The Aging of Population: Expenditure on Education and Social Security

Treballs Finals del Màster d'Economia, Facultat d'Economia i Empresa, Universitat de Barcelona, Curs: 2014-2015, Tutors: Xavier Raurich Puigdevall i Montserrat Vilalta-BufíWe analyze the effects of population aging on public expenditure when government is not fully efficient. We build an overlapping generations model in which government collects money from the households through a proportional tax on wages and distributes the resources in the form of pensions and a subsidy to education. The individual votes for the level of public assistance to receive in order to maximize her utility. We find that the solution of the model depends on the preferences of the median voter and that as population ages, more pensions are demanded in the economy relative to the subsidy to education, which makes the individuals invest less in the human capital formation of their children and lead economy to be less productive. We also demonstrate that government inefficiency plays a crucial role in the redistribution of resources and that the solution of such an inefficiency gap may slow down the negative e¤ects of population aging

Development and performance of Triple-GEM detectors for the upgrade of the muon system of the CMS experiment

The CMS Collaboration is evaluating GEM detectors for the upgrade of the muon system. This contribution will focus on the R&D performed on chambers design features and will discuss the performance of the upgraded detector

A novel application of Fiber Bragg Grating (FBG) sensors in MPGD

We present a novel application of Fiber Bragg Grating (FBG) sensors in the construction and characterisation of Micro Pattern Gaseous Detector (MPGD), with particular attention to the realisation of the largest triple (Gas electron Multiplier) GEM chambers so far operated, the GE1/1 chambers of the CMS experiment at LHC. The GE1/1 CMS project consists of 144 GEM chambers of about 0.5 m2 active area each, employing three GEM foils per chamber, to be installed in the forward region of the CMS endcap during the long shutdown of LHC in 2108-2019. The large active area of each GE1/1 chamber consists of GEM foils that are mechanically stretched in order to secure their flatness and the consequent uniform performance of the GE1/1 chamber across its whole active surface. So far FBGs have been used in high energy physics mainly as high precision positioning and re-positioning sensors and as low cost, easy to mount, low space consuming temperature sensors. FBGs are also commonly used for very precise strain measurements in material studies. In this work we present a novel use of FBGs as flatness and mechanical tensioning sensors applied to the wide GEM foils of the GE1/1 chambers. A network of FBG sensors have been used to determine the optimal mechanical tension applied and to characterise the mechanical tension that should be applied to the foils. We discuss the results of the test done on a full-sized GE1/1 final prototype, the studies done to fully characterise the GEM material, how this information was used to define a standard assembly procedure and possible future developments.Comment: 4 pages, 4 figures, presented by Luigi Benussi at MPGD 2015 (Trieste, Italy). arXiv admin note: text overlap with arXiv:1512.0848

Web-based monitoring tools for Resistive Plate Chambers in the CMS experiment at CERN

The Resistive Plate Chambers (RPC) are used in the CMS experiment at the trigger level and also in the standard offline muon reconstruction. In order to guarantee the quality of the data collected and to monitor online the detector performance, a set of tools has been developed in CMS which is heavily used in the RPC system. The Web-based monitoring (WBM) is a set of java servlets that allows users to check the performance of the hardware during data taking, providing distributions and history plots of all the parameters. The functionalities of the RPC WBM monitoring tools are presented along with studies of the detector performance as a function of growing luminosity and environmental conditions that are tracked over time

Novel pathways induced by melatonin on leukocytes: possible pharmacological and inflammatory perspectives

La melatonina, oltre ad essere un regolatore dei ritmi circadiani, è stato recentemente dimostrato essere un modulatore del sistema immunitario attraverso il controllo del comportamento dei leucociti, i quali sono infatti in grado di sintetizzare la melatonina e possiedono specifici recettori di membrana (MT1 e MT2) ad alta affinità (1nM). L’abilità della melatonina di contrastare l’apoptosi sta ricevendo un grande interesse, un effetto ben accetto, nonostante il suo meccanismo sia ancora abbastanza controverso. In questo studio analizziamo il meccanismo coinvolto nell’effetto anti-apoptotico della melatonina in leucociti normali e tumorali. Abbiamo visto che questo effetto è dovuto a due differenti meccanismi cooperanti i quali coinvolgono due target primari con cui la melatonina interagisce; i recettori MT1/MT2 e la calmodulina, un noto target della melatonina a bassa affinità (63 uM). L’interazione con il recettore ed il legame alla calmodulina da origine a due pathways di trasduzione del segnale indipendenti, che consisono da una parte in una trasduzione del segnale canonica (convolgendo le proteine G e la fosfolipasi C), e dall’altra nell’attivazione della 5-lipossigenasi (5-LOX) tramite calmodulina /fosfolipasi A2 (un noto interattore della calmodulina) che termina con la produzione dei 5-HETE. Questi due pathways convergono nell’effetto anti-apoptotico di melatonina a livello mitocondriale, prevenendo l’attivazione di Bax, la chiave che innesca il pathway apoptotico intrinseco. La novità di questi risultati è che Bax è mantenuto nel mitocondrio in una stato anti-apoptotico. Infatti, la melatonina causa la translocazione di Bcl-2 al mitocondrio, dove si lega direttamente a Bax, inibendo la sua attivazione/dimerizzazione. L’effetto anti-apoptotico è completamente abrogato se uno o l’altro pathway viene inibito. La necessità del legame a bassa affinità con la calmodulina, spiega la necessità di alte dosi di melatonina (>100uM). Il coinvolgimento della 5-LOX nell’effetto anti-apoptotico della melatonina è particolarmente interessante dal momento che la necessità di un enzima chiave della risposta infiammatoria può fare nuova luce sul ruolo che la melatonina gioca nella regolazione della risposta immunitaria. Inoltre, l’attivazione della LOX implica uno sprigionarsi di radicali liberi che immediatamente (100uM). The involvement of 5-LOX in the anti-apoptotic effect of melatonin is particularly intriguing since, the recruitment of a key enzyme of the inflammatory response may shed new lights on the role melatonin plays in the regulation of the immune response. Moreover, LOX activation implies a burst of free radicals that immediately (<1min) and strongly (up to 15folds) follows melatonin administration, peaking at 2hrs to go back to normal values at 6hrs. This is a biological pro-oxidant effect that co-exists with, and contrasts, the well known chemical radical scavenging ability of the melatonin molecule

Operational experience with the GEM detector assembly lines for the CMS forward muon upgrade

The CMS Collaboration has been developing large-area triple-gas electron multiplier (GEM) detectors to be installed in the muon Endcap regions of the CMS experiment in 2019 to maintain forward muon trigger and tracking performance at the High-Luminosity upgrade of the Large Hadron Collider (LHC); 10 preproduction detectors were built at CERN to commission the first assembly line and the quality controls (QCs). These were installed in the CMS detector in early 2017 and participated in the 2017 LHC run. The collaboration has prepared several additional assembly and QC lines for distributed mass production of 160 GEM detectors at various sites worldwide. In 2017, these additional production sites have optimized construction techniques and QC procedures and validated them against common specifications by constructing additional preproduction detectors. Using the specific experience from one production site as an example, we discuss how the QCs make use of independent hardware and trained personnel to ensure fast and reliable production. Preliminary results on the construction status of CMS GEM detectors are presented with details of the assembly sites involvement

Performance of a Large-Area GEM Detector Prototype for the Upgrade of the CMS Muon Endcap System

Gas Electron Multiplier (GEM) technology is being considered for the forward muon upgrade of the CMS experiment in Phase 2 of the CERN LHC. Its first implementation is planned for the GE1/1 system in the $1.5 < \mid\eta\mid < 2.2$ region of the muon endcap mainly to control muon level-1 trigger rates after the second long LHC shutdown. A GE1/1 triple-GEM detector is read out by 3,072 radial strips with 455 $\mu$rad pitch arranged in eight $\eta$-sectors. We assembled a full-size GE1/1 prototype of 1m length at Florida Tech and tested it in 20-120 GeV hadron beams at Fermilab using Ar/CO$_{2}$ 70:30 and the RD51 scalable readout system. Four small GEM detectors with 2-D readout and an average measured azimuthal resolution of 36 $\mu$rad provided precise reference tracks. Construction of this largest GEM detector built to-date is described. Strip cluster parameters, detection efficiency, and spatial resolution are studied with position and high voltage scans. The plateau detection efficiency is [97.1 $\pm$ 0.2 (stat)]\%. The azimuthal resolution is found to be [123.5 $\pm$ 1.6 (stat)] $\mu$rad when operating in the center of the efficiency plateau and using full pulse height information. The resolution can be slightly improved by $\sim$ 10 $\mu$rad when correcting for the bias due to discrete readout strips. The CMS upgrade design calls for readout electronics with binary hit output. When strip clusters are formed correspondingly without charge-weighting and with fixed hit thresholds, a position resolution of [136.8 $\pm$ 2.5 stat] $\mu$rad is measured, consistent with the expected resolution of strip-pitch/$\sqrt{12}$ = 131.3 $\mu$rad. Other $\eta$-sectors of the detector show similar response and performance.Comment: 8 pages, 32 figures, submitted to Proc. 2014 IEEE Nucl. Sci. Symposium, Seattle, WA, reference adde

Quality control and beam test of GEM detectors for future upgrades of the CMS muon high rate region at the LHC

Gas Electron Multipliers (GEM) are a proven position sensitive gas detector technology which nowadays is becoming more widely used in High Energy Physics. GEMs offer an excellent spatial resolution and a high particle rate capability, with a close to 100% detection efficiency. In view of the high luminosity phase of the CERN Large Hadron Collider, these aforementioned features make GEMs suitable candidates for the future upgrades of the Compact Muon Solenoid (CMS) detector. In particular, the CMS GEM Collaboration proposes to cover the high-eta region of the muon system with large-area triple-GEM detectors, which have the ability to provide robust and redundant tracking and triggering functions. In this contribution, after a general introduction and overview of the project, the construction of full-size trapezoidal triple-GEM prototypes will be described in more detail. The procedures for the quality control of the GEM foils, including gain uniformity measurements with an x-ray source will be presented. In the past few years, several CMS triple-GEM prototype detectors were operated with test beams at the CERN SPS. The results of these test beam campaigns will be summarised

Chemical etching of 3D printed α-Al2O3 for catalytic applications

New advances in three-dimensional (3D) printing have made such manufacturing technique suitable for a wide range of applications. The relatively short time to obtain complex geometries, the possibility to control the material usage and lower the energy consumption, are some of the principal characteristics that make the additive manufacturing (AM) an innovative technique to design and produce final parts. Nowadays, what makes the AM and in particular the direct ink writing (DIW) technology stands out among the conventional manufacturing techniques is the possibility to print ceramic materials with lower production costs. The combination of the outstanding properties of these materials and the possibility to create complex geometries with them, lead to a more popular usage of ceramic materials in technologic applications, such as bioengineering, chemistry, energy, among others. In this sense, in several studies it has been demonstrated that, using printed ceramic catalysts has improved catalytic conversions. DIW isin fact able to produce catalysts with large exposed surfaces with continuous and predictable airflow through the reactor. Within the aforementioned information, the purpose of this Bachelor’s project is to enhance the catalytic performance of alumina 3D printed catalysts with a surface modification process though chemical etching. The objective is to obtain a controlled and interconnected porosity on the catalysts surface, in order to increase the internal surface area available for the reaction and the residence time of the reactants into the catalyst. To do so, hydrofluoric acid (HF) was used to etch the alpha alumina (-Al2O3) surface. To study the effect of HF on -Al2O3, samples obtained by means of conventional methods like cold isostatic pressing were etched with HF under both different concentrations (5, 20 and 40 M) and times. The optimal etching conditions were determined analysing the changes in density and roughness of each sample, with the usage of an optical profilometer. Afterwards, cubic geometries with 100% infill were printed and etched with the three optimal etching conditions obtained; one per each investigated concentration. The density, surface roughness, porosity and the mechanical properties in terms of Vickers hardness and indentation fracture toughness have been investigated and compared with those obtained for no-etched samples. Finally, rectilinear catalysts with 50% infill were printed and etched with the same conditions as mentioned above and subsequently the catalysis reaction of dehydrogenation of ethanol were carried out. The catalytic performance was studied in a range of temperatures from 200 to 600°C. The optimal etching time for HF concentration of 5, 20 and 40M are 48, 24 and 5 hours, respectively. The optimal etching condition is with [HF] = 40M, since it shows the greatest increase of the average roughness, which suggest that a controlled porosity have been generated on the surface of the samples. Although these results, the surface modification process by means of chemical etching has not shown improvement on the catalytic performances of the -Al2O3 catalysts.Los nuevos avances en la impresión en tres dimensiones (3D) han permitido que esta técnica de fabricación sea la adecuada para una amplia gama de aplicaciones. El reducido tiempo para obtener geometrías complejas, la posibilidad de controlar el uso de material y el bajo consumo de energía, son algunas de las principales características que hacen que la fabricación aditiva (AM) sea una técnica innovadora para diseñar y producir piezas finales. Hoy en día lo que hace que la AM, y en particular la tecnología direct ink writing (DIW), se destaque entre las tecnologías convencionales de fabricación es la posibilidad de imprimir materiales cerámicos con bajos costes de producción. La combinación de sus destacadas propiedades y la posibilidad de crear geometrías complejas con ellos, lleva a un uso más popular de los materiales cerámicos en aplicaciones tecnológicas, como bioingeniería, química, energía, entre otras. En este sentido, en varios estudios se ha demostrado que usar catalizadores cerámicos impresos mejora las conversiones catalíticas. Mediante la DIW es posible producir catalizadores con amplias superficies expuestas con un continuo y predecible flujo de gas en el reactor. Dentro de la información mencionada, el objetivo de este proyecto final de grado es mejorar las prestaciones catalíticas de catalizadores de alúmina impresa mediante un proceso de modificación superficial con ataque químico. El objetivo es obtener una porosidad controlada e interconectada en la superficie del catalizador, para aumentar la superficie interior disponible y el tiempo de residencia de los reactivos en el catalizador. Para hacerlo, se ha usado ácido fluorhídrico (HF) para atacar la superficie de la alpha alúmina (-Al2O3). Para estudiar el efecto del HF sobre la -Al2O3, las muestras obtenidas mediante prensado isostático en frio se han atacado con diferentes concentraciones (5, 20 y 40 M) y tiempos. Las condiciones óptimas de ataque se han determinado analizando los cambios en la densidad y rugosidad de cada muestra, usando un perfilómetro óptico. A continuación, se han impreso geometrías cúbicas con un 100% de relleno y se han atacado con las tres condiciones óptimas de ataque obtenidas, una para cada concentración investigada. La densidad, la rugosidad, la porosidad y las propiedades mecánicas, en términos de dureza Vickers y resistencia a la fractura, se han analizado y comparado con los resultados obtenidos para muestras no atacadas. Finalmente se han impreso catalizadores rectilíneos con un 50% de relleno y se han atacado con las mismas condiciones mencionadas anteriormente y posteriormente, se ha realizado la reacción catalítica de deshidrogenación de etanol. Las propiedades catalíticas se han estudiado en un rango de temperaturas entre 200 y 600oC. El tiempo de ataque óptimo para las concentraciones de 5, 20 y 40 M es de 48, 24 y 5 horas, respectivamente. La condición óptima de ataque es la de 40 M, ya que muestra el mayor aumento de rugosidad, lo que sugiere que se ha formado una porosidad controlada en la superficie de la muestra. A pesar de los resultados obtenidos, el proceso de modificación superficial mediante ataque químico no muestra una mejora en las prestaciones catalíticas de los catalizadores de -Al2O3.Els nous avanços en la impressió en tres dimensions (3D) han permès que aquesta tècnica de fabricació sigui l'adequada per a una àmplia gamma d'aplicacions. Els reduïts temps per a obtenir geometries complexes, la possibilitat de controlar la utilització de material, i el baix consum energètic són algunes de les principals característiques que fan que la fabricació additiva (AM) sigui una tècnica innovadora per a dissenyar i produir peces finals. Avui dia el que fa que l'AM i en particular la tecnologia de direct ink writing (DIW) es destaqui entre les tecnologies convencionals de fabricació és la possibilitat d'imprimir materials ceràmics amb baixos costos de producció. La combinació de les destacades propietats d’aquests materials i la possibilitat de crear geometries complexes amb ells, porta a una popularització dels materials ceràmics en aplicacions tecnològiques com bioenginyeria, química, o energia, entre altres. En aquest sentit, en diversos estudis s'ha demostrat que usar catalitzadors ceràmics impresos millora les conversions catalítiques. Mitjançant la DIW és possible produir catalitzadors amb àmplies superfícies exposades amb un continu i predictible flux de gas en el reactor. Dins la informació esmenada, l'objectiu d'aquest projecte final de grau és millorar les prestacions catalítiques de catalitzadors d'alúmina mitjançant un procés de modificació superficial amb atac químic. Per fer-ho s’ha buscat obtenir una porositat controlada i interconnectada en la superfície del catalitzador, per a tal d’augmentar la superfície interior disponible i el temps de residència dels reactius al catalitzador. S'ha usat àcid fluorhídric (HF) per a atacar la superfície de l’alpha alúmina (-Al2O3). Per a estudiar l'efecte del HF sobre la -Al2O3, les mostres obtingudes mitjançant premsatge isostàtic en fred s'han atacat amb diferents concentracions (5, 20 i 40 M) i temps. Les condicions òptimes d'atac s'han determinat analitzant els canvis en la densitat i rugositat de cada mostra, usant un perfilòmetre òptic. A continuació, s'han imprès geometries cúbiques amb un 100% de farciment i s'han atacat amb les tres condicions òptimes d'atac obtingudes, una per cada concentració investigada. La densitat, la rugositat, la porositat i les propietats mecàniques, en termes de duresa Vickers i resistència a la fractura, s'han analitzat i comparat amb els resultats obtinguts de mostres no atacades. Finalment, s'han imprès catalitzadors rectilinis amb un 50% de farciment i s'han atacat amb les mateixes condicions esmentades anteriorment, i, posteriorment, s'han realitzat la reacció catalítica de deshidrogenació d'etanol. Les prestacions catalítiques s'han estudiat en un rang de temperatures entre 200 i 600oC. El temps d'atac òptim per a les concentracions de 5, 20 i 40 M és de 48, 24 i 5 hores, respectivament. La condició òptima d'atac és la de 40 M, ja que mostra el major augment de rugositat, la qual cosa suggereix que s'ha format una porositat controlada en la superfície de la mostra. Tot i els prometedors resultats, no s’ha pogut demostrat que el procés de modificació superficial mitjançant atac químic presenti una millora en les prestacions catalítiques dels catalitzadors de -Al2O3

Overview of large area triple-GEM detectors for the CMS forward muon upgrade

In order to cope with the harsh environment expected from the high luminosity LHC, the CMS forward muon system requires an upgrade. The two main challenges expected in this environment are an increase in the trigger rate and increased background radiation leading to a potential degradation of the particle ID performance. Additionally, upgrades to other subdetectors of CMS allow for extended coverage for particle tracking, and adding muon system coverage to this region will further enhance the performance of CMS