23,958 research outputs found

    Constructing a Theory of Educational Administration

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    The development of administrative theory has long been a quest for scholars in the field of educational administration. The beginnings of the development of a theory of educational administration began with Griffiths‘ (1959) now classic Administrative Theory, where he outlined the problem and noted, ―The field [of educational administration] is no longer neatly defined [and] textbooks are characterized by a search for the substance of administration and for a theory which binds the substance together‖ (p. 1-2). The need for such a theory has been important because a theory could serve to guide and support practice, even though the link between theory and practice has not always been articulated. In addition, the complex interactive nature of educational administration and the different school contexts have made it difficult to establish a uniform administrative theory. English (2002) called the theory-practice gap the ―Gordian Knot.‖ He noted, ―The theory-practice gap is a direct result of continuing to use inductive methods in creating theories for use in studying schools and the practices in them. The creation of … theories in educational administration … are not likely to come about under the way theories are constructed…in much of the present research‖ (p. 3)

    Optimizing the ratio of captures to trapping effort in a black rat Rattus rattus control programme in New Zealand

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    The ratio of captures to unit effort is an important cost/benefit measure for volunteer pest control programmes. We describe an experiment designed to investigate the use of pre-feeding and trap pulsing as possible means of increasing this ratio. In 20 traps locked-open and pre-fed with non-toxic pellets for five days, the same number of black rats was caught over the next 5 days as in 20 non pre-fed traps set for the whole 10 days (32 rats each). Allowing for successful traps being unavailable for an average of half a night each, the capture rate in the pre-fed traps was 47% over five days, more than double that in the non pre-fed traps set for twice as long (total 19% in 10 days)

    The Raman Spectrum of Boron Trifluoride Gas

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    The Raman spectrum of BF3 was photographed using a purified preparation obtained from the thermal decomposition of C6H5N2BF4. Of the lines observed, that with the frequency 888 cm^—1 is certainly, and the band at 439–513 cm^—1 is probably due to BF3. The Raman frequencies and the infra-red results of Bailey et al. are assigned to the fundamental modes of vibrations

    Sand Bioreactors for Wastewater Treatment for Ohio Communities

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    The Additivity of the Energies of Normal Covalent Bonds

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    The chemical bond between two identical atoms, as in the molecules H2, Cl2, etc., may be considered as an example of a normal covalent bond, involving an electron pair shared by the two atoms. The wave function representing this bond cannot necessarily be closely approximated by a function of the Heitler-London type, with the electrons staying on different atoms, but may contain ionic terms, corresponding to the two electrons of the bond on the same atom, the term representing the configuration A+A- occurring, of course, with the same coefficient as that for A -A +. The contribution of these ionic terms to the wave function for the normal state of the hydrogen molecule has been discussed by Slater [1]

    The Raman Spectra of CH3CF3 and CCl2CF2

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    Because of the interest attached to ethane and ethane-like molecules in connection with the question of free rotation of the CX3 groups with respect to each other, it was considered that the Raman spectrum of CH3CF3 might yield additional information on this point. Inasmuch as the spectrum of the liquid can be conveniently photographed only at low temperatures (b.p. about -40°), the determination of the polarization of the scattered light would be experimentally very difficult and was not attempted. The fact that the frequencies associated with the CF3 group will be considerably different in magnitude from those of the CH3 group may, in the analysis, compensate for the lack of data on polarization. Only the results of the experiments are presented here; the assignment of the frequencies will be given when completed. The Raman spectrum of the ethylene-like molecule CCl2=CF2 was photographed at room temperature with the substance in the liquid state, and the observed shifts are presented here

    Comparing Aboveground Biomass Predictions for an Uneven-Aged Pine-Dominated Stand Using Local, Regional, and National Models

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    Sequestration by Arkansas forests removes carbon dioxide from the atmosphere, storing this carbon in biomass that fills a number of critical ecological and socioeconomic functions. We need a better understanding of the contribution of forests to the carbon cycle, including the accurate quantification of tree biomass. Models have long been developed to predict aboveground live tree biomass, but few of these have been derived from Arkansas forests. Since there is geographic variability in the growth and yield of pine as a function of genetics, site conditions, growth rate, stand stocking, and other factors, we decided to compare aboveground tree biomass estimates for a naturally regenerated, uneven-aged loblolly pine (Pinus taeda)-dominated stand on the Crossett Experimental Forest (CEF) in southeastern Arkansas. These predictions were made using a new locally derived biomass equation, five regional biomass equations, and the pine model from the National Biomass Estimators. With the local model as the baseline, considerable biomass variation appeared across a range of diameters—at the greatest diameter considered, the minimum value was only 69% of the maximum. Using a recent inventory from the CEF’s Good Farm Forty to compare each model, stand-level biomass estimates ranged from a low of 76.9 Mg/ha (a different Arkansas model) to as much as 96.1 Mg/ha (an Alabama model); the local CEF equation predicted 82.5 Mg/ha. A number of different factors contributed to this variability, including differences in model form and derivation procedures, geographic origins, and utilization standards. Regardless of the source of the departures, their magnitude suggests that care be used when making large-scale biomass estimates

    The Kinetics of the Exchange of Tritium between Hypophosphorous Acid and Water

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    We have measured the rates of exchange of radioactive hydrogen (tritium) between tritiated water, HTO, and the thwo "undissociable" hydrogens of monobasic hydrophosphorous acid, H3PO2

    Deriving Biomass Models for Small-Diameter Loblolly Pine on the Crossett Experimental Forest

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    Foresters and landowners have a growing interest in carbon sequestration and cellulosic biofuels in southern pine forests, and hence need to be able to accurately predict them. To this end, we derived a set of aboveground biomass models using data from 62 small-diameter loblolly pines (Pinus taeda) sampled on the Crossett Experimental Forest in southeastern Arkansas. Of the 25 equations initially evaluated, we chose 17 that best fit our dataset and compared them using a suite of conventional test statistics, including pseudo-R2 , root mean squared error (RMSE), and bias. Because most of the 17 models varied little in pseudoR 2 (ranging between 0.96 and 0.99), bias (all were within ± 0.01), and RMSE, an additional comparison was done using Akaike’s Information Criterion corrected for small sample size (AICc). This test statistic produced considerably more discrimination between the biomass models. Of the 17 models evaluated, six produced ΔAICc scores that met or exceeded the threshold for substantial support. To recommend a single preferred model, we then extrapolated beyond our actual data and qualitatively compared model predictions with those from the National Biomass Estimator. Our “best” model did not have the minimum AICc score, but rather predicted logically consistent aboveground biomass values at both the upper and lower ends of our extrapolation
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