objectif d'examiner les mécanismes cognitifs en jeu dans le cadre de la compréhension en langues voisines et de montrer l'efficience de l'approche par analogie, en prenant pour support de démonstration la question des séquences figées. Après avoir rappelé l'inefficacité de l'approche analytique (médiatisée ou non médiatisée) en compréhension des langues voisines, nous étudierons les diverses relations analogiques qui existent entre les séquences figées équivalentes entre langues voisines et montrerons comment la pratique de l'intercompréhension par approche analogique permet d'accéder, avec plus d'efficience et de subtilité que toute autre approche, à la signification des séquences figées en langues étrangères. Chemin faisant, se renforceront (1) le sentiment que les séquences figées entre langues voisines sont massivement plus transparentes qu'elles ne le paraissent au premier abord, (2) la confirmation que l'approche systémique par analogie constitue l'approche la plus efficiente pour une éducation à l'intercompréhension et au plurilinguisme, et (3) plus largement la piste selon laquelle l'approche systémique par analogie se révèlerait être un vecteur essentiel favorisant l'inclusion culturelle et sociale lors de mobilités dans des espaces européens linguistiquement voisins.The aims of our contribution is to examine the cognitive mechanisms at stake in the frame of the comprehension of neighboring languages and to show the efficiency of the approach by analogy, by means of the example set by phraseological collocations. After recalling the inefficiency of an analytic approach in the understanding (mediatized or non mediatized) between neighboring languages, we will study the various relationships of analogy between equivalent phraseological collocations among neighboring languages. Besides, we will show how the practice of mutual comprehension through an analogical approach provides access, more efficiently and subtly than any other approach, to the meaning of fixed phrases in foreign languages. This sets the stage to strengthen (1) the feeling that the phraseological collocations between neighboring languages are massively more transparent than they appear at first, (2) the confirmation that the systemic approach by analogy is the most efficient approach for an education to intercomprehension and multilingualism, and (3) beyond this, the avenue according to which the systemic approach by analogy could be an essential vector helping cultural and social inclusion during mobility in European territories where are spoken neighboring languages

Developments in finite element simulations of continuous casting

peer reviewedTwo complementary approaches of steel continuous casting modelling using the finite element code LAGAMINE have been developed in the M&S Department. We propose here a description of the context in which the study started, then a description of both macroscopic and mesoscopic approaches. The first one describes the whole continuous casting process, from the free surface in the mould and through the entire machine, including thermal and mechanical behaviour of the steel. The second approach focuses on the prediction of cracks and is developed at the grain scale. Some results are also presented for both models

Cytotoxics compounded sterile preparation control by HPLC during a 16-month assessment in a French university hospital: importance of the mixing bags step

The Centralized Chemotherapy Reconstitution Unit (CCRU) of Paul Brousse Hospital Pharmacy Department assessed the reliability of its Cytotoxics Compounded Sterile Products (CCSP) preparation method in order to improve its CCSP quality assurance system. Five cytotoxic drugs — gemcitabine, 5-fluorouracil, docetaxel, paclitaxel, and oxaliplatin — were assayed by high performance liquid chromatography (HPLC) to determine CCSP concentration. During the observation period, 23,892 CCSP were prepared. Overall, 12,964 preparations contained one of the five analyzed drugs; 7382 (56.9%) out of 12,964 CCSP were analyzed by HPLC; 646 (8.8%) out of 7382 concentrations were outside ± 20% of the prescribed dose; 544 (84.2%) out of 646 were post-administration results and could not be verified. Out of 102 (15.8%) pre-administration results that were re-tested after re-shaking, 94 (92.2%) were found to be acceptable upon re-testing, and 8 (7.8%) were confirmed to be unacceptable and needed to be re-compounded. The 8.8% of tested CCSP were outside ± 20% of the prescribed dose, but extrapolating the results on re-tested CCSP, we can say that our CCSP preparation is reliable with an estimation of only 0.7% of 7382 CCSP analyzed, confirmed as being ± 20% outside the prescribed dose. Nevertheless, this ± 20% magnitude of error should be reduced. Based on pre-administration results, the primary cause of concentration errors appeared to be insufficient mixing of the finished product. Most CCSP dosages occurred after it had been administered, the organization should, therefore, be improved to include testing all CCSP prior to administration. Pharmaceutical companies should endeavor to manufacture compounded injectible drugs in a ‘ready to use’ form and provide vehicles in accurate volumes in order to improve compounding precision

Developments in finite element simulations of continuous casting

peer reviewedTwo complementary approaches of steel continuous casting modelling using the finite element code LAGAMINE have been developed in the M&S Department. We propose here a description of the context in which the study started, then a description of both macroscopic and mesoscopic approaches. The first one describes the whole continuous casting process, from the free surface in the mould and through the entire machine, including thermal and mechanical behaviour of the steel. The second approach focuses on the prediction of cracks and is developed at the grain scale. Some results are also presented for both models

Integrating Aircraft Cost Modeling into Conceptual Design

The article presents cost modeling results from the application of the Genetic-Causal cost modeling principle. Industrial results from redesign are also presented to verify the opportunity for early concept cost optimization by using Genetic-Causal cost drivers to guide the conceptual design process for structural assemblies. The acquisition cost is considered through the modeling of the recurring unit cost and non-recurring design cost. The operational cost is modeled relative to acquisition cost and fuel burn for predominately metal or composites designs. The main contribution of this study is the application of the Genetic-Causal principle to the modeling of cost, helping to understand how conceptual design parameters impact on cost, and linking that to customer requirements and life cycle cost

Comparative study of analytical formulae for the fire resistance of steel beam-columns

peer reviewedThis paper investigates the difference between the buckling formulae published in the Eurocode 3 part 1.2 and the recommendations made in the final report of the Buckling Curves in Case of Fire (BCCF) research project. This study compares the critical temperatures obtained with both formulations to assess the impact on the fire endurance of steel columns subjected to axial compression and bending. An extensive comparison of the ultimate temperatures obtained with both formulations has been performed (382 profiles, buckling about the strong and weak axis, 12 column lengths, 6 M/N ratios and uniform and triangular bending moment distributions). Failure temperatures between 400°C and 860°C have been considered. The formulations are also compared with Finite Elements (F.E.) calculations performed for a S235 HEA 200 at 600ºC. This analysis shows that for buckling about the strong axis the BCCF method is better than the EC3 but for buckling about the weak axis the EC3 predicts failure temperatures closer to the F.E. model than the BCCF formulation. Finally, the ultimate temperatures predicted by the two formulations have also been compared with experimental results from the database SCOFIDAT. This comparison shows that there is no major difference between the two formulations for small and large bending moments. This study concludes that the EC3 and BCCF formulations are generally equivalent and that either formulation can be used

ETUDE DES INTERACTIONS ENTRE LES CYCLODEXTRINES ET LES MEMBRANES LIPOSOMALES OU BIOLOGIQUES

Résumé : A ce jour, l’utilité des cyclodextrines comme adjuvant pharmaceutique n’est plus à démontrer. En biologie cellulaire, la méthyl-b-cyclodextrine est un outil couramment utilisé par les expérimentateurs. La déstructuration qu’elle induit au niveau des microdomaines membranaires que sont les radeaux lipidiques ou les cavéoles est mise à profit pour l’étude des fonctions cellulaires qui y sont associées.Le but de notre recherche est d’étudier les interactions de différentes cyclodextrines couramment utilisées dans le domaine pharmaceutique avec les constituants des membranes liposomales ou biologiques afin de mieux comprendre les conséquences de ces interactions au niveau cellulaire.L’hypothèse d’une interaction des cyclodextrines avec les constituants lipophiles des membranes cellulaires a souvent été énoncée pour expliquer la cytotoxicité de certains dérivés.Nous avons pu montrer à l’aide de liposomes unilamellaires utilisés comme modèles membranaires, que l’interaction des cyclodextrines avec leurs constituants, en particulier le cholestérol, est en relation avec une perte de l’intégrité de la membrane. Ces premières études nous ont permis de prédire quels seraient les dérivés qui induiraient la cytotoxicité la plus importante.La cytotoxicité importante de certains dérivés méthylés (D.S. proche de 2) a été corrélée avec une capacité d’extraction du cholestérol cellulaire relativement élevée. A l’inverse, nous avons montré que les dérivés faiblement substitués extraient peu le cholestérol, ce qui permet d’expliquer la meilleure tolérance observée au niveau biologique avec la Crysmeb et l’HP-b-CD.Nous nous sommes ensuite intéressés à l’effet de la b-CD et de ses dérivés méthylés sur la déstructuration des microdomaines membranaires. Nous avons étudié la relation entre leur capacité de déstructuration des cavéoles et d’extraction du cholestérol cellulaire. Une extraction relativement élevée du lipide induit un effet important au niveau des microdomaines voire très important dans le cas de la Dimeb, le dérivé ayant l’effet le plus délétère sur l’intégrité des membranes artificielles et biologiques. Un effet moins marqué a également pu être corrélé avec une extraction plus faible du cholestérol par certains dérivés (Crysmeb, Trimeb).Les taux d’extraction du cholestérol cellulaire mesurés sont en bonne corrélation, mis à part pour la Trimeb et la b-CD, avec les résultats des diagrammes de solubilité. La capacité de solubilisation du cholestérol par les cyclodextrines est en accord avec les interactions plus ou moins importantes observées en RMN. Les résultats de mesure de l’intégrité des membranes artificielles correspondent à ceux obtenus avec les membranes biologiques excepté pour la b-CD, cette dernière n’ayant pu être testée dans les mêmes conditions que les autres cyclodextrines sur les liposomes.Il est maintenant admis que les cyclodextrines pourraient avoir un intérêt thérapeutique potentiel. En effet, la modulation des taux de cholestérol par l’utilisation de cyclodextrines pourrait être mise à profit pour traiter des maladies ou infections impliquant ces microdomaines membranaires. Summary :Nowadays, the usefulness of cyclodextrins as pharmaceutical adjuvants is obvious. In cell biology, methyl-b-CD is a tool commonly used by scientists. The disruption of membrane microdomains (such as lipid rafts and caveolae) caused by cyclodextrins is used to study cellular functions.The aim of this research is to study the interactions of various cyclodextrins currently used in pharmaceutical development with the components of liposomal and biological membranes for a better understanding of the consequences of these interactions at the cell level.The hypothesis of an interaction between cyclodextrins and lipophilic components of cell membranes has often been suggested to explain the cytotoxicity of some cyclodextrin derivatives.Using unilamellar liposomes as model membranes, this research has shown that the interaction between cyclodextrins and their components, especially cholesterol, is linked with a loss of membrane integrity. This preliminary study has allowed predicting which derivatives will be the most cytotoxic.The high cytotoxicity of some methylated derivatives (D.S. close to 2) has been correlated with a relatively strong extraction capacity of cell cholesterol. On the other hand, it has been shown that low substituted derivatives do not extract much cholesterol, which is in agreement with the better biological compatibility observed with Crysmeb and HP-b-CD.The research has then focused on the effect of b-CD and its methylated derivatives on membrane microdomains disruption. The relation between caveolae disruption and cell cholesterol extraction capacities has been studied. A relatively strong extraction of the lipid highly disturbs the microdomains and this effect is even more important for Dimeb, the derivative showing the highest loss of integrity of artificial and biological membranes. A less marked effect has also been correlated with the lowest cholesterol extraction capacities of some derivatives (Crysmeb, Trimeb).The measured cell cholesterol extraction rates are in good correlation, except for Trimeb and b-CD, with the results of the solubility diagrams. The cholesterol solubilisation capacity of cyclodextrins is in accordance with the intensity of the interactions observed by NMR. The effects on the integrity of artificial membranes correspond to those obtained with biological membranes except for b-CD, which was not tested on liposomes in the same conditions as those used for the other cyclodextrins. It is now agreed that cyclodextrins could have a therapeutical potential. Indeed, the modulation of cholesterol levels could be applied for treating raft-related infections and diseases