Parametric study of optimized liquid-hydrogen thermal protection systems for nuclear interplanetary spacecraft. Volume 2 - Technical details Final report

Technical analyses and computer programs in support of optimization of liquid hydrogen thermal protection systems for nuclear Mars spacecraf

New ⁴⁰Ar/³⁹Ar dating of the Grande Ronde lavas, Columbia River Basalts, USA: Implications for duration of flood basalt eruption episodes

Grande Ronde Basalt (GRB) lavas represent the most voluminous eruptive pulse of the Columbia River-Snake River-Yellowstone hotspot volcanism. With an estimated eruptive volume of 150,000 km3, GRB lavas form at least 66% of the total volume of the Columbia River Basalt Group. New 40Ar/39Ar dates for GRB lavas reveal they were emplaced within a maximum period of 0.42 ± 0.18 My. A well-documented stratigraphy indicates at least 110 GRB flow fields (or individual eruptions), and on this basis suggests an average inter-eruption hiatus of less than 4,000 years. Isotopic age-dating cannot resolve time gaps between GRB eruptions, and it is difficult to otherwise form a picture of the durations of eruptions because of non-uniform weathering in the top of flow fields and a general paucity of sediments between GR lavas. Where sediment has formed on top of the GRB, it varies in thickness from zero to 20-30 cm of silty to fine-sandy material, with occasional diatomaceous sediment. Individual GRB eruptions varied considerably in volume but many were greater than 1000 km3 in size. Most probably eruptive events were not equally spaced in time; some eruptions may have followed short periods of volcanic repose (perhaps 102 to 103 of yrs), whilst others could have been considerably longer (many 1000 s to > 104 yrs). Recent improvements in age-dating for other continental flood basalt (CFB) lava sequences have yielded estimates of total eruptive durations of less than 1 My for high-volume pulses of lava production. The GRB appears to be a similar example, where the main pulse occupied a brief period. Even allowing for moderate to long-duration pahoehoe flow field production, the amount of time the system spends in active lava-producing mode is small – less than c. 2.6% (based on eruption durations of approximately 10,000 yrs, as compared to the duration of the entire eruptive pulse of c. 420,000 yrs). A review of available 40Ar/39Ar data for the major voluminous phases of the Columbia River Basalt Group suggests that activity of the Steens Basalt-Imnaha Basalt-GRB may have, at times, been simultaneous, with obvious implications for climatic effects. Resolving intervals between successive eruptions during CFB province construction, and durations of main eruptive pulses, remains vital to determining the environmental impact of these huge eruptions

Tosio Kato (1917–1999)

Tosio Kato was born August 25, 1917, in Kanuma City, Tochigi-ken, Japan. His early training was in physics. He obtained a B.S. in 1941 and the degree of Doctor of Science in 1951, both at the University of Tokyo. Between these events he published papers on a variety of subjects, including pair creation by gamma rays, motion of an object in a fluid, and results on spectral theory of operators arising in quantum mechanics. His dissertation was entitled “On the convergence of the perturbation method”. Kato was appointed assistant professor of physics at the University of Tokyo in 1951 and was promoted to professor of physics in 1958. During this time he visited the University of California at Berkeley in 1954–55, New York University in 1955, the National Bureau of Standards in 1955–56, and Berkeley and the California Institute of Technology in 1957–58. He was appointed professor of mathematics at Berkeley in 1962 and taught there until his retirement in 1988. He supervised twenty-one Ph.D. students at Berkeley and three at the University of Tokyo. Kato published over 160 papers and 6 monographs, including his famous book Perturbation Theory for Linear Operators [K66b]. Recognition for his important work included the Norbert Wiener Prize in Applied Mathematics, awarded in 1980 by the AMS and the Society for Industrial and Applied Mathematics. He was particularly well known for his work on Schrödinger equations of nonrelativistic quantum mechanics and his work on the Navier-Stokes and Euler equations of classical fluid mechanics. His activity in the latter area remained at a high level well past retirement and continued until his death on October 2, 1999

Writing in your own voice: An intervention that reduces plagiarism and common writing problems in students' scientific writing.

In many of our courses, particularly laboratory courses, students are expected to engage in scientific writing. Despite various efforts by other courses and library resources, as instructors we are often faced with the frustration of student plagiarism and related writing problems. Here, we describe a simple Writing in Your Own Voice intervention designed to help students become more aware of different types of plagiarism and writing problems, avoid those problems, and practice writing in their own voice. In this article, we will introduce the types of plagiarism and writing problems commonly encountered in our molecular biology laboratory course, the intervention, and the results of our study. From the evaluation of 365 student reports, we found the intervention resulted in nearly 50% fewer instances of plagiarism and common writing problems. We also observed significantly fewer instances of severe plagiarism (e.g. several sentences copied from an external source). In addition, we find that the effects last for several weeks after the students complete the intervention assignment. This assignment is particularly easy to implement and can be a very useful tool for teaching students how to write in their own voices. © 2019 International Union of Biochemistry and Molecular Biology, 47(5):589-598, 2019

Agreement between methods of measurement with multiple observations per individual

Limits of agreement provide a straightforward and intuitive approach to agreement between different methods for measuring the same quantity. When pairs of observations using the two methods are independent, i.e., on different subjects, the calculations are very simple and straightforward. Some authors collect repeated data, either as repeated pairs of measurements on the same subject, whose true value of the measured quantity may be changing, or more than one measurement by one or both methods of an unchanging underlying quantity. In this paper we describe methods for analysing such clustered observations, both when the underlying quantity is assumed to be changing and when it is not

Rumen function and digestion parameters associated with differences between sheep in methane emissions when fed chaffed lucerne hay

An indoor experiment involving 10 rumen-cannulated Romney sheep was conducted in May and June 1998 at AgResearch Grasslands, Palmerston North, New Zealand, under restricted feeding conditions. in order to test the hypothesis that animal factors, in particular rumen fractional outflow rate (FOR) and rumen volume, have an influence on the between-sheep variation in methane (CH4) emission. Sheep were fed 2-hourly on chaffed lucerne hay. Following an acclimatization period of 21 days, the experiment lasted 16 days. Energy and nitrogen (N) balances were measured on days 1-6. Cr-EDTA marker was continuously infused into the rumen from day 9 to 16, and rumen contents emptied and sampled on days 13 and 16. Particulate and fluid FOR were estimated using feed lignin and Cr-EDTA, respectively. Daily CH, production was measured by the sulphur hexafluoride tracer technique on days 2, 5, 6, 12 and 15 of the experiment. CH4 production (g/day) was positively correlated with the pool size of organic matter (OM) in the rumen (OM pool, g) (r = 0.84, P = 0.002), OM intake (OMI, g/day) (r = 0.67, P = 0.04), and the rumen fill (g. wet digesta) (r = 0.76, P = 0.01). Multiple regression analysis showed that CH4 production was best predicted (R-2 = 0.88) as a function of OM pool and the molar % of butyrate; however, OM pool alone accounted for a large proportion (R-2 = 0.71) of the variation in CH4 production. CH4 yield (% gross energy intake, % GEI) was negatively correlated with the particulate FOR (%/h) ( r= -0.75, P = 0.01) and buffering capacity of rumen fluid (mmol HCl) (r = -0.72, P = 0.02) but positively correlated with the digestibility of cellulose (r = 0.66, P = 0.04). Multiple regression analysis showed that CH, yield was best predicted as a function of particulate FOR, OMI (g/kg liveweight(0.75)) and the molar % of butyrate (R-2 = 0.88). Particulate FOR alone explained a large proportion (R-2 = 0.57) of the variation in CH4 Yield. Particulate FOR was negatively correlated with rumen fill (r = -0.69, P = 0.03) and digestibility of cellulose (r = -0.65, P = 0.04). These results suggest that sheep with lower rumen particulate FOR (i.e. longer rumen retention times) had larger rumen fills and higher fibre digestibilities and CH4 yields. If rumen particulate FOR is to be used as a tool for CH4 mitigation, the repeatability of its relationship to CH4 emission must be assessed, preferably under grazing conditions

Persistence of differences between sheep in methane emission under generous grazing conditions

Four low and four high methane (CH4) emitters were selected from a flock of 20 Romney sheep on the basis of CH4 production rates per unit of intake, measured at grazing using the sulphur hexafluoride (SF,) tracer technique. Methane emissions from these sheep were monitored at grazing for four periods (P): October, November, January and February 1999/2000. All measurements were carried out on perennial ryegrass/white clover pasture under generous herbage allowance, and the sheep were maintained on similar pastures during non-measurement periods. The tracer technique was used for all the CH4 measurements and feed DM intake was calculated from total faecal collection and estimated DM digestibility. Data for liveweight (LW), gross energy intake (GEI) and CH4 emission were analysed using split-plot analysis of variance. In addition, a between-period rank order correlation analysis was carried out for CH4 emission data. Low CH4 emitters were heavier (P < 0.05) than the high emitters in all the periods, but they did not differ (P < 0.05) in their gross energy intakes (GEL MJ/kg LW0.75). Low and high CH4 emitters consistently maintained their initial rankings in CH4 yield (% GEI) throughout the subsequent periods and the correlation analysis of rank order for CH4 yield showed strong between-period correlation coefficients, although this was weaker in the last period. It is suggested that feeding conditions that maximize feed intake (e.g. generous allowance of good quality pasture under grazing) favour the expression and persistence of between-sheep differences in CH4 yield

Single-qubit optical quantum fingerprinting

We analyze and demonstrate the feasibility and superiority of linear optical single-qubit fingerprinting over its classical counterpart. For one-qubit fingerprinting of two-bit messages, we prepare `tetrahedral' qubit states experimentally and show that they meet the requirements for quantum fingerprinting to exceed the classical capability. We prove that shared entanglement permits 100% reliable quantum fingerprinting, which will outperform classical fingerprinting even with arbitrary amounts of shared randomness.Comment: 4 pages, one figur

Parametric study of optimized liquid-hydrogen thermal protection systems for nuclear interplanetary spacecraft. Volume 1 - Results and summary

Parametric study of optimized liquid hydrogen thermal protection systems for nuclear interplanetary spacecraf