8 research outputs found
Performance evaluation of SiPMʼs for low threshold gamma detection
In the context of the on-line monitoring of short and medium term for radioactive waste repository, a new system has been planned. Such system makes use a new kind of detector, named Silicon Photomultiplier, coupled to scintillating fibres to be positioned around each waste drum in shape of fine grid. The purpose of this design is evaluate the variations of the radioactivity distribution by counting the gamma radiation
On-line remote monitoring of radioactive waste repositories
A low-cost array of modular sensors for online monitoring of radioactive waste was developed at INFN-LNS. We implemented a new kind of gamma counter, based on Silicon PhotoMultipliers and scintillating fibers, that behaves like a cheap scintillating Geiger-Muller counter. It can be placed in shape of a fine grid around each single waste drum in a repository. Front-end electronics and an FPGA-based counting system were developed to handle the field data, also implementing data transmission, a graphical user interface and a data storage system. A test of four sensors in a real radwaste storage site was performed with promising results. Following the tests an agreement was signed between INFN and Sogin for the joint development and installation of a prototype DMNR (Detector Mesh for Nuclear Repository) system inside the Garigliano radwaste repository in Sessa Aurunca (CE, Italy). Such a development is currently under way, with the installation foreseen within 2014
Gestione e miglioramento di pascoli italiani
Experimental results of trials on pastures management and improvement, conducted by 10 University Institutes within
the study team «Characterization of italian pastures» are reported.
The trials carried out in different soil and climate conditions, ranging from the Alps to the southern Appennines and
to the Islands, in different years, provide some conclusive and generaI considerations.
With periodical cuts, the forage availability period becomes longer, while using one cut at flowering yield results are higher.
As far as management techniques are concerned, fertilization with the three main nutrients affects positively quanti-qualitative yield, although in real situations the application of one or two elements may be sufficient and more economically
convenient, and in relation to the botanical composition.
Undersowing determines positive effects both on botanical composition and on pasture utilization. Positive results, furthermore, are obtained by mechanical scrub clearing.
Vengono riferiti i risultati sperimentali delle prove sulla gestione e sul miglioramento dei pascoli condotte da dieci Istituti
Universitari costituenti il gruppo di studio «Caratterizzazione di pascoli italiani», Dalle prove condotte in ambienti pedoclimatici
diversi, dalle alpi all'appennino meridionale ed alle isole, e in annate differenti, sono emerse come generalizzabili
alcune considerazioni conclusive.
Con sfalci periodici si allunga il periodo di disponibilità di foraggio verde, mentre con quello unico alla fioritura la
produzione risulta più elevata.
Per gli interventi tecnici, la concimazione con i tre macroelementi influisce favorevolmente sull'entità e sulla qualità
della produzione, anche se, nelle situazioni concrete, può essere sufficiente, e più vantaggioso dal lato economico, la somministrazione di uno o due elementi, anche in relazione alla facies floristica.
La trasemina determina effetti favorevoli sia sulla composizione floristica sia nella migliore utilizzazione del pascolo.
Risultati positivi, infine, si conseguono con il decespugliamento meccanico
Caratterizzazione della dinamica produttiva di pascoli naturali italiani
This work studies herbage production and its seasonal distribution in indigenous pastures, and analyses the relationship
between the environmental factors (soil, clima, vegetation) and the productivity of these resources.
The investigations have been carried on during the period 1983-90 by the joint activity of 10 different University Istitutions
in 23 different environments distributed along the Italian peninsula and the main islands.
For each environment, pasture production has been measured with the Corrall and Fenlon method, analysing the more
important vegetational and ecological conditions; altogether the total yearly production and the seasonal pattern of herbage
production have been detected on 104 pastures.
The total herbage yield is not significantly influenced by the latitudinal gradient, and the overall regional (alps, central
Appenine, south Apennine and islands) production is about 2.3 t ha-1 year-1 The wide range (0.5-6.3 t ha-1 year-1) of
herbage production, on small or medium scale, seems to be due to evident changeof environmental or management factors.
Five types of seasonal distribution of herbage growth are evidenced with multivariate analysis methods, based on the
growing season and the amplitude of the growth. With mean temperature above 12°C and total rainfall below 800 mm,
herbage distribution shows a standstill during summer period and an evident regrowth in autumn. On the contrary, for
the 4 other distribution types, the winter standstill become important, and the types are distinct by summer growth amplitude
and by the growing season lenght. With cluster analysis method, for each type of herbage distribution, have been
pointed out under-types characterized by interannual herbage production variation.
Among the environmental factors, vegetation characheristics, expressed as Pasture Value following Daget and Poissonet
seems to be strictly correlated with total production. The comparative poor role played by the soil and climatic factor,
may be due to the strong past and present antropic influence, related with management and utilization techniques.
Il presente lavoro ha come scopo l'approfondimento delle conoscenze sulla produzione e sulla distribuzione stagionale
della crescita dell'erba dei pascoli naturali, nonché l'analisi delle interazioni tra i fattori ambientali, pedo-climatici e vegetazionali,
e la risposta produttiva di queste risorse.
La ricerca è stata condotta nel periodo 1983-90 da 10 diverse Istituzioni Universitarie, in 23 ambienti differenti, distribuiti
lungo tutta la penisola e le isole maggiori.
Per ogni ambiente, con il metodo di rilievo di Corrall e Fenlon, è stata saggiata la risposta produttiva di pascoli rappresentativi
delle principali situazioni vegetazionali e di giacitura; complessivamente sono state rilevate la produzione totale
annua e la curva di produttività media pluriennale di 104 pascoli.
Riguardo la produzione annua complessiva si è osservato che essa non presenta variazioni significative lungo il gradiente
latitudinale, collocandosi tra le diverse regioni (alpina, centro appenninica, suq, appenninica e insulare) attorno a 2.3
t ha-1 anno-1. La fitomassa raccolta è soggetta invece a variazioni sensibili (0.5-6.3 t ha-1 anno-1) riconducibili a fattori
ambientali e gestionali che si esprimono su piccola e media scala.
Con metodi di analisi multivariata si sono individuate 5 tipologie distributive della crescita dell'erba, in rapporto alla
stagione vegetativa e alle variazioni dell'intensità di crescita nel corso della stagione stessa. Con temperature medie e precipitazioni
annue rispettivamente maggiori di 12°C e minori di 800 mm, risulta evidente la stasi vegetativa nel trimestre
estivo e la ripresa vegetativa autunnale. Nel caso opposto la stasi è invernale e le 4 tipologie afferenti a questo modello,
sono distinguibili dall'entità della crescita nei mesi estivi e dalla durata della stagione vegetativa. Per ogni tipologia produttiva,
sono state evidenziate, tramite l'analisi cluster, sotto-tipologie distinte per la variabilità produttiva interannuale.
Tra i fattori ambientali, la vegetazione, espressa attraverso l'indice del valore pastorale di Daget e Poissonet, presenta
una buona capacità predittiva nei confronti del livello produttivo dei pascoli. Il contributo comparativamente modesto offerto
dai fattori pedoclimatici sembra attribuibile alla forte influenza antropica, pregressa e attuale, attraverso le cure colturali
e l'utilizzazione
On-line remote monitoring of radioactive waste repositories
A low-cost array of modular sensors for online monitoring of radioactive waste was developed at INFN-LNS. We implemented a new kind of gamma counter, based on Silicon PhotoMultipliers and scintillating fibers, that behaves like a cheap scintillating Geiger-Muller counter. It can be placed in shape of a fine grid around each single waste drum in a repository. Front-end electronics and an FPGA-based counting system were developed to handle the field data, also implementing data transmission, a graphical user interface and a data storage system. A test of four sensors in a real radwaste storage site was performed with promising results. Following the tests an agreement was signed between INFN and Sogin for the joint development and installation of a prototype DMNR (Detector Mesh for Nuclear Repository) system inside the Garigliano radwaste repository in Sessa Aurunca (CE, Italy). Such a development is currently under way, with the installation foreseen within 2014
On-line remote monitoring of radioactive waste repositories
A low-cost array of modular sensors for online monitoring of radioactive waste was developed at INFN-LNS. We implemented a new kind of gamma counter, based on Silicon PhotoMultipliers and scintillating fibers, that behaves like a cheap scintillating Geiger-Muller counter. It can be placed in shape of a fine grid around each single waste drum in a repository. Front-end electronics and an FPGA-based counting system were developed to handle the field data, also implementing data transmission, a graphical user interface and a data storage system. A test of four sensors in a real radwaste storage site was performed with promising results. Following the tests an agreement was signed between INFN and Sogin for the joint development and installation of a prototype DMNR (Detector Mesh for Nuclear Repository) system inside the Garigliano radwaste repository in Sessa Aurunca (CE, Italy). Such a development is currently under way, with the installation foreseen within 2014
A Deep Learning Approach to Optimize Recombinant Protein Production in <i>Escherichia coli</i> Fermentations
Fermentation is a widely used process in the biotechnology industry, in which sugar-based substrates are transformed into a new product through chemical reactions carried out by microorganisms. Fermentation yields depend heavily on critical process parameter (CPP) values which need to be finely tuned throughout the process; this is usually performed by a biotech production expert relying on empirical rules and personal experience. Although developing a mathematical model to analytically describe how yields depend on CPP values is too challenging because the process involves living organisms, we demonstrate the benefits that can be reaped by using a black-box machine learning (ML) approach based on recurrent neural networks (RNN) and long short-term memory (LSTM) neural networks to predict real time OD600nm values from fermentation CPP time series. We tested both networks on an E. coli fermentation process (upstream) optimized to obtain inclusion bodies whose purification (downstream) in a later stage will yield a targeted neurotrophin recombinant protein. We achieved root mean squared error (RMSE) and relative error on final yield (REFY) performances which demonstrate that RNN and LSTM are indeed promising approaches for real-time, in-line process yield estimation, paving the way for machine learning-based fermentation process control algorithms
The Power Board of the KM3NeT Digital Optical Module: Design, Upgrade, and Production
The KM3NeT Collaboration is building an underwater neutrino observatory at the bottom of
the Mediterranean Sea, consisting of two neutrino telescopes, both composed of a three-dimensional
array of light detectors, known as digital optical modules. Each digital optical module contains a
set of 31 three-inch photomultiplier tubes distributed over the surface of a 0.44 m diameter pressure-
resistant glass sphere. The module also includes calibration instruments and electronics for power,
readout, and data acquisition. The power board was developed to supply power to all the elements
of the digital optical module. The design of the power board began in 2013, and ten prototypes
were produced and tested. After an exhaustive validation process in various laboratories within the
KM3NeT Collaboration, a mass production batch began, resulting in the construction of over 1200
power boards so far. These boards were integrated in the digital optical modules that have already
been produced and deployed, which total 828 as of October 2023. In 2017, an upgrade of the power
board, to increase reliability and efficiency, was initiated. The validation of a pre-production series
has been completed, and a production batch of 800 upgraded boards is currently underway. This
paper describes the design, architecture, upgrade, validation, and production of the power board,
including the reliability studies and tests conducted to ensure safe operation at the bottom of the
Mediterranean Sea throughout the observatory’s lifespan