Laser Shock Microforming of Thin Metal Sheets

Continuous and long-pulse lasers have been used for the forming of metal sheets in macroscopic mechanical applications. However, for the manufacturing of micro-electromechanical systems (MEMS), the applicability of such type of lasers is limited by the long-relaxation-time of the thermal fields responsible for the forming phenomena. As a consequence of such slow relaxation, the final sheet deformation state is attained only after a certain time, what makes the generated internal residual stress fields more dependent on ambient conditions and might make difficult the subsequent assembly process from the point of view of residual stresses due to adjustment. The use of ns laser pulses provides a suitable parameter matching for the laser forming of an important range of sheet components used in MEMS that, preserving the short interaction time scale required for the predominantly mechanic (shock) induction of deformation residual stresses, allows for the successful processing of components in a medium range of miniaturization, particularly important according to its frequent use in such systems. In the present paper, a discussion is presented on the physics of laser shock microforming and the influence of the different effects on the net bending angle. The experimental setup used for the experiments, sample fabrication and experimental results of influence of number of laser pulses on the net bending angle are also presented

Laser Shock Microformingof Thin Metal Sheets with ns Lasers

Continuous and long-pulse lasers have been used for the forming of metal sheets in macroscopic mechanical applications. However, for the manufacturing of micro-electromechanical systems (MEMS), the use of ns laser pulses provides a suitable parameter matching over an important range of sheet components that, preserving the short interaction time scale required for the predominantly mechanical (shock) induction of deformation residual stresses, allows for the successful processing of components in a medium range of miniaturization without appreciable thermal deformation.. In the present paper, the physics of laser shock microforming and the influence of the different experimental parameters on the net bending angle are presented

Heteroscedasticity irrelevance when testing means difference

Peer Reviewe

Influence of temperature on the nodal properties of the longitudinal thermal conductivity of YBa2_2Cu3_3O7−x_{7-x}

The angle dependence at different temperatures of the longitudinal thermal conductivity $\kappa_{xx}(\theta)$ in the presence of a planar magnetic field is presented. In order to study the influence of the gap symmetry on the thermal transport angular scans were measured up to a few Kelvin below the critical temperature $T_c$. We found that the four-fold oscillation of $\kappa_{xx}(\theta)$ vanishes at $T > 20$K and transforms into a one-fold oscillation with maximum conductivity for a field of 8 T applied parallel to the heat current. Nevertheless, the results indicate that the d-wave pairing symmetry is the main pairing symmetry of the order parameter up to $T_c$. Numerical results of the thermal conductivity using an Andreev reflection model for the scattering of quasiparticles by supercurrents under the assumption of d-wave symmetry provide a semiquantitative description of the overall results.Comment: 7 figures, EPJ B (in press, 2003

Lactate Oxidation in Endothelial Cells: A Feature of All Endothelial Cells?

Resumen de la comunicaciónMetabolism of endothelial cells is a topic that has gained an increasing interest in the last years. This is due to their role in the angiogenic process, which is pathologically upregulated in several diseases, such as retinopathies, diabetes and cancer. Glycolysis, among other metabolic routes, has been found to be essential for triggering the angiogenic switch. Additionally, it has been seen that endothelial cells are able to take up lactate from the extracellular media, for example in the case of the tumor microenvironment, where cancer cells would have secreted high amounts of this metabolite. Endothelial cells would oxidize this lactate for obtaining energy, but lactate can also act as a signaling molecule for the angiogenic process. However, experiments to determine the molecular fate of lactate have been performed using only macrovascular endothelial cells. The aim of the present work is to prove whether microvascular endothelial cells are also able to take up and oxidize lactate. For this purpose, fluorimetry, isotopic labeling and Seahorse experiments were used to study the metabolism of a human microvascular endothelial cell line (HMEC). The expression levels of transcripts and proteins of different enzymes and transporters related to lactate metabolism were estimated by qPCR and Western blotting. The results obtained indicate that these cells rely on glycolysis for their metabolism, while the oxidation of glucose and glutamine seems to be considerably low. On the other hand, no lactate oxidation could be detected. We then checked the mRNA expression of the two isoenzymes of lactate dehydrogenase (LDH) and the two main lactate transporters, MCT1 and MCT4, and found that levels of LDH-B and MCT1 were undetectable. We failed to measure any MCT1 mRNA or protein expression either in normoxia or hypoxia. Hence, we can conclude that at least this microvascular endothelial cell line cannot use extracellular lactate as a metabolic fuel.Our experimental work is supported by grants BIO2014-56092-R (MINECO and FEDER) and P12-CTS-1507 (Andalusian Government and FEDER) and funds from group BIO-267 (Andalusian Government). The "CIBER de Enfermedades Raras" is an initiative from the ISCIII (Spain). This communicaction has the support of a travel grant "Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech"

The dynamics of durable goods markets: rational expectations and sticky prices

This paper studies price dynamics in a durable good market under the assumption that consumers have rational expectations on future prices. For a wide variety of expectations, optimal consumption plans result in sticky-price demand functions. Market dynamics are characterized by intertemporal price discrimination which provides a possible explanation for the declining path of price observed in many "young" industries. Unexpected shocks on demand result in price overshooting, while unexpected supplyshocks have the opposite effect on price

IndElec: A Software for Analyzing Party Systems and Electoral Systems

IndElec is a software addressed to compute a wide range of indices from electoral data, which are intended to analyze both party systems and electoral systems in political studies. Further, IndElec can calculate such indices from electoral data at several levels of aggregation, even when the acronyms of some political parties change across districts. As the amount of information provided by IndElec may be considerable, this software also aids the user in the analysis of electoral data through three capabilities. First, IndElec automatically elaborates preliminary descriptive statistical reports of computed indices. Second, IndElec saves the computed information into text files in data matrix format, which can be directly loaded by any statistical software to facilitate more sophisticated statistical studies. Third, IndElec provides results in several file formats (text, CSV, HTML, R) to facilitate their visualization and management by using a wide range of application softwares (word processors, spreadsheets, web browsers, etc.). Finally, a graphical user interface is provided for IndElec to manage calculation processes, but no visualization facility is available in this environment. In fact, both the inputs and outputs for IndElec are arranged in files with the aforementioned formats.