6,713 research outputs found
TB82: The Potential of Softwood Thinnings and Standing Dead Softwoods as a Source of Wood Pulp
This study was made to determine the potential of softwood thinnings and standing dead softwood as a source of wood pulp, employing the kraft process. In the thinning studies examined eastern white pine, eastern hemlock, balsam fir, norway spruce, red pine, eastern larch, and northern white cedar. The stem (wood and bark) and the top (wood, bark, and needles) and the stem and top combined were pulped. When compared with pulp from a commercial-size softwood species, the thinnings provided pulps of good strength that were slightly undercooked and that had significantly lower yields. The stem portion pulps were superior in all cases to those made from the top portion. This is attributed to the foliage and higher bark content of the branches of the top which resulted in relatively low yields. The brief study of the characteristics of standing dead softwood trees, either killed by fire or natural attrition, indicated that they compare favorably with the live thinnings as a source of pulp when yield and physical properties are the criteria. It was concluded from this study that 35-4 0 percent of the thinnings material is available as a good grade of wood pulp.https://digitalcommons.library.umaine.edu/aes_techbulletin/1111/thumbnail.jp
EC880 Revised 1947 Cost of Operating Beet Harvesting Machinery in Nebraska 1946
Extension circular 880 reports the cost of operating beet harvesting machinery in Nebraska in 1946
EC873 Annual Farm Business Report : Southeast Nebraska Loess-Drift Hill Area 42 Farms Gage, Johnson, Lancaster and Pawnee Counties for 1942
Extension Circular 873 provides an annual business report of forty-two farms in the Southeast Nebraska Loess-Drift Hill Area of Gage, Johnson, Lancaster, and Pawnee Counties of Nebraska from 1942
A study of the phase transition in the usual statistical model for nuclear multifragmentation
We use a simplified model which is based on the same physics as inherent in
most statistical models for nuclear multifragmentation. The simplified model
allows exact calculations for thermodynamic properties of systems of large
number of particles. This enables us to study a phase transition in the model.
A first order phase transition can be tracked down. There are significant
differences between this phase transition and some other well-known cases
Vacuum-UV negative photoion spectroscopy of CF3Cl, CF3Br and CF3I
Using synchrotron radiation negative ions have been detected by mass spectrometry following vacuum-UV photoexcitation of trifluorochloromethane (CFCl), trifluorobromomethane (CFBr) and trifluoroiodomethane (CFI). The anions F, X, F, FX, CF, CF and CF were observed from all three molecules, where X = Cl, Br or I, and their ion yields recorded in the range 8-35 eV. With the exception of Br and I, the anions observed show a linear dependence of signal with pressure, showing that they arise from unimolecular ion-pair dissociation. Dissociative electron attachment, following photoionization of CFBr and CFI as the source of low-energy electrons, is shown to dominate the observed Br and I signals, respectively. Cross sections for ion-pair formation are put on to an absolute scale by calibrating the signal strengths with those of F from both SF and CF. These anion cross sections are normalized to vacuum-UV absorption cross sections, where available, and the resulting quantum yields are reported. Anion appearance energies are used to calculate upper limits to 298 K bond dissociation energies for (CF-X) which are consistent with literature values. We report new data for (CFI-F) ≤ 2.7 ± 0.2 eV and (CFI) ≤ (598 ± 22) kJ mol. No ion-pair formation is observed below the ionization energy of the parent molecule for CFCl and CFBr, and only weak signals (in both I and F) are detected for CFI. These observations suggest neutral photodissociation is the dominant exit channel to Rydberg state photoexcitation at these lower energies
Studies in the statistical and thermal properties of hadronic matter under some extreme conditions
The thermal and statistical properties of hadronic matter under some extreme
conditions are investigated using an exactly solvable canonical ensemble model.
A unified model describing both the fragmentation of nuclei and the thermal
properties of hadronic matter is developed. Simple expressions are obtained for
quantities such as the hadronic equation of state, specific heat,
compressibility, entropy, and excitation energy as a function of temperature
and density. These expressions encompass the fermionic aspect of nucleons, such
as degeneracy pressure and Fermi energy at low temperatures and the ideal gas
laws at high temperatures and low density. Expressions are developed which
connect these two extremes with behavior that resembles an ideal Bose gas with
its associated Bose condensation. In the thermodynamic limit, an infinite
cluster exists below a certain critical condition in a manner similar to the
sudden appearance of the infinite cluster in percolation theory. The importance
of multiplicity fluctuations is discussed and some recent data from the EOS
collaboration on critical point behavior of nuclei can be accounted for using
simple expressions obtained from the model.Comment: 22 pages, revtex, includes 6 figures, submitted to Phys. Rev.
Molecular Studies of Subfamily Gilliesioideae (Alliaceae)
We present an analysis of relationships in Gilliesioideae (Alliaceae) based on a combined matrix of plastid rbcL, the trnL intron, the trnL-F intergenic spacer, and the rps16 intron and nuclear ITS ribosomal DNA sequences. The results are generally congruent with previous analyses, indicating two well-supported groups: Ipheion plus allied genera ( lpheieae ined.) and Gilliesieae. They also provide higher bootstrap support for many patterns of relationships. Polyphyly of lpheion and Nothoscordum is confirmed. Increased taxon sampling (particularly in Gilliesieae) and additional molecular data would be desirable to provide further resolution and to allow an appropriate taxonomic revision to be made
Single shot parameter estimation via continuous quantum measurement
We present filtering equations for single shot parameter estimation using
continuous quantum measurement. By embedding parameter estimation in the
standard quantum filtering formalism, we derive the optimal Bayesian filter for
cases when the parameter takes on a finite range of values. Leveraging recent
convergence results [van Handel, arXiv:0709.2216 (2008)], we give a condition
which determines the asymptotic convergence of the estimator. For cases when
the parameter is continuous valued, we develop quantum particle filters as a
practical computational method for quantum parameter estimation.Comment: 9 pages, 5 image
A graphical method for practical and informative identifiability analyses of physiological models: A case study of insulin kinetics and sensitivity
peer reviewedBackground: Derivative based a-priori structural identifiability analyses of mathematical models can offer valuable insight into the identifiability of model parameters. However, these analyses are only capable of a binary confirmation of the mathematical distinction of parameters and a positive outcome can begin to lose relevance when measurement error is introduced. This article presents an integral based method that allows the observation of the identifiability of models with two-parameters in the presence of assay error. Methods: The method measures the distinction of the integral formulations of the parameter coefficients at the proposed sampling times. It can thus predict the susceptibility of the parameters to the effects of measurement error. The method is tested in-silico with Monte Carlo analyses of a number of insulin sensitivity test applications. Results: The method successfully captured the analogous nature of identifiability observed in Monte Carlo analyses of a number of cases including protocol alterations, parameter changes and differences in participant behaviour. However, due to the numerical nature of the analyses, prediction was not perfect in all cases. Conclusions: Thus although the current method has valuable and significant capabilities in terms of study or test protocol design, additional developments would further strengthen the predictive capability of the method. Finally, the method captures the experimental reality that sampling error and timing can negate assumed parameter identifiability and that identifiability is a continuous rather than discrete phenomenon
Flavor-singlet light-cone amplitudes and radiative Upsilon decays in SCET
We study the evolution of flavor-singlet, light-cone amplitudes in the
soft-collinear effective theory (SCET), and reproduce results previously
obtained by a different approach. We apply our calculation to the color-singlet
contribution to the photon endpoint in radiative Upsilon decay. In a previous
paper, we studied the color-singlet contributions to the endpoint, but
neglected operator mixing, arguing that it should be a numerically small
effect. Nevertheless the mixing needs to be included in a consistent
calculation, and we do just that in this work. We find that the effects of
mixing are indeed numerically small. This result combined with previous work on
the color-octet contribution and the photon fragmentation contribution provides
a consistent theoretical treatment of the photon spectrum in radiative Upsilon
decay.Comment: 19 pages with 8 figure
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