The Amenability of Kansas Clays to Alumina Extraction by Hydrochloric Acid Treatment

Six kaolinitic clays from the Dakota Formation in north-central Kansas were leached with hydrochloric acid to remove alumina. The alumina was extracted from the leach solution, purified, and recovered as Al2O3. The extraction and recovery processes used gave yields ranging from 147 to 290 lbs/ton of alumina from clays calcined to 650°C. Residues from the leaching process were tested for possible ceramic utilization

The Amenability of Kansas Clays to Alumina Extraction by Hydrochloric Acid Treatment

Six kaolinitic clays from the Dakota Formation in north-central Kansas were leached with hydrochloric acid to remove alumina. The alumina was extracted from the leach solution, purified, and recovered as Al2O3. The extraction and recovery processes used gave yields ranging from 147 to 290 lbs/ton of alumina from clays calcined to 650°C. Residues from the leaching process were tested for possible ceramic utilization

Gathering validity evidence for the Community Service-Learning Assessment Test (CSAT)

Service-learning grew out of the philosophy that effective education should be experiential in nature (Giles & Eyler, 1994b). Alternative Break programs are steeped in this philosophy. Participation in many Alternative Break programs involves the immersion of students in a week-long service trip during academic breaks. Measurement of student learning outcomes is important in determining the effectiveness of these experiential programs. The purpose of this study was to evaluate the psychometric properties of the Community Service-learning Assessment Test (CSAT) and to gather construct validity evidence for the CSAT’s five sub-scales: civic action, interpersonal problem-solving, social justice, interpersonal relationships, and personal competency. Two independent samples of sophomores and juniors were administered the CSAT. A five-factor confirmatory factor analysis model was tested using Sample 1 and did not fit the data. These results replicated in Sample 2. Based on the results, scales and items were removed and a modified two-factor confirmatory analysis with civic action and social justice items was performed using Sample 2. This two-factor model did fit the data and external evidence was gathered for both constructs. External validity evidence provided some support for both the civic action and social justice scales. Recommendations and future research for the improvement of all five scales comprising the CSAT are made

Epitaxial Growth of La1/3_{1/3}Sr2/3_{2/3}FeO3_3 thin films by laser ablation

We report on the synthesis of high quality La$_{1/3}$Sr$_{2/3}$FeO$_3$ (LSFO) thin films using the pulsed laser deposition technique on both SrTiO$_3$ (STO) and LaAlO$_3$ (LAO) substrates (100)-oriented. From X-Ray diffraction (XRD) studies, we find that the films have an out-of-plane lattice parameter around 0.3865nm, almost independent of the substrate (i.e. the nature of the strains). The transport properties reveal that, while LSFO films deposited on STO exhibit an anomaly in the resistivity vs temperature at 180K (corresponding to the charge-ordered transition and associated with a transition from a paramagnetic to an antiferromagnetic state), the films grown on LAO display a very small magnetoresistance behavior and present an hysteresis around 270K under the application of a 4T magnetic field. The changes in transport properties between both substrates are discussed and compared with the corresponding single crystals.Comment: 9 pages, 4 figure

Effect of Pesticide Types on Community Structure of Arthropod in Soy Crops

This study was carried out on three soybean farms located in the Liverpool Plains Shire in New South Wales, Australia. The soybean farms were different in terms of pesticide type used. One of the soy crops was sprayed with broad spectrum synthetic pesticides (synthetic pyrethroids), one site of soy crop was sprayed with natural pyrethrum - an organically certified pesticide, and one of the soy crops was not treated with any pesticides. Arthropod samples were collected on three occasions at every site except in the third site of soy crops which was not treated with any pesticides. Samplings were done using sweep nets and beat sheets. There were no significant differences of community structure change between farms treated with different pesticide regimes (F2,5= 4.2599, P(perm)= 0.188), and no significant differences in arthropod species richness. The abundance of arthropods was significantly different for site treated with biopesticide and site treated with synthetic pyrethroids (G6 = 284.36, P <0.0001), non-sprayed site and site treated with synthetic pyrethroids (G6 = 2110, P < 0.0001), and non-sprayed site to site treated with biopesticide (G6 = 2027, P < 0.0001). The use of synthetic pesticides in agriculture has been found to suppress pests and beneficial arthropods, while the use of biopesticides or without pesticide, to some extent, may let beneficials thrive in the system and also may suppress pest arthropods

Influencing FTO thin film growth with thin seeding layers: a route to microstructural modification

We report on the seeded growth of fluorine doped tin oxide (FTO) polycrystalline transparent conducting oxide (TCO) thin films on float glass using a novel two-step chemical vapour deposition (CVD) method. Aerosol-assisted CVD (AACVD) was used to grow a seed layer to direct and promote full film growth via an atmospheric pressure CVD (APCVD) overlay. The method allowed for reproducible control over morphology and denser, rougher, higher-performing TCO at a relatively low growth temperature (500 °C). Growth promotion depended on seeding time with an optimal seeding time being present, below which morphology control and conformal coverage was unavailable. The film properties and functional characteristics were characterised by SEM, AFM, XRD, XPS, UV-Vis-Near IR transmittance-reflectance and Hall Effect probe measurements. Highly transparent and electrically conductive films, comparable to commercial materials and with high roughness and low transmission haze values indicate the process yields high quality films with a controllable morphology that can be tuned to desired application. The versatile method provides a route towards the morphological control of high-quality FTO thin films with high optical clarity and low-emissivity properties and can be readily extended to a variety of different substrates and metal oxide materials