Surface Electron Channels on Suspended Helium Films

No Heading The profile of a suspended helium film over a narrow channel is calculated self-consistently for several values of the bulk liquid helium level. We also determine the electron distribution in the channel when surface electrons are deposited on the film. It is shown that a thin van der Waals film with spatially dependent thickness is formed in a wide region at the channel center where a large fraction of electrons are confined. We obtain that the effective lateral confining potential can be described by a parabolic one is experimental conditions reported in the literature.PACS numbers: 73.20.Dx, 67.70.+n     

State of the art of the virtual reality applied to design and manufacturing processes

The idea that technology can transfer a person to a different environment without any physical movement and create the illusion of interaction with the artificial environment is not new. Scientists and engineers have been dedicating their efforts to its progressive development over the last fifty years. However, most of the technological advances have been made in the last ten years, undoubtedly thanks to improvements in computer efficiency and the miniaturization of sensorization devices. Nowadays, virtual reality is successfully applied in different fields, such as telemedicine, robotics or cinematography. Following on from this success, the question arises of whether we are ready to apply it to industrial design and manufacturing processes. The lack of recent reviews on this technology applied to CAD/CAM, together with its rapid evolution over the last decade, have been the primary motivations for carrying out this study.     

Thermal and viscoelastic behaviour of copolymers of propene and 1-hexene

Summary The thermal and viscoelastic behaviour of several copolymers of propene and 1-hexene have been studied in a wide range of compositions. The samples were prepared with a Ziegler-Natta catalyst with both internal and external donors. A significant amount of crystallinity has been found for the sample with a comonomer content as high as 19 mol %. The dynamic mechanical results show a considerable decrease of the storage modulus in the copolymers in relation to that of iPP. A single relaxation, corresponding to the glass transition, has been found in all the samples. Only the copolymer with the highest hexene content seems to display the beginning of another relaxation at low temperature.     

Teaching communication skills to hearing-impaired children

The Mehida multimedia system offers hearing-impaired children an easy and appealing way to learn how to communicate with their hearing and deaf peers. Mehida helps them acquire various communication skills simultaneously: sign language, speech, fingerspelling, lip reading, reading, and writing. Didactic activities and games teach the different means of communication. A character shaped like a pear assists and guides the children, explaining each activity and encouraging the children to identify with it throughout the process     

Adverse effects of pharmacological therapy for nicotine addiction in smokers following a smoking cessation program.

This multicenter, community-based, prospective, longitudinal study evaluated the safety of nicotine replacement therapy (NRT), bupropion, and combined therapy of NRT and bupropion for smokers seeking to quit, when these therapies were used under real-world conditions following a smoking cessation program. Participants were smokers aged 18 years or older who attended five smoking cessation clinics. Evaluations were made at 15, 30, 60, and 90 days. We investigated the possible existence of adverse effects as well as the severity of each adverse effect and its influence on the treatment course. The study included 904 smokers: 370 received NRT, 413 received bupropion, and 121 received combined therapy. At 15, 30, 60, and 90 days, adverse effects were reported by 43.8%, 33.1%, 22.3%, and 5.7% of subjects, respectively. Adverse effects were significantly more frequent in subjects receiving combined therapy or bupropion alone than in NRT-treated subjects at the 15-, 30-, and 60-day follow-ups. A total of 83 smokers (9.3%) withdrew from treatment and 116 (12.8%) stopped temporarily because of adverse effects. No differences were found in the percentages of discontinuation among the different treatment options. Adverse effects rarely were severe (n=10). Nevertheless, 41 subjects (4.5%) discontinued drug therapy indefinitely and 55 (6.1%) discontinued it temporarily because of mild adverse effects. Pharmacological therapies for smoking cessation are safe as long as they are appropriately prescribed and supervised by clinicians according to clinical practice guidelines. Adverse effects are primarily mild. Nonetheless, mild adverse effects may be perceived by patients as a serious enough problem to cause them to discontinue treatment.     

Dynamic Contextual Adaptation

When developing systems based on COTS, components need to be adapted in most of the occasions to work under certain conditions which were not initially predicted by their developers. Thus, it is very important to provide systems with the skill to dynamically alter their behaviour while running, depending on the changing conditions of the environment. In this work we describe a context-dependent, dynamic mapping between the interfaces of the components being adapted, overcoming some of the limitations of the static mappings presented in previous works. This is achieved by means of contextual environments, which define flexible adaptation policies. We also present a case study, illustrating the proposal, and discuss the improvements these mappings represent in comparison with previous works, as well as some open issues.     

Communication via Mobile Vesicles in Brane Calculi

P systems and Brane calculi are two (families of) computational models inspired by the structure and the functioning of living cells. Although they have different goals there is a recent growing of interests in results that bridge the two research areas.Here we consider an important kind of communication based on the natural budding of mobile membranes (e.g., Golgi apparatus) that is already defined for P systems and we show how to construct an analogous communication in the basic Phago/Exo/Pino Brane calculus.     

Harmonic distortion analysis using an improved charge sheet model for PD SOI MOSFETs

This work presents an Improved Charge Sheet compact Model (ICSM) especially valuable for distortion analysis, where precise calculation of derivatives of at least third order is required. A new expression for the charge is used in the calculation of the current. Vertical electric field, mobility and DIBL are represented using previously reported for other purposes more precise expressions. The very good agreement obtained between experimental PD SOI MOSFETs with channel lengths from 0.32 to 10 μm and modeled currents, derivatives and distortion figures is shown.