Beyond conventional factorization: Non-Hermitian Hamiltonians with radial oscillator spectrum

The eigenvalue problem of the spherically symmetric oscillator Hamiltonian is revisited in the context of canonical raising and lowering operators. The Hamiltonian is then factorized in terms of two not mutually adjoint factorizing operators which, in turn, give rise to a non-Hermitian radial Hamiltonian. The set of eigenvalues of this new Hamiltonian is exactly the same as the energy spectrum of the radial oscillator and the new square-integrable eigenfunctions are complex Darboux-deformations of the associated Laguerre polynomials.Comment: 13 pages, 7 figure

Los primeros humanos en América

Jornadas de Jóvenes en Investigación Arqueológica, JIA (3as : 5-7 de mayo 2010 : Universitat Autònoma de Barcelona). Sesión 4. Cultura material y transdisciplinariedad en la investigación arqueológica de Latinoamérica.La Prehistoria de America consta de 5 periodos, los tres primeros afectan propiamente a la Prehistoria, los restantes al desarrollo de las civilizaciones americanas. La etapa que ocupan el Paleolitico, Mesolitico, Neolitico y la Edad de los Metales en la Prehistoria universal, en America solo ocupa los periodos Paleoindios y un discutido periodo anterior, Pre-clovis. Los estudios actuales acerca del poblamiento se cimientan en los siguientes interrogantes: Como y por donde tuvo lugar?, Cuando tuvo lugar? y Quienes fueron los primeros colonizadores?. Desde finales del S.XX se ha creado una nueva corriente de investigacion, La Poblacion Temprana, que echa por tierra El Consenso Clovis, defendiendo un poblamiento anterior. Hay investigadores que consideran que la poblacion tuvo lugar hace 16.000-20.000 anos, para otros hace mas de 30.000 anos. En su explicacion exponemos los yacimientos mas distintivos y los argumentos que respaldan dicha teoria (arqueologicos, geneticos, linguisticos). Asi sostienen rutas alternativas para el ingreso de las poblaciones. En el caso de una poblacion independiente para America del sur, destacan las teorias que defienden una entrada desde el noroeste de Asia-Beringia-noroeste de America hacia el sur a traves de la costa. Y la que aboga por un trayecto Oceania-Polinesia-America del Sur. Aunque las teorias geneticas y linguisticas aun no habitan convenientemente con las tecnicas de investigacion arqueologicas, se han convertido en un importante elemento a la hora de discutir los temas que aqui tratamos.The America's prehistory is divided in five periods. Three affect, properly, to the prehistory, the others to the development of American Civilizations. The stages of universal prehistory (Paleolithic, Mesolithic, Neolithic and the Metal Age), for America corresponding to the paleoindian period, and a problematic precious period called Pre-Clovis. At the moment, the great subject of scientific interest makes reference to the occupation of the continent: How?, When?, Who?, and Where? At the end of XXth century, it appears a new current of work that puts in doubt the Clovis Consensus, proposing a previous occupation of continent. In this article are exposed the deposits and arguments that endorse this new theory. In the case of an independent population for South America, There are theories that defend an entry from the northwest of Asia-America-northwest Beringia southward along the coast. And advocating a path Oceania-Polynesia, South America.La Prehistoria d'America consta de 5 periodes, els tres primers afecten propiament a la Prehistoria, la resta al desenvolupament de les civilitzacions americanes. La etapa que ocupa el paleolitic, mesolitic, neolitic i l'edat dels metalls, a la Prehistoria universal, a America nomes ocupa els periodes paleoindis, i un discutit periode anterior anomenat Pre-Clovis. Els actuals estudis es basen en donar resposta els seguents interrogants al voltant de l'arribada dels primers pobladors del continent: com i per on va succeir?, quan va tenir lloc? I quins van ser els primers grups de poblament?. Des de finals de segle XX s'ha creat una nova corrent d'investigacio que deixa sense validesa el Consens Clovis, defensant un poblament previ. Hi ha investigadors que considerant que el poblament va tenir lloc fa 16.000 - 20.000 anys i altres fa mes de 30.000 anys. A aquesta explicacio s'exposaran els jaciments mes caracteristics i els arguments procedents de diferents arees d'investigacio que donen suport a aquesta nova corrent (arqueologia, genetica i linguistica). Sustentant d'aquesta manera vies alternatives per l'entrada de les poblacions. En el cas d'una poblacio independent per a l'area d'America del Sud, destaquen les teories que defensen una arribada des del nord-oest d'Asia - Beringia - nord-est d'America per la costa. I una altra que treballa amb la idea d'una arribada per Oceania - Polinesia - America del Sud. Malgrat que les teories genetiques i linguistiques a les que fan referencia moltes de les tesis esposades encara no habiten convenientment amb les tecniques d'investigacio arqueologica, s'han convertit en un important element alhora de discutir els temes aqui tractats

Supersymmetric partners of the trigonometric Poschl-Teller potentials

The first and second-order supersymmetry transformations are used to generate Hamiltonians with known spectra departing from the trigonometric Poschl-Teller potentials. The several possibilities of manipulating the initial spectrum are fully explored, and it is shown how to modify one or two levels, or even to leave the spectrum unaffected. The behavior of the new potentials at the boundaries of the domain is studied.Comment: 20 pages, 4 figure

Exactly Solvable Hydrogen-like Potentials and Factorization Method

A set of factorization energies is introduced, giving rise to a generalization of the Schr\"{o}dinger (or Infeld and Hull) factorization for the radial hydrogen-like Hamiltonian. An algebraic intertwining technique involving such factorization energies leads to derive $n$-parametric families of potentials in general almost-isospectral to the hydrogen-like radial Hamiltonians. The construction of SUSY partner Hamiltonians with ground state energies greater than the corresponding ground state energy of the initial Hamiltonian is also explicitly performed.Comment: LaTex file, 21 pages, 2 PostScript figures and some references added. To be published in J. Phys. A: Math. Gen. (1998

Increasing serum calcium levels and recent return from transplantation as clues to the tuberculous nature of refractory peritoneal dialysis peritonitis

Peritoneal tuberculosis is an uncommon complication of peritoneal dialysis in Europe. It is more common in Asian immigrants. A delayed diagnosis is frequent and impairs patient outcomes. We present two cases of peritoneal tuberculosis with common features that may help suspect the disease early countries with a low incidence. Both patients were females (of Spanish origin) who had recently restarted peritoneal dialysis following kidney transplantation. Both developed bacterial peritonitis clinically that was refractory to conventional antibiotics, despite clearance of bacteria. Both stopped calcium-containing phosphate binders because of increasing serum calcium that in one case led to frank hypercalcemia that persisted despite low calcium dialysate. Peritoneal biopsy was the first positive test in both cases. This report emphasizes the recent return from transplantation and rising serum calcium levels as features that should alert the physician of a potential underlying tuberculous peritonitisGrant support: ISCII and FEDER funds FIS PS09/00447, PI13/00047, ISCIII-RETIC REDinREN/RD12/0021/0001, Comunidad de Madrid/CIFRA/ S2010/BMD-2378. Salary support: FIS Rio Hortega to BFF, CMC, LRO, Programa Intensificación Actividad Investigadora (ISCIII/Agencia Laín- Entralgo/CM) to A

Quantum mechanical spectral engineering by scaling intertwining

Using the concept of spectral engineering we explore the possibilities of building potentials with prescribed spectra offered by a modified intertwining technique involving operators which are the product of a standard first-order intertwiner and a unitary scaling. In the same context we study the iterations of such transformations finding that the scaling intertwining provides a different and richer mechanism in designing quantum spectra with respect to that given by the standard intertwiningComment: 8 twocolumn pages, 5 figure

Extended WKB method, resonances and supersymmetric radial barriers

Semiclassical approximations are implemented in the calculation of position and width of low energy resonances for radial barriers. The numerical integrations are delimited by t/T<<8, with t the period of a classical particle in the barrier trap and T the resonance lifetime. These energies are used in the construction of `haired' short range potentials as the supersymmetric partners of a given radial barrier. The new potentials could be useful in the study of the transient phenomena which give rise to the Moshinsky's diffraction in time.Comment: 12 pages, 4 figures, 3 table

CFD study of the impact of the deviation on the mass flow inlet on winding hot-spot temperature of a power transformer using mineral and ester oils

This work presents a study where a deviation on the mass flow rate in adjacent sectors of the winding is considered. A CFD model was developed for this study, where heat transfer between sectors is enabled due to the lack of thermal symmetry, and the goal of this study is to determine whether this effect can be neglected or not. To carry out this study, a Low Voltage Winding of a 100 MVA power transformer was selected. This transformer has been manufactured and tested by BEST Transformers, and the results obtained from the heat run test were used to validate the CFD model. The study also considered an alternative dielectric liquid, natural ester, in order to estimate if the different thermal and hydraulic conditions can affect to the relevance of the studied effect. The CFD simulations have been carried out with ANSYS Fluent. The results showed a deviation of 3-4% of the heat dissipated due to the non-symmetric conditions with a 10% of mass flow deviation, which is the heat transfer between the adjacent sectors. This effect is identical when considering mineral oil or natural ester. The results shows there is a small impact of the winding temperatures due to this effect, and that it can be considered negligible.Part of the work was performed during secondments between BEST Transformers and the University of Cantabria executed in the framework of the BIOTRAFO project “Raising knowledge and developing technology for the design and deployment of high-performance power transformers immersed in biodegradable fluids”, H2020-MSCA-RISE2018- 823969, 2019-21. This project has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No 823969. Also, we acknowledge the support of the Spanish Ministry of Science and Innovation by means of the National Research Project Asset management of biodegradable-fluid-based transformers (PID2019-107126RB-C22/AEI/ 10.13039/501100011033

Conformationally-Locked C-Glycosides: Tuning Aglycone Interactions for Optimal Cheperone Behaviour in Gaucher Fibroblasts

A series of conformationally locked C-glycosides based on the 3-aminopyrano[3,2-b]pyrrol-2(1H)-one (APP) scaffold has been synthesized. The key step involved a totally stereocontrolled C-Michael addition of a serine-equivalent C-nucleophile to tri-O-benzyl-2-nitro-D-galactal, previously published by the authors. Stereoselective transformations of the Michael adduct allowed us the synthesis of compounds with mono- or diantennated aglycone moieties and different topologies. In vitro screening showed highly selective inhibition of bovine liver β-glucosidase/β-galactosidase and specific inhibition of human β-glucocerebrosidase among lysosomal glycosidases for compounds bearing palmitoyl chains in the aglycone, with a marked dependence of the inhibition potency upon their number and location. Molecular dynamics simulations highlighted the paramount importance of an optimal orientation of the hydrophobic substituent to warrant efficient non-glycone interactions, which are critical for the binding affinity. The results provide a rationale for the strong decrease of the inhibition potency of APP compounds on going from neutral to acidic pH. The best candidate was found to behave as pharmacological chaperone in Gaucher fibroblasts with homozygous N370S and F213I mutations, with enzyme activity enhancements similar to those encountered for the reference compound AmbroxolMinisterio de Economía y Competitividad CTQ2012-36365, SAF2013-44021-RJunta de Andalucía FQM-1467European Union Seventh Framework Programme FP7-People-2012-CI

New Self-Sufficient Shelter Solutions for Big Cities’ Collapsed Rental Markets

Nowadays, there is a wide variety of problems in the big cities related to the urban frame and to housing. Architects have to provide solutions that not only improve people’s well-being but also have to be efficient during the building’s entire life cycle. Within the European context, big cities like Paris, Berlin and Amsterdam have a huge demand for housing coming mainly from two different groups: people looking for temporary shelter and people looking for a more stable situation. In both cases, the need for new housing have resulted in inefficient urban developments, collapsed city centres and developed satellite cities where low and medium class people have tried to find somewhere to live, running away from infra-housing. In Paris, urban regulations set the minimum area for a rented apartment as 10m2. The research described in this paper analyzes the current situation in big cities from two points of view: apartment sizes and medium fees for temporary shelter. It defines the average architectural conditions of the “affordable” shelter and with this data; an experimental approach for a new completely self-sufficient housing module is provided, placed in a worthless space of existing buildings (roofs). This new module is defined by its sustainability and self-sufficiency and it gives the rental market an opportunity to increase the offer of shelter to rent in the big cities. At the end of the research, the development of an analysis of life cost cycle of the new module shows it as an alternative to the existing examples of infra housing with very short periods for recovering the investment