Morphosynthesis of Molecular Magnetic Materials

Although molecule‐based materials can combine physical and chemical properties associated with molecular‐scale building blocks, their successful integration into real applications depends also on higher‐order properties, such as crystal size, shape, and organization. New approaches involving templating and self‐ or facilitated assembly of nanoscale building blocks to prepare novel multifunctional molecular magnetic materials with complex form and organization are described.     

Silicene Nanoribbons on an Insulating Thin Film

Silicene, a new 2D material has attracted intense research because of the ubiquitous use of silicon in modern technology. However, producing free-standing silicene has proved to be a huge challenge. Until now, silicene could be synthesized only on metal surfaces where it naturally forms strong interactions with the metal substrate that modify its electronic properties. Here, the authors report the first experimental evidence of silicene nanoribbons on an insulating NaCl thin film. This work represents a major breakthrough, for the study of the intrinsic properties of silicene, and by extension to other 2D materials that have so far only been grown on metal surfaces.     

Atomic-scale STM experiments on semiconductor surfaces: towards molecular nanomachines

The electronic or quantum control of individual molecules with the scanning tunnelling microscope offers exciting perspectives on operating molecular nanomachines. This implies the use of semiconductor surfaces rather than metallic surfaces which would rapidly quench the electronic excitations. We review recent results illustrating the state of the art and the main problems which need to be solved: the choice, design and properties of functionalized organic molecules on semiconductor surfaces; the control of the inelastic electronic channels through a single molecule; and the search for well-controlled atomic-scale wide-band-gap semiconductor surfaces.     

Promising Stability of Gold-Based Catalysts Prepared by Direct Anionic Exchange for DeNO x Applications in Lean Burn Conditions

Supported gold catalysts on γ-Al₂O₃ have been investigated in the catalytic reduction of NO _x in simulated Diesel exhaust gas conditions. Different parameters have been examined essentially the mode of gold incorporation via classical deposition–precipitation and anionic exchange methods and the nature of the pre-activation thermal treatment. The resistance to thermal ageing under reactive conditions at 500 °C was found completely different with a significant rate enhancement on anionic-exchange samples. Further comparisons also show that the nature of the pre-activation thermal treatment influences the extent of surface reconstructions during thermal ageing with a detrimental effect of reductive pre-treatment on the catalytic performances.     

4He Binding Energies on Single-Wall Carbon Nanotube Bundles

We have measured the temperature-programmed desorption spectrum of ⁴ He atoms from a sample of Single-Wall Carbon Nanotubes with various initial coverages. Several Analysis techniques have been applied to the data and the results are reported here.     

Reliability study of AlTi/TiW on polysilicon contacts for high temperature sensors

This paper deals with the reliability of metal on polysilicon gauges for sensors operating in harsh environments. Particular test structures and characterization equipment have been developed in order to study AlTi/TiW on highly doped polysilicon contact resistance behaviour and long-term stability. Finite element modeling of current density distribution over the test structures allowed accurate contact resistance extraction. Contact resistance was found to be temperature dependent, having relative good long term stability at 150°C with a slight (lower than 10%) trend of increase.     

Intra and interindividual variations of pelvic mobility in normal adult walk

PURPOSE OF THE STUDY: Pelvis motion appears as a main human gait component, it is linked to the lower limb joints and to the spine. Current devices, especially the opto-electronical systems, allow quantitative and tri-dimensional gait studies. The purpose of this study was to quantify the pelvic motion individual variability in a sample of healthy subjects. MATERIALS AND METHODS: The study based on a 18 volunters sample. There were 14 men and 4 women, ranged in age from 25 to 37 years. A clinical examination and a AP radiograph of pelvis allowed to include healthy subjects. We used the three-dimensional analysis VICON system with five cameras. Nine records were performed for each subject during a free-speed walking. These nine records were distributed on three different days. RESULTS: The step length medianes varied from 1100 to 1600 mm with a significantly (p < 0.05) regression between the step length, the walking speed and the subjects height. Vertical pelvic oscillations varied in this sample from 25 to 60 mm and linked with step length and walking speed. Pelvic rotation around the vertical axis varied from 1.5 to 15 degrees. We did not found regression between this pelvic rotation and the length step. It seems there are three types of pelvic rotation around the vertical axis. At the beginning of the stance phase, in type I, the pelvis is in the transversal plane whereas in the type II, it appears with the maximal rotation. In type III, the value of pelvic rotation is very low. The successive lateral inclinations of pelvic described a complex motion which varied from 1.5 to 9 degrees. The rotation of shoulders around the vertical axis varied from 4 degrees to 13 degrees and the successive inclinations varied from 3.25 degrees to 12 degrees. We did not found any regression between the pelvic and shoulders motion values. DISCUSSION: This study showed that the pelvis motion varied considerably from one subject to another. These variations induce different ways of walking with various consequences on the hip joint and the spine. We suppose that these variations could take a part in etiology of some diseases as hip arthritis or in total hip arthroplasty failure, especially in cup wearing.