Switching devices in sol-gel hybrid thin film technology

Development of non-volatile memories based on organic soft materials is one of two main trends in industry for flash-memories. The electrical bistability of such materials makes them ideal candidates for cost-effective, fast programming switching devices. SiO₂-Rose Bengal (bis-triethylammonium) hybrid thin films are reported here together with their characterizations. The technology yields well reproducible films with good current-voltage switching characteristics. Owing to their physical and chemical stability the films are suited to standard micro-photolitography technology, rendering their fabrication cost-effective.     

Performance of Optical Receivers with Avalanche Photodetection

This paper reports the results of a computer study to numerically evaluate the digital performance of an optical receiver with avalanche photodetectors. Exact and approximate APD statistics were implemented and error probabilities in the rangel0^{-1}tol0^{-4}were computed. Both shot-noise and receiver-noise limited conditions were examined, and on-off keying, binary pulse comparison, multilevel intensity, and PPM signaling formats are considered.     

Forging of metallic foams to reproduce biomechanical components

In this study an analysis of the forging process of a simple-shaped metallic foam billet was carried out using both experimental trials and mathematical models in order to obtain a 3D geometry of the complex form.

In particular, the deforming behaviour of a metallic foam and the development of density gradients were investigated through a series of experimental forging tests in order to produce a selected portion of a hip prosthesis. This type of replacement for human bone was chosen as object of study due to its elevated commercial demand and its particularly complex 3D shape. A commercial finite element code (Deform 3D^®), with an accurate rheology of the material, was utilized to model the foam behaviour during the forging process. The code for the rheology of the material is considered using a model valid for porous materials which also includes a measure of local density. The usefulness of the model used was verified by the comparison of the predicted results (the force necessary for the completion of the forging process and the final shape obtained) and the experimental evidence.     

Sequencing approaches for multiple-aisle automated storage and retrieval systems

Automated storage and retrieval systems (AS/RS) are used in high velocity distribution centres to provide accurate and fast order processing. While almost every industrial system is comprised of many aisles, most of the academic research on the operational aspects of AS/RS is devoted to single-aisle systems, probably due to the broadly accepted hypothesis proposing that an m aisles system can be modelled as m 1-aisle independent systems. In this article, we present two multi-aisles sequencing approaches and evaluate their performance when all the aisles are managed independently first, and then in a global manner. Computational experiments conducted on a multi-aisle AS/RS simulation model clearly demonstrate that a multi-aisle system cannot be accurately represented by multiple single-aisle systems. The numerical results demonstrate that, when dealing with random storage, globally sequencing multi-aisle AS/RS leads to makespan reductions ranging from 14 to 29% for 2- and 3-aisle systems, respectively.     

Synthesis and Biological Characterization of Amidopropenyl Hydroxamates as HDAC Inhibitors

A series of amidopropenyl hydroxamic acid derivatives were prepared as novel inhibitors of human histone deacetylases (HDACs). Several compounds showed potency at <100 nM in the HDAC inhibition assays, sub‐micromolar IC₅₀ values in tests against three tumor cell lines, and remarkable stability in human and mouse microsomes was observed. Three representative compounds were selected for further characterization and submitted to a selectivity profile against a series of class I and class II HDACs as well as to preliminary in vivo pharmacokinetic (PK) experiments. Despite their high microsomal stability, the compounds showed medium‐to‐high clearance rates in in vivo PK studies as well as in rat and human hepatocytes, indicating that a major metabolic pathway is catalyzed by non‐microsomal enzymes.     

Modeling of Dye sensitized solar cells using a finite element method

In this paper we present an electrical model to simulate a Dye sensitized Solar Cell (DSC) based on a Finite Element Method as an extension of the TiberCAD code. The CAD allows to calculate steady-state properties and ideal IV characteristic of the cell using 1, 2 and 3D meshes for the device. We describe the model and its prerogatives, explaining the code-related problems and the implementation of the model. We show a comparison with a measured IV curve, shading light on revealing the role of different parameters involved in the physics of conversion of light. Finally, an application to an experimental set-up, the Incident Photon to Current Efficiency, is presented, estimating the Collection Efficiency spectrum for a standard DSC and the collection efficiency spectrum for a standard DSC.     

Experience on Pre-Series and Series Production of LHC Dipoles Cold Masses in ASG Superconductors

In 1986 Ansaldo Magnet Dept. (now ASG Superconductors) started, in cooperation with CERN, the design activities of the first 1 m-8 T LHC prototype dipoles. After several design steps and the manufacturing of 1+3 prototype dipoles 10 m long, the final design configuration 15 m long was defined by CERN. During the following years, a very close collaboration with CERN engineers and technicians lead to define the parameters about the most critical manufacturing processes, in particular winding of s.c. cable, collaring of coils, cold mass welding and test procedures. In the meantime, installation and commissioning of all the manufacturing plants followed: winding machines, curing presses, collaring press and welding press were installed, as well as geometrical measurements stations and vacuum chamber for leak test. Finally two manufacturing halls were fully dedicated to LHC dipoles production. At the beginning of year 2002, all the manufacturing plants were coming to be operational, ready to start the large scale production of LHC cold masses: 30 pre-series, 386 series and 30 spare cold masses have been produced till May 2007, to get a total number of 446 cold masses. In this paper we summarize all the data collected during a five years production: main manufacturing data, test results and production rate are presented. Final results about tests performed at CERN in superfluid He at 1.9 K are also included as well as correlation between test result and manufacturing rate.     

The Hedgehog-GLI Pathway Regulates MEK5-ERK5 Expression and Activation in Melanoma Cells

Malignant melanoma is the deadliest skin cancer, with a poor prognosis in advanced stages. We recently showed that the extracellular signal-regulated kinase 5 (ERK5), encoded by the MAPK7 gene, plays a pivotal role in melanoma by regulating cell functions necessary for tumour development, such as proliferation. Hedgehog-GLI signalling is constitutively active in melanoma and is required for proliferation. However, no data are available in literature about a possible interplay between Hedgehog-GLI and ERK5 pathways. Here, we show that hyperactivation of the Hedgehog-GLI pathway by genetic inhibition of the negative regulator Patched 1 increases the amount of ERK5 mRNA and protein. Chromatin immunoprecipitation showed that GLI1, the major downstream effector of Hedgehog-GLI signalling, binds to a functional non-canonical GLI consensus sequence at the MAPK7 promoter. Furthermore, we found that ERK5 is required for Hedgehog-GLI-dependent melanoma cell proliferation, and that the combination of GLI and ERK5 inhibitors is more effective than single treatments in reducing cell viability and colony formation ability in melanoma cells. Together, these findings led to the identification of a novel Hedgehog-GLI-ERK5 axis that regulates melanoma cell growth, and shed light on new functions of ERK5, paving the way for new therapeutic options in melanoma and other neoplasms with active Hedgehog-GLI and ERK5 pathways.