Study of Silicon Pixel detectors for the ALICE tracker upgrade

openThe ALICE collaboration at CERN has planned to install a new vertex detector (ITS3) during the LHC Long Shutdown 3 (LS3) to replace the innermost three layers of the present Inner Tracking System (ITS). This novel vertex detector, consisting of curved wafer-scale ultra-thin silicon sensors arranged in perfectly cylindrical layers, is presently under development. It will provide a large reduction of the material budget in the region close to the interaction point and a large improvement of the tracking precision and efficiency at low transverse momentum. The activity for this thesis consisted in the characterization of some pixel test structures exposed to different levels of radiation to understand how the most important characteristics of the sensors - namely charge collection efficiency, speed, noise, etc. - degrade after irradiation. This type of characterization is essential, since one of the main requirements for pixel sensors for future high luminosity runs is high radiation hardness.The ALICE collaboration at CERN has planned to install a new vertex detector (ITS3) during the LHC Long Shutdown 3 (LS3) to replace the innermost three layers of the present Inner Tracking System (ITS). This novel vertex detector, consisting of curved wafer-scale ultra-thin silicon sensors arranged in perfectly cylindrical layers, is presently under development. It will provide a large reduction of the material budget in the region close to the interaction point and a large improvement of the tracking precision and efficiency at low transverse momentum. The activity for this thesis consisted in the characterization of some pixel test structures exposed to different levels of radiation to understand how the most important characteristics of the sensors - namely charge collection efficiency, speed, noise, etc. - degrade after irradiation. This type of characterization is essential, since one of the main requirements for pixel sensors for future high luminosity runs is high radiation hardness

C-tactile fibers mediate Affective Touch: from childhood to individual differences to neural correlates

The emotional aspect of touch has been called ‘Affective Touch’ (AT), a term capturing tactile processing with a hedonic, motivational and social significance (e.g. affiliative behaviors or mother-infant bonding). AT is driven by C-Tactile (CT) fibers that are mainly present in hairy skin and respond specifically to slow, gentle touch. CT fibers project to a neural network including the insular cortex and other areas involved in the social domain. In this thesis, the reader will find three distinct studies that, however, follow a temporal progression that reflects both the way they have been carried out and the logical sequence of the rationale underpinning my doctoral project. In the first study, we studied the development of somatosensation and Affective Touch as central role throughout childhood. In adults, these functions are driven by different, neuroanatomically and functionally segregated fibers. To date, very little is known about the basic features of these fibers in childhood and this lack of knowledge is mirrored in the Affective Touch domain, where there are no studies on the main physiological features of the tactile processes linked to the stimulation of the hairy skin, namely the only body part that modulates Affective Touch. Thus, our study aims to analyse: tactile sensitivity and tactile acuity of children’s hairy forearms; a possible separation between somatosensation and the Affective Touch; and the presence/absence of a mature Affective Touch system already in childhood. To these aims, participants (160 children, aged 6 to 14 years), were administered with the Von Frey (tactile sensitivity) and the 2 Point Discrimination (tactile acuity) tests. Affective Touch was measured following the classic protocol and pleasantness ratings were recorded. Our findings showed a correlation between age and somatosensation, suggesting a progressive reduction of sensitivity and acuity as age grows. Further, there was no overlap between Affective Touch and somatosensation, suggesting a behavioral separation. Lastly, we found higher pleasantness ratings for Affective vs. Neutral stimulations at all ages and an enhanced preference for Affective as age grows. We concluded that both somatosensation and Affective Touch are already present as two separate components of touch in childhood and change as a function of age. In the second and third studies, I investigated the perception of AT on the basis of individual differences. The perception and the neural processing of AT appear to be modulated by psychological and psychopathological factors such as autistic traits, anorexia disorder and attachment patterns. Despite this, nothing is known about the Disorganized attachment pattern which is the one with the highest difficulty in regulating emotions and social skills that are central aspects of the AT network. Our studies aim to compare the perception and brain responses to AT in a sample of adults classified as having a Organized (OA) or a Disorganized attachment (DA). 46 OA and 17 DA individuals (as coded via Adult Attachment Interview) underwent a behavioral tactile procedure for basic somatosensation (comprising Von Frey Monofilaments, 2PD, and thermal sensitivity) and a psychological assessment (including SCL-90-R and PID-5). AT perception was measured applying Affective (AS) and Neutral Stimulations (NS) with a watercolor brush on the forearm, respectively at 3 or 30 cm/s; pleasantness ratings for AS and NS and a index of preference (AT index) were collected. A randomly selected subset of 12 OA and 8 DA underwent also a fMRI block design, during affective and neutral tactile stimulations (four run of 5 repetitions of AS and 5 repetitions of NS each), in addition of two resting-state sessions for a functional connectivity analysis (fc-fMRI). No differences emerged for somatosensation and psychological scales. A MANOVA on AS and NS ratings showed that DA vs OA reported lower ratings for AS and no difference for NS. A t-test on AT index showed that DA vs OA preferred NS. A fMRI F omnibus contrast revealed the involvement of posterior insula (PI), somatosensory primary cortex (S1), supramarginal gyrus (SMG) and amygdala during AS and NS. A 2 (OA vs DA) x 2 (AS vs NS) mixed factorial ANOVA on hemodynamic responses showed an effect of stimulation, with higher activation for NS in PI, S1 and amygdala, and an effect of group, with DA showing higher activation in amygdala. An interaction in amygdala showed higher activation for NS vs AS in DA, but not in OA. fc-fMRI showed connectivity between PI and SMG and PI and S1. Results showed that DA perceived AT as less pleasant and preferred NS compared to OA, suggesting that adults who experience difficulties in the ways to relate to others in the affectivity domain, and, in particular, referring to attachment history, are specifically impaired in AT perception, but not in other basic functions of somatosensation. Altered AT perception appeared to be also mirrored by differences in brain mechanism for processing AT. In fact, we found a higher activation in amygdala for AS and NS in DA compared to OA, suggesting different mechanisms for coding motivational and hedonic aspect of AT. Further studies are needed to understand whether this atypical response to AT refers to attribution of a negative or positive value to these stimuli. The results from my three experiments have shown that it is worth investigating this construct in the future. From a personal point of view, it seems to me that this set of three experiments is a trait d'union between neurosciences, which we all know and fascinate us because of their ability to measure very complex phenomena, and other constructs associated with a more clinical perspective such as attachment. I therefore hope that my doctoral thesis will be a humble contribution to a wider view of clinical and neuroscientific phenomena

Assessment of the Energy Requirements for CO2 Storage by Carbonation of Industrial Residues. Part 1: Definition of the Process Layout

Abstract Mineral carbonation is an ex situ CO 2 storage option that could allow to fix large amounts of CO 2 in a solid and thermodynamically stable form. Its feasibility has been proven at lab-scale both employing natural minerals or alkaline industrial residues. However the energy requirements of this process can be quite significant depending on the type of material and operating conditions adopted and thus represent a crucial factor for its full scale applicability. The focus of this paper is the assessment of the energy requirements of CO 2 storage by accelerated carbonation of alkaline materials applying the direct aqueous route. From the analysis of the main studies on energy penalties associated to the carbonation process large differences were observed on the assumptions made, the selected layout and operating conditions, in particular for alkaline residues. In addition most of the evaluations were carried out considering only experimental tests performed with high liquid to solid ratios (slurry phase route) while specific evaluations for tests with liquid to solid ratios lower than 1 (wet route) were not carried out. The overall aim of this study is to estimate the energy duties required to store the CO 2 emissions of a small-medium size power plant (20 MW) by carbonation of different types of residues (steel slags and waste incineration residues) applying either the slurry phase or wet routes. In this paper the layouts of the proposed carbonation processes are presented and discussed

Optimization of the Biostabilization Process of an Italian Mechanical-Biological Treatment Plant to Account for Changes in Waste Composition

In this paper, we present a case study on the optimization of the biostabilization process of an Italian mechanical-biological treatment (MBT) plant to account for changes in feed waste composition related to a progressive increase in separate collection of MSW fractions, biowaste in particular. After ten years of operation (2009-2019), a decrease of the stabilization degree of the output material of the plant was detected, with Dynamic Respiration Index (DRI) values above the established limit of 1,000 mgO(2)/kg(VS)/h (average values of 4,000 mgO(2)/kg(VS)/h determined weekly for eight weeks). The investigations carried out in 2019 on the waste samples feeding the MBT plant showed that paper and plastic materials constitute around 75% of the input waste to the two aerobic bioreactors of the MBT plant, against 55% at the start-up (2009). Furthermore, the airflow rates and the moisture content analyzed weekly for eight weeks in the bioreactors resulted below the optimal values suggested in the literature. To improve the performances of the biostabilization process, a series of modifications were implemented in the plant. The main modification involved the primary mechanical treatment by varying the mesh size of the screens to 50 mm circular holes mesh. Furthermore, the configuration of the aerobic bioreactors was changed by placing the two bioreactors in series (instead of the previous configuration in parallel) and using a screening unit (25 mm) between the two bioreactors instead of at the end of the process. In this way, the residence time of the materials in the aerobic treatment was enhanced from 16 days with the previous configuration to 27 days. Together with an increase of the airflow rates of around 40% and a water supply of approximately 10% in the bioreactors, these modifications allowed to achieve the desired stability of the output waste, with DRI values below 1000 mgO(2)/kg(VS)/h.[GRAPHICS]

Energy harvesting applied to smart shoes

The appeal of energy harvesting systems lies in the possibility of capturing free energy that would be dissipated and is therefore obtainable without costs. Today, advanced techniques and devices exist for capturing from the environment, storing, and managing quotas of natural energy, which are made available in the form of electrical energy. At the same time, the most recent microprocessors grant an extremely high power efficiency, which permits their operation with minimal power consumption. As a consequence, low-consuming devices can be power supplied by using energy harvesting systems. If this concept is applied to wearable electronics, the most efficient choice is that of exploiting the energy released when the users walk, by developing systems that are embedded in the shoe sole. At each step, the force exerted on the device can be transformed into a relatively high amount of electrical energy, for example by using piezoelectric elements and electromagnetic induction systems. The paper describes the design of four different solutions for smart shoes that make use of energy harvesting apparatuses for the power supply of sensors and complex monitoring systems, for example aimed at GPS localization. An initial comparative assessment of the four architectures is reported, by weighing production costs, ease of manufacture and energy harvesting performance

Estimating conformational traits in dairy cattle with deepAPS : A two-step deep learning automated phenotyping and segmentation approach

Assessing conformation features in an accurate and rapid manner remains a challenge in the dairy industry. While recent developments in computer vision has greatly improved automated background removal, these methods have not been fully translated to biological studies. Here, we present a composite method (DeepAPS) that combines two readily available algorithms in order to create a precise mask for an animal image. This method performs accurately when compared with manual classification of proportion of coat color with an adjusted R2 = 0.926. Using the output mask, we are able to automatically extract useful phenotypic information for 14 additional morphological features. Using pedigree and image information from a web catalog (www.semex.com), we estimated high heritabilities (ranging from h2 = 0.18-0.82), indicating that meaningful biological information has been extracted automatically from imaging data. This method can be applied to other datasets and requires only a minimal number of image annotations (50) to train this partially supervised machinelearning approach. DeepAPS allows for the rapid and accurate quantification of multiple phenotypic measurements while minimizing study cost. The pipeline is available at https://github.com/lauzingaretti/deepaps

Hypokalemic rhabdomyolysis: a rare manifestation of primary aldosteronism

Rhabdomyolysis is a rare presentation of hypokalemia, although muscle weakness is a well-known manifestation of hypokalemia. Primary aldosteronism is characterized by hypertension, suppressed plasma renin activity, increased aldosterone excretion and hypokalemia with metabolic alkalosis. Rhabdomyolysis is not common in primary aldosteronism. We present here a 40-year-old woman presenting with rhabdomyolysis accompanied by severe hypokalemia as heralding symptom of primary aldosteronism

Consumer Buying Behavior of Mobile Phone Devices

The purpose of this study is to investigate the factors affecting the decision of buying mobile phone devices in Hawassa town. In order to accomplish the objectives of the study, a sample of 246 consumers were taken by using simple random sampling technique. Both primary and secondary data were explored. Moreover, six important factors i.e. price, social group, product features, brand name, durability and after sales services were selected and analyzed through the use of correlation and multiple regressions analysis. From the analysis, it was clear that consumer’s value price followed by mobile phone features as the most important variable amongst all and it also acted as a motivational force that influences them to go for a mobile phone purchase decision. The study suggested that the mobile phone sellers should consider the above mentioned factors to equate the opportunity. Keywords: Consumer Buying Behavior, Mobile Phone, Consumer Purchase Decisio