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

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

Parent Involvement and Student Teacher Relationships in Predicting Student Outcomes

As key players in what Bronfenbrenner describes as the mesosystem, parents and teachers interact to play an important and immediate role in child development. While the role of parent involvement and the impact of student teacher relationships are well established in the literature on student outcomes, less is known about how the two function together to impact the student. To expand the literature on this topic, the current study sought to examine how levels of different types of parent involvement (home-based, home-school conferencing, and trust) predict student teacher relationship quality, how parent involvement and student teacher relationships predict student outcomes when examined together, as well as the moderating role parent involvement may play in the association between student teacher relationships and outcomes. Academic and social-emotional outcomes were examined in a sample of kindergarten students. Although the results did not support the moderating role of parent involvement, other important associations impacting both student teacher relationships and student outcomes were supported, further solidifying the important role of parents and teachers in a student’s life

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 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

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

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

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