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Search Results: 1 - 10 of 465989 matches for " Kenneth A. Albrecht "
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Genetic Variation for Biomass and Related Morphological Traits in Cup Plant (Silphium perfoliatum L.)  [PDF]
Teshale Assefa, Jixiang Wu, Kenneth A. Albrecht, Paul J. Johnson, Arvid Boe
American Journal of Plant Sciences (AJPS) , 2015, DOI: 10.4236/ajps.2015.68114
Abstract: Cup plant (Silphium perfoliatum L.) has demonstrated potential for bioenergy production in North America, South America, and Europe. Our objectives were to: 1) determine genetic variation and narrow-sense heritability for biomass and related morphological traits, and 2) identify half-sib families with superior biomass yield and potential for use in cultivar development in cup plant. Thirty three half-sib families and a check were evaluated at two locations in 2011, 2012, and 2013. Annual biomass yield at Brookings ranged from 2183 kg·ha-1 in 2012 to 8053 kg·ha-1 in 2013; whereas, yields at Arlington were similar among years. Mean individual half-sib family biomass yield ranged from 3912 to 6784 kg·ha-1 at Brookings and from 5682 to 11,269 kg·ha-1 at Arlington. Heritability estimates for five biomass-related morphological traits ranged from 0.52 to 0.72. This cup plant population had potential for biomass production in the north central USA and contained sufficient additive genetic variation to expect progress from among-and-within-family selection for biomass yield and related traits.
Biomass Production of Cup Plant (Silphium perfoliatum L.) in Response to Variation in Plant Population Density in the North Central USA  [PDF]
Arvid Boe, Kenneth A. Albrecht, Paul J. Johnson, Jixiang Wu
American Journal of Plant Sciences (AJPS) , 2019, DOI: 10.4236/ajps.2019.106065
Abstract: The North American genus Silphium is receiving global attention for its potential in the development of new food, forage, and industrial crops, including cellulosic biomass for biofuel. Little is known about the effect of plant population density on biomass production in large, coarse perennial forbs. Our objective was to evaluate the effect of variation in plant density on biomass production and stand morphology of cup plant (Silphium perfoliatum L.). Plant population densities of 17,000, 34,000, and 68,000 plants ha-1 were evaluated for biomass production in a single-harvest per annum system for three years at Brookings, SD and Arlington, WI. Biomass increased linearly by 43% between the low and high density at Brookings; whereas, at Arlington, response to variation in plant density was year dependent. Shoots plant-1 was inversely related to plant density with linear regression explaining >95% of the variation. Our results strongly suggested that further studies of effects of plant population density on biomass production in cup plant should include evaluation of, in addition to, densities higher than 68,000 plants ha-1.
Biomass Production of Monocultures and Mixtures of Cup Plant and Native Grasses on Prime and Marginal Cropland  [PDF]
Arvid Boe, Kenneth A. Albrecht, Paul J. Johnson, Jixiang Wu
American Journal of Plant Sciences (AJPS) , 2019, DOI: 10.4236/ajps.2019.106066
Abstract: To date, most candidate systems for producing herbaceous cellulosic biomass have been composed of monocultures of perennial or annual grasses. Ecosystem goods and services provided from these biomass feedstock production systems could be increased dramatically with mixing of one or more forb species that would increase biodiversity and provide habitat for pollinators. Cup plant (Silphium perfoliatum L.) is featured with many desirable characteristics, such as high biomass potential, adaptation to marginal soils, and attractiveness to pollinators, desirable in a dicot species to grow in mixtures with perennial warm-season grasses. The objective of this study was to compare cup plant, switchgrass (Panicum virgatum L.), and prairie cordgrass (Spartina pectinata Link) monocultures to their mixtures for biomass production on prime and poorly drained marginal crop land for two years in both South Dakota and Wisconsin. In Wisconsin, monocultures of prairie cordgrass and cup plant and their mixture produced more biomass (8.1 Mg·ha-1) than the switchgrass monoculture and switchgrass/cup plant mixture (5.3 Mg·ha-1) on both prime and marginal land. While in South Dakota, drought and meristem destruction by the cup plant moth (Eucosma giganteana Riley) caused large reductions in biomass production (1.7 Mg·ha-1) in both years, with the switchgrass/cup plant mixture on marginal land having the highest yield (2.1 Mg·ha-1). Our study showed binary mixtures of cup plant and native warm-season grasses have great potential for increasing biodiversity and other ecosystem goods and services, relative to monocultures, for sustainable biomass feedstock production on poorly
Effects of Fructooligofructoses Chain Length on the Bifidobacteria of the Human Colon: A Pilot Study  [PDF]
Krista Mendlik, Julie A. Albrecht, Marilynn Schnepf
Food and Nutrition Sciences (FNS) , 2012, DOI: 10.4236/fns.2012.312211
Abstract: Human gastrointestinal health may be improved by the consumption of prebiotic food ingredients such as fructooligo-fructoses. A study was initiated to determine the effect of fructooligofructoses of different chain lengths on gastrointes-tinal parameters. Nineteen healthy subjects aged 20 - 57 y took part in a 10-week cross-over designed study. Subjects consumed either inulin or oligofructose for 3 weeks followed by a 2-week washout period between treatments. Stool samples were collected five times (baseline, 2 treatments, 2 washout) and analyzed for bifidobacteria. Daily records were kept for stool frequency, stool consistency and flatulence frequency. Bifidobacteria counts (cfu/ml) were higher (trending toward significance) during inulin and oligofructose intakes (1.2 × 107 ± 4.8 × 107 and 2.0 × 108 ± 4.7 × 108) and washout periods (2.9 × 106 ± 6.5 × 106 and 1.1 × 107 ± 1.6 × 107) than baseline counts (2.2 × 105 ± 5.1 × 105 and 2.9 × 106 ± 6.5 × 106), respectively. Inulin and oligofructose treatment periods had a significant effect on stool consistency (watery/very hard) and flatulence frequency, but not stool frequency, when compared to baseline (P < 0.05). Further research is needed to confirm these results due to small sample size and the need for a longer washout period between treatments.
A. Quirrenbach,S. Albrecht
Revista mexicana de astronomía y astrofísica , 2010,
Abstract: MWC349A es probablemente una estrella masiva joven rodeada por un disco y un fuerte viento ionizado desde la super cie del disco. Las caracter sticas m s espectaculares del disco de MWC349A son l neas m ser y l ser de recombinaci n del hidr geno en longitudes de onda milim trica, sub-milim trica y de IR-medio. Hemos conducido observaciones de MWC349A con el instrumento MIDI del VLTI a 10 um. Las visibilidades en el continuo muestran la rma caracter stica esperada en un disco de polvo. Adem s, las rmas de por lo menos una docena de l neas de emisi n han sido identi cadas en los datos interferom tricos.
PSA - haben wir dazugelernt?
Semjonow A,Albrecht W
Journal für Urologie und Urogyn?kologie , 2007,
Metric properties of the set of orthogonal projections and their applications to operator perturbation theory
Konstantin A. Makarov,Albrecht Seelmann
Mathematics , 2010,
Abstract: We prove that the set of orthogonal projections on a Hilbert space equipped with the length metric is $\frac\pi2$-geodesic. As an application, we consider the problem of variation of spectral subspaces for bounded linear self-adjoint operators and obtain a new estimate on the norm of the difference of two spectral projections associated with isolated parts of the spectrum of the perturbed and unpertubed operators, respectively. In particular, recent results by Kostrykin, Makarov and Motovilov from [Trans. Amer. Math. Soc., V. 359, No. 1, 77 -- 89] and [Proc. Amer. Math. Soc., 131, 3469 -- 3476] are sharpened.
Warm-Mix Asphalt and Pavement Sustainability: A Review  [PDF]
Kenneth A. Tutu, Yaw A. Tuffour
Open Journal of Civil Engineering (OJCE) , 2016, DOI: 10.4236/ojce.2016.62008
Abstract: Within the past two decades or so, the asphalt paving industry has responded positively to increasing global concerns over shrinking natural resource reserves and worsening environmental conditions through the development and deployment of warm-mix asphalt technologies. Such technologies make it possible to produce and place asphalt concrete at reduced temperatures compared to conventional hot-mix methods. Several studies have reported on the potential of warm-mix asphalt with regard to improved pavement performance, efficiency and environmental stewardship. This paper reviews several of those studies in the context of pavement sustainability. Overall, warm-mix asphalt provides substantial sustainability benefits similar to or, in some cases, better than conventional hot-mix asphalt. Sustainability benefits include lower energy use, reduced emissions, and potential for increased reclaimed asphalt pavement usage. Growth in utilization of warm-mix asphalt worldwide may, in the not-too-distant future, make the material the standard for asphalt paving. Regardless, there are concerns over some aspects of warm-mix asphalt such as lower resistance to fatigue cracking, rutting and potential water-susceptibility problems, particularly with mixes prepared with water-based technologies, which require further research to address.
The Dominant Role of the Chemical Potential for Driving Currents in Oceans and Air  [PDF]
Albrecht Elsner
Journal of Geoscience and Environment Protection (GEP) , 2014, DOI: 10.4236/gep.2014.23016

Applying the thermodynamic zeros of the entropy  and internal energy  of the gas mass  in the volume

Thermodynamic Fit Functions of the Two-Phase Fluid and Critical Exponents  [PDF]
Albrecht Elsner
Engineering (ENG) , 2014, DOI: 10.4236/eng.2014.612076
Abstract: Two-phase fluid properties such as entropy, internal energy, and heat capacity are given by thermodynamically defined fit functions. Each fit function is expressed as a temperature function in terms of a power series expansion about the critical point. The leading term with the critical exponent dominates the temperature variation between the critical and triple points. With β being introduced as the critical exponent for the difference between liquid and vapor densities, it is shown that the critical exponent of each fit function depends (if at all) on β. In particular, the critical exponent of the reciprocal heat capacity c﹣1 is α=1-2β and those of the entropy s and internal energy u are 2β, while that of the reciprocal isothermal compressibility κ﹣1T is γ=1. It is thus found that in the case of the two-phase fluid the Rushbrooke equation conjectured α + 2β + γ=2 combines the scaling laws resulting from the two relations c=du/dT and κT=dlnρ/dp. In the context with c, the second temperature derivatives of the chemical potential μ and vapor pressure p are investigated. As the critical point is approached, ﹣d2μ/dT2 diverges as c, while d2p/dT2 converges to a finite limit. This is explicitly pointed out for the two-phase fluid, water (with β=0.3155). The positive and almost vanishing internal energy of the one-phase fluid at temperatures above and close to the critical point causes conditions for large long-wavelength density fluctuations, which are observed as critical opalescence. For negative values of the internal energy, i.e. the two-phase fluid below the critical point, there are only microscopic density fluctuations. Similar critical phenomena occur when cooling a dilute gas to its Bose-Einstein condensate.
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