A model for triggering mechanisms of shallow landslides

Abstract. Rainfall-induced shallow landslides, also called "soil slips", are becoming ever more frequent all over the world and are receiving a rising interest in consequence of the heavy damage they produce. At the University of Parma, a simplified physically based model has been recently set up for the evaluation of the safety factor of slopes which are potentially at risk of a soil slip. This model, based on the limit equilibrium method applied to an infinite slope, takes into account some simplified hypotheses on the water down-flow and defines a direct correlation between the safety factor of the slope and the rainfall depth. In this paper, this model is explained in detail and is used in a back analysis process to verify its capability to foresee the triggering instant of rainfall-induced shallow landslides for some recent case studies in the Emilia Romagna Apennines (Northern Italy). The results of the analyses and of the model implementation are finally shown

Editorial of special issue “natural and artificial unsaturated soil slopes”

Natural and artificial slopes are frequently constituted, at least in part, by soils in unsaturated conditions [...

An Interesting Secondary Airway Lesion in an Infant With Laryngomalacia

A 2-month-old male with a prior diagnosis of laryngomalacia (LM) presented to the emergency department in respiratory distress with worsening inspiratory stridor, suprasternal retractions, and a dry cough. A chest X-ray and lateral neck radiograph were performed and demonstrated no abnormalities. Flexible laryngoscopy revealed the same, previously observed moderately prolapsed arytenoids and an omega-shaped epiglottis with shortened aryepiglottic (AE) folds. He also had a right lower neck mass. He was scheduled for a direct laryngoscopy and bronchoscopy (DLB) and supraglottoplasty. During the DLB, LM and anterior compression of the midtrachea was noted. Lysis of the AE folds was performed in cold-steel fashion, and the infant was then taken for further imaging

Re-Evaluating the Offshoring Decision: A Behavioural Approach to the Role of Performance Discrepancy

Firms are in a continuous process of critically re-evaluating their offshoring strategies due to performance discrepancies. While prior research has focused on the implementation of organizational responses to performance shortfalls, we examine the offline search process, a key antecedent of organizational change, during which firms simultaneously explore alternative solutions when facing either a positive or a negative discrepancy between performance and aspirations. We adopt the Behavioural Theory of the Firm (BTOF) to investigate how the search process is affected by the size and nature (as being positive or negative) of the discrepancy as well as how it is moderated by cognitive biases. By examining 441 offshoring initiatives, we study firms' search processes in a novel context that refers either to ‘local’ solutions that are close to the current activity (i.e., expansion in the same host country) or ‘distant’ solutions that are far from the current one (i.e., relocation to a third country or to the home country). Our results provide new insights into organizational search, namely that performance shortfalls lead to distant search unless this choice is moderated by a location-specific anchor bias relating to the strategic importance of host location, while positive discrepancies trigger local search with decision-makers more inclined to consider expansion in the current host country

Comparison between different approaches to modeling shallow landslide susceptibility: a case history in Oltrepo Pavese, Northern Italy

Abstract. On the 27 and 28 April 2009, the area of Oltrepo Pavese in northern Italy was affected by a very intense rainfall event that caused a great number of shallow landslides. These instabilities occurred on slopes covered by vineyards or recently formed woodlands and caused damage to many roads and one human loss. Based on aerial photographs taken immediately after the event and field surveys, more than 1600 landslides were detected. After acquiring topographical data, geotechnical properties of the soils and land use, susceptibility analysis on a territorial scale was carried out. In particular, different physically based models were applied to two contiguous sites with the same geological context but different typologies and sizes of shallow landslides. This paper presents the comparison between the ex-post results obtained from the different approaches. On the basis of the observed landslide localizations, the accuracy of the different models was evaluated, and the significant results are highlighted

Simulasi Pompa pada Kolam Retensi untuk Penanganan Banjir pada Drainase Jalan Belimbing Kota Dumai

Drainage system with retention pond and pump is the effective and effisien way for handling flood that happens. This study tries to keep the system for handling the flood at Belimbing Street of Dumai City. This study conducted a simulation retention pond and pump capacity by using water balance method. Retention pond and pump drainage system are designed using 10 year return period flood discharge. The discharge had been calculated by Rational method and IDF curve by Mononobe method. Reservoir pond need to be sized 5600 m3 (70m x 40m x 2m) and using effisien pumping capacity of 0,5 m3 / sec to handle the floodwater at Belimbing Street of Dumai City

Innovative strategy for polyhydroxyalkanoates recovery from mixed microbial cultures. Effects of aqueous phase and solvent extraction on polymer properties

This work aimed to investigate various methods of polyhydroxyalkanoates (PHA) extraction and to optimize the recovery in the view of reducing solvents’ use and waste. The extraction tests were applied on PHA-rich biomass collected at the end of the accumulation step, conducted both at pilot and lab scale. PHA-rich biomass obtained from the lab scale process was produced from synthetic feedstock (mixture of acetic and propionic acids), while fermented organic waste was used for PHA production at pilot scale. In the extraction tests, different solutions of NaOH, also in combination with a surfactant (sodium dodecyl sulfate, SDS), were used to recover the polymer from the non-polymeric cellular material (NPCM). Different times (3, 6 and 24 h) and concentrations (0.05 – 1 M) were tested, evaluating also the effect of adding SDS (0.1 % w/v). As a benchmark, solvent extraction with chloroform and oxidation with NaClO were also conducted. Finally, extracted samples were characterized through several techniques: DSC, TGA, GC-FID, capillary viscosimetry. Alkaline treatment at short times and low concentrations resulted to be more efficient in terms of purity (85 – 99 % w/w PHA) and recovery (higher than 80 % w/w), than higher concentration. On the other hand, the presence of SDS had dramatic effects on the recovery (lower than 50 % w/w) and also on the molecular weight, which was two folds lower than that obtained from alkaline extraction. Overall, extraction with aqueous phase reagents had no effects on thermal properties, which resulted to be in the range of those reported in literature