Analyzing Heavy Photon Search Simulations to Determine the Potential for True Muonium Discovery

The Heavy Photon Search (HPS) is a new experiment at Jefferson Laboratory to search for heavy photons, a particle predicted by dark matter and dark energy extensions to the Standard Model of particle physics, in the mass range of 20 MeV/c2 to 1000 MeV/c2 . The experiment also has the potential to discover true muonium, a bound state of a muon and an antimuon that is predicted to exist, but has never been observed. The true muonium atom should be produced by an electron beam incident on a target, such as the tungsten target used in the HPS experiment. Similar to the decay of the heavy photon, a triplet state of true muonium will decay to an electron-positron pair, allowing it to be detected in the same way. Since the mass of the atom will be about twice the mass of a muon, or approximately 211 MeV/c2 , and the decay length is expected to be on the order of centimeters, a precise search window can be specified. Simulations of this experiment were performed and an analysis was carried out to calculate how well we can expect to observe true muonium. Based on this analysis, the Heavy Photon Search will have a reconstruction efficiency of 16-20 %, and will be able to observe and fully reconstruct approximately 35 events after a month of running with a 6.6 MeV electron beam. As a result, the true muonium signal is expected to be statistically significant above the background signal

Semantics Through Pictures: towards a diagrammatic semantics for object-oriented modelling notations

An object-oriented (OO) model has a static component, the set of allowable snapshots or system states, and a dynamic component, the set of filmstrips or sequences of snapshots. Diagrammatic notations, such as those in UML, each places constraints on the static and/or dynamic models. A formal semantics of OO modeling notations can be constructed by providing a formal description of (i) sets of snapshots and filmstrips, (ii) constraints on those sets, and (iii) the derivation of those constraints from diagrammatic notations. In addition, since constraints are contributed by many diagrams for the same model, a way of doing this compositionally is desirable. One approach to the semantics is to use first-order logic for (i) and (ii), and theory inclusion with renaming, as in Larch, to characterize composition. A common approach to (iii) is to bootstrap: provide a semantics for a kernel of the notation and then use the kernel to give a semantics to the other notations. This only works if a kernel which is sufficiently expressive can be identified, and this is not the case for UML. However, we have developed a diagrammatic notation, dubbed constraint diagrams, which seems capable of expressing most if not all static and dynamic constraints, and it is proposed that this be used to give a diagrammatic semantics to OO models

Semantics through Pictures

A diagrammatic approach to the semantics of OO modelling notations is proposed. This is based on an innovative and expressive notation dubbed ''constraint diagrams'', which can be used to precisely characterise a range of sophisticated, static constraints on OO models. Other notations, such as those found in UML, can be viewed as projections of constraint diagrams. Work on using constraint diagrams at the core of a 3D modelling notation is also briefly described as a means of similarly providing the semantics of diagrams imposing constraints on dynamic behaviour

Could the understanding of the strawberry softening process benefit from aquaporins?

The Major Intrinsic Protein (MIP) family includes a main group of key channels known as aquaporins (AQPs), described for sharing a very conservative structure with a pore that facilitates water and/or solute permeation. Since its first member was functionally reported in 1992, AQPs were found to be abundantly expressed in all kingdoms. Although many roles have been attributed to these small integral proteins, it is becoming evident that the number and type of AQPs within a membrane are major determinants of its water transport capacity. Thus, their presence is opening new perspectives to understand the role of plant cell membrane water transport in physiological and developmental processes. Strawberry is a fleshy fruit characterized by a rapid loss of firmness during ripening, limiting the shelf-life of these fruit. Even though fruit texture is influenced by various factors like structural integrity of primary cell wall, sugar accumulation, and the turgor pressure generated within cells by osmosis, main attention has been focused on degradation of cell wall polysaccharides. Turgor pressure, in spite of long being mentioned as a possible player in softening during fruit development, has not received proper consideration. In the light of AQP outbreak, it is worth questioning how these channels could contribute to strawberry fruit softening. In an attempt to answer this question, this review summarizes the current available information on plant AQPs, extending the knowledge to those specifically expressed in fruits to finally discuss the recent reported findings in strawberry, particularly those associated with ripening and softening processes.Fil: Alleva, Karina Edith. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Biodiversidad y Biología Experimental; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Marquez, Mercedes. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Biodiversidad y Biología Experimental; ArgentinaFil: Bellati, Jorge. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Biodiversidad y Biología Experimental; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Villareal, Natalia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - la Plata. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "dr. Raul Alfonsin" (sede Chascomus) | Universidad Nacional de San Martin. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas ; ArgentinaFil: Bustamante, Claudia Anabel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - la Plata. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "dr. Raul Alfonsin" (sede Chascomus) | Universidad Nacional de San Martin. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas ; ArgentinaFil: Martinez, Gustavo Adolfo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - la Plata. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "dr. Raul Alfonsin" (sede Chascomus) | Universidad Nacional de San Martin. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas ; ArgentinaFil: Civello, Pedro Marcos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - la Plata. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "dr. Raul Alfonsin" (sede Chascomus) | Universidad Nacional de San Martin. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas ; ArgentinaFil: Amodeo, Gabriela. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Biodiversidad y Biología Experimental; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

The “Hegelian issue” in Günther Jakobs’ Theory of Criminal Intent (dolus)

The essay concerns the theory of criminal functionalism and in particular the Hegelian roots of the theory of intention developed by Günther Jakobs and recently analyzed in Kritik des Vorsatzbegriffs (Mohr Siebeck, 2020). In particular, the author highlights the aporias and critical issues of a purely functionalist foundation of intention

Indirect evaporative cooling systems : a numerical analysis for data center application

LAUREA MAGISTRALENella maggior parte dei data center una grossa quota di energia elettrica è consumata dalle apparecchiature dedicate al raffreddamento, che sono generalmente basate su macchine a compressione di vapore. Tuttavia, nel 2011, l’ASHRAE ha aggiornato le linee guida riguardanti le condizioni ambiente che devono essere mantenute all’interno del data center, al fine di garantire il corretto funzionamento delle apparecchiature elettroniche. In particolare, sono state definite due nuove classi di sale server che possono funzionare a temperature maggiori rispetto al passato. Grazie alle più elevate temperature mantenute all’interno del data center, nuove tecnologie di raffreddamento basate sul free cooling possono essere utilizzate per supportare, o in certi casi sostituire del tutto, i sistemi di refrigerazione tradizionali. Una di queste nuove tecnologie è il raffreddamento evaporativo indiretto, che è l’oggetto principale di questo studio. In questo lavoro si è svolta un'analisi numerica volta all'ottimizzazione di tale tecnologia, ed in particolare a: stimare il risparmio energetico che può essere ottenuto in diverse condizioni operative; calcolare, per ogni condizione di lavoro, la velocità ottimale dell’aria secondaria e il valore ottimale della portata di acqua introdotta nella corrente d’aria secondaria; testare diverse logiche di regolazione ed individuare la più efficiente; effettuare analisi stagionali per stimare la redditività, in termini di risparmio energetico, del raffreddamento evaporativo indiretto in diverse zone climatiche. Al fine di raggiungere questi obbiettivi, è stato creato un modello matematico in ambiente Matlab, allo scopo di simulare i componenti principali del sistema di raffreddamento di un data center. Lo scambiatore evaporativo indiretto è stato simulato in Matlab a partire da un modello numerico già sviluppato dal gruppo di ricerca. Sono stati ottenuti i seguenti risultati. Il metodo migliore di regolazione consiste nel ridurre contemporaneamente l'acqua erogata e la velocità dell'aria secondaria per mantenere costante il rapporto Q_w/Q_s; quando la v_s raggiunge il suo valore minimo, un’ulteriore regolazione può essere effettuata riducendo la portata di acqua erogata dagli ugelli; infine, se le regolazioni precedenti non sono sufficienti, si può realizzare un bypass parziale dello scambiatore. Riguardo alle analisi stagionali, si è constatato che in un clima molto freddo questa tecnologia garantisce un risparmio energetico superiore al 80%, ma che in tale clima un risultato simile potrebbe essere ottenuto anche con il semplice free cooling indiretto, senza ricorrere all’apporto d’acqua nebulizzata. In un clima temperato il risparmio stimato è stato di nuovo vicino all’80%, mentre il sistema basato sul free cooling indiretto semplice è stato leggermente meno performante. In un clima caldo e secco, lo IEC garantisce un risparmio energetico superiore al 70%, al contrario del semplice free-cooling indiretto, che è risultato questa volta molto meno redditizio. Infine, in un clima caldo e umido, lo IEC ha garantito un elevato risparmio energetico soltanto con un innalzamento delle temperature operative del data center, da 23-35 °C a 27-39 °C.In most data centers. a great share of energy consumption is caused by the cooling equipment, which is usually based on vapour compression refrigeration. However, in 2011 ASHRAE updated the thermal guidelines for safe and reliable operation of electronic equipment, establishing new classes of ICT spaces which can safely operate at higher temperatures. Due to higher operational temperatures, new free cooling-based technologies can be used to backup or replace the traditional systems based on vapour compression refrigeration. One of such technologies is indirect evaporative cooling, which is investigated in this work. In particular, this study has the following scopes: estimating the possible energy savings which can be achieved through indirect evaporative coolers (IEC); calculating the optimal values of secondary air velocity and supplied water in any system working condition; testing different IEC regulation strategies to identify the most efficient one; performing seasonal analysed to evaluate the IEC profitability in different climates. In order to do that, a mathematical model was created in Matlab environment, in order to simulate the main components of a data center cooling system. The IEC was also simulated in Matlab environment, starting from an experimental model developed by De Antonellis et al. in the facilities of Politecnico di Milano [11]. The following results were achieved: the best regulation method consists of reducing both the supplied water and the secondary air velocity in order to maintain a constant ratio Q_w⁄Q_s ; then, once v_s is down to its minimum allowable value, additional regulation can be provided by further reducing the amount of supplied water, and finally performing a partial IEC bypass if necessary. With regard to the seasonal analyses, it was found that in a cold climate this technology gave an energy saving higher than 80%; however it was also found that similar energy savings could be achieved with simple indirect airside free cooling without sprayed water supply. In a temperate locality, the estimated energy saving was once again roughly 80%, and this time simple indirect airside free cooling proved to be slightly less performant. In a hot and dry climate, an energy saving superior than 70% was estimated, whereas simple indirect airside free cooling proved much less profitable. Finally, in a hot and humid climate, high energy savings could only be achieved by increasing the data center operational temperatures from 23-35 °C to 27-39 °C

Gillo “1910-1951”: un territorio in parte inesplorato

The author illustrates the first years of Gillo Dorfles’ life, starting from his childhood in Genoa during the First World War, the years of high schools in Trieste, his studies at the Faculty of Medicine in Milan and Rome. Subsequently, the author analyses Dorfles’ writings on Aesthetics, the poems and the pictorial works produced by Dorfles from the 1930s till 1948 (the year of the creation of the Movement for Concrete Art) and until 1951 (the year of the foundation of the magazine “Aut aut”)