Kinetics of mobile impurities and correlation functions in one-dimensional superfluids at finite temperature

We scrutinize the hydrodynamic approach for calculating dynamical correlations in one-dimensional superfluids near integrability and calculate the characteristic time scale {\tau} beyond which this approach is valid. For time scales shorter than {\tau} hydrodynamics fails and we develop an approach based on kinetics of fermionic quasiparticles described as mobile impurities. New universal results for the dynamical structure factor relevant to experiments in ultracold atomic gases are obtained.Comment: 5 pages, 2 figures. Supplemental material included. Version 3: Minor typos correcte

Infill Modelling Influence on Dynamic Identification and Model Updating of Reinforced Concrete Framed Buildings

In order to correctly capture the dynamic behavior of infilled framed buildings, the importance to take into account in seismic design the infill panels' contribution is nowadays well recognized since they could modify in a significant way the global and local response of the whole building. Despite about sixty years of continuous research in the field, the modelling of the frame-infill interaction still represents a serious issue for the daily practical design since there is no reference model proven to be suitable to cover a wide record of possible cases. Moreover, few works are available in the literature, comparing the results of different modelling proposals with outcomes of dynamic tests on a full-scale building. To this regard, starting from the results of induced vibration dynamic tests performed on a 7-story building with reinforced concrete frames with masonry infill, in the present paper, the effects of the infill presence have been evaluated by comparing experimental outcomes, achieved using a MDOF Circle-Fit identification procedure, with the results obtained by means of numerical analyses performed on finite element models. Using a model updating procedure, the optimal width to assign to the masonry equivalent struts modelling the infill panels was defined. Furthermore, several literature proposals for the definition of the equivalent strut width have been analysed. Thirteen different proposals have been selected and implemented in thirteen different finite element models. The reliability of each proposal has been investigated and quantified by comparing the dynamic properties of the models with the building dynamic response obtained by the experimental tests. The main outcomes of the analyses highlight that different proposals provide a great variability for the strut width. This brings to a large variability of the mechanical properties of the equivalent struts, and as a consequence, the modelling choice also influences the dynamic behaviour of the numerical models. Currently, this represents a serious issue for the daily designers' activity. The outcomes provided in the paper, although established for a specific case study, can be extended to a wide range of buildings and should drive the future research studies in order to provide more robust criteria for the modelling of this worldwide building class

Un bus come spazio pubblico. Multiculturalismo ed etnografia urbana a Milano

Il contributo presenta gli esiti di un‘attività didattica e di ricerca sul campo condotta presso il Politecnico di Milano a ridosso di un tema chiave: il ruolo degli spazi pubblici urbani come supporto per la negoziazione delle differenze e nell’ingaggiare diversi individui e popolazioni in situazioni di confronto e coesistenza. Un’esplorazione di tipo etnografico ha messo sotto osservazione un mezzo di trasporto pubblico quale spazio pubblico “compresso”. Il filobus 90/91 a Milano è stato assunto quale terreno di osservazione privilegiato sui rapidi processi di cambiamento sociale e demografico che hanno investito Milano negli ultimi anni entro una prospettiva di ricerca sulla dimensione quotidiana del multiculturalismo.The paper draws on a research and teaching project carried out with an international class of students in Urban Ethnography in the MSC in Urban Planning and Policy at Politecnico di Milano (Italy). A particular focus of the project was on exploring the role played by public spaces in supporting the coexistence of a multitude of strangers in the city through the continuous negotiation of diversity and difference. In the field work, spatial and social dynamics occurring in a particular and ‘compressed’ public space – the 90-91 trolley-bus circle-line in Milan – are explored and discussed as a space of confrontation in a perspective of daily multiculturalism

Inappropriateness in laboratory medicine: An elephant in the room?

Appropriateness of diagnostic testing can be conventionally described as prescription of the right test, using the right method, at the right time, to the right patient, with the right costs and for producing the right outcome. There is ongoing debate about the real burden of inappropriateness in laboratory diagnostics. The media coverage of this issue has also recently led to either over- or under-emphasizing the clinical, organizational and economic consequences. This is quite problematic, inasmuch as some reliable data are available in the current scientific literature, showing that inappropriateness of laboratory testing can be as high as 70%. This is especially evident for, though not limited to, cancer biomarkers testing, in which the practice of avoidable tests ordering is dramatically magnified. The reasons beyond inappropriateness are many and multifaceted, entailing wrong habits, resistance to changes, poor culture, insufficient education and healthcare inefficiencies. There are many unfavorable consequences attributable to avoidable testing, including unjustified incremental costs, derangement of laboratory efficiency and potential patient safety issues. The tentative solutions to this important problem necessitate that policymakers, local hospital administrators, laboratory professionals, clinicians, patients' associations and diagnostic companies join the efforts and embark in the same landmark effort for disseminating a better culture of appropriateness

Bio-based building components: A newly sustainable solution for traditional walls made of Arundo donax and gypsum

To contribute to the use of bio-based materials in the building sector, a novel bio-based wall panel, with a high thermal performance level, is proposed in this work. The panel is based on an ancient rural technique, widely diffused in southern Italy, which makes use of Arundo donax L. canes combined with gypsum plaster to build walls and ceilings of rural buildings. The enhancement of the thermal capacity of these panels by means of the introduction in the canes of a natural wax oleogel (WO) is proposed in this paper. A specific experimental campaign aiming at the comparison of traditional and innovative panels was carried out to assess the enhanced thermal performance of the proposed solution. The maximum value of heat flow absorbed from the panel with WO was 61.08 W/m(2) around a mean panel temperature of 24 & DEG;C, corresponding to the melting temperature range of the WO. The panel without WO at the same temperature absorbed an incoming heat flow of 34.64 W/m(2) which is about 57% of the panel with WO. The panel with WO released at a temperature of about 27.5 & DEG;C, a heat flow of 43.42 W/m(2). At the same temperature of about 27.5 & DEG;C, the panel without WO released a heat flow of 34.38 W/m(2) which is about 80% that of the panel with WO. The results highlighted that the addition of natural WO has enhanced the thermal capacity of the panel facilitating heat dissipation through the borders. These characteristics make the panel a suitable component for internal partitions of controlled temperature zones such as residential rooms, storage food areas, livestock buildings, and where it is necessary to obtain a constant environmental temperature. In particular, the null or low toxicity of the panel's materials allows for partition use, also in hygienically safe environments

A comparison of energy and thermal performance of rooftop greenhouses and green roofs in Mediterranean climate: A hygrothermal assessment in WuFi

In urban areas, a considerable proportion of energy demand is allocated to buildings. Since rooftops constitute one-fourth of all urban surfaces, an increasing amount of attention is paid to achieving the most efficient shapes and component designs compatible with every climate and urban context, for rooftops of varying sizes. In this study, three types of rooftop technologies, namely insulated, green roof, and rooftop greenhouse, are evaluated for energy and thermal performance using computer simulations. Water surface exposure, absorption, and intrusion are the three important factors in the calculation of hygrothermal models that impact energy consumption and building envelope performance; however, a few studies are specifically focused on providing realistic results in multi-dimensional hygrothermal models and the assessment of the impact of moisture in roofing solutions. This paper aims at evaluating the performance of three different roofing technologies through a two-dimensional hygrothermal simulation in software WUFI. To accomplish this, a precise localized microclimate model of a complex urban context on the scale of a neighborhood was employed to evaluate the cooling and heating loads of the buildings, the impact of the water content in the green roof on the thermal behavior of the roof surface, and the feasibility of designing a building with nearly zero cooling needs. A two-story building in the city center of Bologna, Italy is modelled. Simulation results have shown that during the cooling period, the performance of the designed rooftop greenhouse is the most effective by 50% reduction in cooling loads. Besides, the impact of moisture in green roofs has been detected as a negative factor for thermal and energy performance of the building in the Mediterranean climate. The results ultimately highlighted the capability of passively-designed rooftop greenhouses to create a building with nearly zero cooling needs

Current laboratory diagnostics of coronavirus disease 2019 (COVID-19)

Laboratory medicine provides an almost irreplaceable contribution to the diagnostic reasoning and managed care of most human pathologies. The novel coronavirus disease 2019 (COVID-19) is not an exception to this paradigm. Although the relatively recent emergence does not allow to draw definitive conclusions on severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) diagnostics, some standpoints can be conveyed. First and foremost, it seems now clear that we will be living together with this virus for quite a long time, so that our vigilance and responsiveness against the emergence of new local outbreaks shall be maintained at the highest possible levels. The etiological diagnosis of COVID-19 is, and will remain for the foreseeable future, deeply based on direct identification of viral RNA by means of molecular biology techniques in biological materials, especially upper and lower respiratory tract specimens. Whether other materials, such as blood, urine, stools, saliva and throat washing, will become valid alternatives has not been unequivocally defined so far. As concerns serological testing, promising information can be garnered from preliminary investigations, showing that the vast majority of COVID-19 patients seem to develop a sustained immune response against the virus, characterized especially by emergence of anti-SARS-CoV-2 IgG and IgA, 1 to 2 weeks after the onset of fever and/or respiratory symptoms. Whether these antibodies will have persistent neutralizing activity against the virus is still to be elucidated on individual and general basis. The availability of rapid tests for detecting either viral antigens or anti-SARS-CoV-2 antibodies are a potentially viable opportunity for purposes of epidemiologic surveillance, though more information is needed on accuracy and reliability of these portable immunoassays

Mining livestock genome datasets for an unconventional characterization of animal DNA viromes

Whole genome sequencing (WGS) datasets, usually generated for the investigation of the individual animal genome, can be used for additional mining of the fraction of sequencing reads that remains unmapped to the respective reference genome. A significant proportion of these reads contains viral DNA derived from viruses that infected the sequenced animals. In this study, we mined more than 480 billion sequencing reads derived from 1471 WGS datasets produced from cattle, pigs, chickens and rabbits. We identified 367 different viruses among which 14, 11, 12 and 1 might specifically infect the cattle, pig, chicken and rabbit, respectively. Some of them are ubiquitous, avirulent, highly or potentially damaging for both livestock and humans. Retrieved viral DNA information provided a first unconventional and opportunistic landscape of the livestock viromes that could be useful to understand the distribution of some viruses with potential deleterious impacts on the animal food production systems

Turning agricultural wastes into biomaterials: Assessing the sustainability of scenarios of circular valorization of corn cob in a life-cycle perspective

Circular economy plays a key role in increasing the sustainability of the agricultural sector, given the countless possibilities of transforming crop residues and recycling precious resources. The maize cultivation process produces a significant amount of residual organic materials, commonly left on the field, as a soil conditioner and source of nutrients even if some parts, such as the cob, play a minor role in these actions. The solutions for the valorization of this remnant depend on economic and environmental factors and the evaluation of the environmental performances of the processes in a life-cycle perspective is important to compare the overall sustainability of the valorization alternatives, maximizing their environmental added value. This work reports the results of Life Cycle Analysis, from cradle-to-gate of corn cob valorized as a raw material in two scenarios: corn cob pellet and corn cob abrasive grits to use as blasting or finishing media. A comparative study has been performed with two products available on the market and with the same functions. The results show that cob-based products have lower impact than those currently used. The work provides indication for evaluating the benefits of turning agricultural wastes in natural-based materials and intends to promote circular economy processes in agriculture production