A spatially stabilized TDG based finite element framework for modeling biofilm growth with a multi-dimensional multi-species continuum biofilm model

We consider a model for biofilm growth in the continuum mechanics framework, where the growth of different components of biomass is governed by a time dependent advection–reaction equation. The recently developed time-discontinuous Galerkin (TDG) method combined with two different stabilization techniques, namely the Streamline Upwind Petrov Galerkin (SUPG) method and the finite increment calculus (FIC) method, are discussed as solution strategies for a multi-dimensional multi-species biofilm growth model. The biofilm interface in the model is described by a convective movement following a potential flow coupled to the reaction inside of the biofilm. Growth limiting substrates diffuse through a boundary layer on top of the biofilm interface. A rolling ball method is applied to obtain a boundary layer of constant height. We compare different measures of the numerical dissipation and dispersion of the simulation results in particular for those with non-trivial patterns. By using these measures, a comparative study of the TDG–SUPG and TDG–FIC schemes as well as sensitivity studies on the time step size, the spatial element size and temporal accuracy are presented. The final publication is available at Springer via http://dx.doi.org/10.1007/s00466-017-1388-1State of Lower Saxon

The role of land and water for trade and food production in Latin America: Environmental trade-offs of agricultural intensification versus extensification

One of humanity’s major challenges of the 21st century will be meeting future food demands on an increasingly resource constrained-planet. Global food production will have to rise by 70 percent between 2000 and 2050 to meet effective demand which poses major challenges to food production systems. Doing so without compromising environmental integrity is an even greater challenge. This study looks at the interdependencies between land and water resources, agricultural production and environmental outcomes in Latin America and the Caribbean (LAC), an area of growing importance in international agricultural markets. Special emphasis is given to the role of LAC’s agriculture for (a) global food security and (b) environmental sustainability. We use the International Model for Policy Analysis of Agricultural Commodities and Trade (IMPACT)—a global dynamic partial equilibrium model of the agricultural sector—to run different future production scenarios, and agricultural trade regimes out to 2050, and assess changes in related environmental indicators. Results indicate that further trade liberalization is crucial for improving food security globally, but that it would also lead to more environmental pressures in some regions across Latin America. Contrasting land expansion versus more intensified agriculture shows that productivity improvements are generally superior to agricultural land expansion, from an economic and environmental point of view. Finally, our analysis shows that there are trade-offs between environmental and food security goals for all agricultural development paths

Enhancing POI Testing Approach through the Use of Additional Information

[EN] Recently, a new approach to perform regression testing has been defined: the point of interest (POI) testing. A POI, in this context, is any expression of a program. The approach receives as input a set of relations between POIs from a version of a program and POIs from another version, and also a sequence of entry points, i.e. test cases. Then, a program instrumentation, an input test case generation and different comparison functions are used to obtain the final report which indicates whether the alternative version of the program behaves as expected, e.g. it produces the same outputs or it uses less CPU/memory. In this paper, we present a method to improve POI testing by including additional context information for a certain type of POIs. Concretely, we use this method to obtain an enhanced tracing of calls. Additionally, it enables new comparison modes and a categorization of unexpected behaviours.This work has been partially supported by MINECO/AEI/FEDER (EU) under grant TIN2016-76843-C4-1-R, and by the Generalitat Valenciana under grant PROMETEOII/2015/013 (SmartLogic). Salvador Tamarit was partially supported by the Conselleria de Educación, Investigación, Cultura y Deporte de la Generalitat Valenciana under grant APOSTD/2016/036.Pérez-Rubio, S.; Tamarit Muñoz, S. (2019). Enhancing POI Testing Approach through the Use of Additional Information. Lecture Notes in Computer Science. 11285:74-90. https://doi.org/10.1007/978-3-030-16202-3_5S74901128

Electron effective mass and mobility in heavily doped n-GaAsN probed by Raman scattering

We investigate inelastic light scattering by longitudinal optic phonon-plasmon coupled modes LOPCMs in a series of heavily Se-doped, n-type GaAs1−xNx epilayers with x 0.4%. We perform a line shape analysis of the LOPCM spectra to estimate the optical effective mass, mopt , and the scattering time of the conduction electrons in GaAsN. We use these results to evaluate an effective carrier mobility for our samples. The values thus obtained, which we compare with measured electron Hall mobilities, indicate that the x-dependence of the mobility in GaAs1−xNx is dominated by the scattering time, rather than by the variation of the electron effective mass. The Raman analysis yields mopt values that are lower than those obtained from the band anticrossing model. © 2008 American Institute of Physics.This work is supported by the Spanish Government Projects MAT 2004-0664 and MAT2007-63617, and Ramon y Cajal Program and the EPSRC, United Kingdom. 1M. Henini, Dilute Nitride Semiconductors Elsevier Science, AmsterdamPeer reviewe

Optical emission from Si O2 -embedded silicon nanocrystals: A high-pressure Raman and photoluminescence study

© 2015 American Physical Society. We investigate the optical properties of high-quality Si nanocrystals (NCs)/SiO2 multilayers under high hydrostatic pressure with Raman scattering and photoluminescence (PL) measurements. The aim of our study is to shed light on the origin of the optical emission of the Si NCs/SiO2. The Si NCs were produced by chemical-vapor deposition of Si-rich oxynitride (SRON)/SiO2 multilayers with 5- and 4-nm SRON layer thicknesses on fused silica substrates and subsequent annealing at 1150°C, which resulted in the precipitation of Si NCs with an average size of 4.1 and 3.3 nm, respectively. From the pressure dependence of the Raman spectra we extract a phonon pressure coefficient of 8.5±0.3cm-1/GPa in both samples, notably higher than that of bulk Si(5.1cm-1/GPa). This result is ascribed to a strong pressure amplification effect due to the larger compressibility of the SiO2 matrix. In turn, the PL spectra exhibit two markedly different contributions: a higher-energy band that redshifts with pressure, and a lower-energy band which barely depends on pressure and which can be attributed to defect-related emission. The pressure coefficients of the higher-energy contribution are (-27±6) and (-35±8)meV/GPa for the Si NCs with a size of 4.1 and 3.3 nm, respectively. These values are sizably higher than those of bulk Si(-14meV/GPa). When the pressure amplification effect observed by Raman scattering is incorporated into the analysis of the PL spectra, it can be concluded that the pressure behavior of the high-energy PL band is consistent with that of the indirect transition of Si and, therefore, with the quantum-confined model for the emission of the Si NCs.Work supported by the European Community’s Seventh Framework Programme (FP7/2007-2013) under grant agreement No. 245977 (project NASCEnT). Financial support by the Spanish Government through projects LEOMIS (TEC2012-38540-C02-01) and MAT2012-38664-C02-02 is also acknowledgedPeer Reviewe

A New Hybrid Debugging Architecture for Eclipse

The final publication is available at Springer via http://dx.doi.org/10.1007/978-3-319-14125-1_11[EN] During many years, print debugging has been the most used method for debugging. Nowadays, however, industrial languages come with a trace debugger that allows programmers to trace computations step by step using breakpoints and state viewers. Almost all modern programming environments include a trace debugger that allows us to inspect the state of a computation in any given point. Nevertheless, this debugging method has been criticized for being completely manual and time-consuming. Other debugging techniques have appeared to solve some of the problems of Trace Debugging, but they suffer from other problems such as scalability. In this work we present a new hybrid debugging technique. It is based on a combination of Trace Debugging, Algorithmic Debugging and Omniscient Debugging to produce a synergy that exploits the best properties and strong points of each technique. We describe the architecture of our hybrid debugger and our implementation that has been integrated into Eclipse as a plugin.This work has been partially supported by the Spanish Ministerio de Economía y Competitividad (Secretaria de Estado de Investigación, Desarrollo e Innovación) under grant TIN2008-06622-003-02 and by the Generalitat Valenciana under grant PROMETEO/2011/052. David Insa was partially supported by the Spanish Ministerio de Educación under FPU grant AP2010-4415.González, J.; Insa Cabrera, D.; Silva Galiana, JF. (2013). A New Hybrid Debugging Architecture for Eclipse. En Logic-Based Program Synthesis and Transformation. Springer. 183-201. doi:10.1007/978-3-319-14125-1_11S183201Swi-prolog (1987). http://www.swi-prolog.org/Netbeans (1999). http://www.netbeans.org/Eclipse (2003). http://www.eclipse.org/Omnicore codeguide (2007). http://www.omnicore.com/en/codeguide.htmBorland JBuilder (2008). http://www.embarcadero.com/products/jbuilder/Sicstus prolog spider ide (2009). https://sicstus.sics.se/spider/Caballero, R.: A Declarative Debugger of Incorrect Answers for Constraint Functional-Logic Programs. In: Proceedings of the 2005 ACM-SIGPLAN Workshop on Curry and Functional Logic Programming (WCFLP 2005), pp. 8–13. ACM Press, New York (2005)Davie, T., Chitil, O.: Hat-delta: One Right Does Make a Wrong. In: Proceedings of the 7th Symposium on Trends in Functional Programming (TFP 2006) (April 2006)Gestwicki, P., Jayaraman, B.: JIVE: Java Interactive Visualization Environment. In: Companion to the 19th Annual ACM-SIGPLAN Conference on Object-Oriented Programming Systems, Languages, and Applications (OOPSLA 2004), pp. 226–228. ACM Press, New York (2004)Giammona, D.: ORACLE ADF - Putting It Together. Technical report, ADF Declarative Debugger Archives (November 2009)Girgis, H., Jayaraman, B.: JavaDD: a Declarative Debugger for Java. Technical report,University at Buffalo (2006)González, F., De Miguel, R., Serrano, S.: Depurador Declarativo de Programas Java. Technical report, Universidad Complutense de Madrid (2006). http://eprints.ucm.es/9114/Hermanns, C., Kuchen, H.: Hybrid Debugging of Java Programs. In: Escalona, M.J., Cordeiro, J., Shishkov, B. (eds.) ICSOFT 2011. CCIS, vol. 303, pp. 91–107. Springer, Heidelberg (2013)Montebello, M., Abela, C.: Design and Implementation of a Backward-In-Time. In: Chaudhri, A.B., Jeckle, M., Rahm, E., Unland, R. (eds.) NODe-WS 2002. LNCS, vol. 2593, pp. 46–58. Springer, Heidelberg (2003)Insa, D., Silva, J.: An Algorithmic Debugger for Java. In: Proceedings of the 26th IEEE International Conference on Software Maintenance (ICSM 2010), pp. 1–6 (2010)Insa, D., Silva, J.: Scaling Up Algorithmic Debugging with Virtual Execution Trees. In: Alpuente, M. (ed.) LOPSTR 2010. LNCS, vol. 6564, pp. 149–163. Springer, Heidelberg (2011)Insa, D., Silva, J.: loops2recursion Java Library (2013). http://www.dsic.upv.es/~jsilva/loops2recursion/Kouh, H.-J., Yoo, W.-H.: The Efficient Debugging System for Locating Logical Errors in Java Programs. In: Kumar, V., Gavrilova, M.L., Kenneth Tan, C.J., L’Ecuyer, P. (eds.) ICCSA 2003. LNCS, vol. 2667, pp. 684–693. Springer, Heidelberg (2003)B. Lewis. Debugging Backwards in Time. Available in the Computing Research Repository 2003, ( http://arxiv.org/abs/cs.SE/0310016 ), cs.SE/0310016Lienhard, A., Gîrba, T., Wang, J.: Practical Object-Oriented Back-in-Time Debugging. In: Vitek, J. (ed.) ECOOP 2008. LNCS, vol. 5142, pp. 592–615. Springer, Heidelberg (2008)S. Microsystems. Java Platform Debugger Architecture - JPDA (2010). http://java.sun.com/javase/technologies/core/toolsapis/jpda/Mirghasemi, S., Barton, J., Petitpierre, C.: Debugging by lastChange. Technical report (2011). http://people.epfl.ch/salman.mirghasemiNilsson, H.: Declarative Debugging for Lazy Functional Languages. PhD thesis, Linköping, Sweden (May 1998)Nilsson, H., Fritzson, P.: Algorithmic Debugging for Lazy Functional Languages. Journal of Functional Programming 4(3), 337–370 (1994)Pothier, G.: Towards Practical Omniscient Debugging. PhD thesis, University of Chile (June 2011)Shapiro, E.: Algorithmic Program Debugging. MIT Press (1982)Silva, J.: A Survey on Algorithmic Debugging Strategies. Advances in Engineering Software 42(11), 976–991 (2011

Optical emission from SiO2-embedded silicon nanocrystals: a high pressure Raman and photoluminescence study

We investigate the optical properties of high-quality Si nanocrystals (NCs)/SiO2 multilayers under high hydrostatic pressure with Raman scattering and photoluminescence (PL) measurements. The aim of our study is to shed light on the origin of the optical emission of the Si NCs/SiO2. The Si NCs were produced by chemical-vapor deposition of Si-rich oxynitride (SRON)/SiO2 multilayers with 5- and 4-nm SRON layer thicknesses on fused silica substrates and subsequent annealing at 1150 °C, which resulted in the precipitation of Si NCswith an average size of 4.1 and 3.3 nm, respectively. From the pressure dependence of the Raman spectra we extract a phonon pressure coefficient of 8.5 ± 0.3 cm−1/GPa in both samples, notably higher than that of bulk Si (5.1 cm−1/GPa). This result is ascribed to a strong pressure amplification effect due to the larger compressibility of the SiO2 matrix. In turn, the PL spectra exhibit two markedly different contributions: a higher-energy band that redshifts with pressure, and a lower-energy band which barely depends on pressure and which can be attributed to defect-related emission. The pressure coefficients of the higher-energy contribution are (−27 ± 6) and (−35 ± 8) meV/GPa for the Si NCs with a size of 4.1 and 3.3 nm, respectively. These values are sizably higher than those of bulk Si (−14 meV/GPa). When the pressure amplification effect observed by Raman scattering is incorporated into the analysis of the PL spectra, it can be concluded that the pressure behavior of the high-energy PL band is consistent with that of the indirect transition of Si and, therefore, with the quantum-confined model for the emission of the Si NCs

Borehole image techniques applied to identification of chert and dolomite layers in lacustrine sediments

Geophysical logging tools, particularly ultrasonic acoustic borehole image techniques, are applied on two different wells (CP1 and CP2) to identify and characterize the lacustrine interval (40m) of the Camp dels Ninots maardiatreme infill (Pliocene, Catalan Coastal Ranges). The CP1 well was cored and also geophysical logs and oriented borehole images were acquired. CP2 hole was partially cored but logging (geophysics and borehole images) was fully undertaken. Continuous core recovery in CP1 is compared with oriented images and is further used to identify and characterize highly reflective signals in a section of CP2 borehole that was not cored. These signals are related to silicified zones and belong to discontinuous centimetric chert nodules, while indurated massive carbonates are characterized as intervals of continuous reflectance. Despite opal nodules (chert) can be relatively small, they have a distinctive response in the ultrasonic borehole images.Peer Reviewe

Pressure-induced band-gap energy increase in a metal iodate

A wide band gap is one of the essential requirements for metal iodates to be used as nonlinear optical materials. Usually, the band gap of these materials decreases under the application of pressure. Herein, we introduce a case in which the band-gap energy of a hydrated metal iodate, namely Ca(IO3)2 center dot H2O, has been successfully increased, from 4.52 to 4.92 eV, by applying external pressure without showing signs of saturation upon increasing pres-sure. The pressure-induced nonlinear band-gap opening correlates with the pressure-induced shortening of the I-O bond distances, as obtained from x-ray diffraction measurements. In addition, two pressure-induced isostructural phase transitions are observed in the pressure regions of 6.6-8.0 and 13.0-15.5 GPa. These two isostructural phase transitions cause a nonlinear pressure-induced evolution of the band-gap energy and crystal lattice parameters, as well as the occurrence of several extra peaks and peak splitting in Raman spectra.This study was supported by project MALTA Consolider Team network (RED2018‐102612‐T), financed by MINECO/AEI/10.13039/501100003329, I+D+i project PID2019‐106383GB‐41/42 financed by MCIN/AEI/10.13039/501100011033; as well as by projects PROMETEO CIPROM/2021/075 (GREENMAT) and MFA/2022/007 financed by Generalitat Valenciana. A.L. and D.E. thank the Generalitat Valenciana for the Ph.D. Fellowship No. GRISOLIAP/2019/025. R.T. and D.E. thank the Generalitat Valenciana for the postdoctoral Fellowship No. CIAPOS/2021/20. The authors also thank ALBA synchrotron light source for funded experiment under proposal number AV-2021095390 at the MSPD-BL04 beamline