Some observations about the components of transonic fan noise from narrow-band spectral analysis

Qualitative and quantitative spectral analyses are presented that give the broadband-noise, discrete-tone, and multiple-tone properties of the noise generated by a full-scale high-bypass single-stage axial-flow transonic fan (fan B, NASA Quiet Engine Program). The noise components were obtained from narrow-band spectra in conjunction with 1/3-octave-band spectra. Variations in the pressure levels of the noise components with fan speed, forward-quadrant azimuth angle, and frequency are presented and compared. The study shows that much of the apparent broadband noise on 1/3-octave-band plots consists of a complex system of shaft-order tones. The analyses also indicate the difficulties in determining or defining noise components, especially the broadband level under the discrete tones. The sources which may be associated with the noise components are discussed

Modal structure inferred from static far-field noise directivity

Turbofan noise directivity calculated for two directivity models was compared with experimental, blade passing frequency data from two fans at 60 and 90 percent speeds. Experimental data indicated similar directivity patterns which were well represented by a single average data curve. Calculated points using the equal amplitude model showed over-prediction near the fan axis and near the 90 degree position. Calculated points using the equal power model showed a very good match with the average data lending support to theory of equipartition of modal power from a random source such as the interaction of the rotor with inlet flow distortion. The equal modal power model also gave good agreement with individual data points

Far-field radiation of aft turbofan noise

Approximate expressions were developed for the noise radiation from the aft duct. The results of approximate aft radiation equation compare favorably to more exact Wiener-Hopf radiation results. Refraction as well as convective effects in the multiple flow streams is considered. The peak in the radiation pattern, which occurs nearly at engine sideline, is composed of modes with relatively large cut-off ratios. This implies that aft fan radiation will be inherently more difficult to suppress that the fan inlet noise. The theoretical multimodal radiation pattern is compared to experimental data for the first two harmonics of blade passage frequency for three full scale fans at two speeds. The agreement between theory and experiment is quite good

Analysis of radiation patterns of interaction tones generated by inlet rods in the JT15D engine

Interaction tones were intentionally generated by circumferential arrays of equally spaced rods that protrude radially from the inlet wall near the face of the 28-blade fan. Arrays of 28 and 41 rods, selected to give specific far field radiation properties, were tested. The expected properties were readily apparent in the measured radiation patterns. A more detailed analysis of the test data showed both the precision and limitations of the applied acoustic theory. Rods protruding 23 percent of the radius predominantly generated only lowest radial order modes, as expected. Measured and predicted radiation patterns were generally in good agreement. The agreement, however, depended on a significant degree of implied refraction due to inlet velocity gradients. Refraction, if present, would impact static-flight noise comparisons

SYMULACJA ZAGROŻEŃ BEZPIECZEŃSTWA INFORMACJI W ZAKRESIE DOSTĘPNOŚCI DOKUMENTÓW PROJEKTOWYCH W OPARCIU O LOGIKĘ ROZMYTĄ

The widespread use of computer technology, its rapid development and use in almost all areas of human activity requires constant updating of information security issues. The activities of many enterprises in the field of IT, construction, and other areas are of a project nature and therefore further research on information security management of projects is relevant. Appearance of changes and the current state of the project results at certain points of time describe the documents that accompany it. In this paper, the information structure of the project is considered as a set of specific documents. During the life cycle of each project document, which includes the creation, transfer, preservation and transformation, there are generally threats to its confidentiality, integrity, accessibility and authenticity. This paper develops a method for assessing the risks of violation of the availability of project documents in solving information security problems. A formal description of many project documents in the form of a generalized hierarchical structure is presented, the connection of documents with the operations performed on them and information systems used during these operations is formalized. Given the incompleteness and dimension of the data, the based on fuzzy logic model was developed to assess the risk of document accessibility. Approaches to the assessment of the damage from the violation of the availability of the project document and the method of calculating the overall assessment of the risk of violation of the documents availability are proposed. The results presented in this paper can be used in decision-making processes regarding information security of projects in organizations that have project activities. The approaches proposed in this paper can serve as a basis for the creation of specialized information technologies to automate the calculation of project risk assessments.Powszechne stosowanie techniki komputerowej, jej szybki rozwój i wykorzystanie niemal we wszystkich dziedzinach działalności człowieka wymaga ciągłej aktualizacji zagadnień związanych z bezpieczeństwem informacji. Działalność wielu przedsiębiorstw w zakresie informatyki, budownictwa i innych dziedzin ma charakter projektowy, dlatego istotne są dalsze badania nad zarządzaniem bezpieczeństwem informacji w projektach. Pojawienie się zmian i aktualny stan wyników projektu w określonych momentach czasu opisują towarzyszące mu dokumenty. W niniejszej pracy struktura informacyjna projektu jest rozpatrywana jako zbiór określonych dokumentów. W cyklu życia każdego dokumentu projektu, który obejmuje tworzenie, przekazywanie, przechowywanie i przekształcanie, występują na ogół zagrożenia dla jego poufności, integralności, dostępności i autentyczności. W pracy opracowano metodę oceny ryzyka naruszenia dostępności dokumentów projektowych w rozwiązywaniu problemów bezpieczeństwa informacji. Przedstawiono formalny opis wielu dokumentów projektowych w postaci uogólnionej struktury hierarchicznej, sformalizowano związek dokumentów z wykonywanymi na nich operacjami oraz systemami informatycznymi wykorzystywanymi podczas tych operacji. Biorąc pod uwagę niekompletność i wymiar danych, opracowano oparty na logice rozmytej model oceny ryzyka dostępności dokumentów. Zaproponowano podejście do oceny szkody z tytułu naruszenia dostępności dokumentu projektu oraz metodę obliczania ogólnej oceny ryzyka naruszenia dostępności dokumentów. Wyniki przedstawione w pracy mogą być wykorzystane w procesach decyzyjnych dotyczących bezpieczeństwa informacyjnego projektów w organizacjach prowadzących działalność projektową. Zaproponowane w pracy podejścia mogą stanowić podstawę do tworzenia specjalistycznych technologii informatycznych automatyzujących obliczanie oceny ryzyka projektu

The Microhardness as an Express Method for Estimation the Depth of Metal Particle Distribution

By measurement of microhardness of silver layer on polyimide films and its reduction after removing the stress, the depth of silver distribution in the polyimide films was calculated. A significant hardening of Kapton 100 HN films was observed especially for cobalt-impregnated materials, which was about 10 µm. The distribution of silver in the film layers was obviously deeper that manifested as entirely lower hardening at microhardness measurement. Because of the initial microhardness of Upilex it was observed strong hardening of the effort, which was led to shallow distribution of metals in the films. For example, Cometallized films showed 5 µm distribution in the top film layers. Such method could allow precisely and rapidly estimating the distribution of metal particles impregnated in metallized polymeric materials

Clinical behavior and outcomes of breast cancer in young women with germline BRCA pathogenic variants

Young breast cancer (BC) patients carrying a germline BRCA pathogenic variant (mBRCA) have similar outcomes as non-carriers. However, the impact of the type of gene (BRCA1 vs. BRCA2) and hormone receptor status (positive [HR+] vs. negative [HR 12]) on clinical behavior and outcomes of mBRCA BC remains largely unknown. This is an international, multicenter, hospital-based, retrospective cohort study that included mBRCA patients diagnosed, between January 2000 and December 2012, with stage I\u2013III invasive early BC at age 6440 years. From 30 centers worldwide, 1236 young mBRCA BC patients were included. Among 808 and 428 patients with mBRCA1 or mBRCA2, 191 (23.6%) and 356 (83.2%) had HR+tumors, respectively (P < 0.001). Median follow-up was 7.9 years. Second primary BC (P = 0.009) and non-BC malignancies (P = 0.02) were more frequent among mBRCA1 patients while distant recurrences were less frequent (P = 0.02). Irrespective of hormone receptor status, mBRCA1 patients had worse disease-free survival (DFS; adjusted HR = 0.76, 95% CI = 0.60\u20130.96), with no difference in distant recurrence-free interval (DRFI) and overall survival (OS). Patients with HR+ disease had more frequent distant recurrences (P < 0.001) and less frequent second primary malignancies (BC: P = 0.005; non-BC: P = 0.18). No differences in DFS and OS were observed according to hormone receptor status, with a tendency for worse DRFI (adjusted HR = 1.39, 95% CI = 0.94\u20132.05) in patients with HR+ BC. Type of mBRCA gene and hormone receptor status strongly impact BC clinical behavior and outcomes in mBRCA young patients. These results provide important information for patients\u2019 counseling on treatment, prevention, and surveillance strategies

The Pyrimidine Nucleotide Biosynthetic Pathway Modulates Production of Biofilm Determinants in Escherichia coli

Bacteria are often found in multicellular communities known as biofilms, which constitute a resistance form against environmental stresses. Extracellular adhesion and cell aggregation factors, responsible for bacterial biofilm formation and maintenance, are tightly regulated in response to physiological and environmental cues. We show that, in Escherichia coli, inactivation of genes belonging to the de novo uridine monophosphate (UMP) biosynthetic pathway impairs production of curli fibers and cellulose, important components of the bacterial biofilm matrix, by inhibiting transcription of the csgDEFG operon, thus preventing production of the biofilm master regulator CsgD protein. Supplementing growth media with exogenous uracil, which can be converted to UMP through the pyrimidine nucleotide salvage pathway, restores csgDEFG transcription and curli production. In addition, however, exogenous uracil triggers cellulose production, particularly in strains defective in either carB or pyrB genes, which encode enzymes catalyzing the first steps of de novo UMP biosynthesis. Our results indicate the existence of tight and complex links between pyrimidine metabolism and curli/cellulose production: transcription of the csgDEFG operon responds to pyrimidine nucleotide availability, while cellulose production is triggered by exogenous uracil in the absence of active de novo UMP biosynthesis. We speculate that perturbations in the UMP biosynthetic pathways allow the bacterial cell to sense signals such as starvation, nucleic acids degradation, and availability of exogenous pyrimidines, and to adapt the production of the extracellular matrix to the changing environmental conditions

Proportions of CD4+ memory T cells are altered in individuals chronically infected with Schistosoma haematobium

Characterisation of protective helminth acquired immunity in humans or experimental models has focused on effector responses with little work conducted on memory responses. Here we show for the first time, that human helminth infection is associated with altered proportions of the CD4+ memory T cells, with an associated alteration of TH1 responses. The reduced CD4+ memory T cell proportions are associated with a significantly lower ratio of schistosome-specific IgE/IgG4 (marker for resistance to infection/re-infection) in uninfected older people. Helminth infection does not affect the CD8+ memory T cell pool. Furthermore, we show for the first time in a helminth infection that the CD4+ memory T cell proportions decline following curative anti-helminthic treatment despite increased CD4+ memory cell replication. Reduced accumulation of the CD4+ memory T cells in schistosome-infected people has implications for the development of natural or vaccine induced schistosome-specific protective immunity as well as for unrelated pathogens