Stability of elastically supported columns

A criterion is developed for the stiffness required of elastic lateral supports at the ends of a compression member to provide stability. A method based on this criterion is then developed for checking the stability of a continuous beam-column. A related method is also developed for checking the stability of a member of a pin-jointed truss against rotation in the plane of the truss

Management of anterior skull base defect depending on its size and location.

Introduction: We present our experience in the reconstruction of these leaks depending on their size and location. Material and methods: Fifty-four patients who underwent advanced skull base surgery (large defects, >20 mm) and 62 patients with CSF leaks of different origin (small, 2-10 mm, and midsize, 11-20 mm, defects) were included in the retrospective study. Large defects were reconstructed with a nasoseptal pedicled flap positioned on fat and fascia lata. In small and midsized leaks. Fascia lata in an underlay position was used for its reconstruction covered with mucoperiosteum of either the middle or the inferior turbinate. Results: The most frequent etiology for small and midsized defects was spontaneous (48.4%), followed by trauma (24.2%), iatrogenic (5%). The success rate after the first surgical reconstruction was 91% and 98% in large skull base defects and small/midsized, respectively. Rescue surgery achieved 100%. Conclusions: Endoscopic surgery for any type of skull base defect is the gold standard. The size of the defects does not seem to play a significant role in the success rate. Fascia lata and mucoperiosteum of the turbinate allow a two-layer reconstruction of small and midsized defects. For larger skull base defects, a combination of fat, fascia lata, and nasoseptal pedicled flaps provides a successful reconstruction

Government oriented and commercially oriented business segments of corporations: data and analysis.

This thesis investigates the relationship between Department of Defense oriented corporations and commercially oriented corporations, along with the government and commercially oriented business segments of these same corporations. The data elements of backlog, net sales, operating profits, and identifiable assets are examined, and the methodology for deriving these data elements from the SEC 10K reports in their total and segmented forms is explained. The analyses of variance on the unsegmented data elements determined no difference between corporation groups, however analyses of segmented data elements resulted in significant variations. Segmented data appears to be necessary to explain the variations due to either type of corporation or time period.http://archive.org/details/governmentorient00viscLieutenant, United States NavyApproved for public release; distribution is unlimited

Problema di controllo ottimo per l'economia ambientale con contributo additivo per la biodiversità nella funzione di produzione.

Obiettivo di questa tesi è quello di massimizzare il profitto di un imprenditore agricolo, quando la biodiversità influenza il processo di produzione ed è, a sua volta, influenzata da quest’ultimo. Tale problema viene tradotto in un problema di controllo ottimo ad orizzonte infinito con fattore di attualizzazione, e grazie alle condizioni necessarie del Principio del Massimo di Pontryagin si ottiene un sistema di equazioni differenziali che caratterizza la soluzione ottima del modello. Dal momento che tale sistema di equazioni risulta essere fortemente non lineare e pertanto impossibile da risolvere analiticamente, si caratterizzano le soluzioni qualitativamente tramite uno studio dello spazio delle fasi, ovvero cercando e classificando i punti di equilibrio del sistema. I risultati ottenuti vengono validati mediante lo studio delle condizioni sufficienti date dai Teoremi di Mangasarian e di Arrow. Attraverso delle simulazioni numeriche si è trovato che gli equilibri non sono mai stabili, ma risultano comunque interessanti i punti di sella. Per analizzare, infine, come varia il profitto relativo a tali punti, a seconda dei parametri, sono state condotte delle simulazioni tramite Wolfram Mathematica, andando a fissare i parametri meno significativi e lasciando, invece, variare quelli più rilevanti sia da un punto di vista matematico che economico-ambientale

Storia di Perasto: raccolta di notizie e documenti dalla caduta della Repubblica veneta al ritorno degli austriaci

Università degli Studi di Triest

NACA Technical Notes

A criterion is developed for the stiffness required of elastic lateral supports at the ends of a compression member to provide stability. A method based on this criterion is then developed for checking the stability of a continuous beam-column. A related method is also developed for checking the stability of a member of a pin-jointed truss against rotation in the plane of the truss