The echo boom : developing effective ministry to reach a new generation in the Arkanasas area of the United Methodist Church

https://place.asburyseminary.edu/ecommonsatsdissertations/1520/thumbnail.jp

Germination, emergence, and seed persistence of Panicum miliaceum L.

1984 Summer.Includes bibliographical references (pages 110-115).The effects of varying levels of temperature, moisture, and seed depth on wild proso millet (Panicum miliaceum L.) emergence were observed. The effects of depth and duration of seed burial and the effects of seed overwintering on the soil surface on modes of seed depletion and persistence were studied. Patterns of wild proso millet emergence in the field were studied under conditions of plus or minus intraspecific and corn competition, and with and without soil disturbance. Emergence occurred over a range of 10 to 40 C with percent and speed of emergence increasing with temperature. Under simulated drought conditions induced by polyethylene glycol, germination was reduced at both temperatures tested (25, 30 C) as moisture stress increased. The greatest moisture stress that germination occurred at was -14 bars (1 .5%) at 30 C and -10 bars (2%) at 25 C. Germination at 30 C was higher at all moisture levels than at 25 C. Emergence from soil moisture levels of 35 to 100% field capacity was greater than 87%. Emergence ceased below 25% field capacity. Fluctuations of soil moisture resulted in slightly higher emergence than at a constant soil moisture level. Emergence was equal from 1 to 8 cm of seed depth with 14 cm the maximum depth of emergence. After 21 months of seed burial loss was greatest at 5 cm, with only 23% viable seed remaining. Persistence increased with soil depth with 77 and 93% viable seed at 10 and 30 cm, respectively. The main mode of depletion was in situ germination which decreased with depth. Seed death was not a major factor of depletion and was not affected by depth. The majority of depletion occurred within the first 12 months with seed populations stabilizing from 12 to 21 months of burial. Seeds overwintering on the soil surface were not greatly affected with more than 96% remaining viable seed. With high soil moisture, emergence patterns were influenced by fluctuations in temperatures in late May when emergence began, to June. In July and early August when emergence ceased, soil moisture became the limiting factor. Total emergence was greatest when all competition was removed. Both intraspecific and corn competition reduced emergence in July and early August. Cultivation acted to remove competition resulting in greater total emergence than treatments with competition

Anechoic wind tunnel study of turbulence effects on wind turbine broadband noise

This paper describes recent results obtained at MIT on the experimental and theoretical modelling of aerodynamic broadband noise generated by a downwind rotor horizontal axis wind turbine. The aerodynamic broadband noise generated by the wind turbine rotor is attributed to the interaction of ingested turbulence with the rotor blades. The turbulence was generated in the MIT anechoic wind tunnel facility with the aid of biplanar grids of various sizes. The spectra and the intensity of the aerodynamic broadband noise have been studied as a function of parameters which characterize the turbulence and of wind turbine performance parameters. Specifically, the longitudinal integral scale of turbulence, the size scale of turbulence, the number of turbine blades, and free stream velocity were varied. Simultaneous measurements of acoustic and turbulence signals were made. The sound pressure level was found to vary directly with the integral scale of the ingested turbulence but not with its intensity level. A theoretical model based on unsteady aerodynamics is proposed

Hubungan Asam Lemak Rantai Pendek, Stratifikasi, dan Giberelin pada Perkecambahan Embrio Apel

The objective of the present experiment was to determine the inhibitory properties of short chain fatty acids (SCFA) in apple embryo germination. The result showed that the SCFA inhibition on apple embryo germination was dependent on chain length and was in the millimolar range. No synergistic effect was observed when SCFA were applied simultaneously. The inhibition of SCFA was reversed by GA4+7. A higher concentration of SCFA was needed to inhibit embryo germination as the stratification progressed

HAZMAT VI: The Evolution of Extreme Ultraviolet Radiation Emitted from Early M Star

Quantifying the evolution of stellar extreme ultraviolet (EUV, 100 -- 1000 $\overset{\circ}{A}$) emission is critical for assessing the evolution of planetary atmospheres and the habitability of M dwarf systems. Previous studies from the HAbitable Zones and M dwarf Activity across Time (HAZMAT) program showed the far- and near-UV (FUV, NUV) emission from M stars at various stages of a stellar lifetime through photometric measurements from the Galaxy Evolution Explorer (GALEX). The results revealed increased levels of short-wavelength emission that remain elevated for hundreds of millions of years. The trend for EUV flux as a function of age could not be determined empirically because absorption by the interstellar medium prevents access to the EUV wavelengths for the vast majority of stars. In this paper, we model the evolution of EUV flux from early M stars to address this observational gap. We present synthetic spectra spanning EUV to infrared wavelengths of 0.4 $\pm$ 0.05 M$_{\odot}$ stars at five distinct ages between 10 and 5000 Myr, computed with the PHOENIX atmosphere code and guided by the GALEX photometry. We model a range of EUV fluxes spanning two orders of magnitude, consistent with the observed spread in X-ray, FUV, and NUV flux at each epoch. Our results show that the stellar EUV emission from young M stars is 100 times stronger than field age M stars, and decreases as t$^{-1}$ after remaining constant for a few hundred million years. This decline stems from changes in the chromospheric temperature structure, which steadily shifts outward with time. Our models reconstruct the full spectrally and temporally resolved history of an M star's UV radiation, including the unobservable EUV radiation, which drives planetary atmospheric escape, directly impacting a planet's potential for habitability.Comment: 23 pages, 15 figures, accepted to Ap

Corn and grain sorghum response to limited irrigation, drought, and hail

A field study was conducted for eight years in southwest Kansas near Garden City to measure the response of corn and grain sorghum to limited irrigation in the region. An irrigation variable was imposed on each crop, with six irrigation treatments from full irrigation scheduled to minimize soil water deficits to minimal or no irrigation. To create differences in the amount of irrigation across treatments, the time between 25-mm irrigation events increased as irrigation decreased. A historic drought occurred during 2011 and 2012 when cropping season precipitation, the precipitation occurring from the harvest of the prior crop through the harvest of the next crop, was 60% of the 30-year average. Except for 2008, average cropping season precipitation was 8% above average during the prior six years. Linear regressions of corn and sorghum grain yields (GY) and dry matter yields (DMY) versus crop evapotranspiration (ETc) from all years combined, except hail damaged sorghum in 2005, produced R2 values from 0.71 to 0.79. One hailstorm during 2005 damaged sorghum to the extent that yields did not vary with respect to ETc or irrigation. Hail events in 2005 and 2006 occurred at nearly the same growth stage for corn caused lower leaf area and yields than during other wet years with no hail. Using quadratic regressions, corn yields during wet years with no hail, wet years with hail, and dry years had distinctly different dependence on irrigation. Although sorghum yields during wet years tended to increase as irrigation increased, sorghum’s response to irrigation was less than for corn during the same years. During dry years, sorghum and corn were highly dependent on irrigation. Net economic returns (NR) of continuous corn, continuous sorghum, cornsorghum, corn-wheat, and sorghum-wheat rotations were each higher with a year receiving average precipitation (460 mm) than a year receiving 60% of average precipitation (280 mm). The NR of continuous corn dominated the rest of the rotations when irrigation was more than 230 to 330 mm in the dry year and 90 to 180 mm in wet year. As farmers choose crop rotations, they need to consider management factors and crop tolerance to soil water stress in addition to potential NR