89 research outputs found
Thermal Management of Electrical Systems in a Solar-Electric Stratosphere HALE
No full textInnovations in the various disciplines of aeronautics such as battery technology and composite
structures have opened the door to completely unprecedented aerial vehicle designs. The High
Altitude Long Endurance (HALE) aircraft is a case in point. Jumping on the trend, the German
Aerospace Center (DLR) is betting on the "High-Altitude Platform (HAP)", a solar-powered
HALE Unmanned Aerial Vehicle (UAV) intended for satellite-like operations. Throughout the
mission the HAP will have to cope with extreme environmental conditions characterized by
low air temperatures and densities and high amounts of radiation. Consequently, the correct
operation of the electronic devices will be jeopardized. This contribution covers the thermal
management of the avionics devices on board the HAP. For this purpose, a mathematical
thermal model based on first principles has been constructed. Firstly, the model represents
the current HAP design. From the estimations, it has been predicted that the avionics will
have to face overheating and overcooling challenges, with temperatures between -60°C and
190°C being reached. In a subsequent step, temperature control techniques have been applied.
Selecting passive techniques as preferable, preliminary results show that the introduction of
conductive plates, paints and heat sinks ensures that the temperatures of the avionics devices
are maintained within their specific operating temperature range
Sócrates, la "Piedad" y los márgenes de la convivencia cívica
No full textLa polis clásica fue producto del pluralismo cívico y no conoció ningún\ud
dogmatismo de carácter político o religioso; sin embargo, la "piedad" (hósios,\ud
eusébeia) sirvió de piedra de toque para consolidar la convivencia cívica.\ud
Atenas, la primera democracia que hubo en el mundo, afamada por reinar en ella la libertad de palabra, fue la misma que silenció a Sócrates.\ud
Al célebre filósofo se le condenó a morir por no creer en los dioses de su\ud
ciudad, por haber introducido otros nuevos y por corromper a la juventud.\ud
En realidad, el único cargo contra él en el proceso a que se le sometió en\ud
el año 399 a. de n. e. fue el de "impiedad" (asébeia). En el presente artículo\ud
pretendo poner de relieve esta tensión entre el "individuo" (Sócrates) y la\ud
comunidad cívica (Atenas), y cuáles eran por ende los límites de lo tolerable\ud
y lo intolerable en la polis clásica.The classic polis emerged from civic pluralism without any political or\ud
religious dogmatism. However, "piety" (hósios, eusébeia) set up the touchstone\ud
to consolidate the civic coexistence. Athens was the world's first democracy,\ud
renowned for its freedom of speech, but it silenced Socrates. This\ud
famous philosopher was senteciated to death for allegedly disbelieving in the gods of his city, introducing new gods, and corrupting the youth. Actually\ud
Socrates was brought to trial in 399 B. C. on the single charge of\ud
"impiety" (asebeid). In this contribution I will enphasize the tension between\ud
"individual" (Socrates) and the civic community (Athens), and the limits of\ud
tolerable and intolerable in classic polis
Thermal Management Concept Evaluation for a High-Altitude Solar Platform
No full textHigh Altitude Long Endurance (HALE) aircraft operate under adverse thermal conditions, with air temperatures
very low and at the same time high amounts of heat introduced by sun radiation. Thus, thermal management
of the aircraft systems, such as electronics and battery is a very challenging task. A first step in solving
this is generating accurate models of the thermal dynamics of the HALE. This paper presents the thermal
analysis of a solar-electric stratospheric HALE. For such an analysis, a thermal mathematical model based on
first principles was developed. In a further step, an initial test campaign was performed. The test campaign
included static and dynamic temperature measurements on a segment of the aircraft's wing structure. The
experiments throughout this test campaign showed good compliance of the results with the previously derived
mathematical models, with differences of less than 5◦C between the measured and simulated temperature
curves
Thermal Analysis of a High-Altitude Solar Platform
No full textHigh Altitude Long Endurance (HALE) aircraft operate under adverse
thermal conditions, with ambient pressures and temperatures very
low and at the same time high amounts of heat introduced by sun
radiation. Thus, thermal management of the aircraft systems, such as
electronics and batteries is a very challenging task. A first step in
solving this is generating accurate models of the thermal dynamics
of the HALE. This paper presents the thermal analysis of a solar-electric stratospheric HALE at the ground case. A thermal mathematical
model based on first principles was developed for such an analysis.
In a further step, an initial test campaign was performed. The test
the campaign included static and dynamic temperature measurements
on an aircraft wing structure segment. The experiments throughout
this test campaign showed good compliance of the results with
the previously derived mathematical models, with differences of less
than 5°C between the measured and simulated temperature curves
Sir2 regulates stability of repetitive domains differentially in the human fungal pathogen Candida albicans
No full textDNA repeats, found at the ribosomal DNA locus, telomeres and subtelomeric regions, are unstable sites of eukaryotic genomes. A fine balance between genetic variability and genomic stability tunes plasticity of these chromosomal regions. This tuning mechanism is particularly important for organisms such as microbial pathogens that utilise genome plasticity as a strategy for adaptation. For the first time, we analyse mechanisms promoting genome stability at the rDNA locus and subtelomeric regions in the most common human fungal pathogen: Candida albicans In this organism, the histone deacetylase Sir2, the master regulator of heterochromatin, has acquired novel functions in regulating genome stability. Contrary to any other systems analysed, C. albicans Sir2 is largely dispensable for repressing recombination at the rDNA locus. We demonstrate that recombination at subtelomeric regions is controlled by a novel DNA element, the TLO Recombination Element, TRE, and by Sir2. While the TRE element promotes high levels of recombination, Sir2 represses this recombination rate. Finally, we demonstrate that, in C. albicans, mechanisms regulating genome stability are plastic as different environmental stress conditions lead to general genome instability and mask the Sir2-mediated recombination control at subtelomeres. Our data highlight how mechanisms regulating genome stability are rewired in C. albican
Bridging the Gap Between Traditional Japanese Fabrication and Advanced Digital Tools
No full textTraditional Japanese woodworking techniques have been inherited between generations in the past millennia through the Daiku, the master carpenter that teaches apprentices the precise and valuable skills of carpentry through methodical and time-intensive processes. Throughout the 21st Century, with the development of advanced construction methods, coupled with younger generations exhibiting little interest in following the Daiku, this valuable cultural artform is becoming less prevalent in Japanese culture. However, the development of advanced digital tools offers an avenue through which the knowledge and skills of older generations can be both transferred and developed by younger
generations. In this context, the paper examines the relationship between traditional Japanese woodworking and advanced computational tools by bringing experts from both disciplines for the design and construction of a Japanese Pagoda, in which the significance of bridging the gap
between both domains is highlighted across the design, fabrication and assembly of the project
Short-term effects of a green coffee extract-, Garcinia c ambogia- and l-carnitine-containing chewing gum on snack intake and appetite regulation
No full textIntroduction; Different studies have assessed the influence of chewing gum to aid control of appetite and reduce food intake. Purpose; The aims of the present study were to evaluate the effects of chewing gum on satiety, food hedonics and snack intake and to explore the potential effects of the combination of Garcinia c ambogia, green coffee extract and l-carnitine on satiety, when administered in a gum format. Methods; This was a prospective study in which 57 subjects randomly received three kinds of treatments, in a crossover design: (1) active gum; (2) placebo gum; and (3) no gum. Food preferences and appetite sensations were evaluated by means of the Leeds Food Preference Questionnaire and visual analog scales. Results; There was a significant reduction in low-fat sweet snack intake with placebo gum and the active gum compared to no gum and a reduction in high-fat sweet snack intake with the active gum compared to placebo gum and no gum. Total caloric intake was only reduced in the active gum condition. Both the active and placebo gum conditions significantly reduced hunger and prospective food consumption and increased fullness compared to no gum and were associated with a reduced wanting for sweet food in the LFPQ, consistent in a reduction in the relative preference for sweet snacks versus savoury snacks. Conclusion; This study supports the notion that chewing gum containing nutraceutical products might aid in the control over snack intake and reduce hunger sensations
Aplicación de sistemas electrónicos embebidos a la fabricación de piezas mecánicas mediante máquinas herramienta de accionamiento manual
No full textSe plantea un proyecto de investigación y desarrollo que toma como base las actividades previamente realizadas en el mismo campo por el grupo de investigación. En este caso, se plantea como objetivo a resolver la implementación de un sistema de control, aplicable al manejo y control de máquinas herramientas, que considere los últimos avances tecnológicos en el área de sistemas embebidos, con el objeto de lograr una solución aún más simple y económica para la automatización y control de máquinas herramienta de accionamiento manual. Se consideran al respecto, con relación al proyecto precursor al presente, una serie de situaciones que deben ser analizadas y tomadas en cuenta. Como primera pauta a analizar, se debe considerar el avance tecnológico ocurrido durante los últimos años en la tecnología de componentes electrónicos, y en especial al desarrollo de sistemas embebidos para uso en tiempo real, hoy ampliamente disponibles en el mercado local. Por otra parte, como un tema no menor, se deben considerar las dificultades actualmente existentes para la utilización de determinados tipos de circuitos programables (FPGAs en particular), derivadas tanto desde las exigencias que se plantean en lo que hace a la exportación de los mismos desde los países proveedorescomo a las limitaciones de importación actualmente vigentes en el mercado local.La necesidad de lograr un aumento en la competitividad de los sectores que podrían llegar a ser beneficiados por el presente desarrollo, el costo cada vez mayor de los equipamientos automatizados y sistemas de control numérico de últimas generaciones, la gran cantidad de maquinaria en uso de accionamiento manual, y la necesidad de su tecnificación, derivada de la exigencia de aumentar la competitividad, permiten proponer la implementación de un sistema de control equiparable al desarrollado en el proyecto anterior, que utilice componentes fácilmente accesibles y disponibles en el mercado local.Fil: Szklanny, Fernando Ignacio. Universidad Nacional de La Matanza. Departamento de Ingeniería e Investigaciones Tecnológicas; Argentina.Fil: De María, Elio Augusto. Universidad Nacional de La Matanza. Departamento de Ingeniería e Investigaciones Tecnológicas; Argentina.Fil: Maidana, Carlos Eduardo. Universidad Nacional de La Matanza. Departamento de Ingeniería e Investigaciones Tecnológicas; Argentina.Fil: Rodríguez, Carlos Alberto. Universidad Nacional de La Matanza. Departamento de Ingeniería e Investigaciones Tecnológicas; Argentina.Fil: Di Lorenzo, Roberto Carlos. Universidad Nacional de La Matanza. Departamento de Ingeniería e Investigaciones Tecnológicas; Argentina.Fil: Beneitez, Guillermo. Universidad Nacional de La Matanza. Departamento de Ingeniería e Investigaciones Tecnológicas; Argentina.Fil: Gho, Edgardo. Universidad Nacional de La Matanza. Departamento de Ingeniería e Investigaciones Tecnológicas; Argentina.Fil: Mauro, Andrés. Universidad Nacional de La Matanza. Departamento de Ingeniería e Investigaciones Tecnológicas; Argentina.Fil: Sagarna, Gustavo H. Universidad Nacional de La Matanza. Departamento de Ingeniería e Investigaciones Tecnológicas; Argentina.Fil: Krajnik, Mario Juan. Universidad Nacional de La Matanza. Departamento de Ingeniería e Investigaciones Tecnológicas; Argentina.Fil: Fourcade, Alejandro Gabriel. Universidad Nacional de La Matanza. Departamento de Ingeniería e Investigaciones Tecnológicas; Argentina.Fil: Ferreyra Birón, Martín. Universidad Nacional de La Matanza. Departamento de Ingeniería e Investigaciones Tecnológicas; Argentina.Fil: Cipollone, Mauro. Universidad Nacional de La Matanza. Departamento de Ingeniería e Investigaciones Tecnológicas; Argentina.Fil: Massiolo, Rodrigo. Universidad Nacional de La Matanza. Departamento de Ingeniería e Investigaciones Tecnológicas; Argentina
Aplicación de sistemas electrónicos embebidos a la fabricación de piezas mecánicas mediante máquinas herramienta de accionamiento manual
No full textSe plantea un proyecto de investigación y desarrollo que toma como base las actividades previamente realizadas en el mismo campo por el grupo de investigación. En este caso, se plantea como objetivo a resolver la implementación de un sistema de control, aplicable al manejo y control de máquinas herramientas, que considere los últimos avances tecnológicos en el área de sistemas embebidos, con el objeto de lograr una solución aún más simple y económica para la automatización y control de máquinas herramienta de accionamiento manual. Se consideran al respecto, con relación al proyecto precursor al presente, una serie de situaciones que deben ser analizadas y tomadas en cuenta. Como primera pauta a analizar, se debe considerar el avance tecnológico ocurrido durante los últimos años en la tecnología de componentes electrónicos, y en especial al desarrollo de sistemas embebidos para uso en tiempo real, hoy ampliamente disponibles en el mercado local. Por otra parte, como un tema no menor, se deben considerar las dificultades actualmente existentes para la utilización de determinados tipos de circuitos programables (FPGAs en particular), derivadas tanto desde las exigencias que se plantean en lo que hace a la exportación de los mismos desde los países proveedorescomo a las limitaciones de importación actualmente vigentes en el mercado local.La necesidad de lograr un aumento en la competitividad de los sectores que podrían llegar a ser beneficiados por el presente desarrollo, el costo cada vez mayor de los equipamientos automatizados y sistemas de control numérico de últimas generaciones, la gran cantidad de maquinaria en uso de accionamiento manual, y la necesidad de su tecnificación, derivada de la exigencia de aumentar la competitividad, permiten proponer la implementación de un sistema de control equiparable al desarrollado en el proyecto anterior, que utilice componentes fácilmente accesibles y disponibles en el mercado local.Fil: Szklanny, Fernando Ignacio. Universidad Nacional de La Matanza. Departamento de Ingeniería e Investigaciones Tecnológicas; Argentina.Fil: De María, Elio Augusto. Universidad Nacional de La Matanza. Departamento de Ingeniería e Investigaciones Tecnológicas; Argentina.Fil: Maidana, Carlos Eduardo. Universidad Nacional de La Matanza. Departamento de Ingeniería e Investigaciones Tecnológicas; Argentina.Fil: Rodríguez, Carlos Alberto. Universidad Nacional de La Matanza. Departamento de Ingeniería e Investigaciones Tecnológicas; Argentina.Fil: Di Lorenzo, Roberto Carlos. Universidad Nacional de La Matanza. Departamento de Ingeniería e Investigaciones Tecnológicas; Argentina.Fil: Beneitez, Guillermo. Universidad Nacional de La Matanza. Departamento de Ingeniería e Investigaciones Tecnológicas; Argentina.Fil: Gho, Edgardo. Universidad Nacional de La Matanza. Departamento de Ingeniería e Investigaciones Tecnológicas; Argentina.Fil: Mauro, Andrés. Universidad Nacional de La Matanza. Departamento de Ingeniería e Investigaciones Tecnológicas; Argentina.Fil: Sagarna, Gustavo H. Universidad Nacional de La Matanza. Departamento de Ingeniería e Investigaciones Tecnológicas; Argentina.Fil: Krajnik, Mario Juan. Universidad Nacional de La Matanza. Departamento de Ingeniería e Investigaciones Tecnológicas; Argentina.Fil: Fourcade, Alejandro Gabriel. Universidad Nacional de La Matanza. Departamento de Ingeniería e Investigaciones Tecnológicas; Argentina.Fil: Ferreyra Birón, Martín. Universidad Nacional de La Matanza. Departamento de Ingeniería e Investigaciones Tecnológicas; Argentina.Fil: Cipollone, Mauro. Universidad Nacional de La Matanza. Departamento de Ingeniería e Investigaciones Tecnológicas; Argentina.Fil: Massiolo, Rodrigo. Universidad Nacional de La Matanza. Departamento de Ingeniería e Investigaciones Tecnológicas; Argentina
New Cases and Mutations in SEC23B Gene Causing Congenital Dyserythropoietic Anemia Type II
No full textHereditary anemias; Ineffective erythropoiesis; Rare blood diseaseAnèmies hereditàries; Eritropoesi ineficaç; Malaltia rara de la sangAnemias hereditarias; Eritropoyesis ineficaz; Enfermedad rara de la sangreCongenital dyserythropoietic anemia type II (CDA II) is an inherited autosomal recessive blood disorder which belongs to the wide group of ineffective erythropoiesis conditions. It is characterized by mild to severe normocytic anemia, jaundice, and splenomegaly owing to the hemolytic component. This often leads to liver iron overload and gallstones. CDA II is caused by biallelic mutations in the SEC23B gene. In this study, we report 9 new CDA II cases and identify 16 pathogenic variants, 6 of which are novel. The newly reported variants in SEC23B include three missenses (p.Thr445Arg, p.Tyr579Cys, and p.Arg701His), one frameshift (p.Asp693GlyfsTer2), and two splicing variants (c.1512-2A>G, and the complex intronic variant c.1512-3delinsTT linked to c.1512-16_1512-7delACTCTGGAAT in the same allele). Computational analyses of the missense variants indicated a loss of key residue interactions within the beta sheet and the helical and gelsolin domains, respectively. Analysis of SEC23B protein levels done in patient-derived lymphoblastoid cell lines (LCLs) showed a significant decrease in SEC23B protein expression, in the absence of SEC23A compensation. Reduced SEC23B mRNA expression was only detected in two probands carrying nonsense and frameshift variants; the remaining patients showed either higher gene expression levels or no expression changes at all. The skipping of exons 13 and 14 in the newly reported complex variant c.1512-3delinsTT/c.1512-16_1512-7delACTCTGGAAT results in a shorter protein isoform, as assessed by RT-PCR followed by Sanger sequencing. In this work, we summarize a comprehensive spectrum of SEC23B variants, describe nine new CDA II cases accounting for six previously unreported variants, and discuss innovative therapeutic approaches for CDA II.This work was supported by NEOTEC grant SNEO-20191246 from Spanish CDTI to C.T., RETOS COLABORACION grant RTC2019-007074-1 from: MCIN/AEI/10.13039/501100011033 from Spanish Ministry of Science and Innovation (MICINN) to C.T. and M.S.; ARETHA grant PID2021-122436OB-I00 funded by MCIN/AEI/10.13039/501100011033 to M.S.; RTI-2018-101735-B-I100 from MCIN/AEI/10.13039/501100011033/ERDF “A way to make Europe” from the Spanish Ministry of Science and Innovation (MICINN) to M.S. M.M.M. is supported by a Marie Curie Fellowship from the European Commission under Horizon 2020 Framework Program Project: 894737. G.H. is supported by funds provided by the APU and ADISCON patient associations. L.R.-C. holds an FI-AGAUR predoctoral fellowship (2020FI-B00038) from Generalitat de Catalunya. X.F.-C. is partially supported by funds provided by the grant RTI-2018-101735-B-I100 from MCIN/AEI/10.13039/501100011033/ERDF “A way to make Europe”. V.V. was supported by funds provided by APU and ADISCON patient associations and UIC postdoctoral scholarship; she is currently supported by funds provided by RETOS COLABORACION grant RTC2019-007074-1 from MCIN/AEI/10.13039/501100011033 from Spanish Ministry of Science and Innovation (MICINN)
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