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Full-Text Articles in Physical Sciences and Mathematics

Dissociation Quotients Of Oxalic Acid In Aqueous Sodium Chloride Media To 175c, Richard Kettler, Donald A. Palmer, David J. Wesolowski Jan 1991

Dissociation Quotients Of Oxalic Acid In Aqueous Sodium Chloride Media To 175c, Richard Kettler, Donald A. Palmer, David J. Wesolowski

Department of Earth and Atmospheric Sciences: Faculty Publications

The first and second molal dissociation quotienls of oxalic acid were measured potenliometrically in a concentration cell filled with hydrogen electrodes. The emf of oxalic acid-bioxalate solutions was measured relative to an HCI standard solution from 25 to 125°C over 25° intervals at nine ionic strengths ranging from 0.1 to 5.0 molal (NaCl). The molal dissociation quotients and available literature data were treated in the all anionic form by a five-term equation that yielded the following thermodynamic quantities at infinite dilution and 25°C: logKIa = -1.277±0.010, ΔHl̊a = -4.1± 1.1 kJ-mol-1, ΔSl̊a = 38±4 J-K …


Ice-Wedge Casts Of Wisconsinan Age In Eastern Nebraska, William J. Wayne Jan 1991

Ice-Wedge Casts Of Wisconsinan Age In Eastern Nebraska, William J. Wayne

Department of Earth and Atmospheric Sciences: Faculty Publications

Sand-filled, wedge-shaped structures beneath a thin layer of aeolian sand penetrate a preIllinoian till and gravel in northeastern Nebraska. Interpreted to be relic thermal contraction crack wedges, they provide the first definite evidence in this State of the former presence of permafrost. The wedges are 5- 7 m apart, 1.8-2.8 m deep and 0.6-0.9 m across at the top, taper downward to a crack and intersect to form polygons. They are filled with medium sand that contains mostly rounded and frosted grains. Vertical fabric is present in each wedge. Ventifacts lie along the top of the till, which is covered …


Evolution Of The Aeluroid Camivora: Viverrid Affinities Of The Miocene Camivoran Herpestides, Robert M. Hunt Jr. Jan 1991

Evolution Of The Aeluroid Camivora: Viverrid Affinities Of The Miocene Camivoran Herpestides, Robert M. Hunt Jr.

Department of Earth and Atmospheric Sciences: Faculty Publications

Although the time of origin of viverrid and hyaenid carnivorans has not been clearly documented in the fossil record, their theater of evolution has long been established by a mid-Cenozoic fossil distribution entirely confined to the Old World. Recent examination of the basicranial morphology of important early aeluroid crania from Europe and Asia significantly alters earlier views of viverrid and hyaenid origins. The early Miocene carnivoran Herpestides antiquus, considered a potential ancestral hyaenid or herpestid in earlier studies, is identified as a true viverrid on the basis of a large sample of skulls of both juveniles and adults from …


Evolution Of The Aeluroid Camivora: Hyaenid Affinities Of The Miocene Camivoran Tungurictis Spocki From Inner Mongolia, Robert M. Hunt Jr., Nikos Solounias Jan 1991

Evolution Of The Aeluroid Camivora: Hyaenid Affinities Of The Miocene Camivoran Tungurictis Spocki From Inner Mongolia, Robert M. Hunt Jr., Nikos Solounias

Department of Earth and Atmospheric Sciences: Faculty Publications

Among the mammalian fossils discovered in were crania and mandibles of rare carnivorans, 1930 by the Central Asiatic Expedition of the including the first complete skulls of several Asian American Museum of Natural History (New York) mid-Miocene lineages. Most of these fossils came in the Tung Gur Formation of Inner Mongolia from a single locality termed Wolf Camp Quarry that produced, among other striking finds, a small fox-sized cranium referred to a new genus and species Tungurictis spocki Colbert 1939. Today this remains the only known cranium of Tungurictis yet discovered. Preparation and reinterpretation of the auditory region demonstrate that …


Quaternary Geology Of The Northern Great Plains, William J. Wayne, James S. Aber, Sherry S. Agard, Robert N. Bergantino, John P. Bluemle, Donald A. Coates, Maurice E. Cooley, Richard F. Madole, James E. Martin, Brainerd Mears Jr, Roger B. Morrison, Wayne M. Sutherland Jan 1991

Quaternary Geology Of The Northern Great Plains, William J. Wayne, James S. Aber, Sherry S. Agard, Robert N. Bergantino, John P. Bluemle, Donald A. Coates, Maurice E. Cooley, Richard F. Madole, James E. Martin, Brainerd Mears Jr, Roger B. Morrison, Wayne M. Sutherland

Department of Earth and Atmospheric Sciences: Faculty Publications

The Great Plains physiographic province lies east of the Rocky Mountains and extends from southern Alberta and Saskatchewan nearly to the United States-Mexico border. This chapter covers only the northern part of the unglaciated portion of this huge region, from Oklahoma almost to the United StatesCanada border, a portion that herein will be referred to simply as the Northern Great Plains (Fig. 1). This region is in the rain shadow of the Rocky Mountains. Isoheyets are roughly longitudinal, and mean annual precipitation decreases from about 750 mm at the southeastern margin to less than 380 mm in the western and …