Predicting axial velocity profiles within a diffusing marine propeller jet

A full understanding of the hydrodynamic processes within the jet produced by a manoeuvring ship���s propeller is essential in the development and maintenance of ports, docks and harbours. In this study the predominant axial velocity component of a diffusing propeller jet was studied. The flow fields formed by four propellers, each operating at four power levels (speeds of rotation), were investigated under bollard pull conditions within a large free surface tank using Laser Doppler Anemometry. Comparison were made to existing methodologies by which a prediction of the magnitudes of the axial velocity can be made, and where deficient modifications to the methodologies have been developed. The jets were found to produce a maximum axial velocity along the initial efflux plane at a location near the blade mid-span. The position and magnitude of the axial velocity was seen to decrease as the jet entrained more flow and transitioned from the zone of flow establishment into the zone of established flow.

Report of mission on ports and harbours development and planning in East Caribbean countries, 1 November 1970 to 31 January 1971

Includes bibliography

Investigation of a ship's propeller jet using momentum decay and energy decay

Previous researchers use the velocity decay as an input to investigate the ship���s propeller jet induced scour. A researcher indicated that most of the equations used to predict the stability of various protection systems are often missing a physical background. The momentum decay and energy decay are currently proposed as an initial input for seabed scouring investigation, which are more sensible in physics. Computational fluid dynamics (CFD) and laser Doppler anemometry (LDA) experiments are used to obtain the velocity data and then transforming into momentum and energy decays. The findings proposed several exponential equations of velocity, momentum and energy decays to estimate the region exposed to the seabed scouring.

3D Efflux Velocity Characteristics of Marine Propeller Jets

The determination of the efflux velocity is key to the process of calculating the subsequent value of velocity at any other location within a propeller jet. This paper reports on the findings of an experimental investigation into the magnitude of the efflux velocities within the jets produced by four differing propellers. Measurements of velocity have been made using a 3D LDA system with the test propellers operating at a range of rotational speeds which bound typical operational values. Comparisons are made with existing predictive theories and to aid design engineers, methods are presented by which the 3D efflux velocity components, as well as the resultant efflux value, can be determined.

Kallikrein 14 is down-regulated by androgen receptor signalling and harbours genetic variation that is associated with prostate tumour aggressiveness

Kallikrein 14 (KLK14) has been proposed as a useful prognostic marker in prostate cancer, with expression reported to be associated with tumour characteristics such as higher stage and Gleason score. KLK14 tumour expression has also shown the potential to predict prostate cancer patients at risk of disease recurrence after radical prostatectomy. The KLKs are a remarkably hormone-responsive family of genes, although detailed studies of androgen regulation of KLK14 in prostate cancer have not been undertaken to date. Using in vitro studies, we have demonstrated that unlike many other prostatic KLK genes that are strictly androgen responsive, KLK14 is more broadly expressed and inversely androgen regulated in prostate cancer cells. Given these results and evidence that KLK14 may play a role in prostate cancer prognosis, we also investigated whether common genetic variants in the KLK14 locus are associated with risk and/or aggressiveness of prostate cancer in approximately 1200 prostate cancer cases and 1300 male controls. Of 41 single nucleotide polymorphisms assessed, three were associated with higher Gleason score (���7): rs17728459 and rs4802765, both located upstream of KLK14, and rs35287116, which encodes a p.Gln33Arg substitution in the KLK14 signal peptide region. Our findings provide further support for KLK14 as a marker of prognosis in prostate cancer.

Generation of long, laminar plasma jets at atmospheric pressure and effects of flow turbulence

Long, laminar plasma jets at atmospheric pressure of pure argon and a mixture of argon and nitrogen with jet length up to 45 fi,Hes its diameter could be generated with a DC are torch by! restricting the movement of arc root in the torch channel. Effects of torch structure, gas feeding, and characteristics of power supply on the length of plasma jets were experimentally examined. Plasma jets of considerable length and excellent stability could be obtained by regulating the generating parameters, including are channel geometry gas flow I ate, and feeding methods, etc. Influence of flow turbulence at the torch,nozzle exit on the temperature distribution of plasma jets was numerically simulated. The analysis indicated that laminar flow plasma with very low initial turbulent kinetic energy will produce a long jet, with low axial temperature gradient. This kind of long laminar plasma jet could greatly improve the controllability for materials processing, compared with a short turbulent are let.

Episode of Low Level Jets in the north and northeast coast of state of Para: a case study of 2002 april 21st to 22nd

Neste estudo descreve-se as caracter��sticas da estrutura vertical de um epis��dio de Jatos de Baixos N��veis (JBN) ocorrido no litoral do Par��, utilizando-se para tal, dados das radiossondagens de Ajuruteua, Munic��pio de Bragan��a coletados durante o experimento DESMATA (Impacto do Desmatamento Junto ao Litoral Atl��ntico da Amaz��nia) realizado no per��odo de 08 a 22 de abril de 2002. Dentre os casos detectados no per��odo chuvoso, selecionou-se um que se manteve por 12 horas com velocidade m��dia de 15m/s e que estava direcionado de Nordeste para Leste, no ponto de m��xima velocidade. Os resultados observacionais indicaram que, este JBN localizado no litoral Paraense foi resultado da a����o combinada de dois fatores: (1) oscila����o inercial e (2) baroclinia superficial. Estes dois fatores combinados sustentaram este JBN com intensidades entre 10 e 13m/s durante o dia e entre 14 e 16m/s durante a noite, localizado a uma altitude m��dia de 800m acima da superf��cie.

Search for supersymmetry in final states with jets, missing transverse energy and one charged lepton with the ATLAS-experiment

Im Jahr 2011 wurde am Large Hadron Collider mit dem ATLAS Experiment ein Datensatz von 4.7 inversen Femtobarn bei einer Schwerpunktsenergie von 7 TeV aufgezeichnet. Teil des umfangreichen Physikprogrammes des ATLAS Experiments ist die Suche nach Physik jenseits des Standardmodells. Supersymmetrie - eine neue Symmetrie zwischen Bosonen und Fermionen - wird als aussichtsreichester Kandidat f��r neue Physik angesehen, und zahlreiche direkte und indirekte Suchen nach Supersymmetrie wurden in den letzten Jahrzehnten bereits durchgef��hrt. In der folgenden Arbeit wird eine direkte Suche nach Supersymmetrie in Endzust��nden mit Jets, fehlender Transversalenergie und genau einem Elektron oder Myon durchgef��hrt. Der analysierte Datensatz von 4.7 inversen Femtobarn umfasst die gesamte Datenmenge, welche am ATLAS Experiment bei einer Schwerpunktsenergie von 7 TeV aufgezeichnet wurde. Die Ergebnisse der Analyse werden mit verschiedenen anderen leptonischen Suchkan��len kombiniert, um die Sensitivit��t auf diversen supersymmetrischen Produktions- und Zerfallsmodi zu maximieren. Die gemessenen Daten sind kompatibel mit der Standardmodellerwartung, und neue Ausschlussgrenzen in verschiedenen supersymmetrischen Modellen werden berechnet.

Multiple gradient echo propeller (MGREP) MRI: Technical development and potential applications

The PROPELLER (Periodically Rotated Overlapping Parallel Lines with Enhanced Reconstruction) magnetic resonance imaging (MRI) technique has inherent advantages over other fast imaging methods, including robust motion correction, reduced image distortion, and resistance to off-resonance effects. These features make PROPELLER highly desirable for T2*-sensitive imaging, high-resolution diffusion imaging, and many other applications. However, PROPELLER has been predominantly implemented as a fast spin-echo (FSE) technique, which is insensitive to T2* contrast, and requires time-inefficient signal averaging to achieve adequate signal-to-noise ratio (SNR) for many applications. These issues presently constrain the potential clinical utility of FSE-based PROPELLER. ^ In this research, our aim was to extend and enhance the potential applications of PROPELLER MRI by developing a novel multiple gradient echo PROPELLER (MGREP) technique that can overcome the aforementioned limitations. The MGREP pulse sequence was designed to acquire multiple gradient-echo images simultaneously, without any increase in total scan time or RF energy deposition relative to FSE-based PROPELLER. A new parameter was also introduced for direct user-control over gradient echo spacing, to allow variable sensitivity to T2* contrast. In parallel to pulse sequence development, an improved algorithm for motion correction was also developed and evaluated against the established method through extensive simulations. The potential advantages of MGREP over FSE-based PROPELLER were illustrated via three specific applications: (1) quantitative T2* measurement, (2) time-efficient signal averaging, and (3) high-resolution diffusion imaging. Relative to the FSE-PROPELLER method, the MGREP sequence was found to yield quantitative T2* values, increase SNR by ���40% without any increase in acquisition time or RF energy deposition, and noticeably improve image quality in high-resolution diffusion maps. In addition, the new motion algorithm was found to improve the performance considerably in motion-artifact reduction. ^ Overall, this work demonstrated a number of enhancements and extensions to existing PROPELLER techniques. The new technical capabilities of PROPELLER imaging, developed in this thesis research, are expected to serve as the foundation for further expanding the scope of PROPELLER applications. ^