684 research outputs found
A model for the sustainable selection of building envelope assemblies
The aim of this article is to define an evaluation model for the environmental impacts of building envelopes to support planners in the early phases of materials selection. The model is intended to estimate environmental impacts for different combinations of building envelope assemblies based on scientifically recognised sustainability indicators. These indicators will increase the amount of information that existing catalogues show to support planners in the selection of building assemblies.To define the model, first the environmental indicators were selected based on the specific aims of the intended sustainability assessment. Then, a simplified LCA methodology was developed to estimate the impacts applicable to three types of dwellings considering different envelope assemblies, building orientations and climate zones. This methodology takes into account the manufacturing, installation, maintenance and use phases of the building. Finally, the model was validated and a matrix in Excel was created as implementation of the model
Mutual optical injection in coupled DBR laser pairs
We report an experimental study of nonlinear effects, characteristic of mutual optical coupling, in an ultra-short coupling regime observed in a distributed Bragg reflector laser pair fabricated on the same chip. Optical feedback is amplified via a double pass through a common onchip optical amplifier, which introduces further nonlinear phenomena. Optical coupling has been introduced via back reflection from a cleaveended fibre. The coupling may be varied in strength by varying the distance of the fibre from the output of the chip, without significantly affecting the coupling time. © 2008 Optical. Society of America
A New Simulated Annealing Algorithm for the Multiple Sequence Alignment Problem: The approach of Polymers in a Random Media
We proposed a probabilistic algorithm to solve the Multiple Sequence
Alignment problem. The algorithm is a Simulated Annealing (SA) that exploits
the representation of the Multiple Alignment between sequences as a
directed polymer in dimensions. Within this representation we can easily
track the evolution in the configuration space of the alignment through local
moves of low computational cost. At variance with other probabilistic
algorithms proposed to solve this problem, our approach allows for the creation
and deletion of gaps without extra computational cost. The algorithm was tested
aligning proteins from the kinases family. When D=3 the results are consistent
with those obtained using a complete algorithm. For where the complete
algorithm fails, we show that our algorithm still converges to reasonable
alignments. Moreover, we study the space of solutions obtained and show that
depending on the number of sequences aligned the solutions are organized in
different ways, suggesting a possible source of errors for progressive
algorithms.Comment: 7 pages and 11 figure
Incorporating Ambipolar and Ohmic Diffusion in the AMR MHD code RAMSES
We have implemented non-ideal Magneto-Hydrodynamics (MHD) effects in the
Adaptive Mesh Refinement (AMR) code RAMSES, namely ambipolar diffusion and
Ohmic dissipation, as additional source terms in the ideal MHD equations. We
describe in details how we have discretized these terms using the adaptive
Cartesian mesh, and how the time step is diminished with respect to the ideal
case, in order to perform a stable time integration. We have performed a large
suite of test runs, featuring the Barenblatt diffusion test, the Ohmic
diffusion test, the C-shock test and the Alfven wave test. For the latter, we
have performed a careful truncation error analysis to estimate the magnitude of
the numerical diffusion induced by our Godunov scheme, allowing us to estimate
the spatial resolution that is required to address non-ideal MHD effects
reliably. We show that our scheme is second-order accurate, and is therefore
ideally suited to study non-ideal MHD effects in the context of star formation
and molecular cloud dynamics
Coloring random graphs
We study the graph coloring problem over random graphs of finite average
connectivity . Given a number of available colors, we find that graphs
with low connectivity admit almost always a proper coloring whereas graphs with
high connectivity are uncolorable. Depending on , we find the precise value
of the critical average connectivity . Moreover, we show that below
there exist a clustering phase in which ground states
spontaneously divide into an exponential number of clusters and where the
proliferation of metastable states is responsible for the onset of complexity
in local search algorithms.Comment: 4 pages, 1 figure, version to app. in PR
Stabilization of apple peel by drying. Influence of temperature and ultrasound application on drying kinetics and product quality
This is an Accepted Manuscript of an article published by Taylor & Francis Group in Drying Technology on 2019, available online at: http://www.tandfonline.com/10.1080/07373937.2018.1474476[EN] Increasing the value of the waste generated by food processing is a must from an environmental and economic point of view. This paper addresses the influence of drying temperature and ultrasound application on the drying kinetics and quality of apple peel (Royal Gala var.). Samples were dried at -10, 30, 50 and 70 ºC without and with (50 W) ultrasound application. Color, antioxidant capacity, total phenolic and ascorbic acid content were measured. Ultrasound application and drying temperature significantly shortened the drying time and affected the quality parameters. The drying carried out at 30 ºC with ultrasound application was a fast process that provided samples with good color and antioxidant attributes.The authors acknowledge the financial support of INIA-ERDF throughout the project RTA2015-00060-C04-02.Martins, MP.; Cortés, EJ.; Eim, V.; Mulet Pons, A.; Carcel, JA. (2019). Stabilization of apple peel by drying. Influence of temperature and ultrasound application on drying kinetics and product quality. Drying Technology. 37(5):559-568. https://doi.org/10.1080/07373937.2018.1474476S55956837
Rectal Metastases from Squamous Cell Carcinoma: A Case Report and Review of the Literature
Non-small-cell lung cancer (NSCLC) represents 85% of lung cancer. The most frequent sites of distant metastasis are the liver, adrenal glands, bones and brain. Gastrointestinal metastases are uncommon and rectal metastases are extremely rare. Here we report a case of squamous cell carcinoma of the lung with rectal metastases
Against Chaos in Temperature in Mean-Field Spin-Glass Models
We study the problem of chaos in temperature in some mean-field spin-glass
models by means of a replica computation over a model of coupled systems. We
propose a set of solutions of the saddle point equations which are
intrinsically non-chaotic and solve a general problem regarding the consistency
of their structure. These solutions are relevant in the case of uncoupled
systems too, therefore they imply a non-trivial overlap distribution
between systems at different temperatures. The existence of such
solutions is checked to fifth order in an expansion near the critical
temperature through highly non-trivial cancellations, while it is proved that a
dangerous set of such cancellations holds exactly at all orders in the
Sherrington-Kirkpatrick (SK) model. The SK model with soft-spin distribution is
also considered obtaining analogous results. Previous analytical results are
discussed.Comment: 20 pages, submitted to J.Phys.
Polynomial iterative algorithms for coloring and analyzing random graphs
We study the graph coloring problem over random graphs of finite average
connectivity . Given a number of available colors, we find that graphs
with low connectivity admit almost always a proper coloring whereas graphs with
high connectivity are uncolorable. Depending on , we find the precise value
of the critical average connectivity . Moreover, we show that below
there exist a clustering phase in which ground states
spontaneously divide into an exponential number of clusters. Furthermore, we
extended our considerations to the case of single instances showing consistent
results. This lead us to propose a new algorithm able to color in polynomial
time random graphs in the hard but colorable region, i.e when .Comment: 23 pages, 10 eps figure
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