A novel hybrid testing approach for piping systems of industrial plants

Oreste S. Bursi,Giuseppe Abbiati,Md S. Reza 국제구조공학회 2014 Smart Structures and Systems, An International Jou Vol.14 No.6

The need for assessing dynamic response of typical industrial piping systems subjected to seismic loading motivated the authors to apply model reduction techniques to experimental dynamic substructuring. Initially, a better insight into the dynamic response of the emulated system was provided by means of the principal component analysis. The clear understanding of reduction basis requirements paved the way for the implementation of a number of model reduction techniques aimed at extending the applicability range of the hybrid testing technique beyond its traditional scope. Therefore, several hybrid simulations were performed on a typical full-scale industrial piping system endowed with a number of critical components, like elbows, Tee joints and bolted flange joints, ranging from operational to collapse limit states. Then, the favourable performance of the L-Stable Real-Time compatible time integrator and an effective delay compensation method were also checked throughout the testing campaign. Finally, several aspects of the piping performance were commented and conclusions drawn.

A novel hybrid testing approach for piping systems of industrial plants

Bursi, Oreste S.,Abbiati, Giuseppe,Reza, Md S. Techno-Press 2014 Smart Structures and Systems, An International Jou Vol.14 No.6

The need for assessing dynamic response of typical industrial piping systems subjected to seismic loading motivated the authors to apply model reduction techniques to experimental dynamic substructuring. Initially, a better insight into the dynamic response of the emulated system was provided by means of the principal component analysis. The clear understanding of reduction basis requirements paved the way for the implementation of a number of model reduction techniques aimed at extending the applicability range of the hybrid testing technique beyond its traditional scope. Therefore, several hybrid simulations were performed on a typical full-scale industrial piping system endowed with a number of critical components, like elbows, Tee joints and bolted flange joints, ranging from operational to collapse limit states. Then, the favourable performance of the L-Stable Real-Time compatible time integrator and an effective delay compensation method were also checked throughout the testing campaign. Finally, several aspects of the piping performance were commented and conclusions drawn.

Performance evaluation of smart prefabricated concrete elements

Daniele Zonta,Matteo Pozzi,Oreste S. Bursi 국제구조공학회 2007 Smart Structures and Systems, An International Jou Vol.3 No.4

This paper deals with the development of an innovative distributed construction system based on smart prefabricated concrete elements for the real-time condition assessment of civil infrastructure. So far, two reduced-scale prototypes have been produced, each consisting of a 0.2?.3?.6 m RC beam specifically designed for permanent instrumentation with 8 long-gauge Fiber Optic Sensors (FOS) at the lower edge. The sensing system is Fiber Bragg Grating (FBG)-based and can measure finite displacements both static and dynamic with a sample frequency of 625 Hz per channel. The performance of the system underwent validation in the laboratory. The scope of the experiment was to correlate changes in the dynamic response of the beams with different damage scenarios, using a direct modal strain approach. Each specimen was dynamically characterized in the undamaged state and in various damage conditions, simulating different cracking levels and recurrent deterioration scenarios, including cover spalling and corrosion of the reinforcement. The location and the extent of damage are evaluated by calculating damage indices which take account of changes in frequency and in strain-mode-shapes. The outcomes of the experiment demonstrate how the damage distribution detected by the system is fully compatible with the damage extent appraised by inspection.

Stress and strain state in the segmental linings during mechanized tunnelling

Do, Ngoc-Anh,Oreste, Pierpaolo,Dias, Daniel,Antonello, Croce,Djeran-Maigre, Irini,Livio, Locatelli Techno-Press 2014 Geomechanics & engineering Vol.7 No.1

The application of the mechanized tunnelling has been extended in recent years. There are at present different approaches that are used in the design of segmental tunnel linings supported in mechanized tunnels. Even though segmental lining is utilized for mechanized tunnels, its behaviour is still quite unclear under in situ stress and there is a lack of data regarding the distribution of stresses inside segmental linings. So far no single effective calculation method exists for segmental lining design. The lack of clear solutions makes the use of segmental lining to be more expensive due to the adoption of greater safety factors. Therefore, a particular attention must be given in order to obtain data from monitored tunnels which permits to validate design methods. In this study, strain measurements, which were conducted during the construction of twin tunnels in the Bologna-Florence railway line, have been presented. The behaviour of segmental lining during the excavation and the influence of a new tunnel excavation on an existing tunnel have been shown through the measured data. The data are then compared with the results obtained with Einstein and Schwartz's method and Duddeck and Erdmann's method, which permits to highlight the fact that the two analytical methods underestimate structural forces induced in the segmental lining and then must be used with caution.

Transanal Tube Drainage as a Conservative Treatment for Anastomotic Leakage Following a Rectal Resection

Mostafa Shalaby,Waleed Thabet,Oreste Buonomo,Nicola Di Lorenzo,Mosaad Morshed,Giuseppe Petrella,Mohamed Farid,Pierpaolo Sileri 대한대장항문학회 2018 Annals of Coloproctolgy Vol.34 No.6

Purpose: We evaluate the role of transanal tube drainage (TD) as a conservative treatment for patients with anastomotic leakage (AL). Methods: Patients treated for AL who had undergone a low or an ultralow anterior resection with colorectal or coloanal anastomosis for the treatment of rectal cancer between January 2013 and January 2017 were enrolled in this study. The data were collected prospectively and analyzed retrospectively. The primary outcomes were the diagnosis and the management of AL. Results: Two hundred thirteen consecutive patients, 122 males and 91 females, were included. The mean age was 66.91 ± 11.15 years, and the median body mass index was 24 kg/m2 (range, 20–35 kg/m2). The median tumor distance from the anal verge was 8 cm (range, 4–12 cm). Ninety-three patients (44%) received neoadjuvant therapy for nodal disease and/or locally advanced rectal cancer. Only 13 patients (6%) developed AL. Six patients developed subclinical AL as they had a defunctioning ileostomy at the time of the initial procedure. They were treated conservatively with TD under endoscopic guidance in the endoscopy unit and received intravenous antibiotics. Six weeks after discharge, these 6 patients underwent follow-up flexible sigmoidoscopy which showed a completely healed anastomotic defect with no residual stenosis. Seven patients developed a clinically significant AL and required reoperation with pelvic abscess drainage and Hartmann colostomy formation. Conclusion: These results suggest that TD for management of patients with AL is safe, cheap, and effective. Salvaging the anastomosis will help decrease the need for Hartmann colostomy formation. Proper patient selection is important.

터널 막장보강효과에 대한 연구

Daniele Peila,김상환,Pier Paolo Oreste,Sebastiano Pelizza 사단법인 한국터널지하공간학회 2004 한국터널지하공간학회논문집 Vol.6 No.3

The practice of introducing and grouting reinforced fiber glass pipes or bar into the core to be excavated to maintain stable the tunnel face during excavation has been applied to many tunnels, where difficult geotechnical conditions are present, with good results in terms of safety and speed of works. This reinforcing technique, initially developed to be used jointly with the mechanical precut in clay, has been widely used with other geotechnical conditions as the only type of reinforcement or joined with other ground consolidation and/or reinforcement techniques (i.e. steel pipes or jet-grouting umbrella). At present same numerical researches have been carried out to find which are the real working conditions of the reinforcing elements but no final results have been obtained for the definition of the best design approaches. In this work the results of a three dimensional parametric numerical model is presented.

Performance evaluation of smart prefabricated concrete elements

Zonta, Daniele,Pozzi, Matteo,Bursi, Oreste S. Techno-Press 2007 Smart Structures and Systems, An International Jou Vol.3 No.4

This paper deals with the development of an innovative distributed construction system based on smart prefabricated concrete elements for the real-time condition assessment of civil infrastructure. So far, two reduced-scale prototypes have been produced, each consisting of a $0.2{\times}0.3{\times}5.6$ m RC beam specifically designed for permanent instrumentation with 8 long-gauge Fiber Optic Sensors (FOS) at the lower edge. The sensing system is Fiber Bragg Grating (FBG)-based and can measure finite displacements both static and dynamic with a sample frequency of 625 Hz per channel. The performance of the system underwent validation in the laboratory. The scope of the experiment was to correlate changes in the dynamic response of the beams with different damage scenarios, using a direct modal strain approach. Each specimen was dynamically characterized in the undamaged state and in various damage conditions, simulating different cracking levels and recurrent deterioration scenarios, including cover spalling and corrosion of the reinforcement. The location and the extent of damage are evaluated by calculating damage indices which take account of changes in frequency and in strain-mode-shapes. The outcomes of the experiment demonstrate how the damage distribution detected by the system is fully compatible with the damage extent appraised by inspection.

Imaging Findings of 18F-Choline and 18F-DOPA PET/MRI in a Case of Glioblastoma Multiforme Pseudoprogression: Correlation with Clinical Outcome

Filippi Luca,Angela Spanu,Bagni Oreste,Orazio Schillaci,Barbara Palumbo 대한핵의학회 2022 핵의학 분자영상 Vol.56 No.5

We describe the case of 74-year-old-male, previously treated with fronto-parietal craniotomy due to primary glioblastoma multiforme (GBM), followed by concurrent radiation therapy (RT) and temozolomide (TMZ) chemotherapy. Magnetic resonance imaging (MRI) of the brain, at 1 month after completing RT + TMZ, depicted partial response. Three months later, the patient was submitted to a further brain MRI, that resulted doubtful for therapy induced changes (i.e., pseudoprogression). The patient, who had been previously treated with prostatectomy for prostate cancer (PC), underwent a positron emission tomography/computed tomography (PET/CT) scan with 18F-choline for PC biochemical recurrence. 18F-choline whole body PET/CT resulted negative for PC relapse, while segmental brain PET, co-registered with MRI, demonstrated increased tracer uptake corresponding to tumor boundaries. In order to solve differential diagnosis between pseudoprogression and GBM recurrence, brain PET/CT with 18F-L-dihydroxy-phenil-alanine (18F-DOPA) was subsequently performed: fused axial PET/MRI images showed increased 18F-DOPA incorporation in the peri-tumoral edema, but not in tumor boundaries, consistent with the suspicion of GBM pseudoprogression, as then confirmed by clinical and radiological follow-up.

Numerical investigation of segmental tunnel linings-comparison between the hyperstatic reaction method and a 3D numerical model

Do, Ngoc Anh,Dias, Daniel,Oreste, Pierpaolo Techno-Press 2018 Geomechanics & engineering Vol.14 No.3

This paper has the aim of estimating the applicability of a numerical approach to the Hyperstatic Reaction Method (HRM) for the analysis of segmental tunnel linings. For this purpose, a simplified three-dimensional (3D) numerical model, using the $FLAC^{3D}$ finite difference software, has been developed, which allows analysing in a rigorous way the effect of the lining segmentation on the overall behaviour of the lining. Comparisons between the results obtained with the HRM and those determined by means of the simplified 3D numerical model show that the proposed HRM method can be used to investigate the behaviour of a segmental tunnel lining.

2D numerical investigations of twin tunnel interaction

Do, Ngoc Anh,Dias, Daniel,Oreste, Pierpaolo,Djeran-Maigre, Irini Techno-Press 2014 Geomechanics & engineering Vol.6 No.3

The development of transportation in large cities requires the construction of twin tunnels located at shallow depth. As far as twin tunnels excavated in parallel are concerned, most of the cases reported in literature focused on considering the effect of the ground condition, tunnel size, depth, surface loads, the relative position between two tunnels, and construction process on the structural lining forces. However, the effect of the segment joints was not taken into account. Numerical investigation performed in this study using the $FLAC^{3D}$ finite difference element program made it possible to include considerable influences of the segment joints and tunnel distance on the structural lining forces induced in twin tunnels. The structural lining forces induced in the first tunnel through various phases are considerably affected by the second tunnel construction process. Their values induced in a segmental lining are always lower than those obtained in a continuous lining. However, the influence of joint distribution in the second tunnel on the structural forces induced in the first tunnel is insignificant. The critical influence distance between two tunnels is about two tunnel diameters.