http://hdl.handle.net/2117/7020 Mon, 20 May 2013 09:21:11 GMT 2013-05-20T09:21:11Z webmaster.bupc@upc.edu Universitat Politècnica de Catalunya. Servei de Biblioteques i Documentació no http://hdl.handle.net/2117/16824 Title: Optimization of oxygen transfer through venturi-based systems applied to the biological sweetening of biogas Authors: Rodriguez, Ginesta; Dorado Castaño, Antonio David; Bonsfills Pedrós, Anna; Sanahuja Moliner, Ricard; Gabriel, David; Gamisans Noguera, Javier Wed, 31 Oct 2012 11:49:52 GMT http://hdl.handle.net/2117/16824 2012-10-31T11:49:52Z Rodriguez, Ginesta; Dorado Castaño, Antonio David; Bonsfills Pedrós, Anna; Sanahuja Moliner, Ricard; Gabriel, David; Gamisans Noguera, Javier no Biogas desulfurization, Biotrickling filters, Diffuser, Jet-venturi, Mass transfer, Venturi ejector http://hdl.handle.net/2117/16728 Title: Investigation of nanoscale interactions by means of subharmonic excitation Authors: Santos, Sergio; Phillips, M.A.; Verdaguer, Albert; Font Teixidó, Josep; Chiesa, Matteo; Gadelrab,, K.; Stefancich, M.; Armstrong, P.; Li, G.; Souier, T.; Thomson, Neil H.; Barcons Xixons, Víctor Abstract: Multifrequency atomic force microscopy holds promise as a method to provide qualitative and quantitative information about samples with high spatial resolution. Here, we provide experimental evidence of the excitation of subharmonics in ambient conditions in the regions where capillary interactions are predicted to be the mechanism of excitation. We also experimentally decouple a second mechanism for subharmonic excitation that is highly independent of environmental conditions such as relative humidity. This implies that material properties could be mapped. Subharmonic excitation could lead to experimental determination of surface water affinity in the nanoscale whenever water interactions are the mechanism of excitation. Tue, 16 Oct 2012 10:01:28 GMT http://hdl.handle.net/2117/16728 2012-10-16T10:01:28Z Santos, Sergio; Phillips, M.A.; Verdaguer, Albert; Font Teixidó, Josep; Chiesa, Matteo; Gadelrab,, K.; Stefancich, M.; Armstrong, P.; Li, G.; Souier, T.; Thomson, Neil H.; Barcons Xixons, Víctor no Ambient conditions, Capillary interactions, Environmental conditions, Experimental determination, Experimental evidence, High spatial resolution, Material property, Multi frequency, Nano scale, Nanoscale interactions, Quantitative information, Sub-harmonic excitation, Subharmonics, Water affinity, Water interactions Multifrequency atomic force microscopy holds promise as a method to provide qualitative and quantitative information about samples with high spatial resolution. Here, we provide experimental evidence of the excitation of subharmonics in ambient conditions in the regions where capillary interactions are predicted to be the mechanism of excitation. We also experimentally decouple a second mechanism for subharmonic excitation that is highly independent of environmental conditions such as relative humidity. This implies that material properties could be mapped. Subharmonic excitation could lead to experimental determination of surface water affinity in the nanoscale whenever water interactions are the mechanism of excitation. http://hdl.handle.net/2117/16725 Title: Quantification of dissipation and deformation in ambient atomic force microscopy Authors: Santos, Sergio; Gadelrab,, K.; Barcons Xixons, Víctor; Stefancich, M.; Chiesa, Matteo Abstract: A formalism to extract and quantify unknown quantities such as sample deformation, the viscosity of the sample and surface energy hysteresis in amplitude modulation atomic force microscopy is presented. Recovering the unknowns only requires the cantilever to be accurately calibrated and the dissipative processes occurring during sample deformation to be well modeled. The theory is validated by comparison with numerical simulations and shown to be able to provide, in principle, values of sample deformation with picometer resolution. Tue, 16 Oct 2012 08:18:07 GMT http://hdl.handle.net/2117/16725 2012-10-16T08:18:07Z Santos, Sergio; Gadelrab,, K.; Barcons Xixons, Víctor; Stefancich, M.; Chiesa, Matteo no Dissipative process, Energy hysteresis, Picometer resolution, Sample deformation, Unknown quantity A formalism to extract and quantify unknown quantities such as sample deformation, the viscosity of the sample and surface energy hysteresis in amplitude modulation atomic force microscopy is presented. Recovering the unknowns only requires the cantilever to be accurately calibrated and the dissipative processes occurring during sample deformation to be well modeled. The theory is validated by comparison with numerical simulations and shown to be able to provide, in principle, values of sample deformation with picometer resolution. http://hdl.handle.net/2117/15767 Title: Spatial horizons in amplitude and frequency modulation atomic force microscopy Authors: Font Teixidó, Josep; Santos Hernandez, Sergi; Barcons Xixons, Víctor; Thomson, Neil H.; Verdaguer, Albert; Chiesa, Matteo Abstract: In dynamic atomic force microscopy (AFM) the cantilever is vibrated and its dynamics are monitored to probe the sample with nanoscale and atomic resolution. Amplitude and frequency modulation (AM and FM) atomic force microscopy have established themselves as the most powerful, robust and reliable techniques in the field. Nevertheless, it is still debatable whether one or the other technique is preferred in a given medium or experiment. Here, we quantitatively establish the limitations in resolution of one and the other technique by introducing the concept of space horizon SH and quantifying it. The SH is the limiting space boundary beyond which collective atomic interactions do not affect the detection parameters of a given feedback system. We show that while an FM feedback can resolve an atom where an AM feedback might fail, relative contrast is in fact equivalent for both feedback systems. That is, if the AM feedback could detect sufficiently small amplitude shifts and there was no noise, single atom imaging would be equivalent in AM and FM. Fri, 27 Apr 2012 15:40:55 GMT http://hdl.handle.net/2117/15767 2012-04-27T15:40:55Z Font Teixidó, Josep; Santos Hernandez, Sergi; Barcons Xixons, Víctor; Thomson, Neil H.; Verdaguer, Albert; Chiesa, Matteo no In dynamic atomic force microscopy (AFM) the cantilever is vibrated and its dynamics are monitored to probe the sample with nanoscale and atomic resolution. Amplitude and frequency modulation (AM and FM) atomic force microscopy have established themselves as the most powerful, robust and reliable techniques in the field. Nevertheless, it is still debatable whether one or the other technique is preferred in a given medium or experiment. Here, we quantitatively establish the limitations in resolution of one and the other technique by introducing the concept of space horizon SH and quantifying it. The SH is the limiting space boundary beyond which collective atomic interactions do not affect the detection parameters of a given feedback system. We show that while an FM feedback can resolve an atom where an AM feedback might fail, relative contrast is in fact equivalent for both feedback systems. That is, if the AM feedback could detect sufficiently small amplitude shifts and there was no noise, single atom imaging would be equivalent in AM and FM. http://hdl.handle.net/2117/15691 Title: A high-resolution UWB IR superregenerative receiver front end with an SRD quench shaper Authors: Moncunill Geniz, Francesc Xavier; Bonet Dalmau, Jordi; Palà Schönwälder, Pere; Águila López, Francisco del; Giralt Mas, Ma. Rosa Abstract: We present a simple receiver front end that makes use of the baseband superregeneration principle to detect ultrawideband (UWB) impulse radio signals. The UWB antenna is directly connected to the core circuit consisting of a resistor-capacitor (RC) network coupled to a negative resistance that varies under the control of an external quench generator. Due to a step-recovery-diode quench shaper, 50-ps time-domain sensitivity windows are generated that filter the received pulses and reject noise and interference. The circuit achieves high gain, exhibits automatic gain control, and directly demodulates binary phase modulations. Fri, 30 Mar 2012 15:01:17 GMT http://hdl.handle.net/2117/15691 2012-03-30T15:01:17Z Moncunill Geniz, Francesc Xavier; Bonet Dalmau, Jordi; Palà Schönwälder, Pere; Águila López, Francisco del; Giralt Mas, Ma. Rosa no ultrawideband (UWB) communication., Circuit stability, impulse radio (IR), low-power design, radio receivers, step recovery diode (SRD), superregenerative receiver We present a simple receiver front end that makes use of the baseband superregeneration principle to detect ultrawideband (UWB) impulse radio signals. The UWB antenna is directly connected to the core circuit consisting of a resistor-capacitor (RC) network coupled to a negative resistance that varies under the control of an external quench generator. Due to a step-recovery-diode quench shaper, 50-ps time-domain sensitivity windows are generated that filter the received pulses and reject noise and interference. The circuit achieves high gain, exhibits automatic gain control, and directly demodulates binary phase modulations. http://hdl.handle.net/2117/13457 Title: The intrinsic resolution limit in the atomic force microscope: implications for heights of nano-scale features Authors: Santos, Sergio; Barcons Xixons, Víctor; Christenson, Hugo K.; Font Teixidó, Josep; Thomson, Neil H. Fri, 07 Oct 2011 12:48:33 GMT http://hdl.handle.net/2117/13457 2011-10-07T12:48:33Z Santos, Sergio; Barcons Xixons, Víctor; Christenson, Hugo K.; Font Teixidó, Josep; Thomson, Neil H. no http://hdl.handle.net/2117/13219 Title: How localized are energy dissipation processes in nanoscale interactions? Authors: Santos, Sergio; Barcons Xixons, Víctor; Verdaguer, Albert; Font Teixidó, Josep; Thomson, Neil H.; Chiesa, Mateo Abstract: We describe fundamental energy dissipation in dynamic nanoscale processes in terms of the localization of the interactions. In this respect, the areal density of the energy dissipated and the effective area of interaction in which each process occurs are calculated for four elementary dissipative processes. It is the ratio between these two, which we term M that provides information about how localized the interactions are. We show that neither the phase lag, nor the magnitude of the energy dissipated alone provide information about energy localization but M has to be considered instead. Fri, 16 Sep 2011 13:21:54 GMT http://hdl.handle.net/2117/13219 2011-09-16T13:21:54Z Santos, Sergio; Barcons Xixons, Víctor; Verdaguer, Albert; Font Teixidó, Josep; Thomson, Neil H.; Chiesa, Mateo no We describe fundamental energy dissipation in dynamic nanoscale processes in terms of the localization of the interactions. In this respect, the areal density of the energy dissipated and the effective area of interaction in which each process occurs are calculated for four elementary dissipative processes. It is the ratio between these two, which we term M that provides information about how localized the interactions are. We show that neither the phase lag, nor the magnitude of the energy dissipated alone provide information about energy localization but M has to be considered instead. http://hdl.handle.net/2117/10127 Title: Supervised Gain-Scheduling Multimodel versus Linear Parameter Varying Internal Model Control of Open-Channel Systems for Large Operating Conditions Authors: Duviella, E.; Puig Cayuela, Vicenç; Charbonnaud, P; Escobet Canal, Teresa; Carrillo, F J.; Quevedo Casín, Joseba Jokin Thu, 04 Nov 2010 18:06:20 GMT http://hdl.handle.net/2117/10127 2010-11-04T18:06:20Z Duviella, E.; Puig Cayuela, Vicenç; Charbonnaud, P; Escobet Canal, Teresa; Carrillo, F J.; Quevedo Casín, Joseba Jokin no http://hdl.handle.net/2117/7803 Title: Localization and Electrical Characterization of Interconnect Open Defects Authors: Rodríguez Montañés, Rosa; Arumi Delgado, Daniel; Figueras Pàmies, Joan; Beverloo, Willem; Vries, Dirk K. de; Eichenberger, Stefan; Volf, Paul A. J. Abstract: A technique for extracting the electrical and topological parameters of open defects in process monitor lines is presented. The procedure is based on frequency-domain measurements performed at both end points of the line. The location as well as the resistive value of the open defect are derived from attenuation and phase shift measurements. The characteristic defect-free impedance of the line and its propagation constant are considered to be unknowns, and their values are also derived from the above measurements. In this way, the impact of process parameter variations on the proposed model is diminished. The experimental setup required to perform the characterization measurements and a simple graphical procedure to determine the defect and line parameters are presented. Experimental results show a good agreement between the predicted location of the open and its real location, found by optical beam induced resistance change inspection. Errors smaller than 2% of the total length of the line have been observed in the experiments. Tue, 22 Jun 2010 16:46:52 GMT http://hdl.handle.net/2117/7803 2010-06-22T16:46:52Z Rodríguez Montañés, Rosa; Arumi Delgado, Daniel; Figueras Pàmies, Joan; Beverloo, Willem; Vries, Dirk K. de; Eichenberger, Stefan; Volf, Paul A. J. no A technique for extracting the electrical and topological parameters of open defects in process monitor lines is presented. The procedure is based on frequency-domain measurements performed at both end points of the line. The location as well as the resistive value of the open defect are derived from attenuation and phase shift measurements. The characteristic defect-free impedance of the line and its propagation constant are considered to be unknowns, and their values are also derived from the above measurements. In this way, the impact of process parameter variations on the proposed model is diminished. The experimental setup required to perform the characterization measurements and a simple graphical procedure to determine the defect and line parameters are presented. Experimental results show a good agreement between the predicted location of the open and its real location, found by optical beam induced resistance change inspection. Errors smaller than 2% of the total length of the line have been observed in the experiments.