462 research outputs found
Primordial black hole production during preheating in a chaotic inflationary model
In this paper we review the production of primordial black holes (PBHs)
during preheating after a chaotic inflationary model. All relevant equations of
motion are solved numerically in a modified version of HLattice, and we then
calculate the mass variance to determine structure formation during preheating.
It is found that production of PBHs can be a generic result of the model, even
though the results seem to be sensitive to the values of the smoothing scale.
We consider a constraint for overproduction of PBHs that could uncover some
stress between inflation-preheating models and observations.Comment: 6 pages, 5 figures. Prepared for the conference proceedings of the
9th Mexican School on Gravitation and Mathematical Physics : Cosmology for
the XXI Century: Inflation, Dark Matter and Dark Energ
Process mining applied to the change control board process:discovering real processes in software development process
Excitation Enhancement of a Quantum Dot Coupled to a Plasmonic Antenna
Plasmonic antennas are key elements to control the luminescence of quantum
emitters. However, the antenna's influence is often hidden by quenching losses.
Here, the luminescence of a quantum dot coupled to a gold dimer antenna is
investigated. Detailed analysis of the multiply excited states quantifies the
antenna's influence on the excitation intensity and the luminescence quantum
yield separately
Compliance with International law on IDPs, refugee and stateless persons; A case study of Burmese Refugees in Thailand
Eternal Sunshine of the Solar Panel
The social dynamics of residential solar panel use within a theoretical
population are studied using a compartmental model. In this study we consider
three solar power options commonly available to consumers: the community block,
leasing, and buying. In particular we are interested in studying how social
influence affects the dynamics within these compartments. As a result of this
research a threshold value is determined, beyond which solar panels persist in
the population. In addition, as is standard in this type of study, we perform
equilibrium analysis, as well as uncertainty and sensitivity analyses on the
threshold value. We also perform uncertainty analysis on the population levels
of each compartment. The analysis shows that social influence plays an
important role in the adoption of residential solar panels
Roughness Analysis In Strained Silicon-on-insulator Wires And Films
Strained silicon is used to enhance performance in state-of-the-art CMOS. Under device operating conditions, the effect of strain is to reduce the carrier scattering at the channel by a smoother semiconductor surface. This has never been completely understood. This paper gives first evidence of the variation in surface roughness under realistic strained conditions. At the nanoscale, the SiO2/Si interface roughness is dependent on the scale of observation (self-affinity). To date, there is no experimental study of the SiO2/Si interface roughness scaling with strain. This work presents the effect of uniaxial and biaxial strains on the surface roughness of strained silicon-on-insulator films and wires using atomic force microscopy. Levels of strain ranging from 0% to 2.3%, encompassing those used in present CMOS devices have been investigated. It is shown that the silicon surface is affected by uniaxial and biaxial strains differently. Three surface roughness parameters have been analyzed: root mean square roughness, correlation length, and the Hurst exponent, which is used to describe the scaling behavior of a self-affine surface. The results show that the root mean square roughness decreases (up to ∼ 40%) with increasing tensile strain, whereas the correlation length increases (up to ∼ 63nm/%) with increasing tensile strain. The Hurst exponent also varies with strain and with the undulation wavelength regime (between ∼ 0.8 and 0.2). This dependency explains why some models used to determine the carrier mobility from experiments fit the data better with a Gaussian form, whereas other models fit the data better with an exponential form.11612EPSRC; Engineering and Physical Sciences Research CouncilSong, Y., Zhou, H., Xu, Q., Luo, J., Yin, H., Yan, J., Zhong, H., (2011) J. Electron. Mater., 40, p. 1584Lee, M.L., Fitzgerald, E.A., Bulsara, M.T., Currie, M.T., Lochtefeld, A., (2005) J. Appl. Phys., 97, p. 011101Chu, M., Sun, Y.K., Aghoram, U., Thompson, S.E., (2009) Annu. Rev. Mater. Res., 39, p. 203Zhao, Y., Takenaka, M., Takagi, S., (2009) IEEE Electron Device Lett., 30, p. 987Cheng, Z.Y., Currie, M.T., Leitz, C.W., Taraschi, G., Fitzgerald, E.A., Hoyt, J.L., Antoniadas, D.A., (2001) IEEE Electron Device Lett., 22, p. 321Rim, K., Hoyt, J.L., Gibbons, J.F., (2000) IEEE Trans. Electron Devices, 47, p. 1406Fischetti, M.V., Gamiz, F., Hansch, W., (2002) J. Appl. Phys., 92, p. 7320Bonno, O., Barraud, S., Mariolle, D., Andrieu, F., (2008) J. Appl. Phys., 103, p. 063715Escobedo-Cousin, E., Olsen, S.H., Pardoen, T., Bhaskar, U., Raskin, J.-P., (2011) Appl. Phys. Lett., 99, p. 241906Pirovano, A., Lacaita, A.L., Ghidini, G., Tallarida, G., (2000) IEEE Electron Device Lett., 21, p. 34Goodnick, S.M., Ferry, D.K., Wilmsen, C.W., Liliental, Z., Fathy, D., Krivanek, O.L., (1985) Phys. Rev. B, 32, p. 8171Mazzoni, G., Lacaita, A.L., Perron, L.M., Pirovano, A., (1999) IEEE Trans. Electron Devices, 46, p. 1423Zhao, Y., Matsumoto, H., Sato, T., Koyama, S., Takenaka, M., Takagi, S., (2010) IEEE Trans. Electron Devices, 57, p. 2057Ishihara, T., Matsuzawa, K., Takayanagi, M., Takagi, S.I., (2002) Jpn. J. Appl. Phys., Part 1, 41, p. 2353Pirovano, A., Lacaita, A.L., Zandler, G., Oberhuber, R., Int. Electron Devices Meet. Tech. Dig., 1999, p. 527Yoshinobu, T., Iwamoto, A., Sudoh, K., Iwasaki, H., (1995) J. Vac. Sci. Technol. B, 13, p. 1630Mandelbrot, B.B., (1982) The Fractal Geometry of Nature: Updated and Augment, , (W. H. Freeman and Company)Pelliccione, M., Lu, T.-M., (2007) Evolution of Thin-film Morphology: Modeling and Simulations, , (Springer, Dordrecht)Zhao, Y.P., Wang, G.C., Lu, T.-M., Graef, M.D., Lucatorto, T., (2000) Characterization of Amorphous and Crystalline Rough Surface: Principles and Applications, , (Elsevier Science)Sinha, S.K., Sirota, E.B., Garoff, S., Stanley, H.B., (1988) Phys. Rev. B, 38, p. 2297Stommer, R., Martin, A.R., Geue, T., Goebel, H., Hub, W., Pietsch, U., (1999) Adv. X-Ray Anal., 41, p. 101Vicsek, T., Cserzo, M., Horváth, V.K., (1990) Physica A, 167, p. 315Arnault, J.C., Knoll, A., Smigiel, E., Cornet, A., (2001) Appl. Surf. Sci., 171, p. 189Bhaskar, U.K., Passi, V., Houri, S., Escobedo-Cousin, E., Olsen, S.H., Pardoen, T., Raskin, J.-P., (2012) J. Mater. Res., 27, p. 571Passi, V., Bhaskar, U.K., Pardoen, T., Sodervall, U., Nilsson, B., Petersson, G., Hagberg, M., Raskin, J.P., (2012) J. Microelectromech. Syst., 21, p. 822Bhaskar, U.K., Pardoen, T., Passi, V., Raskin, J.-P., (2013) Appl. Phys. Lett., 102, p. 031911Liu, X.H., Chen, J., Chen, M., Wang, X., (2002) Appl. Surf. Sci., 187, p. 187Vicsek, T., (1992) Fractal Growth Phenomena, , 2nd ed. (World Scientific)Silva, J.B.D., Jr., Vasconcelos, E.A.D., Santos, B.E.C.A.D., Freire, J.A.K., Freire, V.N., Farias, G.A., Silva, E.F.D., Jr., (2005) Microelectron. J., 36, p. 1011Liu, Z.J., Jiang, N., Shen, Y.G., Mai, Y.W., (2002) J. Appl. Phys., 92, p. 3559Gravier, S., Coulombier, M., Safi, A., Andre, N., Boe, A., Raskin, J.-P., Pardoen, T., (2009) J. Microelectromech. Syst., 18, p. 555Bunshah, R.F., (1994) Handbook of Deposition Technologies for Films and Coatings - Science, Technology and Applications, , 2nd ed. (William Andrew Publishing/Noyes)Ureña, F., Olsen, S.H., Šiller, L., Bhaskar, U., Pardoen, T., Raskin, J.-P., (2012) J. Appl. Phys., 112, p. 114506Ureña, F., Olsen, S.H., Raskin, J.-P., (2013) J. Appl. Phys., 114, p. 144507Ghyselen, B., Hartmann, J.M., Ernst, T., Aulnette, C., Osternaud, B., Bogumilowicz, Y., Abbadie, A., Mazure, C., (2004) Solid-State Electron., 48, p. 1285Lai, L., Irene, E.A., (1999) J. Appl. Phys., 86, p. 1729Schwarzenbach, W., Daval, N., Kerdilès, S., Chabanne, G., Figuet, C., Guerroudj, S., Bonnin, O., Maleville, C., (2012) Proceedings of the IEEE International Conference on Integrated Circuit Design and Technology, , (Austin, TX, USA)Xie, Y.H., Gilmer, G.H., Roland, C., Silverman, P.J., Buratto, S.K., Cheng, J.Y., Fitzgerald, E.A., Citrin, P.H., (1994) Phys. Rev. Lett., 73, p. 3006Michielis, M.D., Conzatti, F., Esseni, D., Selmi, L., (2011) IEEE Trans. Electron Devices, 58, p. 321
Sexual identity of enterocytes regulates autophagy to determine intestinal health, lifespan and responses to rapamycin
Pharmacological attenuation of mTOR presents a promising route for delay of age-related disease. Here we show that treatment of Drosophila with the mTOR inhibitor rapamycin extends lifespan in females, but not in males. Female-specific, age-related gut pathology is markedly slowed by rapamycin treatment, mediated by increased autophagy. Treatment increases enterocyte autophagy in females, via the H3/H4 histone-Bchs axis, whereas males show high basal levels of enterocyte autophagy that are not increased by rapamycin feeding. Enterocyte sexual identity, determined by transformerFemale expression, dictates sexually dimorphic cell size, H3/H4-Bchs expression, basal rates of autophagy, fecundity, intestinal homeostasis and lifespan extension in response to rapamycin. Dimorphism in autophagy is conserved in mice, where intestine, brown adipose tissue and muscle exhibit sex differences in autophagy and response to rapamycin. This study highlights tissue sex as a determining factor in the regulation of metabolic processes by mTOR and the efficacy of mTOR-targeted, anti-aging drug treatments
Contributos do projeto de arquitetura para uma restruturação dos modos de vida rurais na aldeia Urzal, em Mafra
Dissertação de Mestrado Integrado em Arquitetura, com a especialização em Arquitetura apresentada na Faculdade de Arquitetura da Universidade de Lisboa para obtenção do grau de Mestre.O presente trabalho desenvolve uma abordagem à problemática do futuro que se
adivinha naquilo que subsiste das aldeias portuguesas sem que estas tenham de se
resignar a transformarem-se num simples escape para os citadinos, levantando
questões e apresentando propostas para solucionar os seus problemas, articulando-as
com os núcleos urbanos. O estudo circunscrever-se-á a uma zona de intervenção,
tendo como objectivo principal reabilitar e revitalizar a Aldeia Urzal, inserida na
Freguesia de Carvoeira do Concelho de Mafra, Distrito de Lisboa. Pretende-se, assim,
estudar os modos de vida rurais e a sua arquitectura, a estrutura socioeconómica e
sociológica do lugar, a estrutura da paisagem, entre outras temáticas, de modo a
entender as transformações dos espaços rurais até aos dias de hoje. Em primeiro
lugar, evidenciam-se as principais razões que fundamentaram o não-ordenamento do
território e a edificação sem articulação com o meio, que conduzirão a danos
irreversÃveis ao território e à s próprias condições de bem-estar dos habitantes. Em
alternativa à presente situação, sugere-se uma proposta arquitectónica adequada para
restaurar a identidade local através de uma renovação do conceito de aldeia assim
como a implementação de novas funções com base nas especificidades do lugar,
visando estabelecer, se possÃvel definitivamente, uma ética ecológica na construção e
na concepção arquitectónicas.ABSTRACT: The follow work is focusing on the future issues that can be made traced for what
survives of Portuguese villages without they having to resign themselves to becoming a
simple escape for citizens, raising questions and presenting proposals to solve their
problems, hinged with the great urban nucleus. The study will be circumscribed in an
intervention area, with the main goal being the rehabilitation and revitalization of Urzal
Village, which is part of the parish of Carvoeira, municipality of Mafra, district of Lisbon.
It is intended to study the rural life way and its architecture, socio-economic and
sociological structure of the place, landscape structure, among other issues, in order to
understand the transformations in rural areas nowadays. Firstly, emphasize the main
reasons for the non-territorial planning and building without articulation with the
environment, leading to irreversible damage to the land's ornamentation and the
inhabitant’s own conditions of well-being. On the other hand, an appropriate
architectural proposal is suggested to restore local identity through a renewal of the
village concept as well as the implementation of new functions based on local
specificities, aiming to establish, if possible definitively, an ecological ethic in
construction and conception.N/
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