Random laser from engineered nanostructures obtained by surface tension driven lithography

The random laser emission from the functionalized thienyl-S,S-dioxide quinquethiophene (T5OCx) in confined patterns with different shapes is demonstrated. Functional patterning of the light emitter organic material in well defined features is obtained by spontaneous molecular self-assembly guided by surface tension driven (STD) lithography. Such controlled supramolecular nano-aggregates act as scattering centers allowing the fabrication of one-component organic lasers with no external resonator and with desired shape and efficiency. Atomic force microscopy shows that different geometric pattern with different supramolecular organization obtained by the lithographic process tailors the coherent emission properties by controlling the distribution and the size of the random scatterers

Landslide forecasting and factors influencing predictability

Forecasting a catastrophic collapse is a key element in landslide risk reduction, but it is also a very difficult task owing to the scientific difficulties in predicting a complex natural event and also to the severe social repercussions caused by a false or missed alarm. A prediction is always affected by a certain error; however, when this error can imply evacuations or other severe consequences a high reliability in the forecast is, at least, desirable. <br><br> In order to increase the confidence of predictions, a new methodology is presented here. In contrast to traditional approaches, this methodology iteratively applies several forecasting methods based on displacement data and, thanks to an innovative data representation, gives a valuation of the reliability of the prediction. This approach has been employed to back-analyse 15 landslide collapses. By introducing a predictability index, this study also contributes to the understanding of how geology and other factors influence the possibility of forecasting a slope failure. The results showed how kinematics, and all the factors influencing it, such as geomechanics, rainfall and other external agents, are key concerning landslide predictability

Experimental evidence of replica symmetry breaking in random lasers

Spin-glass theory is one of the leading paradigms of complex physics and describes condensed matter, neural networks and biological systems, ultracold atoms, random photonics, and many other research fields. According to this theory, identical systems under identical conditions may reach different states and provide different values for observable quantities. This effect is known as Replica Symmetry Breaking and is revealed by the shape of the probability distribution function of an order parameter named the Parisi overlap. However, a direct experimental evidence in any field of research is still missing. Here we investigate pulse-to-pulse fluctuations in random lasers, we introduce and measure the analogue of the Parisi overlap in independent experimental realizations of the same disordered sample, and we find that the distribution function yields evidence of a transition to a glassy light phase compatible with a replica symmetry breaking.Comment: 10 pages, 5 figure

Dissociation Energies of the Ga2, In2, and GaIn Molecules

The group III metal dimers Ga2 and In2 and the newly identified intermetallic molecule GaIn were investigated in a Knudsen cell-mass spectrometric study of the vapors over gallium–indium alloys. From the all-gas equilibria analyzed by the second-law and third-law methods the following dissociation energies were derived; D00 (Ga2)=110.8±4.9 kJ mol−1, D00 (In2)=74.4±5.7 kJ mol−1, D00 (GaIn)=90.7±3.7 kJ mol−1. The value here measured for the dissociation energy of In2 is discussed and compared with a previous experimental determination and with the results of more recent theoretical investigations

Non-collapsed spaces with Ricci curvature bounded from below

\u2014 We propose a definition of non-collapsed space with Ricci curvature bounded from below and we prove the versions of Colding\u2019s volume convergence theorem and of Cheeger-Colding dimension gap estimate for RCD spaces. In particular this establishes the stability of non-collapsed spaces under non-collapsed Gromov-Hausdorff convergence

Mass Spectrometric and Computational Study of SnPb in the Gas Phase

The SnPb molecule has been identified in a Knudsen effusion mass spectrometry experiment. The direct dissociation reaction and two isomolecular exchange reactions involving the Sn(2) and Pb(2) molecules have been studied, in the 1426-1705 K range of temperatures, using both second and third law procedures. The D(degree)0(SnPb,g) has been derived, for the first time, as (122.6+/-4.0) kJ mol(-1). Density functional and ab initio calculations up to the coupled clusters level of theory were also performed. In addition, the anion dissociation energy D(degree)0(SnPb(-),g) of (179.2+/-4.2) kJ mol(-1) was determined using the D(degree)0(SnPb,g) mass spectrometric value derived in this investigation and literature data

A framework for temporal and spatial rockfall early warning using micro-seismic monitoring

Rockfall risk is usually characterized by a high frequency of occurrence, difficulty in prediction (given high velocity, lack of noticeable forerunners, abrupt collapse, and complex mechanism), and a relatively high potential vulnerability, especially against people and communication routes. Considering that larger rockfalls and rockslides are generally anticipated by an increased occurrence of events, in this study, a framework based on microseismic monitoring is introduced for a temporal and spatial rockfall early warning. This approach is realized through the detection, classification, and localization of all the rockfalls recorded during a 6-month-long microseismic monitoring performed in a limestone quarry in central Italy. Then, in order to provide a temporal warning, an observable quantity of accumulated energy, associated to the rockfall rolling and bouncing and function of the number and volume of events in a certain time window, has been defined. This concept is based on the material failure method developed by Fukuzono-Voight. As soon as the first predicted time of failure and relative warning time are declared, all the rockfalls occurred in a previous time window can be located in a topographic map to find the rockfall susceptible area and thus to complement the warning with spatial information. This methodology has been successfully validated in an ex post analysis performed in the aforementioned quarry, where a large rockfall was forecasted with a lead time of 3 min. This framework provides a novel way for rockfall spatiotemporal early warning, and it could be helpful for activating traffic lights and closing mountain roads or other transportation lines using the knowledge of the time and location of a failure. Since this approach is not based on the detection of the triggering events (like for early warnings based on rainfall thresholds), it can be used also for earthquake-induced failures

Experimental and Computational Study of the New Gaseous Molecules OMnF and OMnF[Sub 2]

The new gaseous species OMnF and OMnF2 were identified and studied by high-temperature Knudsen Cell Mass Spectrometry. Their thermochemical atomization energies were derived through the study of several all-gas equilibria in the temperature range 1735–1913 K. FTIR matrix isolation experiments together with ab initio and density functional calculations were performed to determine the molecular parameters, bond distances, and vibrational frequencies of OMnF(g) and OMnF2(g) . The results allowed us to evaluate a set of thermal functions for the new species that were used in the evaluation of the equilibrium data. The proposed atomization energies and enthalpies of formation are DaH0 + (OMnF,g)5(90365) kJ mol21, DfH298.15 + (OMnF,g)5(229765) kJ mol21, and DaH0 + (OMnF2 ,g)5(1470670) kJ mol21, DfH298.15 + (OMnF2 ,g)5(2789670) kJ mol21