Universality of the 1/3 shot-noise suppression factor in nondegenerate diffusive conductors

Shot-noise suppression is investigated in nondegenerate diffusive conductors by means of an ensemble Monte Carlo simulator. The universal 1/3 suppression value is obtained when transport occurs under elastic collision regime provided the following conditions are satisfied: (i) The applied voltage is much larger than the thermal value; (ii) the length of the device is much greater than both the elastic mean free path and the Debye length. By fully suppressing carrier-number fluctuations, long-range Coulomb interaction is essential to obtain the 1/3 value in the low-frequency limit.

González et al. Reply

A Reply to the Comment by K. E. Nagaev

Extension of the impedance field method to the noise analysis of a semiconductor junction: Analytical approach

We present an analytical procedure to perform the local noise analysis of a semiconductor junction when both the drift and diffusive parts of the current are important. The method takes into account space-inhomogeneous and hot-carriers conditions in the framework of the drift-diffusion model, and it can be effectively applied to the local noise analysis of different devices: n+nn+ diodes, Schottky barrier diodes, field-effect transistors, etc., operating under strongly inhomogeneous distributions of the electric field and charge concentration

Quantum suppression of shot noise in field emitters

We have analyzed the shot noise of electron emission under strong applied electric fields within the Landauer-Bttiker scheme. In contrast to the previous studies of vacuum-tube emitters, we show that in new generation electron emitters, scaled down to the nanometer dimensions, shot noise much smaller than the Schottky noise is observable. Carbon nanotube field emitters are among possible candidates to observe the effect of shot-noise suppression caused by quantum partitioning.

Shot-noise spectroscopy of energy resolved ballistic currents

We investigate the shot noise of nonequilibrium carriers injected into a ballistic conductor and interacting via long-range Coulomb forces. Coulomb interactions are shown to act as an energy analyzer of the profile of injected electrons by means of the fluctuations of the potential barrier at the emitter contact. We show that the details in the energy profile can be extracted from shot-noise measurements in the Coulomb interaction regime, but cannot be obtained from time-averaged quantities or shot-noise measurements in the absence of interactions.

BestWishes

El projecte consisteix en la creació d'una plataforma tecnològica, mitjançant tecnologia .NET i anomenada BestWishes, que té com a objectiu proporcionar als consumidors una eina per gestionar productes preferits, comprar o reservar aquests productes i ser una plataforma de comerç electrònic per a comerços que venen productes de regal.

Per una comprensió històrica de les activitats aquàtiques : una mirada educativa

Una atenta observació de les activitats aquàtiques de caire educatiu mostra que aquestes pràctiques es fonamenten, principalment, en constructes que no són propis de la pedagogia, ans provenen de l’antropologia i/o de les cultures establertes a l’entorn de l’aigua. Així, el present article es pregunta pels sentits que acompanyen aquests imaginaris que sorgeixen de la relació que s’estableix entre l’home i el medi aquàtic. Per a fer-ho, s’utilitza el recurs hermenèutic de comprendre quines han estat les pràctiques aquàtiques que han anat sorgint al llarg de la història, ja que la idea principal del treball sosté que l’activitat educativa en el medi aquàtic s’ha construït a partir dels imaginaris culturals, sorgits de les mateixes pràctiques aquàtiques que l’han precedit.

Informed recommender: basing recommendations on consumer product reviews

Recommender systems attempt to predict items in which a user might be interested, given some information about the user's and items' profiles. Most existing recommender systems use content-based or collaborative filtering methods or hybrid methods that combine both techniques (see the sidebar for more details). We created Informed Recommender to address the problem of using consumer opinion about products, expressed online in free-form text, to generate product recommendations. Informed recommender uses prioritized consumer product reviews to make recommendations. Using text-mining techniques, it maps each piece of each review comment automatically into an ontology

Introducing online teaching in Humanities: A case study about the acceptance of online activities by the academic staff of classical languages

The purpose of this paper is to show the perceptions of the academic staff of classical languages (ancient Greek and Latin) concerning use of online activities during their courses. The study was carried out in three countries: Greece (three major Universities), Spain (University of Barcelona) and the United States (University of California, Berkeley) with the participation of thirty-three academic instructors. Depending on the level of use and acceptance of the ICT and following G. Moore¿s classification, we separated the participating academics in three groups: the conservatives, the mainstream and the early adopters. The fact that the smallest group is the third clearly shows the necessity for teachers¿ preparation and training before introducing innovative projects in the classroom. Since the starting point for the application of innovation in the classroom is the teacher, policy makers should focus on helping them become conscious of changes in teaching methods and include their opinion during the design of innovative projects.

Introducing online teaching in Humanities: A case study about the acceptance of online activities by the academic staff of classical languages

The purpose of this paper is to show the perceptions of the academic staff of classical languages (ancient Greek and Latin) concerning use of online activities during their courses. The study was carried out in three countries: Greece (three major Universities), Spain (University of Barcelona) and the United States (University of California, Berkeley) with the participation of thirty-three academic instructors. Depending on the level of use and acceptance of the ICT and following G. Moore¿s classification, we separated the participating academics in three groups: the conservatives, the mainstream and the early adopters. The fact that the smallest group is the third clearly shows the necessity for teachers¿ preparation and training before introducing innovative projects in the classroom. Since the starting point for the application of innovation in the classroom is the teacher, policy makers should focus on helping them become conscious of changes in teaching methods and include their opinion during the design of innovative projects.

La gestió del regadiu a Catalunya: plans, actors i reptes de futur

Irrigation has traditionally constituted one of the most characteristic and emblematic agricultural mosaics of the Mediterranean as a key factor of socio-economic dynamism of the territorial matrix. In recent years there has been an important scientific, intellectual and social environment mobilization around water uses and, in particular, around the main socio-economic use of resource: irrigation, which is undergoing an intense and accelerated transformation process. Thus, in parallel with the decline of traditional irrigation systems, located in areas with natural availability of water, fertile soil and appropriate topographic conditions, the socio-economic changes in the last decade have stimulated the appearance of new irrigated areas with environmental, social and economic disparate characteristics. As a result, the irrigation management model has been conditioned to respond to the new parameters of water scarcity and resource efficiency. In addition, policies and actors have evolved over time as a consequence of disparate priorities –and often conflicting– in terms of irrigation, making necessary the gear of different discourses. In this context, the Model of social commitment of irrigation proposed by the Institutional and Social Innovations in Irrigation Mediterranean Management (ISIIMM) can become a starting example

Aprendre a dir que no

Breu comunicació on es donen alguns consells alhora d'haver de comunicar notícies negatives com: unasubvenció que ha estat denegada, un recurs que ha estat desestimat, una condemna judicial, la denegació d'un permís de residència, etc

L'Aprenentatge virtual com a una nova forma d'ensenyar i d'aprendre a través de les tecnologies de la informació i la comunicació

Els avenços tecnològics de les àrees de la informació i la comunicació estan propiciant un canvi cultural important que repercuteix directament en el món de l'aprenentatge i de l¿ensenyament. L'aprenentatge instrumental d'aquestes tecnologies de la informació i la comunicació (TIC) a priori i l'aprenentatge a través d'aquestes tecnologies amb la finalitat d'accedir a un major coneixement ha provocat que el procés d'ensenyament i aprenentatge s'estengui al llarg de la vida («Life long learning») de qualsevol persona que, per la seva professió, necessiti actualitzar els seus coneixements. Per això, com es podrà apreciar en el present article, les noves línies d'investigació s¿orienten envers dos tipus d'estudi: optimitzar el disseny dels sistemes d'e-learning i analitzar els aspectes diferencials dels e-learners. A més, en l¿article, se¿ns dóna a conèixer com s'està desenvolupant el camp de l'aprenentatge virtual en aquest moment, en particular en l'àmbit de les universitats europees.

L"ús del portafolis europeu de les llengües en versió electrònica (ePEL+14) en l"aprenentatge formal i no formal de la llengua i cultura catalanes

Aquest article presenta el Portafolis Europeu de les Llengües en versió electrònica (ePEL+14) validat pel Consell d'Europa l"any 2010. En primer lloc, s"introdueix en que consisteix un portafolis educatiu, com s"ha passat al portafolis electrònic per l"ensenyament de llengües. En segon lloc, es descriu aquest nou portafolis electrònic europeu adreçat a l"aprenentatge de llengües i cultures, que pot ser utilitzat com a suport de l"ensenyament de llengües, com a instrument transversal per fomentar l"autonomia de l"aprenent de llengües cap a l"adquisició progressiva dels nivells del Marc Comú Europeu de Referència per a les Llengües (MCER) o com a eina d"auto-aprenentatge de les competències lingüístiques assolides per part de l"aprenent de llengües autònom. En darrer lloc, s"extreuen algunes conclusions preliminars de l"experiència d"incorporar l"ePEL+14 en els Erasmus Intensive Language Courses (EILC) de llengua catalana de la Xarxa Vives d"Universitats.