Two-dimensional coupled electron-hole layers in high magnetic fields

Contains fulltext : 18860.pdf (publisher's version ) (Open Access)In solids, it is nowadays possible to create structures in which electrons are confined into a two-dimensional (2D) plane. The physics of a 2D electron gas (2DEG) has proved to be very rich, in particular in the presence of a transverse magnetic field. The Quantum Hall Effect, i.e. the quantization of the 2DEG conductance for specific magnetic field values, has indeed brougth to two Nobel prices in the last 20 years. In the first part of my thesis, I show that when a layer of positive charges (holes) is placed closely to a 2DEG, a transition can occur between the uncoupled layers - each showing the QHE - and a gas of spatially indirect excitons (IE), i.e. bound electron-hole pairs similar to hydrogen atoms. In the second part, I demonstrate a new optical technique to study the motion of the IE as a whole in the 2D plane. Conventional optics can indeed only probe the electron-hole relative motion, but our study is made possible by a magnetic field parallel to the 2D layers.110 p

A pure soul: Ennio De Giorgi, a mathematical genius

This biography illuminates the life of Ennio De Giorgi, a mathematical genius in parallel with John Nash, the Nobel Prize Winner and protagonist of A Beautiful Mind. Beginning with his childhood and early years of research and teaching, into his continued professorship and solution of the 19th problem of Hilbert, this book pushes beyond De Giorgi’s rich contributions to the mathematics community, to present his work in human rights, including involvement in the fight for Leonid Plyushch’s freedom and the defense of dissident Uruguayan mathematician José Luis Massera. Considered by many to be the greatest Italian analyst of the twentieth century, this volume illustrates De Giorgi in full through documents from and direct interviews with friends, family, and colleagues

Prospective Memory, User Experience (UX), and Online Product Configurators

n recent years, the emergence of the mass customization paradigm has led to the development of online configurators as tools to increase the involvement of possible clients in the productive process. The study here presented involved 50 users which interacted with an online configurator for interior design products. Participants were also administered two tests aimed at measuring their prospective memory abilities. When they completed the interaction with the configurator, they were asked to provide ratings of aspects such as their level of satisfaction with the configurator and their willingness to buy the product they created. The results show that prospective memory is relevant in allowing the successful completion of the configuration task. Moreover, the willingness to buy the product is related to the ability to remember events in the distant future, while the degree of satisfaction with the interaction experience is related to the ability to remember what is going to happen in the near future

Homogeneous blue lumps of the nipple-areola complex in pubertal girls

Retroareolar cysts are benign breast lesions caused by the obstruction and consequent dilatation of Montgomery tubercles. Herein, we report two cases of premenarchal girls who developed retroareolar cysts. Their course and differential diagnosis are discussed

Shopping online and online design

Many steps have been taken in recent years to bring production processes closer to customer needs. This trend of mass customisation is best characterised by the emergence of online configurators which help to eliminate barriers between production and market needs. This study involved 82 participants who interacted with an online configurator for interior design products. Participants were administered two tests to measure their prospective memory abilities. After interacting with the product configurator, the participants were asked to rate aspects of the configurator - level of satisfaction, extent to which they had been able to satisfactorily conclude the configuration process, as well as their willingness to buy the product they created. The results show that prospective memory is relevant in relation to the degree of satisfaction with the interaction experience. The results also seem to suggest that prospective memory is involved in the successful completion of the configuration process and in the level of willingness to purchase the configured product

Cervical Spondylotic Myelopathy: From the World Federation of Neurosurgical Societies (WFNS) to the Italian Neurosurgical Society (SINch) Recommendations

Cervical spondylotic myelopathy (CSM) is a progressively growing pathology to afford by a spinal surgeon due to the aging of the population, associated with better treatment manage-ment and the best diagnosis and treatment solutions are greatly discussed. Nowadays that scientific literature is progressively increasing to identify the gold standard in diagnosis and treatment can be very challenging. This is particularly evident in spinal surgery with many different indications not only in different countries but also in the same local reality. In this scenario, many neurosurgical societies works to identify some guideline or recommenda-tions to help spinal surgeons in daily practice. Furthermore, in an era in which legal issues are increasingly present in clinical practice to have some indications globally accepted can be very useful. World Federation of Neurosurgical Societies (WFNS) few years ago starts this process creating a list of recommendations originating from a worldwide steering com-mittee to respect all the local reality. The spinal section of Italian Neurosurgical Society de-cides to adopt the WFNS recommendations with some revision basing on Italian scenario. The steering committee of the Spinal Section of Italian Neurosurgical Society identify 7 groups to review the literature of the last 10 years about different topics on CSM and to analyses the WFNS recommendations to adapt it to the Italian daily practice. The state-ments were discussed and voted in 2 sessions to obtain the final version. A list of recom-mendations on natural course and clinical presentation; diagnostic tests; conservative and surgical treatment; anterior, posterior and combined surgical treatment; role of neurophys-iological monitoring and follow-up and outcome was created with only few new or revised statements respect the ones of WFNS. The Spine Section of Italian Neurosurgical Society create a list of recommendations that represent the more contemporary treatment concepts for CSM as presented in the highest quality clinical literature and best clinical practices available on this subject