Fruit quality sensing:Post-harvest ripeness

Firmness sensing of selected varieties of apples, pears and avocado fruits has been developed using a nondestructive impact technique. In addition to firmness measurements, postharvest ripeness of apples and pears was monitored by spectrophotometric reflectance measurements, and that of avocadoes by Hunter colour measurements. The data obtained from firmness sensing were analyzed by three analytical procedures: principal component, correlation and regression, and stepwise discriminant analysis. A new software was developed to control the impact test, analyse the data, and sort the fruit into specified classes, based on the criteria obtained from a training procedure. Similar procedures were used to analyse the reflectance and colour data. Both sensing systems were able to classify fruits w i th good accuracy

Role of the electric field in surface electron dynamics above the vacuum level

Scanning tunneling spectroscopy (STS) is used to study the dynamics of hot electrons trapped on a Cu(100) surface in field emission resonances (FER) above the vacuum level. Differential conductance maps show isotropic electron interference wave patterns around defects whenever their energy lies within a surface projected band gap. Their Fourier analysis reveals a broad wave vector distribution, interpreted as due to the lateral acceleration of hot electrons in the inhomogeneous tip-induced potential. A line-shape analysis of the characteristic constant-current conductance spectra permits to establish the relation between apparent width of peaks and intrinsic line-width of FERs, as well as the identification of the different broadening mechanisms.Comment: 7 pages, 4 figures, to appear in Phys. Rev.

Educommunication and archaeological heritage in Italy and Spain: an analysis of institutions’ use of Twitter, sustainability, and citizen participation

Improving heritage educommunication on the web 2.0 is key to reaching certain sustainable development goals focused on educational quality and citizen participation. Although numerous partial studies have already been conducted, to date neither assessment tools nor detailed studies are available regarding the quality of educommunicative initiatives. Spain and Italy’s archaeological heritage museums have a consolidated track record on Twitter, which has been bolstered by museum closures due to COVID-19 and has resulted in a significant change to their educommunicative policies. The present article aims to analyze educommunicative actions undertaken on Twitter at Italian archaeological museums, compare their strategies with a previous study on Spanish institutions, and analyze to what degree the sustainability of heritage, citizen participation, learning opportunities, and universal access are being promoted. This mixed method analysis was carried out through the implementation of a web 2.0 heritage educommunication analysis tool focused on three key factors: educational procedure, R-elational interactions, and the prevailing learning paradigm, as well as a content analysis of the variables that comprise them. The key findings suggest that neither country is close to achieving a quality educommunicative strategy. Italian archaeological heritage institutions use Twitter simply as an advertising platform. Despite being a social media platform, participative initiatives are scarcely promoted, although heritage sustainability is promoted through raising awareness of conservation and appreciation. Spanish institutions, however, demonstrated the opposite pattern of use

The role of the spin in quasiparticle interference

Quasiparticle interference patterns measured by scanning tunneling microscopy (STM) can be used to study the local electronic structure of metal surfaces and high temperature superconductors. Here, we show that even in non-magnetic systems the spin of the quasiparticles can have a profound effect on the interference patterns. On Bi(110), where the surface state bands are not spin-degenerate, the patterns are not related to the dispersion of the electronic states in a simple way. In fact, the features which are expected for the spin-independent situation are absent and the observed interference patterns can only be interpreted by taking spin-conserving scattering events into account.Comment: 4 pages, 2 figure