Computation tool for rotor's life consumption in steam turbines according to industrial specifications

Life consumption evaluation presently represents a high priority topic for Industry and University. In the specific work of this paper, we performed an analysis about the effects of thermal transients on life consumption of steam turbine rotors and an optimization of the thermal transient during runups. This kind of operation, more and more recurrent in power generation, produces a stress in the mechanical elements that could compromise their integrity. The work was developed in its larger part in the MGMV laboratory of the University of Genova, using the equipment (hardware and software) present in this structure, in cooperation with industry. The study moves from a classification of the damage mechanism and from a description of the most important manufacturing technologies of turbine rotors. Then, after a glance at the most important commercial software for estimating life consumption, a classification is given referring to the checks that Ansaldo, the industrial collaborator, performs during its service interventions. Finally, the paper reports the calculation module developed according to the specifications given by the industrial collaborator; the software was developed in Matlab and needs as input the characteristic constants of the rotor and the temperature measurements (with high precision transducers) at the inlet of the HP and IP sections of the turbine. This study confirms that thermal transients are very important to define the rotor\u2019s residual life; the results could help the manufacturer, who designed the machines, and the operators, who run the power plant, to ensure a correct use of the installation, without unexpected failures that could create an economical damage connected with a missed production

Tra visibile e invisibile. Storia, conservazione, diagnostica. Otto dipinti del Museo Canonicale di Verona

Breve premessa di tipo iconografico alle indagini diagnostiche non invasive condotte sulla tavola del Museo Canonicale di Verona

Multi-technique investigation of historical Chinese dyestuffs used in Ningxia carpets

In this article, an extensive work is presented concerning the characterization with both chromatographic (high-performance liquid chromatography) and spectroscopic (surface-enhanced Raman spectroscopy and visible reflectance spectroscopy) techniques of historical Chinese dyestuffs in several carpets, mostly coming from the Ningxia region in Northern China and dating to the seventeenth\u2013nineteenth centuries. Notably, the color of the background of these fine artifacts has been an object of debate since, while being depicted as bright red in the ancient iconography, nowadays it appears as orange/yellow. Therefore, in addition to the identification of all the colorants used in the carpets, the present study investigated the reasons of this apparent inconsistency, pointing out an explanation based on the joined use of the yellow dye obtained from the pagoda tree and a \u201cfugitive\u201d dye obtained from brazilwood

Matemilano : percorsi matematici in citta'

Sono qui raccolte le esperienze virtuali proposte nella mostra "matemilano". Si tratta di una successione di inviti ad affrontare stimolanti questioni di matematica o a "fare esperienza" di matematica in una sorta di percorso guidato in un terreno ricco di fatti matematici esposti secondo un filo conduttore ben delineato

Matemilano : percorsi matematici in citt\ue0

Sono qui raccolte le esperienze virtuali proposte nella mostra "matemilano". Si tratta di una successione di inviti ad affrontare stimolanti questioni di matematica o a "fare esperienza" di matematica in una sorta di percorso guidato in un terreno ricco di fatti matematici esposti secondo un filo conduttore ben delineato

Prognostic factors and outcome of resected patients for gastrointestinal stromal tumors

Background/Aims: The aim of this study was to analyze the outcome of 33 patients with primary gastrointestinal stromal tumors (GISTs) who were observed and treated in a single teaching hospital and followed up prospectively. Methodology: Thirty-three GISTs patients (21 male; 12 female; mean age: 57\ub112 years; range: 23-76 years) between June 1994 and October 2004, were reviewed retrospectively. Patient, tumor, and treatment variables were analyzed to identify patterns of tumor relapse and factors affecting survival. Results: Of 33 patients, 30 patients (91%) had primary tumor without metastasis, and all of them underwent complete surgical resection of gross disease. Three patients (9%) had metastasis. Among patients radically resected, the 5-year actuarial survival rate was 85%, and the disease-free survival was 76%. Among patients resected for cure, there were 6 recurrences. The mean time to recurrence was 22\ub111 months (range: 4-36 months), and liver was the prevalent site for relapsing disease (n=5; 83%). After recurrence, survival at 2 and 3 years was 44% and 0%, respectively. Conclusions: GISTs are uncommon sarcomas. Tumor recurrence tends to be intra-abdominal. Investigational protocols are indicated to reduce the rate of recurrence after resection and to improve the outcome for patients with GIST

Surgery for advanced colorectal cancer in elderly patients with special emphasis for radio-chemotherapy role

BACKGROUND/AIMS: To compare the short- and long-term outcome of older and younger patients with advanced colorectal cancer who underwent elective surgery. METHODOLOGY: Six hundred and ninety-two patients were analyzed. Four hundred and seventy-nine patients were or = 70 years (group 2). RESULTS: The overall peroperative mortality rate in younger patients was 0.8% (n = 7), and 1.4% (n = 3) in the elderly (p = NS); morbidity was 35% and 42%, respectively (p = NS). On univariate analysis, elderly patients had a worse overall survival (OS) compared to younger, when only patients undergoing postoperative chemo-radiotherapy were considered (54% OS vs. 67% OS at 5 years; p = 0.03). Using logistic regression analysis, tumor stage (p < 0.0001) and radicality of surgery (p < 0.0001), were strongly associated with OS rates in the elderly. CONCLUSIONS: Colorectal surgery for malignancy can be performed safely in the elderly. Clinical trials are necessary to understand the real advantage of adjuvant or palliative treatments in these patient