27 research outputs found

    Beam Longitudinal Dynamics Simulation Suite BLonD

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    The beam longitudinal dynamics code BLonD has been developed at CERN since 2014 and has become a central tool for longitudinal beam dynamics simulations. In this paper, we present this modular simulation suite and the various physics models that can be included and combined by the user. We detail the reference frame, the equations of motion, the BLonD-specific options for radio-frequency parameters such as phase noise, fixed-field acceleration, and feedback models for the CERN accelerators, as well as the modeling of collective effects and synchrotron radiation. We also present various methods of generating multi-bunch distributions matched to a given impedance model. BLonD is furthermore a well-tested and optimized simulation suite, which is demonstrated through examples, too

    Manual versus rigid intraoperative maxillo-mandibular fixation in the surgical management of mandibular fractures:A European prospective analysis

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    Purpose: Intraoperative stabilisation of bony fragments with maxillo-mandibular fixation (MMF) is an essential step in the surgical treatment of mandibular fractures that are treated with open reduction and internal fixation (ORIF). The MMF can be performed with or without wire-based methods, rigid or manual MMF, respectively. The aim of this study was to compare the use of manual versus rigid MMF, in terms of occlusal outcomes and infective complications. Materials and methods: This multi-centric prospective study involved 12 European maxillofacial centres and included adult patients (age ≥16 years) with mandibular fractures treated with ORIF. The following data were collected: age, gender, pre-trauma dental status (dentate or partially dentate), cause of injury, fracture site, associated facial fractures, surgical approach, modality of intraoperative MMF (manual or rigid), outcome (minor/major malocclusions and infective complications) and revision surgeries. The main outcome was malocclusion at 6 weeks after surgery. Results: Between May 1, 2021 and April 30, 2022, 319 patients-257 males and 62 females (median age, 28 years)-with mandibular fractures (185 single, 116 double and 18 triple fractures) were hospitalised and treated with ORIF. Intraoperative MMF was performed manually on 112 (35%) patients and with rigid MMF on 207 (65%) patients. The study variables did not differ significantly between the two groups, except for age. Minor occlusion disturbances were observed in 4 (3.6%) patients in the manual MMF group and in 10 (4.8%) patients in the rigid MMF group (p &gt; .05). In the rigid MMF group, only one case of major malocclusion required a revision surgery. Infective complications involved 3.6% and 5.8% of patients in the manual and rigid MMF group, respectively (p &gt; .05). Conclusion: Intraoperative MMF was performed manually in nearly one third of the patients, with wide variability among the centres and no difference observed in terms of number, site and displacement of fractures. No significant difference was found in terms of postoperative malocclusion among patients treated with manual or rigid MMF. This suggests that both techniques were equally effective in providing intraoperative MMF.</p

    Epidemiology of maxillofacial trauma in the elderly: a European multicenter study

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    ABSTRACT Introduction: The progressive aging of European population seems to determine a change in the epidemiology, incidence and etiology of maxillofacial fractures with an increase in the frequency of old patients sustaining craniofacial trauma. The objective of the present study was to assess the demographic variables, causes, and patterns of facial fractures in elderly population (with 70 years or more). Materials and Methods: The data from all geriatric patients (70 years or more) with facial fractures between January 1, 2013, and December 31, 2017, were collected. The following data were recorded for each patient: gender, age, voluptuary habits, comorbidities, etiology, site of facial fractures, synchronous body injuries, Facial Injury Severity Score (FISS). Results: A total of 1334 patients (599 male and 735 female patients) were included in the study. Mean age was 79.3 years, and 66% of patients reported one or more comorbidities. The most frequent cause of injury was fall and zygomatic fractures were the most frequently observed injuries. Falls were associated with a low FISS value (p<.005). Concomitant injuries were observed in 27.3% of patients. Falls were associated with the absence of concomitant injuries. The ninth decade (p <.05) and a high FISS score (p <.005) were associated with concomitant body injuries too. Conclusions: This study confirms the role of falls in the epidemiology of facial trauma in the elderly, but also highlights the frequency of involvement of females, and the high frequency of zygomatic fractures.Peer reviewe

    Modelling Control Loops for SPS-LHC Beam Transfer Studies

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    For HL-LHC æraen kan overføring av partikkelstråler fra SPS føre til tap av partikler og begrensninger i elektrisk effekt i radiofrekvens systemene til LHC. Presise numeriske modeller av kontrollsystemene i både SPS og LHC i simulatoren BLonD er essensielle for å gi estimater for både tap av partikler og begrensinger i elektrisk effekt. Denne masteroppgaven presenterer modeller av både SPS og LHC «cavity controllers», viser hvordan disse ble validert og sammenliknet med målinger. Disse kontrollsystemene regulerer spenningen i de akselererende strukturene i akseleratorene, både i amplitude og i fase under forhold med høy effekt grunnet partikkelstrålen. Ved bruk av SPS «cavity controller» modellen kan man skape realistiske høyintensitets stråler, som vil bli viktig for fremtidige studier av stråleoverføring mellom SPS og LHC. Det ble funnet at SPS modellen er i god enighet med eksperimentell data av partikkelstråler. Videre ble det vist at LHC «cavity loop» modellen kunne gjenskape målte overføringsfunksjoner til tilfredsstillende nøyaktighet
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