Investigations on the downwash behind a tapered wing with fuselage and propeller

The new downwash measurements behind a tapered wing with parallel center section described in the present report can be brought into good agreement with theoretical calculations if made on the basis of not-rolled-up vortex sheet and allowance is made for the lowering of the sheet. The test values are about 1 degree higher than the "upper limit" established for it, as against approximately 0.5 degrees in the earlier tests behind a rectangular and elliptical wing. The measurements on lateral axes, especially if lying below the wing on a level with the vortex train, disclosed in accord with the lift distribution, a marked change in angle over the span of the tail in contrast to the rectangular and elliptical wing

The Aerodynamic Aspect of Wing-fuselage Fillets

Model tests prove the feasibility of enhancing the aerodynamic qualities of wing-fuselage fillets by appropriate design of fuselage and wing roots. Abrupt changes from maximum fuselage height to wing chord must be avoided and every longitudinal section of fuselage and wing roots must be so faired and arranged as to preserve the original lift distribution of the continuous wing. Adapting the fuselage to the curvilinear circulation of the wing affords further improvement. The polars of such arrangements are almost the same as those of the "wing alone," thus voiding the superiority of the high-wing type airplane known with conventional design

The interdependence of profile drag and lift with Joukowski type and related airfoils

On the basis of a systematic investigation of Gottingen wind-tunnel data on Joukowski type and related airfoils, it is shown in what manner the profile drag coefficient is dependent on the lift coefficient. The individual factors for the construction of the profile drag polars are given. They afford a more accurate calculation of the performance coefficients of airplane designs than otherwise attainable with the conventional assumption of constant drag coefficient

Razine tropenol estera u mokraći radnika na sintezi tiotropijeva bromida – implikacije za sprječavanje izloženosti i biomonitoring

Tropenol ester is a highly toxic anticholinergic substance and an intermediate used in industrial production of the bronchodilator tiotropium bromide. The aim of this study was to systematically test workers involved in its production for tropenol ester in urine to identify any exposure pathways and define additional preventive measures. Twelve workers performing tasks involving potential exposure to tropenol ester were repeatedly monitored at the end of each production cycle. Medical exams revealed no symptoms of acute poisoning with tropenol ester, but biological monitoring of urine showed 36 positive findings in 79 samples, with tropenol ester concentrations ranging between the detection limit of 54 pg/mL and 2160 pg/mL. We managed to establish the cause of only one positive finding, which was a hole in a protective glove, whereas the rest most likely occurred due to human error. Because of this, the plant decided to modify the production process by replacing tropenol ester with a safer intermediate. While it is the safest course of action, there where it cannot be taken, biological monitoring can be very helpful in raising awareness about exposure to toxic substances, including the new ones that have not been studied for their adverse potential.Tropenol ester je iznimno toksičan antikolinergik, koji se rabi za sintezu bronhodilatatora tiotropijeva bromida. Cilj je ovog ispitivanja bio sustavno testirati radnike koji njime barataju u proizvodnji na tropenol ester u mokraći ne bi li se ustanovili putevi izloženosti i poboljšale preventivne mjere. Ispitivanje je obuhvatilo 12 radnika kroz 12 proizvodnih ciklusa, a uzorkovanje se provodilo na kraju svakog ciklusa. Liječničkim se pregledom nisu otkrili nikakvi simptomi akutnog otrovanja tropenol esterom, ali se biomonitoringom otkrilo 36 pozitivnih uzoraka od njih 79. Razine tropenol estera u pozitivnim uzorcima kretale su se od granice detekcije (54 pg/mL) do 2160 pg/mL. Međutim, samo smo za jedan pozitivan nalaz uspjeli utvrditi uzrok. Radilo se o rupi u zaštitnoj rukavici. Za ostale pozitivne uzorke pretpostavljamo da upućuju na ljudsku pogrešku prilikom skidanja ili čišćenja opreme. Zbog nemogućnosti da utvrdimo uzroke izloženosti, tvornica je promijenila proizvodni proces i tropenol ester zamijenila sigurnijim međuproizvodom. Iako je to najsigurniji način za sprječavanje izloženosti opasnim tvarima u proizvodnji, tamo gdje to nije moguće, biomonitoring može biti itekako koristan za podizanje svijesti o izloženosti, osobito kod novih tvari čije štetno djelovanje za zdravlje još nije istraženo

Wave motion at and inside a rubble mound breakwater - large scale experiments and theoretical considerations

Das Hauptziel dieser Arbeit ist eine umfassende Beschreibung der Wellenbewegung und Ausbreitung an und in einem geschütteten Wellenbrecher auf der Grundlage großmaßstäblicher Modellversuche im Großen Wellenkanal, Hannover und einfacher theoretischer Modelle. Der Wellenbrecher wurde in fünf Bereiche unterteilt. In jedem Bereich wurden die Wasserspiegelauslenkungen und ggf. die Porenwasserdruckoszillationen untersucht. Deren Beschreibung setzt sich zusammen aus einem linearen theoretischen Modell und einem empirischen Ansatz für die nichtlinearen Einflüsse. Darüber hinaus wurden die Unsicherheiten dieser halbempirischen Ansätze und deren Übertragbarkeit bestimmt. Es wurden lineare theoretische Modelle zur Beschreibung (a) der Wellenbewegung über rauhen teildurchlässigen Böschungen, (b) der Wellenausbreitung in homogenen, porösen Medien und (c) der gesamten Energiedissipation am und im Bauwerk entwickelt. Die wichtigsten hydraulischen Prozesse, die in den 5 Bereichen des Wellenbrechers untersucht wurden: 1. Vorstrand: lokale Wellenhöhen im Nahfeld (Shoaling und Wellenreflexion) 2. auf der Böschung: Wellenbewegung über der Bauwerksböschung (Wellenauflauf, Wasserspiegelverlauf und Druckverteilung) 3. unter der Böschung: Wechselwirkung zwischen externen und internen Strömungen (Wellenauflauf auf den Böschungsschichten, Wasserspiegelgradienten und internes Wellenbrechen, Druckverteilung und maximale Druckgradienten, Lufteintrag) 4. Kernbereich: Wellenausbreitung im Kern 5. Hafen: Wellentransmission und gesamte EnergiedissiaptionThe main objective of this thesis is a comprehensive description of the wave motion and wave propagation at and inside a rubble mound breakwater which have been investigated in large scale model tests in the Large Wave Flume, Hannover. The cross section of the rubble mound breakwater has been subdivided into 5 sections, the water surface elevations and if possible the pore pressure oscillations have been studied in each section. The description of the hydraulic processes in each section consists of a linear theoretical model and an empirical approach for the nonlinear effects. Furthermore, the uncertainties and the applicability of these semiempirical approaches have been determined. Linear theoretical models have been developed for: (a) the wave motion on a rough permeable slope, (b) the wave propagation inside homogeneous porous media and (c) the total wave energy dissipation at and inside the breakwater. The most important hydraulic processes investigated are listed below for the 5 breakwater sections: 1. foreshore: local wave height in the near field (wave reflection and wave shoaling) 2. on the seaward slope of the breakwater: wave motion on the slope (wave run-up, water surface elevations and pressure distribution) 3. under the seaward slope of the breakwater: interaction between external and internal flow (wave run-up on different breakwater layers, water surface gradients and internal wave breaking, pressure distribution and pressure gradients, air entrainment) 4. breakwater core: wave propagation inside the core 5. harbour: wave transmission and total wave energy dissipatio

Identification of DeltaN isoform and polyadenylation site choice variants in molluscan p63/p73 -like homologues

Author Posting. © The Author(s), 2006. This is the author's version of the work. It is posted here by permission of Springer for personal use, not for redistribution. The definitive version was published in Marine Biotechnology 9 (2007): 217-230, doi:10.1007/s10126-006-6045-1.The p53 family of transcription factors has been implicated in many vertebrate cancers. Altered p53 and p73 protein expression observed in leukemic cells of mollusks suggests that these transcription factors might be involved in invertebrate cancers as well. Here, we fully characterize the mRNA of four novel p53-like variants in the bivalve mollusks Mytilus trossulus (bay mussel) and Mytilus edulis (blue mussel). These species, widely used for environmental assessment, develop a haemic neoplasia (leukemia) that is frequently fatal. The correlation between expression of p53 and its close relative p73 and onset of molluskan leukemia was documented previously. We report the sequences of two distinct and novel p63/p73-like mRNAs, amplified by polymerase chain reaction (PCR) from both species. One of the p63/p73-like isoforms contains a 360 nt truncation in the 5' coding region. Based on this truncation and concomitant lack of a trans-activation (TA) domain, we designate this variant as a DeltaNp63/p73-like isoform: the first to be reported in an invertebrate species. In mammalian species, DeltaNp73 potently inhibits the tumor-suppressive function of p73 and p53, and its over-expression serves as a robust marker for mammalian cancer. In addition, we report on the occurrence of alternate polyadenylation sites in the molluskan p63/p73: one proximal and one distal site, which differ by 1260 nt. We hypothesize that differential expression of various molluskan p63/p73-like isoforms, controlled in part by polyadenylation site choice variation, may help to interpret the apparently opposing roles of this gene in the development of cancer. Overall, this research further illustrates the utility of the molluskan model for studies involving the molecular mechanisms of oncogenesis in naturally occurring populations. The data presented here require a revisiting of hypotheses regarding evolution of the p53 gene family. Current hypotheses indicate that 1) the protostome gene family does not contain an intronic promoter for DeltaN expression and 2) p53 gene duplication did not occur in protostomes. Our characterization of DeltaN p63/73 in mussel suggests that molluskan p53 gene family members have acquired an intronic promoter or splicing mechanism, either by invention that predates the evolutionary split of deuterostoms from protostomes, or by parallel evolution. Our data also show that Mytilus p53, p63/p73 and DeltaNp63/p73 are identical in their core regions with variation limited to their C- and N-terminals. This supports the notion that alternative splicing, intronic promoter usage and polyadenylation site choice may lead to expression of distinct isoforms originating from one common gene.A.F.M. was supported by the Greater Vancouver Regional District, BC, Canada and a Collaborative Research and Development Grant from the Natural Science and Engineering Research Council of Canada (#CRDP J 323120 –05). R.L.C. was supported by Environmental Protection Agency grant # R82935901 and National Institute of Health grant #1R21ES012273-01

Lernen in informellen, internetbasierten Netzwerken: Einflussfaktoren auf den Aufbau von Kompetenzen in Entwicklungsgemeinschaften der Free / Open-Source Bewegung

Die Dissertation untersucht den Aufbau von Kompetenzen in internetbasierten Gemeinschaften. Anhand verschiedener Software-Entwicklungsgemeinschaften der Free/Libre und Open-Source-Bewegung (FLOSS) wird das informelle Lernen der Beteiligten beschrieben. Es wird gezeigt, wie gelernt wird, warum sich Personen beteiligen und was die Beteiligten bei ihrem selbstgesteuerten, ehrenamtlichen Engagement lernen. Grundlage bilden Beitragsanalysen öffentlicher Mailinglisten, die Metadaten der Versionsverwaltung und Interviews mit Entwickler:innen verschiedener FLOSS-Entwicklungsgemeinschaften.The dissertation examines the building of competencies in Internet-based communities. Using different software development communities of the free / open source movement, the informal learning of the participants is described. It is shown how learning takes place, why people participate, and what participants learn during their self-directed, voluntary engagement. It is based on an analysis of contributions to the public mailing list, version control metadata from the FLOSS project, and interviews with developers