On-site earthquake early warning: a partially non-ergodic perspective from the site effects point of view

We introduce in the on-site earthquake early warning (EEW) a partially non-ergodic perspective from the site effects point of view. We consider the on-site EEW approach where the peak ground velocity (PGV) for S waves is predicted from an early estimate, over the P waves, of either the peak-displacement (PD) or cumulative squared velocity (IV2). The empirical PD-PGV and IV2-PGV relationships are developed by applying a mixed-effect regression where the site-specific modifications of ground shaking are treated as random effects. We considered a large data set composed of almost 31 000 selected recordings in central Italy, a region struck by four earthquakes with magnitude between 6 and 6.5 since the 2009 L’Aquila earthquake. We split the data set into three subsets used for calibrating and validating the on-site EEW models, and for exemplifying their application to stations installed after the calibration phase. We show that the partially non-ergodic models improve the accuracy of the PGV predictions with respect to ergodic models derived for other regions of the world. Moreover, considering PD and accounting for site effects, we reduce the (apparent) aleatory variability of the logarithm of PGV from 0.31 to 0.36, typical values for ergodic on-site EEW models, to about 0.25. Interestingly, a lower variability of 0.15 is obtained by considering IV2 as proxy, which suggests further consideration of this parameter for the design of on-site EEW systems. Since being site-specific is an inherent characteristic of on-site EEW applications, the improved accuracy and precision of the PGV predicted for a target protection translate in a better customization of the alert protocols for automatic actions

The waveform similarity approach to identify dependent events in instrumental seismic catalogues

In this paper, waveform similarity analysis is adapted and implemented in a declustering procedure to identify foreshocks and aftershocks, to obtain instrumental catalogues that are cleaned of dependent events and to perform an independent check of the results of traditional declustering techniques. Unlike other traditional declustering methods (i.e. windowing techniques), the application of cross-correlation analysis allows definition of groups of dependent events (multiplets) characterized by similar location, fault mechanism and propagation pattern. In this way the chain of intervening related events is led by the seismogenetic features of earthquakes. Furthermore, a time-selection criterion is used to define time-independent seismic episodes eventually joined (on the basis of waveform similarity) into a single multiplet. The results, obtained applying our procedure to a test data set, show that the declustered catalogue is drawn by the Poisson distribution with a degree of confidence higher than using the Gardner and Knopoff method. The declustered catalogues, applying these two approaches, are similar with respect to the frequency–magnitude distribution and the number of earthquakes. Nevertheless, the application of our approach leads to declustered catalogues properly related to the seismotectonic background and the reology of the investigated area and the success of the procedure is ensured by the independence of the results on estimated location errors of the events collected in the raw catalogue

Evaluation of liquefaction triggering potential in Italy: a seismic-hazard-based approach

In the present study, we analyze ground-motion hazard maps and hazard disaggregation in order to define areas in Italy where liquefaction triggering due to seismic activity can not be excluded. To this end, we refer to the triggering criteria (not to be confused with liquefaction susceptibility criteria, which essentially take into account soil type and depth to groundwater) proposed by the Italian Guidelines for Seismic Microzonation, which are described in the main body of the paper. However, the study can be replicated in other countries that adopt different criteria. The final goal is the definition of a screening map for all of Italy that classifies sites in terms of liquefaction triggering potential according to their seismic hazard level. The map, which is referred to with the Italian acronym MILQ – Mappa del potenziale d'Innesco della LiQuefazione (i.e., map of liquefaction triggering potential), and the associated data are freely accessible at the following web address: https://distav.unige.it/rsni/milq.php (last access: 28 April 2023). Our results can be useful to guide land-use planners in deciding whether liquefaction is a hazard that needs to be considered within the planning processes or not. Furthermore, they can serve as a guide for recommending geological and geotechnical investigations aimed at the evaluation of liquefaction hazards or, conversely, rule out further studies with consequent savings in efforts and money.</p

Evaluation of Retention among Acid-etch and Self-etch Sealants: An in vivo Study

Aim: The aim of the study is to evaluate the retention of fissure&nbsp;sealants following the use of self-etch priming agent and&nbsp;traditional acid-etch method.&nbsp;Materials and methods: Thirty subjects around the age 8 to&nbsp;12 years old school children was recruited to this study by two&nbsp;dental professionals. Paired lower molars were the principal&nbsp;&nbsp;unit of analysis. Pit and fissure sealant placement lower molars&nbsp;&nbsp;followed by traditional acid-etching done on 36 and self-etch&nbsp;primer (3M ESPE) on 46. After 6 months the retention was&nbsp;evaluated using Smales RJ and Wong KC (1999) retention&nbsp;evaluation criteria. The Chi-square test was used to evaluate&nbsp;the difference in the retention rates.&nbsp;Results: The total retention in the self-etch sealant group seems&nbsp;to be high, the difference between the groups was not statistically&nbsp;significant. The chi-square computed value was found to b e&nbsp;c2 = 0.417, df = 1 and p = 0.519. This means that there was no&nbsp;significance difference between the retention rate of self-etch&nbsp;sealant compared to conventional acid-etch technique. Hence,&nbsp;this study conclude that self-etch primer (3M ESPE Adper) is&nbsp;effective in bonding sealant to enamel and that the simplified&nbsp;method dramatically shortens treatment time and treatment&nbsp;complexity

Self-reported Barriers to Regular Dental Care in Chennai, Tamil Nadu

Aim: The aim of this study was to assess the self-reported&nbsp;barriers to regular dental care in Chennai city, Tamil Nadu.&nbsp;Materials and methods: The cross-sectional study was doneon 352 people, aged 18 to 60 years in Chennai, Tamil Nadu.&nbsp;The study included 154 males and 196 females. The samples&nbsp;were selected by stratified random sampling and a 10 itemquestionnaire was given. Level of significance was set at&nbsp;&lt;0.005, with 5% alpha error and 95% confidence interval.&nbsp;Results: Factor analysis revealed the factors of barriers whichwere daily brushing, practical reasons, unpleasant experiences,&nbsp;laziness and lack of appreciation. Sex showed significant&nbsp;correlation with reasons preventing daily brushing. The moreeducated the patients were the fewer barriers they had related&nbsp;to unpleasant experiences and factors of appreciation and&nbsp;laziness. The older people had more barriers relating practical&nbsp;reasons.&nbsp;Conclusion: The most significance reasons found were lack of&nbsp;knowledge, lack of interest, long distance to a particular dentist,&nbsp;restraint work

Nanomaterials for the diagnosis and treatment of head and neck cancers: A review

Head and neck cancer (HNC) is a category of cancers that typically arise from the nose-, mouth-, and throat-lining squamous cells. The later stage of HNC diagnosis significantly affects the patient’s survival rate. This makes it mandatory to diagnose this cancer with a suitable biomarker and imaging techniques at the earlier stages of growth. There are limitations to traditional technologies for early detection of HNC. Furthermore, the use of nanocarriers for delivering chemo-, radio-, and phototherapeutic drugs represents a promising approach for improving the outcome of HNC treatments. Several studies with nanostructures focus on the development of a targeted and sustained release of anticancer molecules with reduced side effects. Besides, nanovehicles could allow co-delivering of anticancer drugs for synergistic activity to counteract chemo-or radioresistance. Additionally, a new generation of smart nanomaterials with stimuli-responsive properties have been developed to distinguish between unique tumor conditions and healthy tissue. In this light, the present article reviews the mechanisms used by different nanostructures (metallic and metal oxide nanoparticles, polymeric nanoparticles, quantum dots, liposomes, nanomicelles, etc.) to improve cancer diagnosis and treatment, provides an up-to-date picture of the state of the art in this field, and highlights the major challenges for future improvements

A reduced order model for fission gas diffusion in columnar grains

In fast reactors, restructuring of the fuel micro-structure driven by high temperature and high temperature gradient can cause the formation of columnar grains. The non-spheroidal shape and the non-uniform temperature field in such columnar grains implies that standard models for fission gas diffusion can not be applied. To tackle this issue, we present a reduced order model for the fission gas diffusion process which is applicable in different geometries and with non-uniform temperature fields, maintaining a computational requirement in line with its application in fuel performance codes. This innovative application of reduced order models as meso-scale tools within fuel performance codes represents a first-of-a-kind achievement that can be extended beyond fission gas behaviour.</p

A reduced order model for fission gas diffusion in columnar grains

In fast reactors, restructuring of the fuel micro-structure driven by high temperature and high temperature gradient can cause the formation of columnar grains. The non-spheroidal shape and the non-uniform temperature field in such columnar grains implies that standard models for fission gas diffusion can not be applied. To tackle this issue, we present a reduced order model for the fission gas diffusion process which is applicable in different geometries and with non-uniform temperature fields, maintaining a computational requirement in line with its application in fuel performance codes. This innovative application of reduced order models as meso-scale tools within fuel performance codes represents a first-of-a-kind achievement that can be extended beyond fission gas behaviour.</p

Environmental Impact Assessment studies in the Regional Park of Sassi di Roccamalatina (Northern Apennines, Italy).

The present paper describes the state of the art of the Environmental Impact Assessment studies carried out in the Regional Park of Sassi di Roccamalatina (Northern Appennines, Italy) within the framework of a Europena Union funded project concerning the role of geomorphology in the EIA studies (Human Capital and Mobility Project). After some indications on protected areas in Italy, the environmental aspects of the Park are described; the the geomorphological survey analysed. Furthermore a possible appplicatiuon of an EIA procedure based on the above mentioned survey is presentes. Finally a few notes on the digitalisation of topographic data and the realisation of a Digital Terrain Model (DTM) are given