Theoretical Justification for Bond Valence -- Bond Length Empirical Correlations

Bond valence – bond length empirical correlations are of great interest in chemistry, biology, geology and materials science because they offer a quick and convenient way of checking and evaluating molecular structures. Linus Pauling’s relationship is the most commonly used, but is a two-parameter fit where R0 and b must be optimized. In this study, a simplified quantum-mechanical approach was used to derive Pauling’s empirical bond valence – bond length relationship. A covalency factor was also introduced to account for the difference in “softness” between cation and anion (resulting in increased orbital overlap). An expression for the b parameter was determined that yields values that are in agreement with experimental data. The derived relationship for the b parameter allows an independent determination of b using orbital exponents and electronegativity values for the cation and anion

Titanium-Oxygen Bond Length -Bond Valence Relationship

A bond length–bond valence correlation is a simple method of checking and evaluating molecular structures and is of great interest in chemistry, biology, geology, and material science. Recently, we used quantum-mechanical arguments to derive Pauling’s bond length-valence relationship and to define the adjustable fitting parameter b in terms of atomic-orbital exponents. Improved orbital exponents were generated for elements 1-103 using published atomic radii and single-bond covalent radii as well as a continuous function for effective principal quantum number. In this study, we use orbital exponents for titanium (Ti) and oxygen (O) to generate a bond length-valence relationship for Ti-O bonds. Recent crystallographic Ti-O bond lengths from 32 environments were collected and converted to Ti-O bond valences to check the reliability of the bond length-valence relationship where Ro was found (bond length of unit valence). This relationship is expected to apply to any Ti-O bond regardless of environment, physical state, or oxidation number

An Exposition on Bayesian Inference

The Bayesian approach to probability and statistics is described, a brief history of Bayesianism is related, differences between Bayesian and Frequentist schools of statistics are defined, protential applications are investigated, and a literature survey is presented in the form of a machine-sort card file. Bayesian thought is increasing in favor among statisticians because of its ability to attack problems that are unassailable from the Frequentist approach. It should become more popular among practitioners because of the flexibility it allows experimenters and the ease with which prior knowledge can be combined with experimental data. (82 pages

A Quantitative Analysis Of Hugelkultur And Its Potential Application On Karst Rocky Desertified Areas In China

A type of environmental degradation, karst rocky desertification (KRD) refers to areas where the soil loss exposes the bedrock and reduces the land’s ability to sustain life and is particularly widespread through the vast karst area of rural southwest China. Hugelkultur is a permaculture method that harnesses the wood decomposition process by burying logs beneath soil. We proposed that hugel beds will demonstrate a higher water holding capacity and enhance soil development, in a way that may show promise as a potential method to help alleviate problems of KRD. Soil samples were taken from hugel plots, non-hugel plots, and KRD-like areas around Bowling Green, Kentucky to determine respective moisture content and project the amount of soil water potentially held in a one-hectare field. Findings show hugels to demonstrate higher water holding capacity meaning they have potential implications for future productivity of agricultural in areas affected by KRD

A Search for the Natural Vectors of Avian Malaria in Iowa, with Notes on Other Mosquito Parasites

The study of avian malaria has received much attention in recent years because of the recognition that knowledge concerning it is often very helpful in the understanding of human malaria. While many investigators have dissected wild Anopheles mosquitoes in a search for the vectors of human malaria and culicine mosquitoes for the vectors of human filariasis, there apparently has been little effort to find the natural vectors of bird malaria, although numerous species of mosquitoes have been shown to be capable of transmitting the disease under laboratory conditions

A Wasp With Three Pairs of Wings (Hymenoptera; lchneumonidae)

An abnormal male specimen of Cratichneumon unifasciatorius (Say) was collected on June 25, 1949, at Ames, Iowa, by Miss Shirley Sparling, a student in beginning entomology. Because of the nature of the abnormality it appears worthy of a note. This specimen possesses three pairs of wings, one pair on each of the thoracic segments (see fig. 1). Unfortunately, this condition was not noted until sometime after the insect was mounted, so that observations of the living insect and the opportunity to study the musculature were not available. The specimen is in good condition except for the left prothoracic wing which is badly torn

Elementary Pre-service Teachers’ Attitudes Toward Digitized Visual Primary Sources in the Social Studies

This qualitative study examined the attitudes of elementary pre-service teachers toward using digitized visual primary sources in the social studies. Specifically, the researcher attempted to answer the following questions: 1. What are elementary pre-service teachers’ attitudes toward incorporating digitized visual primary sources in social studies instruction prior to a workshop? 2. To what extent if any, does exposure to strategies using digitized visual primary sources affect elementary pre-service teachers’ attitudes? 3. How, if at all, do elementary pre-service teachers think that digitized visual primary sources should be used after a workshop. Data for this qualitative study consisted of pre and post workshop questionnaires, reflection prompts, and the researcher’s journal reflections. These data were collected before, during and after a workshop that trained elementary pre-service teachers in many aspects of teaching and learning with digitized visual primary sources that included four research-based strategies. The researcher drew four conclusions from this study. First, teacher-training workshops can help pre-service teachers transform their beliefs in relation to how best to use digitized visual primary sources. Second, the participants remained optimistic about their beliefs in the benefits in using digitized visual primary sources, while challenges of time to scaffold became apparent in the workshop. The third conclusion was that pre-service teachers were motivated by current, innovative, and technology based teaching strategies with digitized visual primary sources such as creating memes or document analysis strategies. Fourth, the participants perceived obstacles with perspective taking and detecting bias strategies that are sensitive in nature

The Byronic Heroine

This thesis examines the well-used character persona in Western literature, the Byronic hero which can be prominently seen in both George Gordon and Lord Byron’s poetry, as well as the juxtaposition to this hero, the Byronic heroine. Both hero and heroine are characterized by being sensitive, passionate, strong, and having self-destructing tendencies. These romantic heroes can be seen throughout many works of literature

Late Fall and Winter Bird Records, 1938 to 1941, in the Sioux City Area

This paper is a continuation of a series of winter bird lists of Sioux City and the surrounding territory. The series was started by T. C. Stephens in 1916. Dr. Stephens covered the six winters from 1916 to 1922 in four papers1. Charles J. Spiker wrote a paper listing the records of the four winters from 1922 to 19262; William Youngworth, the four winters from 1926 to 19303; and Wilfred D. Crabb, the eight winters from 1930 to 19384. The present paper records the observations of the last three winters, 1938 to 1941. This makes a total of eight papers covering twenty-five winters

Patterns of paleomobility in the ancient Antilles: an isotopic approach

Patterns of paleomobility in the Caribbean were studied through an inter-disciplinary approach using a combination of archaeological, osteological, mortuary, and isotopic data. Samples of human enamel from 360 individuals from multiple sites spanning a broad range of geographic and temporal contexts were analyzed for strontium isotope composition. These results were interpreted in reference to a database of strontium isotope variation for the Caribbean biosphere created through the analysis of 288 modern and archeological animal and plant samples. These combined strontium isotope datasets contributed to assessments of the spatial patterning of bioavailable strontium isotopes in the region and to estimations of the local range of isotope variation for the different site populations. These ranges were used to determine whether individuals were of local or nonlocal origin and were then analyzed to examine variability in patterns of migration, with a specific focus on testing possible relationships between residential origins and biological sex, age at death, chronology, grave goods, and dietary practices. Carbon and oxygen isotope analyses of dental enamel were also conducted on a subset of 50 individuals to assess their potential for provenance studies in the Caribbean region and for investigating the origins of suspected long-distance migrants.Caribbean and Amazonia - ou