9,759 research outputs found

    Seasonal changes in abundance of brown trout (Salmo trutta) and rainbow trout (s. gairdnerii) assessed by drift diving in the Rangitikei river, New Zealand

    Get PDF
    Numbers and approximate sizes of brown trout (Salmo trutta L.) and rainbow trout (5. gairdnerii Richardson) were estimated by snorkel divers at 6 sites in the middle reaches of the Rangitikei River, North Island, New Zealand, over 14 months. The results showed that different species and sizes of trout varied in abundance with time. The species of fingerling trout (6-12 cm FL) could not be identified because of their small size and shoaling behaviour. Rainbow trout abundance varied seasonally and was greatest in January and April (between 18 and 60 fish per kilometre) when fish between 23 and 38 cm FL were the most abundant size class. Brown trout abundance showed much less variation with time (between 5 and 36 fish per kilometre at most sites). Also in contrast to rainbow trout, the majority of brown trout were > 38 cm FL, and in June, when the greatest density was observed (56 fish per kilometre), 70 redds were seen at the same site. Two sites were dived within a 48 h period to test the variability of the method. Comparisons between the 3 dives at each site revealed no significant differences between the numbers offish in different species and size classes

    Quinnat salmon (oncorhynchus tshawytscha) spawning in the Rangitikei river

    Get PDF
    The occurrence of adult quinnat salmon {Oncorhynchus tshawytscha (Walbaum)) in the Rangitikei River, North Island, New Zealand, has been confirmed on several occasions since 1922, but juvenile salmon have not previously been recorded. In late February 1981 a 79-mm-fork-length smolt was caught in a stranded side channel 180 km upstream from the mouth. This suggests that quinnat salmon can spawn successfully in this river

    Numerical Airfoil Optimization Using a Reduced Number of Design Coordinates

    Get PDF
    A method is presented for numerical airfoil optimization whereby a reduced number of design coordinates are used to define the airfoil shape. The approach is to define the airfoil as a linear combination of shapes. These basic shapes may be analytically or numerically defined, allowing the designer to use his insight to propose candidate designs. The design problem becomes one of determining the participation of each such function in defining the optimum airfoil. Examples are presented for two-dimensional airfoil design and are compared with previous results based on a polynomial representation of the airfoil shape. Four existing NACA airfoils are used as basic shapes. Solutions equivalent to previous results are achieved with a factor of more than 3 improvements in efficiency, while superior designs are demonstrated with an efficiency greater than 2 over previous methods. With this shape definition, the optimization process is shown to exploit the simplifying assumptions in the inviscid aerodynamic analysis used here, thus demonstrating the need to use more advanced aerodynamics for airfoil optimization

    Chandra Observation of the Interaction of the Radio Source and Cooling Core in Abell 2063

    Full text link
    We present the results of a Chandra observation of the cooling core cluster Abell 2063. Spectral analysis shows that there is cool gas (2 keV) associated with the cluster core, which is more than a factor of 2 cooler than the outer cluster gas (4.1 keV). There also is spectral evidence for a weak cooling flow, Mdot ~ 20 Msun/yr. The cluster exhibits a complex structure in the center that consists of several bright knots of emission, a depression in the emission to the north of the center of the cluster, and a shell of emission surrounding it. The depression in the X-ray emission is coincident with the position of the north-eastern radio lobe of the radio source associated with the cluster-central galaxy. The shell surrounding this region appears to be hotter, which may be the result of a shock that has been driven into the gas by the radio source. The power output of the radio source appears to be sufficient to offset the cooling flow, and heating of the gas through shocks is a possible explanation of how the energy transfer is established.Comment: Astrophysical Jounal, in press, 26 page with 9 figures, some in color. Uses AASTEX late

    Quantum Layers over Surfaces Ruled Outside a Compact Set

    Full text link
    In this paper, we proved the quantum layer over a surface which is ruled outside a compact set, asymptotically flat but not totally geodesic admits ground states

    An assessment of airfoil design by numerical optimization

    Get PDF
    A practical procedure for optimum design of aerodynamic shapes is demonstrated. The proposed procedure uses an optimization program based on the method of feasible directions coupled with an analysis program that uses a relaxation solution of the inviscid, transonic, small-disturbance equations. Results are presented for low-drag, nonlifting transonic airfoils. Extension of the method to lifting airfoils, other speed regimes, and to three dimensions if feasible

    Role of raltegravir in the management of HIV-1 infection

    Get PDF
    The development of multiple agents with potent antiretroviral activity against HIV has ushered in a new age of optimism in the management of patients infected with the virus. However, the viruses’ dynamic ability to develop resistance against these agents necessitates the investigation of novel targets for viral suppression. Raltegravir represents a first-in-class agent targeting the HIV integrase enzyme, which is responsible for integration of virally encoded DNA into the host genome. Over the last 5 years, clinical trials data has demonstrated an increasing role for raltegravir in the management of both treatment-experienced and treatment-naïve HIV-1-infected patients. This review focuses on the evidence supporting raltegravir’s efficacy in an array of clinical settings. Other HIV-1 integrase inhibitors in development are also briefly discussed

    Diffusion and Transport Coefficients in Synthetic Opals

    Full text link
    Opals are structures composed of the closed packing of spheres in the size range of nano-to-micro meter. They are sintered to create small necks at the points of contact. We have solved the diffusion problem in such structures. The relation between the diffusion coefficient and the termal and electrical conductivity makes possible to estimate the transport coefficients of opal structures. We estimate this changes as function of the neck size and the mean-free path of the carriers. The theory presented is also applicable to the diffusion problem in other periodic structures.Comment: Submitted to PR

    Effects of Clinical Competency in Nursing Students following the Implementation of Student-Led Learning

    Get PDF
    Research and supporting evidence represent a gap identified in didactic learning between students and faculty. This gap shows emotional factors of the nursing curriculum that may suggest negative impacts on nursing students, but also improvements that can be made to increase students’ clinical competency levels. By adhering to strict definitions of student-led learning theory and clinical competency, we were able to create concrete evidence with measurable data that can contribute to the elimination of this gap in learning. Upon inspection of past text, we identified a need for further research on this topic to bring awareness and encourage this method to be implemented in more nursing programs. Past research played a key role in assisting our team to identify factors that contribute to students\u27 emotional impacts of nursing school and aided us in seeing how similar learning methods impacted students who participated. Our findings were gathered through the qualitative analysis of anonymous Google surveys in participants of our student-led skills labs. The survey allowed us to determine that each participant had a substantial improvement in skill level on the topics discussed, as well as an improvement in comfort level. These improvements in clinical competency and emotional influence help create a well-rounded nursing student. This program can be adjusted to encourage further skills practice and improvement in clinical judgment. Factors such as retention of skill and comfort level are continued to be studied and will be analyzed in December of 2023. We recommend there be a leading role as the program grows, ensuring the integrity and advancement of the program. We can say with confidence that our research contributed to past research, further supporting the implementation of student-led learning in the nursing curriculum at Murray State University
    corecore