Investigating the Feasibility and Stability for Modeling Acoustic Wave Scattering Using a Time-Domain Boundary Integral Equation with Impedance Boundary Condition

Reducing aircraft noise is a major objective in the field of computational aeroacoustics. When designing next generation quiet and environmentally friendly aircraft, it is important to be able to accurately and efficiently predict the acoustic scattering by an aircraft body from a given noise source. Acoustic liners are an effective tool for aircraft noise reduction and are characterized by a frequency-dependent impedance. Converted into the time-domain using Fourier transforms, an impedance boundary condition can be used to simulate the acoustic wave scattering by geometric bodies treated with acoustic liners This work considers using either an impedance or an admittance (inverse of impedance) boundary condition to allow for acoustic scattering problems to be modeled with geometries consisting of both unlined and lined surfaces. Three acoustic liner models are discussed: the Extended Helmholtz Resonator Model, the Three-Parameter Impedance Model, and the Broadband Impedance Model. In both the Helmholtz and Three-Parameter models, liner impedance is specified at a given frequency, whereas the Broadband model allows for the investigation of multiple frequencies simultaneously. The impedance and admittance boundary conditions for acoustic liners are derived for each model and coupled with a time-domain boundary integral equation. The scattering solution is obtained iteratively using a boundary element method with constant spatial and third-order temporal basis functions. Time-domain boundary integral equations are unfortunately prone to numerical instabilities due to resonant frequencies resulting from non-trivial solutions in the interior domain. When reformulated with the Burton-Miller method, the instabilities are eliminated. Using a Burton-Miller reformulation, the stability of the boundary element method assuming a liner boundary condition is assessed using eigenvalue analysis. The stability of each liner model is discussed, and it is shown that the Three-Parameter and Broadband models are sufficient for modeling an acoustic liner on the surface of scattering bodies. The Helmholtz model demonstrates strict limitations for stability, whereas the Three-Parameter and Broadband models are stable for most cases. Also included in this work is an assessment of the spatial accuracy of the time-domain boundary element method with respect to the surface element basis functions, as well as a performance study of the numerical algorithm

Facility Implementation, Production, and Use of Biodiesel on a University Campus

During the last two years, Embry-Riddle Aeronautical University has been in the process of having a fully-functional biodiesel processing facility on campus. Within this time, it was shown that biodiesel was a great alternative to diesel fuel based on emissions, performance, and cost, allowing for a grant of $10,000 being awarded to fund the project. Upon properly producing biodiesel, the fuel was tested in a John Deere 2653A tractor to see what differences, if any, existed when using a biodiesel blend over diesel fuel. In doing this, carbon buildup and fuel economy were compared, and a cost analysis conducted. It was concluded that biodiesel can be safely produced on a university campus and can be utilized within diesel engines, while cutting back on costs

Results, questions, perspectives of a study on human polyomavirus BK and molecular actors in prostate cancer development

Background: Prostate cancer (PC) is a common tumor in Western countries. Several risk factors play significant roles. MYC, BIRC5/survivin, CDC25 and P53 may contribute to PC risk. As demonstrated, human Polyomavirus BK (BKV) could affect cellular homeostasis contributing to PC pathogenesis. Materials and Methods: Biological samples were collected from PC patients. Viral RNA was searched using quantitative polymerase chain reaction (PCR), whereas a qualitative PCR was employed to find particular viral sequences. Proper size amplicons were analyzed. Single nucleotide polymorphisms (SNPs) were detected in p53 coding regions by means of a specific PCR. C-MYC, BIRC5/survivin and CDC25 gene expression was investigated using a Retro Transcriptional Quantitative PCR. Results: Viral DNA copy number was higher in cancer tissues taken from Gleason score 9 patients with Gleason score 7. Different p53 mutated compared to patients exons were found according to tumor advanced stage and a statistical significant correlation was found between Gleason score and p53 mutational rate. C-MYC, BIRC5/survivin and CDC25 expression was de-regulated according to the literature. Conclusion: The presence of BKV and its variants in transformed cells does not exclude viral pressure in cell immortalization. Expression of other target genes evidenced a significant change in their regulation, useful for cancer drug discovery and therapies

High frequency of JCV DNA detection in prostate cancer tissues

BACKGROUND: Prostate cancer (PC) represents the most frequently diagnosed cancer in men. Exposure to infectious agents has been considered to induce prostatic inflammation and cancerous transformation. Controversial data exist concerning the role of the human polyomaviruses BK (BKV) and JC (JCV) in PC etiology. Therefore, a possible association between these polyomaviruses and PC was investigated. MATERIALS AND METHODS: Urine, blood and fresh prostatic tissue specimens were collected from 26 patients with PC. The presence of BKV and JCV, the possible non-coding control region (NCCR) variations and the genotyping analysis of viral protein 1 (VP1) of both viruses were assessed. RESULTS: Data showed a preferential viral re-activation in the urinary compartment and a statistically significant prevalence of JC viruria and of BKV in PC tissues. A BKV DDP-like NCCR sequence was isolated in two patients, whereas JCV NCCR was consistently of an archetypal structural organization. A prevalence of the European genotypes was observed for both viruses. CONCLUSION: Our data demonstrated the presence of JCV DNA in 14/24 (58.3%) cancerous prostatic tissue specimens, confirming the results obtained in a previous study, in which JCV has been defined as common inhabitant of the prostate, and opening the discussion about its potential role in PC

EFFICIENT PROPAGATION OF ARCHETYPE JC POLYOMAVIRUS IN COS-7 CELLS: EVALUATION OF REARRANGEMENTS WITHIN NCCR STRUCTURAL ORGANIZATION DURING TRANSFECTION.

John Cunningham virus (JCPyV) is an ubiqui-tous human pathogen that causes disease in immunocom-promised patients. The JCPyV genome is composed of an early region and a late region, which are physically sepa-rated by the non-coding control region (NCCR). The DNA sequence of the NCCR distinguishes two forms of JCPyV, the designated archetype and the prototype, which resulted from a rearrangement of the archetype sequence. To date, the cell culture systems for propagating JCPyV archetype have been very limited in their availability and robust-ness. Prior to this study, it was demonstrated that JCPyV archetype DNA replicates in COS-7 simian kidney cells expressing SV40 TAg and COS-7 cells expressing HIV-1 Tat. Based on these observations, the present study was conducted to reproduce an in vitro model in COS-7 cells transfected with the JCPyV archetype strain in order to study JCPyV DNA replication and analyze NCCR rear-rangements during the viral life cycle. The efficiency of JCPyV replication was evaluated by quantitative PCR (Q-PCR) and by hemagglutination (HA) assay after trans-fection. In parallel, sequence analysis of JCPyV NCCR was performed. JCPyV efficiently replicated in kidney-derived COS-7 cells, as demonstrated by a progressive increase in viral load and virion particle production after transfection. The archetypal structure of NCCR was maintained during the viral cycle, but two characteristic point mutations were detected 28 days after transfection. This model is a useful tool for analyzing NCCR rearrangements during in vitroreplication in cells that are sites of viral persistence, such as tubular epithelial cells of the kidne

Comportamento organizacional no serviço público : desenvolvimento de um programa de avaliação de desempenho periódico na Prefeitura Municipal de Paranaguá

Orientador : Elic VodovozTrabalho de conclusão de curso (especialização) - Universidade Federal do Paraná, Setor de Ciências Sociais Aplicadas, Curso de Especialização em Gestão PúblicaInclui referênciasResumo : O presente trabalho demonstra os aspectos sobre comportamento organizacional, descrevendo as perspectivas de alguns dos principais autores da abordagem comportamental, bem como destacar as características que envolvem a avaliação de desempenho, com ênfase na Administração Pública. Sendo fundamental apresentar as situação atual da Prefeitura Municipal de Paranaguá com relação à ausência de uma avaliação efetiva, ao término do estágio probatório, que contemple todas as classes de servidores. Dessa forma, tornou-se imprescindível após o diagnóstico situacional da instituição, a estruturação de uma proposta de avaliação de desempenho que considere a avaliação tanto por parte do gestor imediato quanto uma autoavalição por parte do próprio servidor, através do método de escalas gráficas, que se caracteriza como um método simples e de fácil compreensão, que permita melhorias e busque atender os princípios da eficiência por parte da gestão..

Appalti, digitalizzazione, economia: spunti alla luce del nuovo codice dei contratti pubblici

Despite being of fundamental importance, Italy has historically had a low level of digitalization compared to other European countries. The adoption of the Digital Administration Code was intended to kickstart the digital revolution in the public sector but was hindered by limited investments in innovation. The slow and partial digitalization of Public Administrations has caused Italy to lag behind other European countries. However, due to the COVID-19 pandemic and the recent approval of the National Recovery and Resilience Plan (PNRR), there has been a renewed focus on digitalization and the strengthening of digital infrastructure and investments have been redirected towards digital transformation, aiming to achieve an evolved and digitized administration. The PNRR allocates a substantial amount of its funding to digital transition, and this has led to an increase in public procurement procedures and their economic value. The new Public Procurement Code reflects the shift towards digitalization, with provisions for digital procedures and interoperability of data among public administrations. The new Code emphasizes principles such as technological neutrality, transparency, personal data protection, and cybersecurity in digital procurement. One notable principle is the "once only" principle, which aims to streamline public procurement procedures by ensuring that data is provided only once to a single information system. The National Database of Public Contracts, maintained by the National Anti-Corruption Authority (ANAC), plays a crucial role in achieving interoperability and quality of data. The Code also enables the use of data from the Database for monitoring the effective utilization of resources and procedural progress in public investment procedures and the use of artificial intelligence to automate procedures. However, the current state of the digital procurement ecosystem and its potential as a digital breakthrough remain uncertain