7,962 research outputs found
Sampling Theorem and Discrete Fourier Transform on the Hyperboloid
Using Coherent-State (CS) techniques, we prove a sampling theorem for
holomorphic functions on the hyperboloid (or its stereographic projection onto
the open unit disk ), seen as a homogeneous space of the
pseudo-unitary group SU(1,1). We provide a reconstruction formula for
bandlimited functions, through a sinc-type kernel, and a discrete Fourier
transform from samples properly chosen. We also study the case of
undersampling of band-unlimited functions and the conditions under which a
partial reconstruction from samples is still possible and the accuracy of
the approximation, which tends to be exact in the limit .Comment: 22 pages, 2 figures. Final version published in J. Fourier Anal. App
Tuning ubiquinone position in biomimetic monolayer membranes
Artificial lipid bilayers have been extensively studied as models that mimic natural membranes (biomimetic membranes). Several attempts of biomimetic membranes inserting ubiquinone (UQ) have been performed to enlighten which the position of UQ in the lipid layer is, although obtaining contradictory results. In this work, pure components (DPPC and UQ) and DPPC:UQ mixtures have been studied using surface pressure-area isotherms and Langmuir-Blodgett (LB) films of the same compounds have been transferred onto solid substrates being topographically characterized on mica using atomic force microscopy and electrochemically on indium tin oxide slides. DPPC:UQ mixtures present less solid-like physical state than pure DPPC indicating a higher-order degree for the latter. UQ influences considerably DPPC during the fluid state, but it is mainly expelled after the phase transition at ËË 26 mN·m^-1 for the 5:1 ratio and at ËË 21 mN·m^-1 for lower UQ content. The thermodynamic studies confirm the stability of the DPPC:UQ mixtures before that event, although presenting a non-ideal behaviour. The results indicate that UQ position can be tuned by means of the surface pressure applied to obtain LB films and the UQ initial content. The UQ positions in the biomimetic membrane are distinguished by their formal potential: UQ located in âdivingâ position with the UQ placed in the DPPC matrix in direct contact with the electrode surface ( -0.04±0.02 V), inserted between lipid chains without contact to the substrate ( 0.00±0.01 V) and parallel to the substrate, above the lipid chains ( 0.09±0.02 V).Peer ReviewedPostprint (author's final draft
A Combined Clinical and Langmuir Film Study of Natural Tear Films
The Langmuir technique has been applied to the study of natural tears and the results obtained from surface pressure-area isotherms have been correlated with those of clinical tests (the Schirmer and the TFBUT tests). The population studied only included people aged over 45. Natural tears were collected from Schirmer strips, which were placed in contact with the water subphase of a Langmuir trough for recording the surface pressure-area isotherms. These isotherms have been classified as good or weak according to the characteristics obtained. From the isotherms, characteristic values such as plimit, CS-1max and pmax were also obtained. The analysis from the Chi-squared test indicates dependence between the Schirmer test and the type of isotherms (P0.05 indicates that the independence cannot be discarded with the significance criteria imposed. Working with the same criteria of significance, we obtain moderate or good Pearson correlation coefficients with statistical significance (P0.05) between the values of the TFBUT test and the plimit, CS-1max and pmax values.Peer ReviewedPostprint (published version
Prototype of a GBAS ground station. Implementation of the differential corrections according to CAT I MOPS ED-114
The accuracy that GNSS and GBAS can provide is the key to improve air traffic
where bottlenecks appear: terminal areas surrounding main airports. Its
implementation would represent lower budgets in cost and maintenance in
comparison to current guidance systems that would remain as backup.
This project focuses on processing raw satellite data and producing a standard
output to increase air traffic navigation, approach and landing capacities in
terminal areas. This involves tasks such as algorithm prototyping in Matlab and
-integrity monitoring testing- with bad ephemeris data to check the output
response. The impact of known errors will be analyzed to obtain a robust and
scalable system.
The next step will be the GBAS message codification and generation (Type 1)
for a GBAS station. This station will be made up of four reference receivers
located in the proximity of airport's Runways to accomplish CAT (I)
requirements and provide the best measurements in approach and landing
maneuvers.
The project is located in the base of an ambitious bigger scheme (CATGOS)
under development by Indra, which aims to implement and certificate a GBAS
station for an airport environment in a four-year prospect
âZombie attackâ a new way to teach Chemistry
The Higher Education requires new models which allow training people able to adapt and survive in changing environments. It is based on the use of technologies and the adaptation of knowledge to people. It is about an education according to circumstances, which is adapted to context and virtual behaviour of people.
One of the main difficulties that lecturers find in the classroom is how to maintain students' attention and interest in their subject, especially when students also think that the subject is not important for their training. In order to motivate these students, innovation in educational techniques and methodologies, such as experiential learning, are progressively being imposed to and/or coordinated with the traditional ones. Escape Room is a very modern concept in education, based on the development of mental skills for the solution of enigmas and problems. It is a tool to develop the cooperative, cognitive, deductive and logical reasoning skills of the students.
In this work, an educational gamification experience based on the escape room concept is presented. The students have 1 hour and 30 minutes to carry out this activity. They will have to solve four puzzles and enigmas that will give them the key to open a treasure chest and finally let them escape from the classroom. Logic, ingenuity and teamwork will allow participants to develop not only chemical competence, but also other basic skills. The story that is told throughout the escape room is a zombie attack: the city has been infected (with a virus) and only the occupants of the room where the activity takes place have not been infected. In addition, they can all protect themselves if they are able to open the chest where the antidote is located. The aim of this activity is to enhance the knowledge acquired throughout the semester as well as the development of skills.Universidad de MĂĄlaga. Campus de Excelencia Internacional AndalucĂa Tec
An Ecosystem Called University
This book is dedicated to the university as a protagonist of change. Its purpose is to see the university as a place where the lines between organization and system are fluid, where the whole is more than the sum of its parts, and the product is knowledge as an end, a means and a way of developing the individual (critical sense) and its interaction with the environment (instrumental reason). The book seeks throughout to foster the image of the Ecosystem University as being a producer of novelty, where the only certainty is uncertainty. The university undergoes a process of permanent spiral growth - the spiral of knowledge without any control of causality - and creating, through its environment, responsible citizens, and free-thinking persons. The Ecosystem University is undeTTast that is assumed in the present. Our work to rediscover the natural feel of an ecosystem embedded in the university and the rich experience of community will take us by the hand and lead us, proud professors, to the purest origin of human knowledge with a flair of joie de vivre: the refreshing purity of the new and the authentic value of ingenuity that will allow us to be ourselves in that very moment: a community that self-organizes, builds projects of life and culture, and determines its own destiny
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