322 research outputs found

    Thermodynamic and transport properties of gaseous tetrafluoromethane in chemical equilibrium

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    Equations and in computer code are presented for the thermodynamic and transport properties of gaseous, undissociated tetrafluoromethane (CF4) in chemical equilibrium. The computer code calculates the thermodynamic and transport properties of CF4 when given any two of five thermodynamic variables (entropy, temperature, volume, pressure, and enthalpy). Equilibrium thermodynamic and transport property data are tabulated and pressure-enthalpy diagrams are presented

    A simple integral method for the calculation of real-gas turbulent boundary layers with variable edge entropy

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    Simple integral method for calculating real gas turbulent boundary layers with variable edge entropy and flight calculations showing effect of nose bluntness at 6.09 km/se

    A method for calculating a real-gas two-dimensional nozzle contour including the effects of gamma

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    A method for calculating two-dimensional inviscid nozzle contours for a real gas or an ideal gas by the method of characteristics is described. The method consists of a modification of an existing nozzle computer program. The ideal-gas nozzle contour can be calculated for any constant value of gamma. Two methods of calculating the center-line boundary values of the Mach number in the throat region are also presented. The use of these three methods of calculating the center-line Mach number distribution in the throat region can change the distance from the throat to the inflection point by a factor of 2.5. A user's guide is presented for input to the computer program for both the two-dimensional and axisymmetric nozzle contours

    A vectorization of the Hess McDonnell Douglas potential flow program NUED for the STAR-100 computer

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    The computer program NUED for analyzing potential flow about arbitrary three dimensional lifting bodies using the panel method was modified to use vector operations and run on the STAR-100 computer. A high speed of computation and ability to approximate the body surface with a large number of panels are characteristics of NUEDV. The new program shows that vector operations can be readily implemented in programs of this type to increase the computational speed on the STAR-100 computer. The virtual memory architecture of the STAR-100 facilitates the use of large numbers of panels to approximate the body surface

    Computer program for calculation of real gas turbulent boundary layers with variable edge entropy

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    A user's manual for a computer program which calculates real gas turbulent boundary layers with variable edge entropy on a blunt cone or flat plate at zero angle of attack is presented. An integral method is used. The method includes the effect of real gas in thermodynamic equilibrium and variable edge entropy. A modified Crocco enthalpy velocity relationship is used for the enthalpy profiles and an empirical correlation of the N-power law profile is used for the velocity profile. The skin-friction-coefficient expressions of Spalding and Chi and Van Driest are used in the solution of the momentum equation and in the heat-transfer predictions that use several modified forms of Reynolds analogy

    Numerical and experimental studies of the natural convection within a horizontal cylinder

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    Numerical solutions are obtained for the quasi-compressible Navier-Stokes equations governing the time-dependent natural convection within a horizontal cylinder. The early flow development and wall heat transfer are obtained after a uniformly cold wall is imposed as a boundary condition on the cylinder. Results are also obtained for a time-varying cold wall as a boundary condition with windward explicit differencing used for the numerical solutions. The viscous truncation error associated with this scheme is controlled so that first-order accuracy is maintained in time and space. Experiments within a small-scale instrumented horizontal cylinder revealed the time development of the temperature distribution across the boundary layer as well as the decay of wall heat transfer with time. Agreement between temperature distributions obtained experimentally and numerically was generally good. The time decay of the dimensionless ratio of the Nusselt number to the one-fourth power of the Grashof number is found both numerically and experimentally, and good agreement is obtained between these two results over most of the cylinder wall

    Lifecourse Childhood Adiposity Trajectories Associated With Adolescent Insulin Resistance

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    OBJECTIVE In the light of the obesity epidemic, we aimed to characterize novel childhood adiposity trajectories from birth to age 14 years and to determine their relation to adolescent insulin resistance. RESEARCH DESIGN ANDMETHODS A total of 1,197 Australian children with cardiovascular/ metabolic proiling at age 14 years were studied serially from birth to age 14 years.Semiparametric mixture modeling was applied to anthropometric data over eight time points to generate adiposity trajectories of z scores (weight-for-height and BMI). Fasting insulin and homeostasis model assessment of insulin resistance (HOMA-IR) were compared at age 14 years between adiposity trajectories. RESULTS Seven adiposity trajectories were identified. Three (two rising and one chronic high adiposity) trajectories comprised 32% of the population and were associated with significantly higher fasting insulin and HOMA-IR compared with a reference trajectory group (with longitudinal adiposity z scores of approximately zero). There was a significant sex by trajectory group interaction (P,0.001). Girls within a rising trajectory fromlow tomoderate adiposity did not show increased insulin resistance. Maternal obesity, excessive weight gain during pregnancy,and gestational diabetes were more prevalent in the chronic high adiposity trajectory. CONCLUSIONS A range of childhood adiposity trajectories exist. The greatest insulin resistance at age 14 years is seen in those with increasing trajectories regardless of birth weight and in high birth weight infants whose adiposity remains high. Public health professionals should urgently target both excessive weight gain in early childhood across all birth weights and maternal obesity and excessive weight gain during pregnancy

    Pathway to Hope: an indigenous approach to healing child sexual abuse

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    Background. The Alaska Native (AN) population has endured multiple historical traumatic events. This population has poorer health outcomes on nearly all factors compared with Alaska non-Natives with more than 75% reportedly being physically assaulted in their lifetime, and child sexual abuse nearly 6 times the national average. Objective. This article describes the Pathway to Hope (PTH) program, which is an indigenous approach to ending silence and denial related to child sexual abuse and encourages multigenerational healing. Design. PTH was developed by ANs who believe that each community is unique, thus strategies for ending denial and support for healing must be woven from the historical context, cultural strengths of individual communities. Strengths-based solutions built on truth, honesty, compassion and shared responsibility for healing and protecting today’s children have been profound and successful. The PTH curriculum addresses child sexual abuse from a historical perspective; that the higher rates of sexual abuse among certain Tribes, regions and communities is linked in part to years of victimisation, but may also be perpetuated by internalised oppression and lateral violence among Tribal members. Results. Data suggest that community-based dialogue and wisdom of Native elders and spiritual leaders paired with readiness of community service providers are necessary for sustained change. At all levels, this Indigenous model for learning, sharing, helping and healing brings hope for an end to denial and silence about child sexual abuse for Native people. Conclusions. The PTH program utilises the wisdom and values that have sustained Native people for generations. Ending silence and denial about child sexual abuse and building upon strengths have assisted many Indigenous communities begin the journey toward wellness. Through the PTH, communities have taken steps to accept the challenges associated with establishing safety for children, supporting child victims in healing and to holding offenders accountable
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