The Corrosion Behaviour of Additively Manufactured AlSi10Mg Parts Compared to Traditional Al Alloys

Additive manufacturing of metal parts in the motorsport industry is becoming a decisive technology for producing lightweight and rigid parts, with increasing applications as the costs decrease. Among the available metal alloys, AlSi10Mg is one of the most widely used. In this paper, the corrosion resistance of additively manufactured AlSi10Mg is compared with that of other traditionally manufactured aluminium alloys widespread in the automotive industry. Several potentially corrosive agents, typical of vehicle applications, were used: salty water, motor oil, suspension oil, cooling fluid and gasoline. Corrosion tests were conducted at both room temperature and 90 C. The effects of heat and surface treatments were evaluated separately. The samples were visually inspected and weighed to evaluate the corrosion rate with the aid of SEM and EDS analysis. Additively manufactured AlSi10Mg generally showed better corrosion resistance in the stress-relieved condition as compared to the T6-treated state, with slightly better results for the polished samples. Motor oil, suspension oil, cooling fluid and gasoline did not significantly corrode the specimens, except for the T6-treated AlSi10Mg samples at 90 C. However, the corrosion rate was always higher than traditionally manufactured aluminium alloys tested for comparison

Chest pain caused by multiple exostoses of the ribs: A case report and a review of literature

Abstract The aim of this paper is to report an exceptional case of multiple internal exostoses of the ribs in a young patient affected by multiple hereditary exostoses (MHE) coming to our observation for chest pain as the only symptom of an intra-thoracic localization. A 16 years old patient with familiar history of MHE came to our observation complaining a left-sided chest pain. This pain had increased in the last months with no correlation to a traumatic event. The computed tomography (CT) scan revealed the presence of three exostoses located on the left third, fourth and sixth ribs, all protruding into the thoracic cavity, directly in contact with visceral pleura. Moreover, the apex of the one located on the sixth rib revealed to be only 12 mm away from pericardium. Patient underwent video-assisted thoracoscopy with an additional 4-cm mini toracotomy approach. At the last 1-year followup, patient was very satisfied and no signs of recurrence or major complication had occured. In conclusion, chest pain could be the only symptom of an intra-thoracic exostoses localization, possibly leading to serious complications. Thoracic localization in MHE must be suspected when patients complain chest pain. A chest CT scan is indicated to confirm exostoses and to clarify relationship with surrounding structures. Video-assisted thoracoscopic surgery can be considered a valuable option for exostoses removal, alone or in addiction to a mini-thoracotomy approach, in order to reduce thoracotomy morbidity

Accurate determination of band tail properties in amorphous semiconductor thin film with Kelvin Probe Force Microscopy

Amorphous oxide semiconductors are receiving significant attention due to their relevance for large area electronics. Their disordered microscopic structure causes the formation of band tails in the density of states (DOS) that strongly affect charge transport properties. Bandtail properties are crucial to understand for optimizing thin film device performance. Among the available techniques to measure the DOS, KPFM is exceptional as it enables precise local electronic investigations combined with microscopic imaging. However, a model to interpret KPFM spectroscopy data on amorphous semiconductors of finite thickness is lacking. To address this issue, we provide an analytical solution to the Poisson's equation for a metal-insulator-semiconductor (MIS) junction interacting with the AFM tip. The solution enables us to fit experimental data for semiconductors with finite thickness and obtain the DOS parameters, such as band tail width (E_t), doping density (N_D), and flat band potential. To demonstrate our method, we perform KPFM experiments on Indium-Gallium-Zinc Oxide (IGZO) thin film transistors (IGZO-TFTs). DOS parameters compare well to values obtained with photocurrent spectroscopy. We demonstrate the potentials of the developed method by investigating the impact of ionizing radiation on DOS parameters and TFT performance. Our results provide clear evidence that the observed shift in threshold voltage is caused by static charge in the gate dielectric leading to a shift in flat band potential. Band-tails and doping density are not affected by the radiation. The developed methodology can be easily translated to different semiconductor materials and paves the way towards quantitative microscopic mapping of local DOS parameters in thin film devices

School violence, depression symptoms, and school climate: a cross-sectional study of Congolese and Burundian refugee children

Forcibly displaced children are at increased risk of violence and mental health disorders. In refugee contexts, schools are generally perceived as protective environments where children can build a sense of belonging and recover from trauma. Evidence shows that positive school climates can support student skills development and socio-emotional wellbeing and protect them against a host of adverse outcomes. However, schools are also places where children may experience violence, from both teachers and peers. Prevalence estimates of violence against children in humanitarian settings are scarce and evidence on the relationship between school climate and student outcomes in these contexts is non-existent. The aim of the study is to estimate the prevalence of school-based violence against children and to explore the association between perceptions of school climate and students’ experiences and use of violence and their depression symptoms. We relied on data from a cross-sectional survey of students and teachers in all primary and secondary schools in Nyarugusu Refugee Camp in Tanzania, conducted as part of a cluster randomised controlled trial, to compute prevalence estimates and used mixed logistic regression analysis to assess the association between school climate and students’ outcomes. We found that students in Nyarugusu experienced high levels of violence from both peers and teachers in both primary and secondary schools in the camp, with little difference between boys and girls. Nearly one in ten students screened positive for symptoms of depression. We found that opportunities for students and teachers to be involved in decision-making were associated with higher odds of violent discipline and teachers’ self-efficacy was a significant protective factor against student depression symptoms. However, generally, school-level perceptions of school climate were not associated with student outcomes after adjusting for potential confounders. Our findings suggest that interventions to prevent and respond to teacher and peer violence in schools and to support students’ mental health are urgently needed. Our results challenge the assumption that education environments are inherently protective for children and call for further investigation of norms around violence among students and teachers to better understand the role of school climate in refugee settings

Application of Virtual Fencing for the management of Limousin cows at pasture

A potential use of pasture-based systems requires an efficient grazing management strategy. Thanks to the Virtual Fencing (VF) physical fences are replaced by virtual ones and, when the animals approach the boundaries, they receive a paired stimulus: an audio cue followed by a low electrical pulse if animals cross over the fences. This study aims to i) to evaluate the animal’s ability to learn, and then respond positively, to VF ii) VFs’ efficiency to manage the herd within grazing areas virtually delimitated; iii) to assess the chronic stress related to the VF, evaluating the hair cortisol concentration (HCC), during the experiment. Twenty Limousine cows were fitted with a commercial VF-GPS collars (Nofence AS, Batnfjordsør, Norway). The experiment was divided into four trials: Trial zero (T0) with inactive collars to let the animals get acquainted with them; Trial one (T1) where three of the four virtual boundaries coincided with the physical ones, while the virtual one was set across the pasture to restrict the grazing area; Trial two (T2) in which the grazing area was further extended moving forwards the virtual board; Trial three (T3) in which the virtual line was set longways to the pasture. Results show a significant decrease of stimuli delivered (i.e., sounds and electrical pulses) (p < 0.001), among trials. Moreover, a reduction (p < 0.0250) in the ratio between sounds and electrical pulses was observed between T1 and T3, with T2 being like both. Regarding the cows’ learning capacity, the events in which the sounds were followed by electrical pulses were significantly less in T3 (p < 0.001). Furthermore, in T3 the duration of the audio tones was lower than T1 and T2 (p < 0.0005). Animals were increasingly kept inside the inclusion zones during the trials, with the lowest number of escape events from the inclusion zone registered in T3 (p < 0.001). No differences were observed in the HCC before and after the VF treatment. The progressive reduction of the studied parameters between following sessions, indicates an increase in associative learning through time. VF virtual fencing has proven to be an effective tool in managing Limousin cows at pasture. However, future research is needed to evaluate the animals’ performances in terms of grazing activities and on the assessment of chronic stress conditions as well

Matrika Household Survey in India

Data produced as part of a study to evaluate the impact of the Matrika social franchising model – a multi-faceted intervention that established a network of private providers and strengthened the skills of both public and private sector clinicians – and determine whether it has improved the quality and coverage of health services along the continuum of care for maternal, newborn and reproductive health in Uttar Pradesh, India. The datasets cover two rounds of a household survey, performed in January 2015 and May 2016, of women who had recently given birth