147 research outputs found
Analogical method, experiment and didacticism in the hippocratic treatises generation/nature of the child/diseases 4
No full textThis essay suggests three different levels at which the text may be analysed. In it, the notion of analogy is used in a strictly technical sense, to refer to the means of parallelism between a known phenomenon and another that must be explained, with the consequent possibility of inferring the latter from the former. The first level of analysis consists in the examination of some important comparisons, which the author treats as verification of the applicability of the analogical method. The second level rests in considering the great attention that is paid to empirical observation from a medical point of view, which produces attempts at experimental research. Finally, there is a didactic aim, since the author presents his observations for those who wish to know the subject and accept the evidence, availing himself of a sound organizational structure (continually referring to what he has already said or what he will later explain) and numerous rhetorical devices
Design and test of readout electronics for medical and astrophysics applications
No full textThe applied particle physics has a strong R&D tradition aimed at rising the instrumentation performances to achieve relevant results for the scientific community. The know-how achieved in developing particle detectors can be applied to apparently divergent fields like hadrontherapy and cosmic ray detection. A proof of this fact is presented in this doctoral thesis, where the results coming from three different projects are discussed in likewise macro-chapters.
A brief introduction (Chapter 1) reports the basic features characterizing a typical particle detector system. This section is developed following the data transmission path: from the sensor, the data moves through the front-end electronics for being readout and collected, ready for the data manipulation. After this general section, the thesis describes the results achieved in two projects developed by the collaboration between the medical physics group of the University of Turin and the Turin section of the Italian Nuclear Institute for Nuclear Physics.
Chapter 2 focuses on the TERA09 project. TERA09 is a 64 channels customized chip that has been realized to equip the front-end readout electronics for the new
generation of beam monitor chambers for particle therapy applications. In this field, the trend in the accelerators development is moving toward compact solutions
providing high-intensity pulsed-beams. However, such a high intensity will saturate the present readout electronics. In order to overcome this critical issue, the TERA09 chip is able to cope with the expected maximum intensity while keeping high resolution by working on a wide conversion-linearity zone which extends from
hundreds of pA to hundreds of μA. The chip gain spread is in the order of 1-3% (r.m.s.), with a 200 fC charge resolution. The thesis author took part in the chip
design and fully characterized the device.
The same group is currently working on behalf of the MoVeIT collaboration for the development of a new silicon strip detector prototype for particle therapy applications. Chapter 3 presents the technical aspects of this project, focusing on the author’s contribution: the front-end electronics design. The sensor adopted for the MoVeIT project is based on 50 μm thin sensors with internal gain, aiming to detect the single beam particle thus counting their number up to 109 cm2/s fluxes, with a pileup probability < 1%. A similar approach would lead to a drastic step forward if compared to the classical and widely used monitoring system based on gas ionization chambers. For what concerns the front-end electronics, the group strategy has been to design two prototypes of custom front-end: one based on a transimpedance preamplifier with a resistive feedback and the other one based on a charge sensitive amplifier. The challenging tasks for the electronics are represented by the charge and dynamic range which are respectively the 3 - 150 fC and the hundreds of MHz instantaneous rate (100 MHz as the milestone, up to 250 MHz ideally).
Chapter 4 is a report on the trigger logic development for the Mini-EUSO detector.
Mini-EUSO is a telescope designed by the JEM-EUSO Collaboration to map the Earth in the UV range from the vantage point of the International Space Station (ISS), in low Earth orbit. This approach will lay the groundwork for the detection of Extreme Energy Cosmic Rays (EECRs) from space. Due to its 2.5 μs time resolution, Mini-EUSO is capable of detecting a wide range of UV phenomena in the Earth’s atmosphere. In order to maximize the scientific return of the mission, it is necessary to implement a multi-level trigger logic for data selection over different timescales.
This logic is key to the success of the mission and thus must be thoroughly tested and carefully integrated into the data processing system prior to the launch. The author took part in the trigger integration in hardware, laboratory trigger tests and also developed the firmware of the trigger ancillary blocks.
Chapter 5 closes this doctoral thesis, with a dedicated summary part for each of the three macro-chapters
Simplifísica
No full textA astronomia é um assunto que instiga a curiosidade de jovens e adultos. É uma ciência que envolve diversas observações procurando respostas para fenômenos físicos que acontecem dentro e fora da Terra. No programa do dia 22 de setembro, o professor Ângelo Neto apresentou uma programação especial para crianças, que abordou temas como o nascimento das estrelas, os cometas e as galáxias
Simplifísica
No full textA astronomia é um assunto que instiga a curiosidade de jovens e adultos. É uma ciência que envolve diversas observações procurando respostas para fenômenos físicos que acontecem dentro e fora da Terra. No programa do dia 22 de setembro, o professor Ângelo Neto apresentou uma programação especial para crianças, que abordou temas como o nascimento das estrelas, os cometas e as galáxias
Estrutura dos halos de matéria escura no modelo ΛCDM
No full textCaracterizamos estatisticamente a estrutura dos halos de matéria escura extraídos da Simulação do Millennium, uma das maiores simulações do modelo cosmológico CDM realizadas até hoje, com 10 bilhões de partículas num volume de 500h−1Mpc3. Nossos resultados confirmam que na época atual, z = 0, o parâmetro de concentração dos halos se correlaciona com a massa. Esta correlação é ajustada por uma lei de potência no intervalo de massas que corresponde a halos de galáxias (1012h−1M) até aglomerados de galáxias (1015h−1M), log10 c ∞ −α log10M, com α = 0.1. Comparamos a previsão de três modelos existentes na literatura para esta correlação. Medimos a distribuição de probilidade do parâmetro de concentração, que é ajustada com boa aproximação por uma função lognormal com dispersão σlog10 c = 0.1 em todo o intervalo de massas. Verificamos que o parâmetro de concentração é independente do spin do halo quando sistemas claramente fora de equilíbrio são removidos da análise. Comparamos modelos que relacionam o parÂmetro de concentração com histórico de formação extraído da simulação. Mostramos que quando definimos a época de formação levando em conta a distribuição de progenitores do halo e não apenas o progenitor mais massivo, obtemos uma correlação melhor entre densidade média do universo nessa época e a densidade característica do halo. Finalmente, testamos a validade de dois modelos que predizem o parâmetro de concentração a z = 0 com base no histórico de acreção de massa do progenitor mais massivo do halo.We use the Millennium Simulation (MS) to study the statistics of CDM halo concentrations at z = 0. Our results confirm that the average halo concentration declines monotonically with mass; the concentration-mass relation is well fit by a power-law over 3 decades in mass, up to the most massive objects that form in a CDM universe (~1015h−1M). We compare this relation with three models in the literature. The large volume surveyed, together with the unprecedented numerical resolution of the MS, allow us to estimate with confidence the distribution of concentrations and, consequently, the abundance of systems with unusual properties. We find that halo concentrations are independent of spin once haloes manifestly out of equilibrium have been removed from the sample. The concentrations of out-ofequilibrium haloes tend to be lower and have more scatter, while their spins tend to be higher. A number of previously noted trends within the halo population are induced primarily by these properties of unrelaxed systems. Finally, we compare the result of predicting halo concentrations using the mass assembly history of the main progenitor with predictions based on simple arguments regarding the assembly time of all progenitors. The latter are typically as good or better than the former, suggesting that halo concentration depends not only on the evolutionary path of a halo’s main progenitor, but on how and when all of its constituents collapsed to form non-linear objects
Dinâmica de satélites da Via-Láctea
No full textNesta dissertação apresentamos o trabalho desenvolvido com a finalidade de estudar alguns aspectos da dinâmica de satélites da Via-Láctea. Discutimos a montagem do computador paralelo CPADA onde realizamos as simulações além da implementação do código GADGET e dos programas auxiliares desenvolvidos para viabilizar nossos estudos sobre interações gravitacionais de N-corpos. Do ponto de vista astrofísico estudamos 3 problemas diferentes: a. Modelamos a órbita do aglomerado globular M92 comparando as estruturas de maré observadas a distâncias de até 3 raios de maré do centro do aglomerado. Concluímos que as velocidades espaciais conhecidas e o modelo usado para o halo da Via Láctea permitem, através das simulacões reproduzir bastante bem estas estruturas e predizer a localização das caudas de maré que se extenderiam a grandes distâncias à frente e atrás do aglomerado. b. A possibilidade de que o par de aglomerados abertos NGC1907 e NGC1912, espacialmente próximos formem um par físico. Demonstramos que as velocidades espaciais observadas não são compatíveis com a possibilidade de eles estarem gravitacionalmente ligados e que a sua aproximação espacial é um fato casual. c. A possibilidade de captura de aglomerados globulares da Via Láctea pela Grande Nuvem de Magalhães. Demonstramos que sob as condições iniciais do nosso modelo o número de capturas é menor que 15, o número de aglomerados velhos existentes na LMC. O que nos permite concluir que a presença desses aglomerados é devida ao processo de formação estelar nessa galáxia.In this work we present the tasks developed in order to study some aspects about the dynamics of Milky Way satellites. We discuss the assembly of the cluster CPADA and the implementation of the GADGET code, as well as the auxiliary softwares developed in order to carry out our studies in the gravitational N-body field. From the astrophysical point oí view we studied three problems: a. We modeled the orbit oí the globular cluster M92 in order to compare the tidally produced structures, observed up to 3 tidal radii of the cluster center. We concluded that the known spatial velocities and our model of the Milky Way allows to fiducially reproduce this structures and predict the orientation of the tidal tails, which extend themselves backwards and frontwards along the cluster orbit, for large distances from the cluster center. b. The possible physical association oí the pair of open clusters NGC1907 and NGC1912, which presently are spatially close to each other. We demonstrated that their observed spatial velocities are not compatible with the hypothesis of the cluster being gravitationally bounded, and that their present spatial approximation is an accidental facto c. The possibility oí Milky Way globular clusters capture by the Large Magellanic Cloud. We demonstrated that under the initial constrains oí our model the captures number is smaller than 15, the number of old clusters belonging to the LMC. We conclude that the presence of these clusters in the LMC is due to the stellar formation process in this galaxy
R. D. Archiepiscopus [Marcus Antonius de Dominis] Contra logicam R. D. Episcopi C[h]anadiensis [Fausti Verantii] ab amico amice observata [cum responsionibus auctoris Fausti Verantii] (1616)
No full textSpis »Contra logicam R. D. Episcopi C[h]anadiensis [Fausti Verantii] ab amico amice observata« ključna je spona između dviju ‘malih logika’ Fausta Vrančića: između Vrančićeva filozofskoga prvijenca Logica (1608) i njegova posljednjega djela Logica nova (1616). On nudi dijalog između Marka Antuna de Dominisa i Fausta Vrančića nad tekstom Logike (1608) i istodobno otvara put prema tekstu Nove logike (1616), s kojom je i tiskan.
Koliko se danas zna, sačuvala su se samo tri primjerka Vrančićeve Nove logike: jedan u Znanstvenoj knjižnici u Dubrovniku koji je, prema rukopisnom ex libris, do 1773. godine pripadao knjižnici isusovačkoga učilišta Collegium Ragusinum u Dubrovniku, sa signaturom CR 20.836; drugi u rimskoj knjižnici Biblioteca Universitaria Alessandrina sa signaturom Miscellanea XIII b 4 3; treći u Bibliothèque nationale de France u Parizu, kako je priopćio Jurić,1 sa signaturom 31556770. Pri transkripciji ‘dijaloga’ između de Dominisa i Fausta Vrančića služio sam se primjercima iz dubrovačke i rimske knjižnice.2 Postojanje dubrovačkoga primjerka zabilježeno je već u Jurićevoj bibliografiji hrvatskoga neolatinizma,3 a dosad ga je istraživao samo Srećko Kovač u 1980-im.4 Iako Logica nova (1616) Fausta Vrančića nije tako rijetka kao njegova Logica (1608), od koje nam je poznat samo jedan jedini primjerak, i ona pripada u rarissima.
I Logica nova tiskana je bez crkvenoga dopuštenja! Tako je Vrančić izbjegao da mu mletački ured za cenzuru postavi neugodno pitanje tko je »preuzvišeni gospodin nadbiskup« (Reverendissimus Dominus Archiepiscopus) koji je uputio prigovore njegovoj Logici (1608). Pri transkripciji spisa »Contra logicam R. D. Episcopi C[h]anadiensis [Fausti Verantii] ab amico amice observata« primijenjena su »Načela izdanja« objavljena uz moju transkripciju Vrančićeve Logike (1608).
Bilješke uz ovu transkripciju sadržavaju:
1. dokumentaciju o uputnicama na tekst Vrančićeve Logike (1608), koje se nalaze bilo u de Dominisovim prigovorima bilo u Vrančićevim odgovorima;
2. dokumentaciju o učincima de Dominisovih prigovora na tekst Vrančićeve Nove logike (1616).The writing “Contra logicam R. D. Episcopi C[h]anadiensis [Fausti Verantii] ab amico amice observata” is the key link between Faust Vrančić’s two works of ‘logic minor’: his first philosophical work Logica (1608) and Logica nova (1616), his last work. He offers a dialogue between Marko Antun de Dominis and Faust Vrančić on the text of Logica (1608), and at the same time paves the path towards the text of Logica nova (1616), with which it was published.
To our current knowledge, only three copies of Vrančić’s Logica nova are extant: one copy is housed at the Research Library in Dubrovnik, which, according to the manuscript ex libris, until 1773 was among the holdings of the library of the Jesuit Collegium Ragusinum in Dubrovnik, under the shelfmark CR 20.836; the second copy is kept at the Biblioteca Universitaria Alessandrina in Rome, under the shelfmark Miscellanea XIII b 4 3; the third is filed at the Bibliothèque nationale de France in Paris, under the shelfmark 31556770. In transcribing the ‘dialogue’ between de Dominis and Faust Vrančić, I used the copies from the libraries of Dubrovnik and Rome. The existence of the Dubrovnik copy was already recorded in Šime Jurić’s bibliography of Croatian Neo-Latin heritage, Croatiae scriptores Latini recentioris aetatis (1971), and until now has been researched only by Srećko Kovač in the 1980s. Although Vrančić’s Logica nova (1616) is not as rare as his Logica (1608), of which only a single copy is extant, it falls among the rarissima. Vrančić’s Logica nova was also published without imprimatur. By doing so, Vrančić by-passed the Censorship Office of Venice and the possible enquiry about the identity of the “Most Reverend Archbishop” (Reverendissimus Dominus Archiepiscopus), the author of the objections to his Logica (1608).
The transcription of the writing “Contra logicam R. D. Episcopi C[h]anadiensis [Fausti Verantii] ab amico amice observata” was carried out according to the “Principles of the Edition,” published with my transcription of Vrančić’s Logica (1608).
The notes to this transcription include: (1) documentation of the references to the text of Vrančić’s Logica (1608), found either in de Dominis’ objections or in Vrančić’s responses; (2) documentation of the effects of de Dominis’ objections to the text of Vrančić’s Logica nova (1616)
Proposta de um framework de apoio ao desenvolvimento de cursos a distância baseados na abordadgem sócio-histórica de Vigotski
No full textDissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico. Programa de Pós-Graduação em Ciência da Computação.Este trabalho propõe um framework que dê suporte a projetistas, designers instrucionais e professores/tutores na concepção e realização de cursos a distância baseados na abordagem sócio-histórica de Vigotski. Sua relevância ao processo educacional se dá pela necessidade de se integrar a tecnologia a um contexto psicopedagógico que subsidie o processo de ensino-aprendizagem na EAD. Assim, o framework proposto é caracterizado por seis princípios de aproximação entre a EAD e Vigotski, o Princípio da Apropriação, o Princípio da Cooperação, o Princípio da Interação com o Conhecimento, o Princípio da Internalização, o Princípio da Auto-Regulação e o Princípio da Atuação na Zona de Desenvolvimento Proximal, os quais norteiam os processos de concepção e realização de um curso on-line
The causes and unintended consequences of a paradigm shift in corn production practices
No full textAbstractIndependent but simultaneously occurring changes in U.S. agricultural and energy policies in conjunction with advances in biotechnology converged to create an economic and regulatory environment that incentivized corn acreage expansion. Advancements in Bt seed and ethanol production technologies contributed to scale efficiency gains in corn and biofuel production. These advancements were accompanied by changes in market forces that altered the balance between corn and other agricultural crop production. The causal linkages among Bt adoption, ethanol production, and corn production are explored along with a discussion of how this shift toward corn production generated unexpected economic and environmental consequences. Alternative policy solutions to mitigate the negative consequences and enhance the resiliency of U.S. agriculture are discussed
Renato Rozzi\u27s critical reflection between subjectivity, history, and society
No full textIn the article, the author talks about his relationship with the man and his work. Interested in social history, he favors this aspect of the master\u27s manifold activity, being the prevailing topic of their long common dialogue. In the narrative, the author highlights Rozzi\u27s fidelity to some fundamental values, his passion for social sciences, particularly for depth psychology, as well as his original methodological framework, focusing on some significant results of his socio-historical analysis concerning the peasant and worker worlds, the destructiveness of labor, and the contemporary history of his city. He also details Renato Rozzi\u27s critique of the traditional rural world\u27s subordination, his explanation of the profound causes of the Fordist factory workers\u27 uprising, his proposal of a new idea of human labor, and his aspirations for a more open urban society
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