Surface characterization techniques for determining the root-mean-square roughness and power spectral densities of optical components

Surface topography and light scattering were measured on 15 samples ranging from those having smooth surfaces to others with ground surfaces. The measurement techniques included an atomic force microscope, mechanical and optical profilers, confocal laser scanning microscope, angle-resolved scattering, and total scattering. The samples included polished and ground fused silica, silicon carbide, sapphire, electroplated gold, and diamond-turned brass. The measurement instruments and techniques had different surface spatial wavelength band limits, so the measured roughnesses were not directly comparable. Two-dimensional power spectral density (PSD) functions were calculated from the digitized measurement data, and we obtained rms roughnesses by integrating areas under the PSD curves between fixed upper and lower band limits. In this way, roughnesses measured with different instruments and techniques could be directly compared. Although smaller differences between measurement techniques remained in the calculated roughnesses, these could be explained mostly by surface topographical features such as isolated particles that affected the instruments in different ways.

Influence of pressure and radio frequency power on deposition rate and structural properties of hydrogenated amorphous silicon thin films prepared by plasma deposition

The influence of radio frequency (rf) power and pressure on deposition rate and structural properties of hydrogenated amorphous silicon (a-Si:H) thin films, prepared by rf glow discharge decomposition of silane, have been studied by phase modulated ellipsometry and Fourier transform infrared spectroscopy. It has been found two pressure regions separated by a threshold value around 20 Pa where the deposition rate increases suddenly. This behavior is more marked as rf power rises and reflects the transition between two rf discharges regimes. The best quality films have been obtained at low pressure and at low rf power but with deposition rates below 0.2 nm/s. In the high pressure region, the enhancement of deposition rate as rf power increases first gives rise to a reduction of film density and an increase of content of hydrogen bonded in polyhydride form because of plasma polymerization reactions. Further rise of rf power leads to a decrease of polyhydride bonding and the material density remains unchanged, thus allowing the growth of a-Si:H films at deposition rates above 1 nm/s without any important detriment of material quality. This overcoming of deposition rate limitation has been ascribed to the beneficial effects of ion bombardment on the a-Si:H growing surface by enhancing the surface mobility of adsorbed reactive species and by eliminating hydrogen bonded in polyhydride configurations.

Integrated random processes exhibiting long tails, finite moments, and power-law spectra

A dynamical model based on a continuous addition of colored shot noises is presented. The resulting process is colored and non-Gaussian. A general expression for the characteristic function of the process is obtained, which, after a scaling assumption, takes on a form that is the basis of the results derived in the rest of the paper. One of these is an expansion for the cumulants, which are all finite, subject to mild conditions on the functions defining the process. This is in contrast with the Lévy distribution¿which can be obtained from our model in certain limits¿which has no finite moments. The evaluation of the spectral density and the form of the probability density function in the tails of the distribution shows that the model exhibits a power-law spectrum and long tails in a natural way. A careful analysis of the characteristic function shows that it may be separated into a part representing a Lévy process together with another part representing the deviation of our model from the Lévy process. This

The Power of Images in Antonio Agustin's. Diálogos de Medallas, inscripciones y otras antigüedades (1587)

Socias ofereix una àmplia mirada sobre l'ús de les imatges en les obres de numismàtica primerenques. Diàlegs de medalles, d'Antonio Agustín

Price transmission and market power analysis in the Spanish seafood market chain

[cat] Espanya és un dels principals mercats de productes pesquers d’Europa i del món. El consum de productes pesquers ha estat tradicionalment molt important a Espanya, el 2005 es varen consumir 36,7 kg per persona (MAPA, diversos anys). Malgrat això, el mercat i cóm interactuen els diversos nivells de la cadena de comercialització han gaudit de poca atenció. En aquest estudi, utilitzant dades setmanals, s’analitza per als dotze principals productes pesquers, l’elasticitat en la transmissió de preus al llarg de la cadena de comercialització a Espanya (llotja, mercat central i detallista). Finalment s’investiga la presència d’assimetria en la transmissió de preus entre aquests nivells de mercat. Els resultats obtinguts tenen importants implicacions a l’hora d’analitzar la demanda, poder de mercat i marges al llarg del mercat per als productes pesquers.

Union power, minimum wage legislation endogenous labor supplies and production

The objective of this work is to study the impact of the unions' bargaining power on production and wages. We present a model where a competitive final good is produced through two substitutable intermediate goods, one produced by unskilled labor and the other by skilled labor. Potential workers decide at their cost to become skilled or unskilled and, thus, labor supplies are determined endogenously. We find that the reallocation of the labor supplies due to changes in the unskilled (or skilled) unions¿ bargaining power may have a positive impact on the final goods production. At the same time, total labor earnings increase with the unskilled unions¿ bargaining power if the final goods production increases too. We also show that the minimum wage legislation has efects similar to an increase in the bargaining power of the unskilled unions.

Power variation of some integral fractional processes

We consider the asymptotic behaviour of the realized power variation of processes of the form ¿t0usdBHs, where BH is a fractional Brownian motion with Hurst parameter H E(0,1), and u is a process with finite q-variation, q<1/(1¿H). We establish the stable convergence of the corresponding fluctuations. These results provide new statistical tools to study and detect the long-memory effect and the Hurst parameter.

Unnatural Mothers, Mothering Unnaturally: Technologies of Reproduction and the Politics of Maternity in Hiromi Goto's "Hopeful Monsters"

Through scientific discourse and reproductive technologies, the reproductive body and the maternal body continue to be constructed as ‘natural’. At the same time,these technologies have begun to blur the boundaries between what is consideredan acceptable reproductive body, and consequently an acceptable maternal body,and an unnatural or a socially undesireable one. As science purports to offerwomen greater control over how and when they choose to procreate, through methods which range between delaying or eliminating the possibility of contraception to those which extend the possibility of conception to postmenopausal or infertile women, these same procedures raise questions about thenature and ‘naturalness’ of reproduction. Added to these concerns are thesuitablility of the reproductive body as a maternal body. Consequently, and moreand more frequently, bodies which defy ideals about maternity and motherhoodemerge, and questions about what it means to mother are raised. Bodies whichcontest the construction of motherhood as natural are frequently represented asmonstrous or freakish, and the debate between science and nature is heightened.Hiromi Goto’s short story ‘Hopeful Monsters’ resists the construction of the‘natural’ maternal body by highlighting the way in which women’s bodies areshaped by scientific discourse. In turn, images of ‘monstrous’ mothers emerge andare challenged, suggesting the need to reimagine what it means to mother and whatit means to be a mother. Through reading a selection of the stories this paper willinterrogate possible alternatives to constructions of the ‘natural’ maternal body and motherhood, suggesting that the Goto’s ‘monsters’ are perhaps only monstrous as a result of scientific discourse which constructs them as such.

A Carrot and Stick Approach to Agenda-Setting

This paper models a legislature in which the same agenda setter serves for two periods, showing how he can exploit a legislature (completely) in the first period by promising future benefits to legislators who support him. In equilibrium, a large majority of legislators vote for the first-period proposal because they thereby maintain the chance of belonging to the minimum winning coalition in the future. Legislators may therefore approve policies by large majorities, or even unanimously, that benefit few, or even none, of them. The results are robust; but institutional arrangements (such as entitlements) can reduce the agenda setter's power by reducing his discretion to reward and punish legislators, and rules (such as sequential voting) can increase a legislator's ability to resist exploitation. Keywords: Legislative bargaining, distributive politics, agenda-setting, proposal power. JEL C72, D72, D78.

The Social Politics of Fatherhood in Spain and France: a Comparative Analysis of Parental Leave and Shared Residence

The Social Politics of Fatherhood in Spain and France: A Comparative Analysis of Parental Leave and Shared Residence The article provides a comparative analysis of policy developments on leaves for fathers and joint custody in Spain and France in the last decade. These two types of measures have been selected because they are both widely recognised as main instruments to promote new fathering styles and consequently more gender equality in the European Union. While the rhetoric of choice has been developed in both countries in relation to maternal employment and childcare, with better results in France than in Spain, it remains to be seen to what extent choice will also be extended to fathers. Keywords: Fatherhood. Family. Comparative social policy. Parental leave. Joint custody.

Corruption in building the image of politics in television news broadcasts

This work analyses the political news of eight Spanish television channels in order to see what image is built of politics, and particularly how the news of corruption affects the image of politics in Spanish news broadcasts. Different cases of corruption such as Gürtel, Palma Arena and those associated with judge Baltasar Garzón in his final stage in office, occupy part of the study. A new methodology is therefore proposed that enables the quality of the political information emitted from inside and outside the political content of the news programmes to be observed. Particular attention is paid to the news broadcasts of Televisión Española and Cuatro as those which offer a more balanced view of politics, and channels such as La Sexta, which give priority to a narrative construction of politics in the news programmes around causes of corruption.

On an asymptotic formula for the maximum voltage drop in a on-chip power distribution network

We present a new asymptotic formula for the maximum static voltage in a simplified model for on-chip power distribution networks of array bonded integrated circuits. In this model the voltage is the solution of a Poisson equation in an infinite planar domain whose boundary is an array of circular pads of radius ", and we deal with the singular limit Ɛ → 0 case. In comparison with approximations that appear in the electronic engineering literature, our formula is more complete since we have obtained terms up to order Ɛ15. A procedure will be presented to compute all the successive terms, which can be interpreted as using multipole solutions of equations involving spatial derivatives of functions. To deduce the formula we use the method of matched asymptotic expansions. Our results are completely analytical and we make an extensive use of special functions and of the Gauss constant G

Net Neutrality and other challenges for the future of the Internet. Proceedings of the 7th International Conference on Internet, Law & Politics. Universitat Oberta de Catalunya, Barcelona, 11-12 July, 2011

Peer-reviewed

The Internet as an enhancer of the consumers' empowerment - A power to be managed by online firms?

Abstract.

The CerdàPlan for the Extension of Barcelona: A Constructivist Analysis of a Town-planning Controversy

Peer-reviewed