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Thermodynamic Stability Of Sn4, Sn5, Sn6, And Sn7 Clusters By Knudsen Cell Mass Spectrometry, Giovanni Meloni, R W. Schmude, J E. Kingcade, Karl A. Gingerich

Chemistry Faculty Publications

The Knudsen cell mass spectrometric method has been employed to measure the partial pressures of Sn[sub n] (n=1-7) under equilibrium conditions above liquid tin or a tin-gold alloy, contained in a graphite Knudsen cell. From the all-gas analyzed equilibria the following atomization enthalpies Δ[sub a]H[sub 0][sup °](Sn[sub n]), and enthalpies of formation, Δ[sub f]H[sub 298.15][sup °](Sn[sub n]), in kJ mol-1, have been obtained: Sn[sub 4], 750.2±14 and 450.6±14; Sn[sub 5], 990.2±22 and 512.3±22; Sn[sub 6], 1349.7±28 and 452.8±28; Sn[sub 7], 1644.2±37 and 460.0±37. The atomization energies are compared with available …

Knudsen Cell Mass Spectrometric Investigation Of The B2n Molecule, Giovanni Meloni, M Sai Baba, Karl A. Gingerich

Chemistry Faculty Publications

High-temperature Knudsen cell mass spectrometry has been used to study the equilibria involving the B2Nmolecule over the Si–BN system. Thermal functions needed in the evaluation of the mass spectrometric equilibrium data have been calculated from available experimental and theoretical molecular parameters. The enthalpy changes for the reactions2B(g)+Si2N(g)=B2N(g)+2Si(g),and BN(s)+B(g)=B2N(g)have been measured. The following atomization enthalpy,ΔaHo0,and enthalpy of formation,ΔfHo298.15,in kJ mol⁻¹, of1045.5±18 and551.3±18 for theB2N molecule have been determined from these reactionenthalpies. Atomization energies of similar molecules have been compared and discussed.

Thermodynamic Study Of The Gaseous Molecules Al2n, Aln, And Al2n2 By Knudsen Cell Mass Spectrometry, Giovanni Meloni, Karl A. Gingerich

Chemistry Faculty Publications

The Knudsen effusion mass spectrometric method has been employed to measure the equilibrium partial pressures of the Al2N molecule over the AlN–Au–graphite system. Theoretical computations were carried out to determine the structure, molecular parameters, and thermodynamic properties of Al2N. The partial pressures have been combined with the calculated thermal functions to determine the atomization enthalpy,ΔaHo0, and enthalpy of formation,ΔfHo298.15, in kJ mol⁻¹, of 783.2±15 and 342.7±15 for Al2N, respectively. Upper values for the dissociation energy of AlN, Do0(AlN,g)⩽368±15 kJ mol−1, and for the atomization enthalpy of Al2N2, ΔaHo0(Al2N2,g)⩽1402 kJ mol−1 have been obtained. These results are discussed and …

Forestry's Role In Sustainable Agriculture, James R. Brandle

School of Natural Resources: Faculty Publications

No abstract provided.

Determination Of Drag Properties Of A Shelterbelt From Measurements And A Numerical Model, James R. Brandle

School of Natural Resources: Faculty Publications

No abstract provided.

Pressure Perturbations Around Shelterbelts: Measurements And Model Results, James R. Brandle

School of Natural Resources: Faculty Publications

No abstract provided.

Windbreaks An Old System With A New Look, James R. Brandle

School of Natural Resources: Faculty Publications

No abstract provided.

Windbreaks: Are They Effective?, James R. Brandle

School of Natural Resources: Faculty Publications

No abstract provided.

Silvopastoral Systems In The Pine Ridge Of Nebraska, James R. Brandle

School of Natural Resources: Faculty Publications

No abstract provided.

Windbreak Practices, James R. Brandle

School of Natural Resources: Faculty Publications

No abstract provided.

Oxygen Budget For Lake Ogallala, Kyle D. Hoagland, John C. Holz, Tadd M. Barrow, Richard J. Ruane

School of Natural Resources: Faculty Publications

Lake Ogallala, located below Kingsley Dam which impounds Lake McConaughy in Keith County, Nebraska, is a 260-surface hectare lake with an average depth of approximately eight meters. The lake provides mUltiple uses including a sport fishery and a hydropower and irrigation regulation basin. Since the installation of the hydroelectric generating plant in 1984 (Kingsley Dam was constructed in 1942) and the continued eutrophication of Lake McConaughy, dissolved oxygen concentrations have generally declined in Lake Ogallala. Hypolimnetic withdrawal from Lake McConaughy results in depressed oxygen levels in Lake Ogallala during the mid to latter part of the summer, particularly in certain …

Late Albian Kiowa-Skull Creek Marine Transgression, Lower Dakota Formation, Eastern Margin Of Western Interior Seaway, R.L. Brenner, G.A. Ludvigson, B.J. Witzke, A.N. Zawistoski, E.P. Kvale, R.L. Ravn, R.M. Joeckel

School of Natural Resources: Faculty Publications

No abstract provided.

Potential Production And Environmental Effects Of Switchgrass And Traditional Crops Under Current And Greenhouse-Altered Climate In The Central United States: A Simulation Study, R.A. Brown, N.J. Rosenberg, Cynthia J. Hays, W.E. Easterling, L.O. Mearns

School of Natural Resources: Faculty Publications

If, as many climate change analysts _ speculate, industrial and other emissions of CO₂ can be offset by substitution of biofuels, large areas of land, including agricultural land, may be converted to the production of biomass feedstocks. This paper explores the feasibility for the Missouri–Iowa–Nebraska–Kansas (MINK) region of the US of converting some agricultural land to the production of switchgrass (Panicum virgatum L.), a perennial warm season grass, as a biomass energy crop. The erosion productivity impact calculator (EPIC) crop growth model simulated production of corn (Zea mays L.), sorghum (Sorghum bicolor (L.) Moench), soybean ( …

Observed Climate Variability And Change Of Relevance To The Biosphere, David R. Easterling, Thomas R. Karl, Kevin P. Gallo, David A. Robinson, Kevin E. Trenberth, Aiguo Dai

School of Natural Resources: Faculty Publications

In this paper we review the current instrumental evidence regarding climate variations and change during the 20th century emphasizing those changes that are likely to have direct interactions with the biosphere.

The Spectral Contribution Of Carotenoids To Light Absorption And Reflectance In Green Leaves, Y. Zur, A. A. Gitelson, O. B. Chivkunova, M. N. Merzlyak

School of Natural Resources: Faculty Publications

Absorbance and reflectance spectra in the visible and near infrared range of the spectrum, acquired for maple (Acer platanoides L.) leaves were studied. Standard deviation of absorbance spectra showed that in yellow to green leaves, with chlorophyll content at least up to 30 nmol/cm2, there is a spectral feature at 520 nm attributable to carotenoids. Reflectance around 520 nm also correlates closely with carotenoids content in yellow to green leaves. Thus, this spectral feature at 520 nm could be used as a measure of carotenoids content in green leaves and plants.

Breeding Season Demography And Movements Of Eastern Towhees At The Savannah River Site, South Carolina, David G. Krementz, Larkin A. Powell

School of Natural Resources: Faculty Publications

The Eastern Towhee (Pipilo erythrophthalmus) has undergone population declines across much of its range, especially in New England. Despite being a widespread and, at one time, a common species, relatively little is known about its natural history, ecology, or demographics. We conducted baseline research on Eastern Towhees at the Savannah River Site, South Carolina, in 1995 and 1996 to estimate breeding season survival rates, nest success rates, breeding densities, and daily movements. We also were interested in whether towhees had differences in survival and movement rates between young and mature managed pine stands. We found that survival rates during the …

Effects Of Temperature Anomalies On The Palmer Drought Severity Index In The Central United States, Q. Steven Hu, Gary D. Willson

School of Natural Resources: Faculty Publications

The purpose of this study is to improve our understanding of temperature and precipitation effects on the Palmer Drought Severity Index (PDSI). Both theoretical and observational analyses were applied to separate and compare temperature and precipitation effects on PDSI. The results showed that because of the dependence of PDSI on the ‘climatologically appropriate rainfall’, which is a function of time and varies with surface air temperature, the PDSI can be equally affected by temperature and precipitation, when both have similar magnitudes of anomalies. Calculations using observational data further illustrated the temperature influence on PDSI in different climate regions in the …

Remote Monitoring Of Selected Ground-Water Dominated Lakes In The Nebraska Sand Hills, David C. Gosselin, Donald C. Rundquist, Stuart K. Mcfeeters

School of Natural Resources: Faculty Publications

The Landsat-Multispectral Scanner (MSS) data were used to measure lake area fluctuations (1972-1989) for 130 groundwater dominated lakes in the Western Lakes Region of the Nebraska Sand Hills. In general, the pattern shown in lake area hydrographs was similar to that for in-situ lake elevations. In-situ lake-elevation data verify that remote monitoring of surface- area fluctuations, even at relatively coarse spatial resolution, is not only practical and useful, but also it elucidates the hydrologic characteristics of groundwater-dominated lakes of the Sand Hills. The apparent differences in behavior between lakes in the northern and southern portions of the study area may …

Process-Oriented Environmental Change Curriculum-Development Workshops, David C. Gosselin, Sherri Lowrey, Steven John Meyer

School of Natural Resources: Faculty Publications

To improve scientific literacy, K-12 educators need to: develop the ability to use and analyze data, incorporate data into their curriculum, and interact with teachers from other disciplines to create interdisciplinary units. A Process-Oriented Environmental Change Education workshop was conducted for eleven interdisciplinary teams, consisting of 21 teachers, in 1997 and 1998. The National Science Standards provided the criteria for the organization of the workshop. Inquiry and interpretation exercises helped to expand scientific knowledge and skills as well as the teachers’ use of technology. We explicitly discussed the uncertainty of science through group discussions and problem-solving activities. More than 85% …

River's Edge Policy Institute Newsletter, Winter 2000, Lindenwood University

River's Edge Policy Institute

The River's Edge Policy Institute was a forum that discussed education policy.

Msu Update, 2000, Office Of Communications & Marketing, Morehead State University.

Communications and Marketing Publications Archive

MSU Update Newsletters for 2000.

The Lion 2000, Langston University

LU Yearbooks, 2000-2009

No abstract provided.

Western Australia Soil Acidity Research And Development Update 2000 : Time To Lime, Department Of Agriculture And Food, Western Australia

Bulletins 4000 -

We have come a long way over the past three or four years in terms of both, the level of understanding and recognition of Soil Acidity as a major land degradation issue for the wheatbelt of Western Australia, and, in our actions to treat the problem.

During 1999 there were three very significant changes relating to acid soils in Western Australia.

• Lime use in WA increased by over 200,000 tonnes from 1998 to 1999 to a record 653,000 tonnes, which was double the amount applied in 1997.
• The Agricultural Lime Industry adopted a voluntary Lime Industry Code of Practice in …

The Tomokan Yearbook 2000, Rollins College Students

The Tomokan

Rollins College's yearbook for the Class of 2000.

Excellence In Teaching Award Citation For Bruce Pourciau, Lawrence University

Faculty Award Citations

No abstract provided.

Cyanonews (Vol. 15, No. 1, July 2000), Jeff Elhai

CyanoNews

CyanoNews was a newsletter that served the cyanobacteriological community from 1985 to 2003, with content provided by readers (sort of a blog before there were blogs). The newsletter reported new findings from the lab, summaries of recent meetings (often provided by graduate students and post-docs entering the field), positions sought or available, life transitions, a compendium of recent cyanobacteria-related articles, and other items of interest to those who study cyanobacteria.

2000 Modulus, Rose-Hulman Institute Of Technology

Modulus (Yearbooks)

2000 Yearbook for Rose-Hulman Institute of Technology Terre Haute, IN 47803

2000 - 2001 Rose News Releases Index, Rose-Hulman Staff

Rose News Releases

No abstract provided.

Cwatset Isomorphism And Its Consequences, Carolyn M. Girod, Matthew Lipinski, Joseph R. Mileti, Jennifer R. Paulhus

Mathematical Sciences Technical Reports (MSTR)

We explore the consequences of cwatset isomorphism (there are a finite number of non-isomorphic cwatsets of each order) and consider parallels between the theory of groups and the theory of cwatsets (cwatsets of prime order are cyclic but direct sums of isomorphic cwatsets aren't necessarily isomorphic).

Post-Common-Envelope Binary Stars And The Precataclysmic Binary Pg 1114+187, Todd C. Hillwig, R. Kent Honeycutt, Jeff W. Robertson

Faculty Publications - Physical & Earth Sciences

We present orbit-resolved spectroscopy and orbit-sampled photometry of the binary system PG 1114+187. Both photometry and radial velocity studies reveal a period P = 1.75992 days, which is taken to be the orbital period of the binary. Strong modulation of emission-line strength with the same period is also present. A preliminary mass ratio, M2/M1 ‰ˆ 0.7, is found from primary- and secondary-star radial velocity amplitudes. No evidence is seen for either an accretion disk or mass transfer, leading to the conclusion that PG 1114+187 is not a cataclysmic variable (CV) but is in a pre-CV state, before the initiation of …