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X-ray Based in Situ Investigation of Silicon Growth Mechanism Dynamics—Application to Grain and Defect Formation

X-ray Based in Situ Investigation of Silicon Growth Mechanism Dynamics—Application to Grain and Defect Formation

To cite this version : Hadjer OUADDAH, Maike BECKER, Thècle RIBERI-BÉRIDOT, Maria TSOUTSOUVA, Vasiliki STAMELOU, Gabrielle REGULA, Guillaume REINHART, Isabelle PÉRICHAUD, Fabrice GUITTONNEAU, Laurent BARRALLIER, Jean-Paul VALADE, Alexander RACK, Elodie BOLLER, José BARUCHEL, Nathalie MANGELINCK-NOËL - X-ray Based in Situ Investigation of Silicon Growth Mechanism Dynamics—Application to Grain and Defect Formation - Crystals - Vol. 10, n°7, p.555 - 2020

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In situ investigation of liquid films in pulsating heat pipe

In situ investigation of liquid films in pulsating heat pipe

Optical grid deflection technique a b s t r a c t To understand functioning of the pulsating (or oscillating) heat pipe (PHP), a liquid film deposited by an oscillating meniscus is studied experimentally inside the simplest, single branch PHP, which is a straight capillary sealed from one end. The PHP capillary is of rectangular section of high aspect ratio. The evap- orator is transparent so that the films can be studied by two complementary optical methods: grid deflec- tion method and interferometry. We were able to measure the dynamic film profile during the self induced meniscus oscillations. It has been shown that the PHP films have the same origin as those of the Taylor bubbles; their thickness right after deposition is well described by the classical formulas. The film shape in PHPs differs from the classical wedge-shaped film observed in capillary heat pipes because both of the larger thickness and of the receding triple liquid-vapor-solid contact line. The film slope is very weak, with a growing in time ridge adjacent to the contact line. It is shown that this ridge is the dewetting ridge. Its dynamics is defined mainly by the capillary effects. Such results can be gener- alized to the conventional multi-branch PHP.
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Oxidation and spallation of FeCrAl alloys and thermal barrier coatings: in situ investigation under controlled temperature gradient

Oxidation and spallation of FeCrAl alloys and thermal barrier coatings: in situ investigation under controlled temperature gradient

particularly true in the case of complex transient temperature conditions as materials are exposed to severe through thickness thermal gradients [5,6] or during fast cooling. As a consequence, it is of primary importance to characterize and analyse the behaviour of such multi-materials in order to understand both the kinetics and the mechanisms of degrada- tion [7,8]. This paper reports recent research aimed at designing and implementing a new, innovative experimental device to investigate the durability of TGO and TBC. Its specificity and originality lie in the possibility to impose a controlled thermal gradient to the investigated material while testing (to reproduce most industrial cases in aeronautics) and to monitor in situ the spallation mechanisms using optical means. Preliminary results showing the influence of (i) the magnitude of the thermal gradient, (ii) the substrate microstructure and mechanical properties and (iii) the scale thickness, on the overall scale damage are presented. 2. MATERIALS AND EXPERIMENTAL
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Transmission electron microscopy in situ investigation of dislocation behaviour in semiconductors and the influence of electronic excitation

Transmission electron microscopy in situ investigation of dislocation behaviour in semiconductors and the influence of electronic excitation

For Peer Review Only 1. Introduction In the low to medium temperature range, moving dislocations in solids with covalent or ionocovalent bonding experience a high lattice friction. This results in a thermally activated motion which, in the appropriate temperature range, could be observed in real time during in situ experiments in a transmission electron microscope (TEM). These experiments make a thorough determination of activation parameters possible . By comparison with other techniques, for example double etching, X-ray topography (for a review, see [1, 2]), where dislocation velocities are averaged over travel distances of a few tenths of a micrometer, the in situ TEM investigation makes possible an analysis of the behaviour of short dislocation segments in the early stages of source operation. Results are available on elemental semiconductors, III-V and II-VI compounds [3]. In these crystals, the dislocation movement is well described by the Peierls mechanism (nucleation and propagation of kink pairs).
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In situ investigation of the structural defect generation and evolution during the directional solidification of 〈110〉 seeded growth Si

In situ investigation of the structural defect generation and evolution during the directional solidification of 〈110〉 seeded growth Si

the twin formation is always accompanied by a significant increase in the local growth rate, despite that the externally imposed cooling rate remains constant (-0.2 K/min) all along the experiment. Moreover, it is confirmed that the growth rate of the global interface is constant (see red curve in Fig. 9), so, it means that a local higher undercooling at the edge of the sample, in comparison to the average undercooling at the solid – liquid interface, exists and has been estimated at about 0.27 K which is sufficient to initiate the observed twin nucleation. As shown in Fig. 4b, at the left edge of the sample, after the initial twin nucleation, the horizontal twin grain grows vertically very fast. Its height is limited by the position of the liquidus melting isotherm (indicated by H in Fig. 4 b), determining in advance the final height of the formed horizontal twin grain. When the first nucleus arrives at the liquidus, stabilization of the growth rate is observed due to the release of the latent heat of solidification until the moment that the solid – liquid interface of the whole sample arrives at the liquidus. This assumption can be confirmed by the growth rate plateau observed in Fig. 9 after each twin nucleation. After nucleation, the twin grows laterally with a rough solid – liquid interface with macro steps, as shown in the X-ray radiography images (Fig. 4b), towards the center of the sample. This growth mechanism is repeated as soon as the undercooling at the edge of the sample is again high enough to form an appropriately oriented new two dimensional twin nucleus. The nucleation always occurs on the common {111} facet that presents a horizontal projection (Fig. 8a and b) followed by a successive alternation of the crystallographic orientation between the one that corresponds to the seed and the other that corresponds to the left horizontal twin Fig. 2. Consequently, this growth model observed in real time can explain the successive twinning growth mechanism experimentally observed.
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In-situ investigation of elemental corrosion reactions during the surface treatment of Al-Cu and Al-Cu-Li alloys.

In-situ investigation of elemental corrosion reactions during the surface treatment of Al-Cu and Al-Cu-Li alloys.

55 1. INTRODUCTION The measurement of corrosion rates under laboratory conditions is a necessary but challenging endeavor. Conventional electrochemical methods are widely used as tools to study corrosion mechanisms, metal dissolution, kinetics and corrosion inhibition [110–112]. However, their application to complex reaction processes such as the dissolution of multi-element and multiphase alloys is fraught with difficulty. It is easy to measure electron transfer, have a high degree of precision and dynamic range, however it is much more difficult to know precisely how the electrons are being distributed amongst a variety of possible chemical reactions. Therefore, it has been of considerable interest to couple the electrochemical technique with other forms of analysis that yield insight into the chemical transformations that occur during electron transfer. Common techniques include UV-Visible, infrared or Raman "spectroelectrochemistry" and coupling with a quartz micro balance [113]. A "classical" example of such a coupled technique is the rotating disk electrode (RDE) or flow jet-cell, designed to investigate the reactions involving the formation of products [114]. With these methods, it is possible to detect electroactive species formed at the working disk electrode downstream at the ring electrode. In this way, the rate of production may be quantified. The major difficulty with this technique is that only a limited number of ions may be detected "downstream" at the ring depending on their electrochemical properties. During the last decades, several experimental techniques have been developed involving the coupling of electrochemical flow cells with different downstream spectroscopic tools such as the inductively coupled plasma atomic emission spectrometer (ICP-AES), also referred as the atomic emission spectroelectrochemistry (AESEC) [111,115–120], inductively coupled plasma mass spectrometer (ICP-MS) [121,122].
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In Situ Investigation of the Early-Stage Growth of Nanoporous Alumina

In Situ Investigation of the Early-Stage Growth of Nanoporous Alumina

broad rods exist at t = 0 s due to the patterned surface and then pores appear at around t = 500 s as evidenced by modu- lations on the rods along the q z direction. For the sample anodized at 40 V in oxalic acid, these modulations appear at around 140 s. The difference between both times of pore initiation is due to experimental conditions: the kinetics increases with voltage, but at the same time, it is clearly slower with phosphoric acid than with oxalic acid. The GISAXS pattern indicates that this porous layer is quite homogeneous and corresponds to the existence of regular pores. When the anodization process progresses, the period of the thickness fringes decreases, and for a very long time, they are no more visible since the fringes are too close to be resolved. The current-voltage (I-V) curve for the 40 V anod- ization in oxalic acid is plotted in Figure 6. The four regimes of anodization can be distinguished as in Figure 4(a), here with regime III starting at around 50 s and regime IV at around 100 s. The pore apparition at 50 s is in agreement with the video observation. The layer thickness was also measured from the thickness fringes period, and its linear evolution is reported on the right axis of Figure 6.
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Straining mechanisms in aluminium alloy 6056. In-situ investigation by transmission electron microscopy

Straining mechanisms in aluminium alloy 6056. In-situ investigation by transmission electron microscopy

a CEMES/CNRS, 29 rue Jeanne Marvig, B.P 4347, 31055 Toulouse Cedex, France b CROMEP, Ecole des Mines d’Albi-Carmaux, Campus Jarlard, 81013 Albi Cedex 09, France Abstract TEM in-situ straining tests, performed in precipitation hardened aluminium alloy 6056-T6, show that precipitates are sheared or by-passed by dislocations. By-passing, assisted by dislocation cross-slip, results in the formation and stress-induced spreading of non-planar loops. The relationship between those elementary mechanisms and the mechanical properties of the alloy is discussed.

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In-situ investigation of adhesion mechanisms on complex micro-structured biological surfaces

In-situ investigation of adhesion mechanisms on complex micro-structured biological surfaces

2 Recently, plant surfaces have attracted great attention given their fascinating functionalities, particularly unique adhesive properties, which are largely resulting from their diverse surface structuring. This paper contributes to the advanced adhesion mechanics investigation on complex biological surface morphologies. Elastomeric replica of three different plant leaves, comprising morphologies at a broad scale (0.5-100 µm), with distinct shapes and complexity, and of a smooth surface were studied in contact with an adhesive probe. To perform precise adhesion measurements, an ultra-nanoindenter was modified based on the JKR (Johnson- Kendall-Roberts) mechanics and equipped with an in-situ real-contact visualization system. The adhesion force on all surfaces was systematically investigated regarding the pre-load conditions. The results were analysed in the light of Hertzian and JKR theories, and underlying morphology-specific mechanisms were identified. A close examination of contact image-force data synchronization revealed unique attachment-detachment mechanisms, arising from different pre-loads and topographies. A significant influence of pre-load on adhesion was observed on the surface with fine micro-structuring and complex morphology, no specific influence was recorded for the remaining two. An overall comparison demonstrates a significant reduction in adhesion on coarse cone-shape patterns and complex micro-structures. The specific adhesion mechanisms arising from biological morphologies may offer assistance to design bio-inspired smart interfaces.
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Localized surface plasmon resonance of Au/TiO2(110): substrate and size influence from in situ optical and structural investigation

Localized surface plasmon resonance of Au/TiO2(110): substrate and size influence from in situ optical and structural investigation

A. Abisset, a A. Bailly, a M. De Santis, a S. Garaud´ ee, a J. Lacipi`ere, a A. Coati, b Y. Garreau c and M.-C. Saint-Lager a Localized Surface Plasmon Resonance (LSPR) of noble metal nanoparticles has attracted a lot of attention in recent years as enhancer of the photocatalytic activity in the visible light domain. Rare are the experimental in situ studies, coupling structural and optical responses, but they are mandatory for a deep understanding of the mechanisms underlying LSPR. Herein we present an in situ investigation during the growth of gold nanoparticles (NPs) on TiO 2 (110) in the 2 –6 nm size range. We probed the structural and morphological properties of the supported nanoparticles by performing GIXRD and GISAXS simultaneously with their optical response in p and s polarizations recorded by SDRS. The rutile surface state turns out to have a major e ffect on the Au NPs growth and on their plasmonic response, both in frequency and vibration modes. The roughening of the TiO 2 (110) surface weakens the interaction strength between the NPs and the substrate, favoring the growth of textured in-plane randomly orientated NPs. Compared to the epitaxial clusters growing on the flat TiO 2 surface, these textured NPs are characterized by a LSPR blue shift and by the presence of LSPR vibration modes perpendicular to the surface for sizes smaller than about 4 nm.
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Quantification in situ des mouvements de truite fario

Quantification in situ des mouvements de truite fario

For this purpose, I first developed a new genetic tool useful for detecting genetic structure in the brown trout, as well as hybridization with captive-bred strains, exhibiting high genotyping success and enabling to successfully identify patterns of isolation-by-distance. This tool was shown cost effective, and especially, should be useful for many population genetics studies on this species across its range. Then, I developed novel assignment approaches combining genetic data and stable isotopes, to study movements at the spatial scale of a river basin, which is of interest for applied matters such as management. This approach, based on machine learning, revealed high accuracy and power to discriminate and assign individuals to their population of origin. Further, I described the genetic effects of captive breeding on patterns of genetic diversity and differentiation, and found that captive-bred genotypes increased diversity and differentiation, and that expected natural patterns could be reversed in the case of higher frequency of captive-bred genotypes occurring at the level of populations. Then, I demonstrated that admixture between wild individuals and those carrying captive-bred ancestry affected dispersal patterns, that the two strains displayed different movement patterns in terms of propensity, distances, and direction, and that admixture between strains considerably reduced dispersal. Finally, I aimed at better understanding how individual, environmental and landscape related factors influence movements in natural populations; here I found that some determinants were universal across rivers, with larger individuals being more prone to movement for instance, or sites that are directly connected by the water flow, and those that are similar in terms of elevation and stream order exchanged more migrants. One the other hand, other drivers were context dependent, for instance the relations between movement patterns and position within riverscapes and habitat availability depended on the river basin considered.
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A kinetic investigation of the in situ polymerization of methyl methacrylate under supercritical fluid CO2 conditions using high-pressure DSC

A kinetic investigation of the in situ polymerization of methyl methacrylate under supercritical fluid CO2 conditions using high-pressure DSC

tory has involved the use of high-pressure DSC to measure CO 2 -induced plasticization, 10 crystalliza- tion, 11,12 and melting 13 of polymers. These studies have allowed us to establish effective in situ tech- niques for the characterization of polymer– gas sys- tems. In this current work, we have used these estab- lished methods to study the polymerization kinetics of methyl methacrylate (MMA) under high-pressure CO 2 .

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Study of in-situ test methods in deltaic silt/ Etude des mé thodes d'essai in-situ dans un limon deltaique

Study of in-situ test methods in deltaic silt/ Etude des mé thodes d'essai in-situ dans un limon deltaique

Access and use of this website and the material on it are subject to the Terms and Conditions set forth at Study of in-situ test methods in deltaic silt/ Etude des mé thodes d'essai in-situ dans un limon deltaique Konrad, J. M.; Bozozuk, M.; Law, K. T.

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Mesure in situ des émissions de N2O dans les procédés de traitement des ERUs. Synthèse des résultats des campagnes de mesure in situ

Mesure in situ des émissions de N2O dans les procédés de traitement des ERUs. Synthèse des résultats des campagnes de mesure in situ

Les données de la littérature portant sur les émissions in situ de N 2 O sont dispersées, indiquant des taux compris entre 0,001 – 4,0% de la charge d’azote entrante pour les procédés intensifs et 0,006 – 1,83% de la charge d’azote entrante pour les procédés extensifs. La dispersion de ces résultats est en partie liée à la diversité des méthodes de prélèvement et d’analyse des gaz. D’autre part, les caractéristiques des effluents et les paramètres de fonctionnement des stations de traitement qui engendrent de multiples conditions de traitement ont également un impact sur le taux d’émission mesuré.
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Complémantarité des gestions in situ et ex situ des ressources génétiques dans les programmes de sélection participative

Complémantarité des gestions in situ et ex situ des ressources génétiques dans les programmes de sélection participative

Cependant, la diversité génétique conservée ex situ est figée et ne répond plus aux pressions de sélection qui continuent de s’exercer dans les champs paysans. L’interruption des processus de co- évolution entre les plantes et les ravageurs des cultures, les pathogènes, pourrait rendre ce matériel génétique inutilisable directement par les paysans après plusieurs années de stockage. A notre connaissance, aucune étude ne relate d’ailleurs des tentatives de rediffusion d’un matériel collecté aux paysans donateurs de semences après plusieurs années (Eva Weltzien, comm. personnelle). En outre, à long terme, les processus physiques de dégradation de la molécule d’Adn peuvent gravement affecter l’intégrité génétique du matériel collecté.
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ACOR -Apport de Connaissances aux Opérations de Repeuplement en anguille. Expérimentation in situ et ex situ

ACOR -Apport de Connaissances aux Opérations de Repeuplement en anguille. Expérimentation in situ et ex situ

Les résultats bruts de l’étude in situ (voir ci-dessus les différences dans les taux de recaptures), l’analyse des recaptures in situ et l’expérimentation ex situ montrent tous que la survie (apparente dans le cas de l’étude in situ) est significativement moins importante (environ -50 %) pour les lots issus de la filière repeuplement (de l’ordre de 20 % à 40 % en 3 mois) comparativement aux lots de civelles naturelles issues de la Sélune ou de l’Oir (de l’ordre de 35 % à 60 % en 3 mois). Ces résultats généraux ne doivent néanmoins pas masquer la variabilité que nous avons rencontrée. La survie apparente a ainsi été moins importante pour l’ensemble des lots en 2018 par rapport à 2017 ; on retrouve des écarts importants entre les lots de naturelles, en particulier pour les lots de fin de période qui peuvent avoir une survie apparente inférieure (mais de manière non significative) au lot de repeuplement de la même année. On notera néanmoins que ces lots sont ceux qui étaient les moins nombreux et que les estimations de mortalité présentent des écarts-types importants pour ces lots. L’expérimentation ex situ présente aussi cette variabilité entre les lots de civelles naturelles.
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Testing Concrete Piles in Situ

Testing Concrete Piles in Situ

"We have had occasional inquiries concerning methods of determining the quality of concrete in piles in place in the ground but we have not attempted to develop a suitable method of [r]

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2019 — Investigation des performances in situ de la numérisation d'une tuyauterie industrielle par photogrammétrie et lumière structurée

2019 — Investigation des performances in situ de la numérisation d'une tuyauterie industrielle par photogrammétrie et lumière structurée

It is common practice to install industrial piping on construction sites or when updating or upgrading existing facilities. Currently, an operator takes manual measurements prior to the installation or modification of industrial piping. Manual measurements are time-consuming, however, and can entail errors. Moreover, the conventional tools that are used (measuring tape, chalk, calipers, lead wire, etc.) are not suitable for accurate dimensional measurement, and conditions are rarely optimal — brightness is variable, factories are congested, and ceiling height can be an issue. When combined, these factors can result in a lack of productivity. With the technological development of optical (contactless) measuring instruments, it is conceivable to replace this manual process with a three-dimensional scanning process. It would then be possible to use this digital measurement process to extract the dimensions and characteristics of interest for the operations in question. However, the relatively high reflectivity of the pipes commonly used for industrial piping (stainless steel, copper, aluminum, etc.) and ambient conditions can be problematic for some 3D capture systems.
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Quand la danse in situ questionne la recherche

Quand la danse in situ questionne la recherche

Une littérature abondante a déjà montré que les danseurs qui s’expriment « hors les murs » ont un rapport particulier aux territoires qu’ils s’approprient. Ce travail s’inscrit pleinement dans ces recherches puisque cette relation sensible entre les danseurs in situ et la ville est au cœur de mon travail de thèse. Cet article a donc pour premier objectif de contribuer à la compréhension de la démarche des danseurs qui accorde une grande importance à l’espace. Dans un deuxième temps, il s’agira de prolonger la réflexion en questionnant l’intérêt des expériences hybrides entre art et géographie, mais aussi les blocages potentiels qui peuvent provenir de ce mélange des genres. En faisant une analyse rétrospective sur mes travaux de recherche, il me semble que le caractère heuristique d’une rencontre entre art et science provient de la possibilité de confronter des représentations du territoire qui diffèrent et qui s’enrichissent mutuellement.
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In Situ and Ex Situ Syntheses of Magnetic Liquid Crystalline Materials: A Comparison

In Situ and Ex Situ Syntheses of Magnetic Liquid Crystalline Materials: A Comparison

We observe in Figure 9 that the cycle is almost square shaped: the coercive field is 8.2 kOe and the remanence ratio is 0.94. As we already observed in the case of longer nanorods [15], the thermal treatment has considerably improved the nanorods orientation. In order to determine the minimum field necessary to orientate the nanorods, the sample was heated up in the isotropic phase and cooled down to room temperature under different magnetic fields (from 50 mT to 5 T). The magnetization of the sample after the treatment was measured and compared with the magnetization at saturation where we consider that all the nanorods are oriented. The curves are shown in Figure 10. These are quite steep at low magnetic fields and more than 50% of nanorods are oriented already at 50 mT and at 500 mT the M o /M s value corresponding to a maximum degree of
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