Multiscale structure of turbulent channel flow and polymer, dynamics in viscoelastic turbulence

This thesis focuses on two important issues in turbulence theory of wall-bounded flows. One is the recent debate on the form of the mean velocity profile (is it a log-law or a power-law with very weak power exponent?) and on its scalings with Reynolds number. In particular, this study relates the mean flow profile of the turbulent channel flow with the underlying topological structure of the fluctuating velocity field through the concept of critical points, a dynamical systems concept that is a natural way to quantify the multiscale structure of turbulence. This connection gives a new phenomenological picture of wall-bounded turbulence in terms of the topology of the flow. This theory validated against existing data, indicates that the issue on the form of the mean velocity profile at the asymptotic limit of infinite Reynolds number could be resolved by understanding the scaling of turbulent kinetic energy with Reynolds number. The other major issue addressed here is on the fundamental mechanism(s) of viscoelastic turbulence that lead to the polymer-induced turbulent drag reduction phenomenon and its dynamical aspects. A great challenge in this problem is the computation of viscoelastic turbulent flows, since the understanding of polymer physics is restricted to mechanical models. An effective numerical method to solve the governing equation for polymers modelled as nonlinear springs, without using any artificial assumptions as usual, was implemented here for the first time on a three-dimensional channel flow geometry. The superiority of this algorithm is depicted on the results, which are much closer to experimental observations. This allowed a more detailed study of the polymer-turbulence dynamical interactions, which yields a clearer picture on a mechanism that is governed by the polymer-turbulence energy transfers

Factors contributing to effective language laboratory use in New Zealand tertiary institutes : a thesis presented in partial fulfilment of the requirements for the degree of Master of Arts in Japanese at Massey University

This study focuses on how language laboratories in New Zealand tertiary institutes can be used more effectively. The language laboratory is an excellent tool of learning which can be used to aid the development of both listening and speaking skills as well as a range of competency skills. Clear guidelines for use and management of this complex equipment with focus on full integration with classroom language teaching are not currently available to users of the language laboratory. The issues are: Our ability to use the language laboratory to its full extent Our ability to effectively manage the language laboratory Our ability to keep pace with the changing nature of language teaching Our awareness of the value of the language laboratory as a learning aid. The importance of the language laboratory to our teaching programmes Self-paced student-centred learning versus teacher control Discussion of the above with particular emphasis on training, preparation of materials, organisation and management, and integration with the classroom, help provide basic guidelines for improved language laboratory use and a basis for future research and debate

Subsidize or Suffer

The standard for energy production and consumption in the US has historically been the use of coal or oil. In the earliest days of the industrial revolution, coal was king. For a society to achieve such a goal as the expansion and fortification of infrastructure, well, society as a whole, the means absolutely justify the ends. But what if the means of producing energy didn’t have to look like what they did over a hundred years ago? Well they don’t. The use of new renewable, sustainable energy could prove to be beneficial in many aspects, environmental health especially. By subsidizing the use of renewables for the purpose of energy production, the state of NE could stand to become a positive influence for the rest of the nation in the fight against climate change. If it isn’t entirely obvious to you by now, the world’s climate is changing due to anthropogenic activities. In other words, we messed up guys. As the ice caps melt and the air turns a stale brown, the “environmental debt” we have dug ourselves into only grows larger and larger. Unfortunately for the earth, economic principles don’t apply and bankruptcy in this case is literally death. To avoid such an event would require a paradigm shift of society, specifically aimed at the energy production sector. Currently, energy production is one of the US markets with the highest rate of subsidies. But that isn’t to say that we are heading in the wrong direction as a society necessarily. The US Energy Information Administration (EIA) reported that in 2010, natural gas received $24B and coal received$21B. In 2016, natural gas received $32B and coal received$14B, a nearly 40% decrease in funding in just 6 years. This is a good sign, it means that we are willing to put our chips into another pile at the very least, and at most means that we are willing to invest in more sustainable fuels – as natural burns slightly cleaner than oil and much cleaner than coal. The fossil fuel industry currently employs millions of people. A shift away from the use of fossil fuels would certainly eliminate these jobs. This could be seen as a negative through the right (or wrong) lens. But that’s not to say that expanding on clean energy wouldn’t make any jobs either. A 2017 report from the Department of Energy shows that nearly 1 million clean energy jobs have been created in the US alone. This number being nearly 5 times that of US fossil fuel workers. By continuing to subsidize the energy industry in the direction of fossil fuels is to cosign on the accelerated heat death of the planet at the hands of the ignorant. But it is not too late! Several regions in the US have or are planning to have economic policies put in place to combat climate change. Currently there is a 30% rebate on solar PV panels at the federal level, which is wonderful for residential and commercial installation. In addition to this, there are currently 14 different financial incentive programs in relation to renewable energy usage. Most of which are locked to specific regions (DSIRE, 2019). In Nebraska there are strong Net metering laws. This means that any energy produced at the household level has to be connected to the collective power grid. This connection could allow for power produced at the individual level to be sold back to the local energy providers. More money doesn’t have to mean a loss in environmental quality! What Nebraska currently lacks is a substantial subsidy for the implementation of renewables. At the individual level this could look like an installation rebate, and at the industrial level it could simply mimic current practices in the fossil fuels industry

James R. Killian, Jr., Sputnik, and Eisenhower: White House Science Advice and the Reformation of American Science Education, 1955-1958

This paper chronicles the often-overlooked relationship between President Dwight D. Eisenhower and Dr. James R. Killian, Jr., the first-ever appointed Presidential Science Advisor. Emphasis is placed on the role of Dr. Killian and the President’s Science Advisory Committee (PSAC) in advocating curricular reform in the fields of science and mathematics, a reformation which became doubly important following the successful launch of the Soviet satellite Sputnik I in 1957. This essay examines the efforts of Eisenhower and Killian to keep pace with the Russian scientific advances by improving American education in the scientific and technical fields. It concludes with a discussion of the National Defense Education Act of 1958 and Killian’s efforts to see the piece of legislation enacted

Use of multivariable asymptotic expansions in a satellite theory

Initial conditions and perturbative force of satellite are restricted to yield motion of equatorial satellite about oblate body. In this manner, exact analytic solution exists and can be used as standard of comparison in numerical accuracy comparisons. Detailed numerical accuracy studies of uniformly valid asymptotic expansions were made

Cosmic Ray Antiprotons

Cosmic ray antiprotons have been detected for over 20 years and are now measured reliably. Standard particle and astrophysics predict a conventional spectrum and abundance of secondary antiprotons consistent with all current measurements. These measurements place limits on exotic Galactic antiproton sources and non-standard antiproton properties. Complications arise, particularly at low energies, with heliospheric modulation of cosmic ray fluxes and production of standard secondaries from A > 1 nuclear targets. Future experiments and theoretical developments are discussed.Comment: 18 pages, 8 .eps figures, 2 tables; extended/revised contribution to PASCOS99 Symposium; includes World Scientific ws-p8-50x6-00.cls macr