On the prediction of psd in antisolvent mediated crystallization processes based on fokker-planck equations

A phenomenological model for the description of antisolvent mediated crystal growth processes is presented. The crystal size growth dynamics is supposed to be driven by a deterministic growth factor coupled to a stochastic component. Two different models for the stochastic component are investigated: a Linear and a Geometric Brownian motion terms. The evolution in time of the particle size distribution is then described in terms of the Fokker-Planck equation. Validations against experimental data are presented for the NaCl-water-ethanol anti-solvent crystallization system. It was found that a proper modeling of the stochastic component does have an impact on the model capabilities to fit the experimental data. In particular, the GBM assumption is better suited to describe the antisolvent crystal growth process under examination

Control of a natural gas liquid recovery plant in a GSP unit under feed and composition disturbances

Recent technological improvements have driven the rapid increase in natural gas production from unconventional reservoirs. The heaviest hydrocarbon fraction of this fossil fuel, the so-called natural gas liquids (NGL), have greater economic interest justifying the attention on its separation process from the raw gas. Various process schemes have been developed and studied for the NGL recovery, including the conventional, cold residue recycle (CRR), and the gas subcooled process (GSP). This study aims to assess different control strategies for a GSP unit and determine the most appropriate and effective process control scheme. For this, the dynamic responses for each control scheme are evaluated by changing feed flow rate and composition. The main targets are the achievement of 84% ethane recovery and low levels of methane impurity at the bottom of the demethanizer column. Due to the high cost of composition analyzers and the high delays introduced by composition controllers under the presence of flow disturbances, the control goals are reached by the knowledge of on-line temperature measurements. This is done by considering different temperature control structures such as the direct temperature control and cascade control, plus a pressure compensator. The results are compared, in presence of composition disturbances, with the action of a hybrid cascade control that uses in-line delayed concentration measurements to update the controller reference at each sampling period. Here, the hybrid and the simple cascade controls show the best control performance

Evaporative CO2 cooling using microchannels etched in silicon for the future LHCb vertex detector

The extreme radiation dose received by vertex detectors at the Large Hadron Collider dictates stringent requirements on their cooling systems. To be robust against radiation damage, sensors should be maintained below -20 degree C and at the same time, the considerable heat load generated in the readout chips and the sensors must be removed. Evaporative CO2 cooling using microchannels etched in a silicon plane in thermal contact with the readout chips is an attractive option. In this paper, we present the first results of microchannel prototypes with circulating, two-phase CO2 and compare them to simulations. We also discuss a practical design of upgraded VELO detector for the LHCb experiment employing this approach.Comment: 12 page

Machine learning for monitoring and control of NGL recovery plants

In this contribution, the monitoring and control problem of the natural gas liquids (NGL) extraction process is addressed by exploiting a data-driven approach. The cold residue reflux (CRR) process scheme is considered and simulated by using the process simulator Aspen HYSYS®, with the main targets of the achievement of 84% ethane recovery and low levels of methane impurity at the bottom of the demethanizer column. The respect of product quality is obtained by designing a proper control strategy that uses a data-driven approach based on a neural network to estimate the unmeasured outputs. The performance of the controlled system is assessed by simulating the process under various input conditions evaluating different control structures such as direct control and cascade control of the temperature in the column

Gres porcelánico: aplicaciones arquitectónicas, procesado y propiedades físico-mecánicas

Porcelainized stoneware is an extremely hard and homogeneous unglazed ceramic material obtained by fastfiring of kaolinitic ceramic bodies containing a large amount of fluxes. The obtained tiles, available in a large variety of colours, shape size and surface finish, are characterized by very low porosity (<0,3wt% expressed as water absorption) and are ideal for heavy-traffic areas subject to mechanical and chemical stresses. Porcelainized stoneware tiles offer alternative valid (and in many cases necessary) solutions to the traditional glazed tiles either for interiors or for exteriors both in modern or classic constructions for flooring and covering.El gres porcelánico es un material cerámico muy duro y homogéneo, no vidriado en su superficie, obtenido por cocción rápida de composiciones ricas en caolinita, conteniendo una gran cantidad de fundentes. Las plaquetas de pavimentos que se obtienen son de una variedad muy extensa en aspectos, diseños y colores, caracterizándose, fundamentalmente, por su muy baja porosidad (<0,3wt%, expresado en porcentaje de capacidad de absorción de agua). Estos materiales son ideales para tráfico pesado en áreas sujetas a intensas tensiones mecánicas y químicas. El gres porcelánico ofrece alternativas válidas (y, en muchos casos, soluciones necesarias) a los pavimentos vidriados tradicionales, en interiores o para usos exteriores, ambos con decoraciones modernas o clásicas para suelos o recubrimientos de paredes

Gres porcelanico: aplicaciones arquitectonicas, procesado ypropiedades fisico - mecanicas [Porcelainized stoneware: architectural, processing and physico-mechanical properties]

Porcelainized stoneware is an extremely hard and homogeneous unglazed ceramic material obtained by fast-firing of kaolinitic ceramic bodies containing a large amount of fluxes. The obtained tiles, available in a large variety of colours, shape size and surface finish, are characterized by very low porosity (<0.3wt% expressed as wafer absorption) and are ideal for heavy-traffic areas subject to mechanical and chemical stresses. Porcelainized stoneware tiles offer alternative valid (and in many cases necessary) solutions to the traditional glazed tiles either for interiors or for exteriors both in modem or classic constructions for flooring and covering.Porcelainized stoneware is an extremely hard and homogeneous unglazed ceramic material obtained by fast-firing of kaolinitic ceramic bodies containing a large amount of fluxes. The obtained tiles, available in a large variety of colours, shape size and surface finish, are characterized by very low porosity (<0.3wt% expressed as wafer absorption) and are ideal for heavy-traffic areas subject to mechanical and chemical stresses. Porcelainized stoneware tiles offer alternative valid (and in many cases necessary) solutions to the traditional glazed tiles either for interiors or for exteriors both in modem or classic constructions for flooring and covering.El gres porcelanico es un material ceramico muy duro yhomogeneo, no vidriado en su superficie, obtenido porcoccion rapida de composiciones ricas en caolinita,conteniendo una gran cantidad de fundentes. Las plaquetasde pavimentos que se obtienen son de una variedad muyextensa en aspectos, disenos y colores, caracterizandose,fundamentalmente, por su muy baja porosidad (<0,3wt%,expresado en porcentaje de capacidad de absorcion deagua). Estos material es son ideal es para trafico pesado enareas sujetas a intensas tensiones mecanicas y quimicas. Elgres porcelanico ofrece altemativas vdlidas (y, en muchoscasos, soluciones necesarias) a los pavimentos vidriadostradicionales, en interiores o para usos exteriores, amboscon decoraciones modernas o clasicas para suelos orecubrimientos de paredes

Integrated polarizers based on tapered highly birefringent photonic crystal fibers

COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESCONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPFINANCIADORA DE ESTUDOS E PROJETOS - FINEPThis paper proposes and demonstrates the creation of sections with a high polarization dependent loss (PDL) in a commercial highly birefringent (polarization maintaining) photonic crystal fiber (PCF), via tapering with pressure applied to the holes. The tapers had a 1-cm-long uniform section with a 66% scale reduction, in which the original microstructure aspect ratio was kept by the pressure application. The resulting waveguides show polarizing action across the entire tested wavelength range, 1510-1600 nm, with a peak PDL of 35.3 dB/cm (c.f. ∼1 dB/cm for a typical commercial polarizing fiber). The resulting structure, as well as its production, is extremely simple, and enable a small section with a high PDL to be obtained in a polarization maintaining PCF, meaning that the polarization axes in the polarizing and polarization maintaining sections are automatically aligned. © 2014 Optical Society of America.This paper proposes and demonstrates the creation of sections with a high polarization dependent loss (PDL) in a commercial highly birefringent (polarization maintaining) photonic crystal fiber (PCF), via tapering with pressure applied to the holes. The tapers had a 1-cm-long uniform section with a 66% scale reduction, in which the original microstructure aspect ratio was kept by the pressure application. The resulting waveguides show polarizing action across the entire tested wavelength range, 1510-1600 nm, with a peak PDL of 35.3 dB/cm (c.f. similar to 1 dB/cm for a typical commercial polarizing fiber). The resulting structure, as well as its production, is extremely simple, and enable a small section with a high PDL to be obtained in a polarization maintaining PCF, meaning that the polarization axes in the polarizing and polarization maintaining sections are automatically aligned.22151776917775COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESCONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPFINANCIADORA DE ESTUDOS E PROJETOS - FINEPCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESCONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPFINANCIADORA DE ESTUDOS E PROJETOS - FINEPSem informaçãoSem informaçãoSem informação0.1.06.1177.00Chraplyvy, A.R., High-capacity lightwave transmission experiments (1999) Bell Labs Tech. J., 4 (1), pp. 230-245Bock, W.J., Chen, J., Eftimov, T., Urbanczyk, W., A photonic crystal fiber sensor for pressure measurements (2006) IEEE Trans. Instrum. Meas., 55 (4), pp. 1119-1123Bergh, R.A., Lefevre, H.C., Shaw, H.J., An overview of fiber-optic gyroscopes (1984) J. Lightwave Technol., 2 (2), pp. 91-107Jacobsen, W., Mayfield, J., Fournier, P., Bolte, D., Elmaola, H., Wang, C.H., Drenzek, G., Soufiane, A., (2013) Single-polarization Fiber, , Verrillon Inc., US Patent 8, 369, 672 B2Nolan, D.A., Berkey, G.E., Li, M.J., Chen, X., Wood, W.A., Zenteno, L.A., Single-polarization fiber with a high extinction ratio (2004) Opt. Lett., 29 (16), pp. 1855-1857Russell, P., Photonic crystal fibers (2006) J. Lightwave Technol., 24 (12), pp. 4729-4749Saitoh, K., Koshiba, M., Single-polarization single-mode photonic crystal fibers (2003) IEEE Photon. Technol. Lett., 15 (10), pp. 1384-1386Ju, J., Jin, W., Demokan, M.S., Design of single-polarization single-mode photonic crystal fiber at 1.30 and 1.55 μm (2006) J. Lightwave Technol., 24 (2), pp. 825-830Zhang, F., Zhang, M., Liu, X., Ye, P., Design of wideband single-polarization single-mode photonic crystal fiber (2007) J. Lightwave Technol., 25 (5), pp. 1184-1189Chen, M.Y., Sun, B., Zhang, Y.K., Broadband single-polarization operation in square-lattice photonic crystal fibers (2010) J. Lightwave Technol., 28 (10), pp. 1443-1446Serrão, V.A., Franco, M.A.R., A new approach to obtain single-polarization hollow-core photonic bandgap fiber (2013) Proc. SPIE 8794, Fifth European Workshop on Optical Fibre Sensors, 879428Kubota, H., Kawanishi, S., Koyanagi, S., Tanaka, M., Yamaguchi, S., Absolutely single polarization photonic crystal fiber (2004) IEEE Photon. Technol. Lett., 16 (1), pp. 182-184Statkiewicz-Barabach, G., Olszewski, J., Napiorkowski, M., Golojuch, G., Martynkien, T., Tarnowski, K., Urbanczyk, W., Thienpont, H., Polarizing photonic crystal fiber with lowindex inclusion in the core (2010) J. Opt., 12 (7), p. 075402Zheng, X., Liu, Y., Wang, Z., Han, T., Tai, B., Tunable single-polarization single mode photonic crystal fiber based on liquid infiltrating (2011) IEEE Photon. Technol. Lett., 23, pp. 709-711Espinel, A.V.Y., Franco, M.A.R., Cordeiro, C.M.B., Tunable single-polarization single-mode microstructure polymer optical fiber (2011) J. Lightwave Technol., 29 (16), pp. 2372-2378Qian, W., Zhao, C.L., Wang, Y., Chan, C.C., Liu, S., Jin, W., Partially liquid-filled hollow-core photonic crystal fiber polarizer (2011) Opt. Lett., 36 (16), pp. 3296-3298Sodré Jr., A.C., Nascimento Jr., A.R., Franco, M.A.R., Oliveira, I., Serrão, V.A., Fragnito, H.L., Numerical and experimental analysis of polarization properties from hybrid PCFs across different photonic bandgaps (2012) Opt. Fiber Technol., 18 (6), pp. 462-469Romagnoli, P., Biazoli, C.R., Franco, M.A.R., Cordeiro, C.M.B., De Matos, C.J.S., Generation of polarizing sections in highly birefringent photonic crystal fibers via post-processing (2013) CLEO:2013, , Optical Society of America, paper JTu4A.12Birks, T.A., Li, Y.W., The shape of fiber tapers (1992) J. Lightwave Technol., 10 (4), pp. 432-438Ju, J., Jin, W., Yang, Y., Introduction of birefringence into photonic crystal fibers (2011) Proc. SPIE 7753, 21st International Conference on Optical Fiber Sensors, 77536JMalitson, I.H., Interspecimen comparison of the refractive index of fused silica (1965) J. Opt. Soc. Am., 55 (10), pp. 1205-1209Gerosa, R.M., Spadoti, D.H., Menezes, L.S., De Matos, C.J.S., In-fiber modal Mach-Zehnder interferometer based on the locally post-processed core of a photonic crystal fiber (2011) Opt. Express, 19 (4), pp. 3124-3129The authors thank CAPES, Mackpesquisa, INCT Fotonicom (CNPq and FAPESP) and FINEP (SIA Project- proc. 0.1.06.1177.00) for financial support

Chirp management in silicon-graphene electro absorption modulators

We study the frequency chirp properties of graphene-on-silicon electro-absorption modulators (EAMs). By experimentally measuring the chirp of a 100 \ub5m long single layer graphene EAM, we show that the optoelectronic properties of graphene induce a large positive linear chirp on the optical signal generated by the modulator, giving rise to a maximum shift of the instantaneous frequency up to 1.8 GHz. We exploit this peculiar feature for chromatic-dispersion compensation in fiber optic transmission thanks to the pulse temporal lensing effect. In particular, we show dispersion compensation in a 10Gb/s transmission experiment on standard single mode fiber with temporal focusing distance (0-dB optical-signal-to-noise ratio penalty) of 60 km, and also demonstrate 100 km transmission with a bit error rate largely lower than the conventional Reed-Solomon forward error correction threshold of 10 123