Dirac materials in parallel non-uniform electromagnetic fields generated by SUSY: A new class of chiral Planar Hall Effect?

Within a Supersymmetric Quantum Mechanics (SUSY-QM) framework, the (3+1) Dirac equation describing a Dirac material in the presence of external parallel electric and magnetic fields is solved. Considering static but non-uniform electric and magnetic profiles with translational symmetry along the y-direction, the Dirac equation is transformed into two decoupled pairs of Schr\"odinger equations, one for each chirality of the fermion fields. Taking trigonometric and hyperbolic profiles for the vector and scalar potentials, respectively, we arrive at SUSY partner P\"oschl-Teller-like quantum potentials. Restricting to the conditions of the potentials that support an analytic zero-mode solution, we obtain a nontrivial current density in the same plane where the electric and magnetic fields lie, but perpendicular to both of them, indicating the possibility of realizing the Planar Hall Effect. Furthermore, this non-vanishing current density is the sum of current densities for the left- and right-chiralities, suggesting that the net current is a consequence of chiral symmetry.Comment: 10 pages, 6 figure

Bandgap and effective mass of epitaxial cadmium oxide

The bandgap and band-edge effective mass of single crystal cadmium oxide, epitaxially grown by metal-organic vapor-phase epitaxy, are determined from infrared reflectivity, ultraviolet/visible absorption, and Hall effect measurements. Analysis and simulation of the optical data, including effects of band nonparabolicity, Moss-Burstein band filling and bandgap renormalization, reveal room temperature bandgap and band-edge effective mass values of 2.16±0.02 eV and 0.21±0.01m0 respectively

Cause of death estimation from verbal autopsies: is the open response redundant or synergistic?

Civil registration and vital statistics systems capture birth and death events to compile vital statistics and to provide legal rights to citizens. Vital statistics are a key factor in promoting public health policies and the health of the population. Medical certification of cause of death is the preferred source of cause of death information. However, two thirds of all deaths worldwide are not captured in routine mortality information systems and their cause of death is unknown. Verbal autopsy is an interim solution for estimating the cause of death distribution at the population level in the absence of medical certification. A Verbal Autopsy (VA) consists of an interview with the relative or the caregiver of the deceased. The VA includes both Closed Questions (CQs) with structured answer options, and an Open Response (OR) consisting of a free narrative of the events expressed in natural language and without any pre-determined structure. There are a number of automated systems to analyze the CQs to obtain cause specific mortality fractions with limited performance. We hypothesize that the incorporation of the text provided by the OR might convey relevant information to discern the CoD. The experimental layout compares existing Computer Coding Verbal Autopsy methods such as Tariff 2.0 with other approaches well suited to the processing of structured inputs as is the case of the CQs. Next, alternative approaches based on language models are employed to analyze the OR. Finally, we propose a new method with a bi-modal input that combines the CQs and the OR. Empirical results corroborated that the CoD prediction capability of the Tariff 2.0 algorithm is outperformed by our method taking into account the valuable information conveyed by the OR. As an added value, with this work we made available the software to enable the reproducibility of the results attained with a version implemented in R to make the comparison with Tariff 2.0 evident

KMOS LENsing Survey (KLENS) : morpho-kinematic analysis of star-forming galaxies at z∼2z \sim 2

We present results from the KMOS lensing survey-KLENS which is exploiting gravitational lensing to study the kinematics of 24 star forming galaxies at $1.4<z<3.5$ with a median mass of $\rm log(M_\star/M_\odot)=9.6$ and median star formation rate (SFR) of $\rm 7.5\,M_\odot\,yr^{-1}$. We find that 25% of these low-mass/low-SFR galaxies are rotation dominated, while the majority of our sample shows no velocity gradient. When combining our data with other surveys, we find that the fraction of rotation dominated galaxies increases with the stellar mass, and decreases for galaxies with a positive offset from the main sequence. We also investigate the evolution of the intrinsic velocity dispersion, $\sigma_0$, as a function of the redshift, $z$, and stellar mass, $\rm M_\star$, assuming galaxies in quasi-equilibrium (Toomre Q parameter equal to 1). From the $z-\sigma_0$ relation, we find that the redshift evolution of the velocity dispersion is mostly expected for massive galaxies ($\rm log(M_\star/M_\odot)>10$). We derive a $\rm M_\star-\sigma_0$ relation, using the Tully-Fisher relation, which highlights that a different evolution of the velocity dispersion is expected depending on the stellar mass, with lower velocity dispersions for lower masses, and an increase for higher masses, stronger at higher redshift. The observed velocity dispersions from this work and from comparison samples spanning $0<z<3.5$ appear to follow this relation, except at higher redshift ($z>2$), where we observe higher velocity dispersions for low masses ($\rm log(M_\star/M_\odot)\sim 9.6$) and lower velocity dispersions for high masses ($\rm log(M_\star/M_\odot)\sim 10.9$) than expected. This discrepancy could, for instance, suggest that galaxies at high-$z$ do not satisfy the stability criterion, or that the adopted parametrisation of the specific star formation rate and molecular properties fail at high redshift.Comment: Accepted for publication in A&A, 21 pages, 10 figure

Master in Water Engineering a “semi-attendance” University-specific degree with international participation

The Water Engineering Master Course is a university-specific degree at the University of Seville which nowadays can be coursed in two different modalities: “on line” and “semi-attendance”. Its first edition took place at 2000 and since then, the average of graduated students has been of 40 students per course. The semi-attendance mode offers the possibility of being followed in an on-line way from November to June. A Moodle platform provides all the documentation that is required to attend every module, at the end of each one some online questionnaires are also uploaded in order to evaluate the students. Only one of the 10 mandatory modules which make up the course have to be attended in a classroom mode. It takes place during 15 days in July and allows the students to come into contact with the lecturers, professionals of the sector and their own mates as well. During this period both, teachers and students, are lodged in the same residence and all of them have the chance of interchanging experiences in a full teaching-learning process, solving doubts and improving their skills thanks to specific courses, specially designed in function of the lack of knowledge which has been detected during de previous modules, o even, the suggestions received directly from students. Most of the students come from Hispanic countries and in less amount from African and European countries. Actually every July about 80 students and teachers from 25 different countries around the world, meet in Seville to attend this Master. The classes are given in Spanish with translator support if it’s necessary. Different environments, problematic and conditioning factors are studied and a large kind of solutions in water cycle are designed during these days. The requirements to elaborate the final master project are mainly that this one can be used to resolve a real local problem in the student’s origin place and moreover the student can obtain better marks if he/she finds financing to carry it out. In the last 8 years a useful module named “Tools for design” has been included in the program of the Master in order to enable the student in IT, specifically spreadsheets, cad, software for budgeting and measurement, topography and decision support systems. Students who graduate are able to evaluate the most proper technology from a social, technic and economic point of view, as well as, select the most efficient alternatives in order to achieve a sustainable development

Spin splitting in a polarized quasi-two-dimensional exciton gas

We have observed a large spin splitting between "spin" $+1$ and $-1$ heavy-hole excitons, having unbalanced populations, in undoped GaAs/AlAs quantum wells in the absence of any external magnetic field. Time-resolved photoluminescence spectroscopy, under excitation with circularly polarized light, reveals that, for high excitonic density and short times after the pulsed excitation, the emission from majority excitons lies above that of minority ones. The amount of the splitting, which can be as large as 50% of the binding energy, increases with excitonic density and presents a time evolution closely connected with the degree of polarization of the luminescence. Our results are interpreted on the light of a recently developed model, which shows that, while intra-excitonic exchange interaction is responsible for the spin relaxation processes, exciton-exciton interaction produces a breaking of the spin degeneracy in two-dimensional semiconductors.Comment: Revtex, four pages; four figures, postscript file Accepted for publication in Physical Review B (Rapid Commun.

Naturalization: a new concept developed and carried out in the subject “Environmental Technology” of degree in Industrial Engineering

Environmental Technology is a 6 credits transversal subject included in the curriculum of all the degrees in Industrial Engineering at the Higher Polytechnic School of the University of Seville. In the last 5 academic courses, the students of this matter have been working with the concept of “Naturalization”. In the different topics which are studied in this subject, they have to apply the naturalization of the systems in order to use natural resources for improving processes. The Naturalization implies improvements in energetic efficiency, development of green spaces and CO2 capture and can be applied the majority of the industrial and urban activities. Some of the most meaningful results that our students have researched are: i) Naturalization of a large pond in a business park in Jaen (Spain) performing its layout and eventually implementing it, using plants to improve water quality and stones for fix them and to give support for bacterial biofilms. The students have improved their skills not only in the increase of new knowledge but in the ability of work in groups and carry out a real project under different points of view. ii) Project of naturalization of a neighbourhood in Seville, based on the increase of green spaces, with vegetal species which are able to capture electromagnetic radiations and CO2 emissions as well. iii) Naturalization of the margins of one lagoon in a park in Seville, transforming the precast panelled walls in breakwater bed of stones planted with bank river plants in order to improve the water quality and the landscape