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Rockfall seismic features analysis based on in situ tests:frequency, amplitude, and duration

Journal of Mountain Science 2019年第5期16卷 955-973页

作者： Liang FENG veronica pazzi Emanuele INTRIERI Teresa GRACCHI Giovanni GIGLI Department of Earth Sciences University of Florence

In the seismic event classification,determining the seismic features of rockfall is significantly important for the automatic classification of seismic events because of the huge amount of raw data recorded by seismic stations in continuous monitoring. At the same time, the rockfall seismic features are still not completely *** study concentrates on the rockfall frequency content, amplitude(ground velocity), seismic waveform and duration analysis, of an artificial rockfall test at Torgiovannetto(a former quarry in Central Italy). A total of 90 blocks were released in the test, and their seismic signals and moving trajectories were recorded by four tri-axial seismic stations and four cameras, respectively. In the analysis processing,all the artificial rockfall signal traces were cut separately and the seismic features were extracted individually and automatically. In this study, the relationships between a) frequency content and impacted materials, b) frequency content and the distance between block releasing position and seismic station(source-receiver distance) were discussed. As a result, we found that the frequency content of rockfall focuses on 10-60 Hz and 80-90 Hz within a source-receiver distance of 200 m, and it is well correlated with impacted material and source-receiver distance. To evaluate the difference between earthquake and rockfall, 23 clear earthquake signals recorded in a seven month-long continuous seismic monitoring, carried out with the four seismic stations, were picked out, according to the Italian national earthquakes database(INGV). On these traces we performed the same analysis as in the artificial rockfall traces, and two parameters were defined to separate rockfall events from earthquake noise. The first one, the amplitude ratio, is related to the amplitude variation of rockfall between two stations and is greater than that of earthquakes, because of the higher attenuation occurring for rockfall events, which consists in high

关键词： Rockfall Seismic noise analysis Fourier transform Seismic events classification Time-series analysis Seismic monitoring

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Debris flow hazard assessment by means of numerical simulations:implications for the Rotolon creek valley(Northern Italy)

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Journal of Mountain Science 2017年第4期14卷 636-648页

作者： SALVATICI Teresa MORELLI Stefano pazzi veronica FRODELLA William FANTI Riccardo Department of Earth Sciences University of FlorenceVia La Pira 450121Firenze(Italy)

On 4th November 2OLO, a debris flow detached from a large debris cover accumulated above the lowermost portion of the Rotolon landslide （Vicentine Pre-AIps, NE Italy） and channelized in the valley below within the Rotolon Creek riverbed. Such event evolved into a highly mobile and sudden debris flow, damaging some hydraulic works and putting at high risk four villages located along the creek banks. A monitoring campaign was carried out by means of a ground based radar interferometer （GB-InSAR） to evaluate any residual displacement risk in the affected area and in the undisturbed neighbouring materials. Moreover, starting from the current slope condition, a landslide runout numerical modelling was performed by means of DAN-3D code to assess the impacted areas, flow velocity, and deposit distribution of the simulated events. The rheological parameters necessary for an accurate modelling were obtained through the back analysis of the 2010 debris flow event. Back analysis was calibrated with all of the available terrain data coming from field surveys and ancillary documents, such as topographic, geomorphological and geological maps, with pre- and post-event LiDAR derived DTMs, and with orthophotos. Finally, to identify new possible future debris flow source areas as input data for the new modelling, all the obtained terrain data were reanalysed and integrated with the GB-InSAR displacement maps; consequently, new simulations were made to forecast future events. The results show that the integration of the selected modelling technique with ancillary data and radar displacement maps can be a very useful tool for managing problems related to debris flow events in the examined area.

关键词： Debris flow DAN-3D GB-InSAR Numerical modelling Deep Seated Gravitational Slope Deformation (DSGSD) Rotolon Creek

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Rockfall localization from seismic polarization considering multiple triaxial geophones and frequency bands

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Journal of Mountain Science 2020年第7期17卷 1541-1552页

作者： Liang FENG veronica pazzi Emanuele INTRIERI Teresa GRACCHI Giovanni GIGLI Grazia TUCCI Department of Earth Sciences University of FlorenceVia G.La Pira 450121FlorenceItaly Department of Civil and Environment Engineering University of FlorenceVia Santa Marta 350139FlorenceItaly

Boulder/rock mass movements generate ground vibrations that can be recorded by geophone ***,there are two methods applied to rockfall trajectory reconstruction or rockfall seismic *** method uses seismic wave arrival times and is achieved by minimizing the differences in signal arrival times between multiple stations by grid map *** other method uses seismic polarization and is achieved by calculating eventsource back azimuths from the seismic polarizations of rockfall *** this study,we proposed the use of an overdetermined matrix for joint localization based on the polarization *** overdetermined matrix considers the contributions of all geophones in the network,and at each geophone is assigned a different weight according to the recorded signal qualities and the reliability of the calibrated back *** method shows a great advantage relative to the case in which only two sensors are ***,we suggested three marker parameters for proper frequency band selection in back azimuth calculations:energy,rectilinearity,and a special permanent frequency band(SPF).We found that the back azimuths calculated with energy and an SPF are generally close to the real back azimuths measured in the field,while the SPF is limited by seismic attenuation due to a long-distance *** localization results of rockfalls were validated by using field camera videos and in situ *** typical cases and 43 artificially released rockfalls are presented in this *** proposed method provides an interesting way to locate rockfall events and track rockfall trajectories and avoids the difficulties of obtaining accurate arrival times,as required by the arrival times method.

关键词： Rockfall Localization Seismic polarization Seismic monitoring Early warning

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Could Ambient Vibrations Be Related to <i>Cerithidea decollate</i>Migration?

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International Journal of Geosciences 2017年第3期8卷 286-295页

作者： Alessia Lotti Anna Marta Lazzeri Saumu Beja veronica pazzi Department of Earth Sciences University of Firenze Firenze Italy Department of Biology University of Florence Sesto Fiorentino Italy Kenyan Marine and Fisheries Research Institute (KMFRI) Mombasa Kenya

Physiological and behavioral systems exist to reduce the stress that the intertidal fauna may face during the unsuitable tidal phase. Cerithidea decollata is a common western Indian Ocean mangrove gastropod. It feeds on the ground at low tide, and climbs the trees two-three hours before the water arrival to avoid submersion. Moreover, it regularly settles on the trunk roughly 40 centimeters above the level that the water will reach, in spite of the irregular East African tidal pattern. Migration usually takes place about twice a day unless at Neap Tide, when snails may remain on the dry ground. Biological clock cannot account for water level foreseeing while direct visual cues or chemical information from the water itself or from previous migrations have already been experimentally discarded. Indirect cues could be hypothesize related to the effect of the oceanic wave reaching the coast and the barrier reef (seismic noise), or alternatively related to changes in ground resistivity (self potential) caused by the sea water moving close. To verify these hypotheses a seismic noise and self potential survey was carried out at Mida Creek (Kenya). This paper presents the first results of the seismic noise measurements. A significant correlation between the time evolution (mean value) of the low frequency seismic signal, tides, and snails movements has been identified.

关键词： Ambient Noise Vibration Microseismic Monitoring Tidal Zeitgeber Ocean Tide Intertidal Migration

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Incidence of gallstone disease in Italy:Results from a multicenter,population-based Italian study (the MICOL project)

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World Journal of Gastroenterology 2008年第34期14卷 5282-5289页

作者： Davide Festi Ada Dormi Simona Capodicasa Tommaso Staniscia Adolfo F Attili Paola Loria Paolo pazzi Giuseppe Mazzella Claudia Sama Enrico Roda Antonio Colecchia Department of Internal Medicine and Gastroenterology University of Bologna Department of Clinical Medicine and Biotech-nology University of Bologna Department of Medicine and Aging University of Chieti Department of Gastroenterology University "La Sapienza" Department of Internal Medicine University of Modena Department of Internal Medicine S. Anna Hospital

AIM:To evaluate gallstone incidence and risk factors in a large population-based study. METHODS: Gallstone incidence and risk factors, were evaluated by structured questionnaire and physical examination, respectively, in 9611 of 11 109 (86.5%) subjects who were gallstone-free at the cross-sectional study. RESULTS: Six centers throughout Italy enrolled 9611 subjects (5477 males, 4134 females, aged 30-79 years), 9517 of whom were included into analysis: 424 subjects (4.4%) had gallstones and 61 (0.6%) had been cholecystectomized yielding a cumulative incidence of 0.67% per year (0.66% in males, 0.81% in females). Increasing age, a high body mass index (BMI), a history of diabetes, peptic ulcer and angina, and low cholesterol and high triglyceride levels were identifi ed as risk factors in men while, in females, the only risk factors were increasing age and a high *** age and pain in the right hypocondrium in men and increasing age in females were identifi ed as predictors of gallstones. Pain in the epigastrium/ right hypocondrium was the only symptom related to gallstones; furthermore, some characteristics of pain (forcing to rest, not relieved by bowel movements) were significantly associated with gallstones. No correlation was found between gallstone characteristics and clinical manifestations, while increasing age in men and increasing age and BMI in females were predictors of pain. CONCLUSION:Increasing age and BMI represent true risk factors for gallstone disease (GD); pain in the right hypocondrium and/or epigastrium is confi rmed as the only symptom related to gallstones.

关键词： Gallstone disease Ultrasonography Epidemiology Prevalence Incidence Abdominal pain Cholecystectomy Body mass index

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住院患者抑酸剂使用不足及其对全科医生的暗示

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世界核心医学期刊文摘（胃肠病学分册） 2006年第6期2卷 3-3页

作者： Scagliarini R. Magnani E. PraticòA. P. pazzi 纪泛扑 Department of Internal Medicine M. Bufalini Hospital Corso Ghirotti 286 47023 Cesena (FC) Italy Dr.

Acid-suppressive therapy (AST) is largely prescribed in both hospital and general practice setting but few data are available on appropriateness of AST use in hospitalized patients and its fallout on prescribing in general practice. We assessed AST in patients consecutively admitted to an internal medicine department to determine the type and timing of prescription and indication for use according to widely accepted guidelines. Prescriptions were rated as indicated, acceptable, or not indicated. Overall, 58.7%of 834 admitted patients received AST, mainly proton pump inhibitors. The prescriptions were indicated in 50.1%of patients, not indicated in 41.5%, and acceptable in 6.5%. The main reason for inappropriate use was prophylaxis in low-risk patients (64.8%). On admission, 35.7%of 112 patients already on AST were judged to receive inappropriate prescription; of 348 patients discharged on AST, overuse was identified in 38.5%. No significant difference was observed for inappropriate use at admission, during hospitalization, and at discharge. In 64 inpatients (7.7%) AST, although indicated, mainly for ulcer prophylaxis in high-risk patients, was not prescribed. In conclusion, AST is substantially overused in both hospital and general practice settings, mainly for ulcer prophylaxis in low-risk patients. On the other hand, AST is underused in a small, but not negligible proportion of high-risk patients.

关键词：住院患者全科医生抑酸剂社区医疗机构治疗处方治疗指征质子泵抑制剂显著性差异

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