Discharge estimation combining flow routing and occasional measurements of velocity

A new procedure is proposed for estimating river discharge hydrographs during flood events, using only water level data at a single gauged site, as well as 1-D shallow water modelling and occasional maximum surface flow velocity measurements. One-dimensional diffusive hydraulic model is used for routing the recorded stage hydrograph in the channel reach considering zero-diffusion downstream boundary condition. Based on synthetic tests concerning a broad prismatic channel, the “suitable” reach length is chosen in order to minimize the effect of the approximated downstream boundary condition on the estimation of the upstream discharge hydrograph. The Manning’s roughness coefficient is calibrated by using occasional instantaneous surface velocity measurements during the rising limb of flood that are used to estimate instantaneous discharges by adopting, in the flow area, a two-dimensional velocity distribution model. Several historical events recorded in three gauged sites along the upper Tiber River, wherein reliable rating curves are available, have been used for the validation. The outcomes of the analysis can be summarized as follows: (1) the criterion adopted for selecting the “suitable” channel length based on synthetic test studies has proved to be reliable for field applications to three gauged sites. Indeed, for each event a downstream reach length not more than 500m is found to be sufficient, for a good performances of the hydraulic model, thereby enabling the drastic reduction of river cross-sections data; (2) the procedure for Manning’s roughness coefficient calibration allowed for high performance in discharge estimation just considering the observed water levels and occasional measurements of maximum surface flow velocity during the Correspondence to: G. Corato ([email protected]) rising limb of flood. Indeed, errors in the peak discharge magnitude, for the optimal calibration, were found not exceeding 5% for all events observed in the three investigated gauged sections, while the Nash-Sutcliffe efficiency was, on average, greater than 0.95. Therefore, the proposed procedure well lend itself to be applied for: (1) the extrapolation of rating curve over the field of velocity measurements (2) discharge estimations in different cross sections during the same flood event using occasional surface flow velocity measures carried out, for instance, by hand-held radar sensors

The role of peening processes as a pre-treatment to anodizing on fatigue behavior of aircraft aluminum alloy

In this work, the possibility of employing shot peening and laser peening as pre-treatments to a tartaric-sulfuric anodizing process on the fatigue behavior of 7050-T7451 aluminum alloy components was investigated. The surface modifications and stress fields induced by the combination of the peening and anodizing processes were evaluated by scanning electron microscopy and residual stress assessment methodologies based on diffraction techniques, respectively. It was found that the anodizing process alone results in a significant reduction in fatigue life compared to the as-machined condition especially in the high-cycle fatigue (HCF) region of the S-N diagrams due to the presence of defects within the anodic layer that act as stress concentrators facilitating the initiation of fatigue cracks. The application of both shot and laser peening treatments is demonstrated to offset the negative effects induced by anodizing, offering greater safety margins useful for the design of critical aeronautical structures.The possibility to employ peening processes as pre-treatments to anodizing was studied.No significant influence of anodizing on residual surface stresses was observed.SP and LP provide significant benefits in the fatigue behavior of anodized components.Thicker anodic layers result in greater susceptibility to fatigue crack nucleation

Diagnostic approach and epidemiology of Microbial Keratitis: findings from an Italian Tertiary Care center

Rapid identification of causative microorganisms of microbial keratitis (MK) and knowledge of the most common local pathogens are prerequisites for rational antimicrobial therapy. We retrospectively reviewed the characteristics of MK diagnosed at the IRCCS Arcispedale Santa Maria Nuova of Reggio Emilia (Italy) in a 5-years period, where the Ophthalmologist Unit is a reference center for corneal infections. During the study period, 183 MK were evaluated through corneal scrapings cultures. The positivity rate was 54,1%. A total of 107 microorganisms have been isolated: Acanthamoeba species was the etiologic agent in 19 cases. Pseudomonas aeruginosa and Staphylococcus aureus were more frequently isolated in bacterial keratitis, while Fusarium spp., Candida albicans, and Alternaria alternata were predominant among the fungal isolates. Strict cooperation between ophthalmologists and clinical microbiologists is advisable to allow the best diagnostic approach for MK

Systematic Preserflo MicroShunt Intraluminal Stenting for Hypotony Prevention in Highly Myopic Patients: A Comparative Study

Transient hypotony is the most common early complication after Preserflo MicroShunt (PMS) implantation. High myopia is a risk factor for the development of postoperative hypotony-related complications; therefore, it is advisable that PMS implantation in patients should be performed while employing hypotony preventive measures. The aim of this study is to compare the frequency of postoperative hypotony and hypotony-related complications in high-risk myopic patients after PMS implantation with and without intraluminal 10.0 nylon suture stenting. This is a retrospective, case–control, comparative study of 42 eyes with primary open-angle glaucoma (POAG) and severe myopia that underwent PMS implantation. A total of 21 eyes underwent a non-stented PMS implantation (nsPMS), while in the remaining eyes (21 eyes), PMS was implanted with an intraluminal suture (isPMS group). Hypotony occurred in six (28.57%) eyes in the nsPMS group and none in the isPMS group. Choroidal detachment occurred in three eyes in the nsPMS group; two of them were associated with the shallow anterior chamber and one was associated with macular folds. At 6 months after surgery, the mean IOP was 12.1 ± 3.16 mmHg and 13.43 ± 5.22 mmHg (p = 0.41) in the nsPMS and isPMS group, respectively. PMS intraluminal stenting is an effective measure to prevent early postoperative hypotony in POAG highly myopic patients

One step minilaparotomy-assisted transmesenteric portal vein recanalization combined with transjugular intrahepatic portosystemic shunt placement: A novel surgical proposal in pediatrics

Transjugular intrahepatic portosystemic shunt (TIPS) placement is a standard procedure for the treatment of portal hypertension complications. When this conventional approach is not feasible, alternative procedures for systemic diversion of portal blood have been proposed. A one-step interventional approach, combining minilaparotomy-assisted transmesenteric (MAT) antegrade portal recanalization and TIPS, is described in an adolescent with recurrent esophageal varice bleeding and portal cavernoma (PC). A 16-year-old girl was admitted to our Unit because of repeated bleeding episodes over a short period of time due to esophageal varices in the context of a PC. A portal vein recanalization through an ileocolic vein isolation with the MAT approach followed by TIPS during the same session was performed. In the case of failed portal recanalization, this approach, would also be useful for varice endovascular embolization. Postoperative recovery was uneventful. Treatment consisting of propanolol, enoxaparin and a proton pump inhibitor was prescribed after the procedure. One month post-op, contrast enhanced computed tomography confirmed the patency of the portal and intrahepatic stent grafts. No residual peritoneal fluid was detected nor opacification of the large varices. Endoscopy showed good improvement of the varices. Doppler ultrasound confirmed the accelerated flow in the portal stent and hepatopetal flow inside the intrahepatic portal branches. Three months post-op, TIPS maintained its hourglass shape despite a slight expansion. Portal hypertension and life threatening conditions related to PC would benefit from one-step portal recanalization. MAT-TIPS is feasible and safe for the treatment of PC even in children. This minimally invasive procedure avoids or delays surgical treatment or re-transplantation when necessary in pediatric patients

Integrazione di metodologie dirette ed indirette per la stima degli idrogrammi di piena in alvei naturali

Le metodologie attualmente disponibili per la misura di pieno campo delle portate possono essere classificate in base al tipo di sensore utilizzato ed al numero delle stazioni idrometriche. Per ognuna delle possibili tipologie vengono presentate le tecniche di analisi più recenti e delineati possibili sviluppi futuri. Viene quindi introdotta una nuova metodologia, basata sull’integrazione di misure dirette ed indirette. Nell’approccio proposto la portata viene calcolata come valore al contorno di monte di un modello di propagazione 1D a cui vengono assegnati i tiranti di monte quale condizione misurata. Il modello viene calibrato attraverso sporadiche misure istantanee di velocità, consentendo di pervenire ad una registrazione continua delle portate mediante l’ausilio delle sole osservazioni dei tiranti in una sola stazione di misura. L’approccio è validato attraverso serie storiche di tiranti e di portate misurate in una stazione idrometrica del Fiume Tevere

Effect of Cromoglycate on Gas Changes, During Bronchial Challenge by UNCDW in Children with Asthma

Eighteen asthmatic children were challenged with ultrasonically nebulized cold distilled water (UNCDW). Blood gas composition was monitored transcutaneously (tcpO2 and tcpCO2) during and after the challenge. Assuming as basal the response to this UNCDW test, nine children (Group A) were then chosen at random to inhale cromoglycate by aerosol delivery for 8 days. Nine children (Group B), acting as a control, inhaled saline for 8 days. At the end of this therapy, each child repeated the UNCDW test. Statistical analysis with t-test for paired data was used to compare the results of each child to both tests. Mean basal tcpO2 and tcpCO2 were all within the expected normal range. In all children, both mean tcpO2 and tcpCO2 were reduced during and after UNCDW inhalation. Mean tcpCO2 values during the challenge were significantly (p < 0.001) lower than the corresponding steady state 2 rain after the UNCDW challenge, with a mean drop of −7% (2.1 S.D.). Mean tcpO2 values remained significantly decreased (p < 0.001) from the fifth mitt of the UNCDW challenge to the end of the observation period, with a mean drop of −20% (15.5 S.D.). After treatment with cromoglycate (Group A), the mean tcpCO2 values during UNCDW did not change significantly from those ofsteady state conditions: −0.8% (0.5 S.D.); whereas mean tcpO2 values decreased by −4% (4.9 S.D.). The control children treated with saline (Group B) showed mean tcpCO2 and tcpO2 values which were significantly different (p < 0.001) from those of the steady state conditions: mean drop of tcpCO2, −6% (4.2 S.D.); mean drop of tcpO2, −20% (4.7 S.D.). In conclusion, it emerges that: UNCDW induces nonspecific broncho-constriction in asthmatic children with a typical drop of tcpCO2 and tcpO2; the treatment with cromoglycate normalizes the time course of tcpCO2 (hyper-reactivity) and reduces dramatically the drop of tcpO2 time course (hyper-responsivity) during and after the UNCDW test

CHILDHOOD BLEPHAROPTOSIS: A REVIEW OF 113 CASES

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ADJUSTABLE SUTURE STRABISMUS SURGERY: A REVIEW OF 850 CASES

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