Search results for "sers"

Funcionamiento neuropsicológico en drogodependientes VIH/SIDA inmunodeprimidos: Importancia de la fase de la infección y del consumo de drogas

2000

Todavía no disponemos de factores de riesgo definitivos que permitan predecir la naturaleza y magnitud de las complicaciones neuropsicológicas asociadas a la infección por VIH. Con este trabajo nos planteamos estudiar la naturaleza del deterioro neuropsicológico asociado al VIH en drogodependientes con historia de consumo de drogas por vía intravenosa inmunodeprimidos, así como determinar la influencia que tienen sobre el mismo la fase clínica de la infección (asintomáticolSIDA) y el consumo de drogas. Para ello hemos utilizado una muestra de 20 drogodependientes voluntarios en distintas fases de la infección (A3 y C3). En cada uno de estos grupos la mitad de los sujetos se encuentra en abs…

"McDonald's" lietotnes uzlabošanas iespējas

2021

Bakalaura darba tēma ir “McDonald’s” lietotnes uzlabošanas iespējas”. Bakalaura darba mērķis ir izpētīt esošo “McDonald’s” mobilo lietotni, izstrādāt priekšlikumus kā uzlabot lietotni, lai vairāk pievērst uzmanību lietotnei un vēl vairāk palielināt klientu skaitu. Darbs sastāv no četrām nodaļām. Pirmajā nodaļa tiek analizēta SIA “Premier Restaurants Latvia”, uzņēmuma biznesa procesi un lietotnes ietekme uz tiem. Otrajā nodaļā tiek raksturota esošā mobilā lietotne un analizēti lietotnes statistiskie dati. Trešajā nodaļā tiek analizēta cilvēku aptauja par “McDonald’s” lietotnes uzlabošanas iespējam. Ceturtajā nodaļā tiek izvirzīti priekšlikumi “McDonald’s” mobilās lietotnes uzlabošanā. Bakala…

Zur Frage der Wasserversorgung Rigas nebst einem neuen Vorschlag zur Lösung darselben: unter Anlehnung an den am 23. Februar c. im Technischen Verein…

1893

Modelling of Laser Operation in RPE Nd3+:LiNbO3 Channel Waveguides

2006

In this work, laser action in RPE Nd3+:LiNbO3 is modelled by using the overlapping integrals method. Different pumping schemes, TE or TM, have been considered in order to reproduce the experimental measurements. Calculated results indicate that the slope efficiency remains basically independent on the pumping scheme while the threshold pump power increases for TE pumping.

Geo-visual analytics for urban design in the context of future Internet

2009

The internet, where much of the information has reference to location, together with the latest generation of geographical web services, represent a very large information space that can be used for planning and design. The wealth of information accessible, which requires new forms of interaction and management of the data available, has brought in recent year to the growth of the domain of visual analytics. In addition, the availability of 3D geobrowsers provides the technological means for interactive 3D environments which can be used to access large-scale geographical information. This technological scenario is paving the way to 3D web-based, geo-visual analytics tools for land planning …

New Technologies and Purchase Behaviour. An Analysis of the Determinant Variables in M-Shopping.

2009

Despite of the growing importance of mobile shopping in a lot of countries, there is still a lack of research work in this field. This paper aims to make an approximation of the M-shopper profile and identify the variables influencing purchase behaviour. Findings obtained from a representative sample of 2,343 Spanish Internet users show that the M-shopping decision can be predicted according to consumer age and experience as Internet user and shopper.

A mathematical tool for describing the behaviour of a dense effluent discharge

2009

In many cases a dense effluent has to be discharged in the environment with possible harmful consequences. The preferred design for the relevant discharge unit is that of a simple or multi-port diffuser issuing jets at a given inclination above the horizontal. This work presents the follow-on developments of a model previously proposed to predict the behaviour of inclined dense jets issuing in a stagnant environment. It consists of a set of three ordinary differential equations that can be solved by standard numerical methods. Model outputs include information on the trajectory, spreading and dilution of inclined dense jets, return point position and concentration. Interestingly the model a…

Ytterbium-doped fiber laser as pulsed source of narrowband amplified spontaneous emission

2019

AbstractWe report random noise pulsed regime of an ytterbium-doped fiber laser arranged in common Fabry-Perot configuration. We show that the laser output obeys the photon statistics inherent to narrowband amplified spontaneous emission and that the noise pulsing is properly addressed in terms of probability density and autocorrelation functions. Our novel approach reveals, in particular, that the regime’s coherence time dramatically shortens, from few ns to tens ps, with increasing laser power.

Highly Efficient Holmium-Doped All-Fiber ∼2.07-μm Laser Pumped by Ytterbium-Doped Fiber Laser at ∼1.13 μm

2018

We report a 2.07-μm Holmium-doped all-fiber laser (HDFL) pumped by a 1.13-μm Ytterbium-doped fiber laser (YDFL). Home-made alumino–germano–silicate holmium-doped fiber (HDF) served here as an active medium, optimized in terms of chemical composition and co-dopants’ concentrations. Laser action at 2.07 μm was assessed in simple Fabry–Perot cavity, formed by a couple of home-made fiber Bragg gratings (FBGs), inscribed directly in the HDF; this allowed notable diminishing of intracavity loss of the 2.07-μm laser. HDF was in-core pumped by the 1.13-μm double-clad YDFL with a power of ∼12.5 W, in turn pumped in-clad by a laser diode (LD) operated at 0.97 μm with ∼24.5-W output. Using optimal len…

Application of WGM Resonances to the Measurement of the Temperature Increment of Ho and Ho-Yb Doped Optical Fibers Pumped at 1125 and 975 nm

2021

Optical fiber characterization using whispering gallery mode resonances of the fiber itself has been demonstrated to be a powerful technique. In this work, we exploit the thermal sensitivity of whispering gallery mode resonances to characterize the pump-induced temperature increment in holmium doped and holmium-ytterbium codoped optical fibers. The technique relies on the measurement of the resonances’ wavelength shift due to temperature variation as a function of the pump power. Holmium doped fibers were pumped to the second excited level 5I6 of the Ho3+ ion using a laser diode at 1125 nm and ytterbium-holmium codoped fibers to the 2F5/2 level of the Yb3+ ion by a laser diode at 975 nm. Ou…