Control and navigation problems for model bio-inspired microswimmers

Navigation problems for a model bio-inspired micro-swimmer, consisting of a cargo head and propelled by multiple rotating flagella or propellers and swimming at low Reynolds numbers, are formulated and solved. We consider both the direct problem, namely, predicting velocity and trajectories of the swimmer as a consequence of prescribed rotation rates of the propellers, and inverse problems, namely, find the rotation rates to best approximate desired translational and rotational velocities and, ultimately, target trajectories. The equations of motion of the swimmer express the balance of the forces and torques acting on the swimmer, and relate translational and rotational velocities of the cargo head to rotation rates of the propellers. The coefficients of these equations, representing hydrodynamic resistance coefficients, are evaluated numerically through a custom-built finite-element code to simulate the (Stokes) fluid flows generated by the movement of the swimmer and of its parts. Several designs of the propulsive rotors are considered: from helical flagella with different chirality to marine propellers, and their relative performance is assessed

The role of architectural reconstruction in a post-war context: the case of Mosul

This work addresses the topic of architectural reconstruction in a post-war context, in this case in Mosul, Iraq. Heavily damaged during the war against ISIS, the city faces the immense task of cleaning, restructuring, and rebuilding. The damaged buildings are diverse, but the ancient monuments require specific care as they carry the memory and the heritage of a traumatized community. Both in the cases of partial or complete destruction, the architectural intervention needs to face both cultural and the preservation dimensions of reconstruction. This approach is based on interventions in strategic neuralgic points for the community life such as the market, a religious structure, and the baths. These symbolic spaces host the social, economic, and religious activities that gather the inhabitants. They are also the stages of the traditions and cultural life of Mosul. The reconstitution of the inhabitants' habits and sense of community is centred around these locations and planned to spread around the urban fabric following the redevelopment of the city. Our three different sites are the Souk, the Great Mosque and the Hammam. These projects address several challenges: the construction of a new building inspired by the existing urban fabric, the partial reconstruction of an ancient monument and the construction of a new building in dialogue with existing Ottoman ruins. The balance between tradition and modernization; memory and oblivion; reconstruction and restoration is the focus of the paper

Urban and Architectural Identity of Mosul. An Analytical Background for City’s Reconstruction

The city of Mosul dramatically represents a paradigmatic case where a condition of pervasive destruction of the built environment has moved the scientific research towards the investigation of possible precautionary strategies in safeguarding those structural characteristics that define the identity of the city. The study here displayed evaluates the elements that compose the urban phenomenon as operational and proactive tools capable to suggest criteria for a critical reconstruction of the urban structure, to integrate a consolidate historical identity with a new architectural intervention. Specifically, the aim of this research consists of detecting how the city of Mosul, although being a city of Islamic foundation – and thus displaying specific morphological and typological characteristics – has developed peculiar aspects affected by other cultural, religious, and geographical factors. And that is recognizable, for instance, in the settlement relationship with the Tigris river, and, in particular, in the construction of a monumental riverfront that often deforms the typical structure of the enclosure, otherwise persistent in the Islamic settlements. Then, those processes identified at an urban level will be extended to a typological one, trying to identify possible relationships between buildings and urban form. As a result, we expect to rebuild a formal and settlement identity of the city of Mosul by combining its individual and peculiar ways of growth, both architectural and urban. And this would have the purpose of enriching the elements to be taken into consideration in the process of defining an operational methodology capable of leading the practice of design towards more aware and responsible ways in dealing with the reconstruction process

Factors related to delayed treatment: A case report of a huge cutaneous horn and review of the literature

We present a case of a man with a giant cutaneous horn over his frontal region. This case has been presented for the size of the lesion, due to delayed treatment, and to illustrate the reasons why the growth of this lesion has been possible in a western country, in the 21st century. It was a solitary, not painful lesion which caused significant aesthetic problems. The diagnosis was based on an ultrasonographic study and the treatment of choice was a surgical excision. This case is an opportunity to review the literature about the cutaneous horns, to talk about the main causes of delayed diagnosis and treatment of cutaneous lesions and, to define the role of the specialist in the assessment of emotions and patient support

Towards joint reconstruction of noise and losses in quantum channels

The calibration of a quantum channel, i.e. the determination of the transmission losses affecting it, is definitely one of the principal objectives in both the quantum communication and quantum metrology frameworks. Another task of the utmost relevance is the identification, e.g. by extracting its photon number distribution, of the noise potentially present in the channel. Here we present a protocol, based on the response of a photon-number-resolving detector at different quantum efficiencies, able to accomplish both of these tasks at once, providing with a single measurement an estimate of the transmission losses as well as the photon statistics of the noise present in the exploited quantum channel. We show and discuss the experimental results obtained in the practical implementation of such protocol, with different kinds and levels of noise.Comment: 6 pages, 4 figure

Homogenization of magnitudes of the ISC Bulletin

We implemented an automatic procedure to download the hypocentral data of the online Bulletin of the International Seismological Centre (ISC) in order to produce in near real-time a homogeneous catalogue of the Global and EuroMediterranean instrumental seismicity to be used for forecasting experiments and other statistical analyses. For the interval covered by the reviewed ISC Bulletin, we adopt the ISC locations and convert the surface wave magnitude (Ms) and short-period body-wave magnitude (mb) as computed by the ISC to moment magnitude (Mw), using empirical relations. We merge the so obtained proxies with real Mw provided by global and EuroMediterranean moment tensor catalogues. For the most recent time interval (about 2 yr) for which the reviewed ISC Bulletin is not available, we do the same but using the preferred (prime) location provided by the ISC Bulletin and converting to Mw the Ms and mb provided by some authoritative agencies. For computing magnitude conversion equations, we use curvilinear relations defined in a previous work and the chi-square regression method that accounts for the uncertainties of both x and y variables

Foot dermatitis and productive traits in broiler chickens kept with different stocking densities, litter types and light regimen

The purpose of the research was to study the effects of high and low stocking density of broiler chickens, different types of litter and the adoption of short and long lighting regimen on broiler welfare through the evaluation of their productivity and incidence of foot pad dermatitis. 2,400 male Ross 508 were divided into 8 groups of four replicates each and reared in 32 pens according to a 3 factors experimental design of two levels each: low (LD) or high (HD) stocking density (11 and 14 birds/m2 for LD and HD respectively), chopped straw (CS) or wood shaving (WS) litters and short (SL) or long (LL) light regimens (16 h light and 8 h dark or 23 h light and 1 h dark respectively for SL and LL). Broiler growth rate and feed efficiency were positively influenced by a stocking density lower than 30 kg of live weight per m2. The adoption of a short light regimen reduced feed intake and improved feed conversion rate without modifying body live weight. Chickens reared on wood shaving litter showed a lower incidence of foot pad dermatitis

Retrospective short-term forecasting experiment in Italy based on the occurrence of strong (fore) shocks

In a recent work, we computed the relative frequencies with which strong shocks (4.0 ≤ Mw < 5.0), widely felt by the population were followed in the same area by po- tentially destructive main shocks (Mw ≥ 5.0) in Italy. Assuming the stationarity of the seismic release properties, such frequencies can be tentatively used to estimate the probabilities of potentially destructive shocks after the occurrence of future strong shocks. This allows us to set up an alarm-based forecasting hypothesis related to strong foreshocks occurrence. Such hypothesis is tested retrospectively on the data of a homogenized seismic catalogue of the Italian area against a purely random hypothesis that simply forecasts the target main shocks proportionally to the space–time fraction occupied by the alarms. We compute the latter frac- tion in two ways (i) as the ratio between the average time covered by the alarms in each area and the total duration of the forecasting experiment (60 yr) and (ii) as the same ratio but weighted by the past frequency of occurrence of earthquakes in each area. In both cases the overall retrospective performance of our forecasting algorithm is definitely better than the random case. Considering an alarm duration of three months, the algorithm retrospectively forecasts more than 70 per cent of all shocks with Mw ≥ 5.5 occurred in Italy from 1960 to 2019 with a total space–time fraction covered by the alarms of the order of 2 per cent. Considering the same space–time coverage, the algorithm is also able to retrospectively forecasts more than 40 per cent of the first main shocks with Mw ≥ 5.5 of the seismic sequences occurred in the same time interval. Given the good reliability of our results, the forecasting algorithm is set and ready to be tested also prospectively, in parallel to other ongoing procedures operating on the Italian territory